the american football conference -lrb- afc -rrb- champion denver broncos defeated the national football conference -lrb- nfc -rrb- champion carolina panthers 24 -- 10 to earn their third super bowl title . 
the american football conference -lrb- afc -rrb- champion denver broncos defeated the national football conference -lrb- nfc -rrb- champion carolina panthers 24 -- 10 to earn their third super bowl title . 
the game was played on february 7 , 2016 , at levi 's stadium in the san francisco bay area at santa clara , california . 
the american football conference -lrb- afc -rrb- champion denver broncos defeated the national football conference -lrb- nfc -rrb- champion carolina panthers 24 -- 10 to earn their third super bowl title . 
as this was the 50th super bowl , the league emphasized the `` golden anniversary '' with various gold-themed initiatives , as well as temporarily suspending the tradition of naming each super bowl game with roman numerals -lrb- under which the game would have been known as `` super bowl l '' -rrb- , so that the logo could prominently feature the arabic numerals 50 . 
as this was the 50th super bowl , the league emphasized the `` golden anniversary '' with various gold-themed initiatives , as well as temporarily suspending the tradition of naming each super bowl game with roman numerals -lrb- under which the game would have been known as `` super bowl l '' -rrb- , so that the logo could prominently feature the arabic numerals 50 . 
the game was played on february 7 , 2016 , at levi 's stadium in the san francisco bay area at santa clara , california . 
the american football conference -lrb- afc -rrb- champion denver broncos defeated the national football conference -lrb- nfc -rrb- champion carolina panthers 24 -- 10 to earn their third super bowl title . 
as this was the 50th super bowl , the league emphasized the `` golden anniversary '' with various gold-themed initiatives , as well as temporarily suspending the tradition of naming each super bowl game with roman numerals -lrb- under which the game would have been known as `` super bowl l '' -rrb- , so that the logo could prominently feature the arabic numerals 50 . 
the american football conference -lrb- afc -rrb- champion denver broncos defeated the national football conference -lrb- nfc -rrb- champion carolina panthers 24 -- 10 to earn their third super bowl title . 
the game was played on february 7 , 2016 , at levi 's stadium in the san francisco bay area at santa clara , california . 
the american football conference -lrb- afc -rrb- champion denver broncos defeated the national football conference -lrb- nfc -rrb- champion carolina panthers 24 -- 10 to earn their third super bowl title . 
the game was played on february 7 , 2016 , at levi 's stadium in the san francisco bay area at santa clara , california . 
the game was played on february 7 , 2016 , at levi 's stadium in the san francisco bay area at santa clara , california . 
as this was the 50th super bowl , the league emphasized the `` golden anniversary '' with various gold-themed initiatives , as well as temporarily suspending the tradition of naming each super bowl game with roman numerals -lrb- under which the game would have been known as `` super bowl l '' -rrb- , so that the logo could prominently feature the arabic numerals 50 . 
super bowl 50 was an american football game to determine the champion of the national football league -lrb- nfl -rrb- for the 2015 season . 
super bowl 50 was an american football game to determine the champion of the national football league -lrb- nfl -rrb- for the 2015 season . 
the game was played on february 7 , 2016 , at levi 's stadium in the san francisco bay area at santa clara , california . 
the game was played on february 7 , 2016 , at levi 's stadium in the san francisco bay area at santa clara , california . 
the american football conference -lrb- afc -rrb- champion denver broncos defeated the national football conference -lrb- nfc -rrb- champion carolina panthers 24 -- 10 to earn their third super bowl title . 
the game was played on february 7 , 2016 , at levi 's stadium in the san francisco bay area at santa clara , california . 
super bowl 50 was an american football game to determine the champion of the national football league -lrb- nfl -rrb- for the 2015 season . 
the american football conference -lrb- afc -rrb- champion denver broncos defeated the national football conference -lrb- nfc -rrb- champion carolina panthers 24 -- 10 to earn their third super bowl title . 
the american football conference -lrb- afc -rrb- champion denver broncos defeated the national football conference -lrb- nfc -rrb- champion carolina panthers 24 -- 10 to earn their third super bowl title . 
the american football conference -lrb- afc -rrb- champion denver broncos defeated the national football conference -lrb- nfc -rrb- champion carolina panthers 24 -- 10 to earn their third super bowl title . 
super bowl 50 was an american football game to determine the champion of the national football league -lrb- nfl -rrb- for the 2015 season . 
the american football conference -lrb- afc -rrb- champion denver broncos defeated the national football conference -lrb- nfc -rrb- champion carolina panthers 24 -- 10 to earn their third super bowl title . 
the game was played on february 7 , 2016 , at levi 's stadium in the san francisco bay area at santa clara , california . 
super bowl 50 was an american football game to determine the champion of the national football league -lrb- nfl -rrb- for the 2015 season . 
the american football conference -lrb- afc -rrb- champion denver broncos defeated the national football conference -lrb- nfc -rrb- champion carolina panthers 24 -- 10 to earn their third super bowl title . 
the panthers finished the regular season with a 15 -- 1 record , and quarterback cam newton was named the nfl most valuable player -lrb- mvp -rrb- . 
the broncos finished the regular season with a 12 -- 4 record , and denied the new england patriots a chance to defend their title from super bowl xlix by defeating them 20 -- 18 in the afc championship game . 
they defeated the arizona cardinals 49 -- 15 in the nfc championship game and advanced to their second super bowl appearance since the franchise was founded in 1995 . 
they defeated the arizona cardinals 49 -- 15 in the nfc championship game and advanced to their second super bowl appearance since the franchise was founded in 1995 . 
the broncos finished the regular season with a 12 -- 4 record , and denied the new england patriots a chance to defend their title from super bowl xlix by defeating them 20 -- 18 in the afc championship game . 
they defeated the arizona cardinals 49 -- 15 in the nfc championship game and advanced to their second super bowl appearance since the franchise was founded in 1995 . 
the broncos finished the regular season with a 12 -- 4 record , and denied the new england patriots a chance to defend their title from super bowl xlix by defeating them 20 -- 18 in the afc championship game . 
the broncos finished the regular season with a 12 -- 4 record , and denied the new england patriots a chance to defend their title from super bowl xlix by defeating them 20 -- 18 in the afc championship game . 
they joined the patriots , dallas cowboys , and pittsburgh steelers as one of four teams that have made eight appearances in the super bowl . 
the panthers finished the regular season with a 15 -- 1 record , and quarterback cam newton was named the nfl most valuable player -lrb- mvp -rrb- . 
the panthers finished the regular season with a 15 -- 1 record , and quarterback cam newton was named the nfl most valuable player -lrb- mvp -rrb- . 
the panthers finished the regular season with a 15 -- 1 record , and quarterback cam newton was named the nfl most valuable player -lrb- mvp -rrb- . 
the broncos finished the regular season with a 12 -- 4 record , and denied the new england patriots a chance to defend their title from super bowl xlix by defeating them 20 -- 18 in the afc championship game . 
they defeated the arizona cardinals 49 -- 15 in the nfc championship game and advanced to their second super bowl appearance since the franchise was founded in 1995 . 
the broncos finished the regular season with a 12 -- 4 record , and denied the new england patriots a chance to defend their title from super bowl xlix by defeating them 20 -- 18 in the afc championship game . 
the panthers finished the regular season with a 15 -- 1 record , and quarterback cam newton was named the nfl most valuable player -lrb- mvp -rrb- . 
they defeated the arizona cardinals 49 -- 15 in the nfc championship game and advanced to their second super bowl appearance since the franchise was founded in 1995 . 
the broncos finished the regular season with a 12 -- 4 record , and denied the new england patriots a chance to defend their title from super bowl xlix by defeating them 20 -- 18 in the afc championship game . 
the broncos finished the regular season with a 12 -- 4 record , and denied the new england patriots a chance to defend their title from super bowl xlix by defeating them 20 -- 18 in the afc championship game . 
the panthers finished the regular season with a 15 -- 1 record , and quarterback cam newton was named the nfl most valuable player -lrb- mvp -rrb- . 
the broncos finished the regular season with a 12 -- 4 record , and denied the new england patriots a chance to defend their title from super bowl xlix by defeating them 20 -- 18 in the afc championship game . 
they defeated the arizona cardinals 49 -- 15 in the nfc championship game and advanced to their second super bowl appearance since the franchise was founded in 1995 . 
the panthers finished the regular season with a 15 -- 1 record , and quarterback cam newton was named the nfl most valuable player -lrb- mvp -rrb- . 
they defeated the arizona cardinals 49 -- 15 in the nfc championship game and advanced to their second super bowl appearance since the franchise was founded in 1995 . 
they defeated the arizona cardinals 49 -- 15 in the nfc championship game and advanced to their second super bowl appearance since the franchise was founded in 1995 . 
denver linebacker von miller was named super bowl mvp , recording five solo tackles , 2 1/2 sacks , and two forced fumbles . 
denver linebacker von miller was named super bowl mvp , recording five solo tackles , 2 1/2 sacks , and two forced fumbles . 
the broncos took an early lead in super bowl 50 and never trailed . 
denver linebacker von miller was named super bowl mvp , recording five solo tackles , 2 1/2 sacks , and two forced fumbles . 
denver linebacker von miller was named super bowl mvp , recording five solo tackles , 2 1/2 sacks , and two forced fumbles . 
newton was limited by denver 's defense , which sacked him seven times and forced him into three turnovers , including a fumble which they recovered for a touchdown . 
newton was limited by denver 's defense , which sacked him seven times and forced him into three turnovers , including a fumble which they recovered for a touchdown . 
denver linebacker von miller was named super bowl mvp , recording five solo tackles , 2 1/2 sacks , and two forced fumbles . 
newton was limited by denver 's defense , which sacked him seven times and forced him into three turnovers , including a fumble which they recovered for a touchdown . 
denver linebacker von miller was named super bowl mvp , recording five solo tackles , 2 1/2 sacks , and two forced fumbles . 
denver linebacker von miller was named super bowl mvp , recording five solo tackles , 2 1/2 sacks , and two forced fumbles . 
denver linebacker von miller was named super bowl mvp , recording five solo tackles , 2 1/2 sacks , and two forced fumbles . 
the broncos took an early lead in super bowl 50 and never trailed . 
denver linebacker von miller was named super bowl mvp , recording five solo tackles , 2 1/2 sacks , and two forced fumbles . 
denver linebacker von miller was named super bowl mvp , recording five solo tackles , 2 1/2 sacks , and two forced fumbles . 
the broncos took an early lead in super bowl 50 and never trailed . 
newton was limited by denver 's defense , which sacked him seven times and forced him into three turnovers , including a fumble which they recovered for a touchdown . 
newton was limited by denver 's defense , which sacked him seven times and forced him into three turnovers , including a fumble which they recovered for a touchdown . 
newton was limited by denver 's defense , which sacked him seven times and forced him into three turnovers , including a fumble which they recovered for a touchdown . 
denver linebacker von miller was named super bowl mvp , recording five solo tackles , 2 1/2 sacks , and two forced fumbles . 
denver linebacker von miller was named super bowl mvp , recording five solo tackles , 2 1/2 sacks , and two forced fumbles . 
newton was limited by denver 's defense , which sacked him seven times and forced him into three turnovers , including a fumble which they recovered for a touchdown . 
newton was limited by denver 's defense , which sacked him seven times and forced him into three turnovers , including a fumble which they recovered for a touchdown . 
denver linebacker von miller was named super bowl mvp , recording five solo tackles , 2 1/2 sacks , and two forced fumbles . 
denver linebacker von miller was named super bowl mvp , recording five solo tackles , 2 1/2 sacks , and two forced fumbles . 
cbs broadcast super bowl 50 in the u.s. , and charged an average of $ 5 million for a 30-second commercial during the game . 
cbs broadcast super bowl 50 in the u.s. , and charged an average of $ 5 million for a 30-second commercial during the game . 
the super bowl 50 halftime show was headlined by the british rock group coldplay with special guest performers beyoncé and bruno mars , who headlined the super bowl xlvii and super bowl xlviii halftime shows , respectively . 
the super bowl 50 halftime show was headlined by the british rock group coldplay with special guest performers beyoncé and bruno mars , who headlined the super bowl xlvii and super bowl xlviii halftime shows , respectively . 
the super bowl 50 halftime show was headlined by the british rock group coldplay with special guest performers beyoncé and bruno mars , who headlined the super bowl xlvii and super bowl xlviii halftime shows , respectively . 
cbs broadcast super bowl 50 in the u.s. , and charged an average of $ 5 million for a 30-second commercial during the game . 
cbs broadcast super bowl 50 in the u.s. , and charged an average of $ 5 million for a 30-second commercial during the game . 
the super bowl 50 halftime show was headlined by the british rock group coldplay with special guest performers beyoncé and bruno mars , who headlined the super bowl xlvii and super bowl xlviii halftime shows , respectively . 
the super bowl 50 halftime show was headlined by the british rock group coldplay with special guest performers beyoncé and bruno mars , who headlined the super bowl xlvii and super bowl xlviii halftime shows , respectively . 
the super bowl 50 halftime show was headlined by the british rock group coldplay with special guest performers beyoncé and bruno mars , who headlined the super bowl xlvii and super bowl xlviii halftime shows , respectively . 
cbs broadcast super bowl 50 in the u.s. , and charged an average of $ 5 million for a 30-second commercial during the game . 
cbs broadcast super bowl 50 in the u.s. , and charged an average of $ 5 million for a 30-second commercial during the game . 
the super bowl 50 halftime show was headlined by the british rock group coldplay with special guest performers beyoncé and bruno mars , who headlined the super bowl xlvii and super bowl xlviii halftime shows , respectively . 
it was the third-most watched u.s. broadcast ever . 
cbs broadcast super bowl 50 in the u.s. , and charged an average of $ 5 million for a 30-second commercial during the game . 
cbs broadcast super bowl 50 in the u.s. , and charged an average of $ 5 million for a 30-second commercial during the game . 
the super bowl 50 halftime show was headlined by the british rock group coldplay with special guest performers beyoncé and bruno mars , who headlined the super bowl xlvii and super bowl xlviii halftime shows , respectively . 
the super bowl 50 halftime show was headlined by the british rock group coldplay with special guest performers beyoncé and bruno mars , who headlined the super bowl xlvii and super bowl xlviii halftime shows , respectively . 
cbs broadcast super bowl 50 in the u.s. , and charged an average of $ 5 million for a 30-second commercial during the game . 
the super bowl 50 halftime show was headlined by the british rock group coldplay with special guest performers beyoncé and bruno mars , who headlined the super bowl xlvii and super bowl xlviii halftime shows , respectively . 
the super bowl 50 halftime show was headlined by the british rock group coldplay with special guest performers beyoncé and bruno mars , who headlined the super bowl xlvii and super bowl xlviii halftime shows , respectively . 
the super bowl 50 halftime show was headlined by the british rock group coldplay with special guest performers beyoncé and bruno mars , who headlined the super bowl xlvii and super bowl xlviii halftime shows , respectively . 
cbs broadcast super bowl 50 in the u.s. , and charged an average of $ 5 million for a 30-second commercial during the game . 
the super bowl 50 halftime show was headlined by the british rock group coldplay with special guest performers beyoncé and bruno mars , who headlined the super bowl xlvii and super bowl xlviii halftime shows , respectively . 
the super bowl 50 halftime show was headlined by the british rock group coldplay with special guest performers beyoncé and bruno mars , who headlined the super bowl xlvii and super bowl xlviii halftime shows , respectively . 
the super bowl 50 halftime show was headlined by the british rock group coldplay with special guest performers beyoncé and bruno mars , who headlined the super bowl xlvii and super bowl xlviii halftime shows , respectively . 
in early 2012 , nfl commissioner roger goodell stated that the league planned to make the 50th super bowl `` spectacular '' and that it would be `` an important game for us as a league '' . 
in early 2012 , nfl commissioner roger goodell stated that the league planned to make the 50th super bowl `` spectacular '' and that it would be `` an important game for us as a league '' . 
in early 2012 , nfl commissioner roger goodell stated that the league planned to make the 50th super bowl `` spectacular '' and that it would be `` an important game for us as a league '' . 
in early 2012 , nfl commissioner roger goodell stated that the league planned to make the 50th super bowl `` spectacular '' and that it would be `` an important game for us as a league '' . 
in early 2012 , nfl commissioner roger goodell stated that the league planned to make the 50th super bowl `` spectacular '' and that it would be `` an important game for us as a league '' . 
in early 2012 , nfl commissioner roger goodell stated that the league planned to make the 50th super bowl `` spectacular '' and that it would be `` an important game for us as a league '' . 
in early 2012 , nfl commissioner roger goodell stated that the league planned to make the 50th super bowl `` spectacular '' and that it would be `` an important game for us as a league '' . 
in early 2012 , nfl commissioner roger goodell stated that the league planned to make the 50th super bowl `` spectacular '' and that it would be `` an important game for us as a league '' . 
in early 2012 , nfl commissioner roger goodell stated that the league planned to make the 50th super bowl `` spectacular '' and that it would be `` an important game for us as a league '' . 
in early 2012 , nfl commissioner roger goodell stated that the league planned to make the 50th super bowl `` spectacular '' and that it would be `` an important game for us as a league '' . 
in early 2012 , nfl commissioner roger goodell stated that the league planned to make the 50th super bowl `` spectacular '' and that it would be `` an important game for us as a league '' . 
the league eventually narrowed the bids to three sites : new orleans ' mercedes-benz superdome , miami 's sun life stadium , and the san francisco bay area 's levi 's stadium . 
the league eventually narrowed the bids to three sites : new orleans ' mercedes-benz superdome , miami 's sun life stadium , and the san francisco bay area 's levi 's stadium . 
the league eventually narrowed the bids to three sites : new orleans ' mercedes-benz superdome , miami 's sun life stadium , and the san francisco bay area 's levi 's stadium . 
the league eventually narrowed the bids to three sites : new orleans ' mercedes-benz superdome , miami 's sun life stadium , and the san francisco bay area 's levi 's stadium . 
the league eventually narrowed the bids to three sites : new orleans ' mercedes-benz superdome , miami 's sun life stadium , and the san francisco bay area 's levi 's stadium . 
the league eventually narrowed the bids to three sites : new orleans ' mercedes-benz superdome , miami 's sun life stadium , and the san francisco bay area 's levi 's stadium . 
the league eventually narrowed the bids to three sites : new orleans ' mercedes-benz superdome , miami 's sun life stadium , and the san francisco bay area 's levi 's stadium . 
the league eventually narrowed the bids to three sites : new orleans ' mercedes-benz superdome , miami 's sun life stadium , and the san francisco bay area 's levi 's stadium . 
the league eventually narrowed the bids to three sites : new orleans ' mercedes-benz superdome , miami 's sun life stadium , and the san francisco bay area 's levi 's stadium . 
the league eventually narrowed the bids to three sites : new orleans ' mercedes-benz superdome , miami 's sun life stadium , and the san francisco bay area 's levi 's stadium . 
the league eventually narrowed the bids to three sites : new orleans ' mercedes-benz superdome , miami 's sun life stadium , and the san francisco bay area 's levi 's stadium . 
the league eventually narrowed the bids to three sites : new orleans ' mercedes-benz superdome , miami 's sun life stadium , and the san francisco bay area 's levi 's stadium . 
the league eventually narrowed the bids to three sites : new orleans ' mercedes-benz superdome , miami 's sun life stadium , and the san francisco bay area 's levi 's stadium . 
the league eventually narrowed the bids to three sites : new orleans ' mercedes-benz superdome , miami 's sun life stadium , and the san francisco bay area 's levi 's stadium . 
the league eventually narrowed the bids to three sites : new orleans ' mercedes-benz superdome , miami 's sun life stadium , and the san francisco bay area 's levi 's stadium . 
the league eventually narrowed the bids to three sites : new orleans ' mercedes-benz superdome , miami 's sun life stadium , and the san francisco bay area 's levi 's stadium . 
the league eventually narrowed the bids to three sites : new orleans ' mercedes-benz superdome , miami 's sun life stadium , and the san francisco bay area 's levi 's stadium . 
the league announced on october 16 , 2012 , that the two finalists were sun life stadium and levi 's stadium . 
the south florida/miami area has previously hosted the event 10 times -lrb- tied for most with new orleans -rrb- , with the most recent one being super bowl xliv in 2010 . 
the south florida/miami area has previously hosted the event 10 times -lrb- tied for most with new orleans -rrb- , with the most recent one being super bowl xliv in 2010 . 
the south florida/miami area has previously hosted the event 10 times -lrb- tied for most with new orleans -rrb- , with the most recent one being super bowl xliv in 2010 . 
the san francisco bay area last hosted in 1985 -lrb- super bowl xix -rrb- , held at stanford stadium in stanford , california , won by the home team 49ers . 
the league announced on october 16 , 2012 , that the two finalists were sun life stadium and levi 's stadium . 
the league announced on october 16 , 2012 , that the two finalists were sun life stadium and levi 's stadium . 
the san francisco bay area last hosted in 1985 -lrb- super bowl xix -rrb- , held at stanford stadium in stanford , california , won by the home team 49ers . 
however , on may 3 , 2013 , the florida legislature refused to approve the funding plan to pay for the renovations , dealing a significant blow to miami 's chances . 
the south florida/miami area has previously hosted the event 10 times -lrb- tied for most with new orleans -rrb- , with the most recent one being super bowl xliv in 2010 . 
the league announced on october 16 , 2012 , that the two finalists were sun life stadium and levi 's stadium . 
the south florida/miami area has previously hosted the event 10 times -lrb- tied for most with new orleans -rrb- , with the most recent one being super bowl xliv in 2010 . 
the league announced on october 16 , 2012 , that the two finalists were sun life stadium and levi 's stadium . 
however , on may 3 , 2013 , the florida legislature refused to approve the funding plan to pay for the renovations , dealing a significant blow to miami 's chances . 
the san francisco bay area last hosted in 1985 -lrb- super bowl xix -rrb- , held at stanford stadium in stanford , california , won by the home team 49ers . 
the south florida/miami area has previously hosted the event 10 times -lrb- tied for most with new orleans -rrb- , with the most recent one being super bowl xliv in 2010 . 
the league announced on october 16 , 2012 , that the two finalists were sun life stadium and levi 's stadium . 
the south florida/miami area has previously hosted the event 10 times -lrb- tied for most with new orleans -rrb- , with the most recent one being super bowl xliv in 2010 . 
the south florida/miami area has previously hosted the event 10 times -lrb- tied for most with new orleans -rrb- , with the most recent one being super bowl xliv in 2010 . 
the san francisco bay area last hosted in 1985 -lrb- super bowl xix -rrb- , held at stanford stadium in stanford , california , won by the home team 49ers . 
however , on may 3 , 2013 , the florida legislature refused to approve the funding plan to pay for the renovations , dealing a significant blow to miami 's chances . 
on may 21 , 2013 , nfl owners at their spring meetings in boston voted and awarded the game to levi 's stadium . 
on may 21 , 2013 , nfl owners at their spring meetings in boston voted and awarded the game to levi 's stadium . 
the $ 1.2 billion stadium opened in 2014 . 
the $ 1.2 billion stadium opened in 2014 . 
it is the first super bowl held in the san francisco bay area since super bowl xix in 1985 , and the first in california since super bowl xxxvii took place in san diego in 2003 . 
on may 21 , 2013 , nfl owners at their spring meetings in boston voted and awarded the game to levi 's stadium . 
on may 21 , 2013 , nfl owners at their spring meetings in boston voted and awarded the game to levi 's stadium . 
the $ 1.2 billion stadium opened in 2014 . 
it is the first super bowl held in the san francisco bay area since super bowl xix in 1985 , and the first in california since super bowl xxxvii took place in san diego in 2003 . 
it is the first super bowl held in the san francisco bay area since super bowl xix in 1985 , and the first in california since super bowl xxxvii took place in san diego in 2003 . 
on may 21 , 2013 , nfl owners at their spring meetings in boston voted and awarded the game to levi 's stadium . 
the $ 1.2 billion stadium opened in 2014 . 
the $ 1.2 billion stadium opened in 2014 . 
it is the first super bowl held in the san francisco bay area since super bowl xix in 1985 , and the first in california since super bowl xxxvii took place in san diego in 2003 . 
it is the first super bowl held in the san francisco bay area since super bowl xix in 1985 , and the first in california since super bowl xxxvii took place in san diego in 2003 . 
on may 21 , 2013 , nfl owners at their spring meetings in boston voted and awarded the game to levi 's stadium . 
the $ 1.2 billion stadium opened in 2014 . 
it is the first super bowl held in the san francisco bay area since super bowl xix in 1985 , and the first in california since super bowl xxxvii took place in san diego in 2003 . 
on may 21 , 2013 , nfl owners at their spring meetings in boston voted and awarded the game to levi 's stadium . 
on may 21 , 2013 , nfl owners at their spring meetings in boston voted and awarded the game to levi 's stadium . 
the $ 1.2 billion stadium opened in 2014 . 
the $ 1.2 billion stadium opened in 2014 . 
it is the first super bowl held in the san francisco bay area since super bowl xix in 1985 , and the first in california since super bowl xxxvii took place in san diego in 2003 . 
coincidentally , both teams were coached by john fox in their last super bowl appearance prior to super bowl 50 . 
the carolina panthers became one of only ten teams to have completed a regular season with only one loss , and one of only six teams to have acquired a 15 -- 1 record , while the denver broncos became one of four teams to have made eight appearances in the super bowl . 
the carolina panthers became one of only ten teams to have completed a regular season with only one loss , and one of only six teams to have acquired a 15 -- 1 record , while the denver broncos became one of four teams to have made eight appearances in the super bowl . 
the carolina panthers became one of only ten teams to have completed a regular season with only one loss , and one of only six teams to have acquired a 15 -- 1 record , while the denver broncos became one of four teams to have made eight appearances in the super bowl . 
the broncos made their second super bowl appearance in three years , having reached super bowl xlviii , while the panthers made their second super bowl appearance in franchise history , their other appearance being super bowl xxxviii . 
coincidentally , both teams were coached by john fox in their last super bowl appearance prior to super bowl 50 . 
the carolina panthers became one of only ten teams to have completed a regular season with only one loss , and one of only six teams to have acquired a 15 -- 1 record , while the denver broncos became one of four teams to have made eight appearances in the super bowl . 
the carolina panthers became one of only ten teams to have completed a regular season with only one loss , and one of only six teams to have acquired a 15 -- 1 record , while the denver broncos became one of four teams to have made eight appearances in the super bowl . 
the broncos made their second super bowl appearance in three years , having reached super bowl xlviii , while the panthers made their second super bowl appearance in franchise history , their other appearance being super bowl xxxviii . 
the carolina panthers became one of only ten teams to have completed a regular season with only one loss , and one of only six teams to have acquired a 15 -- 1 record , while the denver broncos became one of four teams to have made eight appearances in the super bowl . 
for the third straight season , the number one seeds from both conferences met in the super bowl . 
for the third straight season , the number one seeds from both conferences met in the super bowl . 
the broncos made their second super bowl appearance in three years , having reached super bowl xlviii , while the panthers made their second super bowl appearance in franchise history , their other appearance being super bowl xxxviii . 
the broncos made their second super bowl appearance in three years , having reached super bowl xlviii , while the panthers made their second super bowl appearance in franchise history , their other appearance being super bowl xxxviii . 
the carolina panthers became one of only ten teams to have completed a regular season with only one loss , and one of only six teams to have acquired a 15 -- 1 record , while the denver broncos became one of four teams to have made eight appearances in the super bowl . 
for the third straight season , the number one seeds from both conferences met in the super bowl . 
the carolina panthers became one of only ten teams to have completed a regular season with only one loss , and one of only six teams to have acquired a 15 -- 1 record , while the denver broncos became one of four teams to have made eight appearances in the super bowl . 
coincidentally , both teams were coached by john fox in their last super bowl appearance prior to super bowl 50 . 
despite waiving longtime running back deangelo williams and losing top wide receiver kelvin benjamin to a torn acl in the preseason , the carolina panthers had their best regular season in franchise history , becoming the seventh team to win at least 15 regular season games since the league expanded to a 16-game schedule in 1978 . 
despite waiving longtime running back deangelo williams and losing top wide receiver kelvin benjamin to a torn acl in the preseason , the carolina panthers had their best regular season in franchise history , becoming the seventh team to win at least 15 regular season games since the league expanded to a 16-game schedule in 1978 . 
despite waiving longtime running back deangelo williams and losing top wide receiver kelvin benjamin to a torn acl in the preseason , the carolina panthers had their best regular season in franchise history , becoming the seventh team to win at least 15 regular season games since the league expanded to a 16-game schedule in 1978 . 
despite waiving longtime running back deangelo williams and losing top wide receiver kelvin benjamin to a torn acl in the preseason , the carolina panthers had their best regular season in franchise history , becoming the seventh team to win at least 15 regular season games since the league expanded to a 16-game schedule in 1978 . 
despite waiving longtime running back deangelo williams and losing top wide receiver kelvin benjamin to a torn acl in the preseason , the carolina panthers had their best regular season in franchise history , becoming the seventh team to win at least 15 regular season games since the league expanded to a 16-game schedule in 1978 . 
ten players were selected to the pro bowl -lrb- the most in franchise history -rrb- along with eight all-pro selections . 
ten players were selected to the pro bowl -lrb- the most in franchise history -rrb- along with eight all-pro selections . 
despite waiving longtime running back deangelo williams and losing top wide receiver kelvin benjamin to a torn acl in the preseason , the carolina panthers had their best regular season in franchise history , becoming the seventh team to win at least 15 regular season games since the league expanded to a 16-game schedule in 1978 . 
despite waiving longtime running back deangelo williams and losing top wide receiver kelvin benjamin to a torn acl in the preseason , the carolina panthers had their best regular season in franchise history , becoming the seventh team to win at least 15 regular season games since the league expanded to a 16-game schedule in 1978 . 
carolina started the season 14 -- 0 , not only setting franchise records for the best start and the longest single-season winning streak , but also posting the best start to a season by an nfc team in nfl history , breaking the 13 -- 0 record previously shared with the 2009 new orleans saints and the 2011 green bay packers . 
carolina started the season 14 -- 0 , not only setting franchise records for the best start and the longest single-season winning streak , but also posting the best start to a season by an nfc team in nfl history , breaking the 13 -- 0 record previously shared with the 2009 new orleans saints and the 2011 green bay packers . 
despite waiving longtime running back deangelo williams and losing top wide receiver kelvin benjamin to a torn acl in the preseason , the carolina panthers had their best regular season in franchise history , becoming the seventh team to win at least 15 regular season games since the league expanded to a 16-game schedule in 1978 . 
despite waiving longtime running back deangelo williams and losing top wide receiver kelvin benjamin to a torn acl in the preseason , the carolina panthers had their best regular season in franchise history , becoming the seventh team to win at least 15 regular season games since the league expanded to a 16-game schedule in 1978 . 
despite waiving longtime running back deangelo williams and losing top wide receiver kelvin benjamin to a torn acl in the preseason , the carolina panthers had their best regular season in franchise history , becoming the seventh team to win at least 15 regular season games since the league expanded to a 16-game schedule in 1978 . 
despite waiving longtime running back deangelo williams and losing top wide receiver kelvin benjamin to a torn acl in the preseason , the carolina panthers had their best regular season in franchise history , becoming the seventh team to win at least 15 regular season games since the league expanded to a 16-game schedule in 1978 . 
ten players were selected to the pro bowl -lrb- the most in franchise history -rrb- along with eight all-pro selections . 
despite waiving longtime running back deangelo williams and losing top wide receiver kelvin benjamin to a torn acl in the preseason , the carolina panthers had their best regular season in franchise history , becoming the seventh team to win at least 15 regular season games since the league expanded to a 16-game schedule in 1978 . 
despite waiving longtime running back deangelo williams and losing top wide receiver kelvin benjamin to a torn acl in the preseason , the carolina panthers had their best regular season in franchise history , becoming the seventh team to win at least 15 regular season games since the league expanded to a 16-game schedule in 1978 . 
despite waiving longtime running back deangelo williams and losing top wide receiver kelvin benjamin to a torn acl in the preseason , the carolina panthers had their best regular season in franchise history , becoming the seventh team to win at least 15 regular season games since the league expanded to a 16-game schedule in 1978 . 
ten players were selected to the pro bowl -lrb- the most in franchise history -rrb- along with eight all-pro selections . 
the panthers offense , which led the nfl in scoring -lrb- 500 points -rrb- , was loaded with talent , boasting six pro bowl selections . 
pro bowl quarterback cam newton had one of his best seasons , throwing for 3,837 yards and rushing for 636 , while recording a career-high and league-leading 45 total touchdowns -lrb- 35 passing , 10 rushing -rrb- , a career-low 10 interceptions , and a career-best quarterback rating of 99.4 . 
pro bowl quarterback cam newton had one of his best seasons , throwing for 3,837 yards and rushing for 636 , while recording a career-high and league-leading 45 total touchdowns -lrb- 35 passing , 10 rushing -rrb- , a career-low 10 interceptions , and a career-best quarterback rating of 99.4 . 
newton 's leading receivers were tight end greg olsen , who caught a career-high 77 passes for 1,104 yards and seven touchdowns , and wide receiver ted ginn , jr. , who caught 44 passes for 739 yards and 10 touchdowns ; ginn also rushed for 60 yards and returned 27 punts for 277 yards . 
newton 's leading receivers were tight end greg olsen , who caught a career-high 77 passes for 1,104 yards and seven touchdowns , and wide receiver ted ginn , jr. , who caught 44 passes for 739 yards and 10 touchdowns ; ginn also rushed for 60 yards and returned 27 punts for 277 yards . 
pro bowl quarterback cam newton had one of his best seasons , throwing for 3,837 yards and rushing for 636 , while recording a career-high and league-leading 45 total touchdowns -lrb- 35 passing , 10 rushing -rrb- , a career-low 10 interceptions , and a career-best quarterback rating of 99.4 . 
pro bowl quarterback cam newton had one of his best seasons , throwing for 3,837 yards and rushing for 636 , while recording a career-high and league-leading 45 total touchdowns -lrb- 35 passing , 10 rushing -rrb- , a career-low 10 interceptions , and a career-best quarterback rating of 99.4 . 
newton 's leading receivers were tight end greg olsen , who caught a career-high 77 passes for 1,104 yards and seven touchdowns , and wide receiver ted ginn , jr. , who caught 44 passes for 739 yards and 10 touchdowns ; ginn also rushed for 60 yards and returned 27 punts for 277 yards . 
newton 's leading receivers were tight end greg olsen , who caught a career-high 77 passes for 1,104 yards and seven touchdowns , and wide receiver ted ginn , jr. , who caught 44 passes for 739 yards and 10 touchdowns ; ginn also rushed for 60 yards and returned 27 punts for 277 yards . 
the panthers backfield featured pro bowl running back jonathan stewart , who led the team with 989 rushing yards and six touchdowns in 13 games , along with pro bowl fullback mike tolbert , who rushed for 256 yards and caught 18 passes for another 154 yards . 
the panthers offense , which led the nfl in scoring -lrb- 500 points -rrb- , was loaded with talent , boasting six pro bowl selections . 
pro bowl quarterback cam newton had one of his best seasons , throwing for 3,837 yards and rushing for 636 , while recording a career-high and league-leading 45 total touchdowns -lrb- 35 passing , 10 rushing -rrb- , a career-low 10 interceptions , and a career-best quarterback rating of 99.4 . 
pro bowl quarterback cam newton had one of his best seasons , throwing for 3,837 yards and rushing for 636 , while recording a career-high and league-leading 45 total touchdowns -lrb- 35 passing , 10 rushing -rrb- , a career-low 10 interceptions , and a career-best quarterback rating of 99.4 . 
pro bowl quarterback cam newton had one of his best seasons , throwing for 3,837 yards and rushing for 636 , while recording a career-high and league-leading 45 total touchdowns -lrb- 35 passing , 10 rushing -rrb- , a career-low 10 interceptions , and a career-best quarterback rating of 99.4 . 
the panthers offense , which led the nfl in scoring -lrb- 500 points -rrb- , was loaded with talent , boasting six pro bowl selections . 
the panthers offense , which led the nfl in scoring -lrb- 500 points -rrb- , was loaded with talent , boasting six pro bowl selections . 
pro bowl quarterback cam newton had one of his best seasons , throwing for 3,837 yards and rushing for 636 , while recording a career-high and league-leading 45 total touchdowns -lrb- 35 passing , 10 rushing -rrb- , a career-low 10 interceptions , and a career-best quarterback rating of 99.4 . 
pro bowl quarterback cam newton had one of his best seasons , throwing for 3,837 yards and rushing for 636 , while recording a career-high and league-leading 45 total touchdowns -lrb- 35 passing , 10 rushing -rrb- , a career-low 10 interceptions , and a career-best quarterback rating of 99.4 . 
pro bowl quarterback cam newton had one of his best seasons , throwing for 3,837 yards and rushing for 636 , while recording a career-high and league-leading 45 total touchdowns -lrb- 35 passing , 10 rushing -rrb- , a career-low 10 interceptions , and a career-best quarterback rating of 99.4 . 
newton 's leading receivers were tight end greg olsen , who caught a career-high 77 passes for 1,104 yards and seven touchdowns , and wide receiver ted ginn , jr. , who caught 44 passes for 739 yards and 10 touchdowns ; ginn also rushed for 60 yards and returned 27 punts for 277 yards . 
the panthers defense gave up just 308 points , ranking sixth in the league , while also leading the nfl in interceptions with 24 and boasting four pro bowl selections . 
the panthers line also featured veteran defensive end jared allen , a 5-time pro bowler who was the nfl 's active career sack leader with 136 , along with defensive end kony ealy , who had 5 sacks in just 9 starts . 
davis compiled 5 1/2 sacks , four forced fumbles , and four interceptions , while kuechly led the team in tackles -lrb- 118 -rrb- forced two fumbles , and intercepted four passes of his own . 
the panthers defense gave up just 308 points , ranking sixth in the league , while also leading the nfl in interceptions with 24 and boasting four pro bowl selections . 
pro bowl defensive tackle kawann short led the team in sacks with 11 , while also forcing three fumbles and recovering two . 
the panthers defense gave up just 308 points , ranking sixth in the league , while also leading the nfl in interceptions with 24 and boasting four pro bowl selections . 
pro bowl defensive tackle kawann short led the team in sacks with 11 , while also forcing three fumbles and recovering two . 
the panthers defense gave up just 308 points , ranking sixth in the league , while also leading the nfl in interceptions with 24 and boasting four pro bowl selections . 
the panthers defense gave up just 308 points , ranking sixth in the league , while also leading the nfl in interceptions with 24 and boasting four pro bowl selections . 
carolina 's secondary featured pro bowl safety kurt coleman , who led the team with a career high seven interceptions , while also racking up 88 tackles and pro bowl cornerback josh norman , who developed into a shutdown corner during the season and had four interceptions , two of which were returned for touchdowns . 
the panthers defense gave up just 308 points , ranking sixth in the league , while also leading the nfl in interceptions with 24 and boasting four pro bowl selections . 
the panthers line also featured veteran defensive end jared allen , a 5-time pro bowler who was the nfl 's active career sack leader with 136 , along with defensive end kony ealy , who had 5 sacks in just 9 starts . 
behind them , two of the panthers three starting linebackers were also selected to play in the pro bowl : thomas davis and luke kuechly . 
pro bowl defensive tackle kawann short led the team in sacks with 11 , while also forcing three fumbles and recovering two . 
following their loss in the divisional round of the previous season 's playoffs , the denver broncos underwent numerous coaching changes , including a mutual parting with head coach john fox -lrb- who had won four divisional championships in his four years as broncos head coach -rrb- , and the hiring of gary kubiak as the new head coach . 
he set the nfl 's all-time record for career passing yards in this game , but was benched after throwing four interceptions in favor of backup quarterback brock osweiler , who took over as the starter for most of the remainder of the regular season . 
under kubiak , the broncos planned to install a run-oriented offense with zone blocking to blend in with quarterback peyton manning 's shotgun passing skills , but struggled with numerous changes and injuries to the offensive line , as well as manning having his worst statistical season since his rookie year with the indianapolis colts in 1998 , due to a plantar fasciitis injury in his heel that he had suffered since the summer , and the simple fact that manning was getting old , as he turned 39 in the 2015 off-season . 
osweiler was injured , however , leading to manning 's return during the week 17 regular season finale , where the broncos were losing 13 -- 7 against the 4 -- 11 san diego chargers , resulting in manning re-claiming the starting quarterback position for the playoffs by leading the team to a key 27 -- 20 win that enabled the team to clinch the number one overall afc seed . 
under defensive coordinator wade phillips , the broncos ' defense ranked number one in total yards allowed , passing yards allowed and sacks , and like the previous three seasons , the team has continued to set numerous individual , league and franchise records . 
following their loss in the divisional round of the previous season 's playoffs , the denver broncos underwent numerous coaching changes , including a mutual parting with head coach john fox -lrb- who had won four divisional championships in his four years as broncos head coach -rrb- , and the hiring of gary kubiak as the new head coach . 
following their loss in the divisional round of the previous season 's playoffs , the denver broncos underwent numerous coaching changes , including a mutual parting with head coach john fox -lrb- who had won four divisional championships in his four years as broncos head coach -rrb- , and the hiring of gary kubiak as the new head coach . 
under kubiak , the broncos planned to install a run-oriented offense with zone blocking to blend in with quarterback peyton manning 's shotgun passing skills , but struggled with numerous changes and injuries to the offensive line , as well as manning having his worst statistical season since his rookie year with the indianapolis colts in 1998 , due to a plantar fasciitis injury in his heel that he had suffered since the summer , and the simple fact that manning was getting old , as he turned 39 in the 2015 off-season . 
under kubiak , the broncos planned to install a run-oriented offense with zone blocking to blend in with quarterback peyton manning 's shotgun passing skills , but struggled with numerous changes and injuries to the offensive line , as well as manning having his worst statistical season since his rookie year with the indianapolis colts in 1998 , due to a plantar fasciitis injury in his heel that he had suffered since the summer , and the simple fact that manning was getting old , as he turned 39 in the 2015 off-season . 
under kubiak , the broncos planned to install a run-oriented offense with zone blocking to blend in with quarterback peyton manning 's shotgun passing skills , but struggled with numerous changes and injuries to the offensive line , as well as manning having his worst statistical season since his rookie year with the indianapolis colts in 1998 , due to a plantar fasciitis injury in his heel that he had suffered since the summer , and the simple fact that manning was getting old , as he turned 39 in the 2015 off-season . 
following their loss in the divisional round of the previous season 's playoffs , the denver broncos underwent numerous coaching changes , including a mutual parting with head coach john fox -lrb- who had won four divisional championships in his four years as broncos head coach -rrb- , and the hiring of gary kubiak as the new head coach . 
under kubiak , the broncos planned to install a run-oriented offense with zone blocking to blend in with quarterback peyton manning 's shotgun passing skills , but struggled with numerous changes and injuries to the offensive line , as well as manning having his worst statistical season since his rookie year with the indianapolis colts in 1998 , due to a plantar fasciitis injury in his heel that he had suffered since the summer , and the simple fact that manning was getting old , as he turned 39 in the 2015 off-season . 
under kubiak , the broncos planned to install a run-oriented offense with zone blocking to blend in with quarterback peyton manning 's shotgun passing skills , but struggled with numerous changes and injuries to the offensive line , as well as manning having his worst statistical season since his rookie year with the indianapolis colts in 1998 , due to a plantar fasciitis injury in his heel that he had suffered since the summer , and the simple fact that manning was getting old , as he turned 39 in the 2015 off-season . 
under kubiak , the broncos planned to install a run-oriented offense with zone blocking to blend in with quarterback peyton manning 's shotgun passing skills , but struggled with numerous changes and injuries to the offensive line , as well as manning having his worst statistical season since his rookie year with the indianapolis colts in 1998 , due to a plantar fasciitis injury in his heel that he had suffered since the summer , and the simple fact that manning was getting old , as he turned 39 in the 2015 off-season . 
following their loss in the divisional round of the previous season 's playoffs , the denver broncos underwent numerous coaching changes , including a mutual parting with head coach john fox -lrb- who had won four divisional championships in his four years as broncos head coach -rrb- , and the hiring of gary kubiak as the new head coach . 
following their loss in the divisional round of the previous season 's playoffs , the denver broncos underwent numerous coaching changes , including a mutual parting with head coach john fox -lrb- who had won four divisional championships in his four years as broncos head coach -rrb- , and the hiring of gary kubiak as the new head coach . 
under kubiak , the broncos planned to install a run-oriented offense with zone blocking to blend in with quarterback peyton manning 's shotgun passing skills , but struggled with numerous changes and injuries to the offensive line , as well as manning having his worst statistical season since his rookie year with the indianapolis colts in 1998 , due to a plantar fasciitis injury in his heel that he had suffered since the summer , and the simple fact that manning was getting old , as he turned 39 in the 2015 off-season . 
following their loss in the divisional round of the previous season 's playoffs , the denver broncos underwent numerous coaching changes , including a mutual parting with head coach john fox -lrb- who had won four divisional championships in his four years as broncos head coach -rrb- , and the hiring of gary kubiak as the new head coach . 
in week 10 , manning suffered a partial tear of the plantar fasciitis in his left foot . 
under defensive coordinator wade phillips , the broncos ' defense ranked number one in total yards allowed , passing yards allowed and sacks , and like the previous three seasons , the team has continued to set numerous individual , league and franchise records . 
manning finished the year with a career-low 67.9 passer rating , throwing for 2,249 yards and nine touchdowns , with 17 interceptions . 
manning finished the year with a career-low 67.9 passer rating , throwing for 2,249 yards and nine touchdowns , with 17 interceptions . 
veteran receiver demaryius thomas led the team with 105 receptions for 1,304 yards and six touchdowns , while emmanuel sanders caught 76 passes for 1,135 yards and six scores , while adding another 106 yards returning punts . 
running back c. j. anderson was the team 's leading rusher 863 yards and seven touchdowns , while also catching 25 passes for 183 yards . 
in contrast , osweiler threw for 1,967 yards , 10 touchdowns and six interceptions for a rating of 86.4 . 
manning finished the year with a career-low 67.9 passer rating , throwing for 2,249 yards and nine touchdowns , with 17 interceptions . 
manning finished the year with a career-low 67.9 passer rating , throwing for 2,249 yards and nine touchdowns , with 17 interceptions . 
manning finished the year with a career-low 67.9 passer rating , throwing for 2,249 yards and nine touchdowns , with 17 interceptions . 
veteran receiver demaryius thomas led the team with 105 receptions for 1,304 yards and six touchdowns , while emmanuel sanders caught 76 passes for 1,135 yards and six scores , while adding another 106 yards returning punts . 
veteran receiver demaryius thomas led the team with 105 receptions for 1,304 yards and six touchdowns , while emmanuel sanders caught 76 passes for 1,135 yards and six scores , while adding another 106 yards returning punts . 
manning finished the year with a career-low 67.9 passer rating , throwing for 2,249 yards and nine touchdowns , with 17 interceptions . 
manning finished the year with a career-low 67.9 passer rating , throwing for 2,249 yards and nine touchdowns , with 17 interceptions . 
veteran receiver demaryius thomas led the team with 105 receptions for 1,304 yards and six touchdowns , while emmanuel sanders caught 76 passes for 1,135 yards and six scores , while adding another 106 yards returning punts . 
veteran receiver demaryius thomas led the team with 105 receptions for 1,304 yards and six touchdowns , while emmanuel sanders caught 76 passes for 1,135 yards and six scores , while adding another 106 yards returning punts . 
manning finished the year with a career-low 67.9 passer rating , throwing for 2,249 yards and nine touchdowns , with 17 interceptions . 
manning finished the year with a career-low 67.9 passer rating , throwing for 2,249 yards and nine touchdowns , with 17 interceptions . 
veteran receiver demaryius thomas led the team with 105 receptions for 1,304 yards and six touchdowns , while emmanuel sanders caught 76 passes for 1,135 yards and six scores , while adding another 106 yards returning punts . 
running back c. j. anderson was the team 's leading rusher 863 yards and seven touchdowns , while also catching 25 passes for 183 yards . 
running back ronnie hillman also made a big impact with 720 yards , five touchdowns , 24 receptions , and a 4.7 yards per carry average . 
the broncos ' defense ranked first in the nfl yards allowed -lrb- 4,530 -rrb- for the first time in franchise history , and fourth in points allowed -lrb- 296 -rrb- . 
defensive ends derek wolfe and malik jackson each had 5 1/2 sacks . 
linebacker brandon marshall led the team in total tackles with 109 , while danny trevathan ranked second with 102 . 
pro bowl linebacker von miller led the team with 11 sacks , forced four fumbles , and recovered three . 
linebacker demarcus ware was selected to play in the pro bowl for the ninth time in his career , ranking second on the team with 7 1/2 sacks . 
linebacker demarcus ware was selected to play in the pro bowl for the ninth time in his career , ranking second on the team with 7 1/2 sacks . 
defensive ends derek wolfe and malik jackson each had 5 1/2 sacks . 
the broncos ' defense ranked first in the nfl yards allowed -lrb- 4,530 -rrb- for the first time in franchise history , and fourth in points allowed -lrb- 296 -rrb- . 
pro bowl linebacker von miller led the team with 11 sacks , forced four fumbles , and recovered three . 
linebacker brandon marshall led the team in total tackles with 109 , while danny trevathan ranked second with 102 . 
pro bowl linebacker von miller led the team with 11 sacks , forced four fumbles , and recovered three . 
pro bowl linebacker von miller led the team with 11 sacks , forced four fumbles , and recovered three . 
linebacker brandon marshall led the team in total tackles with 109 , while danny trevathan ranked second with 102 . 
defensive ends derek wolfe and malik jackson each had 5 1/2 sacks . 
the panthers beat the seattle seahawks in the divisional round , running up a 31 -- 0 halftime lead and then holding off a furious second half comeback attempt to win 31 -- 24 , avenging their elimination from a year earlier . 
the panthers then blew out the arizona cardinals in the nfc championship game , 49 -- 15 , racking up 487 yards and forcing seven turnovers . 
the panthers then blew out the arizona cardinals in the nfc championship game , 49 -- 15 , racking up 487 yards and forcing seven turnovers . 
the panthers then blew out the arizona cardinals in the nfc championship game , 49 -- 15 , racking up 487 yards and forcing seven turnovers . 
the panthers beat the seattle seahawks in the divisional round , running up a 31 -- 0 halftime lead and then holding off a furious second half comeback attempt to win 31 -- 24 , avenging their elimination from a year earlier . 
the panthers beat the seattle seahawks in the divisional round , running up a 31 -- 0 halftime lead and then holding off a furious second half comeback attempt to win 31 -- 24 , avenging their elimination from a year earlier . 
the panthers beat the seattle seahawks in the divisional round , running up a 31 -- 0 halftime lead and then holding off a furious second half comeback attempt to win 31 -- 24 , avenging their elimination from a year earlier . 
the panthers then blew out the arizona cardinals in the nfc championship game , 49 -- 15 , racking up 487 yards and forcing seven turnovers . 
the panthers beat the seattle seahawks in the divisional round , running up a 31 -- 0 halftime lead and then holding off a furious second half comeback attempt to win 31 -- 24 , avenging their elimination from a year earlier . 
the panthers then blew out the arizona cardinals in the nfc championship game , 49 -- 15 , racking up 487 yards and forcing seven turnovers . 
the panthers then blew out the arizona cardinals in the nfc championship game , 49 -- 15 , racking up 487 yards and forcing seven turnovers . 
the panthers beat the seattle seahawks in the divisional round , running up a 31 -- 0 halftime lead and then holding off a furious second half comeback attempt to win 31 -- 24 , avenging their elimination from a year earlier . 
the panthers then blew out the arizona cardinals in the nfc championship game , 49 -- 15 , racking up 487 yards and forcing seven turnovers . 
the panthers then blew out the arizona cardinals in the nfc championship game , 49 -- 15 , racking up 487 yards and forcing seven turnovers . 
the panthers then blew out the arizona cardinals in the nfc championship game , 49 -- 15 , racking up 487 yards and forcing seven turnovers . 
the broncos defeated the pittsburgh steelers in the divisional round , 23 -- 16 , by scoring 11 points in the final three minutes of the game . 
the broncos defeated the pittsburgh steelers in the divisional round , 23 -- 16 , by scoring 11 points in the final three minutes of the game . 
they then beat the defending super bowl xlix champion new england patriots in the afc championship game , 20 -- 18 , by intercepting a pass on new england 's 2-point conversion attempt with 17 seconds left on the clock . 
they then beat the defending super bowl xlix champion new england patriots in the afc championship game , 20 -- 18 , by intercepting a pass on new england 's 2-point conversion attempt with 17 seconds left on the clock . 
they then beat the defending super bowl xlix champion new england patriots in the afc championship game , 20 -- 18 , by intercepting a pass on new england 's 2-point conversion attempt with 17 seconds left on the clock . 
the broncos defeated the pittsburgh steelers in the divisional round , 23 -- 16 , by scoring 11 points in the final three minutes of the game . 
the broncos defeated the pittsburgh steelers in the divisional round , 23 -- 16 , by scoring 11 points in the final three minutes of the game . 
they then beat the defending super bowl xlix champion new england patriots in the afc championship game , 20 -- 18 , by intercepting a pass on new england 's 2-point conversion attempt with 17 seconds left on the clock . 
they then beat the defending super bowl xlix champion new england patriots in the afc championship game , 20 -- 18 , by intercepting a pass on new england 's 2-point conversion attempt with 17 seconds left on the clock . 
despite manning 's problems with interceptions during the season , he did n't throw any in their two playoff games . 
the broncos defeated the pittsburgh steelers in the divisional round , 23 -- 16 , by scoring 11 points in the final three minutes of the game . 
the broncos defeated the pittsburgh steelers in the divisional round , 23 -- 16 , by scoring 11 points in the final three minutes of the game . 
they then beat the defending super bowl xlix champion new england patriots in the afc championship game , 20 -- 18 , by intercepting a pass on new england 's 2-point conversion attempt with 17 seconds left on the clock . 
the broncos defeated the pittsburgh steelers in the divisional round , 23 -- 16 , by scoring 11 points in the final three minutes of the game . 
they then beat the defending super bowl xlix champion new england patriots in the afc championship game , 20 -- 18 , by intercepting a pass on new england 's 2-point conversion attempt with 17 seconds left on the clock . 
they then beat the defending super bowl xlix champion new england patriots in the afc championship game , 20 -- 18 , by intercepting a pass on new england 's 2-point conversion attempt with 17 seconds left on the clock . 
carolina suffered a major setback when thomas davis , an 11-year veteran who had already overcome three acl tears in his career , went down with a broken arm in the nfc championship game . 
carolina suffered a major setback when thomas davis , an 11-year veteran who had already overcome three acl tears in his career , went down with a broken arm in the nfc championship game . 
carolina suffered a major setback when thomas davis , an 11-year veteran who had already overcome three acl tears in his career , went down with a broken arm in the nfc championship game . 
carolina suffered a major setback when thomas davis , an 11-year veteran who had already overcome three acl tears in his career , went down with a broken arm in the nfc championship game . 
carolina suffered a major setback when thomas davis , an 11-year veteran who had already overcome three acl tears in his career , went down with a broken arm in the nfc championship game . 
carolina suffered a major setback when thomas davis , an 11-year veteran who had already overcome three acl tears in his career , went down with a broken arm in the nfc championship game . 
carolina suffered a major setback when thomas davis , an 11-year veteran who had already overcome three acl tears in his career , went down with a broken arm in the nfc championship game . 
despite this , he insisted he would still find a way to play in the super bowl . 
carolina suffered a major setback when thomas davis , an 11-year veteran who had already overcome three acl tears in his career , went down with a broken arm in the nfc championship game . 
carolina suffered a major setback when thomas davis , an 11-year veteran who had already overcome three acl tears in his career , went down with a broken arm in the nfc championship game . 
carolina suffered a major setback when thomas davis , an 11-year veteran who had already overcome three acl tears in his career , went down with a broken arm in the nfc championship game . 
carolina suffered a major setback when thomas davis , an 11-year veteran who had already overcome three acl tears in his career , went down with a broken arm in the nfc championship game . 
he is also the oldest quarterback ever to play in a super bowl at age 39 . 
the past record was held by john elway , who led the broncos to victory in super bowl xxxiii at age 38 and is currently denver 's executive vice president of football operations and general manager . 
the past record was held by john elway , who led the broncos to victory in super bowl xxxiii at age 38 and is currently denver 's executive vice president of football operations and general manager . 
the past record was held by john elway , who led the broncos to victory in super bowl xxxiii at age 38 and is currently denver 's executive vice president of football operations and general manager . 
the past record was held by john elway , who led the broncos to victory in super bowl xxxiii at age 38 and is currently denver 's executive vice president of football operations and general manager . 
the past record was held by john elway , who led the broncos to victory in super bowl xxxiii at age 38 and is currently denver 's executive vice president of football operations and general manager . 
the past record was held by john elway , who led the broncos to victory in super bowl xxxiii at age 38 and is currently denver 's executive vice president of football operations and general manager . 
the past record was held by john elway , who led the broncos to victory in super bowl xxxiii at age 38 and is currently denver 's executive vice president of football operations and general manager . 
peyton manning became the first quarterback ever to lead two different teams to multiple super bowls . 
peyton manning became the first quarterback ever to lead two different teams to multiple super bowls . 
peyton manning became the first quarterback ever to lead two different teams to multiple super bowls . 
peyton manning became the first quarterback ever to lead two different teams to multiple super bowls . 
the past record was held by john elway , who led the broncos to victory in super bowl xxxiii at age 38 and is currently denver 's executive vice president of football operations and general manager . 
the past record was held by john elway , who led the broncos to victory in super bowl xxxiii at age 38 and is currently denver 's executive vice president of football operations and general manager . 
peyton manning became the first quarterback ever to lead two different teams to multiple super bowls . 
he is also the oldest quarterback ever to play in a super bowl at age 39 . 
the past record was held by john elway , who led the broncos to victory in super bowl xxxiii at age 38 and is currently denver 's executive vice president of football operations and general manager . 
manning was the # 1 selection of the 1998 nfl draft , while newton was picked first in 2011 . 
manning was the # 1 selection of the 1998 nfl draft , while newton was picked first in 2011 . 
manning and newton also set the record for the largest age difference between opposing super bowl quarterbacks at 13 years and 48 days -lrb- manning was 39 , newton was 26 -rrb- . 
manning and newton also set the record for the largest age difference between opposing super bowl quarterbacks at 13 years and 48 days -lrb- manning was 39 , newton was 26 -rrb- . 
the matchup also pits the top two picks of the 2011 draft against each other : newton for carolina and von miller for denver . 
manning was the # 1 selection of the 1998 nfl draft , while newton was picked first in 2011 . 
manning was the # 1 selection of the 1998 nfl draft , while newton was picked first in 2011 . 
manning and newton also set the record for the largest age difference between opposing super bowl quarterbacks at 13 years and 48 days -lrb- manning was 39 , newton was 26 -rrb- . 
this was the first super bowl to feature a quarterback on both teams who was the # 1 pick in their draft classes . 
manning was the # 1 selection of the 1998 nfl draft , while newton was picked first in 2011 . 
manning was the # 1 selection of the 1998 nfl draft , while newton was picked first in 2011 . 
the matchup also pits the top two picks of the 2011 draft against each other : newton for carolina and von miller for denver . 
manning was the # 1 selection of the 1998 nfl draft , while newton was picked first in 2011 . 
manning and newton also set the record for the largest age difference between opposing super bowl quarterbacks at 13 years and 48 days -lrb- manning was 39 , newton was 26 -rrb- . 
manning and newton also set the record for the largest age difference between opposing super bowl quarterbacks at 13 years and 48 days -lrb- manning was 39 , newton was 26 -rrb- . 
with rivera having been a linebacker with the chicago bears in super bowl xx , and kubiak replacing elway at the end of the broncos ' defeats in super bowls xxi and xxiv , this will be the first super bowl in which both head coaches played in the game themselves . 
with rivera having been a linebacker with the chicago bears in super bowl xx , and kubiak replacing elway at the end of the broncos ' defeats in super bowls xxi and xxiv , this will be the first super bowl in which both head coaches played in the game themselves . 
with rivera having been a linebacker with the chicago bears in super bowl xx , and kubiak replacing elway at the end of the broncos ' defeats in super bowls xxi and xxiv , this will be the first super bowl in which both head coaches played in the game themselves . 
with rivera having been a linebacker with the chicago bears in super bowl xx , and kubiak replacing elway at the end of the broncos ' defeats in super bowls xxi and xxiv , this will be the first super bowl in which both head coaches played in the game themselves . 
with rivera having been a linebacker with the chicago bears in super bowl xx , and kubiak replacing elway at the end of the broncos ' defeats in super bowls xxi and xxiv , this will be the first super bowl in which both head coaches played in the game themselves . 
with rivera having been a linebacker with the chicago bears in super bowl xx , and kubiak replacing elway at the end of the broncos ' defeats in super bowls xxi and xxiv , this will be the first super bowl in which both head coaches played in the game themselves . 
with rivera having been a linebacker with the chicago bears in super bowl xx , and kubiak replacing elway at the end of the broncos ' defeats in super bowls xxi and xxiv , this will be the first super bowl in which both head coaches played in the game themselves . 
with rivera having been a linebacker with the chicago bears in super bowl xx , and kubiak replacing elway at the end of the broncos ' defeats in super bowls xxi and xxiv , this will be the first super bowl in which both head coaches played in the game themselves . 
with rivera having been a linebacker with the chicago bears in super bowl xx , and kubiak replacing elway at the end of the broncos ' defeats in super bowls xxi and xxiv , this will be the first super bowl in which both head coaches played in the game themselves . 
concerns were raised over whether levi 's stadium 's field was of a high enough quality to host a super bowl ; during the inaugural season , the field had to be re-sodded multiple times due to various issues , and during a week 6 game earlier in the 2015 season , a portion of the turf collapsed under baltimore ravens kicker justin tucker , causing him to slip and miss a field goal , although the field has not had any major issues since . 
as is customary for super bowl games played at natural grass stadiums , the nfl re-sodded the field with a new playing surface ; a hybrid bermuda 419 turf . 
nfl and atlanta braves field director ed mangan stated that the field was in `` great shape '' for gameday . 
concerns were raised over whether levi 's stadium 's field was of a high enough quality to host a super bowl ; during the inaugural season , the field had to be re-sodded multiple times due to various issues , and during a week 6 game earlier in the 2015 season , a portion of the turf collapsed under baltimore ravens kicker justin tucker , causing him to slip and miss a field goal , although the field has not had any major issues since . 
concerns were raised over whether levi 's stadium 's field was of a high enough quality to host a super bowl ; during the inaugural season , the field had to be re-sodded multiple times due to various issues , and during a week 6 game earlier in the 2015 season , a portion of the turf collapsed under baltimore ravens kicker justin tucker , causing him to slip and miss a field goal , although the field has not had any major issues since . 
concerns were raised over whether levi 's stadium 's field was of a high enough quality to host a super bowl ; during the inaugural season , the field had to be re-sodded multiple times due to various issues , and during a week 6 game earlier in the 2015 season , a portion of the turf collapsed under baltimore ravens kicker justin tucker , causing him to slip and miss a field goal , although the field has not had any major issues since . 
concerns were raised over whether levi 's stadium 's field was of a high enough quality to host a super bowl ; during the inaugural season , the field had to be re-sodded multiple times due to various issues , and during a week 6 game earlier in the 2015 season , a portion of the turf collapsed under baltimore ravens kicker justin tucker , causing him to slip and miss a field goal , although the field has not had any major issues since . 
as is customary for super bowl games played at natural grass stadiums , the nfl re-sodded the field with a new playing surface ; a hybrid bermuda 419 turf . 
concerns were raised over whether levi 's stadium 's field was of a high enough quality to host a super bowl ; during the inaugural season , the field had to be re-sodded multiple times due to various issues , and during a week 6 game earlier in the 2015 season , a portion of the turf collapsed under baltimore ravens kicker justin tucker , causing him to slip and miss a field goal , although the field has not had any major issues since . 
as is customary for super bowl games played at natural grass stadiums , the nfl re-sodded the field with a new playing surface ; a hybrid bermuda 419 turf . 
as is customary for super bowl games played at natural grass stadiums , the nfl re-sodded the field with a new playing surface ; a hybrid bermuda 419 turf . 
however , the turf showed problem throughout the game , with a number of players needing to change their cleats during the game and player slipping during plays all throughout the game . 
concerns were raised over whether levi 's stadium 's field was of a high enough quality to host a super bowl ; during the inaugural season , the field had to be re-sodded multiple times due to various issues , and during a week 6 game earlier in the 2015 season , a portion of the turf collapsed under baltimore ravens kicker justin tucker , causing him to slip and miss a field goal , although the field has not had any major issues since . 
as is customary for super bowl games played at natural grass stadiums , the nfl re-sodded the field with a new playing surface ; a hybrid bermuda 419 turf . 
as the designated home team in the annual rotation between afc and nfc teams , the broncos elected to wear their road white jerseys with matching white pants . 
the broncos last wore matching white jerseys and pants in the super bowl in super bowl xxxiii , elway 's last game as denver qb , when they defeated the atlanta falcons 34 -- 19 . 
the broncos last wore matching white jerseys and pants in the super bowl in super bowl xxxiii , elway 's last game as denver qb , when they defeated the atlanta falcons 34 -- 19 . 
as the designated home team in the annual rotation between afc and nfc teams , the broncos elected to wear their road white jerseys with matching white pants . 
the broncos last wore matching white jerseys and pants in the super bowl in super bowl xxxiii , elway 's last game as denver qb , when they defeated the atlanta falcons 34 -- 19 . 
the broncos last wore matching white jerseys and pants in the super bowl in super bowl xxxiii , elway 's last game as denver qb , when they defeated the atlanta falcons 34 -- 19 . 
the broncos last wore matching white jerseys and pants in the super bowl in super bowl xxxiii , elway 's last game as denver qb , when they defeated the atlanta falcons 34 -- 19 . 
the broncos last wore matching white jerseys and pants in the super bowl in super bowl xxxiii , elway 's last game as denver qb , when they defeated the atlanta falcons 34 -- 19 . 
as the designated home team in the annual rotation between afc and nfc teams , the broncos elected to wear their road white jerseys with matching white pants . 
as the designated home team in the annual rotation between afc and nfc teams , the broncos elected to wear their road white jerseys with matching white pants . 
the only other afc champion team to have worn white as the designated home team in the super bowl was the pittsburgh steelers ; they defeated the seattle seahawks 21 -- 10 in super bowl xl 10 seasons prior . 
the broncos last wore matching white jerseys and pants in the super bowl in super bowl xxxiii , elway 's last game as denver qb , when they defeated the atlanta falcons 34 -- 19 . 
in their only other super bowl win in super bowl xxxii , denver wore blue jerseys , which was their primary color at the time . 
they also lost super bowl xxi when they wore white jerseys , but they are 0-4 in super bowls when wearing orange jerseys , losing in super bowl xii , xxii , xxiv , and xlviii . 
the broncos ' decision to wear white meant the panthers would wear their standard home uniform : black jerseys with silver pants . 
the panthers used the san jose state practice facility and stayed at the san jose marriott . 
the broncos practiced at stanford university and stayed at the santa clara marriott . 
the panthers used the san jose state practice facility and stayed at the san jose marriott . 
the broncos practiced at stanford university and stayed at the santa clara marriott . 
the panthers used the san jose state practice facility and stayed at the san jose marriott . 
the broncos practiced at stanford university and stayed at the santa clara marriott . 
the panthers used the san jose state practice facility and stayed at the san jose marriott . 
the broncos practiced at stanford university and stayed at the santa clara marriott . 
the panthers used the san jose state practice facility and stayed at the san jose marriott . 
the panthers used the san jose state practice facility and stayed at the san jose marriott . 
the broncos practiced at stanford university and stayed at the santa clara marriott . 
the broncos practiced at stanford university and stayed at the santa clara marriott . 
the panthers used the san jose state practice facility and stayed at the san jose marriott . 
the panthers used the san jose state practice facility and stayed at the san jose marriott . 
the broncos practiced at stanford university and stayed at the santa clara marriott . 
the broncos practiced at stanford university and stayed at the santa clara marriott . 
on june 4 , 2014 , the nfl announced that the practice of branding super bowl games with roman numerals , a practice established at super bowl v , would be temporarily suspended , and that the game would be named using arabic numerals as super bowl 50 as opposed to super bowl l . 
on june 4 , 2014 , the nfl announced that the practice of branding super bowl games with roman numerals , a practice established at super bowl v , would be temporarily suspended , and that the game would be named using arabic numerals as super bowl 50 as opposed to super bowl l . 
jaime weston , the league 's vice president of brand and creative , explained that a primary reason for the change was the difficulty of designing an aesthetically pleasing logo with the letter `` l '' using the standardized logo template introduced at super bowl xlv . 
jaime weston , the league 's vice president of brand and creative , explained that a primary reason for the change was the difficulty of designing an aesthetically pleasing logo with the letter `` l '' using the standardized logo template introduced at super bowl xlv . 
the logo also deviates from the template by featuring large numerals , colored in gold , behind the vince lombardi trophy , instead of underneath and in silver as in the standard logo . 
on june 4 , 2014 , the nfl announced that the practice of branding super bowl games with roman numerals , a practice established at super bowl v , would be temporarily suspended , and that the game would be named using arabic numerals as super bowl 50 as opposed to super bowl l . 
the use of roman numerals will be reinstated for super bowl li . 
on june 4 , 2014 , the nfl announced that the practice of branding super bowl games with roman numerals , a practice established at super bowl v , would be temporarily suspended , and that the game would be named using arabic numerals as super bowl 50 as opposed to super bowl l . 
the logo also deviates from the template by featuring large numerals , colored in gold , behind the vince lombardi trophy , instead of underneath and in silver as in the standard logo . 
on june 4 , 2014 , the nfl announced that the practice of branding super bowl games with roman numerals , a practice established at super bowl v , would be temporarily suspended , and that the game would be named using arabic numerals as super bowl 50 as opposed to super bowl l . 
on june 4 , 2014 , the nfl announced that the practice of branding super bowl games with roman numerals , a practice established at super bowl v , would be temporarily suspended , and that the game would be named using arabic numerals as super bowl 50 as opposed to super bowl l . 
on june 4 , 2014 , the nfl announced that the practice of branding super bowl games with roman numerals , a practice established at super bowl v , would be temporarily suspended , and that the game would be named using arabic numerals as super bowl 50 as opposed to super bowl l . 
the logo also deviates from the template by featuring large numerals , colored in gold , behind the vince lombardi trophy , instead of underneath and in silver as in the standard logo . 
the use of roman numerals will be reinstated for super bowl li . 
on june 4 , 2014 , the nfl announced that the practice of branding super bowl games with roman numerals , a practice established at super bowl v , would be temporarily suspended , and that the game would be named using arabic numerals as super bowl 50 as opposed to super bowl l . 
the use of roman numerals will be reinstated for super bowl li . 
various gold-themed promotions and initiatives were held throughout the 2015 nfl season to tie into the `` golden super bowl '' ; gold-tinted logos were implemented across the nfl 's properties and painted on fields , the numbering of the 50-yard line on fields was colored gold , and beginning on week 7 , all sideline jackets and hats featured gold-trimmed logos . 
various gold-themed promotions and initiatives were held throughout the 2015 nfl season to tie into the `` golden super bowl '' ; gold-tinted logos were implemented across the nfl 's properties and painted on fields , the numbering of the 50-yard line on fields was colored gold , and beginning on week 7 , all sideline jackets and hats featured gold-trimmed logos . 
various gold-themed promotions and initiatives were held throughout the 2015 nfl season to tie into the `` golden super bowl '' ; gold-tinted logos were implemented across the nfl 's properties and painted on fields , the numbering of the 50-yard line on fields was colored gold , and beginning on week 7 , all sideline jackets and hats featured gold-trimmed logos . 
various gold-themed promotions and initiatives were held throughout the 2015 nfl season to tie into the `` golden super bowl '' ; gold-tinted logos were implemented across the nfl 's properties and painted on fields , the numbering of the 50-yard line on fields was colored gold , and beginning on week 7 , all sideline jackets and hats featured gold-trimmed logos . 
various gold-themed promotions and initiatives were held throughout the 2015 nfl season to tie into the `` golden super bowl '' ; gold-tinted logos were implemented across the nfl 's properties and painted on fields , the numbering of the 50-yard line on fields was colored gold , and beginning on week 7 , all sideline jackets and hats featured gold-trimmed logos . 
various gold-themed promotions and initiatives were held throughout the 2015 nfl season to tie into the `` golden super bowl '' ; gold-tinted logos were implemented across the nfl 's properties and painted on fields , the numbering of the 50-yard line on fields was colored gold , and beginning on week 7 , all sideline jackets and hats featured gold-trimmed logos . 
gold footballs were given to each high school that has had a player or coach appear in the super bowl , and `` homecoming '' events were also held by super bowl-winning teams at games . 
various gold-themed promotions and initiatives were held throughout the 2015 nfl season to tie into the `` golden super bowl '' ; gold-tinted logos were implemented across the nfl 's properties and painted on fields , the numbering of the 50-yard line on fields was colored gold , and beginning on week 7 , all sideline jackets and hats featured gold-trimmed logos . 
various gold-themed promotions and initiatives were held throughout the 2015 nfl season to tie into the `` golden super bowl '' ; gold-tinted logos were implemented across the nfl 's properties and painted on fields , the numbering of the 50-yard line on fields was colored gold , and beginning on week 7 , all sideline jackets and hats featured gold-trimmed logos . 
the annual nfl experience was held at the moscone center in san francisco . 
the annual nfl experience was held at the moscone center in san francisco . 
san francisco mayor ed lee said of the highly visible homeless presence in this area `` they are going to have to leave '' . 
san francisco city supervisor jane kim unsuccessfully lobbied for the nfl to reimburse san francisco for city services in the amount of $ 5 million . 
in addition , `` super bowl city '' opened on january 30 at justin herman plaza on the embarcadero , featuring games and activities that will highlight the bay area 's technology , culinary creations , and cultural diversity . 
more than 1 million people are expected to attend the festivities in san francisco during super bowl week . 
san francisco mayor ed lee said of the highly visible homeless presence in this area `` they are going to have to leave '' . 
the annual nfl experience was held at the moscone center in san francisco . 
in addition , `` super bowl city '' opened on january 30 at justin herman plaza on the embarcadero , featuring games and activities that will highlight the bay area 's technology , culinary creations , and cultural diversity . 
the annual nfl experience was held at the moscone center in san francisco . 
in addition , `` super bowl city '' opened on january 30 at justin herman plaza on the embarcadero , featuring games and activities that will highlight the bay area 's technology , culinary creations , and cultural diversity . 
san francisco mayor ed lee said of the highly visible homeless presence in this area `` they are going to have to leave '' . 
in addition , `` super bowl city '' opened on january 30 at justin herman plaza on the embarcadero , featuring games and activities that will highlight the bay area 's technology , culinary creations , and cultural diversity . 
more than 1 million people are expected to attend the festivities in san francisco during super bowl week . 
san francisco mayor ed lee said of the highly visible homeless presence in this area `` they are going to have to leave '' . 
san francisco city supervisor jane kim unsuccessfully lobbied for the nfl to reimburse san francisco for city services in the amount of $ 5 million . 
the annual nfl experience was held at the moscone center in san francisco . 
in addition , there are $ 2 million worth of other ancillary events , including a week-long event at the santa clara convention center , a beer , wine and food festival at bellomy field at santa clara university , and a pep rally . 
in addition , there are $ 2 million worth of other ancillary events , including a week-long event at the santa clara convention center , a beer , wine and food festival at bellomy field at santa clara university , and a pep rally . 
in addition , there are $ 2 million worth of other ancillary events , including a week-long event at the santa clara convention center , a beer , wine and food festival at bellomy field at santa clara university , and a pep rally . 
in addition , there are $ 2 million worth of other ancillary events , including a week-long event at the santa clara convention center , a beer , wine and food festival at bellomy field at santa clara university , and a pep rally . 
in addition , there are $ 2 million worth of other ancillary events , including a week-long event at the santa clara convention center , a beer , wine and food festival at bellomy field at santa clara university , and a pep rally . 
a professional fundraiser will aid in finding business sponsors and individual donors , but still may need the city council to help fund the event . 
in addition , there are $ 2 million worth of other ancillary events , including a week-long event at the santa clara convention center , a beer , wine and food festival at bellomy field at santa clara university , and a pep rally . 
a professional fundraiser will aid in finding business sponsors and individual donors , but still may need the city council to help fund the event . 
a professional fundraiser will aid in finding business sponsors and individual donors , but still may need the city council to help fund the event . 
in addition , there are $ 2 million worth of other ancillary events , including a week-long event at the santa clara convention center , a beer , wine and food festival at bellomy field at santa clara university , and a pep rally . 
a professional fundraiser will aid in finding business sponsors and individual donors , but still may need the city council to help fund the event . 
the game 's media day , which was typically held on the tuesday afternoon prior to the game , was moved to the monday evening and re-branded as super bowl opening night . 
the game 's media day , which was typically held on the tuesday afternoon prior to the game , was moved to the monday evening and re-branded as super bowl opening night . 
the event was held on february 1 , 2016 at sap center in san jose . 
the event was held on february 1 , 2016 at sap center in san jose . 
alongside the traditional media availabilities , the event featured an opening ceremony with player introductions on a replica of the golden gate bridge . 
the game 's media day , which was typically held on the tuesday afternoon prior to the game , was moved to the monday evening and re-branded as super bowl opening night . 
the game 's media day , which was typically held on the tuesday afternoon prior to the game , was moved to the monday evening and re-branded as super bowl opening night . 
the game 's media day , which was typically held on the tuesday afternoon prior to the game , was moved to the monday evening and re-branded as super bowl opening night . 
the event was held on february 1 , 2016 at sap center in san jose . 
the event was held on february 1 , 2016 at sap center in san jose . 
the game 's media day , which was typically held on the tuesday afternoon prior to the game , was moved to the monday evening and re-branded as super bowl opening night . 
the game 's media day , which was typically held on the tuesday afternoon prior to the game , was moved to the monday evening and re-branded as super bowl opening night . 
the event was held on february 1 , 2016 at sap center in san jose . 
alongside the traditional media availabilities , the event featured an opening ceremony with player introductions on a replica of the golden gate bridge . 
the game 's media day , which was typically held on the tuesday afternoon prior to the game , was moved to the monday evening and re-branded as super bowl opening night . 
the game 's media day , which was typically held on the tuesday afternoon prior to the game , was moved to the monday evening and re-branded as super bowl opening night . 
the event was held on february 1 , 2016 at sap center in san jose . 
alongside the traditional media availabilities , the event featured an opening ceremony with player introductions on a replica of the golden gate bridge . 
the event was held on february 1 , 2016 at sap center in san jose . 
for the first time , the super bowl 50 host committee and the nfl have openly sought disabled veteran and lesbian , gay , bisexual and transgender-owned businesses in business connect , the super bowl program that provides local companies with contracting opportunities in and around the super bowl . 
the host committee has already raised over $ 40 million through sponsors including apple , google , yahoo! , intel , gap , chevron , and dignity health . 
the host committee has already raised over $ 40 million through sponsors including apple , google , yahoo! , intel , gap , chevron , and dignity health . 
the host committee has already raised over $ 40 million through sponsors including apple , google , yahoo! , intel , gap , chevron , and dignity health . 
the host committee has already raised over $ 40 million through sponsors including apple , google , yahoo! , intel , gap , chevron , and dignity health . 
for the first time , the super bowl 50 host committee and the nfl have openly sought disabled veteran and lesbian , gay , bisexual and transgender-owned businesses in business connect , the super bowl program that provides local companies with contracting opportunities in and around the super bowl . 
the host committee has already raised over $ 40 million through sponsors including apple , google , yahoo! , intel , gap , chevron , and dignity health . 
the host committee has already raised over $ 40 million through sponsors including apple , google , yahoo! , intel , gap , chevron , and dignity health . 
for the first time , the super bowl 50 host committee and the nfl have openly sought disabled veteran and lesbian , gay , bisexual and transgender-owned businesses in business connect , the super bowl program that provides local companies with contracting opportunities in and around the super bowl . 
for the first time , the super bowl 50 host committee and the nfl have openly sought disabled veteran and lesbian , gay , bisexual and transgender-owned businesses in business connect , the super bowl program that provides local companies with contracting opportunities in and around the super bowl . 
the host committee has already raised over $ 40 million through sponsors including apple , google , yahoo! , intel , gap , chevron , and dignity health . 
the super bowl 50 host committee has vowed to be `` the most giving super bowl ever '' , and will dedicate 25 percent of all money it raises for philanthropic causes in the bay area . 
the committee created the 50 fund as its philanthropic initiative and focuses on providing grants to aid with youth development , community investment and sustainable environments . 
the super bowl 50 host committee has vowed to be `` the most giving super bowl ever '' , and will dedicate 25 percent of all money it raises for philanthropic causes in the bay area . 
the committee created the 50 fund as its philanthropic initiative and focuses on providing grants to aid with youth development , community investment and sustainable environments . 
the super bowl 50 host committee has vowed to be `` the most giving super bowl ever '' , and will dedicate 25 percent of all money it raises for philanthropic causes in the bay area . 
the super bowl 50 host committee has vowed to be `` the most giving super bowl ever '' , and will dedicate 25 percent of all money it raises for philanthropic causes in the bay area . 
the committee created the 50 fund as its philanthropic initiative and focuses on providing grants to aid with youth development , community investment and sustainable environments . 
the super bowl 50 host committee has vowed to be `` the most giving super bowl ever '' , and will dedicate 25 percent of all money it raises for philanthropic causes in the bay area . 
the committee created the 50 fund as its philanthropic initiative and focuses on providing grants to aid with youth development , community investment and sustainable environments . 
in addition to the vince lombardi trophy that all super bowl champions receive , the winner of super bowl 50 will also receive a large , 18-karat gold-plated `` 50 '' . 
in addition to the vince lombardi trophy that all super bowl champions receive , the winner of super bowl 50 will also receive a large , 18-karat gold-plated `` 50 '' . 
each digit will weigh 33 lb -lrb- 15 kg -rrb- for a total of 66 lb -lrb- 30 kg -rrb- . 
like the lombardi trophy , the `` 50 '' will be designed by tiffany & co. . 
like the lombardi trophy , the `` 50 '' will be designed by tiffany & co. . 
in addition to the vince lombardi trophy that all super bowl champions receive , the winner of super bowl 50 will also receive a large , 18-karat gold-plated `` 50 '' . 
in addition to the vince lombardi trophy that all super bowl champions receive , the winner of super bowl 50 will also receive a large , 18-karat gold-plated `` 50 '' . 
like the lombardi trophy , the `` 50 '' will be designed by tiffany & co. . 
in addition to the vince lombardi trophy that all super bowl champions receive , the winner of super bowl 50 will also receive a large , 18-karat gold-plated `` 50 '' . 
like the lombardi trophy , the `` 50 '' will be designed by tiffany & co. . 
in the united states , the game was televised by cbs , as part of a cycle between the three main broadcast television partners of the nfl . 
the network 's lead broadcast team of jim nantz and phil simms called the contest , with tracy wolfson and evan washburn on the sidelines . 
the network 's lead broadcast team of jim nantz and phil simms called the contest , with tracy wolfson and evan washburn on the sidelines . 
cbs introduced new features during the telecast , including pylon cameras and microphones along with eyevision 360 -- an array of 36 cameras along the upper deck that can be used to provide a 360-degree view of plays and `` bullet time '' effects . 
-lrb- an earlier version of eyevision was last used in super bowl xxxv ; for super bowl 50 , the cameras were upgraded to 5k resolution . -rrb- 
in the united states , the game was televised by cbs , as part of a cycle between the three main broadcast television partners of the nfl . 
the network 's lead broadcast team of jim nantz and phil simms called the contest , with tracy wolfson and evan washburn on the sidelines . 
cbs introduced new features during the telecast , including pylon cameras and microphones along with eyevision 360 -- an array of 36 cameras along the upper deck that can be used to provide a 360-degree view of plays and `` bullet time '' effects . 
-lrb- an earlier version of eyevision was last used in super bowl xxxv ; for super bowl 50 , the cameras were upgraded to 5k resolution . -rrb- 
the network 's lead broadcast team of jim nantz and phil simms called the contest , with tracy wolfson and evan washburn on the sidelines . 
in the united states , the game was televised by cbs , as part of a cycle between the three main broadcast television partners of the nfl . 
in the united states , the game was televised by cbs , as part of a cycle between the three main broadcast television partners of the nfl . 
in the united states , the game was televised by cbs , as part of a cycle between the three main broadcast television partners of the nfl . 
the network 's lead broadcast team of jim nantz and phil simms called the contest , with tracy wolfson and evan washburn on the sidelines . 
the network 's lead broadcast team of jim nantz and phil simms called the contest , with tracy wolfson and evan washburn on the sidelines . 
-lrb- an earlier version of eyevision was last used in super bowl xxxv ; for super bowl 50 , the cameras were upgraded to 5k resolution . -rrb- 
cbs introduced new features during the telecast , including pylon cameras and microphones along with eyevision 360 -- an array of 36 cameras along the upper deck that can be used to provide a 360-degree view of plays and `` bullet time '' effects . 
on december 28 , 2015 , espn deportes announced that they had reached an agreement with cbs and the nfl to be the exclusive spanish-language broadcaster of the game , marking the third dedicated spanish-language broadcast of the super bowl . 
the game was called by espn deportes ' monday night football commentary crew of alvaro martin and raul allegre , and sideline reporter john sutcliffe . 
the game was called by espn deportes ' monday night football commentary crew of alvaro martin and raul allegre , and sideline reporter john sutcliffe . 
on december 28 , 2015 , espn deportes announced that they had reached an agreement with cbs and the nfl to be the exclusive spanish-language broadcaster of the game , marking the third dedicated spanish-language broadcast of the super bowl . 
on december 28 , 2015 , espn deportes announced that they had reached an agreement with cbs and the nfl to be the exclusive spanish-language broadcaster of the game , marking the third dedicated spanish-language broadcast of the super bowl . 
on december 28 , 2015 , espn deportes announced that they had reached an agreement with cbs and the nfl to be the exclusive spanish-language broadcaster of the game , marking the third dedicated spanish-language broadcast of the super bowl . 
on december 28 , 2015 , espn deportes announced that they had reached an agreement with cbs and the nfl to be the exclusive spanish-language broadcaster of the game , marking the third dedicated spanish-language broadcast of the super bowl . 
the game was called by espn deportes ' monday night football commentary crew of alvaro martin and raul allegre , and sideline reporter john sutcliffe . 
on december 28 , 2015 , espn deportes announced that they had reached an agreement with cbs and the nfl to be the exclusive spanish-language broadcaster of the game , marking the third dedicated spanish-language broadcast of the super bowl . 
the game was called by espn deportes ' monday night football commentary crew of alvaro martin and raul allegre , and sideline reporter john sutcliffe . 
the game was called by espn deportes ' monday night football commentary crew of alvaro martin and raul allegre , and sideline reporter john sutcliffe . 
due to verizon communications exclusivity , streaming on smartphones was only provided to verizon wireless customers via the nfl mobile service . 
the espn deportes spanish broadcast was made available through watchespn . 
cbs provided digital streams of the game via cbssports.com , and the cbs sports apps on tablets , windows 10 , xbox one and other digital media players -lrb- such as chromecast and roku -rrb- . 
cbs provided digital streams of the game via cbssports.com , and the cbs sports apps on tablets , windows 10 , xbox one and other digital media players -lrb- such as chromecast and roku -rrb- . 
cbs provided digital streams of the game via cbssports.com , and the cbs sports apps on tablets , windows 10 , xbox one and other digital media players -lrb- such as chromecast and roku -rrb- . 
cbs provided digital streams of the game via cbssports.com , and the cbs sports apps on tablets , windows 10 , xbox one and other digital media players -lrb- such as chromecast and roku -rrb- . 
cbs provided digital streams of the game via cbssports.com , and the cbs sports apps on tablets , windows 10 , xbox one and other digital media players -lrb- such as chromecast and roku -rrb- . 
due to verizon communications exclusivity , streaming on smartphones was only provided to verizon wireless customers via the nfl mobile service . 
due to verizon communications exclusivity , streaming on smartphones was only provided to verizon wireless customers via the nfl mobile service . 
due to verizon communications exclusivity , streaming on smartphones was only provided to verizon wireless customers via the nfl mobile service . 
due to verizon communications exclusivity , streaming on smartphones was only provided to verizon wireless customers via the nfl mobile service . 
cbs provided digital streams of the game via cbssports.com , and the cbs sports apps on tablets , windows 10 , xbox one and other digital media players -lrb- such as chromecast and roku -rrb- . 
due to verizon communications exclusivity , streaming on smartphones was only provided to verizon wireless customers via the nfl mobile service . 
the espn deportes spanish broadcast was made available through watchespn . 
as opposed to broadcasts of primetime series , cbs broadcast special episodes of its late night talk shows as its lead-out programs for super bowl 50 , beginning with a special episode of the late show with stephen colbert following the game . 
following a break for late local programming , cbs also aired a special episode of the late late show with james corden . 
as opposed to broadcasts of primetime series , cbs broadcast special episodes of its late night talk shows as its lead-out programs for super bowl 50 , beginning with a special episode of the late show with stephen colbert following the game . 
following a break for late local programming , cbs also aired a special episode of the late late show with james corden . 
as opposed to broadcasts of primetime series , cbs broadcast special episodes of its late night talk shows as its lead-out programs for super bowl 50 , beginning with a special episode of the late show with stephen colbert following the game . 
following a break for late local programming , cbs also aired a special episode of the late late show with james corden . 
following a break for late local programming , cbs also aired a special episode of the late late show with james corden . 
cbs set the base rate for a 30-second advertisement at $ 5,000,000 , a record high price for a super bowl ad . 
this would be the final year in a multi-year contract with anheuser-busch inbev that allowed the beer manufacturer to air multiple advertisements during the game at a steep discount . 
it was also the final year that doritos , a longtime sponsor of the game , held its `` crash the super bowl '' contest that allowed viewers to create their own doritos ads for a chance to have it aired during the game . 
nintendo and the pokémon company also made their super bowl debut , promoting the 20th anniversary of the pokémon video game and media franchise . 
cbs set the base rate for a 30-second advertisement at $ 5,000,000 , a record high price for a super bowl ad . 
this would be the final year in a multi-year contract with anheuser-busch inbev that allowed the beer manufacturer to air multiple advertisements during the game at a steep discount . 
it was also the final year that doritos , a longtime sponsor of the game , held its `` crash the super bowl '' contest that allowed viewers to create their own doritos ads for a chance to have it aired during the game . 
nintendo and the pokémon company also made their super bowl debut , promoting the 20th anniversary of the pokémon video game and media franchise . 
nintendo and the pokémon company also made their super bowl debut , promoting the 20th anniversary of the pokémon video game and media franchise . 
this would be the final year in a multi-year contract with anheuser-busch inbev that allowed the beer manufacturer to air multiple advertisements during the game at a steep discount . 
it was also the final year that doritos , a longtime sponsor of the game , held its `` crash the super bowl '' contest that allowed viewers to create their own doritos ads for a chance to have it aired during the game . 
this would be the final year in a multi-year contract with anheuser-busch inbev that allowed the beer manufacturer to air multiple advertisements during the game at a steep discount . 
it was also the final year that doritos , a longtime sponsor of the game , held its `` crash the super bowl '' contest that allowed viewers to create their own doritos ads for a chance to have it aired during the game . 
it was also the final year that doritos , a longtime sponsor of the game , held its `` crash the super bowl '' contest that allowed viewers to create their own doritos ads for a chance to have it aired during the game . 
quickbooks sponsored a `` small business big game '' contest , in which death wish coffee had a 30-second commercial aired free of charge courtesy of quickbooks . 
quickbooks sponsored a `` small business big game '' contest , in which death wish coffee had a 30-second commercial aired free of charge courtesy of quickbooks . 
quickbooks sponsored a `` small business big game '' contest , in which death wish coffee had a 30-second commercial aired free of charge courtesy of quickbooks . 
death wish coffee beat out nine other contenders from across the united states for the free advertisement . 
quickbooks sponsored a `` small business big game '' contest , in which death wish coffee had a 30-second commercial aired free of charge courtesy of quickbooks . 
death wish coffee beat out nine other contenders from across the united states for the free advertisement . 
quickbooks sponsored a `` small business big game '' contest , in which death wish coffee had a 30-second commercial aired free of charge courtesy of quickbooks . 
quickbooks sponsored a `` small business big game '' contest , in which death wish coffee had a 30-second commercial aired free of charge courtesy of quickbooks . 
death wish coffee beat out nine other contenders from across the united states for the free advertisement . 
quickbooks sponsored a `` small business big game '' contest , in which death wish coffee had a 30-second commercial aired free of charge courtesy of quickbooks . 
quickbooks sponsored a `` small business big game '' contest , in which death wish coffee had a 30-second commercial aired free of charge courtesy of quickbooks . 
fox paid for deadpool , x-men : apocalypse , independence day : resurgence and eddie the eagle , lionsgate paid for gods of egypt , paramount paid for teenage mutant ninja turtles : out of the shadows and 10 cloverfield lane , universal paid for the secret life of pets and the debut trailer for jason bourne and disney paid for captain america : civil war , the jungle book and alice through the looking glass . 
fox paid for deadpool , x-men : apocalypse , independence day : resurgence and eddie the eagle , lionsgate paid for gods of egypt , paramount paid for teenage mutant ninja turtles : out of the shadows and 10 cloverfield lane , universal paid for the secret life of pets and the debut trailer for jason bourne and disney paid for captain america : civil war , the jungle book and alice through the looking glass . 
fox paid for deadpool , x-men : apocalypse , independence day : resurgence and eddie the eagle , lionsgate paid for gods of egypt , paramount paid for teenage mutant ninja turtles : out of the shadows and 10 cloverfield lane , universal paid for the secret life of pets and the debut trailer for jason bourne and disney paid for captain america : civil war , the jungle book and alice through the looking glass . 
fox paid for deadpool , x-men : apocalypse , independence day : resurgence and eddie the eagle , lionsgate paid for gods of egypt , paramount paid for teenage mutant ninja turtles : out of the shadows and 10 cloverfield lane , universal paid for the secret life of pets and the debut trailer for jason bourne and disney paid for captain america : civil war , the jungle book and alice through the looking glass . 
fox paid for deadpool , x-men : apocalypse , independence day : resurgence and eddie the eagle , lionsgate paid for gods of egypt , paramount paid for teenage mutant ninja turtles : out of the shadows and 10 cloverfield lane , universal paid for the secret life of pets and the debut trailer for jason bourne and disney paid for captain america : civil war , the jungle book and alice through the looking glass . 
fox paid for deadpool , x-men : apocalypse , independence day : resurgence and eddie the eagle , lionsgate paid for gods of egypt , paramount paid for teenage mutant ninja turtles : out of the shadows and 10 cloverfield lane , universal paid for the secret life of pets and the debut trailer for jason bourne and disney paid for captain america : civil war , the jungle book and alice through the looking glass . 
fox paid for deadpool , x-men : apocalypse , independence day : resurgence and eddie the eagle , lionsgate paid for gods of egypt , paramount paid for teenage mutant ninja turtles : out of the shadows and 10 cloverfield lane , universal paid for the secret life of pets and the debut trailer for jason bourne and disney paid for captain america : civil war , the jungle book and alice through the looking glass . 
fox paid for deadpool , x-men : apocalypse , independence day : resurgence and eddie the eagle , lionsgate paid for gods of egypt , paramount paid for teenage mutant ninja turtles : out of the shadows and 10 cloverfield lane , universal paid for the secret life of pets and the debut trailer for jason bourne and disney paid for captain america : civil war , the jungle book and alice through the looking glass . 
fox paid for deadpool , x-men : apocalypse , independence day : resurgence and eddie the eagle , lionsgate paid for gods of egypt , paramount paid for teenage mutant ninja turtles : out of the shadows and 10 cloverfield lane , universal paid for the secret life of pets and the debut trailer for jason bourne and disney paid for captain america : civil war , the jungle book and alice through the looking glass . 
20th century fox , lionsgate , paramount pictures , universal studios and walt disney studios paid for movie trailers to be aired during the super bowl . 
20th century fox , lionsgate , paramount pictures , universal studios and walt disney studios paid for movie trailers to be aired during the super bowl . 
westwood one will carry the game throughout north america , with kevin harlan as play-by-play announcer , boomer esiason and dan fouts as color analysts , and james lofton and mark malone as sideline reporters . 
westwood one will carry the game throughout north america , with kevin harlan as play-by-play announcer , boomer esiason and dan fouts as color analysts , and james lofton and mark malone as sideline reporters . 
jim gray will anchor the pre-game and halftime coverage . 
westwood one will carry the game throughout north america , with kevin harlan as play-by-play announcer , boomer esiason and dan fouts as color analysts , and james lofton and mark malone as sideline reporters . 
westwood one will carry the game throughout north america , with kevin harlan as play-by-play announcer , boomer esiason and dan fouts as color analysts , and james lofton and mark malone as sideline reporters . 
westwood one will carry the game throughout north america , with kevin harlan as play-by-play announcer , boomer esiason and dan fouts as color analysts , and james lofton and mark malone as sideline reporters . 
westwood one will carry the game throughout north america , with kevin harlan as play-by-play announcer , boomer esiason and dan fouts as color analysts , and james lofton and mark malone as sideline reporters . 
westwood one will carry the game throughout north america , with kevin harlan as play-by-play announcer , boomer esiason and dan fouts as color analysts , and james lofton and mark malone as sideline reporters . 
westwood one will carry the game throughout north america , with kevin harlan as play-by-play announcer , boomer esiason and dan fouts as color analysts , and james lofton and mark malone as sideline reporters . 
jim gray will anchor the pre-game and halftime coverage . 
westwood one will carry the game throughout north america , with kevin harlan as play-by-play announcer , boomer esiason and dan fouts as color analysts , and james lofton and mark malone as sideline reporters . 
westwood one will carry the game throughout north america , with kevin harlan as play-by-play announcer , boomer esiason and dan fouts as color analysts , and james lofton and mark malone as sideline reporters . 
westwood one will carry the game throughout north america , with kevin harlan as play-by-play announcer , boomer esiason and dan fouts as color analysts , and james lofton and mark malone as sideline reporters . 
jim gray will anchor the pre-game and halftime coverage . 
westwood one will carry the game throughout north america , with kevin harlan as play-by-play announcer , boomer esiason and dan fouts as color analysts , and james lofton and mark malone as sideline reporters . 
in denver , koa -lrb- 850 am -rrb- and krfx -lrb- 103.5 fm -rrb- will carry the game , with dave logan on play-by-play and ed mccaffrey on color commentary . 
in denver , koa -lrb- 850 am -rrb- and krfx -lrb- 103.5 fm -rrb- will carry the game , with dave logan on play-by-play and ed mccaffrey on color commentary . 
in north carolina , wbt -lrb- 1110 am -rrb- will carry the game , with mick mixon on play-by-play and eugene robinson and jim szoke on color commentary . 
wbt will also simulcast the game on its sister station wbt-fm -lrb- 99.3 fm -rrb- , which is based in chester , south carolina . 
in north carolina , wbt -lrb- 1110 am -rrb- will carry the game , with mick mixon on play-by-play and eugene robinson and jim szoke on color commentary . 
in denver , koa -lrb- 850 am -rrb- and krfx -lrb- 103.5 fm -rrb- will carry the game , with dave logan on play-by-play and ed mccaffrey on color commentary . 
in denver , koa -lrb- 850 am -rrb- and krfx -lrb- 103.5 fm -rrb- will carry the game , with dave logan on play-by-play and ed mccaffrey on color commentary . 
in north carolina , wbt -lrb- 1110 am -rrb- will carry the game , with mick mixon on play-by-play and eugene robinson and jim szoke on color commentary . 
in north carolina , wbt -lrb- 1110 am -rrb- will carry the game , with mick mixon on play-by-play and eugene robinson and jim szoke on color commentary . 
in denver , koa -lrb- 850 am -rrb- and krfx -lrb- 103.5 fm -rrb- will carry the game , with dave logan on play-by-play and ed mccaffrey on color commentary . 
wbt will also simulcast the game on its sister station wbt-fm -lrb- 99.3 fm -rrb- , which is based in chester , south carolina . 
in the united kingdom , bbc radio 5 live and 5 live sports extra will carry the contest . 
in the united kingdom , bbc radio 5 live and 5 live sports extra will carry the contest . 
the bbc will carry its own british english broadcast , with greg brady , darren fletcher and rocky boiman on commentary . 
in the united kingdom , bbc radio 5 live and 5 live sports extra will carry the contest . 
the bbc will carry its own british english broadcast , with greg brady , darren fletcher and rocky boiman on commentary . 
bart starr -lrb- mvp of super bowls i and ii -rrb- and chuck howley -lrb- mvp of super bowl v -rrb- appeared via video , while peyton manning -lrb- mvp of super bowl xli and current broncos quarterback -rrb- was shown in the locker room preparing for the game . 
bart starr -lrb- mvp of super bowls i and ii -rrb- and chuck howley -lrb- mvp of super bowl v -rrb- appeared via video , while peyton manning -lrb- mvp of super bowl xli and current broncos quarterback -rrb- was shown in the locker room preparing for the game . 
bart starr -lrb- mvp of super bowls i and ii -rrb- and chuck howley -lrb- mvp of super bowl v -rrb- appeared via video , while peyton manning -lrb- mvp of super bowl xli and current broncos quarterback -rrb- was shown in the locker room preparing for the game . 
no plans were announced regarding the recognition of harvey martin , co-mvp of super bowl xii , who died in 2001 . 
bart starr -lrb- mvp of super bowls i and ii -rrb- and chuck howley -lrb- mvp of super bowl v -rrb- appeared via video , while peyton manning -lrb- mvp of super bowl xli and current broncos quarterback -rrb- was shown in the locker room preparing for the game . 
in honor of the 50th super bowl , the pregame ceremony featured the on-field introduction of 39 of the 43 previous super bowl most valuable players . 
bart starr -lrb- mvp of super bowls i and ii -rrb- and chuck howley -lrb- mvp of super bowl v -rrb- appeared via video , while peyton manning -lrb- mvp of super bowl xli and current broncos quarterback -rrb- was shown in the locker room preparing for the game . 
no plans were announced regarding the recognition of harvey martin , co-mvp of super bowl xii , who died in 2001 . 
in honor of the 50th super bowl , the pregame ceremony featured the on-field introduction of 39 of the 43 previous super bowl most valuable players . 
in honor of the 50th super bowl , the pregame ceremony featured the on-field introduction of 39 of the 43 previous super bowl most valuable players . 
bart starr -lrb- mvp of super bowls i and ii -rrb- and chuck howley -lrb- mvp of super bowl v -rrb- appeared via video , while peyton manning -lrb- mvp of super bowl xli and current broncos quarterback -rrb- was shown in the locker room preparing for the game . 
bart starr -lrb- mvp of super bowls i and ii -rrb- and chuck howley -lrb- mvp of super bowl v -rrb- appeared via video , while peyton manning -lrb- mvp of super bowl xli and current broncos quarterback -rrb- was shown in the locker room preparing for the game . 
no plans were announced regarding the recognition of harvey martin , co-mvp of super bowl xii , who died in 2001 . 
six-time grammy winner and academy award nominee lady gaga performed the national anthem , while academy award winner marlee matlin provided american sign language -lrb- asl -rrb- translation . 
six-time grammy winner and academy award nominee lady gaga performed the national anthem , while academy award winner marlee matlin provided american sign language -lrb- asl -rrb- translation . 
six-time grammy winner and academy award nominee lady gaga performed the national anthem , while academy award winner marlee matlin provided american sign language -lrb- asl -rrb- translation . 
six-time grammy winner and academy award nominee lady gaga performed the national anthem , while academy award winner marlee matlin provided american sign language -lrb- asl -rrb- translation . 
six-time grammy winner and academy award nominee lady gaga performed the national anthem , while academy award winner marlee matlin provided american sign language -lrb- asl -rrb- translation . 
six-time grammy winner and academy award nominee lady gaga performed the national anthem , while academy award winner marlee matlin provided american sign language -lrb- asl -rrb- translation . 
six-time grammy winner and academy award nominee lady gaga performed the national anthem , while academy award winner marlee matlin provided american sign language -lrb- asl -rrb- translation . 
six-time grammy winner and academy award nominee lady gaga performed the national anthem , while academy award winner marlee matlin provided american sign language -lrb- asl -rrb- translation . 
six-time grammy winner and academy award nominee lady gaga performed the national anthem , while academy award winner marlee matlin provided american sign language -lrb- asl -rrb- translation . 
six-time grammy winner and academy award nominee lady gaga performed the national anthem , while academy award winner marlee matlin provided american sign language -lrb- asl -rrb- translation . 
six-time grammy winner and academy award nominee lady gaga performed the national anthem , while academy award winner marlee matlin provided american sign language -lrb- asl -rrb- translation . 
six-time grammy winner and academy award nominee lady gaga performed the national anthem , while academy award winner marlee matlin provided american sign language -lrb- asl -rrb- translation . 
on december 3 , the league confirmed that the show would be headlined by the british rock group coldplay . 
on december 3 , the league confirmed that the show would be headlined by the british rock group coldplay . 
on january 7 , 2016 , pepsi confirmed to the associated press that beyoncé , who headlined the super bowl xlvii halftime show and collaborated with coldplay on the single `` hymn for the weekend '' , would be making an appearance . 
on january 7 , 2016 , pepsi confirmed to the associated press that beyoncé , who headlined the super bowl xlvii halftime show and collaborated with coldplay on the single `` hymn for the weekend '' , would be making an appearance . 
bruno mars , who headlined the super bowl xlviii halftime show , and mark ronson also performed . 
on december 3 , the league confirmed that the show would be headlined by the british rock group coldplay . 
on january 7 , 2016 , pepsi confirmed to the associated press that beyoncé , who headlined the super bowl xlvii halftime show and collaborated with coldplay on the single `` hymn for the weekend '' , would be making an appearance . 
on january 7 , 2016 , pepsi confirmed to the associated press that beyoncé , who headlined the super bowl xlvii halftime show and collaborated with coldplay on the single `` hymn for the weekend '' , would be making an appearance . 
on december 3 , the league confirmed that the show would be headlined by the british rock group coldplay . 
on january 7 , 2016 , pepsi confirmed to the associated press that beyoncé , who headlined the super bowl xlvii halftime show and collaborated with coldplay on the single `` hymn for the weekend '' , would be making an appearance . 
on january 7 , 2016 , pepsi confirmed to the associated press that beyoncé , who headlined the super bowl xlvii halftime show and collaborated with coldplay on the single `` hymn for the weekend '' , would be making an appearance . 
bruno mars , who headlined the super bowl xlviii halftime show , and mark ronson also performed . 
denver took the opening kickoff and started out strong with peyton manning completing an 18-yard pass to tight end owen daniels and a 22-yard throw to receiver andre caldwell . 
denver took the opening kickoff and started out strong with peyton manning completing an 18-yard pass to tight end owen daniels and a 22-yard throw to receiver andre caldwell . 
first , linebacker shaq thompson tackled ronnie hillman for a 3-yard loss . 
then after an incompletion , thomas davis tackled anderson for a 1-yard gain on third down , forcing denver to settle for a 3 -- 0 lead on a brandon mcmanus 34-yard field goal . 
a pair of carries by c. j. anderson moved the ball up 20 yards to the panthers 14-yard line , but carolina 's defense dug in over the next three plays . 
denver took the opening kickoff and started out strong with peyton manning completing an 18-yard pass to tight end owen daniels and a 22-yard throw to receiver andre caldwell . 
first , linebacker shaq thompson tackled ronnie hillman for a 3-yard loss . 
then after an incompletion , thomas davis tackled anderson for a 1-yard gain on third down , forcing denver to settle for a 3 -- 0 lead on a brandon mcmanus 34-yard field goal . 
the score marked the first time in the entire postseason that carolina was facing a deficit . 
denver took the opening kickoff and started out strong with peyton manning completing an 18-yard pass to tight end owen daniels and a 22-yard throw to receiver andre caldwell . 
denver took the opening kickoff and started out strong with peyton manning completing an 18-yard pass to tight end owen daniels and a 22-yard throw to receiver andre caldwell . 
a pair of carries by c. j. anderson moved the ball up 20 yards to the panthers 14-yard line , but carolina 's defense dug in over the next three plays . 
then after an incompletion , thomas davis tackled anderson for a 1-yard gain on third down , forcing denver to settle for a 3 -- 0 lead on a brandon mcmanus 34-yard field goal . 
the score marked the first time in the entire postseason that carolina was facing a deficit . 
cbs analyst and retired referee mike carey stated he disagreed with the call and felt the review clearly showed the pass was complete . 
after each team punted , panthers quarterback cam newton appeared to complete a 24-yard pass jerricho cotchery , but the call was ruled an incompletion and upheld after a replay challenge . 
a few plays later , on 3rd-and-10 from the 15-yard line , linebacker von miller knocked the ball out of newton 's hands while sacking him , and malik jackson recovered it in the end zone for a broncos touchdown , giving the team a 10 -- 0 lead . 
a few plays later , on 3rd-and-10 from the 15-yard line , linebacker von miller knocked the ball out of newton 's hands while sacking him , and malik jackson recovered it in the end zone for a broncos touchdown , giving the team a 10 -- 0 lead . 
this was the first fumble return touchdown in a super bowl since super bowl xxviii at the end of the 1993 season . 
after each team punted , panthers quarterback cam newton appeared to complete a 24-yard pass jerricho cotchery , but the call was ruled an incompletion and upheld after a replay challenge . 
cbs analyst and retired referee mike carey stated he disagreed with the call and felt the review clearly showed the pass was complete . 
a few plays later , on 3rd-and-10 from the 15-yard line , linebacker von miller knocked the ball out of newton 's hands while sacking him , and malik jackson recovered it in the end zone for a broncos touchdown , giving the team a 10 -- 0 lead . 
a few plays later , on 3rd-and-10 from the 15-yard line , linebacker von miller knocked the ball out of newton 's hands while sacking him , and malik jackson recovered it in the end zone for a broncos touchdown , giving the team a 10 -- 0 lead . 
this was the first fumble return touchdown in a super bowl since super bowl xxviii at the end of the 1993 season . 
cbs analyst and retired referee mike carey stated he disagreed with the call and felt the review clearly showed the pass was complete . 
a few plays later , on 3rd-and-10 from the 15-yard line , linebacker von miller knocked the ball out of newton 's hands while sacking him , and malik jackson recovered it in the end zone for a broncos touchdown , giving the team a 10 -- 0 lead . 
a few plays later , on 3rd-and-10 from the 15-yard line , linebacker von miller knocked the ball out of newton 's hands while sacking him , and malik jackson recovered it in the end zone for a broncos touchdown , giving the team a 10 -- 0 lead . 
this was the first fumble return touchdown in a super bowl since super bowl xxviii at the end of the 1993 season . 
newton completed 4 of 4 passes for 51 yards and rushed twice for 25 yards , while jonathan stewart finished the drive with a 1-yard touchdown run , cutting the score to 10 -- 7 with 11:28 left in the second quarter . 
later on , broncos receiver jordan norwood received brad nortman 's short 28-yard punt surrounded by panthers players , but none of them attempted to make a tackle , apparently thinking norwood had called a fair catch . 
newton completed 4 of 4 passes for 51 yards and rushed twice for 25 yards , while jonathan stewart finished the drive with a 1-yard touchdown run , cutting the score to 10 -- 7 with 11:28 left in the second quarter . 
norwood had not done so , and with no resistance around him , he took off for a super bowl record 61-yard return before mario addison dragged him down on the panthers 14-yard line . 
despite denver 's excellent field position , they could not get the ball into the end zone , so mcmanus kicked a 33-yard field goal that increased their lead to 13 -- 7 . 
newton completed 4 of 4 passes for 51 yards and rushed twice for 25 yards , while jonathan stewart finished the drive with a 1-yard touchdown run , cutting the score to 10 -- 7 with 11:28 left in the second quarter . 
newton completed 4 of 4 passes for 51 yards and rushed twice for 25 yards , while jonathan stewart finished the drive with a 1-yard touchdown run , cutting the score to 10 -- 7 with 11:28 left in the second quarter . 
newton completed 4 of 4 passes for 51 yards and rushed twice for 25 yards , while jonathan stewart finished the drive with a 1-yard touchdown run , cutting the score to 10 -- 7 with 11:28 left in the second quarter . 
later on , broncos receiver jordan norwood received brad nortman 's short 28-yard punt surrounded by panthers players , but none of them attempted to make a tackle , apparently thinking norwood had called a fair catch . 
despite denver 's excellent field position , they could not get the ball into the end zone , so mcmanus kicked a 33-yard field goal that increased their lead to 13 -- 7 . 
newton completed 4 of 4 passes for 51 yards and rushed twice for 25 yards , while jonathan stewart finished the drive with a 1-yard touchdown run , cutting the score to 10 -- 7 with 11:28 left in the second quarter . 
despite denver 's excellent field position , they could not get the ball into the end zone , so mcmanus kicked a 33-yard field goal that increased their lead to 13 -- 7 . 
on carolina 's next possession fullback mike tolbert lost a fumble while being tackled by safety darian stewart , which linebacker danny trevathan recovered on the broncos 40-yard line . 
on carolina 's next possession fullback mike tolbert lost a fumble while being tackled by safety darian stewart , which linebacker danny trevathan recovered on the broncos 40-yard line . 
however , the panthers soon took the ball back when defensive end kony ealy tipped a manning pass to himself and then intercepted it , returning the ball 19 yards to the panthers 39-yard line with 1:55 left on the clock . 
but with 11 seconds left , newton was sacked by demarcus ware as time expired in the half . 
but with 11 seconds left , newton was sacked by demarcus ware as time expired in the half . 
on carolina 's next possession fullback mike tolbert lost a fumble while being tackled by safety darian stewart , which linebacker danny trevathan recovered on the broncos 40-yard line . 
however , the panthers soon took the ball back when defensive end kony ealy tipped a manning pass to himself and then intercepted it , returning the ball 19 yards to the panthers 39-yard line with 1:55 left on the clock . 
however , the panthers soon took the ball back when defensive end kony ealy tipped a manning pass to himself and then intercepted it , returning the ball 19 yards to the panthers 39-yard line with 1:55 left on the clock . 
but with 11 seconds left , newton was sacked by demarcus ware as time expired in the half . 
on carolina 's next possession fullback mike tolbert lost a fumble while being tackled by safety darian stewart , which linebacker danny trevathan recovered on the broncos 40-yard line . 
on carolina 's next possession fullback mike tolbert lost a fumble while being tackled by safety darian stewart , which linebacker danny trevathan recovered on the broncos 40-yard line . 
however , the panthers soon took the ball back when defensive end kony ealy tipped a manning pass to himself and then intercepted it , returning the ball 19 yards to the panthers 39-yard line with 1:55 left on the clock . 
the panthers could not gain any yards with their possession and had to punt . 
but with 11 seconds left , newton was sacked by demarcus ware as time expired in the half . 
the panthers seemed primed to score on their opening drive of the second half when newton completed a 45-yard pass to ted ginn jr. on the denver 35-yard line on their second offensive play . 
but the broncos defense halted the drive on the 26-yard line , and it ended with no points when graham gano hit the uprights on a 44-yard field goal attempt . 
but the broncos defense halted the drive on the 26-yard line , and it ended with no points when graham gano hit the uprights on a 44-yard field goal attempt . 
after the miss , manning completed a pair of passes to emmanuel sanders for gains of 25 and 22 yards , setting up mcmanus ' 33-yard field goal that gave the broncos a 16 -- 7 lead . 
but once again they came up empty , this time as a result of a newton pass that bounced off the hands of ginn and was intercepted by safety t. j. ward . 
the panthers seemed primed to score on their opening drive of the second half when newton completed a 45-yard pass to ted ginn jr. on the denver 35-yard line on their second offensive play . 
but the broncos defense halted the drive on the 26-yard line , and it ended with no points when graham gano hit the uprights on a 44-yard field goal attempt . 
but once again they came up empty , this time as a result of a newton pass that bounced off the hands of ginn and was intercepted by safety t. j. ward . 
ward fumbled the ball during the return , but trevathan recovered it to enable denver to keep possession . 
the panthers seemed primed to score on their opening drive of the second half when newton completed a 45-yard pass to ted ginn jr. on the denver 35-yard line on their second offensive play . 
but the broncos defense halted the drive on the 26-yard line , and it ended with no points when graham gano hit the uprights on a 44-yard field goal attempt . 
but the broncos defense halted the drive on the 26-yard line , and it ended with no points when graham gano hit the uprights on a 44-yard field goal attempt . 
after the miss , manning completed a pair of passes to emmanuel sanders for gains of 25 and 22 yards , setting up mcmanus ' 33-yard field goal that gave the broncos a 16 -- 7 lead . 
on the next play , ealy knocked the ball out of manning 's hand as he was winding up for a pass , and then recovered it for carolina on the 50-yard line . 
a 16-yard reception by devin funchess and a 12-yard run by stewart then set up gano 's 39-yard field goal , cutting the panthers deficit to one score at 16 -- 10 . 
a 16-yard reception by devin funchess and a 12-yard run by stewart then set up gano 's 39-yard field goal , cutting the panthers deficit to one score at 16 -- 10 . 
a 16-yard reception by devin funchess and a 12-yard run by stewart then set up gano 's 39-yard field goal , cutting the panthers deficit to one score at 16 -- 10 . 
there would be no more scoring in the third quarter , but early in the fourth , the broncos drove to the panthers 41-yard line . 
on the next play , ealy knocked the ball out of manning 's hand as he was winding up for a pass , and then recovered it for carolina on the 50-yard line . 
on the next play , ealy knocked the ball out of manning 's hand as he was winding up for a pass , and then recovered it for carolina on the 50-yard line . 
the next three drives of the game would end in punts . 
on the next play , ealy knocked the ball out of manning 's hand as he was winding up for a pass , and then recovered it for carolina on the 50-yard line . 
on the next play , ealy knocked the ball out of manning 's hand as he was winding up for a pass , and then recovered it for carolina on the 50-yard line . 
a 16-yard reception by devin funchess and a 12-yard run by stewart then set up gano 's 39-yard field goal , cutting the panthers deficit to one score at 16 -- 10 . 
the next three drives of the game would end in punts . 
with 4:51 left in regulation , carolina got the ball on their own 24-yard line with a chance to mount a game-winning drive , and soon faced 3rd-and-9 . 
on the next play , miller stripped the ball away from newton , and after several players dove for it , it took a long bounce backwards and was recovered by ward , who returned it five yards to the panthers 4-yard line . 
meanwhile , denver 's offense was kept out of the end zone for three plays , but a holding penalty on cornerback josh norman gave the broncos a new set of downs . 
then anderson scored on a 2-yard touchdown run and manning completed a pass to bennie fowler for a 2-point conversion , giving denver a 24 -- 10 lead with 3:08 left and essentially putting the game away . 
then anderson scored on a 2-yard touchdown run and manning completed a pass to bennie fowler for a 2-point conversion , giving denver a 24 -- 10 lead with 3:08 left and essentially putting the game away . 
on the next play , miller stripped the ball away from newton , and after several players dove for it , it took a long bounce backwards and was recovered by ward , who returned it five yards to the panthers 4-yard line . 
on the next play , miller stripped the ball away from newton , and after several players dove for it , it took a long bounce backwards and was recovered by ward , who returned it five yards to the panthers 4-yard line . 
on the next play , miller stripped the ball away from newton , and after several players dove for it , it took a long bounce backwards and was recovered by ward , who returned it five yards to the panthers 4-yard line . 
meanwhile , denver 's offense was kept out of the end zone for three plays , but a holding penalty on cornerback josh norman gave the broncos a new set of downs . 
then anderson scored on a 2-yard touchdown run and manning completed a pass to bennie fowler for a 2-point conversion , giving denver a 24 -- 10 lead with 3:08 left and essentially putting the game away . 
with 4:51 left in regulation , carolina got the ball on their own 24-yard line with a chance to mount a game-winning drive , and soon faced 3rd-and-9 . 
on the next play , miller stripped the ball away from newton , and after several players dove for it , it took a long bounce backwards and was recovered by ward , who returned it five yards to the panthers 4-yard line . 
on the next play , miller stripped the ball away from newton , and after several players dove for it , it took a long bounce backwards and was recovered by ward , who returned it five yards to the panthers 4-yard line . 
meanwhile , denver 's offense was kept out of the end zone for three plays , but a holding penalty on cornerback josh norman gave the broncos a new set of downs . 
then anderson scored on a 2-yard touchdown run and manning completed a pass to bennie fowler for a 2-point conversion , giving denver a 24 -- 10 lead with 3:08 left and essentially putting the game away . 
miller had six total tackles -lrb- five solo -rrb- , 2 1/2 sacks , and two forced fumbles . 
manning finished the game 13 of 23 for 141 yards with one interception and zero touchdowns . 
anderson was the game 's leading rusher with 90 yards and a touchdown , along with four receptions for 10 yards . 
linebacker luke kuechly had 11 total tackles , while thomas davis had seven , despite playing just two weeks after breaking his right arm in the nfc title game . 
manning finished the game 13 of 23 for 141 yards with one interception and zero touchdowns . 
manning finished the game 13 of 23 for 141 yards with one interception and zero touchdowns . 
manning finished the game 13 of 23 for 141 yards with one interception and zero touchdowns . 
anderson was the game 's leading rusher with 90 yards and a touchdown , along with four receptions for 10 yards . 
sanders was his top receiver with six receptions for 83 yards . 
linebacker luke kuechly had 11 total tackles , while thomas davis had seven , despite playing just two weeks after breaking his right arm in the nfc title game . 
sanders was his top receiver with six receptions for 83 yards . 
anderson was the game 's leading rusher with 90 yards and a touchdown , along with four receptions for 10 yards . 
mcmanus made all four of his field goals , making him perfect on all 11 attempts during the post-season . 
manning finished the game 13 of 23 for 141 yards with one interception and zero touchdowns . 
anderson was the game 's leading rusher with 90 yards and a touchdown , along with four receptions for 10 yards . 
denver won despite being massively outgained in total yards -lrb- 315 to 194 -rrb- and first downs -lrb- 21 to 11 -rrb- . 
denver won despite being massively outgained in total yards -lrb- 315 to 194 -rrb- and first downs -lrb- 21 to 11 -rrb- . 
the previous record was 244 yards by the baltimore ravens in super bowl xxxv . 
jordan norwood 's 61-yard punt return set a new record , surpassing the old record of 45 yards set by john taylor in super bowl xxiii . 
manning and newton had quarterback passer ratings of 56.6 and 55.4 , respectively , and their added total of 112 is a record lowest aggregate passer rating for a super bowl . 
denver won despite being massively outgained in total yards -lrb- 315 to 194 -rrb- and first downs -lrb- 21 to 11 -rrb- . 
denver won despite being massively outgained in total yards -lrb- 315 to 194 -rrb- and first downs -lrb- 21 to 11 -rrb- . 
the broncos ' seven sacks tied a super bowl record set by the chicago bears in super bowl xx . 
the broncos ' seven sacks tied a super bowl record set by the chicago bears in super bowl xx . 
denver won despite being massively outgained in total yards -lrb- 315 to 194 -rrb- and first downs -lrb- 21 to 11 -rrb- . 
denver won despite being massively outgained in total yards -lrb- 315 to 194 -rrb- and first downs -lrb- 21 to 11 -rrb- . 
the broncos ' seven sacks tied a super bowl record set by the chicago bears in super bowl xx . 
the broncos ' seven sacks tied a super bowl record set by the chicago bears in super bowl xx . 
the two teams ' combined third down conversion percentage of 13.8 was a super bowl low . 
one of the most famous people born in warsaw was maria skłodowska-curie , who achieved international recognition for her research on radioactivity and was the first female recipient of the nobel prize . 
casimir pulaski , a polish general and hero of the american revolutionary war , was born here in 1745 . 
one of the most famous people born in warsaw was maria skłodowska-curie , who achieved international recognition for her research on radioactivity and was the first female recipient of the nobel prize . 
famous musicians include władysław szpilman and frédéric chopin . 
though chopin was born in the village of żelazowa wola , about 60 km -lrb- 37 mi -rrb- from warsaw , he moved to the city with his family when he was seven months old . 
there are over 100 different species of trees and the avenues are a place to sit and relax . 
with its benches , flower carpets , a pond with ducks on and a playground for kids , the krasiński palace garden is a popular strolling destination for the varsovians . 
the saxon garden , covering the area of 15.5 ha , was formally a royal garden . 
at the east end of the park , the tomb of the unknown soldier is situated . 
the łazienki park covers the area of 76 ha . 
about 15 kilometres -lrb- 9 miles -rrb- from warsaw , the vistula river 's environment changes strikingly and features a perfectly preserved ecosystem , with a habitat of animals that includes the otter , beaver and hundreds of bird species . 
about 15 kilometres -lrb- 9 miles -rrb- from warsaw , the vistula river 's environment changes strikingly and features a perfectly preserved ecosystem , with a habitat of animals that includes the otter , beaver and hundreds of bird species . 
there are 13 natural reserves in warsaw -- among others , bielany forest , kabaty woods , czerniaków lake . 
there are also several lakes in warsaw -- mainly the oxbow lakes , like czerniaków lake , the lakes in the łazienki or wilanów parks , kamionek lake . 
there are lot of small lakes in the parks , but only a few are permanent -- the majority are emptied before winter to clean them of plants and sediments . 
demographically , it was the most diverse city in poland , with significant numbers of foreign-born inhabitants . 
in 1933 , out of 1,178,914 inhabitants 833,500 were of polish mother tongue . 
according to russian census of 1897 , out of the total population of 638,000 , jews constituted 219,000 -lrb- around 34 % percent -rrb- . 
in addition to the polish majority , there was a significant jewish minority in warsaw . 
most of the modern day population growth is based on internal migration and urbanisation . 
warsaw university of technology is the second academic school of technology in the country , and one of the largest in east-central europe , employing 2,000 professors . 
warsaw university of technology is the second academic school of technology in the country , and one of the largest in east-central europe , employing 2,000 professors . 
other institutions for higher education include the medical university of warsaw , the largest medical school in poland and one of the most prestigious , the national defence university , highest military academic institution in poland , the fryderyk chopin university of music the oldest and largest music school in poland , and one of the largest in europe , the warsaw school of economics , the oldest and most renowned economic university in the country , and the warsaw university of life sciences the largest agricultural university founded in 1818 . 
the university of warsaw was established in 1816 , when the partitions of poland separated warsaw from the oldest and most influential polish academic center , in kraków . 
other institutions for higher education include the medical university of warsaw , the largest medical school in poland and one of the most prestigious , the national defence university , highest military academic institution in poland , the fryderyk chopin university of music the oldest and largest music school in poland , and one of the largest in europe , the warsaw school of economics , the oldest and most renowned economic university in the country , and the warsaw university of life sciences the largest agricultural university founded in 1818 . 
another important library -- the university library , founded in 1816 , is home to over two million items . 
another important library -- the university library , founded in 1816 , is home to over two million items . 
the building was designed by architects marek budzyński and zbigniew badowski and opened on 15 december 1999 . 
the university library garden , designed by irena bajerska , was opened on 12 june 2002 . 
it is one of the largest and most beautiful roof gardens in europe with an area of more than 10,000 m2 -lrb- 107,639.10 sq ft -rrb- , and plants covering 5,111 m2 -lrb- 55,014.35 sq ft -rrb- . 
like many cities in central and eastern europe , infrastructure in warsaw suffered considerably during its time as an eastern bloc economy -- though it is worth mentioning that the initial three-year plan to rebuild poland -lrb- especially warsaw -rrb- was a major success , but what followed was very much the opposite . 
like many cities in central and eastern europe , infrastructure in warsaw suffered considerably during its time as an eastern bloc economy -- though it is worth mentioning that the initial three-year plan to rebuild poland -lrb- especially warsaw -rrb- was a major success , but what followed was very much the opposite . 
however , over the past decade warsaw has seen many improvements due to solid economic growth , an increase in foreign investment as well as funding from the european union . 
in particular , the city 's metro , roads , sidewalks , health care facilities and sanitation facilities have improved markedly . 
today , warsaw has some of the best medical facilities in poland and east-central europe . 
the city is home to the children 's memorial health institute -lrb- cmhi -rrb- , the highest-reference hospital in all of poland , as well as an active research and education center . 
while the maria skłodowska-curie institute of oncology it is one of the largest and most modern oncological institutions in europe . 
the clinical section is located in a 10-floor building with 700 beds , 10 operating theatres , an intensive care unit , several diagnostic departments as well as an outpatient clinic . 
the infrastructure has developed a lot over the past years . 
thanks to numerous musical venues , including the teatr wielki , the polish national opera , the chamber opera , the national philharmonic hall and the national theatre , as well as the roma and buffo music theatres and the congress hall in the palace of culture and science , warsaw hosts many events and festivals . 
thanks to numerous musical venues , including the teatr wielki , the polish national opera , the chamber opera , the national philharmonic hall and the national theatre , as well as the roma and buffo music theatres and the congress hall in the palace of culture and science , warsaw hosts many events and festivals . 
thanks to numerous musical venues , including the teatr wielki , the polish national opera , the chamber opera , the national philharmonic hall and the national theatre , as well as the roma and buffo music theatres and the congress hall in the palace of culture and science , warsaw hosts many events and festivals . 
thanks to numerous musical venues , including the teatr wielki , the polish national opera , the chamber opera , the national philharmonic hall and the national theatre , as well as the roma and buffo music theatres and the congress hall in the palace of culture and science , warsaw hosts many events and festivals . 
thanks to numerous musical venues , including the teatr wielki , the polish national opera , the chamber opera , the national philharmonic hall and the national theatre , as well as the roma and buffo music theatres and the congress hall in the palace of culture and science , warsaw hosts many events and festivals . 
nearby , in ogród saski -lrb- the saxon garden -rrb- , the summer theatre was in operation from 1870 to 1939 , and in the inter-war period , the theatre complex also included momus , warsaw 's first literary cabaret , and leon schiller 's musical theatre melodram . 
nearby , in ogród saski -lrb- the saxon garden -rrb- , the summer theatre was in operation from 1870 to 1939 , and in the inter-war period , the theatre complex also included momus , warsaw 's first literary cabaret , and leon schiller 's musical theatre melodram . 
nearby , in ogród saski -lrb- the saxon garden -rrb- , the summer theatre was in operation from 1870 to 1939 , and in the inter-war period , the theatre complex also included momus , warsaw 's first literary cabaret , and leon schiller 's musical theatre melodram . 
nearby , in ogród saski -lrb- the saxon garden -rrb- , the summer theatre was in operation from 1870 to 1939 , and in the inter-war period , the theatre complex also included momus , warsaw 's first literary cabaret , and leon schiller 's musical theatre melodram . 
the wojciech bogusławski theatre -lrb- 1922 -- 26 -rrb- , was the best example of `` polish monumental theatre '' . 
gatherings of thousands of people on the banks of the vistula on midsummer 's night for a festival called wianki -lrb- polish for wreaths -rrb- have become a tradition and a yearly event in the programme of cultural events in warsaw . 
gatherings of thousands of people on the banks of the vistula on midsummer 's night for a festival called wianki -lrb- polish for wreaths -rrb- have become a tradition and a yearly event in the programme of cultural events in warsaw . 
gatherings of thousands of people on the banks of the vistula on midsummer 's night for a festival called wianki -lrb- polish for wreaths -rrb- have become a tradition and a yearly event in the programme of cultural events in warsaw . 
the festival traces its roots to a peaceful pagan ritual where maidens would float their wreaths of herbs on the water to predict when they would be married , and to whom . 
each midsummer 's eve , apart from the official floating of wreaths , jumping over fires , looking for the fern flower , there are musical performances , dignitaries ' speeches , fairs and fireworks by the river bank . 
as interesting examples of expositions the most notable are : the world 's first museum of posters boasting one of the largest collections of art posters in the world , museum of hunting and riding and the railway museum . 
from among warsaw 's 60 museums , the most prestigious ones are national museum with a collection of works whose origin ranges in time from antiquity till the present epoch as well as one of the best collections of paintings in the country including some paintings from adolf hitler 's private collection , and museum of the polish army whose set portrays the history of arms . 
from among warsaw 's 60 museums , the most prestigious ones are national museum with a collection of works whose origin ranges in time from antiquity till the present epoch as well as one of the best collections of paintings in the country including some paintings from adolf hitler 's private collection , and museum of the polish army whose set portrays the history of arms . 
from among warsaw 's 60 museums , the most prestigious ones are national museum with a collection of works whose origin ranges in time from antiquity till the present epoch as well as one of the best collections of paintings in the country including some paintings from adolf hitler 's private collection , and museum of the polish army whose set portrays the history of arms . 
from among warsaw 's 60 museums , the most prestigious ones are national museum with a collection of works whose origin ranges in time from antiquity till the present epoch as well as one of the best collections of paintings in the country including some paintings from adolf hitler 's private collection , and museum of the polish army whose set portrays the history of arms . 
a fine tribute to the fall of warsaw and history of poland can be found in the warsaw uprising museum and in the katyń museum which preserves the memory of the crime . 
a fine tribute to the fall of warsaw and history of poland can be found in the warsaw uprising museum and in the katyń museum which preserves the memory of the crime . 
the warsaw uprising museum also operates a rare preserved and operating historic stereoscopic theatre , the warsaw fotoplastikon . 
the museum of independence preserves patriotic and political objects connected with poland 's struggles for independence . 
dating back to 1936 warsaw historical museum contains 60 rooms which host a permanent exhibition of the history of warsaw from its origins until today . 
the 17th century royal ujazdów castle currently houses centre for contemporary art , with some permanent and temporary exhibitions , concerts , shows and creative workshops . 
the centre currently realizes about 500 projects a year . 
zachęta national gallery of art , the oldest exhibition site in warsaw , with a tradition stretching back to the mid-19th century organises exhibitions of modern art by polish and international artists and promotes art in many other ways . 
zachęta national gallery of art , the oldest exhibition site in warsaw , with a tradition stretching back to the mid-19th century organises exhibitions of modern art by polish and international artists and promotes art in many other ways . 
since 2011 warsaw gallery weekend is held on last weekend of september . 
their local rivals , polonia warsaw , have significantly fewer supporters , yet they managed to win ekstraklasa championship in 2000 . 
they also won the country 's championship in 1946 , and won the cup twice as well . 
they also won the country 's championship in 1946 , and won the cup twice as well . 
polonia 's home venue is located at konwiktorska street , a ten-minute walk north from the old town . 
polonia was relegated from the country 's top flight in 2013 because of their disastrous financial situation . 
the mermaid -lrb- syrenka -rrb- is warsaw 's symbol and can be found on statues throughout the city and on the city 's coat of arms . 
the mermaid -lrb- syrenka -rrb- is warsaw 's symbol and can be found on statues throughout the city and on the city 's coat of arms . 
this imagery has been in use since at least the mid-14th century . 
the oldest existing armed seal of warsaw is from the year 1390 , consisting of a round seal bordered with the latin inscription sigilium civitatis varsoviensis -lrb- seal of the city of warsaw -rrb- . 
city records as far back as 1609 document the use of a crude form of a sea monster with a female upper body and holding a sword in its claws . 
the best-known legend , by artur oppman , is that long ago two of triton 's daughters set out on a journey through the depths of the oceans and seas . 
the best-known legend , by artur oppman , is that long ago two of triton 's daughters set out on a journey through the depths of the oceans and seas . 
one of them decided to stay on the coast of denmark and can be seen sitting at the entrance to the port of copenhagen . 
she stopped to rest on a sandy beach by the village of warszowa , where fishermen came to admire her beauty and listen to her beautiful voice . 
a greedy merchant also heard her songs ; he followed the fishermen and captured the mermaid . 
tamara de lempicka was a famous artist born in warsaw . 
she was born maria górska in warsaw to wealthy parents and in 1916 married a polish lawyer tadeusz łempicki . 
better than anyone else she represented the art deco style in painting and art . 
nathan alterman , the israeli poet , was born in warsaw , as was moshe vilenski , the israeli composer , lyricist , and pianist , who studied music at the warsaw conservatory . 
warsaw was the beloved city of isaac bashevis singer , which he described in many of his novels : warsaw has just now been destroyed . 
in 2012 the economist intelligence unit ranked warsaw as the 32nd most liveable city in the world . 
in 2012 the economist intelligence unit ranked warsaw as the 32nd most liveable city in the world . 
warsaw 's economy , by a wide variety of industries , is characterised by fmcg manufacturing , metal processing , steel and electronic manufacturing and food processing . 
the warsaw stock exchange is one of the largest and most important in central and eastern europe . 
frontex , the european union agency for external border security , has its headquarters in warsaw . 
the first historical reference to warsaw dates back to the year 1313 , at a time when kraków served as the polish capital city . 
the first historical reference to warsaw dates back to the year 1313 , at a time when kraków served as the polish capital city . 
due to its central location between the polish -- lithuanian commonwealth 's capitals of kraków and vilnius , warsaw became the capital of the commonwealth and of the crown of the kingdom of poland when king sigismund iii vasa moved his court from kraków to warsaw in 1596 . 
due to its central location between the polish -- lithuanian commonwealth 's capitals of kraków and vilnius , warsaw became the capital of the commonwealth and of the crown of the kingdom of poland when king sigismund iii vasa moved his court from kraków to warsaw in 1596 . 
warsaw gained the title of the `` phoenix city '' because it has survived many wars , conflicts and invasions throughout its long history . 
the city is the seat of a roman catholic archdiocese -lrb- left bank of the vistula -rrb- and diocese -lrb- right bank -rrb- , and possesses various universities , most notably the polish academy of sciences and the university of warsaw , two opera houses , theatres , museums , libraries and monuments . 
the city is the seat of a roman catholic archdiocese -lrb- left bank of the vistula -rrb- and diocese -lrb- right bank -rrb- , and possesses various universities , most notably the polish academy of sciences and the university of warsaw , two opera houses , theatres , museums , libraries and monuments . 
the historic city-centre of warsaw with its picturesque old town in 1980 was listed as a unesco world heritage site . 
other main architectural attractions include the castle square with the royal castle and the iconic king sigismund 's column , st. john 's cathedral , market square , palaces , churches and mansions all displaying a richness of colour and architectural detail . 
warsaw provides many examples of architecture from the gothic , renaissance , baroque and neoclassical periods , and around a quarter of the city is filled with luxurious parks and royal gardens . 
warsaw 's name in the polish language is warszawa , approximately / vɑːrˈʃɑːvə / -lrb- also formerly spelled warszewa and warszowa -rrb- , meaning `` belonging to warsz '' , warsz being a shortened form of the masculine name of slavic origin warcisław ; see also etymology of wrocław . 
warsaw 's name in the polish language is warszawa , approximately / vɑːrˈʃɑːvə / -lrb- also formerly spelled warszewa and warszowa -rrb- , meaning `` belonging to warsz '' , warsz being a shortened form of the masculine name of slavic origin warcisław ; see also etymology of wrocław . 
in actuality , warsz was a 12th/13th-century nobleman who owned a village located at the modern-day site of mariensztat neighbourhood . 
in actuality , warsz was a 12th/13th-century nobleman who owned a village located at the modern-day site of mariensztat neighbourhood . 
the official city name in full is miasto stołeczne warszawa -lrb- english : `` the capital city of warsaw '' -rrb- . 
after jazdów was raided by nearby clans and dukes , a new similar settlement was established on the site of a small fishing village called warszowa . 
the prince of płock , bolesław ii of masovia , established this settlement , the modern-day warsaw , in about 1300 . 
the prince of płock , bolesław ii of masovia , established this settlement , the modern-day warsaw , in about 1300 . 
in the beginning of the 14th century it became one of the seats of the dukes of masovia , becoming the official capital of masovian duchy in 1413 . 
upon the extinction of the local ducal line , the duchy was reincorporated into the polish crown in 1526 . 
in 1529 , warsaw for the first time became the seat of the general sejm , permanent from 1569 . 
in 1529 , warsaw for the first time became the seat of the general sejm , permanent from 1569 . 
in 1573 the city gave its name to the warsaw confederation , formally establishing religious freedom in the polish -- lithuanian commonwealth . 
due to its central location between the commonwealth 's capitals of kraków and vilnius , warsaw became the capital of the commonwealth and the crown of the kingdom of poland when king sigismund iii vasa moved his court from kraków to warsaw in 1596 . 
due to its central location between the commonwealth 's capitals of kraków and vilnius , warsaw became the capital of the commonwealth and the crown of the kingdom of poland when king sigismund iii vasa moved his court from kraków to warsaw in 1596 . 
warsaw remained the capital of the polish -- lithuanian commonwealth until 1796 , when it was annexed by the kingdom of prussia to become the capital of the province of south prussia . 
warsaw remained the capital of the polish -- lithuanian commonwealth until 1796 , when it was annexed by the kingdom of prussia to become the capital of the province of south prussia . 
liberated by napoleon 's army in 1806 , warsaw was made the capital of the newly created duchy of warsaw . 
following the congress of vienna of 1815 , warsaw became the centre of the congress poland , a constitutional monarchy under a personal union with imperial russia . 
the royal university of warsaw was established in 1816 . 
warsaw was occupied by germany from 4 august 1915 until november 1918 . 
the allied armistice terms required in article 12 that germany withdraw from areas controlled by russia in 1914 , which included warsaw . 
germany did so , and underground leader piłsudski returned to warsaw on 11 november and set up what became the second polish republic , with warsaw the capital . 
in the course of the polish-bolshevik war of 1920 , the huge battle of warsaw was fought on the eastern outskirts of the city in which the capital was successfully defended and the red army defeated . 
in the course of the polish-bolshevik war of 1920 , the huge battle of warsaw was fought on the eastern outskirts of the city in which the capital was successfully defended and the red army defeated . 
after the german invasion of poland on 1 september 1939 began the second world war , warsaw was defended till september 27 . 
central poland , including warsaw , came under the rule of the general government , a german nazi colonial administration . 
all higher education institutions were immediately closed and warsaw 's entire jewish population -- several hundred thousand , some 30 % of the city -- herded into the warsaw ghetto . 
when the order came to annihilate the ghetto as part of hitler 's `` final solution '' on 19 april 1943 , jewish fighters launched the warsaw ghetto uprising . 
despite being heavily outgunned and outnumbered , the ghetto held out for almost a month . 
by july 1944 , the red army was deep into polish territory and pursuing the germans toward warsaw . 
knowing that stalin was hostile to the idea of an independent poland , the polish government-in-exile in london gave orders to the underground home army -lrb- ak -rrb- to try to seize control of warsaw from the germans before the red army arrived . 
thus , on 1 august 1944 , as the red army was nearing the city , the warsaw uprising began . 
the armed struggle , planned to last 48 hours , was partially successful , however it went on for 63 days . 
polish civilian deaths are estimated at between 150,000 and 200,000 . 
after world war ii , under a communist regime set up by the conquering soviets , the `` bricks for warsaw '' campaign was initiated , and large prefabricated housing projects were erected in warsaw to address the housing shortage , along with other typical buildings of an eastern bloc city , such as the palace of culture and science , a gift from the soviet union . 
after world war ii , under a communist regime set up by the conquering soviets , the `` bricks for warsaw '' campaign was initiated , and large prefabricated housing projects were erected in warsaw to address the housing shortage , along with other typical buildings of an eastern bloc city , such as the palace of culture and science , a gift from the soviet union . 
after world war ii , under a communist regime set up by the conquering soviets , the `` bricks for warsaw '' campaign was initiated , and large prefabricated housing projects were erected in warsaw to address the housing shortage , along with other typical buildings of an eastern bloc city , such as the palace of culture and science , a gift from the soviet union . 
after world war ii , under a communist regime set up by the conquering soviets , the `` bricks for warsaw '' campaign was initiated , and large prefabricated housing projects were erected in warsaw to address the housing shortage , along with other typical buildings of an eastern bloc city , such as the palace of culture and science , a gift from the soviet union . 
in 1980 , warsaw 's historic old town was inscribed onto unesco 's world heritage list . 
john paul ii 's visits to his native country in 1979 and 1983 brought support to the budding solidarity movement and encouraged the growing anti-communist fervor there . 
john paul ii 's visits to his native country in 1979 and 1983 brought support to the budding solidarity movement and encouraged the growing anti-communist fervor there . 
in 1979 , less than a year after becoming pope , john paul celebrated mass in victory square in warsaw and ended his sermon with a call to `` renew the face '' of poland : let thy spirit descend ! 
in 1979 , less than a year after becoming pope , john paul celebrated mass in victory square in warsaw and ended his sermon with a call to `` renew the face '' of poland : let thy spirit descend ! 
these words were very meaningful for the polish citizens who understood them as the incentive for the democratic changes . 
warsaw lies in east-central poland about 300 km -lrb- 190 mi -rrb- from the carpathian mountains and about 260 km -lrb- 160 mi -rrb- from the baltic sea , 523 km -lrb- 325 mi -rrb- east of berlin , germany . 
warsaw lies in east-central poland about 300 km -lrb- 190 mi -rrb- from the carpathian mountains and about 260 km -lrb- 160 mi -rrb- from the baltic sea , 523 km -lrb- 325 mi -rrb- east of berlin , germany . 
the city straddles the vistula river . 
there are some hills -lrb- mostly artificial -rrb- located within the confines of the city -- e.g. warsaw uprising hill -lrb- 121 metres -lrb- 397.0 ft -rrb- -rrb- , szczęśliwice hill -lrb- 138 metres -lrb- 452.8 ft -rrb- -- the highest point of warsaw in general -rrb- . 
the lowest point lies at a height 75.6 metres -lrb- 248.0 ft -rrb- -lrb- at the right bank of the vistula , by the eastern border of warsaw -rrb- . 
warsaw is located on two main geomorphologic formations : the plain moraine plateau and the vistula valley with its asymmetrical pattern of different terraces . 
warsaw is located on two main geomorphologic formations : the plain moraine plateau and the vistula valley with its asymmetrical pattern of different terraces . 
the left one is situated both on the moraine plateau -lrb- 10 to 25 m -lrb- 32.8 to 82.0 ft -rrb- above vistula level -rrb- and on the vistula terraces -lrb- max . 
the vistula river is the specific axis of warsaw , which divides the city into two parts , left and right . 
the significant element of the relief , in this part of warsaw , is the edge of moraine plateau called warsaw escarpment . 
the plain moraine plateau has only a few natural and artificial ponds and also groups of clay pits . 
the left side consist mainly of two levels : the highest one contains former flooded terraces and the lowest one the flood plain terrace . 
the contemporary flooded terrace still has visible valleys and ground depressions with water systems coming from the vistula old -- riverbed . 
there are several levels of the plain vistula terraces -lrb- flooded as well as former flooded once -rrb- and only small part and not so visible moraine escarpment . 
these are mainly forested areas -lrb- pine forest -rrb- . 
warsaw 's mixture of architectural styles reflects the turbulent history of the city and country . 
during the second world war , warsaw was razed to the ground by bombing raids and planned destruction . 
after liberation , rebuilding began as in other cities of the communist-ruled prl . 
however , some of the buildings from the 19th century that had been preserved in reasonably reconstructible form were nonetheless eradicated in the 1950s and 1960s -lrb- e.g. leopold kronenberg palace -rrb- . 
mass residential blocks were erected , with basic design typical of eastern bloc countries . 
gothic architecture is represented in the majestic churches but also at the burgher houses and fortifications . 
the most significant buildings are st. john 's cathedral -lrb- 14th century -rrb- , the temple is a typical example of the so-called masovian gothic style , st. mary 's church -lrb- 1411 -rrb- , a town house of burbach family -lrb- 14th century -rrb- , gunpowder tower -lrb- after 1379 -rrb- and the royal castle curia maior -lrb- 1407 -- 1410 -rrb- . 
the most significant buildings are st. john 's cathedral -lrb- 14th century -rrb- , the temple is a typical example of the so-called masovian gothic style , st. mary 's church -lrb- 1411 -rrb- , a town house of burbach family -lrb- 14th century -rrb- , gunpowder tower -lrb- after 1379 -rrb- and the royal castle curia maior -lrb- 1407 -- 1410 -rrb- . 
the most notable examples of renaissance architecture in the city are the house of baryczko merchant family -lrb- 1562 -rrb- , building called `` the negro '' -lrb- early 17th century -rrb- and salwator tenement -lrb- 1632 -rrb- . 
the most interesting examples of mannerist architecture are the royal castle -lrb- 1596 -- 1619 -rrb- and the jesuit church -lrb- 1609 -- 1626 -rrb- at old town . 
building activity occurred in numerous noble palaces and churches during the later decades of the 17th century . 
one of the best examples of this architecture are krasiński palace -lrb- 1677 -- 1683 -rrb- , wilanów palace -lrb- 1677 -- 1696 -rrb- and st. kazimierz church -lrb- 1688 -- 1692 -rrb- . 
the most impressive examples of rococo architecture are czapski palace -lrb- 1712 -- 1721 -rrb- , palace of the four winds -lrb- 1730s -rrb- and visitationist church -lrb- façade 1728 -- 1761 -rrb- . 
the neoclassical architecture in warsaw can be described by the simplicity of the geometrical forms teamed with a great inspiration from the roman period . 
some of the best examples of the neoclassical style are the palace on the water -lrb- rebuilt 1775 -- 1795 -rrb- , królikarnia -lrb- 1782 -- 1786 -rrb- , carmelite church -lrb- façade 1761 -- 1783 -rrb- and evangelical holy trinity church -lrb- 1777 -- 1782 -rrb- . 
exceptional examples of the bourgeois architecture of the later periods were not restored by the communist authorities after the war -lrb- like mentioned kronenberg palace and insurance company rosja building -rrb- or they were rebuilt in socialist realism style -lrb- like warsaw philharmony edifice originally inspired by palais garnier in paris -rrb- . 
exceptional examples of the bourgeois architecture of the later periods were not restored by the communist authorities after the war -lrb- like mentioned kronenberg palace and insurance company rosja building -rrb- or they were rebuilt in socialist realism style -lrb- like warsaw philharmony edifice originally inspired by palais garnier in paris -rrb- . 
exceptional examples of the bourgeois architecture of the later periods were not restored by the communist authorities after the war -lrb- like mentioned kronenberg palace and insurance company rosja building -rrb- or they were rebuilt in socialist realism style -lrb- like warsaw philharmony edifice originally inspired by palais garnier in paris -rrb- . 
despite that the warsaw university of technology building -lrb- 1899 -- 1902 -rrb- is the most interesting of the late 19th-century architecture . 
warsaw 's municipal government authorities have decided to rebuild the saxon palace and the brühl palace , the most distinctive buildings in prewar warsaw . 
there are also many places commemorating the heroic history of warsaw . 
pawiak , an infamous german gestapo prison now occupied by a mausoleum of memory of martyrdom and the museum , is only the beginning of a walk in the traces of heroic city . 
the warsaw citadel , an impressive 19th-century fortification built after the defeat of the november uprising , was a place of martyr for the poles . 
another important monument , the statue of little insurgent located at the ramparts of the old town , commemorates the children who served as messengers and frontline troops in the warsaw uprising , while the impressive warsaw uprising monument by wincenty kućma was erected in memory of the largest insurrection of world war ii . 
another important monument , the statue of little insurgent located at the ramparts of the old town , commemorates the children who served as messengers and frontline troops in the warsaw uprising , while the impressive warsaw uprising monument by wincenty kućma was erected in memory of the largest insurrection of world war ii . 
other green spaces in the city include the botanic garden and the university library garden . 
they have extensive botanical collection of rare domestic and foreign plants , while a palm house in the new orangery displays plants of subtropics from all over the world . 
besides , within the city borders , there are also : pole mokotowskie -lrb- a big park in the northern mokotów , where was the first horse racetrack and then the airport -rrb- , park ujazdowski -lrb- close to the sejm and john lennon street -rrb- , park of culture and rest in powsin , by the southern city border , park skaryszewski by the right vistula bank , in praga . 
besides , within the city borders , there are also : pole mokotowskie -lrb- a big park in the northern mokotów , where was the first horse racetrack and then the airport -rrb- , park ujazdowski -lrb- close to the sejm and john lennon street -rrb- , park of culture and rest in powsin , by the southern city border , park skaryszewski by the right vistula bank , in praga . 
in 1927 a zoological garden -lrb- ogród zoologiczny -rrb- was established on the park grounds , and in 1952 a bear run , still open today . 
the species richness is mainly due to the location of warsaw within the border region of several big floral regions comprising substantial proportions of close-to-wilderness areas -lrb- natural forests , wetlands along the vistula -rrb- as well as arable land , meadows and forests . 
bielany forest , located within the borders of warsaw , is the remaining part of the masovian primeval forest . 
bielany forest , located within the borders of warsaw , is the remaining part of the masovian primeval forest . 
other big forest area is kabaty forest by the southern city border . 
warsaw has also two botanic gardens : by the łazienki park -lrb- a didactic-research unit of the university of warsaw -rrb- as well as by the park of culture and rest in powsin -lrb- a unit of the polish academy of science -rrb- . 
in 1939 , c. 1,300,000 people lived in warsaw , but in 1945 -- only 420,000 . 
in 1939 , c. 1,300,000 people lived in warsaw , but in 1945 -- only 420,000 . 
the first remedial measure was the warsaw area enlargement -lrb- 1951 -rrb- -- but the city authorities were still forced to introduce residency registration limitations : only the spouses and children of the permanent residents as well as some persons of public importance -lrb- like renowned specialists -rrb- were allowed to get the registration , hence halving the population growth in the following years . 
it also bolstered some kind of conviction among poles that varsovians thought of themselves as better only because they lived in the capital . 
unfortunately this belief still lives on in poland -lrb- although not as much as it used to be -rrb- -- even though since 1990 there are no limitations to residency registration anymore . 
throughout its existence , warsaw has been a multi-cultural city . 
according to the 1901 census , out of 711,988 inhabitants 56.2 % were catholics , 35.7 % jews , 5 % greek orthodox christians and 2.8 % protestants . 
according to the 1901 census , out of 711,988 inhabitants 56.2 % were catholics , 35.7 % jews , 5 % greek orthodox christians and 2.8 % protestants . 
according to the 1901 census , out of 711,988 inhabitants 56.2 % were catholics , 35.7 % jews , 5 % greek orthodox christians and 2.8 % protestants . 
most of them were destroyed in the aftermath of the warsaw uprising of 1944 . 
the basic unit of territorial division in poland is a commune -lrb- gmina -rrb- . 
some bigger cities obtain the entitlements , i.e. tasks and privileges , which are possessed by the units of the second level of the territorial division -- counties or powiats . 
but for instance the districts in kraków do not have entitlements of powiat , so the registration numbers in kraków are of the same type for all districts . 
legislative power in warsaw is vested in a unicameral warsaw city council -lrb- rada miasta -rrb- , which comprises 60 members . 
legislative power in warsaw is vested in a unicameral warsaw city council -lrb- rada miasta -rrb- , which comprises 60 members . 
council members are elected directly every four years . 
like most legislative bodies , the city council divides itself into committees which have the oversight of various functions of the city government . 
if the mayor vetoes a bill , the council has 30 days to override the veto by a two-thirds majority vote . 
the mayor of warsaw is called president . 
the first warsaw president was jan andrzej menich -lrb- 1695 -- 1696 -rrb- . 
the first warsaw president was jan andrzej menich -lrb- 1695 -- 1696 -rrb- . 
since 1990 the president of warsaw had been elected by the city council . 
in the years of 1994 -- 1999 the mayor of the district centrum automatically was designated as the president of warsaw : the mayor of centrum was elected by the district council of centrum and the council was elected only by the centrum residents . 
warsaw , especially its city centre -lrb- śródmieście -rrb- , is home not only to many national institutions and government agencies , but also to many domestic and international companies . 
in 2006 , 304,016 companies were registered in the city . 
moreover , warsaw was ranked as the 7th greatest emerging market . 
warsaw produces 12 % of poland 's national income , which in 2008 was 305.1 % of the polish average , per capita -lrb- or 160 % of the european union average -rrb- . 
total nominal gdp of the city in 2010 amounted to 191.766 billion pln , 111696 pln per capita , which was 301,1 % of polish average . 
warsaw 's first stock exchange was established in 1817 and continued trading until world war ii . 
warsaw 's first stock exchange was established in 1817 and continued trading until world war ii . 
it was re-established in april 1991 , following the end of the post-war communist control of the country and the reintroduction of a free-market economy . 
today , the warsaw stock exchange -lrb- wse -rrb- is , according to many indicators , the largest market in the region , with 374 companies listed and total capitalization of 162 584 mln eur as of 31 august 2009 . 
from 1991 until 2000 , the stock exchange was , ironically , located in the building previously used as the headquarters of the polish united workers ' party -lrb- pzpr -rrb- . 
the fso car factory was established in 1951 . 
a number of vehicles have been assembled there over the decades , including the warszawa , syrena , fiat 125p -lrb- under license from fiat , later renamed fso 125p when the license expired -rrb- and the polonez . 
in 1995 the factory was purchased by the south korean car manufacturer daewoo , which assembled the tico , espero , nubia , tacuma , leganza , lanos and matiz there for the european market . 
in 2005 the factory was sold to avtozaz , a ukrainian car manufacturer which assembled there the chevrolet aveo . 
in 2005 the factory was sold to avtozaz , a ukrainian car manufacturer which assembled there the chevrolet aveo . 
warsaw -lrb- polish : warszawa -lsb- varˈʂava -rsb- -lrb- listen -rrb- ; see also other names -rrb- is the capital and largest city of poland . 
warsaw -lrb- polish : warszawa -lsb- varˈʂava -rsb- -lrb- listen -rrb- ; see also other names -rrb- is the capital and largest city of poland . 
it stands on the vistula river in east-central poland , roughly 260 kilometres -lrb- 160 mi -rrb- from the baltic sea and 300 kilometres -lrb- 190 mi -rrb- from the carpathian mountains . 
its population is estimated at 1.740 million residents within a greater metropolitan area of 2.666 million residents , which makes warsaw the 9th most-populous capital city in the european union . 
its population is estimated at 1.740 million residents within a greater metropolitan area of 2.666 million residents , which makes warsaw the 9th most-populous capital city in the european union . 
warsaw -lrb- polish : warszawa -lsb- varˈʂava -rsb- -lrb- listen -rrb- ; see also other names -rrb- is the capital and largest city of poland . 
it stands on the vistula river in east-central poland , roughly 260 kilometres -lrb- 160 mi -rrb- from the baltic sea and 300 kilometres -lrb- 190 mi -rrb- from the carpathian mountains . 
it stands on the vistula river in east-central poland , roughly 260 kilometres -lrb- 160 mi -rrb- from the baltic sea and 300 kilometres -lrb- 190 mi -rrb- from the carpathian mountains . 
its population is estimated at 1.740 million residents within a greater metropolitan area of 2.666 million residents , which makes warsaw the 9th most-populous capital city in the european union . 
its population is estimated at 1.740 million residents within a greater metropolitan area of 2.666 million residents , which makes warsaw the 9th most-populous capital city in the european union . 
the normans -lrb- norman : nourmands ; french : normands ; latin : normanni -rrb- were the people who in the 10th and 11th centuries gave their name to normandy , a region in france . 
the normans -lrb- norman : nourmands ; french : normands ; latin : normanni -rrb- were the people who in the 10th and 11th centuries gave their name to normandy , a region in france . 
they were descended from norse -lrb- `` norman '' comes from `` norseman '' -rrb- raiders and pirates from denmark , iceland and norway who , under their leader rollo , agreed to swear fealty to king charles iii of west francia . 
they were descended from norse -lrb- `` norman '' comes from `` norseman '' -rrb- raiders and pirates from denmark , iceland and norway who , under their leader rollo , agreed to swear fealty to king charles iii of west francia . 
the distinct cultural and ethnic identity of the normans emerged initially in the first half of the 10th century , and it continued to evolve over the succeeding centuries . 
norman adventurers founded the kingdom of sicily under roger ii after conquering southern italy on the saracens and byzantines , and an expedition on behalf of their duke , william the conqueror , led to the norman conquest of england at the battle of hastings in 1066 . 
the duchy of normandy , which they formed by treaty with the french crown , was a great fief of medieval france , and under richard i of normandy was forged into a cohesive and formidable principality in feudal tenure . 
the normans were famed for their martial spirit and eventually for their christian piety , becoming exponents of the catholic orthodoxy into which they assimilated . 
the english name `` normans '' comes from the french words normans/normanz , plural of normant , modern french normand , which is itself borrowed from old low franconian nortmann `` northman '' or directly from old norse norðmaðr , latinized variously as nortmannus , normannus , or nordmannus -lrb- recorded in medieval latin , 9th century -rrb- to mean `` norseman , viking '' . 
the english name `` normans '' comes from the french words normans/normanz , plural of normant , modern french normand , which is itself borrowed from old low franconian nortmann `` northman '' or directly from old norse norðmaðr , latinized variously as nortmannus , normannus , or nordmannus -lrb- recorded in medieval latin , 9th century -rrb- to mean `` norseman , viking '' . 
the duchy of normandy , which began in 911 as a fiefdom , was established by the treaty of saint-clair-sur-epte between king charles iii of west francia and the famed viking ruler rollo , and was situated in the former frankish kingdom of neustria . 
the duchy of normandy , which began in 911 as a fiefdom , was established by the treaty of saint-clair-sur-epte between king charles iii of west francia and the famed viking ruler rollo , and was situated in the former frankish kingdom of neustria . 
the area corresponded to the northern part of present-day upper normandy down to the river seine , but the duchy would eventually extend west beyond the seine . 
before rollo 's arrival , its populations did not differ from picardy or the île-de-france , which were considered `` frankish '' . 
the descendants of rollo 's vikings and their frankish wives would replace the norse religion and old norse language with catholicism -lrb- christianity -rrb- and the gallo-romance language of the local people , blending their maternal frankish heritage with old norse traditions and customs to synthesize a unique `` norman '' culture in the north of france . 
the descendants of rollo 's vikings and their frankish wives would replace the norse religion and old norse language with catholicism -lrb- christianity -rrb- and the gallo-romance language of the local people , blending their maternal frankish heritage with old norse traditions and customs to synthesize a unique `` norman '' culture in the north of france . 
most norman knights remained poor and land-hungry , and by 1066 normandy had been exporting fighting horsemen for more than a generation . 
in 999 , according to amatus of montecassino , norman pilgrims returning from jerusalem called in at the port of salerno when a saracen attack occurred . 
william of apulia tells that , in 1016 , norman pilgrims to the shrine of the archangel michael at monte gargano were met by melus of bari , a lombard nobleman and rebel , who persuaded them to return with more warriors to help throw off the byzantine rule , which they did . 
william of apulia tells that , in 1016 , norman pilgrims to the shrine of the archangel michael at monte gargano were met by melus of bari , a lombard nobleman and rebel , who persuaded them to return with more warriors to help throw off the byzantine rule , which they did . 
the drengot family thereafter attained the principality of capua , and emperor henry iii legally ennobled the hauteville leader , drogo , as `` dux et magister italiae comesque normannorum totius apuliae et calabriae '' -lrb- `` duke and master of italy and count of the normans of all apulia and calabria '' -rrb- in 1047 . 
he promptly awarded their elected leader , william iron arm , with the title of count in his capital of melfi . 
from these bases , the normans eventually captured sicily and malta from the saracens , under the leadership of the famous robert guiscard , a hauteville , and his younger brother roger the great count . 
roger 's son , roger ii of sicily , was crowned king in 1130 -lrb- exactly one century after rainulf was `` crowned '' count -rrb- by antipope anacletus ii . 
the normans left their legacy in many castles , such as william iron arm 's citadel at squillace , and cathedrals , such as roger ii 's cappella palatina chapel at palermo , which dot the landscape and give a wholly distinct architectural flavor to accompany its unique history . 
one of the great geographical treatises of the middle ages , the `` tabula rogeriana '' , was written by the andalusian al-idrisi for king roger ii of sicily , and entitled `` kitab rudjdjar '' -lrb- `` the book of roger '' -rrb- . 
one of the great geographical treatises of the middle ages , the `` tabula rogeriana '' , was written by the andalusian al-idrisi for king roger ii of sicily , and entitled `` kitab rudjdjar '' -lrb- `` the book of roger '' -rrb- . 
under this state , there was great religious freedom , and alongside the norman nobles existed a meritocratic bureaucracy of jews , muslims and christians , both catholic and eastern orthodox . 
soon after the normans began to enter italy , they entered the byzantine empire and then armenia , fighting against the pechenegs , the bulgars , and especially the seljuk turks . 
one of the first norman mercenaries to serve as a byzantine general was hervé in the 1050s . 
in the 1060s , robert crispin led the normans of edessa against the turks . 
roussel de bailleul even tried to carve out an independent state in asia minor with support from the local population , but he was stopped by the byzantine general alexius komnenos . 
they even lent their ethnicity to the name of their castle : afranji , meaning `` franks . '' 
a norman named oursel led a force of `` franks '' into the upper euphrates valley in northern syria . 
some normans joined turkish forces to aid in the destruction of the armenians vassal-states of sassoun and taron in far eastern anatolia . 
several families of byzantine greece were of norman mercenary origin during the period of the comnenian restoration , when byzantine emperors were seeking out western european warriors . 
robert guiscard , an other norman adventurer previously elevated to the dignity of count of apulia as the result of his military successes , ultimately drove the byzantines out of southern italy . 
the city 's garrison resisted until february 1082 , when dyrrachium was betrayed to the normans by the venetian and amalfitan merchants who had settled there . 
after allying himself with croatia and the catholic cities of dalmatia , in 1081 he led an army of 30,000 men in 300 ships landing on the southern shores of albania , capturing valona , kanina , jericho -lrb- orikumi -rrb- , and reaching butrint after numerous pillages . 
meanwhile , they occupied petrela , the citadel of mili at the banks of the river deabolis , gllavenica -lrb- ballsh -rrb- , kanina and jericho . 
a few years after the first crusade , in 1107 , the normans under the command of bohemond , robert 's son , landed in valona and besieged dyrrachium using the most sophisticated military equipment of the time , but to no avail . 
meanwhile , they occupied petrela , the citadel of mili at the banks of the river deabolis , gllavenica -lrb- ballsh -rrb- , kanina and jericho . 
the further decline of byzantine state-of-affairs paved the road to a third attack in 1185 , when a large norman army invaded dyrrachium , owing to the betrayal of high byzantine officials . 
the further decline of byzantine state-of-affairs paved the road to a third attack in 1185 , when a large norman army invaded dyrrachium , owing to the betrayal of high byzantine officials . 
some time later , dyrrachium -- one of the most important naval bases of the adriatic -- fell again to byzantine hands . 
this relationship eventually produced closer ties of blood through the marriage of emma , sister of duke richard ii of normandy , and king ethelred ii of england . 
this relationship eventually produced closer ties of blood through the marriage of emma , sister of duke richard ii of normandy , and king ethelred ii of england . 
because of this , ethelred fled to normandy in 1013 , when he was forced from his kingdom by sweyn forkbeard . 
because of this , ethelred fled to normandy in 1013 , when he was forced from his kingdom by sweyn forkbeard . 
when finally edward the confessor returned from his father 's refuge in 1041 , at the invitation of his half-brother harthacnut , he brought with him a norman-educated mind . 
when finally edward the confessor returned from his father 's refuge in 1041 , at the invitation of his half-brother harthacnut , he brought with him a norman-educated mind . 
he appointed robert of jumièges archbishop of canterbury and made ralph the timid earl of hereford . 
in 1066 , duke william ii of normandy conquered england killing king harold ii at the battle of hastings . 
in 1066 , duke william ii of normandy conquered england killing king harold ii at the battle of hastings . 
in 1066 , duke william ii of normandy conquered england killing king harold ii at the battle of hastings . 
the invading normans and their descendants replaced the anglo-saxons as the ruling class of england . 
it in turn evolved into modern english . 
the normans had a profound effect on irish culture and history after their invasion at bannow bay in 1169 . 
the normans settled mostly in an area in the east of ireland , later known as the pale , and also built many fine castles and settlements , including trim castle and dublin castle . 
the normans had a profound effect on irish culture and history after their invasion at bannow bay in 1169 . 
one of the claimants of the english throne opposing william the conqueror , edgar atheling , eventually fled to scotland . 
king malcolm iii of scotland married edgar 's sister margaret , and came into opposition to william who had already disputed scotland 's southern borders . 
william invaded scotland in 1072 , riding as far as abernethy where he met up with his fleet of ships . 
malcolm submitted , paid homage to william and surrendered his son duncan as a hostage , beginning a series of arguments as to whether the scottish crown owed allegiance to the king of england . 
king david i of scotland , whose elder brother alexander i had married sybilla of normandy , was instrumental in introducing normans and norman culture to scotland , part of the process some scholars call the `` davidian revolution '' . 
king david i of scotland , whose elder brother alexander i had married sybilla of normandy , was instrumental in introducing normans and norman culture to scotland , part of the process some scholars call the `` davidian revolution '' . 
edward the confessor had set up the aforementioned ralph as earl of hereford and charged him with defending the marches and warring with the welsh . 
edward the confessor had set up the aforementioned ralph as earl of hereford and charged him with defending the marches and warring with the welsh . 
edward the confessor had set up the aforementioned ralph as earl of hereford and charged him with defending the marches and warring with the welsh . 
these normans began a long period of slow conquest during which almost all of wales was at some point subject to norman interference . 
in 1018 , roger de tosny travelled to the iberian peninsula to carve out a state for himself from moorish lands , but failed . 
in 1064 , during the war of barbastro , william of montreuil led the papal army and took a huge booty . 
after the successful siege of antioch in 1097 , bohemond began carving out an independent principality around that city . 
in 1096 , crusaders passing by the siege of amalfi were joined by bohemond of taranto and his nephew tancred with an army of italo-normans . 
tancred was instrumental in the conquest of jerusalem and he worked for the expansion of the crusader kingdom in transjordan and the region of galilee . 
the conquest of cyprus by the anglo-norman forces of the third crusade opened a new chapter in the history of the island , which would be under western european domination for the following 380 years . 
but a storm dispersed the fleet . 
after some searching , it was discovered that the boat carrying his sister and his fiancée berengaria was anchored on the south coast of cyprus , together with the wrecks of several other ships , including the treasure ship . 
in april 1191 richard the lion-hearted left messina with a large fleet in order to reach acre . 
survivors of the wrecks had been taken prisoner by the island 's despot isaac komnenos . 
all declared their support for richard provided that he support guy against his rival conrad of montferrat . 
isaac surrendered and was confined with silver chains , because richard had promised that he would not place him in irons . 
various princes of the holy land arrived in limassol at the same time , in particular guy de lusignan . 
while in limassol , richard the lion-heart married berengaria of navarre , first-born daughter of king sancho vi of navarre . 
the wedding was held on 12 may 1191 at the chapel of st. george and it was attended by richard 's sister joan , whom he had brought from sicily . 
among other grand ceremonies was a double coronation : richard caused himself to be crowned king of cyprus , and berengaria queen of england and queen of cyprus as well . 
it was only in 1489 that the venetians acquired full control of the island , which remained a christian stronghold until the fall of famagusta in 1571 . 
shortly after the conquest , cyprus was sold to the knights templar and it was subsequently acquired , in 1192 , by guy de lusignan and became a stable feudal kingdom . 
between 1402 and 1405 , the expedition led by the norman noble jean de bethencourt and the poitevine gadifer de la salle conquered the canarian islands of lanzarote , fuerteventura and el hierro off the atlantic coast of africa . 
bethencourt took the title of king of the canary islands , as vassal to henry iii of castile . 
in 1418 , jean 's nephew maciot de bethencourt sold the rights to the islands to enrique pérez de guzmán , 2nd count de niebla . 
in 1418 , jean 's nephew maciot de bethencourt sold the rights to the islands to enrique pérez de guzmán , 2nd count de niebla . 
the customary law of normandy was developed between the 10th and 13th centuries and survives today through the legal systems of jersey and guernsey in the channel islands . 
norman customary law was transcribed in two customaries in latin by two judges for use by them and their colleagues : these are the très ancien coutumier -lrb- very ancient customary -rrb- , authored between 1200 and 1245 ; and the grand coutumier de normandie -lrb- great customary of normandy , originally summa de legibus normanniae in curia laïcali -rrb- , authored between 1235 and 1245 . 
they spread a unique romanesque idiom to england and italy , and the encastellation of these regions with keeps in their north french style fundamentally altered the military landscape . 
their style was characterised by rounded arches , particularly over windows and doorways , and massive proportions . 
in england , the period of norman architecture immediately succeeds that of the anglo-saxon and precedes the early gothic . 
in england , the period of norman architecture immediately succeeds that of the anglo-saxon and precedes the early gothic . 
in southern italy , the normans incorporated elements of islamic , lombard , and byzantine building techniques into their own , initiating a unique style known as norman-arab architecture within the kingdom of sicily . 
however , in the early 11th century the dukes began a programme of church reform , encouraging the cluniac reform of monasteries and patronising intellectual pursuits , especially the proliferation of scriptoria and the reconstitution of a compilation of lost illuminated manuscripts . 
however , in the early 11th century the dukes began a programme of church reform , encouraging the cluniac reform of monasteries and patronising intellectual pursuits , especially the proliferation of scriptoria and the reconstitution of a compilation of lost illuminated manuscripts . 
the french wars of religion in the 16th century and french revolution in the 18th successively destroyed much of what existed in the way of the architectural and artistic remnant of this norman creativity . 
by far the most famous work of norman art is the bayeux tapestry , which is not a tapestry but a work of embroidery . 
by far the most famous work of norman art is the bayeux tapestry , which is not a tapestry but a work of embroidery . 
it was commissioned by odo , the bishop of bayeux and first earl of kent , employing natives from kent who were learned in the nordic traditions imported in the previous half century by the danish vikings . 
many churches preserve sculptured fonts , capitals , and more importantly mosaics , which were common in norman italy and drew heavily on the greek heritage . 
normandy was the site of several important developments in the history of classical music in the 11th century . 
at fécamp , under two italian abbots , william of volpiano and john of ravenna , the system of denoting notes by letters was developed and taught . 
under the norman abbot robert de grantmesnil , several monks of saint-evroul fled to southern italy , where they were patronised by robert guiscard and established a latin monastery at sant ` eufemia . 
under the norman abbot robert de grantmesnil , several monks of saint-evroul fled to southern italy , where they were patronised by robert guiscard and established a latin monastery at sant ` eufemia . 
under the norman abbot robert de grantmesnil , several monks of saint-evroul fled to southern italy , where they were patronised by robert guiscard and established a latin monastery at sant ` eufemia . 
at saint evroul , a tradition of singing had developed and the choir achieved fame in normandy . 
nikola tesla -lrb- serbian cyrillic : никола тесла ; 10 july 1856 -- 7 january 1943 -rrb- was a serbian american inventor , electrical engineer , mechanical engineer , physicist , and futurist best known for his contributions to the design of the modern alternating current -lrb- ac -rrb- electricity supply system . 
nikola tesla -lrb- serbian cyrillic : никола тесла ; 10 july 1856 -- 7 january 1943 -rrb- was a serbian american inventor , electrical engineer , mechanical engineer , physicist , and futurist best known for his contributions to the design of the modern alternating current -lrb- ac -rrb- electricity supply system . 
nikola tesla -lrb- serbian cyrillic : никола тесла ; 10 july 1856 -- 7 january 1943 -rrb- was a serbian american inventor , electrical engineer , mechanical engineer , physicist , and futurist best known for his contributions to the design of the modern alternating current -lrb- ac -rrb- electricity supply system . 
nikola tesla -lrb- serbian cyrillic : никола тесла ; 10 july 1856 -- 7 january 1943 -rrb- was a serbian american inventor , electrical engineer , mechanical engineer , physicist , and futurist best known for his contributions to the design of the modern alternating current -lrb- ac -rrb- electricity supply system . 
nikola tesla -lrb- serbian cyrillic : никола тесла ; 10 july 1856 -- 7 january 1943 -rrb- was a serbian american inventor , electrical engineer , mechanical engineer , physicist , and futurist best known for his contributions to the design of the modern alternating current -lrb- ac -rrb- electricity supply system . 
nikola tesla -lrb- serbian cyrillic : никола тесла ; 10 july 1856 -- 7 january 1943 -rrb- was a serbian american inventor , electrical engineer , mechanical engineer , physicist , and futurist best known for his contributions to the design of the modern alternating current -lrb- ac -rrb- electricity supply system . 
nikola tesla -lrb- serbian cyrillic : никола тесла ; 10 july 1856 -- 7 january 1943 -rrb- was a serbian american inventor , electrical engineer , mechanical engineer , physicist , and futurist best known for his contributions to the design of the modern alternating current -lrb- ac -rrb- electricity supply system . 
tesla gained experience in telephony and electrical engineering before emigrating to the united states in 1884 to work for thomas edison in new york city . 
tesla gained experience in telephony and electrical engineering before emigrating to the united states in 1884 to work for thomas edison in new york city . 
his patented ac induction motor and transformer were licensed by george westinghouse , who also hired tesla for a short time as a consultant . 
tesla gained experience in telephony and electrical engineering before emigrating to the united states in 1884 to work for thomas edison in new york city . 
his work in the formative years of electric power development was involved in a corporate alternating current/direct current `` war of currents '' as well as various patent battles . 
tesla gained experience in telephony and electrical engineering before emigrating to the united states in 1884 to work for thomas edison in new york city . 
tesla gained experience in telephony and electrical engineering before emigrating to the united states in 1884 to work for thomas edison in new york city . 
tesla gained experience in telephony and electrical engineering before emigrating to the united states in 1884 to work for thomas edison in new york city . 
his patented ac induction motor and transformer were licensed by george westinghouse , who also hired tesla for a short time as a consultant . 
his patented ac induction motor and transformer were licensed by george westinghouse , who also hired tesla for a short time as a consultant . 
tesla went on to pursue his ideas of wireless lighting and electricity distribution in his high-voltage , high-frequency power experiments in new york and colorado springs , and made early -lrb- 1893 -rrb- pronouncements on the possibility of wireless communication with his devices . 
tesla went on to pursue his ideas of wireless lighting and electricity distribution in his high-voltage , high-frequency power experiments in new york and colorado springs , and made early -lrb- 1893 -rrb- pronouncements on the possibility of wireless communication with his devices . 
in his lab he also conducted a range of experiments with mechanical oscillators/generators , electrical discharge tubes , and early x-ray imaging . 
tesla went on to pursue his ideas of wireless lighting and electricity distribution in his high-voltage , high-frequency power experiments in new york and colorado springs , and made early -lrb- 1893 -rrb- pronouncements on the possibility of wireless communication with his devices . 
tesla went on to pursue his ideas of wireless lighting and electricity distribution in his high-voltage , high-frequency power experiments in new york and colorado springs , and made early -lrb- 1893 -rrb- pronouncements on the possibility of wireless communication with his devices . 
he also built a wireless controlled boat , one of the first ever exhibited . 
he tried to put these ideas to practical use in an ill-fated attempt at intercontinental wireless transmission , his unfinished wardenclyffe tower project . 
tesla died on 7 january 1943 . 
his work fell into relative obscurity after his death , but in 1960 the general conference on weights and measures named the si unit of magnetic flux density the tesla in his honor . 
his patents earned him a considerable amount of money , much of which was used to finance his own projects with varying degrees of success. :121,154 he lived most of his life in a series of new york hotels , through his retirement . 
tesla was renowned for his achievements and showmanship , eventually earning him a reputation in popular culture as an archetypal `` mad scientist '' . 
his patents earned him a considerable amount of money , much of which was used to finance his own projects with varying degrees of success. :121,154 he lived most of his life in a series of new york hotels , through his retirement . 
tesla died on 7 january 1943 . 
his work fell into relative obscurity after his death , but in 1960 the general conference on weights and measures named the si unit of magnetic flux density the tesla in his honor . 
there has been a resurgence in popular interest in tesla since the 1990s . 
tesla was renowned for his achievements and showmanship , eventually earning him a reputation in popular culture as an archetypal `` mad scientist '' . 
tesla was born on 10 july -lsb- o.s. 28 june -rsb- 1856 into a serb family in the village of smiljan , austrian empire -lrb- modern-day croatia -rrb- . 
his father , milutin tesla , was a serbian orthodox priest . 
nikola credited his eidetic memory and creative abilities to his mother 's genetics and influence . 
nikola credited his eidetic memory and creative abilities to his mother 's genetics and influence . 
his father , milutin tesla , was a serbian orthodox priest . 
his father , milutin tesla , was a serbian orthodox priest . 
tesla 's mother , đuka tesla -lrb- née mandić -rrb- , whose father was also an orthodox priest , :10 had a talent for making home craft tools , mechanical appliances , and the ability to memorize serbian epic poems . 
tesla 's mother , đuka tesla -lrb- née mandić -rrb- , whose father was also an orthodox priest , :10 had a talent for making home craft tools , mechanical appliances , and the ability to memorize serbian epic poems . 
nikola credited his eidetic memory and creative abilities to his mother 's genetics and influence . 
tesla was the fourth of five children . 
in 1861 , tesla attended the `` lower '' or `` primary '' school in smiljan where he studied german , arithmetic , and religion . 
in 1862 , the tesla family moved to gospić , austrian empire , where tesla 's father worked as a pastor . 
he had an older brother named dane and three sisters , milka , angelina and marica . 
he had an older brother named dane and three sisters , milka , angelina and marica . 
dane was killed in a horse-riding accident when nikola was five . 
in 1862 , the tesla family moved to gospić , austrian empire , where tesla 's father worked as a pastor . 
in 1862 , the tesla family moved to gospić , austrian empire , where tesla 's father worked as a pastor . 
in 1870 , tesla moved to karlovac , to attend school at the higher real gymnasium , where he was profoundly influenced by a math teacher martin sekulić. :32 the classes were held in german , as it was a school within the austro-hungarian military frontier . 
in 1870 , tesla moved to karlovac , to attend school at the higher real gymnasium , where he was profoundly influenced by a math teacher martin sekulić. :32 the classes were held in german , as it was a school within the austro-hungarian military frontier . 
tesla was able to perform integral calculus in his head , which prompted his teachers to believe that he was cheating . 
tesla was able to perform integral calculus in his head , which prompted his teachers to believe that he was cheating . 
he finished a four-year term in three years , graduating in 1873. :33 
in 1870 , tesla moved to karlovac , to attend school at the higher real gymnasium , where he was profoundly influenced by a math teacher martin sekulić. :32 the classes were held in german , as it was a school within the austro-hungarian military frontier . 
in 1870 , tesla moved to karlovac , to attend school at the higher real gymnasium , where he was profoundly influenced by a math teacher martin sekulić. :32 the classes were held in german , as it was a school within the austro-hungarian military frontier . 
in 1870 , tesla moved to karlovac , to attend school at the higher real gymnasium , where he was profoundly influenced by a math teacher martin sekulić. :32 the classes were held in german , as it was a school within the austro-hungarian military frontier . 
in 1870 , tesla moved to karlovac , to attend school at the higher real gymnasium , where he was profoundly influenced by a math teacher martin sekulić. :32 the classes were held in german , as it was a school within the austro-hungarian military frontier . 
he finished a four-year term in three years , graduating in 1873. :33 
shortly after he arrived , tesla contracted cholera ; he was bedridden for nine months and was near death multiple times . 
shortly after he arrived , tesla contracted cholera ; he was bedridden for nine months and was near death multiple times . 
tesla 's father , in a moment of despair , promised to send him to the best engineering school if he recovered from the illness -lrb- his father had originally wanted him to enter the priesthood -rrb- . 
tesla 's father , in a moment of despair , promised to send him to the best engineering school if he recovered from the illness -lrb- his father had originally wanted him to enter the priesthood -rrb- . 
in 1873 , tesla returned to his birthtown , smiljan . 
in 1873 , tesla returned to his birthtown , smiljan . 
shortly after he arrived , tesla contracted cholera ; he was bedridden for nine months and was near death multiple times . 
shortly after he arrived , tesla contracted cholera ; he was bedridden for nine months and was near death multiple times . 
tesla 's father , in a moment of despair , promised to send him to the best engineering school if he recovered from the illness -lrb- his father had originally wanted him to enter the priesthood -rrb- . 
tesla 's father , in a moment of despair , promised to send him to the best engineering school if he recovered from the illness -lrb- his father had originally wanted him to enter the priesthood -rrb- . 
in 1874 , tesla evaded being drafted into the austro-hungarian army in smiljan by running away to tomingaj , near gračac . 
he read many books while in tomingaj , and later said that mark twain 's works had helped him to miraculously recover from his earlier illness . 
there , he explored the mountains in hunter 's garb . 
in 1874 , tesla evaded being drafted into the austro-hungarian army in smiljan by running away to tomingaj , near gračac . 
there , he explored the mountains in hunter 's garb . 
in 1874 , tesla evaded being drafted into the austro-hungarian army in smiljan by running away to tomingaj , near gračac . 
in 1874 , tesla evaded being drafted into the austro-hungarian army in smiljan by running away to tomingaj , near gračac . 
there , he explored the mountains in hunter 's garb . 
he read many books while in tomingaj , and later said that mark twain 's works had helped him to miraculously recover from his earlier illness . 
in 1875 , tesla enrolled at austrian polytechnic in graz , austria , on a military frontier scholarship . 
in 1875 , tesla enrolled at austrian polytechnic in graz , austria , on a military frontier scholarship . 
after his father 's death in 1879 , tesla found a package of letters from his professors to his father , warning that unless he were removed from the school , tesla would be killed through overwork . 
at the end of his second year , tesla lost his scholarship and became addicted to gambling . 
tesla claimed that he worked from 3 a.m. to 11 p.m. , no sundays or holidays excepted . 
in 1875 , tesla enrolled at austrian polytechnic in graz , austria , on a military frontier scholarship . 
in 1875 , tesla enrolled at austrian polytechnic in graz , austria , on a military frontier scholarship . 
after his father 's death in 1879 , tesla found a package of letters from his professors to his father , warning that unless he were removed from the school , tesla would be killed through overwork . 
during his third year , tesla gambled away his allowance and his tuition money , later gambling back his initial losses and returning the balance to his family . 
after his father 's death in 1879 , tesla found a package of letters from his professors to his father , warning that unless he were removed from the school , tesla would be killed through overwork . 
in december 1878 , tesla left graz and severed all relations with his family to hide the fact that he dropped out of school . 
in december 1878 , tesla left graz and severed all relations with his family to hide the fact that he dropped out of school . 
tesla went to maribor -lrb- now in slovenia -rrb- , where he worked as a draftsman for 60 florins a month . 
in march 1879 , milutin tesla went to maribor to beg his son to return home , but nikola refused . 
nikola suffered a nervous breakdown at around the same time . 
in december 1878 , tesla left graz and severed all relations with his family to hide the fact that he dropped out of school . 
in december 1878 , tesla left graz and severed all relations with his family to hide the fact that he dropped out of school . 
his friends thought that he had drowned in the mur river . 
tesla went to maribor -lrb- now in slovenia -rrb- , where he worked as a draftsman for 60 florins a month . 
nikola suffered a nervous breakdown at around the same time . 
on 24 march 1879 , tesla was returned to gospić under police guard for not having a residence permit . 
on 24 march 1879 , tesla was returned to gospić under police guard for not having a residence permit . 
on 17 april 1879 , milutin tesla died at the age of 60 after contracting an unspecified illness -lrb- although some sources say that he died of a stroke -rrb- . 
on 17 april 1879 , milutin tesla died at the age of 60 after contracting an unspecified illness -lrb- although some sources say that he died of a stroke -rrb- . 
during that year , tesla taught a large class of students in his old school , higher real gymnasium , in gospić . 
on 24 march 1879 , tesla was returned to gospić under police guard for not having a residence permit . 
on 24 march 1879 , tesla was returned to gospić under police guard for not having a residence permit . 
during that year , tesla taught a large class of students in his old school , higher real gymnasium , in gospić . 
on 17 april 1879 , milutin tesla died at the age of 60 after contracting an unspecified illness -lrb- although some sources say that he died of a stroke -rrb- . 
in january 1880 , two of tesla 's uncles put together enough money to help him leave gospić for prague where he was to study . 
unfortunately , he arrived too late to enroll at charles-ferdinand university ; he never studied greek , a required subject ; and he was illiterate in czech , another required subject . 
tesla did , however , attend lectures at the university , although , as an auditor , he did not receive grades for the courses . 
unfortunately , he arrived too late to enroll at charles-ferdinand university ; he never studied greek , a required subject ; and he was illiterate in czech , another required subject . 
in january 1880 , two of tesla 's uncles put together enough money to help him leave gospić for prague where he was to study . 
in january 1880 , two of tesla 's uncles put together enough money to help him leave gospić for prague where he was to study . 
unfortunately , he arrived too late to enroll at charles-ferdinand university ; he never studied greek , a required subject ; and he was illiterate in czech , another required subject . 
in january 1880 , two of tesla 's uncles put together enough money to help him leave gospić for prague where he was to study . 
in 1881 , tesla moved to budapest to work under ferenc puskás at a telegraph company , the budapest telephone exchange . 
within a few months , the budapest telephone exchange became functional and tesla was allocated the chief electrician position . 
within a few months , the budapest telephone exchange became functional and tesla was allocated the chief electrician position . 
during his employment , tesla made many improvements to the central station equipment and claimed to have perfected a telephone repeater or amplifier , which was never patented nor publicly described . 
upon arrival , tesla realized that the company , then under construction , was not functional , so he worked as a draftsman in the central telegraph office instead . 
in 1881 , tesla moved to budapest to work under ferenc puskás at a telegraph company , the budapest telephone exchange . 
in 1881 , tesla moved to budapest to work under ferenc puskás at a telegraph company , the budapest telephone exchange . 
in 1881 , tesla moved to budapest to work under ferenc puskás at a telegraph company , the budapest telephone exchange . 
within a few months , the budapest telephone exchange became functional and tesla was allocated the chief electrician position . 
in 1882 , tesla began working for the continental edison company in france , designing and making improvements to electrical equipment . 
in 1882 , tesla began working for the continental edison company in france , designing and making improvements to electrical equipment . 
in june 1884 , he relocated to new york city :57 -- 60 where he was hired by thomas edison to work at his edison machine works on manhattan 's lower east side . 
in june 1884 , he relocated to new york city :57 -- 60 where he was hired by thomas edison to work at his edison machine works on manhattan 's lower east side . 
in june 1884 , he relocated to new york city :57 -- 60 where he was hired by thomas edison to work at his edison machine works on manhattan 's lower east side . 
in 1882 , tesla began working for the continental edison company in france , designing and making improvements to electrical equipment . 
in 1882 , tesla began working for the continental edison company in france , designing and making improvements to electrical equipment . 
in june 1884 , he relocated to new york city :57 -- 60 where he was hired by thomas edison to work at his edison machine works on manhattan 's lower east side . 
in june 1884 , he relocated to new york city :57 -- 60 where he was hired by thomas edison to work at his edison machine works on manhattan 's lower east side . 
in june 1884 , he relocated to new york city :57 -- 60 where he was hired by thomas edison to work at his edison machine works on manhattan 's lower east side . 
according to tesla , edison remarked , `` there 's fifty thousand dollars in it for you -- if you can do it . '' 
:64 instead , edison offered a us$ 10 a week raise over tesla 's us$ 18 per week salary ; tesla refused the offer and immediately resigned . 
after months of work , tesla fulfilled the task and inquired about payment . 
according to tesla , edison remarked , `` there 's fifty thousand dollars in it for you -- if you can do it . '' 
edison , saying that he was only joking , replied , `` tesla , you do n't understand our american humor . '' 
:64 instead , edison offered a us$ 10 a week raise over tesla 's us$ 18 per week salary ; tesla refused the offer and immediately resigned . 
after leaving edison 's company tesla partnered with two businessmen in 1886 , robert lane and benjamin vail , who agreed to finance an electric lighting company in tesla 's name , tesla electric light & manufacturing . 
after leaving edison 's company tesla partnered with two businessmen in 1886 , robert lane and benjamin vail , who agreed to finance an electric lighting company in tesla 's name , tesla electric light & manufacturing . 
the company installed electrical arc light based illumination systems designed by tesla and also had designs for dynamo electric machine commutators , the first patents issued to tesla in the us . 
the company installed electrical arc light based illumination systems designed by tesla and also had designs for dynamo electric machine commutators , the first patents issued to tesla in the us . 
the company installed electrical arc light based illumination systems designed by tesla and also had designs for dynamo electric machine commutators , the first patents issued to tesla in the us . 
after leaving edison 's company tesla partnered with two businessmen in 1886 , robert lane and benjamin vail , who agreed to finance an electric lighting company in tesla 's name , tesla electric light & manufacturing . 
after leaving edison 's company tesla partnered with two businessmen in 1886 , robert lane and benjamin vail , who agreed to finance an electric lighting company in tesla 's name , tesla electric light & manufacturing . 
after leaving edison 's company tesla partnered with two businessmen in 1886 , robert lane and benjamin vail , who agreed to finance an electric lighting company in tesla 's name , tesla electric light & manufacturing . 
the company installed electrical arc light based illumination systems designed by tesla and also had designs for dynamo electric machine commutators , the first patents issued to tesla in the us . 
after leaving edison 's company tesla partnered with two businessmen in 1886 , robert lane and benjamin vail , who agreed to finance an electric lighting company in tesla 's name , tesla electric light & manufacturing . 
they eventually forced tesla out leaving him penniless . 
they eventually forced tesla out leaving him penniless . 
he had to work at various electrical repair jobs and even as a ditch digger for $ 2 per day . 
tesla considered the winter of 1886/1887 as a time of `` terrible headaches and bitter tears . '' 
he even lost control of the patents he had generated since he had assigned them to the company in lieu of stock . 
he had to work at various electrical repair jobs and even as a ditch digger for $ 2 per day . 
he had to work at various electrical repair jobs and even as a ditch digger for $ 2 per day . 
in late 1886 tesla met alfred s. brown , a western union superintendent , and new york attorney charles f. peck . 
together in april 1887 they formed the tesla electric company with an agreement that profits from generated patents would go 1/3 to tesla , 1/3 to peck and brown , and 1/3 to fund development . 
together in april 1887 they formed the tesla electric company with an agreement that profits from generated patents would go 1/3 to tesla , 1/3 to peck and brown , and 1/3 to fund development . 
they set up a laboratory for tesla at 89 liberty street in manhattan where he worked on improving and developing new types of electric motors , generators and other devices . 
in late 1886 tesla met alfred s. brown , a western union superintendent , and new york attorney charles f. peck . 
in late 1886 tesla met alfred s. brown , a western union superintendent , and new york attorney charles f. peck . 
in late 1886 tesla met alfred s. brown , a western union superintendent , and new york attorney charles f. peck . 
they set up a laboratory for tesla at 89 liberty street in manhattan where he worked on improving and developing new types of electric motors , generators and other devices . 
together in april 1887 they formed the tesla electric company with an agreement that profits from generated patents would go 1/3 to tesla , 1/3 to peck and brown , and 1/3 to fund development . 
one of the things tesla developed at that laboratory in 1887 was an induction motor that ran on alternating current , a power system format that was starting to be built in europe and the united states because of its advantages in long-distance , high-voltage transmission . 
this innovative electric motor , patented in may 1888 , was a simple self-starting design that did not need a commutator , thus avoiding sparking and the high maintenance of constantly servicing and replacing mechanical brushes . 
this innovative electric motor , patented in may 1888 , was a simple self-starting design that did not need a commutator , thus avoiding sparking and the high maintenance of constantly servicing and replacing mechanical brushes . 
this innovative electric motor , patented in may 1888 , was a simple self-starting design that did not need a commutator , thus avoiding sparking and the high maintenance of constantly servicing and replacing mechanical brushes . 
this innovative electric motor , patented in may 1888 , was a simple self-starting design that did not need a commutator , thus avoiding sparking and the high maintenance of constantly servicing and replacing mechanical brushes . 
one of the things tesla developed at that laboratory in 1887 was an induction motor that ran on alternating current , a power system format that was starting to be built in europe and the united states because of its advantages in long-distance , high-voltage transmission . 
one of the things tesla developed at that laboratory in 1887 was an induction motor that ran on alternating current , a power system format that was starting to be built in europe and the united states because of its advantages in long-distance , high-voltage transmission . 
this innovative electric motor , patented in may 1888 , was a simple self-starting design that did not need a commutator , thus avoiding sparking and the high maintenance of constantly servicing and replacing mechanical brushes . 
this innovative electric motor , patented in may 1888 , was a simple self-starting design that did not need a commutator , thus avoiding sparking and the high maintenance of constantly servicing and replacing mechanical brushes . 
in 1888 , the editor of electrical world magazine , thomas commerford martin -lrb- a friend and publicist -rrb- , arranged for tesla to demonstrate his alternating current system , including his induction motor , at the american institute of electrical engineers -lrb- now ieee -rrb- . 
in 1888 , the editor of electrical world magazine , thomas commerford martin -lrb- a friend and publicist -rrb- , arranged for tesla to demonstrate his alternating current system , including his induction motor , at the american institute of electrical engineers -lrb- now ieee -rrb- . 
in 1888 , the editor of electrical world magazine , thomas commerford martin -lrb- a friend and publicist -rrb- , arranged for tesla to demonstrate his alternating current system , including his induction motor , at the american institute of electrical engineers -lrb- now ieee -rrb- . 
westinghouse looked into getting a patent on a similar commutator-less , rotating magnetic field-based induction motor presented in a paper in march 1888 by the italian physicist galileo ferraris , but decided tesla 's patent would probably control the market . 
in 1888 , the editor of electrical world magazine , thomas commerford martin -lrb- a friend and publicist -rrb- , arranged for tesla to demonstrate his alternating current system , including his induction motor , at the american institute of electrical engineers -lrb- now ieee -rrb- . 
in 1888 , the editor of electrical world magazine , thomas commerford martin -lrb- a friend and publicist -rrb- , arranged for tesla to demonstrate his alternating current system , including his induction motor , at the american institute of electrical engineers -lrb- now ieee -rrb- . 
engineers working for the westinghouse electric & manufacturing company reported to george westinghouse that tesla had a viable ac motor and related power system -- something for which westinghouse had been trying to secure patents . 
westinghouse looked into getting a patent on a similar commutator-less , rotating magnetic field-based induction motor presented in a paper in march 1888 by the italian physicist galileo ferraris , but decided tesla 's patent would probably control the market . 
westinghouse looked into getting a patent on a similar commutator-less , rotating magnetic field-based induction motor presented in a paper in march 1888 by the italian physicist galileo ferraris , but decided tesla 's patent would probably control the market . 
engineers working for the westinghouse electric & manufacturing company reported to george westinghouse that tesla had a viable ac motor and related power system -- something for which westinghouse had been trying to secure patents . 
in july 1888 , brown and peck negotiated a licensing deal with george westinghouse for tesla 's polyphase induction motor and transformer designs for $ 60,000 in cash and stock and a royalty of $ 2.50 per ac horsepower produced by each motor . 
in july 1888 , brown and peck negotiated a licensing deal with george westinghouse for tesla 's polyphase induction motor and transformer designs for $ 60,000 in cash and stock and a royalty of $ 2.50 per ac horsepower produced by each motor . 
in july 1888 , brown and peck negotiated a licensing deal with george westinghouse for tesla 's polyphase induction motor and transformer designs for $ 60,000 in cash and stock and a royalty of $ 2.50 per ac horsepower produced by each motor . 
westinghouse also hired tesla for one year for the large fee of $ 2,000 -lrb- $ 52,700 in today 's dollars -rrb- per month to be a consultant at the westinghouse electric & manufacturing company 's pittsburgh labs . 
in july 1888 , brown and peck negotiated a licensing deal with george westinghouse for tesla 's polyphase induction motor and transformer designs for $ 60,000 in cash and stock and a royalty of $ 2.50 per ac horsepower produced by each motor . 
in july 1888 , brown and peck negotiated a licensing deal with george westinghouse for tesla 's polyphase induction motor and transformer designs for $ 60,000 in cash and stock and a royalty of $ 2.50 per ac horsepower produced by each motor . 
westinghouse also hired tesla for one year for the large fee of $ 2,000 -lrb- $ 52,700 in today 's dollars -rrb- per month to be a consultant at the westinghouse electric & manufacturing company 's pittsburgh labs . 
westinghouse also hired tesla for one year for the large fee of $ 2,000 -lrb- $ 52,700 in today 's dollars -rrb- per month to be a consultant at the westinghouse electric & manufacturing company 's pittsburgh labs . 
during that year , tesla worked in pittsburgh , helping to create an alternating current system to power the city 's streetcars . 
during that year , tesla worked in pittsburgh , helping to create an alternating current system to power the city 's streetcars . 
between them , they settled on a 60-cycle ac current system tesla proposed -lrb- to match the working frequency of tesla 's motor -rrb- , although they soon found that , since tesla 's induction motor could only run at a constant speed , it would not work for street cars . 
they ended up using a dc traction motor instead . 
during that year , tesla worked in pittsburgh , helping to create an alternating current system to power the city 's streetcars . 
they ended up using a dc traction motor instead . 
tesla 's demonstration of his induction motor and westinghouse 's subsequent licensing of the patent , both in 1888 , put tesla firmly on the `` ac '' side of the so-called `` war of currents , '' an electrical distribution battle being waged between thomas edison and george westinghouse that had been simmering since westinghouse 's first ac system in 1886 and had reached the point of all-out warfare by 1888 . 
this started out as a competition between rival lighting systems with edison holding all the patents for dc and the incandescent light and westinghouse using his own patented ac system to power arc lights as well as incandescent lamps of a slightly different design to get around the edison patent . 
the competition resulted in edison machine works pursuing ac development in 1890 and by 1892 thomas edison was no longer in control of his own company , which was consolidated into the conglomerate general electric and converting to an ac delivery system at that point . 
the competition resulted in edison machine works pursuing ac development in 1890 and by 1892 thomas edison was no longer in control of his own company , which was consolidated into the conglomerate general electric and converting to an ac delivery system at that point . 
tesla 's demonstration of his induction motor and westinghouse 's subsequent licensing of the patent , both in 1888 , put tesla firmly on the `` ac '' side of the so-called `` war of currents , '' an electrical distribution battle being waged between thomas edison and george westinghouse that had been simmering since westinghouse 's first ac system in 1886 and had reached the point of all-out warfare by 1888 . 
tesla 's demonstration of his induction motor and westinghouse 's subsequent licensing of the patent , both in 1888 , put tesla firmly on the `` ac '' side of the so-called `` war of currents , '' an electrical distribution battle being waged between thomas edison and george westinghouse that had been simmering since westinghouse 's first ac system in 1886 and had reached the point of all-out warfare by 1888 . 
tesla 's demonstration of his induction motor and westinghouse 's subsequent licensing of the patent , both in 1888 , put tesla firmly on the `` ac '' side of the so-called `` war of currents , '' an electrical distribution battle being waged between thomas edison and george westinghouse that had been simmering since westinghouse 's first ac system in 1886 and had reached the point of all-out warfare by 1888 . 
the acquisition of a feasible ac motor gave westinghouse a key patent in building a completely integrated ac system , but the financial strain of buying up patents and hiring the engineers needed to build it meant development of tesla 's motor had to be put on hold for a while . 
the competition resulted in edison machine works pursuing ac development in 1890 and by 1892 thomas edison was no longer in control of his own company , which was consolidated into the conglomerate general electric and converting to an ac delivery system at that point . 
in 1893 , george westinghouse won the bid to light the 1893 world 's columbian exposition in chicago with alternating current , beating out a general electric bid by one million dollars . 
in 1893 , george westinghouse won the bid to light the 1893 world 's columbian exposition in chicago with alternating current , beating out a general electric bid by one million dollars . 
in 1893 , george westinghouse won the bid to light the 1893 world 's columbian exposition in chicago with alternating current , beating out a general electric bid by one million dollars . 
at the columbian exposition , under a banner announcing the `` tesla polyphase system '' , tesla demonstrated a series of electrical effects previously performed throughout america and europe , :76 included using high-voltage , high-frequency alternating current to light a wireless gas-discharge lamp. :79 an observer noted : 
at the columbian exposition , under a banner announcing the `` tesla polyphase system '' , tesla demonstrated a series of electrical effects previously performed throughout america and europe , :76 included using high-voltage , high-frequency alternating current to light a wireless gas-discharge lamp. :79 an observer noted : 
in 1893 , george westinghouse won the bid to light the 1893 world 's columbian exposition in chicago with alternating current , beating out a general electric bid by one million dollars . 
in 1893 , george westinghouse won the bid to light the 1893 world 's columbian exposition in chicago with alternating current , beating out a general electric bid by one million dollars . 
in 1893 , george westinghouse won the bid to light the 1893 world 's columbian exposition in chicago with alternating current , beating out a general electric bid by one million dollars . 
it was a key event in the history of ac power , as westinghouse demonstrated the safety , reliability , and efficiency of a fully integrated alternating current system to the american public . 
in 1893 richard dean adams , who headed up the niagara falls cataract construction company sought tesla 's opinion on what system would be best to transmit power generated at the falls . 
in 1893 richard dean adams , who headed up the niagara falls cataract construction company sought tesla 's opinion on what system would be best to transmit power generated at the falls . 
based on tesla 's advice and westinghouse 's demonstration that they could build a complete ac system at the columbian exposition , a contract for building a two-phase ac generating system at the niagara falls was awarded to westinghouse electric . 
a further contract to build the ac distribution system was awarded to general electric . 
tesla advised adams that a two-phased system would be the most reliable and that there was a westinghouse system to light incandescent bulbs using two-phase alternating current . 
in 1893 richard dean adams , who headed up the niagara falls cataract construction company sought tesla 's opinion on what system would be best to transmit power generated at the falls . 
in 1893 richard dean adams , who headed up the niagara falls cataract construction company sought tesla 's opinion on what system would be best to transmit power generated at the falls . 
tesla advised adams that a two-phased system would be the most reliable and that there was a westinghouse system to light incandescent bulbs using two-phase alternating current . 
tesla advised adams that a two-phased system would be the most reliable and that there was a westinghouse system to light incandescent bulbs using two-phase alternating current . 
although a patent-sharing agreement was signed between the two companies in 1896 westinghouse was still cash-strapped from the financial warfare . 
westinghouse convinced tesla to release his company from the licensing agreement over tesla 's ac patents in exchange for westinghouse electric purchasing the patents for a lump sum payment of $ 216,000 ; this provided westinghouse a break from what , due to alternating current 's rapid gain in popularity , had turned out to be an overly generous $ 2.50 per ac horsepower royalty . 
westinghouse convinced tesla to release his company from the licensing agreement over tesla 's ac patents in exchange for westinghouse electric purchasing the patents for a lump sum payment of $ 216,000 ; this provided westinghouse a break from what , due to alternating current 's rapid gain in popularity , had turned out to be an overly generous $ 2.50 per ac horsepower royalty . 
to secure further loans , westinghouse was forced to revisit tesla 's ac patent , which bankers considered a financial strain on the company -lrb- at that point westinghouse had paid out an estimated $ 200,000 in licenses and royalties to tesla , brown , and peck -rrb- . 
the mid 1890s saw the conglomerate general electric , backed by financier j. p. morgan , involved in takeover attempts and patent battles with westinghouse electric . 
to secure further loans , westinghouse was forced to revisit tesla 's ac patent , which bankers considered a financial strain on the company -lrb- at that point westinghouse had paid out an estimated $ 200,000 in licenses and royalties to tesla , brown , and peck -rrb- . 
westinghouse convinced tesla to release his company from the licensing agreement over tesla 's ac patents in exchange for westinghouse electric purchasing the patents for a lump sum payment of $ 216,000 ; this provided westinghouse a break from what , due to alternating current 's rapid gain in popularity , had turned out to be an overly generous $ 2.50 per ac horsepower royalty . 
on 30 july 1891 , at the age of 35 , tesla became a naturalized citizen of the united states , and established his south fifth avenue laboratory , and later another at 46 e. houston street , in new york . 
on 30 july 1891 , at the age of 35 , tesla became a naturalized citizen of the united states , and established his south fifth avenue laboratory , and later another at 46 e. houston street , in new york . 
he lit electric lamps wirelessly at both locations , demonstrating the potential of wireless power transmission . 
in the same year , he patented the tesla coil . 
on 30 july 1891 , at the age of 35 , tesla became a naturalized citizen of the united states , and established his south fifth avenue laboratory , and later another at 46 e. houston street , in new york . 
in the same year , he patented the tesla coil . 
on 30 july 1891 , at the age of 35 , tesla became a naturalized citizen of the united states , and established his south fifth avenue laboratory , and later another at 46 e. houston street , in new york . 
he lit electric lamps wirelessly at both locations , demonstrating the potential of wireless power transmission . 
tesla served as a vice president of the american institute of electrical engineers , the forerunner -lrb- along with the institute of radio engineers -rrb- of the modern-day ieee , from 1892 to 1894 . 
tesla served as a vice president of the american institute of electrical engineers , the forerunner -lrb- along with the institute of radio engineers -rrb- of the modern-day ieee , from 1892 to 1894 . 
tesla served as a vice president of the american institute of electrical engineers , the forerunner -lrb- along with the institute of radio engineers -rrb- of the modern-day ieee , from 1892 to 1894 . 
tesla served as a vice president of the american institute of electrical engineers , the forerunner -lrb- along with the institute of radio engineers -rrb- of the modern-day ieee , from 1892 to 1894 . 
tesla served as a vice president of the american institute of electrical engineers , the forerunner -lrb- along with the institute of radio engineers -rrb- of the modern-day ieee , from 1892 to 1894 . 
tesla served as a vice president of the american institute of electrical engineers , the forerunner -lrb- along with the institute of radio engineers -rrb- of the modern-day ieee , from 1892 to 1894 . 
starting in 1894 , tesla began investigating what he referred to as radiant energy of `` invisible '' kinds after he had noticed damaged film in his laboratory in previous experiments -lrb- later identified as `` roentgen rays '' or `` x-rays '' -rrb- . 
soon after , much of tesla 's early research -- hundreds of invention models , plans , notes , laboratory data , tools , photographs , valued at $ 50,000 -- was lost in the 5th avenue laboratory fire of march 1895 . 
tesla may have inadvertently captured an x-ray image -- predating , by a few weeks , wilhelm röntgen 's december 1895 announcement of the discovery of x-rays -- when he tried to photograph mark twain illuminated by a geissler tube , an earlier type of gas discharge tube . 
the only thing captured in the image was the metal locking screw on the camera lens. :134 
starting in 1894 , tesla began investigating what he referred to as radiant energy of `` invisible '' kinds after he had noticed damaged film in his laboratory in previous experiments -lrb- later identified as `` roentgen rays '' or `` x-rays '' -rrb- . 
starting in 1894 , tesla began investigating what he referred to as radiant energy of `` invisible '' kinds after he had noticed damaged film in his laboratory in previous experiments -lrb- later identified as `` roentgen rays '' or `` x-rays '' -rrb- . 
soon after , much of tesla 's early research -- hundreds of invention models , plans , notes , laboratory data , tools , photographs , valued at $ 50,000 -- was lost in the 5th avenue laboratory fire of march 1895 . 
tesla may have inadvertently captured an x-ray image -- predating , by a few weeks , wilhelm röntgen 's december 1895 announcement of the discovery of x-rays -- when he tried to photograph mark twain illuminated by a geissler tube , an earlier type of gas discharge tube . 
tesla may have inadvertently captured an x-ray image -- predating , by a few weeks , wilhelm röntgen 's december 1895 announcement of the discovery of x-rays -- when he tried to photograph mark twain illuminated by a geissler tube , an earlier type of gas discharge tube . 
in march 1896 , after hearing of wilhelm röntgen 's discovery of x-ray and x-ray imaging -lrb- radiography -rrb- , tesla proceeded to do his own experiments in x-ray imaging , developing a high energy single terminal vacuum tube of his own design that had no target electrode and that worked from the output of the tesla coil -lrb- the modern term for the phenomenon produced by this device is bremsstrahlung or braking radiation -rrb- . 
in march 1896 , after hearing of wilhelm röntgen 's discovery of x-ray and x-ray imaging -lrb- radiography -rrb- , tesla proceeded to do his own experiments in x-ray imaging , developing a high energy single terminal vacuum tube of his own design that had no target electrode and that worked from the output of the tesla coil -lrb- the modern term for the phenomenon produced by this device is bremsstrahlung or braking radiation -rrb- . 
in march 1896 , after hearing of wilhelm röntgen 's discovery of x-ray and x-ray imaging -lrb- radiography -rrb- , tesla proceeded to do his own experiments in x-ray imaging , developing a high energy single terminal vacuum tube of his own design that had no target electrode and that worked from the output of the tesla coil -lrb- the modern term for the phenomenon produced by this device is bremsstrahlung or braking radiation -rrb- . 
in his research , tesla devised several experimental setups to produce x-rays . 
in march 1896 , after hearing of wilhelm röntgen 's discovery of x-ray and x-ray imaging -lrb- radiography -rrb- , tesla proceeded to do his own experiments in x-ray imaging , developing a high energy single terminal vacuum tube of his own design that had no target electrode and that worked from the output of the tesla coil -lrb- the modern term for the phenomenon produced by this device is bremsstrahlung or braking radiation -rrb- . 
in march 1896 , after hearing of wilhelm röntgen 's discovery of x-ray and x-ray imaging -lrb- radiography -rrb- , tesla proceeded to do his own experiments in x-ray imaging , developing a high energy single terminal vacuum tube of his own design that had no target electrode and that worked from the output of the tesla coil -lrb- the modern term for the phenomenon produced by this device is bremsstrahlung or braking radiation -rrb- . 
in march 1896 , after hearing of wilhelm röntgen 's discovery of x-ray and x-ray imaging -lrb- radiography -rrb- , tesla proceeded to do his own experiments in x-ray imaging , developing a high energy single terminal vacuum tube of his own design that had no target electrode and that worked from the output of the tesla coil -lrb- the modern term for the phenomenon produced by this device is bremsstrahlung or braking radiation -rrb- . 
tesla held that , with his circuits , the `` instrument will ... enable one to generate roentgen rays of much greater power than obtainable with ordinary apparatus . '' 
tesla incorrectly believed that x-rays were longitudinal waves , such as those produced in waves in plasmas . 
he believed early on that damage to the skin was not caused by the roentgen rays , but by the ozone generated in contact with the skin , and to a lesser extent , by nitrous acid . 
in his many notes on the early investigation of this phenomenon , he attributed the skin damage to various causes . 
tesla noted the hazards of working with his circuit and single-node x-ray-producing devices . 
these plasma waves can occur in force-free magnetic fields . 
he believed early on that damage to the skin was not caused by the roentgen rays , but by the ozone generated in contact with the skin , and to a lesser extent , by nitrous acid . 
tesla incorrectly believed that x-rays were longitudinal waves , such as those produced in waves in plasmas . 
these plasma waves can occur in force-free magnetic fields . 
in his many notes on the early investigation of this phenomenon , he attributed the skin damage to various causes . 
at the beginning of 1893 westinghouse engineer benjamin lamme had made great progress developing an efficient version of tesla 's induction motor and westinghouse electric started branding their complete polyphase phase ac system as the `` tesla polyphase system '' , noting how they believed tesla 's patents gave them patent priority over other ac systems . 
at the beginning of 1893 westinghouse engineer benjamin lamme had made great progress developing an efficient version of tesla 's induction motor and westinghouse electric started branding their complete polyphase phase ac system as the `` tesla polyphase system '' , noting how they believed tesla 's patents gave them patent priority over other ac systems . 
at the beginning of 1893 westinghouse engineer benjamin lamme had made great progress developing an efficient version of tesla 's induction motor and westinghouse electric started branding their complete polyphase phase ac system as the `` tesla polyphase system '' , noting how they believed tesla 's patents gave them patent priority over other ac systems . 
tesla also explained the principles of the rotating magnetic field in an induction motor by demonstrating how to make a copper egg stand on end using a device he constructed known as the egg of columbus . 
tesla also explained the principles of the rotating magnetic field in an induction motor by demonstrating how to make a copper egg stand on end using a device he constructed known as the egg of columbus . 
on 11 july 1934 , the new york herald tribune published an article on tesla , in which he recalled an event that would occasionally take place while experimenting with his single-electrode vacuum tubes ; a minute particle would break off the cathode , pass out of the tube , and physically strike him . 
on 11 july 1934 , the new york herald tribune published an article on tesla , in which he recalled an event that would occasionally take place while experimenting with his single-electrode vacuum tubes ; a minute particle would break off the cathode , pass out of the tube , and physically strike him . 
`` tesla said he could feel a sharp stinging pain where it entered his body , and again at the place where it passed out . '' 
in comparing these particles with the bits of metal projected by his `` electric gun , '' tesla said , `` the particles in the beam of force ... will travel much faster than such particles ... and they will travel in concentrations . '' 
tesla 's theories on the possibility of the transmission by radio waves go back as far as lectures and demonstrations in 1893 in st. louis , missouri , the franklin institute in philadelphia , pennsylvania , and the national electric light association . 
many devices such as the tesla coil were used in the further development of radio . 
tesla 's theories on the possibility of the transmission by radio waves go back as far as lectures and demonstrations in 1893 in st. louis , missouri , the franklin institute in philadelphia , pennsylvania , and the national electric light association . 
in 1898 , tesla demonstrated a radio-controlled boat -- which he dubbed `` teleautomaton '' -- to the public during an electrical exhibition at madison square garden . 
in 1898 , tesla demonstrated a radio-controlled boat -- which he dubbed `` teleautomaton '' -- to the public during an electrical exhibition at madison square garden . 
in 1898 , tesla demonstrated a radio-controlled boat -- which he dubbed `` teleautomaton '' -- to the public during an electrical exhibition at madison square garden . 
in 1898 , tesla demonstrated a radio-controlled boat -- which he dubbed `` teleautomaton '' -- to the public during an electrical exhibition at madison square garden . 
the crowd that witnessed the demonstration made outrageous claims about the workings of the boat , such as magic , telepathy , and being piloted by a trained monkey hidden inside . 
in 1900 , tesla was granted patents for a `` system of transmitting electrical energy '' and `` an electrical transmitter . '' 
when guglielmo marconi made his famous first-ever transatlantic radio transmission in 1901 , tesla quipped that it was done with 17 tesla patents , though there is little to support this claim . 
when guglielmo marconi made his famous first-ever transatlantic radio transmission in 1901 , tesla quipped that it was done with 17 tesla patents , though there is little to support this claim . 
in 1943 , a supreme court of the united states decision restored the prior patents of tesla , oliver lodge , and john stone . 
in 1943 , a supreme court of the united states decision restored the prior patents of tesla , oliver lodge , and john stone . 
on 17 may 1899 , tesla moved to colorado springs , where he would have room for his high-voltage , high-frequency experiments ; his lab was located near foote ave. and kiowa st. he chose this location because the polyphase alternating current power distribution system had been introduced there and he had associates who were willing to give him all the power he needed without charging for it . 
upon his arrival , he told reporters that he was conducting wireless telegraphy experiments , transmitting signals from pikes peak to paris . 
on 15 june 1899 , tesla performed his first experiments at his colorado springs lab ; he recorded his initial spark length at five inches long , but very thick and noisy . 
on 15 june 1899 , tesla performed his first experiments at his colorado springs lab ; he recorded his initial spark length at five inches long , but very thick and noisy . 
tesla investigated atmospheric electricity , observing lightning signals via his receivers . 
he stated that he observed stationary waves during this time . 
the great distances and the nature of what tesla was detecting from lightning storms confirmed his belief that the earth had a resonant frequency . 
he produced artificial lightning , with discharges consisting of millions of volts and up to 135 feet long . 
he produced artificial lightning , with discharges consisting of millions of volts and up to 135 feet long . 
thunder from the released energy was heard 15 miles away in cripple creek , colorado . 
light bulbs within 100 feet of the lab glowed even when turned off . 
butterflies were electrified , swirling in circles with blue halos of st. elmo 's fire around their wings . 
while experimenting , tesla inadvertently faulted a power station generator , causing a power outage . 
in august 1917 , tesla explained what had happened in the electrical experimenter : `` as an example of what has been done with several hundred kilowatts of high frequency energy liberated , it was found that the dynamos in a power house six miles away were repeatedly burned out , due to the powerful high frequency currents set up in them , and which caused heavy sparks to jump through the windings and destroy the insulation ! '' 
in august 1917 , tesla explained what had happened in the electrical experimenter : `` as an example of what has been done with several hundred kilowatts of high frequency energy liberated , it was found that the dynamos in a power house six miles away were repeatedly burned out , due to the powerful high frequency currents set up in them , and which caused heavy sparks to jump through the windings and destroy the insulation ! '' 
in august 1917 , tesla explained what had happened in the electrical experimenter : `` as an example of what has been done with several hundred kilowatts of high frequency energy liberated , it was found that the dynamos in a power house six miles away were repeatedly burned out , due to the powerful high frequency currents set up in them , and which caused heavy sparks to jump through the windings and destroy the insulation ! '' 
during his time at his lab , tesla observed unusual signals from his receiver which he concluded may be communications from another planet . 
reporters treated it as a sensational story and jumped to the conclusion tesla was hearing signals from mars . 
he expanded on the signals he heard in a 9 february 1901 collier 's weekly article `` talking with planets '' where he said it had not been immediately apparent to him that he was hearing `` intelligently controlled signals '' and that the signals could come from mars , venus , or other planets . 
it has been hypothesized that he may have intercepted marconi 's european experiments in july 1899 -- marconi may have transmitted the letter s -lrb- dot/dot/dot -rrb- in a naval demonstration , the same three impulses that tesla hinted at hearing in colorado -- or signals from another experimenter in wireless transmission . 
it has been hypothesized that he may have intercepted marconi 's european experiments in july 1899 -- marconi may have transmitted the letter s -lrb- dot/dot/dot -rrb- in a naval demonstration , the same three impulses that tesla hinted at hearing in colorado -- or signals from another experimenter in wireless transmission . 
in 1899 , john jacob astor iv invested $ 100,000 for tesla to further develop and produce a new lighting system . 
in 1899 , john jacob astor iv invested $ 100,000 for tesla to further develop and produce a new lighting system . 
instead , tesla used the money to fund his colorado springs experiments . 
in 1899 , john jacob astor iv invested $ 100,000 for tesla to further develop and produce a new lighting system . 
on 7 january 1900 , tesla left colorado springs . 
-lsb- citation needed -rsb- his lab was torn down in 1904 , and its contents were sold two years later to satisfy a debt . 
-lsb- citation needed -rsb- his lab was torn down in 1904 , and its contents were sold two years later to satisfy a debt . 
-lsb- citation needed -rsb- his lab was torn down in 1904 , and its contents were sold two years later to satisfy a debt . 
the colorado experiments had prepared tesla for the establishment of the trans-atlantic wireless telecommunications facility known as wardenclyffe near shoreham , long island . 
the colorado experiments had prepared tesla for the establishment of the trans-atlantic wireless telecommunications facility known as wardenclyffe near shoreham , long island . 
the colorado experiments had prepared tesla for the establishment of the trans-atlantic wireless telecommunications facility known as wardenclyffe near shoreham , long island . 
tesla later approached morgan to ask for more funds to build a more powerful transmitter . 
when asked where all the money had gone , tesla responded by saying that he was affected by the panic of 1901 , which he -lrb- morgan -rrb- had caused . 
morgan was shocked by the reminder of his part in the stock market crash and by tesla 's breach of contract by asking for more funds . 
over the next five years , tesla wrote over 50 letters to morgan , pleading for and demanding additional funding to complete the construction of wardenclyffe . 
over the next five years , tesla wrote over 50 letters to morgan , pleading for and demanding additional funding to complete the construction of wardenclyffe . 
in december 1901 , marconi successfully transmitted the letter s from england to newfoundland , terminating tesla 's relationship with morgan . 
the tower was erected to its full 187 feet -lrb- 57 m -rrb- . 
on his 50th birthday in 1906 , tesla demonstrated his 200 horsepower -lrb- 150 kilowatts -rrb- 16,000 rpm bladeless turbine . 
on his 50th birthday in 1906 , tesla demonstrated his 200 horsepower -lrb- 150 kilowatts -rrb- 16,000 rpm bladeless turbine . 
on his 50th birthday in 1906 , tesla demonstrated his 200 horsepower -lrb- 150 kilowatts -rrb- 16,000 rpm bladeless turbine . 
during 1910 -- 1911 at the waterside power station in new york , several of his bladeless turbine engines were tested at 100 -- 5,000 hp . 
tesla invented a steam-powered mechanical oscillator -- tesla 's oscillator . 
while experimenting with mechanical oscillators at his houston street lab , tesla allegedly generated a resonance of several buildings . 
as the speed grew , it is said that the machine oscillated at the resonance frequency of his own building and , belatedly realizing the danger , he was forced to use a sledge hammer to terminate the experiment , just as the police arrived. :162 -- 164 in february 1912 , an article -- `` nikola tesla , dreamer '' by allan l. benson -- was published in world today , in which an artist 's illustration appears showing the entire earth cracking in half with the caption , `` tesla claims that in a few weeks he could set the earth 's crust into such a state of vibration that it would rise and fall hundreds of feet and practically destroy civilization . 
as the speed grew , it is said that the machine oscillated at the resonance frequency of his own building and , belatedly realizing the danger , he was forced to use a sledge hammer to terminate the experiment , just as the police arrived. :162 -- 164 in february 1912 , an article -- `` nikola tesla , dreamer '' by allan l. benson -- was published in world today , in which an artist 's illustration appears showing the entire earth cracking in half with the caption , `` tesla claims that in a few weeks he could set the earth 's crust into such a state of vibration that it would rise and fall hundreds of feet and practically destroy civilization . 
a continuation of this process would , he says , eventually split the earth in two . '' 
tesla theorized that the application of electricity to the brain enhanced intelligence . 
in 1912 , he crafted `` a plan to make dull students bright by saturating them unconsciously with electricity , '' wiring the walls of a schoolroom and , `` saturating -lsb- the schoolroom -rsb- with infinitesimal electric waves vibrating at high frequency . 
the plan was , at least provisionally approved by then superintendent of new york city schools , william h. maxwell . 
the plan was , at least provisionally approved by then superintendent of new york city schools , william h. maxwell . 
before world war i , tesla sought overseas investors . 
after the war started , tesla lost the funding he was receiving from his patents in european countries . 
eventually , he sold wardenclyffe for $ 20,000 -lrb- $ 472,500 in today 's dollars -rrb- . 
eventually , he sold wardenclyffe for $ 20,000 -lrb- $ 472,500 in today 's dollars -rrb- . 
in 1917 , around the time that the wardenclyffe tower was demolished by boldt to make the land a more viable real estate asset , tesla received aiee 's highest honor , the edison medal . 
in the august 1917 edition of the magazine electrical experimenter tesla postulated that electricity could be used to locate submarines via using the reflection of an `` electric ray '' of `` tremendous frequency , '' with the signal being viewed on a fluorescent screen -lrb- a system that has been noted to have a superficial resemblance to modern radar -rrb- . 
in the august 1917 edition of the magazine electrical experimenter tesla postulated that electricity could be used to locate submarines via using the reflection of an `` electric ray '' of `` tremendous frequency , '' with the signal being viewed on a fluorescent screen -lrb- a system that has been noted to have a superficial resemblance to modern radar -rrb- . 
tesla was incorrect in his assumption that high frequency radio waves would penetrate water but émile girardeau , who helped develop france 's first radar system in the 1930s , noted in 1953 that tesla 's general speculation that a very strong high frequency signal would be needed was correct stating '' -lrb- tesla -rrb- was prophesying or dreaming , since he had at his disposal no means of carrying them out , but one must add that if he was dreaming , at least he was dreaming correctly . '' 
tesla was incorrect in his assumption that high frequency radio waves would penetrate water but émile girardeau , who helped develop france 's first radar system in the 1930s , noted in 1953 that tesla 's general speculation that a very strong high frequency signal would be needed was correct stating '' -lrb- tesla -rrb- was prophesying or dreaming , since he had at his disposal no means of carrying them out , but one must add that if he was dreaming , at least he was dreaming correctly . '' 
on 6 november 1915 , a reuters news agency report from london had the 1915 nobel prize in physics awarded to thomas edison and nikola tesla ; however , on 15 november , a reuters story from stockholm stated the prize that year was being awarded to sir william henry bragg and william lawrence bragg `` for their services in the analysis of crystal structure by means of x-rays . '' 
on 6 november 1915 , a reuters news agency report from london had the 1915 nobel prize in physics awarded to thomas edison and nikola tesla ; however , on 15 november , a reuters story from stockholm stated the prize that year was being awarded to sir william henry bragg and william lawrence bragg `` for their services in the analysis of crystal structure by means of x-rays . '' 
:245 there were unsubstantiated rumors at the time that tesla and/or edison had refused the prize. :245 the nobel foundation said , `` any rumor that a person has not been given a nobel prize because he has made known his intention to refuse the reward is ridiculous '' ; a recipient could only decline a nobel prize after he is announced a winner. :245 
:245 there were unsubstantiated rumors at the time that tesla and/or edison had refused the prize. :245 the nobel foundation said , `` any rumor that a person has not been given a nobel prize because he has made known his intention to refuse the reward is ridiculous '' ; a recipient could only decline a nobel prize after he is announced a winner. :245 
there have been subsequent claims by tesla biographers that edison and tesla were the original recipients and that neither was given the award because of their animosity toward each other ; that each sought to minimize the other 's achievements and right to win the award ; that both refused ever to accept the award if the other received it first ; that both rejected any possibility of sharing it ; and even that a wealthy edison refused it to keep tesla from getting the $ 20,000 prize money. :245 
in the years after these rumors , neither tesla nor edison won the prize -lrb- although edison did receive one of 38 possible bids in 1915 and tesla did receive one of 38 possible bids in 1937 -rrb- . 
in the years after these rumors , neither tesla nor edison won the prize -lrb- although edison did receive one of 38 possible bids in 1915 and tesla did receive one of 38 possible bids in 1937 -rrb- . 
in the years after these rumors , neither tesla nor edison won the prize -lrb- although edison did receive one of 38 possible bids in 1915 and tesla did receive one of 38 possible bids in 1937 -rrb- . 
in 1928 , tesla received his last patent , u.s. patent 1,655,114 , for a biplane capable of taking off vertically -lrb- vtol aircraft -rrb- and then be `` gradually tilted through manipulation of the elevator devices '' in flight until it was flying like a conventional plane . 
in 1928 , tesla received his last patent , u.s. patent 1,655,114 , for a biplane capable of taking off vertically -lrb- vtol aircraft -rrb- and then be `` gradually tilted through manipulation of the elevator devices '' in flight until it was flying like a conventional plane . 
tesla thought the plane would sell for less than $ 1,000 . 
:251 although the aircraft was probably impractical , it may be the earliest known design for what became the tiltrotor/tilt-wing concept as well as the earliest proposal for the use of turbine engines in rotor aircraft . 
starting in 1934 , the westinghouse electric & manufacturing company began paying tesla $ 125 per month as well as paying his rent at the hotel new yorker , expenses the company would pay for the rest of tesla 's life . 
starting in 1934 , the westinghouse electric & manufacturing company began paying tesla $ 125 per month as well as paying his rent at the hotel new yorker , expenses the company would pay for the rest of tesla 's life . 
starting in 1934 , the westinghouse electric & manufacturing company began paying tesla $ 125 per month as well as paying his rent at the hotel new yorker , expenses the company would pay for the rest of tesla 's life . 
several sources say westinghouse was worried about potential bad publicity surrounding the impoverished conditions their former star inventor was living under . 
in 1935 , in an annual birthday celebration interview , tesla announced a method of transmitting mechanical energy with minimal loss over any terrestrial distance , a related new means of communication , and a method of accurately determining the location of underground mineral deposits . 
in 1935 , in an annual birthday celebration interview , tesla announced a method of transmitting mechanical energy with minimal loss over any terrestrial distance , a related new means of communication , and a method of accurately determining the location of underground mineral deposits . 
in 1935 , in an annual birthday celebration interview , tesla announced a method of transmitting mechanical energy with minimal loss over any terrestrial distance , a related new means of communication , and a method of accurately determining the location of underground mineral deposits . 
in 1935 , in an annual birthday celebration interview , tesla announced a method of transmitting mechanical energy with minimal loss over any terrestrial distance , a related new means of communication , and a method of accurately determining the location of underground mineral deposits . 
in 1935 , in an annual birthday celebration interview , tesla announced a method of transmitting mechanical energy with minimal loss over any terrestrial distance , a related new means of communication , and a method of accurately determining the location of underground mineral deposits . 
in the fall of 1937 , after midnight one night , tesla left the hotel new yorker to make his regular commute to the cathedral and the library to feed the pigeons . 
tesla 's back was severely wrenched and three of his ribs were broken in the accident -lrb- the full extent of his injuries will never be known ; tesla refused to consult a doctor -- an almost lifelong custom -rrb- . 
tesla 's back was severely wrenched and three of his ribs were broken in the accident -lrb- the full extent of his injuries will never be known ; tesla refused to consult a doctor -- an almost lifelong custom -rrb- . 
in early 1938 , tesla was able to get up . 
in the fall of 1937 , after midnight one night , tesla left the hotel new yorker to make his regular commute to the cathedral and the library to feed the pigeons . 
later in life , tesla made claims concerning a `` teleforce '' weapon after studying the van de graaff generator . 
later in life , tesla made claims concerning a `` teleforce '' weapon after studying the van de graaff generator . 
tesla described the weapon as capable of being used against ground-based infantry or for anti-aircraft purposes . 
tesla described the weapon as capable of being used against ground-based infantry or for anti-aircraft purposes . 
the press variably referred to it as a `` peace ray '' or death ray . 
in 1937 , at a luncheon in his honor concerning the death ray , tesla stated , `` but it is not an experiment ... i have built , demonstrated and used it . 
in 1937 , at a luncheon in his honor concerning the death ray , tesla stated , `` but it is not an experiment ... i have built , demonstrated and used it . 
his records indicate that the device is based on a narrow stream of small tungsten pellets that are accelerated via high voltage -lrb- by means akin to his magnifying transformer -rrb- . 
his records indicate that the device is based on a narrow stream of small tungsten pellets that are accelerated via high voltage -lrb- by means akin to his magnifying transformer -rrb- . 
only a little time will pass before i can give it to the world . '' 
during the same year , tesla wrote a treatise , the art of projecting concentrated non-dispersive energy through the natural media , concerning charged particle beam weapons . 
this treatise is currently in the nikola tesla museum archive in belgrade . 
this treatise is currently in the nikola tesla museum archive in belgrade . 
it describes an open-ended vacuum tube with a gas jet seal that allows particles to exit , a method of charging particles to millions of volts , and a method of creating and directing non-dispersive particle streams -lrb- through electrostatic repulsion -rrb- . 
tesla published the document in an attempt to expound on the technical description of a `` superweapon that would put an end to all war . '' 
during the period in which the negotiations were being conducted , tesla said that efforts had been made to steal the invention . 
he said that there was no danger that his invention could be stolen , for he had at no time committed any part of it to paper ; the blueprint for the teleforce weapon was all in his mind . 
his room had been entered and his papers had been scrutinized , but the thieves , or spies , left empty-handed . 
on 7 january 1943 , at the age of 86 , tesla died alone in room 3327 of the new yorker hotel . 
on 7 january 1943 , at the age of 86 , tesla died alone in room 3327 of the new yorker hotel . 
his body was later found by maid alice monaghan after she had entered tesla 's room , ignoring the `` do not disturb '' sign that tesla had placed on his door two days earlier . 
his body was later found by maid alice monaghan after she had entered tesla 's room , ignoring the `` do not disturb '' sign that tesla had placed on his door two days earlier . 
assistant medical examiner h.w. wembly examined the body and ruled that the cause of death had been coronary thrombosis . 
two days later , the fbi ordered the alien property custodian to seize tesla 's belongings , even though tesla was an american citizen . 
john g. trump , a professor at m.i.t. and a well-known electrical engineer serving as a technical aide to the national defense research committee , was called in to analyze the tesla items in oap custody . 
after a three-day investigation , trump 's report concluded that there was nothing which would constitute a hazard in unfriendly hands , stating : 
tesla 's entire estate from the hotel new yorker and other new york city hotels was transported to the manhattan storage and warehouse company under the office of alien property -lrb- oap -rrb- seal . 
on 10 january 1943 , new york city mayor fiorello la guardia read a eulogy written by slovene-american author louis adamic live over the wnyc radio while violin pieces `` ave maria '' and `` tamo daleko '' were played in the background . 
on 10 january 1943 , new york city mayor fiorello la guardia read a eulogy written by slovene-american author louis adamic live over the wnyc radio while violin pieces `` ave maria '' and `` tamo daleko '' were played in the background . 
on 12 january , two thousand people attended a state funeral for tesla at the cathedral of saint john the divine . 
on 12 january , two thousand people attended a state funeral for tesla at the cathedral of saint john the divine . 
on 12 january , two thousand people attended a state funeral for tesla at the cathedral of saint john the divine . 
in 1952 , following pressure from tesla 's nephew , sava kosanović , tesla 's entire estate was shipped to belgrade in 80 trunks marked n.t. . 
in 1952 , following pressure from tesla 's nephew , sava kosanović , tesla 's entire estate was shipped to belgrade in 80 trunks marked n.t. . 
in 1957 , kosanović 's secretary charlotte muzar transported tesla 's ashes from the united states to belgrade . 
in 1952 , following pressure from tesla 's nephew , sava kosanović , tesla 's entire estate was shipped to belgrade in 80 trunks marked n.t. . 
the ashes are displayed in a gold-plated sphere on a marble pedestal in the nikola tesla museum . 
tesla obtained around 300 patents worldwide for his inventions . 
there are a minimum of 278 patents issued to tesla in 26 countries that have been accounted for . 
many of tesla 's patents were in the united states , britain , and canada , but many other patents were approved in countries around the globe. :62 many inventions developed by tesla were not put into patent protection . 
some of tesla 's patents are not accounted for , and various sources have discovered some that have lain hidden in patent archives . 
tesla worked every day from 9:00 a.m. until 6:00 p.m. or later , with dinner from exactly 8:10 p.m. , at delmonico 's restaurant and later the waldorf-astoria hotel . 
tesla worked every day from 9:00 a.m. until 6:00 p.m. or later , with dinner from exactly 8:10 p.m. , at delmonico 's restaurant and later the waldorf-astoria hotel . 
tesla would then resume his work , often until 3:00 a.m. '' :283 , 286 
tesla would telephone his dinner order to the headwaiter , who also could be the only one to serve him . 
for exercise , tesla walked between 8 to 10 miles per day . 
for exercise , tesla walked between 8 to 10 miles per day . 
he squished his toes one hundred times for each foot every night , saying that it stimulated his brain cells . 
he squished his toes one hundred times for each foot every night , saying that it stimulated his brain cells . 
in an interview with newspaper editor arthur brisbane , tesla said that he did not believe in telepathy , stating , `` suppose i made up my mind to murder you , '' he said , `` in a second you would know it . 
in an interview with newspaper editor arthur brisbane , tesla said that he did not believe in telepathy , stating , `` suppose i made up my mind to murder you , '' he said , `` in a second you would know it . 
in the same interview , tesla said that he believed that all fundamental laws could be reduced to one . 
near the end of his life , tesla walked to the park every day to feed the pigeons and even brought injured ones into his hotel room to nurse back to health . 
tesla spent over $ 2,000 , including building a device that comfortably supported her so her bones could heal , to fix her broken wing and leg . 
tesla spent over $ 2,000 , including building a device that comfortably supported her so her bones could heal , to fix her broken wing and leg . 
near the end of his life , tesla walked to the park every day to feed the pigeons and even brought injured ones into his hotel room to nurse back to health . 
near the end of his life , tesla walked to the park every day to feed the pigeons and even brought injured ones into his hotel room to nurse back to health . 
tesla was 6 feet 2 inches -lrb- 1.88 m -rrb- tall and weighed 142 pounds -lrb- 64 kg -rrb- , with almost no weight variance from 1888 to about 1926. :292 he was an elegant , stylish figure in new york city , meticulous in his grooming , clothing , and regimented in his daily activities . 
tesla was 6 feet 2 inches -lrb- 1.88 m -rrb- tall and weighed 142 pounds -lrb- 64 kg -rrb- , with almost no weight variance from 1888 to about 1926. :292 he was an elegant , stylish figure in new york city , meticulous in his grooming , clothing , and regimented in his daily activities . 
tesla was 6 feet 2 inches -lrb- 1.88 m -rrb- tall and weighed 142 pounds -lrb- 64 kg -rrb- , with almost no weight variance from 1888 to about 1926. :292 he was an elegant , stylish figure in new york city , meticulous in his grooming , clothing , and regimented in his daily activities . 
tesla was 6 feet 2 inches -lrb- 1.88 m -rrb- tall and weighed 142 pounds -lrb- 64 kg -rrb- , with almost no weight variance from 1888 to about 1926. :292 he was an elegant , stylish figure in new york city , meticulous in his grooming , clothing , and regimented in his daily activities . 
tesla read many works , memorizing complete books , and supposedly possessed a photographic memory. :33 he was a polyglot , speaking eight languages : serbo-croatian , czech , english , french , german , hungarian , italian , and latin. :282 tesla related in his autobiography that he experienced detailed moments of inspiration . 
he suffered a peculiar affliction in which blinding flashes of light would appear before his eyes , often accompanied by visions. :33 often , the visions were linked to a word or idea he might have come across ; at other times they would provide the solution to a particular problem he had encountered . 
just by hearing the name of an item , he would be able to envision it in realistic detail. :33 tesla would visualize an invention in his mind with extreme precision , including all dimensions , before moving to the construction stage , a technique sometimes known as picture thinking . 
he suffered a peculiar affliction in which blinding flashes of light would appear before his eyes , often accompanied by visions. :33 often , the visions were linked to a word or idea he might have come across ; at other times they would provide the solution to a particular problem he had encountered . 
tesla read many works , memorizing complete books , and supposedly possessed a photographic memory. :33 he was a polyglot , speaking eight languages : serbo-croatian , czech , english , french , german , hungarian , italian , and latin. :282 tesla related in his autobiography that he experienced detailed moments of inspiration . 
during his second year of study at graz , tesla developed a passion for -lrb- and became very proficient at -rrb- billiards , chess and card-playing , sometimes spending more than 48 hours in a stretch at a gaming table. :43 , 301 on one occasion at his laboratory , tesla worked for a period of 84 hours without sleep or rest. :208 kenneth swezey , a journalist whom tesla had befriended , confirmed that tesla rarely slept . 
during his second year of study at graz , tesla developed a passion for -lrb- and became very proficient at -rrb- billiards , chess and card-playing , sometimes spending more than 48 hours in a stretch at a gaming table. :43 , 301 on one occasion at his laboratory , tesla worked for a period of 84 hours without sleep or rest. :208 kenneth swezey , a journalist whom tesla had befriended , confirmed that tesla rarely slept . 
during his second year of study at graz , tesla developed a passion for -lrb- and became very proficient at -rrb- billiards , chess and card-playing , sometimes spending more than 48 hours in a stretch at a gaming table. :43 , 301 on one occasion at his laboratory , tesla worked for a period of 84 hours without sleep or rest. :208 kenneth swezey , a journalist whom tesla had befriended , confirmed that tesla rarely slept . 
during his second year of study at graz , tesla developed a passion for -lrb- and became very proficient at -rrb- billiards , chess and card-playing , sometimes spending more than 48 hours in a stretch at a gaming table. :43 , 301 on one occasion at his laboratory , tesla worked for a period of 84 hours without sleep or rest. :208 kenneth swezey , a journalist whom tesla had befriended , confirmed that tesla rarely slept . 
during his second year of study at graz , tesla developed a passion for -lrb- and became very proficient at -rrb- billiards , chess and card-playing , sometimes spending more than 48 hours in a stretch at a gaming table. :43 , 301 on one occasion at his laboratory , tesla worked for a period of 84 hours without sleep or rest. :208 kenneth swezey , a journalist whom tesla had befriended , confirmed that tesla rarely slept . 
tesla never married ; he said his chastity was very helpful to his scientific abilities. :33 however , toward the end of his life , he told a reporter , `` sometimes i feel that by not marrying , i made too great a sacrifice to my work ... '' there have been numerous accounts of women vying for tesla 's affection , even some madly in love with him . 
tesla never married ; he said his chastity was very helpful to his scientific abilities. :33 however , toward the end of his life , he told a reporter , `` sometimes i feel that by not marrying , i made too great a sacrifice to my work ... '' there have been numerous accounts of women vying for tesla 's affection , even some madly in love with him . 
tesla never married ; he said his chastity was very helpful to his scientific abilities. :33 however , toward the end of his life , he told a reporter , `` sometimes i feel that by not marrying , i made too great a sacrifice to my work ... '' there have been numerous accounts of women vying for tesla 's affection , even some madly in love with him . 
his loyal secretary , dorothy skerrit , wrote : `` his genial smile and nobility of bearing always denoted the gentlemanly characteristics that were so ingrained in his soul . '' 
robert underwood johnson described him as attaining a `` distinguished sweetness , sincerity , modesty , refinement , generosity , and force . '' 
tesla was asocial and prone to seclude himself with his work . 
tesla was asocial and prone to seclude himself with his work . 
tesla 's friend , julian hawthorne , wrote , `` seldom did one meet a scientist or engineer who was also a poet , a philosopher , an appreciator of fine music , a linguist , and a connoisseur of food and drink . '' 
in middle age , tesla became a close friend of mark twain ; they spent a lot of time together in his lab and elsewhere . 
in middle age , tesla became a close friend of mark twain ; they spent a lot of time together in his lab and elsewhere . 
in the late 1920s , tesla also befriended george sylvester viereck , a poet , writer , mystic , and later , a nazi propagandist . 
tesla could be harsh at times and openly expressed disgust for overweight people , such as when he fired a secretary because of her weight. :110 he was quick to criticize clothing ; on several occasions , tesla directed a subordinate to go home and change her dress. :33 
tesla could be harsh at times and openly expressed disgust for overweight people , such as when he fired a secretary because of her weight. :110 he was quick to criticize clothing ; on several occasions , tesla directed a subordinate to go home and change her dress. :33 
tesla could be harsh at times and openly expressed disgust for overweight people , such as when he fired a secretary because of her weight. :110 he was quick to criticize clothing ; on several occasions , tesla directed a subordinate to go home and change her dress. :33 
tesla could be harsh at times and openly expressed disgust for overweight people , such as when he fired a secretary because of her weight. :110 he was quick to criticize clothing ; on several occasions , tesla directed a subordinate to go home and change her dress. :33 
tesla exhibited a pre-atomic understanding of physics in his writings ; he disagreed with the theory of atoms being composed of smaller subatomic particles , stating there was no such thing as an electron creating an electric charge -lrb- he believed that if electrons existed at all , they were some fourth state of matter or `` sub-atom '' that could only exist in an experimental vacuum and that they had nothing to do with electricity -rrb- . 
he was a believer in the 19th century concept of an all pervasive `` ether '' that transmitted electrical energy . 
he was a believer in the 19th century concept of an all pervasive `` ether '' that transmitted electrical energy . 
he was a believer in the 19th century concept of an all pervasive `` ether '' that transmitted electrical energy . 
tesla was generally antagonistic towards theories about the conversion of matter into energy. :247 he was also critical of einstein 's theory of relativity , saying : 
tesla was generally antagonistic towards theories about the conversion of matter into energy. :247 he was also critical of einstein 's theory of relativity , saying : 
tesla was generally antagonistic towards theories about the conversion of matter into energy. :247 he was also critical of einstein 's theory of relativity , saying : 
tesla claimed to have developed his own physical principle regarding matter and energy that he started working on in 1892 , and in 1937 , at age 81 , claimed in a letter to have completed a `` dynamic theory of gravity '' that '' -lsb- would -rsb- put an end to idle speculations and false conceptions , as that of curved space . '' 
tesla claimed to have developed his own physical principle regarding matter and energy that he started working on in 1892 , and in 1937 , at age 81 , claimed in a letter to have completed a `` dynamic theory of gravity '' that '' -lsb- would -rsb- put an end to idle speculations and false conceptions , as that of curved space . '' 
tesla claimed to have developed his own physical principle regarding matter and energy that he started working on in 1892 , and in 1937 , at age 81 , claimed in a letter to have completed a `` dynamic theory of gravity '' that '' -lsb- would -rsb- put an end to idle speculations and false conceptions , as that of curved space . '' 
tesla claimed to have developed his own physical principle regarding matter and energy that he started working on in 1892 , and in 1937 , at age 81 , claimed in a letter to have completed a `` dynamic theory of gravity '' that '' -lsb- would -rsb- put an end to idle speculations and false conceptions , as that of curved space . '' 
tesla , like many of his era , became a proponent of an imposed selective breeding version of eugenics . 
his opinion stemmed from the belief that humans ' `` pity '' had interfered with the natural `` ruthless workings of nature , '' rather than from conceptions of a `` master race '' or inherent superiority of one person over another . 
his opinion stemmed from the belief that humans ' `` pity '' had interfered with the natural `` ruthless workings of nature , '' rather than from conceptions of a `` master race '' or inherent superiority of one person over another . 
in a 1937 interview , he stated : 
in 1926 , tesla commented on the ills of the social subservience of women and the struggle of women toward gender equality , and indicated that humanity 's future would be run by `` queen bees . '' 
in 1926 , tesla commented on the ills of the social subservience of women and the struggle of women toward gender equality , and indicated that humanity 's future would be run by `` queen bees . '' 
in 1926 , tesla commented on the ills of the social subservience of women and the struggle of women toward gender equality , and indicated that humanity 's future would be run by `` queen bees . '' 
tesla made predictions about the relevant issues of a post-world war i environment in a printed article , `` science and discovery are the great forces which will lead to the consummation of the war '' -lrb- 20 december 1914 -rrb- . 
tesla made predictions about the relevant issues of a post-world war i environment in a printed article , `` science and discovery are the great forces which will lead to the consummation of the war '' -lrb- 20 december 1914 -rrb- . 
tesla made predictions about the relevant issues of a post-world war i environment in a printed article , `` science and discovery are the great forces which will lead to the consummation of the war '' -lrb- 20 december 1914 -rrb- . 
tesla believed that the league of nations was not a remedy for the times and issues . 
tesla was raised an orthodox christian . 
later in his life , he did not consider himself to be a `` believer in the orthodox sense , '' and opposed religious fanaticism . 
despite this , he had a profound respect for both buddhism and christianity . 
for example , in his article , `` a machine to end war '' , published in 1937 , tesla stated : 
however , his religious views remain uncertain due to other statements that he made . 
for example , in his article , `` a machine to end war '' , published in 1937 , tesla stated : 
tesla wrote a number of books and articles for magazines and journals . 
tesla wrote a number of books and articles for magazines and journals . 
among his books are my inventions : the autobiography of nikola tesla , compiled and edited by ben johnston ; the fantastic inventions of nikola tesla , compiled and edited by david hatcher childress ; and the tesla papers . 
many of tesla 's writings are freely available on the web , including the article `` the problem of increasing human energy , '' published in the century magazine in 1900 , and the article `` experiments with alternate currents of high potential and high frequency , '' published in his book inventions , researches and writings of nikola tesla . 
many of tesla 's writings are freely available on the web , including the article `` the problem of increasing human energy , '' published in the century magazine in 1900 , and the article `` experiments with alternate currents of high potential and high frequency , '' published in his book inventions , researches and writings of nikola tesla . 
many of tesla 's writings are freely available on the web , including the article `` the problem of increasing human energy , '' published in the century magazine in 1900 , and the article `` experiments with alternate currents of high potential and high frequency , '' published in his book inventions , researches and writings of nikola tesla . 
the impact of the technologies invented or envisioned by tesla is a recurring theme in several types of science fiction . 
tesla 's legacy has endured in books , films , radio , tv , music , live theater , comics and video games . 
the impact of the technologies invented or envisioned by tesla is a recurring theme in several types of science fiction . 
on tesla 's 75th birthday in 1931 , time magazine put him on its cover . 
on tesla 's 75th birthday in 1931 , time magazine put him on its cover . 
the cover caption `` all the world 's his power house '' noted his contribution to electrical power generation . 
he received congratulatory letters from more than 70 pioneers in science and engineering , including albert einstein . 
he received congratulatory letters from more than 70 pioneers in science and engineering , including albert einstein . 
computational complexity theory is a branch of the theory of computation in theoretical computer science that focuses on classifying computational problems according to their inherent difficulty , and relating those classes to each other . 
computational complexity theory is a branch of the theory of computation in theoretical computer science that focuses on classifying computational problems according to their inherent difficulty , and relating those classes to each other . 
computational complexity theory is a branch of the theory of computation in theoretical computer science that focuses on classifying computational problems according to their inherent difficulty , and relating those classes to each other . 
a problem is regarded as inherently difficult if its solution requires significant resources , whatever the algorithm used . 
the theory formalizes this intuition , by introducing mathematical models of computation to study these problems and quantifying the amount of resources needed to solve them , such as time and storage . 
the theory formalizes this intuition , by introducing mathematical models of computation to study these problems and quantifying the amount of resources needed to solve them , such as time and storage . 
other complexity measures are also used , such as the amount of communication -lrb- used in communication complexity -rrb- , the number of gates in a circuit -lrb- used in circuit complexity -rrb- and the number of processors -lrb- used in parallel computing -rrb- . 
one of the roles of computational complexity theory is to determine the practical limits on what computers can and can not do . 
closely related fields in theoretical computer science are analysis of algorithms and computability theory . 
closely related fields in theoretical computer science are analysis of algorithms and computability theory . 
a key distinction between analysis of algorithms and computational complexity theory is that the former is devoted to analyzing the amount of resources needed by a particular algorithm to solve a problem , whereas the latter asks a more general question about all possible algorithms that could be used to solve the same problem . 
closely related fields in theoretical computer science are analysis of algorithms and computability theory . 
the input string for a computational problem is referred to as a problem instance , and should not be confused with the problem itself . 
the input string for a computational problem is referred to as a problem instance , and should not be confused with the problem itself . 
in contrast , an instance of this problem is a rather concrete utterance , which can serve as the input for a decision problem . 
a computational problem can be viewed as an infinite collection of instances together with a solution for every instance . 
a computational problem can be viewed as an infinite collection of instances together with a solution for every instance . 
to further highlight the difference between a problem and an instance , consider the following instance of the decision version of the traveling salesman problem : is there a route of at most 2000 kilometres passing through all of germany 's 15 largest cities ? 
the quantitative answer to this particular problem instance is of little use for solving other instances of the problem , such as asking for a round trip through all sites in milan whose total length is at most 10 km . 
for this reason , complexity theory addresses computational problems and not particular problem instances . 
when considering computational problems , a problem instance is a string over an alphabet . 
usually , the alphabet is taken to be the binary alphabet -lrb- i.e. , the set -lcb- 0,1 -rcb- -rrb- , and thus the strings are bitstrings . 
usually , the alphabet is taken to be the binary alphabet -lrb- i.e. , the set -lcb- 0,1 -rcb- -rrb- , and thus the strings are bitstrings . 
for example , integers can be represented in binary notation , and graphs can be encoded directly via their adjacency matrices , or by encoding their adjacency lists in binary . 
for example , integers can be represented in binary notation , and graphs can be encoded directly via their adjacency matrices , or by encoding their adjacency lists in binary . 
decision problems are one of the central objects of study in computational complexity theory . 
a decision problem is a special type of computational problem whose answer is either yes or no , or alternately either 1 or 0 . 
a decision problem is a special type of computational problem whose answer is either yes or no , or alternately either 1 or 0 . 
a decision problem is a special type of computational problem whose answer is either yes or no , or alternately either 1 or 0 . 
a decision problem is a special type of computational problem whose answer is either yes or no , or alternately either 1 or 0 . 
the input is an arbitrary graph . 
the formal language associated with this decision problem is then the set of all connected graphs -- of course , to obtain a precise definition of this language , one has to decide how graphs are encoded as binary strings . 
the formal language associated with this decision problem is then the set of all connected graphs -- of course , to obtain a precise definition of this language , one has to decide how graphs are encoded as binary strings . 
a function problem is a computational problem where a single output -lrb- of a total function -rrb- is expected for every input , but the output is more complex than that of a decision problem , that is , it is n't just yes or no . 
a function problem is a computational problem where a single output -lrb- of a total function -rrb- is expected for every input , but the output is more complex than that of a decision problem , that is , it is n't just yes or no . 
a function problem is a computational problem where a single output -lrb- of a total function -rrb- is expected for every input , but the output is more complex than that of a decision problem , that is , it is n't just yes or no . 
notable examples include the traveling salesman problem and the integer factorization problem . 
a function problem is a computational problem where a single output -lrb- of a total function -rrb- is expected for every input , but the output is more complex than that of a decision problem , that is , it is n't just yes or no . 
it is tempting to think that the notion of function problems is much richer than the notion of decision problems . 
for example , the multiplication of two integers can be expressed as the set of triples -lrb- a , b , c -rrb- such that the relation a × b = c holds . 
to measure the difficulty of solving a computational problem , one may wish to see how much time the best algorithm requires to solve the problem . 
however , the running time may , in general , depend on the instance . 
thus the time required to solve a problem -lrb- or the space required , or any measure of complexity -rrb- is calculated as a function of the size of the instance . 
this is usually taken to be the size of the input in bits . 
complexity theory is interested in how algorithms scale with an increase in the input size . 
cobham 's thesis says that a problem can be solved with a feasible amount of resources if it admits a polynomial time algorithm . 
if the input size is n , the time taken can be expressed as a function of n . 
since the time taken on different inputs of the same size can be different , the worst-case time complexity t -lrb- n -rrb- is defined to be the maximum time taken over all inputs of size n . 
since the time taken on different inputs of the same size can be different , the worst-case time complexity t -lrb- n -rrb- is defined to be the maximum time taken over all inputs of size n . 
if t -lrb- n -rrb- is a polynomial in n , then the algorithm is said to be a polynomial time algorithm . 
a turing machine is a mathematical model of a general computing machine . 
it is believed that if a problem can be solved by an algorithm , there exists a turing machine that solves the problem . 
since turing machines are easy to analyze mathematically , and are believed to be as powerful as any other model of computation , the turing machine is the most commonly used model in complexity theory . 
it is a theoretical device that manipulates symbols contained on a strip of tape . 
a deterministic turing machine is the most basic turing machine , which uses a fixed set of rules to determine its future actions . 
a deterministic turing machine is the most basic turing machine , which uses a fixed set of rules to determine its future actions . 
a probabilistic turing machine is a deterministic turing machine with an extra supply of random bits . 
a non-deterministic turing machine is a deterministic turing machine with an added feature of non-determinism , which allows a turing machine to have multiple possible future actions from a given state . 
algorithms that use random bits are called randomized algorithms . 
many types of turing machines are used to define complexity classes , such as deterministic turing machines , probabilistic turing machines , non-deterministic turing machines , quantum turing machines , symmetric turing machines and alternating turing machines . 
they are all equally powerful in principle , but when resources -lrb- such as time or space -rrb- are bounded , some of these may be more powerful than others . 
many types of turing machines are used to define complexity classes , such as deterministic turing machines , probabilistic turing machines , non-deterministic turing machines , quantum turing machines , symmetric turing machines and alternating turing machines . 
many machine models different from the standard multi-tape turing machines have been proposed in the literature , for example random access machines . 
perhaps surprisingly , each of these models can be converted to another without providing any extra computational power . 
the time and memory consumption of these alternate models may vary . 
what all these models have in common is that the machines operate deterministically . 
for example , a non-deterministic turing machine is a computational model that is allowed to branch out to check many different possibilities at once . 
however , some computational problems are easier to analyze in terms of more unusual resources . 
the non-deterministic turing machine has very little to do with how we physically want to compute algorithms , but its branching exactly captures many of the mathematical models we want to analyze , so that non-deterministic time is a very important resource in analyzing computational problems . 
the non-deterministic turing machine has very little to do with how we physically want to compute algorithms , but its branching exactly captures many of the mathematical models we want to analyze , so that non-deterministic time is a very important resource in analyzing computational problems . 
the time required by a deterministic turing machine m on input x is the total number of state transitions , or steps , the machine makes before it halts and outputs the answer -lrb- `` yes '' or `` no '' -rrb- . 
since complexity theory is interested in classifying problems based on their difficulty , one defines sets of problems based on some criteria . 
for instance , the set of problems solvable within time f -lrb- n -rrb- on a deterministic turing machine is then denoted by dtime -lrb- f -lrb- n -rrb- -rrb- . 
for a precise definition of what it means to solve a problem using a given amount of time and space , a computational model such as the deterministic turing machine is used . 
although time and space are the most well-known complexity resources , any complexity measure can be viewed as a computational resource . 
although time and space are the most well-known complexity resources , any complexity measure can be viewed as a computational resource . 
complexity measures are very generally defined by the blum complexity axioms . 
complexity measures are very generally defined by the blum complexity axioms . 
complexity measures are very generally defined by the blum complexity axioms . 
the best , worst and average case complexity refer to three different ways of measuring the time complexity -lrb- or any other complexity measure -rrb- of different inputs of the same size . 
the best , worst and average case complexity refer to three different ways of measuring the time complexity -lrb- or any other complexity measure -rrb- of different inputs of the same size . 
the best , worst and average case complexity refer to three different ways of measuring the time complexity -lrb- or any other complexity measure -rrb- of different inputs of the same size . 
the best , worst and average case complexity refer to three different ways of measuring the time complexity -lrb- or any other complexity measure -rrb- of different inputs of the same size . 
for example , consider the deterministic sorting algorithm quicksort . 
the worst-case is when the input is sorted or sorted in reverse order , and the algorithm takes time o -lrb- n2 -rrb- for this case . 
the worst-case is when the input is sorted or sorted in reverse order , and the algorithm takes time o -lrb- n2 -rrb- for this case . 
to classify the computation time -lrb- or similar resources , such as space consumption -rrb- , one is interested in proving upper and lower bounds on the minimum amount of time required by the most efficient algorithm solving a given problem . 
analyzing a particular algorithm falls under the field of analysis of algorithms . 
to classify the computation time -lrb- or similar resources , such as space consumption -rrb- , one is interested in proving upper and lower bounds on the minimum amount of time required by the most efficient algorithm solving a given problem . 
to show an upper bound t -lrb- n -rrb- on the time complexity of a problem , one needs to show only that there is a particular algorithm with running time at most t -lrb- n -rrb- . 
however , proving lower bounds is much more difficult , since lower bounds make a statement about all possible algorithms that solve a given problem . 
upper and lower bounds are usually stated using the big o notation , which hides constant factors and smaller terms . 
upper and lower bounds are usually stated using the big o notation , which hides constant factors and smaller terms . 
for instance , if t -lrb- n -rrb- = 7n2 + 15n + 40 , in big o notation one would write t -lrb- n -rrb- = o -lrb- n2 -rrb- . 
this makes the bounds independent of the specific details of the computational model used . 
of course , some complexity classes have complicated definitions that do not fit into this framework . 
of course , some complexity classes have complicated definitions that do not fit into this framework . 
of course , some complexity classes have complicated definitions that do not fit into this framework . 
but bounding the computation time above by some concrete function f -lrb- n -rrb- often yields complexity classes that depend on the chosen machine model . 
for instance , the language -lcb- xx | x is any binary string -rcb- can be solved in linear time on a multi-tape turing machine , but necessarily requires quadratic time in the model of single-tape turing machines . 
for instance , the language -lcb- xx | x is any binary string -rcb- can be solved in linear time on a multi-tape turing machine , but necessarily requires quadratic time in the model of single-tape turing machines . 
if we allow polynomial variations in running time , cobham-edmonds thesis states that `` the time complexities in any two reasonable and general models of computation are polynomially related '' -lrb- goldreich 2008 , chapter 1.2 -rrb- . 
this forms the basis for the complexity class p , which is the set of decision problems solvable by a deterministic turing machine within polynomial time . 
many important complexity classes can be defined by bounding the time or space used by the algorithm . 
many important complexity classes can be defined by bounding the time or space used by the algorithm . 
many important complexity classes can be defined by bounding the time or space used by the algorithm . 
other important complexity classes include bpp , zpp and rp , which are defined using probabilistic turing machines ; ac and nc , which are defined using boolean circuits ; and bqp and qma , which are defined using quantum turing machines . 
other important complexity classes include bpp , zpp and rp , which are defined using probabilistic turing machines ; ac and nc , which are defined using boolean circuits ; and bqp and qma , which are defined using quantum turing machines . 
other important complexity classes include bpp , zpp and rp , which are defined using probabilistic turing machines ; ac and nc , which are defined using boolean circuits ; and bqp and qma , which are defined using quantum turing machines . 
# p is an important complexity class of counting problems -lrb- not decision problems -rrb- . 
classes like ip and am are defined using interactive proof systems . 
for the complexity classes defined in this way , it is desirable to prove that relaxing the requirements on -lrb- say -rrb- computation time indeed defines a bigger set of problems . 
in particular , although dtime -lrb- n -rrb- is contained in dtime -lrb- n2 -rrb- , it would be interesting to know if the inclusion is strict . 
for time and space requirements , the answer to such questions is given by the time and space hierarchy theorems respectively . 
they are called hierarchy theorems because they induce a proper hierarchy on the classes defined by constraining the respective resources . 
having deduced such proper set inclusions , we can proceed to make quantitative statements about how much more additional time or space is needed in order to increase the number of problems that can be solved . 
the time and space hierarchy theorems form the basis for most separation results of complexity classes . 
for instance , the time hierarchy theorem tells us that p is strictly contained in exptime , and the space hierarchy theorem tells us that l is strictly contained in pspace . 
for instance , the time hierarchy theorem tells us that p is strictly contained in exptime , and the space hierarchy theorem tells us that l is strictly contained in pspace . 
many complexity classes are defined using the concept of a reduction . 
a reduction is a transformation of one problem into another problem . 
for instance , if a problem x can be solved using an algorithm for y , x is no more difficult than y , and we say that x reduces to y . 
there are many different types of reductions , based on the method of reduction , such as cook reductions , karp reductions and levin reductions , and the bound on the complexity of reductions , such as polynomial-time reductions or log-space reductions . 
there are many different types of reductions , based on the method of reduction , such as cook reductions , karp reductions and levin reductions , and the bound on the complexity of reductions , such as polynomial-time reductions or log-space reductions . 
the most commonly used reduction is a polynomial-time reduction . 
for example , the problem of squaring an integer can be reduced to the problem of multiplying two integers . 
this means that the reduction process takes polynomial time . 
indeed , this can be done by giving the same input to both inputs of the multiplication algorithm . 
indeed , this can be done by giving the same input to both inputs of the multiplication algorithm . 
a problem x is hard for a class of problems c if every problem in c can be reduced to x. thus no problem in c is harder than x , since an algorithm for x allows us to solve any problem in c. of course , the notion of hard problems depends on the type of reduction being used . 
a problem x is hard for a class of problems c if every problem in c can be reduced to x. thus no problem in c is harder than x , since an algorithm for x allows us to solve any problem in c. of course , the notion of hard problems depends on the type of reduction being used . 
a problem x is hard for a class of problems c if every problem in c can be reduced to x. thus no problem in c is harder than x , since an algorithm for x allows us to solve any problem in c. of course , the notion of hard problems depends on the type of reduction being used . 
in particular , the set of problems that are hard for np is the set of np-hard problems . 
this means that x is the hardest problem in c. -lrb- since many problems could be equally hard , one might say that x is one of the hardest problems in c. -rrb- thus the class of np-complete problems contains the most difficult problems in np , in the sense that they are the ones most likely not to be in p. because the problem p = np is not solved , being able to reduce a known np-complete problem , π2 , to another problem , π1 , would indicate that there is no known polynomial-time solution for π1 . 
this means that x is the hardest problem in c. -lrb- since many problems could be equally hard , one might say that x is one of the hardest problems in c. -rrb- thus the class of np-complete problems contains the most difficult problems in np , in the sense that they are the ones most likely not to be in p. because the problem p = np is not solved , being able to reduce a known np-complete problem , π2 , to another problem , π1 , would indicate that there is no known polynomial-time solution for π1 . 
this means that x is the hardest problem in c. -lrb- since many problems could be equally hard , one might say that x is one of the hardest problems in c. -rrb- thus the class of np-complete problems contains the most difficult problems in np , in the sense that they are the ones most likely not to be in p. because the problem p = np is not solved , being able to reduce a known np-complete problem , π2 , to another problem , π1 , would indicate that there is no known polynomial-time solution for π1 . 
this means that x is the hardest problem in c. -lrb- since many problems could be equally hard , one might say that x is one of the hardest problems in c. -rrb- thus the class of np-complete problems contains the most difficult problems in np , in the sense that they are the ones most likely not to be in p. because the problem p = np is not solved , being able to reduce a known np-complete problem , π2 , to another problem , π1 , would indicate that there is no known polynomial-time solution for π1 . 
the complexity class p is often seen as a mathematical abstraction modeling those computational tasks that admit an efficient algorithm . 
this hypothesis is called the cobham -- edmonds thesis . 
the complexity class np , on the other hand , contains many problems that people would like to solve efficiently , but for which no efficient algorithm is known , such as the boolean satisfiability problem , the hamiltonian path problem and the vertex cover problem . 
the complexity class np , on the other hand , contains many problems that people would like to solve efficiently , but for which no efficient algorithm is known , such as the boolean satisfiability problem , the hamiltonian path problem and the vertex cover problem . 
since deterministic turing machines are special non-deterministic turing machines , it is easily observed that each problem in p is also member of the class np . 
if the answer is yes , many important problems can be shown to have more efficient solutions . 
these include various types of integer programming problems in operations research , many problems in logistics , protein structure prediction in biology , and the ability to find formal proofs of pure mathematics theorems . 
there is a us$ 1,000,000 prize for resolving the problem . 
it was shown by ladner that if p ≠ np then there exist problems in np that are neither in p nor np-complete . 
such problems are called np-intermediate problems . 
the graph isomorphism problem , the discrete logarithm problem and the integer factorization problem are examples of problems believed to be np-intermediate . 
the graph isomorphism problem is the computational problem of determining whether two finite graphs are isomorphic . 
an important unsolved problem in complexity theory is whether the graph isomorphism problem is in p , np-complete , or np-intermediate . 
if graph isomorphism is np-complete , the polynomial time hierarchy collapses to its second level . 
if graph isomorphism is np-complete , the polynomial time hierarchy collapses to its second level . 
the best algorithm for this problem , due to laszlo babai and eugene luks has run time 2o -lrb- √ -lrb- n log -lrb- n -rrb- -rrb- -rrb- for graphs with n vertices . 
the integer factorization problem is the computational problem of determining the prime factorization of a given integer . 
phrased as a decision problem , it is the problem of deciding whether the input has a factor less than k. no efficient integer factorization algorithm is known , and this fact forms the basis of several modern cryptographic systems , such as the rsa algorithm . 
phrased as a decision problem , it is the problem of deciding whether the input has a factor less than k. no efficient integer factorization algorithm is known , and this fact forms the basis of several modern cryptographic systems , such as the rsa algorithm . 
the best known algorithm for integer factorization is the general number field sieve , which takes time o -lrb- e -lrb- 64/9 -rrb- 1/3 -lrb- n.log 2 -rrb- 1/3 -lrb- log -lrb- n.log 2 -rrb- -rrb- 2/3 -rrb- to factor an n-bit integer . 
many known complexity classes are suspected to be unequal , but this has not been proved . 
for instance p ⊆ np ⊆ pp ⊆ pspace , but it is possible that p = pspace . 
since there are many known complexity classes between p and pspace , such as rp , bpp , pp , bqp , ma , ph , etc. , it is possible that all these complexity classes collapse to one class . 
proving that any of these classes are unequal would be a major breakthrough in complexity theory . 
along the same lines , co-np is the class containing the complement problems -lrb- i.e. problems with the yes/no answers reversed -rrb- of np problems . 
along the same lines , co-np is the class containing the complement problems -lrb- i.e. problems with the yes/no answers reversed -rrb- of np problems . 
it is believed that np is not equal to co-np ; however , it has not yet been proven . 
it has been shown that if these two complexity classes are not equal then p is not equal to np . 
similarly , it is not known if l -lrb- the set of all problems that can be solved in logarithmic space -rrb- is strictly contained in p or equal to p. again , there are many complexity classes between the two , such as nl and nc , and it is not known if they are distinct or equal classes . 
similarly , it is not known if l -lrb- the set of all problems that can be solved in logarithmic space -rrb- is strictly contained in p or equal to p. again , there are many complexity classes between the two , such as nl and nc , and it is not known if they are distinct or equal classes . 
similarly , it is not known if l -lrb- the set of all problems that can be solved in logarithmic space -rrb- is strictly contained in p or equal to p. again , there are many complexity classes between the two , such as nl and nc , and it is not known if they are distinct or equal classes . 
similarly , it is not known if l -lrb- the set of all problems that can be solved in logarithmic space -rrb- is strictly contained in p or equal to p. again , there are many complexity classes between the two , such as nl and nc , and it is not known if they are distinct or equal classes . 
similarly , it is not known if l -lrb- the set of all problems that can be solved in logarithmic space -rrb- is strictly contained in p or equal to p. again , there are many complexity classes between the two , such as nl and nc , and it is not known if they are distinct or equal classes . 
problems that can be solved in theory -lrb- e.g. , given large but finite time -rrb- , but which in practice take too long for their solutions to be useful , are known as intractable problems . 
to see why exponential-time algorithms might be unusable in practice , consider a program that makes 2n operations before halting . 
if np is not the same as p , then the np-complete problems are also intractable in this sense . 
for example , the decision problem in presburger arithmetic has been shown not to be in p , yet algorithms have been written that solve the problem in reasonable times in most cases . 
for example , the decision problem in presburger arithmetic has been shown not to be in p , yet algorithms have been written that solve the problem in reasonable times in most cases . 
similarly , algorithms can solve the np-complete knapsack problem over a wide range of sizes in less than quadratic time and sat solvers routinely handle large instances of the np-complete boolean satisfiability problem . 
similarly , algorithms can solve the np-complete knapsack problem over a wide range of sizes in less than quadratic time and sat solvers routinely handle large instances of the np-complete boolean satisfiability problem . 
similarly , algorithms can solve the np-complete knapsack problem over a wide range of sizes in less than quadratic time and sat solvers routinely handle large instances of the np-complete boolean satisfiability problem . 
before the actual research explicitly devoted to the complexity of algorithmic problems started off , numerous foundations were laid out by various researchers . 
most influential among these was the definition of turing machines by alan turing in 1936 , which turned out to be a very robust and flexible simplification of a computer . 
most influential among these was the definition of turing machines by alan turing in 1936 , which turned out to be a very robust and flexible simplification of a computer . 
most influential among these was the definition of turing machines by alan turing in 1936 , which turned out to be a very robust and flexible simplification of a computer . 
most influential among these was the definition of turing machines by alan turing in 1936 , which turned out to be a very robust and flexible simplification of a computer . 
as fortnow & homer -lrb- 2003 -rrb- point out , the beginning of systematic studies in computational complexity is attributed to the seminal paper `` on the computational complexity of algorithms '' by juris hartmanis and richard stearns -lrb- 1965 -rrb- , which laid out the definitions of time and space complexity and proved the hierarchy theorems . 
as fortnow & homer -lrb- 2003 -rrb- point out , the beginning of systematic studies in computational complexity is attributed to the seminal paper `` on the computational complexity of algorithms '' by juris hartmanis and richard stearns -lrb- 1965 -rrb- , which laid out the definitions of time and space complexity and proved the hierarchy theorems . 
as fortnow & homer -lrb- 2003 -rrb- point out , the beginning of systematic studies in computational complexity is attributed to the seminal paper `` on the computational complexity of algorithms '' by juris hartmanis and richard stearns -lrb- 1965 -rrb- , which laid out the definitions of time and space complexity and proved the hierarchy theorems . 
as fortnow & homer -lrb- 2003 -rrb- point out , the beginning of systematic studies in computational complexity is attributed to the seminal paper `` on the computational complexity of algorithms '' by juris hartmanis and richard stearns -lrb- 1965 -rrb- , which laid out the definitions of time and space complexity and proved the hierarchy theorems . 
as fortnow & homer -lrb- 2003 -rrb- point out , the beginning of systematic studies in computational complexity is attributed to the seminal paper `` on the computational complexity of algorithms '' by juris hartmanis and richard stearns -lrb- 1965 -rrb- , which laid out the definitions of time and space complexity and proved the hierarchy theorems . 
earlier papers studying problems solvable by turing machines with specific bounded resources include john myhill 's definition of linear bounded automata -lrb- myhill 1960 -rrb- , raymond smullyan 's study of rudimentary sets -lrb- 1961 -rrb- , as well as hisao yamada 's paper on real-time computations -lrb- 1962 -rrb- . 
earlier papers studying problems solvable by turing machines with specific bounded resources include john myhill 's definition of linear bounded automata -lrb- myhill 1960 -rrb- , raymond smullyan 's study of rudimentary sets -lrb- 1961 -rrb- , as well as hisao yamada 's paper on real-time computations -lrb- 1962 -rrb- . 
earlier papers studying problems solvable by turing machines with specific bounded resources include john myhill 's definition of linear bounded automata -lrb- myhill 1960 -rrb- , raymond smullyan 's study of rudimentary sets -lrb- 1961 -rrb- , as well as hisao yamada 's paper on real-time computations -lrb- 1962 -rrb- . 
even though some proofs of complexity-theoretic theorems regularly assume some concrete choice of input encoding , one tries to keep the discussion abstract enough to be independent of the choice of encoding . 
even though some proofs of complexity-theoretic theorems regularly assume some concrete choice of input encoding , one tries to keep the discussion abstract enough to be independent of the choice of encoding . 
in 1967 , manuel blum developed an axiomatic complexity theory based on his axioms and proved an important result , the so-called , speed-up theorem . 
in 1967 , manuel blum developed an axiomatic complexity theory based on his axioms and proved an important result , the so-called , speed-up theorem . 
in 1972 , richard karp took this idea a leap forward with his landmark paper , `` reducibility among combinatorial problems '' , in which he showed that 21 diverse combinatorial and graph theoretical problems , each infamous for its computational intractability , are np-complete . 
in 1972 , richard karp took this idea a leap forward with his landmark paper , `` reducibility among combinatorial problems '' , in which he showed that 21 diverse combinatorial and graph theoretical problems , each infamous for its computational intractability , are np-complete . 
teachers may use a lesson plan to facilitate student learning , providing a course of study which is called the curriculum . 
these professional qualifications may include the study of pedagogy , the science of teaching . 
in many countries , a person who wishes to become a teacher must first obtain specified professional qualifications or credentials from a university or college . 
teachers may use a lesson plan to facilitate student learning , providing a course of study which is called the curriculum . 
the role of teacher is often formal and ongoing , carried out at a school or other place of formal education . 
a teacher 's role may vary among cultures . 
teachers may provide instruction in literacy and numeracy , craftsmanship or vocational training , the arts , religion , civics , community roles , or life skills . 
teachers may provide instruction in literacy and numeracy , craftsmanship or vocational training , the arts , religion , civics , community roles , or life skills . 
teachers may provide instruction in literacy and numeracy , craftsmanship or vocational training , the arts , religion , civics , community roles , or life skills . 
informal learning may be assisted by a teacher occupying a transient or ongoing role , such as a family member , or by anyone with knowledge or skills in the wider community setting . 
in some countries , formal education can take place through home schooling . 
in some countries , formal education can take place through home schooling . 
informal learning may be assisted by a teacher occupying a transient or ongoing role , such as a family member , or by anyone with knowledge or skills in the wider community setting . 
informal learning may be assisted by a teacher occupying a transient or ongoing role , such as a family member , or by anyone with knowledge or skills in the wider community setting . 
religious and spiritual teachers , such as gurus , mullahs , rabbis , pastors/youth pastors and lamas , may teach religious texts such as the quran , torah or bible . 
religious and spiritual teachers , such as gurus , mullahs , rabbis , pastors/youth pastors and lamas , may teach religious texts such as the quran , torah or bible . 
religious and spiritual teachers , such as gurus , mullahs , rabbis , pastors/youth pastors and lamas , may teach religious texts such as the quran , torah or bible . 
religious and spiritual teachers , such as gurus , mullahs , rabbis , pastors/youth pastors and lamas , may teach religious texts such as the quran , torah or bible . 
teaching may be carried out informally , within the family , which is called homeschooling , or in the wider community . 
formal teaching may be carried out by paid professionals . 
such professionals enjoy a status in some societies on a par with physicians , lawyers , engineers , and accountants -lrb- chartered or cpa -rrb- . 
teaching may be carried out informally , within the family , which is called homeschooling , or in the wider community . 
formal teaching may be carried out by paid professionals . 
outside of the classroom teachers may accompany students on field trips , supervise study halls , help with the organization of school functions , and serve as supervisors for extracurricular activities . 
outside of the classroom teachers may accompany students on field trips , supervise study halls , help with the organization of school functions , and serve as supervisors for extracurricular activities . 
outside of the classroom teachers may accompany students on field trips , supervise study halls , help with the organization of school functions , and serve as supervisors for extracurricular activities . 
outside of the classroom teachers may accompany students on field trips , supervise study halls , help with the organization of school functions , and serve as supervisors for extracurricular activities . 
around the world many governments operate teacher 's colleges , which are generally established to serve and protect the public interest through certifying , governing and enforcing the standards of practice for the teaching profession . 
around the world many governments operate teacher 's colleges , which are generally established to serve and protect the public interest through certifying , governing and enforcing the standards of practice for the teaching profession . 
around the world many governments operate teacher 's colleges , which are generally established to serve and protect the public interest through certifying , governing and enforcing the standards of practice for the teaching profession . 
there are a variety of bodies designed to instill , preserve and update the knowledge and professional standing of teachers . 
around the world many governments operate teacher 's colleges , which are generally established to serve and protect the public interest through certifying , governing and enforcing the standards of practice for the teaching profession . 
the functions of the teacher 's colleges may include setting out clear standards of practice , providing for the ongoing education of teachers , investigating complaints involving members , conducting hearings into allegations of professional misconduct and taking appropriate disciplinary action and accrediting teacher education programs . 
the functions of the teacher 's colleges may include setting out clear standards of practice , providing for the ongoing education of teachers , investigating complaints involving members , conducting hearings into allegations of professional misconduct and taking appropriate disciplinary action and accrediting teacher education programs . 
the functions of the teacher 's colleges may include setting out clear standards of practice , providing for the ongoing education of teachers , investigating complaints involving members , conducting hearings into allegations of professional misconduct and taking appropriate disciplinary action and accrediting teacher education programs . 
the functions of the teacher 's colleges may include setting out clear standards of practice , providing for the ongoing education of teachers , investigating complaints involving members , conducting hearings into allegations of professional misconduct and taking appropriate disciplinary action and accrediting teacher education programs . 
the functions of the teacher 's colleges may include setting out clear standards of practice , providing for the ongoing education of teachers , investigating complaints involving members , conducting hearings into allegations of professional misconduct and taking appropriate disciplinary action and accrediting teacher education programs . 
in education , teachers facilitate student learning , often in a school or academy or perhaps in another environment such as outdoors . 
a teacher who teaches on an individual basis may be described as a tutor . 
in education , teachers facilitate student learning , often in a school or academy or perhaps in another environment such as outdoors . 
in education , teachers facilitate student learning , often in a school or academy or perhaps in another environment such as outdoors . 
the objective is typically accomplished through either an informal or formal approach to learning , including a course of study and lesson plan that teaches skills , knowledge and/or thinking skills . 
different ways to teach are often referred to as pedagogy . 
many times , teachers assist in learning outside of the classroom by accompanying students on field trips . 
the increasing use of technology , specifically the rise of the internet over the past decade , has begun to shape the way teachers approach their roles in the classroom . 
the increasing use of technology , specifically the rise of the internet over the past decade , has begun to shape the way teachers approach their roles in the classroom . 
the objective is typically a course of study , lesson plan , or a practical skill . 
a teacher may follow standardized curricula as determined by the relevant authority . 
the teacher may interact with students of different ages , from infants to adults , students with different abilities and students with learning disabilities . 
the teacher may interact with students of different ages , from infants to adults , students with different abilities and students with learning disabilities . 
a teacher may follow standardized curricula as determined by the relevant authority . 
teaching using pedagogy also involve assessing the educational levels of the students on particular skills . 
for example , an experienced teacher and parent described the place of a teacher in learning as follows : `` the real bulk of learning takes place in self-study and problem solving with a lot of feedback around that loop . 
the function of the teacher is to pressure the lazy , inspire the bored , deflate the cocky , encourage the timid , detect and correct individual flaws , and broaden the viewpoint of all . 
the function of the teacher is to pressure the lazy , inspire the bored , deflate the cocky , encourage the timid , detect and correct individual flaws , and broaden the viewpoint of all . 
this function looks like that of a coach using the whole gamut of psychology to get each new class of rookies off the bench and into the game . '' 
perhaps the most significant difference between primary school and secondary school teaching is the relationship between teachers and children . 
in primary schools each class has a teacher who stays with them for most of the week and will teach them the whole curriculum . 
in secondary schools they will be taught by different subject specialists each session during the week and may have ten or more different teachers . 
perhaps the most significant difference between primary school and secondary school teaching is the relationship between teachers and children . 
the relationship between children and their teachers tends to be closer in the primary school where they act as form tutor , specialist teacher and surrogate parent during the course of the day . 
however , alternative approaches for primary education do exist . 
one of these , sometimes referred to as a `` platoon '' system , involves placing a group of students together in one class that moves from one specialist to another for every subject . 
students still derive a strong sense of security by staying with the same group of peers for all classes . 
the advantage here is that students learn from teachers who specialize in one subject and who tend to be more knowledgeable in that one area than a teacher who teaches many subjects . 
this is true throughout most of the united states as well . 
co-teaching has also become a new trend amongst educational institutions . 
co-teaching is defined as two or more teachers working harmoniously to fulfill the needs of every student in the classroom . 
co-teaching focuses the student on learning by providing a social networking support that allows them to reach their full cognitive potential . 
co-teaching is defined as two or more teachers working harmoniously to fulfill the needs of every student in the classroom . 
co-teaching focuses the student on learning by providing a social networking support that allows them to reach their full cognitive potential . 
throughout the history of education the most common form of school discipline was corporal punishment . 
while a child was in school , a teacher was expected to act as a substitute parent , with all the normal forms of parental discipline open to them . 
while a child was in school , a teacher was expected to act as a substitute parent , with all the normal forms of parental discipline open to them . 
throughout the history of education the most common form of school discipline was corporal punishment . 
while a child was in school , a teacher was expected to act as a substitute parent , with all the normal forms of parental discipline open to them . 
in past times , corporal punishment -lrb- spanking or paddling or caning or strapping or birching the student in order to cause physical pain -rrb- was one of the most common forms of school discipline throughout much of the world . 
most western countries , and some others , have now banned it , but it remains lawful in the united states following a us supreme court decision in 1977 which held that paddling did not violate the us constitution . 
most western countries , and some others , have now banned it , but it remains lawful in the united states following a us supreme court decision in 1977 which held that paddling did not violate the us constitution . 
most western countries , and some others , have now banned it , but it remains lawful in the united states following a us supreme court decision in 1977 which held that paddling did not violate the us constitution . 
in past times , corporal punishment -lrb- spanking or paddling or caning or strapping or birching the student in order to cause physical pain -rrb- was one of the most common forms of school discipline throughout much of the world . 
30 us states have banned corporal punishment , the others -lrb- mostly in the south -rrb- have not . 
30 us states have banned corporal punishment , the others -lrb- mostly in the south -rrb- have not . 
it is still used to a significant -lrb- though declining -rrb- degree in some public schools in alabama , arkansas , georgia , louisiana , mississippi , oklahoma , tennessee and texas . 
corporal punishment in american schools is administered to the seat of the student 's trousers or skirt with a specially made wooden paddle . 
this often used to take place in the classroom or hallway , but nowadays the punishment is usually given privately in the principal 's office . 
official corporal punishment , often by caning , remains commonplace in schools in some asian , african and caribbean countries . 
official corporal punishment , often by caning , remains commonplace in schools in some asian , african and caribbean countries . 
for details of individual countries see school corporal punishment . 
currently detention is one of the most common punishments in schools in the united states , the uk , ireland , singapore and other countries . 
currently detention is one of the most common punishments in schools in the united states , the uk , ireland , singapore and other countries . 
currently detention is one of the most common punishments in schools in the united states , the uk , ireland , singapore and other countries . 
during detention , students normally have to sit in a classroom and do work , write lines or a punishment essay , or sit quietly . 
during detention , students normally have to sit in a classroom and do work , write lines or a punishment essay , or sit quietly . 
a modern example of school discipline in north america and western europe relies upon the idea of an assertive teacher who is prepared to impose their will upon a class . 
positive reinforcement is balanced with immediate and fair punishment for misbehavior and firm , clear boundaries define what is appropriate and inappropriate behavior . 
positive reinforcement is balanced with immediate and fair punishment for misbehavior and firm , clear boundaries define what is appropriate and inappropriate behavior . 
teachers are expected to respect their students ; sarcasm and attempts to humiliate pupils are seen as falling outside of what constitutes reasonable discipline . 
teachers are expected to respect their students ; sarcasm and attempts to humiliate pupils are seen as falling outside of what constitutes reasonable discipline . 
whilst this is the consensus viewpoint amongst the majority of academics , some teachers and parents advocate a more assertive and confrontational style of discipline . 
this viewpoint is supported by the educational attainment of countries -- in east asia for instance -- that combine strict discipline with high standards of education . 
-lsb- citation needed -rsb- such individuals claim that many problems with modern schooling stem from the weakness in school discipline and if teachers exercised firm control over the classroom they would be able to teach more efficiently . 
whilst this is the consensus viewpoint amongst the majority of academics , some teachers and parents advocate a more assertive and confrontational style of discipline . 
in japan , for example , although average attainment on standardized tests may exceed those in western countries , classroom discipline and behavior is highly problematic . 
in japan , for example , although average attainment on standardized tests may exceed those in western countries , classroom discipline and behavior is highly problematic . 
in japan , for example , although average attainment on standardized tests may exceed those in western countries , classroom discipline and behavior is highly problematic . 
in japan , for example , although average attainment on standardized tests may exceed those in western countries , classroom discipline and behavior is highly problematic . 
where school class sizes are typically 40 to 50 students , maintaining order in the classroom can divert the teacher from instruction , leaving little opportunity for concentration and focus on what is being taught . 
where school class sizes are typically 40 to 50 students , maintaining order in the classroom can divert the teacher from instruction , leaving little opportunity for concentration and focus on what is being taught . 
in response , teachers may concentrate their attention on motivated students , ignoring attention-seeking and disruptive students . 
in response , teachers may concentrate their attention on motivated students , ignoring attention-seeking and disruptive students . 
in response , teachers may concentrate their attention on motivated students , ignoring attention-seeking and disruptive students . 
sudbury model democratic schools claim that popularly based authority can maintain order more effectively than dictatorial authority for governments and schools alike . 
sudbury model democratic schools claim that popularly based authority can maintain order more effectively than dictatorial authority for governments and schools alike . 
primarily because rules and regulations are made by the community as a whole , thence the school atmosphere is one of persuasion and negotiation , rather than confrontation since there is no one to confront . 
they also claim that in these schools the preservation of public order is easier and more efficient than anywhere else . 
sudbury model democratic schools ' proponents argue that a school that has good , clear laws , fairly and democratically passed by the entire school community , and a good judicial system for enforcing these laws , is a school in which community discipline prevails , and in which an increasingly sophisticated concept of law and order develops , against other schools today , where rules are arbitrary , authority is absolute , punishment is capricious , and due process of law is unknown . 
since teachers can affect how students perceive the course materials , it has been found that teachers who showed enthusiasm towards the course materials and students can affect a positive learning experience towards the course materials . 
on teacher/course evaluations , it was found that teachers who have a positive disposition towards the course content tend to transfer their passion to receptive students . 
these teachers do not teach by rote but attempt to find new invigoration for the course materials on a daily basis . 
students who had enthusiastic teachers tend to rate them higher than teachers who did n't show much enthusiasm for the course materials . 
recent research has found a correlation between teacher enthusiasm and students ' intrinsic motivation to learn and vitality in the classroom . 
students who experienced a very enthusiastic teacher were more likely to read lecture material outside of the classroom . 
controlled , experimental studies exploring intrinsic motivation of college students has shown that nonverbal expressions of enthusiasm , such as demonstrative gesturing , dramatic movements which are varied , and emotional facial expressions , result in college students reporting higher levels of intrinsic motivation to learn . 
controlled , experimental studies exploring intrinsic motivation of college students has shown that nonverbal expressions of enthusiasm , such as demonstrative gesturing , dramatic movements which are varied , and emotional facial expressions , result in college students reporting higher levels of intrinsic motivation to learn . 
controlled , experimental studies exploring intrinsic motivation of college students has shown that nonverbal expressions of enthusiasm , such as demonstrative gesturing , dramatic movements which are varied , and emotional facial expressions , result in college students reporting higher levels of intrinsic motivation to learn . 
enthusiastic teachers may also lead to students becoming more self-determined in their own learning process . 
there are various mechanisms by which teacher enthusiasm may facilitate higher levels of intrinsic motivation . 
finally , the concept of emotional contagion , may also apply . 
teacher enthusiasm may contribute to a classroom atmosphere full of energy and enthusiasm which feed student interest and excitement in learning the subject matter . 
research shows that student motivation and attitudes towards school are closely linked to student-teacher relationships . 
enthusiastic teachers are particularly good at creating beneficial relations with their students . 
here , personal success is a student 's internal goal of improving himself , whereas academic success includes the goals he receives from his superior . 
a teacher must guide his student in aligning his personal goals with his academic goals . 
research shows that student motivation and attitudes towards school are closely linked to student-teacher relationships . 
students are likely to build stronger relations with teachers who are friendly and supportive and will show more interest in courses taught by these teachers . 
students are likely to build stronger relations with teachers who are friendly and supportive and will show more interest in courses taught by these teachers . 
teachers that spend more time interacting and working directly with students are perceived as supportive and effective teachers . 
teachers that spend more time interacting and working directly with students are perceived as supportive and effective teachers . 
the three most important aspects of teacher enthusiasm are enthusiasm about teaching , enthusiasm about the students , and enthusiasm about the subject matter . 
the teacher also needs to be enthusiastic about the subject matter they are teaching . 
a spark in the teacher may create a spark of excitement in the student as well . 
an enthusiastic teacher has the ability to be very influential in the young students life . 
the way a teacher promotes the course they are teaching , the more the student will get out of the subject matter . 
misconduct by teachers , especially sexual misconduct , has been getting increased scrutiny from the media and the courts . 
a study by the american association of university women reported that 9.6 % of students in the united states claim to have received unwanted sexual attention from an adult associated with education ; be they a volunteer , bus driver , teacher , administrator or other adult ; sometime during their educational career . 
a study by the american association of university women reported that 9.6 % of students in the united states claim to have received unwanted sexual attention from an adult associated with education ; be they a volunteer , bus driver , teacher , administrator or other adult ; sometime during their educational career . 
a study by the american association of university women reported that 9.6 % of students in the united states claim to have received unwanted sexual attention from an adult associated with education ; be they a volunteer , bus driver , teacher , administrator or other adult ; sometime during their educational career . 
a study by the american association of university women reported that 9.6 % of students in the united states claim to have received unwanted sexual attention from an adult associated with education ; be they a volunteer , bus driver , teacher , administrator or other adult ; sometime during their educational career . 
a study in england showed a 0.3 % prevalence of sexual abuse by any professional , a group that included priests , religious leaders , and case workers as well as teachers . 
a study in england showed a 0.3 % prevalence of sexual abuse by any professional , a group that included priests , religious leaders , and case workers as well as teachers . 
it is important to note , however , that the british study referenced above is the only one of its kind and consisted of `` a random ... probability sample of 2,869 young people between the ages of 18 and 24 in a computer-assisted study '' and that the questions referred to `` sexual abuse with a professional , '' not necessarily a teacher . 
the aauw study , however , posed questions about fourteen types of sexual harassment and various degrees of frequency and included only abuses by teachers . 
in the united states especially , several high-profile cases such as debra lafave , pamela rogers , and mary kay letourneau have caused increased scrutiny on teacher misconduct . 
in the united states especially , several high-profile cases such as debra lafave , pamela rogers , and mary kay letourneau have caused increased scrutiny on teacher misconduct . 
fears of being labelled a pedophile or hebephile has led to several men who enjoy teaching avoiding the profession . 
chris keates , the general secretary of national association of schoolmasters union of women teachers , said that teachers who have sex with pupils over the age of consent should not be placed on the sex offenders register and that prosecution for statutory rape `` is a real anomaly in the law that we are concerned about . '' 
this has led to outrage from child protection and parental rights groups . 
this has in some jurisdictions reportedly led to a shortage of male teachers . 
chris keates , the general secretary of national association of schoolmasters union of women teachers , said that teachers who have sex with pupils over the age of consent should not be placed on the sex offenders register and that prosecution for statutory rape `` is a real anomaly in the law that we are concerned about . '' 
teachers face several occupational hazards in their line of work , including occupational stress , which can negatively impact teachers ' mental and physical health , productivity , and students ' performance . 
stress can be caused by organizational change , relationships with students , fellow teachers , and administrative personnel , working environment , expectations to substitute , long hours with a heavy workload , and inspections . 
teachers are also at high risk for occupational burnout . 
teachers face several occupational hazards in their line of work , including occupational stress , which can negatively impact teachers ' mental and physical health , productivity , and students ' performance . 
teachers face several occupational hazards in their line of work , including occupational stress , which can negatively impact teachers ' mental and physical health , productivity , and students ' performance . 
a 2000 study found that 42 % of uk teachers experienced occupational stress , twice the figure for the average profession . 
a 2000 study found that 42 % of uk teachers experienced occupational stress , twice the figure for the average profession . 
a 2000 study found that 42 % of uk teachers experienced occupational stress , twice the figure for the average profession . 
a 2012 study found that teachers experienced double the rate of anxiety , depression , and stress than average workers . 
a 2012 study found that teachers experienced double the rate of anxiety , depression , and stress than average workers . 
there are several ways to mitigate the occupational hazards of teaching . 
organizational interventions , like changing teachers ' schedules , providing support networks and mentoring , changing the work environment , and offering promotions and bonuses , may be effective in helping to reduce occupational stress among teachers . 
individual-level interventions , including stress-management training and counseling , are also used to relieve occupational stress among teachers . 
organizational interventions , like changing teachers ' schedules , providing support networks and mentoring , changing the work environment , and offering promotions and bonuses , may be effective in helping to reduce occupational stress among teachers . 
organizational interventions , like changing teachers ' schedules , providing support networks and mentoring , changing the work environment , and offering promotions and bonuses , may be effective in helping to reduce occupational stress among teachers . 
in almost all countries teachers are educated in a university or college . 
governments may require certification by a recognized body before they can teach in a school . 
in many countries , elementary school education certificate is earned after completion of high school . 
in addition to certification , many educational institutions especially within the us , require that prospective teachers pass a background check and psychiatric evaluation to be able to teach in classroom . 
in addition to certification , many educational institutions especially within the us , require that prospective teachers pass a background check and psychiatric evaluation to be able to teach in classroom . 
education in australia is primarily the responsibility of the individual states and territories . 
generally , education in australia follows the three-tier model which includes primary education -lrb- primary schools -rrb- , followed by secondary education -lrb- secondary schools/high schools -rrb- and tertiary education -lrb- universities and/or tafe colleges -rrb- . 
generally , education in australia follows the three-tier model which includes primary education -lrb- primary schools -rrb- , followed by secondary education -lrb- secondary schools/high schools -rrb- and tertiary education -lrb- universities and/or tafe colleges -rrb- . 
generally , education in australia follows the three-tier model which includes primary education -lrb- primary schools -rrb- , followed by secondary education -lrb- secondary schools/high schools -rrb- and tertiary education -lrb- universities and/or tafe colleges -rrb- . 
generally , education in australia follows the three-tier model which includes primary education -lrb- primary schools -rrb- , followed by secondary education -lrb- secondary schools/high schools -rrb- and tertiary education -lrb- universities and/or tafe colleges -rrb- . 
teaching in canada requires a post-secondary degree bachelor 's degree . 
in most provinces a second bachelor 's degree such as a bachelor of education is required to become a qualified teacher . 
teachers have the option to teach for a public school which is funded by the provincial government or teaching in a private school which is funded by the private sector , businesses and sponsors . 
in germany , teachers are mainly civil servants recruited in special university classes , called lehramtstudien -lrb- teaching education studies -rrb- . 
in germany , teachers are mainly civil servants recruited in special university classes , called lehramtstudien -lrb- teaching education studies -rrb- . 
there are many differences between the teachers for elementary schools -lrb- grundschule -rrb- , lower secondary schools -lrb- hauptschule -rrb- , middle level secondary schools -lrb- realschule -rrb- and higher level secondary schools -lrb- gymnasium -rrb- . 
salaries for teachers depend on the civil servants ' salary index scale -lrb- bundesbesoldungsordnung -rrb- . 
there are many differences between the teachers for elementary schools -lrb- grundschule -rrb- , lower secondary schools -lrb- hauptschule -rrb- , middle level secondary schools -lrb- realschule -rrb- and higher level secondary schools -lrb- gymnasium -rrb- . 
extra pay is also given for teaching through the irish language , in a gaeltacht area or on an island . 
the basic pay for a starting teacher is $ 27,814 p.a. , rising incrementally to $ 53,423 for a teacher with 25 years service . 
the basic pay for a starting teacher is $ 27,814 p.a. , rising incrementally to $ 53,423 for a teacher with 25 years service . 
a principal of a large school with many years experience and several qualifications -lrb- m.a. , h.dip. , etc. -rrb- could earn over $ 90,000 . 
teachers are required to be registered with the teaching council ; under section 30 of the teaching council act 2001 , a person employed in any capacity in a recognised teaching post - who is not registered with the teaching council - may not be paid from oireachtas funds . 
teachers are required to be registered with the teaching council ; under section 30 of the teaching council act 2001 , a person employed in any capacity in a recognised teaching post - who is not registered with the teaching council - may not be paid from oireachtas funds . 
teachers are required to be registered with the teaching council ; under section 30 of the teaching council act 2001 , a person employed in any capacity in a recognised teaching post - who is not registered with the teaching council - may not be paid from oireachtas funds . 
teachers are required to be registered with the teaching council ; under section 30 of the teaching council act 2001 , a person employed in any capacity in a recognised teaching post - who is not registered with the teaching council - may not be paid from oireachtas funds . 
from 2006 garda vetting has been introduced for new entrants to the teaching profession . 
from 2006 garda vetting has been introduced for new entrants to the teaching profession . 
existing staff will be vetted on a phased basis . 
these procedures apply to teaching and also to non-teaching posts and those who refuse vetting `` can not be appointed or engaged by the school in any capacity including in a voluntary role '' . 
salaries for nursery , primary and secondary school teachers ranged from # 20,133 to # 41,004 in september 2007 , although some salaries can go much higher depending on experience and extra responsibilities . 
salaries for nursery , primary and secondary school teachers ranged from # 20,133 to # 41,004 in september 2007 , although some salaries can go much higher depending on experience and extra responsibilities . 
preschool teachers may earn # 20,980 annually . 
-lsb- citation needed -rsb- teachers in state schools must have at least a bachelor 's degree , complete an approved teacher education program , and be licensed . 
salaries for nursery , primary and secondary school teachers ranged from # 20,133 to # 41,004 in september 2007 , although some salaries can go much higher depending on experience and extra responsibilities . 
many counties offer alternative licensing programs to attract people into teaching , especially for hard-to-fill positions . 
many counties offer alternative licensing programs to attract people into teaching , especially for hard-to-fill positions . 
excellent job opportunities are expected as retirements , especially among secondary school teachers , outweigh slowing enrollment growth ; opportunities will vary by geographic area and subject taught . 
excellent job opportunities are expected as retirements , especially among secondary school teachers , outweigh slowing enrollment growth ; opportunities will vary by geographic area and subject taught . 
excellent job opportunities are expected as retirements , especially among secondary school teachers , outweigh slowing enrollment growth ; opportunities will vary by geographic area and subject taught . 
in scotland , anyone wishing to teach must be registered with the general teaching council for scotland -lrb- gtcs -rrb- . 
in scotland , anyone wishing to teach must be registered with the general teaching council for scotland -lrb- gtcs -rrb- . 
teaching in scotland is an all graduate profession and the normal route for graduates wishing to teach is to complete a programme of initial teacher education -lrb- ite -rrb- at one of the seven scottish universities who offer these courses . 
once successfully completed , `` provisional registration '' is given by the gtcs which is raised to `` full registration '' status after a year if there is sufficient evidence to show that the `` standard for full registration '' has been met . 
once successfully completed , `` provisional registration '' is given by the gtcs which is raised to `` full registration '' status after a year if there is sufficient evidence to show that the `` standard for full registration '' has been met . 
for the salary year beginning april 2008 , unpromoted teachers in scotland earned from # 20,427 for a probationer , up to # 32,583 after 6 years teaching , but could then go on to earn up to # 39,942 as they complete the modules to earn chartered teacher status -lrb- requiring at least 6 years at up to two modules per year . -rrb- 
for the salary year beginning april 2008 , unpromoted teachers in scotland earned from # 20,427 for a probationer , up to # 32,583 after 6 years teaching , but could then go on to earn up to # 39,942 as they complete the modules to earn chartered teacher status -lrb- requiring at least 6 years at up to two modules per year . -rrb- 
for the salary year beginning april 2008 , unpromoted teachers in scotland earned from # 20,427 for a probationer , up to # 32,583 after 6 years teaching , but could then go on to earn up to # 39,942 as they complete the modules to earn chartered teacher status -lrb- requiring at least 6 years at up to two modules per year . -rrb- 
for the salary year beginning april 2008 , unpromoted teachers in scotland earned from # 20,427 for a probationer , up to # 32,583 after 6 years teaching , but could then go on to earn up to # 39,942 as they complete the modules to earn chartered teacher status -lrb- requiring at least 6 years at up to two modules per year . -rrb- 
teachers in scotland can be registered members of trade unions with the main ones being the educational institute of scotland and the scottish secondary teachers ' association . 
education in wales differs in certain respects from education elsewhere in the united kingdom . 
for example , a significant number of students all over wales are educated either wholly or largely through the medium of welsh : in 2008/09 , 22 per cent of classes in maintained primary schools used welsh as the sole or main medium of instruction . 
welsh medium education is available to all age groups through nurseries , schools , colleges and universities and in adult education ; lessons in the language itself are compulsory for all pupils until the age of 16 . 
for example , a significant number of students all over wales are educated either wholly or largely through the medium of welsh : in 2008/09 , 22 per cent of classes in maintained primary schools used welsh as the sole or main medium of instruction . 
welsh medium education is available to all age groups through nurseries , schools , colleges and universities and in adult education ; lessons in the language itself are compulsory for all pupils until the age of 16 . 
teachers in wales can be registered members of trade unions such as atl , nut or nasuwt and reports in recent years suggest that the average age of teachers in wales is falling with teachers being younger than in previous years . 
teachers in wales can be registered members of trade unions such as atl , nut or nasuwt and reports in recent years suggest that the average age of teachers in wales is falling with teachers being younger than in previous years . 
a growing cause of concern are that attacks on teachers in welsh schools which reached an all-time high between 2005 and 2010 . 
teachers in wales can be registered members of trade unions such as atl , nut or nasuwt and reports in recent years suggest that the average age of teachers in wales is falling with teachers being younger than in previous years . 
a growing cause of concern are that attacks on teachers in welsh schools which reached an all-time high between 2005 and 2010 . 
in the united states , each state determines the requirements for getting a license to teach in public schools . 
teaching certification generally lasts three years , but teachers can receive certificates that last as long as ten years . 
public school teachers are required to have a bachelor 's degree and the majority must be certified by the state in which they teach . 
many charter schools do not require that their teachers be certified , provided they meet the standards to be highly qualified as set by no child left behind . 
many charter schools do not require that their teachers be certified , provided they meet the standards to be highly qualified as set by no child left behind . 
in the past , teachers have been paid relatively low salaries . 
however , average teacher salaries have improved rapidly in recent years . 
teachers with more experience and higher education earn more than those with a standard bachelor 's degree and certificate . 
in a salary survey report for k-12 teachers , elementary school teachers had the lowest median salary earning $ 39,259 . 
also , with the advent of the internet , many teachers are now selling their lesson plans to other teachers through the web in order to earn supplemental income , most notably on teacherspayteachers.com . 
there are many forms of spiritual or religious teachers in christianity , across all three major traditions - -lrb- roman -rrb- catholic , -lrb- eastern -rrb- orthodox catholic , and protestant/non-denominational , with a stronger tradition of spiritual formation in the more historic and authoritarian/hierarchical christian traditions with a long tradition of `` discernment of spirits '' , of vocations , and other aspects of spiritual life , especially the roman and orthodox catholic churches . 
there are many forms of spiritual or religious teachers in christianity , across all three major traditions - -lrb- roman -rrb- catholic , -lrb- eastern -rrb- orthodox catholic , and protestant/non-denominational , with a stronger tradition of spiritual formation in the more historic and authoritarian/hierarchical christian traditions with a long tradition of `` discernment of spirits '' , of vocations , and other aspects of spiritual life , especially the roman and orthodox catholic churches . 
these positions include : the honoured but informal position of starets or elder - a man -lrb- or , less often , woman -rrb- , often a monastic , considered to be graced by god with certain gifts for the guidance of souls and the detection and correction of prelest -lrb- spiritual pride or deception -rrb- - who acts as a spiritual guide or father in the orthodox catholic tradition , especially russian orthodoxy -lrb- see optina monastery , which had a long line of said starets -rrb- ; the priest or confessor in roman catholicism , who is often a man in holy orders but may be a monastic or other person respected for his spiritual accomplishments or acumen -lrb- even the pope of rome has a confessor , who is not always a bishop , and , due to the hierarchical structure of the roman church , can not be his equal in authority -rrb- , which is often a semi-official to official position , as opposed to the unofficial positions of spiritual guides in the orthodox catholic and protestant traditions ; and the almost-exclusively informal arrangements -lrb- generally formal only in members who are under some form of church discipline -rrb- of mentorship -lrb- both of adults and children , in the latter case often a youth pastor -rrb- in the protestant and non-denominational traditions , which boundaries can be blurred with the more typically roman `` confessor '' position in some of the more historic and conservative reformation churches , such as some of the lutheran and anglican . 
there are many forms of spiritual or religious teachers in christianity , across all three major traditions - -lrb- roman -rrb- catholic , -lrb- eastern -rrb- orthodox catholic , and protestant/non-denominational , with a stronger tradition of spiritual formation in the more historic and authoritarian/hierarchical christian traditions with a long tradition of `` discernment of spirits '' , of vocations , and other aspects of spiritual life , especially the roman and orthodox catholic churches . 
in the church of jesus christ of latter-day saints -lrb- lds church -rrb- , the teacher is an office in the aaronic priesthood , generally conferred on young boys or recent converts , and has little in common with the `` spiritual teacher '' archetype . 
the role of `` spiritual teacher '' may be filled by many individuals in the lds church , often a trusted friend , who may hold any office , from elder to bishop , or no office at all . 
in the church of jesus christ of latter-day saints -lrb- lds church -rrb- , the teacher is an office in the aaronic priesthood , generally conferred on young boys or recent converts , and has little in common with the `` spiritual teacher '' archetype . 
the emphasis on spiritual mentorship in the lds church is similar to that in the more `` low-church '' traditions of protestantism , with a stronger emphasis placed on the husband and father of a family to provide spiritual guidance for all of his family , ideally in consultation with his wife , even if the husband is not a member of the lds church , based on interpretatios of certain biblical texts which proclaim the spiritual authority of husbands in marriage . 
even priesthood representatives are expected to defer to the father of the house when in his home . 
in hinduism the spiritual teacher is known as a guru , and , in many traditions of hinduism - especially those common in the west - the emphasis on spiritual mentorship is extremely high , with gurus often exercising a great deal of control over the lives of their disciples . 
in hinduism the spiritual teacher is known as a guru , and , in many traditions of hinduism - especially those common in the west - the emphasis on spiritual mentorship is extremely high , with gurus often exercising a great deal of control over the lives of their disciples . 
in hinduism the spiritual teacher is known as a guru , and , in many traditions of hinduism - especially those common in the west - the emphasis on spiritual mentorship is extremely high , with gurus often exercising a great deal of control over the lives of their disciples . 
in hinduism the spiritual teacher is known as a guru , and , in many traditions of hinduism - especially those common in the west - the emphasis on spiritual mentorship is extremely high , with gurus often exercising a great deal of control over the lives of their disciples . 
in tibetan buddhism the teachers of dharma in tibet are most commonly called a lama . 
a lama who has through phowa and siddhi consciously determined to be reborn , often many times , in order to continue their bodhisattva vow is called a tulku . 
a lama who has through phowa and siddhi consciously determined to be reborn , often many times , in order to continue their bodhisattva vow is called a tulku . 
a lama who has through phowa and siddhi consciously determined to be reborn , often many times , in order to continue their bodhisattva vow is called a tulku . 
a lama who has through phowa and siddhi consciously determined to be reborn , often many times , in order to continue their bodhisattva vow is called a tulku . 
there are many concepts of teachers in islam , ranging from mullahs -lrb- the teachers at madrassas -rrb- to ulemas , who teach of the laws of islam for the proper way of islamic living according to the sunnah and ahadith , and can render legal verdicts upon matters of islamic law in accordance with the teaching of one of the four schools of jurisprudence . 
there are many concepts of teachers in islam , ranging from mullahs -lrb- the teachers at madrassas -rrb- to ulemas , who teach of the laws of islam for the proper way of islamic living according to the sunnah and ahadith , and can render legal verdicts upon matters of islamic law in accordance with the teaching of one of the four schools of jurisprudence . 
in the more spiritual or mystical islamic tradition of sufism , the position of spiritual teacher and an esoteric -lrb- as opposed to exoteric , or actions-oriented , e.g. the five pillars of islam -rrb- spirituality and spiritual knowledge takes on a more important dimension , with emphasis on learning from living saints - the highest of which is a qutb - and of traditions passed down from initiate to initiate , and traceable back to the founder of the order . 
in the more spiritual or mystical islamic tradition of sufism , the position of spiritual teacher and an esoteric -lrb- as opposed to exoteric , or actions-oriented , e.g. the five pillars of islam -rrb- spirituality and spiritual knowledge takes on a more important dimension , with emphasis on learning from living saints - the highest of which is a qutb - and of traditions passed down from initiate to initiate , and traceable back to the founder of the order . 
in the more spiritual or mystical islamic tradition of sufism , the position of spiritual teacher and an esoteric -lrb- as opposed to exoteric , or actions-oriented , e.g. the five pillars of islam -rrb- spirituality and spiritual knowledge takes on a more important dimension , with emphasis on learning from living saints - the highest of which is a qutb - and of traditions passed down from initiate to initiate , and traceable back to the founder of the order . 
martin luther -lrb- / ˈluːθər / or / ˈluːðər / ; german : -lsb- ˈmaɐ̯tiːn ˈlʊtɐ -rsb- -lrb- listen -rrb- ; 10 november 1483 -- 18 february 1546 -rrb- was a german professor of theology , composer , priest , former monk and a seminal figure in the protestant reformation . 
martin luther -lrb- / ˈluːθər / or / ˈluːðər / ; german : -lsb- ˈmaɐ̯tiːn ˈlʊtɐ -rsb- -lrb- listen -rrb- ; 10 november 1483 -- 18 february 1546 -rrb- was a german professor of theology , composer , priest , former monk and a seminal figure in the protestant reformation . 
luther came to reject several teachings and practices of the late medieval catholic church . 
he strongly disputed the claim that freedom from god 's punishment for sin could be purchased with money . 
his refusal to retract all of his writings at the demand of pope leo x in 1520 and the holy roman emperor charles v at the diet of worms in 1521 resulted in his excommunication by the pope and condemnation as an outlaw by the emperor . 
luther taught that salvation and subsequently eternal life is not earned by good deeds but is received only as a free gift of god 's grace through faith in jesus christ as redeemer from sin . 
luther taught that salvation and subsequently eternal life is not earned by good deeds but is received only as a free gift of god 's grace through faith in jesus christ as redeemer from sin . 
his theology challenged the authority and office of the pope by teaching that the bible is the only source of divinely revealed knowledge from god and opposed sacerdotalism by considering all baptized christians to be a holy priesthood . 
his theology challenged the authority and office of the pope by teaching that the bible is the only source of divinely revealed knowledge from god and opposed sacerdotalism by considering all baptized christians to be a holy priesthood . 
his theology challenged the authority and office of the pope by teaching that the bible is the only source of divinely revealed knowledge from god and opposed sacerdotalism by considering all baptized christians to be a holy priesthood . 
his translation of the bible into the vernacular -lrb- instead of latin -rrb- made it more accessible , which had a tremendous impact on the church and german culture . 
it fostered the development of a standard version of the german language , added several principles to the art of translation , and influenced the writing of an english translation , the tyndale bible . 
it fostered the development of a standard version of the german language , added several principles to the art of translation , and influenced the writing of an english translation , the tyndale bible . 
his hymns influenced the development of singing in churches . 
his marriage to katharina von bora set a model for the practice of clerical marriage , allowing protestant clergy to marry . 
martin luther was born to hans luder -lrb- or ludher , later luther -rrb- and his wife margarethe -lrb- née lindemann -rrb- on 10 november 1483 in eisleben , saxony , then part of the holy roman empire . 
martin luther was born to hans luder -lrb- or ludher , later luther -rrb- and his wife margarethe -lrb- née lindemann -rrb- on 10 november 1483 in eisleben , saxony , then part of the holy roman empire . 
martin luther was born to hans luder -lrb- or ludher , later luther -rrb- and his wife margarethe -lrb- née lindemann -rrb- on 10 november 1483 in eisleben , saxony , then part of the holy roman empire . 
he was baptized as a catholic the next morning on the feast day of st. martin of tours . 
hans luther was ambitious for himself and his family , and he was determined to see martin , his eldest son , become a lawyer . 
in 1501 , at the age of 19 , he entered the university of erfurt , which he later described as a beerhouse and whorehouse . 
in 1501 , at the age of 19 , he entered the university of erfurt , which he later described as a beerhouse and whorehouse . 
he was made to wake at four every morning for what has been described as `` a day of rote learning and often wearying spiritual exercises . '' 
he was made to wake at four every morning for what has been described as `` a day of rote learning and often wearying spiritual exercises . '' 
he received his master 's degree in 1505 . 
in accordance with his father 's wishes , luther enrolled in law school at the same university that year but dropped out almost immediately , believing that law represented uncertainty . 
in accordance with his father 's wishes , luther enrolled in law school at the same university that year but dropped out almost immediately , believing that law represented uncertainty . 
luther sought assurances about life and was drawn to theology and philosophy , expressing particular interest in aristotle , william of ockham , and gabriel biel . 
he was deeply influenced by two tutors , bartholomaeus arnoldi von usingen and jodocus trutfetter , who taught him to be suspicious of even the greatest thinkers and to test everything himself by experience . 
for luther , reason could be used to question men and institutions , but not god . 
later telling his father he was terrified of death and divine judgment , he cried out , `` help ! 
he later attributed his decision to an event : on 2 july 1505 , he was returning to university on horseback after a trip home . 
he left law school , sold his books , and entered a closed augustinian cloister in erfurt on 17 july 1505 . 
one friend blamed the decision on luther 's sadness over the deaths of two friends . 
his father was furious over what he saw as a waste of luther 's education . 
luther dedicated himself to the augustinian order , devoting himself to fasting , long hours in prayer , pilgrimage , and frequent confession . 
luther described this period of his life as one of deep spiritual despair . 
he said , `` i lost touch with christ the savior and comforter , and made of him the jailer and hangman of my poor soul . '' 
johann von staupitz , his superior , pointed luther 's mind away from continual reflection upon his sins toward the merits of christ . 
he taught that true repentance does not involve self-inflicted penances and punishments but rather a change of heart . 
in 1507 , he was ordained to the priesthood , and in 1508 , von staupitz , first dean of the newly founded university of wittenberg , sent for luther , to teach theology . 
in 1507 , he was ordained to the priesthood , and in 1508 , von staupitz , first dean of the newly founded university of wittenberg , sent for luther , to teach theology . 
in 1507 , he was ordained to the priesthood , and in 1508 , von staupitz , first dean of the newly founded university of wittenberg , sent for luther , to teach theology . 
he received a bachelor 's degree in biblical studies on 9 march 1508 , and another bachelor 's degree in the sentences by peter lombard in 1509 . 
he received a bachelor 's degree in biblical studies on 9 march 1508 , and another bachelor 's degree in the sentences by peter lombard in 1509 . 
on 19 october 1512 , he was awarded his doctor of theology and , on 21 october 1512 , was received into the senate of the theological faculty of the university of wittenberg , having been called to the position of doctor in bible . 
on 19 october 1512 , he was awarded his doctor of theology and , on 21 october 1512 , was received into the senate of the theological faculty of the university of wittenberg , having been called to the position of doctor in bible . 
on 19 october 1512 , he was awarded his doctor of theology and , on 21 october 1512 , was received into the senate of the theological faculty of the university of wittenberg , having been called to the position of doctor in bible . 
he spent the rest of his career in this position at the university of wittenberg . 
on 19 october 1512 , he was awarded his doctor of theology and , on 21 october 1512 , was received into the senate of the theological faculty of the university of wittenberg , having been called to the position of doctor in bible . 
in 1516 , johann tetzel , a dominican friar and papal commissioner for indulgences , was sent to germany by the roman catholic church to sell indulgences to raise money to rebuild st. peter 's basilica in rome . 
in 1516 , johann tetzel , a dominican friar and papal commissioner for indulgences , was sent to germany by the roman catholic church to sell indulgences to raise money to rebuild st. peter 's basilica in rome . 
roman catholic theology stated that faith alone , whether fiduciary or dogmatic , can not justify man ; justification rather depends only on such faith as is active in charity and good works -lrb- fides caritate formata -rrb- . 
roman catholic theology stated that faith alone , whether fiduciary or dogmatic , can not justify man ; justification rather depends only on such faith as is active in charity and good works -lrb- fides caritate formata -rrb- . 
roman catholic theology stated that faith alone , whether fiduciary or dogmatic , can not justify man ; justification rather depends only on such faith as is active in charity and good works -lrb- fides caritate formata -rrb- . 
on 31 october 1517 , luther wrote to his bishop , albert of mainz , protesting the sale of indulgences . 
on 31 october 1517 , luther wrote to his bishop , albert of mainz , protesting the sale of indulgences . 
he enclosed in his letter a copy of his `` disputation of martin luther on the power and efficacy of indulgences '' , which came to be known as the ninety-five theses . 
hans hillerbrand writes that luther had no intention of confronting the church , but saw his disputation as a scholarly objection to church practices , and the tone of the writing is accordingly `` searching , rather than doctrinaire . '' 
hillerbrand writes that there is nevertheless an undercurrent of challenge in several of the theses , particularly in thesis 86 , which asks : `` why does the pope , whose wealth today is greater than the wealth of the richest crassus , build the basilica of st. peter with the money of poor believers rather than with his own money ? '' 
luther objected to a saying attributed to johann tetzel that `` as soon as the coin in the coffer rings , the soul from purgatory -lrb- also attested as ` into heaven ' -rrb- springs . '' 
luther objected to a saying attributed to johann tetzel that `` as soon as the coin in the coffer rings , the soul from purgatory -lrb- also attested as ` into heaven ' -rrb- springs . '' 
luther objected to a saying attributed to johann tetzel that `` as soon as the coin in the coffer rings , the soul from purgatory -lrb- also attested as ` into heaven ' -rrb- springs . '' 
luther objected to a saying attributed to johann tetzel that `` as soon as the coin in the coffer rings , the soul from purgatory -lrb- also attested as ` into heaven ' -rrb- springs . '' 
he insisted that , since forgiveness was god 's alone to grant , those who claimed that indulgences absolved buyers from all punishments and granted them salvation were in error . 
he insisted that , since forgiveness was god 's alone to grant , those who claimed that indulgences absolved buyers from all punishments and granted them salvation were in error . 
he insisted that , since forgiveness was god 's alone to grant , those who claimed that indulgences absolved buyers from all punishments and granted them salvation were in error . 
christians , he said , must not slacken in following christ on account of such false assurances . 
christians , he said , must not slacken in following christ on account of such false assurances . 
however , this oft-quoted saying of tetzel was by no means representative of contemporary catholic teaching on indulgences , but rather a reflection of his capacity to exaggerate . 
however , this oft-quoted saying of tetzel was by no means representative of contemporary catholic teaching on indulgences , but rather a reflection of his capacity to exaggerate . 
yet if tetzel overstated the matter in regard to indulgences for the dead , his teaching on indulgences for the living was in line with catholic dogma of the time . 
yet if tetzel overstated the matter in regard to indulgences for the dead , his teaching on indulgences for the living was in line with catholic dogma of the time . 
according to scholars walter krämer , götz trenkler , gerhard ritter , and gerhard prause , the story of the posting on the door , even though it has settled as one of the pillars of history , has little foundation in truth . 
according to scholars walter krämer , götz trenkler , gerhard ritter , and gerhard prause , the story of the posting on the door , even though it has settled as one of the pillars of history , has little foundation in truth . 
the story is based on comments made by philipp melanchthon , though it is thought that he was not in wittenberg at the time . 
the story is based on comments made by philipp melanchthon , though it is thought that he was not in wittenberg at the time . 
according to scholars walter krämer , götz trenkler , gerhard ritter , and gerhard prause , the story of the posting on the door , even though it has settled as one of the pillars of history , has little foundation in truth . 
it was not until january 1518 that friends of luther translated the 95 theses from latin into german and printed and widely copied them , making the controversy one of the first in history to be aided by the printing press . 
it was not until january 1518 that friends of luther translated the 95 theses from latin into german and printed and widely copied them , making the controversy one of the first in history to be aided by the printing press . 
it was not until january 1518 that friends of luther translated the 95 theses from latin into german and printed and widely copied them , making the controversy one of the first in history to be aided by the printing press . 
within two weeks , copies of the theses had spread throughout germany ; within two months , they had spread throughout europe . 
within two weeks , copies of the theses had spread throughout germany ; within two months , they had spread throughout europe . 
luther 's writings circulated widely , reaching france , england , and italy as early as 1519 . 
students thronged to wittenberg to hear luther speak . 
this early part of luther 's career was one of his most creative and productive . 
three of his best-known works were published in 1520 : to the christian nobility of the german nation , on the babylonian captivity of the church , and on the freedom of a christian . 
three of his best-known works were published in 1520 : to the christian nobility of the german nation , on the babylonian captivity of the church , and on the freedom of a christian . 
from 1510 to 1520 , luther lectured on the psalms , the books of hebrews , romans , and galatians . 
as he studied these portions of the bible , he came to view the use of terms such as penance and righteousness by the catholic church in new ways . 
he became convinced that the church was corrupt in its ways and had lost sight of what he saw as several of the central truths of christianity . 
he became convinced that the church was corrupt in its ways and had lost sight of what he saw as several of the central truths of christianity . 
the most important for luther was the doctrine of justification -- god 's act of declaring a sinner righteous -- by faith alone through god 's grace . 
luther came to understand justification as entirely the work of god . 
this teaching by luther was clearly expressed in his 1525 publication on the bondage of the will , which was written in response to on free will by desiderius erasmus -lrb- 1524 -rrb- . 
faith , for luther , was a gift from god ; the experience of being justified by faith was `` as though i had been born again . '' 
he explained his concept of `` justification '' in the smalcald articles : 
his entry into paradise , no less , was a discovery about `` the righteousness of god '' -- a discovery that `` the just person '' of whom the bible speaks -lrb- as in romans 1:17 -rrb- lives by faith . 
luther 's rediscovery of `` christ and his salvation '' was the first of two points that became the foundation for the reformation . 
luther 's rediscovery of `` christ and his salvation '' was the first of two points that became the foundation for the reformation . 
his railing against the sale of indulgences was based on it . 
luther 's rediscovery of `` christ and his salvation '' was the first of two points that became the foundation for the reformation . 
archbishop albrecht of mainz and magdeburg did not reply to luther 's letter containing the 95 theses . 
he had the theses checked for heresy and in december 1517 forwarded them to rome . 
he needed the revenue from the indulgences to pay off a papal dispensation for his tenure of more than one bishopric . 
as luther later noted , `` the pope had a finger in the pie as well , because one half was to go to the building of st peter 's church in rome '' . 
he had the theses checked for heresy and in december 1517 forwarded them to rome . 
pope leo x was used to reformers and heretics , and he responded slowly , `` with great care as is proper . '' 
over the next three years he deployed a series of papal theologians and envoys against luther , which served only to harden the reformer 's anti-papal theology . 
there , in october 1518 , under questioning by papal legate cardinal cajetan luther stated that he did not consider the papacy part of the biblical church because historistical interpretation of bible prophecy concluded that the papacy was the antichrist . 
there , in october 1518 , under questioning by papal legate cardinal cajetan luther stated that he did not consider the papacy part of the biblical church because historistical interpretation of bible prophecy concluded that the papacy was the antichrist . 
cajetan 's original instructions had been to arrest luther if he failed to recant , but the legate desisted from doing so . 
in january 1519 , at altenburg in saxony , the papal nuncio karl von miltitz adopted a more conciliatory approach . 
luther made certain concessions to the saxon , who was a relative of the elector , and promised to remain silent if his opponents did . 
the theologian johann eck , however , was determined to expose luther 's doctrine in a public forum . 
luther 's boldest assertion in the debate was that matthew 16:18 does not confer on popes the exclusive right to interpret scripture , and that therefore neither popes nor church councils were infallible . 
for this , eck branded luther a new jan hus , referring to the czech reformer and heretic burned at the stake in 1415 . 
on 15 june 1520 , the pope warned luther with the papal bull -lrb- edict -rrb- exsurge domine that he risked excommunication unless he recanted 41 sentences drawn from his writings , including the 95 theses , within 60 days . 
on 15 june 1520 , the pope warned luther with the papal bull -lrb- edict -rrb- exsurge domine that he risked excommunication unless he recanted 41 sentences drawn from his writings , including the 95 theses , within 60 days . 
on 15 june 1520 , the pope warned luther with the papal bull -lrb- edict -rrb- exsurge domine that he risked excommunication unless he recanted 41 sentences drawn from his writings , including the 95 theses , within 60 days . 
karl von miltitz , a papal nuncio , attempted to broker a solution , but luther , who had sent the pope a copy of on the freedom of a christian in october , publicly set fire to the bull and decretals at wittenberg on 10 december 1520 , an act he defended in why the pope and his recent book are burned and assertions concerning all articles . 
as a consequence , luther was excommunicated by pope leo x on 3 january 1521 , in the bull decet romanum pontificem . 
the enforcement of the ban on the 95 theses fell to the secular authorities . 
on 18 april 1521 , luther appeared as ordered before the diet of worms . 
this was a general assembly of the estates of the holy roman empire that took place in worms , a town on the rhine . 
it was conducted from 28 january to 25 may 1521 , with emperor charles v presiding . 
prince frederick iii , elector of saxony , obtained a safe conduct for luther to and from the meeting . 
johann eck , speaking on behalf of the empire as assistant of the archbishop of trier , presented luther with copies of his writings laid out on a table and asked him if the books were his , and whether he stood by their contents . 
johann eck , speaking on behalf of the empire as assistant of the archbishop of trier , presented luther with copies of his writings laid out on a table and asked him if the books were his , and whether he stood by their contents . 
johann eck , speaking on behalf of the empire as assistant of the archbishop of trier , presented luther with copies of his writings laid out on a table and asked him if the books were his , and whether he stood by their contents . 
he prayed , consulted friends , and gave his response the next day : 
luther confirmed he was their author , but requested time to think about the answer to the second question . 
at the end of this speech , luther raised his arm `` in the traditional salute of a knight winning a bout . '' 
at the end of this speech , luther raised his arm `` in the traditional salute of a knight winning a bout . '' 
michael mullett considers this speech as a `` world classic of epoch-making oratory . '' 
michael mullett considers this speech as a `` world classic of epoch-making oratory . '' 
luther refused to recant his writings . 
luther refused to recant his writings . 
recent scholars consider the evidence for these words to be unreliable , since they were inserted before `` may god help me '' only in later versions of the speech and not recorded in witness accounts of the proceedings . 
however , mullett suggests that given his nature , `` we are free to believe that luther would tend to select the more dramatic form of words . '' 
over the next five days , private conferences were held to determine luther 's fate . 
the emperor presented the final draft of the edict of worms on 25 may 1521 , declaring luther an outlaw , banning his literature , and requiring his arrest : `` we want him to be apprehended and punished as a notorious heretic . '' 
the emperor presented the final draft of the edict of worms on 25 may 1521 , declaring luther an outlaw , banning his literature , and requiring his arrest : `` we want him to be apprehended and punished as a notorious heretic . '' 
the emperor presented the final draft of the edict of worms on 25 may 1521 , declaring luther an outlaw , banning his literature , and requiring his arrest : `` we want him to be apprehended and punished as a notorious heretic . '' 
it permitted anyone to kill luther without legal consequence . 
luther 's disappearance during his return trip back to wittenberg was planned . 
they escorted luther to the security of the wartburg castle at eisenach . 
during his stay at wartburg , which he referred to as `` my patmos '' , luther translated the new testament from greek into german and poured out doctrinal and polemical writings . 
during his stay at wartburg , which he referred to as `` my patmos '' , luther translated the new testament from greek into german and poured out doctrinal and polemical writings . 
these included a renewed attack on archbishop albrecht of mainz , whom he shamed into halting the sale of indulgences in his episcopates , and a `` refutation of the argument of latomus , '' in which he expounded the principle of justification to jacobus latomus , an orthodox theologian from louvain . 
in this work , one of his most emphatic statements on faith , he argued that every good work designed to attract god 's favor is a sin . 
all humans are sinners by nature , he explained , and god 's grace -lrb- which can not be earned -rrb- alone can make them just . 
on 1 august 1521 , luther wrote to melanchthon on the same theme : `` be a sinner , and let your sins be strong , but let your trust in christ be stronger , and rejoice in christ who is the victor over sin , death , and the world . 
on 1 august 1521 , luther wrote to melanchthon on the same theme : `` be a sinner , and let your sins be strong , but let your trust in christ be stronger , and rejoice in christ who is the victor over sin , death , and the world . 
we will commit sins while we are here , for this life is not a place where justice resides . '' 
in the summer of 1521 , luther widened his target from individual pieties like indulgences and pilgrimages to doctrines at the heart of church practices . 
in on the abrogation of the private mass , he condemned as idolatry the idea that the mass is a sacrifice , asserting instead that it is a gift , to be received with thanksgiving by the whole congregation . 
in on the abrogation of the private mass , he condemned as idolatry the idea that the mass is a sacrifice , asserting instead that it is a gift , to be received with thanksgiving by the whole congregation . 
his essay on confession , whether the pope has the power to require it rejected compulsory confession and encouraged private confession and absolution , since `` every christian is a confessor . '' 
he assured monks and nuns that they could break their vows without sin , because vows were an illegitimate and vain attempt to win salvation . 
in 1521 luther dealt largely with prophecy , in which he broadened the foundations of the reformation placing them on prophetic faith . 
in 1521 luther dealt largely with prophecy , in which he broadened the foundations of the reformation placing them on prophetic faith . 
his main interest was centered on the prophecy of the little horn in daniel 8:9 -- 12 , 23 -- 25 . 
his main interest was centered on the prophecy of the little horn in daniel 8:9 -- 12 , 23 -- 25 . 
the antichrist of 2 thessalonians 2 was identified as the power of the papacy . 
andreas karlstadt , supported by the ex-augustinian gabriel zwilling , embarked on a radical programme of reform there in june 1521 , exceeding anything envisaged by luther . 
andreas karlstadt , supported by the ex-augustinian gabriel zwilling , embarked on a radical programme of reform there in june 1521 , exceeding anything envisaged by luther . 
the reforms provoked disturbances , including a revolt by the augustinian friars against their prior , the smashing of statues and images in churches , and denunciations of the magistracy . 
wittenberg became even more volatile after christmas when a band of visionary zealots , the so-called zwickau prophets , arrived , preaching revolutionary doctrines such as the equality of man , adult baptism , and christ 's imminent return . 
when the town council asked luther to return , he decided it was his duty to act . 
luther secretly returned to wittenberg on 6 march 1522 . 
he wrote to the elector : `` during my absence , satan has entered my sheepfold , and committed ravages which i can not repair by writing , but only by my personal presence and living word . '' 
for eight days in lent , beginning on invocavit sunday , 9 march , luther preached eight sermons , which became known as the `` invocavit sermons '' . 
for eight days in lent , beginning on invocavit sunday , 9 march , luther preached eight sermons , which became known as the `` invocavit sermons '' . 
in these sermons , he hammered home the primacy of core christian values such as love , patience , charity , and freedom , and reminded the citizens to trust god 's word rather than violence to bring about necessary change . 
the effect of luther 's intervention was immediate . 
after the sixth sermon , the wittenberg jurist jerome schurf wrote to the elector : `` oh , what joy has dr. martin 's return spread among us ! 
after the sixth sermon , the wittenberg jurist jerome schurf wrote to the elector : `` oh , what joy has dr. martin 's return spread among us ! 
after the sixth sermon , the wittenberg jurist jerome schurf wrote to the elector : `` oh , what joy has dr. martin 's return spread among us ! 
his words , through divine mercy , are bringing back every day misguided people into the way of the truth . '' 
by working alongside the authorities to restore public order , he signalled his reinvention as a conservative force within the reformation . 
by working alongside the authorities to restore public order , he signalled his reinvention as a conservative force within the reformation . 
after banishing the zwickau prophets , he now faced a battle against not only the established church but also the radical reformers who threatened the new order by fomenting social unrest and violence . 
after banishing the zwickau prophets , he now faced a battle against not only the established church but also the radical reformers who threatened the new order by fomenting social unrest and violence . 
after banishing the zwickau prophets , he now faced a battle against not only the established church but also the radical reformers who threatened the new order by fomenting social unrest and violence . 
preachers such as zwickau prophet nicholas storch and thomas müntzer helped instigate the german peasants ' war of 1524 -- 25 , during which many atrocities were committed , often in luther 's name . 
preachers such as zwickau prophet nicholas storch and thomas müntzer helped instigate the german peasants ' war of 1524 -- 25 , during which many atrocities were committed , often in luther 's name . 
preachers such as zwickau prophet nicholas storch and thomas müntzer helped instigate the german peasants ' war of 1524 -- 25 , during which many atrocities were committed , often in luther 's name . 
luther 's pamphlets against the church and the hierarchy , often worded with `` liberal '' phraseology , now led many peasants to believe he would support an attack on the upper classes in general . 
luther 's pamphlets against the church and the hierarchy , often worded with `` liberal '' phraseology , now led many peasants to believe he would support an attack on the upper classes in general . 
luther sympathised with some of the peasants ' grievances , as he showed in his response to the twelve articles in may 1525 , but he reminded the aggrieved to obey the temporal authorities . 
during a tour of thuringia , he became enraged at the widespread burning of convents , monasteries , bishops ' palaces , and libraries . 
in against the murderous , thieving hordes of peasants , written on his return to wittenberg , he gave his interpretation of the gospel teaching on wealth , condemned the violence as the devil 's work , and called for the nobles to put down the rebels like mad dogs : 
in against the murderous , thieving hordes of peasants , written on his return to wittenberg , he gave his interpretation of the gospel teaching on wealth , condemned the violence as the devil 's work , and called for the nobles to put down the rebels like mad dogs : 
in against the murderous , thieving hordes of peasants , written on his return to wittenberg , he gave his interpretation of the gospel teaching on wealth , condemned the violence as the devil 's work , and called for the nobles to put down the rebels like mad dogs : 
luther justified his opposition to the rebels on three grounds . 
first , in choosing violence over lawful submission to the secular government , they were ignoring christ 's counsel to `` render unto caesar the things that are caesar 's '' ; st. paul had written in his epistle to the romans 13:1 -- 7 that all authorities are appointed by god and therefore should not be resisted . 
first , in choosing violence over lawful submission to the secular government , they were ignoring christ 's counsel to `` render unto caesar the things that are caesar 's '' ; st. paul had written in his epistle to the romans 13:1 -- 7 that all authorities are appointed by god and therefore should not be resisted . 
this reference from the bible forms the foundation for the doctrine known as the divine right of kings , or , in the german case , the divine right of the princes . 
second , the violent actions of rebelling , robbing , and plundering placed the peasants `` outside the law of god and empire '' , so they deserved `` death in body and soul , if only as highwaymen and murderers . '' 
without luther 's backing for the uprising , many rebels laid down their weapons ; others felt betrayed . 
their defeat by the swabian league at the battle of frankenhausen on 15 may 1525 , followed by müntzer 's execution , brought the revolutionary stage of the reformation to a close . 
their defeat by the swabian league at the battle of frankenhausen on 15 may 1525 , followed by müntzer 's execution , brought the revolutionary stage of the reformation to a close . 
their defeat by the swabian league at the battle of frankenhausen on 15 may 1525 , followed by müntzer 's execution , brought the revolutionary stage of the reformation to a close . 
thereafter , radicalism found a refuge in the anabaptist movement and other religious movements , while luther 's reformation flourished under the wing of the secular powers . 
martin luther married katharina von bora , one of 12 nuns he had helped escape from the nimbschen cistercian convent in april 1523 , when he arranged for them to be smuggled out in herring barrels . 
martin luther married katharina von bora , one of 12 nuns he had helped escape from the nimbschen cistercian convent in april 1523 , when he arranged for them to be smuggled out in herring barrels . 
at the time of their marriage , katharina was 26 years old and luther was 41 years old . 
at the time of their marriage , katharina was 26 years old and luther was 41 years old . 
martin luther married katharina von bora , one of 12 nuns he had helped escape from the nimbschen cistercian convent in april 1523 , when he arranged for them to be smuggled out in herring barrels . 
on 13 june 1525 , the couple was engaged with johannes bugenhagen , justus jonas , johannes apel , philipp melanchthon and lucas cranach the elder and his wife as witnesses . 
on the evening of the same day , the couple was married by bugenhagen . 
the ceremonial walk to the church and the wedding banquet were left out , and were made up two weeks later on 27 june . 
the ceremonial walk to the church and the wedding banquet were left out , and were made up two weeks later on 27 june . 
on 13 june 1525 , the couple was engaged with johannes bugenhagen , justus jonas , johannes apel , philipp melanchthon and lucas cranach the elder and his wife as witnesses . 
some priests and former religious had already married , including andreas karlstadt and justus jonas , but luther 's wedding set the seal of approval on clerical marriage . 
some priests and former religious had already married , including andreas karlstadt and justus jonas , but luther 's wedding set the seal of approval on clerical marriage . 
he had long condemned vows of celibacy on biblical grounds , but his decision to marry surprised many , not least melanchthon , who called it reckless . 
not that i am insensible to my flesh or sex -lrb- for i am neither wood nor stone -rrb- ; but my mind is averse to wedlock because i daily expect the death of a heretic . '' 
he had long condemned vows of celibacy on biblical grounds , but his decision to marry surprised many , not least melanchthon , who called it reckless . 
luther and his wife moved into a former monastery , `` the black cloister , '' a wedding present from the new elector john the steadfast -lrb- 1525 -- 32 -rrb- . 
luther and his wife moved into a former monastery , `` the black cloister , '' a wedding present from the new elector john the steadfast -lrb- 1525 -- 32 -rrb- . 
between bearing six children , hans -- june 1526 ; elizabeth -- 10 december 1527 , who died within a few months ; magdalene -- 1529 , who died in luther 's arms in 1542 ; martin -- 1531 ; paul -- january 1533 ; and margaret -- 1534 ; katharina helped the couple earn a living by farming the land and taking in boarders . 
luther confided to michael stiefel on 11 august 1526 : `` my katie is in all things so obliging and pleasing to me that i would not exchange my poverty for the riches of croesus . '' 
between bearing six children , hans -- june 1526 ; elizabeth -- 10 december 1527 , who died within a few months ; magdalene -- 1529 , who died in luther 's arms in 1542 ; martin -- 1531 ; paul -- january 1533 ; and margaret -- 1534 ; katharina helped the couple earn a living by farming the land and taking in boarders . 
his biblical ideal of congregations ' choosing their own ministers had proved unworkable . 
from 1525 to 1529 , he established a supervisory church body , laid down a new form of worship service , and wrote a clear summary of the new faith in the form of two catechisms . 
from 1525 to 1529 , he established a supervisory church body , laid down a new form of worship service , and wrote a clear summary of the new faith in the form of two catechisms . 
from 1525 to 1529 , he established a supervisory church body , laid down a new form of worship service , and wrote a clear summary of the new faith in the form of two catechisms . 
luther 's thought is revolutionary to the extent that it is a theology of the cross , the negation of every affirmation : as long as the cross is at the center , the system building tendency of reason is held in check , and system building does not degenerate into system . 
to avoid confusing or upsetting the people , luther avoided extreme change . 
he concentrated on the church in the electorate of saxony , acting only as an adviser to churches in new territories , many of which followed his saxon model . 
he concentrated on the church in the electorate of saxony , acting only as an adviser to churches in new territories , many of which followed his saxon model . 
he worked closely with the new elector , john the steadfast , to whom he turned for secular leadership and funds on behalf of a church largely shorn of its assets and income after the break with rome . 
for luther 's biographer martin brecht , this partnership `` was the beginning of a questionable and originally unintended development towards a church government under the temporal sovereign '' . 
in response to demands for a german liturgy , luther wrote a german mass , which he published in early 1526 . 
he did not intend it as a replacement for his 1523 adaptation of the latin mass but as an alternative for the `` simple people '' , a `` public stimulation for people to believe and become christians . '' 
he did not intend it as a replacement for his 1523 adaptation of the latin mass but as an alternative for the `` simple people '' , a `` public stimulation for people to believe and become christians . '' 
luther based his order on the catholic service but omitted `` everything that smacks of sacrifice '' ; and the mass became a celebration where everyone received the wine as well as the bread . 
he retained the elevation of the host and chalice , while trappings such as the mass vestments , altar , and candles were made optional , allowing freedom of ceremony . 
luther and his colleagues introduced the new order of worship during their visitation of the electorate of saxony , which began in 1527 . 
luther and his colleagues introduced the new order of worship during their visitation of the electorate of saxony , which began in 1527 . 
they also assessed the standard of pastoral care and christian education in the territory . 
`` merciful god , what misery i have seen , '' luther wrote , `` the common people knowing nothing at all of christian doctrine ... and unfortunately many pastors are well-nigh unskilled and incapable of teaching . '' 
`` merciful god , what misery i have seen , '' luther wrote , `` the common people knowing nothing at all of christian doctrine ... and unfortunately many pastors are well-nigh unskilled and incapable of teaching . '' 
luther devised the catechism as a method of imparting the basics of christianity to the congregations . 
in 1529 , he wrote the large catechism , a manual for pastors and teachers , as well as a synopsis , the small catechism , to be memorised by the people themselves . 
in 1529 , he wrote the large catechism , a manual for pastors and teachers , as well as a synopsis , the small catechism , to be memorised by the people themselves . 
in 1529 , he wrote the large catechism , a manual for pastors and teachers , as well as a synopsis , the small catechism , to be memorised by the people themselves . 
luther incorporated questions and answers in the catechism so that the basics of christian faith would not just be learned by rote , `` the way monkeys do it '' , but understood . 
the catechism is one of luther 's most personal works . 
`` regarding the plan to collect my writings in volumes , '' he wrote , `` i am quite cool and not at all eager about it because , roused by a saturnian hunger , i would rather see them all devoured . 
for i acknowledge none of them to be really a book of mine , except perhaps the bondage of the will and the catechism . '' 
the small catechism has earned a reputation as a model of clear religious teaching . 
it remains in use today , along with luther 's hymns and his translation of the bible . 
luther 's small catechism proved especially effective in helping parents teach their children ; likewise the larger catechism was effective for pastors . 
luther 's small catechism proved especially effective in helping parents teach their children ; likewise the larger catechism was effective for pastors . 
using the german vernacular , they expressed the apostles ' creed in simpler , more personal , trinitarian language . 
that is , luther depicted the trinity not as a doctrine to be learned , but as persons to be known . 
salvation originates with the father and draws the believer to the father . 
luther had published his german translation of the new testament in 1522 , and he and his collaborators completed the translation of the old testament in 1534 , when the whole bible was published . 
luther had published his german translation of the new testament in 1522 , and he and his collaborators completed the translation of the old testament in 1534 , when the whole bible was published . 
he continued to work on refining the translation until the end of his life . 
when he was criticised for inserting the word `` alone '' after `` faith '' in romans 3:28 , he replied in part : '' -lsb- t -rsb- he text itself and the meaning of st. paul urgently require and demand it . 
... but when works are so completely cut away -- and that must mean that faith alone justifies -- whoever would speak plainly and clearly about this cutting away of works will have to say , ` faith alone justifies us , and not works ' . '' 
luther 's translation used the variant of german spoken at the saxon chancellery , intelligible to both northern and southern germans . 
luther 's translation used the variant of german spoken at the saxon chancellery , intelligible to both northern and southern germans . 
he intended his vigorous , direct language to make the bible accessible to everyday germans , `` for we are removing impediments and difficulties so that other people may read it without hindrance . '' 
he intended his vigorous , direct language to make the bible accessible to everyday germans , `` for we are removing impediments and difficulties so that other people may read it without hindrance . '' 
he intended his vigorous , direct language to make the bible accessible to everyday germans , `` for we are removing impediments and difficulties so that other people may read it without hindrance . '' 
published at a time of rising demand for german-language publications , luther 's version quickly became a popular and influential bible translation . 
published at a time of rising demand for german-language publications , luther 's version quickly became a popular and influential bible translation . 
as such , it made a significant contribution to the evolution of the german language and literature . 
furnished with notes and prefaces by luther , and with woodcuts by lucas cranach that contained anti-papal imagery , it played a major role in the spread of luther 's doctrine throughout germany . 
the luther bible influenced other vernacular translations , such as william tyndale 's english bible -lrb- 1525 forward -rrb- , a precursor of the king james bible . 
luther was a prolific hymn-writer , authoring hymns such as `` ein feste burg ist unser gott '' -lrb- `` a mighty fortress is our god '' -rrb- , based on psalm 46 , and `` vom himmel hoch , da komm ich her '' -lrb- `` from heaven above to earth i come '' -rrb- , based on luke 2:11 -- 12 . 
luther connected high art and folk music , also all classes , clergy and laity , men , women and children . 
his tool of choice for this connection was the singing of german hymns in connection with worship , school , home , and the public arena . 
he often accompanied the sung hymns with a lute , later recreated as the waldzither that became a national instrument of germany in the 20th century . 
he often accompanied the sung hymns with a lute , later recreated as the waldzither that became a national instrument of germany in the 20th century . 
luther 's hymns were frequently evoked by particular events in his life and the unfolding reformation . 
this behavior started with his learning of the execution of johann esch and heinrich voes , the first individuals to be martyred by the roman catholic church for lutheran views , prompting luther to write the hymn `` ein neues lied wir heben an '' -lrb- `` a new song we raise '' -rrb- , which is generally known in english by john c. messenger 's translation by the title and first line `` flung to the heedless winds '' and sung to the tune ibstone composed in 1875 by maria c. tiddeman . 
this behavior started with his learning of the execution of johann esch and heinrich voes , the first individuals to be martyred by the roman catholic church for lutheran views , prompting luther to write the hymn `` ein neues lied wir heben an '' -lrb- `` a new song we raise '' -rrb- , which is generally known in english by john c. messenger 's translation by the title and first line `` flung to the heedless winds '' and sung to the tune ibstone composed in 1875 by maria c. tiddeman . 
this behavior started with his learning of the execution of johann esch and heinrich voes , the first individuals to be martyred by the roman catholic church for lutheran views , prompting luther to write the hymn `` ein neues lied wir heben an '' -lrb- `` a new song we raise '' -rrb- , which is generally known in english by john c. messenger 's translation by the title and first line `` flung to the heedless winds '' and sung to the tune ibstone composed in 1875 by maria c. tiddeman . 
this behavior started with his learning of the execution of johann esch and heinrich voes , the first individuals to be martyred by the roman catholic church for lutheran views , prompting luther to write the hymn `` ein neues lied wir heben an '' -lrb- `` a new song we raise '' -rrb- , which is generally known in english by john c. messenger 's translation by the title and first line `` flung to the heedless winds '' and sung to the tune ibstone composed in 1875 by maria c. tiddeman . 
luther 's 1524 creedal hymn `` wir glauben all an einen gott '' -lrb- `` we all believe in one true god '' -rrb- is a three-stanza confession of faith prefiguring luther 's 1529 three-part explanation of the apostles ' creed in the small catechism . 
luther 's 1524 creedal hymn `` wir glauben all an einen gott '' -lrb- `` we all believe in one true god '' -rrb- is a three-stanza confession of faith prefiguring luther 's 1529 three-part explanation of the apostles ' creed in the small catechism . 
luther 's 1524 creedal hymn `` wir glauben all an einen gott '' -lrb- `` we all believe in one true god '' -rrb- is a three-stanza confession of faith prefiguring luther 's 1529 three-part explanation of the apostles ' creed in the small catechism . 
luther 's hymn , adapted and expanded from an earlier german creedal hymn , gained widespread use in vernacular lutheran liturgies as early as 1525 . 
sixteenth-century lutheran hymnals also included `` wir glauben all '' among the catechetical hymns , although 18th-century hymnals tended to label the hymn as trinitarian rather than catechetical , and 20th-century lutherans rarely use the hymn because of the perceived difficulty of its tune . 
luther 's 1538 hymnic version of the lord 's prayer , `` vater unser im himmelreich '' , corresponds exactly to luther 's explanation of the prayer in the small catechism , with one stanza for each of the seven prayer petitions , plus opening and closing stanzas . 
luther 's 1538 hymnic version of the lord 's prayer , `` vater unser im himmelreich '' , corresponds exactly to luther 's explanation of the prayer in the small catechism , with one stanza for each of the seven prayer petitions , plus opening and closing stanzas . 
the hymn functioned both as a liturgical setting of the lord 's prayer and as a means of examining candidates on specific catechism questions . 
the extant manuscript shows multiple revisions , demonstrating luther 's concern to clarify and strengthen the text and to provide an appropriately prayerful tune . 
other 16th - and 20th-century versifications of the lord 's prayer have adopted luther 's tune , although modern texts are considerably shorter . 
luther wrote `` aus tiefer not schrei ich zu dir '' -lrb- `` from depths of woe i cry to you '' -rrb- in 1523 as a hymnic version of psalm 130 and sent it as a sample to encourage evangelical colleagues to write psalm-hymns for use in german worship . 
luther wrote `` aus tiefer not schrei ich zu dir '' -lrb- `` from depths of woe i cry to you '' -rrb- in 1523 as a hymnic version of psalm 130 and sent it as a sample to encourage evangelical colleagues to write psalm-hymns for use in german worship . 
luther wrote `` aus tiefer not schrei ich zu dir '' -lrb- `` from depths of woe i cry to you '' -rrb- in 1523 as a hymnic version of psalm 130 and sent it as a sample to encourage evangelical colleagues to write psalm-hymns for use in german worship . 
in a collaboration with paul speratus , this and seven other hymns were published in the achtliederbuch , the first lutheran hymnal . 
because it expressed essential reformation doctrine , this expanded version of `` aus tiefer not '' was designated as a regular component of several regional lutheran liturgies and was widely used at funerals , including luther 's own . 
`` nun komm , der heiden heiland '' -lrb- now come , savior of the gentiles -rrb- , based on veni redemptor gentium , became the main hymn -lrb- hauptlied -rrb- for advent . 
`` nun komm , der heiden heiland '' -lrb- now come , savior of the gentiles -rrb- , based on veni redemptor gentium , became the main hymn -lrb- hauptlied -rrb- for advent . 
`` nun komm , der heiden heiland '' -lrb- now come , savior of the gentiles -rrb- , based on veni redemptor gentium , became the main hymn -lrb- hauptlied -rrb- for advent . 
he wrote two hymns on the ten commandments , `` dies sind die heilgen zehn gebot '' and `` mensch , willst du leben seliglich '' . 
it became known as the german te deum . 
luther 's 1541 hymn `` christ unser herr zum jordan kam '' -lrb- `` to jordan came the christ our lord '' -rrb- reflects the structure and substance of his questions and answers concerning baptism in the small catechism . 
luther adopted a preexisting johann walter tune associated with a hymnic setting of psalm 67 's prayer for grace ; wolf heintz 's four-part setting of the hymn was used to introduce the lutheran reformation in halle in 1541 . 
luther adopted a preexisting johann walter tune associated with a hymnic setting of psalm 67 's prayer for grace ; wolf heintz 's four-part setting of the hymn was used to introduce the lutheran reformation in halle in 1541 . 
preachers and composers of the 18th century , including j. s. bach , used this rich hymn as a subject for their own work , although its objective baptismal theology was displaced by more subjective hymns under the influence of late-19th-century lutheran pietism . 
luther adopted a preexisting johann walter tune associated with a hymnic setting of psalm 67 's prayer for grace ; wolf heintz 's four-part setting of the hymn was used to introduce the lutheran reformation in halle in 1541 . 
luther 's hymns were included in early lutheran hymnals and spread the ideas of the reformation . 
he supplied four of eight songs of the first lutheran hymnal achtliederbuch , 18 of 26 songs of the erfurt enchiridion , and 24 of the 32 songs in the first choral hymnal with settings by johann walter , eyn geystlich gesangk buchleyn , all published in 1524 . 
he supplied four of eight songs of the first lutheran hymnal achtliederbuch , 18 of 26 songs of the erfurt enchiridion , and 24 of the 32 songs in the first choral hymnal with settings by johann walter , eyn geystlich gesangk buchleyn , all published in 1524 . 
he supplied four of eight songs of the first lutheran hymnal achtliederbuch , 18 of 26 songs of the erfurt enchiridion , and 24 of the 32 songs in the first choral hymnal with settings by johann walter , eyn geystlich gesangk buchleyn , all published in 1524 . 
he supplied four of eight songs of the first lutheran hymnal achtliederbuch , 18 of 26 songs of the erfurt enchiridion , and 24 of the 32 songs in the first choral hymnal with settings by johann walter , eyn geystlich gesangk buchleyn , all published in 1524 . 
johann sebastian bach included several verses as chorales in his cantatas and based chorale cantatas entirely on them , namely christ lag in todes banden , bwv 4 , as early as possibly 1707 , in his second annual cycle -lrb- 1724 to 1725 -rrb- ach gott , vom himmel sieh darein , bwv 2 , christ unser herr zum jordan kam , bwv 7 , nun komm , der heiden heiland , bwv 62 , gelobet seist du , jesu christ , bwv 91 , and aus tiefer not schrei ich zu dir , bwv 38 , later ein feste burg ist unser gott , bwv 80 , and in 1735 wär gott nicht mit uns diese zeit , bwv 14 . 
johann sebastian bach included several verses as chorales in his cantatas and based chorale cantatas entirely on them , namely christ lag in todes banden , bwv 4 , as early as possibly 1707 , in his second annual cycle -lrb- 1724 to 1725 -rrb- ach gott , vom himmel sieh darein , bwv 2 , christ unser herr zum jordan kam , bwv 7 , nun komm , der heiden heiland , bwv 62 , gelobet seist du , jesu christ , bwv 91 , and aus tiefer not schrei ich zu dir , bwv 38 , later ein feste burg ist unser gott , bwv 80 , and in 1735 wär gott nicht mit uns diese zeit , bwv 14 . 
johann sebastian bach included several verses as chorales in his cantatas and based chorale cantatas entirely on them , namely christ lag in todes banden , bwv 4 , as early as possibly 1707 , in his second annual cycle -lrb- 1724 to 1725 -rrb- ach gott , vom himmel sieh darein , bwv 2 , christ unser herr zum jordan kam , bwv 7 , nun komm , der heiden heiland , bwv 62 , gelobet seist du , jesu christ , bwv 91 , and aus tiefer not schrei ich zu dir , bwv 38 , later ein feste burg ist unser gott , bwv 80 , and in 1735 wär gott nicht mit uns diese zeit , bwv 14 . 
johann sebastian bach included several verses as chorales in his cantatas and based chorale cantatas entirely on them , namely christ lag in todes banden , bwv 4 , as early as possibly 1707 , in his second annual cycle -lrb- 1724 to 1725 -rrb- ach gott , vom himmel sieh darein , bwv 2 , christ unser herr zum jordan kam , bwv 7 , nun komm , der heiden heiland , bwv 62 , gelobet seist du , jesu christ , bwv 91 , and aus tiefer not schrei ich zu dir , bwv 38 , later ein feste burg ist unser gott , bwv 80 , and in 1735 wär gott nicht mit uns diese zeit , bwv 14 . 
johann sebastian bach included several verses as chorales in his cantatas and based chorale cantatas entirely on them , namely christ lag in todes banden , bwv 4 , as early as possibly 1707 , in his second annual cycle -lrb- 1724 to 1725 -rrb- ach gott , vom himmel sieh darein , bwv 2 , christ unser herr zum jordan kam , bwv 7 , nun komm , der heiden heiland , bwv 62 , gelobet seist du , jesu christ , bwv 91 , and aus tiefer not schrei ich zu dir , bwv 38 , later ein feste burg ist unser gott , bwv 80 , and in 1735 wär gott nicht mit uns diese zeit , bwv 14 . 
in contrast to the views of john calvin and philipp melanchthon , throughout his life luther maintained that it was not false doctrine to believe that a christian 's soul sleeps after it is separated from the body in death ; and , accordingly , he disputed traditional interpretations of some bible passages , such as the parable of the rich man and lazarus . 
this also led luther to reject the idea of torments for the saints : `` it is enough for us to know that souls do not leave their bodies to be threatened by the torments and punishments of hell , but enter a prepared bedchamber in which they sleep in peace . '' 
this also led luther to reject the idea of torments for the saints : `` it is enough for us to know that souls do not leave their bodies to be threatened by the torments and punishments of hell , but enter a prepared bedchamber in which they sleep in peace . '' 
he also rejected the existence of purgatory , which involved christian souls undergoing penitential suffering after death . 
in his smalcald articles , he described the saints as currently residing `` in their graves and in heaven . '' 
the lutheran theologian franz pieper observed that luther 's teaching about the state of the christian 's soul after death differed from the later lutheran theologians such as johann gerhard . 
the lutheran theologian franz pieper observed that luther 's teaching about the state of the christian 's soul after death differed from the later lutheran theologians such as johann gerhard . 
the lutheran theologian franz pieper observed that luther 's teaching about the state of the christian 's soul after death differed from the later lutheran theologians such as johann gerhard . 
lessing -lrb- 1755 -rrb- had earlier reached the same conclusion in his analysis of lutheran orthodoxy on this issue . 
luther 's commentary on genesis contains a passage which concludes that `` the soul does not sleep -lrb- anima non sic dormit -rrb- , but wakes -lrb- sed vigilat -rrb- and experiences visions '' . 
francis blackburne in 1765 argued that john jortin misread this and other passages from luther , while gottfried fritschel pointed out in 1867 that it actually refers to the soul of a man `` in this life '' -lrb- homo enim in hac vita -rrb- tired from his daily labour -lrb- defatigus diurno labore -rrb- who at night enters his bedchamber -lrb- sub noctem intrat in cubiculum suum -rrb- and whose sleep is interrupted by dreams . 
francis blackburne in 1765 argued that john jortin misread this and other passages from luther , while gottfried fritschel pointed out in 1867 that it actually refers to the soul of a man `` in this life '' -lrb- homo enim in hac vita -rrb- tired from his daily labour -lrb- defatigus diurno labore -rrb- who at night enters his bedchamber -lrb- sub noctem intrat in cubiculum suum -rrb- and whose sleep is interrupted by dreams . 
francis blackburne in 1765 argued that john jortin misread this and other passages from luther , while gottfried fritschel pointed out in 1867 that it actually refers to the soul of a man `` in this life '' -lrb- homo enim in hac vita -rrb- tired from his daily labour -lrb- defatigus diurno labore -rrb- who at night enters his bedchamber -lrb- sub noctem intrat in cubiculum suum -rrb- and whose sleep is interrupted by dreams . 
francis blackburne in 1765 argued that john jortin misread this and other passages from luther , while gottfried fritschel pointed out in 1867 that it actually refers to the soul of a man `` in this life '' -lrb- homo enim in hac vita -rrb- tired from his daily labour -lrb- defatigus diurno labore -rrb- who at night enters his bedchamber -lrb- sub noctem intrat in cubiculum suum -rrb- and whose sleep is interrupted by dreams . 
in october 1529 , philip i , landgrave of hesse , convoked an assembly of german and swiss theologians at the marburg colloquy , to establish doctrinal unity in the emerging protestant states . 
in october 1529 , philip i , landgrave of hesse , convoked an assembly of german and swiss theologians at the marburg colloquy , to establish doctrinal unity in the emerging protestant states . 
in october 1529 , philip i , landgrave of hesse , convoked an assembly of german and swiss theologians at the marburg colloquy , to establish doctrinal unity in the emerging protestant states . 
agreement was achieved on fourteen points out of fifteen , the exception being the nature of the eucharist -- the sacrament of the lord 's supper -- an issue crucial to luther . 
agreement was achieved on fourteen points out of fifteen , the exception being the nature of the eucharist -- the sacrament of the lord 's supper -- an issue crucial to luther . 
the theologians , including zwingli , melanchthon , martin bucer , and johannes oecolampadius , differed on the significance of the words spoken by jesus at the last supper : `` this is my body which is for you '' and `` this cup is the new covenant in my blood '' -lrb- 1 corinthians 11:23 -- 26 -rrb- . 
luther insisted on the real presence of the body and blood of christ in the consecrated bread and wine , which he called the sacramental union , while his opponents believed god to be only spiritually or symbolically present . 
luther insisted on the real presence of the body and blood of christ in the consecrated bread and wine , which he called the sacramental union , while his opponents believed god to be only spiritually or symbolically present . 
luther insisted on the real presence of the body and blood of christ in the consecrated bread and wine , which he called the sacramental union , while his opponents believed god to be only spiritually or symbolically present . 
according to transcripts , the debate sometimes became confrontational . 
despite the disagreements on the eucharist , the marburg colloquy paved the way for the signing in 1530 of the augsburg confession , and for the formation of the schmalkaldic league the following year by leading protestant nobles such as john of saxony , philip of hesse , and george , margrave of brandenburg-ansbach . 
despite the disagreements on the eucharist , the marburg colloquy paved the way for the signing in 1530 of the augsburg confession , and for the formation of the schmalkaldic league the following year by leading protestant nobles such as john of saxony , philip of hesse , and george , margrave of brandenburg-ansbach . 
despite the disagreements on the eucharist , the marburg colloquy paved the way for the signing in 1530 of the augsburg confession , and for the formation of the schmalkaldic league the following year by leading protestant nobles such as john of saxony , philip of hesse , and george , margrave of brandenburg-ansbach . 
the swiss cities , however , did not sign these agreements . 
despite the disagreements on the eucharist , the marburg colloquy paved the way for the signing in 1530 of the augsburg confession , and for the formation of the schmalkaldic league the following year by leading protestant nobles such as john of saxony , philip of hesse , and george , margrave of brandenburg-ansbach . 
some scholars have asserted that luther taught that faith and reason were antithetical in the sense that questions of faith could not be illuminated by reason . 
some scholars have asserted that luther taught that faith and reason were antithetical in the sense that questions of faith could not be illuminated by reason . 
and '' -lsb- that -rsb- reason in no way contributes to faith . 
-lsb- ... -rsb- for reason is the greatest enemy that faith has ; it never comes to the aid of spiritual things . '' 
luther 's concern thus in separating them is honoring their different epistemological spheres . 
in 1523 , luther wrote that jesus christ was born a jew which discouraged mistreatment of the jews and advocated their conversion by proving that the old testament could be shown to speak of jesus christ . 
however , as the reformation continued , luther began to lose hope in large-scale jewish conversion to christianity . 
in his later years , luther grew more hostile toward the jews , writing against them with the kind of venom he had already unleashed on the anabaptists , zwinglianism , and the papacy . 
in his later years , luther grew more hostile toward the jews , writing against them with the kind of venom he had already unleashed on the anabaptists , zwinglianism , and the papacy . 
his 1543 treatise von den juden und ihren lügen -lrb- on the jews and their lies -rrb- took its place among other anti-jewish literature of the times , although historians acknowledge that this treatise was particularly extreme , even by the standards of sixteenth century europe . 
he saw the turks as a scourge sent to punish christians by god , as agents of the biblical apocalypse that would destroy the antichrist , whom luther believed to be the papacy , and the roman church . 
he saw the turks as a scourge sent to punish christians by god , as agents of the biblical apocalypse that would destroy the antichrist , whom luther believed to be the papacy , and the roman church . 
he saw the turks as a scourge sent to punish christians by god , as agents of the biblical apocalypse that would destroy the antichrist , whom luther believed to be the papacy , and the roman church . 
he saw the turks as a scourge sent to punish christians by god , as agents of the biblical apocalypse that would destroy the antichrist , whom luther believed to be the papacy , and the roman church . 
by 1529 , in on war against the turk , he was actively urging emperor charles v and the german people to fight a secular war against the turks . 
in 1542 , luther read a latin translation of the qur ` an . 
he went on to produce several critical pamphlets on islam , which he called `` mohammedanism '' or `` the turk '' . 
he went on to produce several critical pamphlets on islam , which he called `` mohammedanism '' or `` the turk '' . 
though luther saw the muslim faith as a tool of the devil , he was indifferent to its practice : `` let the turk believe and live as he will , just as one lets the papacy and other false christians live . '' 
he opposed banning the publication of the qur ` an , wanting it exposed to scrutiny . 
early in 1537 , johannes agricola -lrb- 1494 -- 1566 -rrb- -- serving at the time as pastor in luther 's birthplace , eisleben -- preached a sermon in which he claimed that god 's gospel , not god 's moral law -lrb- the ten commandments -rrb- , revealed god 's wrath to christians . 
early in 1537 , johannes agricola -lrb- 1494 -- 1566 -rrb- -- serving at the time as pastor in luther 's birthplace , eisleben -- preached a sermon in which he claimed that god 's gospel , not god 's moral law -lrb- the ten commandments -rrb- , revealed god 's wrath to christians . 
these theses asserted that the law is no longer to be taught to christians but belonged only to city hall . 
luther responded to these theses with six series of theses against agricola and the antinomians , four of which became the basis for disputations between 1538 and 1540 . 
he also responded to these assertions in other writings , such as his 1539 open letter to c. güttel against the antinomians , and his book on the councils and the church from the same year . 
in his theses and disputations against the antinomians , luther reviews and reaffirms , on the one hand , what has been called the `` second use of the law , '' that is , the law as the holy spirit 's tool to work sorrow over sin in man 's heart , thus preparing him for christ 's fulfillment of the law offered in the gospel . 
in his theses and disputations against the antinomians , luther reviews and reaffirms , on the one hand , what has been called the `` second use of the law , '' that is , the law as the holy spirit 's tool to work sorrow over sin in man 's heart , thus preparing him for christ 's fulfillment of the law offered in the gospel . 
luther states that everything that is used to work sorrow over sin is called the law , even if it is christ 's life , christ 's death for sin , or god 's goodness experienced in creation . 
simply refusing to preach the ten commandments among christians -- thereby , as it were , removing the three letters l-a-w from the church -- does not eliminate the accusing law . 
claiming that the law -- in any form -- should not be preached to christians anymore would be tantamount to asserting that christians are no longer sinners in themselves and that the church consists only of essentially holy people . 
on the other hand , luther also points out that the ten commandments -- when considered not as god 's condemning judgment but as an expression of his eternal will , that is , of the natural law -- also positively teach how the christian ought to live . 
on the other hand , luther also points out that the ten commandments -- when considered not as god 's condemning judgment but as an expression of his eternal will , that is , of the natural law -- also positively teach how the christian ought to live . 
this has traditionally been called the `` third use of the law . '' 
for luther , also christ 's life , when understood as an example , is nothing more than an illustration of the ten commandments , which a christian should follow in his or her vocations on a daily basis . 
for luther , also christ 's life , when understood as an example , is nothing more than an illustration of the ten commandments , which a christian should follow in his or her vocations on a daily basis . 
the ten commandments , and the beginnings of the renewed life of christians accorded to them by the sacrament of baptism , are a present foreshadowing of the believers ' future angel-like life in heaven in the midst of this life . 
the ten commandments , and the beginnings of the renewed life of christians accorded to them by the sacrament of baptism , are a present foreshadowing of the believers ' future angel-like life in heaven in the midst of this life . 
luther 's teaching of the ten commandments , therefore , has clear eschatological overtones , which , characteristically for luther , do not encourage world-flight but direct the christian to service to the neighbor in the common , daily vocations of this perishing world . 
from december 1539 , luther became implicated in the bigamy of philip i , landgrave of hesse , who wanted to marry one of his wife 's ladies-in-waiting . 
from december 1539 , luther became implicated in the bigamy of philip i , landgrave of hesse , who wanted to marry one of his wife 's ladies-in-waiting . 
from december 1539 , luther became implicated in the bigamy of philip i , landgrave of hesse , who wanted to marry one of his wife 's ladies-in-waiting . 
in the view of luther 's biographer martin brecht , `` giving confessional advice for philip of hesse was one of the worst mistakes luther made , and , next to the landgrave himself , who was directly responsible for it , history chiefly holds luther accountable '' . 
the affair caused lasting damage to luther 's reputation . 
luther rarely encountered jews during his life , but his attitudes reflected a theological and cultural tradition which saw jews as a rejected people guilty of the murder of christ , and he lived within a local community that had expelled jews some ninety years earlier . 
luther rarely encountered jews during his life , but his attitudes reflected a theological and cultural tradition which saw jews as a rejected people guilty of the murder of christ , and he lived within a local community that had expelled jews some ninety years earlier . 
luther rarely encountered jews during his life , but his attitudes reflected a theological and cultural tradition which saw jews as a rejected people guilty of the murder of christ , and he lived within a local community that had expelled jews some ninety years earlier . 
he considered the jews blasphemers and liars because they rejected the divinity of jesus , whereas christians believed jesus was the messiah . 
in 1523 , luther advised kindness toward the jews in that jesus christ was born a jew and also aimed to convert them to christianity . 
luther 's other major works on the jews were his 60,000-word treatise von den juden und ihren lügen -lrb- on the jews and their lies -rrb- , and vom schem hamphoras und vom geschlecht christi -lrb- on the holy name and the lineage of christ -rrb- , both published in 1543 , three years before his death . 
luther 's other major works on the jews were his 60,000-word treatise von den juden und ihren lügen -lrb- on the jews and their lies -rrb- , and vom schem hamphoras und vom geschlecht christi -lrb- on the holy name and the lineage of christ -rrb- , both published in 1543 , three years before his death . 
luther 's other major works on the jews were his 60,000-word treatise von den juden und ihren lügen -lrb- on the jews and their lies -rrb- , and vom schem hamphoras und vom geschlecht christi -lrb- on the holy name and the lineage of christ -rrb- , both published in 1543 , three years before his death . 
luther argued that the jews were no longer the chosen people but `` the devil 's people '' , and referred to them with violent , vile language . 
in robert michael 's view , luther 's words `` we are at fault in not slaying them '' amounted to a sanction for murder . 
luther spoke out against the jews in saxony , brandenburg , and silesia . 
josel of rosheim , the jewish spokesman who tried to help the jews of saxony in 1537 , later blamed their plight on `` that priest whose name was martin luther -- may his body and soul be bound up in hell ! 
-- who wrote and issued many heretical books in which he said that whoever would help the jews was doomed to perdition . '' 
josel asked the city of strasbourg to forbid the sale of luther 's anti-jewish works : they refused initially , but did so when a lutheran pastor in hochfelden used a sermon to urge his parishioners to murder jews . 
throughout the 1580s , riots led to the expulsion of jews from several german lutheran states . 
luther was the most widely read author of his generation , and within germany he acquired the status of a prophet . 
according to the prevailing view among historians , his anti-jewish rhetoric contributed significantly to the development of antisemitism in germany , and in the 1930s and 1940s provided an `` ideal underpinning '' for the nazis ' attacks on jews . 
according to the prevailing view among historians , his anti-jewish rhetoric contributed significantly to the development of antisemitism in germany , and in the 1930s and 1940s provided an `` ideal underpinning '' for the nazis ' attacks on jews . 
according to michael , just about every anti-jewish book printed in the third reich contained references to and quotations from luther . 
the city of nuremberg presented a first edition of on the jews and their lies to julius streicher , editor of the nazi newspaper der stürmer , on his birthday in 1937 ; the newspaper described it as the most radically anti-semitic tract ever published . 
on 17 december 1941 , seven protestant regional church confederations issued a statement agreeing with the policy of forcing jews to wear the yellow badge , `` since after his bitter experience luther had already suggested preventive measures against the jews and their expulsion from german territory . '' 
on 17 december 1941 , seven protestant regional church confederations issued a statement agreeing with the policy of forcing jews to wear the yellow badge , `` since after his bitter experience luther had already suggested preventive measures against the jews and their expulsion from german territory . '' 
according to daniel goldhagen , bishop martin sasse , a leading protestant churchman , published a compendium of luther 's writings shortly after kristallnacht , for which diarmaid macculloch , professor of the history of the church in the university of oxford argued that luther 's writing was a `` blueprint . '' 
according to daniel goldhagen , bishop martin sasse , a leading protestant churchman , published a compendium of luther 's writings shortly after kristallnacht , for which diarmaid macculloch , professor of the history of the church in the university of oxford argued that luther 's writing was a `` blueprint . '' 
the german people , he urged , ought to heed these words `` of the greatest antisemite of his time , the warner of his people against the jews . '' 
some scholars see luther 's influence as limited , and the nazis ' use of his work as opportunistic . 
nevertheless , his misguided agitation had the evil result that luther fatefully became one of the ` church fathers ' of anti-semitism and thus provided material for the modern hatred of the jews , cloaking it with the authority of the reformer . '' 
nevertheless , his misguided agitation had the evil result that luther fatefully became one of the ` church fathers ' of anti-semitism and thus provided material for the modern hatred of the jews , cloaking it with the authority of the reformer . '' 
johannes wallmann argues that luther 's writings against the jews were largely ignored in the 18th and 19th centuries , and that there was no continuity between luther 's thought and nazi ideology . 
his position was entirely religious and in no respect racial . '' 
other scholars argue that , even if his views were merely anti-judaic -- that is , opposed to judaism and its adherence rather than the jews as an ethnic group -- their violence lent a new element to the standard christian suspicion of judaism . 
ronald berger writes that luther is credited with `` germanizing the christian critique of judaism and establishing anti-semitism as a key element of german culture and national identity . '' 
paul rose argues that he caused a `` hysterical and demonizing mentality '' about jews to enter german thought and discourse , a mentality that might otherwise have been absent . 
christopher j. probst in his book demonizing the jews : luther and the protestant church in nazi germany -lrb- 2012 -rrb- , shows that a large number of german lutheran clergy and theologians during the nazi third reich used luther 's hostile publications towards the jews and their jewish religion to justify at least in part the anti-semitic policies of the national socialists . 
christopher j. probst in his book demonizing the jews : luther and the protestant church in nazi germany -lrb- 2012 -rrb- , shows that a large number of german lutheran clergy and theologians during the nazi third reich used luther 's hostile publications towards the jews and their jewish religion to justify at least in part the anti-semitic policies of the national socialists . 
some scholars , such as mark u. edwards in his book luther 's last battles : politics and polemics 1531 -- 46 -lrb- 1983 -rrb- , suggest that since luther 's increasingly antisemitic views developed during the years his health deteriorated , it is possible they were at least partly the product of a declining state of mind . 
some scholars , such as mark u. edwards in his book luther 's last battles : politics and polemics 1531 -- 46 -lrb- 1983 -rrb- , suggest that since luther 's increasingly antisemitic views developed during the years his health deteriorated , it is possible they were at least partly the product of a declining state of mind . 
edwards also comments that luther often deliberately used `` vulgarity and violence '' for effect , both in his writings condemning the jews and in diatribes against `` turks '' -lrb- muslims -rrb- and catholics . 
edwards also comments that luther often deliberately used `` vulgarity and violence '' for effect , both in his writings condemning the jews and in diatribes against `` turks '' -lrb- muslims -rrb- and catholics . 
some scholars , such as mark u. edwards in his book luther 's last battles : politics and polemics 1531 -- 46 -lrb- 1983 -rrb- , suggest that since luther 's increasingly antisemitic views developed during the years his health deteriorated , it is possible they were at least partly the product of a declining state of mind . 
since the 1980s , lutheran church denominations have repudiated martin luther 's statements against the jews and have rejected the use of them to incite hatred against lutherans . 
strommen et al. 's 1970 survey of 4,745 north american lutherans aged 15 -- 65 found that , compared to the other minority groups under consideration , lutherans were the least prejudiced toward jews . 
nevertheless , professor richard -lrb- dick -rrb- geary , former professor of modern history at the university of nottingham , england , and the author of hitler and nazism -lrb- routledge 1993 -rrb- , wrote in the journal history today an article on who voted for the nazis in elections held from 1928-1933 , where he claimed that from his research he found that the nazis gained disproportionately more votes from protestant than catholic areas of germany . 
nevertheless , professor richard -lrb- dick -rrb- geary , former professor of modern history at the university of nottingham , england , and the author of hitler and nazism -lrb- routledge 1993 -rrb- , wrote in the journal history today an article on who voted for the nazis in elections held from 1928-1933 , where he claimed that from his research he found that the nazis gained disproportionately more votes from protestant than catholic areas of germany . 
from 1531 to 1546 , his health deteriorated further . 
the years of struggle with rome , the antagonisms with and among his fellow reformers , and the scandal which ensued from the bigamy of the philip of hesse incident , in which luther had played a leading role , all may have contributed . 
in 1536 , he began to suffer from kidney and bladder stones , and arthritis , and an ear infection ruptured an ear drum . 
in 1536 , he began to suffer from kidney and bladder stones , and arthritis , and an ear infection ruptured an ear drum . 
in december 1544 , he began to feel the effects of angina . 
his poor physical health made him short-tempered and even harsher in his writings and comments . 
his poor physical health made him short-tempered and even harsher in his writings and comments . 
his poor physical health made him short-tempered and even harsher in his writings and comments . 
his wife katharina was overheard saying , `` dear husband , you are too rude , '' and he responded , `` they are teaching me to be rude . '' 
in 1545 and 1546 luther preached three times in the market church in halle , staying with his friend justus jonas during christmas . 
his last sermon was delivered at eisleben , his place of birth , on 15 february 1546 , three days before his death . 
his last sermon was delivered at eisleben , his place of birth , on 15 february 1546 , three days before his death . 
it was `` entirely devoted to the obdurate jews , whom it was a matter of great urgency to expel from all german territory , '' according to léon poliakov . 
it was `` entirely devoted to the obdurate jews , whom it was a matter of great urgency to expel from all german territory , '' according to léon poliakov . 
luther said , `` we want to practice christian love toward them and pray that they convert , '' but also that they are `` our public enemies ... and if they could kill us all , they would gladly do so . 
luther 's final journey , to mansfeld , was taken because of his concern for his siblings ' families continuing in their father hans luther 's copper mining trade . 
luther journeyed to mansfeld twice in late 1545 to participate in the negotiations for a settlement , and a third visit was needed in early 1546 for their completion . 
luther journeyed to mansfeld twice in late 1545 to participate in the negotiations for a settlement , and a third visit was needed in early 1546 for their completion . 
luther journeyed to mansfeld twice in late 1545 to participate in the negotiations for a settlement , and a third visit was needed in early 1546 for their completion . 
luther 's final journey , to mansfeld , was taken because of his concern for his siblings ' families continuing in their father hans luther 's copper mining trade . 
the negotiations were successfully concluded on 17 february 1546 . 
after 8 a.m. , he experienced chest pains . 
when he went to his bed , he prayed , `` into your hand i commit my spirit ; you have redeemed me , o lord , faithful god '' -lrb- ps . 
31:5 -rrb- , the common prayer of the dying . 
at 1 a.m. he awoke with more chest pain and was warmed with hot towels . 
an apoplectic stroke deprived him of his speech , and he died shortly afterwards at 2:45 a.m. on 18 february 1546 , aged 62 , in eisleben , the city of his birth . 
an apoplectic stroke deprived him of his speech , and he died shortly afterwards at 2:45 a.m. on 18 february 1546 , aged 62 , in eisleben , the city of his birth . 
an apoplectic stroke deprived him of his speech , and he died shortly afterwards at 2:45 a.m. on 18 february 1546 , aged 62 , in eisleben , the city of his birth . 
he was buried in the castle church in wittenberg , beneath the pulpit . 
the funeral was held by his friends johannes bugenhagen and philipp melanchthon . 
a piece of paper was later found on which luther had written his last statement . 
the statement was in latin , apart from `` we are beggars , '' which was in german . 
the statement was in latin , apart from `` we are beggars , '' which was in german . 
in the 1530s and 1540s , printed images of luther that emphasized his monumental size were crucial to the spread of protestantism . 
in contrast to images of frail catholic saints , luther was presented as a stout man with a `` double chin , strong mouth , piercing deep-set eyes , fleshy face , and squat neck . '' 
he was shown to be physically imposing , an equal in stature to the secular german princes with whom he would join forces to spread lutheranism . 
his large body also let the viewer know that he did not shun earthly pleasures like drinking -- behavior that was a stark contrast to the ascetic life of the medieval religious orders . 
in the 1530s and 1540s , printed images of luther that emphasized his monumental size were crucial to the spread of protestantism . 
luther is honoured on 18 february with a commemoration in the lutheran calendar of saints and in the episcopal -lrb- united states -rrb- calendar of saints . 
luther is honoured on 18 february with a commemoration in the lutheran calendar of saints and in the episcopal -lrb- united states -rrb- calendar of saints . 
in the church of england 's calendar of saints he is commemorated on 31 october . 
in the church of england 's calendar of saints he is commemorated on 31 october . 
luther is honoured on 18 february with a commemoration in the lutheran calendar of saints and in the episcopal -lrb- united states -rrb- calendar of saints . 
southern california , often abbreviated socal , is a geographic and cultural region that generally comprises california 's southernmost 10 counties . 
southern california , often abbreviated socal , is a geographic and cultural region that generally comprises california 's southernmost 10 counties . 
southern california is a major economic center for the state of california and the united states . 
the region is traditionally described as `` eight counties '' , based on demographics and economic ties : imperial , los angeles , orange , riverside , san bernardino , san diego , santa barbara , and ventura . 
the more extensive 10-county definition , including kern and san luis obispo counties , is also used based on historical political divisions . 
the 8 - and 10-county definitions are not used for the greater southern california megaregion , one of the 11 megaregions of the united states . 
the 8 - and 10-county definitions are not used for the greater southern california megaregion , one of the 11 megaregions of the united states . 
the megaregion 's area is more expansive , extending east into las vegas , nevada , and south across the mexican border into tijuana . 
the megaregion 's area is more expansive , extending east into las vegas , nevada , and south across the mexican border into tijuana . 
the megaregion 's area is more expansive , extending east into las vegas , nevada , and south across the mexican border into tijuana . 
southern california includes the heavily built-up urban area stretching along the pacific coast from ventura , through the greater los angeles area and the inland empire , and down to greater san diego . 
southern california 's population encompasses seven metropolitan areas , or msas : the los angeles metropolitan area , consisting of los angeles and orange counties ; the inland empire , consisting of riverside and san bernardino counties ; the san diego metropolitan area ; the oxnard -- thousand oaks -- ventura metropolitan area ; the santa barbara metro area ; the san luis obispo metropolitan area ; and the el centro area . 
out of these , three are heavy populated areas : the los angeles area with over 12 million inhabitants , the riverside-san bernardino area with over four million inhabitants , and the san diego area with over 3 million inhabitants . 
out of these , three are heavy populated areas : the los angeles area with over 12 million inhabitants , the riverside-san bernardino area with over four million inhabitants , and the san diego area with over 3 million inhabitants . 
for csa metropolitan purposes , the five counties of los angeles , orange , riverside , san bernardino , and ventura are all combined to make up the greater los angeles area with over 17.5 million people . 
to the east is the colorado desert and the colorado river at the border with arizona , and the mojave desert at the border with the state of nevada . 
to the east is the colorado desert and the colorado river at the border with arizona , and the mojave desert at the border with the state of nevada . 
to the east is the colorado desert and the colorado river at the border with arizona , and the mojave desert at the border with the state of nevada . 
to the south is the mexico -- united states border . 
within southern california are two major cities , los angeles and san diego , as well as three of the country 's largest metropolitan areas . 
with a population of 3,792,621 , los angeles is the most populous city in california and the second most populous in the united states . 
with a population of 3,792,621 , los angeles is the most populous city in california and the second most populous in the united states . 
to the south and with a population of 1,307,402 is san diego , the second most populous city in the state and the eighth most populous in the nation . 
to the south and with a population of 1,307,402 is san diego , the second most populous city in the state and the eighth most populous in the nation . 
its counties of los angeles , orange , san diego , san bernardino , and riverside are the five most populous in the state and all are in the top 15 most populous counties in the united states . 
its counties of los angeles , orange , san diego , san bernardino , and riverside are the five most populous in the state and all are in the top 15 most populous counties in the united states . 
its counties of los angeles , orange , san diego , san bernardino , and riverside are the five most populous in the state and all are in the top 15 most populous counties in the united states . 
its counties of los angeles , orange , san diego , san bernardino , and riverside are the five most populous in the state and all are in the top 15 most populous counties in the united states . 
its counties of los angeles , orange , san diego , san bernardino , and riverside are the five most populous in the state and all are in the top 15 most populous counties in the united states . 
hollywood , a district within los angeles , is also a name associated with the motion picture industry . 
hollywood , a district within los angeles , is also a name associated with the motion picture industry . 
headquartered in southern california are the walt disney company -lrb- which also owns abc -rrb- , sony pictures , universal , mgm , paramount pictures , 20th century fox , and warner brothers . 
the motion picture , television , and music industry is centered on the los angeles in southern california . 
universal , warner brothers , and sony also run major record companies as well . 
southern california is also home to a large home grown surf and skateboard culture . 
professional skateboarder tony hawk , professional surfers rob machado , tim curran , bobby martinez , pat o'connell , dane reynolds , and chris ward , and professional snowboarder shaun white live in southern california . 
professional skateboarder tony hawk , professional surfers rob machado , tim curran , bobby martinez , pat o'connell , dane reynolds , and chris ward , and professional snowboarder shaun white live in southern california . 
some of the world 's legendary surf spots are in southern california as well , including trestles , rincon , the wedge , huntington beach , and malibu , and it is second only to the island of oahu in terms of famous surf breaks . 
the annual transpacific yacht race , or transpac , from los angeles to hawaii , is one of yachting 's premier events . 
many locals and tourists frequent the southern california coast for its popular beaches , and the desert city of palm springs is popular for its resort feel and nearby open spaces . 
many locals and tourists frequent the southern california coast for its popular beaches , and the desert city of palm springs is popular for its resort feel and nearby open spaces . 
many locals and tourists frequent the southern california coast for its popular beaches , and the desert city of palm springs is popular for its resort feel and nearby open spaces . 
many locals and tourists frequent the southern california coast for its popular beaches , and the desert city of palm springs is popular for its resort feel and nearby open spaces . 
geographically , california 's north-south midway point lies at exactly 37 ° 9 ' 58.23 '' latitude , around 11 miles -lrb- 18 km -rrb- south of san jose ; however , this does not coincide with popular use of the term . 
geographically , california 's north-south midway point lies at exactly 37 ° 9 ' 58.23 '' latitude , around 11 miles -lrb- 18 km -rrb- south of san jose ; however , this does not coincide with popular use of the term . 
when the state is divided into two areas -lrb- northern and southern california -rrb- , the term `` southern california '' usually refers to the ten southern-most counties of the state . 
another definition for southern california uses point conception and the tehachapi mountains as the northern boundary . 
another definition for southern california uses point conception and the tehachapi mountains as the northern boundary . 
though there is no official definition for the northern boundary of southern california , such a division has existed from the time when mexico ruled california , and political disputes raged between the californios of monterey in the upper part and los angeles in the lower part of alta california . 
though there is no official definition for the northern boundary of southern california , such a division has existed from the time when mexico ruled california , and political disputes raged between the californios of monterey in the upper part and los angeles in the lower part of alta california . 
though there is no official definition for the northern boundary of southern california , such a division has existed from the time when mexico ruled california , and political disputes raged between the californios of monterey in the upper part and los angeles in the lower part of alta california . 
following the acquisition of california by the united states , the division continued as part of the attempt by several pro-slavery politicians to arrange the division of alta california at 36 degrees , 30 minutes , the line of the missouri compromise . 
instead , the passing of the compromise of 1850 enabled california to be admitted to the union as a free state , preventing southern california from becoming its own separate slave state . 
subsequently , californios -lrb- dissatisfied with inequitable taxes and land laws -rrb- and pro-slavery southerners in the lightly populated `` cow counties '' of southern california attempted three times in the 1850s to achieve a separate statehood or territorial status separate from northern california . 
subsequently , californios -lrb- dissatisfied with inequitable taxes and land laws -rrb- and pro-slavery southerners in the lightly populated `` cow counties '' of southern california attempted three times in the 1850s to achieve a separate statehood or territorial status separate from northern california . 
subsequently , californios -lrb- dissatisfied with inequitable taxes and land laws -rrb- and pro-slavery southerners in the lightly populated `` cow counties '' of southern california attempted three times in the 1850s to achieve a separate statehood or territorial status separate from northern california . 
it was approved overwhelmingly by nearly 75 % of voters in the proposed territory of colorado . 
the proposal was sent to washington , d.c. with a strong advocate in senator milton latham . 
in 1900 , the los angeles times defined southern california as including `` the seven counties of los angeles , san bernardino , orange , riverside , san diego , ventura and santa barbara . '' 
in 1900 , the los angeles times defined southern california as including `` the seven counties of los angeles , san bernardino , orange , riverside , san diego , ventura and santa barbara . '' 
in 1999 , the times added a newer county -- imperial -- to that list . 
in 1999 , the times added a newer county -- imperial -- to that list . 
in 1900 , the los angeles times defined southern california as including `` the seven counties of los angeles , san bernardino , orange , riverside , san diego , ventura and santa barbara . '' 
the state is most commonly divided and promoted by its regional tourism groups as consisting of northern , central , and southern california regions . 
the two aaa auto clubs of the state , the california state automobile association and the automobile club of southern california , choose to simplify matters by dividing the state along the lines where their jurisdictions for membership apply , as either northern or southern california , in contrast to the three-region point of view . 
the two aaa auto clubs of the state , the california state automobile association and the automobile club of southern california , choose to simplify matters by dividing the state along the lines where their jurisdictions for membership apply , as either northern or southern california , in contrast to the three-region point of view . 
another influence is the geographical phrase south of the tehachapis , which would split the southern region off at the crest of that transverse range , but in that definition , the desert portions of north los angeles county and eastern kern and san bernardino counties would be included in the southern california region due to their remoteness from the central valley and interior desert landscape . 
another influence is the geographical phrase south of the tehachapis , which would split the southern region off at the crest of that transverse range , but in that definition , the desert portions of north los angeles county and eastern kern and san bernardino counties would be included in the southern california region due to their remoteness from the central valley and interior desert landscape . 
it is the third most populated megalopolis in the united states , after the great lakes megalopolis and the northeastern megalopolis . 
southern california consists of a heavily developed urban environment , home to some of the largest urban areas in the state , along with vast areas that have been left undeveloped . 
much of southern california is famous for its large , spread-out , suburban communities and use of automobiles and highways . 
much of southern california is famous for its large , spread-out , suburban communities and use of automobiles and highways . 
the urban area is also host to an international metropolitan region in the form of san diego -- tijuana , created by the urban area spilling over into baja california . 
traveling south on interstate 5 , the main gap to continued urbanization is camp pendleton . 
the cities and communities along interstate 15 and interstate 215 are so inter-related that temecula and murrieta have as much connection with the san diego metropolitan area as they do with the inland empire . 
to the east , the united states census bureau considers the san bernardino and riverside county areas , riverside-san bernardino area as a separate metropolitan area from los angeles county . 
while many commute to l.a. and orange counties , there are some differences in development , as most of san bernardino and riverside counties -lrb- the non-desert portions -rrb- were developed in the 1980s and 1990s . 
while many commute to l.a. and orange counties , there are some differences in development , as most of san bernardino and riverside counties -lrb- the non-desert portions -rrb- were developed in the 1980s and 1990s . 
southern california contains a mediterranean climate , with infrequent rain and many sunny days . 
southern california contains a mediterranean climate , with infrequent rain and many sunny days . 
in the summers , temperature ranges are 90-60 's while as winters are 70-50 's , usually all of southern california have mediterranean climate . 
but snow is very rare in the southwest of the state , it occurs on the southeast of the state . 
in the summers , temperature ranges are 90-60 's while as winters are 70-50 's , usually all of southern california have mediterranean climate . 
the region spans from pacific ocean islands , shorelines , beaches , and coastal plains , through the transverse and peninsular ranges with their peaks , into the large and small interior valleys , to the vast deserts of california . 
southern california consists of one of the more varied collections of geologic , topographic , and natural ecosystem landscapes in a diversity outnumbering other major regions in the state and country . 
southern california consists of one of the more varied collections of geologic , topographic , and natural ecosystem landscapes in a diversity outnumbering other major regions in the state and country . 
the region spans from pacific ocean islands , shorelines , beaches , and coastal plains , through the transverse and peninsular ranges with their peaks , into the large and small interior valleys , to the vast deserts of california . 
the region spans from pacific ocean islands , shorelines , beaches , and coastal plains , through the transverse and peninsular ranges with their peaks , into the large and small interior valleys , to the vast deserts of california . 
each year , the southern california area has about 10,000 earthquakes . 
nearly all of them are so small that they are not felt . 
the magnitude 6.7 1994 northridge earthquake was particularly destructive , causing a substantial number of deaths , injuries , and structural collapses . 
it caused the most property damage of any earthquake in u.s. history , estimated at over $ 20 billion . 
it caused the most property damage of any earthquake in u.s. history , estimated at over $ 20 billion . 
many faults are able to produce a magnitude 6.7 + earthquake , such as the san andreas fault , which can produce a magnitude 8.0 event . 
many faults are able to produce a magnitude 6.7 + earthquake , such as the san andreas fault , which can produce a magnitude 8.0 event . 
other faults include the san jacinto fault , the puente hills fault , and the elsinore fault zone . 
the usgs has released a california earthquake forecast which models earthquake occurrence in california . 
the usgs has released a california earthquake forecast which models earthquake occurrence in california . 
southern california is divided culturally , politically , and economically into distinctive regions , each containing its own culture and atmosphere , anchored usually by a city with both national and sometimes global recognition , which are often the hub of economic activity for its respective region and being home to many tourist destinations . 
southern california is divided culturally , politically , and economically into distinctive regions , each containing its own culture and atmosphere , anchored usually by a city with both national and sometimes global recognition , which are often the hub of economic activity for its respective region and being home to many tourist destinations . 
southern california is divided culturally , politically , and economically into distinctive regions , each containing its own culture and atmosphere , anchored usually by a city with both national and sometimes global recognition , which are often the hub of economic activity for its respective region and being home to many tourist destinations . 
as of the 2010 united states census , southern california has a population of 22,680,010 . 
despite a reputation for high growth rates , southern california 's rate grew less than the state average of 10.0 % in the 2000s as california 's growth became concentrated in the northern part of the state due to a stronger , tech-oriented economy in the bay area and an emerging greater sacramento region . 
despite a reputation for high growth rates , southern california 's rate grew less than the state average of 10.0 % in the 2000s as california 's growth became concentrated in the northern part of the state due to a stronger , tech-oriented economy in the bay area and an emerging greater sacramento region . 
despite a reputation for high growth rates , southern california 's rate grew less than the state average of 10.0 % in the 2000s as california 's growth became concentrated in the northern part of the state due to a stronger , tech-oriented economy in the bay area and an emerging greater sacramento region . 
despite a reputation for high growth rates , southern california 's rate grew less than the state average of 10.0 % in the 2000s as california 's growth became concentrated in the northern part of the state due to a stronger , tech-oriented economy in the bay area and an emerging greater sacramento region . 
southern california consists of one combined statistical area , eight metropolitan statistical areas , one international metropolitan area , and multiple metropolitan divisions . 
the region is home to two extended metropolitan areas that exceed five million in population . 
the region is home to two extended metropolitan areas that exceed five million in population . 
of these metropolitan areas , the los angeles-long beach-santa ana metropolitan area , riverside-san bernardino-ontario metropolitan area , and oxnard-thousand oaks-ventura metropolitan area form greater los angeles ; while the el centro metropolitan area and san diego-carlsbad-san marcos metropolitan area form the southern border region . 
these are the greater los angeles area at 17,786,419 , and san diego -- tijuana at 5,105,768 . 
los angeles -lrb- at 3.7 million people -rrb- and san diego -lrb- at 1.3 million people -rrb- , both in southern california , are the two largest cities in all of california -lrb- and two of the eight largest cities in the united states -rrb- . 
los angeles -lrb- at 3.7 million people -rrb- and san diego -lrb- at 1.3 million people -rrb- , both in southern california , are the two largest cities in all of california -lrb- and two of the eight largest cities in the united states -rrb- . 
in southern california there are also twelve cities with more than 200,000 residents and 34 cities over 100,000 in population . 
in southern california there are also twelve cities with more than 200,000 residents and 34 cities over 100,000 in population . 
many of southern california 's most developed cities lie along or in close proximity to the coast , with the exception of san bernardino and riverside . 
it is dominated and heavily dependent upon abundance of petroleum , as opposed to other regions where automobiles not nearly as dominant , the vast majority of transport runs on this fuel . 
southern california is famous for tourism and hollywood -lrb- film , television , and music -rrb- . 
the region was a leader in the housing bubble 2001 -- 2007 , and has been heavily impacted by the housing crash . 
southern california 's economy is diverse and one of the largest in the united states . 
the region was a leader in the housing bubble 2001 -- 2007 , and has been heavily impacted by the housing crash . 
since the 1920s , motion pictures , petroleum and aircraft manufacturing have been major industries . 
in one of the richest agricultural regions in the u.s. , cattle and citrus were major industries until farmlands were turned into suburbs . 
in one of the richest agricultural regions in the u.s. , cattle and citrus were major industries until farmlands were turned into suburbs . 
in one of the richest agricultural regions in the u.s. , cattle and citrus were major industries until farmlands were turned into suburbs . 
although military spending cutbacks have had an impact , aerospace continues to be a major factor . 
southern california is home to many major business districts . 
central business districts -lrb- cbd -rrb- include downtown los angeles , downtown san diego , downtown san bernardino , downtown bakersfield , south coast metro and downtown riverside . 
central business districts -lrb- cbd -rrb- include downtown los angeles , downtown san diego , downtown san bernardino , downtown bakersfield , south coast metro and downtown riverside . 
within the los angeles area are the major business districts of downtown burbank , downtown santa monica , downtown glendale and downtown long beach . 
within the los angeles area are the major business districts of downtown burbank , downtown santa monica , downtown glendale and downtown long beach . 
los angeles itself has many business districts including the downtown los angeles central business district as well as those lining the wilshire boulevard miracle mile including century city , westwood and warner center in the san fernando valley . 
los angeles itself has many business districts including the downtown los angeles central business district as well as those lining the wilshire boulevard miracle mile including century city , westwood and warner center in the san fernando valley . 
the san bernardino-riverside area maintains the business districts of downtown san bernardino , hospitality business/financial centre , university town which are in san bernardino and downtown riverside . 
the san bernardino-riverside area maintains the business districts of downtown san bernardino , hospitality business/financial centre , university town which are in san bernardino and downtown riverside . 
the san bernardino-riverside area maintains the business districts of downtown san bernardino , hospitality business/financial centre , university town which are in san bernardino and downtown riverside . 
orange county is a rapidly developing business center that includes downtown santa ana , the south coast metro and newport center districts ; as well as the irvine business centers of the irvine spectrum , west irvine , and international corporations headquartered at the university of california , irvine . 
orange county is a rapidly developing business center that includes downtown santa ana , the south coast metro and newport center districts ; as well as the irvine business centers of the irvine spectrum , west irvine , and international corporations headquartered at the university of california , irvine . 
west irvine includes the irvine tech center and jamboree business parks . 
orange county is a rapidly developing business center that includes downtown santa ana , the south coast metro and newport center districts ; as well as the irvine business centers of the irvine spectrum , west irvine , and international corporations headquartered at the university of california , irvine . 
orange county is a rapidly developing business center that includes downtown santa ana , the south coast metro and newport center districts ; as well as the irvine business centers of the irvine spectrum , west irvine , and international corporations headquartered at the university of california , irvine . 
downtown san diego is the central business district of san diego , though the city is filled with business districts . 
most of these districts are located in northern san diego and some within north county regions . 
most of these districts are located in northern san diego and some within north county regions . 
downtown san diego is the central business district of san diego , though the city is filled with business districts . 
southern california is home to los angeles international airport , the second-busiest airport in the united states by passenger volume -lrb- see world 's busiest airports by passenger traffic -rrb- and the third by international passenger volume -lrb- see busiest airports in the united states by international passenger traffic -rrb- ; san diego international airport the busiest single runway airport in the world ; van nuys airport , the world 's busiest general aviation airport ; major commercial airports at orange county , bakersfield , ontario , burbank and long beach ; and numerous smaller commercial and general aviation airports . 
southern california is home to los angeles international airport , the second-busiest airport in the united states by passenger volume -lrb- see world 's busiest airports by passenger traffic -rrb- and the third by international passenger volume -lrb- see busiest airports in the united states by international passenger traffic -rrb- ; san diego international airport the busiest single runway airport in the world ; van nuys airport , the world 's busiest general aviation airport ; major commercial airports at orange county , bakersfield , ontario , burbank and long beach ; and numerous smaller commercial and general aviation airports . 
southern california is home to los angeles international airport , the second-busiest airport in the united states by passenger volume -lrb- see world 's busiest airports by passenger traffic -rrb- and the third by international passenger volume -lrb- see busiest airports in the united states by international passenger traffic -rrb- ; san diego international airport the busiest single runway airport in the world ; van nuys airport , the world 's busiest general aviation airport ; major commercial airports at orange county , bakersfield , ontario , burbank and long beach ; and numerous smaller commercial and general aviation airports . 
southern california is home to los angeles international airport , the second-busiest airport in the united states by passenger volume -lrb- see world 's busiest airports by passenger traffic -rrb- and the third by international passenger volume -lrb- see busiest airports in the united states by international passenger traffic -rrb- ; san diego international airport the busiest single runway airport in the world ; van nuys airport , the world 's busiest general aviation airport ; major commercial airports at orange county , bakersfield , ontario , burbank and long beach ; and numerous smaller commercial and general aviation airports . 
southern california is home to los angeles international airport , the second-busiest airport in the united states by passenger volume -lrb- see world 's busiest airports by passenger traffic -rrb- and the third by international passenger volume -lrb- see busiest airports in the united states by international passenger traffic -rrb- ; san diego international airport the busiest single runway airport in the world ; van nuys airport , the world 's busiest general aviation airport ; major commercial airports at orange county , bakersfield , ontario , burbank and long beach ; and numerous smaller commercial and general aviation airports . 
six of the seven lines of the commuter rail system , metrolink , run out of downtown los angeles , connecting los angeles , ventura , san bernardino , riverside , orange , and san diego counties with the other line connecting san bernardino , riverside , and orange counties directly . 
six of the seven lines of the commuter rail system , metrolink , run out of downtown los angeles , connecting los angeles , ventura , san bernardino , riverside , orange , and san diego counties with the other line connecting san bernardino , riverside , and orange counties directly . 
six of the seven lines of the commuter rail system , metrolink , run out of downtown los angeles , connecting los angeles , ventura , san bernardino , riverside , orange , and san diego counties with the other line connecting san bernardino , riverside , and orange counties directly . 
six of the seven lines of the commuter rail system , metrolink , run out of downtown los angeles , connecting los angeles , ventura , san bernardino , riverside , orange , and san diego counties with the other line connecting san bernardino , riverside , and orange counties directly . 
southern california is also home to the port of los angeles , the united states ' busiest commercial port ; the adjacent port of long beach , the united states ' second busiest container port ; and the port of san diego . 
southern california is also home to the port of los angeles , the united states ' busiest commercial port ; the adjacent port of long beach , the united states ' second busiest container port ; and the port of san diego . 
southern california is also home to the port of los angeles , the united states ' busiest commercial port ; the adjacent port of long beach , the united states ' second busiest container port ; and the port of san diego . 
the tech coast is a moniker that has gained use as a descriptor for the region 's diversified technology and industrial base as well as its multitude of prestigious and world-renowned research universities and other public and private institutions . 
the tech coast is a moniker that has gained use as a descriptor for the region 's diversified technology and industrial base as well as its multitude of prestigious and world-renowned research universities and other public and private institutions . 
amongst these include 5 university of california campuses -lrb- irvine , los angeles , riverside , santa barbara , and san diego -rrb- ; 12 california state university campuses -lrb- bakersfield , channel islands , dominguez hills , fullerton , los angeles , long beach , northridge , pomona , san bernardino , san diego , san marcos , and san luis obispo -rrb- ; and private institutions such as the california institute of technology , chapman university , the claremont colleges -lrb- claremont mckenna college , harvey mudd college , pitzer college , pomona college , and scripps college -rrb- , loma linda university , loyola marymount university , occidental college , pepperdine university , university of redlands , university of san diego , and the university of southern california . 
amongst these include 5 university of california campuses -lrb- irvine , los angeles , riverside , santa barbara , and san diego -rrb- ; 12 california state university campuses -lrb- bakersfield , channel islands , dominguez hills , fullerton , los angeles , long beach , northridge , pomona , san bernardino , san diego , san marcos , and san luis obispo -rrb- ; and private institutions such as the california institute of technology , chapman university , the claremont colleges -lrb- claremont mckenna college , harvey mudd college , pitzer college , pomona college , and scripps college -rrb- , loma linda university , loyola marymount university , occidental college , pepperdine university , university of redlands , university of san diego , and the university of southern california . 
amongst these include 5 university of california campuses -lrb- irvine , los angeles , riverside , santa barbara , and san diego -rrb- ; 12 california state university campuses -lrb- bakersfield , channel islands , dominguez hills , fullerton , los angeles , long beach , northridge , pomona , san bernardino , san diego , san marcos , and san luis obispo -rrb- ; and private institutions such as the california institute of technology , chapman university , the claremont colleges -lrb- claremont mckenna college , harvey mudd college , pitzer college , pomona college , and scripps college -rrb- , loma linda university , loyola marymount university , occidental college , pepperdine university , university of redlands , university of san diego , and the university of southern california . 
professional sports teams in southern california include teams from the nfl -lrb- los angeles rams , san diego chargers -rrb- ; nba -lrb- los angeles lakers , los angeles clippers -rrb- ; mlb -lrb- los angeles dodgers , los angeles angels of anaheim , san diego padres -rrb- ; nhl -lrb- los angeles kings , anaheim ducks -rrb- ; and mls -lrb- la galaxy -rrb- . 
professional sports teams in southern california include teams from the nfl -lrb- los angeles rams , san diego chargers -rrb- ; nba -lrb- los angeles lakers , los angeles clippers -rrb- ; mlb -lrb- los angeles dodgers , los angeles angels of anaheim , san diego padres -rrb- ; nhl -lrb- los angeles kings , anaheim ducks -rrb- ; and mls -lrb- la galaxy -rrb- . 
professional sports teams in southern california include teams from the nfl -lrb- los angeles rams , san diego chargers -rrb- ; nba -lrb- los angeles lakers , los angeles clippers -rrb- ; mlb -lrb- los angeles dodgers , los angeles angels of anaheim , san diego padres -rrb- ; nhl -lrb- los angeles kings , anaheim ducks -rrb- ; and mls -lrb- la galaxy -rrb- . 
professional sports teams in southern california include teams from the nfl -lrb- los angeles rams , san diego chargers -rrb- ; nba -lrb- los angeles lakers , los angeles clippers -rrb- ; mlb -lrb- los angeles dodgers , los angeles angels of anaheim , san diego padres -rrb- ; nhl -lrb- los angeles kings , anaheim ducks -rrb- ; and mls -lrb- la galaxy -rrb- . 
professional sports teams in southern california include teams from the nfl -lrb- los angeles rams , san diego chargers -rrb- ; nba -lrb- los angeles lakers , los angeles clippers -rrb- ; mlb -lrb- los angeles dodgers , los angeles angels of anaheim , san diego padres -rrb- ; nhl -lrb- los angeles kings , anaheim ducks -rrb- ; and mls -lrb- la galaxy -rrb- . 
from 2005 to 2014 , there were two major league soccer teams in los angeles -- the la galaxy and chivas usa -- that both played at the stubhub center and were local rivals . 
from 2005 to 2014 , there were two major league soccer teams in los angeles -- the la galaxy and chivas usa -- that both played at the stubhub center and were local rivals . 
from 2005 to 2014 , there were two major league soccer teams in los angeles -- the la galaxy and chivas usa -- that both played at the stubhub center and were local rivals . 
from 2005 to 2014 , there were two major league soccer teams in los angeles -- the la galaxy and chivas usa -- that both played at the stubhub center and were local rivals . 
however , chivas were suspended following the 2014 mls season , with a second mls team scheduled to return in 2018 . 
college sports are also popular in southern california . 
the ucla bruins and the usc trojans both field teams in ncaa division i in the pac-12 conference , and there is a longtime rivalry between the schools . 
the ucla bruins and the usc trojans both field teams in ncaa division i in the pac-12 conference , and there is a longtime rivalry between the schools . 
the ucla bruins and the usc trojans both field teams in ncaa division i in the pac-12 conference , and there is a longtime rivalry between the schools . 
the ucla bruins and the usc trojans both field teams in ncaa division i in the pac-12 conference , and there is a longtime rivalry between the schools . 
rugby is also a growing sport in southern california , particularly at the high school level , with increasing numbers of schools adding rugby as an official school sport . 
rugby is also a growing sport in southern california , particularly at the high school level , with increasing numbers of schools adding rugby as an official school sport . 
rugby is also a growing sport in southern california , particularly at the high school level , with increasing numbers of schools adding rugby as an official school sport . 
formed in november 1990 by the equal merger of sky television and british satellite broadcasting , bskyb became the uk 's largest digital subscription television company . 
formed in november 1990 by the equal merger of sky television and british satellite broadcasting , bskyb became the uk 's largest digital subscription television company . 
following bskyb 's 2014 acquisition of sky italia and a majority 90.04 % interest in sky deutschland in november 2014 , its holding company british sky broadcasting group plc changed its name to sky plc. . 
following bskyb 's 2014 acquisition of sky italia and a majority 90.04 % interest in sky deutschland in november 2014 , its holding company british sky broadcasting group plc changed its name to sky plc. . 
the united kingdom operations also changed the company name from british sky broadcasting limited to sky uk limited , still trading as sky . 
in may 2006 , the irish broadcaster setanta sports was awarded two of the six premier league packages that the english fa offered to broadcasters . 
in may 2006 , the irish broadcaster setanta sports was awarded two of the six premier league packages that the english fa offered to broadcasters . 
sky picked up the remaining four for # 1.3 bn . 
sky picked up the remaining four for # 1.3 bn . 
while bskyb had been excluded from being a part of the ondigital consortium , thereby making them a competitor by default , bskyb was able to join itv digital 's free-to-air replacement , freeview , in which it holds an equal stake with the bbc , itv , channel 4 and national grid wireless . 
while bskyb had been excluded from being a part of the ondigital consortium , thereby making them a competitor by default , bskyb was able to join itv digital 's free-to-air replacement , freeview , in which it holds an equal stake with the bbc , itv , channel 4 and national grid wireless . 
prior to october 2005 , three bskyb channels were available on this platform : sky news , sky three , and sky sports news . 
however , this was replaced by sky three on 31 october 2005 , which was itself later re-branded as ` pick tv ' in 2011 . 
however , this was replaced by sky three on 31 october 2005 , which was itself later re-branded as ` pick tv ' in 2011 . 
bskyb initially charged additional subscription fees for using a sky + pvr with their service ; waiving the charge for subscribers whose package included two or more premium channels . 
in september 2007 , sky launched a new tv advertising campaign targeting sky + at women . 
customers that do not subscribe to bskyb 's channels can still pay a monthly fee to enable sky + functions . 
in january 2010 bskyb discontinued the sky + box , limited the standard sky box to multiroom upgrade only and started to issue the sky + hd box as standard , thus giving all new subscribers the functions of sky + . 
in january 2010 bskyb discontinued the sky + box , limited the standard sky box to multiroom upgrade only and started to issue the sky + hd box as standard , thus giving all new subscribers the functions of sky + . 
bskyb utilises the videoguard pay-tv scrambling system owned by nds , a cisco systems company . 
bskyb utilises the videoguard pay-tv scrambling system owned by nds , a cisco systems company . 
bskyb utilises the videoguard pay-tv scrambling system owned by nds , a cisco systems company . 
bskyb has design authority over all digital satellite receivers capable of receiving their service . 
this extends to the personal video recorder -lrb- pvr -rrb- offering -lrb- branded sky + -rrb- . 
the failure to renew the existing carriage agreements negotiated with ntl and telewest resulted in virgin media removing the basic channels from the network on 1 march 2007 . 
in 2007 , bskyb and virgin media became involved in a dispute over the carriage of sky channels on cable tv . 
virgin media claimed that bskyb had substantially increased the asking price for the channels , a claim which bskyb denied , on the basis that their new deal offered `` substantially more value '' by including hd channels and video on demand content which was not previously carried by cable . 
virgin media claimed that bskyb had substantially increased the asking price for the channels , a claim which bskyb denied , on the basis that their new deal offered `` substantially more value '' by including hd channels and video on demand content which was not previously carried by cable . 
virgin media claimed that bskyb had substantially increased the asking price for the channels , a claim which bskyb denied , on the basis that their new deal offered `` substantially more value '' by including hd channels and video on demand content which was not previously carried by cable . 
in july 2013 , the english high court of justice found that microsoft 's use of the term `` skydrive '' infringed on sky 's right to the `` sky '' trademark . 
on 31 july 2013 , bskyb and microsoft announced their settlement , in which microsoft will not appeal the ruling , and will rename its skydrive cloud storage service after an unspecified `` reasonable period of time to allow for an orderly transition to a new brand , '' plus `` financial and other terms , the details of which are confidential '' . 
on 27 january 2014 , microsoft announced `` that skydrive will soon become onedrive '' and `` skydrive pro '' becomes `` onedrive for business '' . 
on 27 january 2014 , microsoft announced `` that skydrive will soon become onedrive '' and `` skydrive pro '' becomes `` onedrive for business '' . 
on 31 july 2013 , bskyb and microsoft announced their settlement , in which microsoft will not appeal the ruling , and will rename its skydrive cloud storage service after an unspecified `` reasonable period of time to allow for an orderly transition to a new brand , '' plus `` financial and other terms , the details of which are confidential '' . 
the service started on 1 september 1993 based on the idea from the then chief executive officer , sam chisholm and rupert murdoch , of converting the company business strategy to an entirely fee-based concept . 
the new package included four channels formerly available free-to-air , broadcasting on astra 's satellites , as well as introducing new channels . 
the service continued until the closure of bskyb 's analogue service on 27 september 2001 , due to the launch and expansion of the sky digital platform . 
the service continued until the closure of bskyb 's analogue service on 27 september 2001 , due to the launch and expansion of the sky digital platform . 
within two months of the launch , bskyb gained 400,000 new subscribers , with the majority taking at least one premium channel as well , which helped bskyb reach 3.5 million households by mid-1994 . 
sky uk limited -lrb- formerly british sky broadcasting or bskyb -rrb- is a british telecommunications company which serves the united kingdom . 
sky uk limited -lrb- formerly british sky broadcasting or bskyb -rrb- is a british telecommunications company which serves the united kingdom . 
it is the uk 's largest pay-tv broadcaster with 11 million customers as of 2015 . 
it was the uk 's most popular digital tv service until it was overtaken by freeview in april 2007 . 
the sky q range consists of three set top boxes -lrb- sky q , sky q silver and sky q mini -rrb- , a broadband router -lrb- sky q hub -rrb- and mobile applications . 
the sky q mini set top boxes connect to the sky q silver set top boxes with a wi-fi or power-line connection rather than receive their own satellite feeds . 
this allows all set top boxes in a household to share recordings and other media . 
the sky q silver set top box is capable of receiving and displaying uhd broadcasts , which sky will introduce later in 2016 . 
on 18 november 2015 , sky announced sky q , a range of products and services to be available in 2016 . 
bskyb 's standard definition broadcasts are in dvb-compliant mpeg-2 , with the sky movies and sky box office channels including optional dolby digital soundtracks for recent films , although these are only accessible with a sky + box . 
bskyb 's standard definition broadcasts are in dvb-compliant mpeg-2 , with the sky movies and sky box office channels including optional dolby digital soundtracks for recent films , although these are only accessible with a sky + box . 
sky + hd material is broadcast using mpeg-4 and most of the hd material uses the dvb-s2 standard . 
interactive services and 7-day epg use the proprietary opentv system , with set-top boxes including modems for a return path . 
sky + hd material is broadcast using mpeg-4 and most of the hd material uses the dvb-s2 standard . 
when sky digital was launched in 1998 the new service used the astra 2a satellite which was located at the 28.5 ° e orbital position , unlike the analogue service which was broadcast from 19.2 ° e . 
when sky digital was launched in 1998 the new service used the astra 2a satellite which was located at the 28.5 ° e orbital position , unlike the analogue service which was broadcast from 19.2 ° e . 
this was subsequently followed by more astra satellites as well as eutelsat 's eurobird 1 -lrb- now eutelsat 33c -rrb- at 28.5 ° e -rrb- , enabled the company to launch a new all-digital service , sky , with the potential to carry hundreds of television and radio channels . 
this was subsequently followed by more astra satellites as well as eutelsat 's eurobird 1 -lrb- now eutelsat 33c -rrb- at 28.5 ° e -rrb- , enabled the company to launch a new all-digital service , sky , with the potential to carry hundreds of television and radio channels . 
the old position was shared with broadcasters from several european countries , while the new position at 28.5 ° e came to be used almost exclusively for channels that broadcast to the united kingdom . 
bskyb launched its hdtv service , sky + hd , on 22 may 2006 . 
prior to its launch , bskyb claimed that 40,000 people had registered to receive the hd service . 
in the week before the launch , rumours started to surface that bskyb was having supply issues with its set top box -lrb- stb -rrb- from manufacturer thomson . 
finally , the bbc reported that 17,000 customers had yet to receive the service due to failed deliveries . 
on 31 march 2012 , sky announced the total number of homes with sky + hd was 4,222,000 . 
on 8 february 2007 , bskyb announced its intention to replace its three free-to-air digital terrestrial channels with four subscription channels . 
the announcement came a day after setanta sports confirmed that it would launch in march as a subscription service on the digital terrestrial platform , and on the same day that ntl 's services re-branded as virgin media . 
the announcement came a day after setanta sports confirmed that it would launch in march as a subscription service on the digital terrestrial platform , and on the same day that ntl 's services re-branded as virgin media . 
the announcement came a day after setanta sports confirmed that it would launch in march as a subscription service on the digital terrestrial platform , and on the same day that ntl 's services re-branded as virgin media . 
it was proposed that these channels would offer a range of content from the bskyb portfolio including sport -lrb- including english premier league football -rrb- , films , entertainment and news . 
some broadcasts are free-to-air and unencrypted , some are encrypted but do not require a monthly subscription -lrb- known as free-to-view -rrb- , some are encrypted and require a monthly subscription , and some are pay-per-view services . 
some broadcasts are free-to-air and unencrypted , some are encrypted but do not require a monthly subscription -lrb- known as free-to-view -rrb- , some are encrypted and require a monthly subscription , and some are pay-per-view services . 
to view the encrypted content a videoguard uk equipped receiver -lrb- all of which are dedicated to the sky service , and can not be used to decrypt other services -rrb- needs to be used . 
provided is a universal ku band lnb -lrb- 9.75 / 10.600 ghz -rrb- which is fitted at the end of the dish and pointed at the correct satellite constellation ; most digital receivers will receive the free to air channels . 
to view the encrypted content a videoguard uk equipped receiver -lrb- all of which are dedicated to the sky service , and can not be used to decrypt other services -rrb- needs to be used . 
in the autumn of 1991 , talks were held for the broadcast rights for premier league for a five-year period , from the 1992 season . 
itv were the current rights holders , and fought hard to retain the new rights . 
itv had increased its offer from # 18m to # 34m per year to keep control of the rights . 
the bbc was given the highlights of most of the matches , while bskyb paying # 304m for the premier league rights , would give them a monopoly of all live matches , up to 60 per year from the 1992 season . 
the bbc was given the highlights of most of the matches , while bskyb paying # 304m for the premier league rights , would give them a monopoly of all live matches , up to 60 per year from the 1992 season . 
bskyb has no veto over the presence of channels on their epg , with open access being an enforced part of their operating licence from ofcom . 
any channel which can get carriage on a suitable beam of a satellite at 28 ° east is entitled to access to bskyb 's epg for a fee , ranging from # 15 -- 100,000 . 
bskyb has no veto over the presence of channels on their epg , with open access being an enforced part of their operating licence from ofcom . 
however , even in this case , bskyb does not carry any control over the channel 's content or carriage issues such as picture quality . 
however , even in this case , bskyb does not carry any control over the channel 's content or carriage issues such as picture quality . 
bskyb 's digital service was officially launched on 1 october 1998 under the name sky digital , although small-scale tests were carried out before then . 
bskyb 's digital service was officially launched on 1 october 1998 under the name sky digital , although small-scale tests were carried out before then . 
now called sky active , bskyb competed with the ondigital -lrb- later itv digital -rrb- terrestrial offering and cable services . 
now called sky active , bskyb competed with the ondigital -lrb- later itv digital -rrb- terrestrial offering and cable services . 
within 30 days , over 100,000 digiboxes had been sold , which help bolstered bskyb 's decision to give away free digiboxes and minidishes from may 1999 . 
virgin media -lrb- re-branded in 2007 from ntl : telewest -rrb- started to offer a high-definition television -lrb- hdtv -rrb- capable set top box , although from 30 november 2006 until 30 july 2009 it only carried one linear hd channel , bbc hd , after the conclusion of the itv hd trial . 
virgin media -lrb- re-branded in 2007 from ntl : telewest -rrb- started to offer a high-definition television -lrb- hdtv -rrb- capable set top box , although from 30 november 2006 until 30 july 2009 it only carried one linear hd channel , bbc hd , after the conclusion of the itv hd trial . 
nonetheless , the linear channels were not offered , virgin media instead concentrating on its video on demand service to carry a modest selection of hd content . 
virgin media -lrb- re-branded in 2007 from ntl : telewest -rrb- started to offer a high-definition television -lrb- hdtv -rrb- capable set top box , although from 30 november 2006 until 30 july 2009 it only carried one linear hd channel , bbc hd , after the conclusion of the itv hd trial . 
virgin media has claimed that other hd channels were `` locked up '' or otherwise withheld from their platform , although virgin media did in fact have an option to carry channel 4 hd in the future . 
bskyb 's direct-to-home satellite service became available in 10 million homes in 2010 , europe 's first pay-tv platform in to achieve that milestone . 
confirming it had reached its target , the broadcaster said its reach into 36 % of households in the uk represented an audience of more than 25m people . 
the target was first announced in august 2004 , since then an additional 2.4 m customers had subscribed to bskyb 's direct-to-home service . 
confirming it had reached its target , the broadcaster said its reach into 36 % of households in the uk represented an audience of more than 25m people . 
media commentators had debated whether the figure could be reached as the growth in subscriber numbers elsewhere in europe flattened . 
conservative mp alec shelbrooke was proposing the payments of benefits and tax credits on a `` welfare cash card '' , in the style of the supplemental nutrition assistance program , that could be used to buy only `` essentials '' . 
conservative mp alec shelbrooke was proposing the payments of benefits and tax credits on a `` welfare cash card '' , in the style of the supplemental nutrition assistance program , that could be used to buy only `` essentials '' . 
in december , the uk 's parliament heard a claim that a subscription to bskyb was ` often damaging ' , along with alcohol , tobacco and gambling . 
the daily mail newspaper reported in 2012 that the uk government 's benefits agency was checking claimants ' `` sky tv bills to establish if a woman in receipt of benefits as a single mother is wrongly claiming to be living alone '' -- as , it claimed , subscription to sports channels would betray a man 's presence in the household . 
the daily mail newspaper reported in 2012 that the uk government 's benefits agency was checking claimants ' `` sky tv bills to establish if a woman in receipt of benefits as a single mother is wrongly claiming to be living alone '' -- as , it claimed , subscription to sports channels would betray a man 's presence in the household . 
the agreements include fixed annual carriage fees of # 30m for the channels with both channel suppliers able to secure additional capped payments if their channels meet certain performance-related targets . 
currently there is no indication as to whether the new deal includes the additional video on demand and high definition content which had previously been offered by bskyb . 
as part of the agreements , both bskyb and virgin media agreed to terminate all high court proceedings against each other relating to the carriage of their respective basic channels . 
as part of the agreements , both bskyb and virgin media agreed to terminate all high court proceedings against each other relating to the carriage of their respective basic channels . 
as part of the agreements , both bskyb and virgin media agreed to terminate all high court proceedings against each other relating to the carriage of their respective basic channels . 
the economy of victoria is highly diversified : service sectors including financial and property services , health , education , wholesale , retail , hospitality and manufacturing constitute the majority of employment . 
victoria 's total gross state product -lrb- gsp -rrb- is ranked second in australia , although victoria is ranked fourth in terms of gsp per capita because of its limited mining activity . 
victoria 's total gross state product -lrb- gsp -rrb- is ranked second in australia , although victoria is ranked fourth in terms of gsp per capita because of its limited mining activity . 
the melbourne cricket ground is the largest stadium in australia , and the host of the 1956 summer olympics and the 2006 commonwealth games . 
the melbourne cricket ground is the largest stadium in australia , and the host of the 1956 summer olympics and the 2006 commonwealth games . 
many chinese miners worked in victoria , and their legacy is particularly strong in bendigo and its environs . 
although there was some racism directed at them , there was not the level of anti-chinese violence that was seen at the lambing flat riots in new south wales . 
however , there was a riot at buckland valley near bright in 1857 . 
conditions on the gold fields were cramped and unsanitary ; an outbreak of typhoid at buckland valley in 1854 killed over 1,000 miners . 
conditions on the gold fields were cramped and unsanitary ; an outbreak of typhoid at buckland valley in 1854 killed over 1,000 miners . 
in november 2006 , the victorian legislative council elections were held under a new multi-member proportional representation system . 
the state of victoria was divided into eight electorates with each electorate represented by five representatives elected by single transferable vote . 
the state of victoria was divided into eight electorates with each electorate represented by five representatives elected by single transferable vote . 
the total number of upper house members was reduced from 44 to 40 and their term of office is now the same as the lower house members -- four years . 
elections for the victorian parliament are now fixed and occur in november every four years . 
the centre-left australian labor party -lrb- alp -rrb- , the centre-right liberal party of australia , the rural-based national party of australia , and the environmentalist australian greens are victoria 's main political parties . 
the centre-left australian labor party -lrb- alp -rrb- , the centre-right liberal party of australia , the rural-based national party of australia , and the environmentalist australian greens are victoria 's main political parties . 
the centre-left australian labor party -lrb- alp -rrb- , the centre-right liberal party of australia , the rural-based national party of australia , and the environmentalist australian greens are victoria 's main political parties . 
the greens , who won their first lower house seats in 2014 , are strongest in inner melbourne . 
traditionally , labor is strongest in melbourne 's working class western and northern suburbs , and the regional cities of ballarat , bendigo and geelong . 
about 61.1 % of victorians describe themselves as christian . 
roman catholics form the single largest religious group in the state with 26.7 % of the victorian population , followed by anglicans and members of the uniting church . 
buddhism is the state 's largest non-christian religion , with 168,637 members as of the most recent census . 
buddhism is the state 's largest non-christian religion , with 168,637 members as of the most recent census . 
around 20 % of victorians claim no religion . 
victoria -lrb- abbreviated as vic -rrb- is a state in the south-east of australia . 
victoria is australia 's most densely populated state and its second-most populous state overall . 
victoria is australia 's most densely populated state and its second-most populous state overall . 
most of its population is concentrated in the area surrounding port phillip bay , which includes the metropolitan area of its capital and largest city , melbourne , which is australia 's second-largest city . 
most of its population is concentrated in the area surrounding port phillip bay , which includes the metropolitan area of its capital and largest city , melbourne , which is australia 's second-largest city . 
prior to european settlement , the area now constituting victoria was inhabited by a large number of aboriginal peoples , collectively known as the koori . 
with great britain having claimed the entire australian continent east of the 135th meridian east in 1788 , victoria was included in the wider colony of new south wales . 
with great britain having claimed the entire australian continent east of the 135th meridian east in 1788 , victoria was included in the wider colony of new south wales . 
the first settlement in the area occurred in 1803 at sullivan bay , and much of what is now victoria was included in the port phillip district in 1836 , an administrative division of new south wales . 
the first settlement in the area occurred in 1803 at sullivan bay , and much of what is now victoria was included in the port phillip district in 1836 , an administrative division of new south wales . 
more than 26,000 square kilometres -lrb- 10,000 sq mi -rrb- of victorian farmland are sown for grain , mostly in the state 's west . 
more than 50 % of this area is sown for wheat , 33 % for barley and 7 % for oats . 
a further 6,000 square kilometres -lrb- 2,300 sq mi -rrb- is sown for hay . 
victorian farms produce nearly 90 % of australian pears and third of apples . 
last year , 121,200 tonnes of pears and 270,000 tonnes of tomatoes were produced . 
victoria has a written constitution enacted in 1975 , but based on the 1855 colonial constitution , passed by the united kingdom parliament as the victoria constitution act 1855 , which establishes the parliament as the state 's law-making body for matters coming under state responsibility . 
victoria has a written constitution enacted in 1975 , but based on the 1855 colonial constitution , passed by the united kingdom parliament as the victoria constitution act 1855 , which establishes the parliament as the state 's law-making body for matters coming under state responsibility . 
the victorian constitution can be amended by the parliament of victoria , except for certain `` entrenched '' provisions that require either an absolute majority in both houses , a three-fifths majority in both houses , or the approval of the victorian people in a referendum , depending on the provision . 
the victorian constitution can be amended by the parliament of victoria , except for certain `` entrenched '' provisions that require either an absolute majority in both houses , a three-fifths majority in both houses , or the approval of the victorian people in a referendum , depending on the provision . 
victoria has a written constitution enacted in 1975 , but based on the 1855 colonial constitution , passed by the united kingdom parliament as the victoria constitution act 1855 , which establishes the parliament as the state 's law-making body for matters coming under state responsibility . 
the mallee and upper wimmera are victoria 's warmest regions with hot winds blowing from nearby semi-deserts . 
average temperatures exceed 32 °c -lrb- 90 °f -rrb- during summer and 15 °c -lrb- 59 °f -rrb- in winter . 
average temperatures exceed 32 °c -lrb- 90 °f -rrb- during summer and 15 °c -lrb- 59 °f -rrb- in winter . 
victoria 's highest maximum temperature since world war ii , of 48.8 °c -lrb- 119.8 °f -rrb- was recorded in hopetoun on 7 february 2009 , during the 2009 southeastern australia heat wave . 
victoria 's highest maximum temperature since world war ii , of 48.8 °c -lrb- 119.8 °f -rrb- was recorded in hopetoun on 7 february 2009 , during the 2009 southeastern australia heat wave . 
public schools , also known as state or government schools , are funded and run directly by the victoria department of education . 
public schools , also known as state or government schools , are funded and run directly by the victoria department of education . 
students do not pay tuition fees , but some extra costs are levied . 
private fee-paying schools include parish schools run by the roman catholic church and independent schools similar to british public schools . 
all schools must comply with government-set curriculum standards . 
historically , victoria has been the base for the manufacturing plants of the major car brands ford , toyota and holden ; however , closure announcements by all three companies in the 21st century will mean that australia will no longer be a base for the global car industry , with toyota 's statement in february 2014 outlining a closure year of 2017 . 
historically , victoria has been the base for the manufacturing plants of the major car brands ford , toyota and holden ; however , closure announcements by all three companies in the 21st century will mean that australia will no longer be a base for the global car industry , with toyota 's statement in february 2014 outlining a closure year of 2017 . 
holden 's announcement occurred in may 2013 , followed by ford 's decision in december of the same year -lrb- ford 's victorian plants -- in broadmeadows and geelong -- will close in october 2016 -rrb- . 
holden 's announcement occurred in may 2013 , followed by ford 's decision in december of the same year -lrb- ford 's victorian plants -- in broadmeadows and geelong -- will close in october 2016 -rrb- . 
holden 's announcement occurred in may 2013 , followed by ford 's decision in december of the same year -lrb- ford 's victorian plants -- in broadmeadows and geelong -- will close in october 2016 -rrb- . 
victoria contains many topographically , geologically and climatically diverse areas , ranging from the wet , temperate climate of gippsland in the southeast to the snow-covered victorian alpine areas which rise to almost 2,000 m -lrb- 6,600 ft -rrb- , with mount bogong the highest peak at 1,986 m -lrb- 6,516 ft -rrb- . 
victoria contains many topographically , geologically and climatically diverse areas , ranging from the wet , temperate climate of gippsland in the southeast to the snow-covered victorian alpine areas which rise to almost 2,000 m -lrb- 6,600 ft -rrb- , with mount bogong the highest peak at 1,986 m -lrb- 6,516 ft -rrb- . 
victoria contains many topographically , geologically and climatically diverse areas , ranging from the wet , temperate climate of gippsland in the southeast to the snow-covered victorian alpine areas which rise to almost 2,000 m -lrb- 6,600 ft -rrb- , with mount bogong the highest peak at 1,986 m -lrb- 6,516 ft -rrb- . 
there is an extensive series of river systems in victoria . 
the state symbols include the pink heath -lrb- state flower -rrb- , leadbeater 's possum -lrb- state animal -rrb- and the helmeted honeyeater -lrb- state bird -rrb- . 
the victorian alps in the northeast are the coldest part of victoria . 
the alps are part of the great dividing range mountain system extending east-west through the centre of victoria . 
the alps are part of the great dividing range mountain system extending east-west through the centre of victoria . 
average temperatures are less than 9 °c -lrb- 48 °f -rrb- in winter and below 0 °c -lrb- 32 °f -rrb- in the highest parts of the ranges . 
the state 's lowest minimum temperature of − 11.7 °c -lrb- 10.9 °f -rrb- was recorded at omeo on 13 june 1965 , and again at falls creek on 3 july 1970 . 
rail transport in victoria is provided by several private and public railway operators who operate over government-owned lines . 
major operators include : metro trains melbourne which runs an extensive , electrified , passenger system throughout melbourne and suburbs ; v/line which is now owned by the victorian government , operates a concentrated service to major regional centres , as well as long distance services on other lines ; pacific national , cfcl australia which operate freight services ; great southern rail which operates the overland melbourne -- adelaide ; and nsw trainlink which operates xpts melbourne -- sydney . 
major operators include : metro trains melbourne which runs an extensive , electrified , passenger system throughout melbourne and suburbs ; v/line which is now owned by the victorian government , operates a concentrated service to major regional centres , as well as long distance services on other lines ; pacific national , cfcl australia which operate freight services ; great southern rail which operates the overland melbourne -- adelaide ; and nsw trainlink which operates xpts melbourne -- sydney . 
major operators include : metro trains melbourne which runs an extensive , electrified , passenger system throughout melbourne and suburbs ; v/line which is now owned by the victorian government , operates a concentrated service to major regional centres , as well as long distance services on other lines ; pacific national , cfcl australia which operate freight services ; great southern rail which operates the overland melbourne -- adelaide ; and nsw trainlink which operates xpts melbourne -- sydney . 
major operators include : metro trains melbourne which runs an extensive , electrified , passenger system throughout melbourne and suburbs ; v/line which is now owned by the victorian government , operates a concentrated service to major regional centres , as well as long distance services on other lines ; pacific national , cfcl australia which operate freight services ; great southern rail which operates the overland melbourne -- adelaide ; and nsw trainlink which operates xpts melbourne -- sydney . 
politically , victoria has 37 seats in the australian house of representatives and 12 seats in the australian senate . 
politically , victoria has 37 seats in the australian house of representatives and 12 seats in the australian senate . 
at state level , the parliament of victoria consists of the legislative assembly -lrb- the lower house -rrb- and the legislative council -lrb- the upper house -rrb- . 
at state level , the parliament of victoria consists of the legislative assembly -lrb- the lower house -rrb- and the legislative council -lrb- the upper house -rrb- . 
the personal representative of the queen of australia in the state is the governor of victoria , currently linda dessau . 
on 1 july 1851 , writs were issued for the election of the first victorian legislative council , and the absolute independence of victoria from new south wales was established proclaiming a new colony of victoria . 
days later , still in 1851 gold was discovered near ballarat , and subsequently at bendigo . 
this triggered one of the largest gold rushes the world has ever seen . 
in ten years the population of victoria increased sevenfold from 76,000 to 540,000 . 
victoria produced in the decade 1851 -- 1860 20 million ounces of gold , one third of the world 's output -lsb- citation needed -rsb- . 
as of august 2010 , victoria had 1,548 public schools , 489 catholic schools and 214 independent schools . 
as of august 2010 , victoria had 1,548 public schools , 489 catholic schools and 214 independent schools . 
just under 540,800 students were enrolled in public schools , and just over 311,800 in private schools . 
victoria has about 63,519 full-time teachers . 
over 61 per cent of private students attend catholic schools . 
victoria is the centre of dairy farming in australia . 
it is home to 60 % of australia 's 3 million dairy cattle and produces nearly two-thirds of the nation 's milk , almost 6.4 billion litres . 
it is home to 60 % of australia 's 3 million dairy cattle and produces nearly two-thirds of the nation 's milk , almost 6.4 billion litres . 
it is home to 60 % of australia 's 3 million dairy cattle and produces nearly two-thirds of the nation 's milk , almost 6.4 billion litres . 
most abalone and rock lobster is exported to asia . 
victorian lines mainly use the 1,600 mm -lrb- 5 ft 3 in -rrb- broad gauge . 
however , the interstate trunk routes , as well as a number of branch lines in the west of the state have been converted to 1,435 mm -lrb- 4 ft 8 1⁄2 in -rrb- standard gauge . 
two tourist railways operate over 760 mm -lrb- 2 ft 6 in -rrb- narrow gauge lines , which are the remnants of five formerly government-owned lines which were built in mountainous areas . 
two tourist railways operate over 760 mm -lrb- 2 ft 6 in -rrb- narrow gauge lines , which are the remnants of five formerly government-owned lines which were built in mountainous areas . 
two tourist railways operate over 760 mm -lrb- 2 ft 6 in -rrb- narrow gauge lines , which are the remnants of five formerly government-owned lines which were built in mountainous areas . 
after the founding of the colony of new south wales in 1788 , australia was divided into an eastern half named new south wales and a western half named new holland , under the administration of the colonial government in sydney . 
after the founding of the colony of new south wales in 1788 , australia was divided into an eastern half named new south wales and a western half named new holland , under the administration of the colonial government in sydney . 
after the founding of the colony of new south wales in 1788 , australia was divided into an eastern half named new south wales and a western half named new holland , under the administration of the colonial government in sydney . 
after the founding of the colony of new south wales in 1788 , australia was divided into an eastern half named new south wales and a western half named new holland , under the administration of the colonial government in sydney . 
in 1854 at ballarat there was an armed rebellion against the government of victoria by miners protesting against mining taxes -lrb- the `` eureka stockade '' -rrb- . 
this was crushed by british troops , but the discontents prompted colonial authorities to reform the administration -lrb- particularly reducing the hated mining licence fees -rrb- and extend the franchise . 
in 1854 at ballarat there was an armed rebellion against the government of victoria by miners protesting against mining taxes -lrb- the `` eureka stockade '' -rrb- . 
this was crushed by british troops , but the discontents prompted colonial authorities to reform the administration -lrb- particularly reducing the hated mining licence fees -rrb- and extend the franchise . 
within a short time , the imperial parliament granted victoria responsible government with the passage of the colony of victoria act 1855 . 
the premier of victoria is the leader of the political party or coalition with the most seats in the legislative assembly . 
the premier is the public face of government and , with cabinet , sets the legislative and political agenda . 
cabinet consists of representatives elected to either house of parliament . 
the current premier of victoria is daniel andrews . 
cabinet consists of representatives elected to either house of parliament . 
during 2003 -- 04 , the gross value of victorian agricultural production increased by 17 % to $ 8.7 billion . 
during 2003 -- 04 , the gross value of victorian agricultural production increased by 17 % to $ 8.7 billion . 
as of 2004 , an estimated 32,463 farms occupied around 136,000 square kilometres -lrb- 52,500 sq mi -rrb- of victorian land . 
as of 2004 , an estimated 32,463 farms occupied around 136,000 square kilometres -lrb- 52,500 sq mi -rrb- of victorian land . 
this comprises more than 60 % of the state 's total land surface . 
major events also play a big part in tourism in victoria , particularly cultural tourism and sports tourism . 
major events also play a big part in tourism in victoria , particularly cultural tourism and sports tourism . 
most of these events are centred on melbourne , but others occur in regional cities , such as the v8 supercars and australian motorcycle grand prix at phillip island , the grand annual steeplechase at warrnambool and the australian international airshow at geelong and numerous local festivals such as the popular port fairy folk festival , queenscliff music festival , bells beach surfclassic and the bright autumn festival . 
most of these events are centred on melbourne , but others occur in regional cities , such as the v8 supercars and australian motorcycle grand prix at phillip island , the grand annual steeplechase at warrnambool and the australian international airshow at geelong and numerous local festivals such as the popular port fairy folk festival , queenscliff music festival , bells beach surfclassic and the bright autumn festival . 
most of these events are centred on melbourne , but others occur in regional cities , such as the v8 supercars and australian motorcycle grand prix at phillip island , the grand annual steeplechase at warrnambool and the australian international airshow at geelong and numerous local festivals such as the popular port fairy folk festival , queenscliff music festival , bells beach surfclassic and the bright autumn festival . 
huguenot numbers peaked near an estimated two million by 1562 , concentrated mainly in the southern and central parts of france , about one-eighth the number of french catholics . 
huguenot numbers peaked near an estimated two million by 1562 , concentrated mainly in the southern and central parts of france , about one-eighth the number of french catholics . 
a series of religious conflicts followed , known as the wars of religion , fought intermittently from 1562 to 1598 . 
the wars finally ended with the granting of the edict of nantes , which granted the huguenots substantial religious , political and military autonomy . 
the wars finally ended with the granting of the edict of nantes , which granted the huguenots substantial religious , political and military autonomy . 
a term used originally in derision , huguenot has unclear origins . 
geneva was john calvin 's adopted home and the centre of the calvinist movement . 
the nickname may have been a combined reference to the swiss politician besançon hugues -lrb- died 1532 -rrb- and the religiously conflicted nature of swiss republicanism in his time , using a clever derogatory pun on the name hugues by way of the dutch word huisgenoten -lrb- literally housemates -rrb- , referring to the connotations of a somewhat related word in german eidgenosse -lrb- confederates as in `` a citizen of one of the states of the swiss confederacy '' -rrb- . 
the label huguenot was purportedly first applied in france to those conspirators -lrb- all of them aristocratic members of the reformed church -rrb- involved in the amboise plot of 1560 : a foiled attempt to wrest power in france from the influential house of guise . 
the label huguenot was purportedly first applied in france to those conspirators -lrb- all of them aristocratic members of the reformed church -rrb- involved in the amboise plot of 1560 : a foiled attempt to wrest power in france from the influential house of guise . 
the availability of the bible in vernacular languages was important to the spread of the protestant movement and development of the reformed church in france . 
around 1294 , a french version of the scriptures was prepared by the roman catholic priest , guyard de moulin . 
around 1294 , a french version of the scriptures was prepared by the roman catholic priest , guyard de moulin . 
a two-volume illustrated folio paraphrase version based on his manuscript , by jean de rély , was printed in paris in 1487 . 
a two-volume illustrated folio paraphrase version based on his manuscript , by jean de rély , was printed in paris in 1487 . 
montpellier was among the most important of the 66 `` villes de sûreté '' that the edict of 1598 granted to the huguenots . 
montpellier was among the most important of the 66 `` villes de sûreté '' that the edict of 1598 granted to the huguenots . 
even before the edict of alès -lrb- 1629 -rrb- , protestant rule was dead and the ville de sûreté was no more . 
tension with paris led to a siege by the royal army in 1622 . 
even before the edict of alès -lrb- 1629 -rrb- , protestant rule was dead and the ville de sûreté was no more . 
individual huguenots settled at the cape of good hope from as early as 1671 with the arrival of françois villion -lrb- viljoen -rrb- . 
the first huguenot to arrive at the cape of good hope was however maria de la queillerie , wife of commander jan van riebeeck -lrb- and daughter of a walloon church minister -rrb- , who arrived on 6 april 1652 to establish a settlement at what is today cape town . 
the first huguenot to arrive at the cape of good hope was however maria de la queillerie , wife of commander jan van riebeeck -lrb- and daughter of a walloon church minister -rrb- , who arrived on 6 april 1652 to establish a settlement at what is today cape town . 
on 31 december 1687 the first organised group of huguenots set sail from the netherlands to the dutch east india company post at the cape of good hope . 
the largest portion of the huguenots to settle in the cape arrived between 1688 and 1689 in seven ships as part of the organised migration , but quite a few arrived as late as 1700 ; thereafter , the numbers declined and only small groups arrived at a time . 
barred by the government from settling in new france , huguenots led by jessé de forest , sailed to north america in 1624 and settled instead in the dutch colony of new netherland -lrb- later incorporated into new york and new jersey -rrb- ; as well as great britain 's colonies , including nova scotia . 
barred by the government from settling in new france , huguenots led by jessé de forest , sailed to north america in 1624 and settled instead in the dutch colony of new netherland -lrb- later incorporated into new york and new jersey -rrb- ; as well as great britain 's colonies , including nova scotia . 
in 1628 the huguenots established a congregation as l'église française à la nouvelle-amsterdam -lrb- the french church in new amsterdam -rrb- . 
this parish continues today as l'eglise du saint-esprit , part of the episcopal -lrb- anglican -rrb- communion , and welcomes francophone new yorkers from all over the world . 
upon their arrival in new amsterdam , huguenots were offered land directly across from manhattan on long island for a permanent settlement and chose the harbor at the end of newtown creek , becoming the first europeans to live in brooklyn , then known as boschwick , in the neighborhood now known as bushwick . 
after the revocation of the edict of nantes in 1685 , several huguenot families of norman and carolingian nobility and descent , including edmund bohun of suffolk england from the humphrey de bohun line of french royalty descended from charlemagne , jean postell of dieppe france , alexander pepin , antoine poitevin of orsement france , and jacques de bordeaux of grenoble , immigrated to the charleston orange district . 
after petitioning the british crown in 1697 for the right to own land in the baronies , they prospered as slave owners on the cooper , ashepoo , ashley and santee river plantations they purchased from the british landgrave edmund bellinger . 
in 1685 , rev. elie prioleau from the town of pons in france , was among the first to settle there . 
after petitioning the british crown in 1697 for the right to own land in the baronies , they prospered as slave owners on the cooper , ashepoo , ashley and santee river plantations they purchased from the british landgrave edmund bellinger . 
in the early years , many huguenots also settled in the area of present-day charleston , south carolina . 
stadtholder william iii of orange , who later became king of england , emerged as the strongest opponent of king louis xiv after the french attacked the dutch republic in 1672 . 
stadtholder william iii of orange , who later became king of england , emerged as the strongest opponent of king louis xiv after the french attacked the dutch republic in 1672 . 
william formed the league of augsburg as a coalition to oppose louis and the french state . 
consequently , many huguenots considered the wealthy and calvinist dutch republic , which led the opposition to louis xiv , as the most attractive country for exile after the revocation of the edict of nantes . 
stadtholder william iii of orange , who later became king of england , emerged as the strongest opponent of king louis xiv after the french attacked the dutch republic in 1672 . 
they retained the religious provisions of the edict of nantes until the rule of louis xiv , who progressively increased persecution of them until he issued the edict of fontainebleau -lrb- 1685 -rrb- , which abolished all legal recognition of protestantism in france , and forced the huguenots to convert . 
they retained the religious provisions of the edict of nantes until the rule of louis xiv , who progressively increased persecution of them until he issued the edict of fontainebleau -lrb- 1685 -rrb- , which abolished all legal recognition of protestantism in france , and forced the huguenots to convert . 
they retained the religious provisions of the edict of nantes until the rule of louis xiv , who progressively increased persecution of them until he issued the edict of fontainebleau -lrb- 1685 -rrb- , which abolished all legal recognition of protestantism in france , and forced the huguenots to convert . 
while nearly three-quarters eventually were killed or submitted , roughly 500,000 huguenots had fled france by the early 18th century -lsb- citation needed -rsb- . 
the catholic church in france and many of its members opposed the huguenots . 
the height of this persecution was the st. bartholomew 's day massacre when 5,000 to 30,000 were killed , although there were also underlying political reasons for this as well , as some of the huguenots were nobles trying to establish separate centers of power in southern france . 
the height of this persecution was the st. bartholomew 's day massacre when 5,000 to 30,000 were killed , although there were also underlying political reasons for this as well , as some of the huguenots were nobles trying to establish separate centers of power in southern france . 
retaliating against the french catholics , the huguenots had their own militia . 
the height of this persecution was the st. bartholomew 's day massacre when 5,000 to 30,000 were killed , although there were also underlying political reasons for this as well , as some of the huguenots were nobles trying to establish separate centers of power in southern france . 
a series of three small civil wars known as the huguenot rebellions broke out , mainly in southwestern france , between 1621 and 1629 . 
a series of three small civil wars known as the huguenot rebellions broke out , mainly in southwestern france , between 1621 and 1629 . 
the uprising occurred a decade following the death of henry iv , a huguenot before converting to catholicism , who had protected protestants through the edict of nantes . 
his successor louis xiii , under the regency of his italian catholic mother marie de ' medici , became more intolerant of protestantism . 
a series of three small civil wars known as the huguenot rebellions broke out , mainly in southwestern france , between 1621 and 1629 . 
approximately one million protestants in modern france represent some 2 % of its population . 
approximately one million protestants in modern france represent some 2 % of its population . 
most are concentrated in alsace in northeast france and the cévennes mountain region in the south , who still regard themselves as huguenots to this day . 
most are concentrated in alsace in northeast france and the cévennes mountain region in the south , who still regard themselves as huguenots to this day . 
long integrated into australian society , it is encouraged by the huguenot society of australia to embrace and conserve its cultural heritage , aided by the society 's genealogical research services . 
huguenot immigrants did not disperse or settle in different parts of the country , but rather , formed three societies or congregations ; one in the city of new york , another 21 miles north of new york in a town which they named new rochelle , and a third further upstate in new paltz . 
huguenot immigrants did not disperse or settle in different parts of the country , but rather , formed three societies or congregations ; one in the city of new york , another 21 miles north of new york in a town which they named new rochelle , and a third further upstate in new paltz . 
the `` huguenot street historic district '' in new paltz has been designated a national historic landmark site and contains the oldest street in the united states of america . 
the `` huguenot street historic district '' in new paltz has been designated a national historic landmark site and contains the oldest street in the united states of america . 
a small group of huguenots also settled on the south shore of staten island along the new york harbor , for which the current neighborhood of huguenot was named . 
after the revocation of the edict of nantes , the dutch republic received the largest group of huguenot refugees , an estimated total of 75,000 to 100,000 people . 
after the revocation of the edict of nantes , the dutch republic received the largest group of huguenot refugees , an estimated total of 75,000 to 100,000 people . 
this was a huge influx as the entire population of the dutch republic amounted to ca. 2 million at that time . 
-lsb- citation needed -rsb- in 1705 , amsterdam and the area of west frisia were the first areas to provide full citizens rights to huguenot immigrants , followed by the dutch republic in 1715 . 
after the revocation of the edict of nantes , the dutch republic received the largest group of huguenot refugees , an estimated total of 75,000 to 100,000 people . 
it was in this place in tours that the prétendus réformés -lrb- `` these supposedly ` reformed ' '' -rrb- habitually gathered at night , both for political purposes , and for prayer and singing psalms . 
in this last connection , the name could suggest the derogatory inference of superstitious worship ; popular fancy held that huguon , the gate of king hugo , was haunted by the ghost of le roi huguet -lrb- regarded by roman catholics as an infamous scoundrel -rrb- and other spirits , who instead of being in purgatory came back to harm the living at night . 
in this last connection , the name could suggest the derogatory inference of superstitious worship ; popular fancy held that huguon , the gate of king hugo , was haunted by the ghost of le roi huguet -lrb- regarded by roman catholics as an infamous scoundrel -rrb- and other spirits , who instead of being in purgatory came back to harm the living at night . 
it was in this place in tours that the prétendus réformés -lrb- `` these supposedly ` reformed ' '' -rrb- habitually gathered at night , both for political purposes , and for prayer and singing psalms . 
it was in this place in tours that the prétendus réformés -lrb- `` these supposedly ` reformed ' '' -rrb- habitually gathered at night , both for political purposes , and for prayer and singing psalms . 
other evidence of the walloons and huguenots in canterbury includes a block of houses in turnagain lane , where weavers ' windows survive on the top floor , as many huguenots worked as weavers . 
the weavers , a half-timbered house by the river , was the site of a weaving school from the late 16th century to about 1830 . 
such economic separation was the condition of the refugees ' initial acceptance in the city . 
they also settled elsewhere in kent , particularly sandwich , faversham and maidstone -- towns in which there used to be refugee churches . 
-lrb- it has been adapted as a restaurant -- see illustration above . 
examples include the huguenot district and french church street in cork city ; and d'olier street in dublin , named after a high sheriff and one of the founders of the bank of ireland . 
a number of huguenots served as mayors in dublin , cork , youghal and waterford in the 17th and 18th centuries . 
examples include the huguenot district and french church street in cork city ; and d'olier street in dublin , named after a high sheriff and one of the founders of the bank of ireland . 
examples include the huguenot district and french church street in cork city ; and d'olier street in dublin , named after a high sheriff and one of the founders of the bank of ireland . 
a french church in portarlington dates back to 1696 , and was built to serve the significant new huguenot community in the town . 
the exodus of huguenots from france created a brain drain , as many huguenots had occupied important places in society . 
the french crown 's refusal to allow non-catholics to settle in new france may help to explain that colony 's slow rate of population growth compared to that of the neighbouring british colonies , which opened settlement to religious dissenters . 
the french crown 's refusal to allow non-catholics to settle in new france may help to explain that colony 's slow rate of population growth compared to that of the neighbouring british colonies , which opened settlement to religious dissenters . 
by the time of the french and indian war -lrb- the north american front of the seven years ' war -rrb- , a sizeable population of huguenot descent lived in the british colonies , and many participated in the british defeat of new france in 1759-60 . 
by the time of the french and indian war -lrb- the north american front of the seven years ' war -rrb- , a sizeable population of huguenot descent lived in the british colonies , and many participated in the british defeat of new france in 1759-60 . 
the warfare was definitively quelled in 1598 , when henry of navarre , having succeeded to the french throne as henry iv , and having recanted protestantism in favour of roman catholicism , issued the edict of nantes . 
the warfare was definitively quelled in 1598 , when henry of navarre , having succeeded to the french throne as henry iv , and having recanted protestantism in favour of roman catholicism , issued the edict of nantes . 
the edict reaffirmed catholicism as the state religion of france , but granted the protestants equality with catholics under the throne and a degree of religious and political freedom within their domains . 
the edict simultaneously protected catholic interests by discouraging the founding of new protestant churches in catholic-controlled regions . 
the warfare was definitively quelled in 1598 , when henry of navarre , having succeeded to the french throne as henry iv , and having recanted protestantism in favour of roman catholicism , issued the edict of nantes . 
the revocation forbade protestant services , required education of children as catholics , and prohibited emigration . 
the revocation forbade protestant services , required education of children as catholics , and prohibited emigration . 
four thousand emigrated to the north american colonies , where they settled in new york and virginia , especially . 
those huguenots who stayed in france became catholics and were called `` new converts '' . 
it precipitated civil bloodshed , ruined commerce , and resulted in the illegal flight from the country of hundreds of thousands of protestants , many of whom became intellectuals , doctors and business leaders in britain as well as holland , prussia , and south africa . 
the first huguenots to leave france sought freedom from persecution in switzerland and the netherlands . 
-lsb- citation needed -rsb- a group of huguenots was part of the french colonisers who arrived in brazil in 1555 to found france antarctique . 
-lsb- citation needed -rsb- a group of huguenots was part of the french colonisers who arrived in brazil in 1555 to found france antarctique . 
the fort was destroyed in 1560 by the portuguese , who captured part of the huguenots . 
this document , the guanabara confession of faith , became the first protestant confession of faith in the whole of the americas . 
many families , today mostly afrikaans-speaking , have surnames indicating their french huguenot ancestry . 
the wine industry in south africa owes a significant debt to the huguenots , some of whom had vineyards in france , or were brandy distillers , and used their skills in their new home . 
many of the farms in the western cape province in south africa still bear french names . 
many families , today mostly afrikaans-speaking , have surnames indicating their french huguenot ancestry . 
paul revere was descended from huguenot refugees , as was henry laurens , who signed the articles of confederation for south carolina ; jack jouett , who made the ride from cuckoo tavern to warn thomas jefferson and others that tarleton and his men were on their way to arrest him for crimes against the king ; francis marion , and a number of other leaders of the american revolution and later statesmen . 
paul revere was descended from huguenot refugees , as was henry laurens , who signed the articles of confederation for south carolina ; jack jouett , who made the ride from cuckoo tavern to warn thomas jefferson and others that tarleton and his men were on their way to arrest him for crimes against the king ; francis marion , and a number of other leaders of the american revolution and later statesmen . 
the last active huguenot congregation in north america worships in charleston , south carolina , at a church that dates to 1844 . 
the huguenot society of america maintains manakin episcopal church in virginia as an historic shrine with occasional services . 
the society has chapters in numerous states , with the one in texas being the largest . 
some huguenots settled in bedfordshire , one of the main centres of the british lace industry at the time . 
the implication that the style of lace known as ` bucks point ' demonstrates a huguenot influence , being a `` combination of mechlin patterns on lille ground '' , is fallacious : what is now known as mechlin lace did not develop until first half of the eighteenth century and lace with mechlin patterns and lille ground did not appear until the end of the 18th century , when it was widely copied throughout europe . 
the only reference to immigrant lacemakers in this period is of twenty-five widows who settled in dover , and there is no contemporary documentation to support there being huguenot lacemakers in bedfordshire . 
the implication that the style of lace known as ` bucks point ' demonstrates a huguenot influence , being a `` combination of mechlin patterns on lille ground '' , is fallacious : what is now known as mechlin lace did not develop until first half of the eighteenth century and lace with mechlin patterns and lille ground did not appear until the end of the 18th century , when it was widely copied throughout europe . 
in berlin , the huguenots created two new neighbourhoods : dorotheenstadt and friedrichstadt . 
by 1700 , one-fifth of the city 's population was french speaking . 
they ultimately decided to switch to german in protest against the occupation of prussia by napoleon in 1806-07 . 
they ultimately decided to switch to german in protest against the occupation of prussia by napoleon in 1806-07 . 
several congregations were founded , such as those of fredericia -lrb- denmark -rrb- , berlin , stockholm , hamburg , frankfurt , helsinki , and emden . 
after this , huguenots -lrb- with estimates ranging from 200,000 to 1,000,000 -rrb- fled to surrounding protestant countries : england , the netherlands , switzerland , norway , denmark , and prussia -- whose calvinist great elector frederick william welcomed them to help rebuild his war-ravaged and underpopulated country . 
following this exodus , huguenots remained in large numbers in only one region of france : the rugged cévennes region in the south . 
in the early 18th century , a regional group known as the camisards who were huguenots rioted against the catholic church in the region , burning churches and killing clergy . 
in the early 18th century , a regional group known as the camisards who were huguenots rioted against the catholic church in the region , burning churches and killing clergy . 
it took french troops years to hunt down and destroy all the bands of camisards , between 1702 and 1709 . 
in 1564 a group of norman huguenots under the leadership of jean ribault established the small colony of fort caroline on the banks of the st. johns river in what is today jacksonville , florida . 
in 1564 a group of norman huguenots under the leadership of jean ribault established the small colony of fort caroline on the banks of the st. johns river in what is today jacksonville , florida . 
in 1564 a group of norman huguenots under the leadership of jean ribault established the small colony of fort caroline on the banks of the st. johns river in what is today jacksonville , florida . 
a september 1565 french naval attack against the new spanish colony at st. augustine failed when its ships were hit by a hurricane on their way to the spanish encampment at fort matanzas . 
a september 1565 french naval attack against the new spanish colony at st. augustine failed when its ships were hit by a hurricane on their way to the spanish encampment at fort matanzas . 
in 1562 , naval officer jean ribault led an expedition that explored florida and the present-day southeastern u.s. , and founded the outpost of charlesfort on parris island , south carolina . 
in 1562 , naval officer jean ribault led an expedition that explored florida and the present-day southeastern u.s. , and founded the outpost of charlesfort on parris island , south carolina . 
in 1565 the spanish decided to enforce their claim to la florida , and sent pedro menéndez de avilés , who established the settlement of st. augustine near fort caroline . 
in 1562 , naval officer jean ribault led an expedition that explored florida and the present-day southeastern u.s. , and founded the outpost of charlesfort on parris island , south carolina . 
the wars of religion precluded a return voyage , and the outpost was abandoned . 
in 1700 several hundred french huguenots migrated from england to the colony of virginia , where the english crown had promised them land grants in lower norfolk county . 
in 1700 several hundred french huguenots migrated from england to the colony of virginia , where the english crown had promised them land grants in lower norfolk county . 
when they arrived , colonial authorities offered them instead land 20 miles above the falls of the james river , at the abandoned monacan village known as manakin town , now in powhatan county . 
of the original 390 settlers in the isolated settlement , many had died ; others lived outside town on farms in the english style ; and others moved to different areas . 
on 12 may 1705 , the virginia general assembly passed an act to naturalise the 148 huguenots still resident at manakintown . 
some huguenots fought in the low countries alongside the dutch against spain during the first years of the dutch revolt -lrb- 1568 -- 1609 -rrb- . 
some huguenots fought in the low countries alongside the dutch against spain during the first years of the dutch revolt -lrb- 1568 -- 1609 -rrb- . 
early ties were already visible in the `` apologie '' of william the silent , condemning the spanish inquisition , which was written by his court minister , the huguenot pierre l'oyseleur , lord of villiers . 
louise de coligny , daughter of the murdered huguenot leader gaspard de coligny , married william the silent , leader of the dutch -lrb- calvinist -rrb- revolt against spanish -lrb- catholic -rrb- rule . 
louise de coligny , daughter of the murdered huguenot leader gaspard de coligny , married william the silent , leader of the dutch -lrb- calvinist -rrb- revolt against spanish -lrb- catholic -rrb- rule . 
both before and after the 1708 passage of the foreign protestants naturalization act , an estimated 50,000 protestant walloons and huguenots fled to england , with many moving on to ireland and elsewhere . 
both before and after the 1708 passage of the foreign protestants naturalization act , an estimated 50,000 protestant walloons and huguenots fled to england , with many moving on to ireland and elsewhere . 
both before and after the 1708 passage of the foreign protestants naturalization act , an estimated 50,000 protestant walloons and huguenots fled to england , with many moving on to ireland and elsewhere . 
andrew lortie -lrb- born andré lortie -rrb- , a leading huguenot theologian and writer who led the exiled community in london , became known for articulating their criticism of the pope and the doctrine of transubstantiation during mass. . 
andrew lortie -lrb- born andré lortie -rrb- , a leading huguenot theologian and writer who led the exiled community in london , became known for articulating their criticism of the pope and the doctrine of transubstantiation during mass. . 
huguenot regiments fought for william of orange in the williamite war in ireland , for which they were rewarded with land grants and titles , many settling in dublin . 
huguenot regiments fought for william of orange in the williamite war in ireland , for which they were rewarded with land grants and titles , many settling in dublin . 
significant huguenot settlements were in dublin , cork , portarlington , lisburn , waterford and youghal . 
smaller settlements , which included killeshandra in county cavan , contributed to the expansion of flax cultivation and the growth of the irish linen industry . 
smaller settlements , which included killeshandra in county cavan , contributed to the expansion of flax cultivation and the growth of the irish linen industry . 
prince louis de condé , along with his sons daniel and osias , -lsb- citation needed -rsb- arranged with count ludwig von nassau-saarbrücken to establish a huguenot community in present-day saarland in 1604 . 
prince louis de condé , along with his sons daniel and osias , -lsb- citation needed -rsb- arranged with count ludwig von nassau-saarbrücken to establish a huguenot community in present-day saarland in 1604 . 
the condés established a thriving glass-making works , which provided wealth to the principality for many years . 
some members of this community emigrated to the united states in the 1890s . 
prince louis de condé , along with his sons daniel and osias , -lsb- citation needed -rsb- arranged with count ludwig von nassau-saarbrücken to establish a huguenot community in present-day saarland in 1604 . 
the bulk of huguenot émigrés relocated to protestant european nations such as england , wales , scotland , denmark , sweden , switzerland , the dutch republic , the electorate of brandenburg and electorate of the palatinate in the holy roman empire , the duchy of prussia , the channel islands , and ireland . 
the bulk of huguenot émigrés relocated to protestant european nations such as england , wales , scotland , denmark , sweden , switzerland , the dutch republic , the electorate of brandenburg and electorate of the palatinate in the holy roman empire , the duchy of prussia , the channel islands , and ireland . 
they also spread beyond europe to the dutch cape colony in south africa , the dutch east indies , the caribbean , and several of the english colonies of north america , and quebec , where they were accepted and allowed to worship freely . 
they also spread beyond europe to the dutch cape colony in south africa , the dutch east indies , the caribbean , and several of the english colonies of north america , and quebec , where they were accepted and allowed to worship freely . 
they also spread beyond europe to the dutch cape colony in south africa , the dutch east indies , the caribbean , and several of the english colonies of north america , and quebec , where they were accepted and allowed to worship freely . 
the `` hugues hypothesis '' argues that the name was derived by association with hugues capet , king of france , who reigned long before the reformation . 
the `` hugues hypothesis '' argues that the name was derived by association with hugues capet , king of france , who reigned long before the reformation . 
janet gray and other supporters of the hypothesis suggest that the name huguenote would be roughly equivalent to little hugos , or those who want hugo . 
janet gray and other supporters of the hypothesis suggest that the name huguenote would be roughly equivalent to little hugos , or those who want hugo . 
some disagree with such double or triple non-french linguistic origins , arguing that for the word to have spread into common use in france , it must have originated in the french language . 
other predecessors of the reformed church included the pro-reform and gallican roman catholics , such as jacques lefevre -lrb- c. 1455 -- 1536 -rrb- . 
during the protestant reformation , lefevre , a professor at the university of paris , published his french translation of the new testament in 1523 , followed by the whole bible in the french language in 1530 . 
during the protestant reformation , lefevre , a professor at the university of paris , published his french translation of the new testament in 1523 , followed by the whole bible in the french language in 1530 . 
william farel was a student of lefevre who went on to become a leader of the swiss reformation , establishing a protestant government in geneva . 
jean cauvin -lrb- john calvin -rrb- , another student at the university of paris , also converted to protestantism . 
in what became known as the st. bartholomew 's day massacre of 24 august -- 3 october 1572 , catholics killed thousands of huguenots in paris . 
in what became known as the st. bartholomew 's day massacre of 24 august -- 3 october 1572 , catholics killed thousands of huguenots in paris . 
nearly 3,000 protestants were slaughtered in toulouse alone . 
an amnesty granted in 1573 pardoned the perpetrators . 
by 17 september , almost 25,000 protestants had been massacred in paris alone . 
louis xiv gained the throne in 1643 and acted increasingly aggressively to force the huguenots to convert . 
louis xiv gained the throne in 1643 and acted increasingly aggressively to force the huguenots to convert . 
at first he sent missionaries , backed by a fund to financially reward converts to catholicism . 
then he imposed penalties , closed huguenot schools and excluded them from favored professions . 
escalating , he instituted dragonnades , which included the occupation and looting of huguenot homes by military troops , in an effort to forcibly convert them . 
new rochelle , located in the county of westchester on the north shore of long island sound , seemed to be the great location of the huguenots in new york . 
it is said that they landed on the coastline peninsula of davenports neck called `` bauffet 's point '' after traveling from england where they had previously taken refuge on account of religious persecution , four years before the revocation of the edict of nantes . 
they purchased from john pell , lord of pelham manor , a tract of land consisting of six thousand one hundred acres with the help of jacob leisler . 
it was named new rochelle after la rochelle , their former strong-hold in france . 
the church was eventually replaced by a third , trinity-st . 
most of the huguenot congregations -lrb- or individuals -rrb- in north america eventually affiliated with other protestant denominations with more numerous members . 
the huguenots adapted quickly and often married outside their immediate french communities , which led to their assimilation . 
for example , e.i. du pont , a former student of lavoisier , established the eleutherian gunpowder mills . 
their descendants in many families continued to use french first names and surnames for their children well into the nineteenth century . 
for example , e.i. du pont , a former student of lavoisier , established the eleutherian gunpowder mills . 
one of the most prominent huguenot refugees in the netherlands was pierre bayle . 
he started teaching in rotterdam , where he finished writing and publishing his multi-volume masterpiece , historical and critical dictionary . 
he started teaching in rotterdam , where he finished writing and publishing his multi-volume masterpiece , historical and critical dictionary . 
it became one of the 100 foundational texts of the us library of congress . 
some huguenot families have kept alive various traditions , such as the celebration and feast of their patron saint nicolas , similar to the dutch sint nicolaas -lrb- sinterklaas -rrb- feast . 
the french protestant church of london was established by royal charter in 1550 . 
the french protestant church of london was established by royal charter in 1550 . 
it is now located at soho square . 
huguenot refugees flocked to shoreditch , london . 
the old truman brewery , then known as the black eagle brewery , was founded in 1724 . 
around 1685 , huguenot refugees found a safe haven in the lutheran and reformed states in germany and scandinavia . 
around 1685 , huguenot refugees found a safe haven in the lutheran and reformed states in germany and scandinavia . 
nearly 50,000 huguenots established themselves in germany , 20,000 of whom were welcomed in brandenburg-prussia , where they were granted special privileges -lrb- edict of potsdam -rrb- and churches in which to worship -lrb- such as the church of st. peter and st. paul , angermünde -rrb- by frederick william , elector of brandenburg and duke of prussia . 
nearly 50,000 huguenots established themselves in germany , 20,000 of whom were welcomed in brandenburg-prussia , where they were granted special privileges -lrb- edict of potsdam -rrb- and churches in which to worship -lrb- such as the church of st. peter and st. paul , angermünde -rrb- by frederick william , elector of brandenburg and duke of prussia . 
the huguenots furnished two new regiments of his army : the altpreußische infantry regiments no. 13 -lrb- regiment on foot varenne -rrb- and 15 -lrb- regiment on foot wylich -rrb- . 
frederick william , elector of brandenburg , invited huguenots to settle in his realms , and a number of their descendants rose to positions of prominence in prussia . 
several prominent german military , cultural , and political figures were ethnic huguenot , including poet theodor fontane , general hermann von françois , the hero of the first world war battle of tannenberg , luftwaffe general and fighter ace adolf galland , luftwaffe flying ace hans-joachim marseille , and famed u-boat captain lothar von arnauld de la perière . 
several prominent german military , cultural , and political figures were ethnic huguenot , including poet theodor fontane , general hermann von françois , the hero of the first world war battle of tannenberg , luftwaffe general and fighter ace adolf galland , luftwaffe flying ace hans-joachim marseille , and famed u-boat captain lothar von arnauld de la perière . 
the last prime minister of the -lrb- east -rrb- german democratic republic , lothar de maizière , is also a descendant of a huguenot family , as is the german federal minister of the interior , thomas de maizière . 
the last prime minister of the -lrb- east -rrb- german democratic republic , lothar de maizière , is also a descendant of a huguenot family , as is the german federal minister of the interior , thomas de maizière . 
non-combustion heat sources such as solar power , nuclear power or geothermal energy may be used . 
the ideal thermodynamic cycle used to analyze this process is called the rankine cycle . 
in the cycle , water is heated and transforms into steam within a boiler operating at a high pressure . 
in the cycle , water is heated and transforms into steam within a boiler operating at a high pressure . 
steam engines are external combustion engines , where the working fluid is separate from the combustion products . 
the first commercially successful true engine , in that it could generate power and transmit it to a machine , was the atmospheric engine , invented by thomas newcomen around 1712 . 
the first commercially successful true engine , in that it could generate power and transmit it to a machine , was the atmospheric engine , invented by thomas newcomen around 1712 . 
the first commercially successful true engine , in that it could generate power and transmit it to a machine , was the atmospheric engine , invented by thomas newcomen around 1712 . 
it was an improvement over savery 's steam pump , using a piston as proposed by papin . 
it was an improvement over savery 's steam pump , using a piston as proposed by papin . 
the first full-scale working railway steam locomotive was built by richard trevithick in the united kingdom and , on 21 february 1804 , the world 's first railway journey took place as trevithick 's unnamed steam locomotive hauled a train along the tramway from the pen-y-darren ironworks , near merthyr tydfil to abercynon in south wales . 
the first full-scale working railway steam locomotive was built by richard trevithick in the united kingdom and , on 21 february 1804 , the world 's first railway journey took place as trevithick 's unnamed steam locomotive hauled a train along the tramway from the pen-y-darren ironworks , near merthyr tydfil to abercynon in south wales . 
the first full-scale working railway steam locomotive was built by richard trevithick in the united kingdom and , on 21 february 1804 , the world 's first railway journey took place as trevithick 's unnamed steam locomotive hauled a train along the tramway from the pen-y-darren ironworks , near merthyr tydfil to abercynon in south wales . 
the first full-scale working railway steam locomotive was built by richard trevithick in the united kingdom and , on 21 february 1804 , the world 's first railway journey took place as trevithick 's unnamed steam locomotive hauled a train along the tramway from the pen-y-darren ironworks , near merthyr tydfil to abercynon in south wales . 
the first full-scale working railway steam locomotive was built by richard trevithick in the united kingdom and , on 21 february 1804 , the world 's first railway journey took place as trevithick 's unnamed steam locomotive hauled a train along the tramway from the pen-y-darren ironworks , near merthyr tydfil to abercynon in south wales . 
the rankine cycle and most practical steam engines have a water pump to recycle or top up the boiler water , so that they may be run continuously . 
utility and industrial boilers commonly use multi-stage centrifugal pumps ; however , other types are used . 
injectors became popular in the 1850s but are no longer widely used , except in applications such as steam locomotives . 
injectors became popular in the 1850s but are no longer widely used , except in applications such as steam locomotives . 
another means of supplying lower-pressure boiler feed water is an injector , which uses a steam jet usually supplied from the boiler . 
such engines use either three or four expansion stages and are known as triple and quadruple expansion engines respectively . 
such engines use either three or four expansion stages and are known as triple and quadruple expansion engines respectively . 
in the late 19th century , the yarrow-schlick-tweedy balancing ` system ' was used on some marine triple expansion engines . 
in the late 19th century , the yarrow-schlick-tweedy balancing ` system ' was used on some marine triple expansion engines . 
this made the 4-cylinder triple-expansion engine popular with large passenger liners -lrb- such as the olympic class -rrb- , but this was ultimately replaced by the virtually vibration-free turbine engine . 
corliss , and later , poppet valve gears had separate admission and exhaust valves driven by trip mechanisms or cams profiled so as to give ideal events ; most of these gears never succeeded outside of the stationary marketplace due to various other issues including leakage and more delicate mechanisms . 
this expedient has since been generally considered satisfactory for most purposes and makes possible the use of the simpler stephenson , joy and walschaerts motions . 
the usual compromise solution has been to provide lap by lengthening rubbing surfaces of the valve in such a way as to overlap the port on the admission side , with the effect that the exhaust side remains open for a longer period after cut-off on the admission side has occurred . 
lead fusible plugs may be present in the crown of the boiler 's firebox . 
if the water level drops , such that the temperature of the firebox crown increases significantly , the lead melts and the steam escapes , warning the operators , who may then manually suppress the fire . 
if the water level drops , such that the temperature of the firebox crown increases significantly , the lead melts and the steam escapes , warning the operators , who may then manually suppress the fire . 
if the water level drops , such that the temperature of the firebox crown increases significantly , the lead melts and the steam escapes , warning the operators , who may then manually suppress the fire . 
except in the smallest of boilers the steam escape has little effect on dampening the fire . 
in 1781 james watt patented a steam engine that produced continuous rotary motion . 
in 1781 james watt patented a steam engine that produced continuous rotary motion . 
watt 's ten-horsepower engines enabled a wide range of manufacturing machinery to be powered . 
by 1883 , engines that could provide 10,000 hp had become feasible . 
the stationary steam engine was a key component of the industrial revolution , allowing factories to locate where water power was unavailable . 
the history of the steam engine stretches back as far as the first century ad ; the first recorded rudimentary steam engine being the aeolipile described by greek mathematician hero of alexandria . 
the history of the steam engine stretches back as far as the first century ad ; the first recorded rudimentary steam engine being the aeolipile described by greek mathematician hero of alexandria . 
the history of the steam engine stretches back as far as the first century ad ; the first recorded rudimentary steam engine being the aeolipile described by greek mathematician hero of alexandria . 
a rudimentary steam turbine device was described by taqi al-din in 1551 and by giovanni branca in 1629 . 
jerónimo de ayanz y beaumont received patents in 1606 for fifty steam powered inventions , including a water pump for draining inundated mines . 
near the end of the 19th century compound engines came into widespread use . 
these stages were called expansions , with double and triple expansion engines being common , especially in shipping where efficiency was important to reduce the weight of coal carried . 
these stages were called expansions , with double and triple expansion engines being common , especially in shipping where efficiency was important to reduce the weight of coal carried . 
steam engines remained the dominant source of power until the early 20th century , when advances in the design of electric motors and internal combustion engines gradually resulted in the replacement of reciprocating -lrb- piston -rrb- steam engines , with shipping in the 20th-century relying upon the steam turbine . 
these stages were called expansions , with double and triple expansion engines being common , especially in shipping where efficiency was important to reduce the weight of coal carried . 
the final major evolution of the steam engine design was the use of steam turbines starting in the late part of the 19th century . 
the final major evolution of the steam engine design was the use of steam turbines starting in the late part of the 19th century . 
steam turbines are generally more efficient than reciprocating piston type steam engines -lrb- for outputs above several hundred horsepower -rrb- , have fewer moving parts , and provide rotary power directly instead of through a connecting rod system or similar means . 
in the united states 90 % of the electric power is produced in this way using a variety of heat sources . 
today most electric power is provided by steam turbines . 
the heat required for boiling the water and supplying the steam can be derived from various sources , most commonly from burning combustible materials with an appropriate supply of air in a closed space -lrb- called variously combustion chamber , firebox -rrb- . 
the heat required for boiling the water and supplying the steam can be derived from various sources , most commonly from burning combustible materials with an appropriate supply of air in a closed space -lrb- called variously combustion chamber , firebox -rrb- . 
in some cases the heat source is a nuclear reactor , geothermal energy , solar energy or waste heat from an internal combustion engine or industrial process . 
in the case of model or toy steam engines , the heat source can be an electric heating element . 
the most useful instrument for analyzing the performance of steam engines is the steam engine indicator . 
early versions were in use by 1851 , but the most successful indicator was developed for the high speed engine inventor and manufacturer charles porter by charles richard and exhibited at london exhibition in 1862 . 
early versions were in use by 1851 , but the most successful indicator was developed for the high speed engine inventor and manufacturer charles porter by charles richard and exhibited at london exhibition in 1862 . 
early versions were in use by 1851 , but the most successful indicator was developed for the high speed engine inventor and manufacturer charles porter by charles richard and exhibited at london exhibition in 1862 . 
early versions were in use by 1851 , but the most successful indicator was developed for the high speed engine inventor and manufacturer charles porter by charles richard and exhibited at london exhibition in 1862 . 
with two-cylinder compounds used in railway work , the pistons are connected to the cranks as with a two-cylinder simple at 90 ° out of phase with each other -lrb- quartered -rrb- . 
when the double expansion group is duplicated , producing a 4-cylinder compound , the individual pistons within the group are usually balanced at 180 ° , the groups being set at 90 ° to each other . 
when the double expansion group is duplicated , producing a 4-cylinder compound , the individual pistons within the group are usually balanced at 180 ° , the groups being set at 90 ° to each other . 
in most reciprocating piston engines , the steam reverses its direction of flow at each stroke -lrb- counterflow -rrb- , entering and exhausting from the cylinder by the same port . 
the complete engine cycle occupies one rotation of the crank and two piston strokes ; the cycle also comprises four events -- admission , expansion , exhaust , compression . 
the complete engine cycle occupies one rotation of the crank and two piston strokes ; the cycle also comprises four events -- admission , expansion , exhaust , compression . 
the complete engine cycle occupies one rotation of the crank and two piston strokes ; the cycle also comprises four events -- admission , expansion , exhaust , compression . 
the complete engine cycle occupies one rotation of the crank and two piston strokes ; the cycle also comprises four events -- admission , expansion , exhaust , compression . 
the quasiturbine is a uniflow rotary steam engine where steam intakes in hot areas , while exhausting in cold areas . 
uniflow engines attempt to remedy the difficulties arising from the usual counterflow cycle where , during each stroke , the port and the cylinder walls will be cooled by the passing exhaust steam , whilst the hotter incoming admission steam will waste some of its energy in restoring working temperature . 
the aim of the uniflow is to remedy this defect and improve efficiency by providing an additional port uncovered by the piston at the end of each stroke making the steam flow only in one direction . 
an oscillating cylinder steam engine is a variant of the simple expansion steam engine which does not require valves to direct steam into and out of the cylinder . 
instead of valves , the entire cylinder rocks , or oscillates , such that one or more holes in the cylinder line up with holes in a fixed port face or in the pivot mounting -lrb- trunnion -rrb- . 
these engines are mainly used in toys and models , because of their simplicity , but have also been used in full size working engines , mainly on ships where their compactness is valued . 
these engines are mainly used in toys and models , because of their simplicity , but have also been used in full size working engines , mainly on ships where their compactness is valued . 
the working fluid in a rankine cycle can operate as a closed loop system , where the working fluid is recycled continuously , or may be an `` open loop '' system , where the exhaust steam is directly released to the atmosphere , and a separate source of water feeding the boiler is supplied . 
the working fluid in a rankine cycle can operate as a closed loop system , where the working fluid is recycled continuously , or may be an `` open loop '' system , where the exhaust steam is directly released to the atmosphere , and a separate source of water feeding the boiler is supplied . 
mercury is the working fluid in the mercury vapor turbine . 
normally water is the fluid of choice due to its favourable properties , such as non-toxic and unreactive chemistry , abundance , low cost , and its thermodynamic properties . 
the efficiency of a rankine cycle is usually limited by the working fluid . 
without the pressure reaching supercritical levels for the working fluid , the temperature range the cycle can operate over is quite small ; in steam turbines , turbine entry temperatures are typically 565 °c -lrb- the creep limit of stainless steel -rrb- and condenser temperatures are around 30 °c . 
without the pressure reaching supercritical levels for the working fluid , the temperature range the cycle can operate over is quite small ; in steam turbines , turbine entry temperatures are typically 565 °c -lrb- the creep limit of stainless steel -rrb- and condenser temperatures are around 30 °c . 
this gives a theoretical carnot efficiency of about 63 % compared with an actual efficiency of 42 % for a modern coal-fired power station . 
without the pressure reaching supercritical levels for the working fluid , the temperature range the cycle can operate over is quite small ; in steam turbines , turbine entry temperatures are typically 565 °c -lrb- the creep limit of stainless steel -rrb- and condenser temperatures are around 30 °c . 
steam engines can be said to have been the moving force behind the industrial revolution and saw widespread commercial use driving machinery in factories , mills and mines ; powering pumping stations ; and propelling transport appliances such as railway locomotives , ships , steamboats and road vehicles . 
steam engines can be said to have been the moving force behind the industrial revolution and saw widespread commercial use driving machinery in factories , mills and mines ; powering pumping stations ; and propelling transport appliances such as railway locomotives , ships , steamboats and road vehicles . 
there have at one time or another been steam-powered farm tractors , motorcycles -lrb- without much success -rrb- and even automobiles as the stanley steamer . 
steam engines can be said to have been the moving force behind the industrial revolution and saw widespread commercial use driving machinery in factories , mills and mines ; powering pumping stations ; and propelling transport appliances such as railway locomotives , ships , steamboats and road vehicles . 
their use in agriculture led to an increase in the land available for cultivation . 
trevithick continued his own experiments using a trio of locomotives , concluding with the catch me who can in 1808 . 
only four years later , the successful twin-cylinder locomotive salamanca by matthew murray was used by the edge railed rack and pinion middleton railway . 
only four years later , the successful twin-cylinder locomotive salamanca by matthew murray was used by the edge railed rack and pinion middleton railway . 
only four years later , the successful twin-cylinder locomotive salamanca by matthew murray was used by the edge railed rack and pinion middleton railway . 
in 1825 george stephenson built the locomotion for the stockton and darlington railway . 
a method to lessen the magnitude of this heating and cooling was invented in 1804 by british engineer arthur woolf , who patented his woolf high-pressure compound engine in 1805 . 
a method to lessen the magnitude of this heating and cooling was invented in 1804 by british engineer arthur woolf , who patented his woolf high-pressure compound engine in 1805 . 
by staging the expansion in multiple cylinders , torque variability can be reduced . 
to derive equal work from lower-pressure steam requires a larger cylinder volume as this steam occupies a greater volume . 
the main use for steam turbines is in electricity generation -lrb- in the 1990s about 90 % of the world 's electric production was by use of steam turbines -rrb- however the recent widespread application of large gas turbine units and typical combined cycle power plants has resulted in reduction of this percentage to the 80 % regime for steam turbines . 
in marine service , -lrb- pioneered on the turbinia -rrb- , steam turbines with reduction gearing -lrb- although the turbinia has direct turbines to propellers with no reduction gearbox -rrb- dominated large ship propulsion throughout the late 20th century , being more efficient -lrb- and requiring far less maintenance -rrb- than reciprocating steam engines . 
in recent decades , reciprocating diesel engines , and gas turbines , have almost entirely supplanted steam propulsion for marine applications . 
in marine service , -lrb- pioneered on the turbinia -rrb- , steam turbines with reduction gearing -lrb- although the turbinia has direct turbines to propellers with no reduction gearbox -rrb- dominated large ship propulsion throughout the late 20th century , being more efficient -lrb- and requiring far less maintenance -rrb- than reciprocating steam engines . 
in marine service , -lrb- pioneered on the turbinia -rrb- , steam turbines with reduction gearing -lrb- although the turbinia has direct turbines to propellers with no reduction gearbox -rrb- dominated large ship propulsion throughout the late 20th century , being more efficient -lrb- and requiring far less maintenance -rrb- than reciprocating steam engines . 
the rankine cycle is the fundamental thermodynamic underpinning of the steam engine . 
the heat is supplied externally to a closed loop with some of the heat added being converted to work and the waste heat being removed in a condenser . 
in the 1990s , rankine steam cycles generated about 90 % of all electric power used throughout the world , including virtually all solar , biomass , coal and nuclear power plants . 
in the 1990s , rankine steam cycles generated about 90 % of all electric power used throughout the world , including virtually all solar , biomass , coal and nuclear power plants . 
it is named after william john macquorn rankine , a scottish polymath . 
the historical measure of a steam engine 's energy efficiency was its `` duty '' . 
watt 's original low-pressure designs were able to deliver duty as high as 25 million , but averaged about 17 . 
the best examples of newcomen designs had a duty of about 7 million , but most were closer to 5 million . 
duty is the number of foot-pounds of work delivered by burning one bushel -lrb- 94 pounds -rrb- of coal . 
the concept of duty was first introduced by watt in order to illustrate how much more efficient his engines were over the earlier newcomen designs . 
reciprocating piston type steam engines remained the dominant source of power until the early 20th century , when advances in the design of electric motors and internal combustion engines gradually resulted in the replacement of reciprocating -lrb- piston -rrb- steam engines in commercial usage , and the ascendancy of steam turbines in power generation . 
reciprocating piston type steam engines remained the dominant source of power until the early 20th century , when advances in the design of electric motors and internal combustion engines gradually resulted in the replacement of reciprocating -lrb- piston -rrb- steam engines in commercial usage , and the ascendancy of steam turbines in power generation . 
considering that the great majority of worldwide electric generation is produced by turbine type steam engines , the `` steam age '' is continuing with energy levels far beyond those of the turn of the 19th century . 
reciprocating piston type steam engines remained the dominant source of power until the early 20th century , when advances in the design of electric motors and internal combustion engines gradually resulted in the replacement of reciprocating -lrb- piston -rrb- steam engines in commercial usage , and the ascendancy of steam turbines in power generation . 
the first commercial steam-powered device was a water pump , developed in 1698 by thomas savery . 
the first commercial steam-powered device was a water pump , developed in 1698 by thomas savery . 
the first commercial steam-powered device was a water pump , developed in 1698 by thomas savery . 
bento de moura portugal introduced an ingenious improvement of savery 's construction `` to render it capable of working itself '' , as described by john smeaton in the philosophical transactions published in 1751 . 
bento de moura portugal introduced an ingenious improvement of savery 's construction `` to render it capable of working itself '' , as described by john smeaton in the philosophical transactions published in 1751 . 
around 1800 richard trevithick and , separately , oliver evans in 1801 introduced engines using high-pressure steam ; trevithick obtained his high-pressure engine patent in 1802 . 
around 1800 richard trevithick and , separately , oliver evans in 1801 introduced engines using high-pressure steam ; trevithick obtained his high-pressure engine patent in 1802 . 
around 1800 richard trevithick and , separately , oliver evans in 1801 introduced engines using high-pressure steam ; trevithick obtained his high-pressure engine patent in 1802 . 
these were much more powerful for a given cylinder size than previous engines and could be made small enough for transport applications . 
thereafter , technological developments and improvements in manufacturing techniques -lrb- partly brought about by the adoption of the steam engine as a power source -rrb- resulted in the design of more efficient engines that could be smaller , faster , or more powerful , depending on the intended application . 
the company energiprojekt ab in sweden has made progress in using modern materials for harnessing the power of steam . 
the company energiprojekt ab in sweden has made progress in using modern materials for harnessing the power of steam . 
it is a single-step , 5-cylinder engine -lrb- no compound -rrb- with superheated steam and consumes approx . 
4 kg -lrb- 8.8 lb -rrb- of steam per kwh . 
the efficiency of energiprojekt 's steam engine reaches some 27-30 % on high-pressure engines . 
where chp is not used , steam turbines in power stations use surface condensers as a cold sink . 
a dry type cooling tower is similar to an automobile radiator and is used in locations where water is costly . 
a dry type cooling tower is similar to an automobile radiator and is used in locations where water is costly . 
evaporative -lrb- wet -rrb- cooling towers use the rejected heat to evaporate water ; this water is kept separate from the condensate , which circulates in a closed system and returns to the boiler . 
evaporative cooling towers need less water flow than `` once-through '' cooling by river or lake water ; a 700 megawatt coal-fired power plant may use about 3600 cubic metres of make-up water every hour for evaporative cooling , but would need about twenty times as much if cooled by river water . 
the centrifugal governor was adopted by james watt for use on a steam engine in 1788 after watt 's partner boulton saw one at a flour mill boulton & watt were building . 
the centrifugal governor was adopted by james watt for use on a steam engine in 1788 after watt 's partner boulton saw one at a flour mill boulton & watt were building . 
the centrifugal governor was adopted by james watt for use on a steam engine in 1788 after watt 's partner boulton saw one at a flour mill boulton & watt were building . 
as a consequence , engines equipped only with this governor were not suitable for operations requiring constant speed , such as cotton spinning . 
the governor could not actually hold a set speed , because it would assume a new constant speed in response to load changes . 
the adoption of compounding was common for industrial units , for road engines and almost universal for marine engines after 1880 ; it was not universally popular in railway locomotives where it was often perceived as complicated . 
the adoption of compounding was common for industrial units , for road engines and almost universal for marine engines after 1880 ; it was not universally popular in railway locomotives where it was often perceived as complicated . 
the adoption of compounding was common for industrial units , for road engines and almost universal for marine engines after 1880 ; it was not universally popular in railway locomotives where it was often perceived as complicated . 
this is partly due to the harsh railway operating environment and limited space afforded by the loading gauge -lrb- particularly in britain , where compounding was never common and not employed after 1930 -rrb- . 
the adoption of compounding was common for industrial units , for road engines and almost universal for marine engines after 1880 ; it was not universally popular in railway locomotives where it was often perceived as complicated . 
most however have a reversing mechanism which additionally can provide means for saving steam as speed and momentum are gained by gradually `` shortening the cutoff '' or rather , shortening the admission event ; this in turn proportionately lengthens the expansion period . 
however , as one and the same valve usually controls both steam flows , a short cutoff at admission adversely affects the exhaust and compression periods which should ideally always be kept fairly constant ; if the exhaust event is too brief , the totality of the exhaust steam can not evacuate the cylinder , choking it and giving excessive compression -lrb- `` kick back '' -rrb- . 
however , as one and the same valve usually controls both steam flows , a short cutoff at admission adversely affects the exhaust and compression periods which should ideally always be kept fairly constant ; if the exhaust event is too brief , the totality of the exhaust steam can not evacuate the cylinder , choking it and giving excessive compression -lrb- `` kick back '' -rrb- . 
the simplest valve gears give events of fixed length during the engine cycle and often make the engine rotate in only one direction . 
the spanish inventor jerónimo de ayanz y beaumont obtained the first patent for a steam engine in 1606 . 
the spanish inventor jerónimo de ayanz y beaumont obtained the first patent for a steam engine in 1606 . 
the spanish inventor jerónimo de ayanz y beaumont obtained the first patent for a steam engine in 1606 . 
in 1698 thomas savery patented a steam pump that used steam in direct contact with the water being pumped . 
thomas newcomen 's atmospheric engine was the first commercial true steam engine using a piston , and was used in 1712 for pumping in a mine . 
a steam turbine consists of one or more rotors -lrb- rotating discs -rrb- mounted on a drive shaft , alternating with a series of stators -lrb- static discs -rrb- fixed to the turbine casing . 
a steam turbine consists of one or more rotors -lrb- rotating discs -rrb- mounted on a drive shaft , alternating with a series of stators -lrb- static discs -rrb- fixed to the turbine casing . 
a steam turbine consists of one or more rotors -lrb- rotating discs -rrb- mounted on a drive shaft , alternating with a series of stators -lrb- static discs -rrb- fixed to the turbine casing . 
a steam turbine consists of one or more rotors -lrb- rotating discs -rrb- mounted on a drive shaft , alternating with a series of stators -lrb- static discs -rrb- fixed to the turbine casing . 
typical speeds are 3600 revolutions per minute -lrb- rpm -rrb- in the usa with 60 hertz power , 3000 rpm in europe and other countries with 50 hertz electric power systems . 
the weight of boilers and condensers generally makes the power-to-weight ratio of a steam plant lower than for internal combustion engines . 
for mobile applications steam has been largely superseded by internal combustion engines or electric motors . 
however , most electric power is generated using steam turbine plant , so that indirectly the world 's industry is still dependent on steam power . 
this is becoming known as the advanced steam movement . 
recent concerns about fuel sources and pollution have incited a renewed interest in steam both as a component of cogeneration processes and as a prime mover . 
it is possible to use a mechanism based on a pistonless rotary engine such as the wankel engine in place of the cylinders and valve gear of a conventional reciprocating steam engine . 
it is possible to use a mechanism based on a pistonless rotary engine such as the wankel engine in place of the cylinders and valve gear of a conventional reciprocating steam engine . 
the major problem is the difficulty of sealing the rotors to make them steam-tight in the face of wear and thermal expansion ; the resulting leakage made them very inefficient . 
the next major step occurred when james watt developed -lrb- 1763 -- 1775 -rrb- an improved version of newcomen 's engine , with a separate condenser . 
the next major step occurred when james watt developed -lrb- 1763 -- 1775 -rrb- an improved version of newcomen 's engine , with a separate condenser . 
boulton and watt 's early engines used half as much coal as john smeaton 's improved version of newcomen 's . 
boulton and watt 's early engines used half as much coal as john smeaton 's improved version of newcomen 's . 
they were powered by air pressure pushing a piston into the partial vacuum generated by condensing steam , instead of the pressure of expanding steam . 
steam engines frequently possess two independent mechanisms for ensuring that the pressure in the boiler does not go too high ; one may be adjusted by the user , the second is typically designed as an ultimate fail-safe . 
such safety valves traditionally used a simple lever to restrain a plug valve in the top of a boiler . 
the more recent type of safety valve uses an adjustable spring-loaded valve , which is locked such that operators may not tamper with its adjustment unless a seal illegally is broken . 
the more recent type of safety valve uses an adjustable spring-loaded valve , which is locked such that operators may not tamper with its adjustment unless a seal illegally is broken . 
early valves could be adjusted by engine drivers , leading to many accidents when a driver fastened the valve down to allow greater steam pressure and more power from the engine . 
the acme of the horizontal engine was the corliss steam engine , patented in 1849 , which was a four-valve counter flow engine with separate steam admission and exhaust valves and automatic variable steam cutoff . 
the acme of the horizontal engine was the corliss steam engine , patented in 1849 , which was a four-valve counter flow engine with separate steam admission and exhaust valves and automatic variable steam cutoff . 
in addition to using 30 % less steam , it provided more uniform speed due to variable steam cut off , making it well suited to manufacturing , especially cotton spinning . 
the acme of the horizontal engine was the corliss steam engine , patented in 1849 , which was a four-valve counter flow engine with separate steam admission and exhaust valves and automatic variable steam cutoff . 
when corliss was given the rumford medal the committee said that `` no one invention since watt 's time has so enhanced the efficiency of the steam engine '' . 
the steam engine contributed much to the development of thermodynamic theory ; however , the only applications of scientific theory that influenced the steam engine were the original concepts of harnessing the power of steam and atmospheric pressure and knowledge of properties of heat and steam . 
the experimental measurements made by watt on a model steam engine led to the development of the separate condenser . 
the experimental measurements made by watt on a model steam engine led to the development of the separate condenser . 
watt independently discovered latent heat , which was confirmed by the original discoverer joseph black , who also advised watt on experimental procedures . 
watt independently discovered latent heat , which was confirmed by the original discoverer joseph black , who also advised watt on experimental procedures . 
one of the principal advantages the rankine cycle holds over others is that during the compression stage relatively little work is required to drive the pump , the working fluid being in its liquid phase at this point . 
one of the principal advantages the rankine cycle holds over others is that during the compression stage relatively little work is required to drive the pump , the working fluid being in its liquid phase at this point . 
by condensing the fluid , the work required by the pump consumes only 1 % to 3 % of the turbine power and contributes to a much higher efficiency for a real cycle . 
gas turbines , for instance , have turbine entry temperatures approaching 1500 °c . 
other components are often present ; pumps -lrb- such as an injector -rrb- to supply water to the boiler during operation , condensers to recirculate the water and recover the latent heat of vaporisation , and superheaters to raise the temperature of the steam above its saturated vapour point , and various mechanisms to increase the draft for fireboxes . 
other components are often present ; pumps -lrb- such as an injector -rrb- to supply water to the boiler during operation , condensers to recirculate the water and recover the latent heat of vaporisation , and superheaters to raise the temperature of the steam above its saturated vapour point , and various mechanisms to increase the draft for fireboxes . 
other components are often present ; pumps -lrb- such as an injector -rrb- to supply water to the boiler during operation , condensers to recirculate the water and recover the latent heat of vaporisation , and superheaters to raise the temperature of the steam above its saturated vapour point , and various mechanisms to increase the draft for fireboxes . 
when coal is used , a chain or screw stoking mechanism and its drive engine or motor may be included to move the fuel from a supply bin -lrb- bunker -rrb- to the firebox . 
when coal is used , a chain or screw stoking mechanism and its drive engine or motor may be included to move the fuel from a supply bin -lrb- bunker -rrb- to the firebox . 
land-based steam engines could exhaust much of their steam , as feed water was usually readily available . 
it was however superseded by the british invention steam turbine where speed was required , for instance in warships , such as the dreadnought battleships , and ocean liners . 
it was however superseded by the british invention steam turbine where speed was required , for instance in warships , such as the dreadnought battleships , and ocean liners . 
it was however superseded by the british invention steam turbine where speed was required , for instance in warships , such as the dreadnought battleships , and ocean liners . 
hms dreadnought of 1905 was the first major warship to replace the proven technology of the reciprocating engine with the then-novel steam turbine . 
virtually all nuclear power plants generate electricity by heating water to provide steam that drives a turbine connected to an electrical generator . 
virtually all nuclear power plants generate electricity by heating water to provide steam that drives a turbine connected to an electrical generator . 
virtually all nuclear power plants generate electricity by heating water to provide steam that drives a turbine connected to an electrical generator . 
nuclear-powered ships and submarines either use a steam turbine directly for main propulsion , with generators providing auxiliary power , or else employ turbo-electric transmission , where the steam drives a turbo generator set with propulsion provided by electric motors . 
some non-condensing direct-drive locomotives did meet with some success for long haul freight operations in sweden and for express passenger work in britain , but were not repeated . 
the rankine cycle is sometimes referred to as a practical carnot cycle because , when an efficient turbine is used , the ts diagram begins to resemble the carnot cycle . 
the main difference is that heat addition -lrb- in the boiler -rrb- and rejection -lrb- in the condenser -rrb- are isobaric -lrb- constant pressure -rrb- processes in the rankine cycle and isothermal -lrb- constant temperature -rrb- processes in the theoretical carnot cycle . 
the main difference is that heat addition -lrb- in the boiler -rrb- and rejection -lrb- in the condenser -rrb- are isobaric -lrb- constant pressure -rrb- processes in the rankine cycle and isothermal -lrb- constant temperature -rrb- processes in the theoretical carnot cycle . 
the main difference is that heat addition -lrb- in the boiler -rrb- and rejection -lrb- in the condenser -rrb- are isobaric -lrb- constant pressure -rrb- processes in the rankine cycle and isothermal -lrb- constant temperature -rrb- processes in the theoretical carnot cycle . 
in this cycle a pump is used to pressurize the working fluid which is received from the condenser as a liquid not as a gas . 
oxygen is a chemical element with symbol o and atomic number 8 . 
by mass , oxygen is the third-most abundant element in the universe , after hydrogen and helium . 
at standard temperature and pressure , two atoms of the element bind to form dioxygen , a colorless and odorless diatomic gas with the formula o 2 . 
oxygen is the most abundant element by mass in the earth 's crust as part of oxide compounds such as silicon dioxide , making up almost half of the crust 's mass . 
diatomic oxygen gas constitutes 20.8 % of the earth 's atmosphere . 
diatomic oxygen gas constitutes 20.8 % of the earth 's atmosphere . 
oxygen is the most abundant element by mass in the earth 's crust as part of oxide compounds such as silicon dioxide , making up almost half of the crust 's mass . 
oxygen is a chemical element with symbol o and atomic number 8 . 
however , monitoring of atmospheric oxygen levels show a global downward trend , because of fossil-fuel burning . 
by mass , oxygen is the third-most abundant element in the universe , after hydrogen and helium . 
oxygen is a chemical element with symbol o and atomic number 8 . 
it is a member of the chalcogen group on the periodic table and is a highly reactive nonmetal and oxidizing agent that readily forms compounds -lrb- notably oxides -rrb- with most elements . 
it is a member of the chalcogen group on the periodic table and is a highly reactive nonmetal and oxidizing agent that readily forms compounds -lrb- notably oxides -rrb- with most elements . 
by mass , oxygen is the third-most abundant element in the universe , after hydrogen and helium . 
at standard temperature and pressure , two atoms of the element bind to form dioxygen , a colorless and odorless diatomic gas with the formula o 2 . 
oxygen is used in cellular respiration and released by photosynthesis , which uses the energy of sunlight to produce oxygen from water . 
oxygen is used in cellular respiration and released by photosynthesis , which uses the energy of sunlight to produce oxygen from water . 
another form -lrb- allotrope -rrb- of oxygen , ozone -lrb- o 3 -rrb- , strongly absorbs uvb radiation and consequently the high-altitude ozone layer helps protect the biosphere from ultraviolet radiation , but is a pollutant near the surface where it is a by-product of smog . 
many major classes of organic molecules in living organisms , such as proteins , nucleic acids , carbohydrates , and fats , contain oxygen , as do the major inorganic compounds that are constituents of animal shells , teeth , and bone . 
most of the mass of living organisms is oxygen as it is a part of water , the major constituent of lifeforms . 
oxygen is used in cellular respiration and released by photosynthesis , which uses the energy of sunlight to produce oxygen from water . 
oxygen is used in cellular respiration and released by photosynthesis , which uses the energy of sunlight to produce oxygen from water . 
another form -lrb- allotrope -rrb- of oxygen , ozone -lrb- o 3 -rrb- , strongly absorbs uvb radiation and consequently the high-altitude ozone layer helps protect the biosphere from ultraviolet radiation , but is a pollutant near the surface where it is a by-product of smog . 
in the late 17th century , robert boyle proved that air is necessary for combustion . 
english chemist john mayow -lrb- 1641 -- 1679 -rrb- refined this work by showing that fire requires only a part of air that he called spiritus nitroaereus or just nitroaereus . 
from this he surmised that nitroaereus is consumed in both respiration and combustion . 
english chemist john mayow -lrb- 1641 -- 1679 -rrb- refined this work by showing that fire requires only a part of air that he called spiritus nitroaereus or just nitroaereus . 
in the late 17th century , robert boyle proved that air is necessary for combustion . 
english chemist john mayow -lrb- 1641 -- 1679 -rrb- refined this work by showing that fire requires only a part of air that he called spiritus nitroaereus or just nitroaereus . 
in the late 17th century , robert boyle proved that air is necessary for combustion . 
from this he surmised that nitroaereus is consumed in both respiration and combustion . 
english chemist john mayow -lrb- 1641 -- 1679 -rrb- refined this work by showing that fire requires only a part of air that he called spiritus nitroaereus or just nitroaereus . 
in the meantime , on august 1 , 1774 , an experiment conducted by the british clergyman joseph priestley focused sunlight on mercuric oxide -lrb- hgo -rrb- inside a glass tube , which liberated a gas he named `` dephlogisticated air '' . 
in the meantime , on august 1 , 1774 , an experiment conducted by the british clergyman joseph priestley focused sunlight on mercuric oxide -lrb- hgo -rrb- inside a glass tube , which liberated a gas he named `` dephlogisticated air '' . 
in the meantime , on august 1 , 1774 , an experiment conducted by the british clergyman joseph priestley focused sunlight on mercuric oxide -lrb- hgo -rrb- inside a glass tube , which liberated a gas he named `` dephlogisticated air '' . 
in the meantime , on august 1 , 1774 , an experiment conducted by the british clergyman joseph priestley focused sunlight on mercuric oxide -lrb- hgo -rrb- inside a glass tube , which liberated a gas he named `` dephlogisticated air '' . 
in the meantime , on august 1 , 1774 , an experiment conducted by the british clergyman joseph priestley focused sunlight on mercuric oxide -lrb- hgo -rrb- inside a glass tube , which liberated a gas he named `` dephlogisticated air '' . 
in the meantime , on august 1 , 1774 , an experiment conducted by the british clergyman joseph priestley focused sunlight on mercuric oxide -lrb- hgo -rrb- inside a glass tube , which liberated a gas he named `` dephlogisticated air '' . 
priestley published his findings in 1775 in a paper titled `` an account of further discoveries in air '' which was included in the second volume of his book titled experiments and observations on different kinds of air . 
because he published his findings first , priestley is usually given priority in the discovery . 
he noted that candles burned brighter in the gas and that a mouse was more active and lived longer while breathing it . 
many centuries later leonardo da vinci built on philo 's work by observing that a portion of air is consumed during combustion and respiration . 
one of the first known experiments on the relationship between combustion and air was conducted by the 2nd century bce greek writer on mechanics , philo of byzantium . 
one of the first known experiments on the relationship between combustion and air was conducted by the 2nd century bce greek writer on mechanics , philo of byzantium . 
philo incorrectly surmised that parts of the air in the vessel were converted into the classical element fire and thus were able to escape through pores in the glass . 
one of the first known experiments on the relationship between combustion and air was conducted by the 2nd century bce greek writer on mechanics , philo of byzantium . 
philo incorrectly surmised that parts of the air in the vessel were converted into the classical element fire and thus were able to escape through pores in the glass . 
in his work pneumatica , philo observed that inverting a vessel over a burning candle and surrounding the vessel 's neck with water resulted in some water rising into the neck . 
many centuries later leonardo da vinci built on philo 's work by observing that a portion of air is consumed during combustion and respiration . 
many centuries later leonardo da vinci built on philo 's work by observing that a portion of air is consumed during combustion and respiration . 
fire and explosion hazards exist when concentrated oxidants and fuels are brought into close proximity ; an ignition event , such as heat or a spark , is needed to trigger combustion . 
oxygen is the oxidant , not the fuel , but nevertheless the source of most of the chemical energy released in combustion . 
combustion hazards also apply to compounds of oxygen with a high oxidative potential , such as peroxides , chlorates , nitrates , perchlorates , and dichromates because they can donate oxygen to a fire . 
oxygen is the oxidant , not the fuel , but nevertheless the source of most of the chemical energy released in combustion . 
fire and explosion hazards exist when concentrated oxidants and fuels are brought into close proximity ; an ignition event , such as heat or a spark , is needed to trigger combustion . 
oxygen is the oxidant , not the fuel , but nevertheless the source of most of the chemical energy released in combustion . 
highly concentrated sources of oxygen promote rapid combustion . 
oxygen is the oxidant , not the fuel , but nevertheless the source of most of the chemical energy released in combustion . 
combustion hazards also apply to compounds of oxygen with a high oxidative potential , such as peroxides , chlorates , nitrates , perchlorates , and dichromates because they can donate oxygen to a fire . 
the fire that killed the apollo 1 crew in a launch pad test spread so rapidly because the capsule was pressurized with pure o 2 but at slightly more than atmospheric pressure , instead of the 1⁄3 normal pressure that would be used in a mission . 
steel pipes and storage vessels used to store and transmit both gaseous and liquid oxygen will act as a fuel ; and therefore the design and manufacture of o 2 systems requires special training to ensure that ignition sources are minimized . 
the fire that killed the apollo 1 crew in a launch pad test spread so rapidly because the capsule was pressurized with pure o 2 but at slightly more than atmospheric pressure , instead of the 1⁄3 normal pressure that would be used in a mission . 
steel pipes and storage vessels used to store and transmit both gaseous and liquid oxygen will act as a fuel ; and therefore the design and manufacture of o 2 systems requires special training to ensure that ignition sources are minimized . 
concentrated o 2 will allow combustion to proceed rapidly and energetically . 
steel pipes and storage vessels used to store and transmit both gaseous and liquid oxygen will act as a fuel ; and therefore the design and manufacture of o 2 systems requires special training to ensure that ignition sources are minimized . 
steel pipes and storage vessels used to store and transmit both gaseous and liquid oxygen will act as a fuel ; and therefore the design and manufacture of o 2 systems requires special training to ensure that ignition sources are minimized . 
the fire that killed the apollo 1 crew in a launch pad test spread so rapidly because the capsule was pressurized with pure o 2 but at slightly more than atmospheric pressure , instead of the 1⁄3 normal pressure that would be used in a mission . 
the earth 's crustal rock is composed in large part of oxides of silicon -lrb- silica sio 2 , as found in granite and quartz -rrb- , aluminium -lrb- aluminium oxide al 2o 3 , in bauxite and corundum -rrb- , iron -lrb- iron -lrb- iii -rrb- oxide fe 2o 3 , in hematite and rust -rrb- , and calcium carbonate -lrb- in limestone -rrb- . 
oxygen is present in the atmosphere in trace quantities in the form of carbon dioxide -lrb- co 2 -rrb- . 
the earth 's mantle , of much larger mass than the crust , is largely composed of silicates of magnesium and iron . 
oxygen is present in the atmosphere in trace quantities in the form of carbon dioxide -lrb- co 2 -rrb- . 
the earth 's crustal rock is composed in large part of oxides of silicon -lrb- silica sio 2 , as found in granite and quartz -rrb- , aluminium -lrb- aluminium oxide al 2o 3 , in bauxite and corundum -rrb- , iron -lrb- iron -lrb- iii -rrb- oxide fe 2o 3 , in hematite and rust -rrb- , and calcium carbonate -lrb- in limestone -rrb- . 
the earth 's mantle , of much larger mass than the crust , is largely composed of silicates of magnesium and iron . 
the earth 's mantle , of much larger mass than the crust , is largely composed of silicates of magnesium and iron . 
the rest of the earth 's crust is also made of oxygen compounds , in particular various complex silicates -lrb- in silicate minerals -rrb- . 
john dalton 's original atomic hypothesis assumed that all elements were monatomic and that the atoms in compounds would normally have the simplest atomic ratios with respect to one another . 
john dalton 's original atomic hypothesis assumed that all elements were monatomic and that the atoms in compounds would normally have the simplest atomic ratios with respect to one another . 
for example , dalton assumed that water 's formula was ho , giving the atomic mass of oxygen as 8 times that of hydrogen , instead of the modern value of about 16 . 
in 1805 , joseph louis gay-lussac and alexander von humboldt showed that water is formed of two volumes of hydrogen and one volume of oxygen ; and by 1811 amedeo avogadro had arrived at the correct interpretation of water 's composition , based on what is now called avogadro 's law and the assumption of diatomic elemental molecules . 
in 1805 , joseph louis gay-lussac and alexander von humboldt showed that water is formed of two volumes of hydrogen and one volume of oxygen ; and by 1811 amedeo avogadro had arrived at the correct interpretation of water 's composition , based on what is now called avogadro 's law and the assumption of diatomic elemental molecules . 
air did not play a role in phlogiston theory , nor were any initial quantitative experiments conducted to test the idea ; instead , it was based on observations of what happens when something burns , that most common objects appear to become lighter and seem to lose something in the process . 
highly combustible materials that leave little residue , such as wood or coal , were thought to be made mostly of phlogiston ; whereas non-combustible substances that corrode , such as iron , contained very little . 
air did not play a role in phlogiston theory , nor were any initial quantitative experiments conducted to test the idea ; instead , it was based on observations of what happens when something burns , that most common objects appear to become lighter and seem to lose something in the process . 
indeed , one of the first clues that the phlogiston theory was incorrect was that metals , too , gain weight in rusting -lrb- when they were supposedly losing phlogiston -rrb- . 
air did not play a role in phlogiston theory , nor were any initial quantitative experiments conducted to test the idea ; instead , it was based on observations of what happens when something burns , that most common objects appear to become lighter and seem to lose something in the process . 
the bond can be variously described based on level of theory , but is reasonably and simply described as a covalent double bond that results from the filling of molecular orbitals formed from the atomic orbitals of the individual oxygen atoms , the filling of which results in a bond order of two . 
the bond can be variously described based on level of theory , but is reasonably and simply described as a covalent double bond that results from the filling of molecular orbitals formed from the atomic orbitals of the individual oxygen atoms , the filling of which results in a bond order of two . 
more specifically , the double bond is the result of sequential , low-to-high energy , or aufbau , filling of orbitals , and the resulting cancellation of contributions from the 2s electrons , after sequential filling of the low σ and σ * orbitals ; σ overlap of the two atomic 2p orbitals that lie along the o-o molecular axis and π overlap of two pairs of atomic 2p orbitals perpendicular to the o-o molecular axis , and then cancellation of contributions from the remaining two of the six 2p electrons after their partial filling of the lowest π and π * orbitals . 
in this dioxygen , the two oxygen atoms are chemically bonded to each other . 
the bond can be variously described based on level of theory , but is reasonably and simply described as a covalent double bond that results from the filling of molecular orbitals formed from the atomic orbitals of the individual oxygen atoms , the filling of which results in a bond order of two . 
oxygen was discovered independently by carl wilhelm scheele , in uppsala , in 1773 or earlier , and joseph priestley in wiltshire , in 1774 , but priestley is often given priority because his work was published first . 
oxygen was discovered independently by carl wilhelm scheele , in uppsala , in 1773 or earlier , and joseph priestley in wiltshire , in 1774 , but priestley is often given priority because his work was published first . 
oxygen was discovered independently by carl wilhelm scheele , in uppsala , in 1773 or earlier , and joseph priestley in wiltshire , in 1774 , but priestley is often given priority because his work was published first . 
the name oxygen was coined in 1777 by antoine lavoisier , whose experiments with oxygen helped to discredit the then-popular phlogiston theory of combustion and corrosion . 
the name oxygen was coined in 1777 by antoine lavoisier , whose experiments with oxygen helped to discredit the then-popular phlogiston theory of combustion and corrosion . 
an electron configuration with two unpaired electrons as found in dioxygen -lrb- see the filled π * orbitals in the diagram -rrb- , orbitals that are of equal energy -- i.e. , degenerate -- is a configuration termed a spin triplet state . 
hence , the ground state of the o 2 molecule is referred to as triplet oxygen . 
because of its unpaired electrons , triplet oxygen reacts only slowly with most organic molecules , which have paired electron spins ; this prevents spontaneous combustion . 
because of its unpaired electrons , triplet oxygen reacts only slowly with most organic molecules , which have paired electron spins ; this prevents spontaneous combustion . 
-lsb- b -rsb- the highest energy , partially filled orbitals are antibonding , and so their filling weakens the bond order from three to two . 
he noted that air rushed in when he opened the container , which indicated that part of the trapped air had been consumed . 
he also noted that the tin had increased in weight and that increase was the same as the weight of the air that rushed back in . 
he also noted that the tin had increased in weight and that increase was the same as the weight of the air that rushed back in . 
this and other experiments on combustion were documented in his book sur la combustion en général , which was published in 1777 . 
in that work , he proved that air is a mixture of two gases ; ` vital air ' , which is essential to combustion and respiration , and azote -lrb- gk . 
trioxygen -lrb- o 3 -rrb- is usually known as ozone and is a very reactive allotrope of oxygen that is damaging to lung tissue . 
trioxygen -lrb- o 3 -rrb- is usually known as ozone and is a very reactive allotrope of oxygen that is damaging to lung tissue . 
trioxygen -lrb- o 3 -rrb- is usually known as ozone and is a very reactive allotrope of oxygen that is damaging to lung tissue . 
since ozone absorbs strongly in the uv region of the spectrum , the ozone layer of the upper atmosphere functions as a protective radiation shield for the planet . 
since ozone absorbs strongly in the uv region of the spectrum , the ozone layer of the upper atmosphere functions as a protective radiation shield for the planet . 
the common allotrope of elemental oxygen on earth is called dioxygen , o 2 . 
o2 has a bond length of 121 pm and a bond energy of 498 kj · mol − 1 , which is smaller than the energy of other double bonds or pairs of single bonds in the biosphere and responsible for the exothermic reaction of o2 with any organic molecule . 
it is the form that is a major part of the earth 's atmosphere -lrb- see occurrence -rrb- . 
due to its energy content , o2 is used by complex forms of life , such as animals , in cellular respiration -lrb- see biological role -rrb- . 
due to its energy content , o2 is used by complex forms of life , such as animals , in cellular respiration -lrb- see biological role -rrb- . 
in 1891 scottish chemist james dewar was able to produce enough liquid oxygen to study . 
in 1891 scottish chemist james dewar was able to produce enough liquid oxygen to study . 
the first commercially viable process for producing liquid oxygen was independently developed in 1895 by german engineer carl von linde and british engineer william hampson . 
later , in 1901 , oxyacetylene welding was demonstrated for the first time by burning a mixture of acetylene and compressed o 2 . 
oxygen is more soluble in water than nitrogen is . 
the solubility of oxygen in water is temperature-dependent , and about twice as much -lrb- 14.6 mg · l − 1 -rrb- dissolves at 0 °c than at 20 °c -lrb- 7.6 mg · l − 1 -rrb- . 
at 25 °c and 1 standard atmosphere -lrb- 101.3 kpa -rrb- of air , freshwater contains about 6.04 milliliters -lrb- ml -rrb- of oxygen per liter , whereas seawater contains about 4.95 ml per liter . 
at 25 °c and 1 standard atmosphere -lrb- 101.3 kpa -rrb- of air , freshwater contains about 6.04 milliliters -lrb- ml -rrb- of oxygen per liter , whereas seawater contains about 4.95 ml per liter . 
the solubility of oxygen in water is temperature-dependent , and about twice as much -lrb- 14.6 mg · l − 1 -rrb- dissolves at 0 °c than at 20 °c -lrb- 7.6 mg · l − 1 -rrb- . 
oxygen is the most abundant chemical element by mass in the earth 's biosphere , air , sea and land . 
oxygen is the third most abundant chemical element in the universe , after hydrogen and helium . 
about 0.9 % of the sun 's mass is oxygen . 
oxygen constitutes 49.2 % of the earth 's crust by mass and is the major component of the world 's oceans -lrb- 88.8 % by mass -rrb- . 
the o 2 surrounding these other planets is produced solely by ultraviolet radiation impacting oxygen-containing molecules such as carbon dioxide . 
by the late 19th century scientists realized that air could be liquefied , and its components isolated , by compressing and cooling it . 
by the late 19th century scientists realized that air could be liquefied , and its components isolated , by compressing and cooling it . 
using a cascade method , swiss chemist and physicist raoul pierre pictet evaporated liquid sulfur dioxide in order to liquefy carbon dioxide , which in turn was evaporated to cool oxygen gas enough to liquefy it . 
only a few drops of the liquid were produced in either case so no meaningful analysis could be conducted . 
oxygen was liquified in stable state for the first time on march 29 , 1883 by polish scientists from jagiellonian university , zygmunt wróblewski and karol olszewski . 
planetary geologists have measured different abundances of oxygen isotopes in samples from the earth , the moon , mars , and meteorites , but were long unable to obtain reference values for the isotope ratios in the sun , believed to be the same as those of the primordial solar nebula . 
analysis of a silicon wafer exposed to the solar wind in space and returned by the crashed genesis spacecraft has shown that the sun has a higher proportion of oxygen-16 than does the earth . 
analysis of a silicon wafer exposed to the solar wind in space and returned by the crashed genesis spacecraft has shown that the sun has a higher proportion of oxygen-16 than does the earth . 
the measurement implies that an unknown process depleted oxygen-16 from the sun 's disk of protoplanetary material prior to the coalescence of dust grains that formed the earth . 
the measurement implies that an unknown process depleted oxygen-16 from the sun 's disk of protoplanetary material prior to the coalescence of dust grains that formed the earth . 
singlet oxygen is a name given to several higher-energy species of molecular o 2 in which all the electron spins are paired . 
it is much more reactive towards common organic molecules than is molecular oxygen per se . 
in nature , singlet oxygen is commonly formed from water during photosynthesis , using the energy of sunlight . 
it is also produced in the troposphere by the photolysis of ozone by light of short wavelength , and by the immune system as a source of active oxygen . 
carotenoids in photosynthetic organisms -lrb- and possibly also in animals -rrb- play a major role in absorbing energy from singlet oxygen and converting it to the unexcited ground state before it can cause harm to tissues . 
paleoclimatologists measure the ratio of oxygen-18 and oxygen-16 in the shells and skeletons of marine organisms to determine what the climate was like millions of years ago -lrb- see oxygen isotope ratio cycle -rrb- . 
paleoclimatologists measure the ratio of oxygen-18 and oxygen-16 in the shells and skeletons of marine organisms to determine what the climate was like millions of years ago -lrb- see oxygen isotope ratio cycle -rrb- . 
seawater molecules that contain the lighter isotope , oxygen-16 , evaporate at a slightly faster rate than water molecules containing the 12 % heavier oxygen-18 ; this disparity increases at lower temperatures . 
during periods of lower global temperatures , snow and rain from that evaporated water tends to be higher in oxygen-16 , and the seawater left behind tends to be higher in oxygen-18 . 
during periods of lower global temperatures , snow and rain from that evaporated water tends to be higher in oxygen-16 , and the seawater left behind tends to be higher in oxygen-18 . 
oxygen presents two spectrophotometric absorption bands peaking at the wavelengths 687 and 760 nm . 
the measurement is technically difficult owing to the low signal-to-noise ratio and the physical structure of vegetation ; but it has been proposed as a possible method of monitoring the carbon cycle from satellites on a global scale . 
some remote sensing scientists have proposed using the measurement of the radiance coming from vegetation canopies in those bands to characterize plant health status from a satellite platform . 
the measurement is technically difficult owing to the low signal-to-noise ratio and the physical structure of vegetation ; but it has been proposed as a possible method of monitoring the carbon cycle from satellites on a global scale . 
some remote sensing scientists have proposed using the measurement of the radiance coming from vegetation canopies in those bands to characterize plant health status from a satellite platform . 
in the triplet form , o 2 molecules are paramagnetic . 
liquid oxygen is attracted to a magnet to a sufficient extent that , in laboratory demonstrations , a bridge of liquid oxygen may be supported against its own weight between the poles of a powerful magnet . 
that is , they impart magnetic character to oxygen when it is in the presence of a magnetic field , because of the spin magnetic moments of the unpaired electrons in the molecule , and the negative exchange energy between neighboring o 2 molecules . 
that is , they impart magnetic character to oxygen when it is in the presence of a magnetic field , because of the spin magnetic moments of the unpaired electrons in the molecule , and the negative exchange energy between neighboring o 2 molecules . 
liquid oxygen is attracted to a magnet to a sufficient extent that , in laboratory demonstrations , a bridge of liquid oxygen may be supported against its own weight between the poles of a powerful magnet . 
reactive oxygen species , such as superoxide ion -lrb- o − 2 -rrb- and hydrogen peroxide -lrb- h 2o 2 -rrb- , are dangerous by-products of oxygen use in organisms . 
parts of the immune system of higher organisms create peroxide , superoxide , and singlet oxygen to destroy invading microbes . 
reactive oxygen species also play an important role in the hypersensitive response of plants against pathogen attack . 
oxygen is toxic to obligately anaerobic organisms , which were the dominant form of early life on earth until o 2 began to accumulate in the atmosphere about 2.5 billion years ago during the great oxygenation event , about a billion years after the first appearance of these organisms . 
oxygen is toxic to obligately anaerobic organisms , which were the dominant form of early life on earth until o 2 began to accumulate in the atmosphere about 2.5 billion years ago during the great oxygenation event , about a billion years after the first appearance of these organisms . 
oxygen condenses at 90.20 k -lrb- − 182.95 °c , − 297.31 °f -rrb- , and freezes at 54.36 k -lrb- − 218.79 °c , − 361.82 °f -rrb- . 
both liquid and solid o 2 are clear substances with a light sky-blue color caused by absorption in the red -lrb- in contrast with the blue color of the sky , which is due to rayleigh scattering of blue light -rrb- . 
high-purity liquid o 2 is usually obtained by the fractional distillation of liquefied air . 
liquid oxygen may also be produced by condensation out of air , using liquid nitrogen as a coolant . 
it is a highly reactive substance and must be segregated from combustible materials . 
free oxygen also occurs in solution in the world 's water bodies . 
the increased solubility of o 2 at lower temperatures -lrb- see physical properties -rrb- has important implications for ocean life , as polar oceans support a much higher density of life due to their higher oxygen content . 
the increased solubility of o 2 at lower temperatures -lrb- see physical properties -rrb- has important implications for ocean life , as polar oceans support a much higher density of life due to their higher oxygen content . 
water polluted with plant nutrients such as nitrates or phosphates may stimulate growth of algae by a process called eutrophication and the decay of these organisms and other biomaterials may reduce amounts of o 2 in eutrophic water bodies . 
scientists assess this aspect of water quality by measuring the water 's biochemical oxygen demand , or the amount of o 2 needed to restore it to a normal concentration . 
free oxygen gas was almost nonexistent in earth 's atmosphere before photosynthetic archaea and bacteria evolved , probably about 3.5 billion years ago . 
free oxygen first appeared in significant quantities during the paleoproterozoic eon -lrb- between 3.0 and 2.3 billion years ago -rrb- . 
for the first billion years , any free oxygen produced by these organisms combined with dissolved iron in the oceans to form banded iron formations . 
when such oxygen sinks became saturated , free oxygen began to outgas from the oceans 3 -- 2.7 billion years ago , reaching 10 % of its present level around 1.7 billion years ago . 
when such oxygen sinks became saturated , free oxygen began to outgas from the oceans 3 -- 2.7 billion years ago , reaching 10 % of its present level around 1.7 billion years ago . 
the unusually high concentration of oxygen gas on earth is the result of the oxygen cycle . 
this biogeochemical cycle describes the movement of oxygen within and between its three main reservoirs on earth : the atmosphere , the biosphere , and the lithosphere . 
this biogeochemical cycle describes the movement of oxygen within and between its three main reservoirs on earth : the atmosphere , the biosphere , and the lithosphere . 
the main driving factor of the oxygen cycle is photosynthesis , which is responsible for modern earth 's atmosphere . 
photosynthesis releases oxygen into the atmosphere , while respiration and decay remove it from the atmosphere . 
the other major method of producing o 2 gas involves passing a stream of clean , dry air through one bed of a pair of identical zeolite molecular sieves , which absorbs the nitrogen and delivers a gas stream that is 90 % to 93 % o 2 . 
the other major method of producing o 2 gas involves passing a stream of clean , dry air through one bed of a pair of identical zeolite molecular sieves , which absorbs the nitrogen and delivers a gas stream that is 90 % to 93 % o 2 . 
the other major method of producing o 2 gas involves passing a stream of clean , dry air through one bed of a pair of identical zeolite molecular sieves , which absorbs the nitrogen and delivers a gas stream that is 90 % to 93 % o 2 . 
oxygen gas is increasingly obtained by these non-cryogenic technologies -lrb- see also the related vacuum swing adsorption -rrb- . 
the other major method of producing o 2 gas involves passing a stream of clean , dry air through one bed of a pair of identical zeolite molecular sieves , which absorbs the nitrogen and delivers a gas stream that is 90 % to 93 % o 2 . 
oxygen gas can also be produced through electrolysis of water into molecular oxygen and hydrogen . 
oxygen gas can also be produced through electrolysis of water into molecular oxygen and hydrogen . 
dc electricity must be used : if ac is used , the gases in each limb consist of hydrogen and oxygen in the explosive ratio 2:1 . 
a similar method is the electrocatalytic o 2 evolution from oxides and oxoacids . 
chemical catalysts can be used as well , such as in chemical oxygen generators or oxygen candles that are used as part of the life-support equipment on submarines , and are still part of standard equipment on commercial airliners in case of depressurization emergencies . 
oxygen , as a supposed mild euphoric , has a history of recreational use in oxygen bars and in sports . 
oxygen , as a supposed mild euphoric , has a history of recreational use in oxygen bars and in sports . 
professional athletes , especially in american football , also sometimes go off field between plays to wear oxygen masks in order to get a `` boost '' in performance . 
the pharmacological effect is doubtful ; a placebo effect is a more likely explanation . 
available studies support a performance boost from enriched o 2 mixtures only if they are breathed during aerobic exercise . 
hyperbaric -lrb- high-pressure -rrb- medicine uses special oxygen chambers to increase the partial pressure of o 2 around the patient and , when needed , the medical staff . 
increased o 2 concentration in the lungs helps to displace carbon monoxide from the heme group of hemoglobin . 
oxygen gas is poisonous to the anaerobic bacteria that cause gas gangrene , so increasing its partial pressure helps kill them . 
decompression sickness occurs in divers who decompress too quickly after a dive , resulting in bubbles of inert gas , mostly nitrogen and helium , forming in their blood . 
oxygen therapy is used to treat emphysema , pneumonia , some heart disorders -lrb- congestive heart failure -rrb- , some disorders that cause increased pulmonary artery pressure , and any disease that impairs the body 's ability to take up and use gaseous oxygen . 
treatment not only increases oxygen levels in the patient 's blood , but has the secondary effect of decreasing resistance to blood flow in many types of diseased lungs , easing work load on the heart . 
uptake of o 2 from the air is the essential purpose of respiration , so oxygen supplementation is used in medicine . 
uptake of o 2 from the air is the essential purpose of respiration , so oxygen supplementation is used in medicine . 
oxygen therapy is used to treat emphysema , pneumonia , some heart disorders -lrb- congestive heart failure -rrb- , some disorders that cause increased pulmonary artery pressure , and any disease that impairs the body 's ability to take up and use gaseous oxygen . 
due to its electronegativity , oxygen forms chemical bonds with almost all other elements to give corresponding oxides . 
due to its electronegativity , oxygen forms chemical bonds with almost all other elements to give corresponding oxides . 
for example , the mineral feo -lrb- wüstite -rrb- is written as fe 1 − xo , where x is usually around 0.05 . 
the surface of most metals , such as aluminium and titanium , are oxidized in the presence of air and become coated with a thin film of oxide that passivates the metal and slows further corrosion . 
the surface of most metals , such as aluminium and titanium , are oxidized in the presence of air and become coated with a thin film of oxide that passivates the metal and slows further corrosion . 
-lsb- h -rsb- passengers traveling in -lrb- pressurized -rrb- commercial airplanes have an emergency supply of o 2 automatically supplied to them in case of cabin depressurization . 
sudden cabin pressure loss activates chemical oxygen generators above each seat , causing oxygen masks to drop . 
a steady stream of oxygen gas is then produced by the exothermic reaction . 
a steady stream of oxygen gas is then produced by the exothermic reaction . 
oxygen storage methods include high pressure oxygen tanks , cryogenics and chemical compounds . 
for reasons of economy , oxygen is often transported in bulk as a liquid in specially insulated tankers , since one liter of liquefied oxygen is equivalent to 840 liters of gaseous oxygen at atmospheric pressure and 20 °c -lrb- 68 °f -rrb- . 
for reasons of economy , oxygen is often transported in bulk as a liquid in specially insulated tankers , since one liter of liquefied oxygen is equivalent to 840 liters of gaseous oxygen at atmospheric pressure and 20 °c -lrb- 68 °f -rrb- . 
oxygen is also stored and shipped in smaller cylinders containing the compressed gas ; a form that is useful in certain portable medical applications and oxy-fuel welding and cutting . 
such tankers are used to refill bulk liquid oxygen storage containers , which stand outside hospitals and other institutions with a need for large volumes of pure oxygen gas . 
there are many important organic solvents that contain oxygen , including : acetone , methanol , ethanol , isopropanol , furan , thf , diethyl ether , dioxane , ethyl acetate , dmf , dmso , acetic acid , and formic acid . 
among the most important classes of organic compounds that contain oxygen are -lrb- where `` r '' is an organic group -rrb- : alcohols -lrb- r-oh -rrb- ; ethers -lrb- r-o-r -rrb- ; ketones -lrb- r-co-r -rrb- ; aldehydes -lrb- r-co-h -rrb- ; carboxylic acids -lrb- r-cooh -rrb- ; esters -lrb- r-coo-r -rrb- ; acid anhydrides -lrb- r-co-o-co-r -rrb- ; and amides -lrb- r-c -lrb- o -rrb- - nr 2 -rrb- . 
acetone -lrb- -lrb- ch 3 -rrb- 2co -rrb- and phenol -lrb- c 6h 5oh -rrb- are used as feeder materials in the synthesis of many different substances . 
epoxides are ethers in which the oxygen atom is part of a ring of three atoms . 
among the most important classes of organic compounds that contain oxygen are -lrb- where `` r '' is an organic group -rrb- : alcohols -lrb- r-oh -rrb- ; ethers -lrb- r-o-r -rrb- ; ketones -lrb- r-co-r -rrb- ; aldehydes -lrb- r-co-h -rrb- ; carboxylic acids -lrb- r-cooh -rrb- ; esters -lrb- r-coo-r -rrb- ; acid anhydrides -lrb- r-co-o-co-r -rrb- ; and amides -lrb- r-c -lrb- o -rrb- - nr 2 -rrb- . 
the element is found in almost all biomolecules that are important to -lrb- or generated by -rrb- life . 
only a few common complex biomolecules , such as squalene and the carotenes , contain no oxygen . 
of the organic compounds with biological relevance , carbohydrates contain the largest proportion by mass of oxygen . 
all fats , fatty acids , amino acids , and proteins contain oxygen -lrb- due to the presence of carbonyl groups in these acids and their ester residues -rrb- . 
oxygen also occurs in phosphate -lrb- po3 − 4 -rrb- groups in the biologically important energy-carrying molecules atp and adp , in the backbone and the purines -lrb- except adenine -rrb- and pyrimidines of rna and dna , and in bones as calcium phosphate and hydroxylapatite . 
oxygen toxicity to the lungs and central nervous system can also occur in deep scuba diving and surface supplied diving . 
prolonged breathing of an air mixture with an o 2 partial pressure more than 60 kpa can eventually lead to permanent pulmonary fibrosis . 
exposure to a o 2 partial pressures greater than 160 kpa -lrb- about 1.6 atm -rrb- may lead to convulsions -lrb- normally fatal for divers -rrb- . 
acute oxygen toxicity -lrb- causing seizures , its most feared effect for divers -rrb- can occur by breathing an air mixture with 21 % o 2 at 66 m or more of depth ; the same thing can occur by breathing 100 % o 2 at only 6 m. 
acute oxygen toxicity -lrb- causing seizures , its most feared effect for divers -rrb- can occur by breathing an air mixture with 21 % o 2 at 66 m or more of depth ; the same thing can occur by breathing 100 % o 2 at only 6 m. 
breathing pure o 2 in space applications , such as in some modern space suits , or in early spacecraft such as apollo , causes no damage due to the low total pressures used . 
in the case of spacesuits , the o 2 partial pressure in the breathing gas is , in general , about 30 kpa -lrb- 1.4 times normal -rrb- , and the resulting o 2 partial pressure in the astronaut 's arterial blood is only marginally more than normal sea-level o 2 partial pressure -lrb- for more information on this , see space suit and arterial blood gas -rrb- . 
in the case of spacesuits , the o 2 partial pressure in the breathing gas is , in general , about 30 kpa -lrb- 1.4 times normal -rrb- , and the resulting o 2 partial pressure in the astronaut 's arterial blood is only marginally more than normal sea-level o 2 partial pressure -lrb- for more information on this , see space suit and arterial blood gas -rrb- . 
breathing pure o 2 in space applications , such as in some modern space suits , or in early spacecraft such as apollo , causes no damage due to the low total pressures used . 
in the case of spacesuits , the o 2 partial pressure in the breathing gas is , in general , about 30 kpa -lrb- 1.4 times normal -rrb- , and the resulting o 2 partial pressure in the astronaut 's arterial blood is only marginally more than normal sea-level o 2 partial pressure -lrb- for more information on this , see space suit and arterial blood gas -rrb- . 
oxygen gas -lrb- o 2 -rrb- can be toxic at elevated partial pressures , leading to convulsions and other health problems . 
-lsb- j -rsb- oxygen toxicity usually begins to occur at partial pressures more than 50 kilopascals -lrb- kpa -rrb- , equal to about 50 % oxygen composition at standard pressure or 2.5 times the normal sea-level o 2 partial pressure of about 21 kpa . 
-lsb- j -rsb- oxygen toxicity usually begins to occur at partial pressures more than 50 kilopascals -lrb- kpa -rrb- , equal to about 50 % oxygen composition at standard pressure or 2.5 times the normal sea-level o 2 partial pressure of about 21 kpa . 
this is not a problem except for patients on mechanical ventilators , since gas supplied through oxygen masks in medical applications is typically composed of only 30 % -- 50 % o 2 by volume -lrb- about 30 kpa at standard pressure -rrb- . 
this is not a problem except for patients on mechanical ventilators , since gas supplied through oxygen masks in medical applications is typically composed of only 30 % -- 50 % o 2 by volume -lrb- about 30 kpa at standard pressure -rrb- . 
the 1973 oil crisis began in october 1973 when the members of the organization of arab petroleum exporting countries -lrb- oapec , consisting of the arab members of opec plus egypt and syria -rrb- proclaimed an oil embargo . 
by the end of the embargo in march 1974 , the price of oil had risen from us$ 3 per barrel to nearly $ 12 globally ; us prices were significantly higher . 
it was later called the `` first oil shock '' , followed by the 1979 oil crisis , termed the `` second oil shock . '' 
it was later called the `` first oil shock '' , followed by the 1979 oil crisis , termed the `` second oil shock . '' 
the 1973 oil crisis began in october 1973 when the members of the organization of arab petroleum exporting countries -lrb- oapec , consisting of the arab members of opec plus egypt and syria -rrb- proclaimed an oil embargo . 
some european nations and japan sought to disassociate themselves from united states foreign policy in the middle east to avoid being targeted by the boycott . 
they arranged for israel to pull back from the sinai peninsula and the golan heights . 
by january 18 , 1974 , us secretary of state henry kissinger had negotiated an israeli troop withdrawal from parts of the sinai peninsula . 
the promise of a negotiated settlement between israel and syria was enough to convince arab oil producers to lift the embargo in march 1974 . 
on august 15 , 1971 , the united states unilaterally pulled out of the bretton woods accord . 
the us abandoned the gold exchange standard whereby the value of the dollar had been pegged to the price of gold and all other currencies were pegged to the dollar , whose value was left to `` float '' -lrb- rise and fall according to market demand -rrb- . 
anticipating that currency values would fluctuate unpredictably for a time , the industrialized nations increased their reserves -lrb- by expanding their money supplies -rrb- in amounts far greater than before . 
in september 1971 , opec issued a joint communiqué stating that , from then on , they would price oil in terms of a fixed amount of gold . 
because oil was priced in dollars , oil producers ' real income decreased . 
from 1947 to 1967 , the dollar price of oil had risen by less than two percent per year . 
after 1971 , opec was slow to readjust prices to reflect this depreciation . 
the substantial price increases of 1973 -- 1974 largely returned their prices and corresponding incomes to bretton woods levels in terms of commodities such as gold . 
until the oil shock , the price had also remained fairly stable versus other currencies and commodities . 
on october 6 , 1973 , syria and egypt , with support from other arab nations , launched a surprise attack on israel , on yom kippur . 
at the time , iran was the world 's second-largest oil exporter and a close us ally . 
let 's say ten times more . '' 
at the time , iran was the world 's second-largest oil exporter and a close us ally . 
this renewal of hostilities in the arab -- israeli conflict released the underlying economic pressure on oil prices . 
in response to american aid to israel , on october 16 , 1973 , opec raised the posted price of oil by 70 % , to $ 5.11 a barrel . 
in response to american aid to israel , on october 16 , 1973 , opec raised the posted price of oil by 70 % , to $ 5.11 a barrel . 
the following day , oil ministers agreed to the embargo , a cut in production by five percent from september 's output and to continue to cut production in five percent monthly increments until their economic and political objectives were met . 
on october 19 , nixon requested congress to appropriate $ 2.2 billion in emergency aid to israel , including $ 1.5 billion in outright grants . 
in response to american aid to israel , on october 16 , 1973 , opec raised the posted price of oil by 70 % , to $ 5.11 a barrel . 
saudi arabia spent over 100 billion dollars in the ensuing decades for helping spread its fundamentalist interpretation of islam , known as wahhabism , throughout the world , via religious charities such al-haramain foundation , which often also distributed funds to violent sunni extremist groups such as al-qaeda and the taliban . 
saudi arabia spent over 100 billion dollars in the ensuing decades for helping spread its fundamentalist interpretation of islam , known as wahhabism , throughout the world , via religious charities such al-haramain foundation , which often also distributed funds to violent sunni extremist groups such as al-qaeda and the taliban . 
much went for arms purchases that exacerbated political tensions , particularly in the middle east . 
some of the income was dispensed in the form of aid to other underdeveloped nations whose economies had been caught between higher oil prices and lower prices for their own export commodities , amid shrinking western demand . 
saudi arabia spent over 100 billion dollars in the ensuing decades for helping spread its fundamentalist interpretation of islam , known as wahhabism , throughout the world , via religious charities such al-haramain foundation , which often also distributed funds to violent sunni extremist groups such as al-qaeda and the taliban . 
in the us production , distribution and price disruptions `` have been held responsible for recessions , periods of excessive inflation , reduced productivity , and lower economic growth . '' 
the possibility that the middle east could become another superpower confrontation with the ussr was of more concern to the us than oil . 
in the united states , scholars argue that there already existed a negotiated settlement based on equality between both parties prior to 1973 . 
further , interest groups and government agencies more worried about energy were no match for kissinger 's dominance . 
the embargo had a negative influence on the us economy by causing immediate demands to address the threats to u.s. energy security . 
on an international level , the price increases changed competitive positions in many industries , such as automobiles . 
macroeconomic problems consisted of both inflationary and deflationary impacts . 
the embargo left oil companies searching for new ways to increase oil supplies , even in rugged terrain such as the arctic . 
finding oil and developing new fields usually required five to ten years before significant production . 
of the nine members of the european economic community -lrb- eec -rrb- , the netherlands faced a complete embargo , the uk and france received almost uninterrupted supplies -lrb- having refused to allow america to use their airfields and embargoed arms and supplies to both the arabs and the israelis -rrb- , while the other six faced partial cutbacks . 
of the nine members of the european economic community -lrb- eec -rrb- , the netherlands faced a complete embargo , the uk and france received almost uninterrupted supplies -lrb- having refused to allow america to use their airfields and embargoed arms and supplies to both the arabs and the israelis -rrb- , while the other six faced partial cutbacks . 
the uk had traditionally been an ally of israel , and harold wilson 's government supported the israelis during the six-day war . 
his successor , ted heath , reversed this policy in 1970 , calling for israel to withdraw to its pre-1967 borders . 
his successor , ted heath , reversed this policy in 1970 , calling for israel to withdraw to its pre-1967 borders . 
despite being relatively unaffected by the embargo , the uk nonetheless faced an oil crisis of its own - a series of strikes by coal miners and railroad workers over the winter of 1973 -- 74 became a major factor in the change of government . 
despite being relatively unaffected by the embargo , the uk nonetheless faced an oil crisis of its own - a series of strikes by coal miners and railroad workers over the winter of 1973 -- 74 became a major factor in the change of government . 
despite being relatively unaffected by the embargo , the uk nonetheless faced an oil crisis of its own - a series of strikes by coal miners and railroad workers over the winter of 1973 -- 74 became a major factor in the change of government . 
the uk , germany , italy , switzerland and norway banned flying , driving and boating on sundays . 
sweden rationed gasoline and heating oil . 
price controls exacerbated the crisis in the us . 
the system limited the price of `` old oil '' -lrb- that which had already been discovered -rrb- while allowing newly discovered oil to be sold at a higher price to encourage investment . 
price controls exacerbated the crisis in the us . 
scarcity was addressed by rationing -lrb- as in many countries -rrb- . 
in 1973 , nixon named william e. simon as the first administrator of the federal energy office , a short-term organization created to coordinate the response to the embargo . 
in 1973 , nixon named william e. simon as the first administrator of the federal energy office , a short-term organization created to coordinate the response to the embargo . 
in 1973 , nixon named william e. simon as the first administrator of the federal energy office , a short-term organization created to coordinate the response to the embargo . 
the american automobile association reported that in the last week of february 1974 , 20 % of american gasoline stations had no fuel . 
to help reduce consumption , in 1974 a national maximum speed limit of 55 mph -lrb- about 88 km/h -rrb- was imposed through the emergency highway energy conservation act . 
to help reduce consumption , in 1974 a national maximum speed limit of 55 mph -lrb- about 88 km/h -rrb- was imposed through the emergency highway energy conservation act . 
-lsb- citation needed -rsb- on november 28 , 1995 , bill clinton signed the national highway designation act , ending the federal 55 mph -lrb- 89 km/h -rrb- speed limit , allowing states to restore their prior maximum speed limit . 
-lsb- citation needed -rsb- on november 28 , 1995 , bill clinton signed the national highway designation act , ending the federal 55 mph -lrb- 89 km/h -rrb- speed limit , allowing states to restore their prior maximum speed limit . 
development of the strategic petroleum reserve began in 1975 , and in 1977 the cabinet-level department of energy was created , followed by the national energy act of 1978 . 
the energy crisis led to greater interest in renewable energy , nuclear power and domestic fossil fuels . 
there is criticism that american energy policies since the crisis have been dominated by crisis-mentality thinking , promoting expensive quick fixes and single-shot solutions that ignore market and technology realities . 
instead of providing stable rules that support basic research while leaving plenty of scope for entrepreneurship and innovation , congresses and presidents have repeatedly backed policies which promise solutions that are politically expedient , but whose prospects are doubtful . 
in 2004 , declassified documents revealed that the u.s. was so distraught by the rise in oil prices and being challenged by under-developed countries that they briefly considered military action to forcibly seize middle eastern oilfields in late 1973 . 
british prime minister edward heath was so worried by this prospect that he ordered a british intelligence estimate of u.s. intentions , which concluded america `` might consider it could not tolerate a situation in which the u.s. and its allies were at the mercy of a small group of unreasonable countries , '' and that they would prefer a rapid operation to seize oilfields in saudi arabia and kuwait , and possibly abu dhabi in military action was decided upon . 
although the soviet response to such an act would likely not involve force , intelligence warned `` the american occupation would need to last 10 years as the west developed alternative energy sources , and would result in the ` total alienation ' of the arabs and much of the rest of the third world . '' 
although the soviet response to such an act would likely not involve force , intelligence warned `` the american occupation would need to last 10 years as the west developed alternative energy sources , and would result in the ` total alienation ' of the arabs and much of the rest of the third world . '' 
although lacking historical connections to the middle east , japan was the country most dependent on arab oil . 
71 % of its imported oil came from the middle east in 1970 . 
it received a 5 % production cut in december , causing a panic . 
on november 22 , japan issued a statement `` asserting that israel should withdraw from all of the 1967 territories , advocating palestinian self-determination , and threatening to reconsider its policy toward israel if israel refused to accept these preconditions '' . 
by december 25 , japan was considered an arab-friendly state . 
the ussr 's invasion of afghanistan was only one sign of insecurity in the region , also marked by increased american weapons sales , technology , and outright military presence . 
saudi arabia and iran became increasingly dependent on american security assurances to manage both external and internal threats , including increased military competition between them over increased oil revenues . 
saudi arabia and iran became increasingly dependent on american security assurances to manage both external and internal threats , including increased military competition between them over increased oil revenues . 
another motive for the large scale purchase of arms from the us by saudi arabia was the failure of the shah during january 1979 to maintain control of iran , a non-arabic but largely shiite muslim nation , which fell to a theocratic islamist government under the ayatollah ruhollah khomeini in the wake of the 1979 iranian revolution . 
in the wake of the iranian revolution the saudis were forced to deal with the prospect of internal destabilization via the radicalism of islamism , a reality which would quickly be revealed in the seizure of the grand mosque in mecca by wahhabi extremists during november 1979 and a shiite revolt in the oil rich al-hasa region of saudi arabia in december of the same year . 
the crisis reduced the demand for large cars . 
japanese imports , primarily the toyota corona , the toyota corolla , the datsun b210 , the datsun 510 , the honda civic , the mitsubishi galant -lrb- a captive import from chrysler sold as the dodge colt -rrb- , the subaru dl , and later the honda accord all had four cylinder engines that were more fuel efficient than the typical american v8 and six cylinder engines . 
japanese imports , primarily the toyota corona , the toyota corolla , the datsun b210 , the datsun 510 , the honda civic , the mitsubishi galant -lrb- a captive import from chrysler sold as the dodge colt -rrb- , the subaru dl , and later the honda accord all had four cylinder engines that were more fuel efficient than the typical american v8 and six cylinder engines . 
japanese imports became mass-market leaders with unibody construction and front-wheel drive , which became de facto standards . 
a decade after the 1973 oil crisis , honda , toyota and nissan , affected by the 1981 voluntary export restraints , opened us assembly plants and established their luxury divisions -lrb- acura , lexus and infiniti , respectively -rrb- to distinguish themselves from their mass-market brands . 
some buyers lamented the small size of the first japanese compacts , and both toyota and nissan -lrb- then known as datsun -rrb- introduced larger cars such as the toyota corona mark ii , the toyota cressida , the mazda 616 and datsun 810 , which added passenger space and amenities such as air conditioning , power steering , am-fm radios , and even power windows and central locking without increasing the price of the vehicle . 
some buyers lamented the small size of the first japanese compacts , and both toyota and nissan -lrb- then known as datsun -rrb- introduced larger cars such as the toyota corona mark ii , the toyota cressida , the mazda 616 and datsun 810 , which added passenger space and amenities such as air conditioning , power steering , am-fm radios , and even power windows and central locking without increasing the price of the vehicle . 
a decade after the 1973 oil crisis , honda , toyota and nissan , affected by the 1981 voluntary export restraints , opened us assembly plants and established their luxury divisions -lrb- acura , lexus and infiniti , respectively -rrb- to distinguish themselves from their mass-market brands . 
compact trucks were introduced , such as the toyota hilux and the datsun truck , followed by the mazda truck -lrb- sold as the ford courier -rrb- , and the isuzu-built chevrolet luv . 
mitsubishi rebranded its forte as the dodge d-50 a few years after the oil crisis . 
mazda , mitsubishi and isuzu had joint partnerships with ford , chrysler , and gm , respectively . 
later the american makers introduced their domestic replacements -lrb- ford ranger , dodge dakota and the chevrolet s10/gmc s-15 -rrb- , ending their captive import policy . 
an increase in imported cars into north america forced general motors , ford and chrysler to introduce smaller and fuel-efficient models for domestic sales . 
the dodge omni / plymouth horizon from chrysler , the ford fiesta and the chevrolet chevette all had four-cylinder engines and room for at least four passengers by the late 1970s . 
by 1985 , the average american vehicle moved 17.4 miles per gallon , compared to 13.5 in 1970 . 
the cadillac deville and fleetwood , buick electra , oldsmobile 98 , lincoln continental , mercury marquis , and various other luxury oriented sedans became popular again in the mid-1970s . 
the only full-size models that did not recover were lower price models such as the chevrolet bel air , and ford galaxie 500 . 
by 1979 , virtually all `` full-size '' american cars had shrunk , featuring smaller engines and smaller outside dimensions . 
chrysler ended production of their full-sized luxury sedans at the end of the 1981 model year , moving instead to a full front-wheel drive lineup for 1982 -lrb- except for the m-body dodge diplomat/plymouth gran fury and chrysler new yorker fifth avenue sedans -rrb- . 
federal safety standards , such as nhtsa federal motor vehicle safety standard 215 -lrb- pertaining to safety bumpers -rrb- , and compacts like the 1974 mustang i were a prelude to the dot `` downsize '' revision of vehicle categories . 
opec soon lost its preeminent position , and in 1981 , its production was surpassed by that of other countries . 
the world price , which had peaked during the 1979 energy crisis at nearly $ 40 per barrel , decreased during the 1980s to less than $ 10 per barrel . 
saudi arabia , trying to recover market share , increased production , pushing prices down , shrinking or eliminating profits for high-cost producers . 
the world price , which had peaked during the 1979 energy crisis at nearly $ 40 per barrel , decreased during the 1980s to less than $ 10 per barrel . 
first conceived during dwight d. eisenhower 's administration as a three-man spacecraft to follow the one-man project mercury which put the first americans in space , apollo was later dedicated to president john f. kennedy 's national goal of `` landing a man on the moon and returning him safely to the earth '' by the end of the 1960s , which he proposed in a may 25 , 1961 , address to congress . 
the apollo program , also known as project apollo , was the third united states human spaceflight program carried out by the national aeronautics and space administration -lrb- nasa -rrb- , which accomplished landing the first humans on the moon from 1969 to 1972 . 
the first manned flight of apollo was in 1968 . 
first conceived during dwight d. eisenhower 's administration as a three-man spacecraft to follow the one-man project mercury which put the first americans in space , apollo was later dedicated to president john f. kennedy 's national goal of `` landing a man on the moon and returning him safely to the earth '' by the end of the 1960s , which he proposed in a may 25 , 1961 , address to congress . 
project mercury was followed by the two-man project gemini -lrb- 1962 -- 66 -rrb- . 
apollo ran from 1961 to 1972 , and was supported by the two-man gemini program which ran concurrently with it from 1962 to 1966 . 
apollo ran from 1961 to 1972 , and was supported by the two-man gemini program which ran concurrently with it from 1962 to 1966 . 
apollo/saturn vehicles were also used for an apollo applications program , which consisted of skylab , a space station that supported three manned missions in 1973 -- 74 , and the apollo -- soyuz test project , a joint earth orbit mission with the soviet union in 1975 . 
apollo/saturn vehicles were also used for an apollo applications program , which consisted of skylab , a space station that supported three manned missions in 1973 -- 74 , and the apollo -- soyuz test project , a joint earth orbit mission with the soviet union in 1975 . 
the apollo program succeeded in achieving its goal of manned lunar landing , despite the major setback of a 1967 apollo 1 cabin fire that killed the entire crew during a prelaunch test . 
the apollo program succeeded in achieving its goal of manned lunar landing , despite the major setback of a 1967 apollo 1 cabin fire that killed the entire crew during a prelaunch test . 
budget cuts forced the cancellation of three of these . 
five of the remaining six missions achieved successful landings , but the apollo 13 landing was prevented by an oxygen tank explosion in transit to the moon , which disabled the command spacecraft 's propulsion and life support . 
five of the remaining six missions achieved successful landings , but the apollo 13 landing was prevented by an oxygen tank explosion in transit to the moon , which disabled the command spacecraft 's propulsion and life support . 
apollo 8 was the first manned spacecraft to orbit another celestial body , while the final apollo 17 mission marked the sixth moon landing and the ninth manned mission beyond low earth orbit . 
apollo 8 was the first manned spacecraft to orbit another celestial body , while the final apollo 17 mission marked the sixth moon landing and the ninth manned mission beyond low earth orbit . 
the program returned 842 pounds -lrb- 382 kg -rrb- of lunar rocks and soil to earth , greatly contributing to the understanding of the moon 's composition and geological history . 
apollo also spurred advances in many areas of technology incidental to rocketry and manned spaceflight , including avionics , telecommunications , and computers . 
while the mercury capsule could only support one astronaut on a limited earth orbital mission , apollo would carry three astronauts . 
while the mercury capsule could only support one astronaut on a limited earth orbital mission , apollo would carry three astronauts . 
the program was named after the greek god of light , music , and the sun by nasa manager abe silverstein , who later said that `` i was naming the spacecraft like i 'd name my baby . '' 
possible missions included ferrying crews to a space station , circumlunar flights , and eventual manned lunar landings . 
the apollo program was conceived during the eisenhower administration in early 1960 , as a follow-up to project mercury . 
in july 1960 , nasa deputy administrator hugh l. dryden announced the apollo program to industry representatives at a series of space task group conferences . 
meanwhile , nasa performed its own in-house spacecraft design studies led by maxime faget , to serve as a gauge to judge and monitor the three industry designs . 
on august 30 , a feasibility study competition was announced , and on october 25 , three study contracts were awarded to general dynamics/convair , general electric , and the glenn l. martin company . 
in july 1960 , nasa deputy administrator hugh l. dryden announced the apollo program to industry representatives at a series of space task group conferences . 
in november 1960 , john f. kennedy was elected president after a campaign that promised american superiority over the soviet union in the fields of space exploration and missile defense . 
in november 1960 , john f. kennedy was elected president after a campaign that promised american superiority over the soviet union in the fields of space exploration and missile defense . 
he knew little about the technical details of the space program , and was put off by the massive financial commitment required by a manned moon landing . 
when kennedy 's newly appointed nasa administrator james e. webb requested a 30 percent budget increase for his agency , kennedy supported an acceleration of nasa 's large booster program but deferred a decision on the broader issue . 
up to the election of 1960 , kennedy had been speaking out against the `` missile gap '' that he and many other senators felt had formed between the soviets and themselves due to the inaction of president eisenhower . 
on april 12 , 1961 , soviet cosmonaut yuri gagarin became the first person to fly in space , reinforcing american fears about being left behind in a technological competition with the soviet union . 
on april 12 , 1961 , soviet cosmonaut yuri gagarin became the first person to fly in space , reinforcing american fears about being left behind in a technological competition with the soviet union . 
at a meeting of the us house committee on science and astronautics one day after gagarin 's flight , many congressmen pledged their support for a crash program aimed at ensuring that america would catch up . 
kennedy was circumspect in his response to the news , refusing to make a commitment on america 's response to the soviets . 
on april 20 , kennedy sent a memo to vice president lyndon b. johnson , asking johnson to look into the status of america 's space program , and into programs that could offer nasa the opportunity to catch up . 
on april 20 , kennedy sent a memo to vice president lyndon b. johnson , asking johnson to look into the status of america 's space program , and into programs that could offer nasa the opportunity to catch up . 
johnson responded approximately one week later , concluding that `` we are neither making maximum effort nor achieving results necessary if this country is to reach a position of leadership . '' 
johnson responded approximately one week later , concluding that `` we are neither making maximum effort nor achieving results necessary if this country is to reach a position of leadership . '' 
it became clear that managing the apollo program would exceed the capabilities of robert r. gilruth 's space task group , which had been directing the nation 's manned space program from nasa 's langley research center . 
it became clear that managing the apollo program would exceed the capabilities of robert r. gilruth 's space task group , which had been directing the nation 's manned space program from nasa 's langley research center . 
a site was chosen in houston , texas , on land donated by rice university , and administrator webb announced the conversion on september 19 , 1961 . 
a site was chosen in houston , texas , on land donated by rice university , and administrator webb announced the conversion on september 19 , 1961 . 
it was also clear nasa would soon outgrow its practice of controlling missions from its cape canaveral air force station launch facilities in florida , so a new mission control center would be included in the msc . 
but an even bigger facility would be needed for the mammoth rocket required for the manned lunar mission , so land acquisition was started in july 1961 for a launch operations center -lrb- loc -rrb- immediately north of canaveral at merritt island . 
the design , development and construction of the center was conducted by kurt h. debus , a member of dr. wernher von braun 's original v-2 rocket engineering team . 
debus was named the loc 's first director . 
upon kennedy 's death , president johnson issued an executive order on november 29 , 1963 , to rename the loc and cape canaveral in honor of kennedy . 
although at least three pads were planned , only two , designated a and b , were completed in october 1965 . 
the apollo spacecraft could be tested in two vacuum chambers capable of simulating atmospheric pressure at altitudes up to 250,000 feet -lrb- 76 km -rrb- , which is nearly a vacuum . 
the apollo spacecraft could be tested in two vacuum chambers capable of simulating atmospheric pressure at altitudes up to 250,000 feet -lrb- 76 km -rrb- , which is nearly a vacuum . 
the loc included launch complex 39 , a launch control center , and a 130 million cubic foot -lrb- 3.7 million cubic meter -rrb- vertical assembly building -lrb- vab -rrb- in which the space vehicle -lrb- launch vehicle and spacecraft -rrb- would be assembled on a mobile launcher platform and then moved by a transporter to one of several launch pads . 
administrator webb realized that in order to keep apollo costs under control , he had to develop greater project management skills in his organization , so he recruited dr. george e. mueller for a high management job . 
on july 23 , 1963 , webb announced mueller 's appointment as deputy associate administrator for manned space flight , to replace then associate administrator d. brainerd holmes on his retirement effective september 1 . 
on july 23 , 1963 , webb announced mueller 's appointment as deputy associate administrator for manned space flight , to replace then associate administrator d. brainerd holmes on his retirement effective september 1 . 
under webb 's reorganization , the directors of the manned spacecraft center -lrb- gilruth -rrb- marshall space flight center -lrb- von braun -rrb- and the launch operations center -lrb- debus -rrb- effectively reported to mueller . 
based on his industry experience on air force missile projects , mueller realized some skilled managers could be found among high-ranking officers in the united states air force , so he got webb 's permission to recruit general samuel c. phillips , who gained a reputation for his effective management of the minuteman program , as omsf program controller . 
based on his industry experience on air force missile projects , mueller realized some skilled managers could be found among high-ranking officers in the united states air force , so he got webb 's permission to recruit general samuel c. phillips , who gained a reputation for his effective management of the minuteman program , as omsf program controller . 
based on his industry experience on air force missile projects , mueller realized some skilled managers could be found among high-ranking officers in the united states air force , so he got webb 's permission to recruit general samuel c. phillips , who gained a reputation for his effective management of the minuteman program , as omsf program controller . 
mueller agreed , and phillips managed apollo from january 1964 , until it achieved the first manned landing in july 1969 , after which he returned to air force duty . 
phillips ' superior officer bernard a. schriever agreed to loan phillips to nasa , along with a staff of officers under him , on the condition that phillips be made apollo program director . 
many engineers feared that a rendezvous -- let alone a docking -- neither of which had been attempted even in earth orbit , would be extremely difficult in lunar orbit . 
in early 1961 , direct ascent was generally the mission mode in favor at nasa . 
bypassing the nasa hierarchy , he sent a series of memos and reports on the issue to associate administrator robert seamans ; while acknowledging that he spoke `` somewhat as a voice in the wilderness , '' houbolt pleaded that lor should not be discounted in studies of the question . 
seamans ' establishment of an ad-hoc committee headed by his special technical assistant nicholas e. golovin in july 1961 , to recommend a launch vehicle to be used in the apollo program , represented a turning point in nasa 's mission mode decision . 
seamans ' establishment of an ad-hoc committee headed by his special technical assistant nicholas e. golovin in july 1961 , to recommend a launch vehicle to be used in the apollo program , represented a turning point in nasa 's mission mode decision . 
in late 1961 and early 1962 , members of the manned spacecraft center began to come around to support lor , including the newly hired deputy director of the office of manned space flight , joseph shea , who became a champion of lor . 
in late 1961 and early 1962 , members of the manned spacecraft center began to come around to support lor , including the newly hired deputy director of the office of manned space flight , joseph shea , who became a champion of lor . 
the engineers at marshall space flight center -lrb- msfc -rrb- took longer to become convinced of its merits , but their conversion was announced by wernher von braun at a briefing in june 1962 . 
kennedy 's science advisor jerome wiesner , who had expressed his opposition to manned spaceflight to kennedy before the president took office , and had opposed the decision to land men on the moon , hired golovin , who had left nasa , to chair his own `` space vehicle panel '' , ostensibly to monitor , but actually to second-guess nasa 's decisions on the saturn v launch vehicle and lor by forcing shea , seamans , and even webb to defend themselves , delaying its formal announcement to the press on july 11 , 1962 , and forcing webb to still hedge the decision as `` tentative '' . 
kennedy 's science advisor jerome wiesner , who had expressed his opposition to manned spaceflight to kennedy before the president took office , and had opposed the decision to land men on the moon , hired golovin , who had left nasa , to chair his own `` space vehicle panel '' , ostensibly to monitor , but actually to second-guess nasa 's decisions on the saturn v launch vehicle and lor by forcing shea , seamans , and even webb to defend themselves , delaying its formal announcement to the press on july 11 , 1962 , and forcing webb to still hedge the decision as `` tentative '' . 
kennedy 's science advisor jerome wiesner , who had expressed his opposition to manned spaceflight to kennedy before the president took office , and had opposed the decision to land men on the moon , hired golovin , who had left nasa , to chair his own `` space vehicle panel '' , ostensibly to monitor , but actually to second-guess nasa 's decisions on the saturn v launch vehicle and lor by forcing shea , seamans , and even webb to defend themselves , delaying its formal announcement to the press on july 11 , 1962 , and forcing webb to still hedge the decision as `` tentative '' . 
kennedy 's science advisor jerome wiesner , who had expressed his opposition to manned spaceflight to kennedy before the president took office , and had opposed the decision to land men on the moon , hired golovin , who had left nasa , to chair his own `` space vehicle panel '' , ostensibly to monitor , but actually to second-guess nasa 's decisions on the saturn v launch vehicle and lor by forcing shea , seamans , and even webb to defend themselves , delaying its formal announcement to the press on july 11 , 1962 , and forcing webb to still hedge the decision as `` tentative '' . 
wiesner kept up the pressure , even making the disagreement public during a two-day september visit by the president to marshall space flight center . 
wiesner blurted out `` no , that 's no good '' in front of the press , during a presentation by von braun . 
webb held firm , and issued a request for proposal to candidate lunar excursion module -lrb- lem -rrb- contractors . 
nasa announced the selection of grumman as the lem contractor in november 1962 . 
the lor method had the advantage of allowing the lander spacecraft to be used as a `` lifeboat '' in the event of a failure of the command ship . 
ironically , just such a failure happened on apollo 13 when an oxygen tank explosion left the command ship without electrical power . 
the lunar module provided propulsion , electrical power and life support to get the crew home safely . 
a 1964 msc study concluded , `` the lm -lsb- as lifeboat -rsb- ... was finally dropped , because no single reasonable csm failure could be identified that would prohibit use of the sps . '' 
maxime faget 's preliminary apollo design employed a cone-shaped command module , supported by one of several service modules providing propulsion and electrical power , sized appropriately for the space station , cislunar , and lunar landing missions . 
once kennedy 's moon landing goal became official , detailed design began of a command/service module -lrb- csm -rrb- in which the crew would spend the entire direct-ascent mission and lift off from the lunar surface for the return trip , after being soft-landed by a larger landing propulsion module . 
the final choice of lunar orbit rendezvous changed the csm 's role to the translunar ferry used to transport the crew , along with a new spacecraft , the lunar excursion module -lrb- lem , later shortened to lunar module , lm -rrb- which would take two men to the lunar surface and return them to the csm . 
the command module -lrb- cm -rrb- was the conical crew cabin , designed to carry three astronauts from launch to lunar orbit and back to an earth ocean landing . 
the command module -lrb- cm -rrb- was the conical crew cabin , designed to carry three astronauts from launch to lunar orbit and back to an earth ocean landing . 
its exterior was covered with an ablative heat shield , and had its own reaction control system -lrb- rcs -rrb- engines to control its attitude and steer its atmospheric entry path . 
parachutes were carried to slow its descent to splashdown . 
the module was 11.42 feet -lrb- 3.48 m -rrb- tall , 12.83 feet -lrb- 3.91 m -rrb- in diameter , and weighed approximately 12,250 pounds -lrb- 5,560 kg -rrb- . 
a cylindrical service module -lrb- sm -rrb- supported the command module , with a service propulsion engine and an rcs with propellants , and a fuel cell power generation system with liquid hydrogen and liquid oxygen reactants . 
a high-gain s-band antenna was used for long-distance communications on the lunar flights . 
the service module was discarded just before re-entry . 
the initial lunar flight version weighed approximately 51,300 pounds -lrb- 23,300 kg -rrb- fully fueled , while a later version designed to carry a lunar orbit scientific instrument package weighed just over 54,000 pounds -lrb- 24,000 kg -rrb- . 
on the extended lunar missions , an orbital scientific instrument package was carried . 
north american aviation won the contract to build the csm , and also the second stage of the saturn v launch vehicle for nasa . 
because the csm design was started early before the selection of lunar orbit rendezvous , the service propulsion engine was sized to lift the csm off of the moon , and thus was oversized to about twice the thrust required for translunar flight . 
a 1964 program definition study concluded that the initial design should be continued as block i which would be used for early testing , while block ii , the actual lunar spacecraft , would incorporate the docking equipment and take advantage of the lessons learned in block i development . 
north american aviation won the contract to build the csm , and also the second stage of the saturn v launch vehicle for nasa . 
the lunar module -lrb- lm -rrb- was designed to descend from lunar orbit to land two astronauts on the moon and take them back to orbit to rendezvous with the command module . 
not designed to fly through the earth 's atmosphere or return to earth , its fuselage was designed totally without aerodynamic considerations , and was of an extremely lightweight construction . 
the initial lm model weighed approximately 33,300 pounds -lrb- 15,100 kg -rrb- , and allowed surface stays up to around 34 hours . 
an extended lunar module weighed over 36,200 pounds -lrb- 16,400 kg -rrb- , and allowed surface stays of over 3 days . 
before the apollo program began , wernher von braun and his team of rocket engineers had started work on plans for very large launch vehicles , the saturn series , and the even larger nova series . 
in the midst of these plans , von braun was transferred from the army to nasa , and made director of the marshall space flight center . 
the june 11 , 1962 , decision to use lunar orbit rendezvous enabled the saturn v to replace the nova , and the msfc proceeded to develop the saturn rocket family for apollo . 
the first four saturn i test flights were launched from lc-34 , with only live first stages , carrying dummy upper stages filled with water . 
this was followed by five launches of boilerplate csms -lrb- designated as-101 through as-105 -rrb- into orbit in 1964 and 1965 . 
the last three of these further supported the apollo program by also carrying pegasus satellites , which verified the safety of the translunar environment by measuring the frequency and severity of micrometeorite impacts . 
the last three of these further supported the apollo program by also carrying pegasus satellites , which verified the safety of the translunar environment by measuring the frequency and severity of micrometeorite impacts . 
the saturn ib was an upgraded version of the saturn i . 
the s-ib first stage increased the thrust to 1,600,000 pounds-force -lrb- 7,120 kn -rrb- , and the second stage replaced the s-iv with the s-ivb-200 , powered by a single j-2 engine burning liquid hydrogen fuel with lox , to produce 200,000 lbf -lrb- 890 kn -rrb- of thrust . 
a restartable version of the s-ivb was used as the third stage of the saturn v . 
the saturn ib could send over 40,000 pounds -lrb- 18,100 kg -rrb- into low earth orbit , sufficient for a partially fueled csm or the lm . 
the three-stage saturn v was designed to send a fully fueled csm and lm to the moon . 
it was 33 feet -lrb- 10.1 m -rrb- in diameter and stood 363 feet -lrb- 110.6 m -rrb- tall with its 96,800-pound -lrb- 43,900 kg -rrb- lunar payload . 
the three-stage saturn v was designed to send a fully fueled csm and lm to the moon . 
the second and third stages burned liquid hydrogen , and the third stage was a modified version of the s-ivb , with thrust increased to 230,000 lbf -lrb- 1,020 kn -rrb- and capability to restart the engine for translunar injection after reaching a parking orbit . 
the apollo astronauts were chosen from the project mercury and gemini veterans , plus from two later astronaut groups . 
all missions were commanded by gemini or mercury veterans . 
dr. harrison schmitt , a geologist , was the first nasa scientist astronaut to fly in space , and landed on the moon on the last mission , apollo 17 . 
dr. harrison schmitt , a geologist , was the first nasa scientist astronaut to fly in space , and landed on the moon on the last mission , apollo 17 . 
dr. harrison schmitt , a geologist , was the first nasa scientist astronaut to fly in space , and landed on the moon on the last mission , apollo 17 . 
nasa awarded all 32 of these astronauts its highest honor , the distinguished service medal , given for `` distinguished service , ability , or courage '' , and personal `` contribution representing substantial progress to the nasa mission '' . 
nasa awarded all 32 of these astronauts its highest honor , the distinguished service medal , given for `` distinguished service , ability , or courage '' , and personal `` contribution representing substantial progress to the nasa mission '' . 
the medals were awarded posthumously to grissom , white , and chaffee in 1969 , then to the crews of all missions from apollo 8 onward . 
the crew that flew the first earth orbital test mission apollo 7 , walter m. schirra , donn eisele , and walter cunningham , were awarded the lesser nasa exceptional service medal , because of discipline problems with the flight director 's orders during their flight . 
the medals were awarded posthumously to grissom , white , and chaffee in 1969 , then to the crews of all missions from apollo 8 onward . 
two block i csms were launched from lc-34 on suborbital flights in 1966 with the saturn ib . 
the first , as-201 launched on february 26 , reached an altitude of 265.7 nautical miles -lrb- 492.1 km -rrb- and splashed down 4,577 nautical miles -lrb- 8,477 km -rrb- downrange in the atlantic ocean . 
the second , as-202 on august 25 , reached 617.1 nautical miles -lrb- 1,142.9 km -rrb- altitude and was recovered 13,900 nautical miles -lrb- 25,700 km -rrb- downrange in the pacific ocean . 
these flights validated the service module engine and the command module heat shield . 
after an unmanned lm test flight as-206 , a crew would fly the first block ii csm and lm in a dual mission known as as-207 / 208 , or as-278 -lrb- each spacecraft would be launched on a separate saturn ib . -rrb- 
the astronauts would begin wearing a new apollo spacesuit , designed to accommodate lunar extravehicular activity -lrb- eva -rrb- . 
the traditional visor helmet was replaced with a clear `` fishbowl '' type for greater visibility , and the lunar surface eva suit would include a water-cooled undergarment . 
the traditional visor helmet was replaced with a clear `` fishbowl '' type for greater visibility , and the lunar surface eva suit would include a water-cooled undergarment . 
the block ii crew positions were titled commander -lrb- cdr -rrb- command module pilot -lrb- cmp -rrb- and lunar module pilot -lrb- lmp -rrb- . 
deke slayton , the grounded mercury astronaut who became director of flight crew operations for the gemini and apollo programs , selected the first apollo crew in january 1966 , with grissom as command pilot , white as senior pilot , and rookie donn f. eisele as pilot . 
deke slayton , the grounded mercury astronaut who became director of flight crew operations for the gemini and apollo programs , selected the first apollo crew in january 1966 , with grissom as command pilot , white as senior pilot , and rookie donn f. eisele as pilot . 
deke slayton , the grounded mercury astronaut who became director of flight crew operations for the gemini and apollo programs , selected the first apollo crew in january 1966 , with grissom as command pilot , white as senior pilot , and rookie donn f. eisele as pilot . 
deke slayton , the grounded mercury astronaut who became director of flight crew operations for the gemini and apollo programs , selected the first apollo crew in january 1966 , with grissom as command pilot , white as senior pilot , and rookie donn f. eisele as pilot . 
mercury/gemini veteran wally schirra , eisele , and rookie walter cunningham were announced on september 29 as the prime crew for as-205 . 
in december 1966 , the as-205 mission was canceled , since the validation of the csm would be accomplished on the 14-day first flight , and as-205 would have been devoted to space experiments and contribute no new engineering knowledge about the spacecraft . 
its saturn ib was allocated to the dual mission , now redesignated as-205 / 208 or as-258 , planned for august 1967 . 
its saturn ib was allocated to the dual mission , now redesignated as-205 / 208 or as-258 , planned for august 1967 . 
mcdivitt , scott and schweickart were promoted to the prime as-258 crew , and schirra , eisele and cunningham were reassigned as the apollo 1 backup crew . 
the problems with north american were severe enough in late 1965 to cause manned space flight administrator george mueller to appoint program director samuel phillips to head a `` tiger team '' to investigate north american 's problems and identify corrections . 
the problems with north american were severe enough in late 1965 to cause manned space flight administrator george mueller to appoint program director samuel phillips to head a `` tiger team '' to investigate north american 's problems and identify corrections . 
meanwhile , grumman was also encountering problems with the lunar module , eliminating hopes it would be ready for manned flight in 1967 , not long after the first manned csm flights . 
the problems with north american were severe enough in late 1965 to cause manned space flight administrator george mueller to appoint program director samuel phillips to head a `` tiger team '' to investigate north american 's problems and identify corrections . 
they trained and conducted tests of their spacecraft at north american , and in the altitude chamber at the kennedy space center . 
grissom , white , and chaffee decided to name their flight apollo 1 as a motivational focus on the first manned flight . 
a `` plugs-out '' test was planned for january , which would simulate a launch countdown on lc-34 with the spacecraft transferring from pad-supplied to internal power . 
they trained and conducted tests of their spacecraft at north american , and in the altitude chamber at the kennedy space center . 
first the crew noticed a strange odor in their spacesuits , which delayed the sealing of the hatch . 
the plugs-out test began on the morning of january 27 , 1967 , and immediately was plagued with problems . 
during this hold , an electrical fire began in the cabin , and spread quickly in the high pressure , 100 % oxygen atmosphere . 
the astronauts were asphyxiated before the hatch could be opened . 
during this hold , an electrical fire began in the cabin , and spread quickly in the high pressure , 100 % oxygen atmosphere . 
nasa immediately convened an accident review board , overseen by both houses of congress . 
while the determination of responsibility for the accident was complex , the review board concluded that `` deficiencies existed in command module design , workmanship and quality control . '' 
webb also reassigned apollo spacecraft program office -lrb- aspo -rrb- manager joseph francis shea , replacing him with george low . 
nasa immediately convened an accident review board , overseen by both houses of congress . 
to remedy the causes of the fire , changes were made in the block ii spacecraft and operational procedures , the most important of which were use of a nitrogen/oxygen mixture instead of pure oxygen before and during launch , and removal of flammable cabin and space suit materials . 
to remedy the causes of the fire , changes were made in the block ii spacecraft and operational procedures , the most important of which were use of a nitrogen/oxygen mixture instead of pure oxygen before and during launch , and removal of flammable cabin and space suit materials . 
the block ii design already called for replacement of the block i plug-type hatch cover with a quick-release , outward opening door . 
nasa discontinued the manned block i program , using the block i spacecraft only for unmanned saturn v flights . 
crew members would also exclusively wear modified , fire-resistant block ii space suits , and would be designated by the block ii titles , regardless of whether a lm was present on the flight or not . 
in september 1967 , mueller approved a sequence of mission types which had to be successfully accomplished in order to achieve the manned lunar landing . 
each step had to be successfully accomplished before the next ones could be performed , and it was unknown how many tries of each mission would be necessary ; therefore letters were used instead of numbers . 
each step had to be successfully accomplished before the next ones could be performed , and it was unknown how many tries of each mission would be necessary ; therefore letters were used instead of numbers . 
the delay in the csm caused by the fire enabled nasa to catch up on man-rating the lm and saturn v. apollo 4 -lrb- as-501 -rrb- was the first unmanned flight of the saturn v , carrying a block i csm on november 9 , 1967 . 
the capability of the command module 's heat shield to survive a trans-lunar reentry was demonstrated by using the service module engine to ram it into the atmosphere at higher than the usual earth-orbital reentry speed . 
this was followed on april 4 , 1968 , by apollo 6 -lrb- as-502 -rrb- which carried a csm and a lm test article as ballast . 
based on the good performance of apollo 6 and identification of satisfactory fixes to the apollo 6 problems , nasa declared the saturn v ready to fly men , cancelling a third unmanned test . 
apollo 5 -lrb- as-204 -rrb- was the first unmanned test flight of lm in earth orbit , launched from pad 37 on january 22 , 1968 , by the saturn ib that would have been used for apollo 1 . 
apollo 5 -lrb- as-204 -rrb- was the first unmanned test flight of lm in earth orbit , launched from pad 37 on january 22 , 1968 , by the saturn ib that would have been used for apollo 1 . 
although grumman wanted a second unmanned test , george low decided the next lm flight would be manned . 
the lm engines were successfully test-fired and restarted , despite a computer programming error which cut short the first descent stage firing . 
the ascent engine was fired in abort mode , known as a `` fire-in-the-hole '' test , where it was lit simultaneously with jettison of the descent stage . 
apollo 8 was planned to be the d mission in december 1968 , crewed by mcdivitt , scott and schweickart , launched on a saturn v instead of two saturn ibs . 
the soviet union had sent animals around the moon on september 15 , 1968 , aboard zond 5 , and it was believed they might soon repeat the feat with human cosmonauts . 
gemini veterans frank borman and james lovell , and rookie william anders captured the world 's attention by making 10 lunar orbits in 20 hours , transmitting television pictures of the lunar surface on christmas eve , and returning safely to earth . 
rather than waste the saturn v on another simple earth-orbiting mission , aspo manager george low suggested the bold step of sending apollo 8 to orbit the moon instead , deferring the d mission to the next mission in march 1969 , and eliminating the e mission . 
the soviet union had sent animals around the moon on september 15 , 1968 , aboard zond 5 , and it was believed they might soon repeat the feat with human cosmonauts . 
the g mission was achieved on apollo 11 in july 1969 by an all-gemini veteran crew consisting of neil armstrong , michael collins and buzz aldrin . 
the g mission was achieved on apollo 11 in july 1969 by an all-gemini veteran crew consisting of neil armstrong , michael collins and buzz aldrin . 
they spent a total of 21 hours , 36 minutes on the surface , and spent 2 hours , 31 minutes outside the spacecraft , walking on the surface , taking photographs , collecting material samples , and deploying automated scientific instruments , while continuously sending black-and-white television back to earth . 
the g mission was achieved on apollo 11 in july 1969 by an all-gemini veteran crew consisting of neil armstrong , michael collins and buzz aldrin . 
the astronauts returned safely on july 24 . 
in november 1969 , gemini veteran charles `` pete '' conrad and rookie alan l. bean made a precision landing on apollo 12 within walking distance of the surveyor 3 unmanned lunar probe , which had landed in april 1967 on the ocean of storms . 
in november 1969 , gemini veteran charles `` pete '' conrad and rookie alan l. bean made a precision landing on apollo 12 within walking distance of the surveyor 3 unmanned lunar probe , which had landed in april 1967 on the ocean of storms . 
on one , they walked to the surveyor , photographed it , and removed some parts which they returned to earth . 
conrad and bean carried the first lunar surface color television camera , but it was damaged when accidentally pointed into the sun . 
these missions would also carry the lunar roving vehicle -lrb- lrv -rrb- increasing the exploration area and allowing televised liftoff of the lm . 
also , the block ii spacesuit was revised for the extended missions to allow greater flexibility and visibility for driving the lrv . 
nasa publicized a preliminary list of eight more planned landing sites , with plans to increase the mass of the csm and lm for the last five missions , along with the payload capacity of the saturn v . 
these final missions would combine the i and j types in the 1967 list , allowing the cmp to operate a package of lunar orbital sensors and cameras while his companions were on the surface , and allowing them to stay on the moon for over three days . 
nasa publicized a preliminary list of eight more planned landing sites , with plans to increase the mass of the csm and lm for the last five missions , along with the payload capacity of the saturn v . 
but two days out , a liquid oxygen tank exploded , disabling the service module and forcing the crew to use the lm as a `` life boat '' to return to earth . 
the success of the first two landings allowed the remaining missions to be crewed with a single veteran as commander , with two rookies . 
apollo was grounded again , for the remainder of 1970 while the oxygen tank was redesigned and an extra one was added . 
apollo was grounded again , for the remainder of 1970 while the oxygen tank was redesigned and an extra one was added . 
apollo 13 launched lovell , jack swigert , and fred haise in april 1970 , headed for the fra mauro formation . 
about the time of the first landing in 1969 , it was decided to use an existing saturn v to launch the skylab orbital laboratory pre-built on the ground , replacing the original plan to construct it in orbit from several saturn ib launches ; this eliminated apollo 20 . 
nasa 's yearly budget also began to shrink in light of the successful landing , and nasa also had to make funds available for the development of the upcoming space shuttle . 
the two unused saturn vs became museum exhibits at the john f. kennedy space center on merritt island , florida , george c. marshall space center in huntsville , alabama , michoud assembly facility in new orleans , louisiana , and lyndon b. johnson space center in houston , texas . 
by 1971 , the decision was made to also cancel missions 18 and 19 . 
the rocks collected from the moon are extremely old compared to rocks found on earth , as measured by radiometric dating techniques . 
they range in age from about 3.2 billion years for the basaltic samples derived from the lunar maria , to about 4.6 billion years for samples derived from the highlands crust . 
a geochemical component called kreep was discovered , which has no known terrestrial counterpart . 
one important rock found during the apollo program is dubbed the genesis rock , retrieved by astronauts david scott and james irwin during the apollo 15 mission . 
many samples appear to be pitted with micrometeoroid impact craters , which is never seen on earth rocks , due to the thick atmosphere . 
almost all the rocks show evidence of impact process effects . 
some of the returned samples are of impact melt -lrb- materials melted near an impact crater . -rrb- 
in 2009 , nasa held a symposium on project costs which presented an estimate of the apollo program costs in 2005 dollars as roughly $ 170 billion . 
this included all research and development costs ; the procurement of 15 saturn v rockets , 16 command/service modules , 12 lunar modules , plus program support and management costs ; construction expenses for facilities and their upgrading , and costs for flight operations . 
the space review estimated in 2010 the cost of apollo from 1959 to 1973 as $ 20.4 billion , or $ 109 billion in 2010 dollars . 
the apollo extension series -lrb- apollo x , -rrb- proposed up to 30 flights to earth orbit , using the space in the spacecraft lunar module adapter -lrb- sla -rrb- to house a small orbital laboratory -lrb- workshop -rrb- . 
this study was followed by design of a larger orbital workshop to be built in orbit from an empty s-ivb saturn upper stage , and grew into the apollo applications program -lrb- aap -rrb- . 
the most ambitious plan called for using an empty s-ivb as an interplanetary spacecraft for a venus fly-by mission . 
dubbed skylab , it was constructed complete on the ground rather than in space , and launched in 1973 using the two lower stages of a saturn v . 
dubbed skylab , it was constructed complete on the ground rather than in space , and launched in 1973 using the two lower stages of a saturn v . 
skylab 's last crew departed the station on february 8 , 1974 , and the station itself re-entered the atmosphere in 1979 , by which time it had become the oldest operational apollo-saturn component . 
it was equipped with an apollo telescope mount , the solar telescope that would have been used on the apollo telescope missions . 
in 2009 , nasa 's robotic lunar reconnaissance orbiter , while orbiting 50 kilometers -lrb- 31 mi -rrb- above the moon , began photographing the remnants of the apollo program left on the lunar surface , and photographed each site where manned apollo flights landed . 
all of the u. s. flags left on the moon during the apollo missions were found to still be standing , with the exception of the one left during the apollo 11 mission , which was blown over during that mission 's lift-off from the lunar surface and return to the mission command module in lunar orbit ; the degree to which these flags retain their original colors remains unknown . 
all of the u. s. flags left on the moon during the apollo missions were found to still be standing , with the exception of the one left during the apollo 11 mission , which was blown over during that mission 's lift-off from the lunar surface and return to the mission command module in lunar orbit ; the degree to which these flags retain their original colors remains unknown . 
the crew of apollo 8 sent the first live televised pictures of the earth and the moon back to earth , and read from the creation story in the book of genesis , on christmas eve , 1968 . 
the crew of apollo 8 sent the first live televised pictures of the earth and the moon back to earth , and read from the creation story in the book of genesis , on christmas eve , 1968 . 
an estimated one-quarter of the population of the world saw -- either live or delayed -- the christmas eve transmission during the ninth orbit of the moon . 
the mission and christmas provided an inspiring end to 1968 , which had been a troubled year for the us , marked by vietnam war protests , race riots , and the assassinations of civil rights leader martin luther king , jr. , and senator robert f. kennedy . 
the moon landing data was recorded by a special apollo tv camera which recorded in a format incompatible with broadcast tv . 
the moon landing data was recorded by a special apollo tv camera which recorded in a format incompatible with broadcast tv . 
during the following years , a magnetic tape shortage prompted nasa to remove massive numbers of magnetic tapes from the national archives and records administration to be recorded over with newer satellite data . 
during the following years , a magnetic tape shortage prompted nasa to remove massive numbers of magnetic tapes from the national archives and records administration to be recorded over with newer satellite data . 
stan lebar , who led the team that designed and built the lunar television camera at westinghouse electric corporation , also worked with nafzger to try to locate the missing tapes . 
with a budget of $ 230,000 , the surviving original lunar broadcast data from apollo 11 was compiled by nafzger and assigned to lowry digital for restoration . 
the video was processed to remove random noise and camera shake without destroying historical legitimacy . 
the images were from tapes in australia , the cbs news archive , and kinescope recordings made at johnson space center . 
with a budget of $ 230,000 , the surviving original lunar broadcast data from apollo 11 was compiled by nafzger and assigned to lowry digital for restoration . 
the restored video , remaining in black and white , contains conservative digital enhancements and did not include sound quality improvements . 
the three sources of european union law are primary law , secondary law and supplementary law . 
european union law is a body of treaties and legislation , such as regulations and directives , which have direct effect or indirect effect on the laws of european union member states . 
the main sources of primary law are the treaties establishing the european union . 
secondary sources include regulations and directives which are based on the treaties . 
the legislature of the european union is principally composed of the european parliament and the council of the european union , which under the treaties may establish secondary law to pursue the objective set out in the treaties . 
european union law is a body of treaties and legislation , such as regulations and directives , which have direct effect or indirect effect on the laws of european union member states . 
european union law is a body of treaties and legislation , such as regulations and directives , which have direct effect or indirect effect on the laws of european union member states . 
the three sources of european union law are primary law , secondary law and supplementary law . 
the legislature of the european union is principally composed of the european parliament and the council of the european union , which under the treaties may establish secondary law to pursue the objective set out in the treaties . 
the three sources of european union law are primary law , secondary law and supplementary law . 
the main sources of primary law are the treaties establishing the european union . 
the legislature of the european union is principally composed of the european parliament and the council of the european union , which under the treaties may establish secondary law to pursue the objective set out in the treaties . 
the three sources of european union law are primary law , secondary law and supplementary law . 
european union law is applied by the courts of member states and the court of justice of the european union . 
where the laws of member states provide for lesser rights european union law can be enforced by the courts of member states . 
in case of european union law which should have been transposed into the laws of member states , such as directives , the european commission can take proceedings against the member state under the treaty on the functioning of the european union . 
the european court of justice is the highest court able to interpret european union law . 
supplementary sources of european union law include case law by the court of justice , international law and general principles of european union law . 
european union law is applied by the courts of member states and the court of justice of the european union . 
in case of european union law which should have been transposed into the laws of member states , such as directives , the european commission can take proceedings against the member state under the treaty on the functioning of the european union . 
the european court of justice is the highest court able to interpret european union law . 
supplementary sources of european union law include case law by the court of justice , international law and general principles of european union law . 
european union law is applied by the courts of member states and the court of justice of the european union . 
where the laws of member states provide for lesser rights european union law can be enforced by the courts of member states . 
the european court of justice is the highest court able to interpret european union law . 
supplementary sources of european union law include case law by the court of justice , international law and general principles of european union law . 
the eu 's primary constitutional sources are the treaty on european union -lrb- teu -rrb- and the treaty on the functioning of the european union -lrb- tfeu -rrb- , which have been agreed or adhered to among the governments of all 28 member states . 
the european commission has the initiative to propose legislation . 
during the ordinary legislative procedure , the council -lrb- which are ministers from member state governments -rrb- and the european parliament -lrb- elected by citizens -rrb- can make amendments and must give their consent for laws to pass . 
the european court of justice is the supreme judicial body which interprets eu law , and develops it through precedent . 
the `` european council '' -lrb- rather than the council , made up of different government ministers -rrb- is composed of the prime ministers or executive presidents of the member states . 
the primary law of the eu consists mainly of the founding treaties , the `` core '' treaties being the treaty on european union -lrb- teu -rrb- and the treaty on the functioning of the european union -lrb- tfeu -rrb- . 
the teu specifically excludes certain regions , for example the faroe islands , from the jurisdiction of european union law . 
the court of justice of the european union can interpret the treaties , but it can not rule on their validity , which is subject to international law . 
individuals may rely on primary law in the court of justice of the european union if the treaty provisions have a direct effect and they are sufficiently clear , precise and unconditional . 
treaties apply as soon as they enter into force , unless stated otherwise , and are generally concluded for an unlimited period . 
the primary law of the eu consists mainly of the founding treaties , the `` core '' treaties being the treaty on european union -lrb- teu -rrb- and the treaty on the functioning of the european union -lrb- tfeu -rrb- . 
european union law also applies in territories where a member state is responsible for external relations , for example gibraltar and the åland islands . 
treaties apply as soon as they enter into force , unless stated otherwise , and are generally concluded for an unlimited period . 
the court of justice of the european union can interpret the treaties , but it can not rule on their validity , which is subject to international law . 
the principal treaties that form the european union began with common rules for coal and steel , and then atomic energy , but more complete and formal institutions were established through the treaty of rome 1957 and the maastricht treaty 1992 -lrb- now : tfeu -rrb- . 
the principal treaties that form the european union began with common rules for coal and steel , and then atomic energy , but more complete and formal institutions were established through the treaty of rome 1957 and the maastricht treaty 1992 -lrb- now : tfeu -rrb- . 
since its establishment , more member states have joined through a series of accession treaties , from the uk , ireland , denmark and norway in 1972 -lrb- though norway did not end up joining -rrb- , greece in 1979 , spain and portugal 1985 , austria , finland , norway and sweden in 1994 -lrb- though again norway failed to join , because of lack of support in the referendum -rrb- , the czech republic , cyprus , estonia , hungary , latvia , lithuania , malta , poland , slovakia and slovenia in 2004 , romania and bulgaria in 2007 and croatia in 2013 . 
since its establishment , more member states have joined through a series of accession treaties , from the uk , ireland , denmark and norway in 1972 -lrb- though norway did not end up joining -rrb- , greece in 1979 , spain and portugal 1985 , austria , finland , norway and sweden in 1994 -lrb- though again norway failed to join , because of lack of support in the referendum -rrb- , the czech republic , cyprus , estonia , hungary , latvia , lithuania , malta , poland , slovakia and slovenia in 2004 , romania and bulgaria in 2007 and croatia in 2013 . 
greenland signed a treaty in 1985 giving it a special status . 
the principal treaties that form the european union began with common rules for coal and steel , and then atomic energy , but more complete and formal institutions were established through the treaty of rome 1957 and the maastricht treaty 1992 -lrb- now : tfeu -rrb- . 
the principal treaties that form the european union began with common rules for coal and steel , and then atomic energy , but more complete and formal institutions were established through the treaty of rome 1957 and the maastricht treaty 1992 -lrb- now : tfeu -rrb- . 
major amending treaties were signed to complete the development of a single , internal market in the single european act 1986 , to further the development of a more social europe in the treaty of amsterdam 1997 , and to make minor amendments to the relative power of member states in the eu institutions in the treaty of nice 2001 and the treaty of lisbon 2007 . 
since its establishment , more member states have joined through a series of accession treaties , from the uk , ireland , denmark and norway in 1972 -lrb- though norway did not end up joining -rrb- , greece in 1979 , spain and portugal 1985 , austria , finland , norway and sweden in 1994 -lrb- though again norway failed to join , because of lack of support in the referendum -rrb- , the czech republic , cyprus , estonia , hungary , latvia , lithuania , malta , poland , slovakia and slovenia in 2004 , romania and bulgaria in 2007 and croatia in 2013 . 
greenland signed a treaty in 1985 giving it a special status . 
following the nice treaty , there was an attempt to reform the constitutional law of the european union and make it more transparent ; this would have also produced a single constitutional document . 
however , as a result of the referendum in france and the referendum in the netherlands , the 2004 treaty establishing a constitution for europe never came into force . 
its substance was very similar to the proposed constitutional treaty , but it was formally an amending treaty , and -- though it significantly altered the existing treaties -- it did not completely replace them . 
its substance was very similar to the proposed constitutional treaty , but it was formally an amending treaty , and -- though it significantly altered the existing treaties -- it did not completely replace them . 
its substance was very similar to the proposed constitutional treaty , but it was formally an amending treaty , and -- though it significantly altered the existing treaties -- it did not completely replace them . 
following the nice treaty , there was an attempt to reform the constitutional law of the european union and make it more transparent ; this would have also produced a single constitutional document . 
following the nice treaty , there was an attempt to reform the constitutional law of the european union and make it more transparent ; this would have also produced a single constitutional document . 
however , as a result of the referendum in france and the referendum in the netherlands , the 2004 treaty establishing a constitution for europe never came into force . 
instead , the lisbon treaty was enacted . 
the european commission is the main executive body of the european union . 
this means that the commission has a monopoly on initiating the legislative procedure , although the council is the `` de facto catalyst of many legislative initiatives '' . 
the commission 's president -lrb- currently an ex-luxembourg prime minister , jean-claude juncker -rrb- sets the agenda for the eu 's work . 
-lsb- citation needed -rsb- since ireland refused to consent to changes in the treaty of lisbon 2007 , there remains one commissioner for each of the 28 member states , including the president and the high representative for foreign and security policy -lrb- currently federica mogherini -rrb- . 
-lsb- citation needed -rsb- since ireland refused to consent to changes in the treaty of lisbon 2007 , there remains one commissioner for each of the 28 member states , including the president and the high representative for foreign and security policy -lrb- currently federica mogherini -rrb- . 
article 17 -lrb- 1 -rrb- of the treaty on european union states the commission should `` promote the general interest of the union '' while article 17 -lrb- 3 -rrb- adds that commissioners should be `` completely independent '' and not `` take instructions from any government '' . 
the commission 's president -lrb- currently an ex-luxembourg prime minister , jean-claude juncker -rrb- sets the agenda for the eu 's work . 
decisions are taken by a simple majority vote , usually through a `` written procedure '' of circulating the proposals and adopting if there are no objections . 
-lsb- citation needed -rsb- since ireland refused to consent to changes in the treaty of lisbon 2007 , there remains one commissioner for each of the 28 member states , including the president and the high representative for foreign and security policy -lrb- currently federica mogherini -rrb- . 
this means commissioners are , through the appointment process , the unelected subordinates of member state governments . 
commissioners have sometimes been found to have abused their offices , particularly since the santer commission was censured by parliament in 1999 , and it eventually resigned due to corruption allegations . 
this resulted in one main case , commission v edith cresson where the european court of justice held that a commissioner giving her dentist a job , for which he was clearly unqualified , did in fact not break any law . 
by contrast to the ecj 's relaxed approach , a committee of independent experts found that a culture had developed where few commissioners had ` even the slightest sense of responsibility ' . 
it has a six-person board appointed by the european council , on the council 's recommendation . 
the president of the council and a commissioner can sit in on ecb meetings , but do not have voting rights . 
commissioners have sometimes been found to have abused their offices , particularly since the santer commission was censured by parliament in 1999 , and it eventually resigned due to corruption allegations . 
this resulted in one main case , commission v edith cresson where the european court of justice held that a commissioner giving her dentist a job , for which he was clearly unqualified , did in fact not break any law . 
by contrast to the ecj 's relaxed approach , a committee of independent experts found that a culture had developed where few commissioners had ` even the slightest sense of responsibility ' . 
this led to the creation of the european anti-fraud office . 
in 2012 it investigated the maltese commissioner for health , john dalli , who quickly resigned after allegations that he received a $ 60m bribe in connection with a tobacco products directive . 
while the commission has a monopoly on initiating legislation , the european parliament and the council of the european union have powers of amendment and veto during the legislative process . 
in practice , equality and democracy are deficient because the elected representatives in the parliament can not initiate legislation against the commission 's wishes , citizens of smallest countries have ten times the voting weight in parliament as citizens of the largest countries , and `` qualified majorities '' or consensus of the council are required to legislate . 
parliament elections , take place every five years , and votes for members of the european parliament in member states must be organised by proportional representation or a single transferable vote . 
it can require the commission respond to questions and by a two-thirds majority can censure the whole commission -lrb- as happened to the santer commission in 1999 -rrb- . 
however its role participation in the legislative process still remains limited because no member can actually or pass legislation without the commission and council , meaning power -lrb- `` kratia '' -rrb- is not in the hands of directly elected representatives of the people -lrb- `` demos '' -rrb- : in the eu it is not yet true that `` the administration is in the hands of the many and not of the few . '' 
while the commission has a monopoly on initiating legislation , the european parliament and the council of the european union have powers of amendment and veto during the legislative process . 
while the commission has a monopoly on initiating legislation , the european parliament and the council of the european union have powers of amendment and veto during the legislative process . 
over time , this has meant the parliament gradually assumed more voice : from being an unelected assembly , to its first direct elections in 1979 , to having increasingly more rights in the legislative process . 
parliament elections , take place every five years , and votes for members of the european parliament in member states must be organised by proportional representation or a single transferable vote . 
meps divide , as they do in national parliaments , along political party lines : the conservative european people 's party is currently the largest , and the party of european socialists leads the opposition . 
the second main legislative body is the council , which is composed of different ministers of the member states . 
it meets each six months and its president -lrb- currently former poland prime minister donald tusk -rrb- is meant to ` drive forward its work ' , but it does not itself ` legislative functions ' . 
when voting takes place it is weighted inversely to member state size , so smaller member states are not dominated by larger member states . 
in total there are 352 votes , but for most acts there must be a qualified majority vote , if not consensus . 
teu article 16 -lrb- 4 -rrb- and tfeu article 238 -lrb- 3 -rrb- define this to mean at least 55 per cent of the council members -lrb- not votes -rrb- representing 65 per cent of the population of the eu : currently this means around 74 per cent , or 260 of the 352 votes . 
the second main legislative body is the council , which is composed of different ministers of the member states . 
it meets each six months and its president -lrb- currently former poland prime minister donald tusk -rrb- is meant to ` drive forward its work ' , but it does not itself ` legislative functions ' . 
in total there are 352 votes , but for most acts there must be a qualified majority vote , if not consensus . 
teu article 16 -lrb- 4 -rrb- and tfeu article 238 -lrb- 3 -rrb- define this to mean at least 55 per cent of the council members -lrb- not votes -rrb- representing 65 per cent of the population of the eu : currently this means around 74 per cent , or 260 of the 352 votes . 
the essence is there are three readings , starting with a commission proposal , where the parliament must vote by a majority of all meps -lrb- not just those present -rrb- to block or suggest changes , and the council must vote by qualified majority to approve changes , but by unanimity to block commission amendment . 
the essence is there are three readings , starting with a commission proposal , where the parliament must vote by a majority of all meps -lrb- not just those present -rrb- to block or suggest changes , and the council must vote by qualified majority to approve changes , but by unanimity to block commission amendment . 
this means , legislation can be blocked by a majority in parliament , a minority in the council , and a majority in the commission : it is harder to change eu law than stay the same . 
teu articles 4 and 5 state that powers remain with the member states unless they have been conferred , although there is a debate about the kompetenz-kompetenz question : who ultimately has the `` competence '' to define the eu 's `` competence '' . 
many member state courts believe they decide , other member state parliaments believe they decide , while within the eu , the court of justice believes it has the final say . 
to make new legislation , tfeu article 294 defines the `` ordinary legislative procedure '' that applies for most eu acts . 
this means , legislation can be blocked by a majority in parliament , a minority in the council , and a majority in the commission : it is harder to change eu law than stay the same . 
teu articles 4 and 5 state that powers remain with the member states unless they have been conferred , although there is a debate about the kompetenz-kompetenz question : who ultimately has the `` competence '' to define the eu 's `` competence '' . 
where the different institutions can not agree at any stage , a `` conciliation committee '' is convened , representing meps , ministers and the commission to try and get agreement on a joint text : if this works , it will be sent back to the parliament and council to approve by absolute and qualified majority . 
the judicial branch of the eu has played an important role in the development of eu law , by assuming the task of interpreting the treaties , and accelerating economic and political integration . 
today the court of justice of the european union -lrb- cjeu -rrb- is the main judicial body , within which there is a higher european court of justice -lrb- commonly abbreviated as ecj -rrb- that deals with cases that contain more public importance , and a general court that deals with issues of detail but without general importance . 
under the treaty on european union article 19 -lrb- 2 -rrb- there is one judge from each member state , 28 at present , who are supposed to `` possess the qualifications required for appointment to the highest judicial offices '' -lrb- or for the general court , the `` ability required for appointment to high judicial office '' -rrb- . 
in fact , most eu law is applied by member state courts -lrb- the english court of appeal , the german bundesgerichtshof , the belgian cour du travail , etc. -rrb- but they can refer questions to the eu court for a preliminary ruling . 
the cjeu 's duty is to `` ensure that in the interpretation and application of the treaties the law is observed '' , although realistically it has the ability to expand and develop the law according to the principles it deems to be appropriate . 
the judicial branch of the eu has played an important role in the development of eu law , by assuming the task of interpreting the treaties , and accelerating economic and political integration . 
today the court of justice of the european union -lrb- cjeu -rrb- is the main judicial body , within which there is a higher european court of justice -lrb- commonly abbreviated as ecj -rrb- that deals with cases that contain more public importance , and a general court that deals with issues of detail but without general importance . 
there is also a civil service tribunal to deal with eu staff issues , and then a separate court of auditors . 
a president is elected by the judges for three years . 
the cjeu 's duty is to `` ensure that in the interpretation and application of the treaties the law is observed '' , although realistically it has the ability to expand and develop the law according to the principles it deems to be appropriate . 
within the eu itself , the court of justice 's view is that if eu law conflicts with a provision of national law , then eu law has primacy . 
the italian constitutional court gave an opinion that because the nationalisation law was from 1962 , and the treaty was in force from 1958 , costa had no claim . 
similarly , in amministrazione delle finanze v simmenthal spa , a company , simmenthal spa , claimed that a public health inspection fee under an italian law of 1970 for importing beef from france to italy was contrary to two regulations from 1964 and 1968 . 
this has meant both the european court of justice and the highest national courts have had to develop principles to resolve conflicts of laws between different systems . 
in the first major case in 1964 , costa v enel , a milanese lawyer , and former shareholder of an energy company , named mr costa refused to pay his electricity bill to enel , as a protest against the nationalisation of the italian energy corporations . 
by contrast , the court of justice held that ultimately the treaty of rome in no way prevented energy nationalisation , and in any case under the treaty provisions only the commission could have brought a claim , not mr costa . 
generally speaking , while all member states recognise that eu law takes primacy over national law where this agreed in the treaties , they do not accept that the court of justice has the final say on foundational constitutional questions affecting democracy and human rights . 
generally speaking , while all member states recognise that eu law takes primacy over national law where this agreed in the treaties , they do not accept that the court of justice has the final say on foundational constitutional questions affecting democracy and human rights . 
more recently the uk supreme court noted that in r -lrb- hs2 action alliance ltd -rrb- v secretary of state for transport , although the uk constitution is uncodified , there could be `` fundamental principles '' of common law , and parliament `` did not either contemplate or authorise the abrogation '' of those principles when it enacted the european communities act 1972 . 
this suggests the eu 's legitimacy rests on the ultimate authority of member states , its factual commitment to human rights , and the democratic will of the people . 
the view of the german constitutional court from the solange i and solange ii decisions is that if the eu does not comply with its basic constitutional rights and principles -lrb- particularly democracy , the rule of law and the social state principles -rrb- then it can not override german law . 
while constitutional law concerns the european union 's governance structure , administrative law binds eu institutions and member states to follow the law . 
however , under directives , citizens or corporations were said in 1986 to not be allowed to bring claims against other non-state parties . 
all actions by eu institutions can be subject to judicial review , and judged by standards of proportionality , particularly where general principles of law , or fundamental rights are engaged . 
while constitutional law concerns the european union 's governance structure , administrative law binds eu institutions and member states to follow the law . 
in van gend en loos v nederlandse administratie der belastingen it was held that the provisions of the treaties -lrb- and eu regulations -rrb- are directly effective , if they are -lrb- 1 -rrb- clear and unambiguous -lrb- 2 -rrb- unconditional , and -lrb- 3 -rrb- did not require eu or national authorities to take further action to implement them . 
because article 30 clearly , unconditionally and immediately stated that no quantitative restrictions could be placed on trade , without a good justification , van gend en loos could recover the money it paid for the tariff . 
van gend en loos , a postal company , claimed that what is now tfeu article 30 prevented the dutch customs authorities charging tariffs , when it imported urea-formaldehyde plastics from germany to the netherlands . 
eu regulations are the same as treaty provisions in this sense , because as tfeu article 288 states , they are ` directly applicable in all member states ' . 
while the treaties and regulations will have direct effect -lrb- if clear , unconditional and immediate -rrb- , directives do not generally give citizens -lrb- as opposed to the member state -rrb- standing to sue other citizens . 
for example , the working time directive requires that every worker has at least 4 weeks paid holidays each year , but most member states require more than 28 days in national law . 
for example , the working time directive requires that every worker has at least 4 weeks paid holidays each year , but most member states require more than 28 days in national law . 
this view was instantly controversial , and in the early 1990s three advocate generals persuasively argued that directives should create rights and duties for all citizens . 
first , if a directive 's deadline for implementation is not met , the member state can not enforce conflicting laws , and a citizen may rely on the directive in such an action -lrb- so called `` vertical '' direct effect -rrb- . 
second , a citizen or company can invoke a directive , not just in a dispute with a public authority , but in a dispute with another citizen or company . 
ms kücükdeveci worked for 10 years , from age 18 to 28 , for swedex gmbh & co kg before her dismissal . 
in foster v british gas plc the court of justice held that mrs foster was entitled to bring a sex discrimination claim against her employer , british gas plc , which made women retire at age 60 and men at 65 , if -lrb- 1 -rrb- pursuant to a state measure , -lrb- 2 -rrb- it provided a public service , and -lrb- 3 -rrb- had special powers . 
in foster v british gas plc the court of justice held that mrs foster was entitled to bring a sex discrimination claim against her employer , british gas plc , which made women retire at age 60 and men at 65 , if -lrb- 1 -rrb- pursuant to a state measure , -lrb- 2 -rrb- it provided a public service , and -lrb- 3 -rrb- had special powers . 
fourth , national courts have a duty to interpret domestic law `` as far as possible in the light of the wording and purpose of the directive '' . 
in marleasing sa v la comercial sa the court of justice held that a spanish court had to interpret its general civil code provisions , on contracts lacking cause or defrauding creditors , to conform with the first company law directive article 11 , that required incorporations would only be nullified for a fixed list of reasons . 
so , in francovich v italy , the italian government had failed to set up an insurance fund for employees to claim unpaid wages if their employers had gone insolvent , as the insolvency protection directive required . 
francovich , the former employee of a bankrupt venetian firm , was therefore allowed to claim 6 million lira from the italian government in damages for his loss . 
the principles of european union law are rules of law which have been developed by the european court of justice that constitute unwritten rules which are not expressly provided for in the treaties but which affect how european union law is interpreted and applies . 
accepted general principles of european union law include fundamental rights -lrb- see human rights -rrb- , proportionality , legal certainty , equality before the law and subsidiarity . 
proportionality is recognised one of the general principles of european union law by the european court of justice since the 1950s . 
the principle of proportionality is also recognised in article 5 of the ec treaty , stating that `` any action by the community shall not go beyond what is necessary to achieve the objectives of this treaty '' . 
when there is a choice between several appropriate measures the least onerous must be adopted , and any disadvantage caused must not be disproportionate to the aims pursued . 
the concept of legal certainty is recognised one of the general principles of european union law by the european court of justice since the 1960s . 
it is an important general principle of international law and public law , which predates european union law . 
the adoption of laws which will have legal effect in the european union must have a proper legal basis . 
the doctrine of legitimate expectation , which has its roots in the principles of legal certainty and good faith , is also a central element of the general principle of legal certainty in european union law . 
as such the european court of justice is bound to draw inspiration from the constitutional traditions common to the member states . 
therefore , the european court of justice can not uphold measures which are incompatible with fundamental rights recognised and protected in the constitutions of member states . 
none of the original treaties establishing the european union mention protection for fundamental rights . 
at the time the only concern was that member states should be prevented from violating human rights , hence the establishment of the european convention on human rights in 1950 and the establishment of the european court of human rights . 
at the time the only concern was that member states should be prevented from violating human rights , hence the establishment of the european convention on human rights in 1950 and the establishment of the european court of human rights . 
at the time the only concern was that member states should be prevented from violating human rights , hence the establishment of the european convention on human rights in 1950 and the establishment of the european court of human rights . 
in 1999 the european council set up a body tasked with drafting a european charter of human rights , which could form the constitutional basis for the european union and as such tailored specifically to apply to the european union and its institutions . 
the 2007 lisbon treaty explicitly recognised fundamental rights by providing in article 6 -lrb- 1 -rrb- that `` the union recognises the rights , freedoms and principles set out in the charter of fundamental rights of the european union of 7 december 2000 , as adopted at strasbourg on 12 december 2007 , which shall have the same legal value as the treaties . '' 
therefore , the charter of fundamental rights of the european union has become an integral part of european union law , codifying the fundamental rights which were previously considered general principles of european union law . 
in effect , after the lisbon treaty , the charter and the convention now co-exist under european union law , though the former is enforced by the european court of justice in relation to european union measures , and the latter by the european court of human rights in relation to measures by member states . 
in effect , after the lisbon treaty , the charter and the convention now co-exist under european union law , though the former is enforced by the european court of justice in relation to european union measures , and the latter by the european court of human rights in relation to measures by member states . 
the social chapter is a chapter of the 1997 treaty of amsterdam covering social policy issues in european union law . 
the social chapter is a chapter of the 1997 treaty of amsterdam covering social policy issues in european union law . 
the basis for the social chapter was developed in 1989 by the `` social partners '' representatives , namely unice , the employers ' confederation , the european trade union confederation -lrb- etuc -rrb- and ceep , the european centre of public enterprises . 
the social charter declares 30 general principles , including on fair remuneration of employment , health and safety at work , rights of disabled and elderly , the rights of workers , on vocational training and improvements of living conditions . 
the social charter became the basis for european community legislation on these issues in 40 pieces of legislation . 
the social charter was subsequently adopted in 1989 by 11 of the then 12 member states . 
the uk refused to sign the social charter and was exempt from the legislation covering social charter issues unless it agreed to be bound by the legislation . 
the uk subsequently was the only member state to veto the social charter being included as the `` social chapter '' of the 1992 maastricht treaty - instead , an agreement on social policy was added as a protocol . 
the uk subsequently was the only member state to veto the social charter being included as the `` social chapter '' of the 1992 maastricht treaty - instead , an agreement on social policy was added as a protocol . 
following the election of the uk labour party to government in 1997 , the uk formally subscribed to the agreement on social policy , which allowed it to be included with minor amendments as the social chapter of the 1997 treaty of amsterdam . 
following the election of the uk labour party to government in 1997 , the uk formally subscribed to the agreement on social policy , which allowed it to be included with minor amendments as the social chapter of the 1997 treaty of amsterdam . 
the uk subsequently adopted the main legislation previously agreed under the agreement on social policy , the 1994 works council directive , which required workforce consultation in businesses , and the 1996 parental leave directive . 
the uk subsequently adopted the main legislation previously agreed under the agreement on social policy , the 1994 works council directive , which required workforce consultation in businesses , and the 1996 parental leave directive . 
the uk subsequently adopted the main legislation previously agreed under the agreement on social policy , the 1994 works council directive , which required workforce consultation in businesses , and the 1996 parental leave directive . 
eu competition law has its origins in the european coal and steel community -lrb- ecsc -rrb- agreement between france , italy , belgium , the netherlands , luxembourg and germany in 1951 following the second world war . 
eu competition law has its origins in the european coal and steel community -lrb- ecsc -rrb- agreement between france , italy , belgium , the netherlands , luxembourg and germany in 1951 following the second world war . 
article 65 of the agreement banned cartels and article 66 made provisions for concentrations , or mergers , and the abuse of a dominant position by companies . 
article 65 of the agreement banned cartels and article 66 made provisions for concentrations , or mergers , and the abuse of a dominant position by companies . 
in 1957 competition rules were included in the treaty of rome , also known as the ec treaty , which established the european economic community -lrb- eec -rrb- . 
today , the treaty of lisbon prohibits anti-competitive agreements in article 101 -lrb- 1 -rrb- , including price fixing . 
article 102 prohibits the abuse of dominant position , such as price discrimination and exclusive dealing . 
articles 106 and 107 provide that member state 's right to deliver public services may not be obstructed , but that otherwise public enterprises must adhere to the same competition principles as companies . 
article 102 allows the european council to regulations to govern mergers between firms -lrb- the current regulation is the regulation 139/2004/ec -rrb- . 
while the concept of a `` social market economy '' was only introduced into eu law in 2007 , free movement and trade were central to european development since the treaty of rome 1957 . 
while the concept of a `` social market economy '' was only introduced into eu law in 2007 , free movement and trade were central to european development since the treaty of rome 1957 . 
like in other regional organisations such as the north american free trade association , or the world trade organisation , breaking down barriers to trade , and enhancing free movement of goods , services , labour and capital , is meant to reduce consumer prices . 
the treaties limit free trade , to prioritise other values such as public health , consumer protection , labour rights , fair competition , and environmental improvement . 
increasingly the court of justice has taken the view that the specific goals of free trade are underpinned by the general aims of the treaty for improvement of people 's well being . 
free movement of goods within the european union is achieved by a customs union , and the principle of non-discrimination . 
it discriminated against parallel importers like mr dassonville , who could not get certificates from authorities in france , where they bought the scotch . 
it also means states can be responsible for private actors . 
for instance , in commission v france french farmer vigilantes were continually sabotaging shipments of spanish strawberries , and even belgian tomato imports . 
so , in schmidberger v austria the court of justice held that austria did not infringe article 34 by failing to ban a protest that blocked heavy traffic passing over the a13 , brenner autobahn , en route to italy . 
in the most famous case rewe-zentral ag v bundesmonopol für branntwein , the court of justice found that a german law requiring all spirits and liqueurs -lrb- not just imported ones -rrb- to have a minimum alcohol content of 25 per cent was contrary to tfeu article 34 , because it had a greater negative effect on imports . 
german liqueurs were over 25 per cent alcohol , but cassis de dijon , which rewe-zentrale ag wished to import from france , only had 15 to 20 per cent alcohol . 
in a 2003 case , commission v italy italian law required that cocoa products that included other vegetable fats could not be labelled as `` chocolate '' . 
all italian chocolate was made from cocoa butter alone , but british , danish and irish manufacturers used other vegetable fats . 
so , in a 2009 case , commission v italy , the court of justice held that an italian law prohibiting motorcycles or mopeds pulling trailers infringed article 34 . 
in keck and mithouard two importers claimed that their prosecution under a french competition law , which prevented them selling picon beer under wholesale price , was unlawful . 
the aim of the law was to prevent cut throat competition , not to hinder trade . 
in konsumentombudsmannen v de agostini the court of justice reviewed swedish bans on advertising to children under age 12 , and misleading commercials for skin care products . 
under the unfair commercial practices directive , the eu harmonised restrictions on restrictions on marketing and advertising , to forbid conduct that distorts average consumer behaviour , is misleading or aggressive , and sets out a list of examples that count as unfair . 
since its foundation , the treaties sought to enable people to pursue their life goals in any country through free movement . 
reflecting the economic nature of the project , the european community originally focused upon free movement of workers : as a `` factor of production '' . 
free movement was increasingly based on `` citizenship '' , so that people had rights to empower them to become economically and socially active , rather than economic activity being a precondition for rights . 
for example , in steymann v staatssecretaris van justitie , a german man claimed the right to residence in the netherlands , while he volunteered plumbing and household duties in the bhagwan community , which provided for everyone 's material needs irrespective of their contributions . 
the court of justice held that mr steymann was entitled to stay , so long as there was at least an `` indirect quid pro quo '' for the work he did . 
the free movement of workers regulation articles 1 to 7 set out the main provisions on equal treatment of workers . 
in a famous case , the belgian football association v bosman , a belgian footballer named jean-marc bosman claimed that he should be able to transfer from r.f.c. de liège to usl dunkerque when his contract finished , regardless of whether dunkerque could afford to pay liège the habitual transfer fees . 
in groener v minister for education the court of justice accepted that a requirement to speak gaelic to teach in a dublin design college could be justified as part of the public policy of promoting the irish language , but only if the measure was not disproportionate . 
in hendrix v employee insurance institute the court of justice held that a dutch national was not entitled to continue receiving incapacity benefits when he moved to belgium , because the benefit was `` closely linked to the socio-economic situation '' of the netherlands . 
conversely , in geven v land nordrhein-westfalen the court of justice held that a dutch woman living in the netherlands , but working between 3 and 14 hours a week in germany , did not have a right to receive german child benefits , even though the wife of a man who worked full-time in germany but was resident in austria could . 
citizenship of the eu has increasingly been seen as a `` fundamental '' status of member state nationals by the court of justice , and has accordingly increased the number of social services that people can access wherever they move . 
citizenship of the eu has increasingly been seen as a `` fundamental '' status of member state nationals by the court of justice , and has accordingly increased the number of social services that people can access wherever they move . 
in commission v austria the court held that austria was not entitled to restrict places in austrian universities to austrian students to avoid `` structural , staffing and financial problems '' if -lrb- mainly german -rrb- foreign students applied for places because there was little evidence of an actual problem . 
the court has required that higher education , along with other forms of vocational training , should be more access , albeit with qualifying periods . 
as well as creating rights for `` workers '' who generally lack bargaining power in the market , the treaty on the functioning of the european union also protects the `` freedom of establishment '' in article 49 , and `` freedom to provide services '' in article 56 . 
however , the requirements to be registered in milan before being able to practice would be allowed if they were non-discriminatory , `` justified by imperative requirements in the general interest '' and proportionately applied . 
in reyners v belgium the court of justice held that a refusal to admit a lawyer to the belgian bar because he lacked belgian nationality was unjustified . 
tfeu article 49 says states are exempt from infringing others ' freedom of establishment when they exercise `` official authority '' , but this did an advocate 's work -lrb- as opposed to a court 's -rrb- was not official . 
by contrast in commission v italy the court of justice held that a requirement for lawyers in italy to comply with maximum tariffs unless there was an agreement with a client was not a restriction . 
in 2006 , a toxic waste spill off the coast of côte d'ivoire , from a european ship , prompted the commission to look into legislation against toxic waste . 
with countries such as spain not even having a crime against shipping toxic waste , franco frattini , the justice , freedom and security commissioner , proposed with dimas to create criminal sentences for `` ecological crimes '' . 
however , in october 2007 , the court of justice ruled that the commission could not propose what the criminal sanctions could be , only that there must be some . 
the competence for the union to do this was contested in 2005 at the court of justice resulting in a victory for the commission . 
the `` freedom to provide services '' under tfeu article 56 applies to people who give services `` for remuneration '' , especially commercial or professional activity . 
for example , in van binsbergen v bestuur van de bedrijfvereniging voor de metaalnijverheid a dutch lawyer moved to belgium while advising a client in a social security case , and was told he could not continue because dutch law said only people established in the netherlands could give legal advice . 
the court of justice reasoned that narcotic drugs were controlled in all member states , and so this differed from other cases where prostitution or other quasi-legal activity was subject to restriction . 
the dutch health authorities regarded the treatment unnecessary , so she argued this restricted the freedom -lrb- of the german health clinic -rrb- to provide services . 
this meant the daily mail newspaper 's parent company could not evade tax by shifting its residence to the netherlands without first settling its tax bills in the uk . 
uk law only required # 1 of capital to start a company , while denmark 's legislature took the view companies should only be started up if they had 200,000 danish krone -lrb- around $ 27,000 -rrb- to protect creditors if the company failed and went insolvent . 
uk law only required # 1 of capital to start a company , while denmark 's legislature took the view companies should only be started up if they had 200,000 danish krone -lrb- around $ 27,000 -rrb- to protect creditors if the company failed and went insolvent . 
although restrictions on freedom of establishment could be justified by creditor protection , labour rights to participate in work , or the public interest in collecting taxes , denial of capacity went too far : it was an `` outright negation '' of the right of establishment . 
similarly in überseering bv v nordic construction gmbh the court of justice held that a german court could not deny a dutch building company the right to enforce a contract in germany on the basis that it was not validly incorporated in germany . 
the amazon rainforest -lrb- portuguese : floresta amazônica or amazônia ; spanish : selva amazónica , amazonía or usually amazonia ; french : forêt amazonienne ; dutch : amazoneregenwoud -rrb- , also known in english as amazonia or the amazon jungle , is a moist broadleaf forest that covers most of the amazon basin of south america . 
this basin encompasses 7,000,000 square kilometres -lrb- 2,700,000 sq mi -rrb- , of which 5,500,000 square kilometres -lrb- 2,100,000 sq mi -rrb- are covered by the rainforest . 
this region includes territory belonging to nine nations . 
states or departments in four nations contain `` amazonas '' in their names . 
the amazon represents over half of the planet 's remaining rainforests , and comprises the largest and most biodiverse tract of tropical rainforest in the world , with an estimated 390 billion individual trees divided into 16,000 species . 
the amazon rainforest -lrb- portuguese : floresta amazônica or amazônia ; spanish : selva amazónica , amazonía or usually amazonia ; french : forêt amazonienne ; dutch : amazoneregenwoud -rrb- , also known in english as amazonia or the amazon jungle , is a moist broadleaf forest that covers most of the amazon basin of south america . 
the amazon rainforest -lrb- portuguese : floresta amazônica or amazônia ; spanish : selva amazónica , amazonía or usually amazonia ; french : forêt amazonienne ; dutch : amazoneregenwoud -rrb- , also known in english as amazonia or the amazon jungle , is a moist broadleaf forest that covers most of the amazon basin of south america . 
the majority of the forest is contained within brazil , with 60 % of the rainforest , followed by peru with 13 % , colombia with 10 % , and with minor amounts in venezuela , ecuador , bolivia , guyana , suriname and french guiana . 
the amazon represents over half of the planet 's remaining rainforests , and comprises the largest and most biodiverse tract of tropical rainforest in the world , with an estimated 390 billion individual trees divided into 16,000 species . 
the amazon represents over half of the planet 's remaining rainforests , and comprises the largest and most biodiverse tract of tropical rainforest in the world , with an estimated 390 billion individual trees divided into 16,000 species . 
the amazon rainforest -lrb- portuguese : floresta amazônica or amazônia ; spanish : selva amazónica , amazonía or usually amazonia ; french : forêt amazonienne ; dutch : amazoneregenwoud -rrb- , also known in english as amazonia or the amazon jungle , is a moist broadleaf forest that covers most of the amazon basin of south america . 
this basin encompasses 7,000,000 square kilometres -lrb- 2,700,000 sq mi -rrb- , of which 5,500,000 square kilometres -lrb- 2,100,000 sq mi -rrb- are covered by the rainforest . 
this region includes territory belonging to nine nations . 
the majority of the forest is contained within brazil , with 60 % of the rainforest , followed by peru with 13 % , colombia with 10 % , and with minor amounts in venezuela , ecuador , bolivia , guyana , suriname and french guiana . 
the amazon represents over half of the planet 's remaining rainforests , and comprises the largest and most biodiverse tract of tropical rainforest in the world , with an estimated 390 billion individual trees divided into 16,000 species . 
following the cretaceous -- paleogene extinction event , the extinction of the dinosaurs and the wetter climate may have allowed the tropical rainforest to spread out across the continent . 
climate fluctuations during the last 34 million years have allowed savanna regions to expand into the tropics . 
during the oligocene , for example , the rainforest spanned a relatively narrow band . 
it expanded again during the middle miocene , then retracted to a mostly inland formation at the last glacial maximum . 
however , the rainforest still managed to thrive during these glacial periods , allowing for the survival and evolution of a broad diversity of species . 
following the cretaceous -- paleogene extinction event , the extinction of the dinosaurs and the wetter climate may have allowed the tropical rainforest to spread out across the continent . 
from 66 -- 34 mya , the rainforest extended as far south as 45 ° . 
climate fluctuations during the last 34 million years have allowed savanna regions to expand into the tropics . 
during the oligocene , for example , the rainforest spanned a relatively narrow band . 
it expanded again during the middle miocene , then retracted to a mostly inland formation at the last glacial maximum . 
following the cretaceous -- paleogene extinction event , the extinction of the dinosaurs and the wetter climate may have allowed the tropical rainforest to spread out across the continent . 
from 66 -- 34 mya , the rainforest extended as far south as 45 ° . 
it expanded again during the middle miocene , then retracted to a mostly inland formation at the last glacial maximum . 
it expanded again during the middle miocene , then retracted to a mostly inland formation at the last glacial maximum . 
climate fluctuations during the last 34 million years have allowed savanna regions to expand into the tropics . 
during the mid-eocene , it is believed that the drainage basin of the amazon was split along the middle of the continent by the purus arch . 
water on the eastern side flowed toward the atlantic , while to the west water flowed toward the pacific across the amazonas basin . 
as the andes mountains rose , however , a large basin was created that enclosed a lake ; now known as the solimões basin . 
within the last 5 -- 10 million years , this accumulating water broke through the purus arch , joining the easterly flow toward the atlantic . 
within the last 5 -- 10 million years , this accumulating water broke through the purus arch , joining the easterly flow toward the atlantic . 
during the mid-eocene , it is believed that the drainage basin of the amazon was split along the middle of the continent by the purus arch . 
water on the eastern side flowed toward the atlantic , while to the west water flowed toward the pacific across the amazonas basin . 
water on the eastern side flowed toward the atlantic , while to the west water flowed toward the pacific across the amazonas basin . 
water on the eastern side flowed toward the atlantic , while to the west water flowed toward the pacific across the amazonas basin . 
as the andes mountains rose , however , a large basin was created that enclosed a lake ; now known as the solimões basin . 
during the mid-eocene , it is believed that the drainage basin of the amazon was split along the middle of the continent by the purus arch . 
during the mid-eocene , it is believed that the drainage basin of the amazon was split along the middle of the continent by the purus arch . 
water on the eastern side flowed toward the atlantic , while to the west water flowed toward the pacific across the amazonas basin . 
water on the eastern side flowed toward the atlantic , while to the west water flowed toward the pacific across the amazonas basin . 
as the andes mountains rose , however , a large basin was created that enclosed a lake ; now known as the solimões basin . 
there is evidence that there have been significant changes in amazon rainforest vegetation over the last 21,000 years through the last glacial maximum -lrb- lgm -rrb- and subsequent deglaciation . 
analyses of sediment deposits from amazon basin paleolakes and from the amazon fan indicate that rainfall in the basin during the lgm was lower than for the present , and this was almost certainly associated with reduced moist tropical vegetation cover in the basin . 
some scientists argue that the rainforest was reduced to small , isolated refugia separated by open forest and grassland ; other scientists argue that the rainforest remained largely intact but extended less far to the north , south , and east than is seen today . 
this debate has proved difficult to resolve because the practical limitations of working in the rainforest mean that data sampling is biased away from the center of the amazon basin , and both explanations are reasonably well supported by the available data . 
this debate has proved difficult to resolve because the practical limitations of working in the rainforest mean that data sampling is biased away from the center of the amazon basin , and both explanations are reasonably well supported by the available data . 
there is evidence that there have been significant changes in amazon rainforest vegetation over the last 21,000 years through the last glacial maximum -lrb- lgm -rrb- and subsequent deglaciation . 
there is evidence that there have been significant changes in amazon rainforest vegetation over the last 21,000 years through the last glacial maximum -lrb- lgm -rrb- and subsequent deglaciation . 
analyses of sediment deposits from amazon basin paleolakes and from the amazon fan indicate that rainfall in the basin during the lgm was lower than for the present , and this was almost certainly associated with reduced moist tropical vegetation cover in the basin . 
analyses of sediment deposits from amazon basin paleolakes and from the amazon fan indicate that rainfall in the basin during the lgm was lower than for the present , and this was almost certainly associated with reduced moist tropical vegetation cover in the basin . 
there is evidence that there have been significant changes in amazon rainforest vegetation over the last 21,000 years through the last glacial maximum -lrb- lgm -rrb- and subsequent deglaciation . 
analyses of sediment deposits from amazon basin paleolakes and from the amazon fan indicate that rainfall in the basin during the lgm was lower than for the present , and this was almost certainly associated with reduced moist tropical vegetation cover in the basin . 
analyses of sediment deposits from amazon basin paleolakes and from the amazon fan indicate that rainfall in the basin during the lgm was lower than for the present , and this was almost certainly associated with reduced moist tropical vegetation cover in the basin . 
some scientists argue that the rainforest was reduced to small , isolated refugia separated by open forest and grassland ; other scientists argue that the rainforest remained largely intact but extended less far to the north , south , and east than is seen today . 
this debate has proved difficult to resolve because the practical limitations of working in the rainforest mean that data sampling is biased away from the center of the amazon basin , and both explanations are reasonably well supported by the available data . 
nasa 's calipso satellite has measured the amount of dust transported by wind from the sahara to the amazon : an average 182 million tons of dust are windblown out of the sahara each year , at 15 degrees west longitude , across 1,600 miles -lrb- 2,600 km -rrb- over the atlantic ocean -lrb- some dust falls into the atlantic -rrb- , then at 35 degrees west longitude at the eastern coast of south america , 27.7 million tons -lrb- 15 % -rrb- of dust fall over the amazon basin , 132 million tons of dust remain in the air , 43 million tons of dust are windblown and falls on the caribbean sea , past 75 degrees west longitude . 
nasa 's calipso satellite has measured the amount of dust transported by wind from the sahara to the amazon : an average 182 million tons of dust are windblown out of the sahara each year , at 15 degrees west longitude , across 1,600 miles -lrb- 2,600 km -rrb- over the atlantic ocean -lrb- some dust falls into the atlantic -rrb- , then at 35 degrees west longitude at the eastern coast of south america , 27.7 million tons -lrb- 15 % -rrb- of dust fall over the amazon basin , 132 million tons of dust remain in the air , 43 million tons of dust are windblown and falls on the caribbean sea , past 75 degrees west longitude . 
nasa 's calipso satellite has measured the amount of dust transported by wind from the sahara to the amazon : an average 182 million tons of dust are windblown out of the sahara each year , at 15 degrees west longitude , across 1,600 miles -lrb- 2,600 km -rrb- over the atlantic ocean -lrb- some dust falls into the atlantic -rrb- , then at 35 degrees west longitude at the eastern coast of south america , 27.7 million tons -lrb- 15 % -rrb- of dust fall over the amazon basin , 132 million tons of dust remain in the air , 43 million tons of dust are windblown and falls on the caribbean sea , past 75 degrees west longitude . 
nasa 's calipso satellite has measured the amount of dust transported by wind from the sahara to the amazon : an average 182 million tons of dust are windblown out of the sahara each year , at 15 degrees west longitude , across 1,600 miles -lrb- 2,600 km -rrb- over the atlantic ocean -lrb- some dust falls into the atlantic -rrb- , then at 35 degrees west longitude at the eastern coast of south america , 27.7 million tons -lrb- 15 % -rrb- of dust fall over the amazon basin , 132 million tons of dust remain in the air , 43 million tons of dust are windblown and falls on the caribbean sea , past 75 degrees west longitude . 
nasa 's calipso satellite has measured the amount of dust transported by wind from the sahara to the amazon : an average 182 million tons of dust are windblown out of the sahara each year , at 15 degrees west longitude , across 1,600 miles -lrb- 2,600 km -rrb- over the atlantic ocean -lrb- some dust falls into the atlantic -rrb- , then at 35 degrees west longitude at the eastern coast of south america , 27.7 million tons -lrb- 15 % -rrb- of dust fall over the amazon basin , 132 million tons of dust remain in the air , 43 million tons of dust are windblown and falls on the caribbean sea , past 75 degrees west longitude . 
nasa 's calipso satellite has measured the amount of dust transported by wind from the sahara to the amazon : an average 182 million tons of dust are windblown out of the sahara each year , at 15 degrees west longitude , across 1,600 miles -lrb- 2,600 km -rrb- over the atlantic ocean -lrb- some dust falls into the atlantic -rrb- , then at 35 degrees west longitude at the eastern coast of south america , 27.7 million tons -lrb- 15 % -rrb- of dust fall over the amazon basin , 132 million tons of dust remain in the air , 43 million tons of dust are windblown and falls on the caribbean sea , past 75 degrees west longitude . 
nasa 's calipso satellite has measured the amount of dust transported by wind from the sahara to the amazon : an average 182 million tons of dust are windblown out of the sahara each year , at 15 degrees west longitude , across 1,600 miles -lrb- 2,600 km -rrb- over the atlantic ocean -lrb- some dust falls into the atlantic -rrb- , then at 35 degrees west longitude at the eastern coast of south america , 27.7 million tons -lrb- 15 % -rrb- of dust fall over the amazon basin , 132 million tons of dust remain in the air , 43 million tons of dust are windblown and falls on the caribbean sea , past 75 degrees west longitude . 
nasa 's calipso satellite has measured the amount of dust transported by wind from the sahara to the amazon : an average 182 million tons of dust are windblown out of the sahara each year , at 15 degrees west longitude , across 1,600 miles -lrb- 2,600 km -rrb- over the atlantic ocean -lrb- some dust falls into the atlantic -rrb- , then at 35 degrees west longitude at the eastern coast of south america , 27.7 million tons -lrb- 15 % -rrb- of dust fall over the amazon basin , 132 million tons of dust remain in the air , 43 million tons of dust are windblown and falls on the caribbean sea , past 75 degrees west longitude . 
nasa 's calipso satellite has measured the amount of dust transported by wind from the sahara to the amazon : an average 182 million tons of dust are windblown out of the sahara each year , at 15 degrees west longitude , across 1,600 miles -lrb- 2,600 km -rrb- over the atlantic ocean -lrb- some dust falls into the atlantic -rrb- , then at 35 degrees west longitude at the eastern coast of south america , 27.7 million tons -lrb- 15 % -rrb- of dust fall over the amazon basin , 132 million tons of dust remain in the air , 43 million tons of dust are windblown and falls on the caribbean sea , past 75 degrees west longitude . 
nasa 's calipso satellite has measured the amount of dust transported by wind from the sahara to the amazon : an average 182 million tons of dust are windblown out of the sahara each year , at 15 degrees west longitude , across 1,600 miles -lrb- 2,600 km -rrb- over the atlantic ocean -lrb- some dust falls into the atlantic -rrb- , then at 35 degrees west longitude at the eastern coast of south america , 27.7 million tons -lrb- 15 % -rrb- of dust fall over the amazon basin , 132 million tons of dust remain in the air , 43 million tons of dust are windblown and falls on the caribbean sea , past 75 degrees west longitude . 
nasa 's calipso satellite has measured the amount of dust transported by wind from the sahara to the amazon : an average 182 million tons of dust are windblown out of the sahara each year , at 15 degrees west longitude , across 1,600 miles -lrb- 2,600 km -rrb- over the atlantic ocean -lrb- some dust falls into the atlantic -rrb- , then at 35 degrees west longitude at the eastern coast of south america , 27.7 million tons -lrb- 15 % -rrb- of dust fall over the amazon basin , 132 million tons of dust remain in the air , 43 million tons of dust are windblown and falls on the caribbean sea , past 75 degrees west longitude . 
nasa 's calipso satellite has measured the amount of dust transported by wind from the sahara to the amazon : an average 182 million tons of dust are windblown out of the sahara each year , at 15 degrees west longitude , across 1,600 miles -lrb- 2,600 km -rrb- over the atlantic ocean -lrb- some dust falls into the atlantic -rrb- , then at 35 degrees west longitude at the eastern coast of south america , 27.7 million tons -lrb- 15 % -rrb- of dust fall over the amazon basin , 132 million tons of dust remain in the air , 43 million tons of dust are windblown and falls on the caribbean sea , past 75 degrees west longitude . 
nasa 's calipso satellite has measured the amount of dust transported by wind from the sahara to the amazon : an average 182 million tons of dust are windblown out of the sahara each year , at 15 degrees west longitude , across 1,600 miles -lrb- 2,600 km -rrb- over the atlantic ocean -lrb- some dust falls into the atlantic -rrb- , then at 35 degrees west longitude at the eastern coast of south america , 27.7 million tons -lrb- 15 % -rrb- of dust fall over the amazon basin , 132 million tons of dust remain in the air , 43 million tons of dust are windblown and falls on the caribbean sea , past 75 degrees west longitude . 
nasa 's calipso satellite has measured the amount of dust transported by wind from the sahara to the amazon : an average 182 million tons of dust are windblown out of the sahara each year , at 15 degrees west longitude , across 1,600 miles -lrb- 2,600 km -rrb- over the atlantic ocean -lrb- some dust falls into the atlantic -rrb- , then at 35 degrees west longitude at the eastern coast of south america , 27.7 million tons -lrb- 15 % -rrb- of dust fall over the amazon basin , 132 million tons of dust remain in the air , 43 million tons of dust are windblown and falls on the caribbean sea , past 75 degrees west longitude . 
nasa 's calipso satellite has measured the amount of dust transported by wind from the sahara to the amazon : an average 182 million tons of dust are windblown out of the sahara each year , at 15 degrees west longitude , across 1,600 miles -lrb- 2,600 km -rrb- over the atlantic ocean -lrb- some dust falls into the atlantic -rrb- , then at 35 degrees west longitude at the eastern coast of south america , 27.7 million tons -lrb- 15 % -rrb- of dust fall over the amazon basin , 132 million tons of dust remain in the air , 43 million tons of dust are windblown and falls on the caribbean sea , past 75 degrees west longitude . 
archeologist betty meggers was a prominent proponent of this idea , as described in her book amazonia : man and culture in a counterfeit paradise . 
she claimed that a population density of 0.2 inhabitants per square kilometre -lrb- 0.52 / sq mi -rrb- is the maximum that can be sustained in the rainforest through hunting , with agriculture needed to host a larger population . 
she claimed that a population density of 0.2 inhabitants per square kilometre -lrb- 0.52 / sq mi -rrb- is the maximum that can be sustained in the rainforest through hunting , with agriculture needed to host a larger population . 
however , recent anthropological findings have suggested that the region was actually densely populated . 
some 5 million people may have lived in the amazon region in ad 1500 , divided between dense coastal settlements , such as that at marajó , and inland dwellers . 
for a long time , it was thought that the amazon rainforest was only ever sparsely populated , as it was impossible to sustain a large population through agriculture given the poor soil . 
archeologist betty meggers was a prominent proponent of this idea , as described in her book amazonia : man and culture in a counterfeit paradise . 
she claimed that a population density of 0.2 inhabitants per square kilometre -lrb- 0.52 / sq mi -rrb- is the maximum that can be sustained in the rainforest through hunting , with agriculture needed to host a larger population . 
archeologist betty meggers was a prominent proponent of this idea , as described in her book amazonia : man and culture in a counterfeit paradise . 
archeologist betty meggers was a prominent proponent of this idea , as described in her book amazonia : man and culture in a counterfeit paradise . 
archeologist betty meggers was a prominent proponent of this idea , as described in her book amazonia : man and culture in a counterfeit paradise . 
she claimed that a population density of 0.2 inhabitants per square kilometre -lrb- 0.52 / sq mi -rrb- is the maximum that can be sustained in the rainforest through hunting , with agriculture needed to host a larger population . 
some 5 million people may have lived in the amazon region in ad 1500 , divided between dense coastal settlements , such as that at marajó , and inland dwellers . 
by 1900 the population had fallen to 1 million and by the early 1980s it was less than 200,000 . 
the first european to travel the length of the amazon river was francisco de orellana in 1542 . 
the bbc 's unnatural histories presents evidence that orellana , rather than exaggerating his claims as previously thought , was correct in his observations that a complex civilization was flourishing along the amazon in the 1540s . 
it is believed that the civilization was later devastated by the spread of diseases from europe , such as smallpox . 
since the 1970s , numerous geoglyphs have been discovered on deforested land dating between ad 0 -- 1250 , furthering claims about pre-columbian civilizations . 
since the 1970s , numerous geoglyphs have been discovered on deforested land dating between ad 0 -- 1250 , furthering claims about pre-columbian civilizations . 
the first european to travel the length of the amazon river was francisco de orellana in 1542 . 
the first european to travel the length of the amazon river was francisco de orellana in 1542 . 
since the 1970s , numerous geoglyphs have been discovered on deforested land dating between ad 0 -- 1250 , furthering claims about pre-columbian civilizations . 
ondemar dias is accredited with first discovering the geoglyphs in 1977 and alceu ranzi with furthering their discovery after flying over acre . 
the bbc 's unnatural histories presented evidence that the amazon rainforest , rather than being a pristine wilderness , has been shaped by man for at least 11,000 years through practices such as forest gardening and terra preta . 
terra preta -lrb- black earth -rrb- , which is distributed over large areas in the amazon forest , is now widely accepted as a product of indigenous soil management . 
terra preta -lrb- black earth -rrb- , which is distributed over large areas in the amazon forest , is now widely accepted as a product of indigenous soil management . 
the development of this fertile soil allowed agriculture and silviculture in the previously hostile environment ; meaning that large portions of the amazon rainforest are probably the result of centuries of human management , rather than naturally occurring as has previously been supposed . 
in the region of the xingu tribe , remains of some of these large settlements in the middle of the amazon forest were found in 2003 by michael heckenberger and colleagues of the university of florida . 
in the region of the xingu tribe , remains of some of these large settlements in the middle of the amazon forest were found in 2003 by michael heckenberger and colleagues of the university of florida . 
terra preta -lrb- black earth -rrb- , which is distributed over large areas in the amazon forest , is now widely accepted as a product of indigenous soil management . 
the development of this fertile soil allowed agriculture and silviculture in the previously hostile environment ; meaning that large portions of the amazon rainforest are probably the result of centuries of human management , rather than naturally occurring as has previously been supposed . 
in the region of the xingu tribe , remains of some of these large settlements in the middle of the amazon forest were found in 2003 by michael heckenberger and colleagues of the university of florida . 
in the region of the xingu tribe , remains of some of these large settlements in the middle of the amazon forest were found in 2003 by michael heckenberger and colleagues of the university of florida . 
among those were evidence of roads , bridges and large plazas . 
the region is home to about 2.5 million insect species , tens of thousands of plants , and some 2,000 birds and mammals . 
one in five of all the bird species in the world live in the rainforests of the amazon , and one in five of the fish species live in amazonian rivers and streams . 
to date , at least 40,000 plant species , 2,200 fishes , 1,294 birds , 427 mammals , 428 amphibians , and 378 reptiles have been scientifically classified in the region . 
one in five of all the bird species in the world live in the rainforests of the amazon , and one in five of the fish species live in amazonian rivers and streams . 
scientists have described between 96,660 and 128,843 invertebrate species in brazil alone . 
the region is home to about 2.5 million insect species , tens of thousands of plants , and some 2,000 birds and mammals . 
the region is home to about 2.5 million insect species , tens of thousands of plants , and some 2,000 birds and mammals . 
to date , at least 40,000 plant species , 2,200 fishes , 1,294 birds , 427 mammals , 428 amphibians , and 378 reptiles have been scientifically classified in the region . 
to date , at least 40,000 plant species , 2,200 fishes , 1,294 birds , 427 mammals , 428 amphibians , and 378 reptiles have been scientifically classified in the region . 
one in five of all the bird species in the world live in the rainforests of the amazon , and one in five of the fish species live in amazonian rivers and streams . 
the biodiversity of plant species is the highest on earth with one 2001 study finding a quarter square kilometer -lrb- 62 acres -rrb- of ecuadorian rainforest supports more than 1,100 tree species . 
the biodiversity of plant species is the highest on earth with one 2001 study finding a quarter square kilometer -lrb- 62 acres -rrb- of ecuadorian rainforest supports more than 1,100 tree species . 
a study in 1999 found one square kilometer -lrb- 247 acres -rrb- of amazon rainforest can contain about 90,790 tonnes of living plants . 
the average plant biomass is estimated at 356 ± 47 tonnes per hectare . 
to date , an estimated 438,000 species of plants of economic and social interest have been registered in the region with many more remaining to be discovered or catalogued . 
the biodiversity of plant species is the highest on earth with one 2001 study finding a quarter square kilometer -lrb- 62 acres -rrb- of ecuadorian rainforest supports more than 1,100 tree species . 
the biodiversity of plant species is the highest on earth with one 2001 study finding a quarter square kilometer -lrb- 62 acres -rrb- of ecuadorian rainforest supports more than 1,100 tree species . 
a study in 1999 found one square kilometer -lrb- 247 acres -rrb- of amazon rainforest can contain about 90,790 tonnes of living plants . 
the average plant biomass is estimated at 356 ± 47 tonnes per hectare . 
to date , an estimated 438,000 species of plants of economic and social interest have been registered in the region with many more remaining to be discovered or catalogued . 
in the river , electric eels can produce an electric shock that can stun or kill , while piranha are known to bite and injure humans . 
among the largest predatory creatures are the black caiman , jaguar , cougar , and anaconda . 
in the river , electric eels can produce an electric shock that can stun or kill , while piranha are known to bite and injure humans . 
various species of poison dart frogs secrete lipophilic alkaloid toxins through their flesh . 
vampire bats dwell in the rainforest and can spread the rabies virus . 
deforestation is the conversion of forested areas to non-forested areas . 
prior to the early 1960s , access to the forest 's interior was highly restricted , and the forest remained basically intact . 
farms established during the 1960s were based on crop cultivation and the slash and burn method . 
however , the colonists were unable to manage their fields and the crops because of the loss of soil fertility and weed invasion . 
deforestation is considerable , and areas cleared of forest are visible to the naked eye from outer space . 
between 1991 and 2000 , the total area of forest lost in the amazon rose from 415,000 to 587,000 square kilometres -lrb- 160,000 to 227,000 sq mi -rrb- , with most of the lost forest becoming pasture for cattle . 
between 1991 and 2000 , the total area of forest lost in the amazon rose from 415,000 to 587,000 square kilometres -lrb- 160,000 to 227,000 sq mi -rrb- , with most of the lost forest becoming pasture for cattle . 
between 1991 and 2000 , the total area of forest lost in the amazon rose from 415,000 to 587,000 square kilometres -lrb- 160,000 to 227,000 sq mi -rrb- , with most of the lost forest becoming pasture for cattle . 
currently , brazil is the second-largest global producer of soybeans after the united states . 
seventy percent of formerly forested land in the amazon , and 91 % of land deforested since 1970 , is used for livestock pasture . 
the needs of soy farmers have been used to justify many of the controversial transportation projects that are currently developing in the amazon . 
the first two highways successfully opened up the rainforest and led to increased settlement and deforestation . 
the mean annual deforestation rate from 2000 to 2005 -lrb- 22,392 km2 or 8,646 sq mi per year -rrb- was 18 % higher than in the previous five years -lrb- 19,018 km2 or 7,343 sq mi per year -rrb- . 
although deforestation has declined significantly in the brazilian amazon between 2004 and 2014 , there has been an increase to the present day . 
the mean annual deforestation rate from 2000 to 2005 -lrb- 22,392 km2 or 8,646 sq mi per year -rrb- was 18 % higher than in the previous five years -lrb- 19,018 km2 or 7,343 sq mi per year -rrb- . 
environmentalists are concerned about loss of biodiversity that will result from destruction of the forest , and also about the release of the carbon contained within the vegetation , which could accelerate global warming . 
environmentalists are concerned about loss of biodiversity that will result from destruction of the forest , and also about the release of the carbon contained within the vegetation , which could accelerate global warming . 
environmentalists are concerned about loss of biodiversity that will result from destruction of the forest , and also about the release of the carbon contained within the vegetation , which could accelerate global warming . 
amazonian evergreen forests account for about 10 % of the world 's terrestrial primary productivity and 10 % of the carbon stores in ecosystems -- of the order of 1.1 × 1011 metric tonnes of carbon . 
amazonian evergreen forests account for about 10 % of the world 's terrestrial primary productivity and 10 % of the carbon stores in ecosystems -- of the order of 1.1 × 1011 metric tonnes of carbon . 
one computer model of future climate change caused by greenhouse gas emissions shows that the amazon rainforest could become unsustainable under conditions of severely reduced rainfall and increased temperatures , leading to an almost complete loss of rainforest cover in the basin by 2100 . 
one computer model of future climate change caused by greenhouse gas emissions shows that the amazon rainforest could become unsustainable under conditions of severely reduced rainfall and increased temperatures , leading to an almost complete loss of rainforest cover in the basin by 2100 . 
one computer model of future climate change caused by greenhouse gas emissions shows that the amazon rainforest could become unsustainable under conditions of severely reduced rainfall and increased temperatures , leading to an almost complete loss of rainforest cover in the basin by 2100 . 
the result indicates that the rainforest could be threatened though the 21st century by climate change in addition to deforestation . 
the result indicates that the rainforest could be threatened though the 21st century by climate change in addition to deforestation . 
as indigenous territories continue to be destroyed by deforestation and ecocide , such as in the peruvian amazon indigenous peoples ' rainforest communities continue to disappear , while others , like the urarina continue to struggle to fight for their cultural survival and the fate of their forested territories . 
meanwhile , the relationship between non-human primates in the subsistence and symbolism of indigenous lowland south american peoples has gained increased attention , as have ethno-biology and community-based conservation efforts . 
as indigenous territories continue to be destroyed by deforestation and ecocide , such as in the peruvian amazon indigenous peoples ' rainforest communities continue to disappear , while others , like the urarina continue to struggle to fight for their cultural survival and the fate of their forested territories . 
as indigenous territories continue to be destroyed by deforestation and ecocide , such as in the peruvian amazon indigenous peoples ' rainforest communities continue to disappear , while others , like the urarina continue to struggle to fight for their cultural survival and the fate of their forested territories . 
meanwhile , the relationship between non-human primates in the subsistence and symbolism of indigenous lowland south american peoples has gained increased attention , as have ethno-biology and community-based conservation efforts . 
the use of remote sensing for the conservation of the amazon is also being used by the indigenous tribes of the basin to protect their tribal lands from commercial interests . 
using handheld gps devices and programs like google earth , members of the trio tribe , who live in the rainforests of southern suriname , map out their ancestral lands to help strengthen their territorial claims . 
using handheld gps devices and programs like google earth , members of the trio tribe , who live in the rainforests of southern suriname , map out their ancestral lands to help strengthen their territorial claims . 
using handheld gps devices and programs like google earth , members of the trio tribe , who live in the rainforests of southern suriname , map out their ancestral lands to help strengthen their territorial claims . 
the use of remote sensing for the conservation of the amazon is also being used by the indigenous tribes of the basin to protect their tribal lands from commercial interests . 
to accurately map the amazon 's biomass and subsequent carbon related emissions , the classification of tree growth stages within different parts of the forest is crucial . 
to accurately map the amazon 's biomass and subsequent carbon related emissions , the classification of tree growth stages within different parts of the forest is crucial . 
in 2006 tatiana kuplich organized the trees of the amazon into four categories : -lrb- 1 -rrb- mature forest , -lrb- 2 -rrb- regenerating forest -lsb- less than three years -rsb- , -lrb- 3 -rrb- regenerating forest -lsb- between three and five years of regrowth -rsb- , and -lrb- 4 -rrb- regenerating forest -lsb- eleven to eighteen years of continued development -rsb- . 
in 2006 tatiana kuplich organized the trees of the amazon into four categories : -lrb- 1 -rrb- mature forest , -lrb- 2 -rrb- regenerating forest -lsb- less than three years -rsb- , -lrb- 3 -rrb- regenerating forest -lsb- between three and five years of regrowth -rsb- , and -lrb- 4 -rrb- regenerating forest -lsb- eleven to eighteen years of continued development -rsb- . 
the researcher used a combination of synthetic aperture radar -lrb- sar -rrb- and thematic mapper -lrb- tm -rrb- to accurately place the different portions of the amazon into one of the four classifications . 
in 2005 , parts of the amazon basin experienced the worst drought in one hundred years , and there were indications that 2006 could have been a second successive year of drought . 
scientists at the brazilian national institute of amazonian research argue in the article that this drought response , coupled with the effects of deforestation on regional climate , are pushing the rainforest towards a `` tipping point '' where it would irreversibly start to die . 
scientists at the brazilian national institute of amazonian research argue in the article that this drought response , coupled with the effects of deforestation on regional climate , are pushing the rainforest towards a `` tipping point '' where it would irreversibly start to die . 
it concludes that the forest is on the brink of being turned into savanna or desert , with catastrophic consequences for the world 's climate . 
a july 23 , 2006 article in the uk newspaper the independent reported woods hole research center results showing that the forest in its present form could survive only three years of drought . 
in 2010 the amazon rainforest experienced another severe drought , in some ways more extreme than the 2005 drought . 
the affected region was approximate 1,160,000 square miles -lrb- 3,000,000 km2 -rrb- of rainforest , compared to 734,000 square miles -lrb- 1,900,000 km2 -rrb- in 2005 . 
the 2010 drought had three epicenters where vegetation died off , whereas in 2005 the drought was focused on the southwestern part . 
the 2010 drought had three epicenters where vegetation died off , whereas in 2005 the drought was focused on the southwestern part . 
in a typical year the amazon absorbs 1.5 gigatons of carbon dioxide ; during 2005 instead 5 gigatons were released and in 2010 8 gigatons were released . 
ctenophora -lrb- / tᵻˈnɒfərə / ; singular ctenophore , / ˈtɛnəfɔːr / or / ˈtiːnəfɔːr / ; from the greek κτείς kteis ` comb ' and φέρω pherō ` carry ' ; commonly known as comb jellies -rrb- is a phylum of animals that live in marine waters worldwide . 
ctenophora -lrb- / tᵻˈnɒfərə / ; singular ctenophore , / ˈtɛnəfɔːr / or / ˈtiːnəfɔːr / ; from the greek κτείς kteis ` comb ' and φέρω pherō ` carry ' ; commonly known as comb jellies -rrb- is a phylum of animals that live in marine waters worldwide . 
adults of various species range from a few millimeters to 1.5 m -lrb- 4 ft 11 in -rrb- in size . 
ctenophora -lrb- / tᵻˈnɒfərə / ; singular ctenophore , / ˈtɛnəfɔːr / or / ˈtiːnəfɔːr / ; from the greek κτείς kteis ` comb ' and φέρω pherō ` carry ' ; commonly known as comb jellies -rrb- is a phylum of animals that live in marine waters worldwide . 
their most distinctive feature is the ` combs ' -- groups of cilia which they use for swimming -- they are the largest animals that swim by means of cilia . 
some authors combined ctenophores and cnidarians in one phylum , coelenterata , as both groups rely on water flow through the body cavity for both digestion and respiration . 
adults of various species range from a few millimeters to 1.5 m -lrb- 4 ft 11 in -rrb- in size . 
their most distinctive feature is the ` combs ' -- groups of cilia which they use for swimming -- they are the largest animals that swim by means of cilia . 
ctenophora -lrb- / tᵻˈnɒfərə / ; singular ctenophore , / ˈtɛnəfɔːr / or / ˈtiːnəfɔːr / ; from the greek κτείς kteis ` comb ' and φέρω pherō ` carry ' ; commonly known as comb jellies -rrb- is a phylum of animals that live in marine waters worldwide . 
adults of various species range from a few millimeters to 1.5 m -lrb- 4 ft 11 in -rrb- in size . 
some authors combined ctenophores and cnidarians in one phylum , coelenterata , as both groups rely on water flow through the body cavity for both digestion and respiration . 
ctenophora -lrb- / tᵻˈnɒfərə / ; singular ctenophore , / ˈtɛnəfɔːr / or / ˈtiːnəfɔːr / ; from the greek κτείς kteis ` comb ' and φέρω pherō ` carry ' ; commonly known as comb jellies -rrb- is a phylum of animals that live in marine waters worldwide . 
ctenophora -lrb- / tᵻˈnɒfərə / ; singular ctenophore , / ˈtɛnəfɔːr / or / ˈtiːnəfɔːr / ; from the greek κτείς kteis ` comb ' and φέρω pherō ` carry ' ; commonly known as comb jellies -rrb- is a phylum of animals that live in marine waters worldwide . 
in favorable circumstances , ctenophores can eat ten times their own weight in a day . 
only 100 -- 150 species have been validated , and possibly another 25 have not been fully described and named . 
only 100 -- 150 species have been validated , and possibly another 25 have not been fully described and named . 
only 100 -- 150 species have been validated , and possibly another 25 have not been fully described and named . 
the textbook examples are cydippids with egg-shaped bodies and a pair of retractable tentacles fringed with tentilla -lrb- `` little tentacles '' -rrb- that are covered with colloblasts , sticky cells that capture prey . 
in favorable circumstances , ctenophores can eat ten times their own weight in a day . 
the phylum has a wide range of body forms , including the flattened , deep-sea platyctenids , in which the adults of most species lack combs , and the coastal beroids , which lack tentacles and prey on other ctenophores by using huge mouths armed with groups of large , stiffened cilia that act as teeth . 
the phylum has a wide range of body forms , including the flattened , deep-sea platyctenids , in which the adults of most species lack combs , and the coastal beroids , which lack tentacles and prey on other ctenophores by using huge mouths armed with groups of large , stiffened cilia that act as teeth . 
in favorable circumstances , ctenophores can eat ten times their own weight in a day . 
the textbook examples are cydippids with egg-shaped bodies and a pair of retractable tentacles fringed with tentilla -lrb- `` little tentacles '' -rrb- that are covered with colloblasts , sticky cells that capture prey . 
the phylum has a wide range of body forms , including the flattened , deep-sea platyctenids , in which the adults of most species lack combs , and the coastal beroids , which lack tentacles and prey on other ctenophores by using huge mouths armed with groups of large , stiffened cilia that act as teeth . 
the textbook examples are cydippids with egg-shaped bodies and a pair of retractable tentacles fringed with tentilla -lrb- `` little tentacles '' -rrb- that are covered with colloblasts , sticky cells that capture prey . 
only 100 -- 150 species have been validated , and possibly another 25 have not been fully described and named . 
most species are hermaphrodites -- a single animal can produce both eggs and sperm , meaning it can fertilize its own egg , not needing a mate . 
the young are generally planktonic and in most species look like miniature cydippids , gradually changing into their adult shapes as they grow . 
in at least some species , juveniles are capable of reproduction before reaching the adult size and shape . 
most species are hermaphrodites -- a single animal can produce both eggs and sperm , meaning it can fertilize its own egg , not needing a mate . 
some are simultaneous hermaphrodites , which can produce both eggs and sperm at the same time . 
others are sequential hermaphrodites , in which the eggs and sperm mature at different times . 
fertilization is generally external , although platyctenids ' eggs are fertilized inside their parents ' bodies and kept there until they hatch . 
the combination of hermaphroditism and early reproduction enables small populations to grow at an explosive rate . 
most species are hermaphrodites -- a single animal can produce both eggs and sperm , meaning it can fertilize its own egg , not needing a mate . 
some are simultaneous hermaphrodites , which can produce both eggs and sperm at the same time . 
others are sequential hermaphrodites , in which the eggs and sperm mature at different times . 
fertilization is generally external , although platyctenids ' eggs are fertilized inside their parents ' bodies and kept there until they hatch . 
the exceptions are the beroids , whose young are miniature beroids with large mouths and no tentacles , and the platyctenids , whose young live as cydippid-like plankton until they reach near-adult size , but then sink to the bottom and rapidly metamorphose into the adult form . 
one ctenophore , mnemiopsis , has accidentally been introduced into the black sea , where it is blamed for causing fish stocks to collapse by eating both fish larvae and organisms that would otherwise have fed the fish . 
one ctenophore , mnemiopsis , has accidentally been introduced into the black sea , where it is blamed for causing fish stocks to collapse by eating both fish larvae and organisms that would otherwise have fed the fish . 
the situation was aggravated by other factors , such as over-fishing and long-term environmental changes that promoted the growth of the mnemiopsis population . 
the later accidental introduction of beroe helped to mitigate the problem , as beroe preys on other ctenophores . 
one ctenophore , mnemiopsis , has accidentally been introduced into the black sea , where it is blamed for causing fish stocks to collapse by eating both fish larvae and organisms that would otherwise have fed the fish . 
one ctenophore , mnemiopsis , has accidentally been introduced into the black sea , where it is blamed for causing fish stocks to collapse by eating both fish larvae and organisms that would otherwise have fed the fish . 
in bays where they occur in very high numbers , predation by ctenophores may control the populations of small zooplanktonic organisms such as copepods , which might otherwise wipe out the phytoplankton -lrb- planktonic plants -rrb- , which are a vital part of marine food chains . 
in bays where they occur in very high numbers , predation by ctenophores may control the populations of small zooplanktonic organisms such as copepods , which might otherwise wipe out the phytoplankton -lrb- planktonic plants -rrb- , which are a vital part of marine food chains . 
in bays where they occur in very high numbers , predation by ctenophores may control the populations of small zooplanktonic organisms such as copepods , which might otherwise wipe out the phytoplankton -lrb- planktonic plants -rrb- , which are a vital part of marine food chains . 
one ctenophore , mnemiopsis , has accidentally been introduced into the black sea , where it is blamed for causing fish stocks to collapse by eating both fish larvae and organisms that would otherwise have fed the fish . 
one ctenophore , mnemiopsis , has accidentally been introduced into the black sea , where it is blamed for causing fish stocks to collapse by eating both fish larvae and organisms that would otherwise have fed the fish . 
the later accidental introduction of beroe helped to mitigate the problem , as beroe preys on other ctenophores . 
a recent molecular phylogenetics analysis concluded that the common ancestor of all modern ctenophores was cydippid-like , and that all the modern groups appeared relatively recently , probably after the cretaceous -- paleogene extinction event 66 million years ago . 
evidence accumulating since the 1980s indicates that the `` cydippids '' are not monophyletic , in other words do not include all and only the descendants of a single common ancestor , because all the other traditional ctenophore groups are descendants of various cydippids . 
despite their soft , gelatinous bodies , fossils thought to represent ctenophores , apparently with no tentacles but many more comb-rows than modern forms , have been found in lagerstätten as far back as the early cambrian , about 515 million years ago . 
despite their soft , gelatinous bodies , fossils thought to represent ctenophores , apparently with no tentacles but many more comb-rows than modern forms , have been found in lagerstätten as far back as the early cambrian , about 515 million years ago . 
despite their soft , gelatinous bodies , fossils thought to represent ctenophores , apparently with no tentacles but many more comb-rows than modern forms , have been found in lagerstätten as far back as the early cambrian , about 515 million years ago . 
a recent molecular phylogenetics analysis concluded that the common ancestor of all modern ctenophores was cydippid-like , and that all the modern groups appeared relatively recently , probably after the cretaceous -- paleogene extinction event 66 million years ago . 
evidence accumulating since the 1980s indicates that the `` cydippids '' are not monophyletic , in other words do not include all and only the descendants of a single common ancestor , because all the other traditional ctenophore groups are descendants of various cydippids . 
despite their soft , gelatinous bodies , fossils thought to represent ctenophores , apparently with no tentacles but many more comb-rows than modern forms , have been found in lagerstätten as far back as the early cambrian , about 515 million years ago . 
ctenophores form an animal phylum that is more complex than sponges , about as complex as cnidarians -lrb- jellyfish , sea anemones , etc. -rrb- , and less complex than bilaterians -lrb- which include almost all other animals -rrb- . 
ctenophores are distinguished from all other animals by having colloblasts , which are sticky and adhere to prey , although a few ctenophore species lack them . 
ctenophores form an animal phylum that is more complex than sponges , about as complex as cnidarians -lrb- jellyfish , sea anemones , etc. -rrb- , and less complex than bilaterians -lrb- which include almost all other animals -rrb- . 
ctenophores form an animal phylum that is more complex than sponges , about as complex as cnidarians -lrb- jellyfish , sea anemones , etc. -rrb- , and less complex than bilaterians -lrb- which include almost all other animals -rrb- . 
ctenophores are distinguished from all other animals by having colloblasts , which are sticky and adhere to prey , although a few ctenophore species lack them . 
ctenophores form an animal phylum that is more complex than sponges , about as complex as cnidarians -lrb- jellyfish , sea anemones , etc. -rrb- , and less complex than bilaterians -lrb- which include almost all other animals -rrb- . 
ctenophores are distinguished from all other animals by having colloblasts , which are sticky and adhere to prey , although a few ctenophore species lack them . 
ctenophores are distinguished from all other animals by having colloblasts , which are sticky and adhere to prey , although a few ctenophore species lack them . 
unlike sponges , both ctenophores and cnidarians have : cells bound by inter-cell connections and carpet-like basement membranes ; muscles ; nervous systems ; and some have sensory organs . 
ctenophores form an animal phylum that is more complex than sponges , about as complex as cnidarians -lrb- jellyfish , sea anemones , etc. -rrb- , and less complex than bilaterians -lrb- which include almost all other animals -rrb- . 
like sponges and cnidarians , ctenophores have two main layers of cells that sandwich a middle layer of jelly-like material , which is called the mesoglea in cnidarians and ctenophores ; more complex animals have three main cell layers and no intermediate jelly-like layer . 
hence ctenophores and cnidarians have traditionally been labelled diploblastic , along with sponges . 
like sponges and cnidarians , ctenophores have two main layers of cells that sandwich a middle layer of jelly-like material , which is called the mesoglea in cnidarians and ctenophores ; more complex animals have three main cell layers and no intermediate jelly-like layer . 
hence ctenophores and cnidarians have traditionally been labelled diploblastic , along with sponges . 
ranging from about 1 millimeter -lrb- 0.039 in -rrb- to 1.5 meters -lrb- 4.9 ft -rrb- in size , ctenophores are the largest non-colonial animals that use cilia -lrb- `` hairs '' -rrb- as their main method of locomotion . 
ranging from about 1 millimeter -lrb- 0.039 in -rrb- to 1.5 meters -lrb- 4.9 ft -rrb- in size , ctenophores are the largest non-colonial animals that use cilia -lrb- `` hairs '' -rrb- as their main method of locomotion . 
most species have eight strips , called comb rows , that run the length of their bodies and bear comb-like bands of cilia , called `` ctenes , '' stacked along the comb rows so that when the cilia beat , those of each comb touch the comb below . 
the name `` ctenophora '' means `` comb-bearing '' , from the greek κτείς -lrb- stem-form κτεν - -rrb- meaning `` comb '' and the greek suffix - φορος meaning `` carrying '' . 
at least two textbooks base their descriptions of ctenophores on the cydippid pleurobrachia . 
coastal species need to be tough enough to withstand waves and swirling sediment particles , while some oceanic species are so fragile that it is very difficult to capture them intact for study . 
coastal species need to be tough enough to withstand waves and swirling sediment particles , while some oceanic species are so fragile that it is very difficult to capture them intact for study . 
hence most attention has until recently concentrated on three coastal genera -- pleurobrachia , beroe and mnemiopsis . 
the inner surface of the cavity is lined with an epithelium , the gastrodermis . 
the nearer side is composed of tall nutritive cells that store nutrients in vacuoles -lrb- internal compartments -rrb- , germ cells that produce eggs or sperm , and photocytes that produce bioluminescence . 
the internal cavity forms : a mouth that can usually be closed by muscles ; a pharynx -lrb- `` throat '' -rrb- ; a wider area in the center that acts as a stomach ; and a system of internal canals . 
the internal cavity forms : a mouth that can usually be closed by muscles ; a pharynx -lrb- `` throat '' -rrb- ; a wider area in the center that acts as a stomach ; and a system of internal canals . 
these branch through the mesoglea to the most active parts of the animal : the mouth and pharynx ; the roots of the tentacles , if present ; all along the underside of each comb row ; and four branches round the sensory complex at the far end from the mouth -- two of these four branches terminate in anal pores . 
the outer surface bears usually eight comb rows , called swimming-plates , which are used for swimming . 
the `` combs '' -lrb- also called `` ctenes '' or `` comb plates '' -rrb- run across each row , and each consists of thousands of unusually long cilia , up to 2 millimeters -lrb- 0.079 in -rrb- . 
unlike conventional cilia and flagella , which has a filament structure arranged in a 9 + 2 pattern , these cilia are arranged in a 9 + 3 pattern , where the extra compact filament is suspected to have a supporting function . 
hence ctenophores usually swim in the direction in which the mouth is pointing , unlike jellyfish . 
the `` combs '' -lrb- also called `` ctenes '' or `` comb plates '' -rrb- run across each row , and each consists of thousands of unusually long cilia , up to 2 millimeters -lrb- 0.079 in -rrb- . 
it is uncertain how ctenophores control their buoyancy , but experiments have shown that some species rely on osmotic pressure to adapt to water of different densities . 
if they enter less dense brackish water , the ciliary rosettes in the body cavity may pump this into the mesoglea to increase its bulk and decrease its density , to avoid sinking . 
if they enter less dense brackish water , the ciliary rosettes in the body cavity may pump this into the mesoglea to increase its bulk and decrease its density , to avoid sinking . 
conversely if they move from brackish to full-strength seawater , the rosettes may pump water out of the mesoglea to reduce its volume and increase its density . 
the largest single sensory feature is the aboral organ -lrb- at the opposite end from the mouth -rrb- . 
the largest single sensory feature is the aboral organ -lrb- at the opposite end from the mouth -rrb- . 
the statocyst is protected by a transparent dome made of long , immobile cilia . 
its main component is a statocyst , a balance sensor consisting of a statolith , a solid particle supported on four bundles of cilia , called `` balancers '' , that sense its orientation . 
its main component is a statocyst , a balance sensor consisting of a statolith , a solid particle supported on four bundles of cilia , called `` balancers '' , that sense its orientation . 
cydippid ctenophores have bodies that are more or less rounded , sometimes nearly spherical and other times more cylindrical or egg-shaped ; the common coastal `` sea gooseberry , '' pleurobrachia , sometimes has an egg-shaped body with the mouth at the narrow end , although some individuals are more uniformly round . 
from opposite sides of the body extends a pair of long , slender tentacles , each housed in a sheath into which it can be withdrawn . 
cydippid ctenophores have bodies that are more or less rounded , sometimes nearly spherical and other times more cylindrical or egg-shaped ; the common coastal `` sea gooseberry , '' pleurobrachia , sometimes has an egg-shaped body with the mouth at the narrow end , although some individuals are more uniformly round . 
from opposite sides of the body extends a pair of long , slender tentacles , each housed in a sheath into which it can be withdrawn . 
cydippid ctenophores have bodies that are more or less rounded , sometimes nearly spherical and other times more cylindrical or egg-shaped ; the common coastal `` sea gooseberry , '' pleurobrachia , sometimes has an egg-shaped body with the mouth at the narrow end , although some individuals are more uniformly round . 
the tentacles of cydippid ctenophores are typically fringed with tentilla -lrb- `` little tentacles '' -rrb- , although a few genera have simple tentacles without these sidebranches . 
colloblasts are specialized mushroom-shaped cells in the outer layer of the epidermis , and have three main components : a domed head with vesicles -lrb- chambers -rrb- that contain adhesive ; a stalk that anchors the cell in the lower layer of the epidermis or in the mesoglea ; and a spiral thread that coils round the stalk and is attached to the head and to the root of the stalk . 
the tentilla of euplokamis differ significantly from those of other cydippids : they contain striated muscle , a cell type otherwise unknown in the phylum ctenophora ; and they are coiled when relaxed , while the tentilla of all other known ctenophores elongate when relaxed . 
euplokamis ' tentilla have three types of movement that are used in capturing prey : they may flick out very quickly -lrb- in 40 to 60 milliseconds -rrb- ; they can wriggle , which may lure prey by behaving like small planktonic worms ; and they coil round prey . 
euplokamis ' tentilla have three types of movement that are used in capturing prey : they may flick out very quickly -lrb- in 40 to 60 milliseconds -rrb- ; they can wriggle , which may lure prey by behaving like small planktonic worms ; and they coil round prey . 
there are eight rows of combs that run from near the mouth to the opposite end , and are spaced evenly round the body . 
there are eight rows of combs that run from near the mouth to the opposite end , and are spaced evenly round the body . 
there are eight rows of combs that run from near the mouth to the opposite end , and are spaced evenly round the body . 
from each balancer in the statocyst a ciliary groove runs out under the dome and then splits to connect with two adjacent comb rows , and in some species runs all the way along the comb rows . 
the lobata have a pair of lobes , which are muscular , cuplike extensions of the body that project beyond the mouth . 
between the lobes on either side of the mouth , many species of lobates have four auricles , gelatinous projections edged with cilia that produce water currents that help direct microscopic prey toward the mouth . 
between the lobes on either side of the mouth , many species of lobates have four auricles , gelatinous projections edged with cilia that produce water currents that help direct microscopic prey toward the mouth . 
between the lobes on either side of the mouth , many species of lobates have four auricles , gelatinous projections edged with cilia that produce water currents that help direct microscopic prey toward the mouth . 
this combination of structures enables lobates to feed continuously on suspended planktonic prey . 
members of the lobate genera bathocyroe and ocyropsis can escape from danger by clapping their lobes , so that the jet of expelled water drives them backwards very quickly . 
members of the lobate genera bathocyroe and ocyropsis can escape from danger by clapping their lobes , so that the jet of expelled water drives them backwards very quickly . 
unlike cydippids , the movements of lobates ' combs are coordinated by nerves rather than by water disturbances created by the cilia , yet combs on the same row beat in the same mexican wave style as the mechanically coordinated comb rows of cydippids and beroids . 
unlike cydippids , the movements of lobates ' combs are coordinated by nerves rather than by water disturbances created by the cilia , yet combs on the same row beat in the same mexican wave style as the mechanically coordinated comb rows of cydippids and beroids . 
the beroida , also known as nuda , have no feeding appendages , but their large pharynx , just inside the large mouth and filling most of the saclike body , bears `` macrocilia '' at the oral end . 
the beroida , also known as nuda , have no feeding appendages , but their large pharynx , just inside the large mouth and filling most of the saclike body , bears `` macrocilia '' at the oral end . 
in front of the field of macrocilia , on the mouth `` lips '' in some species of beroe , is a pair of narrow strips of adhesive epithelial cells on the stomach wall that `` zip '' the mouth shut when the animal is not feeding , by forming intercellular connections with the opposite adhesive strip . 
in front of the field of macrocilia , on the mouth `` lips '' in some species of beroe , is a pair of narrow strips of adhesive epithelial cells on the stomach wall that `` zip '' the mouth shut when the animal is not feeding , by forming intercellular connections with the opposite adhesive strip . 
the beroida , also known as nuda , have no feeding appendages , but their large pharynx , just inside the large mouth and filling most of the saclike body , bears `` macrocilia '' at the oral end . 
the cestida -lrb- `` belt animals '' -rrb- are ribbon-shaped planktonic animals , with the mouth and aboral organ aligned in the middle of opposite edges of the ribbon . 
there are two known species , with worldwide distribution in warm , and warm-temperate waters : cestum veneris -lrb- `` venus ' girdle '' -rrb- is among the largest ctenophores -- up to 1.5 meters -lrb- 4.9 ft -rrb- long , and can undulate slowly or quite rapidly . 
the cestida -lrb- `` belt animals '' -rrb- are ribbon-shaped planktonic animals , with the mouth and aboral organ aligned in the middle of opposite edges of the ribbon . 
cestids can swim by undulating their bodies as well as by the beating of their comb-rows . 
velamen parallelum , which is typically less than 20 centimeters -lrb- 0.66 ft -rrb- long , can move much faster in what has been described as a `` darting motion '' . 
most platyctenida have oval bodies that are flattened in the oral-aboral direction , with a pair of tentilla-bearing tentacles on the aboral surface . 
they cling to and creep on surfaces by everting the pharynx and using it as a muscular `` foot '' . 
all but one of the known platyctenid species lack comb-rows . 
platyctenids are usually cryptically colored , live on rocks , algae , or the body surfaces of other invertebrates , and are often revealed by their long tentacles with many sidebranches , seen streaming off the back of the ctenophore into the current . 
the gonads are located in the parts of the internal canal network under the comb rows , and eggs and sperm are released via pores in the epidermis . 
fertilization is external in most species , but platyctenids use internal fertilization and keep the eggs in brood chambers until they hatch . 
self-fertilization has occasionally been seen in species of the genus mnemiopsis , and it is thought that most of the hermaphroditic species are self-fertile . 
the gonads are located in the parts of the internal canal network under the comb rows , and eggs and sperm are released via pores in the epidermis . 
fertilization is external in most species , but platyctenids use internal fertilization and keep the eggs in brood chambers until they hatch . 
in the genus beroe the juveniles , like the adults , lack tentacles and tentacle sheaths . 
in some groups , such as the flat , bottom-dwelling platyctenids , the juveniles behave more like true larvae , as they live among the plankton and thus occupy a different ecological niche from their parents and attain the adult form by a more radical metamorphosis , after dropping to the sea-floor . 
in some groups , such as the flat , bottom-dwelling platyctenids , the juveniles behave more like true larvae , as they live among the plankton and thus occupy a different ecological niche from their parents and attain the adult form by a more radical metamorphosis , after dropping to the sea-floor . 
in some groups , such as the flat , bottom-dwelling platyctenids , the juveniles behave more like true larvae , as they live among the plankton and thus occupy a different ecological niche from their parents and attain the adult form by a more radical metamorphosis , after dropping to the sea-floor . 
in the genus beroe the juveniles , like the adults , lack tentacles and tentacle sheaths . 
when some species , including bathyctena chuni , euplokamis stationis and eurhamphaea vexilligera , are disturbed , they produce secretions -lrb- ink -rrb- that luminesce at much the same wavelengths as their bodies . 
when some species , including bathyctena chuni , euplokamis stationis and eurhamphaea vexilligera , are disturbed , they produce secretions -lrb- ink -rrb- that luminesce at much the same wavelengths as their bodies . 
when some species , including bathyctena chuni , euplokamis stationis and eurhamphaea vexilligera , are disturbed , they produce secretions -lrb- ink -rrb- that luminesce at much the same wavelengths as their bodies . 
juveniles will luminesce more brightly in relation to their body size than adults , whose luminescence is diffused over their bodies . 
almost all ctenophores are predators -- there are no vegetarians and only one genus that is partly parasitic . 
members of the genus haeckelia prey on jellyfish and incorporate their prey 's nematocysts -lrb- stinging cells -rrb- into their own tentacles instead of colloblasts . 
members of the genus haeckelia prey on jellyfish and incorporate their prey 's nematocysts -lrb- stinging cells -rrb- into their own tentacles instead of colloblasts . 
members of the cydippid genus pleurobrachia and the lobate bolinopsis often reach high population densities at the same place and time because they specialize in different types of prey : pleurobrachia 's long tentacles mainly capture relatively strong swimmers such as adult copepods , while bolinopsis generally feeds on smaller , weaker swimmers such as rotifers and mollusc and crustacean larvae . 
the two-tentacled `` cydippid '' lampea feeds exclusively on salps , close relatives of sea-squirts that form large chain-like floating colonies , and juveniles of lampea attach themselves like parasites to salps that are too large for them to swallow . 
ctenophores used to be regarded as `` dead ends '' in marine food chains because it was thought their low ratio of organic matter to salt and water made them a poor diet for other animals . 
detailed investigation of chum salmon , oncorhynchus keta , showed that these fish digest ctenophores 20 times as fast as an equal weight of shrimps , and that ctenophores can provide a good diet if there are enough of them around . 
beroids prey mainly on other ctenophores . 
this is underlined by an observation of herbivorous fishes deliberately feeding on gelatinous zooplankton during blooms in the red sea . 
some jellyfish and turtles eat large quantities of ctenophores , and jellyfish may temporarily wipe out ctenophore populations . 
on the other hand , in the late 1980s the western atlantic ctenophore mnemiopsis leidyi was accidentally introduced into the black sea and sea of azov via the ballast tanks of ships , and has been blamed for causing sharp drops in fish catches by eating both fish larvae and small crustaceans that would otherwise feed the adult fish . 
on the other hand , in the late 1980s the western atlantic ctenophore mnemiopsis leidyi was accidentally introduced into the black sea and sea of azov via the ballast tanks of ships , and has been blamed for causing sharp drops in fish catches by eating both fish larvae and small crustaceans that would otherwise feed the adult fish . 
mnemiopsis populations in those areas were eventually brought under control by the accidental introduction of the mnemiopsis-eating north american ctenophore beroe ovata , and by a cooling of the local climate from 1991 to 1993 , which significantly slowed the animal 's metabolism . 
on the other hand , in the late 1980s the western atlantic ctenophore mnemiopsis leidyi was accidentally introduced into the black sea and sea of azov via the ballast tanks of ships , and has been blamed for causing sharp drops in fish catches by eating both fish larvae and small crustaceans that would otherwise feed the adult fish . 
mnemiopsis populations in those areas were eventually brought under control by the accidental introduction of the mnemiopsis-eating north american ctenophore beroe ovata , and by a cooling of the local climate from 1991 to 1993 , which significantly slowed the animal 's metabolism . 
because of their soft , gelatinous bodies , ctenophores are extremely rare as fossils , and fossils that have been interpreted as ctenophores have been found only in lagerstätten , places where the environment was exceptionally suited to preservation of soft tissue . 
the ediacaran eoandromeda could putatively represent a comb jelly . 
three additional putative species were then found in the burgess shale and other canadian rocks of similar age , about 505 million years ago in the mid-cambrian period . 
three additional putative species were then found in the burgess shale and other canadian rocks of similar age , about 505 million years ago in the mid-cambrian period . 
all three apparently lacked tentacles but had between 24 and 80 comb rows , far more than the 8 typical of living species . 
the early cambrian sessile frond-like fossil stromatoveris , from china 's chengjiang lagerstätte and dated to about 515 million years ago , is very similar to vendobionta of the preceding ediacaran period . 
the early cambrian sessile frond-like fossil stromatoveris , from china 's chengjiang lagerstätte and dated to about 515 million years ago , is very similar to vendobionta of the preceding ediacaran period . 
they suggested that stromatoveris was an evolutionary `` aunt '' of ctenophores , and that ctenophores originated from sessile animals whose descendants became swimmers and changed the cilia from a feeding mechanism to a propulsion system . 
the early cambrian sessile frond-like fossil stromatoveris , from china 's chengjiang lagerstätte and dated to about 515 million years ago , is very similar to vendobionta of the preceding ediacaran period . 
the early cambrian sessile frond-like fossil stromatoveris , from china 's chengjiang lagerstätte and dated to about 515 million years ago , is very similar to vendobionta of the preceding ediacaran period . 
several more recent studies comparing complete sequenced genomes of ctenophores with other sequenced animal genomes have also supported ctenophores as the sister lineage to all other animals . 
however , other researchers have argued that the placement of ctenophora as sister to all other animals is a statistical anomaly caused by the high rate of evolution in ctenophore genomes , and that porifera -lrb- sponges -rrb- is the earliest-diverging animal phylum instead . 
since all modern ctenophores except the beroids have cydippid-like larvae , it has widely been assumed that their last common ancestor also resembled cydippids , having an egg-shaped body and a pair of retractable tentacles . 
a molecular phylogeny analysis in 2001 , using 26 species , including 4 recently discovered ones , confirmed that the cydippids are not monophyletic and concluded that the last common ancestor of modern ctenophores was cydippid-like . 
this suggests that the last common ancestor of modern ctenophores was relatively recent , and perhaps was lucky enough to survive the cretaceous -- paleogene extinction event 65.5 million years ago while other lineages perished . 
richard harbison 's purely morphological analysis in 1985 concluded that the cydippids are not monophyletic , in other words do not contain all and only the descendants of a single common ancestor that was itself a cydippid . 
fresno -lrb- / ˈfrɛznoʊ / frez-noh -rrb- , the county seat of fresno county , is a city in the u.s. state of california . 
it is approximately 220 miles -lrb- 350 km -rrb- northwest of los angeles , 170 miles -lrb- 270 km -rrb- south of the state capital , sacramento , or 185 miles -lrb- 300 km -rrb- south of san francisco . 
the name fresno means `` ash tree '' in spanish , and an ash leaf is featured on the city 's flag . 
the name fresno means `` ash tree '' in spanish , and an ash leaf is featured on the city 's flag . 
fresno -lrb- / ˈfrɛznoʊ / frez-noh -rrb- , the county seat of fresno county , is a city in the u.s. state of california . 
in 1872 , the central pacific railroad established a station near easterby 's -- by now a hugely productive wheat farm -- for its new southern pacific line . 
many millerton residents , drawn by the convenience of the railroad and worried about flooding , moved to the new community . 
fresno became an incorporated city in 1885 . 
by 1931 the fresno traction company operated 47 streetcars over 49 miles of track . 
soon there was a store around the station and the store grew the town of fresno station , later called fresno . 
in 1940 , the census bureau reported fresno 's population as 94.0 % white , 3.3 % black and 2.7 % asian . 
-lrb- incongruously , chinatown was primarily a japanese neighborhood and today japanese-american businesses still remain -rrb- . 
during 1942 , pinedale , in what is now north fresno , was the site of the pinedale assembly center , an interim facility for the relocation of fresno area japanese americans to internment camps . 
during 1942 , pinedale , in what is now north fresno , was the site of the pinedale assembly center , an interim facility for the relocation of fresno area japanese americans to internment camps . 
the fresno fairgrounds was also utilized as an assembly center . 
in september 1958 , bank of america launched a new product called bankamericard in fresno . 
in september 1958 , bank of america launched a new product called bankamericard in fresno . 
after a troubled gestation during which its creator resigned , bankamericard went on to become the first successful credit card ; that is , a financial instrument that was usable across a large number of merchants and also allowed cardholders to revolve a balance -lrb- earlier financial products could do one or the other but not both -rrb- . 
in 1976 , bankamericard was renamed and spun off into a separate company known today as visa inc. . 
in 1976 , bankamericard was renamed and spun off into a separate company known today as visa inc. . 
in the 1970s , the city was the subject of a song , `` walking into fresno '' , written by hall of fame guitarist bill aken and recorded by bob gallion of the world-famous `` wwva jamboree '' radio and television show in wheeling , west virginia . 
in the 1970s , the city was the subject of a song , `` walking into fresno '' , written by hall of fame guitarist bill aken and recorded by bob gallion of the world-famous `` wwva jamboree '' radio and television show in wheeling , west virginia . 
aken , adopted by mexican movie actress lupe mayorga , grew up in the neighboring town of madera and his song chronicled the hardships faced by the migrant farm workers he saw as a child . 
aken also made his first tv appearance playing guitar on the old country-western show at the fresno barn . 
aken , adopted by mexican movie actress lupe mayorga , grew up in the neighboring town of madera and his song chronicled the hardships faced by the migrant farm workers he saw as a child . 
fresno has three large public parks , two in the city limits and one in county land to the southwest . 
roeding park , near downtown fresno , is home to the fresno chaffee zoo , and rotary storyland and playland . 
kearney park is the largest of the fresno region 's park system and is home to historic kearney mansion and plays host to the annual civil war revisited , the largest reenactment of the civil war in the west coast of the u.s. 
woodward park , which features the shinzen japanese gardens , numerous picnic areas and several miles of trails , is in north fresno and is adjacent to the san joaquin river parkway . 
kearney park is the largest of the fresno region 's park system and is home to historic kearney mansion and plays host to the annual civil war revisited , the largest reenactment of the civil war in the west coast of the u.s. 
between the 1880s and world war ii , downtown fresno flourished , filled with electric street cars , and contained some of the san joaquin valley 's most beautiful architectural buildings . 
among them , the original fresno county courthouse -lrb- demolished -rrb- , the fresno carnegie public library -lrb- demolished -rrb- , the fresno water tower , the bank of italy building , the pacific southwest building , the san joaquin light & power building -lrb- currently known as the grand 1401 -rrb- , and the hughes hotel -lrb- burned down -rrb- , to name a few . 
among them , the original fresno county courthouse -lrb- demolished -rrb- , the fresno carnegie public library -lrb- demolished -rrb- , the fresno water tower , the bank of italy building , the pacific southwest building , the san joaquin light & power building -lrb- currently known as the grand 1401 -rrb- , and the hughes hotel -lrb- burned down -rrb- , to name a few . 
among them , the original fresno county courthouse -lrb- demolished -rrb- , the fresno carnegie public library -lrb- demolished -rrb- , the fresno water tower , the bank of italy building , the pacific southwest building , the san joaquin light & power building -lrb- currently known as the grand 1401 -rrb- , and the hughes hotel -lrb- burned down -rrb- , to name a few . 
fulton street in downtown fresno was fresno 's main financial and commercial district before being converted into one of the nation 's first pedestrian malls in 1964 . 
renamed the fulton mall , the area contains the densest collection of historic buildings in fresno . 
while the fulton mall corridor has suffered a sharp decline from its heyday , the mall includes some of the finest public art pieces in the country , including the only pierre-auguste renoir piece in the world that one can walk up to and touch . 
the public art pieces will be restored and placed near their current locations and will feature wide sidewalks -lrb- up to 28 ' on the east side of the street -rrb- to continue with the pedestrian friendly environment of the district . 
the public art pieces will be restored and placed near their current locations and will feature wide sidewalks -lrb- up to 28 ' on the east side of the street -rrb- to continue with the pedestrian friendly environment of the district . 
the neighborhood of sunnyside is on fresno 's far southeast side , bounded by chestnut avenue to the west . 
its major thoroughfares are kings canyon avenue and clovis avenue . 
largely developed in the 1950s through the 1970s , it has recently experienced a surge in new home construction . 
it is also the home of the sunnyside country club , which maintains a golf course designed by william p. bell . 
it is also the home of the sunnyside country club , which maintains a golf course designed by william p. bell . 
the popular neighborhood known as the tower district is centered around the historic tower theatre , which is included on the national list of historic places . 
the theater was built in 1939 and is at olive and wishon avenues in the heart of the tower district . 
-lrb- the name of the theater refers to a well-known landmark water tower , which is actually in another nearby area -rrb- . 
to some extent , the businesses of the tower district were developed due to the proximity of the original fresno normal school , -lrb- later renamed california state university at fresno -rrb- . 
in 1916 the college moved to what is now the site of fresno city college one-half mile north of the tower district . 
-lsb- citation needed -rsb- after decades of neglect and suburban flight , the neighborhood revival followed the re-opening of the tower theatre in the late 1970s , which at that time showed second and third run movies , along with classic films . 
-lsb- citation needed -rsb- after decades of neglect and suburban flight , the neighborhood revival followed the re-opening of the tower theatre in the late 1970s , which at that time showed second and third run movies , along with classic films . 
roger rocka 's dinner theater & good company players also opened nearby in 1978 , -lsb- citation needed -rsb- at olive and wishon avenues . 
fresno native audra mcdonald performed in the leading roles of evita and the wiz at the theater while she was a high school student . 
fresno native audra mcdonald performed in the leading roles of evita and the wiz at the theater while she was a high school student . 
the neighborhood features restaurants , live theater and nightclubs , as well as several independent shops and bookstores , currently operating on or near olive avenue , and all within a few hundred feet of each other . 
the neighborhood features restaurants , live theater and nightclubs , as well as several independent shops and bookstores , currently operating on or near olive avenue , and all within a few hundred feet of each other . 
since renewal , the tower district has become an attractive area for restaurant and other local businesses . 
today , the tower district is also known as the center of fresno 's lgbt and hipster communities. ; additionally , tower district is also known as the center of fresno 's local punk/goth/deathrock and heavy metal community . 
today , the tower district is also known as the center of fresno 's lgbt and hipster communities. ; additionally , tower district is also known as the center of fresno 's local punk/goth/deathrock and heavy metal community . 
the area is also known for its early twentieth century homes , many of which have been restored in recent decades . 
the area includes many california bungalow and american craftsman style homes , spanish colonial revival style architecture , mediterranean revival style architecture , mission revival style architecture , and many storybook houses designed by fresno architects , hilliard , taylor & wheeler . 
the residential architecture of the tower district contrasts with the newer areas of tract homes urban sprawl in north and east areas of fresno . 
the area is also known for its early twentieth century homes , many of which have been restored in recent decades . 
the section of huntington boulevard between first street on the west to cedar avenue on the east is the home to many large , stately homes . 
the alta vista tract , as the land would become known , was mapped by william stranahan for the pacific improvement corporation , and was officially platted in 1911 . 
in 1914 developers billings & meyering acquired the tract , completed street development , provided the last of the necessary municipal improvements including water service , and began marketing the property with fervor . 
a mere half decade later the tract had 267 homes . 
this rapid development was no doubt hastened by the fresno traction company right-of-way along huntington boulevard , which provided streetcar connections between downtown and the county hospital . 
the `` west side '' of fresno , also often called `` southwest fresno '' , is one of the oldest neighborhoods in the city . 
the neighborhood lies southwest of the 99 freeway -lrb- which divides it from downtown fresno -rrb- , west of the 41 freeway and south of nielsen ave -lrb- or the newly constructed 180 freeway -rrb- , and extends to the city limits to the west and south . 
the neighborhood is traditionally considered to be the center of fresno 's african-american community . 
it is culturally diverse and also includes significant mexican-american and asian-american -lrb- principally hmong or laotian -rrb- populations . 
the `` west side '' of fresno , also often called `` southwest fresno '' , is one of the oldest neighborhoods in the city . 
the neighborhood includes kearney boulevard , named after early 20th century entrepreneur and millionaire m. theo kearney , which extends from fresno street in southwest fresno about 20 mi -lrb- 32 km -rrb- west to kerman , california . 
a small , two-lane rural road for most of its length , kearney boulevard is lined with tall palm trees . 
the roughly half-mile stretch of kearney boulevard between fresno street and thorne ave was at one time the preferred neighborhood for fresno 's elite african-american families . 
another section , brookhaven , on the southern edge of the west side south of jensen and west of elm , was given the name by the fresno city council in an effort to revitalize the neighborhood 's image . 
the isolated subdivision was for years known as the `` dogg pound '' in reference to a local gang , and as of late 2008 was still known for high levels of violent crime . 
while many homes in the neighborhood date back to the 1930s or before , the neighborhood is also home to several public housing developments built between the 1960s and 1990s by the fresno housing authority . 
there have been numerous attempts to revitalize the neighborhood , including the construction of a modern shopping center on the corner of fresno and b streets , an aborted attempt to build luxury homes and a golf course on the western edge of the neighborhood , and some new section 8 apartments have been built along church ave west of elm st. cargill meat solutions and foster farms both have large processing facilities in the neighborhood , and the stench from these -lrb- and other small industrial facilities -rrb- has long plagued area residents . 
there have been numerous attempts to revitalize the neighborhood , including the construction of a modern shopping center on the corner of fresno and b streets , an aborted attempt to build luxury homes and a golf course on the western edge of the neighborhood , and some new section 8 apartments have been built along church ave west of elm st. cargill meat solutions and foster farms both have large processing facilities in the neighborhood , and the stench from these -lrb- and other small industrial facilities -rrb- has long plagued area residents . 
the fresno chandler executive airport is also on the west side . 
the neighborhood has very little retail activity , aside from the area near fresno street and state route 99 freeway -lrb- kearney palm shopping center , built in the late 1990s -rrb- and small corner markets scattered throughout . 
in the north eastern part of fresno , woodward park was founded by the late ralph woodward , a long-time fresno resident . 
the initial 235 acres -lrb- 0.95 km2 -rrb- , combined with additional acres acquired later by the city , brings the park to a sizable 300 acres -lrb- 1.2 km2 -rrb- . 
the park has a multi-use amphitheatre that seats up to 2,500 people , authentic japanese garden , fenced dog park , two-mile -lrb- 3 km -rrb- equestrian trail , exercise par course , three children 's playgrounds , a lake , 3 small ponds , 7 picnic areas and five miles -lrb- 8 km -rrb- of multipurpose trails that are part of the san joaquin river parkway 's lewis s. eaton trail . 
when complete , the lewis s. eaton trail system will cover 22 miles -lrb- 35 km -rrb- between highway 99 and friant dam . 
the park is open april through october , 6am to 10pm and november through march , 6am to 7pm . 
formed in 1946 , sierra sky park airport is a residential airport community born of a unique agreement in transportation law to allow personal aircraft and automobiles to share certain roads . 
developer william smilie created the nation 's first planned aviation community . 
sierra sky park was the first aviation community to be built -lsb- citation needed -rsb- and there are now numerous such communities across the united states and around the world . 
formed in 1946 , sierra sky park airport is a residential airport community born of a unique agreement in transportation law to allow personal aircraft and automobiles to share certain roads . 
sierra sky park was the first aviation community to be built -lsb- citation needed -rsb- and there are now numerous such communities across the united states and around the world . 
fresno is marked by a semi-arid climate -lrb- köppen bsh -rrb- , with mild , moist winters and hot and dry summers , thus displaying mediterranean characteristics . 
july is the warmest month , averaging 83.0 °f -lrb- 28.3 °c -rrb- ; normally , there are 32 days of 100 °f -lrb- 37.8 °c -rrb- + highs and 106 days of 90 °f -lrb- 32.2 °c -rrb- + highs , and in july and august , there are only three or four days where the high does not reach 90 °f -lrb- 32.2 °c -rrb- . 
average annual precipitation is around 11.5 inches -lrb- 292.1 mm -rrb- , which , by definition , would classify the area as a semidesert . 
most of the wind rose direction occurrences derive from the northwest , as winds are driven downward along the axis of the california central valley ; in december , january and february there is an increased presence of southeastern wind directions in the wind rose statistics . 
most of the wind rose direction occurrences derive from the northwest , as winds are driven downward along the axis of the california central valley ; in december , january and february there is an increased presence of southeastern wind directions in the wind rose statistics . 
the official record high temperature for fresno is 115 °f -lrb- 46.1 °c -rrb- , set on july 8 , 1905 , while the official record low is 17 °f -lrb- − 8 °c -rrb- , set on january 6 , 1913 . 
the official record high temperature for fresno is 115 °f -lrb- 46.1 °c -rrb- , set on july 8 , 1905 , while the official record low is 17 °f -lrb- − 8 °c -rrb- , set on january 6 , 1913 . 
the most rainfall in one month was 9.54 inches -lrb- 242.3 mm -rrb- in november 1885 and the most rainfall in 24 hours 3.55 inches -lrb- 90.2 mm -rrb- on november 18 , 1885 . 
snow is a rarity ; the heaviest snowfall at the airport was 2.2 inches -lrb- 0.06 m -rrb- on january 21 , 1962 . 
the most rainfall in one month was 9.54 inches -lrb- 242.3 mm -rrb- in november 1885 and the most rainfall in 24 hours 3.55 inches -lrb- 90.2 mm -rrb- on november 18 , 1885 . 
the 2010 united states census reported that fresno had a population of 494,665 . 
the racial makeup of fresno was 245,306 -lrb- 49.6 % -rrb- white , 40,960 -lrb- 8.3 % -rrb- african american , 8,525 -lrb- 1.7 % -rrb- native american , 62,528 -lrb- 12.6 % -rrb- asian -lrb- 3.6 % hmong , 1.7 % indian , 1.2 % filipino , 1.2 % laotian , 1.0 % thai , 0.8 % cambodian , 0.7 % chinese , 0.5 % japanese , 0.4 % vietnamese , 0.2 % korean -rrb- , 849 -lrb- 0.2 % -rrb- pacific islander , 111,984 -lrb- 22.6 % -rrb- from other races , and 24,513 -lrb- 5.0 % -rrb- from two or more races . 
the racial makeup of fresno was 245,306 -lrb- 49.6 % -rrb- white , 40,960 -lrb- 8.3 % -rrb- african american , 8,525 -lrb- 1.7 % -rrb- native american , 62,528 -lrb- 12.6 % -rrb- asian -lrb- 3.6 % hmong , 1.7 % indian , 1.2 % filipino , 1.2 % laotian , 1.0 % thai , 0.8 % cambodian , 0.7 % chinese , 0.5 % japanese , 0.4 % vietnamese , 0.2 % korean -rrb- , 849 -lrb- 0.2 % -rrb- pacific islander , 111,984 -lrb- 22.6 % -rrb- from other races , and 24,513 -lrb- 5.0 % -rrb- from two or more races . 
non-hispanic whites were 30.0 % of the population in 2010 , down from 72.6 % in 1970 . 
the population density was 4,404.5 people per square mile -lrb- 1,700.6 / km ² -rrb- . 
there were 158,349 households , of which 68,511 -lrb- 43.3 % -rrb- had children under the age of 18 living in them , 69,284 -lrb- 43.8 % -rrb- were opposite-sex married couples living together , 30,547 -lrb- 19.3 % -rrb- had a female householder with no husband present , 11,698 -lrb- 7.4 % -rrb- had a male householder with no wife present . 
there were 158,349 households , of which 68,511 -lrb- 43.3 % -rrb- had children under the age of 18 living in them , 69,284 -lrb- 43.8 % -rrb- were opposite-sex married couples living together , 30,547 -lrb- 19.3 % -rrb- had a female householder with no husband present , 11,698 -lrb- 7.4 % -rrb- had a male householder with no wife present . 
there were 12,843 -lrb- 8.1 % -rrb- unmarried opposite-sex partnerships , and 1,388 -lrb- 0.9 % -rrb- same-sex married couples or partnerships . 
there were 111,529 families -lrb- 70.4 % of all households -rrb- ; the average family size was 3.62 . 
the average household size was 3.07 . 
as of the census of 2000 , there were 427,652 people , 140,079 households , and 97,915 families residing in the city . 
there were 149,025 housing units at an average density of 1,427.9 square miles -lrb- 3,698 km2 -rrb- . 
the racial makeup of the city was 50.2 % white , 8.4 % black or african american , 1.6 % native american , 11.2 % asian -lrb- about a third of which is hmong -rrb- , 0.1 % pacific islander , 23.4 % from other races , and 5.2 % from two or more races . 
the racial makeup of the city was 50.2 % white , 8.4 % black or african american , 1.6 % native american , 11.2 % asian -lrb- about a third of which is hmong -rrb- , 0.1 % pacific islander , 23.4 % from other races , and 5.2 % from two or more races . 
the population density was 4,097.9 people per square mile -lrb- 1,582.2 / km ² -rrb- . 
to avoid interference with existing vhf television stations in the san francisco bay area and those planned for chico , sacramento , salinas , and stockton , the federal communications commission decided that fresno would only have uhf television stations . 
the very first fresno television station to begin broadcasting was kmj-tv , which debuted on june 1 , 1953 . 
the very first fresno television station to begin broadcasting was kmj-tv , which debuted on june 1 , 1953 . 
kmj is now known as nbc affiliate ksee . 
other fresno stations include abc o&o kfsn , cbs affiliate kgpe , cw affiliate kfre , fox affiliate kmph , mntv affiliate kail , pbs affiliate kvpt , telemundo o&o knso , univision o&o kftv , and mundofox and azteca affiliate kgmc-dt . 
fresno is served by state route 99 , the main north/south freeway that connects the major population centers of the california central valley . 
state route 168 , the sierra freeway , heads east to the city of clovis and huntington lake . 
state route 41 -lrb- yosemite freeway/eisenhower freeway -rrb- comes into fresno from atascadero in the south , and then heads north to yosemite . 
state route 180 -lrb- kings canyon freeway -rrb- comes from the west via mendota , and from the east in kings canyon national park going towards the city of reedley . 
fresno is the largest u.s. city not directly linked to an interstate highway . 
when the interstate highway system was created in the 1950s , the decision was made to build what is now interstate 5 on the west side of the central valley , and thus bypass many of the population centers in the region , instead of upgrading what is now state route 99 . 
due to rapidly raising population and traffic in cities along sr 99 , as well as the desirability of federal funding , much discussion has been made to upgrade it to interstate standards and eventually incorporate it into the interstate system , most likely as interstate 9 . 
due to rapidly raising population and traffic in cities along sr 99 , as well as the desirability of federal funding , much discussion has been made to upgrade it to interstate standards and eventually incorporate it into the interstate system , most likely as interstate 9 . 
passenger rail service is provided by amtrak san joaquins . 
the main passenger rail station is the recently renovated historic santa fe railroad depot in downtown fresno . 
the bakersfield-stockton mainlines of the burlington northern santa fe railway and union pacific railroad railroads cross in fresno , and both railroads maintain railyards within the city ; the san joaquin valley railroad also operates former southern pacific branchlines heading west and south out of the city . 
the bakersfield-stockton mainlines of the burlington northern santa fe railway and union pacific railroad railroads cross in fresno , and both railroads maintain railyards within the city ; the san joaquin valley railroad also operates former southern pacific branchlines heading west and south out of the city . 
the city of fresno is planned to serve the future california high speed rail . 
starting in the late 1950s , american computer scientist paul baran developed the concept distributed adaptive message block switching with the goal to provide a fault-tolerant , efficient routing method for telecommunication messages as part of a research program at the rand corporation , funded by the us department of defense . 
starting in the late 1950s , american computer scientist paul baran developed the concept distributed adaptive message block switching with the goal to provide a fault-tolerant , efficient routing method for telecommunication messages as part of a research program at the rand corporation , funded by the us department of defense . 
this concept contrasted and contradicted the theretofore established principles of pre-allocation of network bandwidth , largely fortified by the development of telecommunications in the bell system . 
davies is credited with coining the modern name packet switching and inspiring numerous packet switching networks in europe in the decade following , including the incorporation of the concept in the early arpanet in the united states . 
starting in the late 1950s , american computer scientist paul baran developed the concept distributed adaptive message block switching with the goal to provide a fault-tolerant , efficient routing method for telecommunication messages as part of a research program at the rand corporation , funded by the us department of defense . 
starting in the late 1950s , american computer scientist paul baran developed the concept distributed adaptive message block switching with the goal to provide a fault-tolerant , efficient routing method for telecommunication messages as part of a research program at the rand corporation , funded by the us department of defense . 
davies is credited with coining the modern name packet switching and inspiring numerous packet switching networks in europe in the decade following , including the incorporation of the concept in the early arpanet in the united states . 
packet switching contrasts with another principal networking paradigm , circuit switching , a method which pre-allocates dedicated network bandwidth specifically for each communication session , each having a constant bit rate and latency between nodes . 
in cases of billable services , such as cellular communication services , circuit switching is characterized by a fee per unit of connection time , even when no data is transferred , while packet switching may be characterized by a fee per unit of information transmitted , such as characters , packets , or messages . 
in cases of billable services , such as cellular communication services , circuit switching is characterized by a fee per unit of connection time , even when no data is transferred , while packet switching may be characterized by a fee per unit of information transmitted , such as characters , packets , or messages . 
packet switching contrasts with another principal networking paradigm , circuit switching , a method which pre-allocates dedicated network bandwidth specifically for each communication session , each having a constant bit rate and latency between nodes . 
packet switching contrasts with another principal networking paradigm , circuit switching , a method which pre-allocates dedicated network bandwidth specifically for each communication session , each having a constant bit rate and latency between nodes . 
in cases of billable services , such as cellular communication services , circuit switching is characterized by a fee per unit of connection time , even when no data is transferred , while packet switching may be characterized by a fee per unit of information transmitted , such as characters , packets , or messages . 
in cases of billable services , such as cellular communication services , circuit switching is characterized by a fee per unit of connection time , even when no data is transferred , while packet switching may be characterized by a fee per unit of information transmitted , such as characters , packets , or messages . 
packet mode communication may be implemented with or without intermediate forwarding nodes -lrb- packet switches or routers -rrb- . 
packets are normally forwarded by intermediate network nodes asynchronously using first-in , first-out buffering , but may be forwarded according to some scheduling discipline for fair queuing , traffic shaping , or for differentiated or guaranteed quality of service , such as weighted fair queuing or leaky bucket . 
in case of a shared physical medium -lrb- such as radio or 10base5 -rrb- , the packets may be delivered according to a multiple access scheme . 
packet mode communication may be implemented with or without intermediate forwarding nodes -lrb- packet switches or routers -rrb- . 
packets are normally forwarded by intermediate network nodes asynchronously using first-in , first-out buffering , but may be forwarded according to some scheduling discipline for fair queuing , traffic shaping , or for differentiated or guaranteed quality of service , such as weighted fair queuing or leaky bucket . 
in case of a shared physical medium -lrb- such as radio or 10base5 -rrb- , the packets may be delivered according to a multiple access scheme . 
baran developed the concept of distributed adaptive message block switching during his research at the rand corporation for the us air force into survivable communications networks , first presented to the air force in the summer of 1961 as briefing b-265 , later published as rand report p-2626 in 1962 , and finally in report rm 3420 in 1964 . 
baran developed the concept of distributed adaptive message block switching during his research at the rand corporation for the us air force into survivable communications networks , first presented to the air force in the summer of 1961 as briefing b-265 , later published as rand report p-2626 in 1962 , and finally in report rm 3420 in 1964 . 
the work focuses on three key ideas : use of a decentralized network with multiple paths between any two points , dividing user messages into message blocks , later called packets , and delivery of these messages by store and forward switching . 
the work focuses on three key ideas : use of a decentralized network with multiple paths between any two points , dividing user messages into message blocks , later called packets , and delivery of these messages by store and forward switching . 
report p-2626 described a general architecture for a large-scale , distributed , survivable communications network . 
the work focuses on three key ideas : use of a decentralized network with multiple paths between any two points , dividing user messages into message blocks , later called packets , and delivery of these messages by store and forward switching . 
baran developed the concept of distributed adaptive message block switching during his research at the rand corporation for the us air force into survivable communications networks , first presented to the air force in the summer of 1961 as briefing b-265 , later published as rand report p-2626 in 1962 , and finally in report rm 3420 in 1964 . 
the work focuses on three key ideas : use of a decentralized network with multiple paths between any two points , dividing user messages into message blocks , later called packets , and delivery of these messages by store and forward switching . 
starting in 1965 , donald davies at the national physical laboratory , uk , independently developed the same message routing methodology as developed by baran . 
he called it packet switching , a more accessible name than baran 's , and proposed to build a nationwide network in the uk . 
he called it packet switching , a more accessible name than baran 's , and proposed to build a nationwide network in the uk . 
a member of davies ' team -lrb- roger scantlebury -rrb- met lawrence roberts at the 1967 acm symposium on operating system principles and suggested it for use in the arpanet . 
starting in 1965 , donald davies at the national physical laboratory , uk , independently developed the same message routing methodology as developed by baran . 
he called it packet switching , a more accessible name than baran 's , and proposed to build a nationwide network in the uk . 
a member of davies ' team -lrb- roger scantlebury -rrb- met lawrence roberts at the 1967 acm symposium on operating system principles and suggested it for use in the arpanet . 
in connectionless mode each packet includes complete addressing information . 
the packets are routed individually , sometimes resulting in different paths and out-of-order delivery . 
each packet is labeled with a destination address , source address , and port numbers . 
at the destination , the original message/data is reassembled in the correct order , based on the packet sequence number . 
the packet header can be small , as it only needs to contain this code and any information , such as length , timestamp , or sequence number , which is different for different packets . 
routing a packet requires the node to look up the connection id in a table . 
the packets include a connection identifier rather than address information and are negotiated between endpoints so that they are delivered in order and with error checking . 
connection-oriented transmission requires a setup phase in each involved node before any packet is transferred to establish the parameters of communication . 
both x. 25 and frame relay provide connection-oriented operations . 
however , x. 25 and well as frame relay have been supplanted by the internet protocol -lrb- ip -rrb- at the network layer , and the asynchronous transfer mode -lrb- atm -rrb- and or versions of multi-protocol label switching -lrb- mpls -rrb- at layer two . 
for a while , frame relay was used to interconnect lans across wide area networks . 
a typical configuration is to run ip over atm or a version of mpls . 
arpanet and sita hln became operational in 1969 . 
two fundamental differences involved the division of functions and tasks between the hosts at the edge of the network and the network core . 
in the virtual call system , the network guarantees sequenced delivery of data to the host . 
the user datagram protocol -lrb- udp -rrb- is an example of a datagram protocol . 
appletalk was a proprietary suite of networking protocols developed by apple inc. in 1985 for apple macintosh computers . 
appletalk included features that allowed local area networks to be established ad hoc without the requirement for a centralized router or server . 
the appletalk system automatically assigned addresses , updated the distributed namespace , and configured any required inter-network routing . 
it was a plug-n-play system . 
the cyclades packet switching network was a french research network designed and directed by louis pouzin . 
it was the first network to make the hosts responsible for reliable delivery of data , rather than the network itself , using unreliable datagrams and associated end-to-end protocol mechanisms . 
it was the first network to make the hosts responsible for reliable delivery of data , rather than the network itself , using unreliable datagrams and associated end-to-end protocol mechanisms . 
concepts of this network influenced later arpanet architecture . 
decnet is a suite of network protocols created by digital equipment corporation , originally released in 1975 in order to connect two pdp-11 minicomputers . 
decnet is a suite of network protocols created by digital equipment corporation , originally released in 1975 in order to connect two pdp-11 minicomputers . 
initially built with three layers , it later -lrb- 1982 -rrb- evolved into a seven-layer osi-compliant networking protocol . 
however , decnet phase ii -lrb- and later -rrb- were open standards with published specifications , and several implementations were developed outside dec , including one for linux . 
in 1965 , at the instigation of warner sinback , a data network based on this voice-phone network was designed to connect ge 's four computer sales and service centers -lrb- schenectady , phoenix , chicago , and phoenix -rrb- to facilitate a computer time-sharing service , apparently the world 's first commercial online service . 
in 1965 , at the instigation of warner sinback , a data network based on this voice-phone network was designed to connect ge 's four computer sales and service centers -lrb- schenectady , phoenix , chicago , and phoenix -rrb- to facilitate a computer time-sharing service , apparently the world 's first commercial online service . 
they lost money from the beginning , and sinback , a high-level marketing manager , was given the job of turning the business around . 
he decided that a time-sharing system , based on kemney 's work at dartmouth -- which used a computer on loan from ge -- could be profitable . 
merit network , inc. , an independent non-profit 501 -lrb- c -rrb- -lrb- 3 -rrb- corporation governed by michigan 's public universities , was formed in 1966 as the michigan educational research information triad to explore computer networking between three of michigan 's public universities as a means to help the state 's educational and economic development . 
with initial support from the state of michigan and the national science foundation -lrb- nsf -rrb- , the packet-switched network was first demonstrated in december 1971 when an interactive host to host connection was made between the ibm mainframe computer systems at the university of michigan in ann arbor and wayne state university in detroit . 
over the next several years in addition to host to host interactive connections the network was enhanced to support terminal to host connections , host to host batch connections -lrb- remote job submission , remote printing , batch file transfer -rrb- , interactive file transfer , gateways to the tymnet and telenet public data networks , x. 25 host attachments , gateways to x. 25 data networks , ethernet attached hosts , and eventually tcp/ip and additional public universities in michigan join the network . 
telenet was the first fcc-licensed public data network in the united states . 
it was founded by former arpa ipto director larry roberts as a means of making arpanet technology public . 
it was founded by former arpa ipto director larry roberts as a means of making arpanet technology public . 
it initially used arpanet technology but changed the host interface to x. 25 and the terminal interface to x. 29 . 
telenet was incorporated in 1973 and started operations in 1975 . 
tymnet was an international data communications network headquartered in san jose , ca that utilized virtual call packet switched technology and used x. 25 , sna/sdlc , bsc and ascii interfaces to connect host computers -lrb- servers -rrb- at thousands of large companies , educational institutions , and government agencies . 
tymnet was an international data communications network headquartered in san jose , ca that utilized virtual call packet switched technology and used x. 25 , sna/sdlc , bsc and ascii interfaces to connect host computers -lrb- servers -rrb- at thousands of large companies , educational institutions , and government agencies . 
users typically connected via dial-up connections or dedicated async connections . 
the business consisted of a large public network that supported dial-up users and a private network business that allowed government agencies and large companies -lrb- mostly banks and airlines -rrb- to build their own dedicated networks . 
the private networks were often connected via gateways to the public network to reach locations not on the private network . 
there were two kinds of x. 25 networks . 
datapac was developed by bell northern research which was a joint venture of bell canada -lrb- a common carrier -rrb- and northern telecom -lrb- a telecommunications equipment supplier -rrb- . 
a user or host could call a host on a foreign network by including the dnic of the remote network as part of the destination address . 
austpac was an australian public x. 25 network operated by telstra . 
started by telecom australia in the early 1980s , austpac was australia 's first public packet-switched data network , supporting applications such as on-line betting , financial applications -- the australian tax office made use of austpac -- and remote terminal access to academic institutions , who maintained their connections to austpac up until the mid-late 1990s in some cases . 
access can be via a dial-up terminal to a pad , or , by linking a permanent x. 25 node to the network . 
datanet 1 was the public switched data network operated by the dutch ptt telecom -lrb- now known as kpn -rrb- . 
strictly speaking datanet 1 only referred to the network and the connected users via leased lines -lrb- using the x. 121 dnic 2041 -rrb- , the name also referred to the public pad service telepad -lrb- using the dnic 2049 -rrb- . 
strictly speaking datanet 1 only referred to the network and the connected users via leased lines -lrb- using the x. 121 dnic 2041 -rrb- , the name also referred to the public pad service telepad -lrb- using the dnic 2049 -rrb- . 
although this use of the name was incorrect all these services were managed by the same people within one department of kpn contributed to the confusion . 
the computer science network -lrb- csnet -rrb- was a computer network funded by the u.s. national science foundation -lrb- nsf -rrb- that began operation in 1981 . 
its purpose was to extend networking benefits , for computer science departments at academic and research institutions that could not be directly connected to arpanet , due to funding or authorization limitations . 
it played a significant role in spreading awareness of , and access to , national networking and was a major milestone on the path to development of the global internet . 
internet2 is a not-for-profit united states computer networking consortium led by members from the research and education communities , industry , and government . 
the internet2 community , in partnership with qwest , built the first internet2 network , called abilene , in 1998 and was a prime investor in the national lambdarail -lrb- nlr -rrb- project . 
the internet2 community , in partnership with qwest , built the first internet2 network , called abilene , in 1998 and was a prime investor in the national lambdarail -lrb- nlr -rrb- project . 
in 2006 , internet2 announced a partnership with level 3 communications to launch a brand new nationwide network , boosting its capacity from 10 gbit/s to 100 gbit/s . 
in october , 2007 , internet2 officially retired abilene and now refers to its new , higher capacity network as the internet2 network . 
the national science foundation network -lrb- nsfnet -rrb- was a program of coordinated , evolving projects sponsored by the national science foundation -lrb- nsf -rrb- beginning in 1985 to promote advanced research and education networking in the united states . 
the national science foundation network -lrb- nsfnet -rrb- was a program of coordinated , evolving projects sponsored by the national science foundation -lrb- nsf -rrb- beginning in 1985 to promote advanced research and education networking in the united states . 
initially created to link researchers to the nation 's nsf-funded supercomputing centers , through further public funding and private industry partnerships it developed into a major part of the internet backbone . 
the very high-speed backbone network service -lrb- vbns -rrb- came on line in april 1995 as part of a national science foundation -lrb- nsf -rrb- sponsored project to provide high-speed interconnection between nsf-sponsored supercomputing centers and select access points in the united states . 
the very high-speed backbone network service -lrb- vbns -rrb- came on line in april 1995 as part of a national science foundation -lrb- nsf -rrb- sponsored project to provide high-speed interconnection between nsf-sponsored supercomputing centers and select access points in the united states . 
the network was engineered and operated by mci telecommunications under a cooperative agreement with the nsf . 
by 1998 , the vbns had grown to connect more than 100 universities and research and engineering institutions via 12 national points of presence with ds-3 -lrb- 45 mbit/s -rrb- , oc-3c -lrb- 155 mbit/s -rrb- , and oc-12c -lrb- 622 mbit/s -rrb- links on an all oc-12c backbone , a substantial engineering feat for that time . 
the vbns installed one of the first ever production oc-48c -lrb- 2.5 gbit/s -rrb- ip links in february 1999 and went on to upgrade the entire backbone to oc-48c . 
the black death is thought to have originated in the arid plains of central asia , where it then travelled along the silk road , reaching crimea by 1343 . 
from there , it was most likely carried by oriental rat fleas living on the black rats that were regular passengers on merchant ships . 
spreading throughout the mediterranean and europe , the black death is estimated to have killed 30 -- 60 % of europe 's total population . 
the world population as a whole did not recover to pre-plague levels until the 17th century . 
the plague recurred occasionally in europe until the 19th century . 
the plague disease , caused by yersinia pestis , is enzootic -lrb- commonly present -rrb- in populations of fleas carried by ground rodents , including marmots , in various areas including central asia , kurdistan , western asia , northern india and uganda . 
nestorian graves dating to 1338 -- 39 near lake issyk kul in kyrgyzstan have inscriptions referring to plague and are thought by many epidemiologists to mark the outbreak of the epidemic , from which it could easily have spread to china and india . 
in october 2010 , medical geneticists suggested that all three of the great waves of the plague originated in china . 
in the 1330s a large number of natural disasters and plagues led to widespread famine , starting in 1331 , with a deadly plague arriving soon after . 
epidemics that may have included plague killed an estimated 25 million chinese and other asians during the 15 years before it reached constantinople in 1347 . 
plague was reportedly first introduced to europe via genoese traders at the port city of kaffa in the crimea in 1347 . 
after a protracted siege , during which the mongol army under jani beg was suffering from the disease , the army catapulted the infected corpses over the city walls of kaffa to infect the inhabitants . 
after a protracted siege , during which the mongol army under jani beg was suffering from the disease , the army catapulted the infected corpses over the city walls of kaffa to infect the inhabitants . 
the genoese traders fled , taking the plague by ship into sicily and the south of europe , whence it spread north . 
whether or not this hypothesis is accurate , it is clear that several existing conditions such as war , famine , and weather contributed to the severity of the black death . 
from italy , the disease spread northwest across europe , striking france , spain , portugal and england by june 1348 , then turned and spread east through germany and scandinavia from 1348 to 1350 . 
finally it spread to northwestern russia in 1351 . 
the plague was somewhat less common in parts of europe that had smaller trade relations with their neighbours , including the kingdom of poland , the majority of the basque country , isolated parts of belgium and the netherlands , and isolated alpine villages throughout the continent . 
from italy , the disease spread northwest across europe , striking france , spain , portugal and england by june 1348 , then turned and spread east through germany and scandinavia from 1348 to 1350 . 
it was introduced in norway in 1349 when a ship landed at askøy , then spread to bjørgvin -lrb- modern bergen -rrb- and iceland . 
the plague struck various countries in the middle east during the pandemic , leading to serious depopulation and permanent change in both economic and social structures . 
by autumn 1347 , the plague reached alexandria in egypt , probably through the port 's trade with constantinople , and ports on the black sea . 
by autumn 1347 , the plague reached alexandria in egypt , probably through the port 's trade with constantinople , and ports on the black sea . 
the city 's residents fled to the north , most of them dying during the journey , but the infection had been spread to the people of asia minor . 
gasquet -lrb- 1908 -rrb- claimed that the latin name atra mors -lrb- black death -rrb- for the 14th-century epidemic first appeared in modern times in 1631 in a book on danish history by j.i. pontanus : `` vulgo & ab effectu atram mortem vocatibant . 
gasquet -lrb- 1908 -rrb- claimed that the latin name atra mors -lrb- black death -rrb- for the 14th-century epidemic first appeared in modern times in 1631 in a book on danish history by j.i. pontanus : `` vulgo & ab effectu atram mortem vocatibant . 
gasquet -lrb- 1908 -rrb- claimed that the latin name atra mors -lrb- black death -rrb- for the 14th-century epidemic first appeared in modern times in 1631 in a book on danish history by j.i. pontanus : `` vulgo & ab effectu atram mortem vocatibant . 
in england , it was not until 1823 that the medieval epidemic was first called the black death . 
the name spread through scandinavia and then germany , gradually becoming attached to the mid 14th-century epidemic as a proper name . 
the most authoritative account at the time came from the medical faculty in paris in a report to the king of france that blamed the heavens , in the form of a conjunction of three planets in 1345 that caused a `` great pestilence in the air '' . 
the most authoritative account at the time came from the medical faculty in paris in a report to the king of france that blamed the heavens , in the form of a conjunction of three planets in 1345 that caused a `` great pestilence in the air '' . 
that the plague was caused by bad air became the most widely accepted theory . 
today , this is known as the miasma theory . 
the dominant explanation for the black death is the plague theory , which attributes the outbreak to yersinia pestis , also responsible for an epidemic that began in southern china in 1865 , eventually spreading to india . 
the investigation of the pathogen that caused the 19th-century plague was begun by teams of scientists who visited hong kong in 1894 , among whom was the french-swiss bacteriologist alexandre yersin , after whom the pathogen was named yersinia pestis . 
the investigation of the pathogen that caused the 19th-century plague was begun by teams of scientists who visited hong kong in 1894 , among whom was the french-swiss bacteriologist alexandre yersin , after whom the pathogen was named yersinia pestis . 
the mechanism by which y. pestis was usually transmitted was established in 1898 by paul-louis simond and was found to involve the bites of fleas whose midguts had become obstructed by replicating y. pestis several days after feeding on an infected host . 
the bubonic plague mechanism was also dependent on two populations of rodents : one resistant to the disease , which act as hosts , keeping the disease endemic , and a second that lack resistance . 
the historian francis aidan gasquet wrote about the ` great pestilence ' in 1893 and suggested that `` it would appear to be some form of the ordinary eastern or bubonic plague '' . 
the historian francis aidan gasquet wrote about the ` great pestilence ' in 1893 and suggested that `` it would appear to be some form of the ordinary eastern or bubonic plague '' . 
he was able to adopt the epidemiology of the bubonic plague for the black death for the second edition in 1908 , implicating rats and fleas in the process , and his interpretation was widely accepted for other ancient and medieval epidemics , such as the justinian plague that was prevalent in the eastern roman empire from 541 to 700 ce . 
he was able to adopt the epidemiology of the bubonic plague for the black death for the second edition in 1908 , implicating rats and fleas in the process , and his interpretation was widely accepted for other ancient and medieval epidemics , such as the justinian plague that was prevalent in the eastern roman empire from 541 to 700 ce . 
he was able to adopt the epidemiology of the bubonic plague for the black death for the second edition in 1908 , implicating rats and fleas in the process , and his interpretation was widely accepted for other ancient and medieval epidemics , such as the justinian plague that was prevalent in the eastern roman empire from 541 to 700 ce . 
the modern bubonic plague has a mortality rate of 30 -- 75 % and symptoms including fever of 38 -- 41 °c -lrb- 100 -- 106 °f -rrb- , headaches , painful aching joints , nausea and vomiting , and a general feeling of malaise . 
the modern bubonic plague has a mortality rate of 30 -- 75 % and symptoms including fever of 38 -- 41 °c -lrb- 100 -- 106 °f -rrb- , headaches , painful aching joints , nausea and vomiting , and a general feeling of malaise . 
left untreated , of those that contract the bubonic plague , 80 percent die within eight days . 
pneumonic plague has a mortality rate of 90 to 95 percent . 
symptoms are high fevers and purple skin patches -lrb- purpura due to disseminated intravascular coagulation -rrb- . 
in october 2010 , the open-access scientific journal plos pathogens published a paper by a multinational team who undertook a new investigation into the role of yersinia pestis in the black death following the disputed identification by drancourt and raoult in 1998 . 
in october 2010 , the open-access scientific journal plos pathogens published a paper by a multinational team who undertook a new investigation into the role of yersinia pestis in the black death following the disputed identification by drancourt and raoult in 1998 . 
they assessed the presence of dna/rna with polymerase chain reaction -lrb- pcr -rrb- techniques for y. pestis from the tooth sockets in human skeletons from mass graves in northern , central and southern europe that were associated archaeologically with the black death and subsequent resurgences . 
they assessed the presence of dna/rna with polymerase chain reaction -lrb- pcr -rrb- techniques for y. pestis from the tooth sockets in human skeletons from mass graves in northern , central and southern europe that were associated archaeologically with the black death and subsequent resurgences . 
the authors concluded that this new research , together with prior analyses from the south of france and germany , '' ... ends the debate about the etiology of the black death , and unambiguously demonstrates that y. pestis was the causative agent of the epidemic plague that devastated europe during the middle ages '' . 
the study also found that there were two previously unknown but related clades -lrb- genetic branches -rrb- of the y. pestis genome associated with medieval mass graves . 
these clades -lrb- which are thought to be extinct -rrb- were found to be ancestral to modern isolates of the modern y. pestis strains y. p. orientalis and y. p. medievalis , suggesting the plague may have entered europe in two waves . 
these clades -lrb- which are thought to be extinct -rrb- were found to be ancestral to modern isolates of the modern y. pestis strains y. p. orientalis and y. p. medievalis , suggesting the plague may have entered europe in two waves . 
surveys of plague pit remains in france and england indicate the first variant entered europe through the port of marseille around november 1347 and spread through france over the next two years , eventually reaching england in the spring of 1349 , where it spread through the country in three epidemics . 
surveys of plague pit remains in france and england indicate the first variant entered europe through the port of marseille around november 1347 and spread through france over the next two years , eventually reaching england in the spring of 1349 , where it spread through the country in three epidemics . 
the results of the haensch study have since been confirmed and amended . 
based on genetic evidence derived from black death victims in the east smithfield burial site in england , schuenemann et al. concluded in 2011 `` that the black death in medieval europe was caused by a variant of y. pestis that may no longer exist . '' 
based on genetic evidence derived from black death victims in the east smithfield burial site in england , schuenemann et al. concluded in 2011 `` that the black death in medieval europe was caused by a variant of y. pestis that may no longer exist . '' 
a study published in nature in october 2011 sequenced the genome of y. pestis from plague victims and indicated that the strain that caused the black death is ancestral to most modern strains of the disease . 
the plague theory was first significantly challenged by the work of british bacteriologist j. f. d. shrewsbury in 1970 , who noted that the reported rates of mortality in rural areas during the 14th-century pandemic were inconsistent with the modern bubonic plague , leading him to conclude that contemporary accounts were exaggerations . 
the plague theory was first significantly challenged by the work of british bacteriologist j. f. d. shrewsbury in 1970 , who noted that the reported rates of mortality in rural areas during the 14th-century pandemic were inconsistent with the modern bubonic plague , leading him to conclude that contemporary accounts were exaggerations . 
the plague theory was first significantly challenged by the work of british bacteriologist j. f. d. shrewsbury in 1970 , who noted that the reported rates of mortality in rural areas during the 14th-century pandemic were inconsistent with the modern bubonic plague , leading him to conclude that contemporary accounts were exaggerations . 
in 1984 zoologist graham twigg produced the first major work to challenge the bubonic plague theory directly , and his doubts about the identity of the black death have been taken up by a number of authors , including samuel k. cohn , jr. -lrb- 2002 -rrb- , david herlihy -lrb- 1997 -rrb- , and susan scott and christopher duncan -lrb- 2001 -rrb- . 
in 1984 zoologist graham twigg produced the first major work to challenge the bubonic plague theory directly , and his doubts about the identity of the black death have been taken up by a number of authors , including samuel k. cohn , jr. -lrb- 2002 -rrb- , david herlihy -lrb- 1997 -rrb- , and susan scott and christopher duncan -lrb- 2001 -rrb- . 
it is recognised that an epidemiological account of the plague is as important as an identification of symptoms , but researchers are hampered by the lack of reliable statistics from this period . 
it is recognised that an epidemiological account of the plague is as important as an identification of symptoms , but researchers are hampered by the lack of reliable statistics from this period . 
most work has been done on the spread of the plague in england , and even estimates of overall population at the start vary by over 100 % as no census was undertaken between the time of publication of the domesday book and the year 1377 . 
estimates of plague victims are usually extrapolated from figures from the clergy . 
most work has been done on the spread of the plague in england , and even estimates of overall population at the start vary by over 100 % as no census was undertaken between the time of publication of the domesday book and the year 1377 . 
in addition to arguing that the rat population was insufficient to account for a bubonic plague pandemic , sceptics of the bubonic plague theory point out that the symptoms of the black death are not unique -lrb- and arguably in some accounts may differ from bubonic plague -rrb- ; that transference via fleas in goods was likely to be of marginal significance ; and that the dna results may be flawed and might not have been repeated elsewhere , despite extensive samples from other mass graves . 
in addition to arguing that the rat population was insufficient to account for a bubonic plague pandemic , sceptics of the bubonic plague theory point out that the symptoms of the black death are not unique -lrb- and arguably in some accounts may differ from bubonic plague -rrb- ; that transference via fleas in goods was likely to be of marginal significance ; and that the dna results may be flawed and might not have been repeated elsewhere , despite extensive samples from other mass graves . 
other arguments include the lack of accounts of the death of rats before outbreaks of plague between the 14th and 17th centuries ; temperatures that are too cold in northern europe for the survival of fleas ; that , despite primitive transport systems , the spread of the black death was much faster than that of modern bubonic plague ; that mortality rates of the black death appear to be very high ; that , while modern bubonic plague is largely endemic as a rural disease , the black death indiscriminately struck urban and rural areas ; and that the pattern of the black death , with major outbreaks in the same areas separated by 5 to 15 years , differs from modern bubonic plague -- which often becomes endemic for decades with annual flare-ups . 
other arguments include the lack of accounts of the death of rats before outbreaks of plague between the 14th and 17th centuries ; temperatures that are too cold in northern europe for the survival of fleas ; that , despite primitive transport systems , the spread of the black death was much faster than that of modern bubonic plague ; that mortality rates of the black death appear to be very high ; that , while modern bubonic plague is largely endemic as a rural disease , the black death indiscriminately struck urban and rural areas ; and that the pattern of the black death , with major outbreaks in the same areas separated by 5 to 15 years , differs from modern bubonic plague -- which often becomes endemic for decades with annual flare-ups . 
other arguments include the lack of accounts of the death of rats before outbreaks of plague between the 14th and 17th centuries ; temperatures that are too cold in northern europe for the survival of fleas ; that , despite primitive transport systems , the spread of the black death was much faster than that of modern bubonic plague ; that mortality rates of the black death appear to be very high ; that , while modern bubonic plague is largely endemic as a rural disease , the black death indiscriminately struck urban and rural areas ; and that the pattern of the black death , with major outbreaks in the same areas separated by 5 to 15 years , differs from modern bubonic plague -- which often becomes endemic for decades with annual flare-ups . 
twigg suggested that the cause was a form of anthrax , and norman cantor -lrb- 2001 -rrb- thought it may have been a combination of anthrax and other pandemics . 
twigg suggested that the cause was a form of anthrax , and norman cantor -lrb- 2001 -rrb- thought it may have been a combination of anthrax and other pandemics . 
many scholars arguing for the y. pestis as the major agent of the pandemic suggest that its extent and symptoms can be explained by a combination of bubonic plague with other diseases , including typhus , smallpox and respiratory infections . 
in addition to the bubonic infection , others point to additional septicemic -lrb- a type of `` blood poisoning '' -rrb- and pneumonic -lrb- an airborne plague that attacks the lungs before the rest of the body -rrb- forms of the plague , which lengthen the duration of outbreaks throughout the seasons and help account for its high mortality rate and additional recorded symptoms . 
in 2014 , scientists with public health england announced the results of an examination of 25 bodies exhumed from the clerkenwell area of london , as well as of wills registered in london during the period , which supported the pneumonic hypothesis . 
the most widely accepted estimate for the middle east , including iraq , iran and syria , during this time , is for a death rate of about a third . 
half of paris 's population of 100,000 people died . 
interestingly while contemporary reports account of mass burial pits being created in response to the large numbers of dead , recent scientific investigations of a burial pit in central london found well-preserved individuals to be buried in isolated , evenly spaced graves , suggesting at least some pre-planning and christian burials at this time . 
in crowded cities , it was not uncommon for as much as 50 % of the population to die . 
the disease bypassed some areas , and the most isolated areas were less vulnerable to contagion . 
the plague repeatedly returned to haunt europe and the mediterranean throughout the 14th to 17th centuries . 
according to biraben , the plague was present somewhere in europe in every year between 1346 and 1671 . 
according to geoffrey parker , `` france alone lost almost a million people to the plague in the epidemic of 1628 -- 31 . '' 
in england , in the absence of census figures , historians propose a range of preincident population figures from as high as 7 million to as low as 4 million in 1300 , and a postincident population figure as low as 2 million . 
by the end of 1350 , the black death subsided , but it never really died out in england . 
an outbreak in 1471 took as much as 10 -- 15 % of the population , while the death rate of the plague of 1479 -- 80 could have been as high as 20 % . 
the most general outbreaks in tudor and stuart england seem to have begun in 1498 , 1535 , 1543 , 1563 , 1589 , 1603 , 1625 , and 1636 , and ended with the great plague of london in 1665 . 
in 1466 , perhaps 40,000 people died of the plague in paris . 
the black death ravaged europe for three years before it continued on into russia , where the disease was present somewhere in the country 25 times between 1350 to 1490 . 
late outbreaks in central europe included the italian plague of 1629 -- 1631 , which is associated with troop movements during the thirty years ' war , and the great plague of vienna in 1679 . 
the last plague outbreak ravaged oslo in 1654 . 
plague occurred in venice 22 times between 1361 and 1528 . 
in the first half of the 17th century , a plague claimed some 1.7 million victims in italy , or about 14 % of the population . 
in 1656 , the plague killed about half of naples ' 300,000 inhabitants . 
the plague of 1649 probably reduced the population of seville by half . 
in 1709 -- 13 , a plague epidemic that followed the great northern war -lrb- 1700 -- 21 , sweden v. russia and allies -rrb- killed about 100,000 in sweden , and 300,000 in prussia . 
europe 's last major epidemic occurred in 1720 in marseille . 
plague was present in at least one location in the islamic world virtually every year between 1500 and 1850 . 
algiers lost 30 to 50 thousand inhabitants to it in 1620 -- 21 , and again in 1654 -- 57 , 1665 , 1691 , and 1740 -- 42 . 
plague remained a major event in ottoman society until the second quarter of the 19th century . 
baghdad has suffered severely from visitations of the plague , and sometimes two-thirds of its population has been wiped out . 
when a rock crystallizes from melt -lrb- magma and/or lava -rrb- , it is an igneous rock . 
the sedimentary rock can then be subsequently turned into a metamorphic rock due to heat and pressure and is then weathered , eroded , deposited , and lithified , ultimately becoming a sedimentary rock . 
all three types of rocks may be re-melted ; when this happens , a new magma is formed , from which an igneous rock may once again crystallize . 
there are three major types of rock : igneous , sedimentary , and metamorphic . 
this rock can be weathered and eroded , and then redeposited and lithified into a sedimentary rock , or be turned into a metamorphic rock due to heat and pressure that change the mineral content of the rock which gives it a characteristic fabric . 
in the 1960s , a series of discoveries , the most important of which was seafloor spreading , showed that the earth 's lithosphere , which includes the crust and rigid uppermost portion of the upper mantle , is separated into a number of tectonic plates that move across the plastically deforming , solid , upper mantle , which is called the asthenosphere . 
in the 1960s , a series of discoveries , the most important of which was seafloor spreading , showed that the earth 's lithosphere , which includes the crust and rigid uppermost portion of the upper mantle , is separated into a number of tectonic plates that move across the plastically deforming , solid , upper mantle , which is called the asthenosphere . 
in the 1960s , a series of discoveries , the most important of which was seafloor spreading , showed that the earth 's lithosphere , which includes the crust and rigid uppermost portion of the upper mantle , is separated into a number of tectonic plates that move across the plastically deforming , solid , upper mantle , which is called the asthenosphere . 
this coupling between rigid plates moving on the surface of the earth and the convecting mantle is called plate tectonics . 
in the 1960s , a series of discoveries , the most important of which was seafloor spreading , showed that the earth 's lithosphere , which includes the crust and rigid uppermost portion of the upper mantle , is separated into a number of tectonic plates that move across the plastically deforming , solid , upper mantle , which is called the asthenosphere . 
mid-ocean ridges , high regions on the seafloor where hydrothermal vents and volcanoes exist , were explained as divergent boundaries , where two plates move apart . 
arcs of volcanoes and earthquakes were explained as convergent boundaries , where one plate subducts under another . 
transform boundaries , such as the san andreas fault system , resulted in widespread powerful earthquakes . 
plate tectonics also provided a mechanism for alfred wegener 's theory of continental drift , in which the continents move across the surface of the earth over geologic time . 
the power of the theory of plate tectonics lies in its ability to combine all of these observations into a single theory of how the lithosphere moves over the convecting mantle . 
seismologists can use the arrival times of seismic waves in reverse to image the interior of the earth . 
these advances led to the development of a layered model of the earth , with a crust and lithosphere on top , the mantle below -lrb- separated within itself by seismic discontinuities at 410 and 660 kilometers -rrb- , and the outer core and inner core below that . 
these advances led to the development of a layered model of the earth , with a crust and lithosphere on top , the mantle below -lrb- separated within itself by seismic discontinuities at 410 and 660 kilometers -rrb- , and the outer core and inner core below that . 
more recently , seismologists have been able to create detailed images of wave speeds inside the earth in the same way a doctor images a body in a ct scan . 
these advances led to the development of a layered model of the earth , with a crust and lithosphere on top , the mantle below -lrb- separated within itself by seismic discontinuities at 410 and 660 kilometers -rrb- , and the outer core and inner core below that . 
therefore , the second scale shows the most recent eon with an expanded scale . 
since the quaternary is a very short period with short epochs , it is further expanded in the fourth scale . 
the holocene -lrb- the latest epoch -rrb- is too small to be shown clearly on the third timeline on the right , another reason for expanding the fourth scale . 
q stands for the quaternary period . 
the principle of cross-cutting relationships pertains to the formation of faults and the age of the sequences through which they cut . 
faults are younger than the rocks they cut ; accordingly , if a fault is found that penetrates some formations but not those on top of it , then the formations that were cut are older than the fault , and the ones that are not cut must be younger than the fault . 
finding the key bed in these situations may help determine whether the fault is a normal fault or a thrust fault . 
faults are younger than the rocks they cut ; accordingly , if a fault is found that penetrates some formations but not those on top of it , then the formations that were cut are older than the fault , and the ones that are not cut must be younger than the fault . 
as a result , xenoliths are older than the rock which contains them . 
these foreign bodies are picked up as magma or lava flows , and are incorporated , later to cool in the matrix . 
the principle of inclusions and components states that , with sedimentary rocks , if inclusions -lrb- or clasts -rrb- are found in a formation , then the inclusions must be older than the formation that contains them . 
the principle of inclusions and components states that , with sedimentary rocks , if inclusions -lrb- or clasts -rrb- are found in a formation , then the inclusions must be older than the formation that contains them . 
for example , in sedimentary rocks , it is common for gravel from an older formation to be ripped up and included in a newer layer . 
the principle of faunal succession is based on the appearance of fossils in sedimentary rocks . 
based on principles laid out by william smith almost a hundred years before the publication of charles darwin 's theory of evolution , the principles of succession were developed independently of evolutionary thought . 
the principle becomes quite complex , however , given the uncertainties of fossilization , the localization of fossil types due to lateral changes in habitat -lrb- facies change in sedimentary strata -rrb- , and that not all fossils may be found globally at the same time . 
as organisms exist at the same time period throughout the world , their presence or -lrb- sometimes -rrb- absence may be used to provide a relative age of the formations in which they are found . 
based on principles laid out by william smith almost a hundred years before the publication of charles darwin 's theory of evolution , the principles of succession were developed independently of evolutionary thought . 
at the beginning of the 20th century , important advancement in geological science was facilitated by the ability to obtain accurate absolute dates to geologic events using radioactive isotopes and other methods . 
previously , geologists could only use fossils and stratigraphic correlation to date sections of rock relative to one another . 
with isotopic dates it became possible to assign absolute ages to rock units , and these absolute dates could be applied to fossil sequences in which there was datable material , converting the old relative ages into new absolute ages . 
previously , geologists could only use fossils and stratigraphic correlation to date sections of rock relative to one another . 
with isotopic dates it became possible to assign absolute ages to rock units , and these absolute dates could be applied to fossil sequences in which there was datable material , converting the old relative ages into new absolute ages . 
thermochemical techniques can be used to determine temperature profiles within the crust , the uplift of mountain ranges , and paleotopography . 
for many geologic applications , isotope ratios of radioactive elements are measured in minerals that give the amount of time that has passed since a rock passed through its particular closure temperature , the point at which different radiometric isotopes stop diffusing into and out of the crystal lattice . 
for many geologic applications , isotope ratios of radioactive elements are measured in minerals that give the amount of time that has passed since a rock passed through its particular closure temperature , the point at which different radiometric isotopes stop diffusing into and out of the crystal lattice . 
dating of lava and volcanic ash layers found within a stratigraphic sequence can provide absolute age data for sedimentary rock units which do not contain radioactive isotopes and calibrate relative dating techniques . 
when rock units are placed under horizontal compression , they shorten and become thicker . 
in the shallow crust , where brittle deformation can occur , thrust faults form , which cause deeper rock to move on top of shallower rock . 
these folds can either be those where the material in the center of the fold buckles upwards , creating `` antiforms '' , or where it buckles downwards , creating `` synforms '' . 
these folds can either be those where the material in the center of the fold buckles upwards , creating `` antiforms '' , or where it buckles downwards , creating `` synforms '' . 
if the tops of the rock units within the folds remain pointing upwards , they are called anticlines and synclines , respectively . 
extension causes the rock units as a whole to become longer and thinner . 
these stretched rocks can also pinch into lenses , known as boudins , after the french word for `` sausage '' , because of their visual similarity . 
stretching of units can result in their thinning ; in fact , there is a location within the maria fold and thrust belt in which the entire sedimentary sequence of the grand canyon can be seen over a length of less than a meter . 
rocks at the depth to be ductilely stretched are often also metamorphosed . 
this is primarily accomplished through normal faulting and through the ductile stretching and thinning . 
dikes , long , planar igneous intrusions , enter along cracks , and therefore often form in large numbers in areas that are being actively deformed . 
dikes , long , planar igneous intrusions , enter along cracks , and therefore often form in large numbers in areas that are being actively deformed . 
faulting and other deformational processes result in the creation of topographic gradients , causing material on the rock unit that is increasing in elevation to be eroded by hillslopes and channels . 
continual motion along the fault maintains the topographic gradient in spite of the movement of sediment , and continues to create accommodation space for the material to deposit . 
deformational events are often also associated with volcanism and igneous activity . 
the hawaiian islands , for example , consist almost entirely of layered basaltic lava flows . 
even older rocks , such as the acasta gneiss of the slave craton in northwestern canada , the oldest known rock in the world have been metamorphosed to the point where their origin is undiscernable without laboratory analysis . 
the sedimentary sequences of the mid-continental united states and the grand canyon in the southwestern united states contain almost-undeformed stacks of sedimentary rocks that have remained in place since cambrian time . 
the sedimentary sequences of the mid-continental united states and the grand canyon in the southwestern united states contain almost-undeformed stacks of sedimentary rocks that have remained in place since cambrian time . 
even older rocks , such as the acasta gneiss of the slave craton in northwestern canada , the oldest known rock in the world have been metamorphosed to the point where their origin is undiscernable without laboratory analysis . 
in typical geological investigations , geologists use primary information related to petrology -lrb- the study of rocks -rrb- , stratigraphy -lrb- the study of sedimentary layers -rrb- , and structural geology -lrb- the study of positions of rock units and their deformation -rrb- . 
in typical geological investigations , geologists use primary information related to petrology -lrb- the study of rocks -rrb- , stratigraphy -lrb- the study of sedimentary layers -rrb- , and structural geology -lrb- the study of positions of rock units and their deformation -rrb- . 
in typical geological investigations , geologists use primary information related to petrology -lrb- the study of rocks -rrb- , stratigraphy -lrb- the study of sedimentary layers -rrb- , and structural geology -lrb- the study of positions of rock units and their deformation -rrb- . 
in many cases , geologists also study modern soils , rivers , landscapes , and glaciers ; investigate past and current life and biogeochemical pathways , and use geophysical methods to investigate the subsurface . 
in addition to identifying rocks in the field , petrologists identify rock samples in the laboratory . 
in an optical mineralogy analysis , thin sections of rock samples are analyzed through a petrographic microscope , where the minerals can be identified through their different properties in plane-polarized and cross-polarized light , including their birefringence , pleochroism , twinning , and interference properties with a conoscopic lens . 
stable and radioactive isotope studies provide insight into the geochemical evolution of rock units . 
in addition to identifying rocks in the field , petrologists identify rock samples in the laboratory . 
in an optical mineralogy analysis , thin sections of rock samples are analyzed through a petrographic microscope , where the minerals can be identified through their different properties in plane-polarized and cross-polarized light , including their birefringence , pleochroism , twinning , and interference properties with a conoscopic lens . 
petrologists can also use fluid inclusion data and perform high temperature and pressure physical experiments to understand the temperatures and pressures at which different mineral phases appear , and how they change through igneous and metamorphic processes . 
petrologists can also use fluid inclusion data and perform high temperature and pressure physical experiments to understand the temperatures and pressures at which different mineral phases appear , and how they change through igneous and metamorphic processes . 
this research can be extrapolated to the field to understand metamorphic processes and the conditions of crystallization of igneous rocks . 
structural geologists use microscopic analysis of oriented thin sections of geologic samples to observe the fabric within the rocks which gives information about strain within the crystalline structure of the rocks . 
structural geologists use microscopic analysis of oriented thin sections of geologic samples to observe the fabric within the rocks which gives information about strain within the crystalline structure of the rocks . 
they also plot and combine measurements of geological structures in order to better understand the orientations of faults and folds in order to reconstruct the history of rock deformation in the area . 
in addition , they perform analog and numerical experiments of rock deformation in large and small settings . 
among the most well-known experiments in structural geology are those involving orogenic wedges , which are zones in which mountains are built along convergent tectonic plate boundaries . 
among the most well-known experiments in structural geology are those involving orogenic wedges , which are zones in which mountains are built along convergent tectonic plate boundaries . 
in the analog versions of these experiments , horizontal layers of sand are pulled along a lower surface into a back stop , which results in realistic-looking patterns of faulting and the growth of a critically tapered -lrb- all angles remain the same -rrb- orogenic wedge . 
in the analog versions of these experiments , horizontal layers of sand are pulled along a lower surface into a back stop , which results in realistic-looking patterns of faulting and the growth of a critically tapered -lrb- all angles remain the same -rrb- orogenic wedge . 
numerical models work in the same way as these analog models , though they are often more sophisticated and can include patterns of erosion and uplift in the mountain belt . 
in the laboratory , stratigraphers analyze samples of stratigraphic sections that can be returned from the field , such as those from drill cores . 
stratigraphers also analyze data from geophysical surveys that show the locations of stratigraphic units in the subsurface . 
geophysical data and well logs can be combined to produce a better view of the subsurface , and stratigraphers often use computer programs to do this in three dimensions . 
geophysical data and well logs can be combined to produce a better view of the subsurface , and stratigraphers often use computer programs to do this in three dimensions . 
stratigraphers can then use these data to reconstruct ancient processes occurring on the surface of the earth , interpret past environments , and locate areas for water , coal , and hydrocarbon extraction . 
geochronologists precisely date rocks within the stratigraphic section in order to provide better absolute bounds on the timing and rates of deposition . 
in the laboratory , biostratigraphers analyze rock samples from outcrop and drill cores for the fossils found in them . 
magnetic stratigraphers look for signs of magnetic reversals in igneous rock units within the drill cores . 
geochronologists precisely date rocks within the stratigraphic section in order to provide better absolute bounds on the timing and rates of deposition . 
some modern scholars , such as fielding h. garrison , are of the opinion that the origin of the science of geology can be traced to persia after the muslim conquests had come to an end . 
abu al-rayhan al-biruni -lrb- 973 -- 1048 ce -rrb- was one of the earliest persian geologists , whose works included the earliest writings on the geology of india , hypothesizing that the indian subcontinent was once a sea . 
in china , the polymath shen kuo -lrb- 1031 -- 1095 -rrb- formulated a hypothesis for the process of land formation : based on his observation of fossil animal shells in a geological stratum in a mountain hundreds of miles from the ocean , he inferred that the land was formed by erosion of the mountains and by deposition of silt . 
drawing from greek and indian scientific literature that were not destroyed by the muslim conquests , the persian scholar ibn sina -lrb- avicenna , 981 -- 1037 -rrb- proposed detailed explanations for the formation of mountains , the origin of earthquakes , and other topics central to modern geology , which provided an essential foundation for the later development of the science . 
in china , the polymath shen kuo -lrb- 1031 -- 1095 -rrb- formulated a hypothesis for the process of land formation : based on his observation of fossil animal shells in a geological stratum in a mountain hundreds of miles from the ocean , he inferred that the land was formed by erosion of the mountains and by deposition of silt . 
james hutton is often viewed as the first modern geologist . 
in 1785 he presented a paper entitled theory of the earth to the royal society of edinburgh . 
hutton published a two-volume version of his ideas in 1795 -lrb- vol . 
in his paper , he explained his theory that the earth must be much older than had previously been supposed in order to allow enough time for mountains to be eroded and for sediments to form new rocks at the bottom of the sea , which in turn were raised up to become dry land . 
the first geological map of the u.s. was produced in 1809 by william maclure . 
the first geological map of the u.s. was produced in 1809 by william maclure . 
in 1807 , maclure commenced the self-imposed task of making a geological survey of the united states . 
the results of his unaided labours were submitted to the american philosophical society in a memoir entitled observations on the geology of the united states explanatory of a geological map , and published in the society 's transactions , together with the nation 's first geological map . 
the results of his unaided labours were submitted to the american philosophical society in a memoir entitled observations on the geology of the united states explanatory of a geological map , and published in the society 's transactions , together with the nation 's first geological map . 
sir charles lyell first published his famous book , principles of geology , in 1830 . 
this book , which influenced the thought of charles darwin , successfully promoted the doctrine of uniformitarianism . 
this book , which influenced the thought of charles darwin , successfully promoted the doctrine of uniformitarianism . 
in contrast , catastrophism is the theory that earth 's features formed in single , catastrophic events and remained unchanged thereafter . 
this book , which influenced the thought of charles darwin , successfully promoted the doctrine of uniformitarianism . 
newcastle upon tyne -lrb- rp : i / ˌnjuːkɑːsəl əˌpɒn ˈtaɪn / ; locally : i/nju ːˌkæsəl əˌpən ˈtaɪn / -rrb- , commonly known as newcastle , is a city in tyne and wear , north east england , 103 miles -lrb- 166 km -rrb- south of edinburgh and 277 miles -lrb- 446 km -rrb- north of london on the northern bank of the river tyne , 8.5 mi -lrb- 13.7 km -rrb- from the north sea . 
newcastle upon tyne -lrb- rp : i / ˌnjuːkɑːsəl əˌpɒn ˈtaɪn / ; locally : i/nju ːˌkæsəl əˌpən ˈtaɪn / -rrb- , commonly known as newcastle , is a city in tyne and wear , north east england , 103 miles -lrb- 166 km -rrb- south of edinburgh and 277 miles -lrb- 446 km -rrb- north of london on the northern bank of the river tyne , 8.5 mi -lrb- 13.7 km -rrb- from the north sea . 
newcastle is a member of the english core cities group and is a member of the eurocities network of european cities . 
newcastle was part of the county of northumberland until 1400 , when it became a county itself , a status it retained until becoming part of tyne and wear in 1974 . 
-lsb- not in citation given -rsb- the regional nickname and dialect for people from newcastle and the surrounding area is geordie . 
the city developed around the roman settlement pons aelius and was named after the castle built in 1080 by robert curthose , william the conqueror 's eldest son . 
the city grew as an important centre for the wool trade in the 14th century , and later became a major coal mining area . 
the city grew as an important centre for the wool trade in the 14th century , and later became a major coal mining area . 
the port developed in the 16th century and , along with the shipyards lower down the river tyne , was amongst the world 's largest shipbuilding and ship-repairing centres . 
it has hosted the world 's most popular half marathon , the great north run , since it began in 1981 . 
the first recorded settlement in what is now newcastle was pons aelius , a roman fort and bridge across the river tyne . 
the first recorded settlement in what is now newcastle was pons aelius , a roman fort and bridge across the river tyne . 
the population of pons aelius at this period was estimated at 2,000 . 
fragments of hadrian 's wall are still visible in parts of newcastle , particularly along the west road . 
the extent of hadrian 's wall was 73 miles -lrb- 117 km -rrb- , spanning the width of britain ; the wall incorporated the vallum , a large rearward ditch with parallel mounds , and was constructed primarily for defence , to prevent unwanted immigration and the incursion of pictish tribes from the north , not as a fighting line for a major invasion . 
throughout the middle ages , newcastle was england 's northern fortress . 
incorporated first by henry ii , the city had a new charter granted by elizabeth in 1589 . 
a 25-foot -lrb- 7.6 m -rrb- high stone wall was built around the town in the 13th century , to defend it from invaders during the border war against scotland . 
the scots king william the lion was imprisoned in newcastle in 1174 , and edward i brought the stone of scone and william wallace south through the town . 
newcastle was successfully defended against the scots three times during the 14th century , and was created a county corporate with its own sheriff by henry iv in 1400 . 
from 1530 a royal act restricted all shipments of coal from tyneside to newcastle quayside , giving a monopoly in the coal trade to a cartel of newcastle burgesses known as the hostmen . 
from 1530 a royal act restricted all shipments of coal from tyneside to newcastle quayside , giving a monopoly in the coal trade to a cartel of newcastle burgesses known as the hostmen . 
the phrase itself means a pointless pursuit . 
in the 18th century american timothy dexter , an entrepreneur , widely regarded as an eccentric , defied this idiom . 
he was persuaded to sail a shipment of coal to newcastle by merchants plotting to ruin him ; however his shipment arrived on the tyne during a strike that had crippled local production ; unexpectedly he made a considerable profit . 
in the sandgate area , to the east of the city and beside the river , resided the close-knit community of keelmen and their families . 
they were so called because they worked on the keels , boats that were used to transfer coal from the river banks to the waiting colliers , for export to london and elsewhere . 
in the 1630s about 7,000 out of 20,000 inhabitants of newcastle died of plague , more than one-third of the population . 
specifically within the year 1636 , it is roughly estimated with evidence held by the society of antiquaries that 47 % of the then population of newcastle died from the epidemic ; this may also have been the most devastating loss in any british city in this period . 
specifically within the year 1636 , it is roughly estimated with evidence held by the society of antiquaries that 47 % of the then population of newcastle died from the epidemic ; this may also have been the most devastating loss in any british city in this period . 
during the english civil war , the north declared for the king . 
in a bid to gain newcastle and the tyne , cromwell 's allies , the scots , captured the town of newburn . 
in 1644 the city was then besieged for many months and was eventually stormed -lrb- ` with roaring drummes ' -rrb- and sacked by cromwell 's allies . 
the grateful king bestowed the motto `` fortiter defendit triumphans '' -lrb- `` triumphing by a brave defence '' -rrb- upon the town . 
charles i was imprisoned in newcastle by the scots in 1646 -- 7 . 
this revolution resulted in the urbanization of the city . 
in 1817 the maling company , at one time the largest pottery company in the world , moved to the city . 
newcastle was one of the first cities in the world to be lit up by electric lighting . 
in the 19th century , shipbuilding and heavy engineering were central to the city 's prosperity ; and the city was a powerhouse of the industrial revolution . 
innovations in newcastle and surrounding areas included the development of safety lamps , stephenson 's rocket , lord armstrong 's artillery , be-ro flour , joseph swan 's electric light bulbs , and charles parsons ' invention of the steam turbine , which led to the revolution of marine propulsion and the production of cheap electricity . 
in large parts , newcastle still retains a medieval street layout . 
narrow alleys or ` chares ' , most of which can only be traversed by foot , still exist in abundance , particularly around the riverside . 
stairs from the riverside to higher parts of the city centre and the extant castle keep , originally recorded in the 14th century , remain intact in places . 
close , sandhill and quayside contain modern buildings as well as structures dating from the 15th -- 18th centuries , including bessie surtees house , the cooperage and lloyds quayside bars , derwentwater house and `` house of tides '' , a restaurant situated at a grade i-listed 16th century merchant 's house at 28 -- 30 close . 
close , sandhill and quayside contain modern buildings as well as structures dating from the 15th -- 18th centuries , including bessie surtees house , the cooperage and lloyds quayside bars , derwentwater house and `` house of tides '' , a restaurant situated at a grade i-listed 16th century merchant 's house at 28 -- 30 close . 
the city has an extensive neoclassical centre referred to as tyneside classical largely developed in the 1830s by richard grainger and john dobson , and recently extensively restored . 
broadcaster and writer stuart maconie described newcastle as england 's best-looking city and the late german-born british scholar of architecture , nikolaus pevsner , describes grey street as one of the finest streets in england . 
broadcaster and writer stuart maconie described newcastle as england 's best-looking city and the late german-born british scholar of architecture , nikolaus pevsner , describes grey street as one of the finest streets in england . 
a portion of grainger town was demolished in the 1960s to make way for the eldon square shopping centre , including all but one side of the original eldon square itself . 
a portion of grainger town was demolished in the 1960s to make way for the eldon square shopping centre , including all but one side of the original eldon square itself . 
another green space in newcastle is the town moor , lying immediately north of the city centre . 
it is larger than london 's famous hyde park and hampstead heath put together and the freemen of the city have the right to graze cattle on it . 
the hoppings funfair , said to be the largest travelling funfair in europe , is held here annually in june . 
the hoppings funfair , said to be the largest travelling funfair in europe , is held here annually in june . 
honorary freemen include bob geldof , king harald v of norway , bobby robson , alan shearer , the late nelson mandela and the royal shakespeare company . 
large-scale regeneration has replaced former shipping premises with imposing new office developments ; an innovative tilting bridge , the gateshead millennium bridge was commissioned by gateshead council and has integrated the older newcastle quayside more closely with major cultural developments in gateshead , including the baltic centre for contemporary art , the venue for the turner prize 2011 and the norman foster-designed the sage gateshead music centre . 
large-scale regeneration has replaced former shipping premises with imposing new office developments ; an innovative tilting bridge , the gateshead millennium bridge was commissioned by gateshead council and has integrated the older newcastle quayside more closely with major cultural developments in gateshead , including the baltic centre for contemporary art , the venue for the turner prize 2011 and the norman foster-designed the sage gateshead music centre . 
large-scale regeneration has replaced former shipping premises with imposing new office developments ; an innovative tilting bridge , the gateshead millennium bridge was commissioned by gateshead council and has integrated the older newcastle quayside more closely with major cultural developments in gateshead , including the baltic centre for contemporary art , the venue for the turner prize 2011 and the norman foster-designed the sage gateshead music centre . 
as a tourist promotion , newcastle and gateshead have linked together under the banner `` newcastlegateshead '' , to spearhead the regeneration of the north-east . 
the river tyne had the temporary bambuco bridge in 2008 for ten days ; it was not made for walking , road or cycling , but was just a sculpture . 
the historic heart of newcastle is the grainger town area . 
established on classical streets built by richard grainger , a builder and developer , between 1835 and 1842 , some of newcastle upon tyne 's finest buildings and streets lie within this area of the city centre including grainger market , theatre royal , grey street , grainger street and clayton street . 
these buildings are predominantly four stories high , with vertical dormers , domes , turrets and spikes . 
of grainger town 's 450 buildings , 244 are listed , of which 29 are grade i and 49 are grade ii * . 
the grainger market replaced an earlier market originally built in 1808 called the butcher market . 
the grainger market itself , was opened in 1835 and was newcastle 's first indoor market . 
the opening was celebrated with a grand dinner attended by 2000 guests , and the laing art gallery has a painting of this event . 
the opening was celebrated with a grand dinner attended by 2000 guests , and the laing art gallery has a painting of this event . 
the grainger market architecture , like most in grainger town , which are either grade i or ii listed , was listed grade i in 1954 by english heritage . 
the climate in newcastle is oceanic -lrb- köppen cfb -rrb- and significantly milder than some other locations in the world at a similar latitude , due to the warming influence of the gulf stream -lrb- via the north atlantic drift -rrb- . 
the climate in newcastle is oceanic -lrb- köppen cfb -rrb- and significantly milder than some other locations in the world at a similar latitude , due to the warming influence of the gulf stream -lrb- via the north atlantic drift -rrb- . 
being in the rain shadow of the north pennines , it is among the driest cities in the uk . 
temperature extremes recorded at newcastle weather centre include 32.5 °c -lrb- 90.5 °f -rrb- during august 1990 down to − 12.6 °c -lrb- 9.3 °f -rrb- during january 1982 . 
in contrast to other areas influenced by the gulf stream , such as inland scandinavia , newcastle has milder winters and cooler summers , similar to the remainder of the british isles . 
in 2010 , newcastle was positioned ninth in the retail centre expenditure league of the uk . 
the largest of these is the eldon square shopping centre , one of the largest city centre shopping complexes in the uk . 
newcastle store bainbridge 's , opened in 1838 , is often cited as the world 's first department store . 
the bainbridge 's official ledgers reported revenue by department , giving birth to the name department store . 
a new bus station , replacing the old underground bus station , was officially opened in march 2007 . 
other shopping destinations in newcastle include grainger street and the area around grey 's monument , the relatively modern eldon garden and monument mall complexes , the newgate centre , central arcade and the traditional grainger market . 
outside the city centre , the largest suburban shopping areas are gosforth and byker . 
the largest tesco store in the united kingdom is located in kingston park on the edge of newcastle . 
close to newcastle , the largest indoor shopping centre in europe , the metrocentre , is located in gateshead . 
close to newcastle , the largest indoor shopping centre in europe , the metrocentre , is located in gateshead . 
the tyneside flat was the dominant housing form constructed at the time when the industrial centres on tyneside were growing most rapidly . 
tyneside flats were built as terraces , one of each pair of doors led to an upstairs flat while the other led into the ground-floor flat , each of two or three rooms . 
a new development in the ouseburn valley has recreated them ; architects cany ash and robert sakula were attracted by the possibilities of high density without building high and getting rid of common areas . 
a new development in the ouseburn valley has recreated them ; architects cany ash and robert sakula were attracted by the possibilities of high density without building high and getting rid of common areas . 
a new development in the ouseburn valley has recreated them ; architects cany ash and robert sakula were attracted by the possibilities of high density without building high and getting rid of common areas . 
in terms of housing stock , the authority is one of few authorities to see the proportion of detached homes rise in the 2010 census -lrb- to 7.8 % -rrb- , in this instance this was coupled with a similar rise in flats and waterside apartments to 25.6 % , and the proportion of converted or shared houses in 2011 renders this dwelling type within the highest of the five colour-coded brackets at 5.9 % , and on a par with oxford and reading , greater than manchester and liverpool and below a handful of historic densely occupied , arguably overinflated markets in the local authorities : harrogate , cheltenham , bath , inner london , hastings , brighton and tunbridge wells . 
in terms of housing stock , the authority is one of few authorities to see the proportion of detached homes rise in the 2010 census -lrb- to 7.8 % -rrb- , in this instance this was coupled with a similar rise in flats and waterside apartments to 25.6 % , and the proportion of converted or shared houses in 2011 renders this dwelling type within the highest of the five colour-coded brackets at 5.9 % , and on a par with oxford and reading , greater than manchester and liverpool and below a handful of historic densely occupied , arguably overinflated markets in the local authorities : harrogate , cheltenham , bath , inner london , hastings , brighton and tunbridge wells . 
in terms of housing stock , the authority is one of few authorities to see the proportion of detached homes rise in the 2010 census -lrb- to 7.8 % -rrb- , in this instance this was coupled with a similar rise in flats and waterside apartments to 25.6 % , and the proportion of converted or shared houses in 2011 renders this dwelling type within the highest of the five colour-coded brackets at 5.9 % , and on a par with oxford and reading , greater than manchester and liverpool and below a handful of historic densely occupied , arguably overinflated markets in the local authorities : harrogate , cheltenham , bath , inner london , hastings , brighton and tunbridge wells . 
in terms of housing stock , the authority is one of few authorities to see the proportion of detached homes rise in the 2010 census -lrb- to 7.8 % -rrb- , in this instance this was coupled with a similar rise in flats and waterside apartments to 25.6 % , and the proportion of converted or shared houses in 2011 renders this dwelling type within the highest of the five colour-coded brackets at 5.9 % , and on a par with oxford and reading , greater than manchester and liverpool and below a handful of historic densely occupied , arguably overinflated markets in the local authorities : harrogate , cheltenham , bath , inner london , hastings , brighton and tunbridge wells . 
in terms of housing stock , the authority is one of few authorities to see the proportion of detached homes rise in the 2010 census -lrb- to 7.8 % -rrb- , in this instance this was coupled with a similar rise in flats and waterside apartments to 25.6 % , and the proportion of converted or shared houses in 2011 renders this dwelling type within the highest of the five colour-coded brackets at 5.9 % , and on a par with oxford and reading , greater than manchester and liverpool and below a handful of historic densely occupied , arguably overinflated markets in the local authorities : harrogate , cheltenham , bath , inner london , hastings , brighton and tunbridge wells . 
according to the uk government 's returned 2001 census information , the city of newcastle had a population of 189,863 , whereas the metropolitan borough of newcastle had a population of around 259,000 . 
according to the uk government 's returned 2001 census information , the city of newcastle had a population of 189,863 , whereas the metropolitan borough of newcastle had a population of around 259,000 . 
newcastle is also home to a large student population with newcastle and northumbria universities in the local area . 
newcastle is also home to a large student population with newcastle and northumbria universities in the local area . 
areas with predominant student populations include jesmond and heaton . 
according to the same statistics , the average age of people living in newcastle is 37.8 -lrb- the national average being 38.6 -rrb- . 
many people in the city have scottish or irish ancestors . 
there is a strong presence of border reiver surnames , such as armstrong , charlton , elliot , johnstone , kerr , hall , nixon , little and robson . 
there are also estimated to be between 500 and 2,000 bolivians in newcastle , forming up to 1 % of the population -- the largest such percentage of any uk city . 
there are also estimated to be between 500 and 2,000 bolivians in newcastle , forming up to 1 % of the population -- the largest such percentage of any uk city . 
the dialect of newcastle is known as geordie , and contains a large amount of vocabulary and distinctive word pronunciations not used in other parts of the united kingdom . 
the geordie dialect has much of its origins in the language spoken by the anglo-saxon populations who migrated to and conquered much of england after the end of roman imperial rule . 
this language was the forerunner of modern english ; but while the dialects of other english regions have been heavily altered by the influences of other foreign languages -- particularly latin and norman french -- the geordie dialect retains many elements of the old language . 
an example of this is the pronunciation of certain words : `` dead '' , `` cow '' , `` house '' and `` strong '' are pronounced `` deed '' , `` coo '' , `` hoos '' and `` strang '' -- which is how they were pronounced in the anglo-saxon language . 
other geordie words with anglo-saxon origins include : `` larn '' -lrb- from the anglo-saxon `` laeran '' , meaning `` teach '' -rrb- , `` burn '' -lrb- `` stream '' -rrb- and `` gan '' -lrb- `` go '' -rrb- . 
`` bairn '' and `` hyem '' , meaning `` child '' and `` home '' , respectively , are examples of geordie words with origins in scandinavia ; barn and hjem are the corresponding modern norwegian and danish words . 
some words used in the geordie dialect are used elsewhere in the northern united kingdom . 
the words `` bonny '' -lrb- meaning `` pretty '' -rrb- , `` howay '' -lrb- `` come on '' -rrb- , `` stot '' -lrb- `` bounce '' -rrb- and `` hadaway '' -lrb- `` go away '' or `` you 're kidding '' -rrb- , all appear to be used in scots ; `` aye '' -lrb- `` yes '' -rrb- and `` nowt '' -lrb- ipa : / / naʊt / , rhymes with out , `` nothing '' -rrb- are used elsewhere in northern england . 
many words , however , appear to be used exclusively in newcastle and the surrounding area , such as `` canny '' -lrb- a versatile word meaning `` good '' , `` nice '' or `` very '' -rrb- , `` hacky '' -lrb- `` dirty '' -rrb- , `` netty '' -lrb- `` toilet '' -rrb- , `` hoy '' -lrb- `` throw '' , from the dutch gooien , via west frisian -rrb- , `` hockle '' -lrb- `` spit '' -rrb- . 
many words , however , appear to be used exclusively in newcastle and the surrounding area , such as `` canny '' -lrb- a versatile word meaning `` good '' , `` nice '' or `` very '' -rrb- , `` hacky '' -lrb- `` dirty '' -rrb- , `` netty '' -lrb- `` toilet '' -rrb- , `` hoy '' -lrb- `` throw '' , from the dutch gooien , via west frisian -rrb- , `` hockle '' -lrb- `` spit '' -rrb- . 
in a report , published in early february 2007 by the ear institute at the university college london , and widex , a danish hearing aid manufacturer , newcastle was named as the noisiest city in the whole of the uk , with an average level of 80.4 decibels . 
in a report , published in early february 2007 by the ear institute at the university college london , and widex , a danish hearing aid manufacturer , newcastle was named as the noisiest city in the whole of the uk , with an average level of 80.4 decibels . 
in a report , published in early february 2007 by the ear institute at the university college london , and widex , a danish hearing aid manufacturer , newcastle was named as the noisiest city in the whole of the uk , with an average level of 80.4 decibels . 
the report claimed that these noise levels would have a negative long-term impact on the health of the city 's residents . 
the report was criticized , however , for attaching too much weight to readings at arbitrarily selected locations , which in newcastle 's case included a motorway underpass without pedestrian access . 
there are many bars on the bigg market , and other popular areas for nightlife are collingwood street , popularly referred to as the ` diamond strip ' due to its concentration of high-end bars , neville street , the central station area and osborne road in the jesmond area of the city . 
in recent years `` the gate '' has opened in the city centre , a new indoor complex consisting of bars , upmarket clubs , restaurants and a 12-screen empire multiplex cinema . 
in recent years `` the gate '' has opened in the city centre , a new indoor complex consisting of bars , upmarket clubs , restaurants and a 12-screen empire multiplex cinema . 
newcastle 's gay scene - ` the pink triangle ' - is centred on the times square area near the centre for life and has a range of bars , cafés and clubs . 
newcastle 's gay scene - ` the pink triangle ' - is centred on the times square area near the centre for life and has a range of bars , cafés and clubs . 
the city has a proud history of theatre . 
stephen kemble of the famous kemble family successfully managed the original theatre royal , newcastle for fifteen years -lrb- 1791 -- 1806 -rrb- . 
stephen kemble guided the theatre through many celebrated seasons . 
the original theatre royal in newcastle was opened on 21 january 1788 and was located on mosley street . 
it was demolished to make way for grey street , where its replacement was built . 
the city still contains many theatres . 
the largest , the theatre royal on grey street , first opened in 1837 , designed by john and benjamin green . 
it has hosted a season of performances from the royal shakespeare company for over 25 years , as well as touring productions of west end musicals . 
the mill volvo tyne theatre hosts smaller touring productions , whilst other venues feature local talent . 
newcastlegateshead was voted in 2006 as the arts capital of the uk in a survey conducted by the artsworld tv channel . 
the literary and philosophical society of newcastle upon tyne -lrb- popularly known as the ` lit & phil ' -rrb- is the largest independent library outside london , housing more than 150,000 books . 
its music library contains 8000 cds and 10,000 lps . 
the current lit and phil premises were built in 1825 and the building was designed by john and benjamin green . 
operating since 1793 and founded as a ` conversation club , ' its lecture theatre was the first public building to be lit by electric light , during a lecture by joseph swan on 20 october 1880 . 
operating since 1793 and founded as a ` conversation club , ' its lecture theatre was the first public building to be lit by electric light , during a lecture by joseph swan on 20 october 1880 . 
the newcastle beer festival , organized by camra , takes place in april . 
in may , newcastle and gateshead host the evolution festival , a music festival held on the newcastle and gateshead quaysides over the spring bank holiday , with performances by acts from the world of rock , indie and dance music . 
the biennial av festival of international electronic art , featuring exhibitions , concerts , conferences and film screenings , is held in march . 
eat ! 
newcastlegateshead , a festival of food and drink , runs for 2 weeks each year in mid june . 
the hoppings , reputedly the largest travelling fair in europe , takes place on newcastle town moor every june . 
the hoppings , reputedly the largest travelling fair in europe , takes place on newcastle town moor every june . 
the event has its origins in the temperance movement during the early 1880s and coincides with the annual race week at high gosforth park . 
the northern rock cyclone , a cycling festival , takes place within , or starting from , newcastle in june . 
the northern pride festival and parade is held in leazes park and in the city 's gay community in mid july . 
newcastle mela , held on the late august bank holiday weekend , is an annual two-day multicultural event , blending drama , music and food from punjabi , pakistani , bengali and hindu cultures . 
the 2009 event will be in the norman foster designed sage gateshead music and arts centre in september . 
in october , there is the design event festival -- an annual festival providing the public with an opportunity to see work by regional , national and international designers . 
the sama festival , an east asian cultural festival is also held in early october . 
newcastlegateshead also holds an annual international arts fair . 
lindisfarne are a folk-rock group with a strong tyneside connection . 
their most famous song , `` fog on the tyne '' -lrb- 1971 -rrb- , was covered by geordie ex-footballer paul gascoigne in 1990 . 
venom , reckoned by many to be the originators of black metal and extremely influential to the extreme metal scene as a whole , formed in newcastle in 1979 . 
folk metal band skyclad , often regarded as the first folk metal band , also formed in newcastle after the break-up of martin walkyier thrash metal band , sabbat . 
andy taylor , former lead guitarist of duran duran was born here in 1961 . 
the pilgrim street building was refurbished between november 2006 and may 2008 ; during the refurbishment works , the cinema relocated to the old town hall , gateshead . 
the pilgrim street building was refurbished between november 2006 and may 2008 ; during the refurbishment works , the cinema relocated to the old town hall , gateshead . 
the site currently houses three cinemas , including the restored classic -- the united kingdom 's last surviving news cinema still in full-time operation -- alongside two new screens , a roof extension containing the tyneside bar , and dedicated education and teaching suites . 
the site currently houses three cinemas , including the restored classic -- the united kingdom 's last surviving news cinema still in full-time operation -- alongside two new screens , a roof extension containing the tyneside bar , and dedicated education and teaching suites . 
the site currently houses three cinemas , including the restored classic -- the united kingdom 's last surviving news cinema still in full-time operation -- alongside two new screens , a roof extension containing the tyneside bar , and dedicated education and teaching suites . 
there are several museums and galleries in newcastle , including the centre for life with its science village ; the discovery museum a museum highlighting life on tyneside , including tyneside 's shipbuilding heritage , and inventions which changed the world ; the great north museum ; in 2009 the newcastle on tyne museum of antiquities merged with the great north museum -lrb- hancock museum -rrb- ; seven stories a museum dedicated to children 's books , the side gallery historical and contemporary photography from around the world and northern england and the newburn hall motor museum . 
there are several museums and galleries in newcastle , including the centre for life with its science village ; the discovery museum a museum highlighting life on tyneside , including tyneside 's shipbuilding heritage , and inventions which changed the world ; the great north museum ; in 2009 the newcastle on tyne museum of antiquities merged with the great north museum -lrb- hancock museum -rrb- ; seven stories a museum dedicated to children 's books , the side gallery historical and contemporary photography from around the world and northern england and the newburn hall motor museum . 
there are several museums and galleries in newcastle , including the centre for life with its science village ; the discovery museum a museum highlighting life on tyneside , including tyneside 's shipbuilding heritage , and inventions which changed the world ; the great north museum ; in 2009 the newcastle on tyne museum of antiquities merged with the great north museum -lrb- hancock museum -rrb- ; seven stories a museum dedicated to children 's books , the side gallery historical and contemporary photography from around the world and northern england and the newburn hall motor museum . 
there are several museums and galleries in newcastle , including the centre for life with its science village ; the discovery museum a museum highlighting life on tyneside , including tyneside 's shipbuilding heritage , and inventions which changed the world ; the great north museum ; in 2009 the newcastle on tyne museum of antiquities merged with the great north museum -lrb- hancock museum -rrb- ; seven stories a museum dedicated to children 's books , the side gallery historical and contemporary photography from around the world and northern england and the newburn hall motor museum . 
there are several museums and galleries in newcastle , including the centre for life with its science village ; the discovery museum a museum highlighting life on tyneside , including tyneside 's shipbuilding heritage , and inventions which changed the world ; the great north museum ; in 2009 the newcastle on tyne museum of antiquities merged with the great north museum -lrb- hancock museum -rrb- ; seven stories a museum dedicated to children 's books , the side gallery historical and contemporary photography from around the world and northern england and the newburn hall motor museum . 
the earliest known movie featuring some exterior scenes filmed in the city is on the night of the fire -lrb- 1939 -rrb- , though by and large the action is studio-bound . 
the 1971 film get carter was shot on location in and around newcastle and offers an opportunity to see what newcastle looked like in the 1960s and early 1970s . 
the city was also backdrop to another gangster film , the 1988 film noir thriller stormy monday , directed by mike figgis and starring tommy lee jones , melanie griffith , sting and sean bean . 
the city was also backdrop to another gangster film , the 1988 film noir thriller stormy monday , directed by mike figgis and starring tommy lee jones , melanie griffith , sting and sean bean . 
the city was also backdrop to another gangster film , the 1988 film noir thriller stormy monday , directed by mike figgis and starring tommy lee jones , melanie griffith , sting and sean bean . 
newcastle has a horse racing course at gosforth park . 
the city is also home to the newcastle eagles basketball team who play their home games at the new sport central complex at northumbria university . 
the city 's speedway team newcastle diamonds are based at brough park in byker , a venue that is also home to greyhound racing . 
the city 's speedway team newcastle diamonds are based at brough park in byker , a venue that is also home to greyhound racing . 
another famous athletic event is the 5.9-mile -lrb- 9.5 km -rrb- blaydon race -lrb- a road race from newcastle to blaydon -rrb- , which has taken place on 9 june annually since 1981 , to commemorate the celebrated blaydon races horse racing . 
newcastle international airport is located approximately 6 miles -lrb- 9.7 km -rrb- from the city centre on the northern outskirts of the city near ponteland and is the larger of the two main airports serving the north east . 
it is connected to the city via the metro light rail system and a journey into newcastle city centre takes approximately 20 minutes . 
it is connected to the city via the metro light rail system and a journey into newcastle city centre takes approximately 20 minutes . 
the airport handles over five million passengers per year , and is the tenth largest , and the fastest growing regional airport in the uk , expecting to reach 10 million passengers by 2016 , and 15 million by 2030 . 
as of 2007 -lsb- update -rsb- , over 90 destinations are available worldwide . 
glazing was placed over the historic arches and the victorian architecture was enhanced ; transforming the 19th century public portico . 
the station is one of only six grade one listed railway stations in the uk . 
opened in 1850 by queen victoria , it was the first covered railway station in the world and was much copied across the uk . 
it has a neoclassical façade , originally designed by the architect john dobson , and was constructed in collaboration with robert stephenson . 
the city 's other mainline station , manors , is to the east of the city centre . 
train operator virgin trains east coast provides a half-hourly frequency of trains to london king 's cross , with a journey time of about three hours , these services call at durham , darlington , york , doncaster , newark north gate and peterborough and north to scotland with all trains calling at edinburgh and a small number of trains extended to glasgow , aberdeen and inverness . 
train operator virgin trains east coast provides a half-hourly frequency of trains to london king 's cross , with a journey time of about three hours , these services call at durham , darlington , york , doncaster , newark north gate and peterborough and north to scotland with all trains calling at edinburgh and a small number of trains extended to glasgow , aberdeen and inverness . 
train operator virgin trains east coast provides a half-hourly frequency of trains to london king 's cross , with a journey time of about three hours , these services call at durham , darlington , york , doncaster , newark north gate and peterborough and north to scotland with all trains calling at edinburgh and a small number of trains extended to glasgow , aberdeen and inverness . 
crosscountry trains serve destinations in yorkshire , the midlands and the south west . 
northern rail provides local and regional services . 
the city is served by the tyne and wear metro , a system of suburban and underground railways covering much of tyne and wear . 
it was opened in five phases between 1980 and 1984 , and was britain 's first urban light rail transit system ; two extensions were opened in 1991 and 2002 . 
it was developed from a combination of existing and newly built tracks and stations , with deep-level tunnels constructed through newcastle city centre . 
a bridge was built across the tyne , between newcastle and gateshead , and opened by queen elizabeth ii in 1981 . 
the network is operated by db regio on behalf of nexus and carries over 37 million passengers a year , extending as far as newcastle airport , tynemouth , south shields and south hylton in sunderland . 
the system is currently undergoing a period of refurbishment and modernization , entitled ` metro : all change . ' 
the programme has replaced all ticket machines and introduced ticket gates at the busiest stations - part of the transition to smart ticketing . 
in addition ; tracks , signalling and overhead wires are also being overhauled . 
longer term plans include the procurement of an entirely new fleet of trains and further extensions to the system . 
several of the proposed routes would require trams as opposed to the current light rail trains . 
major roads in the area include the a1 -lrb- gateshead newcastle western bypass -rrb- , stretching north to edinburgh and south to london ; the a19 heading south past sunderland and middlesbrough to york and doncaster ; the a69 heading west to carlisle ; the a696 , which becomes the a68 heads past newcastle airport and up through central northumberland and central scottish borders , the a167 , the old `` great north road '' , heading south to gateshead , chester-le-street , durham and darlington ; and the a1058 `` coast road '' , which runs from jesmond to the east coast between tynemouth and cullercoats . 
major roads in the area include the a1 -lrb- gateshead newcastle western bypass -rrb- , stretching north to edinburgh and south to london ; the a19 heading south past sunderland and middlesbrough to york and doncaster ; the a69 heading west to carlisle ; the a696 , which becomes the a68 heads past newcastle airport and up through central northumberland and central scottish borders , the a167 , the old `` great north road '' , heading south to gateshead , chester-le-street , durham and darlington ; and the a1058 `` coast road '' , which runs from jesmond to the east coast between tynemouth and cullercoats . 
major roads in the area include the a1 -lrb- gateshead newcastle western bypass -rrb- , stretching north to edinburgh and south to london ; the a19 heading south past sunderland and middlesbrough to york and doncaster ; the a69 heading west to carlisle ; the a696 , which becomes the a68 heads past newcastle airport and up through central northumberland and central scottish borders , the a167 , the old `` great north road '' , heading south to gateshead , chester-le-street , durham and darlington ; and the a1058 `` coast road '' , which runs from jesmond to the east coast between tynemouth and cullercoats . 
many of these designations are recent -- upon completion of the western bypass , and its designation as the new line of the a1 , the roads between this and the a1 's former alignment through the tyne tunnel were renumbered , with many city centre roads changing from a 6-prefix to their present 1-prefix numbers . 
in november 2011 the capacity of the tyne tunnel was increased when a project to build a second road tunnel and refurbish the first tunnel was completed . 
there are 3 main bus companies providing services in the city ; arriva north east , go north east and stagecoach north east . 
there are two major bus stations in the city : haymarket bus station and eldon square bus station . 
stagecoach is the primary operator in the city proper , with cross-city services mainly between both the west and east ends via the city centre with some services extending out to the metrocentre , killingworth , wallsend and ponteland . 
bus services in newcastle upon tyne and the surrounding boroughs part of the tyne and wear area are coordinated by nexus , the tyne and wear passenger transport executive . 
go-ahead operates from eldon square bus station , providing the majority of services south of the river in gateshead , south tyneside , sunderland , and county durham . 
following guidelines set in the national cycling strategy , newcastle first developed its cycling strategy in 1998 . 
as of 2012 , the local council social aims and objectives for cycling include : highlighting the usage of cycling to cut city congestion ; educating that cycling promotes healthy living ... the authority also has infrastructure aims and objectives which include : developing on road cycle networks on quieter streets ; making safer routes on busier streets ; innovating and implementing contraflows on one way streets ; developing the existing off road cycle route networks and improve signage ; joining up routes that are partially or completely isolated ; increase the number of cycle parking facilities ; working with employers to integrate cycling into workplace travel plans ; link the local networks to national networks . 
as of 2012 , the local council social aims and objectives for cycling include : highlighting the usage of cycling to cut city congestion ; educating that cycling promotes healthy living ... the authority also has infrastructure aims and objectives which include : developing on road cycle networks on quieter streets ; making safer routes on busier streets ; innovating and implementing contraflows on one way streets ; developing the existing off road cycle route networks and improve signage ; joining up routes that are partially or completely isolated ; increase the number of cycle parking facilities ; working with employers to integrate cycling into workplace travel plans ; link the local networks to national networks . 
as of 2012 , the local council social aims and objectives for cycling include : highlighting the usage of cycling to cut city congestion ; educating that cycling promotes healthy living ... the authority also has infrastructure aims and objectives which include : developing on road cycle networks on quieter streets ; making safer routes on busier streets ; innovating and implementing contraflows on one way streets ; developing the existing off road cycle route networks and improve signage ; joining up routes that are partially or completely isolated ; increase the number of cycle parking facilities ; working with employers to integrate cycling into workplace travel plans ; link the local networks to national networks . 
as of 2012 , the local council social aims and objectives for cycling include : highlighting the usage of cycling to cut city congestion ; educating that cycling promotes healthy living ... the authority also has infrastructure aims and objectives which include : developing on road cycle networks on quieter streets ; making safer routes on busier streets ; innovating and implementing contraflows on one way streets ; developing the existing off road cycle route networks and improve signage ; joining up routes that are partially or completely isolated ; increase the number of cycle parking facilities ; working with employers to integrate cycling into workplace travel plans ; link the local networks to national networks . 
from newcastle international ferry terminal , at north shields , danish dfds seaways run a service to ijmuiden -lrb- near amsterdam -rrb- . 
the dfds ferry service to gothenburg , sweden , ceased at the end of october 2006 -- the company cited high fuel prices and new competition from low-cost air services as the cause -- and their service to bergen and stavanger , norway was terminated late 2008 . 
the dfds ferry service to gothenburg , sweden , ceased at the end of october 2006 -- the company cited high fuel prices and new competition from low-cost air services as the cause -- and their service to bergen and stavanger , norway was terminated late 2008 . 
the dfds ferry service to gothenburg , sweden , ceased at the end of october 2006 -- the company cited high fuel prices and new competition from low-cost air services as the cause -- and their service to bergen and stavanger , norway was terminated late 2008 . 
since summer 2007 , thomson cruise lines have included newcastle as a departure port on its norwegian and fjords cruise . 
there are eleven lea-funded 11 to 18 schools and seven independent schools with sixth forms in newcastle . 
there are eleven lea-funded 11 to 18 schools and seven independent schools with sixth forms in newcastle . 
the largest co-ed independent school is the royal grammar school . 
newcastle college is the largest general further education college in the north east and is a beacon status college ; there are two smaller colleges in the newcastle area . 
st cuthbert 's high school and sacred heart are the two primary state-catholic run high schools , and are both achieving results on par with the independent schools in newcastle . 
the city has two universities -- newcastle university and northumbria university . 
newcastle university has its origins in the school of medicine and surgery , established in 1834 and became independent from durham university on 1 august 1963 to form the university of newcastle upon tyne . 
it won the coveted sunday times university of the year award in 2000 . 
northumbria university has its origins in the newcastle polytechnic , established in 1969 and became the university of northumbria at newcastle in 1992 as part of the uk-wide process in which polytechnics became new universities . 
northumbria university was voted ` best new university ' by the times good university guide 2005 and also won a much coveted company award of the `` most it enabled organisation '' -lrb- in the uk -rrb- , by the it industry magazine computing . 
newcastle has three cathedrals , the anglican st. nicholas , with its elegant lantern tower of 1474 , the roman catholic st. mary 's designed by augustus welby pugin and the coptic cathedral located in fenham . 
newcastle has three cathedrals , the anglican st. nicholas , with its elegant lantern tower of 1474 , the roman catholic st. mary 's designed by augustus welby pugin and the coptic cathedral located in fenham . 
newcastle has three cathedrals , the anglican st. nicholas , with its elegant lantern tower of 1474 , the roman catholic st. mary 's designed by augustus welby pugin and the coptic cathedral located in fenham . 
another prominent church in the city centre is the church of st thomas the martyr which is the only parish church in the church of england without a parish and which is not a peculiar . 
all three cathedrals began their lives as parish churches . 
the parish church of st andrew is traditionally recognised as ` the oldest church in this town ' . 
the present building was begun in the 12th century and the last addition to it , apart from the vestries , was the main porch in 1726 . 
the present building was begun in the 12th century and the last addition to it , apart from the vestries , was the main porch in 1726 . 
it is surrounded by the last of the ancient churchyards to retain its original character . 
the church tower received a battering during the siege of newcastle by the scots who finally breached the town wall and forced surrender . 
itv tyne tees was based at city road for over 40 years after its launch in january 1959 . 
in 2005 it moved to a new facility on the watermark business park next to the metrocentre in gateshead . 
the entrance to studio 5 at the city road complex gave its name to the 1980s music television programme , the tube . 
bbc north east and cumbria is located to the north of the city on barrack road , spital tongues , in a building known , as the result of its colouring , as the pink palace . 
it is from here that the corporation broadcasts the look north television regional news programme and local radio station bbc radio newcastle . 
ne1fm launched on 8 june 2007 , the first full-time community radio station in the area . 
newcastle student radio is run by students from both of the city 's universities , broadcasting from newcastle university 's student 's union building during term time . 
radio tyneside has been the voluntary hospital radio service for most hospitals across newcastle and gateshead since 1951 , broadcasting on hospedia and online . 
the city also has a radio lollipop station based at the great north children 's hospital in the newcastle royal victoria infirmary . 
newcastle student radio is run by students from both of the city 's universities , broadcasting from newcastle university 's student 's union building during term time . 
charles avison , the leading british composer of concertos in the 18th century , was born in newcastle upon tyne in 1709 and died there in 1770 . 
basil hume , archbishop of westminster , was born in the city in 1923 . 
other notable people born in or associated with newcastle include : engineer and industrialist lord armstrong , engineer and father of the modern steam railways george stephenson , his son , also an engineer , robert stephenson , engineer and inventor of the steam turbine sir charles parsons , inventor of the incandescent light bulb sir joseph swan , modernist poet basil bunting , and lord chief justice peter taylor . 
other notable people born in or associated with newcastle include : engineer and industrialist lord armstrong , engineer and father of the modern steam railways george stephenson , his son , also an engineer , robert stephenson , engineer and inventor of the steam turbine sir charles parsons , inventor of the incandescent light bulb sir joseph swan , modernist poet basil bunting , and lord chief justice peter taylor . 
former prime minister of thailand abhisit vejjajiva , was born in the city . 
hank marvin and bruce welch were both former pupils of rutherford grammar school , actors charlie hunnam and james scott , entertainers ant and dec and international footballers michael carrick and alan shearer were born in newcastle . 
hank marvin and bruce welch were both former pupils of rutherford grammar school , actors charlie hunnam and james scott , entertainers ant and dec and international footballers michael carrick and alan shearer were born in newcastle . 
multiple circumnavigator david scott cowper , nobel prize winning physicist peter higgs , and former wwe nxt champion neville were born in the city . 
john dunn , inventor of keyed northumbrian smallpipes , the most characteristic musical instrument in the region , lived and worked in the city . 
musicians eric burdon , sting , mark knopfler , alan hull , cheryl cole and neil tennant lived in newcastle . 
the v&a is located in the brompton district of the royal borough of kensington and chelsea , in an area that has become known as `` albertopolis '' because of its association with prince albert , the albert memorial and the major cultural institutions with which he was associated . 
the victoria and albert museum -lrb- often abbreviated as the v&a -rrb- , london , is the world 's largest museum of decorative arts and design , housing a permanent collection of over 4.5 million objects . 
it was founded in 1852 and named after queen victoria and prince albert . 
it was founded in 1852 and named after queen victoria and prince albert . 
the v&a is located in the brompton district of the royal borough of kensington and chelsea , in an area that has become known as `` albertopolis '' because of its association with prince albert , the albert memorial and the major cultural institutions with which he was associated . 
it was founded in 1852 and named after queen victoria and prince albert . 
it was founded in 1852 and named after queen victoria and prince albert . 
the museum is a non-departmental public body sponsored by the department for culture , media and sport . 
like other national british museums , entrance to the museum has been free since 2001 . 
the v&a covers 12.5 acres -lrb- 51,000 m2 -rrb- and 145 galleries . 
the v&a covers 12.5 acres -lrb- 51,000 m2 -rrb- and 145 galleries . 
its collection spans 5,000 years of art , from ancient times to the present day , from the cultures of europe , north america , asia and north africa . 
its collection spans 5,000 years of art , from ancient times to the present day , from the cultures of europe , north america , asia and north africa . 
the museum owns the world 's largest collection of post-classical sculpture , with the holdings of italian renaissance items being the largest outside italy . 
the v&a has its origins in the great exhibition of 1851 , with which henry cole , the museum 's first director , was involved in planning ; initially it was known as the museum of manufactures , first opening in may 1852 at marlborough house , but by september had been transferred to somerset house . 
the v&a has its origins in the great exhibition of 1851 , with which henry cole , the museum 's first director , was involved in planning ; initially it was known as the museum of manufactures , first opening in may 1852 at marlborough house , but by september had been transferred to somerset house . 
the v&a has its origins in the great exhibition of 1851 , with which henry cole , the museum 's first director , was involved in planning ; initially it was known as the museum of manufactures , first opening in may 1852 at marlborough house , but by september had been transferred to somerset house . 
the v&a has its origins in the great exhibition of 1851 , with which henry cole , the museum 's first director , was involved in planning ; initially it was known as the museum of manufactures , first opening in may 1852 at marlborough house , but by september had been transferred to somerset house . 
in 1855 the german architect gottfried semper , at the request of cole , produced a design for the museum , but it was rejected by the board of trade as too expensive . 
the official opening by queen victoria was on 22 june 1857 . 
the official opening by queen victoria was on 22 june 1857 . 
george wallis -lrb- 1811 -- 1891 -rrb- , the first keeper of fine art collection , passionately promoted the idea of wide art education through the museum collections . 
in the following year , late night openings were introduced , made possible by the use of gas lighting . 
this led to the transfer to the museum of the school of design that had been founded in 1837 at somerset house ; after the transfer it was referred to as the art school or art training school , later to become the royal college of art which finally achieved full independence in 1949 . 
before the return of the collections after the war , the britain can make it exhibition was held between september and november 1946 , attracting nearly a million and a half visitors . 
before the return of the collections after the war , the britain can make it exhibition was held between september and november 1946 , attracting nearly a million and a half visitors . 
the success of this exhibition led to the planning of the festival of britain -lrb- 1951 -rrb- . 
the success of this exhibition led to the planning of the festival of britain -lrb- 1951 -rrb- . 
by 1948 most of the collections had been returned to the museum . 
in july 1973 , as part of its outreach programme to young people , the v&a became the first museum in britain to present a rock concert . 
the v&a presented a combined concert/lecture by british progressive folk-rock band gryphon , who explored the lineage of mediaeval music and instrumentation and related how those contributed to contemporary music 500 years later . 
this innovative approach to bringing young people to museums was a hallmark of the directorship of roy strong and was subsequently emulated by some other british museums . 
the v&a presented a combined concert/lecture by british progressive folk-rock band gryphon , who explored the lineage of mediaeval music and instrumentation and related how those contributed to contemporary music 500 years later . 
the v&a is in discussion with the university of dundee , university of abertay , dundee city council and the scottish government with a view to opening a new # 43 million gallery in dundee that would use the v&a brand although it would be funded through and operated independently . 
as of 2015 , with costs estimated at # 76 million , it is the most expensive gallery project ever undertaken in scotland . 
the v&a dundee will be on the city 's waterfront and is intended to focus on fashion , architecture , product design , graphic arts and photography . 
the v&a dundee will be on the city 's waterfront and is intended to focus on fashion , architecture , product design , graphic arts and photography . 
it is planned that it could open within five years . 
the land was occupied by brompton park house , which was extended , most notably by the `` brompton boilers '' , which were starkly utilitarian iron galleries with a temporary look and were later dismantled and used to build the v&a museum of childhood . 
the first building to be erected that still forms part of the museum was the sheepshanks gallery in 1857 on the eastern side of the garden . 
its architect was civil engineer captain francis fowke , royal engineers , who was appointed by cole . 
on the very northern edge of the site is situated the secretariat wing , also built in 1862 this houses the offices and board room etc. and is not open to the public . 
on the very northern edge of the site is situated the secretariat wing , also built in 1862 this houses the offices and board room etc. and is not open to the public . 
to the east of this were additional galleries , the decoration of which was the work of another designer owen jones , these were the oriental courts -lrb- covering india , china and japan -rrb- completed in 1863 , none of this decoration survives , part of these galleries became the new galleries covering the 19th century , opened in december 2006 . 
the style adopted for this part of the museum was italian renaissance , much use was made of terracotta , brick and mosaic , this north façade was intended as the main entrance to the museum with its bronze doors designed by james gamble & reuben townroe having six panels depicting : humphry davy -lrb- chemistry -rrb- ; isaac newton -lrb- astronomy -rrb- ; james watt -lrb- mechanics -rrb- ; bramante -lrb- architecture -rrb- ; michelangelo -lrb- sculpture -rrb- ; titian -lrb- painting -rrb- ; thus representing the range of the museums collections , godfrey sykes also designed the terracotta embellishments and the mosaic in the pediment of the north façade commemorating the great exhibition the profits from which helped to fund the museum , this is flanked by terracotta statue groups by percival ball . 
the style adopted for this part of the museum was italian renaissance , much use was made of terracotta , brick and mosaic , this north façade was intended as the main entrance to the museum with its bronze doors designed by james gamble & reuben townroe having six panels depicting : humphry davy -lrb- chemistry -rrb- ; isaac newton -lrb- astronomy -rrb- ; james watt -lrb- mechanics -rrb- ; bramante -lrb- architecture -rrb- ; michelangelo -lrb- sculpture -rrb- ; titian -lrb- painting -rrb- ; thus representing the range of the museums collections , godfrey sykes also designed the terracotta embellishments and the mosaic in the pediment of the north façade commemorating the great exhibition the profits from which helped to fund the museum , this is flanked by terracotta statue groups by percival ball . 
the style adopted for this part of the museum was italian renaissance , much use was made of terracotta , brick and mosaic , this north façade was intended as the main entrance to the museum with its bronze doors designed by james gamble & reuben townroe having six panels depicting : humphry davy -lrb- chemistry -rrb- ; isaac newton -lrb- astronomy -rrb- ; james watt -lrb- mechanics -rrb- ; bramante -lrb- architecture -rrb- ; michelangelo -lrb- sculpture -rrb- ; titian -lrb- painting -rrb- ; thus representing the range of the museums collections , godfrey sykes also designed the terracotta embellishments and the mosaic in the pediment of the north façade commemorating the great exhibition the profits from which helped to fund the museum , this is flanked by terracotta statue groups by percival ball . 
the style adopted for this part of the museum was italian renaissance , much use was made of terracotta , brick and mosaic , this north façade was intended as the main entrance to the museum with its bronze doors designed by james gamble & reuben townroe having six panels depicting : humphry davy -lrb- chemistry -rrb- ; isaac newton -lrb- astronomy -rrb- ; james watt -lrb- mechanics -rrb- ; bramante -lrb- architecture -rrb- ; michelangelo -lrb- sculpture -rrb- ; titian -lrb- painting -rrb- ; thus representing the range of the museums collections , godfrey sykes also designed the terracotta embellishments and the mosaic in the pediment of the north façade commemorating the great exhibition the profits from which helped to fund the museum , this is flanked by terracotta statue groups by percival ball . 
the green dining room 1866 -- 68 was the work of philip webb and william morris , and displays elizabethan influences . 
the lower part of the walls are panelled in wood with a band of paintings depicting fruit and the occasional figure , with moulded plaster foliage on the main part of the wall and a plaster frieze around the decorated ceiling and stained-glass windows by edward burne-jones . 
the centre refreshment room 1865 -- 77 was designed in a renaissance style by james gamble , the walls and even the ionic columns are covered in decorative and moulded ceramic tile , the ceiling consists of elaborate designs on enamelled metal sheets and matching stained-glass windows , the marble fireplace was designed and sculpted by alfred stevens and was removed from dorchester house prior to that building 's demolition in 1929 . 
the centre refreshment room 1865 -- 77 was designed in a renaissance style by james gamble , the walls and even the ionic columns are covered in decorative and moulded ceramic tile , the ceiling consists of elaborate designs on enamelled metal sheets and matching stained-glass windows , the marble fireplace was designed and sculpted by alfred stevens and was removed from dorchester house prior to that building 's demolition in 1929 . 
the grill room 1876 -- 81 was designed by sir edward poynter , the lower part of the walls consist of blue and white tiles with various figures and foliage enclosed by wood panelling , above there are large tiled scenes with figures depicting the four seasons and the twelve months these were painted by ladies from the art school then based in the museum , the windows are also stained glass , there is an elaborate cast-iron grill still in place . 
with the death of captain francis fowke , royal engineers the next architect to work at the museum was colonel -lrb- later major general -rrb- henry young darracott scott , also of the royal engineers . 
he designed to the north west of the garden the five-storey school for naval architects -lrb- also known as the science schools -rrb- , now the henry cole wing in 1867 -- 72 . 
scott 's assistant j.w. wild designed the impressive staircase that rises the full height of the building , made from cadeby stone the steps are 7 feet -lrb- 2.1 m -rrb- in length , the balustrades and columns are portland stone . 
it is now used to jointly house the prints and architectural drawings of the v&a -lrb- prints , drawings , paintings and photographs -rrb- and royal institute of british architects -lrb- riba drawings and archives collections -rrb- ; and the sackler centre for arts education , which opened in 2008 . 
it is now used to jointly house the prints and architectural drawings of the v&a -lrb- prints , drawings , paintings and photographs -rrb- and royal institute of british architects -lrb- riba drawings and archives collections -rrb- ; and the sackler centre for arts education , which opened in 2008 . 
continuing the style of the earlier buildings , various designers were responsible for the decoration , the terracotta embellishments were again the work of godfrey sykes , although sgraffito was used to decorate the east side of the building designed by f. w. moody , a final embellishment were the wrought iron gates made as late as 1885 designed by starkie gardner , these lead to a passage through the building . 
continuing the style of the earlier buildings , various designers were responsible for the decoration , the terracotta embellishments were again the work of godfrey sykes , although sgraffito was used to decorate the east side of the building designed by f. w. moody , a final embellishment were the wrought iron gates made as late as 1885 designed by starkie gardner , these lead to a passage through the building . 
scott also designed the two cast courts 1870 -- 73 to the southeast of the garden -lrb- the site of the `` brompton boilers '' -rrb- , these vast spaces have ceilings 70 feet -lrb- 21 m -rrb- in height to accommodate the plaster casts of parts of famous buildings , including trajan 's column -lrb- in two separate pieces -rrb- . 
the final part of the museum designed by scott was the art library and what is now the sculpture gallery on the south side of the garden , built 1877 -- 83 , the exterior mosaic panels in the parapet were designed by reuben townroe who also designed the plaster work in the library , sir john taylor designed the book shelves and cases , also this was the first part of the museum to have electric lighting . 
the final part of the museum designed by scott was the art library and what is now the sculpture gallery on the south side of the garden , built 1877 -- 83 , the exterior mosaic panels in the parapet were designed by reuben townroe who also designed the plaster work in the library , sir john taylor designed the book shelves and cases , also this was the first part of the museum to have electric lighting . 
the main façade , built from red brick and portland stone , stretches 720 feet -lrb- 220 m -rrb- along cromwell gardens and was designed by aston webb after winning a competition in 1891 to extend the museum . 
the main façade , built from red brick and portland stone , stretches 720 feet -lrb- 220 m -rrb- along cromwell gardens and was designed by aston webb after winning a competition in 1891 to extend the museum . 
the main façade , built from red brick and portland stone , stretches 720 feet -lrb- 220 m -rrb- along cromwell gardens and was designed by aston webb after winning a competition in 1891 to extend the museum . 
likewise the tower above the main entrance has an open work crown surmounted by a statue of fame , a feature of late gothic architecture and a feature common in scotland , but the detail is classical . 
the main windows to the galleries are also mullioned and transomed , again a gothic feature , the top row of windows are interspersed with statues of many of the british artists whose work is displayed in the museum . 
prince albert appears within the main arch above the twin entrances , queen victoria above the frame around the arches and entrance , sculpted by alfred drury . 
these façades surround four levels of galleries . 
prince albert appears within the main arch above the twin entrances , queen victoria above the frame around the arches and entrance , sculpted by alfred drury . 
the interior makes much use of marble in the entrance hall and flanking staircases , although the galleries as originally designed were white with restrained classical detail and mouldings , very much in contrast to the elaborate decoration of the victorian galleries , although much of this decoration was removed in the early 20th century . 
prince albert appears within the main arch above the twin entrances , queen victoria above the frame around the arches and entrance , sculpted by alfred drury . 
the 1950s and early 1960s saw little in the way of building work ; the first major work was the creation of new storage space for books in the art library in 1966 and 1967 . 
in 1974 the museum had acquired what is now the henry cole wing from the royal college of science . 
to link this to the rest of the museum , a new entrance building was constructed on the site of the former boiler house , the intended site of the spiral , between 1978 and 1982 . 
this building is of concrete and very functional , the only embellishment being the iron gates by christopher hay and douglas coyne of the royal college of art . 
to link this to the rest of the museum , a new entrance building was constructed on the site of the former boiler house , the intended site of the spiral , between 1978 and 1982 . 
a few galleries were redesigned in the 1990s including the indian , japanese , chinese , iron work , the main glass galleries and the main silverware gallery which was further enhanced in 2002 when some of the victorian decoration was recreated . 
as part of the 2006 renovation the mosaic floors in the sculpture gallery were restored -- most of the victorian floors were covered in linoleum after the second world war . 
after the success of the british galleries , opened in 2001 , it was decided to embark on a major redesign of all the galleries in the museum ; this is known as `` futureplan '' , and was created in consultation with the exhibition designers and masterplanners metaphor . 
to date several galleries have been redesigned , notably , in 2002 : the main silver gallery , contemporary ; in 2003 : photography , the main entrance , the painting galleries ; in 2004 : the tunnel to the subway leading to south kensington tube station , new signage throughout the museum , architecture , v&a and riba reading rooms and stores , metalware , members ' room , contemporary glass , the gilbert bayes sculpture gallery ; in 2005 : portrait miniatures , prints and drawings , displays in room 117 , the garden , sacred silver and stained glass ; in 2006 : central hall shop , islamic middle east , the new café , sculpture galleries . 
gareth hoskins was responsible for contemporary and architecture , softroom , islamic middle east and the members ' room , mcinnes usher mcknight architects -lrb- muma -rrb- were responsible for the new cafe and designed the new medieval and renaissance galleries which opened in 2009 . 
the central garden was redesigned by kim wilkie and opened as the john madejski garden , on 5 july 2005 . 
the central garden was redesigned by kim wilkie and opened as the john madejski garden , on 5 july 2005 . 
the design is a subtle blend of the traditional and modern , the layout is formal ; there is an elliptical water feature lined in stone with steps around the edge which may be drained to use the area for receptions , gatherings or exhibition purposes . 
the design is a subtle blend of the traditional and modern , the layout is formal ; there is an elliptical water feature lined in stone with steps around the edge which may be drained to use the area for receptions , gatherings or exhibition purposes . 
this is in front of the bronze doors leading to the refreshment rooms , a central path flanked by lawns leads to the sculpture gallery ; the north , east and west sides have herbaceous borders along the museum walls with paths in front which continues along the south façade ; in the two corners by the north façade there is planted an american sweetgum tree ; the southern , eastern and western edges of the lawns have glass planters which contain orange and lemon trees in summer , these are replaced by bay trees in winter . 
in 2004 , the v&a alongside royal institute of british architects opened the first permanent gallery in the uk covering the history of architecture with displays using models , photographs , elements from buildings and original drawings . 
in 2004 , the v&a alongside royal institute of british architects opened the first permanent gallery in the uk covering the history of architecture with displays using models , photographs , elements from buildings and original drawings . 
with over 600,000 drawings , over 750,000 papers and paraphernalia , and over 700,000 photographs from around the world , together they form the world 's most comprehensive architectural resource . 
with the opening of the new gallery , the riba drawings and archives collection has been transferred to the museum , joining the already extensive collection held by the v&a . 
with over 600,000 drawings , over 750,000 papers and paraphernalia , and over 700,000 photographs from around the world , together they form the world 's most comprehensive architectural resource . 
the riba 's holdings of over 330 drawings by andrea palladio are the largest in the world , other europeans well represented are jacques gentilhatre and antonio visentini . 
british architects whose drawings , and in some cases models of their buildings , in the collection , include : inigo jones , sir christopher wren , sir john vanbrugh , nicholas hawksmoor , william kent , james gibbs , robert adam , sir william chambers , james wyatt , henry holland , john nash , sir john soane , sir charles barry , charles robert cockerell , augustus welby northmore pugin , sir george gilbert scott , john loughborough pearson , george edmund street , richard norman shaw , alfred waterhouse , sir edwin lutyens , charles rennie mackintosh , charles holden , frank hoar , lord richard rogers , lord norman foster , sir nicholas grimshaw , zaha hadid and alick horsnell . 
the riba 's holdings of over 330 drawings by andrea palladio are the largest in the world , other europeans well represented are jacques gentilhatre and antonio visentini . 
british architects whose drawings , and in some cases models of their buildings , in the collection , include : inigo jones , sir christopher wren , sir john vanbrugh , nicholas hawksmoor , william kent , james gibbs , robert adam , sir william chambers , james wyatt , henry holland , john nash , sir john soane , sir charles barry , charles robert cockerell , augustus welby northmore pugin , sir george gilbert scott , john loughborough pearson , george edmund street , richard norman shaw , alfred waterhouse , sir edwin lutyens , charles rennie mackintosh , charles holden , frank hoar , lord richard rogers , lord norman foster , sir nicholas grimshaw , zaha hadid and alick horsnell . 
british architects whose drawings , and in some cases models of their buildings , in the collection , include : inigo jones , sir christopher wren , sir john vanbrugh , nicholas hawksmoor , william kent , james gibbs , robert adam , sir william chambers , james wyatt , henry holland , john nash , sir john soane , sir charles barry , charles robert cockerell , augustus welby northmore pugin , sir george gilbert scott , john loughborough pearson , george edmund street , richard norman shaw , alfred waterhouse , sir edwin lutyens , charles rennie mackintosh , charles holden , frank hoar , lord richard rogers , lord norman foster , sir nicholas grimshaw , zaha hadid and alick horsnell . 
as well as period rooms , the collection includes parts of buildings , for example the two top stories of the facade of sir paul pindar 's house dated c1600 from bishopsgate with elaborately carved wood work and leaded windows , a rare survivor of the great fire of london , there is a brick portal from a london house of the english restoration period and a fireplace from the gallery of northumberland house . 
as well as period rooms , the collection includes parts of buildings , for example the two top stories of the facade of sir paul pindar 's house dated c1600 from bishopsgate with elaborately carved wood work and leaded windows , a rare survivor of the great fire of london , there is a brick portal from a london house of the english restoration period and a fireplace from the gallery of northumberland house . 
as well as period rooms , the collection includes parts of buildings , for example the two top stories of the facade of sir paul pindar 's house dated c1600 from bishopsgate with elaborately carved wood work and leaded windows , a rare survivor of the great fire of london , there is a brick portal from a london house of the english restoration period and a fireplace from the gallery of northumberland house . 
european examples include a dormer window dated 1523 -- 35 from the chateau of montal . 
the main architecture gallery has a series of pillars from various buildings and different periods , for example a column from the alhambra . 
the v&a holds over 19,000 items from the islamic world , ranging from the early islamic period -lrb- the 7th century -rrb- to the early 20th century . 
the jameel gallery of islamic art , opened in 2006 , houses a representative display of 400 objects with the highlight being the ardabil carpet , the centrepiece of the gallery . 
the jameel gallery of islamic art , opened in 2006 , houses a representative display of 400 objects with the highlight being the ardabil carpet , the centrepiece of the gallery . 
the displays in this gallery cover objects from spain , north africa , the middle east , central asia and afghanistan . 
the collection of middle eastern and persian rugs and carpets is amongst the finest in the world , many were part of the salting bequest of 1909 . 
the museum 's collections of south and south-east asian art are the most comprehensive and important in the west comprising nearly 60,000 objects , including about 10,000 textiles and 6000 paintings , the range of the collection is immense . 
the museum 's collections of south and south-east asian art are the most comprehensive and important in the west comprising nearly 60,000 objects , including about 10,000 textiles and 6000 paintings , the range of the collection is immense . 
the museum 's collections of south and south-east asian art are the most comprehensive and important in the west comprising nearly 60,000 objects , including about 10,000 textiles and 6000 paintings , the range of the collection is immense . 
the jawaharlal nehru gallery of indian art , opened in 1991 , contains art from about 500 bc to the 19th century . 
the jawaharlal nehru gallery of indian art , opened in 1991 , contains art from about 500 bc to the 19th century . 
the far eastern collections include more than 70,000 works of art from the countries of east asia : china , japan and korea . 
the far eastern collections include more than 70,000 works of art from the countries of east asia : china , japan and korea . 
the t. t. tsui gallery of chinese art opened in 1991 , displaying a representative collection of the v&a s approximately 16,000 objects from china , dating from the 4th millennium bc to the present day . 
the t. t. tsui gallery of chinese art opened in 1991 , displaying a representative collection of the v&a s approximately 16,000 objects from china , dating from the 4th millennium bc to the present day . 
though the majority of art works on display date from the ming and qing dynasties , there are exquisite examples of objects dating from the tang dynasty and earlier periods . 
the toshiba gallery of japanese art opened in december 1986 . 
the toshiba gallery of japanese art opened in december 1986 . 
the majority of exhibits date from 1550 to 1900 , but one of the oldest pieces displayed is the 13th-century sculpture of amida nyorai . 
the majority of exhibits date from 1550 to 1900 , but one of the oldest pieces displayed is the 13th-century sculpture of amida nyorai . 
one of the finest objects displayed is suzuki chokichi 's bronze incense burner -lrb- koro -rrb- dated 1875 , standing at over 2.25 metres high and 1.25 metres in diameter it is also one of the largest examples made . 
tibetan art from the 14th to the 19th century is represented by notable 14th - and 15th-century religious images in wood and bronze , scroll paintings and ritual objects . 
art from thailand , burma , cambodia , indonesia and sri lanka in gold , silver , bronze , stone , terracotta and ivory represents these rich and complex cultures , the displays span the 6th to 19th centuries . 
refined hindu and buddhist sculptures reflect the influence of india ; items on show include betel-nut cutters , ivory combs and bronze palanquin hooks . 
korean displays include green-glazed ceramics , silk embroideries from officials ' robes and gleaming boxes inlaid with mother-of-pearl made between 500 ad and 2000 . 
refined hindu and buddhist sculptures reflect the influence of india ; items on show include betel-nut cutters , ivory combs and bronze palanquin hooks . 
one of the great treasures in the library is the codex forster , some of leonardo da vinci 's note books . 
the codex consists of three parchment-bound manuscripts , forster i , forster ii , and forster iii , quite small in size , dated between 1490 and 1505 . 
the reverend alexander dyce was another benefactor of the library , leaving over 14,000 books to the museum in 1869 . 
the reverend alexander dyce was another benefactor of the library , leaving over 14,000 books to the museum in 1869 . 
these were bequeathed with over 18,000 books to the museum in 1876 by john forster . 
writers whose papers are in the library are as diverse as charles dickens and beatrix potter . 
writers whose papers are in the library are as diverse as charles dickens and beatrix potter . 
illuminated manuscripts in the library dating from the 12th to 16th centuries include : the eadwine psalter -lsb- citation needed -rsb- , canterbury ; pocket book of hours , reims ; missal from the royal abbey of saint denis , paris ; the simon marmion book of hours , bruges ; 1524 charter illuminated by lucas horenbout , london ; the armagnac manuscript of the trial and rehabilitation of joan of arc , rouen . 
illuminated manuscripts in the library dating from the 12th to 16th centuries include : the eadwine psalter -lsb- citation needed -rsb- , canterbury ; pocket book of hours , reims ; missal from the royal abbey of saint denis , paris ; the simon marmion book of hours , bruges ; 1524 charter illuminated by lucas horenbout , london ; the armagnac manuscript of the trial and rehabilitation of joan of arc , rouen . 
illuminated manuscripts in the library dating from the 12th to 16th centuries include : the eadwine psalter -lsb- citation needed -rsb- , canterbury ; pocket book of hours , reims ; missal from the royal abbey of saint denis , paris ; the simon marmion book of hours , bruges ; 1524 charter illuminated by lucas horenbout , london ; the armagnac manuscript of the trial and rehabilitation of joan of arc , rouen . 
the national art library -lrb- also called word and image department -rrb- at the victoria and albert museum collection catalog used to be kept in different formats including printed exhibit catalogs , and card catalogs . 
a computer system called modes cataloging system was used from the 1980s to the 1990s , but those electronic files were not available to the library users . 
all of the archival material at the national art library is using encoded archival description -lrb- ead -rrb- . 
the victoria and albert museum has a computer system but most of the items in the collection , unless those were newly accessioned into the collection , probably do not show up in the computer system . 
there is a feature on the victoria and albert museum web-site called `` search the collections , '' but not everything is listed there . 
a large scale digitization project began in 2007 in that department . 
the second step of the factory project is to catalog everything . 
that project was entitled the factory project to reference andy warhol and to create a factory to completely digitize the collection . 
15,000 images were taken during the first year of the factory project , including drawings , watercolors , computer-generated art , photographs , posters , and woodcuts . 
the second step of the factory project is to catalog everything . 
not only the work of british artists and craftspeople is on display , but also work produced by european artists that was purchased or commissioned by british patrons , as well as imports from asia , including porcelain , cloth and wallpaper . 
not only the work of british artists and craftspeople is on display , but also work produced by european artists that was purchased or commissioned by british patrons , as well as imports from asia , including porcelain , cloth and wallpaper . 
designers and artists whose work is on display in the galleries include gian lorenzo bernini , grinling gibbons , daniel marot , louis laguerre , antonio verrio , sir james thornhill , william kent , robert adam , josiah wedgwood , matthew boulton , canova , thomas chippendale , pugin , william morris . 
patrons who have influenced taste are also represented by works of art from their collections , these include : horace walpole -lrb- a major influence on the gothic revival -rrb- , william thomas beckford and thomas hope . 
not only the work of british artists and craftspeople is on display , but also work produced by european artists that was purchased or commissioned by british patrons , as well as imports from asia , including porcelain , cloth and wallpaper . 
for example , the increase in tea drinking led to the production of tea paraphernalia such as china and caddies . 
in the georgian age there was increasing emphasis on entertainment and leisure . 
in the later 19th century , the increasing backlash against industrialization , led by john ruskin , contributed to the arts and crafts movement . 
as the industrial revolution took hold , the growth of mass production produced entrepreneurs such as josiah wedgwood , matthew boulton and eleanor coade . 
in the later 19th century , the increasing backlash against industrialization , led by john ruskin , contributed to the arts and crafts movement . 
one of these is dominated by a full-scale replica of trajan 's column , cut in half in order to fit under the ceiling . 
one of these is dominated by a full-scale replica of trajan 's column , cut in half in order to fit under the ceiling . 
the other includes reproductions of various works of italian renaissance sculpture and architecture , including a full-size replica of michelangelo 's david . 
one of the most dramatic parts of the museum is the cast courts in the sculpture wing , comprising two large , skylighted rooms two storeys high housing hundreds of plaster casts of sculptures , friezes and tombs . 
replicas of two earlier davids by donatello 's david and verrocchio 's david , are also included , although for conservation reasons the verrocchio replica is displayed in a glass case . 
among the finest examples are the meissen vulture from 1731 and the möllendorff dinner service , designed in 1762 by frederick ii the great . 
among the finest examples are the meissen vulture from 1731 and the möllendorff dinner service , designed in 1762 by frederick ii the great . 
among the finest examples are the meissen vulture from 1731 and the möllendorff dinner service , designed in 1762 by frederick ii the great . 
a major boost to the collections was the salting bequest made in 1909 , which enriched the museum 's stock of chinese and japanese ceramics . 
a major boost to the collections was the salting bequest made in 1909 , which enriched the museum 's stock of chinese and japanese ceramics . 
many famous potters , such as josiah wedgwood , william de morgan and bernard leach as well as mintons & royal doulton are represented in the collection . 
there is an extensive collection of delftware produced in both britain and holland , which includes a circa 1695 flower pyramid over a metre in height . 
the largest objects in the collection are a series of elaborately ornamented ceramic stoves from the 16th and 17th centuries , made in germany and switzerland . 
the largest objects in the collection are a series of elaborately ornamented ceramic stoves from the 16th and 17th centuries , made in germany and switzerland . 
the largest objects in the collection are a series of elaborately ornamented ceramic stoves from the 16th and 17th centuries , made in germany and switzerland . 
the glass collection covers 4000 years of glass making , and has over 6000 items from africa , britain , europe , america and asia . 
the glass collection covers 4000 years of glass making , and has over 6000 items from africa , britain , europe , america and asia . 
the earliest glassware on display comes from ancient egypt and continues through the ancient roman , medieval , renaissance covering areas such as venetian glass and bohemian glass and more recent periods , including art nouveau glass by louis comfort tiffany and émile gallé , the art deco style is represented by several examples by rené lalique . 
the earliest glassware on display comes from ancient egypt and continues through the ancient roman , medieval , renaissance covering areas such as venetian glass and bohemian glass and more recent periods , including art nouveau glass by louis comfort tiffany and émile gallé , the art deco style is represented by several examples by rené lalique . 
the earliest glassware on display comes from ancient egypt and continues through the ancient roman , medieval , renaissance covering areas such as venetian glass and bohemian glass and more recent periods , including art nouveau glass by louis comfort tiffany and émile gallé , the art deco style is represented by several examples by rené lalique . 
the main gallery was redesigned in 1994 , the glass balustrade on the staircase and mezzanine are the work of danny lane , the gallery covering contemporary glass opened in 2004 and the sacred silver and stained-glass gallery in 2005 . 
the main gallery was redesigned in 1994 , the glass balustrade on the staircase and mezzanine are the work of danny lane , the gallery covering contemporary glass opened in 2004 and the sacred silver and stained-glass gallery in 2005 . 
the main gallery was redesigned in 1994 , the glass balustrade on the staircase and mezzanine are the work of danny lane , the gallery covering contemporary glass opened in 2004 and the sacred silver and stained-glass gallery in 2005 . 
one of the most spectacular items in the collection is the chandelier by dale chihuly in the rotunda at the museum 's main entrance . 
the important 13th-century glass beaker known as the luck of edenhall is also displayed in these galleries . 
the collection of drawings includes over 10,000 british and 2,000 old master works , including works by : dürer , giovanni benedetto castiglione , bernardo buontalenti , rembrandt , antonio verrio , paul sandby , john russell , angelica kauffman , john flaxman , hugh douglas hamilton , thomas rowlandson , william kilburn , thomas girtin , jean auguste dominique ingres , david wilkie , john martin , samuel palmer , sir edwin henry landseer , lord frederic leighton , sir samuel luke fildes and aubrey beardsley . 
the collection of drawings includes over 10,000 british and 2,000 old master works , including works by : dürer , giovanni benedetto castiglione , bernardo buontalenti , rembrandt , antonio verrio , paul sandby , john russell , angelica kauffman , john flaxman , hugh douglas hamilton , thomas rowlandson , william kilburn , thomas girtin , jean auguste dominique ingres , david wilkie , john martin , samuel palmer , sir edwin henry landseer , lord frederic leighton , sir samuel luke fildes and aubrey beardsley . 
the collection of drawings includes over 10,000 british and 2,000 old master works , including works by : dürer , giovanni benedetto castiglione , bernardo buontalenti , rembrandt , antonio verrio , paul sandby , john russell , angelica kauffman , john flaxman , hugh douglas hamilton , thomas rowlandson , william kilburn , thomas girtin , jean auguste dominique ingres , david wilkie , john martin , samuel palmer , sir edwin henry landseer , lord frederic leighton , sir samuel luke fildes and aubrey beardsley . 
the collection of drawings includes over 10,000 british and 2,000 old master works , including works by : dürer , giovanni benedetto castiglione , bernardo buontalenti , rembrandt , antonio verrio , paul sandby , john russell , angelica kauffman , john flaxman , hugh douglas hamilton , thomas rowlandson , william kilburn , thomas girtin , jean auguste dominique ingres , david wilkie , john martin , samuel palmer , sir edwin henry landseer , lord frederic leighton , sir samuel luke fildes and aubrey beardsley . 
the collection of drawings includes over 10,000 british and 2,000 old master works , including works by : dürer , giovanni benedetto castiglione , bernardo buontalenti , rembrandt , antonio verrio , paul sandby , john russell , angelica kauffman , john flaxman , hugh douglas hamilton , thomas rowlandson , william kilburn , thomas girtin , jean auguste dominique ingres , david wilkie , john martin , samuel palmer , sir edwin henry landseer , lord frederic leighton , sir samuel luke fildes and aubrey beardsley . 
the costume collection is the most comprehensive in britain , containing over 14,000 outfits plus accessories , mainly dating from 1600 to the present . 
costume sketches , design notebooks , and other works on paper are typically held by the word and image department . 
because everyday clothing from previous eras has not generally survived , the collection is dominated by fashionable clothes made for special occasions . 
one of the first significant gifts of costume came in 1913 when the v&a received the talbot hughes collection containing 1,442 costumes and items as a gift from harrods following its display at the nearby department store . 
one of the first significant gifts of costume came in 1913 when the v&a received the talbot hughes collection containing 1,442 costumes and items as a gift from harrods following its display at the nearby department store . 
in 2002 , the museum acquired the costiff collection of 178 vivienne westwood costumes . 
in 2002 , the museum acquired the costiff collection of 178 vivienne westwood costumes . 
in 2002 , the museum acquired the costiff collection of 178 vivienne westwood costumes . 
in 2002 , the museum acquired the costiff collection of 178 vivienne westwood costumes . 
the museum continues to acquire examples of modern fashion to add to the collection . 
the soulages collection of italian and french renaissance objects was acquired between 1859 and 1865 , and includes several cassone . 
the soulages collection of italian and french renaissance objects was acquired between 1859 and 1865 , and includes several cassone . 
the john jones collection of french 18th-century art and furnishings was left to the museum in 1882 , then valued at # 250,000 . 
the john jones collection of french 18th-century art and furnishings was left to the museum in 1882 , then valued at # 250,000 . 
the john jones collection of french 18th-century art and furnishings was left to the museum in 1882 , then valued at # 250,000 . 
there are a set of beautiful inlaid doors , dated 1580 from antwerp city hall , attributed to hans vredeman de vries . 
there are a set of beautiful inlaid doors , dated 1580 from antwerp city hall , attributed to hans vredeman de vries . 
one of the finest pieces of continental furniture in the collection is the rococo augustus rex bureau cabinet dated c1750 from germany , with especially fine marquetry and ormolu mounts . 
one of the finest pieces of continental furniture in the collection is the rococo augustus rex bureau cabinet dated c1750 from germany , with especially fine marquetry and ormolu mounts . 
the work of modernists in the collection include le corbusier , marcel breuer , charles and ray eames , and giò ponti . 
the jewellery collection , containing over 6000 items is one of the finest and most comprehensive collections of jewellery in the world and includes works dating from ancient egypt to the present day , as well as jewellery designs on paper . 
the jewellery collection , containing over 6000 items is one of the finest and most comprehensive collections of jewellery in the world and includes works dating from ancient egypt to the present day , as well as jewellery designs on paper . 
major bequests include reverend chauncy hare townshend 's collection of 154 gems bequeathed in 1869 , lady cory 's 1951 gift of major diamond jewellery from the 18th and 19th centuries , and jewellery scholar dame joan evans ' 1977 gift of more than 800 jewels dating from the middle ages to the early 19th century . 
major bequests include reverend chauncy hare townshend 's collection of 154 gems bequeathed in 1869 , lady cory 's 1951 gift of major diamond jewellery from the 18th and 19th centuries , and jewellery scholar dame joan evans ' 1977 gift of more than 800 jewels dating from the middle ages to the early 19th century . 
a new jewellery gallery , funded by william and judith bollinger , opened on 24 may 2008 . 
there are over 10,000 objects made from silver or gold in the collection , the display -lrb- about 15 % of the collection -rrb- is divided into secular and sacred covering both christian -lrb- roman catholic , anglican and greek orthodox -rrb- and jewish liturgical vessels and items . 
the collection includes the earliest known piece of english silver with a dated hallmark , a silver gilt beaker dated 1496 -- 97 . 
one of the largest items is the hereford screen , weighing nearly 8 tonnes , 10.5 metres high and 11 metres wide , designed by sir george gilbert scott in 1862 for the chancel in hereford cathedral , from which it was removed in 1967 . 
one of the largest items is the hereford screen , weighing nearly 8 tonnes , 10.5 metres high and 11 metres wide , designed by sir george gilbert scott in 1862 for the chancel in hereford cathedral , from which it was removed in 1967 . 
there are over 10,000 objects made from silver or gold in the collection , the display -lrb- about 15 % of the collection -rrb- is divided into secular and sacred covering both christian -lrb- roman catholic , anglican and greek orthodox -rrb- and jewish liturgical vessels and items . 
one of the rarest items in the collection is the 58 cm high gloucester candlestick , dated to c1110 , made from gilt bronze ; with highly elaborate and intricate intertwining branches containing small figures and inscriptions , it is a tour de force of bronze casting . 
one of the rarest items in the collection is the 58 cm high gloucester candlestick , dated to c1110 , made from gilt bronze ; with highly elaborate and intricate intertwining branches containing small figures and inscriptions , it is a tour de force of bronze casting . 
also of importance is the becket casket dated c1180 to contain relics of st thomas becket , made from gilt copper , with enamelled scenes of the saint 's martyrdom . 
also of importance is the becket casket dated c1180 to contain relics of st thomas becket , made from gilt copper , with enamelled scenes of the saint 's martyrdom . 
also of importance is the becket casket dated c1180 to contain relics of st thomas becket , made from gilt copper , with enamelled scenes of the saint 's martyrdom . 
an online petition of over 5,100 names on the parliamentary website led to chris smith asking parliament about the future of the collection . 
the answer , from bryan davies was that the museum intended to preserve and care for the collection and keep it available to the public , with items being redistributed to the british galleries , the medieval & renaissance galleries , and the planned new galleries for furniture and europe 1600 -- 1800 , and that the horniman museum and other institutions were possible candidates for loans of material to ensure that the instruments remained publicly viewable . 
the answer , from bryan davies was that the museum intended to preserve and care for the collection and keep it available to the public , with items being redistributed to the british galleries , the medieval & renaissance galleries , and the planned new galleries for furniture and europe 1600 -- 1800 , and that the horniman museum and other institutions were possible candidates for loans of material to ensure that the instruments remained publicly viewable . 
the horniman went on to host a joint exhibition with the v&a of musical instruments , and has the loan of 35 instruments from the museum . 
the musical instruments gallery closed 25 february 2010 , a decision which was highly controversial . 
the collection includes about 1130 british and 650 european oil paintings , 6800 british watercolours , pastels and 2000 miniatures , for which the museum holds the national collection . 
the collection includes about 1130 british and 650 european oil paintings , 6800 british watercolours , pastels and 2000 miniatures , for which the museum holds the national collection . 
the collection includes about 1130 british and 650 european oil paintings , 6800 british watercolours , pastels and 2000 miniatures , for which the museum holds the national collection . 
also on loan to the museum , from her majesty the queen elizabeth ii , are the raphael cartoons : the seven surviving -lrb- there were ten -rrb- full scale designs for tapestries in the sistine chapel , of the lives of peter and paul from the gospels and the acts of the apostles . 
one of the largest objects in the collection is the spanish tempera on wood , 670 x 486 cm , retable of st george , c. 1400 , consisting of numerous scenes and painted by andrés marzal de sax in valencia . 
in 1857 john sheepshanks donated 233 paintings , mainly by contemporary british artists , and a similar number of drawings to the museum with the intention of forming a ' a national gallery of british art ' , a role since taken on by tate britain ; artists represented are william blake , james barry , henry fuseli , sir edwin henry landseer , sir david wilkie , william mulready , william powell frith , millais and hippolyte delaroche . 
in 1857 john sheepshanks donated 233 paintings , mainly by contemporary british artists , and a similar number of drawings to the museum with the intention of forming a ' a national gallery of british art ' , a role since taken on by tate britain ; artists represented are william blake , james barry , henry fuseli , sir edwin henry landseer , sir david wilkie , william mulready , william powell frith , millais and hippolyte delaroche . 
in 1857 john sheepshanks donated 233 paintings , mainly by contemporary british artists , and a similar number of drawings to the museum with the intention of forming a ' a national gallery of british art ' , a role since taken on by tate britain ; artists represented are william blake , james barry , henry fuseli , sir edwin henry landseer , sir david wilkie , william mulready , william powell frith , millais and hippolyte delaroche . 
although some of constable 's works came to the museum with the sheepshanks bequest , the majority of the artist 's works were donated by his daughter isabel in 1888 , including the large number of sketches in oil , the most significant being the 1821 full size oil sketch for the hay wain . 
in 1857 john sheepshanks donated 233 paintings , mainly by contemporary british artists , and a similar number of drawings to the museum with the intention of forming a ' a national gallery of british art ' , a role since taken on by tate britain ; artists represented are william blake , james barry , henry fuseli , sir edwin henry landseer , sir david wilkie , william mulready , william powell frith , millais and hippolyte delaroche . 
several french paintings entered the collection as part of the 260 paintings and miniatures -lrb- not all the works were french , for example carlo crivelli 's virgin and child -rrb- that formed part of the jones bequest of 1882 and as such are displayed in the galleries of continental art 1600 -- 1800 , including the portrait of françois , duc d'alençon by françois clouet , gaspard dughet and works by françois boucher including his portrait of madame de pompadour dated 1758 , jean françois de troy , jean-baptiste pater and their contemporaries . 
several french paintings entered the collection as part of the 260 paintings and miniatures -lrb- not all the works were french , for example carlo crivelli 's virgin and child -rrb- that formed part of the jones bequest of 1882 and as such are displayed in the galleries of continental art 1600 -- 1800 , including the portrait of françois , duc d'alençon by françois clouet , gaspard dughet and works by françois boucher including his portrait of madame de pompadour dated 1758 , jean françois de troy , jean-baptiste pater and their contemporaries . 
several french paintings entered the collection as part of the 260 paintings and miniatures -lrb- not all the works were french , for example carlo crivelli 's virgin and child -rrb- that formed part of the jones bequest of 1882 and as such are displayed in the galleries of continental art 1600 -- 1800 , including the portrait of françois , duc d'alençon by françois clouet , gaspard dughet and works by françois boucher including his portrait of madame de pompadour dated 1758 , jean françois de troy , jean-baptiste pater and their contemporaries . 
several french paintings entered the collection as part of the 260 paintings and miniatures -lrb- not all the works were french , for example carlo crivelli 's virgin and child -rrb- that formed part of the jones bequest of 1882 and as such are displayed in the galleries of continental art 1600 -- 1800 , including the portrait of françois , duc d'alençon by françois clouet , gaspard dughet and works by françois boucher including his portrait of madame de pompadour dated 1758 , jean françois de troy , jean-baptiste pater and their contemporaries . 
one of the more unusual collections is that of eadweard muybridge 's photographs of animal locomotion of 1887 , this consists of 781 plates . 
one of the more unusual collections is that of eadweard muybridge 's photographs of animal locomotion of 1887 , this consists of 781 plates . 
one of the more unusual collections is that of eadweard muybridge 's photographs of animal locomotion of 1887 , this consists of 781 plates . 
these sequences of photographs taken a fraction of a second apart capture images of different animals and humans performimg various actions . 
the museum also holds james lafayette 's society portraits , a collection of more than 600 photographs dating from the late 19th to early 20th centuries and portraying a wide range of society figures of the period , including bishops , generals , society ladies , indian maharajas , ethiopian rulers and other foreign leaders , actresses , people posing in their motor cars and a sequence of photographs recording the guests at the famous fancy-dress ball held at devonshire house in 1897 to celebrate queen victoria 's diamond jubilee . 
the sculpture collection at the v&a is the most comprehensive holding of post-classical european sculpture in the world . 
there are approximately 22,000 objects in the collection that cover the period from about 400 ad to 1914 . 
there are approximately 22,000 objects in the collection that cover the period from about 400 ad to 1914 . 
all uses of sculpture are represented , from tomb and memorial , to portrait , allegorical , religious , mythical , statues for gardens including fountains , as well as architectural decorations . 
it includes canova 's the three graces , which the museum jointly owns with national galleries of scotland . 
italian sculptors whose work is held by the museum include : bartolomeo bon , bartolomeo bellano , luca della robbia , giovanni pisano , donatello , agostino di duccio , andrea riccio , antonio rossellino , andrea del verrocchio , antonio lombardo , pier jacopo alari bonacolsi , andrea della robbia , michelozzo di bartolomeo , michelangelo -lrb- represented by a freehand wax model and casts of his most famous sculptures -rrb- , jacopo sansovino , alessandro algardi , antonio calcagni , benvenuto cellini -lrb- medusa 's head dated c. 1547 -rrb- , agostino busti , bartolomeo ammannati , giacomo della porta , giambologna -lrb- samson slaying a philistine -lrb- giambologna -rrb- c. 1562 , his finest work outside italy -rrb- , bernini -lrb- neptune and triton c. 1622 -- 3 -rrb- , giovanni battista foggini , vincenzo foggini -lrb- samson and the philistines -rrb- , massimiliano soldani benzi , antonio corradini , andrea brustolon , giovanni battista piranesi , innocenzo spinazzi , canova , carlo marochetti and raffaelle monti . 
the largest item from italy is the chancel chapel from santa chiara florence dated 1493 -- 1500 , designed by giuliano da sangallo it is 11.1 metres in height by 5.4 metres square , it includes a grand sculpted tabernacle by antonio rossellino and coloured terracotta decoration . 
the largest item from italy is the chancel chapel from santa chiara florence dated 1493 -- 1500 , designed by giuliano da sangallo it is 11.1 metres in height by 5.4 metres square , it includes a grand sculpted tabernacle by antonio rossellino and coloured terracotta decoration . 
the largest item from italy is the chancel chapel from santa chiara florence dated 1493 -- 1500 , designed by giuliano da sangallo it is 11.1 metres in height by 5.4 metres square , it includes a grand sculpted tabernacle by antonio rossellino and coloured terracotta decoration . 
rodin is represented by more than 20 works in the museum collection , making it one of the largest collections of the sculptor 's work outside france ; these were given to the museum by the sculptor in 1914 , as acknowledgement of britain 's support of france in world war i , although the statue of st john the baptist had been purchased in 1902 by public subscription . 
rodin is represented by more than 20 works in the museum collection , making it one of the largest collections of the sculptor 's work outside france ; these were given to the museum by the sculptor in 1914 , as acknowledgement of britain 's support of france in world war i , although the statue of st john the baptist had been purchased in 1902 by public subscription . 
rodin is represented by more than 20 works in the museum collection , making it one of the largest collections of the sculptor 's work outside france ; these were given to the museum by the sculptor in 1914 , as acknowledgement of britain 's support of france in world war i , although the statue of st john the baptist had been purchased in 1902 by public subscription . 
rodin is represented by more than 20 works in the museum collection , making it one of the largest collections of the sculptor 's work outside france ; these were given to the museum by the sculptor in 1914 , as acknowledgement of britain 's support of france in world war i , although the statue of st john the baptist had been purchased in 1902 by public subscription . 
rodin is represented by more than 20 works in the museum collection , making it one of the largest collections of the sculptor 's work outside france ; these were given to the museum by the sculptor in 1914 , as acknowledgement of britain 's support of france in world war i , although the statue of st john the baptist had been purchased in 1902 by public subscription . 
sculptors both british and europeans who were based in britain and whose work is in the collection include nicholas stone , caius gabriel cibber , grinling gibbons , john michael rysbrack , louis-françois roubiliac , peter scheemakers , sir henry cheere , agostino carlini , thomas banks , joseph nollekens , joseph wilton , john flaxman , sir francis chantrey , john gibson , edward hodges baily , lord leighton , alfred stevens , thomas brock , alfred gilbert , george frampton , and eric gill . 
sculptors both british and europeans who were based in britain and whose work is in the collection include nicholas stone , caius gabriel cibber , grinling gibbons , john michael rysbrack , louis-françois roubiliac , peter scheemakers , sir henry cheere , agostino carlini , thomas banks , joseph nollekens , joseph wilton , john flaxman , sir francis chantrey , john gibson , edward hodges baily , lord leighton , alfred stevens , thomas brock , alfred gilbert , george frampton , and eric gill . 
sculptors both british and europeans who were based in britain and whose work is in the collection include nicholas stone , caius gabriel cibber , grinling gibbons , john michael rysbrack , louis-françois roubiliac , peter scheemakers , sir henry cheere , agostino carlini , thomas banks , joseph nollekens , joseph wilton , john flaxman , sir francis chantrey , john gibson , edward hodges baily , lord leighton , alfred stevens , thomas brock , alfred gilbert , george frampton , and eric gill . 
sculptors both british and europeans who were based in britain and whose work is in the collection include nicholas stone , caius gabriel cibber , grinling gibbons , john michael rysbrack , louis-françois roubiliac , peter scheemakers , sir henry cheere , agostino carlini , thomas banks , joseph nollekens , joseph wilton , john flaxman , sir francis chantrey , john gibson , edward hodges baily , lord leighton , alfred stevens , thomas brock , alfred gilbert , george frampton , and eric gill . 
with the opening of the dorothy and michael hintze sculpture galleries in 2006 it was decided to extend the chronology of the works on display up to 1950 ; this has involved loans by other museums , including tate britain , so works by henry moore and jacob epstein along with other of their contemporaries are now on view . 
with the opening of the dorothy and michael hintze sculpture galleries in 2006 it was decided to extend the chronology of the works on display up to 1950 ; this has involved loans by other museums , including tate britain , so works by henry moore and jacob epstein along with other of their contemporaries are now on view . 
the galleries overlooking the garden are arranged by theme , tomb sculpture , portraiture , garden sculpture and mythology . 
with the opening of the dorothy and michael hintze sculpture galleries in 2006 it was decided to extend the chronology of the works on display up to 1950 ; this has involved loans by other museums , including tate britain , so works by henry moore and jacob epstein along with other of their contemporaries are now on view . 
with the opening of the dorothy and michael hintze sculpture galleries in 2006 it was decided to extend the chronology of the works on display up to 1950 ; this has involved loans by other museums , including tate britain , so works by henry moore and jacob epstein along with other of their contemporaries are now on view . 
the collection of textiles consists of more than 53,000 examples , mainly western european though all populated continents are represented , dating from the 1st century ad to the present , this is the largest such collection in the world . 
the collection of textiles consists of more than 53,000 examples , mainly western european though all populated continents are represented , dating from the 1st century ad to the present , this is the largest such collection in the world . 
the collection of textiles consists of more than 53,000 examples , mainly western european though all populated continents are represented , dating from the 1st century ad to the present , this is the largest such collection in the world . 
the collection of textiles consists of more than 53,000 examples , mainly western european though all populated continents are represented , dating from the 1st century ad to the present , this is the largest such collection in the world . 
these are classified by technique , countries of origin and date of production . 
the tapestry collection includes a fragment of the cloth of st gereon , the oldest known surviving european tapestry . 
a highlight of the collection is the four devonshire hunting tapestries , very rare 15th-century tapestries , woven in the netherlands , depicting the hunting of various animals ; not just their age but their size make these unique . 
a highlight of the collection is the four devonshire hunting tapestries , very rare 15th-century tapestries , woven in the netherlands , depicting the hunting of various animals ; not just their age but their size make these unique . 
a highlight of the collection is the four devonshire hunting tapestries , very rare 15th-century tapestries , woven in the netherlands , depicting the hunting of various animals ; not just their age but their size make these unique . 
also included are tapestries from john vanderbank 's workshop which was the leading english tapestry manufactory in the late 17th century and early 18th century . 
one of the earliest surviving examples of european quilting , the late 14th-century sicilian tristan quilt , is also held by the collection . 
the collection has numerous examples of various types of textiles designed by william morris , including , embroidery , woven fabrics , tapestries -lrb- including ` the forest ' tapestry of 1887 -rrb- , rugs and carpets , as well as pattern books and paper designs . 
the collection has numerous examples of various types of textiles designed by william morris , including , embroidery , woven fabrics , tapestries -lrb- including ` the forest ' tapestry of 1887 -rrb- , rugs and carpets , as well as pattern books and paper designs . 
the art deco period is covered by rugs and fabrics designed by marion dorn . 
from the same period there is a rug designed by serge chermayeff . 
the v&a theatre & performance galleries , formerly the theatre museum , opened in march 2009 . 
the v&a theatre & performance galleries , formerly the theatre museum , opened in march 2009 . 
they hold the uk 's biggest national collection of material about live performance in the uk since shakespeare 's day , covering drama , dance , musical theatre , circus , music hall , rock and pop , and most other forms of live entertainment . 
they hold the uk 's biggest national collection of material about live performance in the uk since shakespeare 's day , covering drama , dance , musical theatre , circus , music hall , rock and pop , and most other forms of live entertainment . 
the collections are stored by the v&a , and are available for research , exhibitions and other shows . 
conservation is responsible for the long-term preservation of the collections , and covers all the collections held by the v&a and the v&a museum of childhood . 
activities include controlling the museum environment -lrb- for example , temperature and light -rrb- and preventing pests -lrb- primarily insects -rrb- from damaging artefacts . 
the other major category is `` interventive '' conservation , this includes : cleaning and reintegration to strengthen fragile objects , reveal original surface decoration , and restore shape . 
conservation is responsible for the long-term preservation of the collections , and covers all the collections held by the v&a and the v&a museum of childhood . 
areas covered by conservator 's work include `` preventive '' conservation this includes : performing surveys , assessments and providing advice on the handling of items , correct packaging , mounting and handling procedures during movement and display to reduce risk of damaging objects . 
the american broadcasting company -lrb- abc -rrb- -lrb- stylized in its logo as abc since 1957 -rrb- is an american commercial broadcast television network that is owned by the disney -- abc television group , a subsidiary of disney media networks division of the walt disney company . 
the american broadcasting company -lrb- abc -rrb- -lrb- stylized in its logo as abc since 1957 -rrb- is an american commercial broadcast television network that is owned by the disney -- abc television group , a subsidiary of disney media networks division of the walt disney company . 
the network is headquartered on columbus avenue and west 66th street in manhattan , with additional major offices and production facilities in new york city , los angeles and burbank , california . 
the network is headquartered on columbus avenue and west 66th street in manhattan , with additional major offices and production facilities in new york city , los angeles and burbank , california . 
the american broadcasting company -lrb- abc -rrb- -lrb- stylized in its logo as abc since 1957 -rrb- is an american commercial broadcast television network that is owned by the disney -- abc television group , a subsidiary of disney media networks division of the walt disney company . 
abc originally launched on october 12 , 1943 as a radio network , separated from and serving as the successor to the nbc blue network , which had been purchased by edward j. noble . 
abc originally launched on october 12 , 1943 as a radio network , separated from and serving as the successor to the nbc blue network , which had been purchased by edward j. noble . 
it extended its operations to television in 1948 , following in the footsteps of established broadcast networks cbs and nbc . 
in the 1980s , after purchasing an 80 % interest in cable sports channel espn , the network 's parent merged with capital cities communications , owner of several print publications , and television and radio stations . 
in the 1980s , after purchasing an 80 % interest in cable sports channel espn , the network 's parent merged with capital cities communications , owner of several print publications , and television and radio stations . 
the television network has eight owned-and-operated and over 232 affiliated television stations throughout the united states and its territories . 
abc news provides news and features content for select radio stations owned by citadel broadcasting , which purchased the abc radio properties in 2007 . 
the television network has eight owned-and-operated and over 232 affiliated television stations throughout the united states and its territories . 
most canadians have access to at least one u.s.-based abc affiliate , either over-the-air -lrb- in areas located within proximity to the canada -- united states border -rrb- or through a cable , satellite or iptv provider , although most abc programs are subject to simultaneous substitution regulations imposed by the canadian radio-television and telecommunications commission that allow pay television providers to replace an american station 's signal with the feed of a canadian broadcaster to protect domestic programming rights and advertising revenue . 
abc news provides news and features content for select radio stations owned by citadel broadcasting , which purchased the abc radio properties in 2007 . 
the last was owned by electronics manufacturer radio corporation of america -lrb- rca -rrb- , which owned two radio networks that each ran different varieties of programming , nbc blue and nbc red . 
the last was owned by electronics manufacturer radio corporation of america -lrb- rca -rrb- , which owned two radio networks that each ran different varieties of programming , nbc blue and nbc red . 
the nbc blue network was created in 1927 for the primary purpose of testing new programs on markets of lesser importance than those served by nbc red , which served the major cities , and to test drama series . 
the nbc blue network was created in 1927 for the primary purpose of testing new programs on markets of lesser importance than those served by nbc red , which served the major cities , and to test drama series . 
the nbc blue network was created in 1927 for the primary purpose of testing new programs on markets of lesser importance than those served by nbc red , which served the major cities , and to test drama series . 
in 1934 , mutual filed a complaint with the federal communications commission -lrb- fcc -rrb- regarding its difficulties in establishing new stations , in a radio market that was already being saturated by nbc and cbs . 
in 1938 , the fcc began a series of investigations into the practices of radio networks and published its report on the broadcasting of network radio programs in 1940 . 
in 1938 , the fcc began a series of investigations into the practices of radio networks and published its report on the broadcasting of network radio programs in 1940 . 
at that time , the nbc red network was the principal radio network in the united states and , according to the fcc , rca was using nbc blue to eliminate any hint of competition . 
at that time , the nbc red network was the principal radio network in the united states and , according to the fcc , rca was using nbc blue to eliminate any hint of competition . 
once mutual 's appeals against the fcc were rejected , rca decided to sell nbc blue in 1941 , and gave the mandate to do so to mark woods . 
rca converted the nbc blue network into an independent subsidiary , formally divorcing the operations of nbc red and nbc blue on january 8 , 1942 , with the blue network being referred to on-air as either `` blue '' or `` blue network '' . 
investment firm dillon , read & co. -lrb- which was later acquired by the swiss bank corporation in 1997 -rrb- offered $ 7.5 million to purchase the network , but the offer was rejected by woods and rca president david sarnoff . 
investment firm dillon , read & co. -lrb- which was later acquired by the swiss bank corporation in 1997 -rrb- offered $ 7.5 million to purchase the network , but the offer was rejected by woods and rca president david sarnoff . 
investment firm dillon , read & co. -lrb- which was later acquired by the swiss bank corporation in 1997 -rrb- offered $ 7.5 million to purchase the network , but the offer was rejected by woods and rca president david sarnoff . 
edward john noble , the owner of life savers candy , drugstore chain rexall and new york city radio station wmca , purchased the network for $ 8 million . 
the commission authorized the transaction on october 12 , 1943 . 
noble subsequently acquired the rights to the `` american broadcasting company '' name from george b. storer in 1944 ; its parent company adopted the corporate name american broadcasting companies , inc. . 
woods retained his position as president and ceo of abc until december 1949 , and was subsequently promoted to vice-chairman of the board before leaving abc altogether on june 30 , 1951 . 
woods retained his position as president and ceo of abc until december 1949 , and was subsequently promoted to vice-chairman of the board before leaving abc altogether on june 30 , 1951 . 
however , abc made a name for itself by utilizing the practice of counterprogramming , with which it often placed shows of its own against the offerings of nbc and cbs , adopting the use of the magnetophon tape recorder , brought to the u.s. from nazi germany after its conquest , to pre-record its programming . 
abc became an aggressive competitor to nbc and cbs when , continuing nbc blue 's traditions of public service , it aired symphony performances conducted by paul whiteman , performances from the metropolitan opera , and jazz concerts aired as part of its broadcast of the chamber music society of lower basin street announced by milton cross . 
abc became an aggressive competitor to nbc and cbs when , continuing nbc blue 's traditions of public service , it aired symphony performances conducted by paul whiteman , performances from the metropolitan opera , and jazz concerts aired as part of its broadcast of the chamber music society of lower basin street announced by milton cross . 
with the help of the magnetophon , abc was able to provide its stars with greater freedom in terms of time , and also attract several big names , such as bing crosby at a time when nbc and cbs did not allow pre-taped shows . 
abc became an aggressive competitor to nbc and cbs when , continuing nbc blue 's traditions of public service , it aired symphony performances conducted by paul whiteman , performances from the metropolitan opera , and jazz concerts aired as part of its broadcast of the chamber music society of lower basin street announced by milton cross . 
a second period of international expansion is linked to that of the espn network in the 1990s , and policies enacted in the 2000s by disney media networks -lrb- which included the expansion of several of the company 's u.s.-based cable networks including disney channel and its spinoffs toon disney , playhouse disney and jetix ; although disney also sold its 33 % stake in european sports channel eurosport for $ 155 million in june 2000 -rrb- . 
the policy regarding wholly owned international networks was revived in 2004 when on september 27 of that year , abc announced the launch of abc1 , a free-to-air channel in the united kingdom owned by the abc group . 
however , on september 8 , 2007 , disney announced that it would discontinue abc1 citing to the channel 's inability to attain sustainable viewership . 
with abc1 's shutdown that october , the company 's attempt to develop abc international were discontinued . 
in contrast to disney 's other channels , abc is broadcast in the united states , although the network 's programming is syndicated in many countries . 
in 1959 , this rerun activity was completed with program syndication , with abc films selling programs to networks not owned by abc . 
the arrival of satellite television ended the need for abc to hold interests in other countries ; many governments also wanted to increase their independence and strengthen legislation to limit foreign ownership of broadcasting properties . 
as a result , abc was forced to sell all of its interests in international networks , mainly in japan and latin america , in the 1970s . 
the arrival of satellite television ended the need for abc to hold interests in other countries ; many governments also wanted to increase their independence and strengthen legislation to limit foreign ownership of broadcasting properties . 
leonard goldenson said that abc 's first international activity was broadcasting the coronation of queen elizabeth ii in june 1953 ; cbs and nbc were unable to cover the coronation live due to respective issues with technical problems and flight delays . 
goldenson also invested in broadcasting properties in beirut in the mid-1960s . 
goldenson also cited interest in japan in the early 1950s , acquiring a 5 % stake in two new domestic networks , the mainichi broadcasting system in 1951 and nihon educational television in 1957 . 
leonard goldenson said that abc 's first international activity was broadcasting the coronation of queen elizabeth ii in june 1953 ; cbs and nbc were unable to cover the coronation live due to respective issues with technical problems and flight delays . 
leonard goldenson said that abc 's first international activity was broadcasting the coronation of queen elizabeth ii in june 1953 ; cbs and nbc were unable to cover the coronation live due to respective issues with technical problems and flight delays . 
since 2000 , abc has also owned the television rights to most of the peanuts television specials , having acquired the broadcast rights from cbs , which originated the specials in 1965 with the debut of a charlie brown christmas -lrb- other peanuts specials broadcast annually by abc , including a charlie brown christmas , include it 's the great pumpkin , charlie brown and a charlie brown thanksgiving -rrb- . 
abc currently holds the broadcast rights to the academy awards , emmy awards -lrb- which are rotated across all four major networks on a year-to-year basis -rrb- , american music awards , disney parks christmas day parade , tournament of roses parade , country music association awards and the cma music festival . 
since 2000 , abc has also owned the television rights to most of the peanuts television specials , having acquired the broadcast rights from cbs , which originated the specials in 1965 with the debut of a charlie brown christmas -lrb- other peanuts specials broadcast annually by abc , including a charlie brown christmas , include it 's the great pumpkin , charlie brown and a charlie brown thanksgiving -rrb- . 
abc currently holds the broadcast rights to the academy awards , emmy awards -lrb- which are rotated across all four major networks on a year-to-year basis -rrb- , american music awards , disney parks christmas day parade , tournament of roses parade , country music association awards and the cma music festival . 
since 2000 , abc has also owned the television rights to most of the peanuts television specials , having acquired the broadcast rights from cbs , which originated the specials in 1965 with the debut of a charlie brown christmas -lrb- other peanuts specials broadcast annually by abc , including a charlie brown christmas , include it 's the great pumpkin , charlie brown and a charlie brown thanksgiving -rrb- . 
since 1974 , abc has generally aired dick clark 's new year 's rockin ' eve on new year 's eve -lrb- hosted first by its creator dick clark , and later by his successor ryan seacrest -rrb- ; the only exception was in 1999 , when abc put it on a one-year hiatus to provide coverage of the international millennium festivities , though clark 's traditional countdown from times square was still featured within the coverage . 
since 1974 , abc has generally aired dick clark 's new year 's rockin ' eve on new year 's eve -lrb- hosted first by its creator dick clark , and later by his successor ryan seacrest -rrb- ; the only exception was in 1999 , when abc put it on a one-year hiatus to provide coverage of the international millennium festivities , though clark 's traditional countdown from times square was still featured within the coverage . 
abc has also aired the miss america pageant from 1954 to 1956 , 1997 to 2005 -lrb- with the television rights being assumed by cable channel tlc in 2006 , when the pageant moved from its longtime homebase in atlantic city to las vegas , before returning to atlantic city in 2013 -rrb- and since 2011 . 
since 1974 , abc has generally aired dick clark 's new year 's rockin ' eve on new year 's eve -lrb- hosted first by its creator dick clark , and later by his successor ryan seacrest -rrb- ; the only exception was in 1999 , when abc put it on a one-year hiatus to provide coverage of the international millennium festivities , though clark 's traditional countdown from times square was still featured within the coverage . 
abc has also aired the miss america pageant from 1954 to 1956 , 1997 to 2005 -lrb- with the television rights being assumed by cable channel tlc in 2006 , when the pageant moved from its longtime homebase in atlantic city to las vegas , before returning to atlantic city in 2013 -rrb- and since 2011 . 
abc 's daytime schedule currently features talk shows the view and the chew , and the soap opera general hospital , the latter of which is the longest-running entertainment program in the history of the abc television network , having aired since 1963 . 
abc also broadcasts the morning news program good morning america and has done so since 1975 , though that program is not considered to be part of the abc daytime block . 
abc also aired the last nine years of the procter & gamble-produced soap the edge of night , following its cancellation by cbs in 1975 . 
abc 's daytime schedule currently features talk shows the view and the chew , and the soap opera general hospital , the latter of which is the longest-running entertainment program in the history of the abc television network , having aired since 1963 . 
abc 's daytime schedule currently features talk shows the view and the chew , and the soap opera general hospital , the latter of which is the longest-running entertainment program in the history of the abc television network , having aired since 1963 . 
abc also carries various x games weekend events not broadcast by espn . 
due to the erratic and -lrb- outside of college football season -rrb- highly inconsistent scheduling of sports programming on weekend afternoons since espn took over responsibilities for abc 's sports division in 2006 , abc carries the espn sports saturday block on saturday late afternoons -lrb- featuring various espn-produced documentaries -rrb- , and on sundays either encores of primetime reality series , cancelled series being burned off that had no room on the primetime schedule , occasional theatrical films which were acquired by the network in the early to mid-2000s that no longer have a primetime slot to air in or more recently , figure skating and gymnastics specials supplied by disson skating , when no sports telecasts are scheduled , usually airing between 4:00 and 6:00 p.m. eastern and pacific time . 
sports programming is also provided on some weekend afternoons at any time from 12:00 to 6:00 p.m. eastern time -lrb- 9:00 a.m. to 3:00 p.m. pacific -rrb- and , during college football season , during prime time on saturday nights as part of the saturday night football package . 
abc airs nba games on sundays , normally starting in january as `` nba sunday showcase '' during the regular season , and shows christmas day games , regularly between 2 -- 7 pm et , and nba playoff games during the weekends , and exclusive rights to the nba finals . 
during the summer , abc airs espn-produced highlight compilation programs for the open championship golf and the wimbledon tennis tournaments to provide some presence for both events on american broadcast television . 
these applications all requested for the stations to broadcast on vhf channel 7 , as frank marx , then abc 's vice-president of engineering , thought that the low-band vhf frequencies -lrb- corresponding to channels 2 through 6 -rrb- would be requisitioned from broadcasting use and reallocated for the u.s. army . 
these applications all requested for the stations to broadcast on vhf channel 7 , as frank marx , then abc 's vice-president of engineering , thought that the low-band vhf frequencies -lrb- corresponding to channels 2 through 6 -rrb- would be requisitioned from broadcasting use and reallocated for the u.s. army . 
to ensure a space , in 1947 , abc submitted five applications for television station licenses , one for each market where it owned and operated a radio station -lrb- new york city , los angeles , chicago , san francisco and detroit -rrb- . 
these applications all requested for the stations to broadcast on vhf channel 7 , as frank marx , then abc 's vice-president of engineering , thought that the low-band vhf frequencies -lrb- corresponding to channels 2 through 6 -rrb- would be requisitioned from broadcasting use and reallocated for the u.s. army . 
before the freeze ended in 1952 , there were only 108 existing television stations in the united states ; a few major cities -lrb- such as boston -rrb- had only two television stations , many other cities -lrb- such as pittsburgh and st. louis -rrb- had only one , and still many others -lrb- such as denver and portland -rrb- did not yet have any television service . 
before the freeze ended in 1952 , there were only 108 existing television stations in the united states ; a few major cities -lrb- such as boston -rrb- had only two television stations , many other cities -lrb- such as pittsburgh and st. louis -rrb- had only one , and still many others -lrb- such as denver and portland -rrb- did not yet have any television service . 
in the fall of 1949 , abc found itself in the position of an outsider , with less coverage than two of its competing networks , cbs and nbc , even though it was on par with them in some major cities and had a headstart over its third rival at the time , the dumont television network . 
in the fall of 1949 , abc found itself in the position of an outsider , with less coverage than two of its competing networks , cbs and nbc , even though it was on par with them in some major cities and had a headstart over its third rival at the time , the dumont television network . 
at the end of 1949 , movie theater operator united paramount theatres -lrb- upt -rrb- was forced by the u.s. supreme court to become an independent entity , separating itself from paramount pictures . 
at the end of 1949 , movie theater operator united paramount theatres -lrb- upt -rrb- was forced by the u.s. supreme court to become an independent entity , separating itself from paramount pictures . 
for its part , abc was on the verge of bankruptcy , with only five owned-and-operated stations and nine full-time affiliates . 
in 1951 , a rumor even mentioned that the network would be sold to cbs . 
in 1951 , noble held a 58 % ownership stake in abc , giving him $ 5 million with which to prevent abc from going bankrupt ; as banks refused further credit , that amount was obtained through a loan from the prudential insurance company of america . 
leonard goldenson , the president of upt -lrb- which sought to diversify itself at the time -rrb- , approached noble in 1951 on a proposal for upt to purchase abc . 
noble received other offers , including one from cbs founder william s. paley ; however , a merger with cbs would have forced that network to sell its new york city and los angeles stations at the very least . 
on june 6 , 1951 , the tentative agreement was approved by upt 's board of directors . 
in 1952 , when the release of the fcc 's sixth report and order announced the end of its freeze on new station license applications , among the issues the commission was slated to address was whether to approve the upt-abc merger . 
on february 9 , 1953 , the fcc approved upt 's purchase of abc in exchange for $ 25 million in shares . 
the merged company , renamed american broadcasting-paramount theatres , inc. and headquartered in the paramount building at 1501 broadway in manhattan , owned six am and several fm radio stations , five television stations and 644 cinemas in 300 u.s. cities . 
the merged company , renamed american broadcasting-paramount theatres , inc. and headquartered in the paramount building at 1501 broadway in manhattan , owned six am and several fm radio stations , five television stations and 644 cinemas in 300 u.s. cities . 
the network 's flagship owned-and-operated station , wjz-tv in new york city -lrb- later re-called wabc-tv -rrb- , signed on the air on august 10 , 1948 , with its first broadcast running for two hours that evening . 
in october 1948 , as a result of an influx of television station license applications that it had issued as well as a study it undertook on the use of the vhf spectrum for broadcasting purposes , the fcc implemented a freeze on new station applications . 
on may 7 , 1949 , billboard revealed that abc had proposed an investment of $ 6.25 million , of which it would spend $ 2.5 million to convert 20 acres -lrb- 80,937 m2 -rrb- of land in hollywood into what would become the prospect studios , and construct a transmitter on mount wilson , in anticipation of the launch of keca-tv , which was scheduled to begin operations on august 1 -lrb- but would not actually sign on until september 16 -rrb- . 
on may 7 , 1949 , billboard revealed that abc had proposed an investment of $ 6.25 million , of which it would spend $ 2.5 million to convert 20 acres -lrb- 80,937 m2 -rrb- of land in hollywood into what would become the prospect studios , and construct a transmitter on mount wilson , in anticipation of the launch of keca-tv , which was scheduled to begin operations on august 1 -lrb- but would not actually sign on until september 16 -rrb- . 
on september 30 , 1960 , abc premiered the flintstones , another example of counterprogramming ; although the animated series from william hanna and joseph barbera was filmed in color from the beginning , it was initially broadcast in black-and-white , as abc had not made the necessary technical upgrades to broadcast its programming in color at the time . 
the 1960s would be marked by the rise of family-oriented series in an attempt by abc to counterprogram its established competitors , but the decade was also marked by the network 's gradual transition to color . 
on september 30 , 1960 , abc premiered the flintstones , another example of counterprogramming ; although the animated series from william hanna and joseph barbera was filmed in color from the beginning , it was initially broadcast in black-and-white , as abc had not made the necessary technical upgrades to broadcast its programming in color at the time . 
the 1960s would be marked by the rise of family-oriented series in an attempt by abc to counterprogram its established competitors , but the decade was also marked by the network 's gradual transition to color . 
in 1959 , walt disney productions , having improved its financial situation , had purchased abc 's shares in the disneyland theme park for $ 7.5 million and initiated discussions to renew abc 's television contract for walt disney presents , which was due to expire in 1961 . 
walt disney was approached by nbc to produce color broadcasts of his anthology series -lrb- which would be renamed walt disney 's wonderful world of color -rrb- . 
as a result , abc and disney 's first television collaboration ended in 1961 -lrb- the network would resume its relationship with disney in 1985 , when the anthology series returned to the network for a three-season run as the disney sunday movie until it lost the rights to nbc again in 1988 ; the disney anthology series would return to abc in 1996 , following the company 's purchase of the future capital cities/abc , as the wonderful world of disney -rrb- . 
as a result , abc and disney 's first television collaboration ended in 1961 -lrb- the network would resume its relationship with disney in 1985 , when the anthology series returned to the network for a three-season run as the disney sunday movie until it lost the rights to nbc again in 1988 ; the disney anthology series would return to abc in 1996 , following the company 's purchase of the future capital cities/abc , as the wonderful world of disney -rrb- . 
in 2000 , abc launched a web-based promotional campaign focused around its circle logo , also called `` the dot '' , in which comic book character little dot prompted visitors to `` download the dot '' , a program which would cause the abc logo to fly around the screen and settle in the bottom-right corner . 
the network hired the troika design group to design and produce its 2001 -- 02 identity , which continued using the black-and-yellow coloring of the logo and featured dots and stripes in various promotional and identification spots . 
the network hired the troika design group to design and produce its 2001 -- 02 identity , which continued using the black-and-yellow coloring of the logo and featured dots and stripes in various promotional and identification spots . 
in 2000 , abc launched a web-based promotional campaign focused around its circle logo , also called `` the dot '' , in which comic book character little dot prompted visitors to `` download the dot '' , a program which would cause the abc logo to fly around the screen and settle in the bottom-right corner . 
in 1998 , the network began using a minimalist graphical identity , designed by pittard sullivan , featuring a small black-and-white `` abc circle '' logo on a yellow background -lrb- promotions during this time also featured a sequence of still photos of the stars of its programs during the timeslot card as well as the schedule sequence that began each night 's prime time lineup -rrb- . 
in the fall of 2015 , abc is stopped with its 1998 -- 2002 four-note jingles for promotions and production company vanity cards following the closing credits of most of its programs over seventeen years , now it have a different and adventure-type music -lrb- with the drums of the network 's four-note signature in the ending -rrb- . 
a new four-note theme tune was introduced alongside the package , based around the network 's `` we love tv '' image campaign introduced that year , creating an audio signature on par with the nbc chimes , cbs ' various three-note soundmarks -lrb- including the current version used since 2000 -rrb- and the fox fanfare . 
the old four-note theme tune is still used by abc on demand to the beginning of the abc show . 
the abc logo first appeared as a on-screen bug in the 1993 -- 94 season , appearing initially only for 60 seconds at the beginning of an act or segment , before appearing throughout programs -lrb- except during commercial breaks -rrb- beginning in the 1995 -- 96 season ; the respective iterations of the translucent logo bug were also incorporated within program promotions until the 2011 -- 12 season . 
the abc logo first appeared as a on-screen bug in the 1993 -- 94 season , appearing initially only for 60 seconds at the beginning of an act or segment , before appearing throughout programs -lrb- except during commercial breaks -rrb- beginning in the 1995 -- 96 season ; the respective iterations of the translucent logo bug were also incorporated within program promotions until the 2011 -- 12 season . 
in 1983 , for the 40th anniversary of the network 's founding , id sequences had the logo appear in a gold cgi design on a blue background , accompanied by the slogan `` that special feeling '' in a script font . 
in 1983 , for the 40th anniversary of the network 's founding , id sequences had the logo appear in a gold cgi design on a blue background , accompanied by the slogan `` that special feeling '' in a script font . 
among the `` abc circle '' logo 's many variants was a 1977 id sequence that featured a bubble on a black background representing the circle with glossy gold letters , and as such , was the first abc identification card to have a three-dimensional appearance . 
among the `` abc circle '' logo 's many variants was a 1977 id sequence that featured a bubble on a black background representing the circle with glossy gold letters , and as such , was the first abc identification card to have a three-dimensional appearance . 
among the `` abc circle '' logo 's many variants was a 1977 id sequence that featured a bubble on a black background representing the circle with glossy gold letters , and as such , was the first abc identification card to have a three-dimensional appearance . 
in 1962 , graphic designer paul rand redesigned the abc logo into its best-known -lrb- and current -rrb- form , with the lowercase letters `` abc '' enclosed in a single black circle . 
the letters are strongly reminiscent of the bauhaus typeface designed by herbert bayer in the 1920s , but also share similarities with several other fonts , such as itc avant garde and horatio , and most closely resembling chalet . 
the letters are strongly reminiscent of the bauhaus typeface designed by herbert bayer in the 1920s , but also share similarities with several other fonts , such as itc avant garde and horatio , and most closely resembling chalet . 
the new logo debuted on-air for abc 's promos at the start of the 1963 -- 64 season . 
between may and september 2005 , rumors circulated that disney -- abc was considering a sale of abc radio , with clear channel communications and westwood one -lrb- which had earlier purchased nbc 's radio division , as well as the distribution rights to cbs 's , and the mutual broadcasting system during the 1990s -rrb- as potential buyers . 
on october 19 , 2005 , abc announced the restructuring of the group into six divisions : entertainment communications , communications resources , kids communications , news communications , corporate communications , and international communications . 
on october 19 , 2005 , abc announced the restructuring of the group into six divisions : entertainment communications , communications resources , kids communications , news communications , corporate communications , and international communications . 
in 2004 , abc 's average viewership declined by ten ratings points , landing the network in fourth place , behind nbc , cbs and fox -lrb- by the following year , the combined season-ending average audience share of abc , nbc and cbs represented only 32 % of u.s. households -rrb- . 
however , during the 2004 -- 05 season , the network experienced unexpected success with new series such as desperate housewives , lost and grey 's anatomy as well as reality series dancing with the stars , which helped abc rise to second place , jumping ahead of cbs , but behind a surging fox . 
on april 21 , 2004 , disney announced a restructuring of its disney media networks division with anne sweeney being named president of abc parent disney -- abc television group , and espn president george bodenheimer becoming co-ceo of the division with sweeney , as well as president of abc sports . 
on december 7 , 2005 , abc sports and espn signed an eight-year broadcast rights agreement with nascar , allowing abc and espn to broadcast 17 nextel cup races each season -lrb- comprising just over half of the 36 races held annually -rrb- effective with the 2006 season . 
networks affiliates approved a two-year affiliate agreement in 2002 . 
in september , disney chairman/ceo michael eisner outlined a proposed realignment of the abc broadcast network day parts with the similar unit in its cable channels : abc saturday mornings with disney channels -lrb- toon & playhouse -rrb- , abc daytime with soapnet and abc prime time with abc family . 
2002 saw the debut of the network 's first hit reality series , the bachelor -lrb- the elimination-style dating show 's success led to a spinoff , the bachelorette , which premiered the following year , as well as two additional spinoffs that later debuted in the early 2010s -rrb- . 
2002 saw the debut of the network 's first hit reality series , the bachelor -lrb- the elimination-style dating show 's success led to a spinoff , the bachelorette , which premiered the following year , as well as two additional spinoffs that later debuted in the early 2010s -rrb- . 
on april 30 , 2000 , as a result of a carriage dispute with abc , time warner cable removed abc owned-and-operated stations from the cable provider 's systems in four markets -lrb- wabc-tv in new york city , kabc-tv in los angeles , ktrk in houston and wtvd in raleigh-durham -rrb- . 
abc filed an emergency petition to the federal communications commission on may 1 to force twc to restore the affected stations ; the fcc ruled in favor of abc , ordering time warner cable to restore the stations , doing so on the afternoon of may 2 . 
abc ended the 2000 -- 01 season as the most-watched network , ahead of nbc . 
abc filed an emergency petition to the federal communications commission on may 1 to force twc to restore the affected stations ; the fcc ruled in favor of abc , ordering time warner cable to restore the stations , doing so on the afternoon of may 2 . 
2000 saw the end of `` tgif '' , which was struggling to find new hits -lrb- with boy meets world and sabrina , the teenage witch , the latter of which moved to the wb in september 2000 , beginning to wane as well by this point -rrb- following the loss of family matters and step by step to cbs as part of its own failed attempt at a family-oriented friday comedy block in the 1997 -- 98 season . 
2000 saw the end of `` tgif '' , which was struggling to find new hits -lrb- with boy meets world and sabrina , the teenage witch , the latter of which moved to the wb in september 2000 , beginning to wane as well by this point -rrb- following the loss of family matters and step by step to cbs as part of its own failed attempt at a family-oriented friday comedy block in the 1997 -- 98 season . 
2000 saw the end of `` tgif '' , which was struggling to find new hits -lrb- with boy meets world and sabrina , the teenage witch , the latter of which moved to the wb in september 2000 , beginning to wane as well by this point -rrb- following the loss of family matters and step by step to cbs as part of its own failed attempt at a family-oriented friday comedy block in the 1997 -- 98 season . 
in august 1999 , abc premiered a special series event , who wants to be a millionaire , a game show based on the british program of the same title . 
hosted throughout its abc tenure by regis philbin , the program became a major ratings success throughout its initial summer run , which led abc to renew millionaire as a regular series , returning on january 18 , 2000 . 
millionaire ended its run on the network 's primetime lineup after three years in 2002 , with buena vista television relaunching the show as a syndicated program -lrb- under that incarnation 's original host meredith vieira -rrb- in september of that year . 
millionaire ended its run on the network 's primetime lineup after three years in 2002 , with buena vista television relaunching the show as a syndicated program -lrb- under that incarnation 's original host meredith vieira -rrb- in september of that year . 
on july 31 , 1995 , the walt disney company announced an agreement to merge with capital cities/abc for $ 19 billion . 
disney shareholders approved the merger at a special conference in new york city on january 4 , 1996 , with the acquisition of capital cities/abc being completed on february 9 ; following the sale , disney renamed its new subsidiary abc inc. . 
on april 4 , disney sold the four newspapers that abc had controlled under capital cities to knight ridder for $ 1.65 billion . 
following the merger , thomas s. murphy left abc with robert iger taking his place as president and ceo . 
in 1998 , abc premiered the aaron sorkin-created sitcom sports night , centering on the travails of the staff of a sportscenter-style sports news program ; despite earning critical praise and multiple emmy awards , the series was cancelled in 2000 after two seasons . 
it was not until the 1965 -- 66 season that color became the dominant format for the three broadcast television networks . 
abc , meanwhile , remained in third place and still needed money to grow itself into a major competitor . 
however , abc 's issues with its transition to color became secondary compared to the network 's financial problems ; in 1964 , the network found itself , as goldenson later wrote in the 1991 book `` beating the odds : the untold story behind the rise of abc '' , `` in the middle of a war -lsb- where -rsb- the battlefield was wall street '' . 
on may 1 , 1953 , abc 's new york city flagship stations -- wjz , wjz-fm and wjz-tv -- changed their respective callsigns to wabc , wabc-fm and wabc-tv , and moved their operations to facilities at 7 west 66th street , one block away from central park . 
on may 1 , 1953 , abc 's new york city flagship stations -- wjz , wjz-fm and wjz-tv -- changed their respective callsigns to wabc , wabc-fm and wabc-tv , and moved their operations to facilities at 7 west 66th street , one block away from central park . 
the wjz calls would later be reassigned to the then-abc affiliate in baltimore in 1959 , in an historical nod to the fact that wjz was originally established by the baltimore station 's owner at the time , westinghouse . 
in 1950 , noble appointed robert kintner to be abc 's president while he himself served as its ceo , a position he would hold until his death in 1958 . 
goldenson added to the confusion when , in october 1954 , he proposed a merger between upt and the dumont television network , which was also mired in financial trouble . 
as part of this merger , the network would have been renamed `` abc-dumont '' for five years , and dumont would have received $ 5 million in cash , room on the schedule for existing dumont programming , and guaranteed advertising time for dumont laboratories receivers . 
as part of this merger , the network would have been renamed `` abc-dumont '' for five years , and dumont would have received $ 5 million in cash , room on the schedule for existing dumont programming , and guaranteed advertising time for dumont laboratories receivers . 
at the same time he made attempts to help grow abc , goldenson had been trying since mid-1953 to provide content for the network by contacting his old acquaintances in hollywood , with whom he had worked when upt was a subsidiary of paramount pictures . 
abc 's flagship productions at the time were the lone ranger , based on the radio program of the same title , and the adventures of ozzie and harriet , the latter of which -lrb- at 13 seasons , running from 1952 to 1965 -rrb- held the record for the longest-running prime time comedy in u.s. television history , until it was surpassed by the simpsons in 2002 . 
abc 's flagship productions at the time were the lone ranger , based on the radio program of the same title , and the adventures of ozzie and harriet , the latter of which -lrb- at 13 seasons , running from 1952 to 1965 -rrb- held the record for the longest-running prime time comedy in u.s. television history , until it was surpassed by the simpsons in 2002 . 
airing during the 1955 -- 56 season , it showcased television adaptations of the 1942 films kings row and casablanca ; cheyenne -lrb- adapted from the 1947 film wyoming kid -rrb- ; sugarfoot -lrb- a remake of the 1954 film the boy from oklahoma -rrb- ; and maverick . 
airing during the 1955 -- 56 season , it showcased television adaptations of the 1942 films kings row and casablanca ; cheyenne -lrb- adapted from the 1947 film wyoming kid -rrb- ; sugarfoot -lrb- a remake of the 1954 film the boy from oklahoma -rrb- ; and maverick . 
however , the most iconic of abc 's relationships with hollywood producers was its agreement with walt disney ; after the start of the network 's bond with the disney studio , james lewis baughman , who worked as a columnist at that time , observed that `` at abc 's headquarters in new york , the secretaries -lsb- were now -rsb- wearing hats with mickey mouse ears '' . 
warner tried with mixed success to adapt some of its most successful films as abc television series , and showcase these adaptations as part of the wheel series warner bros. . 
walt disney and his brother roy contacted goldenson at the end of 1953 for abc to agree to finance part of the disneyland project in exchange for producing a television program for the network . 
walt wanted abc to invest $ 500,000 and accrued a guarantee of $ 4.5 million in additional loans , a third of the budget intended for the park . 
around 1954 , abc agreed to finance disneyland in exchange for the right to broadcast a new sunday night program , disneyland , which debuted on the network on october 27 , 1954 as the first of many anthology television programs that disney would broadcast over the course of the next 50 years . 
around 1954 , abc agreed to finance disneyland in exchange for the right to broadcast a new sunday night program , disneyland , which debuted on the network on october 27 , 1954 as the first of many anthology television programs that disney would broadcast over the course of the next 50 years . 
in july 1968 , abc radio launched a special programming project for its fm stations , which was spearheaded by allen shaw , a former program manager at wcfl in chicago who was approached by abc radio president harold l. neal to develop a format to compete with the new progressive rock and dj-helmed stations . 
in july 1968 , abc radio launched a special programming project for its fm stations , which was spearheaded by allen shaw , a former program manager at wcfl in chicago who was approached by abc radio president harold l. neal to develop a format to compete with the new progressive rock and dj-helmed stations . 
the new concept called `` love radio '' , which featured a limited selection of music genres , was launched on abc 's seven owned-and-operated fm stations in late november 1968 ; the concept replaced nearly all of the programming provided by these stations ; however , several affiliates -lrb- such as kxyz -rrb- retained the majority of their content . 
the new concept called `` love radio '' , which featured a limited selection of music genres , was launched on abc 's seven owned-and-operated fm stations in late november 1968 ; the concept replaced nearly all of the programming provided by these stations ; however , several affiliates -lrb- such as kxyz -rrb- retained the majority of their content . 
on the television side , in september 1969 , abc launched the movie of the week , a weekly showcase aimed at capitalizing on the growing success of made-for-tv movies since the early 1960s . 
the movie of the week broadcast feature-length dramatic films directed by such talented filmmakers as aaron spelling , david wolper and steven spielberg -lrb- the latter of whom gained early success through the showcase for his 1971 film duel -rrb- that were produced on an average budget of $ 400,000 -- $ 450,000 . 
the movie of the week broadcast feature-length dramatic films directed by such talented filmmakers as aaron spelling , david wolper and steven spielberg -lrb- the latter of whom gained early success through the showcase for his 1971 film duel -rrb- that were produced on an average budget of $ 400,000 -- $ 450,000 . 
the movie of the week broadcast feature-length dramatic films directed by such talented filmmakers as aaron spelling , david wolper and steven spielberg -lrb- the latter of whom gained early success through the showcase for his 1971 film duel -rrb- that were produced on an average budget of $ 400,000 -- $ 450,000 . 
in the early 1970s , abc completed its transition to color ; the decade as a whole would mark a turning point for abc , as it began to pass cbs and nbc in the ratings to become the first place network . 
in the early 1970s , abc completed its transition to color ; the decade as a whole would mark a turning point for abc , as it began to pass cbs and nbc in the ratings to become the first place network . 
it also began to use behavioral and demographic data to better determine what types of sponsors to sell advertising slots to and provide programming that would appeal towards certain audiences . 
in 1970 , abc debuted monday night football as part of its monday prime time schedule ; the program became a hit for the network and served as the national football league -lrb- nfl -rrb- 's premier game of the week until 2006 , when sunday night football , which moved to nbc that year as part of a broadcast deal that in turn saw mnf move to espn , took over as the league 's marquee game . 
in 1970 , abc debuted monday night football as part of its monday prime time schedule ; the program became a hit for the network and served as the national football league -lrb- nfl -rrb- 's premier game of the week until 2006 , when sunday night football , which moved to nbc that year as part of a broadcast deal that in turn saw mnf move to espn , took over as the league 's marquee game . 
in 1970 , abc debuted monday night football as part of its monday prime time schedule ; the program became a hit for the network and served as the national football league -lrb- nfl -rrb- 's premier game of the week until 2006 , when sunday night football , which moved to nbc that year as part of a broadcast deal that in turn saw mnf move to espn , took over as the league 's marquee game . 
according to goldenson , monday night football helped earn abc regularly score an audience share of 15 % -- 16 % ; abc sports managed the budget for the monday night time slot to reallocate the weekly budget for abc 's prime time schedule to just six days , as opposed to seven on competing networks . 
in 1970 , the fcc voted to pass the financial interest and syndication rules , a set of regulations aimed at preventing the major networks from monopolizing the broadcast landscape by barring them from owning any of the prime time programming that they broadcast . 
in 1972 , the new rules resulted in the company 's decision to split abc films into two separate companies : the existing worldvision enterprises , which would produce and distribute programming for u.s. syndication , and abc circle films as a production unit . 
in 1972 , the new rules resulted in the company 's decision to split abc films into two separate companies : the existing worldvision enterprises , which would produce and distribute programming for u.s. syndication , and abc circle films as a production unit . 
in april 1970 , congress passed the public health cigarette smoking act which banned cigarette advertising from all television and radio networks , including abc , when it took effect on january 2 , 1971 . 
in april 1970 , congress passed the public health cigarette smoking act which banned cigarette advertising from all television and radio networks , including abc , when it took effect on january 2 , 1971 . 
citing limited profitability of its cinemas , abc great states , the central west division of abc theatres , was sold to henry plitt in 1974 . 
on january 17 , 1972 , elton rule was named president and chief operating officer of abc a few months after goldenson reduced his role in the company after suffering a heart attack . 
in the early 1970s , michael eisner , who joined abc in 1966 , became the network 's program development manager . 
he helped bring about ideas for many series including happy days -lrb- which originated as a segment on the anthology series love , american style -rrb- , as well as several soap operas ; however , eisner 's main credit at abc was for developing youth-oriented programming . 
he helped bring about ideas for many series including happy days -lrb- which originated as a segment on the anthology series love , american style -rrb- , as well as several soap operas ; however , eisner 's main credit at abc was for developing youth-oriented programming . 
eisner left abc in 1976 to become president of paramount pictures -lrb- and would later become the president of abc 's eventual parent company , disney -rrb- . 
in the spring of 1975 , fred pierce , the newly appointed president of abc television , convinced fred silverman to become the first president and director of programming of the independent television production subsidiary abc entertainment , created from the network 's namesake programming division . 
in the spring of 1975 , fred pierce , the newly appointed president of abc television , convinced fred silverman to become the first president and director of programming of the independent television production subsidiary abc entertainment , created from the network 's namesake programming division . 
in 1974 , abc premiered the detective series s.w.a.t. . 
discovering that their formats seemed to appeal to their viewers , the network became the first to adopt them for a new national morning show , good morning america , which debuted on november 3 , 1975 . 
many of these series were greenlit by silverman , who left abc in 1978 to become president of nbc 's entertainment division . 
the rousing success of happy days also led to a successful spin-off series , laverne & shirley , which debuted in 1976 . 
charlie 's angels and three 's company -lrb- which debuted in 1977 -rrb- were two prime examples of a trend among the major networks during the 1970s known as `` jiggle tv '' , featuring attractive , often buxom , women in main and guest roles . 
for its part , the television network produced a few new hits during 1977 : january saw the premiere of roots , a miniseries based on an alex haley novel that was published the previous year ; in september , the love boat , a comedy-drama anthology series produced by aaron spelling which was based around the crew of a cruise ship and featured three stories centered partly on the ship 's various passengers ; although critically lambasted , the series turned out to be a ratings success and lasted nine seasons . 
for its part , the television network produced a few new hits during 1977 : january saw the premiere of roots , a miniseries based on an alex haley novel that was published the previous year ; in september , the love boat , a comedy-drama anthology series produced by aaron spelling which was based around the crew of a cruise ship and featured three stories centered partly on the ship 's various passengers ; although critically lambasted , the series turned out to be a ratings success and lasted nine seasons . 
for its part , the television network produced a few new hits during 1977 : january saw the premiere of roots , a miniseries based on an alex haley novel that was published the previous year ; in september , the love boat , a comedy-drama anthology series produced by aaron spelling which was based around the crew of a cruise ship and featured three stories centered partly on the ship 's various passengers ; although critically lambasted , the series turned out to be a ratings success and lasted nine seasons . 
the success of roots , happy days and the love boat allowed the network to take first place in the ratings for the first time in the 1976 -- 77 season . 
on september 13 , 1977 , the network debuted soap , a controversial soap opera parody which became known for being the first television series to feature an openly gay main character -lrb- played by a then-unknown billy crystal -rrb- ; it last ran on the network on april 20 , 1981 . 
in 1977 , roone arledge was named president of the new abc news in addition to being president of abc sports . 
in 1977 , roone arledge was named president of the new abc news in addition to being president of abc sports . 
the company first constructed a new 10-story building on land previously occupied by an abandoned warehouse on the corner of columbus avenue and west 66th street ; the facility that was built in its place is nicknamed `` 7 lincoln square '' -lrb- although it is actually located at 149 columbus avenue -rrb- . 
both buildings were completed in june 1979 . 
in june 1978 , arledge created the newsmagazine 20/20 ; after its first episode received harshly negative reviews , the program -- which debuted as a summer series , before becoming a year-round program in 1979 -- was immediately revamped to feature a mix of in-depth stories and interviews , with hugh downs appointed as its anchor -lrb- later paired alongside his former today colleague barbara walters -rrb- . 
in june 1978 , arledge created the newsmagazine 20/20 ; after its first episode received harshly negative reviews , the program -- which debuted as a summer series , before becoming a year-round program in 1979 -- was immediately revamped to feature a mix of in-depth stories and interviews , with hugh downs appointed as its anchor -lrb- later paired alongside his former today colleague barbara walters -rrb- . 
in june 1978 , arledge created the newsmagazine 20/20 ; after its first episode received harshly negative reviews , the program -- which debuted as a summer series , before becoming a year-round program in 1979 -- was immediately revamped to feature a mix of in-depth stories and interviews , with hugh downs appointed as its anchor -lrb- later paired alongside his former today colleague barbara walters -rrb- . 
in february 1979 , abc sold its recording division to mca inc. for $ 20 million ; the label was discontinued by march 5 of that year , and all of its 300 employees were laid off -lrb- the rights to the works of abc records and all of mca 's other labels have since been acquired by universal music group -rrb- . 
in order to compete with cnn , abc proposed a 24-hour news channel called abc cable news , with plans to launch the network in 1995 ; however , the plan would ultimately be shelved by company management . 
abc would reattempt such a concept in july 2004 with the launch of abc news now , a 24-hour news channel distributed for viewing on the internet and mobile phones . 
on august 29 , 1994 , abc purchased flint , michigan affiliate wjrt-tv and wtvg in toledo , ohio -lrb- which was previously affiliated with abc from 1958 to 1970 -rrb- from sjl broadcast management , with the latter switching to abc once its contract with nbc expired two months after the purchase was finalized in early 1995 . 
on august 29 , 1994 , abc purchased flint , michigan affiliate wjrt-tv and wtvg in toledo , ohio -lrb- which was previously affiliated with abc from 1958 to 1970 -rrb- from sjl broadcast management , with the latter switching to abc once its contract with nbc expired two months after the purchase was finalized in early 1995 . 
the writers guild of america strike that halted production of network programs for much of the 2007 -- 08 season affected the network in 2007 -- 08 and 2008 -- 09 , as various abc shows that premiered in 2007 , such as dirty sexy money , pushing daisies , eli stone and samantha who ? 
one of the network 's strike-replacement programs during that time was the game show duel , which premiered in december 2007 . 
on august 15 , 2008 , disney denied rumors started by caris & co. that it would be selling the ten abc owned-and-operated stations . 
in early 2009 , disney -- abc television group merged abc entertainment and abc studios into a new division , abc entertainment group , which would be responsible for both its production and broadcasting operations . 
in early 2009 , disney -- abc television group merged abc entertainment and abc studios into a new division , abc entertainment group , which would be responsible for both its production and broadcasting operations . 
on april 2 , 2009 , citadel communications announced that it would rebrand abc radio as citadel media ; however , abc news continued to provide news content for citadel . 
on december 22 , disney -- abc television group announced a partnership with apple inc. to make individual episodes of abc and disney channel programs available for purchase on itunes . 
the network began running into some trouble in the ratings by 2010 . 
that year , the sixth and final season of lost became the drama 's lowest-rated season since its debut in 2004 . 
ratings for the once-instant hit ugly betty collapsed dramatically after it was moved to fridays at the start of its fourth season in the fall of 2009 ; an attempt to boost ratings by moving the dramedy to wednesdays failed , with its ultimate cancellation by the network eliciting negative reaction from the public , and particularly the show 's fanbase . 
ratings for the once-instant hit ugly betty collapsed dramatically after it was moved to fridays at the start of its fourth season in the fall of 2009 ; an attempt to boost ratings by moving the dramedy to wednesdays failed , with its ultimate cancellation by the network eliciting negative reaction from the public , and particularly the show 's fanbase . 
when the fcc imposed its fin-syn rules in 1970 , abc proactively created two companies : worldvision enterprises as a syndication distributor , and abc circle films as a production company . 
when the fcc imposed its fin-syn rules in 1970 , abc proactively created two companies : worldvision enterprises as a syndication distributor , and abc circle films as a production company . 
when the fcc imposed its fin-syn rules in 1970 , abc proactively created two companies : worldvision enterprises as a syndication distributor , and abc circle films as a production company . 
nonetheless , worldvision sold portions of its catalog , including the ruby-spears and hanna-barbera libraries , to turner broadcasting system in 1990 . 
also part of the library is the aforementioned selznick library , the cinerama productions/palomar theatrical library and the selmur productions catalog that the network acquired some years back , and the in-house productions it continues to produce -lrb- such as america 's funniest home videos , general hospital , and abc news productions -rrb- , although disney -- abc domestic television -lrb- formerly known as buena vista television -rrb- handles domestic television distribution , while disney -- abc international television -lrb- formerly known as buena vista international television -rrb- handles international television distribution . 
also part of the library is the aforementioned selznick library , the cinerama productions/palomar theatrical library and the selmur productions catalog that the network acquired some years back , and the in-house productions it continues to produce -lrb- such as america 's funniest home videos , general hospital , and abc news productions -rrb- , although disney -- abc domestic television -lrb- formerly known as buena vista television -rrb- handles domestic television distribution , while disney -- abc international television -lrb- formerly known as buena vista international television -rrb- handles international television distribution . 
also part of the library is the aforementioned selznick library , the cinerama productions/palomar theatrical library and the selmur productions catalog that the network acquired some years back , and the in-house productions it continues to produce -lrb- such as america 's funniest home videos , general hospital , and abc news productions -rrb- , although disney -- abc domestic television -lrb- formerly known as buena vista television -rrb- handles domestic television distribution , while disney -- abc international television -lrb- formerly known as buena vista international television -rrb- handles international television distribution . 
also part of the library is the aforementioned selznick library , the cinerama productions/palomar theatrical library and the selmur productions catalog that the network acquired some years back , and the in-house productions it continues to produce -lrb- such as america 's funniest home videos , general hospital , and abc news productions -rrb- , although disney -- abc domestic television -lrb- formerly known as buena vista television -rrb- handles domestic television distribution , while disney -- abc international television -lrb- formerly known as buena vista international television -rrb- handles international television distribution . 
since its inception , abc has had many affiliated stations , which include wabc-tv and wpvi-tv , the first two stations to carry the network 's programming . 
as of march 2015 -lsb- update -rsb- , abc has eight owned-and-operated stations , and current and pending affiliation agreements with 235 additional television stations encompassing 49 states , the district of columbia , four u.s. possessions , bermuda and saba ; this makes abc the largest u.s. broadcast television network by total number of affiliates . 
as of march 2015 -lsb- update -rsb- , abc has eight owned-and-operated stations , and current and pending affiliation agreements with 235 additional television stations encompassing 49 states , the district of columbia , four u.s. possessions , bermuda and saba ; this makes abc the largest u.s. broadcast television network by total number of affiliates . 
the network has an estimated national reach of 96.26 % of all households in the united states -lrb- or 300,794,157 americans with at least one television set -rrb- . 
the network 's first logo , introduced in 1946 , consisted of a television screen containing the letters `` t '' and `` v '' , with a vertical abc microphone in the center , referencing the network 's roots in radio . 
when the abc-upt merger was finalized in 1953 , the network introduced a new logo based on the seal of the federal communications commission , with the letters `` abc '' enclosed in a circular shield surmounted by the bald eagle . 
in 1957 , just before the television network began its first color broadcasts , the abc logo consisted of a tiny lowercase `` abc '' in the center of a large lowercase letter a , a design known as the `` abc circle a '' . 
with the 2011 cancellation of supernanny , extreme makeover : home edition became the only remaining program on the network 's schedule that was broadcast in 4:3 standard definition . 
with the 2011 cancellation of supernanny , extreme makeover : home edition became the only remaining program on the network 's schedule that was broadcast in 4:3 standard definition . 
all of the network 's programming has been presented in hd since january 2012 -lrb- with the exception of certain holiday specials produced prior to 2005 -- such as the peanuts specials and rudolph 's shiny new year -- which continue to be presented in 4:3 sd -rrb- , when extreme makeover : home edition ended its run as a regular series and one life to live -lrb- which had been presented in 16:9 standard definition since 2010 -rrb- also ended its abc run . 
the affiliate-syndicated saturday morning e/i block litton 's weekend aventure is also broadcast in hd , and was the first children 's program block on any u.s. broadcast network to feature programs available in the format upon its september 2011 debut . 
abc 's master feed is transmitted in 720p high definition , the native resolution format for the walt disney company 's u.s. television properties . 
however , most of hearst television 's 16 abc-affiliated stations transmit the network 's programming in 1080i hd , while 11 other affiliates owned by various companies carry the network feed in 480i standard definition either due to technical considerations for affiliates of other major networks that carry abc programming on a digital subchannel or because a primary feed abc affiliate has not yet upgraded their transmission equipment to allow content to be presented in hd . 
however , most of hearst television 's 16 abc-affiliated stations transmit the network 's programming in 1080i hd , while 11 other affiliates owned by various companies carry the network feed in 480i standard definition either due to technical considerations for affiliates of other major networks that carry abc programming on a digital subchannel or because a primary feed abc affiliate has not yet upgraded their transmission equipment to allow content to be presented in hd . 
abc 's master feed is transmitted in 720p high definition , the native resolution format for the walt disney company 's u.s. television properties . 
the network 's troubles with sustaining existing series and gaining new hits spilled over into its 2010 -- 11 schedule : abc 's dramas during that season continued to fail , with the midseason forensic investigation drama body of proof being the only one that was renewed for a second season . 
the network also struggled to establish new comedies to support the previous year 's debuts , with only late-season premiere happy endings earning a second season . 
despite this and another noticeable ratings decline , abc would manage to outrate nbc for third place by a larger margin than the previous year . 
meanwhile , the new lows hit by brothers & sisters led to its cancellation , and the previous year 's only drama renewal , v , also failed to earn another season after a low-rated midseason run . 
on april 14 , 2011 , abc canceled the long-running soap operas all my children and one life to live after 41 and 43 years on the air , respectively -lrb- following backlash from fans , abc sold the rights to both shows to prospect park , which eventually revived the soaps on hulu for one additional season in 2013 and with both companies suing one another for allegations of interference with the process of reviving the shows , failure to pay licensing fees and issues over abc 's use of certain characters from one live to live on general hospital during the transition -rrb- . 
on april 14 , 2011 , abc canceled the long-running soap operas all my children and one life to live after 41 and 43 years on the air , respectively -lrb- following backlash from fans , abc sold the rights to both shows to prospect park , which eventually revived the soaps on hulu for one additional season in 2013 and with both companies suing one another for allegations of interference with the process of reviving the shows , failure to pay licensing fees and issues over abc 's use of certain characters from one live to live on general hospital during the transition -rrb- . 
on april 14 , 2011 , abc canceled the long-running soap operas all my children and one life to live after 41 and 43 years on the air , respectively -lrb- following backlash from fans , abc sold the rights to both shows to prospect park , which eventually revived the soaps on hulu for one additional season in 2013 and with both companies suing one another for allegations of interference with the process of reviving the shows , failure to pay licensing fees and issues over abc 's use of certain characters from one live to live on general hospital during the transition -rrb- . 
the talk/lifestyle show that replaced one life to live , the revolution , failed to generate satisfactory ratings and was in turn canceled after only seven months . 
the 2011 -- 12 season saw abc drop to fourth place in the 18 -- 49 demographic despite renewing a handful of new shows -lrb- including freshmen dramas scandal , revenge and once upon a time -rrb- for second seasons . 
nbc , which had lagged behind abc for eight years , finished the season in first place in the 18 -- 49 demographic for the first time since 2004 , and in second place in total viewership behind long-dominant cbs . 
nbc , which had lagged behind abc for eight years , finished the season in first place in the 18 -- 49 demographic for the first time since 2004 , and in second place in total viewership behind long-dominant cbs . 
the 2013 -- 14 season was a slight improvement for abc with three new hits in the goldbergs , agents of s.h.i.e.l.d. and resurrection , all of which were renewed ; however , that season saw the cancellations of holdovers the neighbors -lrb- which languished in its new friday time slot despite being bookended by last man standing and shark tank -rrb- and suburgatory . 
the 2013 -- 14 season was a slight improvement for abc with three new hits in the goldbergs , agents of s.h.i.e.l.d. and resurrection , all of which were renewed ; however , that season saw the cancellations of holdovers the neighbors -lrb- which languished in its new friday time slot despite being bookended by last man standing and shark tank -rrb- and suburgatory . 
among the few bright spots during this season were the midseason crime dramedy castle as well as the success of two family sitcoms that anchored the network 's revamped wednesday comedy lineup , the middle and modern family , the latter of which was both a critical and commercial success . 
shark tank -lrb- based on the dragon 's den reality format -rrb- also became a midseason sleeper hit on sundays in the spring of 2010 ; the following season , it became the tentpole of the network 's friday night schedule , gradually helping make abc a strong competitor -lrb- after being paired with 20/20 and beginning with the 2012 -- 13 season , the tim allen sitcom last man standing -rrb- against cbs ' long-dominant drama/reality lineup on that night for the first time since the `` tgif '' lineup ended in 2000 . 
shark tank -lrb- based on the dragon 's den reality format -rrb- also became a midseason sleeper hit on sundays in the spring of 2010 ; the following season , it became the tentpole of the network 's friday night schedule , gradually helping make abc a strong competitor -lrb- after being paired with 20/20 and beginning with the 2012 -- 13 season , the tim allen sitcom last man standing -rrb- against cbs ' long-dominant drama/reality lineup on that night for the first time since the `` tgif '' lineup ended in 2000 . 
shark tank -lrb- based on the dragon 's den reality format -rrb- also became a midseason sleeper hit on sundays in the spring of 2010 ; the following season , it became the tentpole of the network 's friday night schedule , gradually helping make abc a strong competitor -lrb- after being paired with 20/20 and beginning with the 2012 -- 13 season , the tim allen sitcom last man standing -rrb- against cbs ' long-dominant drama/reality lineup on that night for the first time since the `` tgif '' lineup ended in 2000 . 
daniel burke departed from capital cities/abc in february 1994 , with thomas murphy taking over as president before ceding control to robert iger . 
daniel burke departed from capital cities/abc in february 1994 , with thomas murphy taking over as president before ceding control to robert iger . 
september 1994 saw the debut of nypd blue , a gritty police procedural from steven bochco -lrb- who created doogie howser , m.d. and the critically pilloried cop rock for abc earlier in the decade -rrb- ; lasting ten seasons , the drama became known for its boundary pushing of network television standards -lrb- particularly its occasional use of graphic language and rear nudity -rrb- , which led some affiliates to initially refuse to air the show in its first season . 
september 1994 saw the debut of nypd blue , a gritty police procedural from steven bochco -lrb- who created doogie howser , m.d. and the critically pilloried cop rock for abc earlier in the decade -rrb- ; lasting ten seasons , the drama became known for its boundary pushing of network television standards -lrb- particularly its occasional use of graphic language and rear nudity -rrb- , which led some affiliates to initially refuse to air the show in its first season . 
september 1994 saw the debut of nypd blue , a gritty police procedural from steven bochco -lrb- who created doogie howser , m.d. and the critically pilloried cop rock for abc earlier in the decade -rrb- ; lasting ten seasons , the drama became known for its boundary pushing of network television standards -lrb- particularly its occasional use of graphic language and rear nudity -rrb- , which led some affiliates to initially refuse to air the show in its first season . 
in 1993 , the fcc repealed the financial interest and syndication rules , once again allowing networks to hold interests in television production studios . 
that same year , capital cities/abc purchased the french animation studio dic entertainment ; it also signed an agreement with time warner cable to carry its owned-and-operated television stations on the provider 's systems in abc o&o markets . 
that same year , capital cities/abc purchased the french animation studio dic entertainment ; it also signed an agreement with time warner cable to carry its owned-and-operated television stations on the provider 's systems in abc o&o markets . 
by that year , abc had a total viewership share of 23.63 % of american households , just below the limit of 25 % imposed by the fcc . 
in may 1960 , abc purchased chicago radio station wls , which had shared airtime with wenr since the 1920s . 
on may 9 , 1960 , wls launched a new lineup consisting of abc radio programming . 
in 1960 , canadian entrepreneur john bassett , who was trying to establish a television station in toronto , sought the help of abc to launch the station . 
leonard goldenson agreed to acquire a 25 % interest in cfto-tv ; however , legislation by the canadian radio-television commission prohibited abc 's involvement , resulting in the company withdrawing from the project before the station 's launch . 
on april 29 , 1961 , abc debuted wide world of sports , an anthology series created by edgar scherick through his company sports programs , inc. and produced by a young roone arledge which featured a different sporting event each broadcast . 
on april 29 , 1961 , abc debuted wide world of sports , an anthology series created by edgar scherick through his company sports programs , inc. and produced by a young roone arledge which featured a different sporting event each broadcast . 
on april 29 , 1961 , abc debuted wide world of sports , an anthology series created by edgar scherick through his company sports programs , inc. and produced by a young roone arledge which featured a different sporting event each broadcast . 
abc purchased sports programs , inc. in exchange for shares in the company , leading it to become the future core of abc sports , with arledge as the executive producer of that division 's shows . 
in 1965 , the corporate entity , american broadcasting-paramount theatres , was renamed as the american broadcasting companies , while its cinema division became abc theatres ; -lsb- citation needed -rsb- its recording division was renamed abc records in 1966 . 
in december of that year , the abc television network premiered the dating game , a pioneer series in its genre , which was a reworking of the blind date concept in which a suitor selected one of three contestants sight unseen based on the answers to selected questions . 
this was followed up in july 1966 by the newlywed game , featuring three recently married couples who guessed the responses to their partner 's questions -lrb- some of which were fairly risque -rrb- . 
as abc began to outgrow its facilities at 7 west 66th street , goldenson found a new headquarters for abc in a 44 story building located at 1330 avenue of the americas in manhattan , at the corner of 54th street -lrb- now occupied by the financial times 's new york office -rrb- . 
abc dominated the american television landscape during the 1970s and early 1980s -lrb- by 1980 , the three major networks represented 90 % of all prime-time television viewership in the u.s. -rrb- . 
several flagship series debuted on the network during this time including dynasty , an opulent drama from aaron spelling that became a hit when it premiered as a midseason series in 1981 , five months before spelling 's other abc hit charlie 's angels ended its run . 
the network was also propelled during the early 1980s by the continued successes of happy days , three 's company , laverne & shirley and fantasy island , and gained new hits in too close for comfort , soap spinoff benson and happy days spinoff mork & mindy . 
in 1981 , abc -lrb- through its abc video services division -rrb- launched the alpha repertory television service -lrb- arts -rrb- , a cable channel operated as a joint venture with the hearst corporation offering cultural and arts programming , which aired as a nighttime service over the channel space of nickelodeon . 
in 1983 , abc sold kxyz to the infinity broadcasting corporation . 
on january 4 , 1984 , the new york times reported that abc , through its subsidiary abc video enterprises , had exercised its option to purchase up to 15 % -lrb- or between $ 25 million and $ 30 million -rrb- of getty oil 's shares in espn , which would allow it to expand its shares at a later date . 
that year , abc and hearst reached an agreement with rca to merge arts and competing arts service , the entertainment channel , into a single cable channel called arts & entertainment television -lrb- a&e -rrb- ; the new channel subsequently leased a separate satellite transponder , ending its sharing agreement with nickelodeon to become a 24-hour service . 
that year , abc and hearst reached an agreement with rca to merge arts and competing arts service , the entertainment channel , into a single cable channel called arts & entertainment television -lrb- a&e -rrb- ; the new channel subsequently leased a separate satellite transponder , ending its sharing agreement with nickelodeon to become a 24-hour service . 
in 1990 , thomas s. murphy delegated his position as president to daniel b. burke while remaining abc 's chairman and ceo . 
in 1990 , thomas s. murphy delegated his position as president to daniel b. burke while remaining abc 's chairman and ceo . 
capital cities/abc reported revenues of $ 465 million . 
now at a strong second place , the network entered the 1990s with additional family-friendly hits including america 's funniest home videos -lrb- which has gone on to become the longest-running prime time entertainment program in the network 's history -rrb- , step by step , hangin ' with mr. cooper , boy meets world and perfect strangers spinoff family matters , as well as series such as doogie howser , m.d. , life goes on , cult favorite twin peaks and the commish . 
in september 1991 , the network premiered home improvement , a sitcom starring stand-up comic tim allen centering on the family and work life of an accident-prone host of a cable-access home improvement show . 
daytime programming is also provided from 11:00 a.m. to 3:00 p.m. weekdays -lrb- with a one-hour break at 12:00 p.m. eastern/pacific for stations to air newscasts , other locally produced programming such as talk shows , or syndicated programs -rrb- featuring the talk/lifestyle shows the view and the chew and the soap opera general hospital . 
daytime programming is also provided from 11:00 a.m. to 3:00 p.m. weekdays -lrb- with a one-hour break at 12:00 p.m. eastern/pacific for stations to air newscasts , other locally produced programming such as talk shows , or syndicated programs -rrb- featuring the talk/lifestyle shows the view and the chew and the soap opera general hospital . 
abc news programming includes good morning america from 7:00 to 9:00 a.m. weekdays -lrb- along with one-hour weekend editions -rrb- ; nightly editions of abc world news tonight -lrb- whose weekend editions are occasionally subject to abbreviation or preemption due to sports telecasts overrunning into the program 's timeslot -rrb- , the sunday political talk show this week , early morning news programs world news now and america this morning and the late night newsmagazine nightline . 
late nights feature the weeknight talk show jimmy kimmel live ! 
currently , new jersey , rhode island and delaware are the only u.s. states where abc does not have a locally licensed affiliate -lrb- new jersey is served by new york city o&o wabc-tv and philadelphia o&o wpvi-tv ; rhode island is served by new bedford , massachusetts-licensed wlne ; and delaware is served by wpvi and salisbury , maryland affiliate wmdt -rrb- . 
abc maintains affiliations with low-power stations -lrb- broadcasting either in analog or digital -rrb- in a few markets , such as birmingham , alabama -lrb- wbma-ld -rrb- , lima , ohio -lrb- wlqp-lp -rrb- and south bend , indiana -lrb- wbnd-ld -rrb- . 
abc maintains affiliations with low-power stations -lrb- broadcasting either in analog or digital -rrb- in a few markets , such as birmingham , alabama -lrb- wbma-ld -rrb- , lima , ohio -lrb- wlqp-lp -rrb- and south bend , indiana -lrb- wbnd-ld -rrb- . 
abc maintains affiliations with low-power stations -lrb- broadcasting either in analog or digital -rrb- in a few markets , such as birmingham , alabama -lrb- wbma-ld -rrb- , lima , ohio -lrb- wlqp-lp -rrb- and south bend , indiana -lrb- wbnd-ld -rrb- . 
as a result , television series were produced by abc circle films beginning in 1962 and by touchstone television beginning in 1985 , before touchstone was reorganized as abc studios in february 2007 . 
as a result , television series were produced by abc circle films beginning in 1962 and by touchstone television beginning in 1985 , before touchstone was reorganized as abc studios in february 2007 . 
since the 1950s , abc has had two main production facilities : the abc television center -lrb- now the prospect studios -rrb- on prospect avenue in hollywood , california , shared with the operations of kabc-tv until 1999 ; and the abc television center , east , a set of studios located throughout the new york city . 
since the 1950s , abc has had two main production facilities : the abc television center -lrb- now the prospect studios -rrb- on prospect avenue in hollywood , california , shared with the operations of kabc-tv until 1999 ; and the abc television center , east , a set of studios located throughout the new york city . 
abc also owns the times square studios at 1500 broadway on land in times square owned by a development fund for the 42nd street project ; opened in 1999 , good morning america and nightline are broadcast from this particular facility . 
abc also owns the times square studios at 1500 broadway on land in times square owned by a development fund for the 42nd street project ; opened in 1999 , good morning america and nightline are broadcast from this particular facility . 
the block of west end avenue housing the abc news building was renamed peter jennings way in 2006 in honor of the recently deceased longtime abc news chief anchor and anchor of world news tonight . 
the block of west end avenue housing the abc news building was renamed peter jennings way in 2006 in honor of the recently deceased longtime abc news chief anchor and anchor of world news tonight . 
abc maintains several video on demand services for delayed viewing of the network 's programming , including a traditional vod service called abc on demand , which is carried on most traditional cable and iptv providers . 
the walt disney company is also a part-owner of hulu -lrb- as part of a consortium that includes , among other parties , the respective parent companies of nbc and fox , nbcuniversal and 21st century fox -rrb- , and has offered full-length episodes of most of abc 's programming through the streaming service since july 6 , 2009 -lrb- which are available for viewing on hulu 's website and mobile app -rrb- , as part of an agreement reached in april that year that also allowed disney to acquire a 27 % ownership stake in hulu . 
the walt disney company is also a part-owner of hulu -lrb- as part of a consortium that includes , among other parties , the respective parent companies of nbc and fox , nbcuniversal and 21st century fox -rrb- , and has offered full-length episodes of most of abc 's programming through the streaming service since july 6 , 2009 -lrb- which are available for viewing on hulu 's website and mobile app -rrb- , as part of an agreement reached in april that year that also allowed disney to acquire a 27 % ownership stake in hulu . 
the walt disney company is also a part-owner of hulu -lrb- as part of a consortium that includes , among other parties , the respective parent companies of nbc and fox , nbcuniversal and 21st century fox -rrb- , and has offered full-length episodes of most of abc 's programming through the streaming service since july 6 , 2009 -lrb- which are available for viewing on hulu 's website and mobile app -rrb- , as part of an agreement reached in april that year that also allowed disney to acquire a 27 % ownership stake in hulu . 
the most recent episodes of the network 's shows are usually made available on watch abc , hulu and abc on demand the day after their original broadcast . 
restrictions implemented by disney -- abc television group on january 7 , 2014 restrict streaming of the most recent episode of any abc program on hulu and watch abc until eight days after their initial broadcast , in order to encourage live or same-week -lrb- via both dvr and cable on demand -rrb- viewing , with day-after-air streaming on either service limited to subscribers of participating pay television providers -lrb- such as comcast , verizon fios and time warner cable -rrb- using an isp account via an authenticated user login . 
in addition , abc on demand -lrb- like the video-on-demand television services provided by the other u.s. broadcast networks -rrb- disallows fast forwarding of accessed content . 
restrictions implemented by disney -- abc television group on january 7 , 2014 restrict streaming of the most recent episode of any abc program on hulu and watch abc until eight days after their initial broadcast , in order to encourage live or same-week -lrb- via both dvr and cable on demand -rrb- viewing , with day-after-air streaming on either service limited to subscribers of participating pay television providers -lrb- such as comcast , verizon fios and time warner cable -rrb- using an isp account via an authenticated user login . 
a revised version of the abc logo was introduced for promotions for the 2013 -- 14 season during the network 's upfront presentation on may 14 , 2013 , and officially introduced on-air on june 17 -lrb- although some affiliates implemented the new design prior to then -rrb- , as part of an overhaul of abc 's identity by design agency loyalkaspar . 
the logo is displayed on-air , online and in print advertising in four variants shading the respective color used with the circle design 's native black coloring : a gold version is primarily used on entertainment-oriented outlets -lrb- such as abc.com , watch abc , and by abc studios -rrb- and the on-screen bug ; steel blue and dark grey versions are used primarily by abc news ; a red version is used for espn on abc , while all four variants are used selectively in advertising and by affiliates . 
a new custom typeface , `` abc modern '' -lrb- which was inspired by the logotype -rrb- , was also created for use in advertising and other promotional materials . 
the logo is displayed on-air , online and in print advertising in four variants shading the respective color used with the circle design 's native black coloring : a gold version is primarily used on entertainment-oriented outlets -lrb- such as abc.com , watch abc , and by abc studios -rrb- and the on-screen bug ; steel blue and dark grey versions are used primarily by abc news ; a red version is used for espn on abc , while all four variants are used selectively in advertising and by affiliates . 
however that year , abc had only 14 primary affiliates compared to the 74 that carried the majority of cbs programs and the 71 that were primarily affiliated with nbc . 
however that year , abc had only 14 primary affiliates compared to the 74 that carried the majority of cbs programs and the 71 that were primarily affiliated with nbc . 
until the all-channel receiver act -lrb- passed by congress in 1961 -rrb- mandated the inclusion of uhf tuning , most viewers needed to purchase a converter to be able to watch uhf stations , and the signal quality was marginal at best even with a converter . 
until the all-channel receiver act -lrb- passed by congress in 1961 -rrb- mandated the inclusion of uhf tuning , most viewers needed to purchase a converter to be able to watch uhf stations , and the signal quality was marginal at best even with a converter . 
as a result , with the exception of the largest markets , abc was relegated to secondary status on one or both of the existing stations , usually via off-hours clearances -lrb- a notable exception during this time was wkst-tv in youngstown , ohio , now wytv , despite the small size of the surrounding market and its close proximity to cleveland and pittsburgh even decades before the city 's economic collapse -rrb- . 
according to goldenson , this meant that an hour of abc programming reported five times lower viewership than its competitors . 
still , abc 's limited reach would continue to hobble it for the next two decades ; several smaller markets would not grow large enough to support a full-time abc affiliate until the 1960s , with some very small markets having to wait as late as the 1980s or even the advent of digital television in the 2000s , which allowed stations like wtrf-tv in wheeling , west virginia to begin airing abc programming on a digital subchannel after airing the network 's programs outside of recommended timeslots decades before . 
still , abc 's limited reach would continue to hobble it for the next two decades ; several smaller markets would not grow large enough to support a full-time abc affiliate until the 1960s , with some very small markets having to wait as late as the 1980s or even the advent of digital television in the 2000s , which allowed stations like wtrf-tv in wheeling , west virginia to begin airing abc programming on a digital subchannel after airing the network 's programs outside of recommended timeslots decades before . 
on september 3 , 1958 , the disneyland anthology series was retitled walt disney presents as it became disassociated with the theme park of the same name . 
in late 1958 , desilu productions pitched its detective series the untouchables to cbs ; after that network rejected the show because of its use of violence , desilu then presented it to abc , which agreed to pick up the show , and debuted the untouchables in april 1959 . 
in late 1958 , desilu productions pitched its detective series the untouchables to cbs ; after that network rejected the show because of its use of violence , desilu then presented it to abc , which agreed to pick up the show , and debuted the untouchables in april 1959 . 
in late 1958 , desilu productions pitched its detective series the untouchables to cbs ; after that network rejected the show because of its use of violence , desilu then presented it to abc , which agreed to pick up the show , and debuted the untouchables in april 1959 . 
due to pressure from film studios wanting to increase their production , as the major networks began airing theatrically released films , abc joined cbs and nbc in broadcasting films on sunday nights in 1962 , with the launch of the abc sunday night movie , which debuted a year behind its competitors and was initially presented in black-and-white . 
despite a significant increase in viewership -lrb- with its audience share having increased to 33 % from the 15 % share it had in 1953 -rrb- , abc remained in third place ; the company had a total revenue of $ 15.5 million , a third of the revenue pulled in by cbs at the same period . 
to catch up , abc followed up the flintstones with another animated series from hanna-barbera , the jetsons , which debuted on september 23 , 1962 as the first television series to be broadcast in color on the network . 
to catch up , abc followed up the flintstones with another animated series from hanna-barbera , the jetsons , which debuted on september 23 , 1962 as the first television series to be broadcast in color on the network . 
on april 1 , 1963 , abc debuted the soap opera general hospital , which would go on to become the television network 's long-running entertainment program . 
on december 7 , 1965 , goldenson announced a merger proposal with itt to abc management ; the two companies agreed to the deal on april 27 , 1966 . 
the fcc approved the merger on december 21 , 1966 ; however , the previous day -lrb- december 20 -rrb- , donald f. turner , head antitrust regulator for the united states department of justice , expressed doubts related to such issues as the emerging cable television market , and concerns over the journalistic integrity of abc and how it could be influenced by the overseas ownership of itt . 
the merger was suspended , and a complaint was filed by the department of justice in july 1967 , with itt going to trial in october 1967 ; the merger was officially canceled after the trial 's conclusion on january 1 , 1968 . 
the merger was suspended , and a complaint was filed by the department of justice in july 1967 , with itt going to trial in october 1967 ; the merger was officially canceled after the trial 's conclusion on january 1 , 1968 . 
in december 1984 , thomas s. murphy , chief executive officer of capital cities communications , contacted leonard goldenson about a proposal to merge their respective companies . 
on march 16 , 1985 , abc 's executive committee accepted the merger offer , which was formally announced on march 18 , 1985 , with capital cities purchasing abc and its related properties for $ 3.5 billion and $ 118 for each of abc 's shares as well as a guarantee of 10 % -lrb- or $ 3 -rrb- for a total of $ 121 per share . 
the remaining $ 500 million was loaned by warren buffett , who promised that his company berkshire hathaway would purchase $ 3 million in shares , at $ 172.50 apiece . 
due to an fcc ban on same-market ownership of television and radio stations by a single company -lrb- although the deal would have otherwise complied with new ownership rules implemented by the fcc in january 1985 , that allowed broadcasters to own a maximum of 12 television stations -rrb- , abc and capital cities respectively decided to sell wxyz-tv and tampa independent station wfts-tv to the e. w. scripps company -lrb- although capital cities/abc originally intended to seek a cross-ownership waiver to retain wxyz and capital cities-owned radio stations wjr and whyt -rrb- . 
due to an fcc ban on same-market ownership of television and radio stations by a single company -lrb- although the deal would have otherwise complied with new ownership rules implemented by the fcc in january 1985 , that allowed broadcasters to own a maximum of 12 television stations -rrb- , abc and capital cities respectively decided to sell wxyz-tv and tampa independent station wfts-tv to the e. w. scripps company -lrb- although capital cities/abc originally intended to seek a cross-ownership waiver to retain wxyz and capital cities-owned radio stations wjr and whyt -rrb- . 
the merger between abc and capital cities received federal approval on september 5 , 1985 . 
after the abc/capital cities merger was finalized on january 3 , 1986 , the combined company -- which became known as capital cities/abc , inc. -- added four television stations -lrb- wpvi-tv/philadelphia , ktrk-tv/houston , kfsn-tv/fresno and wtvd/raleigh -rrb- and several radio stations to abc 's broadcasting portfolio , and also included fairchild publications and four newspapers -lrb- including the kansas city star and fort worth star-telegram -rrb- . 
it also initiated several changes in its management : frederick s. pierce was named president of abc 's broadcasting division ; michael p. millardi became vice president of abc broadcasting , and president of abc owned stations and abc video enterprises ; john b. sias was appointed president of the abc television network ; brandon stoddard became president of abc entertainment -lrb- a position to which he had been appointed in november 1985 -rrb- ; and roone arledge became president of abc news and abc sports . 
it also initiated several changes in its management : frederick s. pierce was named president of abc 's broadcasting division ; michael p. millardi became vice president of abc broadcasting , and president of abc owned stations and abc video enterprises ; john b. sias was appointed president of the abc television network ; brandon stoddard became president of abc entertainment -lrb- a position to which he had been appointed in november 1985 -rrb- ; and roone arledge became president of abc news and abc sports . 
it also initiated several changes in its management : frederick s. pierce was named president of abc 's broadcasting division ; michael p. millardi became vice president of abc broadcasting , and president of abc owned stations and abc video enterprises ; john b. sias was appointed president of the abc television network ; brandon stoddard became president of abc entertainment -lrb- a position to which he had been appointed in november 1985 -rrb- ; and roone arledge became president of abc news and abc sports . 
as far as programming is concerned , four of abc 's marquee shows of the 1970s ended their runs during the mid-1980s : laverne & shirley ended its run in 1983 , happy days and three 's company ended in 1984 -lrb- with the latter producing a short-lived spinoff that year -rrb- , while the love boat ended its run in 1986 . 
as far as programming is concerned , four of abc 's marquee shows of the 1970s ended their runs during the mid-1980s : laverne & shirley ended its run in 1983 , happy days and three 's company ended in 1984 -lrb- with the latter producing a short-lived spinoff that year -rrb- , while the love boat ended its run in 1986 . 
after nearly a decade of ratings trouble , nbc had regained the ratings lead among the big three networks in 1984 on the success of series such as the cosby show , cheers and miami vice . 
as far as programming is concerned , four of abc 's marquee shows of the 1970s ended their runs during the mid-1980s : laverne & shirley ended its run in 1983 , happy days and three 's company ended in 1984 -lrb- with the latter producing a short-lived spinoff that year -rrb- , while the love boat ended its run in 1986 . 
to counteract nbc , abc decided to refocus itself on comedies and family-oriented series beginning in the mid-1980s including mr. belvedere , roseanne , who 's the boss ? 
following the initial success of these series , abc revamped its friday night schedule around family-friendly comedies in the late 1980s , culminating in the 1989 debut of the `` tgif '' block -lrb- which promotions referenced stood for `` thank goodness it 's funny '' -rrb- . 
following the initial success of these series , abc revamped its friday night schedule around family-friendly comedies in the late 1980s , culminating in the 1989 debut of the `` tgif '' block -lrb- which promotions referenced stood for `` thank goodness it 's funny '' -rrb- . 
many of the series featured during the run of the block were produced by miller-boyett productions , a warner bros.-based studio that briefly programmed the entire friday lineup during the 1990 -- 91 season -lrb- with going places joining family matters , full house and perfect strangers on the `` tgif '' schedule -rrb- and through its development deal with paramount television prior to 1986 -lrb- as miller-milkis , and later , miller-milkis-boyett productions -rrb- , had earlier produced happy days and its various spinoffs among other series for the network . 
many of the series featured during the run of the block were produced by miller-boyett productions , a warner bros.-based studio that briefly programmed the entire friday lineup during the 1990 -- 91 season -lrb- with going places joining family matters , full house and perfect strangers on the `` tgif '' schedule -rrb- and through its development deal with paramount television prior to 1986 -lrb- as miller-milkis , and later , miller-milkis-boyett productions -rrb- , had earlier produced happy days and its various spinoffs among other series for the network . 
in 1968 , abc took advantage of new fcc ownership regulations that allowed broadcasting companies to own a maximum of seven radio stations nationwide in order to purchase houston radio stations kxyz and kxyz-fm for $ 1 million in shares and $ 1.5 million in bonds . 
that year , roone arledge was named president of abc sports ; the company also founded abc pictures , a film production company which released its first picture that year , the ralph nelson-directed charly . 
that year , roone arledge was named president of abc sports ; the company also founded abc pictures , a film production company which released its first picture that year , the ralph nelson-directed charly . 
it was renamed abc motion pictures in 1979 ; the unit was dissolved in 1985 . 
in july 1968 , abc continued its acquisitions in the amusement parks sector with the opening of abc marine world in redwood city , california ; that park was sold in 1972 and demolished in 1986 , with the land that occupied the park later becoming home to the headquarters of oracle corporation . 
it was not until the late 1950s that the abc network became a serious contender to nbc and cbs , and this was in large part due to the diverse range of programming that met the expectations of the public , such as westerns and detective series . 
despite an almost 500 % increase in advertising revenues between 1953 and 1958 , the network only had a national reach of between 10 % and 18 % of the total u.s. population , as it still had relatively fewer affiliates than nbc and cbs . 
despite an almost 500 % increase in advertising revenues between 1953 and 1958 , the network only had a national reach of between 10 % and 18 % of the total u.s. population , as it still had relatively fewer affiliates than nbc and cbs . 
in 1957 , abc entertainment president ollie treiz discovered that the locally produced variety show bandstand had pulled very strong ratings in the philadelphia market on wfil-tv ; treiz ultimately negotiated a deal to take the show national , under the revised title american bandstand ; the show quickly became a social phenomenon by presenting new musical talent and dances to america 's youth and helped make a star out of its host , dick clark . 
in 1957 , abc entertainment president ollie treiz discovered that the locally produced variety show bandstand had pulled very strong ratings in the philadelphia market on wfil-tv ; treiz ultimately negotiated a deal to take the show national , under the revised title american bandstand ; the show quickly became a social phenomenon by presenting new musical talent and dances to america 's youth and helped make a star out of its host , dick clark . 
these kinds of programs presented abc with an image of the `` philosophy of counterprogramming against its competitors '' , offering a strong lineup of programs that contrasted with those seen on its rival networks , which helped goldenson give the network a continuum between film and television . 
abc 's western series -lrb- as well as series such as the actioner zorro -rrb- went up against and defeated the variety shows aired by nbc and cbs in the fall of 1957 , and its detective shows did the same in the fall of 1959 . 
in may 1961 , life criticized the public enthusiasm and sponsorship for these types of shows at the expense of news programming and denounced an unofficial law `` replacing the good programs with the bad ones '' . 
abc 's western series -lrb- as well as series such as the actioner zorro -rrb- went up against and defeated the variety shows aired by nbc and cbs in the fall of 1957 , and its detective shows did the same in the fall of 1959 . 
in may 2013 , abc launched `` watch abc '' , a revamp of its traditional multi-platform streaming services encompassing the network 's existing streaming portal at abc.com and a mobile app for smartphones and tablet computers ; in addition to providing full-length episodes of abc programs , the service allows live programming streams of local abc affiliates in select markets -lrb- the first such offering by a u.s. broadcast network -rrb- . 
new york city o&o wabc-tv and philadelphia o&o wpvi-tv were the first stations to offer streams of their programming on the service -lrb- with a free preview for non-subscribers through june 2013 -rrb- , with the six remaining abc o&o s offering streams by the start of the 2013 -- 14 season . 
hearst television also reached a deal to offer streams of its abc affiliates -lrb- including stations in boston , kansas city , milwaukee and west palm beach -rrb- on the service . 
similar to sister network espn 's watchespn service -lrb- which originated the `` watch '' brand used by the streaming services of disney 's television networks -rrb- , live streams of abc stations are only available to authenticated subscribers of participating pay television providers in certain markets . 
the sinclair broadcast group is the largest operator of abc stations by numerical total , owning or providing services to 28 abc affiliates and two additional subchannel-only affiliates ; sinclair owns the largest abc subchannel affiliate by market size , wabm-dt2 / wdbb-dt2 in the birmingham market , which serve as repeaters of wbma-ld -lrb- the largest low-power `` big four '' affiliate by market size , which itself is also simulcast on a subchannel of former wbma satellite wgww , owned by sinclair partner company howard stirk holdings -rrb- . 
the sinclair broadcast group is the largest operator of abc stations by numerical total , owning or providing services to 28 abc affiliates and two additional subchannel-only affiliates ; sinclair owns the largest abc subchannel affiliate by market size , wabm-dt2 / wdbb-dt2 in the birmingham market , which serve as repeaters of wbma-ld -lrb- the largest low-power `` big four '' affiliate by market size , which itself is also simulcast on a subchannel of former wbma satellite wgww , owned by sinclair partner company howard stirk holdings -rrb- . 
the e. w. scripps company is the largest operator of abc stations in terms of overall market reach , owning 15 abc-affiliated stations -lrb- including affiliates in larger markets such as cleveland , phoenix , detroit and denver -rrb- , and through its ownership of phoenix affiliate knxv , las vegas affiliate ktnv-tv and tucson affiliate kgun-tv , the only provider of abc programming for the majority of arizona -lrb- outside of the yuma-el centro market -rrb- and southern nevada . 
the sinclair broadcast group is the largest operator of abc stations by numerical total , owning or providing services to 28 abc affiliates and two additional subchannel-only affiliates ; sinclair owns the largest abc subchannel affiliate by market size , wabm-dt2 / wdbb-dt2 in the birmingham market , which serve as repeaters of wbma-ld -lrb- the largest low-power `` big four '' affiliate by market size , which itself is also simulcast on a subchannel of former wbma satellite wgww , owned by sinclair partner company howard stirk holdings -rrb- . 
the e. w. scripps company is the largest operator of abc stations in terms of overall market reach , owning 15 abc-affiliated stations -lrb- including affiliates in larger markets such as cleveland , phoenix , detroit and denver -rrb- , and through its ownership of phoenix affiliate knxv , las vegas affiliate ktnv-tv and tucson affiliate kgun-tv , the only provider of abc programming for the majority of arizona -lrb- outside of the yuma-el centro market -rrb- and southern nevada . 
on june 16 , 2007 , abc began to phase in a new imaging campaign for the upcoming 2007 -- 08 season , `` start here '' . 
also developed by troika , the on-air design was intended to emphasize the availability of abc content across multiple platforms -lrb- in particular , using a system of icons representing different devices , such as television , computers and mobile devices -rrb- , and `` simplify and bring a lot more consistency and continuity to the visual representation of abc '' . 
red ribbons were used to represent the entertainment division , while blue ribbons were used for abc news . 
red ribbons were used to represent the entertainment division , while blue ribbons were used for abc news . 
the network has the unusual distinction of having separately owned and operated affiliates which serve the same market in tampa , florida -lrb- wfts-tv and wwsb -rrb- and grand rapids , michigan -lrb- wzzm and wotv -rrb- , with an analogous situation arising in kansas city , missouri -lrb- kmbc-tv and kqtv -rrb- . 
the network has the unusual distinction of having separately owned and operated affiliates which serve the same market in tampa , florida -lrb- wfts-tv and wwsb -rrb- and grand rapids , michigan -lrb- wzzm and wotv -rrb- , with an analogous situation arising in kansas city , missouri -lrb- kmbc-tv and kqtv -rrb- . 
the network has the unusual distinction of having separately owned and operated affiliates which serve the same market in tampa , florida -lrb- wfts-tv and wwsb -rrb- and grand rapids , michigan -lrb- wzzm and wotv -rrb- , with an analogous situation arising in kansas city , missouri -lrb- kmbc-tv and kqtv -rrb- . 
kqtv is licensed to st. joseph , missouri , which is designated by nielsen as a separate market from kansas city despite being located within 55 miles -lrb- 89 km -rrb- of one another , while wwsb and wotv serve areas that do not receive an adequate signal from their market 's primary abc affiliate -lrb- in the case of wwsb , this dates back to when wtsp was tampa 's primary abc affiliate prior to 1994 , with the former being necessitated to serve the southern part of the tampa market including the station 's city of license , sarasota , due to wtsp 's transmitter being short-spaced to avoid interfering with the analog signal of miami affiliate wplg -- which like wtsp , broadcast on vhf channel 10 -rrb- . 
after founding the mongol empire and being proclaimed `` genghis khan '' , he started the mongol invasions that resulted in the conquest of most of eurasia . 
he came to power by uniting many of the nomadic tribes of northeast asia . 
these campaigns were often accompanied by wholesale massacres of the civilian populations -- especially in the khwarezmian and xia controlled lands . 
by the end of his life , the mongol empire occupied a substantial portion of central asia and china . 
these included raids or invasions of the qara khitai , caucasus , khwarezmid empire , western xia and jin dynasties . 
before genghis khan died , he assigned ögedei khan as his successor and split his empire into khanates among his sons and grandsons . 
he died in 1227 after defeating the western xia . 
he died in 1227 after defeating the western xia . 
before genghis khan died , he assigned ögedei khan as his successor and split his empire into khanates among his sons and grandsons . 
he was buried in an unmarked grave somewhere in mongolia at an unknown location . 
temüjin was probably born in 1162 in delüün boldog , near burkhan khaldun mountain and the onon and kherlen rivers in modern-day northern mongolia , not far from the current capital ulaanbaatar . 
he was the second-oldest son of his father yesügei , a khamag mongol 's major chief of the kiyad and an ally of toghrul khan of the keraite tribe , and the oldest son of his mother hoelun . 
temüjin was probably born in 1162 in delüün boldog , near burkhan khaldun mountain and the onon and kherlen rivers in modern-day northern mongolia , not far from the current capital ulaanbaatar . 
according to the secret history , temüjin was named after a tatar chieftain , temüjin-üge , whom his father had just captured . 
temüjin had three brothers named hasar , hachiun , and temüge , and one sister named temülen , as well as two half-brothers named begter and belgutei . 
temüjin had three brothers named hasar , hachiun , and temüge , and one sister named temülen , as well as two half-brothers named begter and belgutei . 
his father arranged a marriage for him , and at nine years of age he was delivered by his father to the family of his future wife börte , who was a member of the tribe khongirad . 
his father arranged a marriage for him , and at nine years of age he was delivered by his father to the family of his future wife börte , who was a member of the tribe khongirad . 
temüjin was to live there in service to dai setsen , the head of the new household , until he reached the marriageable age of 12 . 
begter , temujin 's older half-brother , began to exercise the power of the eldest male in the family and eventually temujin 's mother hoelun -lrb- not begter 's mother -rrb- would have to accept him as her husband if and when he became an adult . 
begter , temujin 's older half-brother , began to exercise the power of the eldest male in the family and eventually temujin 's mother hoelun -lrb- not begter 's mother -rrb- would have to accept him as her husband if and when he became an adult . 
temujin 's resentment erupted during one hunting excursion that temüjin and his brother khasar killed their half-brother begter . 
temujin 's resentment erupted during one hunting excursion that temüjin and his brother khasar killed their half-brother begter . 
in another incident , around 1177 , he was captured in a raid and held prisoner by his father 's former allies , the tayichi'ud . 
the tayichi'ud enslaved temüjin -lrb- reportedly with a cangue , a sort of portable stocks -rrb- , but with the help of a sympathetic guard , the father of chilaun -lrb- who later became a general of genghis khan -rrb- , he was able to escape from the ger -lrb- yurt -rrb- in the middle of the night by hiding in a river crevice . 
the tayichi'ud enslaved temüjin -lrb- reportedly with a cangue , a sort of portable stocks -rrb- , but with the help of a sympathetic guard , the father of chilaun -lrb- who later became a general of genghis khan -rrb- , he was able to escape from the ger -lrb- yurt -rrb- in the middle of the night by hiding in a river crevice . 
-lsb- citation needed -rsb- it was around this time that jelme and bo'orchu , two of genghis khan 's future generals , joined forces with him . 
the tayichi'ud enslaved temüjin -lrb- reportedly with a cangue , a sort of portable stocks -rrb- , but with the help of a sympathetic guard , the father of chilaun -lrb- who later became a general of genghis khan -rrb- , he was able to escape from the ger -lrb- yurt -rrb- in the middle of the night by hiding in a river crevice . 
at this time , none of the tribal confederations of mongolia were united politically , and arranged marriages were often used to solidify temporary alliances . 
temüjin 's mother hoelun taught him many lessons about the unstable political climate of mongolia , especially the need for alliances . 
temüjin grew up observing the tough political climate of mongolia , which included tribal warfare , thievery , raids , corruption , and continual acts of revenge carried out between the various confederations , all compounded by interference from foreign forces such as the chinese dynasties to the south . 
temüjin 's mother hoelun taught him many lessons about the unstable political climate of mongolia , especially the need for alliances . 
as previously arranged by his father , temüjin married börte of the onggirat tribe when he was around 16 in order to cement alliances between their respective tribes . 
soon after börte 's marriage to temüjin , she was kidnapped by the merkits and reportedly given away as a wife . 
temüjin rescued her with the help of his friend and future rival , jamukha , and his protector , toghrul khan of the keraite tribe . 
she gave birth to a son , jochi -lrb- 1185 -- 1226 -rrb- , nine months later , clouding the issue of his parentage . 
she gave birth to a son , jochi -lrb- 1185 -- 1226 -rrb- , nine months later , clouding the issue of his parentage . 
börte had three more sons , chagatai -lrb- 1187 -- 1241 -rrb- , ögedei -lrb- 1189 -- 1241 -rrb- , and tolui -lrb- 1190 -- 1232 -rrb- . 
börte had three more sons , chagatai -lrb- 1187 -- 1241 -rrb- , ögedei -lrb- 1189 -- 1241 -rrb- , and tolui -lrb- 1190 -- 1232 -rrb- . 
börte had three more sons , chagatai -lrb- 1187 -- 1241 -rrb- , ögedei -lrb- 1189 -- 1241 -rrb- , and tolui -lrb- 1190 -- 1232 -rrb- . 
börte had three more sons , chagatai -lrb- 1187 -- 1241 -rrb- , ögedei -lrb- 1189 -- 1241 -rrb- , and tolui -lrb- 1190 -- 1232 -rrb- . 
the names of at least six daughters are known , and while they played significant roles behind the scenes during his lifetime , no documents have survived that definitively provide the number or names of daughters born to the consorts of genghis khan . 
temüjin began his ascent to power by offering himself as an ally -lrb- or , according to other sources , a vassal -rrb- to his father 's anda -lrb- sworn brother or blood brother -rrb- toghrul , who was khan of the keraites , and is better known by the chinese title `` wang khan '' , which the jurchen jin dynasty granted him in 1197 . 
temüjin began his ascent to power by offering himself as an ally -lrb- or , according to other sources , a vassal -rrb- to his father 's anda -lrb- sworn brother or blood brother -rrb- toghrul , who was khan of the keraites , and is better known by the chinese title `` wang khan '' , which the jurchen jin dynasty granted him in 1197 . 
temüjin began his ascent to power by offering himself as an ally -lrb- or , according to other sources , a vassal -rrb- to his father 's anda -lrb- sworn brother or blood brother -rrb- toghrul , who was khan of the keraites , and is better known by the chinese title `` wang khan '' , which the jurchen jin dynasty granted him in 1197 . 
temüjin turned to toghrul for support , and in response , toghrul offered his vassal 20,000 of his keraite warriors and suggested that he also involve his childhood friend jamukha , who had himself become khan -lrb- ruler -rrb- of his own tribe , the jadaran . 
temüjin turned to toghrul for support , and in response , toghrul offered his vassal 20,000 of his keraite warriors and suggested that he also involve his childhood friend jamukha , who had himself become khan -lrb- ruler -rrb- of his own tribe , the jadaran . 
jamukha supported the traditional mongolian aristocracy , while temüjin followed a meritocratic method , and attracted a broader , though lower class , range of followers . 
due to his earlier defeat of the merkits , and a proclamation by the shaman kokochu that the eternal blue sky had set aside the world for temüjin , temüjin began rising to power . 
in 1186 , temüjin was elected khan of the mongols . 
temüjin hastily gathered together his followers to defend against the attack , but he was decisively beaten in the battle of dalan balzhut . 
toghrul , as temüjin 's patron , was exiled to the qara khitai . 
as an incentive for absolute obedience and following his rule of law , the yassa code , temüjin promised civilians and soldiers wealth from future possible war spoils . 
as an incentive for absolute obedience and following his rule of law , the yassa code , temüjin promised civilians and soldiers wealth from future possible war spoils . 
he would even have his mother adopt orphans from the conquered tribe , bringing them into his family . 
instead , he took the conquered tribe under his protection and integrated its members into his own tribe . 
one of the later ruptures between toghrul and temüjin was toghrul 's refusal to give his daughter in marriage to jochi , the eldest son of temüjin , a sign of disrespect in the mongolian culture . 
toghrul allied himself with jamukha , who already opposed temüjin 's forces ; however , the internal dispute between toghrul and jamukha , plus the desertion of a number of their allies to temüjin , led to toghrul 's defeat . 
jamukha escaped during the conflict . 
this defeat was a catalyst for the fall and eventual dissolution of the keraite tribe . 
the next direct threat to temüjin was the naimans -lrb- naiman mongols -rrb- , with whom jamukha and his followers took refuge . 
in 1201 , a khuruldai elected jamukha as gür khan , `` universal ruler '' , a title used by the rulers of the qara khitai . 
in 1201 , a khuruldai elected jamukha as gür khan , `` universal ruler '' , a title used by the rulers of the qara khitai . 
before the conflict , however , several generals abandoned jamukha , including subutai , jelme 's well-known younger brother . 
after several battles , jamukha was finally turned over to temüjin by his own men in 1206 . 
according to the secret history , temüjin again offered his friendship to jamukha , asking him to return to his side . 
temüjin had killed the men who betrayed jamukha , stating that he did not want disloyal men in his army . 
jamukha refused the offer of friendship and reunion , saying that there can only be one sun in the sky , and he asked for a noble death . 
the custom is to die without spilling blood , which is granted by breaking the back . 
he seemed to be a quick student , adopting new technologies and ideas that he encountered , such as siege warfare from the chinese . 
he was also ruthless , demonstrated by his tactic of measuring against the linchpin , used against the tribes led by jamukha . 
these include rifts with his early allies such as jamukha -lrb- who also wanted to be a ruler of mongol tribes -rrb- and wang khan -lrb- his and his father 's ally -rrb- , his son jochi , and problems with the most important shaman , who was allegedly trying to drive a wedge between him and his loyal brother khasar . 
his military strategies showed a deep interest in gathering good intelligence and understanding the motivations of his rivals , exemplified by his extensive spy network and yam route systems . 
these include rifts with his early allies such as jamukha -lrb- who also wanted to be a ruler of mongol tribes -rrb- and wang khan -lrb- his and his father 's ally -rrb- , his son jochi , and problems with the most important shaman , who was allegedly trying to drive a wedge between him and his loyal brother khasar . 
as a result , by 1206 temüjin had managed to unite or subdue the merkits , naimans , mongols , keraites , tatars , uyghurs , and other disparate smaller tribes under his rule . 
at a khuruldai , a council of mongol chiefs , temüjin was acknowledged as `` khan '' of the consolidated tribes and took the new title `` genghis khan '' . 
the title khagan was not conferred on genghis until after his death , when his son and successor , ögedei , took the title for himself and extended it posthumously to his father -lrb- as he was also to be posthumously declared the founder of the yuan dynasty -rrb- . 
the title khagan was not conferred on genghis until after his death , when his son and successor , ögedei , took the title for himself and extended it posthumously to his father -lrb- as he was also to be posthumously declared the founder of the yuan dynasty -rrb- . 
at a khuruldai , a council of mongol chiefs , temüjin was acknowledged as `` khan '' of the consolidated tribes and took the new title `` genghis khan '' . 
in 1211 , after the conquest of western xia , genghis khan planned again to conquer the jin dynasty . 
instead , the jin commander sent a messenger , ming-tan , to the mongol side , who defected and told the mongols that the jin army was waiting on the other side of the pass . 
in 1215 genghis besieged , captured , and sacked the jin capital of zhongdu -lrb- modern-day beijing -rrb- . 
this forced the emperor xuanzong to move his capital south to kaifeng , abandoning the northern half of his kingdom to the mongols . 
between 1232 and 1233 , kaifeng fell to the mongols under the reign of genghis ' third son , ögedei khan . 
kuchlug , the deposed khan of the naiman confederation that temüjin defeated and folded into his mongol empire , fled west and usurped the khanate of qara khitai -lrb- also known as the western liao , as it was originally established as remnants of the liao dynasty -rrb- . 
kuchlug , the deposed khan of the naiman confederation that temüjin defeated and folded into his mongol empire , fled west and usurped the khanate of qara khitai -lrb- also known as the western liao , as it was originally established as remnants of the liao dynasty -rrb- . 
therefore , genghis sent only two tumen -lrb- 20,000 soldiers -rrb- against kuchlug , under his younger general , jebe , known as `` the arrow '' . 
therefore , genghis sent only two tumen -lrb- 20,000 soldiers -rrb- against kuchlug , under his younger general , jebe , known as `` the arrow '' . 
therefore , genghis sent only two tumen -lrb- 20,000 soldiers -rrb- against kuchlug , under his younger general , jebe , known as `` the arrow '' . 
with such a small force , the invading mongols were forced to change strategies and resort to inciting internal revolt among kuchlug 's supporters , leaving the qara khitai more vulnerable to mongol conquest . 
as a result , kuchlug 's army was defeated west of kashgar . 
by 1218 , as a result of defeat of qara khitai , the mongol empire and its control extended as far west as lake balkhash , which bordered the khwarezmia -lrb- khwarezmid empire -rrb- , a muslim state that reached the caspian sea to the west and persian gulf and the arabian sea to the south . 
by 1218 , as a result of defeat of qara khitai , the mongol empire and its control extended as far west as lake balkhash , which bordered the khwarezmia -lrb- khwarezmid empire -rrb- , a muslim state that reached the caspian sea to the west and persian gulf and the arabian sea to the south . 
by 1218 , as a result of defeat of qara khitai , the mongol empire and its control extended as far west as lake balkhash , which bordered the khwarezmia -lrb- khwarezmid empire -rrb- , a muslim state that reached the caspian sea to the west and persian gulf and the arabian sea to the south . 
in the early 13th century , the khwarazmian dynasty was governed by shah ala ad-din muhammad . 
however , inalchuq , the governor of the khwarezmian city of otrar , attacked the caravan that came from mongolia , claiming that the caravan contained spies and therefore was a conspiracy against khwarezmia . 
the shah had all the men shaved and the muslim beheaded and sent his head back with the two remaining ambassadors . 
outraged , genghis khan planned one of his largest invasion campaigns by organizing together around 100,000 soldiers -lrb- 10 tumens -rrb- , his most capable generals and some of his sons . 
genghis khan saw the potential advantage in khwarezmia as a commercial trading partner using the silk road , and he initially sent a 500-man caravan to establish official trade ties with the empire . 
the mongol army under genghis khan , generals and his sons crossed the tien shan mountains by entering the area controlled by the khwarezmian empire . 
after compiling intelligence from many sources genghis khan carefully prepared his army , which was divided into three groups . 
the second division under jebe marched secretly to the southeast part of khwarzemia to form , with the first division , a pincer attack on samarkand . 
the third division under genghis khan and tolui marched to the northwest and attacked khwarzemia from that direction . 
the second division under jebe marched secretly to the southeast part of khwarzemia to form , with the first division , a pincer attack on samarkand . 
this fragmentation was decisive in khwarezmia 's defeats , as it allowed the mongols , although exhausted from the long journey , to immediately set about defeating small fractions of the khwarzemi forces instead of facing a unified defense . 
the mongol army quickly seized the town of otrar , relying on superior strategy and tactics . 
genghis khan ordered the wholesale massacre of many of the civilians , enslaved the rest of the population and executed inalchuq by pouring molten silver into his ears and eyes , as retribution for his actions . 
near the end of the battle the shah fled rather than surrender . 
genghis khan ordered subutai and jebe to hunt him down , giving them 20,000 men and two years to do this . 
after the capital samarkand fell , the capital was moved to bukhara by the remaining men , while genghis khan ordered two of his generals and their forces to completely destroy the remnants of the khwarezmid empire , including not only royal buildings , but entire towns , populations , and even vast swaths of farmland . 
after the capital samarkand fell , the capital was moved to bukhara by the remaining men , while genghis khan ordered two of his generals and their forces to completely destroy the remnants of the khwarezmid empire , including not only royal buildings , but entire towns , populations , and even vast swaths of farmland . 
according to legend , genghis khan even went so far as to divert a river through the khwarezmid emperor 's birthplace , erasing it from the map . 
the mongols attacked samarkand using captured enemies as body shields . 
after the fortress fell , genghis supposedly reneged on his surrender terms and executed every soldier that had taken arms against him at samarkand . 
the people of samarkand were ordered to evacuate and assemble in a plain outside the city , where they were killed and pyramids of severed heads raised as a symbol of victory . 
the city leaders opened the gates to the mongols , though a unit of turkish defenders held the city 's citadel for another twelve days . 
the city leaders opened the gates to the mongols , though a unit of turkish defenders held the city 's citadel for another twelve days . 
survivors from the citadel were executed , artisans and craftsmen were sent back to mongolia , young men who had not fought were drafted into the mongolian army and the rest of the population was sent into slavery . 
genghis khan had the city 's surviving population assemble in the main mosque of the town , where he declared that he was the flail of god , sent to punish them for their sins . 
survivors from the citadel were executed , artisans and craftsmen were sent back to mongolia , young men who had not fought were drafted into the mongolian army and the rest of the population was sent into slavery . 
after the defeat of the khwarezmian empire in 1220 , genghis khan gathered his forces in persia and armenia to return to the mongolian steppes . 
under the suggestion of subutai , the mongol army was split into two forces . 
the mongols destroyed the kingdom of georgia , sacked the genoese trade-fortress of caffa in crimea and overwintered near the black sea . 
at the battle of kalka river in 1223 , subutai 's forces defeated the larger kievan force . 
heading home , subutai 's forces attacked the allied forces of the cuman -- kipchaks and the poorly coordinated 80,000 kievan rus ' troops led by mstislav the bold of halych and mstislav iii of kiev who went out to stop the mongols ' actions in the area . 
later under genghis khan 's grandson batu and the golden horde , the mongols returned to conquer volga bulgaria and kievan rus ' in 1237 , concluding the campaign in 1240 . 
later under genghis khan 's grandson batu and the golden horde , the mongols returned to conquer volga bulgaria and kievan rus ' in 1237 , concluding the campaign in 1240 . 
the famous cavalry expedition led by subutai and jebe , in which they encircled the entire caspian sea defeating all armies in their path , remains unparalleled to this day , and word of the mongol triumphs began to trickle to other nations , particularly europe . 
in 1225 both divisions returned to mongolia . 
genghis khan recalled subutai back to mongolia soon afterwards , and jebe died on the road back to samarkand . 
in 1226 , immediately after returning from the west , genghis khan began a retaliatory attack on the tanguts . 
his armies quickly took heisui , ganzhou , and suzhou -lrb- not the suzhou in jiangsu province -rrb- , and in the autumn he took xiliang-fu -lsb- disambiguation needed -rsb- . 
one of the tangut generals challenged the mongols to a battle near helan mountains but was defeated . 
in november , genghis laid siege to the tangut city lingzhou and crossed the yellow river , defeating the tangut relief army . 
according to legend , it was here that genghis khan reportedly saw a line of five stars arranged in the sky and interpreted it as an omen of his victory . 
in 1227 , genghis khan 's army attacked and destroyed the tangut capital of ning hia and continued to advance , seizing lintiao-fu , xining province , xindu-fu , and deshun province in quick succession in the spring . 
at deshun , the tangut general ma jianlong put up a fierce resistance for several days and personally led charges against the invaders outside the city gate . 
ma jianlong later died from wounds received from arrows in battle . 
genghis khan , after conquering deshun , went to liupanshan -lrb- qingshui county , gansu province -rrb- to escape the severe summer . 
not happy with their betrayal and resistance , genghis khan ordered the entire imperial family to be executed , effectively ending the tangut lineage . 
the long running paternity discussion about genghis ' oldest son jochi was particularly contentious because of the seniority of jochi among the brothers . 
in the secret history of the mongols , just before the invasion of the khwarezmid empire by genghis khan , chagatai declared before his father and brothers that he would never accept jochi as genghis khan 's successor . 
in the secret history of the mongols , just before the invasion of the khwarezmid empire by genghis khan , chagatai declared before his father and brothers that he would never accept jochi as genghis khan 's successor . 
in response to this tension , and possibly for other reasons , ögedei was appointed as successor . 
genghis khan was aware of the friction between his sons -lrb- particularly between chagatai and jochi -rrb- and worried of possible conflict between them if he died . 
chagatai was considered unstable due to his temper and rash behavior , because of statements he made that he would not follow jochi if he were to become his father 's successor . 
tolui , genghis khan 's youngest son , was not to be his successor because he was the youngest and in the mongol culture , youngest sons were not given much responsibility due to their age . 
ögedei was seen by genghis khan as dependable in character and relatively stable and down to earth and would be a neutral candidate and might defuse the situation between his brothers . 
jochi died in 1226 , during his father 's lifetime . 
rashid al-din reports that the great khan sent for his sons in the spring of 1223 , and while his brothers heeded the order , jochi remained in khorasan . 
juzjani suggests that the disagreement arose from a quarrel between jochi and his brothers in the siege of urgench . 
i would be doing a service if i killed my father when he is hunting , made an alliance with sultan muhammad , brought this land to life and gave assistance and support to the muslims . '' 
juzjani claims that it was in response to hearing of these plans that genghis khan ordered his son secretly poisoned ; however , as sultan muhammad was already dead in 1223 , the accuracy of this story is questionable . 
in august 1227 , during the fall of yinchuan , the capital of western xia , genghis khan died . 
according to the secret history of the mongols genghis khan fell from his horse while hunting and died because of the injury . 
the galician -- volhynian chronicle alleges he was killed by the western xia in battle , while marco polo wrote that he died after the infection of an arrow wound he received during his final campaign . 
later mongol chronicles connect genghis ' death with a western xia princess taken as war booty . 
one chronicle from the early 17th century even relates the legend that the princess hid a small dagger and stabbed him , though some mongol authors have doubted this version and suspected it to be an invention by the rival oirads . 
years before his death , genghis khan asked to be buried without markings , according to the customs of his tribe . 
after he died , his body was returned to mongolia and presumably to his birthplace in khentii aimag , where many assume he is buried somewhere close to the onon river and the burkhan khaldun mountain -lrb- part of the kentii mountain range -rrb- . 
after he died , his body was returned to mongolia and presumably to his birthplace in khentii aimag , where many assume he is buried somewhere close to the onon river and the burkhan khaldun mountain -lrb- part of the kentii mountain range -rrb- . 
the genghis khan mausoleum , constructed many years after his death , is his memorial , but not his burial site . 
in 1939 chinese nationalist soldiers took the mausoleum from its position at the ` lord 's enclosure ' -lrb- mongolian : edsen khoroo -rrb- in mongolia to protect it from japanese troops . 
it was taken through communist-held territory in yan ` an some 900 km on carts to safety at a buddhist monastery , the dongshan dafo dian , where it remained for ten years . 
in 1949 , as communist troops advanced , the nationalist soldiers moved it another 200 km farther west to the famous tibetan monastery of kumbum monastery or ta'er shi near xining , which soon fell under communist control . 
in early 1954 , genghis khan 's bier and relics were returned to the lord 's enclosure in mongolia . 
in 1968 during the cultural revolution , red guards destroyed almost everything of value . 
on october 6 , 2004 , a joint japanese-mongolian archaeological dig uncovered what is believed to be genghis khan 's palace in rural mongolia , which raises the possibility of actually locating the ruler 's long-lost burial site . 
folklore says that a river was diverted over his grave to make it impossible to find -lrb- the same manner of burial as the sumerian king gilgamesh of uruk and atilla the hun -rrb- . 
folklore says that a river was diverted over his grave to make it impossible to find -lrb- the same manner of burial as the sumerian king gilgamesh of uruk and atilla the hun -rrb- . 
other tales state that his grave was stampeded over by many horses , and that trees were then planted over the site , and the permafrost also did its part in hiding the burial site . 
the mongol empire was governed by a civilian and military code , called the yassa , created by genghis khan . 
the mongol empire was governed by a civilian and military code , called the yassa , created by genghis khan . 
the mongol empire did not emphasize the importance of ethnicity and race in the administrative realm , instead adopting an approach grounded in meritocracy . 
the exception was the role of genghis khan and his family . 
many of the empire 's nomadic inhabitants considered themselves mongols in military and civilian life , including mongols , turks and others and included many diverse khans of various ethnicities as part of the mongol empire such as muhammad khan . 
there were tax exemptions for religious figures and , to some extent , teachers and doctors . 
-lsb- citation needed -rsb- sometime before the rise of genghis khan , ong khan , his mentor and eventual rival , had converted to nestorian christianity . 
the mongol empire practiced religious tolerance because mongol tradition had long held that religion was a personal concept , and not subject to law or interference . 
various mongol tribes were shamanist , buddhist or christian . 
women played a relatively important role in mongol empire and in family , for example töregene khatun was briefly in charge of the mongol empire when next male khagan was being chosen . 
modern scholars refer to the alleged policy of encouraging trade and communication as the pax mongolica -lrb- mongol peace -rrb- . 
however , there is no evidence of this , or of the lifting of discriminatory policies towards sedentary peoples such as the chinese . 
modern mongolian historians say that towards the end of his life , genghis khan attempted to create a civil state under the great yassa that would have established the legal equality of all individuals , including women . 
for this purpose genghis khan invited a khitan prince , chu'tsai , who worked for the jin and had been captured by the mongol army after the jin dynasty was defeated . 
he also realised that such administrators could not be found among his mongol people because they were nomads and thus had no experience governing cities . 
jin had captured power by displacing khitan . 
genghis told chu'tsai , who was a lineal descendant of khitan rulers , that he had avenged chu'tsai 's forefathers . 
genghis khan put absolute trust in his generals , such as muqali , jebe and subutai , and regarded them as close advisors , often extending them the same privileges and trust normally reserved for close family members . 
he allowed them to make decisions on their own when they embarked on campaigns far from the mongol empire capital karakorum . 
muqali , a trusted lieutenant , was given command of the mongol forces against the jin dynasty while genghis khan was fighting in central asia , and subutai and jebe were allowed to pursue the great raid into the caucasus and kievan rus ' , an idea they had presented to the khagan on their own initiative . 
muqali , a trusted lieutenant , was given command of the mongol forces against the jin dynasty while genghis khan was fighting in central asia , and subutai and jebe were allowed to pursue the great raid into the caucasus and kievan rus ' , an idea they had presented to the khagan on their own initiative . 
while granting his generals a great deal of autonomy in making command decisions , genghis khan also expected unwavering loyalty from them . 
the mongol military was also successful in siege warfare , cutting off resources for cities and towns by diverting certain rivers , taking enemy prisoners and driving them in front of the army , and adopting new ideas , techniques and tools from the people they conquered , particularly in employing muslim and chinese siege engines and engineers to aid the mongol cavalry in capturing cities . 
the mongol military was also successful in siege warfare , cutting off resources for cities and towns by diverting certain rivers , taking enemy prisoners and driving them in front of the army , and adopting new ideas , techniques and tools from the people they conquered , particularly in employing muslim and chinese siege engines and engineers to aid the mongol cavalry in capturing cities . 
another standard tactic of the mongol military was the commonly practiced feigned retreat to break enemy formations and to lure small enemy groups away from the larger group and defended position for ambush and counterattack . 
the mongol military was also successful in siege warfare , cutting off resources for cities and towns by diverting certain rivers , taking enemy prisoners and driving them in front of the army , and adopting new ideas , techniques and tools from the people they conquered , particularly in employing muslim and chinese siege engines and engineers to aid the mongol cavalry in capturing cities . 
at the time of his death , the mongol empire stretched from the caspian sea to the sea of japan . 
at the time of his death , the mongol empire stretched from the caspian sea to the sea of japan . 
under genghis 's successor ögedei khan the speed of expansion reached its peak . 
mongol armies pushed into persia , finished off the western xia and the remnants of the khwarezmids , and came into conflict with the imperial song dynasty of china , starting a war that lasted until 1279 and that concluded with the mongols gaining control of all of china . 
genghis khan is credited with bringing the silk road under one cohesive political environment . 
in turkey , genghis khan is looked on as a great military leader , and it is popular for male children to carry his title as name . 
some historians have noted that genghis khan instituted certain levels of meritocracy in his rule , was tolerant of religions and explained his policies clearly to all his soldiers . 
this allowed increased communication and trade between the west , middle east and asia , thus expanding the horizons of all three cultural areas . 
in the early 1990s the memory of genghis khan with the mongolian national identity has had a powerful revival partly because of his perception during the mongolian people 's republic period . 
he is looked upon positively by mongolians for his role in uniting warring tribes . 
for example , it is not uncommon for mongolians to refer to their country as `` genghis khan 's mongolia '' , to themselves as `` genghis khan 's children '' , and to genghis khan as the `` father of the mongols '' especially among the younger generation . 
however , there is a chasm in the perception of his brutality . 
mongolians maintain that the historical records written by non-mongolians are unfairly biased against genghis khan and that his butchery is exaggerated , while his positive role is underrated . 
his face can be found on everyday commodities , from liquor bottles to candy products , and on the largest denominations of 500 , 1,000 , 5,000 , 10,000 , and 20,000 mongolian tögrög -lrb- -rrb- . 
in mongolia today , genghis khan 's name and likeness are endorsed on products , streets , buildings , and other places . 
mongolia 's main international airport in ulaanbaatar is named chinggis khaan international airport . 
there have been repeated discussions about regulating the use of his name and image to avoid trivialization . 
major genghis khan statues have been erected before the parliament and near ulaanbaatar . 
he is also given credit for the introduction of the traditional mongolian script and the creation of the ikh zasag -lrb- great administration -rrb- , the first written mongolian law . 
`` ikh zasag law adopted during genghis khan 's time in mongolia had points to punish illegal matters related to corruption and bribery very heavily , '' mongolian president tsakhiagiin elbegdorj noted . 
`` ikh zasag law adopted during genghis khan 's time in mongolia had points to punish illegal matters related to corruption and bribery very heavily , '' mongolian president tsakhiagiin elbegdorj noted . 
he is also given credit for the introduction of the traditional mongolian script and the creation of the ikh zasag -lrb- great administration -rrb- , the first written mongolian law . 
there are conflicting views of genghis khan in the people 's republic of china with some viewing him positively in the inner mongolia region where there are a monument and buildings about him and where there is a considerable number of mongols in the area with a population of around 5 million , almost twice the population of mongolia . 
there are conflicting views of genghis khan in the people 's republic of china with some viewing him positively in the inner mongolia region where there are a monument and buildings about him and where there is a considerable number of mongols in the area with a population of around 5 million , almost twice the population of mongolia . 
while genghis khan never conquered all of china , his grandson kublai khan completed that conquest and established the yuan dynasty that is often credited with re-uniting china . 
while genghis khan never conquered all of china , his grandson kublai khan completed that conquest and established the yuan dynasty that is often credited with re-uniting china . 
while genghis khan never conquered all of china , his grandson kublai khan completed that conquest and established the yuan dynasty that is often credited with re-uniting china . 
in the middle east , and particularly in iran , genghis khan is almost universally condemned as a destructive and genocidal warlord who caused enormous damage and destruction to the population of these areas . 
steven r. ward wrote that `` overall , the mongol violence and depredations killed up to three-fourths of the population of the iranian plateau , possibly 10 to 15 million people . 
steven r. ward wrote that `` overall , the mongol violence and depredations killed up to three-fourths of the population of the iranian plateau , possibly 10 to 15 million people . 
his descendant hulagu khan destroyed much of iran 's northern part and sacked baghdad although his forces were halted by the mamluks of egypt , but hulagu 's descendant ghazan khan would return to beat the egyptian mamluks right out of levant , palestine and even gaza . 
his descendant hulagu khan destroyed much of iran 's northern part and sacked baghdad although his forces were halted by the mamluks of egypt , but hulagu 's descendant ghazan khan would return to beat the egyptian mamluks right out of levant , palestine and even gaza . 
his descendant hulagu khan destroyed much of iran 's northern part and sacked baghdad although his forces were halted by the mamluks of egypt , but hulagu 's descendant ghazan khan would return to beat the egyptian mamluks right out of levant , palestine and even gaza . 
in 1237 batu khan , a grandson of genghis khan , launched an invasion into kievan rus ' . 
over the course of three years , the mongols destroyed and annihilated all of the major cities of eastern europe with the exceptions of novgorod and pskov . 
although the famous mughal emperors were proud descendants of genghis khan and particularly timur , they clearly distanced themselves from the mongol atrocities committed against the khwarizim shahs , turks , persians , the citizens of baghdad and damascus , nishapur , bukhara and historical figures such as attar of nishapur and many other notable muslims . 
however , mughal emperors directly patronized the legacies of genghis khan and timur ; together their names were synonymous with the names of other distinguished personalities particularly among the muslim populations of south asia . 
although the famous mughal emperors were proud descendants of genghis khan and particularly timur , they clearly distanced themselves from the mongol atrocities committed against the khwarizim shahs , turks , persians , the citizens of baghdad and damascus , nishapur , bukhara and historical figures such as attar of nishapur and many other notable muslims . 
one theory suggests the name stems from a palatalised version of the mongolian and turkic word tenggis , meaning `` ocean '' , `` oceanic '' or `` wide-spreading '' . 
-lrb- lake baikal and ocean were called tenggis by the mongols . 
zhèng -lrb- chinese : 正 -rrb- meaning `` right '' , `` just '' , or `` true '' , would have received the mongolian adjectival modifier - s , creating `` jenggis '' , which in medieval romanization would be written `` genghis '' . 
zhèng -lrb- chinese : 正 -rrb- meaning `` right '' , `` just '' , or `` true '' , would have received the mongolian adjectival modifier - s , creating `` jenggis '' , which in medieval romanization would be written `` genghis '' . 
it is likely that the 13th century mongolian pronunciation would have closely matched `` chinggis '' . 
genghis khan , the title is spelled in variety of ways in different languages such as mongolian chinggis khaan , english chinghiz , chinghis , and chingiz , chinese : 成吉思汗 ; pinyin : chéngjísī hán , turkic : cengiz han , çingiz xan , çingiz han , chingizxon , çıñğız xan , chengez khan , chinggis khan , chinggis xaan , chingis khan , jenghis khan , chinggis qan , djingis kahn , russian : чингисхан -lrb- čingiskhan -rrb- or чингиз-хан -lrb- čingiz-khan -rrb- , etc. . 
genghis khan , the title is spelled in variety of ways in different languages such as mongolian chinggis khaan , english chinghiz , chinghis , and chingiz , chinese : 成吉思汗 ; pinyin : chéngjísī hán , turkic : cengiz han , çingiz xan , çingiz han , chingizxon , çıñğız xan , chengez khan , chinggis khan , chinggis xaan , chingis khan , jenghis khan , chinggis qan , djingis kahn , russian : чингисхан -lrb- čingiskhan -rrb- or чингиз-хан -lrb- čingiz-khan -rrb- , etc. . 
temüjin is written in chinese as simplified chinese : 铁木真 ; traditional chinese : 鐵木眞 ; pinyin : tiěmùzhēn . 
genghis khan , the title is spelled in variety of ways in different languages such as mongolian chinggis khaan , english chinghiz , chinghis , and chingiz , chinese : 成吉思汗 ; pinyin : chéngjísī hán , turkic : cengiz han , çingiz xan , çingiz han , chingizxon , çıñğız xan , chengez khan , chinggis khan , chinggis xaan , chingis khan , jenghis khan , chinggis qan , djingis kahn , russian : чингисхан -lrb- čingiskhan -rrb- or чингиз-хан -lrb- čingiz-khan -rrb- , etc. . 
genghis khan , the title is spelled in variety of ways in different languages such as mongolian chinggis khaan , english chinghiz , chinghis , and chingiz , chinese : 成吉思汗 ; pinyin : chéngjísī hán , turkic : cengiz han , çingiz xan , çingiz han , chingizxon , çıñğız xan , chengez khan , chinggis khan , chinggis xaan , chingis khan , jenghis khan , chinggis qan , djingis kahn , russian : чингисхан -lrb- čingiskhan -rrb- or чингиз-хан -lrb- čingiz-khan -rrb- , etc. . 
the word pharmacy is derived from its root word pharma which was a term used since the 15th -- 17th centuries . 
the pharma -lrb- as it was referred to -rrb- often operated through a retail shop which , in addition to ingredients for medicines , sold tobacco and patent medicines . 
however , the original greek roots from pharmakos imply sorcery or even poison . 
often the place that did this was called an apothecary and several languages have this as the dominant term , though their practices are more akin to a modern pharmacy , in english the term apothecary would today be seen as outdated or only approproriate if herbal remedies were on offer to a large extent . 
the pharmas also used many other herbs not listed . 
pharmacists are healthcare professionals with specialised education and training who perform various roles to ensure optimal health outcomes for their patients through the quality use of medicines . 
pharmacists are healthcare professionals with specialised education and training who perform various roles to ensure optimal health outcomes for their patients through the quality use of medicines . 
since pharmacists know about the mode of action of a particular drug , and its metabolism and physiological effects on the human body in great detail , they play an important role in optimisation of a drug treatment for an individual . 
pharmacists may also be small-business proprietors , owning the pharmacy in which they practice . 
pharmacists are healthcare professionals with specialised education and training who perform various roles to ensure optimal health outcomes for their patients through the quality use of medicines . 
a pharmacy technician in the uk is considered a health care professional and often does not work under the direct supervision of a pharmacist -lrb- if employed in a hospital pharmacy -rrb- but instead is supervised and managed by other senior pharmacy technicians . 
a pharmacy technician once qualified has to register as a professional on the general pharmaceutical council -lrb- gphc -rrb- register . 
the gphc is the governing body for pharmacy health care professionals and this is who regulates the practice of pharmacists and pharmacy technicians . 
a pharmacy technician in the uk is considered a health care professional and often does not work under the direct supervision of a pharmacist -lrb- if employed in a hospital pharmacy -rrb- but instead is supervised and managed by other senior pharmacy technicians . 
in the uk the role of a pht has grown and responsibility has been passed on to them to manage the pharmacy department and specialised areas in pharmacy practice allowing pharmacists the time to specialise in their expert field as medication consultants spending more time working with patients and in research . 
the greek physician pedanius dioscorides is famous for writing a five volume book in his native greek περί ύλης ιατρικής in the 1st century ad . 
the latin translation de materia medica -lrb- concerning medical substances -rrb- was used a basis for many medieval texts , and was built upon by many middle eastern scientists during the islamic golden age . 
the title coined the term materia medica . 
in ancient greece , diocles of carystus -lrb- 4th century bc -rrb- was one of several men studying the medicinal properties of plants . 
the latin translation de materia medica -lrb- concerning medical substances -rrb- was used a basis for many medieval texts , and was built upon by many middle eastern scientists during the islamic golden age . 
in japan , at the end of the asuka period -lrb- 538 -- 710 -rrb- and the early nara period -lrb- 710 -- 794 -rrb- , the men who fulfilled roles similar to those of modern pharmacists were highly respected . 
the place of pharmacists in society was expressly defined in the taihō code -lrb- 701 -rrb- and re-stated in the yōrō code -lrb- 718 -rrb- . 
ranked positions in the pre-heian imperial court were established ; and this organizational structure remained largely intact until the meiji restoration -lrb- 1868 -rrb- . 
in this highly stable hierarchy , the pharmacists -- and even pharmacist assistants -- were assigned status superior to all others in health-related fields such as physicians and acupuncturists . 
in the imperial household , the pharmacist was even ranked above the two personal physicians of the emperor . 
the advances made in the middle east in botany and chemistry led medicine in medieval islam substantially to develop pharmacology . 
muhammad ibn zakarīya rāzi -lrb- rhazes -rrb- -lrb- 865 -- 915 -rrb- , for instance , acted to promote the medical uses of chemical compounds . 
abu al-qasim al-zahrawi -lrb- abulcasis -rrb- -lrb- 936 -- 1013 -rrb- pioneered the preparation of medicines by sublimation and distillation . 
al-muwaffaq 's contributions in the field are also pioneering . 
he made clear distinction between sodium carbonate and potassium carbonate , and drew attention to the poisonous nature of copper compounds , especially copper vitriol , and also lead compounds . 
in europe there are old pharmacies still operating in dubrovnik , croatia , located inside the franciscan monastery , opened in 1317 ; and in the town hall square of tallinn , estonia , dating from at least 1422 . 
the oldest is claimed to have been set up in 1221 in the church of santa maria novella in florence , italy , which now houses a perfume museum . 
the medieval esteve pharmacy , located in llívia , a catalan enclave close to puigcerdà , also now a museum , dates back to the 15th century , keeping albarellos from the 16th and 17th centuries , old prescription books and antique drugs . 
the medieval esteve pharmacy , located in llívia , a catalan enclave close to puigcerdà , also now a museum , dates back to the 15th century , keeping albarellos from the 16th and 17th centuries , old prescription books and antique drugs . 
the oldest is claimed to have been set up in 1221 in the church of santa maria novella in florence , italy , which now houses a perfume museum . 
in most countries , the dispensary is subject to pharmacy legislation ; with requirements for storage conditions , compulsory texts , equipment , etc. , specified in legislation . 
where it was once the case that pharmacists stayed within the dispensary compounding/dispensing medications , there has been an increasing trend towards the use of trained pharmacy technicians while the pharmacist spends more time communicating with patients . 
pharmacy technicians are now more dependent upon automation to assist them in their new role dealing with patients ' prescriptions and patient safety issues . 
pharmacy technicians are now more dependent upon automation to assist them in their new role dealing with patients ' prescriptions and patient safety issues . 
in most countries , the dispensary is subject to pharmacy legislation ; with requirements for storage conditions , compulsory texts , equipment , etc. , specified in legislation . 
because of the complexity of medications including specific indications , effectiveness of treatment regimens , safety of medications -lrb- i.e. , drug interactions -rrb- and patient compliance issues -lrb- in the hospital and at home -rrb- many pharmacists practicing in hospitals gain more education and training after pharmacy school through a pharmacy practice residency and sometimes followed by another residency in a specific area . 
those pharmacists are often referred to as clinical pharmacists and they often specialize in various disciplines of pharmacy . 
because of the complexity of medications including specific indications , effectiveness of treatment regimens , safety of medications -lrb- i.e. , drug interactions -rrb- and patient compliance issues -lrb- in the hospital and at home -rrb- many pharmacists practicing in hospitals gain more education and training after pharmacy school through a pharmacy practice residency and sometimes followed by another residency in a specific area . 
because of the complexity of medications including specific indications , effectiveness of treatment regimens , safety of medications -lrb- i.e. , drug interactions -rrb- and patient compliance issues -lrb- in the hospital and at home -rrb- many pharmacists practicing in hospitals gain more education and training after pharmacy school through a pharmacy practice residency and sometimes followed by another residency in a specific area . 
hospital pharmacies can often be found within the premises of the hospital . 
most hospital medications are unit-dose , or a single dose of medicine . 
several hospital pharmacies have decided to outsource high risk preparations and some other compounding functions to companies who specialize in compounding . 
the high cost of medications and drug-related technology , combined with the potential impact of medications and pharmacy services on patient-care outcomes and patient safety , make it imperative that hospital pharmacies perform at the highest level possible . 
hospital pharmacies usually stock a larger range of medications , including more specialized medications , than would be feasible in the community setting . 
pharmacists provide direct patient care services that optimizes the use of medication and promotes health , wellness , and disease prevention . 
clinical pharmacists care for patients in all health care settings , but the clinical pharmacy movement initially began inside hospitals and clinics . 
clinical pharmacists often collaborate with physicians and other healthcare professionals to improve pharmaceutical care . 
they often participate in patient care rounds drug product selection . 
clinical pharmacists care for patients in all health care settings , but the clinical pharmacy movement initially began inside hospitals and clinics . 
the clinical pharmacist 's role involves creating a comprehensive drug therapy plan for patient-specific problems , identifying goals of therapy , and reviewing all prescribed medications prior to dispensing and administration to the patient . 
the review process often involves an evaluation of the appropriateness of the drug therapy -lrb- e.g. , drug choice , dose , route , frequency , and duration of therapy -rrb- and its efficacy . 
the review process often involves an evaluation of the appropriateness of the drug therapy -lrb- e.g. , drug choice , dose , route , frequency , and duration of therapy -rrb- and its efficacy . 
the pharmacist must also monitor for potential drug interactions , adverse drug reactions , and assess patient drug allergies while designing and initiating a drug therapy plan . 
in the u.s. federal health care system -lrb- including the va , the indian health service , and nih -rrb- ambulatory care pharmacists are given full independent prescribing authority . 
in some states such north carolina and new mexico these pharmacist clinicians are given collaborative prescriptive and diagnostic authority . 
in 2011 the board of pharmaceutical specialties approved ambulatory care pharmacy practice as a separate board certification . 
the official designation for pharmacists who pass the ambulatory care pharmacy specialty certification exam will be board certified ambulatory care pharmacist and these pharmacists will carry the initials bcacp . 
in the u.s. federal health care system -lrb- including the va , the indian health service , and nih -rrb- ambulatory care pharmacists are given full independent prescribing authority . 
consultant pharmacy practice focuses more on medication regimen review -lrb- i.e. `` cognitive services '' -rrb- than on actual dispensing of drugs . 
consultant pharmacists most typically work in nursing homes , but are increasingly branching into other institutions and non-institutional settings . 
traditionally consultant pharmacists were usually independent business owners , though in the united states many now work for several large pharmacy management companies -lrb- primarily omnicare , kindred healthcare and pharmerica -rrb- . 
this trend may be gradually reversing as consultant pharmacists begin to work directly with patients , primarily because many elderly people are now taking numerous medications but continue to live outside of institutional settings . 
some community pharmacies employ consultant pharmacists and/or provide consulting services . 
since about the year 2000 , a growing number of internet pharmacies have been established worldwide . 
many of these pharmacies are similar to community pharmacies , and in fact , many of them are actually operated by brick-and-mortar community pharmacies that serve consumers online and those that walk in their door . 
internet pharmacies -lrb- also known as online pharmacies -rrb- are also recommended to some patients by their physicians if they are homebound . 
some customers consider this to be more convenient and private method rather than traveling to a community drugstore where another customer might overhear about the drugs that they take . 
the primary difference is the method by which the medications are requested and received . 
many customers order drugs from such pharmacies to avoid the `` inconvenience '' of visiting a doctor or to obtain medications which their doctors were unwilling to prescribe . 
however , this practice has been criticized as potentially dangerous , especially by those who feel that only doctors can reliably assess contraindications , risk/benefit ratios , and an individual 's overall suitability for use of a medication . 
there also have been reports of such pharmacies dispensing substandard products . 
while most internet pharmacies sell prescription drugs and require a valid prescription , some internet pharmacies sell prescription drugs without requiring a prescription . 
while most internet pharmacies sell prescription drugs and require a valid prescription , some internet pharmacies sell prescription drugs without requiring a prescription . 
of particular concern with internet pharmacies is the ease with which people , youth in particular , can obtain controlled substances -lrb- e.g. , vicodin , generically known as hydrocodone -rrb- via the internet without a prescription issued by a doctor/practitioner who has an established doctor-patient relationship . 
-lsb- citation needed -rsb- in the united states , in order for a prescription for a controlled substance to be valid , it must be issued for a legitimate medical purpose by a licensed practitioner acting in the course of legitimate doctor-patient relationship . 
of particular concern with internet pharmacies is the ease with which people , youth in particular , can obtain controlled substances -lrb- e.g. , vicodin , generically known as hydrocodone -rrb- via the internet without a prescription issued by a doctor/practitioner who has an established doctor-patient relationship . 
-lsb- citation needed -rsb- in the united states , in order for a prescription for a controlled substance to be valid , it must be issued for a legitimate medical purpose by a licensed practitioner acting in the course of legitimate doctor-patient relationship . 
the filling pharmacy has a corresponding responsibility to ensure that the prescription is valid . 
often , individual state laws outline what defines a valid patient-doctor relationship . 
of particular concern with internet pharmacies is the ease with which people , youth in particular , can obtain controlled substances -lrb- e.g. , vicodin , generically known as hydrocodone -rrb- via the internet without a prescription issued by a doctor/practitioner who has an established doctor-patient relationship . 
in the united states , there has been a push to legalize importation of medications from canada and other countries , in order to reduce consumer costs . 
in the united states , there has been a push to legalize importation of medications from canada and other countries , in order to reduce consumer costs . 
while in most cases importation of prescription medications violates food and drug administration -lrb- fda -rrb- regulations and federal laws , enforcement is generally targeted at international drug suppliers , rather than consumers . 
there is no known case of any u.s. citizens buying canadian drugs for personal use with a prescription , who has ever been charged by authorities . 
in the united states , there has been a push to legalize importation of medications from canada and other countries , in order to reduce consumer costs . 
pharmacy informatics is the combination of pharmacy practice science and applied information science . 
pharmacy informaticists work in many practice areas of pharmacy , however , they may also work in information technology departments or for healthcare information technology vendor companies . 
as a practice area and specialist domain , pharmacy informatics is growing quickly to meet the needs of major national and international patient information projects and health system interoperability goals . 
pharmacists in this area are trained to participate in medication management system development , deployment and optimization . 
as a practice area and specialist domain , pharmacy informatics is growing quickly to meet the needs of major national and international patient information projects and health system interoperability goals . 
in addition to supplying these drugs , specialty pharmacies also provide lab monitoring , adherence counseling , and assist patients with cost-containment strategies needed to obtain their expensive specialty drugs . 
it is currently the fastest growing sector of the pharmaceutical industry with 19 of 28 newly fda approved medications in 2013 being specialty drugs . 
specialty pharmacies supply high cost injectable , oral , infused , or inhaled medications that are used for chronic and complex disease states such as cancer , hepatitis , and rheumatoid arthritis . 
unlike a traditional community pharmacy where prescriptions for any common medication can be brought in and filled , specialty pharmacies carry novel medications that need to be properly stored , administered , carefully monitored , and clinically managed . 
in addition to supplying these drugs , specialty pharmacies also provide lab monitoring , adherence counseling , and assist patients with cost-containment strategies needed to obtain their expensive specialty drugs . 
in most jurisdictions -lrb- such as the united states -rrb- , pharmacists are regulated separately from physicians . 
these jurisdictions also usually specify that only pharmacists may supply scheduled pharmaceuticals to the public , and that pharmacists can not form business partnerships with physicians or give them `` kickback '' payments . 
however , the american medical association -lrb- ama -rrb- code of ethics provides that physicians may dispense drugs within their office practices as long as there is no patient exploitation and patients have the right to a written prescription that can be filled elsewhere . 
7 to 10 percent of american physicians practices reportedly dispense drugs on their own . 
these jurisdictions also usually specify that only pharmacists may supply scheduled pharmaceuticals to the public , and that pharmacists can not form business partnerships with physicians or give them `` kickback '' payments . 
this law also exists in austria for general physicians if the nearest pharmacy is more than 4 kilometers away , or where none is registered in the city . 
in some rural areas in the united kingdom , there are dispensing physicians who are allowed to both prescribe and dispense prescription-only medicines to their patients from within their practices . 
the law requires that the gp practice be located in a designated rural area and that there is also a specified , minimum distance -lrb- currently 1.6 kilometres -rrb- between a patient 's home and the nearest retail pharmacy . 
this law also exists in austria for general physicians if the nearest pharmacy is more than 4 kilometers away , or where none is registered in the city . 
the reason for the majority rule is the high risk of a conflict of interest and/or the avoidance of absolute powers . 
otherwise , the physician has a financial self-interest in `` diagnosing '' as many conditions as possible , and in exaggerating their seriousness , because he or she can then sell more medications to the patient . 
this system reflects much similarity to the checks and balances system of the u.s. and many other governments . 
otherwise , the physician has a financial self-interest in `` diagnosing '' as many conditions as possible , and in exaggerating their seriousness , because he or she can then sell more medications to the patient . 
such self-interest directly conflicts with the patient 's interest in obtaining cost-effective medication and avoiding the unnecessary use of medication that may have side-effects . 
in the coming decades , pharmacists are expected to become more integral within the health care system . 
rather than simply dispensing medication , pharmacists are increasingly expected to be compensated for their patient care skills . 
in particular , medication therapy management -lrb- mtm -rrb- includes the clinical services that pharmacists can provide for their patients . 
such services include the thorough analysis of all medication -lrb- prescription , non-prescription , and herbals -rrb- currently being taken by an individual . 
the result is a reconciliation of medication and patient education resulting in increased patient health outcomes and decreased costs to the health care system . 
in canada , pharmacists in certain provinces have limited prescribing rights -lrb- as in alberta and british columbia -rrb- or are remunerated by their provincial government for expanded services such as medications reviews -lrb- medschecks in ontario -rrb- . 
this shift has already commenced in some countries ; for instance , pharmacists in australia receive remuneration from the australian government for conducting comprehensive home medicines reviews . 
they are also being paid for by the government for medicine use reviews . 
in the united states , pharmaceutical care or clinical pharmacy has had an evolving influence on the practice of pharmacy . 
moreover , the doctor of pharmacy -lrb- pharm . 
the two symbols most commonly associated with pharmacy in english-speaking countries are the mortar and pestle and the ℞ -lrb- recipere -rrb- character , which is often written as `` rx '' in typed text . 
the show globe was also used until the early 20th century . 
pharmacy organizations often use other symbols , such as the bowl of hygieia which is often used in the netherlands , conical measures , and caduceuses in their logos . 
other symbols are common in different countries : the green greek cross in france , argentina , the united kingdom , belgium , ireland , italy , spain , and india , the increasingly rare gaper in the netherlands , and a red stylized letter a in germany and austria -lrb- from apotheke , the german word for pharmacy , from the same greek root as the english word ` apothecary ' -rrb- . 
other symbols are common in different countries : the green greek cross in france , argentina , the united kingdom , belgium , ireland , italy , spain , and india , the increasingly rare gaper in the netherlands , and a red stylized letter a in germany and austria -lrb- from apotheke , the german word for pharmacy , from the same greek root as the english word ` apothecary ' -rrb- . 
the immune system is a system of many biological structures and processes within an organism that protects against disease . 
to function properly , an immune system must detect a wide variety of agents , known as pathogens , from viruses to parasitic worms , and distinguish them from the organism 's own healthy tissue . 
in many species , the immune system can be classified into subsystems , such as the innate immune system versus the adaptive immune system , or humoral immunity versus cell-mediated immunity . 
in humans , the blood -- brain barrier , blood -- cerebrospinal fluid barrier , and similar fluid -- brain barriers separate the peripheral immune system from the neuroimmune system which protects the brain . 
the immune system is a system of many biological structures and processes within an organism that protects against disease . 
to function properly , an immune system must detect a wide variety of agents , known as pathogens , from viruses to parasitic worms , and distinguish them from the organism 's own healthy tissue . 
in many species , the immune system can be classified into subsystems , such as the innate immune system versus the adaptive immune system , or humoral immunity versus cell-mediated immunity . 
the immune system is a system of many biological structures and processes within an organism that protects against disease . 
to function properly , an immune system must detect a wide variety of agents , known as pathogens , from viruses to parasitic worms , and distinguish them from the organism 's own healthy tissue . 
in humans , the blood -- brain barrier , blood -- cerebrospinal fluid barrier , and similar fluid -- brain barriers separate the peripheral immune system from the neuroimmune system which protects the brain . 
in humans , the blood -- brain barrier , blood -- cerebrospinal fluid barrier , and similar fluid -- brain barriers separate the peripheral immune system from the neuroimmune system which protects the brain . 
to function properly , an immune system must detect a wide variety of agents , known as pathogens , from viruses to parasitic worms , and distinguish them from the organism 's own healthy tissue . 
in many species , the immune system can be classified into subsystems , such as the innate immune system versus the adaptive immune system , or humoral immunity versus cell-mediated immunity . 
in many species , the immune system can be classified into subsystems , such as the innate immune system versus the adaptive immune system , or humoral immunity versus cell-mediated immunity . 
in humans , the blood -- brain barrier , blood -- cerebrospinal fluid barrier , and similar fluid -- brain barriers separate the peripheral immune system from the neuroimmune system which protects the brain . 
pathogens can rapidly evolve and adapt , and thereby avoid detection and neutralization by the immune system ; however , multiple defense mechanisms have also evolved to recognize and neutralize pathogens . 
even simple unicellular organisms such as bacteria possess a rudimentary immune system , in the form of enzymes that protect against bacteriophage infections . 
other basic immune mechanisms evolved in ancient eukaryotes and remain in their modern descendants , such as plants and invertebrates . 
adaptive -lrb- or acquired -rrb- immunity creates immunological memory after an initial response to a specific pathogen , leading to an enhanced response to subsequent encounters with that same pathogen . 
even simple unicellular organisms such as bacteria possess a rudimentary immune system , in the form of enzymes that protect against bacteriophage infections . 
these mechanisms include phagocytosis , antimicrobial peptides called defensins , and the complement system . 
this process of acquired immunity is the basis of vaccination . 
adaptive -lrb- or acquired -rrb- immunity creates immunological memory after an initial response to a specific pathogen , leading to an enhanced response to subsequent encounters with that same pathogen . 
disorders of the immune system can result in autoimmune diseases , inflammatory diseases and cancer . 
immunodeficiency occurs when the immune system is less active than normal , resulting in recurring and life-threatening infections . 
immunodeficiency occurs when the immune system is less active than normal , resulting in recurring and life-threatening infections . 
in humans , immunodeficiency can either be the result of a genetic disease such as severe combined immunodeficiency , acquired conditions such as hiv/aids , or the use of immunosuppressive medication . 
common autoimmune diseases include hashimoto 's thyroiditis , rheumatoid arthritis , diabetes mellitus type 1 , and systemic lupus erythematosus . 
immunodeficiency occurs when the immune system is less active than normal , resulting in recurring and life-threatening infections . 
in contrast , autoimmunity results from a hyperactive immune system attacking normal tissues as if they were foreign organisms . 
immunology covers the study of all aspects of the immune system . 
in humans , immunodeficiency can either be the result of a genetic disease such as severe combined immunodeficiency , acquired conditions such as hiv/aids , or the use of immunosuppressive medication . 
the earliest known reference to immunity was during the plague of athens in 430 bc . 
in the 18th century , pierre-louis moreau de maupertuis made experiments with scorpion venom and observed that certain dogs and mice were immune to this venom . 
this and other observations of acquired immunity were later exploited by louis pasteur in his development of vaccination and his proposed germ theory of disease . 
viruses were confirmed as human pathogens in 1901 , with the discovery of the yellow fever virus by walter reed . 
it was not until robert koch 's 1891 proofs , for which he was awarded a nobel prize in 1905 , that microorganisms were confirmed as the cause of infectious disease . 
it was not until robert koch 's 1891 proofs , for which he was awarded a nobel prize in 1905 , that microorganisms were confirmed as the cause of infectious disease . 
viruses were confirmed as human pathogens in 1901 , with the discovery of the yellow fever virus by walter reed . 
the earliest known reference to immunity was during the plague of athens in 430 bc . 
this improved response is then retained after the pathogen has been eliminated , in the form of an immunological memory , and allows the adaptive immune system to mount faster and stronger attacks each time this pathogen is encountered . 
if a pathogen breaches these barriers , the innate immune system provides an immediate , but non-specific response . 
if pathogens successfully evade the innate response , vertebrates possess a second layer of protection , the adaptive immune system , which is activated by the innate response . 
innate immune systems are found in all plants and animals . 
if pathogens successfully evade the innate response , vertebrates possess a second layer of protection , the adaptive immune system , which is activated by the innate response . 
this improved response is then retained after the pathogen has been eliminated , in the form of an immunological memory , and allows the adaptive immune system to mount faster and stronger attacks each time this pathogen is encountered . 
in simple terms , physical barriers prevent pathogens such as bacteria and viruses from entering the organism . 
both innate and adaptive immunity depend on the ability of the immune system to distinguish between self and non-self molecules . 
in immunology , self molecules are those components of an organism 's body that can be distinguished from foreign substances by the immune system . 
conversely , non-self molecules are those recognized as foreign molecules . 
one class of non-self molecules are called antigens -lrb- short for antibody generators -rrb- and are defined as substances that bind to specific immune receptors and elicit an immune response . 
one class of non-self molecules are called antigens -lrb- short for antibody generators -rrb- and are defined as substances that bind to specific immune receptors and elicit an immune response . 
the innate response is usually triggered when microbes are identified by pattern recognition receptors , which recognize components that are conserved among broad groups of microorganisms , or when damaged , injured or stressed cells send out alarm signals , many of which -lrb- but not all -rrb- are recognized by the same receptors as those that recognize pathogens . 
the innate immune system is the dominant system of host defense in most organisms . 
the innate response is usually triggered when microbes are identified by pattern recognition receptors , which recognize components that are conserved among broad groups of microorganisms , or when damaged , injured or stressed cells send out alarm signals , many of which -lrb- but not all -rrb- are recognized by the same receptors as those that recognize pathogens . 
innate immune defenses are non-specific , meaning these systems respond to pathogens in a generic way . 
the waxy cuticle of many leaves , the exoskeleton of insects , the shells and membranes of externally deposited eggs , and skin are examples of mechanical barriers that are the first line of defense against infection . 
the waxy cuticle of many leaves , the exoskeleton of insects , the shells and membranes of externally deposited eggs , and skin are examples of mechanical barriers that are the first line of defense against infection . 
in the lungs , coughing and sneezing mechanically eject pathogens and other irritants from the respiratory tract . 
the flushing action of tears and urine also mechanically expels pathogens , while mucus secreted by the respiratory and gastrointestinal tract serves to trap and entangle microorganisms . 
the flushing action of tears and urine also mechanically expels pathogens , while mucus secreted by the respiratory and gastrointestinal tract serves to trap and entangle microorganisms . 
the skin and respiratory tract secrete antimicrobial peptides such as the β-defensins . 
enzymes such as lysozyme and phospholipase a2 in saliva , tears , and breast milk are also antibacterials . 
vaginal secretions serve as a chemical barrier following menarche , when they become slightly acidic , while semen contains defensins and zinc to kill pathogens . 
in the stomach , gastric acid and proteases serve as powerful chemical defenses against ingested pathogens . 
vaginal secretions serve as a chemical barrier following menarche , when they become slightly acidic , while semen contains defensins and zinc to kill pathogens . 
within the genitourinary and gastrointestinal tracts , commensal flora serve as biological barriers by competing with pathogenic bacteria for food and space and , in some cases , by changing the conditions in their environment , such as ph or available iron . 
however , since most antibiotics non-specifically target bacteria and do not affect fungi , oral antibiotics can lead to an `` overgrowth '' of fungi and cause conditions such as a vaginal candidiasis -lrb- a yeast infection -rrb- . 
there is good evidence that re-introduction of probiotic flora , such as pure cultures of the lactobacilli normally found in unpasteurized yogurt , helps restore a healthy balance of microbial populations in intestinal infections in children and encouraging preliminary data in studies on bacterial gastroenteritis , inflammatory bowel diseases , urinary tract infection and post-surgical infections . 
within the genitourinary and gastrointestinal tracts , commensal flora serve as biological barriers by competing with pathogenic bacteria for food and space and , in some cases , by changing the conditions in their environment , such as ph or available iron . 
inflammation is one of the first responses of the immune system to infection . 
the symptoms of inflammation are redness , swelling , heat , and pain , which are caused by increased blood flow into tissue . 
inflammation is produced by eicosanoids and cytokines , which are released by injured or infected cells . 
eicosanoids include prostaglandins that produce fever and the dilation of blood vessels associated with inflammation , and leukotrienes that attract certain white blood cells -lrb- leukocytes -rrb- . 
common cytokines include interleukins that are responsible for communication between white blood cells ; chemokines that promote chemotaxis ; and interferons that have anti-viral effects , such as shutting down protein synthesis in the host cell . 
phagocytosis is an important feature of cellular innate immunity performed by cells called ` phagocytes ' that engulf , or eat , pathogens or particles . 
phagocytes generally patrol the body searching for pathogens , but can be called to specific locations by cytokines . 
once a pathogen has been engulfed by a phagocyte , it becomes trapped in an intracellular vesicle called a phagosome , which subsequently fuses with another vesicle called a lysosome to form a phagolysosome . 
the pathogen is killed by the activity of digestive enzymes or following a respiratory burst that releases free radicals into the phagolysosome . 
phagocytosis evolved as a means of acquiring nutrients , but this role was extended in phagocytes to include engulfment of pathogens as a defense mechanism . 
neutrophils and macrophages are phagocytes that travel throughout the body in pursuit of invading pathogens . 
neutrophils are normally found in the bloodstream and are the most abundant type of phagocyte , normally representing 50 % to 60 % of the total circulating leukocytes . 
neutrophils are normally found in the bloodstream and are the most abundant type of phagocyte , normally representing 50 % to 60 % of the total circulating leukocytes . 
during the acute phase of inflammation , particularly as a result of bacterial infection , neutrophils migrate toward the site of inflammation in a process called chemotaxis , and are usually the first cells to arrive at the scene of infection . 
macrophages are versatile cells that reside within tissues and produce a wide array of chemicals including enzymes , complement proteins , and regulatory factors such as interleukin 1 . 
leukocytes -lrb- white blood cells -rrb- act like independent , single-celled organisms and are the second arm of the innate immune system . 
leukocytes -lrb- white blood cells -rrb- act like independent , single-celled organisms and are the second arm of the innate immune system . 
innate cells are also important mediators in the activation of the adaptive immune system . 
the innate leukocytes include the phagocytes -lrb- macrophages , neutrophils , and dendritic cells -rrb- , mast cells , eosinophils , basophils , and natural killer cells . 
dendritic cells -lrb- dc -rrb- are phagocytes in tissues that are in contact with the external environment ; therefore , they are located mainly in the skin , nose , lungs , stomach , and intestines . 
they are named for their resemblance to neuronal dendrites , as both have many spine-like projections , but dendritic cells are in no way connected to the nervous system . 
dendritic cells serve as a link between the bodily tissues and the innate and adaptive immune systems , as they present antigens to t cells , one of the key cell types of the adaptive immune system . 
dendritic cells serve as a link between the bodily tissues and the innate and adaptive immune systems , as they present antigens to t cells , one of the key cell types of the adaptive immune system . 
rather , nk cells destroy compromised host cells , such as tumor cells or virus-infected cells , recognizing such cells by a condition known as `` missing self . '' 
natural killer cells , or nk cells , are a component of the innate immune system which does not directly attack invading microbes . 
this term describes cells with low levels of a cell-surface marker called mhc i -lrb- major histocompatibility complex -rrb- -- a situation that can arise in viral infections of host cells . 
those mhc antigens are recognized by killer cell immunoglobulin receptors -lrb- kir -rrb- which essentially put the brakes on nk cells . 
the adaptive immune system evolved in early vertebrates and allows for a stronger immune response as well as immunological memory , where each pathogen is `` remembered '' by a signature antigen . 
the adaptive immune response is antigen-specific and requires the recognition of specific `` non-self '' antigens during a process called antigen presentation . 
antigen specificity allows for the generation of responses that are tailored to specific pathogens or pathogen-infected cells . 
there are two major subtypes of t cells : the killer t cell and the helper t cell . 
in addition there are regulatory t cells which have a role in modulating immune response . 
killer t cells only recognize antigens coupled to class i mhc molecules , while helper t cells and regulatory t cells only recognize antigens coupled to class ii mhc molecules . 
killer t cells only recognize antigens coupled to class i mhc molecules , while helper t cells and regulatory t cells only recognize antigens coupled to class ii mhc molecules . 
a third , minor subtype are the γδ t cells that recognize intact antigens that are not bound to mhc receptors . 
killer t cells are a sub-group of t cells that kill cells that are infected with viruses -lrb- and other pathogens -rrb- , or are otherwise damaged or dysfunctional . 
recognition of this mhc : antigen complex is aided by a co-receptor on the t cell , called cd8 . 
killer t cells are activated when their t cell receptor -lrb- tcr -rrb- binds to this specific antigen in a complex with the mhc class i receptor of another cell . 
the entry of another toxin called granulysin -lrb- a protease -rrb- induces the target cell to undergo apoptosis . 
when an activated t cell contacts such cells , it releases cytotoxins , such as perforin , which form pores in the target cell 's plasma membrane , allowing ions , water and toxins to enter . 
the mhc : antigen complex is also recognized by the helper cell 's cd4 co-receptor , which recruits molecules inside the t cell -lrb- e.g. , lck -rrb- that are responsible for the t cell 's activation . 
helper t cells have a weaker association with the mhc : antigen complex than observed for killer t cells , meaning many receptors -lrb- around 200 -- 300 -rrb- on the helper t cell must be bound by an mhc : antigen in order to activate the helper cell , while killer t cells can be activated by engagement of a single mhc : antigen molecule . 
helper t cells have a weaker association with the mhc : antigen complex than observed for killer t cells , meaning many receptors -lrb- around 200 -- 300 -rrb- on the helper t cell must be bound by an mhc : antigen in order to activate the helper cell , while killer t cells can be activated by engagement of a single mhc : antigen molecule . 
the activation of a resting helper t cell causes it to release cytokines that influence the activity of many cell types . 
in addition , helper t cell activation causes an upregulation of molecules expressed on the t cell 's surface , such as cd40 ligand -lrb- also called cd154 -rrb- , which provide extra stimulatory signals typically required to activate antibody-producing b cells . 
gamma delta t cells -lrb- γδ t cells -rrb- possess an alternative t cell receptor -lrb- tcr -rrb- as opposed to cd4 + and cd8 + -lrb- αβ -rrb- t cells and share the characteristics of helper t cells , cytotoxic t cells and nk cells . 
gamma delta t cells -lrb- γδ t cells -rrb- possess an alternative t cell receptor -lrb- tcr -rrb- as opposed to cd4 + and cd8 + -lrb- αβ -rrb- t cells and share the characteristics of helper t cells , cytotoxic t cells and nk cells . 
like other ` unconventional ' t cell subsets bearing invariant tcrs , such as cd1d-restricted natural killer t cells , γδ t cells straddle the border between innate and adaptive immunity . 
on one hand , γδ t cells are a component of adaptive immunity as they rearrange tcr genes to produce receptor diversity and can also develop a memory phenotype . 
for example , large numbers of human vγ9 / vδ2 t cells respond within hours to common molecules produced by microbes , and highly restricted vδ1 + t cells in epithelia respond to stressed epithelial cells . 
a b cell identifies pathogens when antibodies on its surface bind to a specific foreign antigen . 
this antigen/antibody complex is taken up by the b cell and processed by proteolysis into peptides . 
this combination of mhc and antigen attracts a matching helper t cell , which releases lymphokines and activates the b cell . 
when b cells and t cells are activated and begin to replicate , some of their offspring become long-lived memory cells . 
this is `` adaptive '' because it occurs during the lifetime of an individual as an adaptation to infection with that pathogen and prepares the immune system for future challenges . 
immunological memory can be in the form of either passive short-term memory or active long-term memory . 
throughout the lifetime of an animal , these memory cells remember each specific pathogen encountered and can mount a strong response if the pathogen is detected again . 
newborn infants have no prior exposure to microbes and are particularly vulnerable to infection . 
during pregnancy , a particular type of antibody , called igg , is transported from mother to baby directly across the placenta , so human babies have high levels of antibodies even at birth , with the same range of antigen specificities as their mother . 
breast milk or colostrum also contains antibodies that are transferred to the gut of the infant and protect against bacterial infections until the newborn can synthesize its own antibodies . 
this passive immunity is usually short-term , lasting from a few days up to several months . 
hormones can act as immunomodulators , altering the sensitivity of the immune system . 
for example , female sex hormones are known immunostimulators of both adaptive and innate immune responses . 
some autoimmune diseases such as lupus erythematosus strike women preferentially , and their onset often coincides with puberty . 
by contrast , male sex hormones such as testosterone seem to be immunosuppressive . 
additionally , proteins such as nfil3 , which have been shown to be closely intertwined with both t-cell differentiation and our circadian rhythms , can be affected through the disturbance of natural light and dark cycles through instances of sleep deprivation , shift work , etc. . 
as a result , these disruptions can lead to an increase in chronic conditions such as heart disease , chronic pain , and asthma . 
when suffering from sleep deprivation , active immunizations may have a diminished effect and may result in lower antibody production , and a lower immune response , than would be noted in a well-rested individual . 
it is conjectured that a progressive decline in hormone levels with age is partially responsible for weakened immune responses in aging individuals . 
second , as a person ages the skin becomes less adept at producing vitamin d. 
conversely , some hormones are regulated by the immune system , notably thyroid hormone activity . 
this means that they get less sun and therefore produce less cholecalciferol via uvb radiation . 
the main response of the immune system to tumors is to destroy the abnormal cells using killer t cells , sometimes with the assistance of helper t cells . 
nk cells also kill tumorous cells in a similar way , especially if the tumor cells have fewer mhc class i molecules on their surface than normal ; this is a common phenomenon with tumors . 
tumor antigens are presented on mhc class i molecules in a similar way to viral antigens . 
sometimes antibodies are generated against tumor cells allowing for their destruction by the complement system . 
unlike animals , plants lack phagocytic cells , but many plant immune responses involve systemic chemical signals that are sent through a plant . 
individual plant cells respond to molecules associated with pathogens known as pathogen-associated molecular patterns or pamps . 
when a part of a plant becomes infected , the plant produces a localized hypersensitive response , whereby cells at the site of infection undergo rapid apoptosis to prevent the spread of the disease to other parts of the plant . 
systemic acquired resistance -lrb- sar -rrb- is a type of defensive response used by plants that renders the entire plant resistant to a particular infectious agent . 
rna silencing mechanisms are particularly important in this systemic response as they can block virus replication . 
overactive immune responses comprise the other end of immune dysfunction , particularly the autoimmune disorders . 
here , the immune system fails to properly distinguish between self and non-self , and attacks part of the body . 
one of the functions of specialized cells -lrb- located in the thymus and bone marrow -rrb- is to present young lymphocytes with self antigens produced throughout the body and to eliminate those cells that recognize self-antigens , preventing autoimmunity . 
under normal circumstances , many t cells and antibodies react with `` self '' peptides . 
immunodeficiencies occur when one or more of the components of the immune system are inactive . 
the ability of the immune system to respond to pathogens is diminished in both the young and the elderly , with immune responses beginning to decline at around 50 years of age due to immunosenescence . 
the ability of the immune system to respond to pathogens is diminished in both the young and the elderly , with immune responses beginning to decline at around 50 years of age due to immunosenescence . 
in developed countries , obesity , alcoholism , and drug use are common causes of poor immune function . 
however , malnutrition is the most common cause of immunodeficiency in developing countries . 
active immunity can also be generated artificially , through vaccination . 
the principle behind vaccination -lrb- also called immunization -rrb- is to introduce an antigen from a pathogen in order to stimulate the immune system and develop specific immunity against that particular pathogen without causing disease associated with that organism . 
the principle behind vaccination -lrb- also called immunization -rrb- is to introduce an antigen from a pathogen in order to stimulate the immune system and develop specific immunity against that particular pathogen without causing disease associated with that organism . 
this deliberate induction of an immune response is successful because it exploits the natural specificity of the immune system , as well as its inducibility . 
bacteria often overcome physical barriers by secreting enzymes that digest the barrier , for example , by using a type ii secretion system . 
alternatively , using a type iii secretion system , they may insert a hollow tube into the host cell , providing a direct route for proteins to move from the pathogen to the host . 
these proteins are often used to shut down host defenses . 
the success of any pathogen depends on its ability to elude host immune responses . 
in the mid-1950s , frank burnet , inspired by a suggestion made by niels jerne , formulated the clonal selection theory -lrb- cst -rrb- of immunity . 
on the basis of cst , burnet developed a theory of how an immune response is triggered according to the self/nonself distinction : `` self '' constituents -lrb- constituents of the body -rrb- do not trigger destructive immune responses , while `` nonself '' entities -lrb- pathogens , an allograft -rrb- trigger a destructive immune response . 
the theory was later modified to reflect new discoveries regarding histocompatibility or the complex `` two-signal '' activation of t cells . 
in the mid-1950s , frank burnet , inspired by a suggestion made by niels jerne , formulated the clonal selection theory -lrb- cst -rrb- of immunity . 
glucocorticoids are the most powerful of these drugs ; however , these drugs can have many undesirable side effects , such as central obesity , hyperglycemia , osteoporosis , and their use must be tightly controlled . 
lower doses of anti-inflammatory drugs are often used in conjunction with cytotoxic or immunosuppressive drugs such as methotrexate or azathioprine . 
lower doses of anti-inflammatory drugs are often used in conjunction with cytotoxic or immunosuppressive drugs such as methotrexate or azathioprine . 
immunosuppressive drugs such as cyclosporin prevent t cells from responding to signals correctly by inhibiting signal transduction pathways . 
in contrast , during wake periods differentiated effector cells , such as cytotoxic natural killer cells and ctls -lrb- cytotoxic t lymphocytes -rrb- , peak in order to elicit an effective response against any intruding pathogens . 
as well during awake active times , anti-inflammatory molecules , such as cortisol and catecholamines , peak . 
second , inflammation may occur during sleep times due to the presence of melatonin . 
inflammation causes a great deal of oxidative stress and the presence of melatonin during sleep times could actively counteract free radical production during this time . 
when a t-cell encounters a foreign pathogen , it extends a vitamin d receptor . 
this is essentially a signaling device that allows the t-cell to bind to the active form of vitamin d , the steroid hormone calcitriol . 
t-cells have a symbiotic relationship with vitamin d. not only does the t-cell extend a vitamin d receptor , in essence asking to bind to the steroid hormone version of vitamin d , calcitriol , but the t-cell expresses the gene cyp27b1 , which is the gene responsible for converting the pre-hormone version of vitamin d , calcidiol into the steroid hormone version , calcitriol . 
t-cells have a symbiotic relationship with vitamin d. not only does the t-cell extend a vitamin d receptor , in essence asking to bind to the steroid hormone version of vitamin d , calcitriol , but the t-cell expresses the gene cyp27b1 , which is the gene responsible for converting the pre-hormone version of vitamin d , calcidiol into the steroid hormone version , calcitriol . 
other immune system cells that are known to express cyp27b1 and thus activate vitamin d calcidiol , are dendritic cells , keratinocytes and macrophages . 
pattern recognition receptors are proteins used by nearly all organisms to identify molecules associated with pathogens . 
antimicrobial peptides called defensins are an evolutionarily conserved component of the innate immune response found in all animals and plants , and represent the main form of invertebrate systemic immunity . 
the complement system and phagocytic cells are also used by most forms of invertebrate life . 
ribonucleases and the rna interference pathway are conserved across all eukaryotes , and are thought to play a role in the immune response to viruses . 
many of the classical molecules of the adaptive immune system -lrb- e.g. , immunoglobulins and t cell receptors -rrb- exist only in jawed vertebrates . 
however , a distinct lymphocyte-derived molecule has been discovered in primitive jawless vertebrates , such as the lamprey and hagfish . 
these animals possess a large array of molecules called variable lymphocyte receptors -lrb- vlrs -rrb- that , like the antigen receptors of jawed vertebrates , are produced from only a small number -lrb- one or two -rrb- of genes . 
evolution of the adaptive immune system occurred in an ancestor of the jawed vertebrates . 
it is likely that a multicomponent , adaptive immune system arose with the first vertebrates , as invertebrates do not generate lymphocytes or an antibody-based humoral response . 
immune systems appear even in the structurally most simple forms of life , with bacteria using a unique defense mechanism , called the restriction modification system to protect themselves from viral pathogens , called bacteriophages . 
immune systems appear even in the structurally most simple forms of life , with bacteria using a unique defense mechanism , called the restriction modification system to protect themselves from viral pathogens , called bacteriophages . 
prokaryotes also possess acquired immunity , through a system that uses crispr sequences to retain fragments of the genomes of phage that they have come into contact with in the past , which allows them to block virus replication through a form of rna interference . 
the end of the 19th century and the beginning of the 20th century saw a battle between `` cellular '' and `` humoral '' theories of immunity . 
according to the cellular theory of immunity , represented in particular by elie metchnikoff , it was cells -- more precisely , phagocytes -- that were responsible for immune responses . 
according to the cellular theory of immunity , represented in particular by elie metchnikoff , it was cells -- more precisely , phagocytes -- that were responsible for immune responses . 
in contrast , the humoral theory of immunity , held , among others , by robert koch and emil von behring , stated that the active immune agents were soluble components -lrb- molecules -rrb- found in the organism 's `` humors '' rather than its cells . 
in contrast , the humoral theory of immunity , held , among others , by robert koch and emil von behring , stated that the active immune agents were soluble components -lrb- molecules -rrb- found in the organism 's `` humors '' rather than its cells . 
clearly , some tumors evade the immune system and go on to become cancers . 
tumor cells often have a reduced number of mhc class i molecules on their surface , thus avoiding detection by killer t cells . 
some tumor cells also release products that inhibit the immune response ; for example by secreting the cytokine tgf-β , which suppresses the activity of macrophages and lymphocytes . 
some tumor cells also release products that inhibit the immune response ; for example by secreting the cytokine tgf-β , which suppresses the activity of macrophages and lymphocytes . 
hypersensitivity is an immune response that damages the body 's own tissues . 
they are divided into four classes -lrb- type i -- iv -rrb- based on the mechanisms involved and the time course of the hypersensitive reaction . 
type i hypersensitivity is an immediate or anaphylactic reaction , often associated with allergy . 
type i hypersensitivity is mediated by ige , which triggers degranulation of mast cells and basophils when cross-linked by antigen . 
type ii hypersensitivity occurs when antibodies bind to antigens on the patient 's own cells , marking them for destruction . 
an evasion strategy used by several pathogens to avoid the innate immune system is to hide within the cells of their host -lrb- also called intracellular pathogenesis -rrb- . 
some examples of intracellular pathogens include viruses , the food poisoning bacterium salmonella and the eukaryotic parasites that cause malaria -lrb- plasmodium falciparum -rrb- and leishmaniasis -lrb- leishmania spp . -rrb- 
some examples of intracellular pathogens include viruses , the food poisoning bacterium salmonella and the eukaryotic parasites that cause malaria -lrb- plasmodium falciparum -rrb- and leishmaniasis -lrb- leishmania spp . -rrb- 
other bacteria , such as mycobacterium tuberculosis , live inside a protective capsule that prevents lysis by complement . 
other bacteria generate surface proteins that bind to antibodies , rendering them ineffective ; examples include streptococcus -lrb- protein g -rrb- , staphylococcus aureus -lrb- protein a -rrb- , and peptostreptococcus magnus -lrb- protein l -rrb- . 
this is called antigenic variation . 
an example is hiv , which mutates rapidly , so the proteins on its viral envelope that are essential for entry into its host target cell are constantly changing . 
the parasite trypanosoma brucei uses a similar strategy , constantly switching one type of surface protein for another , allowing it to stay one step ahead of the antibody response . 
masking antigens with host molecules is another common strategy for avoiding detection by the immune system . 
this is called immune surveillance . 
the antigens expressed by tumors have several sources ; some are derived from oncogenic viruses like human papillomavirus , which causes cervical cancer , while others are the organism 's own proteins that occur at low levels in normal cells but reach high levels in tumor cells . 
one example is an enzyme called tyrosinase that , when expressed at high levels , transforms certain skin cells -lrb- e.g. melanocytes -rrb- into tumors called melanomas . 
one example is an enzyme called tyrosinase that , when expressed at high levels , transforms certain skin cells -lrb- e.g. melanocytes -rrb- into tumors called melanomas . 
one example is an enzyme called tyrosinase that , when expressed at high levels , transforms certain skin cells -lrb- e.g. melanocytes -rrb- into tumors called melanomas . 
larger drugs -lrb- > 500 da -rrb- can provoke a neutralizing immune response , particularly if the drugs are administered repeatedly , or in larger doses . 
early techniques relied mainly on the observation that hydrophilic amino acids are overrepresented in epitope regions than hydrophobic amino acids ; however , more recent developments rely on machine learning techniques using databases of existing known epitopes , usually on well-studied virus proteins , as a training set . 
immunoproteomics is the study of large sets of proteins -lrb- proteomics -rrb- involved in the immune response . 
a publicly accessible database has been established for the cataloguing of epitopes from pathogens known to be recognizable by b cells . 
the emerging field of bioinformatics-based studies of immunogenicity is referred to as immunoinformatics . 
first , during the early slow-wave-sleep stage , a sudden drop in blood levels of cortisol , epinephrine , and norepinephrine induce increased blood levels of the hormones leptin , pituitary growth hormone , and prolactin . 
in addition to these effects , the milieu of hormones produced at this time -lrb- leptin , pituitary growth hormone , and prolactin -rrb- support the interactions between apcs and t-cells , a shift of the th1/th2 cytokine balance towards one that supports th1 , an increase in overall th cell proliferation , and naïve t cell migration to lymph nodes . 
in addition to these effects , the milieu of hormones produced at this time -lrb- leptin , pituitary growth hormone , and prolactin -rrb- support the interactions between apcs and t-cells , a shift of the th1/th2 cytokine balance towards one that supports th1 , an increase in overall th cell proliferation , and naïve t cell migration to lymph nodes . 
this milieu is also thought to support the formation of long-lasting immune memory through the initiation of th1 immune responses . 
in humans , this response is activated by complement binding to antibodies that have attached to these microbes or the binding of complement proteins to carbohydrates on the surfaces of microbes . 
this deposition of complement can also kill cells directly by disrupting their plasma membrane . 
the speed of the response is a result of signal amplification that occurs following sequential proteolytic activation of complement molecules , which are also proteases . 
this produces a catalytic cascade that amplifies the initial signal by controlled positive feedback . 
civil disobedience is one of the many ways people have rebelled against what they deem to be unfair laws . 
it has been used in many nonviolent resistance movements in india -lrb- gandhi 's campaigns for independence from the british empire -rrb- , in czechoslovakia 's velvet revolution and in east germany to oust their communist governments , in south africa in the fight against apartheid , in the american civil rights movement , in the singing revolution to bring independence to the baltic countries from the soviet union , recently with the 2003 rose revolution in georgia and the 2004 orange revolution in ukraine , among other various movements worldwide . 
it has been used in many nonviolent resistance movements in india -lrb- gandhi 's campaigns for independence from the british empire -rrb- , in czechoslovakia 's velvet revolution and in east germany to oust their communist governments , in south africa in the fight against apartheid , in the american civil rights movement , in the singing revolution to bring independence to the baltic countries from the soviet union , recently with the 2003 rose revolution in georgia and the 2004 orange revolution in ukraine , among other various movements worldwide . 
it has been used in many nonviolent resistance movements in india -lrb- gandhi 's campaigns for independence from the british empire -rrb- , in czechoslovakia 's velvet revolution and in east germany to oust their communist governments , in south africa in the fight against apartheid , in the american civil rights movement , in the singing revolution to bring independence to the baltic countries from the soviet union , recently with the 2003 rose revolution in georgia and the 2004 orange revolution in ukraine , among other various movements worldwide . 
it has been used in many nonviolent resistance movements in india -lrb- gandhi 's campaigns for independence from the british empire -rrb- , in czechoslovakia 's velvet revolution and in east germany to oust their communist governments , in south africa in the fight against apartheid , in the american civil rights movement , in the singing revolution to bring independence to the baltic countries from the soviet union , recently with the 2003 rose revolution in georgia and the 2004 orange revolution in ukraine , among other various movements worldwide . 
one of its earliest massive implementations was brought about by egyptians against the british occupation in the 1919 revolution . 
one of its earliest massive implementations was brought about by egyptians against the british occupation in the 1919 revolution . 
it has been used in many nonviolent resistance movements in india -lrb- gandhi 's campaigns for independence from the british empire -rrb- , in czechoslovakia 's velvet revolution and in east germany to oust their communist governments , in south africa in the fight against apartheid , in the american civil rights movement , in the singing revolution to bring independence to the baltic countries from the soviet union , recently with the 2003 rose revolution in georgia and the 2004 orange revolution in ukraine , among other various movements worldwide . 
civil disobedience is one of the many ways people have rebelled against what they deem to be unfair laws . 
it has been used in many nonviolent resistance movements in india -lrb- gandhi 's campaigns for independence from the british empire -rrb- , in czechoslovakia 's velvet revolution and in east germany to oust their communist governments , in south africa in the fight against apartheid , in the american civil rights movement , in the singing revolution to bring independence to the baltic countries from the soviet union , recently with the 2003 rose revolution in georgia and the 2004 orange revolution in ukraine , among other various movements worldwide . 
one of the oldest depictions of civil disobedience is in sophocles ' play antigone , in which antigone , one of the daughters of former king of thebes , oedipus , defies creon , the current king of thebes , who is trying to stop her from giving her brother polynices a proper burial . 
one of the oldest depictions of civil disobedience is in sophocles ' play antigone , in which antigone , one of the daughters of former king of thebes , oedipus , defies creon , the current king of thebes , who is trying to stop her from giving her brother polynices a proper burial . 
one of the oldest depictions of civil disobedience is in sophocles ' play antigone , in which antigone , one of the daughters of former king of thebes , oedipus , defies creon , the current king of thebes , who is trying to stop her from giving her brother polynices a proper burial . 
one of the oldest depictions of civil disobedience is in sophocles ' play antigone , in which antigone , one of the daughters of former king of thebes , oedipus , defies creon , the current king of thebes , who is trying to stop her from giving her brother polynices a proper burial . 
one of the oldest depictions of civil disobedience is in sophocles ' play antigone , in which antigone , one of the daughters of former king of thebes , oedipus , defies creon , the current king of thebes , who is trying to stop her from giving her brother polynices a proper burial . 
one of the oldest depictions of civil disobedience is in sophocles ' play antigone , in which antigone , one of the daughters of former king of thebes , oedipus , defies creon , the current king of thebes , who is trying to stop her from giving her brother polynices a proper burial . 
one of the oldest depictions of civil disobedience is in sophocles ' play antigone , in which antigone , one of the daughters of former king of thebes , oedipus , defies creon , the current king of thebes , who is trying to stop her from giving her brother polynices a proper burial . 
one of the oldest depictions of civil disobedience is in sophocles ' play antigone , in which antigone , one of the daughters of former king of thebes , oedipus , defies creon , the current king of thebes , who is trying to stop her from giving her brother polynices a proper burial . 
one of the oldest depictions of civil disobedience is in sophocles ' play antigone , in which antigone , one of the daughters of former king of thebes , oedipus , defies creon , the current king of thebes , who is trying to stop her from giving her brother polynices a proper burial . 
she gives a stirring speech in which she tells him that she must obey her conscience rather than human law . 
following the peterloo massacre of 1819 , poet percy shelley wrote the political poem the mask of anarchy later that year , that begins with the images of what he thought to be the unjust forms of authority of his time -- and then imagines the stirrings of a new form of social action . 
it is perhaps the first modern -lsb- vague -rsb- statement of the principle of nonviolent protest . 
gandhi 's satyagraha was partially influenced and inspired by shelley 's nonviolence in protest and political action . 
in particular , it is known that gandhi would often quote shelley 's masque of anarchy to vast audiences during the campaign for a free india . 
a version was taken up by the author henry david thoreau in his essay civil disobedience , and later by gandhi in his doctrine of satyagraha . 
following the peterloo massacre of 1819 , poet percy shelley wrote the political poem the mask of anarchy later that year , that begins with the images of what he thought to be the unjust forms of authority of his time -- and then imagines the stirrings of a new form of social action . 
following the peterloo massacre of 1819 , poet percy shelley wrote the political poem the mask of anarchy later that year , that begins with the images of what he thought to be the unjust forms of authority of his time -- and then imagines the stirrings of a new form of social action . 
it is perhaps the first modern -lsb- vague -rsb- statement of the principle of nonviolent protest . 
a version was taken up by the author henry david thoreau in his essay civil disobedience , and later by gandhi in his doctrine of satyagraha . 
a version was taken up by the author henry david thoreau in his essay civil disobedience , and later by gandhi in his doctrine of satyagraha . 
indeed , for vice president agnew it has become a code-word describing the activities of muggers , arsonists , draft evaders , campaign hecklers , campus militants , anti-war demonstrators , juvenile delinquents and political assassins . '' 
marshall cohen notes , `` it has been used to describe everything from bringing a test-case in the federal courts to taking aim at a federal official . 
it has been argued that the term `` civil disobedience '' has always suffered from ambiguity and in modern times , become utterly debased . 
it has been argued that the term `` civil disobedience '' has always suffered from ambiguity and in modern times , become utterly debased . 
it has been argued that the term `` civil disobedience '' has always suffered from ambiguity and in modern times , become utterly debased . 
marshall cohen notes , `` it has been used to describe everything from bringing a test-case in the federal courts to taking aim at a federal official . 
indeed , for vice president agnew it has become a code-word describing the activities of muggers , arsonists , draft evaders , campaign hecklers , campus militants , anti-war demonstrators , juvenile delinquents and political assassins . '' 
indeed , for vice president agnew it has become a code-word describing the activities of muggers , arsonists , draft evaders , campaign hecklers , campus militants , anti-war demonstrators , juvenile delinquents and political assassins . '' 
it has been argued that the term `` civil disobedience '' has always suffered from ambiguity and in modern times , become utterly debased . 
legrande writes that `` the formulation of a single all-encompassing definition of the term is extremely difficult , if not impossible . 
legrande writes that `` the formulation of a single all-encompassing definition of the term is extremely difficult , if not impossible . 
he encourages a distinction between lawful protest demonstration , nonviolent civil disobedience , and violent civil disobedience . 
in reviewing the voluminous literature on the subject , the student of civil disobedience rapidly finds himself surrounded by a maze of semantical problems and grammatical niceties . 
like alice in wonderland , he often finds that specific terminology has no more -lrb- or no less -rrb- meaning than the individual orator intends it to have . '' 
legrande writes that `` the formulation of a single all-encompassing definition of the term is extremely difficult , if not impossible . 
in reviewing the voluminous literature on the subject , the student of civil disobedience rapidly finds himself surrounded by a maze of semantical problems and grammatical niceties . 
in reviewing the voluminous literature on the subject , the student of civil disobedience rapidly finds himself surrounded by a maze of semantical problems and grammatical niceties . 
he encourages a distinction between lawful protest demonstration , nonviolent civil disobedience , and violent civil disobedience . 
he encourages a distinction between lawful protest demonstration , nonviolent civil disobedience , and violent civil disobedience . 
civil disobedience is usually defined as pertaining to a citizen 's relation to the state and its laws , as distinguished from a constitutional impasse in which two public agencies , especially two equally sovereign branches of government , conflict . 
civil disobedience is usually defined as pertaining to a citizen 's relation to the state and its laws , as distinguished from a constitutional impasse in which two public agencies , especially two equally sovereign branches of government , conflict . 
civil disobedience is usually defined as pertaining to a citizen 's relation to the state and its laws , as distinguished from a constitutional impasse in which two public agencies , especially two equally sovereign branches of government , conflict . 
for instance , if the head of government of a country were to refuse to enforce a decision of that country 's highest court , it would not be civil disobedience , since the head of government would be acting in her or his capacity as public official rather than private citizen . 
civil disobedience is usually defined as pertaining to a citizen 's relation to the state and its laws , as distinguished from a constitutional impasse in which two public agencies , especially two equally sovereign branches of government , conflict . 
civil disobedience is usually defined as pertaining to a citizen 's relation to the state and its laws , as distinguished from a constitutional impasse in which two public agencies , especially two equally sovereign branches of government , conflict . 
for instance , if the head of government of a country were to refuse to enforce a decision of that country 's highest court , it would not be civil disobedience , since the head of government would be acting in her or his capacity as public official rather than private citizen . 
for instance , if the head of government of a country were to refuse to enforce a decision of that country 's highest court , it would not be civil disobedience , since the head of government would be acting in her or his capacity as public official rather than private citizen . 
for instance , if the head of government of a country were to refuse to enforce a decision of that country 's highest court , it would not be civil disobedience , since the head of government would be acting in her or his capacity as public official rather than private citizen . 
civil disobedience is usually defined as pertaining to a citizen 's relation to the state and its laws , as distinguished from a constitutional impasse in which two public agencies , especially two equally sovereign branches of government , conflict . 
however , this definition is disputed by thoreau 's political philosophy pitching the conscience vs. the collective . 
before thoreau 's imprisonment , when a confused taxman had wondered aloud about how to handle his refusal to pay , thoreau had advised , `` resign . '' 
the majority may be powerful but it is not necessarily right . 
before thoreau 's imprisonment , when a confused taxman had wondered aloud about how to handle his refusal to pay , thoreau had advised , `` resign . '' 
thoreau admits that government may express the will of the majority but it may also express nothing more than the will of elite politicians . 
the individual is the final judge of right and wrong . 
more than this , since only individuals act , only individuals can act unjustly . 
before thoreau 's imprisonment , when a confused taxman had wondered aloud about how to handle his refusal to pay , thoreau had advised , `` resign . '' 
before thoreau 's imprisonment , when a confused taxman had wondered aloud about how to handle his refusal to pay , thoreau had advised , `` resign . '' 
the majority may be powerful but it is not necessarily right . 
some theories of civil disobedience hold that civil disobedience is only justified against governmental entities . 
brownlee argues that disobedience in opposition to the decisions of non-governmental agencies such as trade unions , banks , and private universities can be justified if it reflects `` a larger challenge to the legal system that permits those decisions to be taken '' . 
brownlee argues that disobedience in opposition to the decisions of non-governmental agencies such as trade unions , banks , and private universities can be justified if it reflects `` a larger challenge to the legal system that permits those decisions to be taken '' . 
the same principle , she argues , applies to breaches of law in protest against international organizations and foreign governments . 
brownlee argues that disobedience in opposition to the decisions of non-governmental agencies such as trade unions , banks , and private universities can be justified if it reflects `` a larger challenge to the legal system that permits those decisions to be taken '' . 
brownlee argues that disobedience in opposition to the decisions of non-governmental agencies such as trade unions , banks , and private universities can be justified if it reflects `` a larger challenge to the legal system that permits those decisions to be taken '' . 
some theories of civil disobedience hold that civil disobedience is only justified against governmental entities . 
brownlee argues that disobedience in opposition to the decisions of non-governmental agencies such as trade unions , banks , and private universities can be justified if it reflects `` a larger challenge to the legal system that permits those decisions to be taken '' . 
it is usually recognized that lawbreaking , if it is not done publicly , at least must be publicly announced in order to constitute civil disobedience . 
but stephen eilmann argues that if it is necessary to disobey rules that conflict with morality , we might ask why disobedience should take the form of public civil disobedience rather than simply covert lawbreaking . 
the fully informed jury association 's publication `` a primer for prospective jurors '' notes , `` think of the dilemma faced by german citizens when hitler 's secret police demanded to know if they were hiding a jew in their house . '' 
-lrb- exodus 1 : 15-19 -rrb- 
by this definition , civil disobedience could be traced back to the book of exodus , where shiphrah and puah refused a direct order of pharaoh but misrepresented how they did it . 
it is usually recognized that lawbreaking , if it is not done publicly , at least must be publicly announced in order to constitute civil disobedience . 
but stephen eilmann argues that if it is necessary to disobey rules that conflict with morality , we might ask why disobedience should take the form of public civil disobedience rather than simply covert lawbreaking . 
if a lawyer wishes to help a client overcome legal obstacles to securing her or his natural rights , he might , for instance , find that assisting in fabricating evidence or committing perjury is more effective than open disobedience . 
the fully informed jury association 's publication `` a primer for prospective jurors '' notes , `` think of the dilemma faced by german citizens when hitler 's secret police demanded to know if they were hiding a jew in their house . '' 
by this definition , civil disobedience could be traced back to the book of exodus , where shiphrah and puah refused a direct order of pharaoh but misrepresented how they did it . 
black 's law dictionary includes non-violence in its definition of civil disobedience . 
black 's law dictionary includes non-violence in its definition of civil disobedience . 
it has been argued that , while both civil disobedience and civil rebellion are justified by appeal to constitutional defects , rebellion is much more destructive ; therefore , the defects justifying rebellion must be much more serious than those justifying disobedience , and if one can not justify civil rebellion , then one can not justify a civil disobedients ' use of force and violence and refusal to submit to arrest . 
civil disobedients ' refraining from violence is also said to help preserve society 's tolerance of civil disobedience . 
black 's law dictionary includes non-violence in its definition of civil disobedience . 
there have been debates as to whether civil disobedience must necessarily be non-violent . 
it has been argued that , while both civil disobedience and civil rebellion are justified by appeal to constitutional defects , rebellion is much more destructive ; therefore , the defects justifying rebellion must be much more serious than those justifying disobedience , and if one can not justify civil rebellion , then one can not justify a civil disobedients ' use of force and violence and refusal to submit to arrest . 
it has been argued that , while both civil disobedience and civil rebellion are justified by appeal to constitutional defects , rebellion is much more destructive ; therefore , the defects justifying rebellion must be much more serious than those justifying disobedience , and if one can not justify civil rebellion , then one can not justify a civil disobedients ' use of force and violence and refusal to submit to arrest . 
civil disobedients ' refraining from violence is also said to help preserve society 's tolerance of civil disobedience . 
revolutionary civil disobedience is more of an active attempt to overthrow a government -lrb- or to change cultural traditions , social customs , religious beliefs , etc. . 
it has been claimed that the hungarians under ferenc deák directed revolutionary civil disobedience against the austrian government . 
it has been claimed that the hungarians under ferenc deák directed revolutionary civil disobedience against the austrian government . 
gandhi 's acts have been described as revolutionary civil disobedience . 
revolutionary civil disobedience is more of an active attempt to overthrow a government -lrb- or to change cultural traditions , social customs , religious beliefs , etc. . 
non-revolutionary civil disobedience is a simple disobedience of laws on the grounds that they are judged `` wrong '' by an individual conscience , or as part of an effort to render certain laws ineffective , to cause their repeal , or to exert pressure to get one 's political wishes on some other issue . 
non-revolutionary civil disobedience is a simple disobedience of laws on the grounds that they are judged `` wrong '' by an individual conscience , or as part of an effort to render certain laws ineffective , to cause their repeal , or to exert pressure to get one 's political wishes on some other issue . 
non-revolutionary civil disobedience is a simple disobedience of laws on the grounds that they are judged `` wrong '' by an individual conscience , or as part of an effort to render certain laws ineffective , to cause their repeal , or to exert pressure to get one 's political wishes on some other issue . 
revolutionary civil disobedience is more of an active attempt to overthrow a government -lrb- or to change cultural traditions , social customs , religious beliefs , etc. . 
gandhi 's acts have been described as revolutionary civil disobedience . 
the earliest recorded incidents of collective civil disobedience took place during the roman empire -lsb- citation needed -rsb- . 
unarmed jews gathered in the streets to prevent the installation of pagan images in the temple in jerusalem . 
thoreau , at the time of his arrest , was not yet a well-known author , and his arrest was not covered in any newspapers in the days , weeks and months after it happened . 
the tax collector who arrested him rose to higher political office , and thoreau 's essay was not published until after the end of the mexican war . 
the tax collector who arrested him rose to higher political office , and thoreau 's essay was not published until after the end of the mexican war . 
the earliest recorded incidents of collective civil disobedience took place during the roman empire -lsb- citation needed -rsb- . 
unarmed jews gathered in the streets to prevent the installation of pagan images in the temple in jerusalem . 
in modern times , some activists who commit civil disobedience as a group collectively refuse to sign bail until certain demands are met , such as favorable bail conditions , or the release of all the activists . 
this is a form of jail solidarity . 
the tax collector who arrested him rose to higher political office , and thoreau 's essay was not published until after the end of the mexican war . 
civil disobedients have chosen a variety of different illegal acts . 
bedau also notes , though , that the very harmlessness of such entirely symbolic illegal protests toward public policy goals may serve a propaganda purpose . 
some civil disobedients , such as the proprietors of illegal medical cannabis dispensaries and voice in the wilderness , which brought medicine to iraq without the permission of the u.s. government , directly achieve a desired social goal -lrb- such as the provision of medication to the sick -rrb- while openly breaking the law . 
julia butterfly hill lived in luna , a 180-foot -lrb- 55 m -rrb- - tall , 600-year-old california redwood tree for 738 days , successfully preventing it from being cut down . 
julia butterfly hill lived in luna , a 180-foot -lrb- 55 m -rrb- - tall , 600-year-old california redwood tree for 738 days , successfully preventing it from being cut down . 
civil disobedients have chosen a variety of different illegal acts . 
bedau writes , `` there is a whole class of acts , undertaken in the name of civil disobedience , which , even if they were widely practiced , would in themselves constitute hardly more than a nuisance -lrb- e.g. trespassing at a nuclear-missile installation -rrb- ... such acts are often just a harassment and , at least to the bystander , somewhat inane ... the remoteness of the connection between the disobedient act and the objectionable law lays such acts open to the charge of ineffectiveness and absurdity . '' 
bedau also notes , though , that the very harmlessness of such entirely symbolic illegal protests toward public policy goals may serve a propaganda purpose . 
some civil disobedients , such as the proprietors of illegal medical cannabis dispensaries and voice in the wilderness , which brought medicine to iraq without the permission of the u.s. government , directly achieve a desired social goal -lrb- such as the provision of medication to the sick -rrb- while openly breaking the law . 
julia butterfly hill lived in luna , a 180-foot -lrb- 55 m -rrb- - tall , 600-year-old california redwood tree for 738 days , successfully preventing it from being cut down . 
for example , joseph haas was arrested for allegedly sending an email to the lebanon , new hampshire city councilors stating , `` wise up or die . '' 
for example , joseph haas was arrested for allegedly sending an email to the lebanon , new hampshire city councilors stating , `` wise up or die . '' 
in cases where the criminalized behavior is pure speech , civil disobedience can consist simply of engaging in the forbidden speech . 
an example would be wbai 's broadcasting the track `` filthy words '' from a george carlin comedy album , which eventually led to the 1978 supreme court case of fcc v. pacifica foundation . 
an example would be wbai 's broadcasting the track `` filthy words '' from a george carlin comedy album , which eventually led to the 1978 supreme court case of fcc v. pacifica foundation . 
in cases where the criminalized behavior is pure speech , civil disobedience can consist simply of engaging in the forbidden speech . 
an example would be wbai 's broadcasting the track `` filthy words '' from a george carlin comedy album , which eventually led to the 1978 supreme court case of fcc v. pacifica foundation . 
threatening government officials is another classic way of expressing defiance toward the government and unwillingness to stand for its policies . 
for example , joseph haas was arrested for allegedly sending an email to the lebanon , new hampshire city councilors stating , `` wise up or die . '' 
some forms of civil disobedience , such as illegal boycotts , refusals to pay taxes , draft dodging , distributed denial-of-service attacks , and sit-ins , make it more difficult for a system to function . 
the plowshares organization temporarily closed gcsb waihopai by padlocking the gates and using sickles to deflate one of the large domes covering two satellite dishes . 
the plowshares organization temporarily closed gcsb waihopai by padlocking the gates and using sickles to deflate one of the large domes covering two satellite dishes . 
brownlee notes that `` although civil disobedients are constrained in their use of coercion by their conscientious aim to engage in moral dialogue , nevertheless they may find it necessary to employ limited coercion in order to get their issue onto the table . '' 
in this way , they might be considered coercive . 
some forms of civil disobedience , such as illegal boycotts , refusals to pay taxes , draft dodging , distributed denial-of-service attacks , and sit-ins , make it more difficult for a system to function . 
brownlee notes that `` although civil disobedients are constrained in their use of coercion by their conscientious aim to engage in moral dialogue , nevertheless they may find it necessary to employ limited coercion in order to get their issue onto the table . '' 
brownlee notes that `` although civil disobedients are constrained in their use of coercion by their conscientious aim to engage in moral dialogue , nevertheless they may find it necessary to employ limited coercion in order to get their issue onto the table . '' 
the plowshares organization temporarily closed gcsb waihopai by padlocking the gates and using sickles to deflate one of the large domes covering two satellite dishes . 
many of the same decisions and principles that apply in other criminal investigations and arrests arise also in civil disobedience cases . 
for example , the suspect may need to decide whether or not to grant a consent search of his property , and whether or not to talk to police officers . 
it is generally agreed within the legal community , and is often believed within the activist community , that a suspect 's talking to criminal investigators can serve no useful purpose , and may be harmful . 
however , some civil disobedients have nonetheless found it hard to resist responding to investigators ' questions , sometimes due to a lack of understanding of the legal ramifications , or due to a fear of seeming rude . 
also , some civil disobedients seek to use the arrest as an opportunity to make an impression on the officers . 
some civil disobedients feel it is incumbent upon them to accept punishment because of their belief in the validity of the social contract , which is held to bind all to obey the laws that a government meeting certain standards of legitimacy has established , or else suffer the penalties set out in the law . 
some civil disobedients feel it is incumbent upon them to accept punishment because of their belief in the validity of the social contract , which is held to bind all to obey the laws that a government meeting certain standards of legitimacy has established , or else suffer the penalties set out in the law . 
other civil disobedients who favor the existence of government still do n't believe in the legitimacy of their particular government , or do n't believe in the legitimacy of a particular law it has enacted . 
and still other civil disobedients , being anarchists , do n't believe in the legitimacy of any government , and therefore see no need to accept punishment for a violation of criminal law that does not infringe the rights of others . 
and still other civil disobedients , being anarchists , do n't believe in the legitimacy of any government , and therefore see no need to accept punishment for a violation of criminal law that does not infringe the rights of others . 
an important decision for civil disobedients is whether or not to plead guilty . 
there is much debate on this point , as some believe that it is a civil disobedient 's duty to submit to the punishment prescribed by law , while others believe that defending oneself in court will increase the possibility of changing the unjust law . 
i feel i did the right thing by violating this particular law ; i am guilty as charged , '' but that pleading not guilty sends a message of , `` guilt implies wrong-doing . 
i feel i did the right thing by violating this particular law ; i am guilty as charged , '' but that pleading not guilty sends a message of , `` guilt implies wrong-doing . 
one defendant accused of illegally protesting nuclear power , when asked to enter his plea , stated , `` i plead for the beauty that surrounds us '' ; this is known as a `` creative plea , '' and will usually be interpreted as a plea of not guilty . 
when the committee for non-violent action sponsored a protest in august 1957 , at the camp mercury nuclear test site near las vegas , nevada , 13 of the protesters attempted to enter the test site knowing that they faced arrest . 
when the committee for non-violent action sponsored a protest in august 1957 , at the camp mercury nuclear test site near las vegas , nevada , 13 of the protesters attempted to enter the test site knowing that they faced arrest . 
at a pre-arranged announced time , one at a time they stepped across the `` line '' and were immediately arrested . 
a well known civil rights attorney , francis heisler , had volunteered to defend the arrested persons , advising them to plead `` nolo contendere '' , as an alternative to pleading either guilty or not-guilty . 
the arrested persons were found `` guilty , '' nevertheless , and given suspended sentences , conditional on their not reentering the test site grounds . 
howard zinn writes , `` there may be many times when protesters choose to go to jail , as a way of continuing their protest , as a way of reminding their countrymen of injustice . 
howard zinn writes , `` there may be many times when protesters choose to go to jail , as a way of continuing their protest , as a way of reminding their countrymen of injustice . 
the key point is that the spirit of protest should be maintained all the way , whether it is done by remaining in jail , or by evading it . 
to accept jail penitently as an accession to ` the rules ' is to switch suddenly to a spirit of subservience , to demean the seriousness of the protest ... in particular , the neo-conservative insistence on a guilty plea should be eliminated . '' 
sometimes the prosecution proposes a plea bargain to civil disobedients , as in the case of the camden 28 , in which the defendants were offered an opportunity to plead guilty to one misdemeanor count and receive no jail time . 
sometimes the prosecution proposes a plea bargain to civil disobedients , as in the case of the camden 28 , in which the defendants were offered an opportunity to plead guilty to one misdemeanor count and receive no jail time . 
in some mass arrest situations , the activists decide to use solidarity tactics to secure the same plea bargain for everyone . 
but some activists have opted to enter a blind plea , pleading guilty without any plea agreement in place . 
mohandas gandhi pleaded guilty and told the court , `` i am here to ... submit cheerfully to the highest penalty that can be inflicted upon me for what in law is a deliberate crime and what appears to me to be the highest duty of a citizen . '' 
some civil disobedience defendants choose to make a defiant speech , or a speech explaining their actions , in allocution . 
some civil disobedience defendants choose to make a defiant speech , or a speech explaining their actions , in allocution . 
this action was upheld because , according to the u.s. court of appeals for the first circuit , her statement suggested a lack of remorse , an attempt to avoid responsibility for her actions , and even a likelihood of repeating her illegal actions . 
this action was upheld because , according to the u.s. court of appeals for the first circuit , her statement suggested a lack of remorse , an attempt to avoid responsibility for her actions , and even a likelihood of repeating her illegal actions . 
some of the other allocution speeches given by the protesters complained about mistreatment from government officials . 
steven barkan writes that if defendants plead not guilty , `` they must decide whether their primary goal will be to win an acquittal and avoid imprisonment or a fine , or to use the proceedings as a forum to inform the jury and the public of the political circumstances surrounding the case and their reasons for breaking the law via civil disobedience . '' 
steven barkan writes that if defendants plead not guilty , `` they must decide whether their primary goal will be to win an acquittal and avoid imprisonment or a fine , or to use the proceedings as a forum to inform the jury and the public of the political circumstances surrounding the case and their reasons for breaking the law via civil disobedience . '' 
steven barkan writes that if defendants plead not guilty , `` they must decide whether their primary goal will be to win an acquittal and avoid imprisonment or a fine , or to use the proceedings as a forum to inform the jury and the public of the political circumstances surrounding the case and their reasons for breaking the law via civil disobedience . '' 
during the vietnam war era , the chicago eight used a political defense , while benjamin spock used a technical defense . 
over the years , this has been made more difficult by court decisions such as sparf v. united states , which held that the judge need not inform jurors of their nullification prerogative , and united states v. dougherty , which held that the judge need not allow defendants to openly seek jury nullification . 
one theory is that , while disobedience may be helpful , any great amount of it would undermine the law by encouraging general disobedience which is neither conscientious nor of social benefit . 
one theory is that , while disobedience may be helpful , any great amount of it would undermine the law by encouraging general disobedience which is neither conscientious nor of social benefit . 
it has also been argued that breaking the law for self-gratification , as in the case of a homosexual or cannabis user who does not direct his act at securing the repeal of amendment of the law , is not civil disobedience . 
likewise , a protestor who attempts to escape punishment by committing the crime covertly and avoiding attribution , or by denying having committed the crime , or by fleeing the jurisdiction , is generally viewed as not being a civil disobedient . 
likewise , a protestor who attempts to escape punishment by committing the crime covertly and avoiding attribution , or by denying having committed the crime , or by fleeing the jurisdiction , is generally viewed as not being a civil disobedient . 
courts have distinguished between two types of civil disobedience : `` indirect civil disobedience involves violating a law which is not , itself , the object of protest , whereas direct civil disobedience involves protesting the existence of a particular law by breaking that law . '' 
courts have distinguished between two types of civil disobedience : `` indirect civil disobedience involves violating a law which is not , itself , the object of protest , whereas direct civil disobedience involves protesting the existence of a particular law by breaking that law . '' 
during the vietnam war , courts typically refused to excuse the perpetrators of illegal protests from punishment on the basis of their challenging the legality of the vietnam war ; the courts ruled it was a political question . 
likewise , when carter wentworth was charged for his role in the clamshell alliance 's 1977 illegal occupation of the seabrook station nuclear power plant , the judge instructed the jury to disregard his competing harms defense , and he was found guilty . 
fully informed jury association activists have sometimes handed out educational leaflets inside courthouses despite admonitions not to ; according to fija , many of them have escaped prosecution because `` prosecutors have reasoned -lrb- correctly -rrb- that if they arrest fully informed jury leafleters , the leaflets will have to be given to the leafleter 's own jury as evidence . '' 
along with giving the offender his `` just deserts '' , achieving crime control via incapacitation and deterrence is a major goal of criminal punishment . 
leonard hubert hoffmann writes , `` in deciding whether or not to impose punishment , the most important consideration would be whether it would do more harm than good . 
it is a matter for the state -lrb- including the judges -rrb- to decide on utilitarian grounds whether to do so or not . '' 
brownlee argues , `` bringing in deterrence at the level of justification detracts from the law 's engagement in a moral dialogue with the offender as a rational person because it focuses attention on the threat of punishment and not the moral reasons to follow this law . '' 
construction is the process of constructing a building or infrastructure . 
construction differs from manufacturing in that manufacturing typically involves mass production of similar items without a designated purchaser , while construction typically takes place on location for a known client . 
construction as an industry comprises six to nine percent of the gross domestic product of developed countries . 
construction starts with planning , -lsb- citation needed -rsb- design , and financing and continues until the project is built and ready for use . 
construction differs from manufacturing in that manufacturing typically involves mass production of similar items without a designated purchaser , while construction typically takes place on location for a known client . 
an architect normally manages the job , and a construction manager , design engineer , construction engineer or project manager supervises it . 
an architect normally manages the job , and a construction manager , design engineer , construction engineer or project manager supervises it . 
for the successful execution of a project , effective planning is essential . 
the largest construction projects are referred to as megaprojects . 
those involved with the design and execution of the infrastructure in question must consider zoning requirements , the environmental impact of the job , the successful scheduling , budgeting , construction-site safety , availability and transportation of building materials , logistics , inconvenience to the public caused by construction delays and bidding , etc. . 
in general , there are three sectors of construction : buildings , infrastructure and industrial . 
building construction is usually further divided into residential and non-residential -lrb- commercial/institutional -rrb- . 
infrastructure is often called heavy/highway , heavy civil or heavy engineering . 
infrastructure is often called heavy/highway , heavy civil or heavy engineering . 
industrial includes refineries , process chemical , power generation , mills and manufacturing plants . 
engineering news-record -lrb- enr -rrb- is a trade magazine for the construction industry . 
each year , enr compiles and reports on data about the size of design and construction companies . 
in 2014 , enr compiled the data in nine market segments . 
in their reporting on the top 400 , they used data on transportation , sewer , hazardous waste and water to rank firms as heavy contractors . 
to recognize the differences of companies in this sector , it is divided into three subsectors : building construction , heavy and civil engineering construction , and specialty trade contractors . 
there are also categories for construction service firms -lrb- e.g. , engineering , architecture -rrb- and construction managers -lrb- firms engaged in managing construction projects without assuming direct financial responsibility for completion of the construction project -rrb- . 
the standard industrial classification and the newer north american industry classification system have a classification system for companies that perform or otherwise engage in construction . 
there are also categories for construction service firms -lrb- e.g. , engineering , architecture -rrb- and construction managers -lrb- firms engaged in managing construction projects without assuming direct financial responsibility for completion of the construction project -rrb- . 
building construction is the process of adding structure to real property or construction of buildings . 
the majority of building construction jobs are small renovations , such as addition of a room , or renovation of a bathroom . 
often , the owner of the property acts as laborer , paymaster , and design team for the entire project . 
although building construction projects typically include various common elements , such as design , financial , estimating and legal considerations , many projects of varying sizes reach undesirable end results , such as structural collapse , cost overruns , and/or litigation . 
for this reason , those with experience in the field make detailed plans and maintain careful oversight during the project to ensure a positive outcome . 
residential construction practices , technologies , and resources must conform to local building authority regulations and codes of practice . 
materials readily available in the area generally dictate the construction materials used -lrb- e.g. brick versus stone , versus timber -rrb- . 
as residential construction -lrb- as well as all other types of construction -rrb- can generate a lot of waste , careful planning again is needed here . 
cost of construction on a per square meter -lrb- or per square foot -rrb- basis for houses can vary dramatically based on site conditions , local regulations , economies of scale -lrb- custom designed homes are often more expensive to build -rrb- and the availability of skilled tradespeople . 
new techniques of building construction are being researched , made possible by advances in 3d printing technology . 
in a form of additive building construction , similar to the additive manufacturing techniques for manufactured parts , building printing is making it possible to flexibly construct small commercial buildings and private habitations in around 20 hours , with built-in plumbing and electrical facilities , in one continuous build , using large 3d printers . 
working versions of 3d-printing building technology are already printing 2 metres -lrb- 6 ft 7 in -rrb- of building material per hour as of january 2013 -lsb- update -rsb- , with the next-generation printers capable of 3.5 metres -lrb- 11 ft -rrb- per hour , sufficient to complete a building in a week . 
working versions of 3d-printing building technology are already printing 2 metres -lrb- 6 ft 7 in -rrb- of building material per hour as of january 2013 -lsb- update -rsb- , with the next-generation printers capable of 3.5 metres -lrb- 11 ft -rrb- per hour , sufficient to complete a building in a week . 
a formal design team may be assembled to plan the physical proceedings , and to integrate those proceedings with the other parts . 
in the modern industrialized world , construction usually involves the translation of designs into reality . 
the design team is most commonly employed by -lrb- i.e. in contract with -rrb- the property owner . 
under this system , once the design is completed by the design team , a number of construction companies or construction management companies may then be asked to make a bid for the work , either based directly on the design , or on the basis of drawings and a bill of quantities provided by a quantity surveyor . 
following evaluation of bids , the owner typically awards a contract to the most cost efficient bidder . 
the modern trend in design is toward integration of previously separated specialties , especially among large firms . 
in the past , architects , interior designers , engineers , developers , construction managers , and general contractors were more likely to be entirely separate companies , even in the larger firms . 
thus , each such firm may offer itself as `` one-stop shopping '' for a construction project , from beginning to end . 
this is designated as a `` design build '' contract where the contractor is given a performance specification and must undertake the project from design to construction , while adhering to the performance specifications . 
several project structures can assist the owner in this integration , including design-build , partnering and construction management . 
in general , each of these project structures allows the owner to integrate the services of architects , interior designers , engineers and constructors throughout design and construction . 
in response , many companies are growing beyond traditional offerings of design or construction services alone and are placing more emphasis on establishing relationships with other necessary participants through the design-build process . 
construction projects can suffer from preventable financial problems . 
underbids happen when builders ask for too little money to complete the project . 
cash flow problems exist when the present amount of funding can not cover the current costs for labour and materials , and because they are a matter of having sufficient funds at a specific time , can arise even when the overall total is enough . 
fraud is a problem in many fields , but is notoriously prevalent in the construction field . 
mortgage bankers , accountants , and cost engineers are likely participants in creating an overall plan for the financial management of the building construction project . 
the presence of the mortgage banker is highly likely , even in relatively small projects since the owner 's equity in the property is the most obvious source of funding for a building project . 
accountants act to study the expected monetary flow over the life of the project and to monitor the payouts throughout the process . 
cost overruns with government projects have occurred when the contractor identified change orders or project changes that increased costs , which are not subject to competition from other firms as they have already been eliminated from consideration after the initial bid . 
cost engineers and estimators apply expertise to relate the work and materials involved to a proper valuation . 
the project must adhere to zoning and building code requirements . 
constructing a project that fails to adhere to codes does not benefit the owner . 
some legal requirements come from malum in se considerations , or the desire to prevent things that are indisputably bad -- bridge collapses or explosions . 
other legal requirements come from malum prohibitum considerations , or things that are a matter of custom or expectation , such as isolating businesses to a business district and residences to a residential district . 
an attorney may seek changes or exemptions in the law that governs the land where the building will be built , either by arguing that a rule is inapplicable -lrb- the bridge design will not cause a collapse -rrb- , or that the custom is no longer needed -lrb- acceptance of live-work spaces has grown in the community -rrb- . 
a construction project is a complex net of contracts and other legal obligations , each of which all parties must carefully consider . 
a contract is the exchange of a set of obligations between two or more parties , but it is not so simple a matter as trying to get the other side to agree to as much as possible in exchange for as little as possible . 
the time element in construction means that a delay costs money , and in cases of bottlenecks , the delay can be extremely expensive . 
thus , the contracts must be designed to ensure that each side is capable of performing the obligations set out . 
contracts that set out clear expectations and clear paths to accomplishing those expectations are far more likely to result in the project flowing smoothly , whereas poorly drafted contracts lead to confusion and collapse . 
there is also a growing number of new forms of procurement that involve relationship contracting where the emphasis is on a co-operative relationship between the principal and contractor and other stakeholders within a construction project . 
new forms include partnering such as public-private partnering -lrb- ppps -rrb- aka private finance initiatives -lrb- pfis -rrb- and alliances such as `` pure '' or `` project '' alliances and `` impure '' or `` strategic '' alliances . 
new forms include partnering such as public-private partnering -lrb- ppps -rrb- aka private finance initiatives -lrb- pfis -rrb- and alliances such as `` pure '' or `` project '' alliances and `` impure '' or `` strategic '' alliances . 
the focus on co-operation is to ameliorate the many problems that arise from the often highly competitive and adversarial practices within the construction industry . 
in this arrangement , the architect or engineer acts as the project coordinator . 
in this arrangement , the architect or engineer acts as the project coordinator . 
there are direct contractual links between the architect 's client and the main contractor . 
there are direct contractual links between the architect 's client and the main contractor . 
the procedure continues until the building is ready to occupy . 
the owner produces a list of requirements for a project , giving an overall view of the project 's goals . 
several d&b contractors present different ideas about how to accomplish these goals . 
the owner selects the ideas he or she likes best and hires the appropriate contractor . 
often , it is not just one contractor , but a consortium of several contractors working together . 
as they build phase 1 , they design phase 2 . 
before the foundation can be dug , contractors are typically required to verify and have existing utility lines marked , either by the utilities themselves or through a company specializing in such services . 
this lessens the likelihood of damage to the existing electrical , water , sewage , phone , and cable facilities , which could cause outages and potentially hazardous situations . 
this lessens the likelihood of damage to the existing electrical , water , sewage , phone , and cable facilities , which could cause outages and potentially hazardous situations . 
during the construction of a building , the municipal building inspector inspects the building periodically to ensure that the construction adheres to the approved plans and the local building code . 
once construction is complete and a final inspection has been passed , an occupancy permit may be issued . 
in the united states , the industry in 2014 has around $ 960 billion in annual revenue according to statistics tracked by the census bureau , of which $ 680 billion is private -lrb- split evenly between residential and nonresidential -rrb- and the remainder is government . 
in the united states , the industry in 2014 has around $ 960 billion in annual revenue according to statistics tracked by the census bureau , of which $ 680 billion is private -lrb- split evenly between residential and nonresidential -rrb- and the remainder is government . 
as of 2005 , there were about 667,000 firms employing 1 million contractors -lrb- 200,000 general contractors , 38,000 heavy , and 432,000 specialty -rrb- ; the average contractor employed fewer than 10 employees . 
as of 2005 , there were about 667,000 firms employing 1 million contractors -lrb- 200,000 general contractors , 38,000 heavy , and 432,000 specialty -rrb- ; the average contractor employed fewer than 10 employees . 
in the united states , approximately 828,000 women were employed in the construction industry as of 2011 . 
the average earning for a professional in the construction industry in the middle east , across all sectors , job types and levels of experience , is # 42,090 , compared to # 26,719 in the uk . 
the average earning for a professional in the construction industry in the middle east , across all sectors , job types and levels of experience , is # 42,090 , compared to # 26,719 in the uk . 
some construction workers in the us/canada have made more than $ 100,000 annually , depending on their trade . 
construction is one of the most dangerous occupations in the world , incurring more occupational fatalities than any other sector in both the united states and in the european union . 
falls are one of the most common causes of fatal and non-fatal injuries among construction workers . 
other major causes of fatalities in the construction industry include electrocution , transportation accidents , and trench cave-ins . 
proper safety equipment such as harnesses and guardrails and procedures such as securing ladders and inspecting scaffolding can curtail the risk of occupational injuries in the construction industry . 
private schools , also known as independent schools , non-governmental , or nonstate schools , are not administered by local , state or national governments ; thus , they retain the right to select their students and are funded in whole or in part by charging their students tuition , rather than relying on mandatory taxation through public -lrb- government -rrb- funding ; at some private schools students may be able to get a scholarship , which makes the cost cheaper , depending on a talent the student may have -lrb- e.g. sport scholarship , art scholarship , academic scholarship -rrb- , financial need , or tax credit scholarships that might be available . 
private schools , also known as independent schools , non-governmental , or nonstate schools , are not administered by local , state or national governments ; thus , they retain the right to select their students and are funded in whole or in part by charging their students tuition , rather than relying on mandatory taxation through public -lrb- government -rrb- funding ; at some private schools students may be able to get a scholarship , which makes the cost cheaper , depending on a talent the student may have -lrb- e.g. sport scholarship , art scholarship , academic scholarship -rrb- , financial need , or tax credit scholarships that might be available . 
private schools , also known as independent schools , non-governmental , or nonstate schools , are not administered by local , state or national governments ; thus , they retain the right to select their students and are funded in whole or in part by charging their students tuition , rather than relying on mandatory taxation through public -lrb- government -rrb- funding ; at some private schools students may be able to get a scholarship , which makes the cost cheaper , depending on a talent the student may have -lrb- e.g. sport scholarship , art scholarship , academic scholarship -rrb- , financial need , or tax credit scholarships that might be available . 
private schools , also known as independent schools , non-governmental , or nonstate schools , are not administered by local , state or national governments ; thus , they retain the right to select their students and are funded in whole or in part by charging their students tuition , rather than relying on mandatory taxation through public -lrb- government -rrb- funding ; at some private schools students may be able to get a scholarship , which makes the cost cheaper , depending on a talent the student may have -lrb- e.g. sport scholarship , art scholarship , academic scholarship -rrb- , financial need , or tax credit scholarships that might be available . 
annual tuition fees at k-12 schools range from nothing at so called ` tuition-free ' schools to more than $ 45,000 at several new england preparatory schools . 
annual tuition fees at k-12 schools range from nothing at so called ` tuition-free ' schools to more than $ 45,000 at several new england preparatory schools . 
in the united kingdom and several other commonwealth countries including australia and canada , the use of the term is generally restricted to primary and secondary educational levels ; it is almost never used of universities and other tertiary institutions . 
private education in north america covers the whole gamut of educational activity , ranging from pre-school to tertiary level institutions . 
the secondary level includes schools offering years 7 through 12 -lrb- year twelve is known as lower sixth -rrb- and year 13 -lrb- upper sixth -rrb- . 
the secondary level includes schools offering years 7 through 12 -lrb- year twelve is known as lower sixth -rrb- and year 13 -lrb- upper sixth -rrb- . 
this category includes university-preparatory schools or `` prep schools '' , boarding schools and day schools . 
tuition at private secondary schools varies from school to school and depends on many factors , including the location of the school , the willingness of parents to pay , peer tuitions and the school 's financial endowment . 
high tuition , schools claim , is used to pay higher salaries for the best teachers and also used to provide enriched learning environments , including a low student to teacher ratio , small class sizes and services , such as libraries , science laboratories and computers . 
they include parochial schools , a term which is often used to denote roman catholic schools . 
other religious groups represented in the k-12 private education sector include protestants , jews , muslims and the orthodox christians . 
some such schools teach religious education , together with the usual academic subjects to impress their particular faith 's beliefs and traditions in the students who attend . 
some schools offer the removal of the purported distractions of co-education ; the presence of boarding facilities ; or stricter discipline based on their power of expulsion , a tool not readily available to government schools . 
student uniforms for australian private schools are generally stricter and more formal than in government schools - for example , a compulsory blazer . 
private schools in australia are always more expensive than their public counterparts . 
although most are non-aligned , some of the best known independent schools also belong to the large , long-established religious foundations , such as the anglican church , uniting church and presbyterian church , but in most cases , they do not insist on their students ' religious allegiance . 
they are usually expensive schools that tend to be up-market and traditional in style , some catholic schools fall into this category as well , e.g. st joseph 's college , gregory terrace , saint ignatius ' college , riverview , st gregory 's college , campbelltown , st aloysius ' college -lrb- sydney -rrb- and st joseph 's college , hunters hill , as well as loreto kirribilli , monte sant angelo mercy college , st ursula 's college and loreto normanhurst for girls . 
they are usually expensive schools that tend to be up-market and traditional in style , some catholic schools fall into this category as well , e.g. st joseph 's college , gregory terrace , saint ignatius ' college , riverview , st gregory 's college , campbelltown , st aloysius ' college -lrb- sydney -rrb- and st joseph 's college , hunters hill , as well as loreto kirribilli , monte sant angelo mercy college , st ursula 's college and loreto normanhurst for girls . 
they are usually expensive schools that tend to be up-market and traditional in style , some catholic schools fall into this category as well , e.g. st joseph 's college , gregory terrace , saint ignatius ' college , riverview , st gregory 's college , campbelltown , st aloysius ' college -lrb- sydney -rrb- and st joseph 's college , hunters hill , as well as loreto kirribilli , monte sant angelo mercy college , st ursula 's college and loreto normanhurst for girls . 
the right to create private schools in germany is in article 7 , paragraph 4 of the grundgesetz and can not be suspended even in a state of emergency . 
this unusual protection of private schools was implemented to protect these schools from a second gleichschaltung or similar event in the future . 
overall , between 1992 and 2008 the percent of pupils in such schools in germany increased from 6.1 % to 7.8 % -lrb- including rise from 0.5 % to 6.1 % in the former gdr -rrb- . 
percent of students in private high schools reached 11.1 % . 
overall , between 1992 and 2008 the percent of pupils in such schools in germany increased from 6.1 % to 7.8 % -lrb- including rise from 0.5 % to 6.1 % in the former gdr -rrb- . 
teachers at ersatzschulen must have at least the same education and at least the same wages as teachers at public schools , an ersatzschule must have at least the same academic standards as a public school and article 7 , paragraph 4 of the grundgesetz , also forbids segregation of pupils according to the means of their parents -lrb- the so-called sonderungsverbot -rrb- . 
ersatzschulen are ordinary primary or secondary schools , which are run by private individuals , private organizations or religious groups . 
therefore , most ersatzschulen have very low tuition fees and/or offer scholarships , compared to most other western european countries . 
ergänzungsschulen are secondary or post-secondary -lrb- non-tertiary -rrb- schools , which are run by private individuals , private organizations or rarely , religious groups and offer a type of education which is not available at public schools . 
most of these schools are vocational schools . 
ergänzungsschulen have the freedom to operate outside of government regulation and are funded in whole by charging their students tuition fees . 
ergänzungsschulen are secondary or post-secondary -lrb- non-tertiary -rrb- schools , which are run by private individuals , private organizations or rarely , religious groups and offer a type of education which is not available at public schools . 
in india , private schools are called independent schools , but since some private schools receive financial aid from the government , it can be an aided or an unaided school . 
prominent examination boards that are present in multiple states are the cbse and the cisce , nenbse 
among other things , this has also resulted in 30 different examination boards or academic authorities that conduct examinations for school leaving certificates . 
the practice has been for the union government to provide the broad policy directions while the states create their own rules and regulations for the administration of the sector . 
legally , only non-profit trusts and societies can run schools in india . 
legally , only non-profit trusts and societies can run schools in india . 
the annual status of education report -lrb- aser -rrb- , which evaluates learning levels in rural india , has been reporting poorer academic achievement in government schools than in private schools . 
the annual status of education report -lrb- aser -rrb- , which evaluates learning levels in rural india , has been reporting poorer academic achievement in government schools than in private schools . 
a key difference between the government and private schools is that the medium of education in private schools is english while it is the local language in government schools . 
in ireland , private schools -lrb- irish : scoil phríobháideach -rrb- are unusual because a certain number of teacher 's salaries are paid by the state . 
in ireland , private schools -lrb- irish : scoil phríobháideach -rrb- are unusual because a certain number of teacher 's salaries are paid by the state . 
the average fee is around $ 5,000 annually for most schools , but some of these schools also provide boarding and the fees may then rise up to $ 25,000 per year . 
the fee-paying schools are usually run by a religious order , i.e. , the society of jesus or congregation of christian brothers , etc. . 
the average fee is around $ 5,000 annually for most schools , but some of these schools also provide boarding and the fees may then rise up to $ 25,000 per year . 
after malaysia 's independence in 1957 , the government instructed all schools to surrender their properties and be assimilated into the national school system . 
while chinese primary schools were allowed to retain chinese as the medium of instruction , chinese secondary schools are required to change into english-medium schools . 
while chinese primary schools were allowed to retain chinese as the medium of instruction , chinese secondary schools are required to change into english-medium schools . 
after malaysia 's independence in 1957 , the government instructed all schools to surrender their properties and be assimilated into the national school system . 
over 60 schools converted to become national type schools . 
the ones that accept government funds are called ` aided ' schools . 
the private ` un-aided ' schools are fully funded by private parties . 
technically , these would be categorized as private schools , but many of them have the name `` public school '' appended to them , e.g. , the galaxy public school in kathmandu . 
the medium of education is english , but as a compulsory subject , nepali and/or the state 's official language is also taught . 
the medium of education is english , but as a compulsory subject , nepali and/or the state 's official language is also taught . 
as of april 2014 , there are 88 private schools in new zealand , catering for around 28,000 students or 3.7 % of the entire student population . 
as of april 2014 , there are 88 private schools in new zealand , catering for around 28,000 students or 3.7 % of the entire student population . 
as of april 2014 , there are 88 private schools in new zealand , catering for around 28,000 students or 3.7 % of the entire student population . 
the largest decline in private school numbers occurred between 1979 and 1984 , when the nation 's then-private catholic school system integrated . 
as a result , private schools in new zealand are now largely restricted to the largest cities -lrb- auckland , hamilton , wellington and christchurch -rrb- and niche markets . 
private schools are often anglican , such as king 's college and diocesan school for girls in auckland , st paul 's collegiate school in hamilton , st peter 's school in cambridge , samuel marsden collegiate school in wellington , and christ 's college and st margaret 's college in christchurch ; or presbyterian , such as saint kentigern college and st cuthbert 's college in auckland , scots college and queen margaret college in wellington , and st andrew 's college and rangi ruru girls ' school in christchurch . 
private schools are often anglican , such as king 's college and diocesan school for girls in auckland , st paul 's collegiate school in hamilton , st peter 's school in cambridge , samuel marsden collegiate school in wellington , and christ 's college and st margaret 's college in christchurch ; or presbyterian , such as saint kentigern college and st cuthbert 's college in auckland , scots college and queen margaret college in wellington , and st andrew 's college and rangi ruru girls ' school in christchurch . 
private schools are often anglican , such as king 's college and diocesan school for girls in auckland , st paul 's collegiate school in hamilton , st peter 's school in cambridge , samuel marsden collegiate school in wellington , and christ 's college and st margaret 's college in christchurch ; or presbyterian , such as saint kentigern college and st cuthbert 's college in auckland , scots college and queen margaret college in wellington , and st andrew 's college and rangi ruru girls ' school in christchurch . 
private schools are often anglican , such as king 's college and diocesan school for girls in auckland , st paul 's collegiate school in hamilton , st peter 's school in cambridge , samuel marsden collegiate school in wellington , and christ 's college and st margaret 's college in christchurch ; or presbyterian , such as saint kentigern college and st cuthbert 's college in auckland , scots college and queen margaret college in wellington , and st andrew 's college and rangi ruru girls ' school in christchurch . 
there are three private schools -lrb- including the secondary school , st dominic 's college -rrb- operated by the catholic schismatic group , the society of st pius x in wanganui . 
in the philippines , the private sector has been a major provider of educational services , accounting for about 7.5 % of primary enrollment , 32 % of secondary enrollment and about 80 % of tertiary enrollment . 
in the philippines , the private sector has been a major provider of educational services , accounting for about 7.5 % of primary enrollment , 32 % of secondary enrollment and about 80 % of tertiary enrollment . 
in the philippines , the private sector has been a major provider of educational services , accounting for about 7.5 % of primary enrollment , 32 % of secondary enrollment and about 80 % of tertiary enrollment . 
government regulations have given private education more flexibility and autonomy in recent years , notably by lifting the moratorium on applications for new courses , new schools and conversions , by liberalizing tuition fee policy for private schools , by replacing values education for third and fourth years with english , mathematics and natural science at the option of the school , and by issuing the revised manual of regulations for private schools in august 1992 . 
government regulations have given private education more flexibility and autonomy in recent years , notably by lifting the moratorium on applications for new courses , new schools and conversions , by liberalizing tuition fee policy for private schools , by replacing values education for third and fourth years with english , mathematics and natural science at the option of the school , and by issuing the revised manual of regulations for private schools in august 1992 . 
the education service contracting scheme of the government provides financial assistance for tuition and other school fees of students turned away from public high schools because of enrollment overflows . 
the tuition fee supplement is geared to students enrolled in priority courses in post-secondary and non-degree programmes , including vocational and technical courses . 
the private education student financial assistance is made available to underprivileged , but deserving high school graduates , who wish to pursue college/technical education in private colleges and universities . 
the south african schools act of 1996 recognises two categories of schools : `` public '' -lrb- state-controlled -rrb- and `` independent '' -lrb- which includes traditional private schools and schools which are privately governed -lsb- clarification needed -rsb- . -rrb- 
the south african schools act of 1996 recognises two categories of schools : `` public '' -lrb- state-controlled -rrb- and `` independent '' -lrb- which includes traditional private schools and schools which are privately governed -lsb- clarification needed -rsb- . -rrb- 
the south african schools act of 1996 recognises two categories of schools : `` public '' -lrb- state-controlled -rrb- and `` independent '' -lrb- which includes traditional private schools and schools which are privately governed -lsb- clarification needed -rsb- . -rrb- 
the south african schools act of 1996 recognises two categories of schools : `` public '' -lrb- state-controlled -rrb- and `` independent '' -lrb- which includes traditional private schools and schools which are privately governed -lsb- clarification needed -rsb- . -rrb- 
some of the oldest schools in south africa are private church schools that were established by missionaries in the early nineteenth century . 
following the transition to democracy , the legal form of `` model c '' was abolished , however , the term continues to be used to describe government schools formerly reserved for white children . 
these schools tend to produce better academic results than government schools formerly reserved for other race groups . 
all schools in south africa -lrb- including both independent schools and public schools -rrb- have the right to set compulsory school fees , and formerly model c schools tend to set much higher school fees than other public schools . 
over 10 % of swedish pupils were enrolled in private schools in 2008 . 
for instance , the biggest school chain , kunskapsskolan -lrb- `` the knowledge school '' -rrb- , offers 30 schools and a web-based environment , has 700 employees and teaches nearly 10,000 pupils . 
for instance , the biggest school chain , kunskapsskolan -lrb- `` the knowledge school '' -rrb- , offers 30 schools and a web-based environment , has 700 employees and teaches nearly 10,000 pupils . 
for instance , the biggest school chain , kunskapsskolan -lrb- `` the knowledge school '' -rrb- , offers 30 schools and a web-based environment , has 700 employees and teaches nearly 10,000 pupils . 
sweden is internationally known for this innovative school voucher model that provides swedish pupils with the opportunity to choose the school they prefer . 
preparatory schools in the uk prepare pupils aged up to 13 years old to enter public schools . 
preparatory schools in the uk prepare pupils aged up to 13 years old to enter public schools . 
according to the good schools guide approximately 9 per cent of children being educated in the uk are doing so at fee-paying schools at gsce level and 13 per cent at a-level . 
according to the good schools guide approximately 9 per cent of children being educated in the uk are doing so at fee-paying schools at gsce level and 13 per cent at a-level . 
fees range from under # 3,000 to # 21,000 and above per year for day pupils , rising to # 27,000 + per year for boarders . 
in many parts of the united states , after the 1954 decision in the landmark court case brown v. board of education of topeka that demanded united states schools desegregate `` with all deliberate speed '' , local families organized a wave of private `` christian academies '' . 
since the 1970s , many of these `` segregation academies '' have shut down , although some continue to operate . 
in much of the u.s. south , many white students migrated to the academies , while public schools became in turn more heavily concentrated with african-american students -lrb- see list of private schools in mississippi -rrb- . 
in much of the u.s. south , many white students migrated to the academies , while public schools became in turn more heavily concentrated with african-american students -lrb- see list of private schools in mississippi -rrb- . 
in much of the u.s. south , many white students migrated to the academies , while public schools became in turn more heavily concentrated with african-american students -lrb- see list of private schools in mississippi -rrb- . 
funding for private schools is generally provided through student tuition , endowments , scholarship/voucher funds , and donations and grants from religious organizations or private individuals . 
government funding for religious schools is either subject to restrictions or possibly forbidden , according to the courts ' interpretation of the establishment clause of the first amendment or individual state blaine amendments . 
government funding for religious schools is either subject to restrictions or possibly forbidden , according to the courts ' interpretation of the establishment clause of the first amendment or individual state blaine amendments . 
non-religious private schools theoretically could qualify for such funding without hassle , preferring the advantages of independent control of their student admissions and course content instead of the public funding they could get with charter status . 
private schooling in the united states has been debated by educators , lawmakers and parents , since the beginnings of compulsory education in massachusetts in 1852 . 
private schooling in the united states has been debated by educators , lawmakers and parents , since the beginnings of compulsory education in massachusetts in 1852 . 
some of the most relevant supreme court case law on this is as follows : runyon v. mccrary , 427 u.s. 160 -lrb- 1976 -rrb- ; wisconsin v. yoder , 406 u.s. 205 -lrb- 1972 -rrb- ; pierce v. society of sisters , 268 u.s. 510 -lrb- 1925 -rrb- ; meyer v. nebraska , 262 u.s. 390 -lrb- 1923 -rrb- . 
some of the most relevant supreme court case law on this is as follows : runyon v. mccrary , 427 u.s. 160 -lrb- 1976 -rrb- ; wisconsin v. yoder , 406 u.s. 205 -lrb- 1972 -rrb- ; pierce v. society of sisters , 268 u.s. 510 -lrb- 1925 -rrb- ; meyer v. nebraska , 262 u.s. 390 -lrb- 1923 -rrb- . 
some of the most relevant supreme court case law on this is as follows : runyon v. mccrary , 427 u.s. 160 -lrb- 1976 -rrb- ; wisconsin v. yoder , 406 u.s. 205 -lrb- 1972 -rrb- ; pierce v. society of sisters , 268 u.s. 510 -lrb- 1925 -rrb- ; meyer v. nebraska , 262 u.s. 390 -lrb- 1923 -rrb- . 
as of 2012 , quality private schools in the united states charged substantial tuition , close to $ 40,000 annually for day schools in new york city , and nearly $ 50,000 for boarding schools . 
as of 2012 , quality private schools in the united states charged substantial tuition , close to $ 40,000 annually for day schools in new york city , and nearly $ 50,000 for boarding schools . 
the leading schools such as the groton school had substantial endowments running to hundreds of millions of dollars supplemented by fundraising drives . 
the leading schools such as the groton school had substantial endowments running to hundreds of millions of dollars supplemented by fundraising drives . 
established originally by the massachusetts legislature and soon thereafter named for john harvard -lrb- its first benefactor -rrb- , harvard is the united states ' oldest institution of higher learning , and the harvard corporation -lrb- formally , the president and fellows of harvard college -rrb- is its first chartered corporation . 
the undergraduate college became coeducational after its 1977 merger with radcliffe college . 
james bryant conant led the university through the great depression and world war ii and began to reform the curriculum and liberalize admissions after the war . 
following the american civil war , president charles w. eliot 's long tenure -lrb- 1869 -- 1909 -rrb- transformed the college and affiliated professional schools into a modern research university ; harvard was a founding member of the association of american universities in 1900 . 
following the american civil war , president charles w. eliot 's long tenure -lrb- 1869 -- 1909 -rrb- transformed the college and affiliated professional schools into a modern research university ; harvard was a founding member of the association of american universities in 1900 . 
it operates several arts , cultural , and scientific museums , alongside the harvard library , which is the world 's largest academic and private library system , comprising 79 individual libraries with over 18 million volumes . 
it operates several arts , cultural , and scientific museums , alongside the harvard library , which is the world 's largest academic and private library system , comprising 79 individual libraries with over 18 million volumes . 
it operates several arts , cultural , and scientific museums , alongside the harvard library , which is the world 's largest academic and private library system , comprising 79 individual libraries with over 18 million volumes . 
harvard 's alumni include eight u.s. presidents , several foreign heads of state , 62 living billionaires , 335 rhodes scholars , and 242 marshall scholars . 
to date , some 150 nobel laureates , 18 fields medalists and 13 turing award winners have been affiliated as students , faculty , or staff . 
the university is organized into eleven separate academic units -- ten faculties and the radcliffe institute for advanced study -- with campuses throughout the boston metropolitan area : its 209-acre -lrb- 85 ha -rrb- main campus is centered on harvard yard in cambridge , approximately 3 miles -lrb- 5 km -rrb- northwest of boston ; the business school and athletics facilities , including harvard stadium , are located across the charles river in the allston neighborhood of boston and the medical , dental , and public health schools are in the longwood medical area . 
harvard 's $ 37.6 billion financial endowment is the largest of any academic institution . 
the university is organized into eleven separate academic units -- ten faculties and the radcliffe institute for advanced study -- with campuses throughout the boston metropolitan area : its 209-acre -lrb- 85 ha -rrb- main campus is centered on harvard yard in cambridge , approximately 3 miles -lrb- 5 km -rrb- northwest of boston ; the business school and athletics facilities , including harvard stadium , are located across the charles river in the allston neighborhood of boston and the medical , dental , and public health schools are in the longwood medical area . 
the university is organized into eleven separate academic units -- ten faculties and the radcliffe institute for advanced study -- with campuses throughout the boston metropolitan area : its 209-acre -lrb- 85 ha -rrb- main campus is centered on harvard yard in cambridge , approximately 3 miles -lrb- 5 km -rrb- northwest of boston ; the business school and athletics facilities , including harvard stadium , are located across the charles river in the allston neighborhood of boston and the medical , dental , and public health schools are in the longwood medical area . 
the university is organized into eleven separate academic units -- ten faculties and the radcliffe institute for advanced study -- with campuses throughout the boston metropolitan area : its 209-acre -lrb- 85 ha -rrb- main campus is centered on harvard yard in cambridge , approximately 3 miles -lrb- 5 km -rrb- northwest of boston ; the business school and athletics facilities , including harvard stadium , are located across the charles river in the allston neighborhood of boston and the medical , dental , and public health schools are in the longwood medical area . 
harvard was formed in 1636 by vote of the great and general court of the massachusetts bay colony . 
harvard was formed in 1636 by vote of the great and general court of the massachusetts bay colony . 
in 1638 , the college became home for north america 's first known printing press , carried by the ship john of london . 
in 1639 , the college was renamed harvard college after deceased clergyman john harvard , who was an alumnus of the university of cambridge . 
the charter creating the harvard corporation was granted in 1650 . 
in the early years the college trained many puritan ministers . 
it offered a classic curriculum on the english university model -- many leaders in the colony had attended the university of cambridge -- but conformed puritanism . 
it was never affiliated with any particular denomination , but many of its earliest graduates went on to become clergymen in congregational and unitarian churches . 
throughout the 18th century , enlightenment ideas of the power of reason and free will became widespread among congregationalist ministers , putting those ministers and their congregations in tension with more traditionalist , calvinist parties. :1 -- 4 when the hollis professor of divinity david tappan died in 1803 and the president of harvard joseph willard died a year later , in 1804 , a struggle broke out over their replacements . 
henry ware was elected to the chair in 1805 , and the liberal samuel webber was appointed to the presidency of harvard two years later , which signaled the changing of the tide from the dominance of traditional ideas at harvard to the dominance of liberal , arminian ideas -lrb- defined by traditionalists as unitarian ideas -rrb- . 
henry ware was elected to the chair in 1805 , and the liberal samuel webber was appointed to the presidency of harvard two years later , which signaled the changing of the tide from the dominance of traditional ideas at harvard to the dominance of liberal , arminian ideas -lrb- defined by traditionalists as unitarian ideas -rrb- . 
in 1846 , the natural history lectures of louis agassiz were acclaimed both in new york and on the campus at harvard college . 
agassiz 's perspective on science combined observation with intuition and the assumption that a person can grasp the `` divine plan '' in all phenomena . 
this dual view of knowledge was in concert with the teachings of common sense realism derived from scottish philosophers thomas reid and dugald stewart , whose works were part of the harvard curriculum at the time . 
charles w. eliot , president 1869 -- 1909 , eliminated the favored position of christianity from the curriculum while opening it to student self-direction . 
while eliot was the most crucial figure in the secularization of american higher education , he was motivated not by a desire to secularize education , but by transcendentalist unitarian convictions . 
derived from william ellery channing and ralph waldo emerson , these convictions were focused on the dignity and worth of human nature , the right and ability of each person to perceive truth , and the indwelling god in each person . 
james bryant conant -lrb- president , 1933 -- 1953 -rrb- reinvigorated creative scholarship to guarantee its preeminence among research institutions . 
he saw higher education as a vehicle of opportunity for the talented rather than an entitlement for the wealthy , so conant devised programs to identify , recruit , and support talented youth . 
the resulting report , published in 1945 , was one of the most influential manifestos in the history of american education in the 20th century . 
nonetheless , harvard 's undergraduate population remained predominantly male , with about four men attending harvard college for every woman studying at radcliffe . 
following the merger of harvard and radcliffe admissions in 1977 , the proportion of female undergraduates steadily increased , mirroring a trend throughout higher education in the united states . 
following the merger of harvard and radcliffe admissions in 1977 , the proportion of female undergraduates steadily increased , mirroring a trend throughout higher education in the united states . 
harvard 's 209-acre -lrb- 85 ha -rrb- main campus is centered on harvard yard in cambridge , about 3 miles -lrb- 5 km -rrb- west-northwest of the state house in downtown boston , and extends into the surrounding harvard square neighborhood . 
sophomore , junior , and senior undergraduates live in twelve residential houses , nine of which are south of harvard yard along or near the charles river . 
sophomore , junior , and senior undergraduates live in twelve residential houses , nine of which are south of harvard yard along or near the charles river . 
the other three are located in a residential neighborhood half a mile northwest of the yard at the quadrangle -lrb- commonly referred to as the quad -rrb- , which formerly housed radcliffe college students until radcliffe merged its residential system with harvard . 
the harvard business school and many of the university 's athletics facilities , including harvard stadium , are located on a 358-acre -lrb- 145 ha -rrb- campus opposite the cambridge campus in allston . 
the john w. weeks bridge is a pedestrian bridge over the charles river connecting both campuses . 
the harvard medical school , harvard school of dental medicine , and the harvard school of public health are located on a 21-acre -lrb- 8.5 ha -rrb- campus in the longwood medical and academic area approximately 3.3 miles -lrb- 5.3 km -rrb- southwest of downtown boston and 3.3 miles -lrb- 5.3 km -rrb- south of the cambridge campus . 
the university now owns approximately fifty percent more land in allston than in cambridge . 
proposals to connect the cambridge campus with the new allston campus include new and enlarged bridges , a shuttle service and/or a tram . 
the institution asserts that such expansion will benefit not only the school , but surrounding community , pointing to such features as the enhanced transit infrastructure , possible shuttles open to the public , and park space which will also be publicly accessible . 
harvard 's 2,400 professors , lecturers , and instructors instruct 7,200 undergraduates and 14,000 graduate students . 
harvard 's 2,400 professors , lecturers , and instructors instruct 7,200 undergraduates and 14,000 graduate students . 
harvard 's 2,400 professors , lecturers , and instructors instruct 7,200 undergraduates and 14,000 graduate students . 
the color was unofficially adopted -lrb- in preference to magenta -rrb- by an 1875 vote of the student body , although the association with some form of red can be traced back to 1858 , when charles william eliot , a young graduate student who would later become harvard 's 21st and longest-serving president -lrb- 1869 -- 1909 -rrb- , bought red bandanas for his crew so they could more easily be distinguished by spectators at a regatta . 
the color was unofficially adopted -lrb- in preference to magenta -rrb- by an 1875 vote of the student body , although the association with some form of red can be traced back to 1858 , when charles william eliot , a young graduate student who would later become harvard 's 21st and longest-serving president -lrb- 1869 -- 1909 -rrb- , bought red bandanas for his crew so they could more easily be distinguished by spectators at a regatta . 
it was worth $ 32 billion in 2011 , up from $ 28 billion in september 2010 and $ 26 billion in 2009 . 
it suffered about 30 % loss in 2008-09 . 
one of the most visible results of harvard 's attempt to re-balance its budget was their halting of construction of the $ 1.2 billion allston science complex that had been scheduled to be completed by 2011 , resulting in protests from local residents . 
as of 2012 -lsb- update -rsb- , harvard university had a total financial aid reserve of $ 159 million for students , and a pell grant reserve of $ 4.093 million available for disbursement . 
as of 2012 -lsb- update -rsb- , harvard university had a total financial aid reserve of $ 159 million for students , and a pell grant reserve of $ 4.093 million available for disbursement . 
during the divestment from south africa movement in the late 1980s , student activists erected a symbolic `` shantytown '' on harvard yard and blockaded a speech given by south african vice consul duke kent-brown . 
during the divestment from south africa movement in the late 1980s , student activists erected a symbolic `` shantytown '' on harvard yard and blockaded a speech given by south african vice consul duke kent-brown . 
however , the university did eventually reduce its south african holdings by $ 230 million -lrb- out of $ 400 million -rrb- in response to the pressure . 
harvard college accepted 5.3 % of applicants for the class of 2019 , a record low and the second lowest acceptance rate among all national universities . 
harvard college ended its early admissions program in 2007 as the program was believed to disadvantage low-income and under-represented minority applicants applying to selective universities , yet for the class of 2016 an early action program was reintroduced . 
harvard college ended its early admissions program in 2007 as the program was believed to disadvantage low-income and under-represented minority applicants applying to selective universities , yet for the class of 2016 an early action program was reintroduced . 
harvard college ended its early admissions program in 2007 as the program was believed to disadvantage low-income and under-represented minority applicants applying to selective universities , yet for the class of 2016 an early action program was reintroduced . 
between 1978 and 2008 , entering students were required to complete a core curriculum of seven classes outside of their concentration . 
since 2008 , undergraduate students have been required to complete courses in eight general education categories : aesthetic and interpretive understanding , culture and belief , empirical and mathematical reasoning , ethical reasoning , science of living systems , science of the physical universe , societies of the world , and united states in the world . 
the carnegie foundation for the advancement of teaching , the new york times , and some students have criticized harvard for its reliance on teaching fellows for some aspects of undergraduate education ; they consider this to adversely affect the quality of education . 
harvard 's academic programs operate on a semester calendar beginning in early september and ending in mid-may . 
undergraduates typically take four half-courses per term and must maintain a four-course rate average to be considered full-time . 
students graduating in the top 4 -- 5 % of the class are awarded degrees summa cum laude , students in the next 15 % of the class are awarded magna cum laude , and the next 30 % of the class are awarded cum laude . 
harvard college reduced the number of students who receive latin honors from 90 % in 2004 to 60 % in 2005 . 
for the 2012 -- 13 school year annual tuition was $ 38,000 , with a total cost of attendance of $ 57,000 . 
for the 2012 -- 13 school year annual tuition was $ 38,000 , with a total cost of attendance of $ 57,000 . 
beginning 2007 , families with incomes below $ 60,000 pay nothing for their children to attend , including room and board . 
in 2009 , harvard offered grants totaling $ 414 million across all eleven divisions ; -lsb- further explanation needed -rsb- $ 340 million came from institutional funds , $ 35 million from federal support , and $ 39 million from other outside support . 
grants total 88 % of harvard 's aid for undergraduate students , with aid also provided by loans -lrb- 8 % -rrb- and work-study -lrb- 4 % -rrb- . 
the harvard university library system is centered in widener library in harvard yard and comprises nearly 80 individual libraries holding over 18 million volumes . 
cabot science library , lamont library , and widener library are three of the most popular libraries for undergraduates to use , with easy access and central locations . 
america 's oldest collection of maps , gazetteers , and atlases both old and new is stored in pusey library and open to the public . 
the harvard university library system is centered in widener library in harvard yard and comprises nearly 80 individual libraries holding over 18 million volumes . 
the harvard art museums comprises three museums . 
the arthur m. sackler museum includes collections of ancient , asian , islamic and later indian art , the busch-reisinger museum , formerly the germanic museum , covers central and northern european art , and the fogg museum of art , covers western art from the middle ages to the present emphasizing italian early renaissance , british pre-raphaelite , and 19th-century french art . 
other museums include the carpenter center for the visual arts , designed by le corbusier , housing the film archive , the peabody museum of archaeology and ethnology , specializing in the cultural history and civilizations of the western hemisphere , and the semitic museum featuring artifacts from excavations in the middle east . 
in particular , it has consistently topped the academic ranking of world universities -lrb- arwu -rrb- since 2003 , and the the world reputation rankings since 2011 , when the first time such league tables were published . 
in particular , it has consistently topped the academic ranking of world universities -lrb- arwu -rrb- since 2003 , and the the world reputation rankings since 2011 , when the first time such league tables were published . 
from a poll done by the princeton review , harvard is the second most commonly named `` dream college '' , both for students and parents in 2013 , and was the first nominated by parents in 2009 . 
the harvard crimson competes in 42 intercollegiate sports in the ncaa division i ivy league . 
harvard has an intense athletic rivalry with yale university culminating in the game , although the harvard -- yale regatta predates the football game . 
this rivalry , though , is put aside every two years when the harvard and yale track and field teams come together to compete against a combined oxford university and cambridge university team , a competition that is the oldest continuous international amateur competition in the world . 
harvard 's athletic rivalry with yale is intense in every sport in which they meet , coming to a climax each fall in the annual football meeting , which dates back to 1875 and is usually called simply `` the game '' . 
in 1903 , harvard stadium introduced a new era into football with the first-ever permanent reinforced concrete stadium of its kind in the country . 
camp would instead support revolutionary new rules for the 1906 season . 
seeking to reduce the alarming number of deaths and serious injuries in the sport , walter camp -lrb- former captain of the yale football team -rrb- , suggested widening the field to open up the game . 
harvard has several athletic facilities , such as the lavietes pavilion , a multi-purpose arena and home to the harvard basketball teams . 
the malkin athletic center , known as the `` mac '' , serves both as the university 's primary recreation facility and as a satellite location for several varsity sports . 
the five-story building includes two cardio rooms , an olympic-size swimming pool , a smaller pool for aquaerobics and other activities , a mezzanine , where all types of classes are held , an indoor cycling studio , three weight rooms , and a three-court gym floor to play basketball . 
older than the game by 23 years , the harvard-yale regatta was the original source of the athletic rivalry between the two schools . 
it is held annually in june on the thames river in eastern connecticut . 
today , harvard fields top teams in several other sports , such as the harvard crimson men 's ice hockey team -lrb- with a strong rivalry against cornell -rrb- , squash , and even recently won ncaa titles in men 's and women 's fencing . 
harvard also won the intercollegiate sailing association national championships in 2003 . 
politics : u.n. secretary general ban ki-moon ; american political leaders john hancock , john adams , john quincy adams , rutherford b. hayes , theodore roosevelt , franklin d. roosevelt , john f. kennedy , al gore , george w. bush and barack obama ; chilean president sebastián piñera ; colombian president juan manuel santos ; costa rican president josé maría figueres ; mexican presidents felipe calderón , carlos salinas de gortari and miguel de la madrid ; mongolian president tsakhiagiin elbegdorj ; peruvian president alejandro toledo ; taiwanese president ma ying-jeou ; canadian governor general david lloyd johnston ; indian member of parliament jayant sinha ; albanian prime minister fan s. noli ; canadian prime ministers mackenzie king and pierre trudeau ; greek prime minister antonis samaras ; israeli prime minister benjamin netanyahu ; former pakistani prime minister benazir bhutto ; u. s. secretary of housing and urban development shaun donovan ; canadian political leader michael ignatieff ; pakistani members of provincial assembly murtaza bhutto and sanam bhutto ; bangladesh minister of finance abul maal abdul muhith ; president of puntland abdiweli mohamed ali ; u.s. ambassador to the european union anthony luzzatto gardner . 
politics : u.n. secretary general ban ki-moon ; american political leaders john hancock , john adams , john quincy adams , rutherford b. hayes , theodore roosevelt , franklin d. roosevelt , john f. kennedy , al gore , george w. bush and barack obama ; chilean president sebastián piñera ; colombian president juan manuel santos ; costa rican president josé maría figueres ; mexican presidents felipe calderón , carlos salinas de gortari and miguel de la madrid ; mongolian president tsakhiagiin elbegdorj ; peruvian president alejandro toledo ; taiwanese president ma ying-jeou ; canadian governor general david lloyd johnston ; indian member of parliament jayant sinha ; albanian prime minister fan s. noli ; canadian prime ministers mackenzie king and pierre trudeau ; greek prime minister antonis samaras ; israeli prime minister benjamin netanyahu ; former pakistani prime minister benazir bhutto ; u. s. secretary of housing and urban development shaun donovan ; canadian political leader michael ignatieff ; pakistani members of provincial assembly murtaza bhutto and sanam bhutto ; bangladesh minister of finance abul maal abdul muhith ; president of puntland abdiweli mohamed ali ; u.s. ambassador to the european union anthony luzzatto gardner . 
politics : u.n. secretary general ban ki-moon ; american political leaders john hancock , john adams , john quincy adams , rutherford b. hayes , theodore roosevelt , franklin d. roosevelt , john f. kennedy , al gore , george w. bush and barack obama ; chilean president sebastián piñera ; colombian president juan manuel santos ; costa rican president josé maría figueres ; mexican presidents felipe calderón , carlos salinas de gortari and miguel de la madrid ; mongolian president tsakhiagiin elbegdorj ; peruvian president alejandro toledo ; taiwanese president ma ying-jeou ; canadian governor general david lloyd johnston ; indian member of parliament jayant sinha ; albanian prime minister fan s. noli ; canadian prime ministers mackenzie king and pierre trudeau ; greek prime minister antonis samaras ; israeli prime minister benjamin netanyahu ; former pakistani prime minister benazir bhutto ; u. s. secretary of housing and urban development shaun donovan ; canadian political leader michael ignatieff ; pakistani members of provincial assembly murtaza bhutto and sanam bhutto ; bangladesh minister of finance abul maal abdul muhith ; president of puntland abdiweli mohamed ali ; u.s. ambassador to the european union anthony luzzatto gardner . 
politics : u.n. secretary general ban ki-moon ; american political leaders john hancock , john adams , john quincy adams , rutherford b. hayes , theodore roosevelt , franklin d. roosevelt , john f. kennedy , al gore , george w. bush and barack obama ; chilean president sebastián piñera ; colombian president juan manuel santos ; costa rican president josé maría figueres ; mexican presidents felipe calderón , carlos salinas de gortari and miguel de la madrid ; mongolian president tsakhiagiin elbegdorj ; peruvian president alejandro toledo ; taiwanese president ma ying-jeou ; canadian governor general david lloyd johnston ; indian member of parliament jayant sinha ; albanian prime minister fan s. noli ; canadian prime ministers mackenzie king and pierre trudeau ; greek prime minister antonis samaras ; israeli prime minister benjamin netanyahu ; former pakistani prime minister benazir bhutto ; u. s. secretary of housing and urban development shaun donovan ; canadian political leader michael ignatieff ; pakistani members of provincial assembly murtaza bhutto and sanam bhutto ; bangladesh minister of finance abul maal abdul muhith ; president of puntland abdiweli mohamed ali ; u.s. ambassador to the european union anthony luzzatto gardner . 
other : civil rights leader w. e. b. du bois ; philosopher henry david thoreau ; authors ralph waldo emerson and william s. burroughs ; educators werner baer , harlan hanson ; poets wallace stevens , t. s. eliot and e. e. cummings ; conductor leonard bernstein ; cellist yo yo ma ; pianist and composer charlie albright ; composer john alden carpenter ; comedian , television show host and writer conan o'brien ; actors tatyana ali , nestor carbonell , matt damon , fred gwynne , hill harper , rashida jones , tommy lee jones , ashley judd , jack lemmon , natalie portman , mira sorvino , elisabeth shue , and scottie thompson ; film directors darren aronofsky , terrence malick , mira nair , and whit stillman ; architect philip johnson ; musicians rivers cuomo , tom morello , and gram parsons ; musician , producer and composer ryan leslie ; serial killer ted kaczynski ; programmer and activist richard stallman ; nfl quarterback ryan fitzpatrick ; nfl center matt birk ; nba player jeremy lin ; us ski team skier ryan max riley ; physician sachin h. jain ; physicist j. robert oppenheimer ; computer pioneer and inventor an wang ; tibetologist george de roerich ; and marshall admiral isoroku yamamoto . 
other : civil rights leader w. e. b. du bois ; philosopher henry david thoreau ; authors ralph waldo emerson and william s. burroughs ; educators werner baer , harlan hanson ; poets wallace stevens , t. s. eliot and e. e. cummings ; conductor leonard bernstein ; cellist yo yo ma ; pianist and composer charlie albright ; composer john alden carpenter ; comedian , television show host and writer conan o'brien ; actors tatyana ali , nestor carbonell , matt damon , fred gwynne , hill harper , rashida jones , tommy lee jones , ashley judd , jack lemmon , natalie portman , mira sorvino , elisabeth shue , and scottie thompson ; film directors darren aronofsky , terrence malick , mira nair , and whit stillman ; architect philip johnson ; musicians rivers cuomo , tom morello , and gram parsons ; musician , producer and composer ryan leslie ; serial killer ted kaczynski ; programmer and activist richard stallman ; nfl quarterback ryan fitzpatrick ; nfl center matt birk ; nba player jeremy lin ; us ski team skier ryan max riley ; physician sachin h. jain ; physicist j. robert oppenheimer ; computer pioneer and inventor an wang ; tibetologist george de roerich ; and marshall admiral isoroku yamamoto . 
other : civil rights leader w. e. b. du bois ; philosopher henry david thoreau ; authors ralph waldo emerson and william s. burroughs ; educators werner baer , harlan hanson ; poets wallace stevens , t. s. eliot and e. e. cummings ; conductor leonard bernstein ; cellist yo yo ma ; pianist and composer charlie albright ; composer john alden carpenter ; comedian , television show host and writer conan o'brien ; actors tatyana ali , nestor carbonell , matt damon , fred gwynne , hill harper , rashida jones , tommy lee jones , ashley judd , jack lemmon , natalie portman , mira sorvino , elisabeth shue , and scottie thompson ; film directors darren aronofsky , terrence malick , mira nair , and whit stillman ; architect philip johnson ; musicians rivers cuomo , tom morello , and gram parsons ; musician , producer and composer ryan leslie ; serial killer ted kaczynski ; programmer and activist richard stallman ; nfl quarterback ryan fitzpatrick ; nfl center matt birk ; nba player jeremy lin ; us ski team skier ryan max riley ; physician sachin h. jain ; physicist j. robert oppenheimer ; computer pioneer and inventor an wang ; tibetologist george de roerich ; and marshall admiral isoroku yamamoto . 
other : civil rights leader w. e. b. du bois ; philosopher henry david thoreau ; authors ralph waldo emerson and william s. burroughs ; educators werner baer , harlan hanson ; poets wallace stevens , t. s. eliot and e. e. cummings ; conductor leonard bernstein ; cellist yo yo ma ; pianist and composer charlie albright ; composer john alden carpenter ; comedian , television show host and writer conan o'brien ; actors tatyana ali , nestor carbonell , matt damon , fred gwynne , hill harper , rashida jones , tommy lee jones , ashley judd , jack lemmon , natalie portman , mira sorvino , elisabeth shue , and scottie thompson ; film directors darren aronofsky , terrence malick , mira nair , and whit stillman ; architect philip johnson ; musicians rivers cuomo , tom morello , and gram parsons ; musician , producer and composer ryan leslie ; serial killer ted kaczynski ; programmer and activist richard stallman ; nfl quarterback ryan fitzpatrick ; nfl center matt birk ; nba player jeremy lin ; us ski team skier ryan max riley ; physician sachin h. jain ; physicist j. robert oppenheimer ; computer pioneer and inventor an wang ; tibetologist george de roerich ; and marshall admiral isoroku yamamoto . 
harvard 's faculty includes scholars such as biologist e. o. wilson , cognitive scientist steven pinker , physicists lisa randall and roy glauber , chemists elias corey , dudley r. herschbach and george m. whitesides , computer scientists michael o. rabin and leslie valiant , shakespeare scholar stephen greenblatt , writer louis menand , critic helen vendler , historians henry louis gates , jr. and niall ferguson , economists amartya sen , n. gregory mankiw , robert barro , stephen a. marglin , don m. wilson iii and martin feldstein , political philosophers harvey mansfield , baroness shirley williams and michael sandel , fields medalist mathematician shing-tung yau , political scientists robert putnam , joseph nye , and stanley hoffmann , scholar/composers robert levin and bernard rands , astrophysicist alyssa a. goodman , and legal scholars alan dershowitz and lawrence lessig . 
harvard 's faculty includes scholars such as biologist e. o. wilson , cognitive scientist steven pinker , physicists lisa randall and roy glauber , chemists elias corey , dudley r. herschbach and george m. whitesides , computer scientists michael o. rabin and leslie valiant , shakespeare scholar stephen greenblatt , writer louis menand , critic helen vendler , historians henry louis gates , jr. and niall ferguson , economists amartya sen , n. gregory mankiw , robert barro , stephen a. marglin , don m. wilson iii and martin feldstein , political philosophers harvey mansfield , baroness shirley williams and michael sandel , fields medalist mathematician shing-tung yau , political scientists robert putnam , joseph nye , and stanley hoffmann , scholar/composers robert levin and bernard rands , astrophysicist alyssa a. goodman , and legal scholars alan dershowitz and lawrence lessig . 
harvard 's faculty includes scholars such as biologist e. o. wilson , cognitive scientist steven pinker , physicists lisa randall and roy glauber , chemists elias corey , dudley r. herschbach and george m. whitesides , computer scientists michael o. rabin and leslie valiant , shakespeare scholar stephen greenblatt , writer louis menand , critic helen vendler , historians henry louis gates , jr. and niall ferguson , economists amartya sen , n. gregory mankiw , robert barro , stephen a. marglin , don m. wilson iii and martin feldstein , political philosophers harvey mansfield , baroness shirley williams and michael sandel , fields medalist mathematician shing-tung yau , political scientists robert putnam , joseph nye , and stanley hoffmann , scholar/composers robert levin and bernard rands , astrophysicist alyssa a. goodman , and legal scholars alan dershowitz and lawrence lessig . 
jacksonville is the largest city by population in the u.s. state of florida , and the largest city by area in the contiguous united states . 
jacksonville is the principal city in the jacksonville metropolitan area , with a population of 1,345,596 in 2010 . 
consolidation gave jacksonville its great size and placed most of its metropolitan population within the city limits ; with an estimated population of 853,382 in 2014 , it is the most populous city proper in florida and the southeast , and the 12th most populous in the united states . 
it is the county seat of duval county , with which the city government consolidated in 1968 . 
it is the county seat of duval county , with which the city government consolidated in 1968 . 
jacksonville is in the first coast region of northeast florida and is centered on the banks of the st. johns river , about 25 miles -lrb- 40 km -rrb- south of the georgia state line and about 340 miles -lrb- 550 km -rrb- north of miami . 
jacksonville is in the first coast region of northeast florida and is centered on the banks of the st. johns river , about 25 miles -lrb- 40 km -rrb- south of the georgia state line and about 340 miles -lrb- 550 km -rrb- north of miami . 
the area was originally inhabited by the timucua people , and in 1564 was the site of the french colony of fort caroline , one of the earliest european settlements in what is now the continental united states . 
the area was originally inhabited by the timucua people , and in 1564 was the site of the french colony of fort caroline , one of the earliest european settlements in what is now the continental united states . 
a platted town was established there in 1822 , a year after the united states gained florida from spain ; it was named after andrew jackson , the first military governor of the florida territory and seventh president of the united states . 
the two us navy bases , blount island command and the nearby naval submarine base kings bay form the third largest military presence in the united states . 
as with much of florida , tourism is also important to the jacksonville area , particularly tourism related to golf . 
the two us navy bases , blount island command and the nearby naval submarine base kings bay form the third largest military presence in the united states . 
people from jacksonville may be called `` jacksonvillians '' or `` jaxsons '' -lrb- also spelled `` jaxons '' -rrb- . 
the area of the modern city of jacksonville has been inhabited for thousands of years . 
on black hammock island in the national timucuan ecological and historic preserve , a university of north florida team discovered some of the oldest remnants of pottery in the united states , dating to 2500 bc . 
in the 16th century , the beginning of the historical era , the region was inhabited by the mocama , a coastal subgroup of the timucua people . 
in the 16th century , the beginning of the historical era , the region was inhabited by the mocama , a coastal subgroup of the timucua people . 
one early map shows a village called ossachite at the site of what is now downtown jacksonville ; this may be the earliest recorded name for that area . 
french huguenot explorer jean ribault charted the st. johns river in 1562 calling it the river of may because he discovered it in may . 
ribault erected a stone column near present-day jacksonville claiming the newly discovered land for france . 
philip ii of spain ordered pedro menéndez de avilés to protect the interest of spain by attacking the french presence at fort caroline . 
the spanish renamed the fort san mateo , and following the ejection of the french , st. augustine 's position as the most important settlement in florida was solidified . 
the location of fort caroline is subject to debate but a reconstruction of the fort was established on the st. johns river in 1964 . 
spain ceded florida to the british in 1763 after the french and indian war , and the british soon constructed the king 's road connecting st. augustine to georgia . 
spain ceded florida to the british in 1763 after the french and indian war , and the british soon constructed the king 's road connecting st. augustine to georgia . 
the road crossed the st. johns river at a narrow point , which the seminole called wacca pilatka and the british called the cow ford or cowford ; these names ostensibly reflect the fact that cattle were brought across the river there . 
after spain ceded the florida territory to the united states in 1821 , american settlers on the north side of the cow ford decided to plan a town , laying out the streets and plats . 
led by isaiah d. hart , residents wrote a charter for a town government , which was approved by the florida legislative council on february 9 , 1832 . 
during the american civil war , jacksonville was a key supply point for hogs and cattle being shipped from florida to aid the confederate cause . 
the skirmish of the brick church in 1862 just outside jacksonville proper resulted in the first confederate victory in florida . 
in february 1864 union forces left jacksonville and confronted a confederate army at the battle of olustee resulting in a confederate victory . 
warfare and the long occupation left the city disrupted after the war . 
in march 1864 a confederate cavalry confronted a union expedition resulting in the battle of cedar creek . 
during reconstruction and the gilded age , jacksonville and nearby st. augustine became popular winter resorts for the rich and famous . 
president grover cleveland attended the sub-tropical exposition in the city on february 22 , 1888 during his trip to florida . 
the city 's tourism , however , was dealt major blows in the late 19th century by yellow fever outbreaks . 
in addition , extension of the florida east coast railway further south drew visitors to other areas . 
visitors arrived by steamboat and later by railroad . 
spanish moss at a nearby mattress factory was quickly engulfed in flames and enabling the fire to spread rapidly . 
in just eight hours , it swept through 146 city blocks , destroyed over 2,000 buildings , left about 10,000 homeless and killed 7 residents . 
governor jennings declare martial law and sent the state militia to maintain order . 
known as the `` great fire of 1901 '' , it was one of the worst disasters in florida history and the largest urban fire in the southeastern united states . 
in the 1910s , new york -- based filmmakers were attracted to jacksonville 's warm climate , exotic locations , excellent rail access , and cheap labor . 
over the course of the decade , more than 30 silent film studios were established , earning jacksonville the title of `` winter film capital of the world '' . 
over the course of the decade , more than 30 silent film studios were established , earning jacksonville the title of `` winter film capital of the world '' . 
however , the emergence of hollywood as a major film production center ended the city 's film industry . 
the construction of highways led residents to move to newer housing in the suburbs . 
the city 's most populous ethnic group , non-hispanic white , declined from 75.8 % in 1970 to 55.1 % by 2010 . 
however , the development of suburbs and a subsequent wave of middle class `` white flight '' left jacksonville with a much poorer population than before . 
mayor w. haydon burns ' jacksonville story resulted in the construction of a new city hall , civic auditorium , public library and other projects that created a dynamic sense of civic pride . 
jacksonville , like most large cities in the united states , suffered from negative effects of rapid urban sprawl after world war ii . 
much of the city 's tax base dissipated , leading to problems with funding education , sanitation , and traffic control within the city limits . 
in addition , residents in unincorporated suburbs had difficulty obtaining municipal services , such as sewage and building code enforcement . 
in 1958 , a study recommended that the city of jacksonville begin annexing outlying communities in order to create the needed tax base to improve services throughout the county . 
voters outside the city limits rejected annexation plans in six referendums between 1960 and 1965 . 
in the mid-1960s , corruption scandals began to arise among many of the city 's officials , who were mainly elected through the traditional old boy network . 
after a grand jury was convened to investigate , 11 officials were indicted and more were forced to resign . 
jacksonville consolidation , led by j. j. daniel and claude yates , began to win more support during this period , from both inner city blacks , who wanted more involvement in government , and whites in the suburbs , who wanted more services and more control over the central city . 
in 1964 all 15 of duval county 's public high schools lost their accreditation . 
when a consolidation referendum was held in 1967 , voters approved the plan . 
in honor of the occasion , then-mayor hans tanzler posed with actress lee meredith behind a sign marking the new border of the `` bold new city of the south '' at florida 13 and julington creek . 
in honor of the occasion , then-mayor hans tanzler posed with actress lee meredith behind a sign marking the new border of the `` bold new city of the south '' at florida 13 and julington creek . 
the better jacksonville plan , promoted as a blueprint for jacksonville 's future and approved by jacksonville voters in 2000 , authorized a half-penny sales tax . 
the better jacksonville plan , promoted as a blueprint for jacksonville 's future and approved by jacksonville voters in 2000 , authorized a half-penny sales tax . 
according to the united states census bureau , the city has a total area of 874.3 square miles -lrb- 2,264 km2 -rrb- , making jacksonville the largest city in land area in the contiguous united states ; of this , 86.66 % -lrb- 757.7 sq mi or 1,962 km2 -rrb- is land and ; 13.34 % -lrb- 116.7 sq mi or 302 km2 -rrb- is water . 
the st. johns river divides the city . 
the trout river , a major tributary of the st. johns river , is located entirely within jacksonville . 
according to the united states census bureau , the city has a total area of 874.3 square miles -lrb- 2,264 km2 -rrb- , making jacksonville the largest city in land area in the contiguous united states ; of this , 86.66 % -lrb- 757.7 sq mi or 1,962 km2 -rrb- is land and ; 13.34 % -lrb- 116.7 sq mi or 302 km2 -rrb- is water . 
jacksonville surrounds the town of baldwin . 
the tallest building in downtown jacksonville 's skyline is the bank of america tower , constructed in 1990 as the barnett center . 
the tallest building in downtown jacksonville 's skyline is the bank of america tower , constructed in 1990 as the barnett center . 
it has a height of 617 ft -lrb- 188 m -rrb- and includes 42 floors . 
other notable structures include the 37-story wells fargo center -lrb- with its distinctive flared base making it the defining building in the jacksonville skyline -rrb- , originally built in 1972-74 by the independent life and accident insurance company , and the 28 floor riverplace tower which , when completed in 1967 , was the tallest precast , post-tensioned concrete structure in the world . 
other notable structures include the 37-story wells fargo center -lrb- with its distinctive flared base making it the defining building in the jacksonville skyline -rrb- , originally built in 1972-74 by the independent life and accident insurance company , and the 28 floor riverplace tower which , when completed in 1967 , was the tallest precast , post-tensioned concrete structure in the world . 
like much of the south atlantic region of the united states , jacksonville has a humid subtropical climate -lrb- köppen cfa -rrb- , with mild weather during winters and hot and humid weather during summers . 
seasonal rainfall is concentrated in the warmest months from may through september , while the driest months are from november through april . 
like much of the south atlantic region of the united states , jacksonville has a humid subtropical climate -lrb- köppen cfa -rrb- , with mild weather during winters and hot and humid weather during summers . 
due to jacksonville 's low latitude and coastal location , the city sees very little cold weather , and winters are typically mild and sunny . 
the highest temperature recorded was 104 °f -lrb- 40 °c -rrb- on july 11 , 1879 and july 28 , 1872 . 
it is common for thunderstorms to erupt during a typical summer afternoon . 
these are caused by the rapid heating of the land relative to the water , combined with extremely high humidity . 
mean monthly temperatures range from around 53 f in january to 82 f in july . 
the strongest effect on jacksonville was from hurricane dora in 1964 , the only recorded storm to hit the first coast with sustained hurricane-force winds . 
the eye crossed st. augustine with winds that had just barely diminished to 110 mph -lrb- 180 km/h -rrb- , making it a strong category 2 on the saffir-simpson scale . 
on may 28 , 2012 , jacksonville was hit by tropical storm beryl , packing winds up to 70 miles per hour -lrb- 113 km/h -rrb- which made landfall near jacksonville beach . 
the eye crossed st. augustine with winds that had just barely diminished to 110 mph -lrb- 180 km/h -rrb- , making it a strong category 2 on the saffir-simpson scale . 
jacksonville also suffered damage from 2008 's tropical storm fay which crisscrossed the state , bringing parts of jacksonville under darkness for four days . 
jacksonville has the country 's tenth-largest arab population , with a total population of 5,751 according to the 2000 united states census . 
as of 2010 -lsb- update -rsb- , there were 821,784 people and 366,273 households in the city . 
jacksonville has florida 's largest filipino american community , with 25,033 in the metropolitan area as of the 2010 census . 
much of jacksonville 's filipino community served in or has ties to the united states navy . 
29.7 % of all households were made up of individuals and 7.9 % had someone living alone who was 65 years of age or older . 
in the city , the population was spread out with 23.9 % under the age of 18 , 10.5 % from 18 to 24 , 28.5 % from 25 to 44 , 26.2 % from 45 to 64 , and 10.9 % who were 65 years of age or older . 
for every 100 females there were 94.1 males . 
for every 100 females age 18 and over , there were 91.3 males . 
a study by the world institute for development economics research at united nations university reports that the richest 1 % of adults alone owned 40 % of global assets in the year 2000 . 
a january 2014 report by oxfam claims that the 85 wealthiest individuals in the world have a combined wealth equal to that of the bottom 50 % of the world 's population , or about 3.5 billion people . 
in october 2015 , credit suisse published a study which shows global inequality continues to increase , and that half of the world 's wealth is now in the hands of those in the top percentile , whose assets each exceed $ 759,900 . 
oxfam 's claims have however been questioned on the basis of the methodology used : by using net wealth -lrb- adding up assets and subtracting debts -rrb- , the oxfam report , for instance , finds that there are more poor people in the united states and western europe than in china -lrb- due to a greater tendency to take on debts -rrb- . 
anthony shorrocks , the lead author of the credit suisse report which is one of the sources of oxfam 's data , considers the criticism about debt to be a `` silly argument '' and `` a non-issue ... a diversion . '' 
a study by the world institute for development economics research at united nations university reports that the richest 1 % of adults alone owned 40 % of global assets in the year 2000 . 
the three richest people in the world possess more financial assets than the lowest 48 nations combined . 
the combined wealth of the `` 10 million dollar millionaires '' grew to nearly $ 41 trillion in 2008 . 
more recently , in january 2015 , oxfam reported that the wealthiest 1 percent will own more than half of the global wealth by 2016 . 
oxfam 's claims have however been questioned on the basis of the methodology used : by using net wealth -lrb- adding up assets and subtracting debts -rrb- , the oxfam report , for instance , finds that there are more poor people in the united states and western europe than in china -lrb- due to a greater tendency to take on debts -rrb- . 
according to politifact the top 400 richest americans `` have more wealth than half of all americans combined . '' 
according to the new york times on july 22 , 2014 , the `` richest 1 percent in the united states now own more wealth than the bottom 90 percent '' . 
inherited wealth may help explain why many americans who have become rich may have had a `` substantial head start '' . 
in september 2012 , according to the institute for policy studies , `` over 60 percent '' of the forbes richest 400 americans `` grew up in substantial privilege '' . 
according to politifact the top 400 richest americans `` have more wealth than half of all americans combined . '' 
according to the new york times on july 22 , 2014 , the `` richest 1 percent in the united states now own more wealth than the bottom 90 percent '' . 
inherited wealth may help explain why many americans who have become rich may have had a `` substantial head start '' . 
in september 2012 , according to the institute for policy studies , `` over 60 percent '' of the forbes richest 400 americans `` grew up in substantial privilege '' . 
in september 2012 , according to the institute for policy studies , `` over 60 percent '' of the forbes richest 400 americans `` grew up in substantial privilege '' . 
neoclassical economics views inequalities in the distribution of income as arising from differences in value added by labor , capital and land . 
neoclassical economics views inequalities in the distribution of income as arising from differences in value added by labor , capital and land . 
within labor income distribution is due to differences in value added by different classifications of workers . 
thus , in a market economy , inequality is a reflection of the productivity gap between highly-paid professions and lower-paid professions . 
in this perspective , wages and profits are determined by the marginal value added of each economic actor -lrb- worker , capitalist/business owner , landlord -rrb- . 
neoclassical economics views inequalities in the distribution of income as arising from differences in value added by labor , capital and land . 
within labor income distribution is due to differences in value added by different classifications of workers . 
in this perspective , wages and profits are determined by the marginal value added of each economic actor -lrb- worker , capitalist/business owner , landlord -rrb- . 
in this perspective , wages and profits are determined by the marginal value added of each economic actor -lrb- worker , capitalist/business owner , landlord -rrb- . 
thus , in a market economy , inequality is a reflection of the productivity gap between highly-paid professions and lower-paid professions . 
in marxian analysis , capitalist firms increasingly substitute capital equipment for labor inputs -lrb- workers -rrb- under competitive pressure to reduce costs and maximize profits . 
over the long-term , this trend increases the organic composition of capital , meaning that less workers are required in proportion to capital inputs , increasing unemployment -lrb- the `` reserve army of labour '' -rrb- . 
over the long-term , this trend increases the organic composition of capital , meaning that less workers are required in proportion to capital inputs , increasing unemployment -lrb- the `` reserve army of labour '' -rrb- . 
the substitution of capital equipment for labor -lrb- mechanization and automation -rrb- raises the productivity of each worker , resulting in a situation of relatively stagnant wages for the working class amidst rising levels of property income for the capitalist class . 
in marxian analysis , capitalist firms increasingly substitute capital equipment for labor inputs -lrb- workers -rrb- under competitive pressure to reduce costs and maximize profits . 
in marxian analysis , capitalist firms increasingly substitute capital equipment for labor inputs -lrb- workers -rrb- under competitive pressure to reduce costs and maximize profits . 
in marxian analysis , capitalist firms increasingly substitute capital equipment for labor inputs -lrb- workers -rrb- under competitive pressure to reduce costs and maximize profits . 
the substitution of capital equipment for labor -lrb- mechanization and automation -rrb- raises the productivity of each worker , resulting in a situation of relatively stagnant wages for the working class amidst rising levels of property income for the capitalist class . 
the substitution of capital equipment for labor -lrb- mechanization and automation -rrb- raises the productivity of each worker , resulting in a situation of relatively stagnant wages for the working class amidst rising levels of property income for the capitalist class . 
in a purely capitalist mode of production -lrb- i.e. where professional and labor organizations can not limit the number of workers -rrb- the workers wages will not be controlled by these organizations , or by the employer , but rather by the market . 
under the law of supply and demand , the price of skill is determined by a race between the demand for the skilled worker and the supply of the skilled worker . 
employers who offer a below market wage will find that their business is chronically understaffed . 
their competitors will take advantage of the situation by offering a higher wage the best of their labor . 
`` markets , by themselves , even when they are stable , often lead to high levels of inequality , outcomes that are widely viewed as unfair . '' 
in a purely capitalist mode of production -lrb- i.e. where professional and labor organizations can not limit the number of workers -rrb- the workers wages will not be controlled by these organizations , or by the employer , but rather by the market . 
wages work in the same way as prices for any other good . 
thus , wages can be considered as a function of market price of skill . 
`` on the other hand , markets can also concentrate wealth , pass environmental costs on to society , and abuse workers and consumers . '' 
`` markets , by themselves , even when they are stable , often lead to high levels of inequality , outcomes that are widely viewed as unfair . '' 
competition amongst workers tends to drive down wages due to the expendable nature of the worker in relation to his or her particular job . 
a job where there are many workers willing to work a large amount of time -lrb- high supply -rrb- competing for a job that few require -lrb- low demand -rrb- will result in a low wage for that job . 
a job where there are few able or willing workers -lrb- low supply -rrb- , but a large need for the positions -lrb- high demand -rrb- , will result in high wages for that job . 
members may also receive higher wages through collective bargaining , political influence , or corruption . 
professional and labor organizations may limit the supply of workers which results in higher demand and greater incomes for members . 
a job where there are many workers willing to work a large amount of time -lrb- high supply -rrb- competing for a job that few require -lrb- low demand -rrb- will result in a low wage for that job . 
this is because competition between workers drives down the wage . 
competition amongst workers tends to drive down wages due to the expendable nature of the worker in relation to his or her particular job . 
a job where there are few able or willing workers -lrb- low supply -rrb- , but a large need for the positions -lrb- high demand -rrb- , will result in high wages for that job . 
competition amongst employers tends to drive up wages due to the nature of the job , since there is a relative shortage of workers for the particular position . 
on the other hand , higher economic inequality tends to increase entrepreneurship rates at the individual level -lrb- self-employment -rrb- . 
necessity-based entrepreneurship is motivated by survival needs such as income for food and shelter -lrb- `` push '' motivations -rrb- , whereas opportunity-based entrepreneurship is driven by achievement-oriented motivations -lrb- `` pull '' -rrb- such as vocation and more likely to involve the pursue of new products , services , or underserved market needs . 
necessity-based entrepreneurship is motivated by survival needs such as income for food and shelter -lrb- `` push '' motivations -rrb- , whereas opportunity-based entrepreneurship is driven by achievement-oriented motivations -lrb- `` pull '' -rrb- such as vocation and more likely to involve the pursue of new products , services , or underserved market needs . 
necessity-based entrepreneurship is motivated by survival needs such as income for food and shelter -lrb- `` push '' motivations -rrb- , whereas opportunity-based entrepreneurship is driven by achievement-oriented motivations -lrb- `` pull '' -rrb- such as vocation and more likely to involve the pursue of new products , services , or underserved market needs . 
necessity-based entrepreneurship is motivated by survival needs such as income for food and shelter -lrb- `` push '' motivations -rrb- , whereas opportunity-based entrepreneurship is driven by achievement-oriented motivations -lrb- `` pull '' -rrb- such as vocation and more likely to involve the pursue of new products , services , or underserved market needs . 
on the other hand , higher economic inequality tends to increase entrepreneurship rates at the individual level -lrb- self-employment -rrb- . 
however , most of it is often based on necessity rather than opportunity . 
necessity-based entrepreneurship is motivated by survival needs such as income for food and shelter -lrb- `` push '' motivations -rrb- , whereas opportunity-based entrepreneurship is driven by achievement-oriented motivations -lrb- `` pull '' -rrb- such as vocation and more likely to involve the pursue of new products , services , or underserved market needs . 
necessity-based entrepreneurship is motivated by survival needs such as income for food and shelter -lrb- `` push '' motivations -rrb- , whereas opportunity-based entrepreneurship is driven by achievement-oriented motivations -lrb- `` pull '' -rrb- such as vocation and more likely to involve the pursue of new products , services , or underserved market needs . 
the economic impact of the former type of entrepreneurialism tends to be redistributive while the latter is expected to foster technological progress and thus have a more positive impact on economic growth . 
a progressive tax is a tax by which the tax rate increases as the taxable base amount increases . 
in a progressive tax system , the level of the top tax rate will often have a direct impact on the level of inequality within a society , either increasing it or decreasing it , provided that income does not change as a result of the change in tax regime . 
additionally , steeper tax progressivity applied to social spending can result in a more equal distribution of income across the board . 
another cause is the rate at which income is taxed coupled with the progressivity of the tax system . 
a progressive tax is a tax by which the tax rate increases as the taxable base amount increases . 
in a progressive tax system , the level of the top tax rate will often have a direct impact on the level of inequality within a society , either increasing it or decreasing it , provided that income does not change as a result of the change in tax regime . 
additionally , steeper tax progressivity applied to social spending can result in a more equal distribution of income across the board . 
the difference between the gini index for an income distribution before taxation and the gini index after taxation is an indicator for the effects of such taxation . 
an important factor in the creation of inequality is variation in individuals ' access to education . 
as a result , those who are unable to afford an education , or choose not to pursue optional education , generally receive much lower wages . 
as a result , those who are unable to afford an education , or choose not to pursue optional education , generally receive much lower wages . 
conversely , education raises incomes and promotes growth because it helps to unleash the productive potential of the poor . 
the justification for this is that a lack of education leads directly to lower incomes , and thus lower aggregate savings and investment . 
an important factor in the creation of inequality is variation in individuals ' access to education . 
education , especially in an area where there is a high demand for workers , creates high wages for those with this education , however , increases in education first increase and then decrease growth as well as income inequality . 
as a result , those who are unable to afford an education , or choose not to pursue optional education , generally receive much lower wages . 
the justification for this is that a lack of education leads directly to lower incomes , and thus lower aggregate savings and investment . 
conversely , education raises incomes and promotes growth because it helps to unleash the productive potential of the poor . 
to partially remedy the wealth gap and the resulting slow growth , s&p recommended increasing access to education . 
it estimated that if the average united states worker had completed just one more year of school , it would add an additional $ 105 billion in growth to the country 's economy over five years . 
in 2014 , economists with the standard & poor 's rating agency concluded that the widening disparity between the u.s. 's wealthiest citizens and the rest of the nation had slowed its recovery from the 2008-2009 recession and made it more prone to boom-and-bust cycles . 
in 2014 , economists with the standard & poor 's rating agency concluded that the widening disparity between the u.s. 's wealthiest citizens and the rest of the nation had slowed its recovery from the 2008-2009 recession and made it more prone to boom-and-bust cycles . 
in 2014 , economists with the standard & poor 's rating agency concluded that the widening disparity between the u.s. 's wealthiest citizens and the rest of the nation had slowed its recovery from the 2008-2009 recession and made it more prone to boom-and-bust cycles . 
in 2014 , economists with the standard & poor 's rating agency concluded that the widening disparity between the u.s. 's wealthiest citizens and the rest of the nation had slowed its recovery from the 2008-2009 recession and made it more prone to boom-and-bust cycles . 
to partially remedy the wealth gap and the resulting slow growth , s&p recommended increasing access to education . 
it estimated that if the average united states worker had completed just one more year of school , it would add an additional $ 105 billion in growth to the country 's economy over five years . 
in 2014 , economists with the standard & poor 's rating agency concluded that the widening disparity between the u.s. 's wealthiest citizens and the rest of the nation had slowed its recovery from the 2008-2009 recession and made it more prone to boom-and-bust cycles . 
during the mass high school education movement from 1910 -- 1940 , there was an increase in skilled workers , which led to a decrease in the price of skilled labor . 
during the mass high school education movement from 1910 -- 1940 , there was an increase in skilled workers , which led to a decrease in the price of skilled labor . 
during the mass high school education movement from 1910 -- 1940 , there was an increase in skilled workers , which led to a decrease in the price of skilled labor . 
lagerlof and galor stated that gender inequality in education can result to low economic growth , and continued gender inequality in education , thus creating a poverty trap . 
this decrease in wages caused a period of compression and decreased inequality between skilled and unskilled workers . 
during the mass high school education movement from 1910 -- 1940 , there was an increase in skilled workers , which led to a decrease in the price of skilled labor . 
during the mass high school education movement from 1910 -- 1940 , there was an increase in skilled workers , which led to a decrease in the price of skilled labor . 
high school education during the period was designed to equip students with necessary skill sets to be able to perform at work . 
education is very important for the growth of the economy , however educational inequality in gender also influence towards the economy . 
lagerlof and galor stated that gender inequality in education can result to low economic growth , and continued gender inequality in education , thus creating a poverty trap . 
in an analysis of the effects of intensive anglo-american liberal policies in comparison to continental european liberalism , where unions have remained strong , they concluded `` the u.s. economic and social model is associated with substantial levels of social exclusion , including high levels of income inequality , high relative and absolute poverty rates , poor and unequal educational outcomes , poor health outcomes , and high rates of crime and incarceration . 
despite popular prejudices to the contrary , the u.s. economy consistently affords a lower level of economic mobility than all the continental european countries for which data is available . '' 
at the same time , the available evidence provides little support for the view that u.s.-style labor-market flexibility dramatically improves labor-market outcomes . 
in an analysis of the effects of intensive anglo-american liberal policies in comparison to continental european liberalism , where unions have remained strong , they concluded `` the u.s. economic and social model is associated with substantial levels of social exclusion , including high levels of income inequality , high relative and absolute poverty rates , poor and unequal educational outcomes , poor health outcomes , and high rates of crime and incarceration . 
john schmitt and ben zipperer -lrb- 2006 -rrb- of the cepr point to economic liberalism and the reduction of business regulation along with the decline of union membership as one of the causes of economic inequality . 
in an analysis of the effects of intensive anglo-american liberal policies in comparison to continental european liberalism , where unions have remained strong , they concluded `` the u.s. economic and social model is associated with substantial levels of social exclusion , including high levels of income inequality , high relative and absolute poverty rates , poor and unequal educational outcomes , poor health outcomes , and high rates of crime and incarceration . 
john schmitt and ben zipperer -lrb- 2006 -rrb- of the cepr point to economic liberalism and the reduction of business regulation along with the decline of union membership as one of the causes of economic inequality . 
at the same time , the available evidence provides little support for the view that u.s.-style labor-market flexibility dramatically improves labor-market outcomes . 
despite popular prejudices to the contrary , the u.s. economy consistently affords a lower level of economic mobility than all the continental european countries for which data is available . '' 
he points out that nations with high rates of unionization , particularly in scandinavia , have very low levels of inequality , and concludes `` the historical pattern is clear ; the cross-national pattern is clear : high inequality goes hand-in-hand with weak labor movements and vice-versa . '' 
he points out that nations with high rates of unionization , particularly in scandinavia , have very low levels of inequality , and concludes `` the historical pattern is clear ; the cross-national pattern is clear : high inequality goes hand-in-hand with weak labor movements and vice-versa . '' 
sociologist jake rosenfield of the university of washington asserts that the decline of organized labor in the united states has played a more significant role in expanding the income gap than technological changes and globalization , which were also experienced by other industrialized nations that did n't experience steep surges in inequality . 
sociologist jake rosenfield of the university of washington asserts that the decline of organized labor in the united states has played a more significant role in expanding the income gap than technological changes and globalization , which were also experienced by other industrialized nations that did n't experience steep surges in inequality . 
sociologist jake rosenfield of the university of washington asserts that the decline of organized labor in the united states has played a more significant role in expanding the income gap than technological changes and globalization , which were also experienced by other industrialized nations that did n't experience steep surges in inequality . 
sociologist jake rosenfield of the university of washington asserts that the decline of organized labor in the united states has played a more significant role in expanding the income gap than technological changes and globalization , which were also experienced by other industrialized nations that did n't experience steep surges in inequality . 
sociologist jake rosenfield of the university of washington asserts that the decline of organized labor in the united states has played a more significant role in expanding the income gap than technological changes and globalization , which were also experienced by other industrialized nations that did n't experience steep surges in inequality . 
he points out that nations with high rates of unionization , particularly in scandinavia , have very low levels of inequality , and concludes `` the historical pattern is clear ; the cross-national pattern is clear : high inequality goes hand-in-hand with weak labor movements and vice-versa . '' 
he points out that nations with high rates of unionization , particularly in scandinavia , have very low levels of inequality , and concludes `` the historical pattern is clear ; the cross-national pattern is clear : high inequality goes hand-in-hand with weak labor movements and vice-versa . '' 
when rich countries trade with poor countries , the low-skilled workers in the rich countries may see reduced wages as a result of the competition , while low-skilled workers in the poor countries may see increased wages . 
when rich countries trade with poor countries , the low-skilled workers in the rich countries may see reduced wages as a result of the competition , while low-skilled workers in the poor countries may see increased wages . 
however , he concedes that the effect of trade on inequality in america is minor when compared to other causes , such as technological innovation , a view shared by other experts . 
robert lawrence argues that technological innovation and automation has meant that low-skilled jobs have been replaced by machine labor in wealthier nations , and that wealthier countries no longer have significant numbers of low-skilled manufacturing workers that could be affected by competition from poor countries . 
trade liberalization may shift economic inequality from a global to a domestic scale . 
when rich countries trade with poor countries , the low-skilled workers in the rich countries may see reduced wages as a result of the competition , while low-skilled workers in the poor countries may see increased wages . 
trade economist paul krugman estimates that trade liberalisation has had a measurable effect on the rising inequality in the united states . 
however , he concedes that the effect of trade on inequality in america is minor when compared to other causes , such as technological innovation , a view shared by other experts . 
robert lawrence argues that technological innovation and automation has meant that low-skilled jobs have been replaced by machine labor in wealthier nations , and that wealthier countries no longer have significant numbers of low-skilled manufacturing workers that could be affected by competition from poor countries . 
the income gap in other countries ranges from 53 % in botswana to -40 % in bahrain . 
the income gap in other countries ranges from 53 % in botswana to -40 % in bahrain . 
on average , women are more likely than men to consider factors other than pay when looking for work , and may be less willing to travel or relocate . 
in many countries , there is a gender pay gap in favor of males in the labor market . 
in many countries , there is a gender pay gap in favor of males in the labor market . 
in many countries , there is a gender pay gap in favor of males in the labor market . 
on average , women are more likely than men to consider factors other than pay when looking for work , and may be less willing to travel or relocate . 
thomas sowell , in his book knowledge and decisions , claims that this difference is due to women not taking jobs due to marriage or pregnancy , but income studies show that that does not explain the entire difference . 
a u.s. census 's report stated that in us once other factors are accounted for there is still a difference in earnings between women and men . 
eventually , through various possible redistribution mechanisms such as social welfare programs , more developed countries move back to lower levels of inequality . 
according to kuznets , countries with low levels of development have relatively equal distributions of wealth . 
as a country develops , it acquires more capital , which leads to the owners of this capital having more wealth and income and introducing inequality . 
eventually , through various possible redistribution mechanisms such as social welfare programs , more developed countries move back to lower levels of inequality . 
economist simon kuznets argued that levels of economic inequality are in large part the result of stages of development . 
economist simon kuznets argued that levels of economic inequality are in large part the result of stages of development . 
as a country develops , it acquires more capital , which leads to the owners of this capital having more wealth and income and introducing inequality . 
as a country develops , it acquires more capital , which leads to the owners of this capital having more wealth and income and introducing inequality . 
eventually , through various possible redistribution mechanisms such as social welfare programs , more developed countries move back to lower levels of inequality . 
as an example , income inequality did fall in the united states during its high school movement from 1910 to 1940 and thereafter . 
-lsb- citation needed -rsb- however , recent data shows that the level of income inequality began to rise after the 1970s . 
-lsb- citation needed -rsb- it may be possible that another kuznets ' cycle is occurring , specifically the move from the manufacturing sector to the service sector . 
-lsb- citation needed -rsb- it may be possible that another kuznets ' cycle is occurring , specifically the move from the manufacturing sector to the service sector . 
plotting the relationship between level of income and inequality , kuznets saw middle-income developing economies level of inequality bulging out to form what is now known as the kuznets curve . 
plotting the relationship between level of income and inequality , kuznets saw middle-income developing economies level of inequality bulging out to form what is now known as the kuznets curve . 
however , more recent testing of this theory with superior panel data has shown it to be very weak . 
kuznets ' curve predicts that income inequality will eventually decrease given time . 
-lsb- citation needed -rsb- this implies that it may be possible for multiple kuznets ' cycles to be in effect at any given time . 
wealth concentration is a theoretical -lsb- according to whom ? -rsb- 
according to this theory , those who already hold wealth have the means to invest in new sources of creating wealth or to otherwise leverage the accumulation of wealth , thus are the beneficiaries of the new wealth . 
thomas piketty in his book capital in the twenty-first century argues that the fundamental force for divergence is the usually greater return of capital -lrb- r -rrb- than economic growth -lrb- g -rrb- , and that larger fortunes generate higher returns -lsb- pp. 384 table 12.2 , u.s. university endowment size vs. real annual rate of return -rsb- 
thomas piketty in his book capital in the twenty-first century argues that the fundamental force for divergence is the usually greater return of capital -lrb- r -rrb- than economic growth -lrb- g -rrb- , and that larger fortunes generate higher returns -lsb- pp. 384 table 12.2 , u.s. university endowment size vs. real annual rate of return -rsb- 
process by which , under certain conditions , newly created wealth concentrates in the possession of already-wealthy individuals or entities . 
according to this theory , those who already hold wealth have the means to invest in new sources of creating wealth or to otherwise leverage the accumulation of wealth , thus are the beneficiaries of the new wealth . 
over time , wealth condensation can significantly contribute to the persistence of inequality within society . 
thomas piketty in his book capital in the twenty-first century argues that the fundamental force for divergence is the usually greater return of capital -lrb- r -rrb- than economic growth -lrb- g -rrb- , and that larger fortunes generate higher returns -lsb- pp. 384 table 12.2 , u.s. university endowment size vs. real annual rate of return -rsb- 
thomas piketty in his book capital in the twenty-first century argues that the fundamental force for divergence is the usually greater return of capital -lrb- r -rrb- than economic growth -lrb- g -rrb- , and that larger fortunes generate higher returns -lsb- pp. 384 table 12.2 , u.s. university endowment size vs. real annual rate of return -rsb- 
economist joseph stiglitz argues that rather than explaining concentrations of wealth and income , market forces should serve as a brake on such concentration , which may better be explained by the non-market force known as `` rent-seeking '' . 
economist joseph stiglitz argues that rather than explaining concentrations of wealth and income , market forces should serve as a brake on such concentration , which may better be explained by the non-market force known as `` rent-seeking '' . 
while the market will bid up compensation for rare and desired skills to reward wealth creation , greater productivity , etc. , it will also prevent successful entrepreneurs from earning excess profits by fostering competition to cut prices , profits and large compensation . 
a better explainer of growing inequality , according to stiglitz , is the use of political power generated by wealth by certain groups to shape government policies financially beneficial to them . 
this process , known to economists as rent-seeking , brings income not from creation of wealth but from `` grabbing a larger share of the wealth that would otherwise have been produced without their effort '' 
effects of inequality researchers have found include higher rates of health and social problems , and lower rates of social goods , a lower level of economic utility in society from resources devoted on high-end consumption , and even a lower level of economic growth when human capital is neglected for high-end consumption . 
effects of inequality researchers have found include higher rates of health and social problems , and lower rates of social goods , a lower level of economic utility in society from resources devoted on high-end consumption , and even a lower level of economic growth when human capital is neglected for high-end consumption . 
for the top 21 industrialised countries , counting each person equally , life expectancy is lower in more unequal countries -lrb- r = -.907 -rrb- . 
effects of inequality researchers have found include higher rates of health and social problems , and lower rates of social goods , a lower level of economic utility in society from resources devoted on high-end consumption , and even a lower level of economic growth when human capital is neglected for high-end consumption . 
for the top 21 industrialised countries , counting each person equally , life expectancy is lower in more unequal countries -lrb- r = -.907 -rrb- . 
2013 economics nobel prize winner robert j. shiller said that rising inequality in the united states and elsewhere is the most important problem . 
2013 economics nobel prize winner robert j. shiller said that rising inequality in the united states and elsewhere is the most important problem . 
high and persistent unemployment , in which inequality increases , has a negative effect on subsequent long-run economic growth . 
unemployment can harm growth not only because it is a waste of resources , but also because it generates redistributive pressures and subsequent distortions , drives people to poverty , constrains liquidity limiting labor mobility , and erodes self-esteem promoting social dislocation , unrest and conflict . 
policies aiming at controlling unemployment and in particular at reducing its inequality-associated effects support economic growth . 
british researchers richard g. wilkinson and kate pickett have found higher rates of health and social problems -lrb- obesity , mental illness , homicides , teenage births , incarceration , child conflict , drug use -rrb- , and lower rates of social goods -lrb- life expectancy by country , educational performance , trust among strangers , women 's status , social mobility , even numbers of patents issued -rrb- in countries and states with higher inequality . 
british researchers richard g. wilkinson and kate pickett have found higher rates of health and social problems -lrb- obesity , mental illness , homicides , teenage births , incarceration , child conflict , drug use -rrb- , and lower rates of social goods -lrb- life expectancy by country , educational performance , trust among strangers , women 's status , social mobility , even numbers of patents issued -rrb- in countries and states with higher inequality . 
british researchers richard g. wilkinson and kate pickett have found higher rates of health and social problems -lrb- obesity , mental illness , homicides , teenage births , incarceration , child conflict , drug use -rrb- , and lower rates of social goods -lrb- life expectancy by country , educational performance , trust among strangers , women 's status , social mobility , even numbers of patents issued -rrb- in countries and states with higher inequality . 
using statistics from 23 developed countries and the 50 states of the us , they found social/health problems lower in countries like japan and finland and states like utah and new hampshire with high levels of equality , than in countries -lrb- us and uk -rrb- and states -lrb- mississippi and new york -rrb- with large differences in household income . 
using statistics from 23 developed countries and the 50 states of the us , they found social/health problems lower in countries like japan and finland and states like utah and new hampshire with high levels of equality , than in countries -lrb- us and uk -rrb- and states -lrb- mississippi and new york -rrb- with large differences in household income . 
for most of human history higher material living standards -- full stomachs , access to clean water and warmth from fuel -- led to better health and longer lives . 
this pattern of higher incomes-longer lives still holds among poorer countries , where life expectancy increases rapidly as per capita income increases , but in recent decades it has slowed down among middle income countries and plateaued among the richest thirty or so countries in the world . 
this pattern of higher incomes-longer lives still holds among poorer countries , where life expectancy increases rapidly as per capita income increases , but in recent decades it has slowed down among middle income countries and plateaued among the richest thirty or so countries in the world . 
americans live no longer on average -lrb- about 77 years in 2004 -rrb- than greeks -lrb- 78 years -rrb- or new zealanders -lrb- 78 -rrb- , though the usa has a higher gdp per capita . 
life expectancy in sweden -lrb- 80 years -rrb- and japan -lrb- 82 -rrb- -- where income was more equally distributed -- was longer . 
in recent years the characteristic that has strongly correlated with health in developed countries is income inequality . 
creating an index of `` health and social problems '' from nine factors , authors richard wilkinson and kate pickett found health and social problems `` more common in countries with bigger income inequalities '' , and more common among states in the us with larger income inequalities . 
creating an index of `` health and social problems '' from nine factors , authors richard wilkinson and kate pickett found health and social problems `` more common in countries with bigger income inequalities '' , and more common among states in the us with larger income inequalities . 
creating an index of `` health and social problems '' from nine factors , authors richard wilkinson and kate pickett found health and social problems `` more common in countries with bigger income inequalities '' , and more common among states in the us with larger income inequalities . 
the unicef index of `` child well-being in rich countries '' , studying 40 indicators in 22 countries , correlates with greater equality but not per capita income . 
crime rate has also been shown to be correlated with inequality in society . 
most studies looking into the relationship have concentrated on homicides -- since homicides are almost identically defined across all nations and jurisdictions . 
there have been over fifty studies showing tendencies for violence to be more common in societies where income differences are larger . 
they estimated that about half of all variation in homicide rates can be accounted for by differences in the amount of inequality in each province or state . 
daly et al. 2001 found that among u.s states and canadian provinces there is a tenfold difference in homicide rates related to inequality . 
following the utilitarian principle of seeking the greatest good for the greatest number -- economic inequality is problematic . 
a house that provides less utility to a millionaire as a summer home than it would to a homeless family of five , is an example of reduced `` distributive efficiency '' within society , that decreases marginal utility of wealth and thus the sum total of personal utility . 
an additional dollar spent by a poor person will go to things providing a great deal of utility to that person , such as basic necessities like food , water , and healthcare ; while , an additional dollar spent by a much richer person will very likely go to luxury items providing relatively less utility to that person . 
thus , the marginal utility of wealth per person -lrb- `` the additional dollar '' -rrb- decreases as a person becomes richer . 
from this standpoint , for any given amount of wealth in society , a society with more equality will have higher aggregate utility . 
conservative researchers have argued that income inequality is not significant because consumption , rather than income should be the measure of inequality , and inequality of consumption is less extreme than inequality of income in the us . 
will wilkinson of the libertarian cato institute states that `` the weight of the evidence shows that the run-up in consumption inequality has been considerably less dramatic than the rise in income inequality , '' and consumption is more important than income . 
according to johnson , smeeding , and tory , consumption inequality was actually lower in 2001 than it was in 1986 . 
the debate is summarized in `` the hidden prosperity of the poor '' by journalist thomas b. edsall . 
the debate is summarized in `` the hidden prosperity of the poor '' by journalist thomas b. edsall . 
central banking economist raghuram rajan argues that `` systematic economic inequalities , within the united states and around the world , have created deep financial ` fault lines ' that have made -lsb- financial -rsb- crises more likely to happen than in the past '' -- the financial crisis of 2007 -- 08 being the most recent example . 
central banking economist raghuram rajan argues that `` systematic economic inequalities , within the united states and around the world , have created deep financial ` fault lines ' that have made -lsb- financial -rsb- crises more likely to happen than in the past '' -- the financial crisis of 2007 -- 08 being the most recent example . 
central banking economist raghuram rajan argues that `` systematic economic inequalities , within the united states and around the world , have created deep financial ` fault lines ' that have made -lsb- financial -rsb- crises more likely to happen than in the past '' -- the financial crisis of 2007 -- 08 being the most recent example . 
to compensate for stagnating and declining purchasing power , political pressure has developed to extend easier credit to the lower and middle income earners -- particularly to buy homes -- and easier credit in general to keep unemployment rates low . 
to compensate for stagnating and declining purchasing power , political pressure has developed to extend easier credit to the lower and middle income earners -- particularly to buy homes -- and easier credit in general to keep unemployment rates low . 
according to international monetary fund economists , inequality in wealth and income is negatively correlated with the duration of economic growth spells -lrb- not the rate of growth -rrb- . 
high levels of inequality prevent not just economic prosperity , but also the quality of a country 's institutions and high levels of education . 
according to imf staff economists , `` if the income share of the top 20 percent -lrb- the rich -rrb- increases , then gdp growth actually declines over the medium term , suggesting that the benefits do not trickle down . 
in contrast , an increase in the income share of the bottom 20 percent -lrb- the poor -rrb- is associated with higher gdp growth . 
the poor and the middle class matter the most for growth via a number of interrelated economic , social , and political channels . '' 
according to economists david castells-quintana and vicente royuela , increasing inequality harms economic growth . 
according to economists david castells-quintana and vicente royuela , increasing inequality harms economic growth . 
high and persistent unemployment , in which inequality increases , has a negative effect on subsequent long-run economic growth . 
unemployment can harm growth not only because it is a waste of resources , but also because it generates redistributive pressures and subsequent distortions , drives people to poverty , constrains liquidity limiting labor mobility , and erodes self-esteem promoting social dislocation , unrest and conflict . 
policies aiming at controlling unemployment and in particular at reducing its inequality-associated effects support economic growth . 
economist joseph stiglitz presented evidence in 2009 that both global inequality and inequality within countries prevent growth by limiting aggregate demand . 
economist joseph stiglitz presented evidence in 2009 that both global inequality and inequality within countries prevent growth by limiting aggregate demand . 
economist branko milanovic , wrote in 2001 that , `` the view that income inequality harms growth -- or that improved equality can help sustain growth -- has become more widely held in recent years . 
... the main reason for this shift is the increasing importance of human capital in development . 
but now that human capital is scarcer than machines , widespread education has become the secret to growth . '' 
in 1993 , galor and zeira showed that inequality in the presence of credit market imperfections has a long lasting detrimental effect on human capital formation and economic development . 
in 1993 , galor and zeira showed that inequality in the presence of credit market imperfections has a long lasting detrimental effect on human capital formation and economic development . 
a 1996 study by perotti examined the channels through which inequality may affect economic growth . 
he found that inequality is associated with higher levels of redistributive taxation , which is associated with lower levels of growth from reductions in private savings and investment . 
also , very unequal societies tend to be politically and socially unstable , which is reflected in lower rates of investment and therefore growth . '' 
according to work by barro in 1999 and 2000 , high levels of inequality reduce growth in relatively poor countries but encourage growth in richer countries . 
according to work by barro in 1999 and 2000 , high levels of inequality reduce growth in relatively poor countries but encourage growth in richer countries . 
research by harvard economist robert barro , found that there is `` little overall relation between income inequality and rates of growth and investment '' . 
research by harvard economist robert barro , found that there is `` little overall relation between income inequality and rates of growth and investment '' . 
a study of swedish counties between 1960 and 2000 found a positive impact of inequality on growth with lead times of five years or less , but no correlation after ten years . 
studies on income inequality and growth have sometimes found evidence confirming the kuznets curve hypothesis , which states that with economic development , inequality first increases , then decreases . 
studies on income inequality and growth have sometimes found evidence confirming the kuznets curve hypothesis , which states that with economic development , inequality first increases , then decreases . 
economist thomas piketty challenges this notion , claiming that from 1914 to 1945 wars and `` violent economic and political shocks '' reduced inequality . 
economist thomas piketty challenges this notion , claiming that from 1914 to 1945 wars and `` violent economic and political shocks '' reduced inequality . 
economist thomas piketty challenges this notion , claiming that from 1914 to 1945 wars and `` violent economic and political shocks '' reduced inequality . 
some theories developed in the 1970s established possible avenues through which inequality may have a positive effect on economic development . 
according to a 1955 review , savings by the wealthy , if these increase with inequality , were thought to offset reduced consumer demand . 
a 2013 report on nigeria suggests that growth has risen with increased income inequality . 
analyses based on comparing yearly equality figures to yearly growth rates were misleading because it takes several years for effects to manifest as changes to economic growth . 
developing countries with high inequality have `` succeeded in initiating growth at high rates for a few years '' but `` longer growth spells are robustly associated with more equality in the income distribution . '' 
while acknowledging the central role economic growth can potentially play in human development , poverty reduction and the achievement of the millennium development goals , it is becoming widely understood amongst the development community that special efforts must be made to ensure poorer sections of society are able to participate in economic growth . 
the effect of economic growth on poverty reduction -- the growth elasticity of poverty -- can depend on the existing level of inequality . 
for instance , with low inequality a country with a growth rate of 2 % per head and 40 % of its population living in poverty , can halve poverty in ten years , but a country with high inequality would take nearly 60 years to achieve the same reduction . 
in the words of the secretary general of the united nations ban ki-moon : `` while economic growth is necessary , it is not sufficient for progress on reducing poverty . '' 
in the words of the secretary general of the united nations ban ki-moon : `` while economic growth is necessary , it is not sufficient for progress on reducing poverty . '' 
in many poor and developing countries much land and housing is held outside the formal or legal property ownership registration system . 
much unregistered property is held in informal form through various associations and other arrangements . 
reasons for extra-legal ownership include excessive bureaucratic red tape in buying property and building , in some countries it can take over 200 steps and up to 14 years to build on government land . 
reasons for extra-legal ownership include excessive bureaucratic red tape in buying property and building , in some countries it can take over 200 steps and up to 14 years to build on government land . 
reasons for extra-legal ownership include excessive bureaucratic red tape in buying property and building , in some countries it can take over 200 steps and up to 14 years to build on government land . 
a number of researchers -lrb- david rodda , jacob vigdor , and janna matlack -rrb- , argue that a shortage of affordable housing -- at least in the us -- is caused in part by income inequality . 
david rodda noted that from 1984 and 1991 , the number of quality rental units decreased as the demand for higher quality housing increased -lrb- rhoda 1994:148 -rrb- . 
david rodda noted that from 1984 and 1991 , the number of quality rental units decreased as the demand for higher quality housing increased -lrb- rhoda 1994:148 -rrb- . 
through gentrification of older neighbourhoods , for example , in east new york , rental prices increased rapidly as landlords found new residents willing to pay higher market rate for housing and left lower income families without rental units . 
the ad valorem property tax policy combined with rising prices made it difficult or impossible for low income residents to keep pace . 
firstly , certain costs are difficult to avoid and are shared by everyone , such as the costs of housing , pensions , education and health care . 
if the state does not provide these services , then for those on lower incomes , the costs must be borrowed and often those on lower incomes are those who are worse equipped to manage their finances . 
secondly , aspirational consumption describes the process of middle income earners aspiring to achieve the standards of living enjoyed by their wealthier counterparts and one method of achieving this aspiration is by taking on debt . 
secondly , aspirational consumption describes the process of middle income earners aspiring to achieve the standards of living enjoyed by their wealthier counterparts and one method of achieving this aspiration is by taking on debt . 
the result leads to even greater inequality and potential economic instability . 
the smaller the economic inequality , the more waste and pollution is created , resulting in many cases , in more environmental degradation . 
also note that the whole of the increase in environmental degradation is the result of the increase of emissions per person being multiplied by a multiplier . 
also note that the whole of the increase in environmental degradation is the result of the increase of emissions per person being multiplied by a multiplier . 
if -lrb- as wwf argued -rrb- , population levels would start to drop to a sustainable level -lrb- 1/3 of current levels , so about 2 billion people -rrb- , human inequality can be addressed/corrected , while still not resulting in an increase of environmental damage . 
socialists attribute the vast disparities in wealth to the private ownership of the means of production by a class of owners , creating a situation where a small portion of the population lives off unearned property income by virtue of ownership titles in capital equipment , financial assets and corporate stock . 
socialists attribute the vast disparities in wealth to the private ownership of the means of production by a class of owners , creating a situation where a small portion of the population lives off unearned property income by virtue of ownership titles in capital equipment , financial assets and corporate stock . 
by contrast , the vast majority of the population is dependent on income in the form of a wage or salary . 
in order to rectify this situation , socialists argue that the means of production should be socially owned so that income differentials would be reflective of individual contributions to the social product . 
in order to rectify this situation , socialists argue that the means of production should be socially owned so that income differentials would be reflective of individual contributions to the social product . 
robert nozick argued that government redistributes wealth by force -lrb- usually in the form of taxation -rrb- , and that the ideal moral society would be one where all individuals are free from force . 
robert nozick argued that government redistributes wealth by force -lrb- usually in the form of taxation -rrb- , and that the ideal moral society would be one where all individuals are free from force . 
robert nozick argued that government redistributes wealth by force -lrb- usually in the form of taxation -rrb- , and that the ideal moral society would be one where all individuals are free from force . 
however , nozick recognized that some modern economic inequalities were the result of forceful taking of property , and a certain amount of redistribution would be justified to compensate for this force but not because of the inequalities themselves . 
john rawls argued in a theory of justice that inequalities in the distribution of wealth are only justified when they improve society as a whole , including the poorest members . 
the capabilities approach -- sometimes called the human development approach -- looks at income inequality and poverty as form of `` capability deprivation '' . 
unlike neoliberalism , which `` defines well-being as utility maximization '' , economic growth and income are considered a means to an end rather than the end itself . 
its goal is to `` wid -lsb- en -rsb- people 's choices and the level of their achieved well-being '' through increasing functionings -lrb- the things a person values doing -rrb- , capabilities -lrb- the freedom to enjoy functionings -rrb- and agency -lrb- the ability to pursue valued goals -rrb- . 
its goal is to `` wid -lsb- en -rsb- people 's choices and the level of their achieved well-being '' through increasing functionings -lrb- the things a person values doing -rrb- , capabilities -lrb- the freedom to enjoy functionings -rrb- and agency -lrb- the ability to pursue valued goals -rrb- . 
its goal is to `` wid -lsb- en -rsb- people 's choices and the level of their achieved well-being '' through increasing functionings -lrb- the things a person values doing -rrb- , capabilities -lrb- the freedom to enjoy functionings -rrb- and agency -lrb- the ability to pursue valued goals -rrb- . 
when a person 's capabilities are lowered , they are in some way deprived of earning as much income as they would otherwise . 
an old , ill man can not earn as much as a healthy young man ; gender roles and customs may prevent a woman from receiving an education or working outside the home . 
an old , ill man can not earn as much as a healthy young man ; gender roles and customs may prevent a woman from receiving an education or working outside the home . 
there may be an epidemic that causes widespread panic , or there could be rampant violence in the area that prevents people from going to work for fear of their lives . 
to prevent such inequality , this approach believes it 's important to have political freedom , economic facilities , social opportunities , transparency guarantees , and protective security to ensure that people are n't denied their functionings , capabilities , and agency and can thus work towards a better relevant income . 
doctor who is a british science-fiction television programme produced by the bbc since 1963 . 
doctor who is a british science-fiction television programme produced by the bbc since 1963 . 
he explores the universe in his tardis , a sentient time-travelling space ship . 
its exterior appears as a blue british police box , which was a common sight in britain in 1963 when the series first aired . 
doctor who is a british science-fiction television programme produced by the bbc since 1963 . 
the programme originally ran from 1963 to 1989 . 
the programme was relaunched in 2005 by russell t davies , who was showrunner and head writer for the first five years of its revival , produced in-house by bbc wales in cardiff . 
doctor who also spawned spin-offs in multiple media , including torchwood -lrb- 2006 -- 2011 -rrb- and the sarah jane adventures -lrb- 2007 -- 2011 -rrb- , both created by russell t davies ; k-9 -lrb- 2009 -- 2010 -rrb- ; and a single pilot episode of k-9 and company -lrb- 1981 -rrb- . 
the programme was relaunched in 2005 by russell t davies , who was showrunner and head writer for the first five years of its revival , produced in-house by bbc wales in cardiff . 
the first series of the 21st century featured christopher eccleston in the title role and was produced by the bbc . 
twelve actors have headlined the series as the doctor . 
peter capaldi took on the role after matt smith 's exit in the 2013 christmas special `` the time of the doctor '' . 
peter capaldi took on the role after matt smith 's exit in the 2013 christmas special `` the time of the doctor '' . 
the show 's premise is that this is a life process of time lords through which the character of the doctor takes on a new body and , to some extent , new personality , which occurs after sustaining an injury which would be fatal to most other species . 
the show 's premise is that this is a life process of time lords through which the character of the doctor takes on a new body and , to some extent , new personality , which occurs after sustaining an injury which would be fatal to most other species . 
doctor who follows the adventures of the primary character , a rogue time lord from the planet gallifrey , who simply goes by the name `` the doctor '' . 
he fled from gallifrey in a stolen mark i type 40 tardis -- `` time and relative dimension in space '' -- time machine which allows him to travel across time and space . 
he fled from gallifrey in a stolen mark i type 40 tardis -- `` time and relative dimension in space '' -- time machine which allows him to travel across time and space . 
the tardis has a `` chameleon circuit '' which normally allows the machine to take on the appearance of local objects as a disguise . 
however , the doctor 's tardis remains fixed as a blue british police box due to a malfunction in the chameleon circuit . 
the doctor rarely travels alone and often brings one or more companions to share these adventures . 
the doctor has gained numerous reoccurring enemies during his travels , including the daleks , the cybermen , and the master , another renegade time lord . 
as a time lord , the doctor has the ability to regenerate when his body is mortally damaged , taking on a new appearance and personality . 
his companions are usually humans , as he has found a fascination with planet earth . 
as a time lord , the doctor has the ability to regenerate when his body is mortally damaged , taking on a new appearance and personality . 
doctor who first appeared on bbc tv at 17:16:20 gmt , eighty seconds after the scheduled programme time , 5:15 pm , on saturday , 23 november 1963 . 
nation 's script became the second doctor who serial -- the daleks -lrb- a.k.a. . 
when the script was presented to newman and wilson it was immediately rejected as the programme was not permitted to contain any `` bug-eyed monsters '' . 
on 31 july 1963 whitaker commissioned terry nation to write a story under the title the mutants . 
it was to be a regular weekly programme , each episode 25 minutes of transmission length . 
the bbc drama department 's serials division produced the programme for 26 seasons , broadcast on bbc 1 . 
falling viewing numbers , a decline in the public perception of the show and a less-prominent transmission slot saw production suspended in 1989 by jonathan powell , controller of bbc 1 . 
although -lrb- as series co-star sophie aldred reported in the documentary doctor who : more than 30 years in the tardis -rrb- it was effectively , if not formally , cancelled with the decision not to commission a planned 27th series of the show for transmission in 1990 , the bbc repeatedly affirmed that the series would return . 
although -lrb- as series co-star sophie aldred reported in the documentary doctor who : more than 30 years in the tardis -rrb- it was effectively , if not formally , cancelled with the decision not to commission a planned 27th series of the show for transmission in 1990 , the bbc repeatedly affirmed that the series would return . 
the bbc drama department 's serials division produced the programme for 26 seasons , broadcast on bbc 1 . 
while in-house production had ceased , the bbc hoped to find an independent production company to relaunch the show . 
philip segal , a british expatriate who worked for columbia pictures ' television arm in the united states , had approached the bbc about such a venture as early as july 1989 , while the 26th series was still in production . 
segal 's negotiations eventually led to a doctor who television film , broadcast on the fox network in 1996 as a co-production between fox , universal pictures , the bbc and bbc worldwide . 
although the film was successful in the uk -lrb- with 9.1 million viewers -rrb- , it was less so in the united states and did not lead to a series . 
although the film was successful in the uk -lrb- with 9.1 million viewers -rrb- , it was less so in the united states and did not lead to a series . 
doctor who finally returned with the episode `` rose '' on bbc one on 26 march 2005 . 
doctor who finally returned with the episode `` rose '' on bbc one on 26 march 2005 . 
no full series was filmed in 2009 , although four additional specials starring david tennant were made . 
in january 2016 , moffat announced that he would step down after the 2017 finale , to be replaced by chris chibnall in 2018 . 
there have since been nine further series in 2006 -- 2008 and 2010 -- 2015 , and christmas day specials every year since 2005 . 
the 2005 version of doctor who is a direct plot continuation of the original 1963 -- 1989 series -lsb- note 2 -rsb- and the 1996 telefilm . 
the 2005 version of doctor who is a direct plot continuation of the original 1963 -- 1989 series -lsb- note 2 -rsb- and the 1996 telefilm . 
the 2005 version of doctor who is a direct plot continuation of the original 1963 -- 1989 series -lsb- note 2 -rsb- and the 1996 telefilm . 
this is similar to the 1988 continuation of mission impossible , but differs from most other series relaunches which have either been reboots -lrb- for example , battlestar galactica and bionic woman -lsb- citation needed -rsb- -rrb- or set in the same universe as the original but in a different time period and with different characters -lrb- for example , star trek : the next generation and spin-offs -lsb- citation needed -rsb- -rrb- . 
this is similar to the 1988 continuation of mission impossible , but differs from most other series relaunches which have either been reboots -lrb- for example , battlestar galactica and bionic woman -lsb- citation needed -rsb- -rrb- or set in the same universe as the original but in a different time period and with different characters -lrb- for example , star trek : the next generation and spin-offs -lsb- citation needed -rsb- -rrb- . 
the bbc believed that many viewers had missed this introduction to a new series due to the coverage of the assassination , as well as a series of power blackouts across the country , and they broadcast it again on 30 november 1963 , just before episode two . 
it has been claimed that the transmission of the first episode was delayed by ten minutes due to extended news coverage of the assassination of us president john f. kennedy the previous day ; whereas in fact it went out after a delay of eighty seconds . 
it has been claimed that the transmission of the first episode was delayed by ten minutes due to extended news coverage of the assassination of us president john f. kennedy the previous day ; whereas in fact it went out after a delay of eighty seconds . 
it has been claimed that the transmission of the first episode was delayed by ten minutes due to extended news coverage of the assassination of us president john f. kennedy the previous day ; whereas in fact it went out after a delay of eighty seconds . 
the bbc believed that many viewers had missed this introduction to a new series due to the coverage of the assassination , as well as a series of power blackouts across the country , and they broadcast it again on 30 november 1963 , just before episode two . 
the phrase `` hiding behind -lrb- or ` watching from behind ' -rrb- the sofa '' entered british pop culture , signifying in humour the stereotypical early-series behaviour of children who wanted to avoid seeing frightening parts of a television programme while remaining in the room to watch the remainder of it . 
the phrase retains this association with doctor who , to the point that in 1991 the museum of the moving image in london named their exhibition celebrating the programme `` behind the sofa '' . 
the phrase retains this association with doctor who , to the point that in 1991 the museum of the moving image in london named their exhibition celebrating the programme `` behind the sofa '' . 
a 2012 article placed this childhood juxtaposition of fear and thrill `` at the center of many people 's relationship with the show '' , and a 2011 online vote at digital spy deemed the series the `` scariest tv show of all time '' . 
a 2012 article placed this childhood juxtaposition of fear and thrill `` at the center of many people 's relationship with the show '' , and a 2011 online vote at digital spy deemed the series the `` scariest tv show of all time '' . 
a bbc audience research survey conducted in 1972 found that , by their own definition of violence -lrb- `` any act -lsb- s -rsb- which may cause physical and/or psychological injury , hurt or death to persons , animals or property , whether intentional or accidental '' -rrb- doctor who was the most violent of the drama programmes the corporation produced at the time . 
the same report found that 3 % of the surveyed audience regarded the show as `` very unsuitable '' for family viewing . 
responding to the findings of the survey in the times newspaper , journalist philip howard maintained that , `` to compare the violence of dr who , sired by a horse-laugh out of a nightmare , with the more realistic violence of other television series , where actors who look like human beings bleed paint that looks like blood , is like comparing monopoly with the property market in london : both are fantasies , but one is meant to be taken seriously . '' 
responding to the findings of the survey in the times newspaper , journalist philip howard maintained that , `` to compare the violence of dr who , sired by a horse-laugh out of a nightmare , with the more realistic violence of other television series , where actors who look like human beings bleed paint that looks like blood , is like comparing monopoly with the property market in london : both are fantasies , but one is meant to be taken seriously . '' 
responding to the findings of the survey in the times newspaper , journalist philip howard maintained that , `` to compare the violence of dr who , sired by a horse-laugh out of a nightmare , with the more realistic violence of other television series , where actors who look like human beings bleed paint that looks like blood , is like comparing monopoly with the property market in london : both are fantasies , but one is meant to be taken seriously . '' 
the image of the tardis has become firmly linked to the show in the public 's consciousness ; bbc scriptwriter anthony coburn , who lived in the resort of herne bay , kent , was one of the people who conceived the idea of a police box as a time machine . 
in 1996 , the bbc applied for a trade mark to use the tardis ' blue police box design in merchandising associated with doctor who . 
the image of the tardis has become firmly linked to the show in the public 's consciousness ; bbc scriptwriter anthony coburn , who lived in the resort of herne bay , kent , was one of the people who conceived the idea of a police box as a time machine . 
in 1998 , the metropolitan police authority filed an objection to the trade mark claim ; but in 2002 , the patent office ruled in favour of the bbc . 
in 1998 , the metropolitan police authority filed an objection to the trade mark claim ; but in 2002 , the patent office ruled in favour of the bbc . 
doctor who originally ran for 26 seasons on bbc one , from 23 november 1963 until 6 december 1989 . 
doctor who originally ran for 26 seasons on bbc one , from 23 november 1963 until 6 december 1989 . 
notable exceptions were : the daleks ' master plan , which aired in 12 episodes -lrb- plus an earlier one-episode teaser , `` mission to the unknown '' , featuring none of the regular cast -rrb- ; almost an entire season of seven-episode serials -lrb- season 7 -rrb- ; the 10-episode serial the war games ; and the trial of a time lord , which ran for 14 episodes -lrb- albeit divided into three production codes and four narrative segments -rrb- during season 23 . 
occasionally serials were loosely connected by a storyline , such as season 8 being devoted to the doctor battling a rogue time lord called the master , season 16 's quest for the key to time , season 18 's journey through e-space and the theme of entropy , and season 20 's black guardian trilogy . 
occasionally serials were loosely connected by a storyline , such as season 8 being devoted to the doctor battling a rogue time lord called the master , season 16 's quest for the key to time , season 18 's journey through e-space and the theme of entropy , and season 20 's black guardian trilogy . 
the serial format changed for the 2005 revival , with each series usually consisting of 13 45-minute , self-contained episodes -lrb- 60 minutes with adverts , on overseas commercial channels -rrb- , and an extended episode broadcast on christmas day . 
the serial format changed for the 2005 revival , with each series usually consisting of 13 45-minute , self-contained episodes -lrb- 60 minutes with adverts , on overseas commercial channels -rrb- , and an extended episode broadcast on christmas day . 
the serial format changed for the 2005 revival , with each series usually consisting of 13 45-minute , self-contained episodes -lrb- 60 minutes with adverts , on overseas commercial channels -rrb- , and an extended episode broadcast on christmas day . 
occasionally , regular-series episodes will exceed the 45-minute run time ; notably , the episodes `` journey 's end '' from 2008 and `` the eleventh hour '' from 2010 exceeded an hour in length . 
occasionally , regular-series episodes will exceed the 45-minute run time ; notably , the episodes `` journey 's end '' from 2008 and `` the eleventh hour '' from 2010 exceeded an hour in length . 
826 doctor who instalments have been televised since 1963 , ranging between 25-minute episodes -lrb- the most common format -rrb- , 45-minute episodes -lrb- for resurrection of the daleks in the 1984 series , a single season in 1985 , and the revival -rrb- , two feature-length productions -lrb- 1983 's the five doctors and the 1996 television film -rrb- , eight christmas specials -lrb- most of 60 minutes ' duration , one of 72 minutes -rrb- , and four additional specials ranging from 60 to 75 minutes in 2009 , 2010 and 2013 . 
826 doctor who instalments have been televised since 1963 , ranging between 25-minute episodes -lrb- the most common format -rrb- , 45-minute episodes -lrb- for resurrection of the daleks in the 1984 series , a single season in 1985 , and the revival -rrb- , two feature-length productions -lrb- 1983 's the five doctors and the 1996 television film -rrb- , eight christmas specials -lrb- most of 60 minutes ' duration , one of 72 minutes -rrb- , and four additional specials ranging from 60 to 75 minutes in 2009 , 2010 and 2013 . 
826 doctor who instalments have been televised since 1963 , ranging between 25-minute episodes -lrb- the most common format -rrb- , 45-minute episodes -lrb- for resurrection of the daleks in the 1984 series , a single season in 1985 , and the revival -rrb- , two feature-length productions -lrb- 1983 's the five doctors and the 1996 television film -rrb- , eight christmas specials -lrb- most of 60 minutes ' duration , one of 72 minutes -rrb- , and four additional specials ranging from 60 to 75 minutes in 2009 , 2010 and 2013 . 
826 doctor who instalments have been televised since 1963 , ranging between 25-minute episodes -lrb- the most common format -rrb- , 45-minute episodes -lrb- for resurrection of the daleks in the 1984 series , a single season in 1985 , and the revival -rrb- , two feature-length productions -lrb- 1983 's the five doctors and the 1996 television film -rrb- , eight christmas specials -lrb- most of 60 minutes ' duration , one of 72 minutes -rrb- , and four additional specials ranging from 60 to 75 minutes in 2009 , 2010 and 2013 . 
starting with the 2009 special `` planet of the dead '' , the series was filmed in 1080i for hdtv , and broadcast simultaneously on bbc one and bbc hd . 
this included many old episodes of doctor who , mostly stories featuring the first two doctors : william hartnell and patrick troughton . 
in all , 97 of 253 episodes produced during the first six years of the programme are not held in the bbc 's archives -lrb- most notably seasons 3 , 4 , & 5 , from which 79 episodes are missing -rrb- . 
in all , 97 of 253 episodes produced during the first six years of the programme are not held in the bbc 's archives -lrb- most notably seasons 3 , 4 , & 5 , from which 79 episodes are missing -rrb- . 
in 1972 , almost all episodes then made were known to exist at the bbc , while by 1978 the practice of wiping tapes and destroying `` spare '' film copies had been brought to a stop . 
between about 1964 and 1973 , large amounts of older material stored in the bbc 's various video tape and film libraries were either destroyed , -lsb- note 3 -rsb- wiped , or suffered from poor storage which led to severe deterioration from broadcast quality . 
some episodes have been returned to the bbc from the archives of other countries who bought prints for broadcast , or by private individuals who acquired them by various means . 
early colour videotape recordings made off-air by fans have also been retrieved , as well as excerpts filmed from the television screen onto 8 mm cine film and clips that were shown on other programmes . 
short clips from every story with the exception of marco polo , `` mission to the unknown '' and the massacre of st bartholomew 's eve also exist . 
early colour videotape recordings made off-air by fans have also been retrieved , as well as excerpts filmed from the television screen onto 8 mm cine film and clips that were shown on other programmes . 
audio versions of all of the lost episodes exist from home viewers who made tape recordings of the show . 
`` official '' reconstructions have also been released by the bbc on vhs , on mp3 cd-rom , and as special features on dvd . 
the bbc , in conjunction with animation studio cosgrove hall , reconstructed the missing episodes 1 and 4 of the invasion -lrb- 1968 -rrb- , using remastered audio tracks and the comprehensive stage notes for the original filming , for the serial 's dvd release in november 2006 . 
the bbc , in conjunction with animation studio cosgrove hall , reconstructed the missing episodes 1 and 4 of the invasion -lrb- 1968 -rrb- , using remastered audio tracks and the comprehensive stage notes for the original filming , for the serial 's dvd release in november 2006 . 
the missing episodes of the reign of terror were animated by animation company theta-sigma , in collaboration with big finish , and became available for purchase in may 2013 through amazon.com . 
the bbc , in conjunction with animation studio cosgrove hall , reconstructed the missing episodes 1 and 4 of the invasion -lrb- 1968 -rrb- , using remastered audio tracks and the comprehensive stage notes for the original filming , for the serial 's dvd release in november 2006 . 
producers introduced the concept of regeneration to permit the recasting of the main character . 
the actual term `` regeneration '' was not initially conceived of until the doctor 's third on-screen regeneration however ; hartnell 's doctor had merely described undergoing a `` renewal , '' and the second doctor underwent a `` change of appearance '' . 
this was first prompted by original star william hartnell 's poor health . 
the actual term `` regeneration '' was not initially conceived of until the doctor 's third on-screen regeneration however ; hartnell 's doctor had merely described undergoing a `` renewal , '' and the second doctor underwent a `` change of appearance '' . 
the actual term `` regeneration '' was not initially conceived of until the doctor 's third on-screen regeneration however ; hartnell 's doctor had merely described undergoing a `` renewal , '' and the second doctor underwent a `` change of appearance '' . 
the serials the deadly assassin and mawdryn undead and the 1996 tv film would later establish that a time lord can only regenerate 12 times , for a total of 13 incarnations . 
the serials the deadly assassin and mawdryn undead and the 1996 tv film would later establish that a time lord can only regenerate 12 times , for a total of 13 incarnations . 
the episode `` the time of the doctor '' depicted the doctor acquiring a new cycle of regenerations , starting from the twelfth doctor , due to the eleventh doctor being the product of the doctor 's twelfth regeneration from his original set . 
the serials the deadly assassin and mawdryn undead and the 1996 tv film would later establish that a time lord can only regenerate 12 times , for a total of 13 incarnations . 
the serials the deadly assassin and mawdryn undead and the 1996 tv film would later establish that a time lord can only regenerate 12 times , for a total of 13 incarnations . 
notably , in 2013 , john hurt guest-starred as a hitherto unknown incarnation of the doctor known as the war doctor in the run-up to the show 's 50th anniversary special `` the day of the doctor '' . 
notably , in 2013 , john hurt guest-starred as a hitherto unknown incarnation of the doctor known as the war doctor in the run-up to the show 's 50th anniversary special `` the day of the doctor '' . 
another example is from the 1986 serial the trial of a time lord , where michael jayston portrayed the valeyard , who is described as an amalgamation of the darker sides of the doctor 's nature , somewhere between his twelfth and final incarnation . 
another example is from the 1986 serial the trial of a time lord , where michael jayston portrayed the valeyard , who is described as an amalgamation of the darker sides of the doctor 's nature , somewhere between his twelfth and final incarnation . 
he is shown in mini-episode `` the night of the doctor '' to have been retroactively inserted into the show 's fictional chronology between mcgann and eccleston 's doctors , although his introduction was written so as not to disturb the established numerical naming of the doctors . 
in `` the name of the doctor '' , the eleventh doctor meets an unknown incarnation of himself , whom he refers to as `` his secret '' and who is subsequently revealed to be the war doctor . 
in 1973 's the three doctors , william hartnell and patrick troughton returned alongside jon pertwee . 
in 2007 , peter davison returned in the children in need short `` time crash '' alongside david tennant , and most recently in 2013 's 50th anniversary special episode , `` the day of the doctor '' , david tennant 's tenth doctor appeared alongside matt smith as the eleventh doctor and john hurt as the war doctor , as well as brief footage from all of the previous actors . 
the first doctor encounters himself in the story the space museum -lrb- albeit frozen and as an exhibit -rrb- , the third doctor encounters and interacts with himself in the story day of the daleks , the fourth doctor encounters and interacts with the future incarnation of himself -lrb- the ` watcher ' -rrb- in the story logopolis , the ninth doctor observes a former version of his current incarnation in `` father 's day '' , and the eleventh doctor briefly comes face to face with himself in `` the big bang '' . 
in 2007 , peter davison returned in the children in need short `` time crash '' alongside david tennant , and most recently in 2013 's 50th anniversary special episode , `` the day of the doctor '' , david tennant 's tenth doctor appeared alongside matt smith as the eleventh doctor and john hurt as the war doctor , as well as brief footage from all of the previous actors . 
peter davison , colin baker and sylvester mccoy appeared together in the 1999 audio adventure the sirens of time . 
to celebrate the 40th anniversary in 2003 , an audio drama titled zagreus featuring paul mcgann , colin baker , sylvester mccoy and peter davison was released with additional archive recordings of jon pertwee . 
in 2010 , peter davison , colin baker , sylvester mccoy and paul mcgann came together again to star in the audio drama the four doctors . 
again in 2003 , colin baker and sylvester mccoy appeared together in the audio adventure project : lazarus . 
to celebrate the 40th anniversary in 2003 , an audio drama titled zagreus featuring paul mcgann , colin baker , sylvester mccoy and peter davison was released with additional archive recordings of jon pertwee . 
in the 2013 episode `` the time of the doctor , '' the eleventh doctor clarified he was the product of the twelfth regeneration , due to a previous incarnation which he chose not to count and one other aborted regeneration . 
in the brain of morbius -lrb- 1976 -rrb- , it was hinted that the first doctor may not have been the first incarnation -lrb- although the other faces depicted may have been incarnations of the time lord morbius -rrb- . 
in mawdryn undead -lrb- 1983 -rrb- , the fifth doctor explicitly confirmed that he was then currently in his fifth incarnation . 
in 2010 , the eleventh doctor similarly calls himself `` the eleventh '' in `` the lodger '' . 
later that same year , during 1983 's 20th anniversary special the five doctors , the first doctor enquires as to the fifth doctor 's regeneration ; when the fifth doctor confirms `` fourth '' , the first doctor excitedly replies `` goodness me . 
the programme 's first serial , an unearthly child , shows that the doctor has a granddaughter , susan foreman . 
the programme 's first serial , an unearthly child , shows that the doctor has a granddaughter , susan foreman . 
the 2005 series reveals that the ninth doctor thought he was the last surviving time lord , and that his home planet had been destroyed ; in `` the empty child '' -lrb- 2005 -rrb- , dr. constantine states that , `` before the war even began , i was a father and a grandfather . 
the 2005 series reveals that the ninth doctor thought he was the last surviving time lord , and that his home planet had been destroyed ; in `` the empty child '' -lrb- 2005 -rrb- , dr. constantine states that , `` before the war even began , i was a father and a grandfather . 
in `` smith and jones '' -lrb- 2007 -rrb- , when asked if he had a brother , he replied , `` no , not any more . '' 
the companion figure -- generally a human -- has been a constant feature in doctor who since the programme 's inception in 1963 . 
the only story from the original series in which the doctor travels alone is the deadly assassin . 
the doctor 's first companions seen on screen were his granddaughter susan foreman -lrb- carole ann ford -rrb- and her teachers barbara wright -lrb- jacqueline hill -rrb- and ian chesterton -lrb- william russell -rrb- . 
the doctor 's first companions seen on screen were his granddaughter susan foreman -lrb- carole ann ford -rrb- and her teachers barbara wright -lrb- jacqueline hill -rrb- and ian chesterton -lrb- william russell -rrb- . 
notable companions from the earlier series included romana -lrb- mary tamm and lalla ward -rrb- , a time lady ; sarah jane smith -lrb- elisabeth sladen -rrb- ; and jo grant -lrb- katy manning -rrb- . 
since the 2005 revival , the doctor generally travels with a primary female companion , who occupies a larger narrative role . 
the primary companions of the ninth and tenth doctors were rose tyler -lrb- billie piper -rrb- , martha jones -lrb- freema agyeman -rrb- , and donna noble -lrb- catherine tate -rrb- with mickey smith -lrb- noel clarke -rrb- and jack harkness -lrb- john barrowman -rrb- recurring as secondary companion figures . 
the eleventh doctor became the first to travel with a married couple , amy pond -lrb- karen gillan -rrb- and rory williams -lrb- arthur darvill -rrb- , whilst out-of-sync meetings with river song -lrb- alex kingston -rrb- and clara oswald -lrb- jenna coleman -rrb- provided ongoing story arcs . 
the tenth series will introduce pearl mackie as bill , the doctor 's newest traveling companion . 
the primary companions of the ninth and tenth doctors were rose tyler -lrb- billie piper -rrb- , martha jones -lrb- freema agyeman -rrb- , and donna noble -lrb- catherine tate -rrb- with mickey smith -lrb- noel clarke -rrb- and jack harkness -lrb- john barrowman -rrb- recurring as secondary companion figures . 
with the show 's 2005 revival , executive producer russell t davies stated his intention to reintroduce classic icons of doctor who one step at a time : the autons with the nestene consciousness and daleks in series 1 , cybermen in series 2 , the macra and the master in series 3 , the sontarans and davros in series 4 , and the time lords -lrb- rassilon -rrb- in the 2009 -- 10 specials . 
with the show 's 2005 revival , executive producer russell t davies stated his intention to reintroduce classic icons of doctor who one step at a time : the autons with the nestene consciousness and daleks in series 1 , cybermen in series 2 , the macra and the master in series 3 , the sontarans and davros in series 4 , and the time lords -lrb- rassilon -rrb- in the 2009 -- 10 specials . 
with the show 's 2005 revival , executive producer russell t davies stated his intention to reintroduce classic icons of doctor who one step at a time : the autons with the nestene consciousness and daleks in series 1 , cybermen in series 2 , the macra and the master in series 3 , the sontarans and davros in series 4 , and the time lords -lrb- rassilon -rrb- in the 2009 -- 10 specials . 
with the show 's 2005 revival , executive producer russell t davies stated his intention to reintroduce classic icons of doctor who one step at a time : the autons with the nestene consciousness and daleks in series 1 , cybermen in series 2 , the macra and the master in series 3 , the sontarans and davros in series 4 , and the time lords -lrb- rassilon -rrb- in the 2009 -- 10 specials . 
davies ' successor , steven moffat , has continued the trend by reviving the silurians in series 5 , cybermats in series 6 , the great intelligence and the ice warriors in series 7 , and zygons in the 50th anniversary special . 
the dalek race , which first appeared in the show 's second serial in 1963 , are doctor who 's oldest villains . 
the daleks are kaleds from the planet skaro , mutated by the scientist davros and housed in mechanical armour shells for mobility . 
their chief role in the series plot , as they frequently remark in their instantly recognisable metallic voices , is to `` exterminate '' all non-dalek beings . 
the daleks are kaleds from the planet skaro , mutated by the scientist davros and housed in mechanical armour shells for mobility . 
their main weakness is their eyestalk ; attacks upon them using various weapons can blind a dalek , making it go mad . 
the master is the doctor 's archenemy , a renegade time lord who desires to rule the universe . 
the master is the doctor 's archenemy , a renegade time lord who desires to rule the universe . 
the master returned in the 1996 television movie of doctor who , and was played by american actor eric roberts . 
conceived as `` professor moriarty to the doctor 's sherlock holmes '' , the character first appeared in 1971 . 
as with the doctor , the role has been portrayed by several actors , since the master is a time lord as well and able to regenerate ; the first of these actors was roger delgado , who continued in the role until his death in 1973 . 
following the series revival in 2005 , derek jacobi provided the character 's re-introduction in the 2007 episode `` utopia '' . 
following the series revival in 2005 , derek jacobi provided the character 's re-introduction in the 2007 episode `` utopia '' . 
as of the 2014 episode `` dark water , '' it was revealed that the master had become a female incarnation or `` time lady , '' going by the name of `` missy '' -lrb- short for mistress , the feminine equivalent of `` master '' -rrb- . 
as of the 2014 episode `` dark water , '' it was revealed that the master had become a female incarnation or `` time lady , '' going by the name of `` missy '' -lrb- short for mistress , the feminine equivalent of `` master '' -rrb- . 
this incarnation is played by michelle gomez . 
the original theme was composed by ron grainer and realised by delia derbyshire of the bbc radiophonic workshop , with assistance from dick mills . 
the original theme was composed by ron grainer and realised by delia derbyshire of the bbc radiophonic workshop , with assistance from dick mills . 
the various parts were built up using musique concrète techniques , by creating tape loops of an individually struck piano string and individual test oscillators and filters . 
the derbyshire arrangement served , with minor edits , as the theme tune up to the end of season 17 -lrb- 1979 -- 80 -rrb- . 
on hearing the finished result , grainer asked , `` did i write that ? '' 
a different arrangement was recorded by peter howell for season 18 -lrb- 1980 -rrb- , which was in turn replaced by dominic glynn 's arrangement for the season-long serial the trial of a time lord in season 23 -lrb- 1986 -rrb- . 
a different arrangement was recorded by peter howell for season 18 -lrb- 1980 -rrb- , which was in turn replaced by dominic glynn 's arrangement for the season-long serial the trial of a time lord in season 23 -lrb- 1986 -rrb- . 
keff mcculloch provided the new arrangement for the seventh doctor 's era which lasted from season 24 -lrb- 1987 -rrb- until the series ' suspension in 1989 . 
for the return of the series in 2005 , murray gold provided a new arrangement which featured samples from the 1963 original with further elements added ; in the 2005 christmas episode `` the christmas invasion '' , gold introduced a modified closing credits arrangement that was used up until the conclusion of the 2007 series . 
for the return of the series in 2005 , murray gold provided a new arrangement which featured samples from the 1963 original with further elements added ; in the 2005 christmas episode `` the christmas invasion '' , gold introduced a modified closing credits arrangement that was used up until the conclusion of the 2007 series . 
a new arrangement of the theme , once again by gold , was introduced in the 2007 christmas special episode , `` voyage of the damned '' ; gold returned as composer for the 2010 series . 
in 2011 , the theme tune charted at number 228 of radio station classic fm 's hall of fame , a survey of classical music tastes . 
a new arrangement of the theme , once again by gold , was introduced in the 2007 christmas special episode , `` voyage of the damned '' ; gold returned as composer for the 2010 series . 
in 2011 , the theme tune charted at number 228 of radio station classic fm 's hall of fame , a survey of classical music tastes . 
a revised version of gold 's 2010 arrangement had its debut over the opening titles of the 2012 christmas special `` the snowmen '' , and a further revision of the arrangement was made for the 50th anniversary special `` the day of the doctor '' in november 2013 . 
in the early 1970s , jon pertwee , who had played the third doctor , recorded a version of the doctor who theme with spoken lyrics , titled , `` who is the doctor '' . 
-lsb- note 6 -rsb- in 1978 a disco version of the theme was released in the uk , denmark and australia by the group mankind , which reached number 24 in the uk charts . 
-lsb- note 6 -rsb- in 1978 a disco version of the theme was released in the uk , denmark and australia by the group mankind , which reached number 24 in the uk charts . 
in 1988 the band the justified ancients of mu mu -lrb- later known as the klf -rrb- released the single `` doctorin ' the tardis '' under the name the timelords , which reached no. 1 in the uk and no. 2 in australia ; this version incorporated several other songs , including `` rock and roll part 2 '' by gary glitter -lrb- who recorded vocals for some of the cd-single remix versions of `` doctorin ' the tardis '' -rrb- . 
in 1988 the band the justified ancients of mu mu -lrb- later known as the klf -rrb- released the single `` doctorin ' the tardis '' under the name the timelords , which reached no. 1 in the uk and no. 2 in australia ; this version incorporated several other songs , including `` rock and roll part 2 '' by gary glitter -lrb- who recorded vocals for some of the cd-single remix versions of `` doctorin ' the tardis '' -rrb- . 
the most frequent musical contributor during the first 15 years was dudley simpson , who is also well known for his theme and incidental music for blake 's 7 , and for his haunting theme music and score for the original 1970s version of the tomorrow people . 
simpson 's first doctor who score was planet of giants -lrb- 1964 -rrb- and he went on to write music for many adventures of the 1960s and 1970s , including most of the stories of the jon pertwee/tom baker periods , ending with the horns of nimon -lrb- 1979 -rrb- . 
simpson 's first doctor who score was planet of giants -lrb- 1964 -rrb- and he went on to write music for many adventures of the 1960s and 1970s , including most of the stories of the jon pertwee/tom baker periods , ending with the horns of nimon -lrb- 1979 -rrb- . 
simpson 's first doctor who score was planet of giants -lrb- 1964 -rrb- and he went on to write music for many adventures of the 1960s and 1970s , including most of the stories of the jon pertwee/tom baker periods , ending with the horns of nimon -lrb- 1979 -rrb- . 
he also made a cameo appearance in the talons of weng-chiang -lrb- as a music hall conductor -rrb- . 
all the incidental music for the 2005 revived series has been composed by murray gold and ben foster and has been performed by the bbc national orchestra of wales from the 2005 christmas episode `` the christmas invasion '' onwards . 
all the incidental music for the 2005 revived series has been composed by murray gold and ben foster and has been performed by the bbc national orchestra of wales from the 2005 christmas episode `` the christmas invasion '' onwards . 
a doctor who prom was celebrated on 27 july 2008 in the royal albert hall as part of the annual bbc proms . 
it also featured the specially filmed mini-episode `` music of the spheres '' , written by russell t davies and starring david tennant . 
all the incidental music for the 2005 revived series has been composed by murray gold and ben foster and has been performed by the bbc national orchestra of wales from the 2005 christmas episode `` the christmas invasion '' onwards . 
six soundtrack releases have been released since 2005 . 
the first featured tracks from the first two series , the second and third featured music from the third and fourth series respectively . 
the fourth was released on 4 october 2010 as a two disc special edition and contained music from the 2008 -- 2010 specials -lrb- the next doctor to end of time part 2 -rrb- . 
in february 2011 , a soundtrack was released for the 2010 christmas special : `` a christmas carol '' , and in december 2011 the soundtrack for series 6 was released , both by silva screen records . 
the soundtrack for series 5 was released on 8 november 2010 . 
the original logo used for the first doctor -lrb- and briefly for the second doctor -rrb- was reused in a slightly modified format for the 50th anniversary special `` the day of the doctor '' during the eleventh doctor 's run . 
the logo for the twelfth doctor had the `` dw '' tardis insignia removed and the font was subtly altered , as well as made slightly larger . 
as of 2014 , the logo used for the third and eighth doctors is the primary logo used on all media and merchandise relating to past doctors , and the current doctor who logo is used for all merchandise relating to the current doctor . 
the logo from 1973 -- 80 was used for the third doctor 's final season and for the majority of the fourth doctor 's tenure . 
the original logo used for the first doctor -lrb- and briefly for the second doctor -rrb- was reused in a slightly modified format for the 50th anniversary special `` the day of the doctor '' during the eleventh doctor 's run . 
premiering the day after the assassination of john f. kennedy , the first episode of doctor who was repeated with the second episode the following week . 
doctor who has always appeared initially on the bbc 's mainstream bbc one channel , where it is regarded as a family show , drawing audiences of many millions of viewers ; episodes are now repeated on bbc three . 
the second was the late 1970s , when tom baker occasionally drew audiences of over 12 million . 
the first of these was the `` dalekmania '' period -lrb- circa 1964 -- 1965 -rrb- , when the popularity of the daleks regularly brought doctor who ratings of between 9 and 14 million , even for stories which did not feature them . 
doctor who has always appeared initially on the bbc 's mainstream bbc one channel , where it is regarded as a family show , drawing audiences of many millions of viewers ; episodes are now repeated on bbc three . 
during the itv network strike of 1979 , viewership peaked at 16 million . 
its late 1980s performance of three to five million viewers was seen as poor at the time and was , according to the bbc board of control , a leading cause of the programme 's 1989 suspension . 
some fans considered this disingenuous , since the programme was scheduled against the soap opera coronation street , the most popular show at the time . 
some fans considered this disingenuous , since the programme was scheduled against the soap opera coronation street , the most popular show at the time . 
after the series ' revival in 2005 -lrb- the third notable period of high ratings -rrb- , it has consistently had high viewership levels for the evening on which the episode is broadcast . 
the 1983 20th anniversary special the five doctors had its début on 23 november -lrb- the actual date of the anniversary -rrb- on a number of pbs stations two days prior to its bbc one broadcast . 
the 1988 story silver nemesis was broadcast with all three episodes airing back to back on tvnz in new zealand in november , after the first episode had been shown in the uk but before the final two instalments had aired there . 
finally , the 1996 television film premièred on 12 may 1996 on citv in edmonton , canada , 15 days before the bbc one showing , and two days before it aired on fox in the united states . 
finally , the 1996 television film premièred on 12 may 1996 on citv in edmonton , canada , 15 days before the bbc one showing , and two days before it aired on fox in the united states . 
the 1983 20th anniversary special the five doctors had its début on 23 november -lrb- the actual date of the anniversary -rrb- on a number of pbs stations two days prior to its bbc one broadcast . 
in australia , the show has had a strong fan base since its inception , having been exclusively first run by the australian broadcasting corporation -lrb- abc -rrb- since january 1965 . 
the abc also provided partial funding for the 20th anniversary special the five doctors in 1983 . 
repeats of both the classic and modern series have also been shown on subscription television channels bbc uktv , sf and later on syfy upon sf 's closure . 
the abc has periodically repeated episodes ; of note were the weekly screenings of all available classic episodes starting in 2003 , for the show 's 40th anniversary , and the weekdaily screenings of all available revived episodes in 2013 for the show 's 50th anniversary . 
the abc broadcasts the modern series first run on abc1 , with repeats on abc2 . 
tvontario picked up the show in 1976 beginning with the three doctors and aired each series -lrb- several years late -rrb- through to series 24 in 1991 . 
tvontario picked up the show in 1976 beginning with the three doctors and aired each series -lrb- several years late -rrb- through to series 24 in 1991 . 
the series moved to the canadian cable channel space in 2009 . 
its airing of the talons of weng-chiang was cancelled as a result of accusations that the story was racist ; the story was later broadcast in the 1990s on cable station ytv . 
from 1979 to 1981 , tvo airings were bookended by science-fiction writer judith merril who would introduce the episode and then , after the episode concluded , try to place it in an educational context in keeping with tvo 's status as an educational channel . 
for the canadian broadcast , christopher eccleston recorded special video introductions for each episode -lrb- including a trivia question as part of a viewer contest -rrb- and excerpts from the doctor who confidential documentary were played over the closing credits ; for the broadcast of `` the christmas invasion '' on 26 december 2005 , billie piper recorded a special video introduction . 
for the canadian broadcast , christopher eccleston recorded special video introductions for each episode -lrb- including a trivia question as part of a viewer contest -rrb- and excerpts from the doctor who confidential documentary were played over the closing credits ; for the broadcast of `` the christmas invasion '' on 26 december 2005 , billie piper recorded a special video introduction . 
for the canadian broadcast , christopher eccleston recorded special video introductions for each episode -lrb- including a trivia question as part of a viewer contest -rrb- and excerpts from the doctor who confidential documentary were played over the closing credits ; for the broadcast of `` the christmas invasion '' on 26 december 2005 , billie piper recorded a special video introduction . 
cbc began airing series two on 9 october 2006 at 20:00 e/p -lrb- 20:30 in newfoundland and labrador -rrb- , shortly after that day 's cfl double header on thanksgiving in most of the country . 
cbc began airing series two on 9 october 2006 at 20:00 e/p -lrb- 20:30 in newfoundland and labrador -rrb- , shortly after that day 's cfl double header on thanksgiving in most of the country . 
a wide selection of serials are available from bbc video on dvd , on sale in the united kingdom , australia , canada and the united states . 
eight original series serials have been released on laserdisc and many have also been released on betamax tape and video 2000 . 
one episode of doctor who -lrb- the infinite quest -rrb- was released on vcd . 
only the series from 2009 onwards are available on blu-ray , except for the 1970 story spearhead from space , released in july 2013 . 
only the series from 2009 onwards are available on blu-ray , except for the 1970 story spearhead from space , released in july 2013 . 
in the early 1970s , trevor martin played the role in doctor who and the daleks in the seven keys to doomsday . 
in the late 1980s , jon pertwee and colin baker both played the doctor at different times during the run of a play titled doctor who -- the ultimate adventure . 
other original plays have been staged as amateur productions , with other actors playing the doctor , while terry nation wrote the curse of the daleks , a stage play mounted in the late 1960s , but without the doctor . 
in the early 1970s , trevor martin played the role in doctor who and the daleks in the seven keys to doomsday . 
for two performances , while pertwee was ill , david banks -lrb- better known for playing cybermen -rrb- played the doctor . 
following the success of the 2005 series produced by russell t davies , the bbc commissioned davies to produce a 13-part spin-off series titled torchwood -lrb- an anagram of `` doctor who '' -rrb- , set in modern-day cardiff and investigating alien activities and crime . 
the series debuted on bbc three on 22 october 2006 . 
a second series of torchwood aired in 2008 ; for three episodes , the cast was joined by freema agyeman reprising her doctor who role of martha jones . 
a third series was broadcast from 6 to 10 july 2009 , and consisted of a single five-part story called children of earth which was set largely in london . 
a fourth series , torchwood : miracle day jointly produced by bbc wales , bbc worldwide and the american entertainment company starz debuted in 2011 . 
the sarah jane adventures , starring elisabeth sladen who reprised her role as investigative journalist sarah jane smith , was developed by cbbc ; a special aired on new year 's day 2007 and a full series began on 24 september 2007 . 
the sarah jane adventures , starring elisabeth sladen who reprised her role as investigative journalist sarah jane smith , was developed by cbbc ; a special aired on new year 's day 2007 and a full series began on 24 september 2007 . 
a third in 2009 featured a crossover appearance from the main show by david tennant as the tenth doctor . 
in 2010 , a further such appearance featured matt smith as the eleventh doctor alongside former companion actress katy manning reprising her role as jo grant . 
a final , three-story fifth series was transmitted in autumn 2011 -- uncompleted due to the death of elisabeth sladen in early 2011 . 
in 1993 , for the franchise 's 30th anniversary , another charity special , titled dimensions in time was produced for children in need , featuring all of the surviving actors who played the doctor and a number of previous companions . 
in 1993 , for the franchise 's 30th anniversary , another charity special , titled dimensions in time was produced for children in need , featuring all of the surviving actors who played the doctor and a number of previous companions . 
it also featured a crossover with the soap opera eastenders , the action taking place in the latter 's albert square location and around greenwich . 
the special was one of several special 3d programmes the bbc produced at the time , using a 3d system that made use of the pulfrich effect requiring glasses with one darkened lens ; the picture would look normal to those viewers who watched without the glasses . 
the special was one of several special 3d programmes the bbc produced at the time , using a 3d system that made use of the pulfrich effect requiring glasses with one darkened lens ; the picture would look normal to those viewers who watched without the glasses . 
in 1999 , another special , doctor who and the curse of fatal death , was made for comic relief and later released on vhs . 
an affectionate parody of the television series , it was split into four segments , mimicking the traditional serial format , complete with cliffhangers , and running down the same corridor several times when being chased -lrb- the version released on video was split into only two episodes -rrb- . 
in the story , the doctor -lrb- rowan atkinson -rrb- encounters both the master -lrb- jonathan pryce -rrb- and the daleks . 
during the special the doctor is forced to regenerate several times , with his subsequent incarnations played by , in order , richard e. grant , jim broadbent , hugh grant and joanna lumley . 
the script was written by steven moffat , later to be head writer and executive producer to the revived series . 
there have also been many references to doctor who in popular culture and other science fiction , including star trek : the next generation -lrb- `` the neutral zone '' -rrb- and leverage . 
references to doctor who have also appeared in the young adult fantasy novels brisingr and high wizardry , the video game rock band , the soap opera eastenders , the adult swim comedy show robot chicken , the family guy episodes `` blue harvest '' and `` 420 '' , and the game runescape . 
in the channel 4 series queer as folk -lrb- created by later doctor who executive producer russell t. davies -rrb- , the character of vince was portrayed as an avid doctor who fan , with references appearing many times throughout in the form of clips from the programme . 
in a similar manner , the character of oliver on coupling -lrb- created and written by current show runner steven moffat -rrb- is portrayed as a doctor who collector and enthusiast . 
references to doctor who have also appeared in the young adult fantasy novels brisingr and high wizardry , the video game rock band , the soap opera eastenders , the adult swim comedy show robot chicken , the family guy episodes `` blue harvest '' and `` 420 '' , and the game runescape . 
the earliest doctor who-related audio release was a 21-minute narrated abridgement of the first doctor television story the chase released in 1966 . 
the earliest doctor who-related audio release was a 21-minute narrated abridgement of the first doctor television story the chase released in 1966 . 
ten years later , the first original doctor who audio was released on lp record ; doctor who and the pescatons featuring the fourth doctor . 
the first commercially available audiobook was an abridged reading of the fourth doctor story state of decay in 1981 . 
in 1988 , during a hiatus in the television show , slipback , the first radio drama , was transmitted . 
the earliest of these featured the fifth , sixth and seventh doctors , with paul mcgann 's eight doctor joining the line in 2001 . 
the 2013 series destiny of the doctor , produced as part of the series ' 50th anniversary celebrations , marked the first time big finish created stories -lrb- in this case audiobooks -rrb- featuring the doctors from the revived show . 
since 1999 , big finish productions has released several different series of doctor who audios on cd . 
since 1999 , big finish productions has released several different series of doctor who audios on cd . 
tom baker 's fourth doctor began appearing for big finish in 2012 . 
from 1965 to 1991 the books published were primarily novelised adaptations of broadcast episodes ; beginning in 1991 an extensive line of original fiction was launched , the virgin new adventures and virgin missing adventures . 
doctor who books have been published from the mid-sixties through to the present day . 
numerous non-fiction books about the series , including guidebooks and critical studies , have also been published , and a dedicated doctor who magazine with newsstand circulation has been published regularly since 1979 . 
this is published by panini , as is the doctor who adventures magazine for younger fans . 
since the relaunch of the programme in 2005 , a new range of novels have been published by bbc books . 
since the creation of the doctor who character by bbc television in the early 1960s , a myriad of stories have been published about doctor who , in different media : apart from the actual television episodes that continue to be produced by the bbc , there have also been novels , comics , short stories , audio books , radio plays , interactive video games , game books , webcasts , dvd extras , and even stage performances . 
since the creation of the doctor who character by bbc television in the early 1960s , a myriad of stories have been published about doctor who , in different media : apart from the actual television episodes that continue to be produced by the bbc , there have also been novels , comics , short stories , audio books , radio plays , interactive video games , game books , webcasts , dvd extras , and even stage performances . 
in this respect it is noteworthy that the bbc takes no position on the canonicity of any of such stories , and producers of the show have expressed distaste for the idea . 
in this respect it is noteworthy that the bbc takes no position on the canonicity of any of such stories , and producers of the show have expressed distaste for the idea . 
the show has received recognition as one of britain 's finest television programmes , winning the 2006 british academy television award for best drama series and five consecutive -lrb- 2005 -- 2010 -rrb- awards at the national television awards during russell t davies ' tenure as executive producer . 
the show has received recognition as one of britain 's finest television programmes , winning the 2006 british academy television award for best drama series and five consecutive -lrb- 2005 -- 2010 -rrb- awards at the national television awards during russell t davies ' tenure as executive producer . 
in 2011 , matt smith became the first doctor to be nominated for a bafta television award for best actor and in 2016 , michelle gomez became the first female to receive a bafta nomination for the series , getting a best supporting actress nomination for her work as missy . 
in 2011 , matt smith became the first doctor to be nominated for a bafta television award for best actor and in 2016 , michelle gomez became the first female to receive a bafta nomination for the series , getting a best supporting actress nomination for her work as missy . 
in 2011 , matt smith became the first doctor to be nominated for a bafta television award for best actor and in 2016 , michelle gomez became the first female to receive a bafta nomination for the series , getting a best supporting actress nomination for her work as missy . 
the programme is listed in guinness world records as the longest-running science fiction television show in the world , the `` most successful '' science fiction series of all time -- based on its over-all broadcast ratings , dvd and book sales , and itunes traffic -- and for the largest ever simulcast of a tv drama with its 50th anniversary special . 
in 2013 , the peabody awards honoured doctor who with an institutional peabody `` for evolving with technology and the times like nothing else in the known television universe . '' 
during its original run , it was recognised for its imaginative stories , creative low-budget special effects , and pioneering use of electronic music -lrb- originally produced by the bbc radiophonic workshop -rrb- . 
in 2013 , the peabody awards honoured doctor who with an institutional peabody `` for evolving with technology and the times like nothing else in the known television universe . '' 
the programme is listed in guinness world records as the longest-running science fiction television show in the world , the `` most successful '' science fiction series of all time -- based on its over-all broadcast ratings , dvd and book sales , and itunes traffic -- and for the largest ever simulcast of a tv drama with its 50th anniversary special . 
in 1975 , season 11 of the series won a writers ' guild of great britain award for best writing in a children 's serial . 
in 1996 , bbc television held the `` auntie awards '' as the culmination of their `` tv60 '' series , celebrating 60 years of bbc television broadcasting , where doctor who was voted as the `` best popular drama '' the corporation had ever produced , ahead of such ratings heavyweights as eastenders and casualty . 
in 2000 , doctor who was ranked third in a list of the 100 greatest british television programmes of the 20th century , produced by the british film institute and voted on by industry professionals . 
in 2005 , the series came first in a survey by sfx magazine of `` the greatest uk science fiction and fantasy television series ever '' . 
also , in the 100 greatest kids ' tv shows -lrb- a channel 4 countdown in 2001 -rrb- , the 1963 -- 1989 run was placed at number eight . 
it won five bafta tv awards , including best drama series , the highest-profile and most prestigious british television award for which the series has ever been nominated . 
it won five bafta tv awards , including best drama series , the highest-profile and most prestigious british television award for which the series has ever been nominated . 
it was very popular at the bafta cymru awards , with 25 wins overall including best drama series -lrb- twice -rrb- , best screenplay/screenwriter -lrb- thrice -rrb- and best actor . 
in 2009 , doctor who was voted the 3rd greatest show of the 2000s by channel 4 , behind top gear and the apprentice . 
the episode `` vincent and the doctor '' was shortlisted for a mind award at the 2010 mind mental health media awards for its `` touching '' portrayal of vincent van gogh . 
it has won the short form of the hugo award for best dramatic presentation , the oldest science fiction/fantasy award for films and series , six times -lrb- every year since 2006 , except for 2009 , 2013 and 2014 -rrb- . 
doctor who has been nominated for over 200 awards and has won over a hundred of them . 
doctor who has been nominated for over 200 awards and has won over a hundred of them . 
doctor who star matt smith won best actor in the 2012 national television awards alongside karen gillan who won best actress . 
the winning episodes were `` the empty child '' / `` the doctor dances '' -lrb- 2006 -rrb- , `` the girl in the fireplace '' -lrb- 2007 -rrb- , `` blink '' -lrb- 2008 -rrb- , `` the waters of mars '' -lrb- 2010 -rrb- , `` the pandorica opens '' / `` the big bang '' -lrb- 2011 -rrb- , and `` the doctor 's wife '' -lrb- 2012 -rrb- . 
doctor who has been satirised and spoofed on many occasions by comedians including spike milligan -lrb- a dalek invades his bathroom -- milligan , naked , hurls a soap sponge at it -rrb- and lenny henry . 
jon culshaw frequently impersonates the fourth doctor in the bbc dead ringers series . 
doctor who has been satirised and spoofed on many occasions by comedians including spike milligan -lrb- a dalek invades his bathroom -- milligan , naked , hurls a soap sponge at it -rrb- and lenny henry . 
doctor who fandom has also been lampooned on programs such as saturday night live , the chaser 's war on everything , mystery science theater 3000 , family guy , american dad ! 
jon culshaw frequently impersonates the fourth doctor in the bbc dead ringers series . 
the university of chicago -lrb- uchicago , chicago , or u of c -rrb- is a private research university in chicago . 
the university , established in 1890 , consists of the college , various graduate programs , interdisciplinary committees organized into four academic research divisions and seven professional schools . 
the university , established in 1890 , consists of the college , various graduate programs , interdisciplinary committees organized into four academic research divisions and seven professional schools . 
the university , established in 1890 , consists of the college , various graduate programs , interdisciplinary committees organized into four academic research divisions and seven professional schools . 
the university currently enrolls approximately 5,000 students in the college and around 15,000 students overall . 
university of chicago scholars have played a major role in the development of various academic disciplines , including : the chicago school of economics , the chicago school of sociology , the law and economics movement in legal analysis , the chicago school of literary criticism , the chicago school of religion , and the behavioralism school of political science . 
chicago 's physics department helped develop the world 's first man-made , self-sustaining nuclear reaction beneath the university 's stagg field . 
chicago 's physics department helped develop the world 's first man-made , self-sustaining nuclear reaction beneath the university 's stagg field . 
the university is also home to the university of chicago press , the largest university press in the united states . 
with an estimated completion date of 2020 , the barack obama presidential center will be housed at the university and include both the obama presidential library and offices of the obama foundation . 
founded by the american baptist education society with a donation from oil magnate and wealthiest man in history john d. rockefeller , the university of chicago was incorporated in 1890 ; william rainey harper became the university 's first president in 1891 , and the first classes were held in 1892 . 
founded by the american baptist education society with a donation from oil magnate and wealthiest man in history john d. rockefeller , the university of chicago was incorporated in 1890 ; william rainey harper became the university 's first president in 1891 , and the first classes were held in 1892 . 
founded by the american baptist education society with a donation from oil magnate and wealthiest man in history john d. rockefeller , the university of chicago was incorporated in 1890 ; william rainey harper became the university 's first president in 1891 , and the first classes were held in 1892 . 
founded by the american baptist education society with a donation from oil magnate and wealthiest man in history john d. rockefeller , the university of chicago was incorporated in 1890 ; william rainey harper became the university 's first president in 1891 , and the first classes were held in 1892 . 
founded by the american baptist education society with a donation from oil magnate and wealthiest man in history john d. rockefeller , the university of chicago was incorporated in 1890 ; william rainey harper became the university 's first president in 1891 , and the first classes were held in 1892 . 
the university of chicago was created and incorporated as a coeducational , secular institution in 1890 by the american baptist education society and a donation from oil magnate and philanthropist john d. rockefeller on land donated by marshall field . 
the original physical campus was financed by donations from wealthy chicagoans like silas b. cobb who provided the funds for the campus ' first building , cobb lecture hall , and matched marshall field 's pledge of $ 100,000 . 
the original physical campus was financed by donations from wealthy chicagoans like silas b. cobb who provided the funds for the campus ' first building , cobb lecture hall , and matched marshall field 's pledge of $ 100,000 . 
the original physical campus was financed by donations from wealthy chicagoans like silas b. cobb who provided the funds for the campus ' first building , cobb lecture hall , and matched marshall field 's pledge of $ 100,000 . 
other early benefactors included businessmen charles l. hutchinson -lrb- trustee , treasurer and donor of hutchinson commons -rrb- , martin a. ryerson -lrb- president of the board of trustees and donor of the ryerson physical laboratory -rrb- adolphus clay bartlett and leon mandel , who funded the construction of the gymnasium and assembly hall , and george c. walker of the walker museum , a relative of cobb who encouraged his inaugural donation for facilities . 
in the 1890s , the university of chicago , fearful that its vast resources would injure smaller schools by drawing away good students , affiliated with several regional colleges and universities : des moines college , kalamazoo college , butler university , and stetson university . 
in 1896 , the university affiliated with shimer college in mount carroll , illinois . 
the university of chicago agreed to confer a degree on any graduating senior from an affiliated school who made a grade of a for all four years , and on any other graduate who took twelve weeks additional study at the university of chicago . 
the program passed into history by 1910 . 
the program passed into history by 1910 . 
in 1929 , the university 's fifth president , robert maynard hutchins , took office ; the university underwent many changes during his 24-year tenure . 
hutchins eliminated varsity football from the university in an attempt to emphasize academics over athletics , instituted the undergraduate college 's liberal-arts curriculum known as the common core , and organized the university 's graduate work into its current -lsb- when ? -rsb- 
hutchins eliminated varsity football from the university in an attempt to emphasize academics over athletics , instituted the undergraduate college 's liberal-arts curriculum known as the common core , and organized the university 's graduate work into its current -lsb- when ? -rsb- 
in 1929 , the university 's fifth president , robert maynard hutchins , took office ; the university underwent many changes during his 24-year tenure . 
in 1929 , the university 's fifth president , robert maynard hutchins , took office ; the university underwent many changes during his 24-year tenure . 
in the early 1950s , student applications declined as a result of increasing crime and poverty in the hyde park neighborhood . 
in the early 1950s , student applications declined as a result of increasing crime and poverty in the hyde park neighborhood . 
during this period the university , like shimer college and 10 others , adopted an early entrant program that allowed very young students to attend college ; in addition , students enrolled at shimer were enabled to transfer automatically to the university of chicago after their second year , having taken comparable or identical examinations and courses . 
in response , the university became a major sponsor of a controversial urban renewal project for hyde park , which profoundly affected both the neighborhood 's architecture and street plan . 
during this period the university , like shimer college and 10 others , adopted an early entrant program that allowed very young students to attend college ; in addition , students enrolled at shimer were enabled to transfer automatically to the university of chicago after their second year , having taken comparable or identical examinations and courses . 
the university experienced its share of student unrest during the 1960s , beginning in 1962 , when students occupied president george beadle 's office in a protest over the university 's off-campus rental policies . 
the university experienced its share of student unrest during the 1960s , beginning in 1962 , when students occupied president george beadle 's office in a protest over the university 's off-campus rental policies . 
after continued turmoil , a university committee in 1967 issued what became known as the kalven report . 
the report , a two-page statement of the university 's policy in `` social and political action , '' declared that `` to perform its mission in the society , a university must sustain an extraordinary environment of freedom of inquiry and maintain an independence from political fashions , passions , and pressures . '' 
the report , a two-page statement of the university 's policy in `` social and political action , '' declared that `` to perform its mission in the society , a university must sustain an extraordinary environment of freedom of inquiry and maintain an independence from political fashions , passions , and pressures . '' 
from the mid-2000s , the university began a number of multimillion-dollar expansion projects . 
in 2008 , the university of chicago announced plans to establish the milton friedman institute which attracted both support and controversy from faculty members and students . 
the institute will cost around $ 200 million and occupy the buildings of the chicago theological seminary . 
the institute will cost around $ 200 million and occupy the buildings of the chicago theological seminary . 
during the same year , investor david g. booth donated $ 300 million to the university 's booth school of business , which is the largest gift in the university 's history and the largest gift ever to any business school . 
the first buildings of the university of chicago campus , which make up what is now known as the main quadrangles , were part of a `` master plan '' conceived by two university of chicago trustees and plotted by chicago architect henry ives cobb . 
the main quadrangles consist of six quadrangles , each surrounded by buildings , bordering one larger quadrangle . 
the buildings of the main quadrangles were designed by cobb , shepley , rutan and coolidge , holabird & roche , and other architectural firms in a mixture of the victorian gothic and collegiate gothic styles , patterned on the colleges of the university of oxford . 
-lrb- mitchell tower , for example , is modeled after oxford 's magdalen tower , and the university commons , hutchinson hall , replicates christ church hall . -rrb- 
-lrb- mitchell tower , for example , is modeled after oxford 's magdalen tower , and the university commons , hutchinson hall , replicates christ church hall . -rrb- 
after the 1940s , the gothic style on campus began to give way to modern styles . 
in 1955 , eero saarinen was contracted to develop a second master plan , which led to the construction of buildings both north and south of the midway , including the laird bell law quadrangle -lrb- a complex designed by saarinen -rrb- ; a series of arts buildings ; a building designed by ludwig mies van der rohe for the university 's school of social service administration ; , a building which is to become the home of the harris school of public policy studies by edward durrell stone , and the regenstein library , the largest building on campus , a brutalist structure designed by walter netsch of the chicago firm skidmore , owings & merrill . 
in 1955 , eero saarinen was contracted to develop a second master plan , which led to the construction of buildings both north and south of the midway , including the laird bell law quadrangle -lrb- a complex designed by saarinen -rrb- ; a series of arts buildings ; a building designed by ludwig mies van der rohe for the university 's school of social service administration ; , a building which is to become the home of the harris school of public policy studies by edward durrell stone , and the regenstein library , the largest building on campus , a brutalist structure designed by walter netsch of the chicago firm skidmore , owings & merrill . 
in 1955 , eero saarinen was contracted to develop a second master plan , which led to the construction of buildings both north and south of the midway , including the laird bell law quadrangle -lrb- a complex designed by saarinen -rrb- ; a series of arts buildings ; a building designed by ludwig mies van der rohe for the university 's school of social service administration ; , a building which is to become the home of the harris school of public policy studies by edward durrell stone , and the regenstein library , the largest building on campus , a brutalist structure designed by walter netsch of the chicago firm skidmore , owings & merrill . 
another master plan , designed in 1999 and updated in 2004 , produced the gerald ratner athletics center -lrb- 2003 -rrb- , the max palevsky residential commons -lrb- 2001 -rrb- , south campus residence hall and dining commons -lrb- 2009 -rrb- , a new children 's hospital , and other construction , expansions , and restorations . 
the university 's booth school of business maintains campuses in singapore , london , and the downtown streeterville neighborhood of chicago . 
the center in paris , a campus located on the left bank of the seine in paris , hosts various undergraduate and graduate study programs . 
in fall 2010 , the university of chicago also opened a center in beijing , near renmin university 's campus in haidian district . 
in fall 2010 , the university of chicago also opened a center in beijing , near renmin university 's campus in haidian district . 
the most recent additions are a center in new delhi , india , which opened in 2014 , and a center in hong kong which opened in 2015 . 
the university of chicago is governed by a board of trustees . 
the board of trustees oversees the long-term development and plans of the university and manages fundraising efforts , and is composed of 50 members including the university president . 
directly beneath the president are the provost , fourteen vice presidents -lrb- including the chief financial officer , chief investment officer , and dean of students of the university -rrb- , the directors of argonne national laboratory and fermilab , the secretary of the university , and the student ombudsperson . 
as of august 2009 -lsb- update -rsb- , the chairman of the board of trustees is andrew alper , and the president of the university is robert zimmer . 
as of august 2009 -lsb- update -rsb- , the chairman of the board of trustees is andrew alper , and the president of the university is robert zimmer . 
the university is accredited by the higher learning commission . 
the academic bodies of the university of chicago consist of the college , four divisions of graduate research and seven professional schools . 
the academic bodies of the university of chicago consist of the college , four divisions of graduate research and seven professional schools . 
the college of the university of chicago grants bachelor of arts and bachelor of science degrees in 50 academic majors and 28 minors . 
the college of the university of chicago grants bachelor of arts and bachelor of science degrees in 50 academic majors and 28 minors . 
the college 's academics are divided into five divisions : the biological sciences collegiate division , the physical sciences collegiate division , the social sciences collegiate division , the humanities collegiate division , and the new collegiate division . 
the first four are sections within their corresponding graduate divisions , while the new collegiate division administers interdisciplinary majors and studies which do not fit in one of the other four divisions . 
undergraduate students are required to take a distribution of courses to satisfy the university 's core curriculum known as the common core . 
in 2012-2013 , the core classes at chicago were limited to 17 students , and are generally led by a full-time professor -lrb- as opposed to a teaching assistant -rrb- . 
undergraduate courses at the university of chicago are known for their demanding standards , heavy workload and academic difficulty ; according to uni in the usa , `` among the academic cream of american universities -- harvard , yale , princeton , mit , and the university of chicago -- it is uchicago that can most convincingly claim to provide the most rigorous , intense learning experience . '' 
undergraduate courses at the university of chicago are known for their demanding standards , heavy workload and academic difficulty ; according to uni in the usa , `` among the academic cream of american universities -- harvard , yale , princeton , mit , and the university of chicago -- it is uchicago that can most convincingly claim to provide the most rigorous , intense learning experience . '' 
it operates the university of chicago laboratory schools -lrb- a private day school for k-12 students and day care -rrb- , the sonia shankman orthogenic school -lrb- a residential treatment program for those with behavioral and emotional problems -rrb- , and four public charter schools on the south side of chicago administered by the university 's urban education institute . 
it operates the university of chicago laboratory schools -lrb- a private day school for k-12 students and day care -rrb- , the sonia shankman orthogenic school -lrb- a residential treatment program for those with behavioral and emotional problems -rrb- , and four public charter schools on the south side of chicago administered by the university 's urban education institute . 
it operates the university of chicago laboratory schools -lrb- a private day school for k-12 students and day care -rrb- , the sonia shankman orthogenic school -lrb- a residential treatment program for those with behavioral and emotional problems -rrb- , and four public charter schools on the south side of chicago administered by the university 's urban education institute . 
it operates the university of chicago laboratory schools -lrb- a private day school for k-12 students and day care -rrb- , the sonia shankman orthogenic school -lrb- a residential treatment program for those with behavioral and emotional problems -rrb- , and four public charter schools on the south side of chicago administered by the university 's urban education institute . 
in addition , the hyde park day school , a school for students with learning disabilities , maintains a location on the university of chicago campus . 
the university of chicago library system encompasses six libraries that contain a total of 9.8 million volumes , the 11th most among library systems in the united states . 
the university of chicago library system encompasses six libraries that contain a total of 9.8 million volumes , the 11th most among library systems in the united states . 
the university 's main library is the regenstein library , which contains one of the largest collections of print volumes in the united states . 
the joe and rika mansueto library , built in 2011 , houses a large study space and an automatic book storage and retrieval system . 
the john crerar library contains more than 1.3 million volumes in the biological , medical and physical sciences and collections in general science and the philosophy and history of science , medicine , and technology . 
the university operates 12 research institutes and 113 research centers on campus . 
the university operates 12 research institutes and 113 research centers on campus . 
among these are the oriental institute -- a museum and research center for near eastern studies owned and operated by the university -- and a number of national resource centers , including the center for middle eastern studies . 
the university partially manages argonne national laboratory , part of the united states department of energy 's national laboratory system , and has a joint stake in fermilab , a nearby particle physics laboratory , as well as a stake in the apache point observatory in sunspot , new mexico . 
the university partially manages argonne national laboratory , part of the united states department of energy 's national laboratory system , and has a joint stake in fermilab , a nearby particle physics laboratory , as well as a stake in the apache point observatory in sunspot , new mexico . 
in economics , the university has played an important role in shaping ideas about the free market and is the namesake of the chicago school of economics , the school of economic thought supported by milton friedman and other economists . 
in physics , the university was the site of the chicago pile-1 -lrb- the first self-sustained man-made nuclear reaction , part of the manhattan project -rrb- , of robert millikan 's oil-drop experiment that calculated the charge of the electron , and of the development of radiocarbon dating by willard f. libby in 1947 . 
the chemical experiment that tested how life originated on early earth , the miller -- urey experiment , was conducted at the university . 
rem sleep was discovered at the university in 1953 by nathaniel kleitman and eugene aserinsky . 
it has offered a doctorate in music composition since 1933 and in cinema & media studies since 2000 , a master of fine arts in visual arts -lrb- early 1970s -rrb- , and a master of arts in the humanities with a creative writing track -lrb- 2000 -rrb- . 
it has offered a doctorate in music composition since 1933 and in cinema & media studies since 2000 , a master of fine arts in visual arts -lrb- early 1970s -rrb- , and a master of arts in the humanities with a creative writing track -lrb- 2000 -rrb- . 
it has bachelor 's degree programs in visual arts , music , and art history , and , more recently , cinema & media studies -lrb- 1996 -rrb- and theater & performance studies -lrb- 2002 -rrb- . 
it has bachelor 's degree programs in visual arts , music , and art history , and , more recently , cinema & media studies -lrb- 1996 -rrb- and theater & performance studies -lrb- 2002 -rrb- . 
several thousand major and non-major undergraduates enroll annually in creative and performing arts classes . 
in the fall quarter of 2014 , the university of chicago enrolled 5,792 students in the college , 3,468 students in its four graduate divisions , 5,984 students in its professional schools , and 15,244 students overall . 
in the fall quarter of 2014 , the university of chicago enrolled 5,792 students in the college , 3,468 students in its four graduate divisions , 5,984 students in its professional schools , and 15,244 students overall . 
in the fall quarter of 2014 , the university of chicago enrolled 5,792 students in the college , 3,468 students in its four graduate divisions , 5,984 students in its professional schools , and 15,244 students overall . 
in the fall quarter of 2014 , the university of chicago enrolled 5,792 students in the college , 3,468 students in its four graduate divisions , 5,984 students in its professional schools , and 15,244 students overall . 
in the 2012 spring quarter , international students comprised almost 19 % of the overall study body , over 26 % of students were domestic ethnic minorities , and about 44 % of enrolled students were female . 
the maroons compete in the ncaa 's division iii as members of the university athletic association -lrb- uaa -rrb- . 
the maroons compete in the ncaa 's division iii as members of the university athletic association -lrb- uaa -rrb- . 
the university was a founding member of the big ten conference and participated in the ncaa division i men 's basketball and football and was a regular participant in the men 's basketball tournament . 
in 1935 , chicago maroons football player jay berwanger became the first winner of the heisman trophy . 
however , the university chose to withdraw from the conference in 1946 after university president robert maynard hutchins de-emphasized varsity athletics in 1939 and dropped football . 
students at the university of chicago run over 400 clubs and organizations known as recognized student organizations -lrb- rsos -rrb- . 
students at the university of chicago run over 400 clubs and organizations known as recognized student organizations -lrb- rsos -rrb- . 
notable extracurricular groups include the university of chicago college bowl team , which has won 118 tournaments and 15 national championships , leading both categories internationally . 
among notable rsos are the nation 's longest continuously running student film society doc films , organizing committee for the university of chicago scavenger hunt , the twice-weekly student newspaper the chicago maroon , the alternative weekly student newspaper south side weekly , the nation 's second oldest continuously running student improvisational theater troupe off-off campus , and the university-owned radio station whpk . 
among notable rsos are the nation 's longest continuously running student film society doc films , organizing committee for the university of chicago scavenger hunt , the twice-weekly student newspaper the chicago maroon , the alternative weekly student newspaper south side weekly , the nation 's second oldest continuously running student improvisational theater troupe off-off campus , and the university-owned radio station whpk . 
student government is made up of graduate and undergraduate students elected to represent members from their respective academic unit . 
it is led by an executive committee , chaired by a president with the assistance of two vice presidents , one for administration and the other for student life , elected together as a slate by the student body each spring . 
it is led by an executive committee , chaired by a president with the assistance of two vice presidents , one for administration and the other for student life , elected together as a slate by the student body each spring . 
its annual budget is greater than $ 2 million . 
there are fifteen fraternities and seven sororities at the university of chicago , as well as one co-ed community service fraternity , alpha phi omega . 
there are fifteen fraternities and seven sororities at the university of chicago , as well as one co-ed community service fraternity , alpha phi omega . 
there are fifteen fraternities and seven sororities at the university of chicago , as well as one co-ed community service fraternity , alpha phi omega . 
there are fifteen fraternities and seven sororities at the university of chicago , as well as one co-ed community service fraternity , alpha phi omega . 
four of the sororities are members of the national panhellenic conference , and ten of the fraternities form the university of chicago interfraternity council . 
every may since 1987 , the university of chicago has held the university of chicago scavenger hunt , in which large teams of students compete to obtain notoriously esoteric items from a list . 
every may since 1987 , the university of chicago has held the university of chicago scavenger hunt , in which large teams of students compete to obtain notoriously esoteric items from a list . 
since 1963 , the festival of the arts -lrb- fota -rrb- takes over campus for 7 -- 10 days of exhibitions and interactive artistic endeavors . 
every january , the university holds a week-long winter festival , kuviasungnerk/kangeiko , which include early morning exercise routines and fitness workshops . 
the university also annually holds a summer carnival and concert called summer breeze that hosts outside musicians , and is home to doc films , a student film society founded in 1932 that screens films nightly at the university . 
in business , notable alumni include microsoft ceo satya nadella , oracle corporation founder and the third richest man in america larry ellison , goldman sachs and mf global ceo as well as former governor of new jersey jon corzine , mckinsey & company founder and author of the first management accounting textbook james o. mckinsey , arley d. cathey , bloomberg l.p. ceo daniel doctoroff , credit suisse ceo brady dougan , morningstar , inc. founder and ceo joe mansueto , chicago cubs owner and chairman thomas s. ricketts , and nba commissioner adam silver . 
in business , notable alumni include microsoft ceo satya nadella , oracle corporation founder and the third richest man in america larry ellison , goldman sachs and mf global ceo as well as former governor of new jersey jon corzine , mckinsey & company founder and author of the first management accounting textbook james o. mckinsey , arley d. cathey , bloomberg l.p. ceo daniel doctoroff , credit suisse ceo brady dougan , morningstar , inc. founder and ceo joe mansueto , chicago cubs owner and chairman thomas s. ricketts , and nba commissioner adam silver . 
in business , notable alumni include microsoft ceo satya nadella , oracle corporation founder and the third richest man in america larry ellison , goldman sachs and mf global ceo as well as former governor of new jersey jon corzine , mckinsey & company founder and author of the first management accounting textbook james o. mckinsey , arley d. cathey , bloomberg l.p. ceo daniel doctoroff , credit suisse ceo brady dougan , morningstar , inc. founder and ceo joe mansueto , chicago cubs owner and chairman thomas s. ricketts , and nba commissioner adam silver . 
in business , notable alumni include microsoft ceo satya nadella , oracle corporation founder and the third richest man in america larry ellison , goldman sachs and mf global ceo as well as former governor of new jersey jon corzine , mckinsey & company founder and author of the first management accounting textbook james o. mckinsey , arley d. cathey , bloomberg l.p. ceo daniel doctoroff , credit suisse ceo brady dougan , morningstar , inc. founder and ceo joe mansueto , chicago cubs owner and chairman thomas s. ricketts , and nba commissioner adam silver . 
in business , notable alumni include microsoft ceo satya nadella , oracle corporation founder and the third richest man in america larry ellison , goldman sachs and mf global ceo as well as former governor of new jersey jon corzine , mckinsey & company founder and author of the first management accounting textbook james o. mckinsey , arley d. cathey , bloomberg l.p. ceo daniel doctoroff , credit suisse ceo brady dougan , morningstar , inc. founder and ceo joe mansueto , chicago cubs owner and chairman thomas s. ricketts , and nba commissioner adam silver . 
notable alumni in the field of government and politics include the founder of modern community organizing saul alinsky , obama campaign advisor and top political advisor to president bill clinton david axelrod , attorney general and federal judge robert bork , attorney general ramsey clark , prohibition agent eliot ness , supreme court justice john paul stevens , prime minister of canada william lyon mackenzie king , 11th prime minister of poland marek belka , governor of the bank of japan masaaki shirakawa , the first female african-american senator carol moseley braun , united states senator from vermont and 2016 democratic presidential candidate bernie sanders , and former world bank president paul wolfowitz . 
notable alumni in the field of government and politics include the founder of modern community organizing saul alinsky , obama campaign advisor and top political advisor to president bill clinton david axelrod , attorney general and federal judge robert bork , attorney general ramsey clark , prohibition agent eliot ness , supreme court justice john paul stevens , prime minister of canada william lyon mackenzie king , 11th prime minister of poland marek belka , governor of the bank of japan masaaki shirakawa , the first female african-american senator carol moseley braun , united states senator from vermont and 2016 democratic presidential candidate bernie sanders , and former world bank president paul wolfowitz . 
notable alumni in the field of government and politics include the founder of modern community organizing saul alinsky , obama campaign advisor and top political advisor to president bill clinton david axelrod , attorney general and federal judge robert bork , attorney general ramsey clark , prohibition agent eliot ness , supreme court justice john paul stevens , prime minister of canada william lyon mackenzie king , 11th prime minister of poland marek belka , governor of the bank of japan masaaki shirakawa , the first female african-american senator carol moseley braun , united states senator from vermont and 2016 democratic presidential candidate bernie sanders , and former world bank president paul wolfowitz . 
notable alumni in the field of government and politics include the founder of modern community organizing saul alinsky , obama campaign advisor and top political advisor to president bill clinton david axelrod , attorney general and federal judge robert bork , attorney general ramsey clark , prohibition agent eliot ness , supreme court justice john paul stevens , prime minister of canada william lyon mackenzie king , 11th prime minister of poland marek belka , governor of the bank of japan masaaki shirakawa , the first female african-american senator carol moseley braun , united states senator from vermont and 2016 democratic presidential candidate bernie sanders , and former world bank president paul wolfowitz . 
notable alumni in the field of government and politics include the founder of modern community organizing saul alinsky , obama campaign advisor and top political advisor to president bill clinton david axelrod , attorney general and federal judge robert bork , attorney general ramsey clark , prohibition agent eliot ness , supreme court justice john paul stevens , prime minister of canada william lyon mackenzie king , 11th prime minister of poland marek belka , governor of the bank of japan masaaki shirakawa , the first female african-american senator carol moseley braun , united states senator from vermont and 2016 democratic presidential candidate bernie sanders , and former world bank president paul wolfowitz . 
in literature , author of the new york times bestseller before i fall lauren oliver , pulitzer prize winning novelist philip roth , canadian-born pulitzer prize and nobel prize for literature winning writer saul bellow , political philosopher , literary critic and author of the new york times bestseller `` the closing of the american mind '' allan bloom , '' the good war '' author studs terkel , american writer , essayist , filmmaker , teacher , and political activist susan sontag , analytic philosopher and stanford university professor of comparative literature richard rorty , and american writer and satirist kurt vonnegut are notable alumni . 
in literature , author of the new york times bestseller before i fall lauren oliver , pulitzer prize winning novelist philip roth , canadian-born pulitzer prize and nobel prize for literature winning writer saul bellow , political philosopher , literary critic and author of the new york times bestseller `` the closing of the american mind '' allan bloom , '' the good war '' author studs terkel , american writer , essayist , filmmaker , teacher , and political activist susan sontag , analytic philosopher and stanford university professor of comparative literature richard rorty , and american writer and satirist kurt vonnegut are notable alumni . 
in literature , author of the new york times bestseller before i fall lauren oliver , pulitzer prize winning novelist philip roth , canadian-born pulitzer prize and nobel prize for literature winning writer saul bellow , political philosopher , literary critic and author of the new york times bestseller `` the closing of the american mind '' allan bloom , '' the good war '' author studs terkel , american writer , essayist , filmmaker , teacher , and political activist susan sontag , analytic philosopher and stanford university professor of comparative literature richard rorty , and american writer and satirist kurt vonnegut are notable alumni . 
in literature , author of the new york times bestseller before i fall lauren oliver , pulitzer prize winning novelist philip roth , canadian-born pulitzer prize and nobel prize for literature winning writer saul bellow , political philosopher , literary critic and author of the new york times bestseller `` the closing of the american mind '' allan bloom , '' the good war '' author studs terkel , american writer , essayist , filmmaker , teacher , and political activist susan sontag , analytic philosopher and stanford university professor of comparative literature richard rorty , and american writer and satirist kurt vonnegut are notable alumni . 
in literature , author of the new york times bestseller before i fall lauren oliver , pulitzer prize winning novelist philip roth , canadian-born pulitzer prize and nobel prize for literature winning writer saul bellow , political philosopher , literary critic and author of the new york times bestseller `` the closing of the american mind '' allan bloom , '' the good war '' author studs terkel , american writer , essayist , filmmaker , teacher , and political activist susan sontag , analytic philosopher and stanford university professor of comparative literature richard rorty , and american writer and satirist kurt vonnegut are notable alumni . 
in the arts and entertainment , minimalist composer philip glass , dancer , choreographer and leader in the field of dance anthropology katherine dunham , bungie founder and developer of the halo video game series alex seropian , serial host sarah koenig , actor ed asner , pulitzer prize for criticism winning film critic and the subject of the 2014 documentary film life itself roger ebert , director , writer , and comedian mike nichols , film director and screenwriter philip kaufman , and carl van vechten , photographer and writer , are graduates . 
in the arts and entertainment , minimalist composer philip glass , dancer , choreographer and leader in the field of dance anthropology katherine dunham , bungie founder and developer of the halo video game series alex seropian , serial host sarah koenig , actor ed asner , pulitzer prize for criticism winning film critic and the subject of the 2014 documentary film life itself roger ebert , director , writer , and comedian mike nichols , film director and screenwriter philip kaufman , and carl van vechten , photographer and writer , are graduates . 
in the arts and entertainment , minimalist composer philip glass , dancer , choreographer and leader in the field of dance anthropology katherine dunham , bungie founder and developer of the halo video game series alex seropian , serial host sarah koenig , actor ed asner , pulitzer prize for criticism winning film critic and the subject of the 2014 documentary film life itself roger ebert , director , writer , and comedian mike nichols , film director and screenwriter philip kaufman , and carl van vechten , photographer and writer , are graduates . 
in the arts and entertainment , minimalist composer philip glass , dancer , choreographer and leader in the field of dance anthropology katherine dunham , bungie founder and developer of the halo video game series alex seropian , serial host sarah koenig , actor ed asner , pulitzer prize for criticism winning film critic and the subject of the 2014 documentary film life itself roger ebert , director , writer , and comedian mike nichols , film director and screenwriter philip kaufman , and carl van vechten , photographer and writer , are graduates . 
in the arts and entertainment , minimalist composer philip glass , dancer , choreographer and leader in the field of dance anthropology katherine dunham , bungie founder and developer of the halo video game series alex seropian , serial host sarah koenig , actor ed asner , pulitzer prize for criticism winning film critic and the subject of the 2014 documentary film life itself roger ebert , director , writer , and comedian mike nichols , film director and screenwriter philip kaufman , and carl van vechten , photographer and writer , are graduates . 
in science , alumni include astronomers carl sagan , a prominent contributor to the scientific research of extraterrestrial life , and edwin hubble , known for `` hubble 's law '' , nasa astronaut john m. grunsfeld , geneticist james watson , best known as one of the co-discoverers of the structure of dna , experimental physicist luis alvarez , popular environmentalist david suzuki , balloonist jeannette piccard , biologists ernest everett just and lynn margulis , computer scientist richard hamming , the creator of the hamming code , lithium-ion battery developer john b. goodenough , mathematician and fields medal recipient paul joseph cohen , and geochemist clair cameron patterson , who developed the uranium-lead dating method into lead-lead dating . 
in science , alumni include astronomers carl sagan , a prominent contributor to the scientific research of extraterrestrial life , and edwin hubble , known for `` hubble 's law '' , nasa astronaut john m. grunsfeld , geneticist james watson , best known as one of the co-discoverers of the structure of dna , experimental physicist luis alvarez , popular environmentalist david suzuki , balloonist jeannette piccard , biologists ernest everett just and lynn margulis , computer scientist richard hamming , the creator of the hamming code , lithium-ion battery developer john b. goodenough , mathematician and fields medal recipient paul joseph cohen , and geochemist clair cameron patterson , who developed the uranium-lead dating method into lead-lead dating . 
in science , alumni include astronomers carl sagan , a prominent contributor to the scientific research of extraterrestrial life , and edwin hubble , known for `` hubble 's law '' , nasa astronaut john m. grunsfeld , geneticist james watson , best known as one of the co-discoverers of the structure of dna , experimental physicist luis alvarez , popular environmentalist david suzuki , balloonist jeannette piccard , biologists ernest everett just and lynn margulis , computer scientist richard hamming , the creator of the hamming code , lithium-ion battery developer john b. goodenough , mathematician and fields medal recipient paul joseph cohen , and geochemist clair cameron patterson , who developed the uranium-lead dating method into lead-lead dating . 
in science , alumni include astronomers carl sagan , a prominent contributor to the scientific research of extraterrestrial life , and edwin hubble , known for `` hubble 's law '' , nasa astronaut john m. grunsfeld , geneticist james watson , best known as one of the co-discoverers of the structure of dna , experimental physicist luis alvarez , popular environmentalist david suzuki , balloonist jeannette piccard , biologists ernest everett just and lynn margulis , computer scientist richard hamming , the creator of the hamming code , lithium-ion battery developer john b. goodenough , mathematician and fields medal recipient paul joseph cohen , and geochemist clair cameron patterson , who developed the uranium-lead dating method into lead-lead dating . 
in science , alumni include astronomers carl sagan , a prominent contributor to the scientific research of extraterrestrial life , and edwin hubble , known for `` hubble 's law '' , nasa astronaut john m. grunsfeld , geneticist james watson , best known as one of the co-discoverers of the structure of dna , experimental physicist luis alvarez , popular environmentalist david suzuki , balloonist jeannette piccard , biologists ernest everett just and lynn margulis , computer scientist richard hamming , the creator of the hamming code , lithium-ion battery developer john b. goodenough , mathematician and fields medal recipient paul joseph cohen , and geochemist clair cameron patterson , who developed the uranium-lead dating method into lead-lead dating . 
in economics , notable nobel memorial prize in economic sciences winners milton friedman , a major advisor to republican u.s. president ronald reagan and conservative british prime minister margaret thatcher , george stigler , nobel laureate and proponent of regulatory capture theory , gary becker , an important contributor to the family economics branch of economics , herbert a. simon , responsible for the modern interpretation of the concept of organizational decision-making , paul samuelson , the first american to win the nobel memorial prize in economic sciences , and eugene fama , known for his work on portfolio theory , asset pricing and stock market behaviour , are all graduates . 
in economics , notable nobel memorial prize in economic sciences winners milton friedman , a major advisor to republican u.s. president ronald reagan and conservative british prime minister margaret thatcher , george stigler , nobel laureate and proponent of regulatory capture theory , gary becker , an important contributor to the family economics branch of economics , herbert a. simon , responsible for the modern interpretation of the concept of organizational decision-making , paul samuelson , the first american to win the nobel memorial prize in economic sciences , and eugene fama , known for his work on portfolio theory , asset pricing and stock market behaviour , are all graduates . 
in economics , notable nobel memorial prize in economic sciences winners milton friedman , a major advisor to republican u.s. president ronald reagan and conservative british prime minister margaret thatcher , george stigler , nobel laureate and proponent of regulatory capture theory , gary becker , an important contributor to the family economics branch of economics , herbert a. simon , responsible for the modern interpretation of the concept of organizational decision-making , paul samuelson , the first american to win the nobel memorial prize in economic sciences , and eugene fama , known for his work on portfolio theory , asset pricing and stock market behaviour , are all graduates . 
in economics , notable nobel memorial prize in economic sciences winners milton friedman , a major advisor to republican u.s. president ronald reagan and conservative british prime minister margaret thatcher , george stigler , nobel laureate and proponent of regulatory capture theory , gary becker , an important contributor to the family economics branch of economics , herbert a. simon , responsible for the modern interpretation of the concept of organizational decision-making , paul samuelson , the first american to win the nobel memorial prize in economic sciences , and eugene fama , known for his work on portfolio theory , asset pricing and stock market behaviour , are all graduates . 
other prominent alumni include anthropologists david graeber and donald johanson , who is best known for discovering the fossil of a female hominid australopithecine known as `` lucy '' in the afar triangle region , psychologist john b. watson , american psychologist who established the psychological school of behaviorism , communication theorist harold innis , chess grandmaster samuel reshevsky , and conservative international relations scholar and white house coordinator of security planning for the national security council samuel p. huntington . 
other prominent alumni include anthropologists david graeber and donald johanson , who is best known for discovering the fossil of a female hominid australopithecine known as `` lucy '' in the afar triangle region , psychologist john b. watson , american psychologist who established the psychological school of behaviorism , communication theorist harold innis , chess grandmaster samuel reshevsky , and conservative international relations scholar and white house coordinator of security planning for the national security council samuel p. huntington . 
other prominent alumni include anthropologists david graeber and donald johanson , who is best known for discovering the fossil of a female hominid australopithecine known as `` lucy '' in the afar triangle region , psychologist john b. watson , american psychologist who established the psychological school of behaviorism , communication theorist harold innis , chess grandmaster samuel reshevsky , and conservative international relations scholar and white house coordinator of security planning for the national security council samuel p. huntington . 
notable faculty in physics have included the speed of light calculator a. a. michelson , elementary charge calculator robert a. millikan , discoverer of the compton effect arthur h. compton , the creator of the first nuclear reactor enrico fermi , `` the father of the hydrogen bomb '' edward teller , `` one of the most brilliant and productive experimental physicists of the twentieth century '' luis walter alvarez , murray gell-mann who introduced the quark , second female nobel laureate maria goeppert-mayer , the youngest american winner of the nobel prize tsung-dao lee , and astrophysicist subrahmanyan chandrasekhar . 
notable faculty in physics have included the speed of light calculator a. a. michelson , elementary charge calculator robert a. millikan , discoverer of the compton effect arthur h. compton , the creator of the first nuclear reactor enrico fermi , `` the father of the hydrogen bomb '' edward teller , `` one of the most brilliant and productive experimental physicists of the twentieth century '' luis walter alvarez , murray gell-mann who introduced the quark , second female nobel laureate maria goeppert-mayer , the youngest american winner of the nobel prize tsung-dao lee , and astrophysicist subrahmanyan chandrasekhar . 
notable faculty in physics have included the speed of light calculator a. a. michelson , elementary charge calculator robert a. millikan , discoverer of the compton effect arthur h. compton , the creator of the first nuclear reactor enrico fermi , `` the father of the hydrogen bomb '' edward teller , `` one of the most brilliant and productive experimental physicists of the twentieth century '' luis walter alvarez , murray gell-mann who introduced the quark , second female nobel laureate maria goeppert-mayer , the youngest american winner of the nobel prize tsung-dao lee , and astrophysicist subrahmanyan chandrasekhar . 
notable faculty in physics have included the speed of light calculator a. a. michelson , elementary charge calculator robert a. millikan , discoverer of the compton effect arthur h. compton , the creator of the first nuclear reactor enrico fermi , `` the father of the hydrogen bomb '' edward teller , `` one of the most brilliant and productive experimental physicists of the twentieth century '' luis walter alvarez , murray gell-mann who introduced the quark , second female nobel laureate maria goeppert-mayer , the youngest american winner of the nobel prize tsung-dao lee , and astrophysicist subrahmanyan chandrasekhar . 
notable faculty in physics have included the speed of light calculator a. a. michelson , elementary charge calculator robert a. millikan , discoverer of the compton effect arthur h. compton , the creator of the first nuclear reactor enrico fermi , `` the father of the hydrogen bomb '' edward teller , `` one of the most brilliant and productive experimental physicists of the twentieth century '' luis walter alvarez , murray gell-mann who introduced the quark , second female nobel laureate maria goeppert-mayer , the youngest american winner of the nobel prize tsung-dao lee , and astrophysicist subrahmanyan chandrasekhar . 
past faculty have also included egyptologist james henry breasted , mathematician alberto calderón , nobel prize winning economist and classical liberalism defender friedrich hayek , meteorologist ted fujita , chemists glenn t. seaborg , the developer of the actinide concept and nobel prize winner yuan t. lee , nobel prize winning novelist saul bellow , political philosopher and author allan bloom , cancer researchers charles brenton huggins and janet rowley , astronomer gerard kuiper , one of the most important figures in the early development of the discipline of linguistics edward sapir , and the founder of mckinsey & co. , james o. mckinsey . 
past faculty have also included egyptologist james henry breasted , mathematician alberto calderón , nobel prize winning economist and classical liberalism defender friedrich hayek , meteorologist ted fujita , chemists glenn t. seaborg , the developer of the actinide concept and nobel prize winner yuan t. lee , nobel prize winning novelist saul bellow , political philosopher and author allan bloom , cancer researchers charles brenton huggins and janet rowley , astronomer gerard kuiper , one of the most important figures in the early development of the discipline of linguistics edward sapir , and the founder of mckinsey & co. , james o. mckinsey . 
past faculty have also included egyptologist james henry breasted , mathematician alberto calderón , nobel prize winning economist and classical liberalism defender friedrich hayek , meteorologist ted fujita , chemists glenn t. seaborg , the developer of the actinide concept and nobel prize winner yuan t. lee , nobel prize winning novelist saul bellow , political philosopher and author allan bloom , cancer researchers charles brenton huggins and janet rowley , astronomer gerard kuiper , one of the most important figures in the early development of the discipline of linguistics edward sapir , and the founder of mckinsey & co. , james o. mckinsey . 
past faculty have also included egyptologist james henry breasted , mathematician alberto calderón , nobel prize winning economist and classical liberalism defender friedrich hayek , meteorologist ted fujita , chemists glenn t. seaborg , the developer of the actinide concept and nobel prize winner yuan t. lee , nobel prize winning novelist saul bellow , political philosopher and author allan bloom , cancer researchers charles brenton huggins and janet rowley , astronomer gerard kuiper , one of the most important figures in the early development of the discipline of linguistics edward sapir , and the founder of mckinsey & co. , james o. mckinsey . 
past faculty have also included egyptologist james henry breasted , mathematician alberto calderón , nobel prize winning economist and classical liberalism defender friedrich hayek , meteorologist ted fujita , chemists glenn t. seaborg , the developer of the actinide concept and nobel prize winner yuan t. lee , nobel prize winning novelist saul bellow , political philosopher and author allan bloom , cancer researchers charles brenton huggins and janet rowley , astronomer gerard kuiper , one of the most important figures in the early development of the discipline of linguistics edward sapir , and the founder of mckinsey & co. , james o. mckinsey . 
current faculty include the anthropologist marshall sahlins , historian dipesh chakrabarty , paleontologists neil shubin and paul sereno , evolutionary biologist jerry coyne , nobel prize winning physicist yoichiro nambu , nobel prize winning physicist james cronin , nobel prize winning economists eugene fama , james heckman , lars peter hansen , roger myerson and robert lucas , jr. , freakonomics author and noted economist steven levitt , current governor of india 's central bank raghuram rajan , the 74th united states secretary of the treasury and former goldman sachs chairman and ceo hank paulson , former chairman of president barack obama 's council of economic advisors austan goolsbee , shakespeare scholar david bevington , and renowned political scientists john mearsheimer and robert pape . 
current faculty include the anthropologist marshall sahlins , historian dipesh chakrabarty , paleontologists neil shubin and paul sereno , evolutionary biologist jerry coyne , nobel prize winning physicist yoichiro nambu , nobel prize winning physicist james cronin , nobel prize winning economists eugene fama , james heckman , lars peter hansen , roger myerson and robert lucas , jr. , freakonomics author and noted economist steven levitt , current governor of india 's central bank raghuram rajan , the 74th united states secretary of the treasury and former goldman sachs chairman and ceo hank paulson , former chairman of president barack obama 's council of economic advisors austan goolsbee , shakespeare scholar david bevington , and renowned political scientists john mearsheimer and robert pape . 
current faculty include the anthropologist marshall sahlins , historian dipesh chakrabarty , paleontologists neil shubin and paul sereno , evolutionary biologist jerry coyne , nobel prize winning physicist yoichiro nambu , nobel prize winning physicist james cronin , nobel prize winning economists eugene fama , james heckman , lars peter hansen , roger myerson and robert lucas , jr. , freakonomics author and noted economist steven levitt , current governor of india 's central bank raghuram rajan , the 74th united states secretary of the treasury and former goldman sachs chairman and ceo hank paulson , former chairman of president barack obama 's council of economic advisors austan goolsbee , shakespeare scholar david bevington , and renowned political scientists john mearsheimer and robert pape . 
current faculty include the anthropologist marshall sahlins , historian dipesh chakrabarty , paleontologists neil shubin and paul sereno , evolutionary biologist jerry coyne , nobel prize winning physicist yoichiro nambu , nobel prize winning physicist james cronin , nobel prize winning economists eugene fama , james heckman , lars peter hansen , roger myerson and robert lucas , jr. , freakonomics author and noted economist steven levitt , current governor of india 's central bank raghuram rajan , the 74th united states secretary of the treasury and former goldman sachs chairman and ceo hank paulson , former chairman of president barack obama 's council of economic advisors austan goolsbee , shakespeare scholar david bevington , and renowned political scientists john mearsheimer and robert pape . 
current faculty include the anthropologist marshall sahlins , historian dipesh chakrabarty , paleontologists neil shubin and paul sereno , evolutionary biologist jerry coyne , nobel prize winning physicist yoichiro nambu , nobel prize winning physicist james cronin , nobel prize winning economists eugene fama , james heckman , lars peter hansen , roger myerson and robert lucas , jr. , freakonomics author and noted economist steven levitt , current governor of india 's central bank raghuram rajan , the 74th united states secretary of the treasury and former goldman sachs chairman and ceo hank paulson , former chairman of president barack obama 's council of economic advisors austan goolsbee , shakespeare scholar david bevington , and renowned political scientists john mearsheimer and robert pape . 
the yuan dynasty -lrb- chinese : 元朝 ; pinyin : yuán cháo -rrb- , officially the great yuan -lrb- chinese : 大元 ; pinyin : dà yuán ; mongolian : yehe yuan ulus -lsb- a -rsb- -rrb- , was the empire or ruling dynasty of china established by kublai khan , leader of the mongolian borjigin clan . 
the yuan dynasty -lrb- chinese : 元朝 ; pinyin : yuán cháo -rrb- , officially the great yuan -lrb- chinese : 大元 ; pinyin : dà yuán ; mongolian : yehe yuan ulus -lsb- a -rsb- -rrb- , was the empire or ruling dynasty of china established by kublai khan , leader of the mongolian borjigin clan . 
the yuan dynasty -lrb- chinese : 元朝 ; pinyin : yuán cháo -rrb- , officially the great yuan -lrb- chinese : 大元 ; pinyin : dà yuán ; mongolian : yehe yuan ulus -lsb- a -rsb- -rrb- , was the empire or ruling dynasty of china established by kublai khan , leader of the mongolian borjigin clan . 
the yuan dynasty -lrb- chinese : 元朝 ; pinyin : yuán cháo -rrb- , officially the great yuan -lrb- chinese : 大元 ; pinyin : dà yuán ; mongolian : yehe yuan ulus -lsb- a -rsb- -rrb- , was the empire or ruling dynasty of china established by kublai khan , leader of the mongolian borjigin clan . 
although the mongols had ruled territories including today 's north china for decades , it was not until 1271 that kublai khan officially proclaimed the dynasty in the traditional chinese style . 
the yuan dynasty is considered both a successor to the mongol empire and an imperial chinese dynasty . 
in official chinese histories , the yuan dynasty bore the mandate of heaven , following the song dynasty and preceding the ming dynasty . 
in official chinese histories , the yuan dynasty bore the mandate of heaven , following the song dynasty and preceding the ming dynasty . 
the dynasty was established by kublai khan , yet he placed his grandfather genghis khan on the imperial records as the official founder of the dynasty as taizu . 
in 1271 , kublai khan imposed the name great yuan -lrb- chinese : 大元 ; pinyin : dà yuán ; wade -- giles : ta-yüan -rrb- , establishing the yuan dynasty . 
`` dà yuán '' -lrb- 大元 -rrb- is from the sentence '' 大哉乾元 '' -lrb- dà zai qián yuán / `` great is qián , the primal '' -rrb- in the commentaries on the classic of changes -lrb- i ching -rrb- section regarding qián -lrb- 乾 -rrb- . 
the counterpart in mongolian language was dai ön ulus , also rendered as ikh yuan üls or yekhe yuan ulus . 
`` great mongol state '' -rrb- , resulting in dai ön yeke mongghul ulus -lrb- mongolian script : -rrb- , meaning `` great yuan great mongol state '' . 
furthermore , the yuan is sometimes known as the `` empire of the great khan '' or `` khanate of the great khan '' , which particularly appeared on some yuan maps , since yuan emperors held the nominal title of great khan . 
genghis khan united the mongol and turkic tribes of the steppes and became great khan in 1206 . 
genghis khan united the mongol and turkic tribes of the steppes and became great khan in 1206 . 
under the reign of genghis ' third son , ögedei khan , the mongols destroyed the weakened jin dynasty in 1234 , conquering most of northern china . 
möngke khan succeeded ögedei 's son , güyük , as great khan in 1251 . 
ögedei offered his nephew kublai a position in xingzhou , hebei . 
many han chinese and khitan defected to the mongols to fight against the jin . 
two han chinese leaders , shi tianze , liu heima -lrb- 劉黑馬 , liu ni -rrb- , and the khitan xiao zhala -lrb- 蕭札剌 -rrb- defected and commanded the 3 tumens in the mongol army . 
two han chinese leaders , shi tianze , liu heima -lrb- 劉黑馬 , liu ni -rrb- , and the khitan xiao zhala -lrb- 蕭札剌 -rrb- defected and commanded the 3 tumens in the mongol army . 
there were 4 han tumens and 3 khitan tumens , with each tumen consisting of 10,000 troops . 
there were 4 han tumens and 3 khitan tumens , with each tumen consisting of 10,000 troops . 
shi tianze was a han chinese who lived in the jin dynasty . 
shi tianze was a han chinese who lived in the jin dynasty . 
interethnic marriage between han and jurchen became common at this time . 
his father was shi bingzhi -lrb- 史秉直 , shih ping-chih -rrb- . 
chagaan -lrb- tsagaan -rrb- and zhang rou jointly launched an attack on the song dynasty ordered by töregene khatun . 
möngke khan commenced a military campaign against the chinese song dynasty in southern china . 
möngke khan commenced a military campaign against the chinese song dynasty in southern china . 
he died in 1259 without a successor . 
kublai returned from fighting the song in 1260 when he learned that his brother , ariq böke , was challenging his claim to the throne . 
he bolstered his popularity among his subjects by modeling his government on the bureaucracy of traditional chinese dynasties and adopting the chinese era name of zhongtong . 
ogedei 's grandson kaidu refused to submit to kublai and threatened the western frontier of kublai 's domain . 
the hostile but weakened song dynasty remained an obstacle in the south . 
kublai secured the northeast border in 1259 by installing the hostage prince wonjong as the ruler of korea , making it a mongol tributary state . 
kublai secured the northeast border in 1259 by installing the hostage prince wonjong as the ruler of korea , making it a mongol tributary state . 
li tan , the son-in-law of a powerful official , instigated a revolt against mongol rule in 1262 . 
kublai 's government after 1262 was a compromise between preserving mongol interests in china and satisfying the demands of his chinese subjects . 
he restored the imperial secretariat and left the local administrative structure of past chinese dynasties unchanged . 
however , kublai rejected plans to revive the confucian imperial examinations and divided yuan society into three , later four , classes with the han chinese occupying the lowest rank . 
however , kublai rejected plans to revive the confucian imperial examinations and divided yuan society into three , later four , classes with the han chinese occupying the lowest rank . 
he instituted the reforms proposed by his chinese advisers by centralizing the bureaucracy , expanding the circulation of paper money , and maintaining the traditional monopolies on salt and iron . 
kublai readied the move of the mongol capital from karakorum in mongolia to khanbaliq in 1264 , constructing a new city near the former jurchen capital zhongdu , now modern beijing , in 1266 . 
kublai readied the move of the mongol capital from karakorum in mongolia to khanbaliq in 1264 , constructing a new city near the former jurchen capital zhongdu , now modern beijing , in 1266 . 
kublai readied the move of the mongol capital from karakorum in mongolia to khanbaliq in 1264 , constructing a new city near the former jurchen capital zhongdu , now modern beijing , in 1266 . 
kublai readied the move of the mongol capital from karakorum in mongolia to khanbaliq in 1264 , constructing a new city near the former jurchen capital zhongdu , now modern beijing , in 1266 . 
khublai evoked his public image as a sage emperor by following the rituals of confucian propriety and ancestor veneration , while simultaneously retaining his roots as a leader from the steppes . 
kublai khan promoted commercial , scientific , and cultural growth . 
pax mongolica , mongol peace , enabled the spread of technologies , commodities , and culture between china and the west . 
kublai expanded the grand canal from southern china to daidu in the north . 
kublai expanded the grand canal from southern china to daidu in the north . 
he welcomed foreign visitors to his court , such as the venetian merchant marco polo , who wrote the most influential european account of yuan china . 
during the southern song dynasty the descendant of confucius at qufu , the duke yansheng kong duanyou fled south with the song emperor to quzhou , while the newly established jin dynasty -lrb- 1115 -- 1234 -rrb- in the north appointed kong duanyou 's brother kong duancao who remained in qufu as duke yansheng . 
during the southern song dynasty the descendant of confucius at qufu , the duke yansheng kong duanyou fled south with the song emperor to quzhou , while the newly established jin dynasty -lrb- 1115 -- 1234 -rrb- in the north appointed kong duanyou 's brother kong duancao who remained in qufu as duke yansheng . 
during the southern song dynasty the descendant of confucius at qufu , the duke yansheng kong duanyou fled south with the song emperor to quzhou , while the newly established jin dynasty -lrb- 1115 -- 1234 -rrb- in the north appointed kong duanyou 's brother kong duancao who remained in qufu as duke yansheng . 
during the southern song dynasty the descendant of confucius at qufu , the duke yansheng kong duanyou fled south with the song emperor to quzhou , while the newly established jin dynasty -lrb- 1115 -- 1234 -rrb- in the north appointed kong duanyou 's brother kong duancao who remained in qufu as duke yansheng . 
confucius 's descendants in quzhou alone number 30,000 . 
after strengthening his government in northern china , kublai pursued an expansionist policy in line with the tradition of mongol and chinese imperialism . 
kublai besieged xiangyang between 1268 and 1273 , the last obstacle in his way to capture the rich yangzi river basin . 
kublai besieged xiangyang between 1268 and 1273 , the last obstacle in his way to capture the rich yangzi river basin . 
kublai captured the song capital of hangzhou in 1276 , the wealthiest city of china . 
the last song emperor drowned , bringing an end to the song dynasty . 
kublai 's government faced financial difficulties after 1279 . 
kublai 's second invasion of japan in 1281 failed because of an inauspicious typhoon . 
the tran dynasty which ruled annam -lrb- dai viet -rrb- crushed and defeated the mongols at the battle of bạch đằng -lrb- 1288 -rrb- . 
the tran dynasty which ruled annam -lrb- dai viet -rrb- crushed and defeated the mongols at the battle of bạch đằng -lrb- 1288 -rrb- . 
the tran dynasty which ruled annam -lrb- dai viet -rrb- crushed and defeated the mongols at the battle of bạch đằng -lrb- 1288 -rrb- . 
following the conquest of dali in 1253 , the former ruling duan dynasty were appointed as governors-general , recognized as imperial officials by the yuan , ming , and qing-era governments , principally in the province of yunnan . 
kublai originally named his eldest son , zhenjin , as the crown prince , but he died before kublai in 1285 . 
kublai originally named his eldest son , zhenjin , as the crown prince , but he died before kublai in 1285 . 
thus , zhenjin 's third son , with the support of his mother kökejin and the minister bayan , succeeded the throne and ruled as temür khan , or emperor chengzong , from 1294 to 1307 . 
thus , zhenjin 's third son , with the support of his mother kökejin and the minister bayan , succeeded the throne and ruled as temür khan , or emperor chengzong , from 1294 to 1307 . 
the fourth yuan emperor , buyantu khan -lrb- ayurbarwada -rrb- , was a competent emperor . 
he was the first yuan emperor to actively support and adopt mainstream chinese culture after the reign of kublai , to the discontent of some mongol elite . 
he had been mentored by li meng , a confucian academic . 
he made many reforms , including the liquidation of the department of state affairs -lrb- chinese : 尚書省 -rrb- , which resulted in the execution of five of the highest-ranking officials . 
starting in 1313 the traditional imperial examinations were reintroduced for prospective officials , testing their knowledge on significant historical works . 
emperor gegeen khan , ayurbarwada 's son and successor , ruled for only two years , from 1321 to 1323 . 
emperor gegeen khan , ayurbarwada 's son and successor , ruled for only two years , from 1321 to 1323 . 
he continued his father 's policies to reform the government based on the confucian principles , with the help of his newly appointed grand chancellor baiju . 
during his reign , the da yuan tong zhi -lrb- chinese : 大元通制 , `` the comprehensive institutions of the great yuan '' -rrb- , a huge collection of codes and regulations of the yuan dynasty begun by his father , was formally promulgated . 
gegeen was assassinated in a coup involving five princes from a rival faction , perhaps steppe elite opposed to confucian reforms . 
when yesün temür died in shangdu in 1328 , tugh temür was recalled to khanbaliq by the qipchaq commander el temür . 
gaining support from princes and officers in northern china and some other parts of the dynasty , khanbaliq-based tugh temür eventually won the civil war against ragibagh known as the war of the two capitals . 
however , kusala suddenly died only four days after a banquet with tugh temür . 
he was supposedly killed with poison by el temür , and tugh temür then remounted the throne . 
he was supposedly killed with poison by el temür , and tugh temür then remounted the throne . 
due to the fact that the bureaucracy was dominated by el temür , tugh temür is known for his cultural contribution instead . 
his most concrete effort to patronize chinese learning was founding the academy of the pavilion of the star of literature -lrb- chinese : 奎章閣學士院 -rrb- , first established in the spring of 1329 and designed to undertake `` a number of tasks relating to the transmission of confucian high culture to the mongolian imperial establishment '' . 
his most concrete effort to patronize chinese learning was founding the academy of the pavilion of the star of literature -lrb- chinese : 奎章閣學士院 -rrb- , first established in the spring of 1329 and designed to undertake `` a number of tasks relating to the transmission of confucian high culture to the mongolian imperial establishment '' . 
the academy was responsible for compiling and publishing a number of books , but its most important achievement was its compilation of a vast institutional compendium named jingshi dadian -lrb- chinese : 經世大典 -rrb- . 
tugh temür supported zhu xi 's neo-confucianism and also devoted himself in buddhism . 
after the death of tugh temür in 1332 and subsequent death of rinchinbal -lrb- emperor ningzong -rrb- the same year , the 13-year-old toghun temür -lrb- emperor huizong -rrb- , the last of the nine successors of kublai khan , was summoned back from guangxi and succeeded to the throne . 
after the death of tugh temür in 1332 and subsequent death of rinchinbal -lrb- emperor ningzong -rrb- the same year , the 13-year-old toghun temür -lrb- emperor huizong -rrb- , the last of the nine successors of kublai khan , was summoned back from guangxi and succeeded to the throne . 
after the death of tugh temür in 1332 and subsequent death of rinchinbal -lrb- emperor ningzong -rrb- the same year , the 13-year-old toghun temür -lrb- emperor huizong -rrb- , the last of the nine successors of kublai khan , was summoned back from guangxi and succeeded to the throne . 
after the death of tugh temür in 1332 and subsequent death of rinchinbal -lrb- emperor ningzong -rrb- the same year , the 13-year-old toghun temür -lrb- emperor huizong -rrb- , the last of the nine successors of kublai khan , was summoned back from guangxi and succeeded to the throne . 
one of his successful projects was to finish the long-stalled official histories of the liao , jin , and song dynasties , which were eventually completed in 1345 . 
the final years of the yuan dynasty were marked by struggle , famine , and bitterness among the populace . 
in time , kublai khan 's successors lost all influence on other mongol lands across asia , while the mongols beyond the middle kingdom saw them as too chinese . 
uninterested in administration , they were separated from both the army and the populace , and china was torn by dissension and unrest . 
outlaws ravaged the country without interference from the weakening yuan armies . 
uninterested in administration , they were separated from both the army and the populace , and china was torn by dissension and unrest . 
from the late 1340s onwards , people in the countryside suffered from frequent natural disasters such as droughts , floods and the resulting famines , and the government 's lack of effective policy led to a loss of popular support . 
in 1351 , the red turban rebellion started and grew into a nationwide uprising . 
in 1354 , when toghtogha led a large army to crush the red turban rebels , toghun temür suddenly dismissed him for fear of betrayal . 
in 1354 , when toghtogha led a large army to crush the red turban rebels , toghun temür suddenly dismissed him for fear of betrayal . 
he fled north to shangdu from khanbaliq -lrb- present-day beijing -rrb- in 1368 after the approach of the forces of the míng dynasty -lrb- 1368 -- 1644 -rrb- , founded by zhu yuanzhang in the south . 
the political unity of china and much of central asia promoted trade between east and west . 
the mongols ' extensive west asian and european contacts produced a fair amount of cultural exchange . 
it had significantly eased trade and commerce across asia until its decline ; the communications between yuan dynasty and its ally and subordinate in persia , the ilkhanate , encouraged this development . 
eastern crops such as carrots , turnips , new varieties of lemons , eggplants , and melons , high-quality granulated sugar , and cotton were all either introduced or successfully popularized during the yuan dynasty . 
western musical instruments were introduced to enrich chinese performing arts . 
nestorianism and roman catholicism also enjoyed a period of toleration . 
buddhism -lrb- especially tibetan buddhism -rrb- flourished , although taoism endured certain persecutions in favor of buddhism from the yuan government . 
confucian governmental practices and examinations based on the classics , which had fallen into disuse in north china during the period of disunity , were reinstated by the yuan court , probably in the hope of maintaining order over han society . 
advances were realized in the fields of travel literature , cartography , geography , and scientific education . 
the most famous traveler of the period was the venetian marco polo , whose account of his trip to `` cambaluc , '' the capital of the great khan , and of life there astounded the people of europe . 
the most famous traveler of the period was the venetian marco polo , whose account of his trip to `` cambaluc , '' the capital of the great khan , and of life there astounded the people of europe . 
the account of his travels , il milione -lrb- or , the million , known in english as the travels of marco polo -rrb- , appeared about the year 1299 . 
the account of his travels , il milione -lrb- or , the million , known in english as the travels of marco polo -rrb- , appeared about the year 1299 . 
some suggest that marco polo acquired much of his knowledge through contact with persian traders since many of the places he named were in persian . 
among kublai khan 's top engineers and scientists was the astronomer guo shoujing , who was tasked with many public works projects and helped the yuan reform the lunisolar calendar to provide an accuracy of 365.2425 days of the year , which was only 26 seconds off the modern gregorian calendar 's measurement . 
among kublai khan 's top engineers and scientists was the astronomer guo shoujing , who was tasked with many public works projects and helped the yuan reform the lunisolar calendar to provide an accuracy of 365.2425 days of the year , which was only 26 seconds off the modern gregorian calendar 's measurement . 
to provide against possible famines , granaries were ordered built throughout the empire . 
during the yuan period , beijing became the terminus of the grand canal of china , which was completely renovated . 
contacts with the west also brought the introduction to china of a major food crop , sorghum , along with other foreign food products and methods of preparation . 
the yuan dynasty was the first time that non-native chinese people ruled all of china . 
mongols are widely known to worship the eternal heaven , and according to the traditional mongolian ideology yuan is considered to be `` the beginning of an infinite number of beings , the foundation of peace and happiness , state power , the dream of many peoples , besides it there is nothing great or precious . '' 
in traditional historiography of china , on the other hand , the yuan dynasty is usually considered to be the legitimate dynasty between the song dynasty and the ming dynasty . 
in traditional historiography of china , on the other hand , the yuan dynasty is usually considered to be the legitimate dynasty between the song dynasty and the ming dynasty . 
who did not consider the yuan dynasty as a legitimate dynasty of china , but rather as a period of foreign domination . 
the system of bureaucracy created by kublai khan reflected various cultures in the empire , including that of the han chinese , khitans , jurchens , mongols , and tibetan buddhists . 
the chinese-style elements of the bureaucracy mainly came from the native tang , song , as well as khitan liao and jurchen jin dynasties . 
chinese advisers such as liu bingzhong and yao shu gave strong influence to kublai 's early court , and the central government administration was established within the first decade of kublai 's reign . 
this government adopted the traditional chinese tripartite division of authority among civil , military , and censorial offices , including the central secretariat -lrb- zhongshu sheng -rrb- to manage civil affairs , the privy council -lrb- chinese : 樞密院 -rrb- to manage military affairs , and the censorate to conduct internal surveillance and inspection . 
this government adopted the traditional chinese tripartite division of authority among civil , military , and censorial offices , including the central secretariat -lrb- zhongshu sheng -rrb- to manage civil affairs , the privy council -lrb- chinese : 樞密院 -rrb- to manage military affairs , and the censorate to conduct internal surveillance and inspection . 
another example was the insignificance of the ministry of war compared with native chinese dynasties , as the real military authority in yuan times resided in the privy council . 
while the existence of these central government departments and the six ministries -lrb- which had been introduced since the sui and tang dynasties -rrb- gave a sinicized image in the yuan administration , the actual functions of these ministries also reflected how mongolian priorities and policies reshaped and redirected those institutions . 
for example , the authority of the yuan legal system , the ministry of justice , did not extend to legal cases involving mongols and semuren , who had separate courts of justice . 
another example was the insignificance of the ministry of war compared with native chinese dynasties , as the real military authority in yuan times resided in the privy council . 
since its invention in 1269 , the ` phags-pa script , a unified script for spelling mongolian , tibetan , and chinese languages , was preserved in the court until the end of the dynasty . 
since its invention in 1269 , the ` phags-pa script , a unified script for spelling mongolian , tibetan , and chinese languages , was preserved in the court until the end of the dynasty . 
most of the emperors could not master written chinese , but they could generally converse well in the language . 
the mongol custom of long standing quda/marriage alliance with mongol clans , the onggirat , and the ikeres , kept the imperial blood purely mongol until the reign of tugh temur , whose mother was a tangut concubine . 
nevertheless , a few other yuan emperors actively sponsored cultural activities ; an example is tugh temur -lrb- emperor wenzong -rrb- , who wrote poetry , painted , read chinese classical texts , and ordered the compilation of books . 
the mongols practiced debt slavery , and by 1290 in all parts of the mongol empire commoners were selling their children into slavery . 
seeing this as damaging to the mongol nation , kublai in 1291 forbade the sale abroad of mongols . 
the average mongol garrison family of the yuan dynasty seems to have lived a life of decaying rural leisure , with income from the harvests of their chinese tenants eaten up by costs of equipping and dispatching men for their tours of duty . 
in the china of the yuan , or mongol era , various important developments in the arts occurred or continued in their development , including the areas of painting , mathematics , calligraphy , poetry , and theater , with many great artists and writers being famous today . 
due to the coming together of painting , poetry , and calligraphy at this time many of the artists practicing these different pursuits were the same individuals , though perhaps more famed for one area of their achievements than others . 
often in terms of the further development of landscape painting as well as the classical joining together of the arts of painting , poetry , and calligraphy , the song dynasty and the yuan dynasty are linked together . 
in yuan poetry , the main development was the qu , which was used among other poetic forms by most of the famous yuan poets . 
one of the key factors in the mix of the zaju variety show was the incorporation of poetry both classical and of the newer qu form . 
however , unlike the western khanates , the yuan dynasty never converted to islam . 
instead , kublai khan , the founder of the yuan dynasty , favored buddhism , especially the tibetan variants . 
as a result , tibetan buddhism was established as the de facto state religion . 
the top-level department and government agency known as the bureau of buddhist and tibetan affairs -lrb- xuanzheng yuan -rrb- was set up in khanbaliq -lrb- modern beijing -rrb- to supervise buddhist monks throughout the empire . 
since kublai khan only esteemed the sakya sect of tibetan buddhism , other religions became less important . 
the mathematician zhu shijie -lrb- 1249 -- 1314 -rrb- solved simultaneous equations with up to four unknowns using a rectangular array of coefficients , equivalent to modern matrices . 
the mathematician zhu shijie -lrb- 1249 -- 1314 -rrb- solved simultaneous equations with up to four unknowns using a rectangular array of coefficients , equivalent to modern matrices . 
the mathematician zhu shijie -lrb- 1249 -- 1314 -rrb- solved simultaneous equations with up to four unknowns using a rectangular array of coefficients , equivalent to modern matrices . 
advances in polynomial algebra were made by mathematicians during the yuan era . 
his method is described in the jade mirror of the four unknowns , written in 1303 . 
guo shoujing applied mathematics to the construction of calendars . 
gou derived a cubic interpolation formula for his astronomical calculations . 
his calendar , the shoushi li -lrb- 授時暦 -rrb- or calendar for fixing the seasons , was disseminated in 1281 as the official calendar of the yuan dynasty . 
his calendar , the shoushi li -lrb- 授時暦 -rrb- or calendar for fixing the seasons , was disseminated in 1281 as the official calendar of the yuan dynasty . 
his calendar , the shoushi li -lrb- 授時暦 -rrb- or calendar for fixing the seasons , was disseminated in 1281 as the official calendar of the yuan dynasty . 
healers were divided into non-mongol physicians called otachi and traditional mongol shamans . 
the mongols characterized otachi doctors by their use of herbal remedies , which was distinguished from the spiritual cures of mongol shamanism . 
the mongols characterized otachi doctors by their use of herbal remedies , which was distinguished from the spiritual cures of mongol shamanism . 
kublai created the imperial academy of medicine to manage medical treatises and the education of new doctors . 
confucian scholars were attracted to the medical profession because it ensured a high income and medical ethics were compatible with confucian virtues . 
all four schools were based on the same intellectual foundation , but advocated different theoretical approaches toward medicine . 
the chinese medical tradition of the yuan had `` four great schools '' that the yuan inherited from the jin dynasty . 
chinese physicians were brought along military campaigns by the mongols as they expanded towards the west . 
chinese medical techniques such as acupuncture , moxibustion , pulse diagnosis , and various herbal drugs and elixirs were transmitted westward to the middle east and the rest of the empire . 
the physician wei yilin -lrb- 1277 -- 1347 -rrb- invented a suspension method for reducing dislocated joints , which he performed using anesthetics . 
western medicine was also practiced in china by the nestorian christians of the yuan court , where it was sometimes labeled as huihui or muslim medicine . 
the nestorian physician jesus the interpreter founded the office of western medicine in 1263 during the reign of kublai . 
the nestorian physician jesus the interpreter founded the office of western medicine in 1263 during the reign of kublai . 
chinese physicians opposed western medicine because its humoral system contradicted the yin-yang and wuxing philosophy underlying traditional chinese medicine . 
chinese physicians opposed western medicine because its humoral system contradicted the yin-yang and wuxing philosophy underlying traditional chinese medicine . 
chinese printing technology was transferred to the mongols through kingdom of qocho and tibetan intermediaries . 
some yuan documents such as wang zhen 's nong shu were printed with earthenware movable type , a technology invented in the 12th century . 
some yuan documents such as wang zhen 's nong shu were printed with earthenware movable type , a technology invented in the 12th century . 
the publication of a taoist text inscribed with the name of töregene khatun , ögedei 's wife , is one of the first printed works sponsored by the mongols . 
in 1273 , the mongols created the imperial library directorate , a government-sponsored printing office . 
one of the more notable applications of printing technology was the chao , the paper money of the yuan . 
chao were made from the bark of mulberry trees . 
the yuan government used woodblocks to print paper money , but switched to bronze plates in 1275 . 
the yuan government used woodblocks to print paper money , but switched to bronze plates in 1275 . 
the il-khanate government issued paper money in 1294 , but public distrust of the exotic new currency doomed the experiment . 
politically , the system of government created by kublai khan was the product of a compromise between mongolian patrimonial feudalism and the traditional chinese autocratic-bureaucratic system . 
politically , the system of government created by kublai khan was the product of a compromise between mongolian patrimonial feudalism and the traditional chinese autocratic-bureaucratic system . 
although the traditional chinese elite were not given their share of power , the mongols and the semuren -lrb- various allied groups from central asia and the western end of the empire -rrb- largely remained strangers to the mainstream chinese culture , and this dichotomy gave the yuan regime a somewhat strong `` colonial '' coloration . 
although the traditional chinese elite were not given their share of power , the mongols and the semuren -lrb- various allied groups from central asia and the western end of the empire -rrb- largely remained strangers to the mainstream chinese culture , and this dichotomy gave the yuan regime a somewhat strong `` colonial '' coloration . 
in general there were very few north chinese or southerners reaching the highest-post in the government compared with the possibility that persians did so in the ilkhanate . 
at the same time the mongols imported central asian muslims to serve as administrators in china , the mongols also sent han chinese and khitans from china to serve as administrators over the muslim population in bukhara in central asia , using foreigners to curtail the power of the local peoples of both lands . 
at the same time the mongols imported central asian muslims to serve as administrators in china , the mongols also sent han chinese and khitans from china to serve as administrators over the muslim population in bukhara in central asia , using foreigners to curtail the power of the local peoples of both lands . 
han chinese were moved to central asian areas like besh baliq , almaliq , and samarqand by the mongols where they worked as artisans and farmers . 
han chinese were moved to central asian areas like besh baliq , almaliq , and samarqand by the mongols where they worked as artisans and farmers . 
the mongol appointed governor of samarqand was a qara-khitay -lrb- khitan -rrb- , held the title taishi , familiar with chinese culture his name was ahai 
despite the high position given to muslims , some policies of the yuan emperors severely discriminated against them , restricting halal slaughter and other islamic practices like circumcision , as well as kosher butchering for jews , forcing them to eat food the mongol way . 
despite the high position given to muslims , some policies of the yuan emperors severely discriminated against them , restricting halal slaughter and other islamic practices like circumcision , as well as kosher butchering for jews , forcing them to eat food the mongol way . 
the ming founder zhu yuanzhang had muslim generals like lan yu who rebelled against the mongols and defeated them in combat . 
some muslim communities had a chinese surname which meant `` barracks '' and could also mean `` thanks '' . 
the muslims in the semu class also revolted against the yuan dynasty in the ispah rebellion but the rebellion was crushed and the muslims were massacred by the yuan loyalist commander chen youding . 
the historian frederick w. mote wrote that the usage of the term `` social classes '' for this system was misleading and that the position of people within the four-class system was not an indication of their actual social power and wealth , but just entailed `` degrees of privilege '' to which they were entitled institutionally and legally , so a person 's standing within the classes was not a guarantee of their standing , since there were rich and well socially standing chinese while there were less rich mongol and semu than there were mongol and semu who lived in poverty and were ill treated . 
the historian frederick w. mote wrote that the usage of the term `` social classes '' for this system was misleading and that the position of people within the four-class system was not an indication of their actual social power and wealth , but just entailed `` degrees of privilege '' to which they were entitled institutionally and legally , so a person 's standing within the classes was not a guarantee of their standing , since there were rich and well socially standing chinese while there were less rich mongol and semu than there were mongol and semu who lived in poverty and were ill treated . 
the historian frederick w. mote wrote that the usage of the term `` social classes '' for this system was misleading and that the position of people within the four-class system was not an indication of their actual social power and wealth , but just entailed `` degrees of privilege '' to which they were entitled institutionally and legally , so a person 's standing within the classes was not a guarantee of their standing , since there were rich and well socially standing chinese while there were less rich mongol and semu than there were mongol and semu who lived in poverty and were ill treated . 
the historian frederick w. mote wrote that the usage of the term `` social classes '' for this system was misleading and that the position of people within the four-class system was not an indication of their actual social power and wealth , but just entailed `` degrees of privilege '' to which they were entitled institutionally and legally , so a person 's standing within the classes was not a guarantee of their standing , since there were rich and well socially standing chinese while there were less rich mongol and semu than there were mongol and semu who lived in poverty and were ill treated . 
the northern chinese were ranked higher and southern chinese were ranked lower because southern china withstood and fought to the last before caving in . 
the northern chinese were ranked higher and southern chinese were ranked lower because southern china withstood and fought to the last before caving in . 
the northern chinese were ranked higher and southern chinese were ranked lower because southern china withstood and fought to the last before caving in . 
the earlier they surrendered to the mongols , the higher they were placed , the more the held out , the lower they were ranked . 
major commerce during this era gave rise to favorable conditions for private southern chinese manufacturers and merchants . 
when the mongols placed the uighurs of the kingdom of qocho over the koreans at the court the korean king objected , then the mongol emperor kublai khan rebuked the korean king , saying that the uighur king of qocho was ranked higher than the karluk kara-khanid ruler , who in turn was ranked higher than the korean king , who was ranked last , because the uighurs surrendered to the mongols first , the karluks surrendered after the uighurs , and the koreans surrendered last , and that the uighurs surrendered peacefully without violently resisting . 
when the mongols placed the uighurs of the kingdom of qocho over the koreans at the court the korean king objected , then the mongol emperor kublai khan rebuked the korean king , saying that the uighur king of qocho was ranked higher than the karluk kara-khanid ruler , who in turn was ranked higher than the korean king , who was ranked last , because the uighurs surrendered to the mongols first , the karluks surrendered after the uighurs , and the koreans surrendered last , and that the uighurs surrendered peacefully without violently resisting . 
when the mongols placed the uighurs of the kingdom of qocho over the koreans at the court the korean king objected , then the mongol emperor kublai khan rebuked the korean king , saying that the uighur king of qocho was ranked higher than the karluk kara-khanid ruler , who in turn was ranked higher than the korean king , who was ranked last , because the uighurs surrendered to the mongols first , the karluks surrendered after the uighurs , and the koreans surrendered last , and that the uighurs surrendered peacefully without violently resisting . 
when the mongols placed the uighurs of the kingdom of qocho over the koreans at the court the korean king objected , then the mongol emperor kublai khan rebuked the korean king , saying that the uighur king of qocho was ranked higher than the karluk kara-khanid ruler , who in turn was ranked higher than the korean king , who was ranked last , because the uighurs surrendered to the mongols first , the karluks surrendered after the uighurs , and the koreans surrendered last , and that the uighurs surrendered peacefully without violently resisting . 
the central region , consisting of present-day hebei , shandong , shanxi , the south-eastern part of present-day inner mongolia and the henan areas to the north of the yellow river , was considered the most important region of the dynasty and directly governed by the central secretariat -lrb- or zhongshu sheng -rrb- at khanbaliq -lrb- modern beijing -rrb- ; similarly , another top-level administrative department called the bureau of buddhist and tibetan affairs -lrb- or xuanzheng yuan -rrb- held administrative rule over the whole of modern-day tibet and a part of sichuan , qinghai and kashmir . 
the central region , consisting of present-day hebei , shandong , shanxi , the south-eastern part of present-day inner mongolia and the henan areas to the north of the yellow river , was considered the most important region of the dynasty and directly governed by the central secretariat -lrb- or zhongshu sheng -rrb- at khanbaliq -lrb- modern beijing -rrb- ; similarly , another top-level administrative department called the bureau of buddhist and tibetan affairs -lrb- or xuanzheng yuan -rrb- held administrative rule over the whole of modern-day tibet and a part of sichuan , qinghai and kashmir . 
the central region , consisting of present-day hebei , shandong , shanxi , the south-eastern part of present-day inner mongolia and the henan areas to the north of the yellow river , was considered the most important region of the dynasty and directly governed by the central secretariat -lrb- or zhongshu sheng -rrb- at khanbaliq -lrb- modern beijing -rrb- ; similarly , another top-level administrative department called the bureau of buddhist and tibetan affairs -lrb- or xuanzheng yuan -rrb- held administrative rule over the whole of modern-day tibet and a part of sichuan , qinghai and kashmir . 
the central region , consisting of present-day hebei , shandong , shanxi , the south-eastern part of present-day inner mongolia and the henan areas to the north of the yellow river , was considered the most important region of the dynasty and directly governed by the central secretariat -lrb- or zhongshu sheng -rrb- at khanbaliq -lrb- modern beijing -rrb- ; similarly , another top-level administrative department called the bureau of buddhist and tibetan affairs -lrb- or xuanzheng yuan -rrb- held administrative rule over the whole of modern-day tibet and a part of sichuan , qinghai and kashmir . 
the central region , consisting of present-day hebei , shandong , shanxi , the south-eastern part of present-day inner mongolia and the henan areas to the north of the yellow river , was considered the most important region of the dynasty and directly governed by the central secretariat -lrb- or zhongshu sheng -rrb- at khanbaliq -lrb- modern beijing -rrb- ; similarly , another top-level administrative department called the bureau of buddhist and tibetan affairs -lrb- or xuanzheng yuan -rrb- held administrative rule over the whole of modern-day tibet and a part of sichuan , qinghai and kashmir . 
kenya -lrb- / ˈkɛnjə / ; locally -lsb- ˈkɛɲa -rsb- -lrb- listen -rrb- -rrb- , officially the republic of kenya , is a country in africa and a founding member of the east african community -lrb- eac -rrb- . 
kenya -lrb- / ˈkɛnjə / ; locally -lsb- ˈkɛɲa -rsb- -lrb- listen -rrb- -rrb- , officially the republic of kenya , is a country in africa and a founding member of the east african community -lrb- eac -rrb- . 
its capital and largest city is nairobi . 
it is bordered by tanzania to the south , uganda to the west , south sudan to the north-west , ethiopia to the north and somalia to the north-east . 
kenya covers 581,309 km2 -lrb- 224,445 sq mi -rrb- , and had a population of approximately 45 million people in july 2014 . 
kenya has a warm and humid tropical climate on its indian ocean coastline . 
the climate is cooler in the savannah grasslands around the capital city , nairobi , and especially closer to mount kenya , which has snow permanently on its peaks . 
the climate is cooler in the savannah grasslands around the capital city , nairobi , and especially closer to mount kenya , which has snow permanently on its peaks . 
the north-eastern regions along the border with somalia and ethiopia are arid and semi-arid areas with near-desert landscapes . 
kenya is known for its safaris , diverse climate and geography , and expansive wildlife reserves and national parks such as the east and west tsavo national park , the maasai mara , lake nakuru national park , and aberdares national park . 
the african great lakes region , which kenya is a part of , has been inhabited by humans since the lower paleolithic period . 
by the first millennium ad , the bantu expansion had reached the area from west-central africa . 
bantu and nilotic populations together constitute around 97 % of the nation 's residents . 
european and arab presence in coastal mombasa dates to the early modern period ; european exploration of the interior began in the 19th century . 
kenya obtained independence in december 1963 . 
the republic of kenya is named after mount kenya . 
the origin of the name kenya is not clear , but perhaps linked to the kikuyu , embu and kamba words kirinyaga , kirenyaa and kiinyaa which mean `` god 's resting place '' in all three languages . 
the origin of the name kenya is not clear , but perhaps linked to the kikuyu , embu and kamba words kirinyaga , kirenyaa and kiinyaa which mean `` god 's resting place '' in all three languages . 
ludwig krapf recorded the name as both kenia and kegnia believed by most to be a corruption of the kamba version . 
others say that this was -- on the contrary -- a very precise notation of a correct african pronunciation / ˈkɛnjə / . 
an 1882 map drawn by joseph thompsons , a scottish geologist and naturalist , indicated mt. kenya as mt. kenia , 1862 . 
an 1882 map drawn by joseph thompsons , a scottish geologist and naturalist , indicated mt. kenya as mt. kenia , 1862 . 
the `` big five '' game animals of africa , that is the lion , leopard , buffalo , rhinoceros , and elephant , can be found in kenya and in the masai mara in particular . 
the `` big five '' game animals of africa , that is the lion , leopard , buffalo , rhinoceros , and elephant , can be found in kenya and in the masai mara in particular . 
the `` big five '' game animals of africa , that is the lion , leopard , buffalo , rhinoceros , and elephant , can be found in kenya and in the masai mara in particular . 
the annual animal migration occurs between june and september with millions of animals taking part , attracting valuable foreign tourism . 
two million wildebeest migrate a distance of 2,900 kilometres -lrb- 1,802 mi -rrb- from the serengeti in neighbouring tanzania to the masai mara in kenya , in a constant clockwise fashion , searching for food and water supplies . 
fossils found in kenya suggest that primates roamed the area more than 20 million years ago . 
recent findings near lake turkana indicate that hominids such as homo habilis -lrb- 1.8 and 2.5 million years ago -rrb- and homo erectus -lrb- 1.8 million to 350,000 years ago -rrb- are possible direct ancestors of modern homo sapiens , and lived in kenya in the pleistocene epoch . 
during excavations at lake turkana in 1984 , paleoanthropologist richard leakey assisted by kamoya kimeu discovered the turkana boy , a 1.6-million-year-old fossil belonging to homo erectus . 
during excavations at lake turkana in 1984 , paleoanthropologist richard leakey assisted by kamoya kimeu discovered the turkana boy , a 1.6-million-year-old fossil belonging to homo erectus . 
previous research on early hominids is particularly identified with mary leakey and louis leakey , who were responsible for the preliminary archaeological research at olorgesailie and hyrax hill . 
the swahili built mombasa into a major port city and established trade links with other nearby city-states , as well as commercial centres in persia , arabia , and even india . 
the swahili built mombasa into a major port city and established trade links with other nearby city-states , as well as commercial centres in persia , arabia , and even india . 
by the 15th-century , portuguese voyager duarte barbosa claimed that `` mombasa is a place of great traffic and has a good harbour in which there are always moored small craft of many kinds and also great ships , both of which are bound from sofala and others which come from cambay and melinde and others which sail to the island of zanzibar . '' 
throughout the centuries , the kenyan coast has played host to many merchants and explorers . 
among the cities that line the kenyan coast is the city of malindi . 
it has remained an important swahili settlement since the 14th century and once rivalled mombasa for dominance in the african great lakes region . 
at the outbreak of world war i in august 1914 , the governors of british east africa -lrb- as the protectorate was generally known -rrb- and german east africa agreed a truce in an attempt to keep the young colonies out of direct hostilities . 
at the outbreak of world war i in august 1914 , the governors of british east africa -lrb- as the protectorate was generally known -rrb- and german east africa agreed a truce in an attempt to keep the young colonies out of direct hostilities . 
lt col paul von lettow-vorbeck took command of the german military forces , determined to tie down as many british resources as possible . 
completely cut off from germany , von lettow conducted an effective guerrilla warfare campaign , living off the land , capturing british supplies , and remaining undefeated . 
he eventually surrendered in northern rhodesia -lrb- today zambia -rrb- fourteen days after the armistice was signed in 1918 . 
the central highlands were already home to over a million members of the kikuyu people , most of whom had no land claims in european terms and lived as itinerant farmers . 
the central highlands were already home to over a million members of the kikuyu people , most of whom had no land claims in european terms and lived as itinerant farmers . 
to protect their interests , the settlers banned the growing of coffee , introduced a hut tax , and the landless were granted less and less land in exchange for their labour . 
there were 80,000 white settlers living in kenya in the 1950s . 
the capture of warũhiũ itote -lrb- aka general china -rrb- on 15 january 1954 and the subsequent interrogation led to a better understanding of the mau mau command structure . 
the capture of warũhiũ itote -lrb- aka general china -rrb- on 15 january 1954 and the subsequent interrogation led to a better understanding of the mau mau command structure . 
operation anvil opened on 24 april 1954 , after weeks of planning by the army with the approval of the war council . 
by the end of the emergency , the home guard had killed 4,686 mau mau , amounting to 42 % of the total insurgents . 
the most important of these was the swynnerton plan , which was used to both reward loyalists and punish mau mau . 
the first direct elections for native kenyans to the legislative council took place in 1957 . 
despite british hopes of handing power to `` moderate '' local rivals , it was the kenya african national union -lrb- kanu -rrb- of jomo kenyatta that formed a government . 
the colony of kenya and the protectorate of kenya each came to an end on 12 december 1963 with independence being conferred on all of kenya . 
in this way , kenya became an independent country under the kenya independence act 1963 of the united kingdom . 
exactly 12 months later on 12 december 1964 , kenya became a republic under the name `` republic of kenya '' . 
the election held in 1988 saw the advent of the mlolongo -lrb- queuing -rrb- system , where voters were supposed to line up behind their favoured candidates instead of a secret ballot . 
this was seen as the climax of a very undemocratic regime and it led to widespread agitation for constitutional reform . 
in democratic , multiparty elections in 1992 and 1997 , daniel arap moi won re-election . 
kenya is a presidential representative democratic republic . 
the president is both the head of state and head of government , and of a multi-party system . 
executive power is exercised by the government . 
legislative power is vested in both the government and the national assembly and the senate . 
the judiciary is independent of the executive and the legislature . 
kenya ranks low on transparency international 's corruption perception index -lrb- cpi -rrb- , a metric which attempts to gauge the prevalence of public sector corruption in various countries . 
kenya ranks low on transparency international 's corruption perception index -lrb- cpi -rrb- , a metric which attempts to gauge the prevalence of public sector corruption in various countries . 
in 2012 , the nation placed 139th out of 176 total countries in the cpi , with a score of 27/100 . 
however , there are several rather significant developments with regards to curbing corruption from the kenyan government , for instance , the establishment of a new and independent ethics and anti-corruption commission -lrb- eacc -rrb- . 
in the presidential elections , president kibaki under the party of national unity ran for re-election against the main opposition party , the orange democratic movement -lrb- odm -rrb- . 
in the presidential elections , president kibaki under the party of national unity ran for re-election against the main opposition party , the orange democratic movement -lrb- odm -rrb- . 
as the eck continued to count the votes , kibaki closed the gap and then overtook his opponent by a substantial margin after votes from his stronghold arrived later . 
this led to protests and open discrediting of the eck for complicity and to odinga declaring himself the `` people 's president '' and calling for a recount . 
since the election riots , the government and civil society organisations started programmes to avoid similar disasters in the future , said agnes r. m. aboum -- executive director of taabco research and development consultants in nairobi -- in the magazine d+c development and cooperation . 
for example , the truth , justice and reconciliation commission initiated community dialogues , the evangelical lutheran church in kenya started peace meetings and the kenya national dialogue and reconciliation process was started . 
for example , the truth , justice and reconciliation commission initiated community dialogues , the evangelical lutheran church in kenya started peace meetings and the kenya national dialogue and reconciliation process was started . 
for example , the truth , justice and reconciliation commission initiated community dialogues , the evangelical lutheran church in kenya started peace meetings and the kenya national dialogue and reconciliation process was started . 
on 28 february 2008 , kibaki and odinga signed an agreement on the formation of a coalition government in which odinga would become kenya 's second prime minister . 
on 28 february 2008 , kibaki and odinga signed an agreement on the formation of a coalition government in which odinga would become kenya 's second prime minister . 
under the deal , the president would appoint cabinet ministers from both pnu and odm camps depending on each party 's strength in parliament . 
under the deal , the president would appoint cabinet ministers from both pnu and odm camps depending on each party 's strength in parliament . 
after debates , it was passed by parliament , the coalition would hold until the end of the current parliament or if either of the parties withdraws from the deal before then . 
the new office of the pm will have power and authority to co-ordinate and supervise the functions of the government and will be occupied by an elected mp who will be the leader of the party or coalition with majority members in parliament . 
the world watched annan and his un-backed panel and african union chairman jakaya kikwete as they brought together the former rivals to the signing ceremony , beamed live on national tv from the steps of nairobi 's harambee house . 
the world watched annan and his un-backed panel and african union chairman jakaya kikwete as they brought together the former rivals to the signing ceremony , beamed live on national tv from the steps of nairobi 's harambee house . 
on 29 february 2008 , representatives of pnu and odm began working on the finer details of the power-sharing agreement . 
the deal brought kibaki 's pnu and odinga 's odm together and heralded the formation of the grand coalition , in which the two political parties would share power equally . 
a constitutional change was considered that would eliminate the position of prime minister and simultaneously reduce the powers of the president . 
a referendum to vote on the proposed constitution was held on 4 august 2010 , and the new constitution passed by a wide margin . 
among other things , the new constitution delegates more power to local governments and gives kenyans a bill of rights . 
it was promulgated on 27 august 2010 at a euphoric ceremony in nairobi 's uhuru park , accompanied by a 21-gun salute . 
as of that day , the new constitution heralding the second republic came into force . 
in december 2014 , president uhuru kenyatta signed a security laws amendment bill , which supporters of the law suggested was necessary to guard against armed groups . 
in december 2014 , president uhuru kenyatta signed a security laws amendment bill , which supporters of the law suggested was necessary to guard against armed groups . 
opposition politicians , human rights groups , and nine western countries criticised the security bill , arguing that it infringed on democratic freedoms . 
opposition politicians , human rights groups , and nine western countries criticised the security bill , arguing that it infringed on democratic freedoms . 
the governments of the united states , britain , germany and france also collectively issued a press statement cautioning about the law 's potential impact . 
with international criminal court trial dates in 2013 for both president kenyatta and deputy president william ruto related to the 2007 election aftermath , us president barack obama chose not to visit the country during his mid-2013 african trip . 
with international criminal court trial dates in 2013 for both president kenyatta and deputy president william ruto related to the 2007 election aftermath , us president barack obama chose not to visit the country during his mid-2013 african trip . 
later in the summer , kenyatta visited china at the invitation of president xi jinping after a stop in russia and not having visited the united states as president . 
in july 2015 obama visited kenya , as the first american president to visit the country while in office . 
the armed forces are regularly deployed in peacekeeping missions around the world . 
further , in the aftermath of the national elections of december 2007 and the violence that subsequently engulfed the country , a commission of inquiry , the waki commission , commended its readiness and adjudged it to `` have performed its duty well . '' 
nevertheless , there have been serious allegations of human rights violations , most recently while conducting counter-insurgency operations in the mt elgon area and also in the district of mandera central . 
kenya 's armed forces , like many government institutions in the country , have been tainted by corruption allegations . 
because the operations of the armed forces have been traditionally cloaked by the ubiquitous blanket of `` state security '' , the corruption has been less in public view , and thus less subject to public scrutiny and notoriety . 
in what are by kenyan standards unprecedented revelations , in 2010 , credible claims of corruption were made with regard to recruitment and procurement of armoured personnel carriers . 
further , the wisdom and prudence of certain decisions of procurement have been publicly questioned . 
although kenya is the biggest and most advanced economy in east and central africa , and has an affluent urban minority , it has a human development index -lrb- hdi -rrb- of 0.519 , ranked 145 out of 186 in the world . 
although kenya is the biggest and most advanced economy in east and central africa , and has an affluent urban minority , it has a human development index -lrb- hdi -rrb- of 0.519 , ranked 145 out of 186 in the world . 
as of 2005 , 17.7 % of kenyans lived on less than $ 1.25 a day . 
kenya is usually classified as a frontier market or occasionally an emerging market , but it is not one of the least developed countries . 
east and central africa 's biggest economy has posted tremendous growth in the service sector , boosted by rapid expansion in telecommunication and financial activity over the last decade , and now -lsb- when ? -rsb- 
22 % of gdp still comes from the unreliable agricultural sector which employs 75 % of the labour force -lrb- a consistent characteristic of under-developed economies that have not attained food security -- an important catalyst of economic growth -rrb- a small portion of the population relies on food aid . 
-lsb- citation needed -rsb- industry and manufacturing is the smallest sector , accounting for 16 % of gdp . 
22 % of gdp still comes from the unreliable agricultural sector which employs 75 % of the labour force -lrb- a consistent characteristic of under-developed economies that have not attained food security -- an important catalyst of economic growth -rrb- a small portion of the population relies on food aid . 
kenya 's services sector , which contributes 61 % of gdp , is dominated by tourism . 
kenya 's services sector , which contributes 61 % of gdp , is dominated by tourism . 
the tourism sector has exhibited steady growth in most years since independence and by the late 1980s had become the country 's principal source of foreign exchange . 
tourists , the largest number being from germany and the united kingdom , are attracted mainly to the coastal beaches and the game reserves , notably , the expansive east and west tsavo national park 20,808 square kilometres -lrb- 8,034 sq mi -rrb- in the southeast . 
tourists , the largest number being from germany and the united kingdom , are attracted mainly to the coastal beaches and the game reserves , notably , the expansive east and west tsavo national park 20,808 square kilometres -lrb- 8,034 sq mi -rrb- in the southeast . 
in 2005 agriculture , including forestry and fishing , accounted for 24 % of gdp , as well as for 18 % of wage employment and 50 % of revenue from exports . 
the principal cash crops are tea , horticultural produce , and coffee . 
agriculture is the second largest contributor to kenya 's gross domestic product -lrb- gdp -rrb- , after the service sector . 
the production of major food staples such as corn is subject to sharp weather-related fluctuations . 
a consortium led by the international crops research institute for the semi-arid tropics -lrb- icrisat -rrb- has had some success in helping farmers grow new pigeon pea varieties , instead of maize , in particularly dry areas . 
pigeon peas are very drought resistant , so can be grown in areas with less than 650 mm annual rainfall . 
successive projects encouraged the commercialisation of legumes , by stimulating the growth of local seed production and agro-dealer networks for distribution and marketing . 
this work , which included linking producers to wholesalers , helped to increase local producer prices by 20 -- 25 % in nairobi and mombasa . 
the commercialisation of the pigeon pea is now enabling some farmers to buy assets , ranging from mobile phones to productive land and livestock , and is opening pathways for them to move out of poverty . 
tea , coffee , sisal , pyrethrum , corn , and wheat are grown in the fertile highlands , one of the most successful agricultural production regions in africa . 
tea , coffee , sisal , pyrethrum , corn , and wheat are grown in the fertile highlands , one of the most successful agricultural production regions in africa . 
livestock predominates in the semi-arid savanna to the north and east . 
unfortunately , the country has not attained the level of investment and efficiency in agriculture that can guarantee food security and coupled with resulting poverty -lrb- 53 % of the population lives below the poverty line -rrb- , a significant portion of the population regularly starves and is heavily dependent on food aid . 
this was last seen in august and september 2011 prompting the kenyans for kenya initiative by the red cross . 
although kenya is the most industrially developed country in the african great lakes region , manufacturing still accounts for only 14 % of the gdp . 
although kenya is the most industrially developed country in the african great lakes region , manufacturing still accounts for only 14 % of the gdp . 
industrial activity , concentrated around the three largest urban centres , nairobi , mombasa and kisumu , is dominated by food-processing industries such as grain milling , beer production , and sugarcane crushing , and the fabrication of consumer goods , e.g. , vehicles from kits . 
in addition , a substantial and expanding informal sector commonly referred to as jua kali engages in small-scale manufacturing of household goods , motor-vehicle parts , and farm implements . 
kenya 's inclusion among the beneficiaries of the us government 's african growth and opportunity act -lrb- agoa -rrb- has given a boost to manufacturing in recent years . 
since agoa took effect in 2000 , kenya 's clothing sales to the united states increased from us$ 44 million to us$ 270 million -lrb- 2006 -rrb- . 
the largest share of kenya 's electricity supply comes from hydroelectric stations at dams along the upper tana river , as well as the turkwel gorge dam in the west . 
the largest share of kenya 's electricity supply comes from hydroelectric stations at dams along the upper tana river , as well as the turkwel gorge dam in the west . 
the state-owned kenya electricity generating company -lrb- kengen -rrb- , established in 1997 under the name of kenya power company , handles the generation of electricity , while kenya power handles the electricity transmission and distribution system in the country . 
kenya has proven deposits of oil in turkana and the commercial viability was just discovered . 
tullow oil estimates kenya 's oil reserves to be around 10 billion barrels . 
exploration is still continuing to determine if there are more reserves . 
petroleum accounts for 20 % to 25 % of the national import bill . 
published comments on kenya 's capital fm website by liu guangyuan , china 's ambassador to kenya , at the time of president kenyatta 's 2013 trip to beijing , said , `` chinese investment in kenya ... reached $ 474 million , representing kenya 's largest source of foreign direct investment , and ... bilateral trade ... reached $ 2.84 billion '' in 2012 . 
published comments on kenya 's capital fm website by liu guangyuan , china 's ambassador to kenya , at the time of president kenyatta 's 2013 trip to beijing , said , `` chinese investment in kenya ... reached $ 474 million , representing kenya 's largest source of foreign direct investment , and ... bilateral trade ... reached $ 2.84 billion '' in 2012 . 
kenyatta was '' -lsb- a -rsb- ccompanied by 60 kenyan business people -lsb- and hoped to -rsb- ... gain support from china for a planned $ 2.5 billion railway from the southern kenyan port of mombasa to neighboring uganda , as well as a nearly $ 1.8 billion dam '' , according to a statement from the president 's office also at the time of the trip . 
base titanium , a subsidiary of base resources of australia , shipped its first major consignment of minerals to china . 
china has been causing environmental and social problems that include the recent suspension of the railway project . 
in 2007 , the kenyan government unveiled vision 2030 , an economic development programme it hopes will put the country in the same league as the asian economic tigers by the year 2030 . 
in 2007 , the kenyan government unveiled vision 2030 , an economic development programme it hopes will put the country in the same league as the asian economic tigers by the year 2030 . 
in 2013 , it launched a national climate change action plan , having acknowledged that omitting climate as a key development issue in vision 2030 was an oversight . 
in 2013 , it launched a national climate change action plan , having acknowledged that omitting climate as a key development issue in vision 2030 was an oversight . 
at the launch in march 2013 , the secretary of the ministry of planning , national development and vision 2030 emphasised that climate will be a central issue in the renewed medium term plan that will be launched in the coming months . 
most working children are active in agriculture . 
in 2006 , unicef estimated that up to 30 % of girls in the coastal areas of malindi , mombasa , kilifi , and diani were subject to prostitution . 
most of the prostitutes in kenya are aged 9 -- 18 . 
the causes of child labour include poverty , the lack of access to education and weak government institutions . 
kenya 's various ethnic groups typically speak their mother tongues within their own communities . 
the two official languages , english and swahili , are used in varying degrees of fluency for communication with other populations . 
english is widely spoken in commerce , schooling and government . 
british english is primarily used in the country . 
the vast majority of kenyans are christian -lrb- 83 % -rrb- , with 47.7 % regarding themselves as protestant and 23.5 % as roman catholic of the latin rite . 
the vast majority of kenyans are christian -lrb- 83 % -rrb- , with 47.7 % regarding themselves as protestant and 23.5 % as roman catholic of the latin rite . 
the presbyterian church of east africa has 3 million followers in kenya and the surrounding countries . 
the only jewish synagogue in the country is located in the capital , nairobi . 
sizeable minorities of other faiths do exist -lrb- muslim 11.2 % , indigenous beliefs 1.7 % -rrb- , and nonreligious 2.4 % . 
sixty percent of the muslim population lives in kenya 's coastal region , comprising 50 % of the total population there . 
western areas of the coast region are mostly christian . 
in addition , there is a large hindu population in kenya -lrb- around 300,000 -rrb- , who have played a key role in the local economy ; they are mostly of indian origin . 
nurses treat 80 % of the population who visit dispensaries , health centres and private clinics in rural and under-served urban areas . 
complicated cases are referred to clinical officers , medical officers and medical practitioners . 
according to the kenya national bureau of statistics , in 2011 there were 65,000 qualified nurses registered in the country ; 8,600 clinical officers and 7,000 doctors for the population of 43 million people -lrb- these figures from official registers include those who have died or left the profession hence the actual number of these workers may be lower -rrb- . 
according to the kenya national bureau of statistics , in 2011 there were 65,000 qualified nurses registered in the country ; 8,600 clinical officers and 7,000 doctors for the population of 43 million people -lrb- these figures from official registers include those who have died or left the profession hence the actual number of these workers may be lower -rrb- . 
diseases of poverty directly correlate with a country 's economic performance and wealth distribution : half of kenyans live below the poverty level . 
diseases of poverty directly correlate with a country 's economic performance and wealth distribution : half of kenyans live below the poverty level . 
preventable diseases like malaria , hiv/aids , pneumonia , diarrhoea and malnutrition are the biggest burden , major child-killers , and responsible for much morbidity ; weak policies , corruption , inadequate health workers , weak management and poor leadership in the public health sector are largely to blame . 
preventable diseases like malaria , hiv/aids , pneumonia , diarrhoea and malnutrition are the biggest burden , major child-killers , and responsible for much morbidity ; weak policies , corruption , inadequate health workers , weak management and poor leadership in the public health sector are largely to blame . 
kenya had an estimated 15 million cases of malaria in 2006 . 
kenya 's first system of education was introduced by british colonists . 
after kenya 's independence on 12 december 1963 , an authority named the ominde commission was formed to introduce changes that would reflect the nation 's sovereignty . 
after kenya 's independence on 12 december 1963 , an authority named the ominde commission was formed to introduce changes that would reflect the nation 's sovereignty . 
the commission focused on identity and unity , which were critical issues at the time . 
between 1964 and 1985 , the 7 -- 4 -- 2 -- 3 system was adopted -- seven years of primary , four years of lower secondary , two years of upper secondary , and three years of university . 
in 1981 , the presidential working party on the second university was commissioned to look at both the possibilities of setting up a second university in kenya as well as the reforming of the entire education system . 
the committee recommended that the 7 -- 4 -- 2 -- 3 system be changed to an 8 -- 4 -- 4 system -lrb- eight years in primary , four years in secondary , and four years in university education -rrb- . 
the table under present-day education in kenya below shows the structure of the 8 -- 4 -- 4 system . 
although the 7 -- 4 -- 2 -- 3 system theoretically ended with the introduction of the new 8 -- 4 -- 4 system in 1985 , the last batch of students from the former system graduated from kenyan universities in 1992 . 
the current 8 -- 4 -- 4 system was launched in january 1985 . 
it put more emphasis on vocational subjects on the assumption that the new structure would enable school drop-outs at all levels either to be self-employed or to secure employment in the informal sector . 
it put more emphasis on vocational subjects on the assumption that the new structure would enable school drop-outs at all levels either to be self-employed or to secure employment in the informal sector . 
in january 2003 , the government of kenya announced the introduction of free primary education . 
as a result , primary school enrolment increased by about 70 % . 
basic formal education starts at age six years and lasts 12 years comprising eight years in primary school and four years in high school or secondary school . 
basic formal education starts at age six years and lasts 12 years comprising eight years in primary school and four years in high school or secondary school . 
primary school is free in public schools and those who exit at this level can join a vocational youth/village polytechnic or make their own arrangements for an apprenticeship program and learn a trade such as tailoring , carpentry , motor vehicle repair , brick-laying and masonry for about two years . 
those who complete high school can join a polytechnic or other technical college and study for three years or proceed directly to the university and study for four years . 
the country 's literacy level stands at 85 % of the whole population . 
preschool , which targets children from age three to five , is an integral component of the education system and is a key requirement for admission to standard one -lrb- first grade -rrb- . 
preschool , which targets children from age three to five , is an integral component of the education system and is a key requirement for admission to standard one -lrb- first grade -rrb- . 
at the end of primary education , pupils sit the kenya certificate of primary education -lrb- kcpe -rrb- , which determines those who proceed to secondary school or vocational training . 
for those who proceed to secondary level , there is a national examination at the end of form four -- the kenya certificate of secondary education -lrb- kcse -rrb- , which determines those proceeding to the universities , other professional training or employment . 
other than the curriculum led learning , there are also national and public library services led by the kenya national library service -lrb- knls -rrb- . 
knls is the body mandated to establish , equip , manage and maintain national and public libraries in the country . 
a public library is seen as a peoples university since it is open to all irrespective of age , literacy level and has materials relevant to people of all walks of life . 
a public library is seen as a peoples university since it is open to all irrespective of age , literacy level and has materials relevant to people of all walks of life . 
kenya is active in several sports , among them cricket , rallying , football , rugby union and boxing . 
the country is known chiefly for its dominance in middle-distance and long-distance athletics , having consistently produced olympic and commonwealth games champions in various distance events , especially in 800 m , 1,500 m , 3,000 m steeplechase , 5,000 m , 10,000 m and the marathon . 
kenyan athletes -lrb- particularly kalenjin -rrb- continue to dominate the world of distance running , although competition from morocco and ethiopia has reduced this supremacy . 
kenyan athletes -lrb- particularly kalenjin -rrb- continue to dominate the world of distance running , although competition from morocco and ethiopia has reduced this supremacy . 
kenya won several medals during the beijing olympics , six gold , four silver and four bronze , making it africa 's most successful nation in the 2008 olympics . 
kenya won several medals during the beijing olympics , six gold , four silver and four bronze , making it africa 's most successful nation in the 2008 olympics . 
new athletes gained attention , such as pamela jelimo , the women 's 800m gold medalist who went ahead to win the iaaf golden league jackpot , and samuel wanjiru who won the men 's marathon . 
lately , there has been controversy in kenyan athletics circles , with the defection of a number of kenyan athletes to represent other countries , chiefly bahrain and qatar . 
most of these defections occur because of economic or financial factors . 
kenya has been a dominant force in women 's volleyball within africa , with both the clubs and the national team winning various continental championships in the past decade . 
cricket is another popular and the most successful team sport . 
they upset some of the world 's best teams and reached semi-finals of the 2003 tournament . 
their current captain is rakep patel . 
however , its dominance has been eroded by wrangles within the now defunct kenya football federation , leading to a suspension by fifa which was lifted in march 2007 . 
in the motor rallying arena , kenya is home to the world famous safari rally , commonly acknowledged as one of the toughest rallies in the world . 
in the motor rallying arena , kenya is home to the world famous safari rally , commonly acknowledged as one of the toughest rallies in the world . 
some of the best rally drivers in the world have taken part in and won the rally , such as björn waldegård , hannu mikkola , tommi mäkinen , shekhar mehta , carlos sainz and colin mcrae . 
kenyans generally have three meals in a day -- breakfast in the morning -lrb- kiamsha kinywa -rrb- , lunch in the afternoon -lrb- chakula cha mchana -rrb- and supper in the evening -lrb- chakula cha jioni or known simply as `` chajio '' -rrb- . 
in between , they have the 10 o'clock tea -lrb- chai ya saa nne -rrb- and 4 pm tea -lrb- chai ya saa kumi -rrb- . 
breakfast is usually tea or porridge with bread , chapati , mahamri , boiled sweet potatoes or yams . 
ugali with vegetables , sour milk , meat , fish or any other stew is generally eaten by much of the population for lunch or supper . 
the intergovernmental panel on climate change -lrb- ipcc -rrb- is a scientific intergovernmental body under the auspices of the united nations , set up at the request of member governments . 
it was first established in 1988 by two united nations organizations , the world meteorological organization -lrb- wmo -rrb- and the united nations environment programme -lrb- unep -rrb- , and later endorsed by the united nations general assembly through resolution 43/53 . 
the ultimate objective of the unfccc is to `` stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic -lsb- i.e. , human-induced -rsb- interference with the climate system '' . 
the ipcc produces reports that support the united nations framework convention on climate change -lrb- unfccc -rrb- , which is the main international treaty on climate change . 
it was first established in 1988 by two united nations organizations , the world meteorological organization -lrb- wmo -rrb- and the united nations environment programme -lrb- unep -rrb- , and later endorsed by the united nations general assembly through resolution 43/53 . 
korean economist hoesung lee is the chair of the ipcc since october 8 , 2015 , following the election of the new ipcc bureau . 
korean economist hoesung lee is the chair of the ipcc since october 8 , 2015 , following the election of the new ipcc bureau . 
before this election , the ipcc was led by his vice-chair ismail el gizouli , who was designated acting chair after the resignation of rajendra k. pachauri in february 2015 . 
the previous chairs were rajendra k. pachauri , elected in may 2002 ; robert watson in 1997 ; and bert bolin in 1988 . 
before this election , the ipcc was led by his vice-chair ismail el gizouli , who was designated acting chair after the resignation of rajendra k. pachauri in february 2015 . 
the ipcc panel is composed of representatives appointed by governments and organizations . 
attendance at the 2003 meeting included 350 government officials and climate change experts . 
attendance at the 2003 meeting included 350 government officials and climate change experts . 
the meeting report states there were 322 persons in attendance at sessions with about seven-eighths of participants being from governmental organizations . 
the ipcc receives funding through the ipcc trust fund , established in 1989 by the united nations environment programme -lrb- unep -rrb- and the world meteorological organization -lrb- wmo -rrb- , costs of the secretary and of housing the secretariat are provided by the wmo , while unep meets the cost of the depute secretary . 
the ipcc receives funding through the ipcc trust fund , established in 1989 by the united nations environment programme -lrb- unep -rrb- and the world meteorological organization -lrb- wmo -rrb- , costs of the secretary and of housing the secretariat are provided by the wmo , while unep meets the cost of the depute secretary . 
the ipcc receives funding through the ipcc trust fund , established in 1989 by the united nations environment programme -lrb- unep -rrb- and the world meteorological organization -lrb- wmo -rrb- , costs of the secretary and of housing the secretariat are provided by the wmo , while unep meets the cost of the depute secretary . 
the organisation is required to comply with the financial regulations and rules of the wmo . 
the ipcc receives funding through the ipcc trust fund , established in 1989 by the united nations environment programme -lrb- unep -rrb- and the world meteorological organization -lrb- wmo -rrb- , costs of the secretary and of housing the secretariat are provided by the wmo , while unep meets the cost of the depute secretary . 
the ipcc does not carry out research nor does it monitor climate related data . 
lead authors of ipcc reports assess the available information about climate change based on published sources . 
authors may refer to non-peer-reviewed sources -lrb- the `` grey literature '' -rrb- , provided that they are of sufficient quality . 
examples of non-peer-reviewed sources include model results , reports from government agencies and non-governmental organizations , and industry journals . 
a chapter typically has two `` coordinating lead authors '' , ten to fifteen `` lead authors '' , and a somewhat larger number of `` contributing authors '' . 
a chapter typically has two `` coordinating lead authors '' , ten to fifteen `` lead authors '' , and a somewhat larger number of `` contributing authors '' . 
a chapter typically has two `` coordinating lead authors '' , ten to fifteen `` lead authors '' , and a somewhat larger number of `` contributing authors '' . 
the coordinating lead authors are responsible for assembling the contributions of the other authors , ensuring that they meet stylistic and formatting requirements , and reporting to the working group chairs . 
the coordinating lead authors are responsible for assembling the contributions of the other authors , ensuring that they meet stylistic and formatting requirements , and reporting to the working group chairs . 
the executive summary of the wg i summary for policymakers report says they are certain that emissions resulting from human activities are substantially increasing the atmospheric concentrations of the greenhouse gases , resulting on average in an additional warming of the earth 's surface . 
the executive summary of the wg i summary for policymakers report says they are certain that emissions resulting from human activities are substantially increasing the atmospheric concentrations of the greenhouse gases , resulting on average in an additional warming of the earth 's surface . 
they calculate with confidence that co2 has been responsible for over half the enhanced greenhouse effect . 
they predict that under a `` business as usual '' -lrb- bau -rrb- scenario , global mean temperature will increase by about 0.3 °c per decade during the -lsb- 21st -rsb- century . 
they judge that global mean surface air temperature has increased by 0.3 to 0.6 °c over the last 100 years , broadly consistent with prediction of climate models , but also of the same magnitude as natural climate variability . 
in 2001 , 16 national science academies issued a joint statement on climate change . 
in 2001 , 16 national science academies issued a joint statement on climate change . 
the statement , also published as an editorial in the journal science , stated `` we support the -lsb- tar 's -rsb- conclusion that it is at least 90 % certain that temperatures will continue to rise , with average global surface temperature projected to increase by between 1.4 and 5.8 °c above 1990 levels by 2100 '' . 
the statement , also published as an editorial in the journal science , stated `` we support the -lsb- tar 's -rsb- conclusion that it is at least 90 % certain that temperatures will continue to rise , with average global surface temperature projected to increase by between 1.4 and 5.8 °c above 1990 levels by 2100 '' . 
the statement , also published as an editorial in the journal science , stated `` we support the -lsb- tar 's -rsb- conclusion that it is at least 90 % certain that temperatures will continue to rise , with average global surface temperature projected to increase by between 1.4 and 5.8 °c above 1990 levels by 2100 '' . 
ipcc author richard lindzen has made a number of criticisms of the tar . 
among his criticisms , lindzen has stated that the wgi summary for policymakers -lrb- spm -rrb- does not faithfully summarize the full wgi report . 
john houghton , who was a co-chair of tar wgi , has responded to lindzen 's criticisms of the spm . 
john houghton , who was a co-chair of tar wgi , has responded to lindzen 's criticisms of the spm . 
houghton has stressed that the spm is agreed upon by delegates from many of the world 's governments , and that any changes to the spm must be supported by scientific evidence . 
the preparation and approval process for all ipcc special reports follows the same procedures as for ipcc assessment reports . 
in the year 2011 two ipcc special report were finalized , the special report on renewable energy sources and climate change mitigation -lrb- srren -rrb- and the special report on managing risks of extreme events and disasters to advance climate change adaptation -lrb- srex -rrb- . 
in the year 2011 two ipcc special report were finalized , the special report on renewable energy sources and climate change mitigation -lrb- srren -rrb- and the special report on managing risks of extreme events and disasters to advance climate change adaptation -lrb- srex -rrb- . 
both special reports were requested by governments . 
while the preparation of the assessment reports is a major ipcc function , it also supports other activities , such as the data distribution centre and the national greenhouse gas inventories programme , required under the unfccc . 
this involves publishing default emission factors , which are factors used to derive emissions estimates based on the levels of fuel consumption , industrial production and so on . 
this involves publishing default emission factors , which are factors used to derive emissions estimates based on the levels of fuel consumption , industrial production and so on . 
the ipcc concentrates its activities on the tasks allotted to it by the relevant wmo executive council and unep governing council resolutions and decisions as well as on actions in support of the unfccc process . 
the ipcc has since acknowledged that the date is incorrect , while reaffirming that the conclusion in the final summary was robust . 
they expressed regret for `` the poor application of well-established ipcc procedures in this instance '' . 
the date of 2035 has been correctly quoted by the ipcc from the wwf report , which has misquoted its own source , an icsi report `` variations of snow and ice in the past and at present on a global and regional scale '' . 
the date of 2035 has been correctly quoted by the ipcc from the wwf report , which has misquoted its own source , an icsi report `` variations of snow and ice in the past and at present on a global and regional scale '' . 
former ipcc chairman robert watson has said `` the mistakes all appear to have gone in the direction of making it seem like climate change is more serious by overstating the impact . 
former ipcc chairman robert watson has said `` the mistakes all appear to have gone in the direction of making it seem like climate change is more serious by overstating the impact . 
martin parry , a climate expert who had been co-chair of the ipcc working group ii , said that `` what began with a single unfortunate error over himalayan glaciers has become a clamour without substance '' and the ipcc had investigated the other alleged mistakes , which were `` generally unfounded and also marginal to the assessment '' . 
martin parry , a climate expert who had been co-chair of the ipcc working group ii , said that `` what began with a single unfortunate error over himalayan glaciers has become a clamour without substance '' and the ipcc had investigated the other alleged mistakes , which were `` generally unfounded and also marginal to the assessment '' . 
martin parry , a climate expert who had been co-chair of the ipcc working group ii , said that `` what began with a single unfortunate error over himalayan glaciers has become a clamour without substance '' and the ipcc had investigated the other alleged mistakes , which were `` generally unfounded and also marginal to the assessment '' . 
the third assessment report -lrb- tar -rrb- prominently featured a graph labeled `` millennial northern hemisphere temperature reconstruction '' based on a 1999 paper by michael e. mann , raymond s. bradley and malcolm k. hughes -lrb- mbh99 -rrb- , which has been referred to as the `` hockey stick graph '' . 
the third assessment report -lrb- tar -rrb- prominently featured a graph labeled `` millennial northern hemisphere temperature reconstruction '' based on a 1999 paper by michael e. mann , raymond s. bradley and malcolm k. hughes -lrb- mbh99 -rrb- , which has been referred to as the `` hockey stick graph '' . 
the third assessment report -lrb- tar -rrb- prominently featured a graph labeled `` millennial northern hemisphere temperature reconstruction '' based on a 1999 paper by michael e. mann , raymond s. bradley and malcolm k. hughes -lrb- mbh99 -rrb- , which has been referred to as the `` hockey stick graph '' . 
the mbh99 finding was supported by cited reconstructions by jones et al. 1998 , pollack , huang & shen 1998 , crowley & lowery 2000 and briffa 2000 , using differing data and methods . 
these studies were widely presented as demonstrating that the current warming period is exceptional in comparison to temperatures between 1000 and 1900 , and the mbh99 based graph featured in publicity . 
even at the draft stage , this finding was disputed by contrarians : in may 2000 fred singer 's science and environmental policy project held a press event on capitol hill , washington , d.c. , featuring comments on the graph wibjörn karlén and singer argued against the graph at a united states senate committee on commerce , science and transportation hearing on 18 july 2000 . 
even at the draft stage , this finding was disputed by contrarians : in may 2000 fred singer 's science and environmental policy project held a press event on capitol hill , washington , d.c. , featuring comments on the graph wibjörn karlén and singer argued against the graph at a united states senate committee on commerce , science and transportation hearing on 18 july 2000 . 
even at the draft stage , this finding was disputed by contrarians : in may 2000 fred singer 's science and environmental policy project held a press event on capitol hill , washington , d.c. , featuring comments on the graph wibjörn karlén and singer argued against the graph at a united states senate committee on commerce , science and transportation hearing on 18 july 2000 . 
even at the draft stage , this finding was disputed by contrarians : in may 2000 fred singer 's science and environmental policy project held a press event on capitol hill , washington , d.c. , featuring comments on the graph wibjörn karlén and singer argued against the graph at a united states senate committee on commerce , science and transportation hearing on 18 july 2000 . 
on 23 june 2005 , rep. joe barton , chairman of the house committee on energy and commerce wrote joint letters with ed whitfield , chairman of the subcommittee on oversight and investigations demanding full records on climate research , as well as personal information about their finances and careers , from mann , bradley and hughes . 
on 23 june 2005 , rep. joe barton , chairman of the house committee on energy and commerce wrote joint letters with ed whitfield , chairman of the subcommittee on oversight and investigations demanding full records on climate research , as well as personal information about their finances and careers , from mann , bradley and hughes . 
on 23 june 2005 , rep. joe barton , chairman of the house committee on energy and commerce wrote joint letters with ed whitfield , chairman of the subcommittee on oversight and investigations demanding full records on climate research , as well as personal information about their finances and careers , from mann , bradley and hughes . 
sherwood boehlert , chairman of the house science committee , said this was a `` misguided and illegitimate investigation '' apparently aimed at intimidating scientists , and at his request the u.s. national academy of sciences arranged for its national research council to set up a special investigation . 
sherwood boehlert , chairman of the house science committee , said this was a `` misguided and illegitimate investigation '' apparently aimed at intimidating scientists , and at his request the u.s. national academy of sciences arranged for its national research council to set up a special investigation . 
the ipcc fourth assessment report -lrb- ar4 -rrb- published in 2007 featured a graph showing 12 proxy based temperature reconstructions , including the three highlighted in the 2001 third assessment report -lrb- tar -rrb- ; mann , bradley & hughes 1999 as before , jones et al. 1998 and briffa 2000 had both been calibrated by newer studies . 
the ipcc fourth assessment report -lrb- ar4 -rrb- published in 2007 featured a graph showing 12 proxy based temperature reconstructions , including the three highlighted in the 2001 third assessment report -lrb- tar -rrb- ; mann , bradley & hughes 1999 as before , jones et al. 1998 and briffa 2000 had both been calibrated by newer studies . 
ten of these 14 reconstructions covered 1,000 years or longer . 
the section discussed the divergence problem affecting certain tree ring data . 
ten of these 14 reconstructions covered 1,000 years or longer . 
on 1 february 2007 , the eve of the publication of ipcc 's major report on climate , a study was published suggesting that temperatures and sea levels have been rising at or above the maximum rates proposed during the last ipcc report in 2001 . 
on 1 february 2007 , the eve of the publication of ipcc 's major report on climate , a study was published suggesting that temperatures and sea levels have been rising at or above the maximum rates proposed during the last ipcc report in 2001 . 
over the six years studied , the actual temperature rise was near the top end of the range given by ipcc 's 2001 projection , and the actual sea level rise was above the top of the range of the ipcc projection . 
over the six years studied , the actual temperature rise was near the top end of the range given by ipcc 's 2001 projection , and the actual sea level rise was above the top of the range of the ipcc projection . 
another example of scientific research which suggests that previous estimates by the ipcc , far from overstating dangers and risks , have actually understated them is a study on projected rises in sea levels . 
these values are much greater than the 9 -- 88 cm as projected by the ipcc itself in its third assessment report , published in 2001 '' . 
when the researchers ' analysis was `` applied to the possible scenarios outlined by the intergovernmental panel on climate change -lrb- ipcc -rrb- , the researchers found that in 2100 sea levels would be 0.5 -- 1.4 m -lsb- 50 -- 140 cm -rsb- above 1990 levels . 
these values are much greater than the 9 -- 88 cm as projected by the ipcc itself in its third assessment report , published in 2001 '' . 
michael oppenheimer , a long-time participant in the ipcc and coordinating lead author of the fifth assessment report conceded in science magazine 's state of the planet 2008-2009 some limitations of the ipcc consensus approach and asks for concurring , smaller assessments of special problems instead of the large scale approach as in the previous ipcc assessment reports . 
michael oppenheimer , a long-time participant in the ipcc and coordinating lead author of the fifth assessment report conceded in science magazine 's state of the planet 2008-2009 some limitations of the ipcc consensus approach and asks for concurring , smaller assessments of special problems instead of the large scale approach as in the previous ipcc assessment reports . 
michael oppenheimer , a long-time participant in the ipcc and coordinating lead author of the fifth assessment report conceded in science magazine 's state of the planet 2008-2009 some limitations of the ipcc consensus approach and asks for concurring , smaller assessments of special problems instead of the large scale approach as in the previous ipcc assessment reports . 
in case of the ozone depletion global regulation based on the montreal protocol has been successful , in case of climate change , the kyoto protocol failed . 
in case of the ozone depletion global regulation based on the montreal protocol has been successful , in case of climate change , the kyoto protocol failed . 
the lockstep situation of the ipcc is having built a broad science consensus while states and governments still follow different , if not opposing goals . 
according to sheldon ungar 's comparison with global warming , the actors in the ozone depletion case had a better understanding of scientific ignorance and uncertainties . 
in case of the ipcc conclusions and the failure of the kyoto protocol , varying regional cost-benefit analysis and burden-sharing conflicts with regard to the distribution of emission reductions remain an unsolved problem . 
the stepwise mitigation of the ozone layer challenge was based as well on successfully reducing regional burden sharing conflicts . 
in the uk , a report for a house of lords committee asked to urge the ipcc to involve better assessments of costs and benefits of climate change but the stern review ordered by the uk government made a stronger argument in favor to combat human-made climate change . 
since the ipcc does not carry out its own research , it operates on the basis of scientific papers and independently documented results from other scientific bodies , and its schedule for producing reports requires a deadline for submissions prior to the report 's final release . 
in principle , this means that any significant new evidence or events that change our understanding of climate science between this deadline and publication of an ipcc report can not be included . 
in principle , this means that any significant new evidence or events that change our understanding of climate science between this deadline and publication of an ipcc report can not be included . 
in february 2010 , in response to controversies regarding claims in the fourth assessment report , five climate scientists -- all contributing or lead ipcc report authors -- wrote in the journal nature calling for changes to the ipcc . 
in february 2010 , in response to controversies regarding claims in the fourth assessment report , five climate scientists -- all contributing or lead ipcc report authors -- wrote in the journal nature calling for changes to the ipcc . 
they suggested a range of new organizational options , from tightening the selection of lead authors and contributors , to dumping it in favor of a small permanent body , or even turning the whole climate science assessment process into a moderated `` living '' wikipedia-ipcc . 
other recommendations included that the panel employ a full-time staff and remove government oversight from its processes to avoid political interference . 
chloroplasts ' main role is to conduct photosynthesis , where the photosynthetic pigment chlorophyll captures the energy from sunlight and converts it and stores it in the energy-storage molecules atp and nadph while freeing oxygen from water . 
chloroplasts ' main role is to conduct photosynthesis , where the photosynthetic pigment chlorophyll captures the energy from sunlight and converts it and stores it in the energy-storage molecules atp and nadph while freeing oxygen from water . 
chloroplasts ' main role is to conduct photosynthesis , where the photosynthetic pigment chlorophyll captures the energy from sunlight and converts it and stores it in the energy-storage molecules atp and nadph while freeing oxygen from water . 
they then use the atp and nadph to make organic molecules from carbon dioxide in a process known as the calvin cycle . 
the number of chloroplasts per cell varies from 1 in algae up to 100 in plants like arabidopsis and wheat . 
chloroplasts are highly dynamic -- they circulate and are moved around within plant cells , and occasionally pinch in two to reproduce . 
their behavior is strongly influenced by environmental factors like light color and intensity . 
chloroplasts , like mitochondria , contain their own dna , which is thought to be inherited from their ancestor -- a photosynthetic cyanobacterium that was engulfed by an early eukaryotic cell . 
chloroplasts , like mitochondria , contain their own dna , which is thought to be inherited from their ancestor -- a photosynthetic cyanobacterium that was engulfed by an early eukaryotic cell . 
chloroplasts can not be made by the plant cell and must be inherited by each daughter cell during cell division . 
chloroplasts are only found in plants and algae . 
this origin of chloroplasts was first suggested by the russian biologist konstantin mereschkowski in 1905 after andreas schimper observed in 1883 that chloroplasts closely resemble cyanobacteria . 
this origin of chloroplasts was first suggested by the russian biologist konstantin mereschkowski in 1905 after andreas schimper observed in 1883 that chloroplasts closely resemble cyanobacteria . 
this origin of chloroplasts was first suggested by the russian biologist konstantin mereschkowski in 1905 after andreas schimper observed in 1883 that chloroplasts closely resemble cyanobacteria . 
this origin of chloroplasts was first suggested by the russian biologist konstantin mereschkowski in 1905 after andreas schimper observed in 1883 that chloroplasts closely resemble cyanobacteria . 
cyanobacteria are considered the ancestors of chloroplasts . 
they are sometimes called blue-green algae even though they are prokaryotes . 
they are a diverse phylum of bacteria capable of carrying out photosynthesis , and are gram-negative , meaning that they have two cell membranes . 
cyanobacteria also contain a peptidoglycan cell wall , which is thicker than in other gram-negative bacteria , and which is located between their two cell membranes . 
they are sometimes called blue-green algae even though they are prokaryotes . 
somewhere around a billion years ago , a free-living cyanobacterium entered an early eukaryotic cell , either as food or as an internal parasite , but managed to escape the phagocytic vacuole it was contained in . 
somewhere around a billion years ago , a free-living cyanobacterium entered an early eukaryotic cell , either as food or as an internal parasite , but managed to escape the phagocytic vacuole it was contained in . 
the two innermost lipid-bilayer membranes that surround all chloroplasts correspond to the outer and inner membranes of the ancestral cyanobacterium 's gram negative cell wall , and not the phagosomal membrane from the host , which was probably lost . 
the two innermost lipid-bilayer membranes that surround all chloroplasts correspond to the outer and inner membranes of the ancestral cyanobacterium 's gram negative cell wall , and not the phagosomal membrane from the host , which was probably lost . 
over time , the cyanobacterium was assimilated , and many of its genes were lost or transferred to the nucleus of the host . 
these chloroplasts , which can be traced back directly to a cyanobacterial ancestor , are known as primary plastids -lrb- `` plastid '' in this context means almost the same thing as chloroplast -rrb- . 
all primary chloroplasts belong to one of three chloroplast lineages -- the glaucophyte chloroplast lineage , the rhodophyte , or red algal chloroplast lineage , or the chloroplastidan , or green chloroplast lineage . 
all primary chloroplasts belong to one of three chloroplast lineages -- the glaucophyte chloroplast lineage , the rhodophyte , or red algal chloroplast lineage , or the chloroplastidan , or green chloroplast lineage . 
all primary chloroplasts belong to one of three chloroplast lineages -- the glaucophyte chloroplast lineage , the rhodophyte , or red algal chloroplast lineage , or the chloroplastidan , or green chloroplast lineage . 
the second two are the largest , and the green chloroplast lineage is the one that contains the land plants . 
the alga cyanophora , a glaucophyte , is thought to be one of the first organisms to contain a chloroplast . 
the alga cyanophora , a glaucophyte , is thought to be one of the first organisms to contain a chloroplast . 
for this reason , glaucophyte chloroplasts are also known as muroplasts . 
glaucophyte chloroplasts also contain concentric unstacked thylakoids , which surround a carboxysome - an icosahedral structure that glaucophyte chloroplasts and cyanobacteria keep their carbon fixation enzyme rubisco in . 
glaucophyte chloroplasts also contain concentric unstacked thylakoids , which surround a carboxysome - an icosahedral structure that glaucophyte chloroplasts and cyanobacteria keep their carbon fixation enzyme rubisco in . 
rhodoplasts have chlorophyll a and phycobilins for photosynthetic pigments ; the phycobilin phycoerytherin is responsible for giving many red algae their distinctive red color . 
rhodoplasts have a double membrane with an intermembrane space and phycobilin pigments organized into phycobilisomes on the thylakoid membranes , preventing their thylakoids from stacking . 
rhodoplasts have chlorophyll a and phycobilins for photosynthetic pigments ; the phycobilin phycoerytherin is responsible for giving many red algae their distinctive red color . 
the red phycoerytherin pigment is an adaptation to help red algae catch more sunlight in deep water -- as such , some red algae that live in shallow water have less phycoerytherin in their rhodoplasts , and can appear more greenish . 
rhodoplasts synthesize a form of starch called floridean , which collects into granules outside the rhodoplast , in the cytoplasm of the red alga . 
they differ from glaucophyte and red algal chloroplasts in that they have lost their phycobilisomes , and contain chlorophyll b instead . 
most green chloroplasts are -lrb- obviously -rrb- green , though some are n't , like some forms of hæmatococcus pluvialis , due to accessory pigments that override the chlorophylls ' green colors . 
chloroplastidan chloroplasts have lost the peptidoglycan wall between their double membrane , and have replaced it with an intermembrane space . 
some plants seem to have kept the genes for the synthesis of the peptidoglycan layer , though they 've been repurposed for use in chloroplast division instead . 
they differ from glaucophyte and red algal chloroplasts in that they have lost their phycobilisomes , and contain chlorophyll b instead . 
while primary chloroplasts have a double membrane from their cyanobacterial ancestor , secondary chloroplasts have additional membranes outside of the original two , as a result of the secondary endosymbiotic event , when a nonphotosynthetic eukaryote engulfed a chloroplast-containing alga but failed to digest it -- much like the cyanobacterium at the beginning of this story . 
while primary chloroplasts have a double membrane from their cyanobacterial ancestor , secondary chloroplasts have additional membranes outside of the original two , as a result of the secondary endosymbiotic event , when a nonphotosynthetic eukaryote engulfed a chloroplast-containing alga but failed to digest it -- much like the cyanobacterium at the beginning of this story . 
while primary chloroplasts have a double membrane from their cyanobacterial ancestor , secondary chloroplasts have additional membranes outside of the original two , as a result of the secondary endosymbiotic event , when a nonphotosynthetic eukaryote engulfed a chloroplast-containing alga but failed to digest it -- much like the cyanobacterium at the beginning of this story . 
the engulfed alga was broken down , leaving only its chloroplast , and sometimes its cell membrane and nucleus , forming a chloroplast with three or four membranes -- the two cyanobacterial membranes , sometimes the eaten alga 's cell membrane , and the phagosomal vacuole from the host 's cell membrane . 
the engulfed alga was broken down , leaving only its chloroplast , and sometimes its cell membrane and nucleus , forming a chloroplast with three or four membranes -- the two cyanobacterial membranes , sometimes the eaten alga 's cell membrane , and the phagosomal vacuole from the host 's cell membrane . 
euglenophytes are a group of common flagellated protists that contain chloroplasts derived from a green alga . 
euglenophytes are a group of common flagellated protists that contain chloroplasts derived from a green alga . 
euglenophyte chloroplasts have a pyrenoid and thylakoids stacked in groups of three . 
starch is stored in the form of paramylon , which is contained in membrane-bound granules in the cytoplasm of the euglenophyte . 
euglenophyte chloroplasts have three membranes -- it is thought that the membrane of the primary endosymbiont was lost , leaving the cyanobacterial membranes , and the secondary host 's phagosomal membrane . 
cryptophytes , or cryptomonads are a group of algae that contain a red-algal derived chloroplast . 
cryptophytes , or cryptomonads are a group of algae that contain a red-algal derived chloroplast . 
cryptophyte chloroplasts contain a nucleomorph that superficially resembles that of the chlorarachniophytes . 
they synthesize ordinary starch , which is stored in granules found in the periplastid space -- outside the original double membrane , in the place that corresponds to the red alga 's cytoplasm . 
inside cryptophyte chloroplasts is a pyrenoid and thylakoids in stacks of two . 
like the helicosproidia , they 're parasitic , and have a nonphotosynthetic chloroplast . 
apicomplexans are another group of chromalveolates . 
the apicomplexans include plasmodium , the malaria parasite . 
many apicomplexans keep a vestigial red algal derived chloroplast called an apicoplast , which they inherited from their ancestors . 
apicomplexans store their energy in amylopectin starch granules that are located in their cytoplasm , even though they are nonphotosynthetic . 
plant chloroplasts provide plant cells with many important things besides sugar , and apicoplasts are no different -- they synthesize fatty acids , isopentenyl pyrophosphate , iron-sulfur clusters , and carry out part of the heme pathway . 
this makes the apicoplast an attractive target for drugs to cure apicomplexan-related diseases . 
the most important apicoplast function is isopentenyl pyrophosphate synthesis -- in fact , apicomplexans die when something interferes with this apicoplast function , and when apicomplexans are grown in an isopentenyl pyrophosphate-rich medium , they dump the organelle . 
apicoplasts have lost all photosynthetic function , and contain no photosynthetic pigments or true thylakoids . 
they are bounded by four membranes , but the membranes are not connected to the endoplasmic reticulum . 
peridinin is not found in any other group of chloroplasts . 
the most common dinophyte chloroplast is the peridinin-type chloroplast , characterized by the carotenoid pigment peridinin in their chloroplasts , along with chlorophyll a and chlorophyll c2 . 
they contain a pyrenoid , and have triplet-stacked thylakoids . 
the peridinin chloroplast is bounded by three membranes -lrb- occasionally two -rrb- , having lost the red algal endosymbiont 's original cell membrane . 
the fucoxanthin dinophyte lineages -lrb- including karlodinium and karenia -rrb- lost their original red algal derived chloroplast , and replaced it with a new chloroplast derived from a haptophyte endosymbiont . 
the fucoxanthin dinophyte lineages -lrb- including karlodinium and karenia -rrb- lost their original red algal derived chloroplast , and replaced it with a new chloroplast derived from a haptophyte endosymbiont . 
because the haptophyte chloroplast has four membranes , tertiary endosymbiosis would be expected to create a six membraned chloroplast , adding the haptophyte 's cell membrane and the dinophyte 's phagosomal vacuole . 
because the haptophyte chloroplast has four membranes , tertiary endosymbiosis would be expected to create a six membraned chloroplast , adding the haptophyte 's cell membrane and the dinophyte 's phagosomal vacuole . 
members of the genus dinophysis have a phycobilin-containing chloroplast taken from a cryptophyte . 
however , the cryptophyte is not an endosymbiont -- only the chloroplast seems to have been taken , and the chloroplast has been stripped of its nucleomorph and outermost two membranes , leaving just a two-membraned chloroplast . 
members of the genus dinophysis have a phycobilin-containing chloroplast taken from a cryptophyte . 
however , the cryptophyte is not an endosymbiont -- only the chloroplast seems to have been taken , and the chloroplast has been stripped of its nucleomorph and outermost two membranes , leaving just a two-membraned chloroplast . 
some dinophytes , like kryptoperidinium and durinskia have a diatom -lrb- heterokontophyte -rrb- derived chloroplast . 
some dinophytes , like kryptoperidinium and durinskia have a diatom -lrb- heterokontophyte -rrb- derived chloroplast . 
these chloroplasts are bounded by up to five membranes , -lrb- depending on whether you count the entire diatom endosymbiont as the chloroplast , or just the red algal derived chloroplast inside it -rrb- . 
these chloroplasts are bounded by up to five membranes , -lrb- depending on whether you count the entire diatom endosymbiont as the chloroplast , or just the red algal derived chloroplast inside it -rrb- . 
however the diatom endosymbiont ca n't store its own food -- its starch is found in granules in the dinophyte host 's cytoplasm instead . 
the chloroplast is surrounded by two membranes and has no nucleomorph -- all the nucleomorph genes have been transferred to the dinophyte nucleus . 
lepidodinium is the only dinophyte that has a chloroplast that 's not from the rhodoplast lineage . 
lepidodinium viride and its close relatives are dinophytes that lost their original peridinin chloroplast and replaced it with a green algal derived chloroplast -lrb- more specifically , a prasinophyte -rrb- . 
lepidodinium viride and its close relatives are dinophytes that lost their original peridinin chloroplast and replaced it with a green algal derived chloroplast -lrb- more specifically , a prasinophyte -rrb- . 
lepidodinium viride and its close relatives are dinophytes that lost their original peridinin chloroplast and replaced it with a green algal derived chloroplast -lrb- more specifically , a prasinophyte -rrb- . 
while most chloroplasts originate from that first set of endosymbiotic events , paulinella chromatophora is an exception that acquired a photosynthetic cyanobacterial endosymbiont more recently . 
while most chloroplasts originate from that first set of endosymbiotic events , paulinella chromatophora is an exception that acquired a photosynthetic cyanobacterial endosymbiont more recently . 
chromatophore dna is about a million base pairs long , containing around 850 protein encoding genes -- far less than the three million base pair synechococcus genome , but much larger than the approximately 150,000 base pair genome of the more assimilated chloroplast . 
chromatophore dna is about a million base pairs long , containing around 850 protein encoding genes -- far less than the three million base pair synechococcus genome , but much larger than the approximately 150,000 base pair genome of the more assimilated chloroplast . 
chromatophore dna is about a million base pairs long , containing around 850 protein encoding genes -- far less than the three million base pair synechococcus genome , but much larger than the approximately 150,000 base pair genome of the more assimilated chloroplast . 
chloroplasts have their own dna , often abbreviated as ctdna , or cpdna . 
it is also known as the plastome . 
its existence was first proved in 1962 , and first sequenced in 1986 -- when two japanese research teams sequenced the chloroplast dna of liverwort and tobacco . 
its existence was first proved in 1962 , and first sequenced in 1986 -- when two japanese research teams sequenced the chloroplast dna of liverwort and tobacco . 
its existence was first proved in 1962 , and first sequenced in 1986 -- when two japanese research teams sequenced the chloroplast dna of liverwort and tobacco . 
the inverted repeat regions are highly conserved among land plants , and accumulate few mutations . 
similar inverted repeats exist in the genomes of cyanobacteria and the other two chloroplast lineages -lrb- glaucophyta and rhodophyceæ -rrb- , suggesting that they predate the chloroplast , though some chloroplast dnas have since lost or flipped the inverted repeats -lrb- making them direct repeats -rrb- . 
it is possible that the inverted repeats help stabilize the rest of the chloroplast genome , as chloroplast dnas which have lost some of the inverted repeat segments tend to get rearranged more . 
scientists have attempted to observe chloroplast replication via electron microscopy since the 1970s . 
the mechanism for chloroplast dna -lrb- cpdna -rrb- replication has not been conclusively determined , but two main models have been proposed . 
as the d-loop moves through the circular dna , it adopts a theta intermediary form , also known as a cairns replication intermediate , and completes replication with a rolling circle mechanism . 
as the d-loop moves through the circular dna , it adopts a theta intermediary form , also known as a cairns replication intermediate , and completes replication with a rolling circle mechanism . 
as the d-loop moves through the circular dna , it adopts a theta intermediary form , also known as a cairns replication intermediate , and completes replication with a rolling circle mechanism . 
in cpdna , there are several a → g deamination gradients . 
dna becomes susceptible to deamination events when it is single stranded . 
this mechanism is still the leading theory today ; however , a second theory suggests that most cpdna is actually linear and replicates through homologous recombination . 
this mechanism is still the leading theory today ; however , a second theory suggests that most cpdna is actually linear and replicates through homologous recombination . 
it further contends that only a minority of the genetic material is kept in circular chromosomes while the rest is in branched , linear , or other complex structures . 
one of competing model for cpdna replication asserts that most cpdna is linear and participates in homologous recombination and replication structures similar to bacteriophage t4 . 
it has been established that some plants have linear cpdna , such as maize , and that more species still contain complex structures that scientists do not yet understand . 
because of the failure to explain the deamination gradient as well as the numerous plant species that have been shown to have circular cpdna , the predominant theory continues to hold that most cpdna is circular and most likely replicates via a d loop mechanism . 
because of the failure to explain the deamination gradient as well as the numerous plant species that have been shown to have circular cpdna , the predominant theory continues to hold that most cpdna is circular and most likely replicates via a d loop mechanism . 
endosymbiotic gene transfer is how we know about the lost chloroplasts in many chromalveolate lineages . 
even if a chloroplast is eventually lost , the genes it donated to the former host 's nucleus persist , providing evidence for the lost chloroplast 's existence . 
for example , while diatoms -lrb- a heterokontophyte -rrb- now have a red algal derived chloroplast , the presence of many green algal genes in the diatom nucleus provide evidence that the diatom ancestor -lrb- probably the ancestor of all chromalveolates too -rrb- had a green algal derived chloroplast at some point , which was subsequently replaced by the red chloroplast . 
for example , while diatoms -lrb- a heterokontophyte -rrb- now have a red algal derived chloroplast , the presence of many green algal genes in the diatom nucleus provide evidence that the diatom ancestor -lrb- probably the ancestor of all chromalveolates too -rrb- had a green algal derived chloroplast at some point , which was subsequently replaced by the red chloroplast . 
a few chloroplast genes found new homes in the mitochondrial genome -- most became nonfunctional pseudogenes , though a few trna genes still work in the mitochondrion . 
curiously , around half of the protein products of transferred genes are n't even targeted back to the chloroplast . 
many became exaptations , taking on new functions like participating in cell division , protein routing , and even disease resistance . 
some transferred chloroplast dna protein products get directed to the secretory pathway -lrb- though it should be noted that many secondary plastids are bounded by an outermost membrane derived from the host 's cell membrane , and therefore topologically outside of the cell , because to reach the chloroplast from the cytosol , you have to cross the cell membrane , just like if you were headed for the extracellular space . 
after a chloroplast polypeptide is synthesized on a ribosome in the cytosol , an enzyme specific to chloroplast proteins phosphorylates , or adds a phosphate group to many -lrb- but not all -rrb- of them in their transit sequences . 
after a chloroplast polypeptide is synthesized on a ribosome in the cytosol , an enzyme specific to chloroplast proteins phosphorylates , or adds a phosphate group to many -lrb- but not all -rrb- of them in their transit sequences . 
phosphorylation helps many proteins bind the polypeptide , keeping it from folding prematurely . 
phosphorylation helps many proteins bind the polypeptide , keeping it from folding prematurely . 
in land plants , chloroplasts are generally lens-shaped , 5 -- 8 μm in diameter and 1 -- 3 μm thick . 
in land plants , chloroplasts are generally lens-shaped , 5 -- 8 μm in diameter and 1 -- 3 μm thick . 
in land plants , chloroplasts are generally lens-shaped , 5 -- 8 μm in diameter and 1 -- 3 μm thick . 
greater diversity in chloroplast shapes exists among the algae , which often contain a single chloroplast that can be shaped like a net -lrb- e.g. , oedogonium -rrb- , a cup -lrb- e.g. , chlamydomonas -rrb- , a ribbon-like spiral around the edges of the cell -lrb- e.g. , spirogyra -rrb- , or slightly twisted bands at the cell edges -lrb- e.g. , sirogonium -rrb- . 
greater diversity in chloroplast shapes exists among the algae , which often contain a single chloroplast that can be shaped like a net -lrb- e.g. , oedogonium -rrb- , a cup -lrb- e.g. , chlamydomonas -rrb- , a ribbon-like spiral around the edges of the cell -lrb- e.g. , spirogyra -rrb- , or slightly twisted bands at the cell edges -lrb- e.g. , sirogonium -rrb- . 
the fact that chloroplasts are surrounded by a double membrane is often cited as evidence that they are the descendants of endosymbiotic cyanobacteria . 
this is often interpreted as meaning the outer chloroplast membrane is the product of the host 's cell membrane infolding to form a vesicle to surround the ancestral cyanobacterium -- which is not true -- both chloroplast membranes are homologous to the cyanobacterium 's original double membranes . 
this is often interpreted as meaning the outer chloroplast membrane is the product of the host 's cell membrane infolding to form a vesicle to surround the ancestral cyanobacterium -- which is not true -- both chloroplast membranes are homologous to the cyanobacterium 's original double membranes . 
the chloroplast double membrane is also often compared to the mitochondrial double membrane . 
this is not a valid comparison -- the inner mitochondria membrane is used to run proton pumps and carry out oxidative phosphorylation across to generate atp energy . 
this is not a valid comparison -- the inner mitochondria membrane is used to run proton pumps and carry out oxidative phosphorylation across to generate atp energy . 
the only chloroplast structure that can considered analogous to it is the internal thylakoid system . 
in addition , in terms of function , the inner chloroplast membrane , which regulates metabolite passage and synthesizes some materials , has no counterpart in the mitochondrion . 
stromules are very rare in chloroplasts , and are much more common in other plastids like chromoplasts and amyloplasts in petals and roots , respectively . 
the chloroplast membranes sometimes protrude out into the cytoplasm , forming a stromule , or stroma-containing tubule . 
they may exist to increase the chloroplast 's surface area for cross-membrane transport , because they are often branched and tangled with the endoplasmic reticulum . 
when they were first observed in 1962 , some plant biologists dismissed the structures as artifactual , claiming that stromules were just oddly shaped chloroplasts with constricted regions or dividing chloroplasts . 
it is often found in the chloroplasts of c4 plants , though it has also been found in some c3 angiosperms , and even some gymnosperms . 
it is often found in the chloroplasts of c4 plants , though it has also been found in some c3 angiosperms , and even some gymnosperms . 
the chloroplast peripheral reticulum consists of a maze of membranous tubes and vesicles continuous with the inner chloroplast membrane that extends into the internal stromal fluid of the chloroplast . 
its purpose is thought to be to increase the chloroplast 's surface area for cross-membrane transport between its stroma and the cell cytoplasm . 
the small vesicles sometimes observed may serve as transport vesicles to shuttle stuff between the thylakoids and intermembrane space . 
chloroplasts have their own ribosomes , which they use to synthesize a small fraction of their proteins . 
chloroplast ribosomes are about two-thirds the size of cytoplasmic ribosomes -lrb- around 17 nm vs 25 nm -rrb- . 
chloroplast ribosomes are about two-thirds the size of cytoplasmic ribosomes -lrb- around 17 nm vs 25 nm -rrb- . 
small subunit ribosomal rnas in several chlorophyta and euglenid chloroplasts lack motifs for shine-dalgarno sequence recognition , which is considered essential for translation initiation in most chloroplasts and prokaryotes . 
small subunit ribosomal rnas in several chlorophyta and euglenid chloroplasts lack motifs for shine-dalgarno sequence recognition , which is considered essential for translation initiation in most chloroplasts and prokaryotes . 
plastoglobuli -lrb- singular plastoglobulus , sometimes spelled plastoglobule -lrb- s -rrb- -rrb- , are spherical bubbles of lipids and proteins about 45 -- 60 nanometers across . 
plastoglobuli -lrb- singular plastoglobulus , sometimes spelled plastoglobule -lrb- s -rrb- -rrb- , are spherical bubbles of lipids and proteins about 45 -- 60 nanometers across . 
plastoglobuli -lrb- singular plastoglobulus , sometimes spelled plastoglobule -lrb- s -rrb- -rrb- , are spherical bubbles of lipids and proteins about 45 -- 60 nanometers across . 
plastoglobuli -lrb- singular plastoglobulus , sometimes spelled plastoglobule -lrb- s -rrb- -rrb- , are spherical bubbles of lipids and proteins about 45 -- 60 nanometers across . 
they are surrounded by a lipid monolayer . 
plastoglobuli were once thought to be free-floating in the stroma , but it is now thought that they are permanently attached either to a thylakoid or to another plastoglobulus attached to a thylakoid , a configuration that allows a plastoglobulus to exchange its contents with the thylakoid network . 
plastoglobuli were once thought to be free-floating in the stroma , but it is now thought that they are permanently attached either to a thylakoid or to another plastoglobulus attached to a thylakoid , a configuration that allows a plastoglobulus to exchange its contents with the thylakoid network . 
in normal green chloroplasts , the vast majority of plastoglobuli occur singularly , attached directly to their parent thylakoid . 
in old or stressed chloroplasts , plastoglobuli tend to occur in linked groups or chains , still always anchored to a thylakoid . 
the chloroplasts of some hornworts and algae contain structures called pyrenoids . 
pyrenoids are roughly spherical and highly refractive bodies which are a site of starch accumulation in plants that contain them . 
pyrenoids are roughly spherical and highly refractive bodies which are a site of starch accumulation in plants that contain them . 
pyrenoids are roughly spherical and highly refractive bodies which are a site of starch accumulation in plants that contain them . 
pyrenoids can divide to form new pyrenoids , or be produced `` de novo '' . 
in the helical thylakoid model , grana consist of a stack of flattened circular granal thylakoids that resemble pancakes . 
in the helical thylakoid model , grana consist of a stack of flattened circular granal thylakoids that resemble pancakes . 
each granum can contain anywhere from two to a hundred thylakoids , though grana with 10 -- 20 thylakoids are most common . 
each granum can contain anywhere from two to a hundred thylakoids , though grana with 10 -- 20 thylakoids are most common . 
wrapped around the grana are helicoid stromal thylakoids , also known as frets or lamellar thylakoids . 
photosystem ii and photosystem i contain light-harvesting complexes with chlorophyll and carotenoids that absorb light energy and use it to energize electrons . 
photosystem ii and photosystem i contain light-harvesting complexes with chlorophyll and carotenoids that absorb light energy and use it to energize electrons . 
photosystem ii and photosystem i contain light-harvesting complexes with chlorophyll and carotenoids that absorb light energy and use it to energize electrons . 
molecules in the thylakoid membrane use the energized electrons to pump hydrogen ions into the thylakoid space , decreasing the ph and turning it acidic . 
atp synthase is a large protein complex that harnesses the concentration gradient of the hydrogen ions in the thylakoid space to generate atp energy as the hydrogen ions flow back out into the stroma -- much like a dam turbine . 
there are two types of thylakoids -- granal thylakoids , which are arranged in grana , and stromal thylakoids , which are in contact with the stroma . 
there are two types of thylakoids -- granal thylakoids , which are arranged in grana , and stromal thylakoids , which are in contact with the stroma . 
there are two types of thylakoids -- granal thylakoids , which are arranged in grana , and stromal thylakoids , which are in contact with the stroma . 
granal thylakoids are pancake-shaped circular disks about 300 -- 600 nanometers in diameter . 
granal thylakoids are pancake-shaped circular disks about 300 -- 600 nanometers in diameter . 
there are about thirty photosynthetic carotenoids . 
they help transfer and dissipate excess energy , and their bright colors sometimes override the chlorophyll green , like during the fall , when the leaves of some land plants change color . 
they help transfer and dissipate excess energy , and their bright colors sometimes override the chlorophyll green , like during the fall , when the leaves of some land plants change color . 
β-carotene is a bright red-orange carotenoid found in nearly all chloroplasts , like chlorophyll a. xanthophylls , especially the orange-red zeaxanthin , are also common . 
β-carotene is a bright red-orange carotenoid found in nearly all chloroplasts , like chlorophyll a. xanthophylls , especially the orange-red zeaxanthin , are also common . 
phycobilins are a third group of pigments found in cyanobacteria , and glaucophyte , red algal , and cryptophyte chloroplasts . 
phycobilins come in all colors , though phycoerytherin is one of the pigments that makes many red algae red . 
phycobilins come in all colors , though phycoerytherin is one of the pigments that makes many red algae red . 
phycobilins often organize into relatively large protein complexes about 40 nanometers across called phycobilisomes . 
phycobilins often organize into relatively large protein complexes about 40 nanometers across called phycobilisomes . 
to fix carbon dioxide into sugar molecules in the process of photosynthesis , chloroplasts use an enzyme called rubisco . 
rubisco has a problem -- it has trouble distinguishing between carbon dioxide and oxygen , so at high oxygen concentrations , rubisco starts accidentally adding oxygen to sugar precursors . 
rubisco has a problem -- it has trouble distinguishing between carbon dioxide and oxygen , so at high oxygen concentrations , rubisco starts accidentally adding oxygen to sugar precursors . 
this is a big problem , since o2 is produced by the initial light reactions of photosynthesis , causing issues down the line in the calvin cycle which uses rubisco . 
this has the end result of atp energy being wasted and co2 being released , all with no sugar being produced . 
in mesophyll cells , chloroplasts are specialized for the light reactions , so they lack rubisco , and have normal grana and thylakoids , which they use to make atp and nadph , as well as oxygen . 
in mesophyll cells , chloroplasts are specialized for the light reactions , so they lack rubisco , and have normal grana and thylakoids , which they use to make atp and nadph , as well as oxygen . 
in mesophyll cells , chloroplasts are specialized for the light reactions , so they lack rubisco , and have normal grana and thylakoids , which they use to make atp and nadph , as well as oxygen . 
they store co2 in a four-carbon compound , which is why the process is called c4 photosynthesis . 
because the job of bundle sheath chloroplasts is to carry out the calvin cycle and make sugar , they often contain large starch grains . 
all green parts of a plant contain chloroplasts -- the chloroplasts , or more specifically , the chlorophyll in them are what make the photosynthetic parts of a plant green . 
all green parts of a plant contain chloroplasts -- the chloroplasts , or more specifically , the chlorophyll in them are what make the photosynthetic parts of a plant green . 
the plant cells which contain chloroplasts are usually parenchyma cells , though chloroplasts can also be found in collenchyma tissue . 
the plant cells which contain chloroplasts are usually parenchyma cells , though chloroplasts can also be found in collenchyma tissue . 
a plant cell which contains chloroplasts is known as a chlorenchyma cell . 
in some plants such as cacti , chloroplasts are found in the stems , though in most plants , chloroplasts are concentrated in the leaves . 
in some plants such as cacti , chloroplasts are found in the stems , though in most plants , chloroplasts are concentrated in the leaves . 
palisade mesophyll cells can contain 30 -- 70 chloroplasts per cell , while stomatal guard cells contain only around 8 -- 15 per cell , as well as much less chlorophyll . 
one square millimeter of leaf tissue can contain half a million chloroplasts . 
within a leaf , chloroplasts are mainly found in the mesophyll layers of a leaf , and the guard cells of stomata . 
in low-light conditions , they will spread out in a sheet -- maximizing the surface area to absorb light . 
under intense light , they will seek shelter by aligning in vertical columns along the plant cell 's cell wall or turning sideways so that light strikes them edge-on . 
this reduces exposure and protects them from photooxidative damage . 
this ability to distribute chloroplasts so that they can take shelter behind each other or spread out may be the reason why land plants evolved to have many small chloroplasts instead of a few big ones . 
mitochondria have also been observed to follow chloroplasts as they move . 
plants have two main immune responses -- the hypersensitive response , in which infected cells seal themselves off and undergo programmed cell death , and systemic acquired resistance , where infected cells release signals warning the rest of the plant of a pathogen 's presence . 
plants have two main immune responses -- the hypersensitive response , in which infected cells seal themselves off and undergo programmed cell death , and systemic acquired resistance , where infected cells release signals warning the rest of the plant of a pathogen 's presence . 
plants have two main immune responses -- the hypersensitive response , in which infected cells seal themselves off and undergo programmed cell death , and systemic acquired resistance , where infected cells release signals warning the rest of the plant of a pathogen 's presence . 
chloroplasts stimulate both responses by purposely damaging their photosynthetic system , producing reactive oxygen species . 
chloroplasts stimulate both responses by purposely damaging their photosynthetic system , producing reactive oxygen species . 
after detecting stress in a cell , which might be due to a pathogen , chloroplasts begin producing molecules like salicylic acid , jasmonic acid , nitric oxide and reactive oxygen species which can serve as defense-signals . 
after detecting stress in a cell , which might be due to a pathogen , chloroplasts begin producing molecules like salicylic acid , jasmonic acid , nitric oxide and reactive oxygen species which can serve as defense-signals . 
as cellular signals , reactive oxygen species are unstable molecules , so they probably do n't leave the chloroplast , but instead pass on their signal to an unknown second messenger molecule . 
all these molecules initiate retrograde signaling -- signals from the chloroplast that regulate gene expression in the nucleus . 
one of the main functions of the chloroplast is its role in photosynthesis , the process by which light is transformed into chemical energy , to subsequently produce food in the form of sugars . 
one of the main functions of the chloroplast is its role in photosynthesis , the process by which light is transformed into chemical energy , to subsequently produce food in the form of sugars . 
one of the main functions of the chloroplast is its role in photosynthesis , the process by which light is transformed into chemical energy , to subsequently produce food in the form of sugars . 
water -lrb- h2o -rrb- and carbon dioxide -lrb- co2 -rrb- are used in photosynthesis , and sugar and oxygen -lrb- o2 -rrb- is made , using light energy . 
water -lrb- h2o -rrb- and carbon dioxide -lrb- co2 -rrb- are used in photosynthesis , and sugar and oxygen -lrb- o2 -rrb- is made , using light energy . 
like mitochondria , chloroplasts use the potential energy stored in an h + , or hydrogen ion gradient to generate atp energy . 
the molecules between the photosystems harness the electrons ' energy to pump hydrogen ions into the thylakoid space , creating a concentration gradient , with more hydrogen ions -lrb- up to a thousand times as many -rrb- inside the thylakoid system than in the stroma . 
the molecules between the photosystems harness the electrons ' energy to pump hydrogen ions into the thylakoid space , creating a concentration gradient , with more hydrogen ions -lrb- up to a thousand times as many -rrb- inside the thylakoid system than in the stroma . 
atp synthase uses the energy from the flowing hydrogen ions to phosphorylate adenosine diphosphate into adenosine triphosphate , or atp . 
atp synthase uses the energy from the flowing hydrogen ions to phosphorylate adenosine diphosphate into adenosine triphosphate , or atp . 
normally , the reenergized electrons are taken by nadp + , though sometimes they can flow back down more h + - pumping electron transport chains to transport more hydrogen ions into the thylakoid space to generate more atp . 
this is termed cyclic photophosphorylation because the electrons are recycled . 
cyclic photophosphorylation is common in c4 plants , which need more atp than nadph . 
cyclic photophosphorylation is common in c4 plants , which need more atp than nadph . 
the calvin cycle starts by using the enzyme rubisco to fix co2 into five-carbon ribulose bisphosphate -lrb- rubp -rrb- molecules . 
the result is unstable six-carbon molecules that immediately break down into three-carbon molecules called 3-phosphoglyceric acid , or 3-pga . 
the result is unstable six-carbon molecules that immediately break down into three-carbon molecules called 3-phosphoglyceric acid , or 3-pga . 
most of the g3p molecules are recycled back into rubp using energy from more atp , but one out of every six produced leaves the cycle -- the end product of the dark reactions . 
alternatively , glucose monomers in the chloroplast can be linked together to make starch , which accumulates into the starch grains found in the chloroplast . 
under conditions such as high atmospheric co2 concentrations , these starch grains may grow very large , distorting the grana and thylakoids . 
under conditions such as high atmospheric co2 concentrations , these starch grains may grow very large , distorting the grana and thylakoids . 
waterlogged roots can also cause starch buildup in the chloroplasts , possibly due to less sucrose being exported out of the chloroplast -lrb- or more accurately , the plant cell -rrb- . 
while linked to low photosynthesis rates , the starch grains themselves may not necessarily interfere significantly with the efficiency of photosynthesis , and might simply be a side effect of another photosynthesis-depressing factor . 
rubisco can not distinguish between oxygen and carbon dioxide very well , so it can accidentally add o2 instead of co2 to rubp . 
photorespiration can occur when the oxygen concentration is too high . 
this process reduces the efficiency of photosynthesis -- it consumes atp and oxygen , releases co2 , and produces no sugar . 
it can waste up to half the carbon fixed by the calvin cycle . 
chloroplasts in c4 plants are notable as they exhibit a distinct chloroplast dimorphism . 
chloroplasts alone make almost all of a plant cell 's amino acids in their stroma except the sulfur-containing ones like cysteine and methionine . 
chloroplasts alone make almost all of a plant cell 's amino acids in their stroma except the sulfur-containing ones like cysteine and methionine . 
cysteine is made in the chloroplast -lrb- the proplastid too -rrb- but it is also synthesized in the cytosol and mitochondria , probably because it has trouble crossing membranes to get to where it is needed . 
the chloroplast is known to make the precursors to methionine but it is unclear whether the organelle carries out the last leg of the pathway or if it happens in the cytosol . 
chloroplasts are a special type of a plant cell organelle called a plastid , though the two terms are sometimes used interchangeably . 
all chloroplasts in a plant are descended from undifferentiated proplastids found in the zygote , or fertilized egg . 
proplastids are commonly found in an adult plant 's apical meristems . 
chloroplasts do not normally develop from proplastids in root tip meristems -- instead , the formation of starch-storing amyloplasts is more common . 
if angiosperm shoots are not exposed to the required light for chloroplast formation , proplastids may develop into an etioplast stage before becoming chloroplasts . 
an etioplast is a plastid that lacks chlorophyll , and has inner membrane invaginations that form a lattice of tubes in their stroma , called a prolamellar body . 
an etioplast is a plastid that lacks chlorophyll , and has inner membrane invaginations that form a lattice of tubes in their stroma , called a prolamellar body . 
while etioplasts lack chlorophyll , they have a yellow chlorophyll precursor stocked . 
gymnosperms do not require light to form chloroplasts . 
chloroplasts may be converted to chromoplasts , which are pigment-filled plastids responsible for the bright colors seen in flowers and ripe fruit . 
chloroplasts may be converted to chromoplasts , which are pigment-filled plastids responsible for the bright colors seen in flowers and ripe fruit . 
starch storing amyloplasts can also be converted to chromoplasts , and it is possible for proplastids to develop straight into chromoplasts . 
starch storing amyloplasts can also be converted to chromoplasts , and it is possible for proplastids to develop straight into chromoplasts . 
if a plant is injured , or something else causes a plant cell to revert to a meristematic state , chloroplasts and other plastids can turn back into proplastids . 
the division process starts when the proteins ftsz1 and ftsz2 assemble into filaments , and with the help of a protein arc6 , form a structure called a z-ring within the chloroplast 's stroma . 
the division process starts when the proteins ftsz1 and ftsz2 assemble into filaments , and with the help of a protein arc6 , form a structure called a z-ring within the chloroplast 's stroma . 
the division process starts when the proteins ftsz1 and ftsz2 assemble into filaments , and with the help of a protein arc6 , form a structure called a z-ring within the chloroplast 's stroma . 
the division process starts when the proteins ftsz1 and ftsz2 assemble into filaments , and with the help of a protein arc6 , form a structure called a z-ring within the chloroplast 's stroma . 
the min system manages the placement of the z-ring , ensuring that the chloroplast is cleaved more or less evenly . 
next , the two plastid-dividing rings , or pd rings form . 
next , the two plastid-dividing rings , or pd rings form . 
it consists of filaments about 5 nanometers across , arranged in rows 6.4 nanometers apart , and shrinks to squeeze the chloroplast . 
it consists of filaments about 5 nanometers across , arranged in rows 6.4 nanometers apart , and shrinks to squeeze the chloroplast . 
in a few species like cyanidioschyzon merolæ , chloroplasts have a third plastid-dividing ring located in the chloroplast 's intermembrane space . 
light has been shown to be a requirement for chloroplast division . 
chloroplasts can grow and progress through some of the constriction stages under poor quality green light , but are slow to complete division -- they require exposure to bright white light to complete division . 
spinach leaves grown under green light have been observed to contain many large dumbbell-shaped chloroplasts . 
chloroplasts can grow and progress through some of the constriction stages under poor quality green light , but are slow to complete division -- they require exposure to bright white light to complete division . 
since , in most flowering plants , chloroplasts are not inherited from the male parent , transgenes in these plastids can not be disseminated by pollen . 
this makes plastid transformation a valuable tool for the creation and cultivation of genetically modified plants that are biologically contained , thus posing significantly lower environmental risks . 
while the reliability of this mechanism has not yet been studied for all relevant crop species , recent results in tobacco plants are promising , showing a failed containment rate of transplastomic plants at 3 in 1,000,000 . 
while the reliability of this mechanism has not yet been studied for all relevant crop species , recent results in tobacco plants are promising , showing a failed containment rate of transplastomic plants at 3 in 1,000,000 . 
a prime number -lrb- or a prime -rrb- is a natural number greater than 1 that has no positive divisors other than 1 and itself . 
a natural number greater than 1 that is not a prime number is called a composite number . 
the fundamental theorem of arithmetic establishes the central role of primes in number theory : any integer greater than 1 can be expressed as a product of primes that is unique up to ordering . 
the fundamental theorem of arithmetic establishes the central role of primes in number theory : any integer greater than 1 can be expressed as a product of primes that is unique up to ordering . 
the uniqueness in this theorem requires excluding 1 as a prime because one can include arbitrarily many instances of 1 in any factorization , e.g. , 3 , 1 · 3 , 1 · 1 · 3 , etc. are all valid factorizations of 3 . 
the property of being prime -lrb- or not -rrb- is called primality . 
a simple but slow method of verifying the primality of a given number n is known as trial division . 
these include the miller -- rabin primality test , which is fast but has a small probability of error , and the aks primality test , which always produces the correct answer in polynomial time but is too slow to be practical . 
these include the miller -- rabin primality test , which is fast but has a small probability of error , and the aks primality test , which always produces the correct answer in polynomial time but is too slow to be practical . 
as of january 2016 -lsb- update -rsb- , the largest known prime number has 22,338,618 decimal digits . 
there are infinitely many primes , as demonstrated by euclid around 300 bc . 
there are infinitely many primes , as demonstrated by euclid around 300 bc . 
however , the distribution of primes , that is to say , the statistical behaviour of primes in the large , can be modelled . 
the first result in that direction is the prime number theorem , proven at the end of the 19th century , which says that the probability that a given , randomly chosen number n is prime is inversely proportional to its number of digits , or to the logarithm of n. 
the first result in that direction is the prime number theorem , proven at the end of the 19th century , which says that the probability that a given , randomly chosen number n is prime is inversely proportional to its number of digits , or to the logarithm of n. 
many questions regarding prime numbers remain open , such as goldbach 's conjecture -lrb- that every even integer greater than 2 can be expressed as the sum of two primes -rrb- , and the twin prime conjecture -lrb- that there are infinitely many pairs of primes whose difference is 2 -rrb- . 
many questions regarding prime numbers remain open , such as goldbach 's conjecture -lrb- that every even integer greater than 2 can be expressed as the sum of two primes -rrb- , and the twin prime conjecture -lrb- that there are infinitely many pairs of primes whose difference is 2 -rrb- . 
such questions spurred the development of various branches of number theory , focusing on analytic or algebraic aspects of numbers . 
primes are used in several routines in information technology , such as public-key cryptography , which makes use of properties such as the difficulty of factoring large numbers into their prime factors . 
prime numbers give rise to various generalizations in other mathematical domains , mainly algebra , such as prime elements and prime ideals . 
no even number greater than 2 is prime because by definition , any such number n has at least three distinct divisors , namely 1 , 2 , and n . 
no even number greater than 2 is prime because by definition , any such number n has at least three distinct divisors , namely 1 , 2 , and n . 
accordingly , the term odd prime refers to any prime number greater than 2 . 
similarly , when written in the usual decimal system , all prime numbers larger than 5 end in 1 , 3 , 7 , or 9 , since even numbers are multiples of 2 and numbers ending in 0 or 5 are multiples of 5 . 
similarly , when written in the usual decimal system , all prime numbers larger than 5 end in 1 , 3 , 7 , or 9 , since even numbers are multiples of 2 and numbers ending in 0 or 5 are multiples of 5 . 
most early greeks did not even consider 1 to be a number , so they could not consider it to be a prime . 
in the mid-18th century christian goldbach listed 1 as the first prime in his famous correspondence with leonhard euler -- who did not agree . 
in the mid-18th century christian goldbach listed 1 as the first prime in his famous correspondence with leonhard euler -- who did not agree . 
for example , derrick norman lehmer 's list of primes up to 10,006,721 , reprinted as late as 1956 , started with 1 as its first prime . 
by the early 20th century , mathematicians began to accept that 1 is not a prime number , but rather forms its own special category as a `` unit '' . 
a large body of mathematical work would still be valid when calling 1 a prime , but euclid 's fundamental theorem of arithmetic -lrb- mentioned above -rrb- would not hold as stated . 
similarly , the sieve of eratosthenes would not work correctly if 1 were considered a prime : a modified version of the sieve that considers 1 as prime would eliminate all multiples of 1 -lrb- that is , all other numbers -rrb- and produce as output only the single number 1 . 
furthermore , the prime numbers have several properties that the number 1 lacks , such as the relationship of the number to its corresponding value of euler 's totient function or the sum of divisors function . 
furthermore , the prime numbers have several properties that the number 1 lacks , such as the relationship of the number to its corresponding value of euler 's totient function or the sum of divisors function . 
similarly , the sieve of eratosthenes would not work correctly if 1 were considered a prime : a modified version of the sieve that considers 1 as prime would eliminate all multiples of 1 -lrb- that is , all other numbers -rrb- and produce as output only the single number 1 . 
there are hints in the surviving records of the ancient egyptians that they had some knowledge of prime numbers : the egyptian fraction expansions in the rhind papyrus , for instance , have quite different forms for primes and for composites . 
however , the earliest surviving records of the explicit study of prime numbers come from the ancient greeks . 
euclid 's elements -lrb- circa 300 bc -rrb- contain important theorems about primes , including the infinitude of primes and the fundamental theorem of arithmetic . 
euclid also showed how to construct a perfect number from a mersenne prime . 
the sieve of eratosthenes , attributed to eratosthenes , is a simple method to compute primes , although the large primes found today with computers are not generated this way . 
in 1640 pierre de fermat stated -lrb- without proof -rrb- fermat 's little theorem -lrb- later proved by leibniz and euler -rrb- . 
in 1640 pierre de fermat stated -lrb- without proof -rrb- fermat 's little theorem -lrb- later proved by leibniz and euler -rrb- . 
fermat also conjectured that all numbers of the form 22n + 1 are prime -lrb- they are called fermat numbers -rrb- and he verified this up to n = 4 -lrb- or 216 + 1 -rrb- . 
the french monk marin mersenne looked at primes of the form 2p − 1 , with p a prime . 
fermat also conjectured that all numbers of the form 22n + 1 are prime -lrb- they are called fermat numbers -rrb- and he verified this up to n = 4 -lrb- or 216 + 1 -rrb- . 
the most basic method of checking the primality of a given integer n is called trial division . 
this routine can be implemented more efficiently if a complete list of primes up to is known -- then trial divisions need to be checked only for those m that are prime . 
this routine consists of dividing n by each integer m that is greater than 1 and less than or equal to the square root of n . 
for example , to check the primality of 37 , only three divisions are necessary -lrb- m = 2 , 3 , and 5 -rrb- , given that 4 and 6 are composite . 
this routine consists of dividing n by each integer m that is greater than 1 and less than or equal to the square root of n . 
modern primality tests for general numbers n can be divided into two main classes , probabilistic -lrb- or `` monte carlo '' -rrb- and deterministic algorithms . 
modern primality tests for general numbers n can be divided into two main classes , probabilistic -lrb- or `` monte carlo '' -rrb- and deterministic algorithms . 
modern primality tests for general numbers n can be divided into two main classes , probabilistic -lrb- or `` monte carlo '' -rrb- and deterministic algorithms . 
for example , trial division is a deterministic algorithm because , if performed correctly , it will always identify a prime number as prime and a composite number as composite . 
if we repeat the test n times and pass every time , then the probability that our number is composite is 1 / -lrb- 1-p -rrb- n , which decreases exponentially with the number of tests , so we can be as sure as we like -lrb- though never perfectly sure -rrb- that the number is prime . 
a particularly simple example of a probabilistic test is the fermat primality test , which relies on the fact -lrb- fermat 's little theorem -rrb- that np ≡ n -lrb- mod p -rrb- for any n if p is a prime number . 
a particularly simple example of a probabilistic test is the fermat primality test , which relies on the fact -lrb- fermat 's little theorem -rrb- that np ≡ n -lrb- mod p -rrb- for any n if p is a prime number . 
a flaw with this test is that there are some composite numbers -lrb- the carmichael numbers -rrb- that satisfy the fermat identity even though they are not prime , so the test has no way of distinguishing between prime numbers and carmichael numbers . 
more powerful extensions of the fermat primality test , such as the baillie-psw , miller-rabin , and solovay-strassen tests , are guaranteed to fail at least some of the time when applied to a composite number . 
more powerful extensions of the fermat primality test , such as the baillie-psw , miller-rabin , and solovay-strassen tests , are guaranteed to fail at least some of the time when applied to a composite number . 
other primes where either p + 1 or p − 1 is of a particular shape include the sophie germain primes -lrb- primes of the form 2p + 1 with p prime -rrb- , primorial primes , fermat primes and mersenne primes , that is , prime numbers that are of the form 2p − 1 , where p is an arbitrary prime . 
other primes where either p + 1 or p − 1 is of a particular shape include the sophie germain primes -lrb- primes of the form 2p + 1 with p prime -rrb- , primorial primes , fermat primes and mersenne primes , that is , prime numbers that are of the form 2p − 1 , where p is an arbitrary prime . 
the lucas -- lehmer test is particularly fast for numbers of this form . 
other primes where either p + 1 or p − 1 is of a particular shape include the sophie germain primes -lrb- primes of the form 2p + 1 with p prime -rrb- , primorial primes , fermat primes and mersenne primes , that is , prime numbers that are of the form 2p − 1 , where p is an arbitrary prime . 
other primes where either p + 1 or p − 1 is of a particular shape include the sophie germain primes -lrb- primes of the form 2p + 1 with p prime -rrb- , primorial primes , fermat primes and mersenne primes , that is , prime numbers that are of the form 2p − 1 , where p is an arbitrary prime . 
some of these primes have been found using distributed computing . 
in 2009 , the great internet mersenne prime search project was awarded a us$ 100,000 prize for first discovering a prime with at least 10 million digits . 
in 2009 , the great internet mersenne prime search project was awarded a us$ 100,000 prize for first discovering a prime with at least 10 million digits . 
the electronic frontier foundation also offers $ 150,000 and $ 250,000 for primes with at least 100 million digits and 1 billion digits , respectively . 
some of the largest primes not known to have any particular form -lrb- that is , no simple formula such as that of mersenne primes -rrb- have been found by taking a piece of semi-random binary data , converting it to a number n , multiplying it by 256k for some positive integer k , and searching for possible primes within the interval -lsb- 256kn + 1 , 256k -lrb- n + 1 -rrb- − 1 -rsb- . 
here represents the floor function , i.e. , largest integer not greater than the number in question . 
the latter formula can be shown using bertrand 's postulate -lrb- proven first by chebyshev -rrb- , which states that there always exists at least one prime number p with n < p < 2n − 2 , for any natural number n > 3 . 
the latter formula can be shown using bertrand 's postulate -lrb- proven first by chebyshev -rrb- , which states that there always exists at least one prime number p with n < p < 2n − 2 , for any natural number n > 3 . 
the latter formula can be shown using bertrand 's postulate -lrb- proven first by chebyshev -rrb- , which states that there always exists at least one prime number p with n < p < 2n − 2 , for any natural number n > 3 . 
another formula is based on wilson 's theorem and generates the number 2 many times and all other primes exactly once . 
can have infinitely many primes only when a and q are coprime , i.e. , their greatest common divisor is one . 
if this necessary condition is satisfied , dirichlet 's theorem on arithmetic progressions asserts that the progression contains infinitely many primes . 
what is more , the primes are distributed equally among those rows in the long run -- the density of all primes congruent a modulo 9 is 1/6 . 
the rows -lrb- = progressions -rrb- starting with a = 3 , 6 , or 9 contain at most one prime number . 
in all other rows -lrb- a = 1 , 2 , 4 , 5 , 7 , and 8 -rrb- there are infinitely many prime numbers . 
the zeta function is closely related to prime numbers . 
for example , the aforementioned fact that there are infinitely many primes can also be seen using the zeta function : if there were only finitely many primes then ζ -lrb- 1 -rrb- would have a finite value . 
however , the harmonic series 1 + 1/2 + 1/3 + 1/4 + ... diverges -lrb- i.e. , exceeds any given number -rrb- , so there must be infinitely many primes . 
however , the harmonic series 1 + 1/2 + 1/3 + 1/4 + ... diverges -lrb- i.e. , exceeds any given number -rrb- , so there must be infinitely many primes . 
another example of the richness of the zeta function and a glimpse of modern algebraic number theory is the following identity -lrb- basel problem -rrb- , due to euler , 
the unproven riemann hypothesis , dating from 1859 , states that except for s = − 2 , − 4 , ... , all zeroes of the ζ-function have real part equal to 1/2 . 
the unproven riemann hypothesis , dating from 1859 , states that except for s = − 2 , − 4 , ... , all zeroes of the ζ-function have real part equal to 1/2 . 
-lsb- clarification needed -rsb- from a physical viewpoint , it roughly states that the irregularity in the distribution of primes only comes from random noise . 
from a mathematical viewpoint , it roughly states that the asymptotic distribution of primes -lrb- about x/log x of numbers less than x are primes , the prime number theorem -rrb- also holds for much shorter intervals of length about the square root of x -lrb- for intervals near x -rrb- . 
from a mathematical viewpoint , it roughly states that the asymptotic distribution of primes -lrb- about x/log x of numbers less than x are primes , the prime number theorem -rrb- also holds for much shorter intervals of length about the square root of x -lrb- for intervals near x -rrb- . 
one of them is goldbach 's conjecture , which asserts that every even integer n greater than 2 can be written as a sum of two primes . 
often having an elementary formulation , many of these conjectures have withstood a proof for decades : all four of landau 's problems from 1912 are still unsolved . 
as of february 2011 -lsb- update -rsb- , this conjecture has been verified for all numbers up to n = 2 · 1017 . 
weaker statements than this have been proven , for example vinogradov 's theorem says that every sufficiently large odd integer can be written as a sum of three primes . 
chen 's theorem says that every sufficiently large even number can be expressed as the sum of a prime and a semiprime , the product of two primes . 
it is conjectured that there are infinitely many twin primes , pairs of primes with difference 2 -lrb- twin prime conjecture -rrb- . 
it is conjectured that there are infinitely many twin primes , pairs of primes with difference 2 -lrb- twin prime conjecture -rrb- . 
polignac 's conjecture is a strengthening of that conjecture , it states that for every positive integer n , there are infinitely many pairs of consecutive primes that differ by 2n . 
it is conjectured there are infinitely many primes of the form n2 + 1 . 
these conjectures are special cases of the broad schinzel 's hypothesis h. brocard 's conjecture says that there are always at least four primes between the squares of consecutive primes greater than 2 . 
for a long time , number theory in general , and the study of prime numbers in particular , was seen as the canonical example of pure mathematics , with no applications outside of the self-interest of studying the topic with the exception of use of prime numbered gear teeth to distribute wear evenly . 
in particular , number theorists such as british mathematician g. h. hardy prided themselves on doing work that had absolutely no military significance . 
however , this vision was shattered in the 1970s , when it was publicly announced that prime numbers could be used as the basis for the creation of public key cryptography algorithms . 
prime numbers are also used for hash tables and pseudorandom number generators . 
prime numbers are also used for hash tables and pseudorandom number generators . 
another consequence of fermat 's little theorem is the following : if p is a prime number other than 2 and 5 , 1/p is always a recurring decimal , whose period is p − 1 or a divisor of p − 1 . 
another consequence of fermat 's little theorem is the following : if p is a prime number other than 2 and 5 , 1/p is always a recurring decimal , whose period is p − 1 or a divisor of p − 1 . 
the fraction 1/p expressed likewise in base q -lrb- rather than base 10 -rrb- has similar effect , provided that p is not a prime factor of q. wilson 's theorem says that an integer p > 1 is prime if and only if the factorial -lrb- p − 1 -rrb- ! 
+ 1 is divisible by p. moreover , an integer n > 4 is composite if and only if -lrb- n − 1 -rrb- ! 
the fraction 1/p expressed likewise in base q -lrb- rather than base 10 -rrb- has similar effect , provided that p is not a prime factor of q. wilson 's theorem says that an integer p > 1 is prime if and only if the factorial -lrb- p − 1 -rrb- ! 
several public-key cryptography algorithms , such as rsa and the diffie -- hellman key exchange , are based on large prime numbers -lrb- for example , 512-bit primes are frequently used for rsa and 1024-bit primes are typical for diffie -- hellman . -rrb- 
several public-key cryptography algorithms , such as rsa and the diffie -- hellman key exchange , are based on large prime numbers -lrb- for example , 512-bit primes are frequently used for rsa and 1024-bit primes are typical for diffie -- hellman . -rrb- 
several public-key cryptography algorithms , such as rsa and the diffie -- hellman key exchange , are based on large prime numbers -lrb- for example , 512-bit primes are frequently used for rsa and 1024-bit primes are typical for diffie -- hellman . -rrb- 
the diffie -- hellman key exchange relies on the fact that there are efficient algorithms for modular exponentiation , while the reverse operation the discrete logarithm is thought to be a hard problem . 
several public-key cryptography algorithms , such as rsa and the diffie -- hellman key exchange , are based on large prime numbers -lrb- for example , 512-bit primes are frequently used for rsa and 1024-bit primes are typical for diffie -- hellman . -rrb- 
the evolutionary strategy used by cicadas of the genus magicicada make use of prime numbers . 
these insects spend most of their lives as grubs underground . 
they only pupate and then emerge from their burrows after 7 , 13 or 17 years , at which point they fly about , breed , and then die after a few weeks at most . 
the logic for this is believed to be that the prime number intervals between emergences make it very difficult for predators to evolve that could specialize as predators on magicicadas . 
over a 200-year period , average predator populations during hypothetical outbreaks of 14 - and 15-year cicadas would be up to 2 % higher than during outbreaks of 13 - and 17-year cicadas . 
generally , `` prime '' indicates minimality or indecomposability , in an appropriate sense . 
for example , the prime field is the smallest subfield of a field f containing both 0 and 1 . 
any knot can be uniquely expressed as a connected sum of prime knots . 
often a second , additional meaning is intended by using the word prime , namely that any object can be , essentially uniquely , decomposed into its prime components . 
for example , in knot theory , a prime knot is a knot that is indecomposable in the sense that it can not be written as the knot sum of two nontrivial knots . 
prime numbers give rise to two more general concepts that apply to elements of any commutative ring r , an algebraic structure where addition , subtraction and multiplication are defined : prime elements and irreducible elements . 
prime numbers give rise to two more general concepts that apply to elements of any commutative ring r , an algebraic structure where addition , subtraction and multiplication are defined : prime elements and irreducible elements . 
prime numbers give rise to two more general concepts that apply to elements of any commutative ring r , an algebraic structure where addition , subtraction and multiplication are defined : prime elements and irreducible elements . 
an element p of r is called prime element if it is neither zero nor a unit -lrb- i.e. , does not have a multiplicative inverse -rrb- and satisfies the following requirement : given x and y in r such that p divides the product xy , then p divides x or y . 
an element is irreducible if it is not a unit and can not be written as a product of two ring elements that are not units . 
the fundamental theorem of arithmetic continues to hold in unique factorization domains . 
an example of such a domain is the gaussian integers z -lsb- i -rsb- , that is , the set of complex numbers of the form a + bi where i denotes the imaginary unit and a and b are arbitrary integers . 
an example of such a domain is the gaussian integers z -lsb- i -rsb- , that is , the set of complex numbers of the form a + bi where i denotes the imaginary unit and a and b are arbitrary integers . 
an example of such a domain is the gaussian integers z -lsb- i -rsb- , that is , the set of complex numbers of the form a + bi where i denotes the imaginary unit and a and b are arbitrary integers . 
rational primes -lrb- i.e. prime elements in z -rrb- of the form 4k + 3 are gaussian primes , whereas rational primes of the form 4k + 1 are not . 
in ring theory , the notion of number is generally replaced with that of ideal . 
prime ideals , which generalize prime elements in the sense that the principal ideal generated by a prime element is a prime ideal , are an important tool and object of study in commutative algebra , algebraic number theory and algebraic geometry . 
prime ideals , which generalize prime elements in the sense that the principal ideal generated by a prime element is a prime ideal , are an important tool and object of study in commutative algebra , algebraic number theory and algebraic geometry . 
the prime ideals of the ring of integers are the ideals -lrb- 0 -rrb- , -lrb- 2 -rrb- , -lrb- 3 -rrb- , -lrb- 5 -rrb- , -lrb- 7 -rrb- , -lrb- 11 -rrb- , ... the fundamental theorem of arithmetic generalizes to the lasker -- noether theorem , which expresses every ideal in a noetherian commutative ring as an intersection of primary ideals , which are the appropriate generalizations of prime powers . 
the prime ideals of the ring of integers are the ideals -lrb- 0 -rrb- , -lrb- 2 -rrb- , -lrb- 3 -rrb- , -lrb- 5 -rrb- , -lrb- 7 -rrb- , -lrb- 11 -rrb- , ... the fundamental theorem of arithmetic generalizes to the lasker -- noether theorem , which expresses every ideal in a noetherian commutative ring as an intersection of primary ideals , which are the appropriate generalizations of prime powers . 
prime ideals are the points of algebro-geometric objects , via the notion of the spectrum of a ring . 
for example , factorization or ramification of prime ideals when lifted to an extension field , a basic problem of algebraic number theory , bears some resemblance with ramification in geometry . 
for example , prime ideals in the ring of integers of quadratic number fields can be used in proving quadratic reciprocity , a statement that concerns the solvability of quadratic equations 
for example , prime ideals in the ring of integers of quadratic number fields can be used in proving quadratic reciprocity , a statement that concerns the solvability of quadratic equations 
in particular , this norm gets smaller when a number is multiplied by p , in sharp contrast to the usual absolute value -lrb- also referred to as the infinite prime -rrb- . 
certain arithmetic questions related to q or more general global fields may be transferred back and forth to the completed -lrb- or local -rrb- fields . 
while completing q -lrb- roughly , filling the gaps -rrb- with respect to the absolute value yields the field of real numbers , completing with respect to the p-adic norm | − | p yields the field of p-adic numbers . 
this local-global principle again underlines the importance of primes to number theory . 
the french composer olivier messiaen used prime numbers to create ametrical music through `` natural phenomena '' . 
in works such as la nativité du seigneur -lrb- 1935 -rrb- and quatre études de rythme -lrb- 1949 -- 50 -rrb- , he simultaneously employs motifs with lengths given by different prime numbers to create unpredictable rhythms : the primes 41 , 43 , 47 and 53 appear in the third étude , `` neumes rythmiques '' . 
in works such as la nativité du seigneur -lrb- 1935 -rrb- and quatre études de rythme -lrb- 1949 -- 50 -rrb- , he simultaneously employs motifs with lengths given by different prime numbers to create unpredictable rhythms : the primes 41 , 43 , 47 and 53 appear in the third étude , `` neumes rythmiques '' . 
in works such as la nativité du seigneur -lrb- 1935 -rrb- and quatre études de rythme -lrb- 1949 -- 50 -rrb- , he simultaneously employs motifs with lengths given by different prime numbers to create unpredictable rhythms : the primes 41 , 43 , 47 and 53 appear in the third étude , `` neumes rythmiques '' . 
according to messiaen this way of composing was `` inspired by the movements of nature , movements of free and unequal durations '' . 
the rhine -lrb- romansh : rein , german : rhein , french : le rhin , dutch : rijn -rrb- is a european river that begins in the swiss canton of graubünden in the southeastern swiss alps , forms part of the swiss-austrian , swiss-liechtenstein border , swiss-german and then the franco-german border , then flows through the rhineland and eventually empties into the north sea in the netherlands . 
the rhine -lrb- romansh : rein , german : rhein , french : le rhin , dutch : rijn -rrb- is a european river that begins in the swiss canton of graubünden in the southeastern swiss alps , forms part of the swiss-austrian , swiss-liechtenstein border , swiss-german and then the franco-german border , then flows through the rhineland and eventually empties into the north sea in the netherlands . 
the biggest city on the river rhine is cologne , germany with a population of more than 1,050,000 people . 
it is the second-longest river in central and western europe -lrb- after the danube -rrb- , at about 1,230 km -lrb- 760 mi -rrb- , -lsb- note 2 -rsb- -lsb- note 1 -rsb- with an average discharge of about 2,900 m3/s -lrb- 100,000 cu ft/s -rrb- . 
it is the second-longest river in central and western europe -lrb- after the danube -rrb- , at about 1,230 km -lrb- 760 mi -rrb- , -lsb- note 2 -rsb- -lsb- note 1 -rsb- with an average discharge of about 2,900 m3/s -lrb- 100,000 cu ft/s -rrb- . 
it is the second-longest river in central and western europe -lrb- after the danube -rrb- , at about 1,230 km -lrb- 760 mi -rrb- , -lsb- note 2 -rsb- -lsb- note 1 -rsb- with an average discharge of about 2,900 m3/s -lrb- 100,000 cu ft/s -rrb- . 
the rhine -lrb- romansh : rein , german : rhein , french : le rhin , dutch : rijn -rrb- is a european river that begins in the swiss canton of graubünden in the southeastern swiss alps , forms part of the swiss-austrian , swiss-liechtenstein border , swiss-german and then the franco-german border , then flows through the rhineland and eventually empties into the north sea in the netherlands . 
it is the second-longest river in central and western europe -lrb- after the danube -rrb- , at about 1,230 km -lrb- 760 mi -rrb- , -lsb- note 2 -rsb- -lsb- note 1 -rsb- with an average discharge of about 2,900 m3/s -lrb- 100,000 cu ft/s -rrb- . 
the variant forms of the name of the rhine in modern languages are all derived from the gaulish name rēnos , which was adapted in roman-era geography -lrb- 1st century bc -rrb- as greek ῥῆνος -lrb- rhēnos -rrb- , latin rhenus . 
-lsb- note 3 -rsb- the spelling with rh - in english rhine as well as in german rhein and french rhin is due to the influence of greek orthography , while the vocalisation - i - is due to the proto-germanic adoption of the gaulish name as * rīnaz , via old frankish giving old english rín , old high german rīn , dutch rijn -lrb- formerly also spelled rhijn -rrb- -rrb- . 
-lsb- note 3 -rsb- the spelling with rh - in english rhine as well as in german rhein and french rhin is due to the influence of greek orthography , while the vocalisation - i - is due to the proto-germanic adoption of the gaulish name as * rīnaz , via old frankish giving old english rín , old high german rīn , dutch rijn -lrb- formerly also spelled rhijn -rrb- -rrb- . 
the variant forms of the name of the rhine in modern languages are all derived from the gaulish name rēnos , which was adapted in roman-era geography -lrb- 1st century bc -rrb- as greek ῥῆνος -lrb- rhēnos -rrb- , latin rhenus . 
the variant forms of the name of the rhine in modern languages are all derived from the gaulish name rēnos , which was adapted in roman-era geography -lrb- 1st century bc -rrb- as greek ῥῆνος -lrb- rhēnos -rrb- , latin rhenus . 
-lsb- note 3 -rsb- the spelling with rh - in english rhine as well as in german rhein and french rhin is due to the influence of greek orthography , while the vocalisation - i - is due to the proto-germanic adoption of the gaulish name as * rīnaz , via old frankish giving old english rín , old high german rīn , dutch rijn -lrb- formerly also spelled rhijn -rrb- -rrb- . 
-lsb- note 3 -rsb- the spelling with rh - in english rhine as well as in german rhein and french rhin is due to the influence of greek orthography , while the vocalisation - i - is due to the proto-germanic adoption of the gaulish name as * rīnaz , via old frankish giving old english rín , old high german rīn , dutch rijn -lrb- formerly also spelled rhijn -rrb- -rrb- . 
-lsb- note 3 -rsb- the spelling with rh - in english rhine as well as in german rhein and french rhin is due to the influence of greek orthography , while the vocalisation - i - is due to the proto-germanic adoption of the gaulish name as * rīnaz , via old frankish giving old english rín , old high german rīn , dutch rijn -lrb- formerly also spelled rhijn -rrb- -rrb- . 
-lsb- note 3 -rsb- the spelling with rh - in english rhine as well as in german rhein and french rhin is due to the influence of greek orthography , while the vocalisation - i - is due to the proto-germanic adoption of the gaulish name as * rīnaz , via old frankish giving old english rín , old high german rīn , dutch rijn -lrb- formerly also spelled rhijn -rrb- -rrb- . 
the length of the rhine is conventionally measured in `` rhine-kilometers '' -lrb- rheinkilometer -rrb- , a scale introduced in 1939 which runs from the old rhine bridge at constance -lrb- 0 km -rrb- to hoek van holland -lrb- 1036.20 km -rrb- . 
the length of the rhine is conventionally measured in `` rhine-kilometers '' -lrb- rheinkilometer -rrb- , a scale introduced in 1939 which runs from the old rhine bridge at constance -lrb- 0 km -rrb- to hoek van holland -lrb- 1036.20 km -rrb- . 
the length of the rhine is conventionally measured in `` rhine-kilometers '' -lrb- rheinkilometer -rrb- , a scale introduced in 1939 which runs from the old rhine bridge at constance -lrb- 0 km -rrb- to hoek van holland -lrb- 1036.20 km -rrb- . 
the length of the rhine is conventionally measured in `` rhine-kilometers '' -lrb- rheinkilometer -rrb- , a scale introduced in 1939 which runs from the old rhine bridge at constance -lrb- 0 km -rrb- to hoek van holland -lrb- 1036.20 km -rrb- . 
the river length is significantly shortened from the river 's natural course due to number of canalisation projects completed in the 19th and 20th century . 
the length of the rhine is conventionally measured in `` rhine-kilometers '' -lrb- rheinkilometer -rrb- , a scale introduced in 1939 which runs from the old rhine bridge at constance -lrb- 0 km -rrb- to hoek van holland -lrb- 1036.20 km -rrb- . 
the length of the rhine is conventionally measured in `` rhine-kilometers '' -lrb- rheinkilometer -rrb- , a scale introduced in 1939 which runs from the old rhine bridge at constance -lrb- 0 km -rrb- to hoek van holland -lrb- 1036.20 km -rrb- . 
the length of the rhine is conventionally measured in `` rhine-kilometers '' -lrb- rheinkilometer -rrb- , a scale introduced in 1939 which runs from the old rhine bridge at constance -lrb- 0 km -rrb- to hoek van holland -lrb- 1036.20 km -rrb- . 
the river length is significantly shortened from the river 's natural course due to number of canalisation projects completed in the 19th and 20th century . 
the length of the rhine is conventionally measured in `` rhine-kilometers '' -lrb- rheinkilometer -rrb- , a scale introduced in 1939 which runs from the old rhine bridge at constance -lrb- 0 km -rrb- to hoek van holland -lrb- 1036.20 km -rrb- . 
the river makes a distinctive turn to the north near chur . 
this section is nearly 86 km long , and descends from a height of 599 m to 396 m . 
it flows through a wide glacial alpine valley known as the rhine valley -lrb- german : rheintal -rrb- . 
near sargans a natural dam , only a few metres high , prevents it from flowing into the open seeztal valley and then through lake walen and lake zurich into the river aare . 
the alpine rhine begins in the most western part of the swiss canton of graubünden , and later forms the border between switzerland to the west and liechtenstein and later austria to the east . 
the river makes a distinctive turn to the north near chur . 
this section is nearly 86 km long , and descends from a height of 599 m to 396 m . 
this section is nearly 86 km long , and descends from a height of 599 m to 396 m . 
it flows through a wide glacial alpine valley known as the rhine valley -lrb- german : rheintal -rrb- . 
the alpine rhine begins in the most western part of the swiss canton of graubünden , and later forms the border between switzerland to the west and liechtenstein and later austria to the east . 
the mouth of the rhine into lake constance forms an inland delta . 
the delta is delimited in the west by the alter rhein -lrb- `` old rhine '' -rrb- and in the east by a modern canalized section . 
the delta is delimited in the west by the alter rhein -lrb- `` old rhine '' -rrb- and in the east by a modern canalized section . 
in the local alemannic dialect , the singular is pronounced `` isel '' and this is also the local pronunciation of esel -lrb- `` donkey '' -rrb- . 
in the local alemannic dialect , the singular is pronounced `` isel '' and this is also the local pronunciation of esel -lrb- `` donkey '' -rrb- . 
the mouth of the rhine into lake constance forms an inland delta . 
the delta is delimited in the west by the alter rhein -lrb- `` old rhine '' -rrb- and in the east by a modern canalized section . 
the delta is delimited in the west by the alter rhein -lrb- `` old rhine '' -rrb- and in the east by a modern canalized section . 
the natural rhine originally branched into at least two arms and formed small islands by precipitating sediments . 
in the local alemannic dialect , the singular is pronounced `` isel '' and this is also the local pronunciation of esel -lrb- `` donkey '' -rrb- . 
a regulation of the rhine was called for , with an upper canal near diepoldsau and a lower canal at fußach , in order to counteract the constant flooding and strong sedimentation in the western rhine delta . 
a regulation of the rhine was called for , with an upper canal near diepoldsau and a lower canal at fußach , in order to counteract the constant flooding and strong sedimentation in the western rhine delta . 
a regulation of the rhine was called for , with an upper canal near diepoldsau and a lower canal at fußach , in order to counteract the constant flooding and strong sedimentation in the western rhine delta . 
the dornbirner ach had to be diverted , too , and it now flows parallel to the canalized rhine into the lake . 
it is expected that the continuous input of sediment into the lake will silt up the lake . 
a regulation of the rhine was called for , with an upper canal near diepoldsau and a lower canal at fußach , in order to counteract the constant flooding and strong sedimentation in the western rhine delta . 
a regulation of the rhine was called for , with an upper canal near diepoldsau and a lower canal at fußach , in order to counteract the constant flooding and strong sedimentation in the western rhine delta . 
a regulation of the rhine was called for , with an upper canal near diepoldsau and a lower canal at fußach , in order to counteract the constant flooding and strong sedimentation in the western rhine delta . 
the dornbirner ach had to be diverted , too , and it now flows parallel to the canalized rhine into the lake . 
it is expected that the continuous input of sediment into the lake will silt up the lake . 
lake constance consists of three bodies of water : the obersee -lrb- `` upper lake '' -rrb- , the untersee -lrb- `` lower lake '' -rrb- , and a connecting stretch of the rhine , called the seerhein -lrb- `` lake rhine '' -rrb- . 
lake constance consists of three bodies of water : the obersee -lrb- `` upper lake '' -rrb- , the untersee -lrb- `` lower lake '' -rrb- , and a connecting stretch of the rhine , called the seerhein -lrb- `` lake rhine '' -rrb- . 
lake constance consists of three bodies of water : the obersee -lrb- `` upper lake '' -rrb- , the untersee -lrb- `` lower lake '' -rrb- , and a connecting stretch of the rhine , called the seerhein -lrb- `` lake rhine '' -rrb- . 
the rhine flows into it from the south following the swiss-austrian border . 
lake constance consists of three bodies of water : the obersee -lrb- `` upper lake '' -rrb- , the untersee -lrb- `` lower lake '' -rrb- , and a connecting stretch of the rhine , called the seerhein -lrb- `` lake rhine '' -rrb- . 
lake constance consists of three bodies of water : the obersee -lrb- `` upper lake '' -rrb- , the untersee -lrb- `` lower lake '' -rrb- , and a connecting stretch of the rhine , called the seerhein -lrb- `` lake rhine '' -rrb- . 
the lake is situated in germany , switzerland and austria near the alps . 
the lake is situated in germany , switzerland and austria near the alps . 
it is located at approximately 47 ° 39 ′ n 9 ° 19 ′ e / 47.650 ° n 9.317 ° e / 47.650 ; 9.317 . 
specifically , its shorelines lie in the german states of bavaria and baden-württemberg , the austrian state of vorarlberg , and the swiss cantons of thurgau and st. gallen . 
but then , at the so-called rheinbrech , the rhine water abruptly falls into the depths because of the greater density of cold water . 
a small fraction of the flow is diverted off the island of mainau into lake überlingen . 
but then , at the so-called rheinbrech , the rhine water abruptly falls into the depths because of the greater density of cold water . 
depending on the water level , this flow of the rhine water is clearly visible along the entire length of the lake . 
the flow reappears on the surface at the northern -lrb- german -rrb- shore of the lake , off the island of lindau . 
but then , at the so-called rheinbrech , the rhine water abruptly falls into the depths because of the greater density of cold water . 
the flow reappears on the surface at the northern -lrb- german -rrb- shore of the lake , off the island of lindau . 
a small fraction of the flow is diverted off the island of mainau into lake überlingen . 
most of the water flows via the constance hopper into the rheinrinne -lrb- `` rhine gutter '' -rrb- and seerhein . 
depending on the water level , this flow of the rhine water is clearly visible along the entire length of the lake . 
the rhine emerges from lake constance , flows generally westward , as the hochrhein , passes the rhine falls , and is joined by its major tributary , the river aare . 
the rhine emerges from lake constance , flows generally westward , as the hochrhein , passes the rhine falls , and is joined by its major tributary , the river aare . 
the aare more than doubles the rhine 's water discharge , to an average of nearly 1,000 m3/s -lrb- 35,000 cu ft/s -rrb- , and provides more than a fifth of the discharge at the dutch border . 
the aare also contains the waters from the 4,274 m -lrb- 14,022 ft -rrb- summit of finsteraarhorn , the highest point of the rhine basin . 
the rhine roughly forms the german-swiss border from lake constance with the exceptions of the canton of schaffhausen and parts of the cantons of zürich and basel-stadt , until it turns north at the so-called rhine knee at basel , leaving switzerland . 
the rhine emerges from lake constance , flows generally westward , as the hochrhein , passes the rhine falls , and is joined by its major tributary , the river aare . 
the rhine emerges from lake constance , flows generally westward , as the hochrhein , passes the rhine falls , and is joined by its major tributary , the river aare . 
the aare more than doubles the rhine 's water discharge , to an average of nearly 1,000 m3/s -lrb- 35,000 cu ft/s -rrb- , and provides more than a fifth of the discharge at the dutch border . 
the aare also contains the waters from the 4,274 m -lrb- 14,022 ft -rrb- summit of finsteraarhorn , the highest point of the rhine basin . 
the rhine roughly forms the german-swiss border from lake constance with the exceptions of the canton of schaffhausen and parts of the cantons of zürich and basel-stadt , until it turns north at the so-called rhine knee at basel , leaving switzerland . 
in the centre of basel , the first major city in the course of the stream , is located the `` rhine knee '' ; this is a major bend , where the overall direction of the rhine changes from west to north . 
in the centre of basel , the first major city in the course of the stream , is located the `` rhine knee '' ; this is a major bend , where the overall direction of the rhine changes from west to north . 
legally , the central bridge is the boundary between high and upper rhine . 
the river now flows north as upper rhine through the upper rhine plain , which is about 300 km long and up to 40 km wide . 
the river now flows north as upper rhine through the upper rhine plain , which is about 300 km long and up to 40 km wide . 
in the centre of basel , the first major city in the course of the stream , is located the `` rhine knee '' ; this is a major bend , where the overall direction of the rhine changes from west to north . 
in the centre of basel , the first major city in the course of the stream , is located the `` rhine knee '' ; this is a major bend , where the overall direction of the rhine changes from west to north . 
in the centre of basel , the first major city in the course of the stream , is located the `` rhine knee '' ; this is a major bend , where the overall direction of the rhine changes from west to north . 
here the high rhine ends . 
legally , the central bridge is the boundary between high and upper rhine . 
the upper rhine region was changed significantly by a rhine straightening program in the 19th century . 
the rate of flow was increased and the ground water level fell significantly . 
the rate of flow was increased and the ground water level fell significantly . 
on the french side , the grand canal d'alsace was dug , which carries a significant part of the river water , and all of the traffic . 
in some places , there are large compensation pools , for example the huge bassin de compensation de plobsheim in alsace . 
the upper rhine region was changed significantly by a rhine straightening program in the 19th century . 
the upper rhine region was changed significantly by a rhine straightening program in the 19th century . 
the rate of flow was increased and the ground water level fell significantly . 
the rate of flow was increased and the ground water level fell significantly . 
on the french side , the grand canal d'alsace was dug , which carries a significant part of the river water , and all of the traffic . 
the rhine is the longest river in germany . 
it is here that the rhine encounters some more of its main tributaries , such as the neckar , the main and , later , the moselle , which contributes an average discharge of more than 300 m3/s -lrb- 11,000 cu ft/s -rrb- . 
the rhine is the longest river in germany . 
most of luxembourg and a very small part of belgium also drain to the rhine via the moselle . 
as it approaches the dutch border , the rhine has an annual mean discharge of 2,290 m3/s -lrb- 81,000 cu ft/s -rrb- and an average width of 400 m -lrb- 1,300 ft -rrb- . 
the rhine is the longest river in germany . 
the rhine is the longest river in germany . 
it is here that the rhine encounters some more of its main tributaries , such as the neckar , the main and , later , the moselle , which contributes an average discharge of more than 300 m3/s -lrb- 11,000 cu ft/s -rrb- . 
northeastern france drains to the rhine via the moselle ; smaller rivers drain the vosges and jura mountains uplands . 
as it approaches the dutch border , the rhine has an annual mean discharge of 2,290 m3/s -lrb- 81,000 cu ft/s -rrb- and an average width of 400 m -lrb- 1,300 ft -rrb- . 
between bingen and bonn , the middle rhine flows through the rhine gorge , a formation which was created by erosion . 
between bingen and bonn , the middle rhine flows through the rhine gorge , a formation which was created by erosion . 
between bingen and bonn , the middle rhine flows through the rhine gorge , a formation which was created by erosion . 
it is a unesco world heritage site -lrb- 2002 -rrb- and known as `` the romantic rhine '' , with more than 40 castles and fortresses from the middle ages and many quaint and lovely country villages . 
between bingen and bonn , the middle rhine flows through the rhine gorge , a formation which was created by erosion . 
between bingen and bonn , the middle rhine flows through the rhine gorge , a formation which was created by erosion . 
the gorge is quite deep and is the stretch of the river which is known for its many castles and vineyards . 
it is a unesco world heritage site -lrb- 2002 -rrb- and known as `` the romantic rhine '' , with more than 40 castles and fortresses from the middle ages and many quaint and lovely country villages . 
although many plants and factories can be found along the rhine up into switzerland , it is along the lower rhine that the bulk of them are concentrated , as the river passes the major cities of cologne , düsseldorf and duisburg . 
duisburg is the home of europe 's largest inland port and functions as a hub to the sea ports of rotterdam , antwerp and amsterdam . 
the ruhr , which joins the rhine in duisburg , is nowadays a clean river , thanks to a combination of stricter environmental controls , a transition from heavy industry to light industry and cleanup measures , such as the reforestation of slag and brownfields . 
the ruhr currently provides the region with drinking water . 
although many plants and factories can be found along the rhine up into switzerland , it is along the lower rhine that the bulk of them are concentrated , as the river passes the major cities of cologne , düsseldorf and duisburg . 
until the early 1980s , industry was a major source of water pollution . 
although many plants and factories can be found along the rhine up into switzerland , it is along the lower rhine that the bulk of them are concentrated , as the river passes the major cities of cologne , düsseldorf and duisburg . 
although many plants and factories can be found along the rhine up into switzerland , it is along the lower rhine that the bulk of them are concentrated , as the river passes the major cities of cologne , düsseldorf and duisburg . 
duisburg is the home of europe 's largest inland port and functions as a hub to the sea ports of rotterdam , antwerp and amsterdam . 
the ruhr , which joins the rhine in duisburg , is nowadays a clean river , thanks to a combination of stricter environmental controls , a transition from heavy industry to light industry and cleanup measures , such as the reforestation of slag and brownfields . 
the dominant economic sectors in the middle rhine area are viniculture and tourism . 
the rhine gorge between rüdesheim am rhein and koblenz is listed as a unesco world heritage site . 
near sankt goarshausen , the rhine flows around the famous rock lorelei . 
with its outstanding architectural monuments , the slopes full of vines , settlements crowded on the narrow river banks and scores of castles lined up along the top of the steep slopes , the middle rhine valley can be considered the epitome of the rhine romanticism . 
the dominant economic sectors in the middle rhine area are viniculture and tourism . 
the rhine gorge between rüdesheim am rhein and koblenz is listed as a unesco world heritage site . 
the rhine gorge between rüdesheim am rhein and koblenz is listed as a unesco world heritage site . 
near sankt goarshausen , the rhine flows around the famous rock lorelei . 
near sankt goarshausen , the rhine flows around the famous rock lorelei . 
one of the most important cities in this region is duisburg with the largest river port in europe -lrb- duisport -rrb- . 
in wesel , 30 km downstream of duisburg , is located the western end of the second east-west shipping route , the wesel-datteln canal , which runs parallel to the lippe . 
in wesel , 30 km downstream of duisburg , is located the western end of the second east-west shipping route , the wesel-datteln canal , which runs parallel to the lippe . 
between emmerich and cleves the emmerich rhine bridge , the longest suspension bridge in germany , crosses the 400 m wide river . 
between emmerich and cleves the emmerich rhine bridge , the longest suspension bridge in germany , crosses the 400 m wide river . 
the lower rhine flows through north rhine-westphalia . 
here the rhine flows through the largest conurbation in germany , the rhine-ruhr region . 
one of the most important cities in this region is duisburg with the largest river port in europe -lrb- duisport -rrb- . 
between emmerich and cleves the emmerich rhine bridge , the longest suspension bridge in germany , crosses the 400 m wide river . 
between emmerich and cleves the emmerich rhine bridge , the longest suspension bridge in germany , crosses the 400 m wide river . 
two thirds of the water flow volume of the rhine flows farther west , through the waal and then , via the merwede and nieuwe merwede -lrb- de biesbosch -rrb- , merging with the meuse , through the hollands diep and haringvliet estuaries , into the north sea . 
from here , the situation becomes more complicated , as the dutch name rijn no longer coincides with the main flow of water . 
two thirds of the water flow volume of the rhine flows farther west , through the waal and then , via the merwede and nieuwe merwede -lrb- de biesbosch -rrb- , merging with the meuse , through the hollands diep and haringvliet estuaries , into the north sea . 
two thirds of the water flow volume of the rhine flows farther west , through the waal and then , via the merwede and nieuwe merwede -lrb- de biesbosch -rrb- , merging with the meuse , through the hollands diep and haringvliet estuaries , into the north sea . 
two thirds of the water flow volume of the rhine flows farther west , through the waal and then , via the merwede and nieuwe merwede -lrb- de biesbosch -rrb- , merging with the meuse , through the hollands diep and haringvliet estuaries , into the north sea . 
two thirds of the water flow volume of the rhine flows farther west , through the waal and then , via the merwede and nieuwe merwede -lrb- de biesbosch -rrb- , merging with the meuse , through the hollands diep and haringvliet estuaries , into the north sea . 
the oude maas branches off , near dordrecht , farther down rejoining the nieuwe maas to form het scheur . 
the other third of the water flows through the pannerdens kanaal and redistributes in the ijssel and nederrijn . 
the other third of the water flows through the pannerdens kanaal and redistributes in the ijssel and nederrijn . 
however , at wijk bij duurstede , the nederrijn changes its name and becomes the lek . 
it flows farther west , to rejoin the noord river into the nieuwe maas and to the north sea . 
the other third of the water flows through the pannerdens kanaal and redistributes in the ijssel and nederrijn . 
the other third of the water flows through the pannerdens kanaal and redistributes in the ijssel and nederrijn . 
the ijssel branch carries one ninth of the water flow of the rhine north into the ijsselmeer -lrb- a former bay -rrb- , while the nederrijn carries approximately two ninths of the flow west along a route parallel to the waal . 
however , at wijk bij duurstede , the nederrijn changes its name and becomes the lek . 
however , at wijk bij duurstede , the nederrijn changes its name and becomes the lek . 
the name rijn , from here on , is used only for smaller streams farther to the north , which together formed the main river rhine in roman times . 
though they retained the name , these streams no longer carry water from the rhine , but are used for draining the surrounding land and polders . 
from wijk bij duurstede , the old north branch of the rhine is called kromme rijn -lrb- `` bent rhine '' -rrb- past utrecht , first leidse rijn -lrb- `` rhine of leiden '' -rrb- and then , oude rijn -lrb- `` old rhine '' -rrb- . 
from wijk bij duurstede , the old north branch of the rhine is called kromme rijn -lrb- `` bent rhine '' -rrb- past utrecht , first leidse rijn -lrb- `` rhine of leiden '' -rrb- and then , oude rijn -lrb- `` old rhine '' -rrb- . 
from wijk bij duurstede , the old north branch of the rhine is called kromme rijn -lrb- `` bent rhine '' -rrb- past utrecht , first leidse rijn -lrb- `` rhine of leiden '' -rrb- and then , oude rijn -lrb- `` old rhine '' -rrb- . 
the rhine-meuse delta , the most important natural region of the netherlands begins near millingen aan de rijn , close to the dutch-german border with the division of the rhine into waal and nederrijn . 
the rhine-meuse delta , the most important natural region of the netherlands begins near millingen aan de rijn , close to the dutch-german border with the division of the rhine into waal and nederrijn . 
since the rhine contributes most of the water , the shorter term rhine delta is commonly used . 
the shape of the rhine delta is determined by two bifurcations : first , at millingen aan de rijn , the rhine splits into waal and pannerdens kanaal , which changes its name to nederrijn at angeren , and second near arnhem , the ijssel branches off from the nederrijn . 
this creates three main flows , two of which change names rather often . 
the largest and southern main branch begins as waal and continues as boven merwede -lrb- `` upper merwede '' -rrb- , beneden merwede -lrb- `` lower merwede '' -rrb- , noord river -lrb- `` north river '' -rrb- , nieuwe maas -lrb- `` new meuse '' -rrb- , het scheur -lrb- `` the rip '' -rrb- and nieuwe waterweg -lrb- `` new waterway '' -rrb- . 
three more flows carry significant amounts of water : the nieuwe merwede -lrb- `` new merwede '' -rrb- , which branches off from the southern branch where it changes from boven to beneden merwede ; the oude maas -lrb- `` old meuse '' -rrb- , which branches off from the southern branch where it changes from beneden merwede into noord , and dordtse kil , which branches off from oude maas . 
the largest and southern main branch begins as waal and continues as boven merwede -lrb- `` upper merwede '' -rrb- , beneden merwede -lrb- `` lower merwede '' -rrb- , noord river -lrb- `` north river '' -rrb- , nieuwe maas -lrb- `` new meuse '' -rrb- , het scheur -lrb- `` the rip '' -rrb- and nieuwe waterweg -lrb- `` new waterway '' -rrb- . 
before the st. elizabeth 's flood -lrb- 1421 -rrb- , the meuse flowed just south of today 's line merwede-oude maas to the north sea and formed an archipelago-like estuary with waal and lek . 
before the st. elizabeth 's flood -lrb- 1421 -rrb- , the meuse flowed just south of today 's line merwede-oude maas to the north sea and formed an archipelago-like estuary with waal and lek . 
before the st. elizabeth 's flood -lrb- 1421 -rrb- , the meuse flowed just south of today 's line merwede-oude maas to the north sea and formed an archipelago-like estuary with waal and lek . 
from 1421 to 1904 , the meuse and waal merged further upstream at gorinchem to form merwede . 
before the st. elizabeth 's flood -lrb- 1421 -rrb- , the meuse flowed just south of today 's line merwede-oude maas to the north sea and formed an archipelago-like estuary with waal and lek . 
many rivers have been closed -lrb- `` dammed '' -rrb- and now serve as drainage channels for the numerous polders . 
the construction of delta works changed the delta in the second half of the 20th century fundamentally . 
many rivers have been closed -lrb- `` dammed '' -rrb- and now serve as drainage channels for the numerous polders . 
the construction of delta works changed the delta in the second half of the 20th century fundamentally . 
the rhine-meuse delta is a tidal delta , shaped not only by the sedimentation of the rivers , but also by tidal currents . 
the rhine-meuse delta is a tidal delta , shaped not only by the sedimentation of the rivers , but also by tidal currents . 
this meant that high tide formed a serious risk because strong tidal currents could tear huge areas of land into the sea . 
at the waal , for example , the most landward tidal influence can be detected between brakel and zaltbommel . 
the present mediterranean sea descends from this somewhat larger tethys sea . 
at about 180 mbp , in the jurassic period , the two plates reversed direction and began to compress the tethys floor , causing it to be subducted under eurasia and pushing up the edge of the latter plate in the alpine orogeny of the oligocene and miocene periods . 
several microplates were caught in the squeeze and rotated or were pushed laterally , generating the individual features of mediterranean geography : iberia pushed up the pyrenees ; italy , the alps , and anatolia , moving west , the mountains of greece and the islands . 
in southern europe , the stage was set in the triassic period of the mesozoic era , with the opening of the tethys ocean , between the eurasian and african tectonic plates , between about 240 mbp and 220 mbp -lrb- million years before present -rrb- . 
several microplates were caught in the squeeze and rotated or were pushed laterally , generating the individual features of mediterranean geography : iberia pushed up the pyrenees ; italy , the alps , and anatolia , moving west , the mountains of greece and the islands . 
from the eocene onwards , the ongoing alpine orogeny caused a n -- s rift system to develop in this zone . 
the main elements of this rift are the upper rhine graben , in southwest germany and eastern france and the lower rhine embayment , in northwest germany and the southeastern netherlands . 
by the time of the miocene , a river system had developed in the upper rhine graben , that continued northward and is considered the first rhine river . 
at that time , it did not yet carry discharge from the alps ; instead , the watersheds of the rhone and danube drained the northern flanks of the alps . 
through stream capture , the rhine extended its watershed southward . 
by the pliocene period , the rhine had captured streams down to the vosges mountains , including the mosel , the main and the neckar . 
by the pliocene period , the rhine had captured streams down to the vosges mountains , including the mosel , the main and the neckar . 
around 2.5 million years ago -lrb- ending 11,600 years ago -rrb- was the geological period of the ice ages . 
since approximately 600,000 years ago , six major ice ages have occurred , in which sea level dropped 120 m -lrb- 390 ft -rrb- and much of the continental margins became exposed . 
since approximately 600,000 years ago , six major ice ages have occurred , in which sea level dropped 120 m -lrb- 390 ft -rrb- and much of the continental margins became exposed . 
in the early pleistocene , the rhine followed a course to the northwest , through the present north sea . 
since then , during glacial times , the river mouth was located offshore of brest , france and rivers , like the thames and the seine , became tributaries to the rhine . 
the last glacial ran from ~ 74,000 -lrb- bp = before present -rrb- , until the end of the pleistocene -lrb- ~ 11,600 bp -rrb- . 
the last glacial ran from ~ 74,000 -lrb- bp = before present -rrb- , until the end of the pleistocene -lrb- ~ 11,600 bp -rrb- . 
during this time , the lower rhine flowed roughly west through the netherlands and extended to the southwest , through the english channel and finally , to the atlantic ocean . 
the english channel , the irish channel and most of the north sea were dry land , mainly because sea level was approximately 120 m -lrb- 390 ft -rrb- lower than today . 
the english channel , the irish channel and most of the north sea were dry land , mainly because sea level was approximately 120 m -lrb- 390 ft -rrb- lower than today . 
most of the rhine 's current course was not under the ice during the last ice age ; although , its source must still have been a glacier . 
a tundra , with ice age flora and fauna , stretched across middle europe , from asia to the atlantic ocean . 
such was the case during the last glacial maximum , ca. 22,000 -- 14,000 yr bp , when ice-sheets covered scandinavia , the baltics , scotland and the alps , but left the space between as open tundra . 
such was the case during the last glacial maximum , ca. 22,000 -- 14,000 yr bp , when ice-sheets covered scandinavia , the baltics , scotland and the alps , but left the space between as open tundra . 
the loess or wind-blown dust over that tundra , settled in and around the rhine valley , contributing to its current agricultural usefulness . 
as northwest europe slowly began to warm up from 22,000 years ago onward , frozen subsoil and expanded alpine glaciers began to thaw and fall-winter snow covers melted in spring . 
as northwest europe slowly began to warm up from 22,000 years ago onward , frozen subsoil and expanded alpine glaciers began to thaw and fall-winter snow covers melted in spring . 
much of the discharge was routed to the rhine and its downstream extension . 
rapid warming and changes of vegetation , to open forest , began about 13,000 bp . 
by 9000 bp , europe was fully forested . 
since 7500 yr ago , a situation with tides and currents , very similar to present has existed . 
rates of sea-level rise had dropped so far , that natural sedimentation by the rhine and coastal processes together , could compensate the transgression by the sea ; in the last 7000 years , the coast line was roughly at the same location . 
rates of sea-level rise had dropped so far , that natural sedimentation by the rhine and coastal processes together , could compensate the transgression by the sea ; in the last 7000 years , the coast line was roughly at the same location . 
in the southern north sea , due to ongoing tectonic subsidence , the sea level is still rising , at the rate of about 1 -- 3 cm -lrb- 0.39 -- 1.18 in -rrb- per century -lrb- 1 metre or 39 inches in last 3000 years -rrb- . 
in the southern north sea , due to ongoing tectonic subsidence , the sea level is still rising , at the rate of about 1 -- 3 cm -lrb- 0.39 -- 1.18 in -rrb- per century -lrb- 1 metre or 39 inches in last 3000 years -rrb- . 
at the begin of the holocene -lrb- ~ 11,700 years ago -rrb- , the rhine occupied its late-glacial valley . 
as sea-level continued to rise in the netherlands , the formation of the holocene rhine-meuse delta began -lrb- ~ 8,000 years ago -rrb- . 
at the begin of the holocene -lrb- ~ 11,700 years ago -rrb- , the rhine occupied its late-glacial valley . 
as sea-level continued to rise in the netherlands , the formation of the holocene rhine-meuse delta began -lrb- ~ 8,000 years ago -rrb- . 
since ~ 3000 yr bp -lrb- = years before present -rrb- , human impact is seen in the delta . 
this caused increased flooding and sedimentation , ending peat formation in the delta . 
as a result of increasing land clearance -lrb- bronze age agriculture -rrb- , in the upland areas -lrb- central germany -rrb- , the sediment load of the rhine has strongly increased and delta growth has sped up . 
this was followed by embankment , of the major distributaries and damming of minor distributaries , which took place in the 11 -- 13th century ad . 
over the past 6000 years , approximately 80 avulsions have occurred . 
at present , the branches waal and nederrijn-lek discharge to the north sea , through the former meuse estuary , near rotterdam . 
at present , the branches waal and nederrijn-lek discharge to the north sea , through the former meuse estuary , near rotterdam . 
the river ijssel branch flows to the north and enters the ijsselmeer , formerly the zuider zee brackish lagoon ; however , since 1932 , a freshwater lake . 
the river ijssel branch flows to the north and enters the ijsselmeer , formerly the zuider zee brackish lagoon ; however , since 1932 , a freshwater lake . 
the discharge of the rhine is divided among three branches : the river waal -lrb- 6/9 of total discharge -rrb- , the river nederrijn -- lek -lrb- 2/9 of total discharge -rrb- and the river ijssel -lrb- 1/9 of total discharge -rrb- . 
the rhine was not known to herodotus and first enters the historical period in the 1st century bc in roman-era geography . 
at that time , it formed the boundary between gaul and germania . 
the upper rhine had been part of the areal of the late hallstatt culture since the 6th century bc , and by the 1st century bc , the areal of the la tène culture covered almost its entire length , forming a contact zone with the jastorf culture , i.e. the locus of early celtic-germanic cultural contact . 
in roman geography , the rhine formed the boundary between gallia and germania by definition ; e.g. maurus servius honoratus , commentary on the aeneid of vergil -lrb- 8.727 -rrb- -lrb- rhenus -rrb- fluvius galliae , qui germanos a gallia dividit '' -lrb- the rhine is a -rrb- river of gaul , which divides the germanic people from gaul . '' 
from the death of augustus in ad 14 until after ad 70 , rome accepted as her germanic frontier the water-boundary of the rhine and upper danube . 
from the death of augustus in ad 14 until after ad 70 , rome accepted as her germanic frontier the water-boundary of the rhine and upper danube . 
the northern section of this frontier , where the rhine is deep and broad , remained the roman boundary until the empire fell . 
the germanic populations of these lands seem in roman times to have been scanty , and roman subjects from the modern alsace-lorraine had drifted across the river eastwards . 
the southern part was different . 
the romans kept eight legions in five bases along the rhine . 
between about ad 14 and 180 , the assignment of legions was as follows : for the army of germania inferior , two legions at vetera -lrb- xanten -rrb- , i germanica and xx valeria -lrb- pannonian troops -rrb- ; two legions at oppidum ubiorum -lrb- `` town of the ubii '' -rrb- , which was renamed to colonia agrippina , descending to cologne , v alaudae , a celtic legion recruited from gallia narbonensis and xxi , possibly a galatian legion from the other side of the empire . 
between about ad 14 and 180 , the assignment of legions was as follows : for the army of germania inferior , two legions at vetera -lrb- xanten -rrb- , i germanica and xx valeria -lrb- pannonian troops -rrb- ; two legions at oppidum ubiorum -lrb- `` town of the ubii '' -rrb- , which was renamed to colonia agrippina , descending to cologne , v alaudae , a celtic legion recruited from gallia narbonensis and xxi , possibly a galatian legion from the other side of the empire . 
the actual number of legions present at any base or in all , depended on whether a state or threat of war existed . 
between about ad 14 and 180 , the assignment of legions was as follows : for the army of germania inferior , two legions at vetera -lrb- xanten -rrb- , i germanica and xx valeria -lrb- pannonian troops -rrb- ; two legions at oppidum ubiorum -lrb- `` town of the ubii '' -rrb- , which was renamed to colonia agrippina , descending to cologne , v alaudae , a celtic legion recruited from gallia narbonensis and xxi , possibly a galatian legion from the other side of the empire . 
germanic tribes crossed the rhine in the migration period , by the 5th century establishing the kingdoms of francia on the lower rhine , burgundy on the upper rhine and alemannia on the high rhine . 
germanic tribes crossed the rhine in the migration period , by the 5th century establishing the kingdoms of francia on the lower rhine , burgundy on the upper rhine and alemannia on the high rhine . 
this `` germanic heroic age '' is reflected in medieval legend , such as the nibelungenlied which tells of the hero siegfried killing a dragon on the drachenfels -lrb- siebengebirge -rrb- -lrb- `` dragons rock '' -rrb- , near bonn at the rhine and of the burgundians and their court at worms , at the rhine and kriemhild 's golden treasure , which was thrown into the rhine by hagen . 
this `` germanic heroic age '' is reflected in medieval legend , such as the nibelungenlied which tells of the hero siegfried killing a dragon on the drachenfels -lrb- siebengebirge -rrb- -lrb- `` dragons rock '' -rrb- , near bonn at the rhine and of the burgundians and their court at worms , at the rhine and kriemhild 's golden treasure , which was thrown into the rhine by hagen . 
this `` germanic heroic age '' is reflected in medieval legend , such as the nibelungenlied which tells of the hero siegfried killing a dragon on the drachenfels -lrb- siebengebirge -rrb- -lrb- `` dragons rock '' -rrb- , near bonn at the rhine and of the burgundians and their court at worms , at the rhine and kriemhild 's golden treasure , which was thrown into the rhine by hagen . 
by the 6th century , the rhine was within the borders of francia . 
in the 9th , it formed part of the border between middle and western francia , but in the 10th century , it was fully within the holy roman empire , flowing through swabia , franconia and lower lorraine . 
in the 9th , it formed part of the border between middle and western francia , but in the 10th century , it was fully within the holy roman empire , flowing through swabia , franconia and lower lorraine . 
the alsace on the left banks of the upper rhine was sold to burgundy by archduke sigismund of austria in 1469 and eventually fell to france in the thirty years ' war . 
the alsace on the left banks of the upper rhine was sold to burgundy by archduke sigismund of austria in 1469 and eventually fell to france in the thirty years ' war . 
since the peace of westphalia , the upper rhine formed a contentious border between france and germany . 
establishing `` natural borders '' on the rhine was a long-term goal of french foreign policy , since the middle ages , though the language border was -- and is -- far more to the west . 
the confederation of the rhine was established by napoleon , as a french client state , in 1806 and lasted until 1814 , during which time it served as a significant source of resources and military manpower for the first french empire . 
the confederation of the rhine was established by napoleon , as a french client state , in 1806 and lasted until 1814 , during which time it served as a significant source of resources and military manpower for the first french empire . 
in 1840 , the rhine crisis , prompted by french prime minister adolphe thiers 's desire to reinstate the rhine as a natural border , led to a diplomatic crisis and a wave of nationalism in germany . 
at the end of world war i , the rhineland was subject to the treaty of versailles . 
this decreed that it would be occupied by the allies , until 1935 and after that , it would be a demilitarised zone , with the german army forbidden to enter . 
this decreed that it would be occupied by the allies , until 1935 and after that , it would be a demilitarised zone , with the german army forbidden to enter . 
the treaty of versailles and this particular provision , in general , caused much resentment in germany and is often cited as helping adolf hitler 's rise to power . 
the allies left the rhineland , in 1930 and the german army re-occupied it in 1936 , which was enormously popular in germany . 
the rhine bridge at arnhem , immortalized in the book , a bridge too far and the film , was a central focus of the battle for arnhem , during the failed operation market garden of september 1944 . 
in world war ii , it was recognised that the rhine would present a formidable natural obstacle to the invasion of germany , by the western allies . 
the rhine bridge at arnhem , immortalized in the book , a bridge too far and the film , was a central focus of the battle for arnhem , during the failed operation market garden of september 1944 . 
in a separate operation , the ludendorff bridge , crossing the rhine at remagen , became famous , when u.s. forces were able to capture it intact -- much to their own surprise -- after the germans failed to demolish it . 
seven days to the river rhine was a warsaw pact war plan for an invasion of western europe during the cold war . 
until 1932 the generally accepted length of the rhine was 1,230 kilometres -lrb- 764 miles -rrb- . 
in 1932 the german encyclopedia knaurs lexikon stated the length as 1,320 kilometres -lrb- 820 miles -rrb- , presumably a typographical error . 
in 1932 the german encyclopedia knaurs lexikon stated the length as 1,320 kilometres -lrb- 820 miles -rrb- , presumably a typographical error . 
in 1932 the german encyclopedia knaurs lexikon stated the length as 1,320 kilometres -lrb- 820 miles -rrb- , presumably a typographical error . 
the error was discovered in 2010 , and the dutch rijkswaterstaat confirms the length at 1,232 kilometres -lrb- 766 miles -rrb- . 
following a referendum in 1997 , in which the scottish electorate voted for devolution , the current parliament was convened by the scotland act 1998 , which sets out its powers as a devolved legislature . 
following a referendum in 1997 , in which the scottish electorate voted for devolution , the current parliament was convened by the scotland act 1998 , which sets out its powers as a devolved legislature . 
the act delineates the legislative competence of the parliament -- the areas in which it can make laws -- by explicitly specifying powers that are `` reserved '' to the parliament of the united kingdom . 
the act delineates the legislative competence of the parliament -- the areas in which it can make laws -- by explicitly specifying powers that are `` reserved '' to the parliament of the united kingdom . 
the scottish parliament has the power to legislate in all areas that are not explicitly reserved to westminster . 
for the next three hundred years , scotland was directly governed by the parliament of great britain and the subsequent parliament of the united kingdom , both seated at westminster , and the lack of a parliament of scotland remained an important element in scottish national identity . 
for the next three hundred years , scotland was directly governed by the parliament of great britain and the subsequent parliament of the united kingdom , both seated at westminster , and the lack of a parliament of scotland remained an important element in scottish national identity . 
suggestions for a ` devolved ' parliament were made before 1914 , but were shelved due to the outbreak of the first world war . 
a sharp rise in nationalism in scotland during the late 1960s fuelled demands for some form of home rule or complete independence , and in 1969 prompted the incumbent labour government of harold wilson to set up the kilbrandon commission to consider the british constitution . 
kilbrandon published his report in 1973 recommending the establishment of a directly elected scottish assembly to legislate for the majority of domestic scottish affairs . 
during this time , the discovery of oil in the north sea and the following `` it 's scotland 's oil '' campaign of the scottish national party -lrb- snp -rrb- resulted in rising support for scottish independence , as well as the snp . 
during this time , the discovery of oil in the north sea and the following `` it 's scotland 's oil '' campaign of the scottish national party -lrb- snp -rrb- resulted in rising support for scottish independence , as well as the snp . 
the combined effect of these events led to prime minister wilson committing his government to some form of devolved legislature in 1974 . 
the party argued that the revenues from the oil were not benefitting scotland as much as they should . 
however , it was not until 1978 that final legislative proposals for a scottish assembly were passed by the united kingdom parliament . 
under the terms of the scotland act 1978 , an elected assembly would be set up in edinburgh provided that the majority of the scottish electorate voted for it in a referendum to be held on 1 march 1979 that represented at least 40 % of the total electorate . 
under the terms of the scotland act 1978 , an elected assembly would be set up in edinburgh provided that the majority of the scottish electorate voted for it in a referendum to be held on 1 march 1979 that represented at least 40 % of the total electorate . 
although the vote was 51.6 % in favour of a scottish assembly , this figure did not equal the 40 % of the total electorate threshold deemed necessary to pass the measure , as 32.9 % of the eligible voting population did not , or had been unable to , vote . 
the 1979 scottish devolution referendum to establish a devolved scottish assembly failed . 
although the vote was 51.6 % in favour of a scottish assembly , this figure did not equal the 40 % of the total electorate threshold deemed necessary to pass the measure , as 32.9 % of the eligible voting population did not , or had been unable to , vote . 
throughout the 1980s and 1990s , demand for a scottish parliament grew , in part because the government of the united kingdom was controlled by the conservative party , while scotland itself elected relatively few conservative mps . 
throughout the 1980s and 1990s , demand for a scottish parliament grew , in part because the government of the united kingdom was controlled by the conservative party , while scotland itself elected relatively few conservative mps . 
in the aftermath of the 1979 referendum defeat , the campaign for a scottish assembly was initiated as a pressure group , leading to the 1989 scottish constitutional convention with various organisations such as scottish churches , political parties and representatives of industry taking part . 
publishing its blueprint for devolution in 1995 , the convention provided much of the basis for the structure of the parliament . 
since september 2004 , the official home of the scottish parliament has been a new scottish parliament building , in the holyrood area of edinburgh . 
the scottish parliament building was designed by spanish architect enric miralles in partnership with local edinburgh architecture firm rmjm which was led by design principal tony kettle . 
the scottish parliament building was designed by spanish architect enric miralles in partnership with local edinburgh architecture firm rmjm which was led by design principal tony kettle . 
some of the principal features of the complex include leaf-shaped buildings , a grass-roofed branch merging into adjacent parkland and gabion walls formed from the stones of previous buildings . 
queen elizabeth ii opened the new building on 9 october 2004 . 
this building was vacated twice to allow for the meeting of the church 's general assembly . 
whilst the permanent building at holyrood was being constructed , the parliament 's temporary home was the general assembly hall of the church of scotland on the royal mile in edinburgh . 
official photographs and television interviews were held in the courtyard adjoining the assembly hall , which is part of the school of divinity of the university of edinburgh . 
in may 2000 , the parliament was temporarily relocated to the former strathclyde regional council debating chamber in glasgow , and to the university of aberdeen in may 2002 . 
in may 2000 , the parliament was temporarily relocated to the former strathclyde regional council debating chamber in glasgow , and to the university of aberdeen in may 2002 . 
in addition to the general assembly hall , the parliament also used buildings rented from the city of edinburgh council . 
the former administrative building of lothian regional council on george iv bridge was used for the msp 's offices . 
following the move to holyrood in 2004 this building was demolished . 
the former midlothian county buildings facing parliament square , high street and george iv bridge in edinburgh -lrb- originally built as the headquarters of the pre-1975 midlothian county council -rrb- housed the parliament 's visitors ' centre and shop , whilst the main hall was used as the parliament 's principal committee room . 
the former midlothian county buildings facing parliament square , high street and george iv bridge in edinburgh -lrb- originally built as the headquarters of the pre-1975 midlothian county council -rrb- housed the parliament 's visitors ' centre and shop , whilst the main hall was used as the parliament 's principal committee room . 
after each election to the scottish parliament , at the beginning of each parliamentary session , parliament elects one msp to serve as presiding officer , the equivalent of the speaker -lrb- currently tricia marwick -rrb- , and two msps to serve as deputies -lrb- currently elaine smith and john scott -rrb- . 
after each election to the scottish parliament , at the beginning of each parliamentary session , parliament elects one msp to serve as presiding officer , the equivalent of the speaker -lrb- currently tricia marwick -rrb- , and two msps to serve as deputies -lrb- currently elaine smith and john scott -rrb- . 
the presiding officer and deputies are elected by a secret ballot of the 129 msps , which is the only secret ballot conducted in the scottish parliament . 
the presiding officer and deputies are elected by a secret ballot of the 129 msps , which is the only secret ballot conducted in the scottish parliament . 
a vote clerk sits in front of the presiding officer and operates the electronic voting equipment and chamber clocks . 
as a member of the scottish parliamentary corporate body , the presiding officer is responsible for ensuring that the parliament functions effectively and has the staff , property and resources it requires to operate . 
convening the parliamentary bureau , which allocates time and sets the work agenda in the chamber , is another of the roles of the presiding officer . 
under the standing orders of the parliament the bureau consists of the presiding officer and one representative from each political parties with five or more seats in the parliament . 
the presiding officer also represents the scottish parliament at home and abroad in an official capacity . 
the debating chamber of the scottish parliament has seating arranged in a hemicycle , which reflects the desire to encourage consensus amongst elected members . 
the debating chamber of the scottish parliament has seating arranged in a hemicycle , which reflects the desire to encourage consensus amongst elected members . 
there are 131 seats in the debating chamber . 
of the total 131 seats , 129 are occupied by the parliament 's elected msps and 2 are seats for the scottish law officers -- the lord advocate and the solicitor general for scotland , who are not elected members of the parliament but are members of the scottish government . 
as such the law officers may attend and speak in the plenary meetings of the parliament but , as they are not elected msps , can not vote . 
in front of the presiding officers ' desk is the parliamentary mace , which is made from silver and inlaid with gold panned from scottish rivers and inscribed with the words : wisdom , compassion , justice and integrity . 
in front of the presiding officers ' desk is the parliamentary mace , which is made from silver and inlaid with gold panned from scottish rivers and inscribed with the words : wisdom , compassion , justice and integrity . 
presented to the scottish parliament by the queen upon its official opening in july 1999 , the mace is displayed in a glass case suspended from the lid . 
in front of the presiding officers ' desk is the parliamentary mace , which is made from silver and inlaid with gold panned from scottish rivers and inscribed with the words : wisdom , compassion , justice and integrity . 
presented to the scottish parliament by the queen upon its official opening in july 1999 , the mace is displayed in a glass case suspended from the lid . 
parliament typically sits tuesdays , wednesdays and thursdays from early january to late june and from early september to mid december , with two-week recesses in april and october . 
plenary meetings in the debating chamber usually take place on wednesday afternoons from 2 pm to 6 pm and on thursdays from 9:15 am to 6 pm . 
chamber debates and committee meetings are open to the public . 
entry is free , but booking in advance is recommended due to limited space . 
proceedings are also recorded in text form , in print and online , in the official report , which is the substantially verbatim transcript of parliamentary debates . 
the first item of business on wednesdays is usually time for reflection , at which a speaker addresses members for up to four minutes , sharing a perspective on issues of faith . 
the first item of business on wednesdays is usually time for reflection , at which a speaker addresses members for up to four minutes , sharing a perspective on issues of faith . 
invitations to address parliament in this manner are determined by the presiding officer on the advice of the parliamentary bureau . 
speakers are drawn from across scotland and are chosen to represent the balance of religious beliefs according to the scottish census . 
faith groups can make direct representations to the presiding officer to nominate speakers . 
the presiding officer -lrb- or deputy presiding officer -rrb- decides who speaks in chamber debates and the amount of time for which they are allowed to speak . 
the presiding officer -lrb- or deputy presiding officer -rrb- decides who speaks in chamber debates and the amount of time for which they are allowed to speak . 
normally , the presiding officer tries to achieve a balance between different viewpoints and political parties when selecting members to speak . 
typically , ministers or party leaders open debates , with opening speakers given between 5 and 20 minutes , and succeeding speakers allocated less time . 
the scottish parliament has conducted debates in the gaelic language . 
each sitting day , normally at 5 pm , msps decide on all the motions and amendments that have been moved that day . 
this `` decision time '' is heralded by the sounding of the division bell , which is heard throughout the parliamentary campus and alerts msps who are not in the chamber to return and vote . 
this `` decision time '' is heralded by the sounding of the division bell , which is heard throughout the parliamentary campus and alerts msps who are not in the chamber to return and vote . 
if there is audible dissent , the presiding officer announces `` there will be a division '' and members vote by means of electronic consoles on their desks . 
as a result , the outcome of each division is known in seconds . 
the outcome of most votes can be predicted beforehand since political parties normally instruct members which way to vote . 
the outcome of most votes can be predicted beforehand since political parties normally instruct members which way to vote . 
parties entrust some msps , known as whips , with the task of ensuring that party members vote according to the party line . 
this is typically done on moral issues . 
errant members can be deselected as official party candidates during future elections , and , in serious cases , may be expelled from their parties outright . 
immediately after decision time a `` members debate '' is held , which lasts for 45 minutes . 
members business is a debate on a motion proposed by an msp who is not a scottish minister . 
immediately after decision time a `` members debate '' is held , which lasts for 45 minutes . 
as well as the proposer , other members normally contribute to the debate . 
the relevant minister , whose department the debate and motion relate to `` winds up '' the debate by speaking after all other participants . 
much of the work of the scottish parliament is done in committee . 
the role of committees is stronger in the scottish parliament than in other parliamentary systems , partly as a means of strengthening the role of backbenchers in their scrutiny of the government and partly to compensate for the fact that there is no revising chamber . 
the role of committees is stronger in the scottish parliament than in other parliamentary systems , partly as a means of strengthening the role of backbenchers in their scrutiny of the government and partly to compensate for the fact that there is no revising chamber . 
the principal role of committees in the scottish parliament is to take evidence from witnesses , conduct inquiries and scrutinise legislation . 
committees can also meet at other locations throughout scotland . 
committees comprise a small number of msps , with membership reflecting the balance of parties across parliament . 
committees comprise a small number of msps , with membership reflecting the balance of parties across parliament . 
there are different committees with their functions set out in different ways . 
mandatory committees are committees which are set down under the scottish parliament 's standing orders , which govern their remits and proceedings . 
the current mandatory committees in the fourth session of the scottish parliament are : public audit ; equal opportunities ; european and external relations ; finance ; public petitions ; standards , procedures and public appointments ; and delegated powers and law reform . 
subject committees are established at the beginning of each parliamentary session , and again the members on each committee reflect the balance of parties across parliament . 
typically each committee corresponds with one -lrb- or more -rrb- of the departments -lrb- or ministries -rrb- of the scottish government . 
the current subject committees in the fourth session are : economy , energy and tourism ; education and culture ; health and sport ; justice ; local government and regeneration ; rural affairs , climate change and environment ; welfare reform ; and infrastructure and capital investment . 
the current subject committees in the fourth session are : economy , energy and tourism ; education and culture ; health and sport ; justice ; local government and regeneration ; rural affairs , climate change and environment ; welfare reform ; and infrastructure and capital investment . 
a further type of committee is normally set up to scrutinise private bills submitted to the scottish parliament by an outside party or promoter who is not a member of the scottish parliament or scottish government . 
private bills normally relate to large-scale development projects such as infrastructure projects that require the use of land or property . 
a further type of committee is normally set up to scrutinise private bills submitted to the scottish parliament by an outside party or promoter who is not a member of the scottish parliament or scottish government . 
private bill committees have been set up to consider legislation on issues such as the development of the edinburgh tram network , the glasgow airport rail link , the airdrie-bathgate rail link and extensions to the national gallery of scotland . 
the scotland act 1998 , which was passed by the parliament of the united kingdom and given royal assent by queen elizabeth ii on 19 november 1998 , governs the functions and role of the scottish parliament and delimits its legislative competence . 
the scotland act 1998 , which was passed by the parliament of the united kingdom and given royal assent by queen elizabeth ii on 19 november 1998 , governs the functions and role of the scottish parliament and delimits its legislative competence . 
the scotland act 2012 extends the devolved competencies . 
for the purposes of parliamentary sovereignty , the parliament of the united kingdom at westminster continues to constitute the supreme legislature of scotland . 
the scottish parliament has the power to pass laws and has limited tax-varying capability . 
the specific devolved matters are all subjects which are not explicitly stated in schedule 5 to the scotland act as reserved matters . 
all matters that are not specifically reserved are automatically devolved to the scottish parliament . 
all matters that are not specifically reserved are automatically devolved to the scottish parliament . 
the scottish parliament has the ability to alter income tax in scotland by up to 3 pence in the pound . 
the 2012 act conferred further fiscal devolution including borrowing powers and some other unconnected matters such as setting speed limits and control of air guns . 
reserved matters are subjects that are outside the legislative competence of the scotland parliament . 
the scottish parliament is unable to legislate on such issues that are reserved to , and dealt with at , westminster -lrb- and where ministerial functions usually lie with uk government ministers -rrb- . 
the scottish parliament is unable to legislate on such issues that are reserved to , and dealt with at , westminster -lrb- and where ministerial functions usually lie with uk government ministers -rrb- . 
the scottish parliament is unable to legislate on such issues that are reserved to , and dealt with at , westminster -lrb- and where ministerial functions usually lie with uk government ministers -rrb- . 
bills can be introduced to parliament in a number of ways ; the scottish government can introduce new laws or amendments to existing laws as a bill ; a committee of the parliament can present a bill in one of the areas under its remit ; a member of the scottish parliament can introduce a bill as a private member ; or a private bill can be submitted to parliament by an outside proposer . 
bills can be introduced to parliament in a number of ways ; the scottish government can introduce new laws or amendments to existing laws as a bill ; a committee of the parliament can present a bill in one of the areas under its remit ; a member of the scottish parliament can introduce a bill as a private member ; or a private bill can be submitted to parliament by an outside proposer . 
bills can be introduced to parliament in a number of ways ; the scottish government can introduce new laws or amendments to existing laws as a bill ; a committee of the parliament can present a bill in one of the areas under its remit ; a member of the scottish parliament can introduce a bill as a private member ; or a private bill can be submitted to parliament by an outside proposer . 
bills can be introduced to parliament in a number of ways ; the scottish government can introduce new laws or amendments to existing laws as a bill ; a committee of the parliament can present a bill in one of the areas under its remit ; a member of the scottish parliament can introduce a bill as a private member ; or a private bill can be submitted to parliament by an outside proposer . 
bills pass through parliament in a number of stages : 
stage 1 is the first , or introductory stage of the bill , where the minister or member in charge of the bill will formally introduce it to parliament together with its accompanying documents -- explanatory notes , a policy memorandum setting out the policy underlying the bill , and a financial memorandum setting out the costs and savings associated with it . 
stage 1 is the first , or introductory stage of the bill , where the minister or member in charge of the bill will formally introduce it to parliament together with its accompanying documents -- explanatory notes , a policy memorandum setting out the policy underlying the bill , and a financial memorandum setting out the costs and savings associated with it . 
statements from the presiding officer and the member in charge of the bill are also lodged indicating whether the bill is within the legislative competence of the parliament . 
stage 1 usually takes place , initially , in the relevant committee or committees and is then submitted to the whole parliament for a full debate in the chamber on the general principles of the bill . 
if the whole parliament agrees in a vote to the general principles of the bill , it then proceeds to stage 2 . 
stage 3 is the final stage of the bill and is considered at a meeting of the whole parliament . 
this stage comprises two parts : consideration of amendments to the bill as a general debate , and a final vote on the bill . 
this stage comprises two parts : consideration of amendments to the bill as a general debate , and a final vote on the bill . 
opposition members can table `` wrecking amendments '' to the bill , designed to thwart further progress and take up parliamentary time , to cause the bill to fall without a final vote being taken . 
after a general debate on the final form of the bill , members proceed to vote at decision time on whether they agree to the general principles of the final bill . 
royal assent : after the bill has been passed , the presiding officer submits it to the monarch for royal assent and it becomes an act of the scottish parliament . 
royal assent : after the bill has been passed , the presiding officer submits it to the monarch for royal assent and it becomes an act of the scottish parliament . 
however he can not do so until a 4-week period has elapsed , during which the law officers of the scottish government or uk government can refer the bill to the supreme court of the united kingdom for a ruling on whether it is within the powers of the parliament . 
however he can not do so until a 4-week period has elapsed , during which the law officers of the scottish government or uk government can refer the bill to the supreme court of the united kingdom for a ruling on whether it is within the powers of the parliament . 
instead they begin with a phrase that reads : `` the bill for this act of the scottish parliament was passed by the parliament on -lsb- date -rsb- and received royal assent on -lsb- date -rsb- '' . 
the party , or parties , that hold the majority of seats in the parliament forms the scottish government . 
any member can put their name forward to be first minister , and a vote is taken by all members of parliament . 
in contrast to many other parliamentary systems , parliament elects a first minister from a number of candidates at the beginning of each parliamentary term -lrb- after a general election -rrb- . 
most ministers and their juniors are drawn from amongst the elected msps , with the exception of scotland 's chief law officers : the lord advocate and the solicitor general . 
whilst the first minister chooses the ministers -- and may decide to remove them at any time -- the formal appointment or dismissal is made by the sovereign . 
under the scotland act 1998 , ordinary general elections for the scottish parliament are held on the first thursday in may every four years -lrb- 1999 , 2003 , 2007 and so on -rrb- . 
under the scotland act 1998 , ordinary general elections for the scottish parliament are held on the first thursday in may every four years -lrb- 1999 , 2003 , 2007 and so on -rrb- . 
the date of the poll may be varied by up to one month either way by the monarch on the proposal of the presiding officer . 
extraordinary general elections are in addition to ordinary general elections , unless held less than six months before the due date of an ordinary general election , in which case they supplant it . 
if the parliament itself resolves that it should be dissolved -lrb- with at least two-thirds of the members voting in favour -rrb- , or if the parliament fails to nominate one of its members to be first minister within 28 days of a general election or of the position becoming vacant , the presiding officer proposes a date for an extraordinary general election and the parliament is dissolved by the queen by royal proclamation . 
several procedures enable the scottish parliament to scrutinise the government . 
the first minister or members of the cabinet can deliver statements to parliament upon which msps are invited to question . 
for example , at the beginning of each parliamentary year , the first minister delivers a statement to the chamber setting out the government 's legislative programme for the forthcoming year . 
after the statement has been delivered , the leaders of the opposition parties and other msps question the first minister on issues related to the substance of the statement . 
parliamentary time is also set aside for question periods in the debating chamber . 
a `` general question time '' takes place on a thursday between 11:40 a.m. and 12 p.m. where members can direct questions to any member of the scottish government . 
a `` general question time '' takes place on a thursday between 11:40 a.m. and 12 p.m. where members can direct questions to any member of the scottish government . 
this gives members an opportunity to question the first minister directly on issues under their jurisdiction . 
the four general questions available to opposition leaders are : 
of the 129 msps , 73 are elected to represent first past the post constituencies and are known as `` constituency msps '' . 
the 73 scottish parliament constituencies shared the same boundaries as the uk parliament constituencies in scotland , prior to the 2005 reduction in the number of scottish mps , with the exception of orkney and shetland which each return their own constituency msp . 
voters choose one member to represent the constituency , and the member with most votes is returned as a constituency msp . 
the island archipelagos of orkney , shetland and the western isles comprise a much smaller number of electors , due to their dispersed population and distance from the scottish parliament in edinburgh . 
currently , the average scottish parliament constituency comprises 55,000 electors . 
the total number of seats in the parliament are allocated to parties proportionally to the number of votes received in the second vote of the ballot using the d'hondt method . 
the total number of seats in the parliament are allocated to parties proportionally to the number of votes received in the second vote of the ballot using the d'hondt method . 
the party with the highest quotient is awarded the seat , which is then added to its constituency seats in allocating the second seat . 
the party with the highest quotient is awarded the seat , which is then added to its constituency seats in allocating the second seat . 
this is repeated iteratively until all available list seats are allocated . 
as in the house of commons , a number of qualifications apply to being an msp . 
such qualifications were introduced under the house of commons disqualification act 1975 and the british nationality act 1981 . 
specifically , members must be over the age of 18 and must be a citizen of the united kingdom , the republic of ireland , one of the countries in the commonwealth of nations , a citizen of a british overseas territory , or a european union citizen resident in the uk . 
members of the police and the armed forces are disqualified from sitting in the scottish parliament as elected msps , and similarly , civil servants and members of foreign legislatures are disqualified . 
an individual may not sit in the scottish parliament if he or she is judged to be insane under the terms of the mental health -lrb- care and treatment -rrb- -lrb- scotland -rrb- act 2003 . 
the election produced a majority snp government , making this the first time in the scottish parliament where a party has commanded a parliamentary majority . 
the snp took 16 seats from labour , with many of their key figures not returned to parliament , although labour leader iain gray retained east lothian by 151 votes . 
the snp took 16 seats from labour , with many of their key figures not returned to parliament , although labour leader iain gray retained east lothian by 151 votes . 
the snp took a further eight seats from the liberal democrats and one seat from the conservatives . 
the snp overall majority meant that there was sufficient support in the scottish parliament to hold a referendum on scottish independence . 
for the conservatives , the main disappointment was the loss of edinburgh pentlands , the seat of former party leader david mcletchie , to the snp . 
for the conservatives , the main disappointment was the loss of edinburgh pentlands , the seat of former party leader david mcletchie , to the snp . 
mcletchie was elected on the lothian regional list and the conservatives suffered a net loss of five seats , with leader annabel goldie claiming that their support had held firm . 
mcletchie was elected on the lothian regional list and the conservatives suffered a net loss of five seats , with leader annabel goldie claiming that their support had held firm . 
cameron congratulated the snp on their victory but vowed to campaign for the union in the independence referendum . 
a procedural consequence of the establishment of the scottish parliament is that scottish mps sitting in the uk house of commons are able to vote on domestic legislation that applies only to england , wales and northern ireland -- whilst english , scottish , welsh and northern irish westminster mps are unable to vote on the domestic legislation of the scottish parliament . 
a procedural consequence of the establishment of the scottish parliament is that scottish mps sitting in the uk house of commons are able to vote on domestic legislation that applies only to england , wales and northern ireland -- whilst english , scottish , welsh and northern irish westminster mps are unable to vote on the domestic legislation of the scottish parliament . 
this phenomenon is known as the west lothian question and has led to criticism . 
following the conservative victory in the 2015 uk election , standing orders of the house of commons were changed to give mps representing english constituencies a new `` veto '' over laws only affecting england . 
following the conservative victory in the 2015 uk election , standing orders of the house of commons were changed to give mps representing english constituencies a new `` veto '' over laws only affecting england . 
islamism , also known as political islam -lrb- arabic : إسلام سياسي islām siyāsī -rrb- , is an islamic revival movement often characterized by moral conservatism , literalism , and the attempt `` to implement islamic values in all spheres of life . '' 
islamism , also known as political islam -lrb- arabic : إسلام سياسي islām siyāsī -rrb- , is an islamic revival movement often characterized by moral conservatism , literalism , and the attempt `` to implement islamic values in all spheres of life . '' 
islamism favors the reordering of government and society in accordance with the shari'a . 
the different islamist movements have been described as `` oscillating between two poles '' : at one end is a strategy of islamization of society through state power seized by revolution or invasion ; at the other `` reformist '' pole islamists work to islamize society gradually `` from the bottom up '' . 
the different islamist movements have been described as `` oscillating between two poles '' : at one end is a strategy of islamization of society through state power seized by revolution or invasion ; at the other `` reformist '' pole islamists work to islamize society gradually `` from the bottom up '' . 
moderate and reformist islamists who accept and work within the democratic process include parties like the tunisian ennahda movement . 
the islamist groups like hezbollah in lebanon and hamas in palestine participate in democratic and political process as well as armed attacks , seeking to abolish the state of israel . 
the islamist groups like hezbollah in lebanon and hamas in palestine participate in democratic and political process as well as armed attacks , seeking to abolish the state of israel . 
radical islamist organizations like al-qaeda and the egyptian islamic jihad , and groups such as the taliban , entirely reject democracy , often declaring as kuffar those muslims who support it -lrb- see takfirism -rrb- , as well as calling for violent/offensive jihad or urging and conducting attacks on a religious basis . 
radical islamist organizations like al-qaeda and the egyptian islamic jihad , and groups such as the taliban , entirely reject democracy , often declaring as kuffar those muslims who support it -lrb- see takfirism -rrb- , as well as calling for violent/offensive jihad or urging and conducting attacks on a religious basis . 
another major division within islamism is between what graham e. fuller has described as the fundamentalist `` guardians of the tradition '' -lrb- salafis , such as those in the wahhabi movement -rrb- and the `` vanguard of change and islamic reform '' centered around the muslim brotherhood . 
olivier roy argues that `` sunni pan-islamism underwent a remarkable shift in the second half of the 20th century '' when the muslim brotherhood movement and its focus on islamisation of pan-arabism was eclipsed by the salafi movement with its emphasis on `` sharia rather than the building of islamic institutions , '' and rejection of shia islam . 
olivier roy argues that `` sunni pan-islamism underwent a remarkable shift in the second half of the 20th century '' when the muslim brotherhood movement and its focus on islamisation of pan-arabism was eclipsed by the salafi movement with its emphasis on `` sharia rather than the building of islamic institutions , '' and rejection of shia islam . 
following the arab spring , roy has described islamism as `` increasingly interdependent '' with democracy in much of the arab muslim world , such that `` neither can now survive without the other . '' 
while islamist political culture itself may not be democratic , islamists need democratic elections to maintain their legitimacy . 
islamism is a controversial concept not just because it posits a political role for islam but also because its supporters believe their views merely reflect islam , while the contrary idea that islam is , or can be , apolitical is an error . 
islamism is a controversial concept not just because it posits a political role for islam but also because its supporters believe their views merely reflect islam , while the contrary idea that islam is , or can be , apolitical is an error . 
islamism is a controversial concept not just because it posits a political role for islam but also because its supporters believe their views merely reflect islam , while the contrary idea that islam is , or can be , apolitical is an error . 
hayri abaza argues the failure to distinguish between islam and islamism leads many in the west to support illiberal islamic regimes , to the detriment of progressive moderates who seek to separate religion from politics . 
hayri abaza argues the failure to distinguish between islam and islamism leads many in the west to support illiberal islamic regimes , to the detriment of progressive moderates who seek to separate religion from politics . 
islamists have asked the question , `` if islam is a way of life , how can we say that those who want to live by its principles in legal , social , political , economic , and political spheres of life are not muslims , but islamists and believe in islamism , not -lsb- just -rsb- islam ? '' 
similarly , a writer for the international crisis group maintains that `` the conception of ` political islam ' '' is a creation of americans to explain the iranian islamic revolution and apolitical islam was a historical fluke of the `` short-lived era of the heyday of secular arab nationalism between 1945 and 1970 '' , and it is quietist/non-political islam , not islamism , that requires explanation . 
similarly , a writer for the international crisis group maintains that `` the conception of ` political islam ' '' is a creation of americans to explain the iranian islamic revolution and apolitical islam was a historical fluke of the `` short-lived era of the heyday of secular arab nationalism between 1945 and 1970 '' , and it is quietist/non-political islam , not islamism , that requires explanation . 
similarly , a writer for the international crisis group maintains that `` the conception of ` political islam ' '' is a creation of americans to explain the iranian islamic revolution and apolitical islam was a historical fluke of the `` short-lived era of the heyday of secular arab nationalism between 1945 and 1970 '' , and it is quietist/non-political islam , not islamism , that requires explanation . 
similarly , a writer for the international crisis group maintains that `` the conception of ` political islam ' '' is a creation of americans to explain the iranian islamic revolution and apolitical islam was a historical fluke of the `` short-lived era of the heyday of secular arab nationalism between 1945 and 1970 '' , and it is quietist/non-political islam , not islamism , that requires explanation . 
during the 1970s and sometimes later , western and pro-western governments often supported sometimes fledgling islamists and islamist groups that later came to be seen as dangerous enemies . 
during the 1970s and sometimes later , western and pro-western governments often supported sometimes fledgling islamists and islamist groups that later came to be seen as dangerous enemies . 
the us spent billions of dollars to aid the mujahideen muslim afghanistan enemies of the soviet union , and non-afghan veterans of the war returned home with their prestige , `` experience , ideology , and weapons '' , and had considerable impact . 
the us spent billions of dollars to aid the mujahideen muslim afghanistan enemies of the soviet union , and non-afghan veterans of the war returned home with their prestige , `` experience , ideology , and weapons '' , and had considerable impact . 
islamists were considered by western governments bulwarks against -- what were thought to be at the time -- more dangerous leftist/communist/nationalist insurgents/opposition , which islamists were correctly seen as opposing . 
the us spent billions of dollars to aid the mujahideen muslim afghanistan enemies of the soviet union , and non-afghan veterans of the war returned home with their prestige , `` experience , ideology , and weapons '' , and had considerable impact . 
egyptian president anwar sadat -- whose policies included opening egypt to western investment -lrb- infitah -rrb- ; transferring egypt 's allegiance from the soviet union to the united states ; and making peace with israel -- released islamists from prison and welcomed home exiles in tacit exchange for political support in his struggle against leftists . 
egyptian president anwar sadat -- whose policies included opening egypt to western investment -lrb- infitah -rrb- ; transferring egypt 's allegiance from the soviet union to the united states ; and making peace with israel -- released islamists from prison and welcomed home exiles in tacit exchange for political support in his struggle against leftists . 
egyptian president anwar sadat -- whose policies included opening egypt to western investment -lrb- infitah -rrb- ; transferring egypt 's allegiance from the soviet union to the united states ; and making peace with israel -- released islamists from prison and welcomed home exiles in tacit exchange for political support in his struggle against leftists . 
this `` gentlemen 's agreement '' between sadat and islamists broke down in 1975 but not before islamists came to completely dominate university student unions . 
sadat was later assassinated and a formidable insurgency was formed in egypt in the 1990s . 
the interpretation of islam promoted by this funding was the strict , conservative saudi-based wahhabism or salafism . 
in its harshest form it preached that muslims should not only `` always oppose '' infidels `` in every way , '' but `` hate them for their religion ... for allah 's sake , '' that democracy `` is responsible for all the horrible wars of the 20th century , '' that shia and other non-wahhabi muslims were infidels , etc. . 
in its harshest form it preached that muslims should not only `` always oppose '' infidels `` in every way , '' but `` hate them for their religion ... for allah 's sake , '' that democracy `` is responsible for all the horrible wars of the 20th century , '' that shia and other non-wahhabi muslims were infidels , etc. . 
in its harshest form it preached that muslims should not only `` always oppose '' infidels `` in every way , '' but `` hate them for their religion ... for allah 's sake , '' that democracy `` is responsible for all the horrible wars of the 20th century , '' that shia and other non-wahhabi muslims were infidels , etc. . 
while this effort has by no means converted all , or even most muslims to the wahhabist interpretation of islam , it has done much to overwhelm more moderate local interpretations , and has set the saudi-interpretation of islam as the `` gold standard '' of religion in minds of some or many muslims . 
islamist movements such as the muslim brotherhood , `` are well known for providing shelters , educational assistance , free or low cost medical clinics , housing assistance to students from out of town , student advisory groups , facilitation of inexpensive mass marriage ceremonies to avoid prohibitively costly dowry demands , legal assistance , sports facilities , and women 's groups . '' 
all this compares very favourably against incompetent , inefficient , or neglectful governments whose commitment to social justice is limited to rhetoric . 
islamist movements such as the muslim brotherhood , `` are well known for providing shelters , educational assistance , free or low cost medical clinics , housing assistance to students from out of town , student advisory groups , facilitation of inexpensive mass marriage ceremonies to avoid prohibitively costly dowry demands , legal assistance , sports facilities , and women 's groups . '' 
all this compares very favourably against incompetent , inefficient , or neglectful governments whose commitment to social justice is limited to rhetoric . 
islamist movements such as the muslim brotherhood , `` are well known for providing shelters , educational assistance , free or low cost medical clinics , housing assistance to students from out of town , student advisory groups , facilitation of inexpensive mass marriage ceremonies to avoid prohibitively costly dowry demands , legal assistance , sports facilities , and women 's groups . '' 
while studying law and philosophy in england and germany , iqbal became a member of the london branch of the all india muslim league . 
while studying law and philosophy in england and germany , iqbal became a member of the london branch of the all india muslim league . 
he was a critic of the mainstream indian nationalist and secularist indian national congress . 
he came back to lahore in 1908 . 
iqbal 's seven english lectures were published by oxford university press in 1934 in a book titled the reconstruction of religious thought in islam . 
iqbal expressed fears that not only would secularism and secular nationalism weaken the spiritual foundations of islam and muslim society , but that india 's hindu-majority population would crowd out muslim heritage , culture and political influence . 
iqbal expressed fears that not only would secularism and secular nationalism weaken the spiritual foundations of islam and muslim society , but that india 's hindu-majority population would crowd out muslim heritage , culture and political influence . 
in his travels to egypt , afghanistan , palestine and syria , he promoted ideas of greater islamic political co-operation and unity , calling for the shedding of nationalist differences . 
sir muhammad iqbal was elected president of the muslim league in 1930 at its session in allahabad as well as for the session in lahore in 1932 . 
this address later inspired the pakistan movement . 
sayyid abul ala maududi was an important early twentieth-century figure in the islamic revival in india , and then after independence from britain , in pakistan . 
trained as a lawyer he chose the profession of journalism , and wrote about contemporary issues and most importantly about islam and islamic law . 
maududi founded the jamaat-e-islami party in 1941 and remained its leader until 1972 . 
however , maududi had much more impact through his writing than through his political organising . 
his extremely influential books -lrb- translated into many languages -rrb- placed islam in a modern context , and influenced not only conservative ulema but liberal modernizer islamists such as al-faruqi , whose `` islamization of knowledge '' carried forward some of maududi 's key principles . 
sayyid abul ala maududi was an important early twentieth-century figure in the islamic revival in india , and then after independence from britain , in pakistan . 
trained as a lawyer he chose the profession of journalism , and wrote about contemporary issues and most importantly about islam and islamic law . 
however , maududi had much more impact through his writing than through his political organising . 
his extremely influential books -lrb- translated into many languages -rrb- placed islam in a modern context , and influenced not only conservative ulema but liberal modernizer islamists such as al-faruqi , whose `` islamization of knowledge '' carried forward some of maududi 's key principles . 
maududi also believed that muslim society could not be islamic without sharia , and islam required the establishment of an islamic state . 
maududi also believed that muslim society could not be islamic without sharia , and islam required the establishment of an islamic state . 
this state should be a `` theo-democracy , '' based on the principles of : tawhid -lrb- unity of god -rrb- , risala -lrb- prophethood -rrb- and khilafa -lrb- caliphate -rrb- . 
although maududi talked about islamic revolution , by `` revolution '' he meant not the violence or populist policies of the iranian revolution , but the gradual changing the hearts and minds of individuals from the top of society downward through an educational process or da ` wah . 
although maududi talked about islamic revolution , by `` revolution '' he meant not the violence or populist policies of the iranian revolution , but the gradual changing the hearts and minds of individuals from the top of society downward through an educational process or da ` wah . 
roughly contemporaneous with maududi was the founding of the muslim brotherhood in ismailiyah , egypt in 1928 by hassan al banna . 
roughly contemporaneous with maududi was the founding of the muslim brotherhood in ismailiyah , egypt in 1928 by hassan al banna . 
roughly contemporaneous with maududi was the founding of the muslim brotherhood in ismailiyah , egypt in 1928 by hassan al banna . 
under the motto `` the qur ` an is our constitution , '' it sought islamic revival through preaching and also by providing basic community services including schools , mosques , and workshops . 
like maududi , al banna believed in the necessity of government rule based on shariah law implemented gradually and by persuasion , and of eliminating all imperialist influence in the muslim world . 
some elements of the brotherhood , though perhaps against orders , did engage in violence against the government , and its founder al-banna was assassinated in 1949 in retaliation for the assassination of egypt 's premier mahmud fami naqrashi three months earlier . 
some elements of the brotherhood , though perhaps against orders , did engage in violence against the government , and its founder al-banna was assassinated in 1949 in retaliation for the assassination of egypt 's premier mahmud fami naqrashi three months earlier . 
some elements of the brotherhood , though perhaps against orders , did engage in violence against the government , and its founder al-banna was assassinated in 1949 in retaliation for the assassination of egypt 's premier mahmud fami naqrashi three months earlier . 
the brotherhood has suffered periodic repression in egypt and has been banned several times , in 1948 and several years later following confrontations with egyptian president gamal abdul nasser , who jailed thousands of members for several years . 
the brotherhood has suffered periodic repression in egypt and has been banned several times , in 1948 and several years later following confrontations with egyptian president gamal abdul nasser , who jailed thousands of members for several years . 
despite periodic repression , the brotherhood has become one of the most influential movements in the islamic world , particularly in the arab world . 
in the egyptian parliamentary election , 2011 -- 2012 , the political parties identified as `` islamist '' -lrb- the brotherhood 's freedom and justice party , salafi al-nour party and liberal islamist al-wasat party -rrb- won 75 % of the total seats . 
for many years it was described as `` semi-legal '' and was the only opposition group in egypt able to field candidates during elections . 
for many years it was described as `` semi-legal '' and was the only opposition group in egypt able to field candidates during elections . 
mohamed morsi , an islamist democrat of muslim brotherhood , was the first democratically elected president of egypt . 
the quick and decisive defeat of the arab troops during the six-day war by israeli troops constituted a pivotal event in the arab muslim world . 
the quick and decisive defeat of the arab troops during the six-day war by israeli troops constituted a pivotal event in the arab muslim world . 
the defeat along with economic stagnation in the defeated countries , was blamed on the secular arab nationalism of the ruling regimes . 
a steep and steady decline in the popularity and credibility of secular , socialist and nationalist politics ensued . 
ba'athism , arab socialism , and arab nationalism suffered , and different democratic and anti-democratic islamist movements inspired by maududi and sayyid qutb gained ground . 
the views of ali shariati , ideologue of the iranian revolution , had resemblance with mohammad iqbal , ideological father of the state of pakistan , but khomeini 's beliefs is perceived to be placed somewhere between beliefs of sunni islamic thinkers like mawdudi and qutb . 
the views of ali shariati , ideologue of the iranian revolution , had resemblance with mohammad iqbal , ideological father of the state of pakistan , but khomeini 's beliefs is perceived to be placed somewhere between beliefs of sunni islamic thinkers like mawdudi and qutb . 
the views of ali shariati , ideologue of the iranian revolution , had resemblance with mohammad iqbal , ideological father of the state of pakistan , but khomeini 's beliefs is perceived to be placed somewhere between beliefs of sunni islamic thinkers like mawdudi and qutb . 
he believed that complete imitation of the prophet mohammad and his successors such as ali for restoration of sharia law was essential to islam , that many secular , westernizing muslims were actually agents of the west serving western interests , and that the acts such as `` plundering '' of muslim lands was part of a long-term conspiracy against islam by the western governments . 
he believed that complete imitation of the prophet mohammad and his successors such as ali for restoration of sharia law was essential to islam , that many secular , westernizing muslims were actually agents of the west serving western interests , and that the acts such as `` plundering '' of muslim lands was part of a long-term conspiracy against islam by the western governments . 
the islamic republic has also maintained its hold on power in iran in spite of us economic sanctions , and has created or assisted like-minded shia terrorist groups in iraq , egypt , syria , jordan -lrb- sciri -rrb- and lebanon -lrb- hezbollah -rrb- -lrb- two muslim countries that also have large shiite populations -rrb- . 
the islamic republic has also maintained its hold on power in iran in spite of us economic sanctions , and has created or assisted like-minded shia terrorist groups in iraq , egypt , syria , jordan -lrb- sciri -rrb- and lebanon -lrb- hezbollah -rrb- -lrb- two muslim countries that also have large shiite populations -rrb- . 
the islamic republic has also maintained its hold on power in iran in spite of us economic sanctions , and has created or assisted like-minded shia terrorist groups in iraq , egypt , syria , jordan -lrb- sciri -rrb- and lebanon -lrb- hezbollah -rrb- -lrb- two muslim countries that also have large shiite populations -rrb- . 
during the 2006 israel-lebanon conflict , the iranian government enjoyed something of a resurgence in popularity amongst the predominantly sunni `` arab street , '' due to its support for hezbollah and to president mahmoud ahmadinejad 's vehement opposition to the united states and his call that israel shall vanish . 
during the 2006 israel-lebanon conflict , the iranian government enjoyed something of a resurgence in popularity amongst the predominantly sunni `` arab street , '' due to its support for hezbollah and to president mahmoud ahmadinejad 's vehement opposition to the united states and his call that israel shall vanish . 
in 1979 , the soviet union deployed its 40th army into afghanistan , attempting to suppress an islamic rebellion against an allied marxist regime in the afghan civil war . 
in 1979 , the soviet union deployed its 40th army into afghanistan , attempting to suppress an islamic rebellion against an allied marxist regime in the afghan civil war . 
the conflict , pitting indigenous impoverished muslims -lrb- mujahideen -rrb- against an anti-religious superpower , galvanized thousands of muslims around the world to send aid and sometimes to go themselves to fight for their faith . 
while the military effectiveness of these `` afghan arabs '' was marginal , an estimated 16,000 to 35,000 muslim volunteers came from around the world came to fight in afghanistan . 
while the military effectiveness of these `` afghan arabs '' was marginal , an estimated 16,000 to 35,000 muslim volunteers came from around the world came to fight in afghanistan . 
another factor in the early 1990s that worked to radicalize the islamist movement was the gulf war , which brought several hundred thousand us and allied non-muslim military personnel to saudi arabian soil to put an end to saddam hussein 's occupation of kuwait . 
another factor in the early 1990s that worked to radicalize the islamist movement was the gulf war , which brought several hundred thousand us and allied non-muslim military personnel to saudi arabian soil to put an end to saddam hussein 's occupation of kuwait . 
prior to 1990 saudi arabia played an important role in restraining the many islamist groups that received its aid . 
but when saddam , secularist and ba'athist dictator of neighboring iraq , attacked saudi arabia -lrb- his enemy in the war -rrb- , western troops came to protect the saudi monarchy . 
islamists accused the saudi regime of being a puppet of the west . 
these attacks resonated with conservative muslims and the problem did not go away with saddam 's defeat either , since american troops remained stationed in the kingdom , and a de facto cooperation with the palestinian-israeli peace process developed . 
saudi arabia attempted to compensate for its loss of prestige among these groups by repressing those domestic islamists who attacked it -lrb- bin laden being a prime example -rrb- , and increasing aid to islamic groups -lrb- islamist madrassas around the world and even aiding some violent islamist groups -rrb- that did not , but its pre-war influence on behalf of moderation was greatly reduced . 
these attacks resonated with conservative muslims and the problem did not go away with saddam 's defeat either , since american troops remained stationed in the kingdom , and a de facto cooperation with the palestinian-israeli peace process developed . 
one result of this was a campaign of attacks on government officials and tourists in egypt , a bloody civil war in algeria and osama bin laden 's terror attacks climaxing in the 9/11 attack . 
one result of this was a campaign of attacks on government officials and tourists in egypt , a bloody civil war in algeria and osama bin laden 's terror attacks climaxing in the 9/11 attack . 
while qutb 's ideas became increasingly radical during his imprisonment prior to his execution in 1966 , the leadership of the brotherhood , led by hasan al-hudaybi , remained moderate and interested in political negotiation and activism . 
while qutb 's ideas became increasingly radical during his imprisonment prior to his execution in 1966 , the leadership of the brotherhood , led by hasan al-hudaybi , remained moderate and interested in political negotiation and activism . 
while qutb 's ideas became increasingly radical during his imprisonment prior to his execution in 1966 , the leadership of the brotherhood , led by hasan al-hudaybi , remained moderate and interested in political negotiation and activism . 
fringe or splinter movements inspired by the final writings of qutb in the mid-1960s -lrb- particularly the manifesto milestones , a.k.a. ma'alim fi-l-tariq -rrb- did , however , develop and they pursued a more radical direction . 
by the 1970s , the brotherhood had renounced violence as a means of achieving its goals . 
the path of violence and military struggle was then taken up by the egyptian islamic jihad organization responsible for the assassination of anwar sadat in 1981 . 
the path of violence and military struggle was then taken up by the egyptian islamic jihad organization responsible for the assassination of anwar sadat in 1981 . 
unlike earlier anti-colonial movements the extremist group directed its attacks against what it believed were `` apostate '' leaders of muslim states , leaders who held secular leanings or who had introduced or promoted western/foreign ideas and practices into islamic societies . 
unlike earlier anti-colonial movements the extremist group directed its attacks against what it believed were `` apostate '' leaders of muslim states , leaders who held secular leanings or who had introduced or promoted western/foreign ideas and practices into islamic societies . 
its views were outlined in a pamphlet written by muhammad abd al-salaam farag , in which he states : 
another of the egyptian groups which employed violence in their struggle for islamic order was al-gama ' a al-islamiyya -lrb- islamic group -rrb- . 
another of the egyptian groups which employed violence in their struggle for islamic order was al-gama ' a al-islamiyya -lrb- islamic group -rrb- . 
ultimately the campaign to overthrow the government was unsuccessful , and the major jihadi group , jamaa islamiya -lrb- or al-gama ' a al-islamiyya -rrb- , renounced violence in 2003 . 
ultimately the campaign to overthrow the government was unsuccessful , and the major jihadi group , jamaa islamiya -lrb- or al-gama ' a al-islamiyya -rrb- , renounced violence in 2003 . 
other lesser known groups include the islamic liberation party , salvation from hell and takfir wal-hijra , and these groups have variously been involved in activities such as attempted assassinations of political figures , arson of video shops and attempted takeovers of government buildings . 
for some decades prior to the first palestine intifada in 1987 , the muslim brotherhood in palestine took a `` quiescent '' stance towards israel , focusing on preaching , education and social services , and benefiting from israel 's `` indulgence '' to build up a network of mosques and charitable organizations . 
as the first intifada gathered momentum and palestinian shopkeepers closed their shops in support of the uprising , the brotherhood announced the formation of hamas -lrb- `` zeal '' -rrb- , devoted to jihad against israel . 
rather than being more moderate than the plo , the 1988 hamas charter took a more uncompromising stand , calling for the destruction of israel and the establishment of an islamic state in palestine . 
the brotherhood 's base of devout middle class found common cause with the impoverished youth of the intifada in their cultural conservatism and antipathy for activities of the secular middle class such as drinking alcohol and going about without hijab . 
rather than being more moderate than the plo , the 1988 hamas charter took a more uncompromising stand , calling for the destruction of israel and the establishment of an islamic state in palestine . 
hamas has continued to be a major player in palestine . 
from 2000 to 2007 it killed 542 people in 140 suicide bombing or `` martyrdom operations '' . 
in the january 2006 legislative election -- its first foray into the political process -- it won the majority of the seats , and in 2007 it drove the plo out of gaza . 
in the january 2006 legislative election -- its first foray into the political process -- it won the majority of the seats , and in 2007 it drove the plo out of gaza . 
hamas has been praised by muslims for driving israel out of the gaza strip , but criticized for failure to achieve its demands in the 2008-9 and 2014 gaza wars despite heavy destruction and significant loss of life . 
for many years , sudan had an islamist regime under the leadership of hassan al-turabi . 
for many years , sudan had an islamist regime under the leadership of hassan al-turabi . 
his national islamic front first gained influence when strongman general gaafar al-nimeiry invited members to serve in his government in 1979 . 
turabi built a powerful economic base with money from foreign islamist banking systems , especially those linked with saudi arabia . 
he also recruited and built a cadre of influential loyalists by placing sympathetic students in the university and military academy while serving as minister of education . 
after al-nimeiry was overthrown in 1985 the party did poorly in national elections , but in 1989 it was able to overthrow the elected post-al-nimeiry government with the help of the military . 
after al-nimeiry was overthrown in 1985 the party did poorly in national elections , but in 1989 it was able to overthrow the elected post-al-nimeiry government with the help of the military . 
turabi was noted for proclaiming his support for the democratic process and a liberal government before coming to power , but strict application of sharia law , torture and mass imprisonment of the opposition , and an intensification of the long-running war in southern sudan , once in power . 
the nif regime also harbored osama bin laden for a time -lrb- before 9/11 -rrb- , and worked to unify islamist opposition to the american attack on iraq in the 1991 gulf war . 
the nif regime also harbored osama bin laden for a time -lrb- before 9/11 -rrb- , and worked to unify islamist opposition to the american attack on iraq in the 1991 gulf war . 
taking advantage of economic failure and unpopular social liberalization and secularization by the ruling leftist-nationalist fln government , it used its preaching to advocate the establishment of a legal system following sharia law , economic liberalization and development program , education in arabic rather than french , and gender segregation , with women staying home to alleviate the high rate of unemployment among young algerian men . 
founded as a broad islamist coalition in 1989 it was led by abbassi madani , and a charismatic islamist young preacher , ali belhadj . 
an islamist movement influenced by salafism and the jihad in afghanistan , as well as the muslim brotherhood , was the fis or front islamique de salut -lrb- the islamic salvation front -rrb- in algeria . 
an islamist movement influenced by salafism and the jihad in afghanistan , as well as the muslim brotherhood , was the fis or front islamique de salut -lrb- the islamic salvation front -rrb- in algeria . 
the fis won sweeping victories in local elections and it was going to win national elections in 1991 when voting was canceled by a military coup d'état . 
in afghanistan , the mujahideen 's victory against the soviet union in the 1980s did not lead to justice and prosperity , due to a vicious and destructive civil war between political and tribal warlords , making afghanistan one of the poorest countries on earth . 
in afghanistan , the mujahideen 's victory against the soviet union in the 1980s did not lead to justice and prosperity , due to a vicious and destructive civil war between political and tribal warlords , making afghanistan one of the poorest countries on earth . 
in 1992 , the democratic republic of afghanistan ruled by communist forces collapsed , and democratic islamist elements of mujahdeen founded the islamic state of afghanistan . 
in afghanistan , the mujahideen 's victory against the soviet union in the 1980s did not lead to justice and prosperity , due to a vicious and destructive civil war between political and tribal warlords , making afghanistan one of the poorest countries on earth . 
in 1996 , a more conservative and anti-democratic islamist movement known as the taliban rose to power , defeated most of the warlords and took over roughly 80 % of afghanistan . 
the taliban were spawned by the thousands of madrasahs the deobandi movement established for impoverished afghan refugees and supported by governmental and religious groups in neighboring pakistan . 
the taliban were spawned by the thousands of madrasahs the deobandi movement established for impoverished afghan refugees and supported by governmental and religious groups in neighboring pakistan . 
the taliban differed from other islamist movements to the point where they might be more properly described as islamic fundamentalist or neofundamentalist , interested in spreading `` an idealized and systematized version of conservative tribal village customs '' under the label of sharia to an entire country . 
the taliban differed from other islamist movements to the point where they might be more properly described as islamic fundamentalist or neofundamentalist , interested in spreading `` an idealized and systematized version of conservative tribal village customs '' under the label of sharia to an entire country . 
their ideology was also described as being influenced by wahhabism , and the extremist jihadism of their guest osama bin laden . 
in july 1977 , general zia-ul-haq overthrew prime minister zulfiqar ali bhutto 's regime in pakistan . 
ali bhutto , a leftist in democratic competition with islamists , had announced banning alcohol and nightclubs within six months , shortly before he was overthrown . 
zia-ul-haq was much more committed to islamism , and `` islamization '' or implementation of islamic law , became a cornerstone of his eleven-year military dictatorship and islamism became his `` official state ideology '' . 
in pakistan this islamization from above was `` probably '' more complete `` than under any other regime except those in iran and sudan , '' but zia-ul-haq was also criticized by many islamists for imposing `` symbols '' rather than substance , and using islamization to legitimize his means of seizing power . 
zia-ul-haq was killed in 1988 but islamization remains an important element in pakistani society . 
`` the islamic state '' , formerly known as the `` islamic state of iraq and the levant '' and before that as the `` islamic state of iraq '' , -lrb- and called the acronym daesh by its many detractors -rrb- , is a wahhabi/salafi jihadist extremist militant group which is led by and mainly composed of sunni arabs from iraq and syria . 
`` the islamic state '' , formerly known as the `` islamic state of iraq and the levant '' and before that as the `` islamic state of iraq '' , -lrb- and called the acronym daesh by its many detractors -rrb- , is a wahhabi/salafi jihadist extremist militant group which is led by and mainly composed of sunni arabs from iraq and syria . 
as of march 2015 -lsb- update -rsb- , it had control over territory occupied by ten million people in iraq and syria , and has nominal control over small areas of libya , nigeria and afghanistan . 
-lrb- while a self-described state , it lacks international recognition . -rrb- 
in 2014 , the group proclaimed itself a caliphate , with religious , political and military authority over all muslims worldwide . 
originating as the jama'at al-tawhid wal-jihad in 1999 , it pledged allegiance to al-qaeda in 2004 , participated in the iraqi insurgency that followed the march 2003 invasion of iraq by western forces , joined the fight in the syrian civil war beginning in march 2011 , and was expelled from al-qaeda in early 2014 , -lrb- which complained of its failure to consult and `` notorious intransigence '' -rrb- . 
originating as the jama'at al-tawhid wal-jihad in 1999 , it pledged allegiance to al-qaeda in 2004 , participated in the iraqi insurgency that followed the march 2003 invasion of iraq by western forces , joined the fight in the syrian civil war beginning in march 2011 , and was expelled from al-qaeda in early 2014 , -lrb- which complained of its failure to consult and `` notorious intransigence '' -rrb- . 
originating as the jama'at al-tawhid wal-jihad in 1999 , it pledged allegiance to al-qaeda in 2004 , participated in the iraqi insurgency that followed the march 2003 invasion of iraq by western forces , joined the fight in the syrian civil war beginning in march 2011 , and was expelled from al-qaeda in early 2014 , -lrb- which complained of its failure to consult and `` notorious intransigence '' -rrb- . 
originating as the jama'at al-tawhid wal-jihad in 1999 , it pledged allegiance to al-qaeda in 2004 , participated in the iraqi insurgency that followed the march 2003 invasion of iraq by western forces , joined the fight in the syrian civil war beginning in march 2011 , and was expelled from al-qaeda in early 2014 , -lrb- which complained of its failure to consult and `` notorious intransigence '' -rrb- . 
the group has been designated a terrorist organisation by the united nations , the european union and member states , the united states , india , indonesia , turkey , saudi arabia , syria and other countries . 
in its focus on the caliphate , the party takes a different view of muslim history than some other islamists such as muhammad qutb . 
ht sees islam 's pivotal turning point as occurring not with the death of ali , or one of the other four rightly guided caliphs in the 7th century , but with the abolition of the ottoman caliphate in 1924 . 
ht sees islam 's pivotal turning point as occurring not with the death of ali , or one of the other four rightly guided caliphs in the 7th century , but with the abolition of the ottoman caliphate in 1924 . 
this is believed to have ended the true islamic system , something for which it blames `` the disbelieving -lrb- kafir -rrb- colonial powers '' working through turkish modernist mustafa kemal atatürk . 
this is believed to have ended the true islamic system , something for which it blames `` the disbelieving -lrb- kafir -rrb- colonial powers '' working through turkish modernist mustafa kemal atatürk . 
ht does not engage in armed jihad or work for a democratic system , but works to take power through `` ideological struggle '' to change muslim public opinion , and in particular through elites who will `` facilitate '' a `` change of the government , '' i.e. , launch a `` bloodless '' coup . 
ht does not engage in armed jihad or work for a democratic system , but works to take power through `` ideological struggle '' to change muslim public opinion , and in particular through elites who will `` facilitate '' a `` change of the government , '' i.e. , launch a `` bloodless '' coup . 
ht does not engage in armed jihad or work for a democratic system , but works to take power through `` ideological struggle '' to change muslim public opinion , and in particular through elites who will `` facilitate '' a `` change of the government , '' i.e. , launch a `` bloodless '' coup . 
it allegedly attempted and failed such coups in 1968 and 1969 in jordan , and in 1974 in egypt , and is now banned in both countries . 
but many ht members have gone on to join terrorist groups and many jihadi terrorists have cited ht as their key influence . 
greater london has over 900,000 muslims , -lrb- most of south asian origins and concentrated in the east london boroughs of newham , tower hamlets and waltham forest -rrb- , and among them are some with a strong islamist outlook . 
greater london has over 900,000 muslims , -lrb- most of south asian origins and concentrated in the east london boroughs of newham , tower hamlets and waltham forest -rrb- , and among them are some with a strong islamist outlook . 
their presence , combined with a perceived british policy of allowing them free rein , heightened by exposés such as the 2007 channel 4 documentary programme undercover mosque , has given rise to the term londonistan . 
their presence , combined with a perceived british policy of allowing them free rein , heightened by exposés such as the 2007 channel 4 documentary programme undercover mosque , has given rise to the term londonistan . 
following the 9/11 attacks , however , abu hamza al-masri , the imam of the finsbury park mosque , was arrested and charged with incitement to terrorism which has caused many islamists to leave the uk to avoid internment . 
the u.s. government has engaged in efforts to counter islamism , or violent islamism , since 2001 . 
these efforts were centred in the u.s. around public diplomacy programmes conducted by the state department . 
christian whiton , an official in the george w. bush administration , called for a new agency focused on the nonviolent practice of `` political warfare '' aimed at undermining the ideology . 
u.s. defense secretary robert gates called for establishing something similar to the defunct u.s. information agency , which was charged with undermining the communist ideology during the cold war . 
u.s. defense secretary robert gates called for establishing something similar to the defunct u.s. information agency , which was charged with undermining the communist ideology during the cold war . 
its name originated from the latin word `` imperium '' , which means to rule over large territories . 
imperialism is `` a policy of extending a country 's power and influence through colonization , use of military force , or other means '' . 
the term imperialism has been applied to western -lrb- and japanese -rrb- political and economic dominance especially in asia and africa in the 19th and 20th centuries . 
it has also allowed for the rapid spread of technologies and ideas . 
imperialism is defined as `` a policy of extending a country 's power and influence through diplomacy or military force . '' 
`` formal imperialism '' is defined as `` physical control or full-fledged colonial rule '' . 
this is often through various forms of `` othering '' -lrb- see other -rrb- based on racial , religious , or cultural stereotypes . 
`` informal imperialism '' is less direct ; however , it is still a powerful form of dominance . 
to clear out this confusion about the definition of imperialism one could speak of `` formal '' and `` informal '' imperialism , the first meaning physical control or `` full-fledged colonial rule '' while the second implied less direct rule though still containing perceivable kinds of dominance . 
to clear out this confusion about the definition of imperialism one could speak of `` formal '' and `` informal '' imperialism , the first meaning physical control or `` full-fledged colonial rule '' while the second implied less direct rule though still containing perceivable kinds of dominance . 
the definition of imperialism has not been finalized for centuries and was confusedly seen to represent the policies of major powers , or simply , general-purpose aggressiveness . 
this is because , with informal rule , the control is spread more subtly through technological superiority , enforcing land officials into large debts that can not be repaid , ownership of private industries thus expanding the controlled area , or having countries agree to uneven trade agreements forcefully . 
this is because , with informal rule , the control is spread more subtly through technological superiority , enforcing land officials into large debts that can not be repaid , ownership of private industries thus expanding the controlled area , or having countries agree to uneven trade agreements forcefully . 
the greatest distinction of an empire is through the amount of land that a nation has conquered and expanded . 
european expansion caused the world to be divided by how developed and developing nation are portrayed through the world systems theory . 
the russian leader lenin suggested that `` imperialism was the highest form of capitalism , claiming that imperialism developed after colonialism , and was distinguished from colonialism by monopoly capitalism '' . 
geopolitics now focuses on states becoming major economic players in the market ; some states today are viewed as empires due to their political and economic authority over other nations . 
european empires in asia and africa `` have come to be seen as the classic forms of imperialism : and indeed most books on the subject confine themselves to the european seaborne empires '' . 
the term `` imperialism '' is often conflated with `` colonialism '' , however many scholars have argued that each have their own distinct definition . 
contiguous land empires such as the russian or ottoman are generally excluded from discussions of colonialism. :116 thus it can be said that imperialism includes some form of colonialism , but colonialism itself does not automatically imply imperialism , as it lacks a political focus . 
robert young writes that while imperialism operates from the center , is a state policy and is developed for ideological as well as financial reasons , colonialism is simply the development for settlement or commercial intentions . 
contiguous land empires such as the russian or ottoman are generally excluded from discussions of colonialism. :116 thus it can be said that imperialism includes some form of colonialism , but colonialism itself does not automatically imply imperialism , as it lacks a political focus . 
imperialism and colonialism have been used in order to describe one 's superiority , domination and influence upon a person or group of people . 
imperialism and colonialism both dictate the political and economic advantage over a land and the indigenous populations they control , yet scholars sometimes find it difficult to illustrate the difference between the two . 
although imperialism and colonialism focus on the suppression of an other , if colonialism refers to the process of a country taking physical control of another , imperialism refers to the political and monetary dominance , either formally or informally . 
the meaning of imperialism is to create an empire , by conquering the other state 's lands and therefore increasing its own dominance . 
colonialism 's core meaning is the exploitation of the valuable assets and supplies of the nation that was conquered and the conquering nation then gaining the benefits from the spoils of the war . 
colonialism can completely change the existing social structure , physical structure and economics of an area ; it is not unusual that the characteristics of the conquering peoples are inherited by the conquered indigenous populations . 
a controversial aspect of imperialism is the defense and justification of empire-building based on seemingly rational grounds . 
friedrich ratzel believed that in order for a state to survive , imperialism was needed . 
j. a. hobson identifies this justification on general grounds as : `` it is desirable that the earth should be peopled , governed , and developed , as far as possible , by the races which can do this work best , i.e. by the races of highest ` social efficiency ' '' . 
the purportedly scientific nature of `` social darwinism '' and a theory of races formed a supposedly rational justification for imperialism . 
the rhetoric of colonizers being racially superior appears to have achieved its purpose , for example throughout latin america `` whiteness '' is still prized today and various forms of blanqueamiento -lrb- whitening -rrb- are common . 
these societies also served as a space for travellers to share these stories.political geographers such as friedrich ratzel of germany and halford mackinder of britain also supported imperialism . 
these societies also served as a space for travellers to share these stories.political geographers such as friedrich ratzel of germany and halford mackinder of britain also supported imperialism . 
these societies also served as a space for travellers to share these stories.political geographers such as friedrich ratzel of germany and halford mackinder of britain also supported imperialism . 
the royal geographical society of london and other geographical societies in europe had great influence and were able to fund travelers who would come back with tales of their discoveries . 
the royal geographical society of london and other geographical societies in europe had great influence and were able to fund travelers who would come back with tales of their discoveries . 
geographical theories such as environmental determinism also suggested that tropical environments created uncivilized people in need of european guidance . 
for instance , american geographer ellen churchill semple argued that even though human beings originated in the tropics they were only able to become fully human in the temperate zone . 
tropicality can be paralleled with edward said 's orientalism as the west 's construction of the east as the `` other '' . 
geographical theories such as environmental determinism also suggested that tropical environments created uncivilized people in need of european guidance . 
according to siad , orientalism allowed europe to establish itself as the superior and the norm , which justified its dominance over the essentialized orient . 
british imperialism often used the concept of terra nullius -lrb- latin expression which stems from roman law meaning 'em pty land ' -rrb- . 
the country of australia serves as a case study in relation to british settlement and colonial rule of the continent in the eighteenth century , as it was premised on terra nullius , and its settlers considered it unused by its sparse aboriginal inhabitants . 
the principles of imperialism are often generalizable to the policies and practices of the british empire `` during the last generation , and proceeds rather by diagnosis than by historical description '' . 
the country of australia serves as a case study in relation to british settlement and colonial rule of the continent in the eighteenth century , as it was premised on terra nullius , and its settlers considered it unused by its sparse aboriginal inhabitants . 
british imperialism often used the concept of terra nullius -lrb- latin expression which stems from roman law meaning 'em pty land ' -rrb- . 
orientalism , as theorized by edward said , refers to how the west developed an imaginative geography of the east . 
this difference was particularly apparent in textual and visual works of early european studies of the orient that positioned the east as irrational and backward in opposition to the rational and progressive west . 
defining the east as a negative vision of itself , as its inferior , not only increased the west 's sense of self , but also was a way of ordering the east and making it known to the west so that it could be dominated and controlled . 
the discourse of orientalism therefore served as an ideological justification of early western imperialism , as it formed a body of knowledge and ideas that rationalized social , cultural , political , and economic control of other territories . 
this difference was particularly apparent in textual and visual works of early european studies of the orient that positioned the east as irrational and backward in opposition to the rational and progressive west . 
to better illustrate this idea , bassett focuses his analysis of the role of nineteenth-century maps during the `` scramble for africa '' . 
this provided incentives for imperial and colonial powers to obtain `` information to fill in blank spaces on contemporary maps '' . 
during his analysis of nineteenth-century cartographic techniques , he highlights the use of blank space to denote unknown or unexplored territory . 
during his analysis of nineteenth-century cartographic techniques , he highlights the use of blank space to denote unknown or unexplored territory . 
he states that maps `` contributed to empire by promoting , assisting , and legitimizing the extension of french and british power into west africa '' . 
the americas during the pre-columbian era also had large empires such as the aztec empire and the incan empire . 
imperialism was a basic component to the conquests of genghis khan during the mongol empire , and of other war-lords . 
sub-saharan africa has also featured dozens of empires that predate the european colonial era , for example the ethiopian empire , oyo empire , asante union , luba empire , lunda empire , and mutapa empire . 
sub-saharan africa has also featured dozens of empires that predate the european colonial era , for example the ethiopian empire , oyo empire , asante union , luba empire , lunda empire , and mutapa empire . 
sub-saharan africa has also featured dozens of empires that predate the european colonial era , for example the ethiopian empire , oyo empire , asante union , luba empire , lunda empire , and mutapa empire . 
cultural imperialism is when a country 's influence is felt in social and cultural circles , i.e. its soft power , such that it changes the moral , cultural and societal worldview of another . 
the importance of soft power is not lost on authoritarian regimes , fighting such influence with bans on foreign popular culture , control of the internet and unauthorised satellite dishes etc. . 
for example , depictions of opulent american lifestyles in the soap opera dallas during the cold war changed the expectations of romanians ; a more recent example is the influence of smuggled south korean drama series in north korea . 
nor is such a usage of culture recent , as part of roman imperialism local elites would be exposed to the benefits and luxuries of roman culture and lifestyle , with the aim that they would then become willing participants . 
the importance of soft power is not lost on authoritarian regimes , fighting such influence with bans on foreign popular culture , control of the internet and unauthorised satellite dishes etc. . 
the age of imperialism , a time period beginning around 1700 , saw -lrb- generally european -rrb- industrializing nations engaging in the process of colonizing , influencing , and annexing other parts of the world in order to gain political power . 
the age of imperialism , a time period beginning around 1700 , saw -lrb- generally european -rrb- industrializing nations engaging in the process of colonizing , influencing , and annexing other parts of the world in order to gain political power . 
-lsb- citation needed -rsb- although imperialist practices have existed for thousands of years , the term `` age of imperialism '' generally refers to the activities of european powers from the early 18th century through to the middle of the 20th century , for example , the `` the great game '' in persian lands , the `` scramble for africa '' and the `` open door policy '' in china . 
-lsb- citation needed -rsb- although imperialist practices have existed for thousands of years , the term `` age of imperialism '' generally refers to the activities of european powers from the early 18th century through to the middle of the 20th century , for example , the `` the great game '' in persian lands , the `` scramble for africa '' and the `` open door policy '' in china . 
-lsb- citation needed -rsb- although imperialist practices have existed for thousands of years , the term `` age of imperialism '' generally refers to the activities of european powers from the early 18th century through to the middle of the 20th century , for example , the `` the great game '' in persian lands , the `` scramble for africa '' and the `` open door policy '' in china . 
during the 20th century , historians john gallagher -lrb- 1919 -- 1980 -rrb- and ronald robinson -lrb- 1920 -- 1999 -rrb- constructed a framework for understanding european imperialism . 
during the 20th century , historians john gallagher -lrb- 1919 -- 1980 -rrb- and ronald robinson -lrb- 1920 -- 1999 -rrb- constructed a framework for understanding european imperialism . 
during the 20th century , historians john gallagher -lrb- 1919 -- 1980 -rrb- and ronald robinson -lrb- 1920 -- 1999 -rrb- constructed a framework for understanding european imperialism . 
-lsb- attribution needed -rsb- because of the resources made available by imperialism , the world 's economy grew significantly and became much more interconnected in the decades before world war i , making the many imperial powers rich and prosperous . 
-lsb- attribution needed -rsb- because of the resources made available by imperialism , the world 's economy grew significantly and became much more interconnected in the decades before world war i , making the many imperial powers rich and prosperous . 
europe 's expansion into territorial imperialism was largely focused on economic growth by collecting resources from colonies , in combination with assuming political control by military and political means . 
the colonization of india in the mid-18th century offers an example of this focus : there , the `` british exploited the political weakness of the mughal state , and , while military activity was important at various times , the economic and administrative incorporation of local elites was also of crucial significance '' for the establishment of control over the subcontinent 's resources , markets , and manpower . 
europe 's expansion into territorial imperialism was largely focused on economic growth by collecting resources from colonies , in combination with assuming political control by military and political means . 
the colonization of india in the mid-18th century offers an example of this focus : there , the `` british exploited the political weakness of the mughal state , and , while military activity was important at various times , the economic and administrative incorporation of local elites was also of crucial significance '' for the establishment of control over the subcontinent 's resources , markets , and manpower . 
along with advancements in communication , europe also continued to advance in military technology . 
european chemists made deadly explosives that could be used in combat , and with innovations in machinery they were able to manufacture improved firearms . 
by the 1880s , the machine gun had become an effective battlefield weapon . 
this technology gave european armies an advantage over their opponents , as armies in less-developed countries were still fighting with arrows , swords , and leather shields -lrb- e.g. the zulus in southern africa during the anglo-zulu war of 1879 -rrb- . 
this technology gave european armies an advantage over their opponents , as armies in less-developed countries were still fighting with arrows , swords , and leather shields -lrb- e.g. the zulus in southern africa during the anglo-zulu war of 1879 -rrb- . 
in anglophone academic works , theories regarding imperialism are often based on the british experience . 
the term `` imperialism '' was originally introduced into english in its present sense in the late 1870s by opponents of the allegedly aggressive and ostentatious imperial policies of british prime minister benjamin disraeli . 
for some , imperialism designated a policy of idealism and philanthropy ; others alleged that it was characterized by political self-interest , and a growing number associated it with capitalist greed . 
in his writings lenin portrayed imperialism as a natural extension of capitalism that arose from need for capitalist economies to constantly expand investment , material resources and manpower in such a way that necessitated colonial expansion . 
the correlation between capitalism , aristocracy , and imperialism has long been debated among historians and political theorists . 
their combined work informed the study of imperialism and it 's impact on europe , as well as contributed to reflections on the rise of the military-political complex in the united states from the 1950s . 
while these non-marxist writers were at their most prolific before world war i , they remained active in the interwar years . 
hobson argued that domestic social reforms could cure the international disease of imperialism by removing its economic foundation . 
hobson theorized that state intervention through taxation could boost broader consumption , create wealth , and encourage a peaceful , tolerant , multipolar world order . 
the concept environmental determinism served as a moral justification for domination of certain territories and peoples . 
it was believed that a certain person 's behaviours were determined by the environment in which they lived and thus validated their domination . 
for example , people living in tropical environments were seen as `` less civilized '' therefore justifying colonial control as a civilizing mission . 
across the three waves of european colonialism -lrb- first in the americas , second in asia and lastly in africa -rrb- , environmental determinism was used to categorically place indigenous people in a racial hierarchy . 
this takes two forms , orientalism and tropicality . 
according to geographic scholars under colonizing empires , the world could be split into climatic zones . 
these scholars believed that northern europe and the mid-atlantic temperate climate produced a hard-working , moral , and upstanding human being . 
the people of these climates were believed to be in need of guidance and intervention from the european empire to aid in the governing of a more evolved social structure ; they were seen as incapable of such a feat . 
similarly , orientalism is a view of a people based on their geographical location . 
according to geographic scholars under colonizing empires , the world could be split into climatic zones . 
britain 's imperialist ambitions can be seen as early as the sixteenth century . 
in 1599 the british east india company was established and was chartered by queen elizabeth in the following year . 
in 1599 the british east india company was established and was chartered by queen elizabeth in the following year . 
in 1767 political activity caused exploitation of the east india company causing the plundering of the local economy , almost bringing the company into bankruptcy . 
with the establishment of trading posts in india , the british were able to maintain strength relative to others empires such as the portuguese who already had set up trading posts in india . 
france took control of algeria in 1830 but began in earnest to rebuild its worldwide empire after 1850 , concentrating chiefly in north and west africa , as well as south-east asia , with other conquests in central and east africa , as well as the south pacific . 
france took control of algeria in 1830 but began in earnest to rebuild its worldwide empire after 1850 , concentrating chiefly in north and west africa , as well as south-east asia , with other conquests in central and east africa , as well as the south pacific . 
as it developed , the new empire took on roles of trade with france , supplying raw materials and purchasing manufactured items , as well as lending prestige to the motherland and spreading french civilization and language as well as catholicism . 
france took control of algeria in 1830 but began in earnest to rebuild its worldwide empire after 1850 , concentrating chiefly in north and west africa , as well as south-east asia , with other conquests in central and east africa , as well as the south pacific . 
republicans , at first hostile to empire , only became supportive when germany started to build her own colonial empire . 
in 1884 the leading exponent of colonialism , jules ferry declared france had a civilising mission : `` the higher races have a right over the lower races , they have a duty to civilize the inferior '' . 
full citizenship rights -- `' assimilation '' -- were offered , although in reality assimilation was always on the distant horizon . 
contrasting from britain , france sent small numbers of settlers to its colonies , with the only notable exception of algeria , where french settlers nevertheless always remained a small minority . 
it became a moral justification to lift the world up to french standards by bringing christianity and french culture . 
contrasting from britain , france sent small numbers of settlers to its colonies , with the only notable exception of algeria , where french settlers nevertheless always remained a small minority . 
in world war ii , charles de gaulle and the free french used the overseas colonies as bases from which they fought to liberate france . 
however after 1945 anti-colonial movements began to challenge the empire . 
france fought and lost a bitter war in vietnam in the 1950s . 
whereas they won the war in algeria , the french leader at the time , charles de gaulle , decided to grant algeria independence anyway in 1962 . 
nearly all of france 's colonies gained independence by 1960 , but france retained great financial and diplomatic influence . 
from their original homelands in scandinavia and northern europe , germanic tribes expanded throughout northern and western europe in the middle period of classical antiquity ; southern europe in late antiquity , conquering celtic and other peoples ; and by 800 ce , forming the holy roman empire , the first german empire . 
although by 1000 ce , the germanic conquest of central , western , and southern europe -lrb- west of and including italy -rrb- was complete , excluding only muslim iberia . 
from their original homelands in scandinavia and northern europe , germanic tribes expanded throughout northern and western europe in the middle period of classical antiquity ; southern europe in late antiquity , conquering celtic and other peoples ; and by 800 ce , forming the holy roman empire , the first german empire . 
from their original homelands in scandinavia and northern europe , germanic tribes expanded throughout northern and western europe in the middle period of classical antiquity ; southern europe in late antiquity , conquering celtic and other peoples ; and by 800 ce , forming the holy roman empire , the first german empire . 
there was , however , little cultural integration or national identity , and `` germany '' remained largely a conceptual term referring to an amorphous area of central europe . 
not a maritime power , and not a nation-state , as it would eventually become , germany 's participation in western imperialism was negligible until the late 19th century . 
after prussia unified the other states into the second german empire after the franco-german war , its long-time chancellor , otto von bismarck -lrb- 1862 -- 90 -rrb- , long opposed colonial acquisitions , arguing that the burden of obtaining , maintaining , and defending such possessions would outweigh any potential benefits . 
after prussia unified the other states into the second german empire after the franco-german war , its long-time chancellor , otto von bismarck -lrb- 1862 -- 90 -rrb- , long opposed colonial acquisitions , arguing that the burden of obtaining , maintaining , and defending such possessions would outweigh any potential benefits . 
-lsb- further explanation needed -rsb- after the defeat of napoleon , who caused the dissolution of that holy roman empire , prussia and the german states continued to stand aloof from imperialism , preferring to manipulate the european system through the concert of europe . 
he felt that colonies did not pay for themselves , that the german bureaucratic system would not work well in the tropics and the diplomatic disputes over colonies would distract germany from its central interest , europe itself . 
however , in 1883 -- 84 germany began to build a colonial empire in africa and the south pacific , before losing interest in imperialism . 
-lsb- verification needed -rsb- bismarck was aware that public opinion had started to demand colonies for reasons of german prestige . 
the establishment of the german colonial empire proceeded smoothly , starting with german new guinea in 1884 . 
the establishment of the german colonial empire proceeded smoothly , starting with german new guinea in 1884 . 
he was influenced by hamburg merchants and traders , his neighbors at friedrichsruh . 
as a result of the russo-japanese war in 1905 , japan took part of sakhalin island from russia . 
during the first sino-japanese war in 1894 , japan absorbed taiwan . 
japan also invaded thailand , pressuring the country into a thai/japanese alliance . 
in 1931 japan conquered manchuria from china . 
the soviet union and the people 's republic of china supported post -- world war ii communist movements in foreign nations and colonies to advance their own interests , but were not always successful . 
never formally revoked , it stopped being implemented after 1932 . 
bolshevik leaders had effectively reestablished a polity with roughly the same extent as that empire by 1921 , however with an internationalist ideology : lenin in particular asserted the right to limited self-determination for national minorities within the new territory . 
after world war ii , the soviet union installed socialist regimes modeled on those it had installed in 1919 -- 20 in the old tsarist empire in areas its forces occupied in eastern europe . 
bolshevik leaders had effectively reestablished a polity with roughly the same extent as that empire by 1921 , however with an internationalist ideology : lenin in particular asserted the right to limited self-determination for national minorities within the new territory . 
trotsky , and others , believed that the revolution could only succeed in russia as part of a world revolution . 
lenin wrote extensively on the matter and famously declared that imperialism was the highest stage of capitalism . 
mao zedong once argued that the soviet union had itself become an imperialist power while maintaining a socialist façade . 
with the beginning of the new era , the after stalin period called the `` thaw '' , in the late 1950s , the new political leader nikita khrushchev put even more pressure on the soviet-american relations starting a new wave of anti-imperialist propaganda . 
however , after lenin 's death , joseph stalin established ` socialism in one country ' for the soviet union , creating the model for subsequent inward looking stalinist states and purging the early internationalist elements . 
the first british empire was based on mercantilism , and involved colonies and holdings primarily in north america , the caribbean , and india . 
its growth was reversed by the loss of the american colonies in 1776 . 
by the 1840s , britain had adopted a highly successful policy of free trade that gave it dominance in the trade of much of the world . 
britain made compensating gains in india , australia , and in constructing an informal economic empire through control of trade and finance in latin america after the independence of spanish and portuguese colonies about 1820 . 
following the defeat of napoleonic france in 1815 , britain enjoyed a century of almost unchallenged dominance and expanded its imperial holdings around the globe . 
the british empire was the largest empire that the world has ever seen both in terms of landmass and population . 
the pseudo-sciences of social darwinism and theories of race formed an ideological underpinning during this time . 
the british spirit of imperialism was expressed by joseph chamberlain and lord rosebury , and implemented in africa by cecil rhodes . 
a resurgence came in the late 19th century , with the scramble for africa and major additions in asia and the middle east . 
the early united states expressed its opposition to imperialism , at least in a form distinct from its own manifest destiny , through policies such as the monroe doctrine . 
however , beginning in the late 19th and early 20th century , policies such as theodore roosevelt 's interventionism in central america and woodrow wilson 's mission to `` make the world safe for democracy '' changed all this . 
one year later , a war erupted in the philippines causing business , labor and government leaders in the us to condemn america 's occupation in the philippines as they also denounced them for causing the deaths of many filipinos . 
in 1898 , americans who opposed imperialism created the anti-imperialist league to oppose the us annexation of the philippines and cuba . 
american foreign policy was denounced as a `` racket '' by smedley butler , an american general . 
one key figure in the plans for what would come to be known as american empire , was a geographer named isiah bowman . 
three years later in 1917 , he was appointed to then president woodrow wilson 's inquiry in 1917 . 
the inquiry was the idea of president wilson and the american delegation from the paris peace conference . 
the point of this inquiry was to build a premise that would allow for u.s authorship of a ` new world ' which was to be characterized by geographical order . 
as a result of his role in the inquiry , isiah bowman would come to be known as wilson 's geographer . 
some have described the internal strife between various people groups as a form of imperialism or colonialism . 
this internal form of empire has been referred to as `` internal colonialism '' . 
participation in the african slave trade and the subsequent treatment of its 12 to 15 million africans is viewed by some to be a more modern extension of america 's `` internal colonialism '' . 
in his lecture on april 16 , 2003 , edward said made a bold statement on modern imperialism in the united states , whom he described as using aggressive means of attack towards the contemporary orient , `` due to their backward living , lack of democracy and the violation of women 's rights . 
the ottoman empire was an imperial state that lasted from 1299 to 1923 . 
during the 16th and 17th centuries , in particular at the height of its power under the reign of suleiman the magnificent , the ottoman empire was a powerful multinational , multilingual empire controlling much of southeast europe , western asia , the caucasus , north africa , and the horn of africa . 
at the beginning of the 17th century the empire contained 32 provinces and numerous vassal states . 
during the 16th and 17th centuries , in particular at the height of its power under the reign of suleiman the magnificent , the ottoman empire was a powerful multinational , multilingual empire controlling much of southeast europe , western asia , the caucasus , north africa , and the horn of africa . 
during the 16th and 17th centuries , in particular at the height of its power under the reign of suleiman the magnificent , the ottoman empire was a powerful multinational , multilingual empire controlling much of southeast europe , western asia , the caucasus , north africa , and the horn of africa . 
with istanbul as its capital and control of lands around the mediterranean basin , the ottoman empire was at the center of interactions between the eastern and western worlds for six centuries . 
the empire allied with germany in the early 20th century , with the imperial ambition of recovering its lost territories , but it dissolved in the aftermath of world war i , leading to the emergence of the new state of turkey in the ottoman anatolian heartland , as well as the creation of modern balkan and middle eastern states , thus ending turkish colonial ambitions . 
the empire allied with germany in the early 20th century , with the imperial ambition of recovering its lost territories , but it dissolved in the aftermath of world war i , leading to the emergence of the new state of turkey in the ottoman anatolian heartland , as well as the creation of modern balkan and middle eastern states , thus ending turkish colonial ambitions . 
the empire allied with germany in the early 20th century , with the imperial ambition of recovering its lost territories , but it dissolved in the aftermath of world war i , leading to the emergence of the new state of turkey in the ottoman anatolian heartland , as well as the creation of modern balkan and middle eastern states , thus ending turkish colonial ambitions . 
the united methodist church -lrb- umc -rrb- is a mainline protestant methodist denomination . 
the united methodist church -lrb- umc -rrb- is a mainline protestant methodist denomination . 
founded in 1968 by the union of the methodist church -lrb- usa -rrb- and the evangelical united brethren church , the umc traces its roots back to the revival movement of john and charles wesley in england as well as the great awakening in the united states . 
founded in 1968 by the union of the methodist church -lrb- usa -rrb- and the evangelical united brethren church , the umc traces its roots back to the revival movement of john and charles wesley in england as well as the great awakening in the united states . 
as such , the church 's theological orientation is decidedly wesleyan . 
the united methodist church is the largest denomination within the wider methodist movement , which has approximately 80 million adherents across the world . 
the united methodist church is the largest denomination within the wider methodist movement , which has approximately 80 million adherents across the world . 
in the united states , the umc ranks as the largest mainline protestant denomination , the largest protestant church after the southern baptist convention , and the third largest christian denomination . 
in 2015 , pew research estimated that 3.6 % of the u.s population , or 9 million adult adherents , self-identify with the united methodist church revealing a much larger number of adherents than registered membership . 
the movement which would become the united methodist church began in the mid-18th century within the church of england . 
the movement which would become the united methodist church began in the mid-18th century within the church of england . 
other students mocked them , saying they were the `` holy club '' and `` the methodists '' , being methodical and exceptionally detailed in their bible study , opinions and disciplined lifestyle . 
in 1735 , john and charles wesley went to america to teach the gospel to the american indians in the colony of georgia . 
in 1735 , john and charles wesley went to america to teach the gospel to the american indians in the colony of georgia . 
in 1735 , john and charles wesley went to america to teach the gospel to the american indians in the colony of georgia . 
though not always emphasized or appreciated in the anglican churches of their day , their teaching emphasized salvation by god 's grace , acquired through faith in christ . 
though john wesley originally wanted the methodists to stay within the church of england , the american revolution decisively separated the methodists in the american colonies from the life and sacraments of the anglican church . 
in 1784 , after unsuccessful attempts to have the church of england send a bishop to start a new church in the colonies , wesley decisively appointed fellow priest thomas coke as superintendent -lrb- bishop -rrb- to organize a separate methodist society . 
in 1784 , after unsuccessful attempts to have the church of england send a bishop to start a new church in the colonies , wesley decisively appointed fellow priest thomas coke as superintendent -lrb- bishop -rrb- to organize a separate methodist society . 
the conference was held at the lovely lane methodist church , considered the mother church of american methodism . 
the conference was held at the lovely lane methodist church , considered the mother church of american methodism . 
st. george 's united methodist church , located at the corner of 4th and new streets , in the old city neighborhood of philadelphia , is the oldest methodist church in continuous use in the united states , beginning in 1769 . 
st. george 's united methodist church , located at the corner of 4th and new streets , in the old city neighborhood of philadelphia , is the oldest methodist church in continuous use in the united states , beginning in 1769 . 
the congregation was founded in 1767 , meeting initially in a sail loft on dock street , and in 1769 it purchased the shell of a building which had been erected in 1763 by a german reformed congregation . 
the congregation was founded in 1767 , meeting initially in a sail loft on dock street , and in 1769 it purchased the shell of a building which had been erected in 1763 by a german reformed congregation . 
at this time , methodists had not yet broken away from the anglican church and the methodist episcopal church was not founded until 1784 . 
richard allen and absalom jones became the first african americans ordained by the methodist church . 
they were licensed by st. george 's church in 1784 . 
they were licensed by st. george 's church in 1784 . 
in 1830 , the methodist protestant church split from the methodist episcopal church over the issue of laity having a voice and vote in the administration of the church , insisting that clergy should not be the only ones to have any determination in how the church was to be operated . 
in 1830 , the methodist protestant church split from the methodist episcopal church over the issue of laity having a voice and vote in the administration of the church , insisting that clergy should not be the only ones to have any determination in how the church was to be operated . 
in 1844 , the general conference of the methodist episcopal church split into two conferences because of tensions over slavery and the power of bishops in the denomination . 
in 1844 , the general conference of the methodist episcopal church split into two conferences because of tensions over slavery and the power of bishops in the denomination . 
on april 23 , 1968 , the united methodist church was created when the evangelical united brethren church -lrb- represented by bishop reuben h. mueller -rrb- and the methodist church -lrb- represented by bishop lloyd christ wicke -rrb- joined hands at the constituting general conference in dallas , texas . 
on april 23 , 1968 , the united methodist church was created when the evangelical united brethren church -lrb- represented by bishop reuben h. mueller -rrb- and the methodist church -lrb- represented by bishop lloyd christ wicke -rrb- joined hands at the constituting general conference in dallas , texas . 
on april 23 , 1968 , the united methodist church was created when the evangelical united brethren church -lrb- represented by bishop reuben h. mueller -rrb- and the methodist church -lrb- represented by bishop lloyd christ wicke -rrb- joined hands at the constituting general conference in dallas , texas . 
the united methodist church understands itself to be part of the holy catholic -lrb- or universal -rrb- church and it recognizes the historic ecumenical creeds , the apostle 's creed and the nicene creed ; which are used frequently in services of worship . 
the book of discipline also recognizes the importance of the chalcedonian creed of the council of chalcedon . 
it upholds the concept of the `` visible and invisible church , '' meaning that all who are truly believers in every age belong to the holy church invisible , while the united methodist church is a branch of the church visible , to which all believers must be connected as it is the only institution wherein the word of god is preached and the sacraments are administered . 
as a result of the american revolution , john wesley was compelled in 1784 to break with standard practice and ordain two of his lay preachers as presbyters , thomas vasey and richard whatcoat . 
dr. thomas coke , already an anglican priest , assisted wesley in this action . 
as a result of the american revolution , john wesley was compelled in 1784 to break with standard practice and ordain two of his lay preachers as presbyters , thomas vasey and richard whatcoat . 
with the formation of the united methodist church in 1968 , theologian albert c. outler led the team which systematized denominational doctrine . 
although united methodist practices and interpretation of beliefs have evolved over time , these practices and beliefs can be traced to the writings of the church 's founders , especially john wesley and charles wesley -lrb- anglicans -rrb- , but also philip william otterbein and martin boehm -lrb- united brethren -rrb- , and jacob albright -lrb- evangelical association -rrb- . 
with the formation of the united methodist church in 1968 , theologian albert c. outler led the team which systematized denominational doctrine . 
with the formation of the united methodist church in 1968 , theologian albert c. outler led the team which systematized denominational doctrine . 
prevenient grace , or the grace that `` goes before '' us , is given to all people . 
prevenient grace , or the grace that `` goes before '' us , is given to all people . 
prevenient grace , or the grace that `` goes before '' us , is given to all people . 
prevenient grace allows those tainted by sin to nevertheless make a truly free choice to accept or reject god 's salvation in christ . 
justifying grace or accepting grace is that grace , offered by god to all people , that we receive by faith and trust in christ , through which god pardons the believer of sin . 
the justifying grace cancels our guilt and empowers us to resist the power of sin and to fully love god and neighbor . 
today , justifying grace is also known as conversion , `` accepting jesus as your personal lord and savior , '' or being `` born again '' . 
today , justifying grace is also known as conversion , `` accepting jesus as your personal lord and savior , '' or being `` born again '' . 
john wesley originally called this experience the new birth . 
sanctifying grace is that grace of god which sustains the believers in the journey toward christian perfection : a genuine love of god with heart , soul , mind , and strength , and a genuine love of our neighbors as ourselves . 
sanctifying grace is that grace of god which sustains the believers in the journey toward christian perfection : a genuine love of god with heart , soul , mind , and strength , and a genuine love of our neighbors as ourselves . 
sanctifying grace is that grace of god which sustains the believers in the journey toward christian perfection : a genuine love of god with heart , soul , mind , and strength , and a genuine love of our neighbors as ourselves . 
sanctifying grace is that grace of god which sustains the believers in the journey toward christian perfection : a genuine love of god with heart , soul , mind , and strength , and a genuine love of our neighbors as ourselves . 
wesleyan theology stands at a unique cross-roads between evangelical and sacramental , between liturgical and charismatic , and between anglo-catholic and reformed theology and practice . 
the united methodist church believes in prima scriptura , seeing the holy bible as the primary authority in the church and using sacred tradition , reason , and experience to interpret it , with the aid of the holy spirit -lrb- see wesleyan quadrilateral -rrb- . 
today , the umc is generally considered one of the more moderate and tolerant denominations with respect to race , gender , and ideology , though the denomination itself actually includes a very wide spectrum of attitudes . 
therefore , according to the book of discipline , united methodist theology is at once `` catholic , evangelical , and reformed . '' 
still , the denomination is pro-choice and also `` was a founding member of the religious coalition for reproductive choice ... -lsb- and -rsb- 2008 general conference -lsb- went -rsb- on record in support of the work of the religious coalition for reproductive choice '' . 
still , the denomination is pro-choice and also `` was a founding member of the religious coalition for reproductive choice ... -lsb- and -rsb- 2008 general conference -lsb- went -rsb- on record in support of the work of the religious coalition for reproductive choice '' . 
still , the denomination is pro-choice and also `` was a founding member of the religious coalition for reproductive choice ... -lsb- and -rsb- 2008 general conference -lsb- went -rsb- on record in support of the work of the religious coalition for reproductive choice '' . 
as such , two official bodies of the united methodist church are part of the religious coalition for reproductive choice 's governing coalition , the general board of church and society , and the united methodist women . 
the church emphasizes the need to be in supportive ministry with all women , regardless of their choice . 
the church also holds that they `` are equally bound to respect the sacredness of the life and well-being of the mother , for whom devastating damage may result from an unacceptable pregnancy . 
members of the united methodist church who identify with the pro-life position have organized into the taskforce of united methodists on abortion and sexuality -lrb- tumas -rrb- to further their position within the denomination . 
there was an attempt to withdraw the united methodist church membership in the religious coalition for reproductive choice at their general conference , held in may 2012 , with a petition that passed through the legislative subcommittee and committee votes , but was not given a floor vote . 
rev. paul t. stallsworth , president of the taskforce of united methodists on abortion and sexuality said he `` had every reason to believe '' that pro-life delegates would have won a floor vote . 
historically , the methodist church has supported the temperance movement . 
moreover , in 2011 and 2012 , the united methodist church 's general board of church and society called on all united methodists to abstain from alcohol for lent . 
john wesley warned against the dangers of drinking in his famous sermon , `` the use of money , '' and in his letter to an alcoholic . 
in fact , the united methodist church uses unfermented grape juice in the sacrament of holy communion , thus `` expressing pastoral concern for recovering alcoholics , enabling the participation of children and youth , and supporting the church 's witness of abstinence . '' 
the united methodist church , along with other methodist churches , condemns capital punishment , saying that it can not accept retribution or social vengeance as a reason for taking human life . 
the united methodist church also believes that jesus explicitly repudiated the lex talionis in matthew 5:38 -39 and abolished the death penalty in john 8:7 . 
the united methodist church also believes that jesus explicitly repudiated the lex talionis in matthew 5:38 -39 and abolished the death penalty in john 8:7 . 
the general conference of the united methodist church calls for its bishops to uphold opposition to capital punishment and for governments to enact an immediate moratorium on carrying out the death penalty sentence . 
in addition , the united methodist church prohibits the celebration of same-sex unions . 
rev. jimmy creech was defrocked after a highly publicized church trial in 1999 on account of his participation in same-sex union ceremonies . 
moreover , some churches , especially in 2016 after same-sex marriage was legalized nationwide , have provided blessings for same-sex marriages . 
for example , the connectional table , a governing committee , has voted in favor of a proposal that calls for a localized option , which would permit ministers to officiate same-sex weddings , and it would allow conferences to ordain gay clergy . 
additionally , many organizations , conferences , and congregations have recently called for broader acceptance of the lgbt community within the umc . 
moreover , many conferences have taken a position by voting in favor of same-gender marriages with resolutions . 
in 1987 , a united methodist church court in new hampshire defrocked methodist minister rose mary denman for openly living with a same-sex partner . 
in 2005 , clergy credentials were removed from irene elizabeth stroud after she was convicted in a church trial of violating church law by engaging in a lesbian relationship ; this conviction was later upheld by the judicial council , the highest court in the denomination . 
the baltimore-washington conference of the umc has approved the appointment of an openly partnered lesbian to the provisional diaconate . 
the united methodist church opposes conscription as incompatible with the teaching of scripture . 
the church also states that `` as christians they are aware that neither the way of military action , nor the way of inaction is always righteous before god . '' 
therefore , the church supports and extends its ministry to those persons who conscientiously oppose all war , or any particular war , and who therefore refuse to serve in the armed forces or to cooperate with systems of military conscription . 
the united methodist church maintains that war is incompatible with christ 's message and teachings . 
therefore , the church rejects war as an instrument of national foreign policy , to be employed only as a last resort in the prevention of such evils as genocide , brutal suppression of human rights , and unprovoked international aggression . 
consequently , the united methodist church endorses general and complete disarmament under strict and effective international control . 
the sexual ethics task force of the united methodist church states that `` research shows it -lsb- pornography -rsb- is not an ` innocent activity . ' 
the united methodist church teaches that pornography is `` about violence , degradation , exploitation , and coercion '' and `` deplore -lsb- s -rsb- all forms of commercialization , abuse , and exploitation of sex . '' 
persons who are addicted to pornography are physiologically altered , as is their perspective , relationships with parishioners and family , and their perceptions of girls and women . '' 
the umc supports federal funding for research on embryos created for ivf that remain after the procreative efforts have ceased , if the embryos were provided for research instead of being destroyed , were not obtained by sale , and those donating had given prior informed consent for the research purposes . 
it supports research on stem cells retrieved from umbilical cords and adult stem cells , stating that there are `` few moral questions '' raised by this issue . 
the umc stands in `` opposition to the creation of embryos for the sake of research '' as `` a human embryo , even at its earliest stages , commands our reverence . '' 
when the methodists in america were separated from the church of england , john wesley himself provided a revised version of the book of common prayer called the sunday service of the methodists in north america . 
when the methodists in america were separated from the church of england , john wesley himself provided a revised version of the book of common prayer called the sunday service of the methodists in north america . 
when the methodists in america were separated from the church of england , john wesley himself provided a revised version of the book of common prayer called the sunday service of the methodists in north america . 
some clergy offer healing services , while exorcism is an occasional practice by some clergy in the united methodist church in africa . 
many of these liturgies are derived from the anglican tradition 's book of common prayer . 
these services involve the laying on of hands and anointing with oil . 
methodist institutions may be named after a biblical figure -lrb- e.g. , `` st. james umc '' -rrb- . 
such exemplary saints include martyrs , confessors of the faith , evangelists , or important biblical figures such as saint matthew , lutheran theologian and martyr to the nazis dietrich bonhoeffer , salvation army founder william booth , african missionary david livingstone and methodism 's revered founder john wesley are among many cited as protestant saints . 
such exemplary saints include martyrs , confessors of the faith , evangelists , or important biblical figures such as saint matthew , lutheran theologian and martyr to the nazis dietrich bonhoeffer , salvation army founder william booth , african missionary david livingstone and methodism 's revered founder john wesley are among many cited as protestant saints . 
the united methodist church is organized into conferences . 
the highest level is called the general conference and is the only organization which may speak officially for the church . 
legislative changes are recorded in the book of discipline which is revised after each general conference . 
the highest level is called the general conference and is the only organization which may speak officially for the church . 
the general conference meets every four years -lrb- quadrennium -rrb- . 
the united states is divided into five jurisdictions : northeastern , southeastern , north central , south central and western . 
outside the united states the church is divided into seven central conferences : africa , congo , west africa , central & southern europe , germany , northern europe and the philippines . 
the main purpose of the jurisdictions and central conferences is to elect and appoint bishops , the chief administrators of the church . 
the main purpose of the jurisdictions and central conferences is to elect and appoint bishops , the chief administrators of the church . 
bishops thus elected serve episcopal areas , which consist of one or more annual conferences . 
decisions in-between the four-year meetings are made by the mission council -lrb- usually consisting of church bishops -rrb- . 
decisions in-between the four-year meetings are made by the mission council -lrb- usually consisting of church bishops -rrb- . 
one of the most high profile decisions in recent years by one of the councils was a decision by the mission council of the south central jurisdiction which in march 2007 approved a 99-year lease of 36 acres -lrb- 150,000 m2 -rrb- at southern methodist university for the george w. bush presidential library . 
one of the most high profile decisions in recent years by one of the councils was a decision by the mission council of the south central jurisdiction which in march 2007 approved a 99-year lease of 36 acres -lrb- 150,000 m2 -rrb- at southern methodist university for the george w. bush presidential library . 
one of the most high profile decisions in recent years by one of the councils was a decision by the mission council of the south central jurisdiction which in march 2007 approved a 99-year lease of 36 acres -lrb- 150,000 m2 -rrb- at southern methodist university for the george w. bush presidential library . 
it consists of nine members , both laity and clergy , elected by the general conference for an eight-year term . 
the judicial council is the highest court in the denomination . 
it consists of nine members , both laity and clergy , elected by the general conference for an eight-year term . 
the council meets twice a year at various locations throughout the world . 
the council meets twice a year at various locations throughout the world . 
the annual conference , roughly the equivalent of a diocese in the anglican communion and the roman catholic church or a synod in some lutheran denominations such as the evangelical lutheran church in america , is the basic unit of organization within the umc . 
the term annual conference is often used to refer to the geographical area it covers as well as the frequency of meeting . 
clergy are members of their annual conference rather than of any local congregation , and are appointed to a local church or other charge annually by the conference 's resident bishop at the meeting of the annual conference . 
the book of discipline is the guidebook for local churches and pastors and describes in considerable detail the organizational structure of local united methodist churches . 
all um churches must have a board of trustees with at least three members and no more than nine members and it is recommended that no gender should hold more than a 2/3 majority . 
all um churches must have a board of trustees with at least three members and no more than nine members and it is recommended that no gender should hold more than a 2/3 majority . 
the church conference is an annual meeting of all the officers of the church and any interested members . 
the church conference is an annual meeting of all the officers of the church and any interested members . 
as such , the united methodist church established and is affiliated with around one hundred colleges and universities in the united states , including syracuse university , boston university , emory university , duke university , drew university , university of denver , university of evansville , and southern methodist university . 
the church operates three hundred sixty schools and institutions overseas . 
most are members of the international association of methodist-related schools , colleges , and universities . 
the first methodist clergy were ordained by john wesley , a priest of the church of england , because of the crisis caused by the american revolution which isolated the methodists in the states from the church of england and its sacraments . 
they generally serve as pastors in local congregations . 
elders in full connection are each a member of their annual conference order of elders . 
likewise each deacon in full connection is a member of their annual conference order of deacons . 
all clergy appointments are made and fixed annually by the resident bishop on the advice of the annual conference cabinet , which is composed of the area provost/dean -lrb- if one is appointed -rrb- and the several district superintendents of the districts of the annual conference . 
while an appointment is made one year at a time , it is most common for an appointment to be continued for multiple years . 
until the bishop has read the appointments at the session of the annual conference , no appointments are officially fixed . 
elders are called by god , affirmed by the church , and ordained by a bishop to a ministry of word , sacrament , order and service within the church . 
they may be appointed to the local church , or to other valid extension ministries of the church . 
elders serve a term of 2 -- 3 years as provisional elders prior to their ordination . 
elders may also be assigned as district superintendents , and they are eligible for election to the episcopacy . 
deacons serve a term of 2 -- 3 years as provisional deacons prior to their ordination . 
deacons give leadership , preach the word , contribute in worship , conduct marriages , bury the dead , and aid the church in embodying its mission within the world . 
deacons assist elders in the sacraments of holy communion and baptism , and may be granted sacramental authority if they are appointed as the pastor in a local church . 
deacons assist elders in the sacraments of holy communion and baptism , and may be granted sacramental authority if they are appointed as the pastor in a local church . 
at the 1996 general conference the ordination order of transitional deacon was abolished . 
the provisional elder/deacon is a seminary graduate who serves a two-three-year term in a full-time appointment after being commissioned . 
at the 1996 general conference the ordination order of transitional deacon was abolished . 
a local pastor 's official title is ` licensed local pastor ' and is appointed as clergy to the local church where they preach , conduct divine worship and perform the regular duties of a pastor . 
the licensed local pastor has the authority of a pastor only within the context and during the time of the appointment and shall not extend beyond it . 
local pastors are not required to have advanced degrees but are required to attend licensing school and attend and pass an approved five-year course of study at an approved united methodist seminary or course of study school , successfully complete written and oral examinations , and appear before the district committee on ministry and the conference board of ordained ministry . 
they may continue towards associate membership allowing them to retire as clergy . 
baptized members are those who have been baptized as an infant or child , but who have not subsequently professed their own faith . 
these baptized members become professing members through confirmation and sometimes the profession of faith . 
individuals may also become a professing member through transfer from another christian denomination . 
unlike confirmation and profession of faith , baptism is a sacrament in the umc . 
in confirmation and membership preparation classes , students learn about church and the methodist-christian theological tradition in order to profess their ultimate faith in christ . 
the book of discipline of the united methodist church directs the local church to offer membership preparation or confirmation classes to all people , including adults . 
in confirmation and membership preparation classes , students learn about church and the methodist-christian theological tradition in order to profess their ultimate faith in christ . 
there are two categories of lay servants : local church lay servant , who serve in and through their local churches , and certified lay servants , who serve in their own churches , in other churches , and through district or conference projects and programs . 
to be recognized as local church lay servant , they must be recommended by their pastor and church council or charge conference , and complete the basic course for lay servant . 
they must report and reapply annually ; and they must complete at least one advanced course every three years . 
they must report and reapply annually ; and they must complete at least one advanced course every three years . 
the united methodist church is one tradition within the christian church . 
in addition , it voted to seek observer status in the national association of evangelicals and in the world evangelical fellowship . 
however , there are some in the united methodist church who feel that false ecumenism might result in the `` blurring of theological and confessional differences in the interests of unity . '' 
a commission on pan methodist cooperation and union formed in 2000 to carry out work on such a merger . 
in may 2012 , the united methodist church entered into full communion with the african methodist episcopal church , african methodist episcopal zion church , african union methodist protestant church , christian methodist episcopal church , and union american methodist episcopal church , in which these churches agreed to `` recognize each other 's churches , share sacraments , and affirm their clergy and ministries . '' 
the united methodist church has since 1985 been exploring a possible merger with three historically african-american methodist denominations : the african methodist episcopal church , the african methodist episcopal zion church , and the christian methodist episcopal church . 
at the time of its formation , the umc had about 11 million members in nearly 42,000 congregations . 
at the time of its formation , the umc had about 11 million members in nearly 42,000 congregations . 
in 2005 , there were about 8 million members in over 34,000 congregations . 
in 2005 , there were about 8 million members in over 34,000 congregations . 
texas has the largest number of members , with about 1 million . 
by the opening of the 2008 general conference , total umc membership was estimated at 11.4 million , with about 7.9 million in the u.s. and 3.5 million overseas . 
by the opening of the 2008 general conference , total umc membership was estimated at 11.4 million , with about 7.9 million in the u.s. and 3.5 million overseas . 
by the opening of the 2008 general conference , total umc membership was estimated at 11.4 million , with about 7.9 million in the u.s. and 3.5 million overseas . 
the umc is also a member of the wesleyan holiness consortium , which seeks to reconceive and promote biblical holiness in today 's church . 
it is also active in the world methodist council , an interdenominational group composed of various churches in the tradition of john wesley to promote the gospel throughout the world . 
on july 18 , 2006 , delegates to the world methodist council voted unanimously to adopt the `` joint declaration on the doctrine of justification '' , which was approved in 1999 by the vatican and the lutheran world federation . 
the french and indian war -lrb- 1754 -- 1763 -rrb- was the north american theater of the worldwide seven years ' war . 
the war was fought between the colonies of british america and new france , with both sides supported by military units from their parent countries of great britain and france , as well as native american allies . 
at the start of the war , the french north american colonies had a population of roughly 60,000 european settlers , compared with 2 million in the british north american colonies . 
at the start of the war , the french north american colonies had a population of roughly 60,000 european settlers , compared with 2 million in the british north american colonies . 
the war was fought primarily along the frontiers between new france and the british colonies , from virginia in the south to nova scotia in the north . 
it began with a dispute over control of the confluence of the allegheny and monongahela rivers , called the forks of the ohio , and the site of the french fort duquesne and present-day pittsburgh , pennsylvania . 
the dispute erupted into violence in the battle of jumonville glen in may 1754 , during which virginia militiamen under the command of 22-year-old george washington ambushed a french patrol . 
in 1755 , six colonial governors in north america met with general edward braddock , the newly arrived british army commander , and planned a four-way attack on the french . 
none succeeded and the main effort by braddock was a disaster ; he was defeated in the battle of the monongahela on july 9 , 1755 and died a few days later . 
british operations in 1755 , 1756 and 1757 in the frontier areas of pennsylvania and new york all failed , due to a combination of poor management , internal divisions , and effective canadian scouts , french regular forces , and indian warrior allies . 
in 1755 , the british captured fort beauséjour on the border separating nova scotia from acadia ; soon afterward they ordered the expulsion of the acadians . 
in 1755 , the british captured fort beauséjour on the border separating nova scotia from acadia ; soon afterward they ordered the expulsion of the acadians . 
william pitt came to power and significantly increased british military resources in the colonies at a time when france was unwilling to risk large convoys to aid the limited forces it had in new france . 
william pitt came to power and significantly increased british military resources in the colonies at a time when france was unwilling to risk large convoys to aid the limited forces it had in new france . 
france concentrated its forces against prussia and its allies in the european theatre of the war . 
though the british were later defeated at sainte foy in quebec , the french ceded canada in accordance with the 1763 treaty . 
france ceded its territory east of the mississippi to great britain . 
it ceded french louisiana west of the mississippi river -lrb- including new orleans -rrb- to its ally spain , in compensation for spain 's loss to britain of florida -lrb- spain had ceded this to britain in exchange for the return of havana , cuba -rrb- . 
france 's colonial presence north of the caribbean was reduced to the islands of saint pierre and miquelon , confirming britain 's position as the dominant colonial power in eastern north america . 
as there had already been a king george 's war in the 1740s , british colonists named the second war in king george 's reign after their opponents , and it became known as the french and indian war . 
this traditional name continues as the standard in the united states , but it obscures the fact that indians fought on both sides of the conflict , and that this was part of the seven years ' war , a much larger conflict between france and great britain . 
this traditional name continues as the standard in the united states , but it obscures the fact that indians fought on both sides of the conflict , and that this was part of the seven years ' war , a much larger conflict between france and great britain . 
other , less frequently used names for the war include the fourth intercolonial war and the great war for the empire . 
`` seven years '' refers to events in europe , from the official declaration of war in 1756 to the signing of the peace treaty in 1763 . 
these dates do not correspond with the fighting on mainland north america , where the fighting between the two colonial powers was largely concluded in six years , from the battle of jumonville glen in 1754 to the capture of montreal in 1760 . 
these dates do not correspond with the fighting on mainland north america , where the fighting between the two colonial powers was largely concluded in six years , from the battle of jumonville glen in 1754 to the capture of montreal in 1760 . 
these dates do not correspond with the fighting on mainland north america , where the fighting between the two colonial powers was largely concluded in six years , from the battle of jumonville glen in 1754 to the capture of montreal in 1760 . 
the french population numbered about 75,000 and was heavily concentrated along the st. lawrence river valley , with some also in acadia -lrb- present-day new brunswick and parts of nova scotia , including île royale -lrb- present-day cape breton island -rrb- -rrb- . 
the french population numbered about 75,000 and was heavily concentrated along the st. lawrence river valley , with some also in acadia -lrb- present-day new brunswick and parts of nova scotia , including île royale -lrb- present-day cape breton island -rrb- -rrb- . 
french fur traders and trappers traveled throughout the st. lawrence and mississippi watersheds , did business with local tribes , and often married indian women . 
british settlers outnumbered the french 20 to 1 with a population of about 1.5 million ranged along the eastern coast of the continent , from nova scotia and newfoundland in the north , to georgia in the south . 
british settlers outnumbered the french 20 to 1 with a population of about 1.5 million ranged along the eastern coast of the continent , from nova scotia and newfoundland in the north , to georgia in the south . 
while their population centers were along the coast , the settlements were growing into the interior . 
in between the french and the british , large areas were dominated by native tribes . 
to the north , the mi ` kmaq and the abenaki were engaged in father le loutre 's war and still held sway in parts of nova scotia , acadia , and the eastern portions of the province of canada , as well as much of present-day maine . 
the iroquois confederation dominated much of present-day upstate new york and the ohio country , although the latter also included algonquian-speaking populations of delaware and shawnee , as well as iroquoian-speaking mingo . 
these tribes were formally under iroquois rule , and were limited by them in authority to make agreements . 
further south the southeast interior was dominated by siouan-speaking catawba , muskogee-speaking creek and choctaw , and the iroquoian-speaking cherokee tribes . 
when war broke out , the french used their trading connections to recruit fighters from tribes in western portions of the great lakes region -lrb- an area not directly subject to the conflict between the french and british -rrb- , including the huron , mississauga , ojibwa , winnebago , and potawatomi . 
the british were supported in the war by the iroquois six nations , and also by the cherokee -- until differences sparked the anglo-cherokee war in 1758 . 
at the start of the war , no french regular army troops were stationed in north america , and few british troops . 
at the start of the war , no french regular army troops were stationed in north america , and few british troops . 
most british colonies mustered local militia companies , generally ill trained and available only for short periods , to deal with native threats , but did not have any standing forces . 
the expedition covered about 3,000 miles -lrb- 4,800 km -rrb- between june and november 1749 . 
céloron 's expedition force consisted of about 200 troupes de la marine and 30 indians . 
whenever he encountered british merchants or fur-traders , céloron informed them of the french claims on the territory and told them to leave . 
when céloron 's expedition arrived at logstown , the native americans in the area informed céloron that they owned the ohio country and that they would trade with the british regardless of the french . 
céloron continued south until his expedition reached the confluence of the ohio and the miami rivers , which lay just south of the village of pickawillany , the home of the miami chief known as `` old briton '' . 
céloron threatened `` old briton '' with severe consequences if he continued to trade with the british . 
`` old briton '' ignored the warning . 
in his extensively detailed report , céloron wrote , `` all i can say is that the natives of these localities are very badly disposed towards the french , and are entirely devoted to the english . 
even before his return to montreal , reports on the situation in the ohio country were making their way to london and paris , each side proposing that action be taken . 
william shirley , the expansionist governor of the province of massachusetts bay , was particularly forceful , stating that british colonists would not be safe as long as the french were present . 
in 1749 the british government gave land to the ohio company of virginia for the purpose of developing trade and settlements in the ohio country . 
in 1749 the british government gave land to the ohio company of virginia for the purpose of developing trade and settlements in the ohio country . 
in 1750 christopher gist , acting on behalf of both virginia and the company , explored the ohio territory and opened negotiations with the indian tribes at logstown . 
he completed the 1752 treaty of logstown in which the local indians , through their `` half-king '' tanacharison and an iroquois representative , agreed to terms that included permission to build a `` strong house '' at the mouth of the monongahela river -lrb- the site of present-day pittsburgh , pennsylvania -rrb- . 
he completed the 1752 treaty of logstown in which the local indians , through their `` half-king '' tanacharison and an iroquois representative , agreed to terms that included permission to build a `` strong house '' at the mouth of the monongahela river -lrb- the site of present-day pittsburgh , pennsylvania -rrb- . 
the war of the austrian succession -lrb- whose north american theater is known as king george 's war -rrb- formally ended in 1748 with the signing of the treaty of aix-la-chapelle . 
the war of the austrian succession -lrb- whose north american theater is known as king george 's war -rrb- formally ended in 1748 with the signing of the treaty of aix-la-chapelle . 
the issues of conflicting territorial claims between british and french colonies in north america were turned over to a commission to resolve , but it reached no decision . 
frontiers from between nova scotia and acadia in the north , to the ohio country in the south , were claimed by both sides . 
on march 17 , 1752 , the governor-general of new france , marquis de la jonquière , died and was temporarily replaced by charles le moyne de longueuil . 
langlade was given 300 men , including french-canadians and warriors of the ottawa . 
his objective was to punish the miami people of pickawillany for not following céloron 's orders to cease trading with the british . 
on june 21 , the french war party attacked the trading centre at pickawillany , capturing three traders and killing 14 people of the miami nation , including old briton . 
in the spring of 1753 , paul marin de la malgue was given command of a 2,000-man force of troupes de la marine and indians . 
he first constructed fort presque isle -lrb- near present-day erie , pennsylvania -rrb- on lake erie 's south shore . 
marin constructed a second fort at fort le boeuf -lrb- present-day waterford , pennsylvania -rrb- , designed to guard the headwaters of leboeuf creek . 
his orders were to protect the king 's land in the ohio valley from the british . 
tanaghrisson , a chief of the mingo , who were remnants of iroquois and other tribes who had been driven west by colonial expansion . 
the british superintendent for indian affairs in the new york region and beyond , johnson was known to the iroquois as warraghiggey , meaning `` he who does great things . '' 
the british superintendent for indian affairs in the new york region and beyond , johnson was known to the iroquois as warraghiggey , meaning `` he who does great things . '' 
in 1746 , johnson was made a colonel of the iroquois . 
mohawk chief hendrick , speaker of their tribal council , insisted that the british abide by their obligations and block french expansion . 
governor robert dinwiddie of virginia was an investor in the ohio company , which stood to lose money if the french held their claim . 
to counter the french military presence in ohio , in october 1753 dinwiddie ordered the 21-year-old major george washington -lrb- whose brother was another ohio company investor -rrb- of the virginia regiment to warn the french to leave virginia territory . 
washington left with a small party , picking up along the way jacob van braam as an interpreter ; christopher gist , a company surveyor working in the area ; and a few mingo led by tanaghrisson . 
on december 12 , washington and his men reached fort le boeuf . 
jacques legardeur de saint-pierre , who succeeded marin as commander of the french forces after the latter died on october 29 , invited washington to dine with him . 
over dinner , washington presented saint-pierre with the letter from dinwiddie demanding an immediate french withdrawal from the ohio country . 
saint-pierre said , `` as to the summons you send me to retire , i do not think myself obliged to obey it . '' 
he told washington that france 's claim to the region was superior to that of the british , since rené-robert cavelier , sieur de la salle had explored the ohio country nearly a century earlier . 
governor duquesne sent additional french forces under claude-pierre pecaudy de contrecœur to relieve saint-pierre during the same period , and contrecœur led 500 men south from fort venango on april 5 , 1754 . 
even before washington returned , dinwiddie had sent a company of 40 men under william trent to that point , where in the early months of 1754 they began construction of a small stockaded fort . 
he purchased their construction tools to continue building what became fort duquesne . 
learning of a french scouting party in the area , washington , with tanaghrisson and his party , surprised the canadians on may 28 in what became known as the battle of jumonville glen . 
they killed many of the canadians , including their commanding officer , joseph coulon de jumonville , whose head was reportedly split open by tanaghrisson with a tomahawk . 
the historian fred anderson suggests that tanaghrisson was acting to gain the support of the british and regain authority over his own people . 
after several months of negotiations , the government of the duke of newcastle decided to send an army expedition the following year to dislodge the french . 
word of the british military plans leaked to france well before braddock 's departure for north america . 
in response , king louis xv dispatched six regiments to new france under the command of baron dieskau in 1755 . 
the british , intending to blockade french ports , sent out their fleet in february 1755 , but the french fleet had already sailed . 
an early important political response to the opening of hostilities was the convening of the albany congress in june and july , 1754 . 
the goal of the congress was to formalize a unified front in trade and negotiations with various indians , since allegiance of the various tribes and nations was seen to be pivotal in the success in the war that was unfolding . 
the plan that the delegates agreed to was never ratified by the colonial legislatures nor approved of by the crown . 
nevertheless , the format of the congress and many specifics of the plan became the prototype for confederation during the war of independence . 
braddock -lrb- with george washington as one of his aides -rrb- led about 1,500 army troops and provincial militia on an expedition in june 1755 to take fort duquesne . 
the expedition was a disaster . 
approximately 1,000 british soldiers were killed or injured . 
two future opponents in the american revolutionary war , washington and thomas gage , played key roles in organizing the retreat . 
the french acquired a copy of the british war plans , including the activities of shirley and johnson . 
shirley 's efforts to fortify oswego were bogged down in logistical difficulties , exacerbated by shirley 's inexperience in managing large expeditions . 
in conjunction , shirley was made aware that the french were massing for an attack on fort oswego in his absence when he planned to attack fort niagara . 
as a response , shirley left garrisons at oswego , fort bull , and fort williams -lrb- the latter two located on the oneida carry between the mohawk river and wood creek at present-day rome , new york -rrb- . 
johnson 's expedition was better organized than shirley 's , which was noticed by new france 's governor , the marquis de vaudreuil . 
when johnson was seen as the larger threat , vaudreuil sent dieskau to fort st. frédéric to meet that threat . 
the battle ended inconclusively , with both sides withdrawing from the field . 
johnson 's advance stopped at fort william henry , and the french withdrew to ticonderoga point , where they began the construction of fort carillon -lrb- later renamed fort ticonderoga after british capture in 1759 -rrb- . 
johnson 's advance stopped at fort william henry , and the french withdrew to ticonderoga point , where they began the construction of fort carillon -lrb- later renamed fort ticonderoga after british capture in 1759 -rrb- . 
colonel monckton , in the sole british success that year , captured fort beauséjour in june 1755 , cutting the french fortress at louisbourg off from land-based reinforcements . 
to cut vital supplies to louisbourg , nova scotia 's governor charles lawrence ordered the deportation of the french-speaking acadian population from the area . 
other than the campaigns to expel the acadians -lrb- ranging around the bay of fundy , on the petitcodiac and st. john rivers , and île saint-jean -rrb- , the only clashes of any size were at petitcodiac in 1755 and at bloody creek near annapolis royal in 1757 . 
following the death of braddock , william shirley assumed command of british forces in north america . 
at a meeting in albany in december 1755 , he laid out his plans for 1756 . 
in addition to renewing the efforts to capture niagara , crown point and duquesne , he proposed attacks on fort frontenac on the north shore of lake ontario and an expedition through the wilderness of the maine district and down the chaudière river to attack the city of quebec . 
in addition to renewing the efforts to capture niagara , crown point and duquesne , he proposed attacks on fort frontenac on the north shore of lake ontario and an expedition through the wilderness of the maine district and down the chaudière river to attack the city of quebec . 
newcastle replaced him in january 1756 with lord loudoun , with major general james abercrombie as his second in command . 
french regular army reinforcements arrived in new france in may 1756 , led by major general louis-joseph de montcalm and seconded by the chevalier de lévis and colonel françois-charles de bourlamaque , all experienced veterans from the war of the austrian succession . 
during that time in europe , on may 18 , 1756 , england formally declared war on france , which expanded the war into europe , which was later to be known as the seven years ' war . 
scouts had reported the weakness of the british supply chain , so he ordered an attack against the forts shirley had erected at the oneida carry . 
in the march battle of fort bull , french forces destroyed the fort and large quantities of supplies , including 45,000 pounds of gunpowder . 
in the march battle of fort bull , french forces destroyed the fort and large quantities of supplies , including 45,000 pounds of gunpowder . 
they set back any british hopes for campaigns on lake ontario , and endangered the oswego garrison , already short on supplies . 
when he arrived in albany , abercrombie refused to take any significant actions until loudoun approved them . 
building on vaudreuil 's work harassing the oswego garrison , montcalm executed a strategic feint by moving his headquarters to ticonderoga , as if to presage another attack along lake george . 
with abercrombie pinned down at albany , montcalm slipped away and led the successful attack on oswego in august . 
in the aftermath , montcalm and the indians under his command disagreed about the disposition of prisoners ' personal effects . 
loudoun , a capable administrator but a cautious field commander , planned one major operation for 1757 : an attack on new france 's capital , quebec . 
leaving a sizable force at fort william henry to distract montcalm , he began organizing for the expedition to quebec . 
he was then ordered by william pitt , the secretary of state responsible for the colonies , to attack louisbourg first . 
faced with this strength , loudoun returned to new york amid news that a massacre had occurred at fort william henry . 
french irregular forces -lrb- canadian scouts and indians -rrb- harassed fort william henry throughout the first half of 1757 . 
in february they launched a daring raid against the position across the frozen lake george , destroying storehouses and buildings outside the main fortification . 
when the withdrawal began , some of montcalm 's indian allies , angered at the lost opportunity for loot , attacked the british column , killing and capturing several hundred men , women , children , and slaves . 
vaudreuil and montcalm were minimally resupplied in 1758 , as the british blockade of the french coastline limited french shipping . 
the situation in new france was further exacerbated by a poor harvest in 1757 , a difficult winter , and the allegedly corrupt machinations of françois bigot , the intendant of the territory . 
montcalm focused his meager resources on the defense of the st. lawrence , with primary defenses at carillon , quebec , and louisbourg , while vaudreuil argued unsuccessfully for a continuation of the raiding tactics that had worked quite effectively in previous years . 
the british failures in north america , combined with other failures in the european theater , led to the fall from power of newcastle and his principal military advisor , the duke of cumberland . 
he embarked on a plan for the 1758 campaign that was largely developed by loudoun . 
pitt 's plan called for three major offensive actions involving large numbers of regular troops , supported by the provincial militias , aimed at capturing the heartlands of new france . 
two of the expeditions were successful , with fort duquesne and louisbourg falling to sizable british forces . 
the third invasion was stopped with the improbable french victory in the battle of carillon , in which 3,600 frenchmen famously and decisively defeated abercrombie 's force of 18,000 regulars , militia and native american allies outside the fort the french called carillon and the british called ticonderoga . 
the third invasion was stopped with the improbable french victory in the battle of carillon , in which 3,600 frenchmen famously and decisively defeated abercrombie 's force of 18,000 regulars , militia and native american allies outside the fort the french called carillon and the british called ticonderoga . 
abercrombie saved something from the disaster when he sent john bradstreet on an expedition that successfully destroyed fort frontenac , including caches of supplies destined for new france 's western forts and furs destined for europe . 
abercrombie was recalled and replaced by jeffery amherst , victor at louisbourg . 
in the aftermath of generally poor french results in most theaters of the seven years ' war in 1758 , france 's new foreign minister , the duc de choiseul , decided to focus on an invasion of britain , to draw british resources away from north america and the european mainland . 
the invasion failed both militarily and politically , as pitt again planned significant campaigns against new france , and sent funds to britain 's ally on the mainland , prussia , and the french navy failed in the 1759 naval battles at lagos and quiberon bay . 
the invasion failed both militarily and politically , as pitt again planned significant campaigns against new france , and sent funds to britain 's ally on the mainland , prussia , and the french navy failed in the 1759 naval battles at lagos and quiberon bay . 
british victories continued in all theaters in the annus mirabilis of 1759 , when they finally captured ticonderoga , james wolfe defeated montcalm at quebec -lrb- in a battle that claimed the lives of both commanders -rrb- , and victory at fort niagara successfully cut off the french frontier forts further to the west and south . 
british victories continued in all theaters in the annus mirabilis of 1759 , when they finally captured ticonderoga , james wolfe defeated montcalm at quebec -lrb- in a battle that claimed the lives of both commanders -rrb- , and victory at fort niagara successfully cut off the french frontier forts further to the west and south . 
the victory was made complete in 1760 when , despite losing outside quebec city in the battle of sainte-foy , the british were able to prevent the arrival of french relief ships in the naval battle of the restigouche while armies marched on montreal from three sides . 
the victory was made complete in 1760 when , despite losing outside quebec city in the battle of sainte-foy , the british were able to prevent the arrival of french relief ships in the naval battle of the restigouche while armies marched on montreal from three sides . 
in september 1760 , and before any hostilities erupted , governor vaudreuil negotiated from montreal a capitulation with general amherst . 
amherst granted vaudreuil 's request that any french residents who chose to remain in the colony would be given freedom to continue worshiping in their roman catholic tradition , continued ownership of their property , and the right to remain undisturbed in their homes . 
in september 1760 , and before any hostilities erupted , governor vaudreuil negotiated from montreal a capitulation with general amherst . 
the war in north america officially ended with the signing of the treaty of paris on 10 february 1763 , and war in the european theatre of the seven years ' war was settled by the treaty of hubertusburg on 15 february 1763 . 
the war in north america officially ended with the signing of the treaty of paris on 10 february 1763 , and war in the european theatre of the seven years ' war was settled by the treaty of hubertusburg on 15 february 1763 . 
the british offered france the choice of surrendering either its continental north american possessions east of the mississippi or the caribbean islands of guadeloupe and martinique , which had been occupied by the british . 
they viewed the economic value of the caribbean islands ' sugar cane to be greater and easier to defend than the furs from the continent . 
britain gained control of french canada and acadia , colonies containing approximately 80,000 primarily french-speaking roman catholic residents . 
the deportation of acadians beginning in 1755 resulted in land made available to migrants from europe and the colonies further south . 
the british resettled many acadians throughout its north american provinces , but many went to france , and some went to new orleans , which they had expected to remain french . 
others migrated to places like saint-domingue , and fled to new orleans after the haitian revolution . 
following the treaty , king george iii issued the royal proclamation of 1763 on october 7 , 1763 , which outlined the division and administration of the newly conquered territory , and to some extent continues to govern relations between the government of modern canada and the first nations . 
following the treaty , king george iii issued the royal proclamation of 1763 on october 7 , 1763 , which outlined the division and administration of the newly conquered territory , and to some extent continues to govern relations between the government of modern canada and the first nations . 
included in its provisions was the reservation of lands west of the appalachian mountains to its indian population , a demarcation that was at best a temporary impediment to a rising tide of westward-bound settlers . 
most went to cuba , including the entire governmental records from st. augustine , although some christianized yamasee were resettled to the coast of mexico . 
the ohio country was particularly vulnerable to legal and illegal settlement due to the construction of military roads to the area by braddock and forbes . 
although the spanish takeover of the louisiana territory -lrb- which was not completed until 1769 -rrb- had modest repercussions , the british takeover of spanish florida resulted in the westward migration of tribes that did not want to do business with the british , and a rise in tensions between the choctaw and the creek , historic enemies whose divisions the british at times exploited . 
although the spanish takeover of the louisiana territory -lrb- which was not completed until 1769 -rrb- had modest repercussions , the british takeover of spanish florida resulted in the westward migration of tribes that did not want to do business with the british , and a rise in tensions between the choctaw and the creek , historic enemies whose divisions the british at times exploited . 
for many native populations , the elimination of french power in north america meant the disappearance of a strong ally and counterweight to british expansion , leading to their ultimate dispossession . 
philosophers in antiquity used the concept of force in the study of stationary and moving objects and simple machines , but thinkers such as aristotle and archimedes retained fundamental errors in understanding force . 
a fundamental error was the belief that a force is required to maintain motion , even at a constant velocity . 
with his mathematical insight , sir isaac newton formulated laws of motion that were not improved-on for nearly three hundred years . 
with his mathematical insight , sir isaac newton formulated laws of motion that were not improved-on for nearly three hundred years . 
by the early 20th century , einstein developed a theory of relativity that correctly predicted the action of forces on objects with increasing momenta near the speed of light , and also provided insight into the forces produced by gravitation and inertia . 
with modern insights into quantum mechanics and technology that can accelerate particles close to the speed of light , particle physics has devised a standard model to describe forces between particles smaller than atoms . 
the standard model predicts that exchanged particles called gauge bosons are the fundamental means by which forces are emitted and absorbed . 
only four main interactions are known : in order of decreasing strength , they are : strong , electromagnetic , weak , and gravitational. :2 -- 10:79 high-energy particle physics observations made during the 1970s and 1980s confirmed that the weak and electromagnetic forces are expressions of a more fundamental electroweak interaction . 
only four main interactions are known : in order of decreasing strength , they are : strong , electromagnetic , weak , and gravitational. :2 -- 10:79 high-energy particle physics observations made during the 1970s and 1980s confirmed that the weak and electromagnetic forces are expressions of a more fundamental electroweak interaction . 
only four main interactions are known : in order of decreasing strength , they are : strong , electromagnetic , weak , and gravitational. :2 -- 10:79 high-energy particle physics observations made during the 1970s and 1980s confirmed that the weak and electromagnetic forces are expressions of a more fundamental electroweak interaction . 
aristotle provided a philosophical discussion of the concept of a force as an integral part of aristotelian cosmology . 
aristotle provided a philosophical discussion of the concept of a force as an integral part of aristotelian cosmology . 
in aristotle 's view , the terrestrial sphere contained four elements that come to rest at different `` natural places '' therein . 
aristotle believed that motionless objects on earth , those composed mostly of the elements earth and water , to be in their natural place on the ground and that they will stay that way if left alone . 
he distinguished between the innate tendency of objects to find their `` natural place '' -lrb- e.g. , for heavy bodies to fall -rrb- , which led to `` natural motion '' , and unnatural or forced motion , which required continued application of a force . 
the shortcomings of aristotelian physics would not be fully corrected until the 17th century work of galileo galilei , who was influenced by the late medieval idea that objects in forced motion carried an innate force of impetus . 
the shortcomings of aristotelian physics would not be fully corrected until the 17th century work of galileo galilei , who was influenced by the late medieval idea that objects in forced motion carried an innate force of impetus . 
the shortcomings of aristotelian physics would not be fully corrected until the 17th century work of galileo galilei , who was influenced by the late medieval idea that objects in forced motion carried an innate force of impetus . 
galileo constructed an experiment in which stones and cannonballs were both rolled down an incline to disprove the aristotelian theory of motion early in the 17th century . 
he showed that the bodies were accelerated by gravity to an extent that was independent of their mass and argued that objects retain their velocity unless acted on by a force , for example friction . 
newton 's first law of motion states that objects continue to move in a state of constant velocity unless acted upon by an external net force or resultant force . 
this law is an extension of galileo 's insight that constant velocity was associated with a lack of net force -lrb- see a more detailed description of this below -rrb- . 
newton proposed that every object with mass has an innate inertia that functions as the fundamental equilibrium `` natural state '' in place of the aristotelian idea of the `` natural state of rest '' . 
by making rest physically indistinguishable from non-zero constant velocity , newton 's first law directly connects inertia with the concept of relative velocities . 
in other words , to phrase matters more technically , the laws of physics are the same in every inertial frame of reference , that is , in all frames related by a galilean transformation . 
for instance , while traveling in a moving vehicle at a constant velocity , the laws of physics do not change from being at rest . 
this is true even though another person who is observing the moving vehicle pass by also observes the ball follow a curving parabolic path in the same direction as the motion of the vehicle . 
from the perspective of the person in the car , the vehicle and everything inside of it is at rest : it is the outside world that is moving with a constant speed in the opposite direction . 
inertia therefore applies equally well to constant velocity motion as it does to rest . 
the concept of inertia can be further generalized to explain the tendency of objects to continue in many different forms of constant motion , even those that are not strictly constant velocity . 
the rotational inertia of planet earth is what fixes the constancy of the length of a day and the length of a year . 
albert einstein extended the principle of inertia further when he explained that reference frames subject to constant acceleration , such as those free-falling toward a gravitating object , were physically equivalent to inertial reference frames . 
this is why , for example , astronauts experience weightlessness when in free-fall orbit around the earth , and why newton 's laws of motion are more easily discernible in such environments . 
this principle of equivalence was one of the foundational underpinnings for the development of the general theory of relativity . 
newton 's second law asserts the direct proportionality of acceleration to force and the inverse proportionality of acceleration to mass . 
accelerations can be defined through kinematic measurements . 
general relativity offers an equivalence between space-time and mass , but lacking a coherent theory of quantum gravity , it is unclear as to how or whether this connection is relevant on microscales . 
general relativity offers an equivalence between space-time and mass , but lacking a coherent theory of quantum gravity , it is unclear as to how or whether this connection is relevant on microscales . 
with some justification , newton 's second law can be taken as a quantitative definition of mass by writing the law as an equality ; the relative units of force and mass then are fixed . 
newton 's third law is a result of applying symmetry to situations where forces can be attributed to the presence of different objects . 
newton 's third law is a result of applying symmetry to situations where forces can be attributed to the presence of different objects . 
the third law means that all forces are interactions between different bodies , -lsb- note 3 -rsb- and thus that there is no such thing as a unidirectional force or a force that acts on only one body . 
f and − f are equal in magnitude and opposite in direction . 
alternatively , if an external force acts on the system , then the center of mass will experience an acceleration proportional to the magnitude of the external force divided by the mass of the system. :19 -1 
this means that in a closed system of particles , there are no internal forces that are unbalanced . 
alternatively , if an external force acts on the system , then the center of mass will experience an acceleration proportional to the magnitude of the external force divided by the mass of the system. :19 -1 
since forces are perceived as pushes or pulls , this can provide an intuitive understanding for describing forces . 
as with other physical concepts -lrb- e.g. temperature -rrb- , the intuitive understanding of forces is quantified using precise operational definitions that are consistent with direct observations and compared to a standard measurement scale . 
through experimentation , it is determined that laboratory measurements of forces are fully consistent with the conceptual definition of force offered by newtonian mechanics . 
through experimentation , it is determined that laboratory measurements of forces are fully consistent with the conceptual definition of force offered by newtonian mechanics . 
because of these characteristics , forces are classified as `` vector quantities '' . 
this means that forces follow a different set of mathematical rules than physical quantities that do not have direction -lrb- denoted scalar quantities -rrb- . 
associating forces with vectors avoids such problems . 
if both of these pieces of information are not known for each force , the situation is ambiguous . 
associating forces with vectors avoids such problems . 
historically , forces were first quantitatively investigated in conditions of static equilibrium where several forces canceled each other out . 
such experiments demonstrate the crucial properties that forces are additive vector quantities : they have magnitude and direction . 
when two forces act on a point particle , the resulting force , the resultant -lrb- also called the net force -rrb- , can be determined by following the parallelogram rule of vector addition : the addition of two vectors represented by sides of a parallelogram , gives an equivalent resultant vector that is equal in magnitude and direction to the transversal of the parallelogram . 
however , if the forces are acting on an extended body , their respective lines of application must also be specified in order to account for their effects on the motion of the body . 
when two forces act on a point particle , the resulting force , the resultant -lrb- also called the net force -rrb- , can be determined by following the parallelogram rule of vector addition : the addition of two vectors represented by sides of a parallelogram , gives an equivalent resultant vector that is equal in magnitude and direction to the transversal of the parallelogram . 
as well as being added , forces can also be resolved into independent components at right angles to each other . 
a horizontal force pointing northeast can therefore be split into two forces , one pointing north , and one pointing east . 
summing these component forces using vector addition yields the original force . 
this is because , for orthogonal components , the components of the vector sum are uniquely determined by the scalar addition of the components of the individual vectors . 
orthogonal force vectors can be three-dimensional with the third component being at right-angles to the other two . 
pushing against an object on a frictional surface can result in a situation where the object does not move because the applied force is opposed by static friction , generated between the object and the table surface . 
pushing against an object on a frictional surface can result in a situation where the object does not move because the applied force is opposed by static friction , generated between the object and the table surface . 
for a situation with no movement , the static friction force exactly balances the applied force resulting in no acceleration . 
the static friction increases or decreases in response to the applied force up to an upper limit determined by the characteristics of the contact between the surface and the object . 
a static equilibrium between two forces is the most usual way of measuring forces , using simple devices such as weighing scales and spring balances . 
for example , an object suspended on a vertical spring scale experiences the force of gravity acting on the object balanced by a force applied by the `` spring reaction force '' , which equals the object 's weight . 
for example , an object suspended on a vertical spring scale experiences the force of gravity acting on the object balanced by a force applied by the `` spring reaction force '' , which equals the object 's weight . 
using such tools , some quantitative force laws were discovered : that the force of gravity is proportional to volume for objects of constant density -lrb- widely exploited for millennia to define standard weights -rrb- ; archimedes ' principle for buoyancy ; archimedes ' analysis of the lever ; boyle 's law for gas pressure ; and hooke 's law for springs . 
these were all formulated and experimentally verified before isaac newton expounded his three laws of motion . 
dynamic equilibrium was first described by galileo who noticed that certain assumptions of aristotelian physics were contradicted by observations and logic . 
galileo concluded that motion in a constant velocity was completely equivalent to rest . 
galileo concluded that motion in a constant velocity was completely equivalent to rest . 
thus , in an aristotelian universe , the falling cannonball would land behind the foot of the mast of a moving ship . 
however , when this experiment is actually conducted , the cannonball always falls at the foot of the mast , as if the cannonball knows to travel with the ship despite being separated from it . 
a simple case of dynamic equilibrium occurs in constant velocity motion across a surface with kinetic friction . 
in such a situation , a force is applied in the direction of motion while the kinetic friction force exactly opposes the applied force . 
however , when kinetic friction is taken into consideration it is clear that there is no net force causing constant velocity motion . 
aristotle misinterpreted this motion as being caused by the applied force . 
the notion `` force '' keeps its meaning in quantum mechanics , though one is now dealing with operators instead of classical variables and though the physics is now described by the schrödinger equation instead of newtonian equations . 
the notion `` force '' keeps its meaning in quantum mechanics , though one is now dealing with operators instead of classical variables and though the physics is now described by the schrödinger equation instead of newtonian equations . 
however , the potentials v -lrb- x , y , z -rrb- or fields , from which the forces generally can be derived , are treated similar to classical position variables , i.e. , . 
this has the consequence that the results of a measurement are now sometimes `` quantized '' , i.e. they appear in discrete portions . 
the notion `` force '' keeps its meaning in quantum mechanics , though one is now dealing with operators instead of classical variables and though the physics is now described by the schrödinger equation instead of newtonian equations . 
however , already in quantum mechanics there is one `` caveat '' , namely the particles acting onto each other do not only possess the spatial variable , but also a discrete intrinsic angular momentum-like variable called the `` spin '' , and there is the pauli principle relating the space and the spin variables . 
however , already in quantum mechanics there is one `` caveat '' , namely the particles acting onto each other do not only possess the spatial variable , but also a discrete intrinsic angular momentum-like variable called the `` spin '' , and there is the pauli principle relating the space and the spin variables . 
depending on the value of the spin , identical particles split into two different classes , fermions and bosons . 
if two identical fermions -lrb- e.g. electrons -rrb- have a symmetric spin function -lrb- e.g. parallel spins -rrb- the spatial variables must be antisymmetric -lrb- i.e. they exclude each other from their places much as if there was a repulsive force -rrb- , and vice versa , i.e. for antiparallel spins the position variables must be symmetric -lrb- i.e. the apparent force must be attractive -rrb- . 
if two identical fermions -lrb- e.g. electrons -rrb- have a symmetric spin function -lrb- e.g. parallel spins -rrb- the spatial variables must be antisymmetric -lrb- i.e. they exclude each other from their places much as if there was a repulsive force -rrb- , and vice versa , i.e. for antiparallel spins the position variables must be symmetric -lrb- i.e. the apparent force must be attractive -rrb- . 
in modern particle physics , forces and the acceleration of particles are explained as a mathematical by-product of exchange of momentum-carrying gauge bosons . 
with the development of quantum field theory and general relativity , it was realized that force is a redundant concept arising from conservation of momentum -lrb- 4-momentum in relativity and momentum of virtual particles in quantum electrodynamics -rrb- . 
the conservation of momentum can be directly derived from the homogeneity or symmetry of space and so is usually considered more fundamental than the concept of a force . 
while sophisticated mathematical descriptions are needed to predict , in full detail , the accurate result of such interactions , there is a conceptually simple way to describe such interactions through the use of feynman diagrams . 
in a feynman diagram , each matter particle is represented as a straight line -lrb- see world line -rrb- traveling through time , which normally increases up or to the right in the diagram . 
all of the forces in the universe are based on four fundamental interactions . 
the strong and weak forces are nuclear forces that act only at very short distances , and are responsible for the interactions between subatomic particles , including nucleons and compound nuclei . 
the electromagnetic force acts between electric charges , and the gravitational force acts between masses . 
the electromagnetic force acts between electric charges , and the gravitational force acts between masses . 
for example , friction is a manifestation of the electromagnetic force acting between the atoms of two surfaces , and the pauli exclusion principle , which does not permit atoms to pass through each other . 
for example , isaac newton unified the force responsible for objects falling at the surface of the earth with the force responsible for the orbits of celestial mechanics in his universal theory of gravitation . 
in the 20th century , the development of quantum mechanics led to a modern understanding that the first three fundamental forces -lrb- all except gravity -rrb- are manifestations of matter -lrb- fermions -rrb- interacting by exchanging virtual particles called gauge bosons . 
physicists are still attempting to develop self-consistent unification models that would combine all four fundamental interactions into a theory of everything . 
physicists are still attempting to develop self-consistent unification models that would combine all four fundamental interactions into a theory of everything . 
what we now call gravity was not identified as a universal force until the work of isaac newton . 
galileo was instrumental in describing the characteristics of falling objects by determining that the acceleration of every object in free-fall was constant and independent of the mass of the object . 
today , this acceleration due to gravity towards the surface of the earth is usually designated as and has a magnitude of about 9.81 meters per second squared -lrb- this measurement is taken from sea level and may vary depending on location -rrb- , and points toward the center of the earth . 
today , this acceleration due to gravity towards the surface of the earth is usually designated as and has a magnitude of about 9.81 meters per second squared -lrb- this measurement is taken from sea level and may vary depending on location -rrb- , and points toward the center of the earth . 
this observation means that the force of gravity on an object at the earth 's surface is directly proportional to the object 's mass . 
newton came to realize that the effects of gravity might be observed in different ways at larger distances . 
in particular , newton determined that the acceleration of the moon around the earth could be ascribed to the same force of gravity if the acceleration due to gravity decreased as an inverse square law . 
further , newton realized that the acceleration due to gravity is proportional to the mass of the attracting body . 
combining these ideas gives a formula that relates the mass -lrb- -rrb- and the radius -lrb- -rrb- of the earth to the gravitational acceleration : 
this constant has come to be known as newton 's universal gravitation constant , though its value was unknown in newton 's lifetime . 
not until 1798 was henry cavendish able to make the first measurement of using a torsion balance ; this was widely reported in the press as a measurement of the mass of the earth since knowing could allow one to solve for the earth 's mass given the above equation . 
not until 1798 was henry cavendish able to make the first measurement of using a torsion balance ; this was widely reported in the press as a measurement of the mass of the earth since knowing could allow one to solve for the earth 's mass given the above equation . 
newton , however , realized that since all celestial bodies followed the same laws of motion , his law of gravity had to be universal . 
it was only the orbit of the planet mercury that newton 's law of gravitation seemed not to fully explain . 
some astrophysicists predicted the existence of another planet -lrb- vulcan -rrb- that would explain the discrepancies ; however , despite some early indications , no such planet could be found . 
when albert einstein formulated his theory of general relativity -lrb- gr -rrb- he turned his attention to the problem of mercury 's orbit and found that his theory added a correction , which could account for the discrepancy . 
when albert einstein formulated his theory of general relativity -lrb- gr -rrb- he turned his attention to the problem of mercury 's orbit and found that his theory added a correction , which could account for the discrepancy . 
when albert einstein formulated his theory of general relativity -lrb- gr -rrb- he turned his attention to the problem of mercury 's orbit and found that his theory added a correction , which could account for the discrepancy . 
since then , and so far , general relativity has been acknowledged as the theory that best explains gravity . 
thus , the straight line path in space-time is seen as a curved line in space , and it is called the ballistic trajectory of the object . 
the time derivative of the changing momentum of the object is what we label as `` gravitational force '' . 
it is only when observing the motion in a global sense that the curvature of space-time can be observed and the force is inferred from the object 's curved path . 
through combining the definition of electric current as the time rate of change of electric charge , a rule of vector multiplication called lorentz 's law describes the force on a charge moving in a magnetic field . 
the connection between electricity and magnetism allows for the description of a unified electromagnetic force that acts on a charge . 
through combining the definition of electric current as the time rate of change of electric charge , a rule of vector multiplication called lorentz 's law describes the force on a charge moving in a magnetic field . 
this force can be written as a sum of the electrostatic force -lrb- due to the electric field -rrb- and the magnetic force -lrb- due to the magnetic field -rrb- . 
the origin of electric and magnetic fields would not be fully explained until 1864 when james clerk maxwell unified a number of earlier theories into a set of 20 scalar equations , which were later reformulated into 4 vector equations by oliver heaviside and josiah willard gibbs . 
the origin of electric and magnetic fields would not be fully explained until 1864 when james clerk maxwell unified a number of earlier theories into a set of 20 scalar equations , which were later reformulated into 4 vector equations by oliver heaviside and josiah willard gibbs . 
the origin of electric and magnetic fields would not be fully explained until 1864 when james clerk maxwell unified a number of earlier theories into a set of 20 scalar equations , which were later reformulated into 4 vector equations by oliver heaviside and josiah willard gibbs . 
the origin of electric and magnetic fields would not be fully explained until 1864 when james clerk maxwell unified a number of earlier theories into a set of 20 scalar equations , which were later reformulated into 4 vector equations by oliver heaviside and josiah willard gibbs . 
this led maxwell to discover that electric and magnetic fields could be `` self-generating '' through a wave that traveled at a speed that he calculated to be the speed of light . 
however , attempting to reconcile electromagnetic theory with two observations , the photoelectric effect , and the nonexistence of the ultraviolet catastrophe , proved troublesome . 
through the work of leading theoretical physicists , a new theory of electromagnetism was developed using quantum mechanics . 
this final modification to electromagnetic theory ultimately led to quantum electrodynamics -lrb- or qed -rrb- , which fully describes all electromagnetic phenomena as being mediated by wave -- particles known as photons . 
this final modification to electromagnetic theory ultimately led to quantum electrodynamics -lrb- or qed -rrb- , which fully describes all electromagnetic phenomena as being mediated by wave -- particles known as photons . 
this final modification to electromagnetic theory ultimately led to quantum electrodynamics -lrb- or qed -rrb- , which fully describes all electromagnetic phenomena as being mediated by wave -- particles known as photons . 
it is a common misconception to ascribe the stiffness and rigidity of solid matter to the repulsion of like charges under the influence of the electromagnetic force . 
however , these characteristics actually result from the pauli exclusion principle . 
this means that it takes energy to pack them together . 
while this effect is manifested macroscopically as a structural force , it is technically only the result of the existence of a finite set of electron states . 
it is a common misconception to ascribe the stiffness and rigidity of solid matter to the repulsion of like charges under the influence of the electromagnetic force . 
however , these characteristics actually result from the pauli exclusion principle . 
this means that it takes energy to pack them together . 
while this effect is manifested macroscopically as a structural force , it is technically only the result of the existence of a finite set of electron states . 
the strong force only acts directly upon elementary particles . 
however , a residual of the force is observed between hadrons -lrb- the best known example being the force that acts between nucleons in atomic nuclei -rrb- as the nuclear force . 
however , a residual of the force is observed between hadrons -lrb- the best known example being the force that acts between nucleons in atomic nuclei -rrb- as the nuclear force . 
here the strong force acts indirectly , transmitted as gluons , which form part of the virtual pi and rho mesons , which classically transmit the nuclear force -lrb- see this topic for more -rrb- . 
this phenomenon is called color confinement . 
the weak force is due to the exchange of the heavy w and z bosons . 
its most familiar effect is beta decay -lrb- of neutrons in atomic nuclei -rrb- and the associated radioactivity . 
its most familiar effect is beta decay -lrb- of neutrons in atomic nuclei -rrb- and the associated radioactivity . 
the word `` weak '' derives from the fact that the field strength is some 1013 times less than that of the strong force . 
a consistent electroweak theory has also been developed , which shows that electromagnetic forces and the weak force are indistinguishable at a temperatures in excess of approximately 1015 kelvins . 
the normal force is due to repulsive forces of interaction between atoms at close contact . 
when their electron clouds overlap , pauli repulsion -lrb- due to fermionic nature of electrons -rrb- follows resulting in the force that acts in a direction normal to the surface interface between two objects. :93 the normal force , for example , is responsible for the structural integrity of tables and floors as well as being the force that responds whenever an external force pushes on a solid object . 
when their electron clouds overlap , pauli repulsion -lrb- due to fermionic nature of electrons -rrb- follows resulting in the force that acts in a direction normal to the surface interface between two objects. :93 the normal force , for example , is responsible for the structural integrity of tables and floors as well as being the force that responds whenever an external force pushes on a solid object . 
when their electron clouds overlap , pauli repulsion -lrb- due to fermionic nature of electrons -rrb- follows resulting in the force that acts in a direction normal to the surface interface between two objects. :93 the normal force , for example , is responsible for the structural integrity of tables and floors as well as being the force that responds whenever an external force pushes on a solid object . 
tension forces can be modeled using ideal strings that are massless , frictionless , unbreakable , and unstretchable . 
they can be combined with ideal pulleys , which allow ideal strings to switch physical direction . 
ideal strings transmit tension forces instantaneously in action-reaction pairs so that if two objects are connected by an ideal string , any force directed along the string by the first object is accompanied by a force directed along the string in the opposite direction by the second object . 
these tandem effects result ultimately in the conservation of mechanical energy since the work done on the load is the same no matter how complicated the machine . 
by connecting the same string multiple times to the same object through the use of a set-up that uses movable pulleys , the tension force on a load can be multiplied . 
newton 's laws and newtonian mechanics in general were first developed to describe how forces affect idealized point particles rather than three-dimensional objects . 
newton 's laws and newtonian mechanics in general were first developed to describe how forces affect idealized point particles rather than three-dimensional objects . 
for example , in extended fluids , differences in pressure result in forces being directed along the pressure gradients as follows : 
however , in real life , matter has extended structure and forces that act on one part of an object might affect other parts of an object . 
however , in real life , matter has extended structure and forces that act on one part of an object might affect other parts of an object . 
the stress tensor accounts for forces that cause all strains -lrb- deformations -rrb- including also tensile stresses and compressions. :133 -- 134:38 -1 -- 38-11 
this formalism includes pressure terms associated with forces that act normal to the cross-sectional area -lrb- the matrix diagonals of the tensor -rrb- as well as shear terms associated with forces that act parallel to the cross-sectional area -lrb- the off-diagonal elements -rrb- . 
this formalism includes pressure terms associated with forces that act normal to the cross-sectional area -lrb- the matrix diagonals of the tensor -rrb- as well as shear terms associated with forces that act parallel to the cross-sectional area -lrb- the off-diagonal elements -rrb- . 
this formalism includes pressure terms associated with forces that act normal to the cross-sectional area -lrb- the matrix diagonals of the tensor -rrb- as well as shear terms associated with forces that act parallel to the cross-sectional area -lrb- the off-diagonal elements -rrb- . 
torque is the rotation equivalent of force in the same way that angle is the rotational equivalent for position , angular velocity for velocity , and angular momentum for momentum . 
as a consequence of newton 's first law of motion , there exists rotational inertia that ensures that all bodies maintain their angular momentum unless acted upon by an unbalanced torque . 
likewise , newton 's second law of motion can be used to derive an analogous equation for the instantaneous angular acceleration of the rigid body : 
this means that the unbalanced centripetal force felt by any object is always directed toward the center of the curving path . 
such forces act perpendicular to the velocity vector associated with the motion of an object , and therefore do not change the speed of the object -lrb- magnitude of the velocity -rrb- , but only the direction of the velocity vector . 
this yields both the tangential force , which accelerates the object by either slowing it down or speeding it up , and the radial -lrb- centripetal -rrb- force , which changes its direction . 
this yields both the tangential force , which accelerates the object by either slowing it down or speeding it up , and the radial -lrb- centripetal -rrb- force , which changes its direction . 
this yields both the tangential force , which accelerates the object by either slowing it down or speeding it up , and the radial -lrb- centripetal -rrb- force , which changes its direction . 
a conservative force that acts on a closed system has an associated mechanical work that allows energy to convert only between kinetic or potential forms . 
a conservative force that acts on a closed system has an associated mechanical work that allows energy to convert only between kinetic or potential forms . 
this means that for a closed system , the net mechanical energy is conserved whenever a conservative force acts on the system . 
the force , therefore , is related directly to the difference in potential energy between two different locations in space , and can be considered to be an artifact of the potential field in the same way that the direction and amount of a flow of water can be considered to be an artifact of the contour map of the elevation of an area . 
the force , therefore , is related directly to the difference in potential energy between two different locations in space , and can be considered to be an artifact of the potential field in the same way that the direction and amount of a flow of water can be considered to be an artifact of the contour map of the elevation of an area . 
for certain physical scenarios , it is impossible to model forces as being due to gradient of potentials . 
for certain physical scenarios , it is impossible to model forces as being due to gradient of potentials . 
for example , friction is caused by the gradients of numerous electrostatic potentials between the atoms , but manifests as a force model that is independent of any macroscale position vector . 
nonconservative forces other than friction include other contact forces , tension , compression , and drag . 
the connection between macroscopic nonconservative forces and microscopic conservative forces is described by detailed treatment with statistical mechanics . 
in macroscopic closed systems , nonconservative forces act to change the internal energies of the system , and are often associated with the transfer of heat . 
in macroscopic closed systems , nonconservative forces act to change the internal energies of the system , and are often associated with the transfer of heat . 
according to the second law of thermodynamics , nonconservative forces necessarily result in energy transformations within closed systems from ordered to more random conditions as entropy increases . 
according to the second law of thermodynamics , nonconservative forces necessarily result in energy transformations within closed systems from ordered to more random conditions as entropy increases . 
the pound-force has a metric counterpart , less commonly used than the newton : the kilogram-force -lrb- kgf -rrb- -lrb- sometimes kilopond -rrb- , is the force exerted by standard gravity on one kilogram of mass . 
the pound-force has a metric counterpart , less commonly used than the newton : the kilogram-force -lrb- kgf -rrb- -lrb- sometimes kilopond -rrb- , is the force exerted by standard gravity on one kilogram of mass . 
the kilogram-force leads to an alternate , but rarely used unit of mass : the metric slug -lrb- sometimes mug or hyl -rrb- is that mass that accelerates at 1 m · s − 2 when subjected to a force of 1 kgf . 
other arcane units of force include the sthène , which is equivalent to 1000 n , and the kip , which is equivalent to 1000 lbf . 
other arcane units of force include the sthène , which is equivalent to 1000 n , and the kip , which is equivalent to 1000 lbf .