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2846158 | https://en.wikipedia.org/wiki/451%20Patientia | 451 Patientia | Patientia (minor planet designation: 451 Patientia) is approximately the 15th-largest asteroid in the asteroid belt with a diameter of 225 km. It was discovered by French astronomer Auguste Charlois on 4 December 1899, and assigned a provisional designation 1899 EY.
It regularly reaches 11th magnitude in brightness, as on 11 January 2013, and 12 December 2017, when in favorable oppositions will be at magnitudes 10.7 and 10.4 respectively, very bright for a later-discovered minor planet.
Multiple photometric studies of this asteroid were performed between 1969 and 2003. The combined data gave an irregular light curve with a synodic period of 9.730 ± 0.004 hours and a brightness variation of 0.05–0.10 in magnitude.
References
External links
Background asteroids
Patientia
Patientia
CU-type asteroids (Tholen)
18991204 |
2846166 | https://en.wikipedia.org/wiki/452%20Hamiltonia | 452 Hamiltonia | Hamiltonia (minor planet designation: 452 Hamiltonia) is an asteroid. It was discovered by James Edward Keeler on 6 December 1899, but was then lost until 1981. Its provisional name was 1899 FD. The asteroid is named for Mount Hamilton, the site of Lick Observatory where Keeler was working when he discovered the asteroid. It was the last asteroid discovery of the 1800s.
L. K. Kristensen at Aarhus University rediscovered 452 Hamiltonia along with 1537 Transylvania along with numerous other small objects in 1981.
These rediscoveries left only nine numbered minor planets unobserved since their discoveries: 330 Adalberta (which never existed in the first place), 473 Nolli, 719 Albert, 724 Hapag, 843 Nicolaia, 878 Mildred, 1009 Sirene, 1026 Ingrid, and 1179 Mally. However, by the mid-1980s the only remaining lost asteroids of this group were 719 Albert (rediscovered in 2000), 724 Hapag (rediscovered in 1988), and 878 Mildred (rediscovered in 1991).
References
External links
Koronis asteroids
Hamiltonia
18991206
Hamiltonia |
2846174 | https://en.wikipedia.org/wiki/453%20Tea | 453 Tea | Tea (minor planet designation: 453 Tea) is an S-type asteroid belonging to the Flora family in the Main Belt. Its diameter is about 21 km and it has an albedo of 0.183. Its rotation period is 6.4 hours.
In the 1980s Tea was considered as a target for the planned French Vesta spacecraft. The spacecraft was not built.
Tea was discovered by Auguste Charlois on February 22, 1900. Its provisional name was 1900 FA. It is unknown after what it was named.
It came to opposition at apparent magnitude 12.2 on 3 May 2023 and then perihelion on 27 May 2023.
References
External links
Flora asteroids
Tea
Tea
S-type asteroids (Tholen)
S-type asteroids (SMASS)
19000222 |
2846183 | https://en.wikipedia.org/wiki/454%20Mathesis | 454 Mathesis | Mathesis (minor planet designation: 454 Mathesis) is a main-belt asteroid that was discovered by German astronomer Friedrich Karl Arnold Schwassmann on March 28, 1900. Its provisional name was 1900 FC.
Photometric observations of this asteroid at the Altimira Observatory in 2004 gave a light curve with a period of 8.37784 ± 0.00003 hours and a brightness variation of 0.32 in magnitude. This differs from periods of 7.075 hours reported in 1994 and 7.745 hours in 1998.
References
External links
Background asteroids
Mathesis
Mathesis
CB-type asteroids (Tholen)
19000328 |
2846194 | https://en.wikipedia.org/wiki/455%20Bruchsalia | 455 Bruchsalia | Bruchsalia (minor planet designation: 455 Bruchsalia) is a main-belt asteroid. It was discovered by Max Wolf and Friedrich Karl Arnold Schwassmann on May 22, 1900. Its provisional name was 1900 FG.
References
External links
Lightcurve plot of (455) Bruchsalia, Antelope Hills Observatory
Background asteroids
Bruchsalia
Bruchsalia
Bruchsalia
CP-type asteroids (Tholen)
19000522 |
2846199 | https://en.wikipedia.org/wiki/456%20Abnoba | 456 Abnoba | Abnoba (minor planet designation: 456 Abnoba), provisional designation , is a stony background asteroid from the central regions of the asteroid belt, approximately 40 kilometers in diameter. It was discovered on 4 June 1900, by astronomers Max Wolf and Arnold Schwassmann at the Heidelberg-Königstuhl State Observatory in southwest Germany. The asteroid was named after the Celtic deity Abnoba.
Orbit and classification
Abnoba is a non-family asteroid from the main belt's background population. It orbits the Sun in the central main-belt at a distance of 2.3–3.3 AU once every 4 years and 8 months (1,701 days). Its orbit has an eccentricity of 0.18 and an inclination of 14° with respect to the ecliptic.
The body's observation arc begins at Bordeaux Observatory, eleven days after its official discovery observation at Heidelberg.
Physical characteristics
In the SMASS classification, Abnoba is a stony S-type asteroid. Its stony composition was also confirmed by polarimetric observations in 2017.
Rotation period
Several rotational lightcurves of Abnoba have been obtained from photometric observations since 2004. Analysis of the best-rated lightcurve from the Bigmuskie Observatory () in Italy, gave a rotation period of 18.281 hours with a brightness amplitude of 0.32 magnitude ().
Diameter and albedo
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Abnoba measures between 37.64 and 50.495 kilometers in diameter and its surface has an albedo between 0.1467 and 0.286.
The Collaborative Asteroid Lightcurve Link derives an albedo of 0.2537 and a diameter of 39.94 kilometers based on an absolute magnitude of 9.1.
Naming
This minor planet was named after the Gaulish goddess Abnoba from Celtic mythology. The goddess was worshipped in the Black Forest of southern Germany, and known as "Diana Abnoba" to the Roman troops stationed in this region. The official naming citation was authored by Lutz D. Schmadel based on his own research.
Notes
References
External links
Asteroid Lightcurve Database (LCDB), query form (info )
Dictionary of Minor Planet Names, Google books
Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
000456
Discoveries by Max Wolf
Discoveries by Friedrich Karl Arnold Schwassmann
Named minor planets
000456
19000604 |
2846205 | https://en.wikipedia.org/wiki/457%20Alleghenia | 457 Alleghenia | Alleghenia (minor planet designation: 457 Alleghenia), provisional designation 1900 FJ, is a carbonaceous asteroid from the outer region of the asteroid belt, about 34 kilometers in diameter. It was discovered on 15 September 1900, by German astronomers Max Wolf and Friedrich Schwassmann at Heidelberg Observatory in southern Germany.
The C-type asteroid orbits the Sun at a distance of 2.6–3.6 AU once every 5 years and 5 months (1,987 days). Its orbit is tilted by 13 degrees to the plane of the ecliptic and shows an eccentricity of 0.17. Based on assumptions made by the Collaborative Asteroid Lightcurve Link, the body has a low albedo of 0.06, a typical value for a carbonaceous asteroid. In 2014, photometric light-curve observations at the Los Algarrobos Observatory (OLASU, I38), Uruguay, has given a rotation period of hours with a brightness amplitude of 0.20 in magnitude. It was the last among the first 500 numbered asteroids to have its period measured for the first time (also see 398 Admete).
The minor planet was named by Max Wolf in honor and gratitude of U.S. optician John Brashear at Allegheny in Pennsylvania, who equipped Wolf's new telescope with state of the art optics (lenses for the 16-inch photographic doublet). Some of the finest astronomy equipment of the early 20th century were produced at Allegheny by Brashear. The body was the first discovery Wolf made with his new instrument. Wolf also expressed his gratitude by granting the naming of another of his discoveries to the American optician, who named it 484 Pittsburghia, after his home city. Brashear is also honored by a Martian and a lunar crater. The minor planet 5502 Brashear was later directly named after the famous American astronomer and instrument builder.
See also
Allegheny Observatory
Notes
References
External links
Asteroid Lightcurve Database (LCDB), query form (info )
Dictionary of Minor Planet Names, Google books
Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
000457
Discoveries by Max Wolf
Discoveries by Friedrich Karl Arnold Schwassmann
Named minor planets
19000915 |
2846209 | https://en.wikipedia.org/wiki/458%20Hercynia | 458 Hercynia | Hercynia (minor planet designation: 458 Hercynia), provisional designation , is a background asteroid from the outer regions of the asteroid belt, approximately 38 kilometers in diameter. It was discovered on 21 September 1900, by astronomers Max Wolf and Arnold Schwassmann at the Heidelberg-Königstuhl State Observatory in southwest Germany. The asteroid was named for the ancient Hercynian Forest, known to the Romans as "Hercynia silva".
Orbit and classification
Hercynia is a non-family asteroid of the main belt's background population. It orbits the Sun in the outer asteroid belt at a distance of 2.3–3.7 AU once every 5 years and 2 months (1,896 days; semi-major axis of 3.00 AU). Its orbit has an eccentricity of 0.24 and an inclination of 13° with respect to the ecliptic. The body's observation arc begins two days after to its official discovery observation at Heidelberg.
Physical characteristics
In the Tholen classification, Hercynia is a common S-type, while in the SMASS classification it is a rare L-type asteroid. Polarimetric observations also determined an L-type. Alternatively, the Wide-field Infrared Survey Explorer (WISE) characterized Hercynia as a metallic M-type asteroid.
Rotation period
Several rotational lightcurves of Hercynia have been obtained from photometric observations since 1985. Lightcurve analysis gave a consolidated, slightly longer-than average rotation period of 21.806 hours with a brightness amplitude between 0.10 and 0.36 magnitude ().
Diameter and albedo
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's WISE telescope, Hercynia measures between 33.70 and 42.27 kilometers in diameter and its surface has an albedo between 0.1435 and 0.191.
The Collaborative Asteroid Lightcurve Link adopts an albedo of 0.1654 from IRAS, and derives a diameter of 38.57 kilometers based on an absolute magnitude of 9.64.
Naming
This minor planet was named after the ancient Central European Hercynian Forest, known as "Hercynia silva" to the Romans. The mountainous and dense forest stretched from the upper part of the Rhine to the Carpathian Mountains in southeastern Europe. According to Caesar, it required a nine-day journey to cross the forest. (The Black Forest located to the south of the discovering observatory is a remnant of the western part of this forest). The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 ().
References
External links
Asteroid Lightcurve Database (LCDB), query form (info )
Dictionary of Minor Planet Names, Google books
Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
000458
Discoveries by Max Wolf
Discoveries by Friedrich Karl Arnold Schwassmann
Named minor planets
000458
000458
19000921 |
2846213 | https://en.wikipedia.org/wiki/459%20Signe | 459 Signe | Signe (minor planet designation: 459 Signe), provisional designation , is a stony asteroid from the background population of the intermediate asteroid belt, approximately 26 kilometers in diameter. It was discovered by German astronomer Max Wolf at Heidelberg-Königstuhl State Observatory on 22 October 1900. The asteroid was presumably named after Signy, a character of the Scandinavian Völsunga saga and Norse mythology. Signy is the daughter of Völsung and sister of Sigmund.
References
External links
Asteroid Lightcurve Database (LCDB), query form (info )
Dictionary of Minor Planet Names, Google books
Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
000459
Discoveries by Max Wolf
Named minor planets
000459
19001022 |
2846225 | https://en.wikipedia.org/wiki/460%20Scania | 460 Scania | 460 Scania (; prov. designation: or ) is a background asteroid and a slow rotator from the central regions of the asteroid belt. It was discovered by German astronomer Max Wolf at the Heidelberg-Königstuhl State Observatory on 22 October 1900. The uncommon K-type asteroid has an exceptionally long rotation period of 164.1 hours and measures approximately in diameter. It was named after the Swedish region of Scania, where a meeting was held by the Astronomische Gesellschaft in 1904.
Orbit and classification
Scania is a non-family asteroid from the main belt's background population. It orbits the Sun in the central asteroid belt at a distance of 2.4–3.0 AU once every 4 years and 6 months (1,637 days; semi-major axis of 2.72 AU). Its orbit has an eccentricity of 0.11 and an inclination of 5° with respect to the ecliptic. The body's observation arc begins at Vienna Observatory on 25 October 1900, three nights after its official discovery observation at Heidelberg.
Naming
This minor planet was named after the Swedish region of Scania or Skåne by its Latin name, on the occasion of a meeting held in Lund by the Astronomische Gesellschaft in 1904 (). The was also mentioned in The Names of the Minor Planets by Paul Herget in 1955 ().
Physical characteristics
In the Bus–Binzel SMASS classification, Scania is an uncommon K-type asteroid.
Rotation period
In December 2017, a rotational lightcurve of Scania was obtained from photometric observations by Frederick Pilcher. Lightcurve analysis gave a well defined rotation period of hours with a brightness variation of magnitude (). The results supersedes previous observations.
Diameter and albedo
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Scania measures between 19.689 and 23.58 kilometers in diameter and its surface has an albedo between 0.189 and 0.262. The Collaborative Asteroid Lightcurve Link derives an albedo of 0.1808 and a diameter of 21.63 kilometers based on an absolute magnitude of 10.8.
References
External links
Lightcurve Database Query (LCDB), at www.minorplanet.info
Dictionary of Minor Planet Names, Google books
Asteroids and comets rotation curves, CdR – Geneva Observatory, Raoul Behrend
Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
000460
Discoveries by Max Wolf
Named minor planets
460 Scania
000460
19001022 |
2846230 | https://en.wikipedia.org/wiki/461%20Saskia | 461 Saskia | Saskia (minor planet designation: 461 Saskia), provisional designation , is a Themistian asteroid from the outer regions of the asteroid belt, approximately in diameter. It was discovered on 22 October 1900, by German astronomer Max Wolf at the Heidelberg Observatory in southwest Germany. The X-type asteroid has a rotation period of 7.3 hours. It was named after Rembrandt's wife, Saskia van Uylenburgh.
Orbit and classification
Saskia is a core member of the carbonaceous Themis family (), one of the largest asteroid families named after 24 Themis. It orbits the Sun in the outer asteroid belt at a distance of 2.7–3.6 AU once every 5 years and 6 months (2,016 days; semi-major axis of 3.12 AU). Its orbit has an eccentricity of 0.14 and an inclination of 1° with respect to the ecliptic. The body's observation arc begins at Heidelberg the night after its official discovery observation.
Naming
This minor planet was named after Saskia van Uylenburgh (1612–1642), wife of renowned Dutch painter Rembrandt (4511 Rembrandt). The official naming citation was mentioned in The Names of the Minor Planets by Paul Herget in 1955 ().
Physical characteristics
In the Tholen classification, this asteroid's spectral type is ambiguous, closest to a dark F-type asteroid, and somewhat similar to that of a C- and X-type (FCX), while in both the Tholen- and SMASS-like taxonomy of the Small Solar System Objects Spectroscopic Survey (S3OS2), Saskia is an X-type asteroid. It has also been characterized as a primitive P-type asteroid by the Wide-field Infrared Survey Explorer (WISE).
Rotation period
In April 2007, a rotational lightcurve of Saskia was obtained from photometric observations by French amateur astronomer Pierre Antonini. Lightcurve analysis gave a well-defined rotation period of hours with a brightness variation of 0.36 magnitude (). In December 2016, an identical period with an amplitude of 0.28 magnitude was determined by Daniel Klinglesmith at Etscorn Campus Observatory , New Mexico (). This result supersedes two previous observations that gave a period of 7.34 and 7.349 hours, respectively ().
Diameter and albedo
According to the survey carried out by the NEOWISE mission of NASA's WISE telescope, Saskia measures between 39.8 and 44.1 kilometers in diameter and its surface has an albedo between 0.06 and 0.112, while the Japanese Akari satellite determined a diameter of 43.10 kilometers with an albedo of 0.069. The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.10 and derives a smaller diameter of 33.69 kilometers based on an absolute magnitude of 10.48.
References
External links
Asteroid Lightcurve Database (LCDB), query form (info )
Dictionary of Minor Planet Names, Google books
Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
000461
Discoveries by Max Wolf
Named minor planets
000461
19001022 |
2846243 | https://en.wikipedia.org/wiki/462%20Eriphyla | 462 Eriphyla | 462 Eriphyla (prov. designation: or ) is a Koronian asteroid from the outer regions of the asteroid belt. It was discovered by German astronomer Max Wolf at the Heidelberg-Königstuhl State Observatory on 22 October 1900. The stony S-type asteroid has a rotation period of 8.7 hours and measures approximately in diameter. It was named after Eriphyle, from Greek mythology.
Orbit and classification
Eriphyla is a core member of the Koronis family (), a very large outer asteroid family with nearly co-planar ecliptical orbits. It orbits the Sun in the outer asteroid belt at a distance of 2.6–3.1 AU once every 4 years and 10 months (1,777 days; semi-major axis of 2.87 AU). Its orbit has an eccentricity of 0.09 and an inclination of 3° with respect to the ecliptic. The asteroid was first observed as at Nice Observatory on 31 December 1896. The body's observation arc begins at Heidelberg on 11 November 1900, three weeks after its official discovery observation.
Naming
This minor planet was named from Greek mythology after Eriphyle, wife of Amphiaraus whom she persuaded to take part in a raiding venture which lead to the tragic war of the Seven against Thebes. The was also mentioned in The Names of the Minor Planets by Paul Herget in 1955 ().
Physical characteristics
In both the Tholen and SMASS classification, Eriphyla is a common stony S-type asteroid.
Rotation period
In October 2002, a rotational lightcurve of Eriphyla was obtained from photometric observations by Stephen M. Slivan. Lightcurve analysis gave a well-defined rotation period of hours with a brightness variation of magnitude (). Several more lightcurves were published since 1987.
A modeled lightcurve using photometric data from the Lowell Photometric Database and from the Wide-field Infrared Survey Explorer (WISE) was published in 2018. It gave a concurring sidereal period of hours and includes two spin axes at (119.0°, 7.0°) and (301.0°, 5.0°) in ecliptic coordinates (λ, β).
Diameter and albedo
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's WISE telescope, Eriphyla measures between 34.274 and 41.882 kilometers in diameter and its surface has an albedo between 0.1746 and 0.2829. The Collaborative Asteroid Lightcurve Link assumes an albedo of 0.2438 and derives a diameter of 35.32 kilometers based on an absolute magnitude of 9.41.
References
External links
Lightcurve Database Query (LCDB), at www.minorplanet.info
Dictionary of Minor Planet Names, Google books
Asteroids and comets rotation curves, CdR – Geneva Observatory, Raoul Behrend
Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
Koronis asteroids
Eriphyla
Eriphyla
S-type asteroids (Tholen)
S-type asteroids (SMASS)
19001022 |
2846245 | https://en.wikipedia.org/wiki/463%20Lola | 463 Lola | Lola (minor planet designation: 463 Lola) (1900 FS) is a Main-belt asteroid discovered on 31 October 1900 by Max Wolf at Heidelberg. It is named after Lola, a character from Pietro Mascagni's opera Cavalleria Rusticana.
References
External links
000463
Discoveries by Max Wolf
Named minor planets
000463
000463
19001031 |
2846253 | https://en.wikipedia.org/wiki/464%20Megaira | 464 Megaira | 464 Megaira (prov. designation: or ) is a dark and large background asteroid, approximately in diameter, located in the central region of the asteroid belt. It was discovered by astronomer Max Wolf at the Heidelberg Observatory in southwest Germany on 9 January 1901. The carbonaceous C-type asteroid (FX) has a rotation period of 12.9 hours. It was named after Megaera from Greek mythology.
Orbit and classification
Megaira is a non-family asteroid of the main belt's background population when applying the hierarchical clustering method to its proper orbital elements. It orbits the Sun in the central asteroid belt at a distance of 2.2–3.4 AU once every 4 years and 8 months (1,712 days; semi-major axis of 2.8 AU). Its orbit has an eccentricity of 0.21 and an inclination of 10° with respect to the ecliptic. The body's observation arc begins at Heidelberg Observatory with its official discovery observation on 9 January 1901.
Naming
This minor planet was named after Megaera, the avenging spirit from Greek mythology. She is one of the three Erinyes (Furies), who bring retribution on those guilty of sins. The was also mentioned in The Names of the Minor Planets by Paul Herget in 1955 (). It was the first numbered minor planet detected in the 20th century.
Physical characteristics
In the Tholen classification-SMASS classification, Megaira is closest to a dark F-type asteroid, and somewhat similar to an X-type, though with an unusual (U) and noisy spectra (:). In the Bus–Binzel SMASS classification it is a common carbonaceous C-type asteroid.
Rotation period
In March 2019, a rotational lightcurve of Megaira was obtained from photometric observations by Frederick Pilcher. Lightcurve analysis gave a well-defined rotation period of hours with a brightness variation of magnitude (). The result supersedes previously published period determinations.
Diameter and albedo
According to the surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite and the NEOWISE mission of NASA's Wide-field Infrared Survey Explorer, Megaira measures between 55.09 and 85.50 kilometers in diameter and its surface has an albedo between 0.03 and 0.06. The Collaborative Asteroid Lightcurve Link takes an albedo of 0.0469 from Petr Pravec's revised WISE data and calculates a diameter of 78.29 kilometers based on an absolute magnitude of 9.47.
References
External links
Lightcurve Database Query (LCDB), at www.minorplanet.info
Dictionary of Minor Planet Names, Google books
Asteroids and comets rotation curves, CdR – Geneva Observatory, Raoul Behrend
Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
000464
Discoveries by Max Wolf
Named minor planets
000464
000464
19010109
vec:Lista de asteroidi#464 Megaira |
2846258 | https://en.wikipedia.org/wiki/465%20Alekto | 465 Alekto | Alekto (minor planet designation: 465 Alekto) is a main-belt asteroid. It was discovered by Max Wolf on January 13, 1901. Its provisional name was 1901 FW. It is named for Alecto from Greek Mythology.
References
External links
Background asteroids
Alekto
Alekto
19010113 |
2846266 | https://en.wikipedia.org/wiki/466%20Tisiphone | 466 Tisiphone | Tisiphone (minor planet designation: 466 Tisiphone) is an asteroid which orbits among the Cybele family of asteroids.
Discovery
It was discovered by Max Wolf and Luigi Carnera on January 17, 1901, and was assigned the provisional designation 1901 FX. It was named after Tisiphone of Greek mythology.
Physical properties
A number of positional observations of Tisiphone were carried out in 1907, 1913, and 1914.
In 1992 a simple check of 466 Tisiphone's position was made by the Association of Lunar and Planetary Observers (ALPO). The asteroid was found to be in the expected position to within observational errors. Further checks were carried out in 1996, and 2006 with the asteroid in its expected position both times.
In 1997 Tisiphone was studied by Worman and Christianson at the Feder Observatory located near Minnesota State University, Moorhead, with the goal of determining its rotational period. A period of 8.824 ± 0.009 was arrived at, with the lightcurve data showing two distinct maxima and minima in its rotation.
In 2001 Lagerkvist et al. published their results on a study of the Cybele asteroid family, which includes 466 Tisiphone. Relative photometric observations of Tisiphone were carried out in 1998 and 1999 using the 1.2 m telescope at the Calar Alto Observatory located at the Max-Planck-Institut für Astronomie in Heidelberg, Germany. They were able to confirm the 8.8 hour rotation period obtained by Worman and Christianson.
In 2006 Fornasier et al. published polarimetric data for a number of asteroids, including 466 Tisiphone.
Further reading
References
External links
Cybele asteroids
Tisiphone
Tisiphone
Tisiphone
C-type asteroids (Tholen)
19010117 |
2846270 | https://en.wikipedia.org/wiki/467%20Laura | 467 Laura | Laura (minor planet designation: 467 Laura) (1901 FY) is Main-belt asteroid discovered on 9 January 1901 by Max Wolf at Heidelberg. The semi-major axis of the orbit of 467 Laura lies just inside the 7/3 Kirkwood gap, located at 2.95 AU. It's named after the character Laura from Amilcare Ponchielli's opera La Gioconda.
References
External links
000467
Discoveries by Max Wolf
Named minor planets
19010109 |
2846276 | https://en.wikipedia.org/wiki/468%20Lina | 468 Lina | Lina (minor planet designation: 468 Lina), provisional designation , is a dark Themistian asteroid from the outer region of the asteroid belt, approximately in diameter. It was discovered on 18 January 1901, by German astronomer Max Wolf at the Heidelberg Observatory in southwest Germany. The carbonaceous asteroid was named for the housemaid of the discoverer's family.
Classification and orbit
Lina is a core member of the Themis family, an ancient population of carbonaceous outer-belt asteroids with nearly coplanar ecliptical orbits. It orbits the Sun at a distance of 2.5–3.8 AU once every 5 years and 6 months (2,025 days). Its orbit has an eccentricity of 0.20 and an inclination of 0.4° with respect to the ecliptic. Lina was first observed at Heidelberg a few days prior to its official discovery observation. The body's observation arc begins with its identification as at Heidelberg in 1915, or 14 years after its official discovery observation.
Naming
This minor planet was named for "Lina", a domestic housemaid of the discoverer's family at Heidelberg. The members of Max Wolfs household figure prominently in the names of his discoveries, but background information on the name's origin behind most of them have been lost. Wolf also named 482 Petrina and 483 Seppina after the household's two dogs, a practice that was later discouraged by the IAU. Naming citation for Lina was first mentioned in The Names of the Minor Planets by Paul Herget in 1955 ().
Physical characteristics
It has been characterized as a CPF-type and P-type asteroid by Tholen and NEOWISE, respectively.
Photometry
In December 2006, a rotational lightcurve of Lina was obtained by American astronomer Robert Buchheim at Altimira Observatory () in California. Light-curve analysis gave a rotation period of 16.33 hours with a brightness variation of 0.15 magnitude (U=3). Its odd light curve shows multiple peaks, contrary to the classically shaped double-peaks seen in bimodal light curves, that have two maximums and two minimums per rotation. Linas unusual triple-peak shape made it difficult to fit a period.
Other photometric observations were taken by Edward Tedesco in the 1970s (8.3 hours; Δ mag; U=1), by Pierre Antonini and Raoul Behrend in January 2006 (16.478 hours; Δ0.18 mag; U=2), and by Scott Marks and Michael Fauerbach in February 2007 (16.54 hours; Δ0.13 mag; U=2).
Diameter and albedo
According to the space-based surveys carried out by the Infrared Astronomical Satellite IRAS, the Japanese Akari satellite, the Spitzer Space Telescope, and NASA's Wide-field Infrared Survey Explorer with its subsequent NEOWISE mission, Lina measures between 58.60 and 69.34 kilometers in diameter, and its surface has an albedo between 0.043 and 0.06.
The Collaborative Asteroid Lightcurve Link still adopts the results obtained by IRAS, that is an albedo of 0.043 and a diameter of 69.34 kilometers at an absolute magnitude of 9.83, while more recent results by NEOWISE and Spitzer tend toward a higher albedo of 0.06 and a shorter diameter of 58.60 and 59.7 kilometer, respectively. Spitzer's spectra of Lina shows an emissivity plateau in the wavelength range of 9 to 12 μm, which is indicative of silicates.
References
External links
Asteroid Lightcurve Database (LCDB), query form (info )
Rock Legends: The Asteroids and Their Discoverers, Google books
Dictionary of Minor Planet Names, Google books
Asteroids and comets rotation curves, CdR – Observatoire de Genève, Raoul Behrend
Discovery Circumstances: Numbered Minor Planets (1)-(5000) – Minor Planet Center
000468
Discoveries by Max Wolf
Named minor planets
000468
19010118 |
2846282 | https://en.wikipedia.org/wiki/469%20Argentina | 469 Argentina | Argentina (minor planet designation: 469 Argentina) is an asteroid that was discovered by Luigi Carnera on 20 February 1901. Its provisional name was 1901 GE. 469 Argentina has an estimated rotation period of 12.3 hours.
References
External links
Lightcurve plot of 469 Argentina, Palmer Divide Observatory, B. D. Warner (2006)
Asteroid Lightcurve Database (LCDB), query form (info )
Dictionary of Minor Planet Names, Google books
Asteroids and comets rotation curves, CdR Observatoire de Genève, Raoul Behrend
Discovery Circumstances: Numbered Minor Planets (1)–(5000) Minor Planet Center
Background asteroids
Argentina
Argentina
X-type asteroids (Tholen)
19010220 |
2846285 | https://en.wikipedia.org/wiki/470%20Kilia | 470 Kilia | Kilia (minor planet designation: 470 Kilia) (1901 GJ) is a 27 km main-belt asteroid discovered on 21 April 1901 by Luigi Carnera at Heidelberg, the 470th asteroid discovered. It was one of the 16 asteroid discoveries made by Carnera.
Photometric observations of this asteroid in 2021 were used to produce a light curve showing a rotation period of with a brightness amplitude of in magnitude.
References
External links
Background asteroids
Kilia
Kilia
Slow rotating minor planets
S-type asteroids (Tholen)
S-type asteroids (SMASS)
19010421 |
2846292 | https://en.wikipedia.org/wiki/471%20Papagena | 471 Papagena | Papagena (minor planet designation: 471 Papagena) is an asteroid that was discovered by German astronomer Max Wolf on 7 June 1901. Its provisional name was 1901 GN.
Papagena comes to a favorable near-opposition apparent magnitude of better than magnitude 9.8 every five years. On 30 September 2010, it was magnitude 9.68 and it will get brighter every five years until 12 December 2035, when this late-to-be-discovered asteroid will be at magnitude 9.28. It is named for a character in Mozart's opera, The Magic Flute.
References
External links
000471
Discoveries by Max Wolf
Named minor planets
471 Papagena
000471
000471
19010607 |
2846293 | https://en.wikipedia.org/wiki/472%20Roma | 472 Roma | Roma (minor planet designation: 472 Roma) is an asteroid. It was discovered by Luigi Carnera on July 11, 1901. Its provisional name was 1901 GP. This asteroid was named by Antonio Abetti for the city of Rome in Italy, the
native country of its discoverer.
At 21:57 UT, on Thursday, July 8, 2010, this 50 km wide asteroid occulted the star Delta Ophiuchi in an event lasting about five seconds. The occultation path crossed central Europe along a band that ran through Stockholm, Copenhagen, Bremen, Nantes and Bilbao.
This is a member of the dynamic Maria family of asteroids that were probably formed as the result of a collisional breakup of a parent body.
References
External links
Maria asteroids
Roma
Roma
S-type asteroids (Tholen)
19010711 |
2846298 | https://en.wikipedia.org/wiki/473%20Nolli | 473 Nolli | Nolli (minor planet designation: 473 Nolli) is a rather small asteroid that may be in the Eunomia family. It was discovered by Max Wolf on February 13, 1901, but only observed for 1 month so it became a lost asteroid for many decades. It was recovered in 1987, 86 years after its discovery.
References
External links
Eunomia asteroids
Nolli
Nolli
19010213 |
2846303 | https://en.wikipedia.org/wiki/474%20Prudentia | 474 Prudentia | Prudentia (minor planet designation: 474 Prudentia) (1901 GD) is a Main-belt asteroid discovered on 13 February 1901 by Max Wolf at Heidelberg.
References
External links
Background asteroids
Prudentia
19010213
Prudentia |
2846312 | https://en.wikipedia.org/wiki/475%20Ocllo | 475 Ocllo | Ocllo (minor planet designation: 475 Ocllo) is a large Mars-crossing asteroid. It was discovered by American astronomer DeLisle Stewart on August 14, 1901 and was assigned a provisional name of 1901 HN.
Photometric observations of this asteroid at the Organ Mesa Observatory in Las Cruces, New Mexico during 2010 gave a light curve with a period of 7.3151 ± 0.0002 hours and a brightness variation of 0.66 ± 0.04 in magnitude.
References
External links
Mars-crossing asteroids
Ocllo
Ocllo
X-type asteroids (Tholen)
19010814 |
2847083 | https://en.wikipedia.org/wiki/Lacus%20Autumni | Lacus Autumni | Lacus Autumni (Latin autumnī, "Lake of Autumn") is a region of lunar mare that lies near the western limb of the Moon. Along this side of the lunar surface is a huge impact basin centered on the Mare Orientale. Two concentric mountain rings surround the Orientale mare, the inner ring being named Montes Rook and an outer ring called the Montes Cordillera. Lacus Autumni lies in the northeastern quadrant of the gap between these two mountain rings. This section of the lunar surface is difficult to observe directly from the Earth.
The selenographic coordinates of the center of the mare are 9.9° S, 83.9° W. It is approximately long and trends from the southeast to the northwest, reaching a maximum width of . The irregular appearance results from the lunar basalt emerging from the surface to fill in low areas between hummocky hills.
The name of the feature was approved by the IAU in 1970.
References
External links
NASA lunar Atlas
Lunar Orbiter Photo Number IV-181-H2
Autumni, Lacus |
2847572 | https://en.wikipedia.org/wiki/And%20Having%20Writ... | And Having Writ... | And Having Writ... is a 1978 science fiction/alternate history novel by American writer Donald R. Bensen. Nominated for the 1979 John W. Campbell Award, it tells the story of aliens who crash-land on Earth in 1908 and then journey around the planet, trying to jump-start World War I. Even though they fail to do this, they succeed in creating the circumstances for their ultimate departure from Earth after a period of suspended animation.
Plot summary
According to the novel, the Siberian explosion was originally caused by the crash landing of the spacecraft named The Wanderer. In this alternate reality, however, the alien astronauts are able to commandeer their failing vessel so that it lands in the Pacific Ocean, just outside San Francisco.
Shortly after landing, the quartet of spacemen are rescued from the sea by an American ship and taken to California. The Wanderer sinks into the ocean, and the team reasons that they must find a way to accelerate Earth's technological advances so that they can get back home. The eventual conclusion at which they arrive is that they must provoke the planet into what Ari claims is an inevitable global conflict, one that will (through weaponry innovations) result in a boom of new science and industry.
Characters
The astronauts and their roles
The four astronauts never identify their home world, merely saying that they are a team of Explorers sent to gather information about foreign planets.
Raf: The main character of the book, Raf tells the story in first person. He is a Recorder, and is responsible for ensuring that every detail of the expedition is written down. Raf is quite detached in his observations and seems to be fairly optimistic. While on Earth, he develops a strong taste for alcoholic beverages.
Ari: Ari is a Metahistorian, which seems to signify a study of universal historical trends among people of different galaxies and solar systems. His has a tendency to be very long-winded and often clashes with Dark.
Valmis: Valmis is an Integrator. This is a rather obscure occupation that somehow involves interpreting the "Patterns" of the universe, of civilizations, of individual people, of anything and everything. Valmis is very mystical and often frustrates his crew-mates, particularly Dark.
Dark: Dark is the Captain of The Wanderer and as such is an expert in all things mechanical. He is practical to a fault and is ceaselessly annoyed by what he sees as the meaningless ramblings of Valmis and Ari.
Historical characters
The astronauts interact with a number of important global personages during their stay on Earth.
Theodore Roosevelt: In the book, Theodore Roosevelt becomes the 26th President of the United States in 1901 after William McKinley is assassinated. He is elected to a full term in 1904. He is elected as the 28th President in 1912 and reelected in 1916 and serves until 1921. Roosevelt was the first major world leader with whom the spacemen acquaint themselves, and acts as a benevolent and friendly presence. In the book, he is quoted as saying that if he could only take back his promise not to run for reelection in 1908, he would cut off his right hand.“If I hadn’t promised not to run again...by George, I’d cut my hand off to here!”Roosevelt helps the aliens to escape house arrest in New York in 1909. In 1925, while he is attending a demonstration of an experimental Moon rocket, Roosevelt is killed when the device's engines explode and destroy the platform he was on.
J.P. Morgan: Mr. Morgan, the industrial titan of the Gilded Age, makes a brief appearance at the very beginning of the book, in 1908. He is concerned that the revelation that aliens exist will turn the U.S. financial markets asunder, and he works with President Roosevelt through the U.S. Treasury Department to ensure that the economy is unshaken by the news.
William Howard Taft: Secretary of War William Howard Taft, who in reality served as the 27th President from 1909 to 1913 and then became a Supreme Court Justice, appears very briefly at the beginning of the book. His one and only cameo comes in 1908, when he and Theodore Roosevelt are discussing the effects that the presence of extraterrestrials could have on the election. He is asked by the Republican National Committee to relinquish their nomination for President, news that overjoys President Roosevelt, who assumes that he will be the new nominee. It is Taft who delivers the startling news that the Committee plans to nominate Thomas Alva Edison.
Thomas Alva Edison: In the book, Thomas Edison also arrives at the White House in 1908, chiefly to interview the aliens and learn about their technology, which fascinates him. The aliens are able to create an effective hearing aid for Edison to help him with his poor hearing. When word of the spacemen goes public, the Republican Party bounces William Howard Taft as their 1908 nominee, reasoning that only a man as brilliant as Edison would be able to steer America through such incredible new times.In 1909, Edison has the aliens placed under house arrest in New York so that he can pry technological secrets from them. They escape (thanks to former president Roosevelt), however, and head to Europe, and Edison is obliged to dispatch Marines to go after them. When he finally has them in his clutches again, President Edison realizes that the amount of technology the aliens possess would, if widely distributed, cause widespread upheaval."Nearly free power for everyone, available tomorrow, ain’t that grand? No need to buy coal, gasoline, oil, wood, anything like that. And no need to pay the coal miners, oil people, filling stations, anybody like that. I calculate it’d take about six weeks for the country to turn into a howling wilderness of starving mobs...We’re an industrious and inventive people, and I don’t see any easy gifts you could let us have be worth losing that."In 1912, Edison decides not to run for reelection, and rather goes back to inventing.
H. G. Wells: The famous science fiction writer acts as an escort for the extraterrestrials, summoned to learn about their culture and distribute the news of their coming. He becomes one of their closest companions.
George M. Cohan: The aliens befriend the famous songwriter and performer during their stay in New York.
King Edward VII: King of the United Kingdom since 1901. After escaping the United States, the aliens head to France in 1909, where they are to have an audience with King Edward VII regarding the inevitability of a coming world war.Raf, in wondering why the King of England should be in France, notes, "The King, it appeared, made a habit of leaving his country for substantial periods of time, especially during the uncertain weather of late winter and early spring, which he spent in France, but also in summer and autumn.His subjects, far from resenting this, were gratified, as most of them would themselves have preferred to be elsewhere much of the time, and so took a prideful vicarious pleasure in their monarch’s travels."In meeting with Edward, the Explorers demonstrate their stunning lack of tact, having not yet become accustomed to human social norms.When he hears of the widespread destruction and misery that World War I will bring, Edward is upset."'If it must be, so it must. God grant I do not live to see it.'"'That’s about an even chance,' Ari said, looking at him appraisingly. 'If you were to get at it pretty quickly...you’d probably see it pretty well launched. If you and your fellow kings just let things drag on another couple of years or so, why, I’d have to agree you’d probably be pretty well out of it.'"Edward nearly dies right in front of the Explorers, and they are obliged to revive him using their highly advanced medical technology, thus restoring him to full health as he has not enjoyed since young manhood. Out of gratitude, Edward shields them from the U.S. Marines seeking to arrest them and sees to it that they make it safely to Berlin.
Kaiser Wilhelm II of Germany: Emperor of Germany. After leaving France, the Explorers head to the Imperial Palace in Berlin, where they are received by Wilhelm II. When the team tries to tell him about the coming World War, he is incredulous, insisting that such a conflict is impossible due to the sheer military might of his empire. He, like his uncle Edward VII, is humbled by the alien visitors’ complete and uninhibited honesty. After Wilhelm states that Germans believe a healthy body houses a healthy mind, Dark questions, "'Look here. That healthy body business—how does that square with that arm of yours?'"The Kaiser's left arm had been pulled from its socket at birth as a result of his Breech birth that caused Erb's palsy, the topic was an extremely sensitive one for him. As a child, he was forced by cruel tutors to learn to ride horseback without any assistance whatsoever. They would watch callously as the young crown prince fell from his steed, never once making a move to come to his aid. Wilhelm consequently developed an extremely bellicose personality, one that, in the real world, contributed to the outbreak of World War I.When the Kaiser hears Dark's remark regarding his arm, he is so furious that he attempts to attack the alien with his ceremonial sword. This merely results in Wilhelm falling to the ground and being unable to get up. Dark, completely oblivious to the fact that he is responsible for the episode, extends his arm towards the emperor, saying compassionately, "'Here, let me give you a hand, as you've only got one that's of any use to you.'"The Kaiser forgives Dark's insolence, however, when the spaceman repairs his shriveled limb so that it is in good working order. When the Explorers leave Berlin, their human companions are shocked to see Kaiser Wilhelm waving at them with two healthy arms. The Kaiser gets the troupe on a train to St. Petersburg first thing, so that they might conference with his cousin, Czar Nicholas II.
Czar Nicholas II of Russia: When the Explorers first meet Czar Nicholas at Tsarskoe Selo, the Imperial palace outside of St. Petersburg, he is timid and unwilling to accept the reality of what they are telling him. He protests that he already has enough trouble on his hands without this new burden, and that "it's all too much for me."When the Czar's son, five-year-old Czarevitch Alexei, walks right into the room, Nicholas softly objects, "Alexei, you know you're not supposed to come in here while Papa is doing business."Nicholas is just about to dismiss his visitors when Alexei falls and strikes his head on the desk. Nicholas immediately leaps up, cradling his son and screaming frantically for "Grigori!"The Czar tearfully lays his son on the couch until the filthy monk Grigori Rasputin enters the room, chants over the suffering child, and leaves. Alexei is calm after this, and is taken back to the children's quarters.The Czar is deeply shaken by the incident, and begins to discuss the czarevitch's illness with the Explorers.Valmis, usually withdrawn and ethereal, says that the only thing afflicting the boy is a bad set of Patterns.Valmis analyses some of Alexei's blood and finds that a certain protein is missing. He then views the Czar's blood, finds the necessary protein, and is able to reproduce it using machinery of Dark's. A sample of this new blood is injected into the czarevitch, who is completely cured within three days.There is nationwide rejoicing at this news in Russia, and, the very day of Alexei's recovery, Rasputin is dragged from the Palace by Imperial soldiers.Czar Nicholas is so boundlessly thankful that he arranges safe passage to Spain for the Explorers, who are still being pursued by Marines.In addition, the Czar promises to seriously consider everything that Ari has told him about the possibility of a World War. Nicholas II would remain the Russian Czar until his death between 1918 and 1933 and would be succeeded by his son Alexi.
Grigori Rasputin: With the Czarevitch cured, Rasputin has no further use at the Imperial court and was thrown out of the palace by Imperial soldiers. He eventually makes his way to New York and becomes successful in the advertising and film industries.
Czarevitch Alexei Nicholaevitch Romanov: In the book, young Czarevitch Alexei of Russia is cured of his Haemophilia by the visiting aliens in 1909. Following his father's death between 1918 and 1933, he became the Czar of Russia. During their 1933 tour of Earth, which they undertake just prior to their departure from the planet, the Explorers are received by Alexei, who is now the Czar of Russia. During the encounter, Raf describes him as a "strapping young lad." In reality, of course, Czarevitch Alexei was murdered, along with the rest of his family, by Bolshevik revolutionaries in 1918, when he was only thirteen years old.
Literary significance and criticism
"a smoothly humorous sf novel set in an alternate world engendered by the survival of the aliens whose crash-landing caused the Siberian Tunguska explosion of 1908. Thomas Alva Edison and H.G. Wells make appearances (John Clute/Encyclopedia of SF).
Allusions/references to actual history, geography and current science
The actual Tunguska Event was a massive explosion in Siberia, in June 1908. The explosion, unexplained even today, felled sixty million trees and produced shockwaves that could be felt four hundred miles away. A popular explanation is that a small comet disintegrated just before impact; conspiracy theorists have more fanciful explanations.
Release details
1978, USA, Bobbs-Merrill (), Pub date ? ? 1978, hardback (First edition)
1979, USA, Ace Books (), Pub date ? March 1979, paperback
Footnotes
References
External links
1978 American novels
American alternate history novels
1978 science fiction novels
American science fiction novels
Fiction set in 1908
Novels set in California
Cultural depictions of Theodore Roosevelt
Cultural depictions of Thomas Edison
Cultural depictions of William Howard Taft
Cultural depictions of H. G. Wells
Cultural depictions of Edward VII
Cultural depictions of Wilhelm II
Cultural depictions of Grigori Rasputin
Cultural depictions of Nicholas II of Russia
Bobbs-Merrill Company books |
2853846 | https://en.wikipedia.org/wiki/Umlalazi%20Nature%20Reserve | Umlalazi Nature Reserve | The Umlalazi Nature Reserve is a coastal reserve situated from Mtunzini on the KwaZulu-Natal North Coast. Umlalazi was established as a protected area in 1948 and is in extent. Home of the palm-nut vulture, which is one of the rarest birds of prey in South Africa.
Lagoons can have crocodiles. There are three trails in the reserve. One of which passes examples of mangrove swamps in South Africa, where several species of mangrove can be found. Another walk leads through the dune forest where bushpig, bushbuck and red, grey and blue duiker may occasionally be seen.
The third trail leads through dune forest and mangrove swamp along the edge of the river. Wildflowers and a variety of bird life can be seen. There are also colonies of fiddler crabs and mud-skippers.
References
External links
Information about the reserve.
Nature reserves in South Africa
Mangroves
Ezemvelo KZN Wildlife Parks |
2854213 | https://en.wikipedia.org/wiki/Orbita%20%28TV%20system%29 | Orbita (TV system) | Orbita () is a Soviet-Russian system of broadcasting and delivering TV signals via satellites. It is considered to be the first national network of satellite television.
The Orbita system is based on communication satellites in highly elliptical Molniya orbits, as well as on many ground downlink TV stations for reception and relaying TV signals to antennas of TV sets of many local areas. The full deployment of the Orbita satellite system took place on 25 October 1967 when ground downlink stations of some cities of Soviet Siberia and the Far East began to receive regular TV programmes from Moscow-based uplink stations via a constellation of Molniya satellites.
External links
Molniya satellites : the description
Molniya satellites
Russian TV celebrates 70th Anniversary
Communications
Earth Application Satellites
Communications satellites of the Soviet Union
Earth observation satellites of the Soviet Union
Television in the Soviet Union
Satellite television
Telecommunications-related introductions in 1967 |
2855451 | https://en.wikipedia.org/wiki/Gleti | Gleti | Gleti is a moon goddess of the Fon people from the Kingdom of Dahomey, situated in what is now Benin.
In Dahomey mythology, she is the mother of all the stars. An eclipse is caused by the shadow of the moon's husband crossing her face.
See also
List of lunar deities
Nix (moon)
References
Dahomean goddesses
Lunar goddesses
Voodoo goddesses |
2860441 | https://en.wikipedia.org/wiki/Great%20dodecahedron | Great dodecahedron | In geometry, the great dodecahedron is a Kepler–Poinsot polyhedron, with Schläfli symbol and Coxeter–Dynkin diagram of . It is one of four nonconvex regular polyhedra. It is composed of 12 pentagonal faces (six pairs of parallel pentagons), intersecting each other making a pentagrammic path, with five pentagons meeting at each vertex.
The discovery of the great dodecahedron is sometimes credited to Louis Poinsot in 1810, though there is a drawing of something very similar to a great dodecahedron in the 1568 book Perspectiva Corporum Regularium by Wenzel Jamnitzer.
The great dodecahedron can be constructed analogously to the pentagram, its two-dimensional analogue, via the extension of the -pentagonal polytope faces of the core -polytope (pentagons for the great dodecahedron, and line segments for the pentagram) until the figure again closes.
Images
Related polyhedra
It shares the same edge arrangement as the convex regular icosahedron; the compound with both is the small complex icosidodecahedron.
If only the visible surface is considered, it has the same topology as a triakis icosahedron with concave pyramids rather than convex ones. The excavated dodecahedron can be seen as the same process applied to a regular dodecahedron, although this result is not regular.
A truncation process applied to the great dodecahedron produces a series of nonconvex uniform polyhedra. Truncating edges down to points produces the dodecadodecahedron as a rectified great dodecahedron. The process completes as a birectification, reducing the original faces down to points, and producing the small stellated dodecahedron.
Usage
This shape was the basis for the Rubik's Cube-like Alexander's Star puzzle.
The great dodecahedron provides an easy mnemonic for the binary Golay code
See also
Compound of small stellated dodecahedron and great dodecahedron
References
External links
Uniform polyhedra and duals
Metal sculpture of Great Dodecahedron
Kepler–Poinsot polyhedra
Regular polyhedra
Polyhedral stellation
Toroidal polyhedra |
2860618 | https://en.wikipedia.org/wiki/Near%20vertical%20incidence%20skywave | Near vertical incidence skywave | Near vertical incidence skywave, or NVIS, is a skywave radio-wave propagation path that provides usable signals in the medium distances range — usually . It is used for military and paramilitary communications, broadcasting, especially in the tropics, and by radio amateurs for nearby contacts circumventing line-of-sight barriers. The radio waves travel near-vertically upwards into the ionosphere, where they are refracted back down and can be received within a circular region up to from the transmitter. If the frequency is too high (that is, above the critical frequency of the ionospheric F layer), refraction is insufficient to return the signal to earth and if it is too low, absorption in the ionospheric D layer may reduce the signal strength.
There is no fundamental difference between NVIS and conventional skywave propagation; the practical distinction arises solely from different desirable radiation patterns of the antennas (near vertical for NVIS, near horizontal for conventional long-range skywave propagation).
Frequencies and propagation
The most reliable frequencies for NVIS communications are between 1.8 MHz and 8 MHz. Above 8 MHz, the probability of success begins to decrease, dropping to near zero at 30 MHz. Usable frequencies are dictated by local ionospheric conditions, which have a strong systematic dependence on geographical location. Common bands used in amateur radio at mid-latitudes are 3.5 MHz at night and 7 MHz during daylight, with experimental use of 5 MHz (60 m) frequencies. During winter nights at the bottom of the sunspot cycle, the 1.8 MHz band may be required. Broadcasting uses the tropical broadcast bands between 2.3–5.06 MHz, and the international broadcast bands between 3.9 and 6.2 MHz. Military NVIS communications mostly take place on 2–4 MHz at night, and 5–7 MHz during daylight.
Optimum NVIS frequencies tend to be higher towards the tropics and lower towards the arctic regions. They are also higher during high sunspot activity years. The usable frequencies change from day to night, because sunlight causes the lowest layer of the ionosphere, called the D layer, to increase, causing attenuation of low frequencies during the day while the maximum usable frequency (MUF) which is the critical frequency of the F layer rises with greater sunlight. Real time maps of the critical frequency are available. Use of a frequency about 15% below the critical frequency should provide reliable NVIS service. This is sometimes referred to as the optimum working frequency or FOT.
NVIS is most useful in mountainous areas where line-of-sight propagation is ineffective, or when the communication distance is beyond the range of groundwave (or the terrain is so rugged and barren that groundwave is not effective), and less than the range of lower-angle sky-wave propagation. Another interesting aspect of NVIS communication is that direction finding of the sender is more difficult than for ground-wave communication (i.e. VHF or UHF). For broadcasters, NVIS allows coverage of an entire medium-sized country at much lower cost than with VHF (FM), and daytime coverage, similar to mediumwave (AM broadcast) nighttime coverage at lower cost and often with less interference.
Antennas
An NVIS antenna configuration is a horizontally polarized (parallel with the surface of the earth) radiating element that is from th wavelength (λ) to wave above the ground. Optimum height is about wavelength, and high angle radiation declines only slightly for heights up to about wave. That proximity to the ground forces the majority of the radiation to go straight up. Overall efficiency of the antenna can be increased by placing a ground wire slightly longer than the antenna parallel to and directly underneath the antenna. One source says that a single ground wire can provide antenna gain in the 3–6 dB range. Such a wire 5% longer than the dipole driven element above it. This is a reflector element forming a 2 element yagi beam antenna. The dipole is .15 wavelengths above the reflector element. Said reflector is strung between 2 insulators, touching nothing else. It is inches above the ground, or up to 10 feet (or 3 meters) above the soil, which greatly facilitates mowing the lawn. This antenna is simply a 2 element beam pointed straight up.
Another suitable antenna for NVIS service is the inverted v dipole. It has the advantage of being quickly built.
Another source indicates 2 dB for a single wire and nearly 4 dB for multiple ground wires. Ground wires are more necessary when using lower dipoles over poor soils as without them considerable energy goes into heating the ground.
Depending on the specific requirements, various antennas (i.e. Sloper, T2FD, Dipole) can be used for NVIS communication, with horizontal dipoles or inverted V dipoles at about wavelength above ground giving the best results on transmit and at about wavelength on receive, according to military sources and an extensive study by Dutch researchers.
Very low antennas are much inferior on transmit, less so on receive, where both noise and signal are attenuated.
Significant increases in communication will obviously be realized when both the transmitting station and the receiving station use NVIS configuration for their antennas. In particular for low profile operations NVIS antennas are a good option.
For broadcasting, typical antennas consist of a dipole about wavelength above ground, or arrays of such dipoles. Up to 16 dipoles can be used, allowing strong signals with relatively low power by concentrating the signal in a smaller area. Limiting the coverage may be dictated by licensing, language or political considerations. Arrays of dipoles can be used to "slew" the pattern, so that the transmitter need not be in the center of the coverage footprint. Broadcast NVIS antennas usually use an extensive ground screen to increase gain and stabilize the pattern and feed impedance with changing ground moisture.
AS-2259 antenna
A military NVIS antenna is the AS-2259 Antenna, which consists of two 'V'-shaped dipoles: The four dipole wires also serve as guy rope for the antenna mast. An alternative configuration consists of a transmitting loop antenna which is configured for maximum signal transmission upwards.
See also
Refraction
References
External links
Analysis of height vs gain
QSL.net NVIS Article
Make A Quick, Easy, Cheap, NVIS Antenna for Roadside Operating
NVIS tutorial
Ionosphere
Radio frequency antenna types
Radio frequency propagation
Antennas (radio) |
2863667 | https://en.wikipedia.org/wiki/Merchant%20Mariner%27s%20Document | Merchant Mariner's Document |
Under the Seafarers' Identity Documents Convention, 1958, countries with a merchant navy (also called a merchant marine) require identifying credentials for their mariners. The Merchant Mariner's Document (MMD) or Z-card in the United States, and the Ordinary Seaman's Certificate in the United Kingdom are examples of these credentials.
United Kingdom
An Ordinary Seaman Certificate is a required certification to obtain a job as an Ordinary Seaman, a rating in a merchant ship's deck department. It consists mostly of proof of identity, proof of some minimal health (possibly including a drug test) and some minimal age, and the standards defined under Standards of Training, Certification and Watchkeeping for Seafarers (STCW).
United States
The Merchant Mariner's Document (MMD), previously called a Z-Card, is a kind of Merchant Mariner Credential previously issued by the United States Coast Guard in accordance with the STCW guidelines, and, until completely phased out, remains one of the standard documents required for all crewmembers of U.S. ships with a Gross Tonnage of over 100. An entry-level MMD allows a mariner to work on the deck as an Ordinary Seaman (OS), in the engine department as a Wiper, or in the steward's department as a Food Handler (FH). With experience and testing, qualified ratings such as Able Seaman (AB) or Qualified Member of the Engine Department (QMED) can be obtained. The document is about the size of a passport, and contains the sailor's information regarding date of birth, the location of issue, nationality, and the shipboard duties he or she is qualified for.
The document was created shortly after World War II ended in 1945 in order to maintain security in ports around the world when sabotage was still a major concern. Today, the document still serves this purpose, and is regarded as a proof of identity and a passport when a sailor is in a foreign country. The document has to be renewed every five years.
Prior to the early 1990s, Z-Cards were obtained free of charge and were good for life, but increased safety standards in the maritime industry sought to require all active mariners to renew these documents and constantly train to stay abreast of any advancements in their field. All applicants for a Z-Card are required to apply, take a drug test, and wait for a criminal background check to complete before receiving their documents, which can take from a few weeks to several years.
The name Z-Card comes from its early days, when a sailor's ID number always started with the letter 'Z'.
The Coast Guard has begun replacing the Merchant Mariner's Document, STCW Certificate, and Certificate of Registry with a new credential, a passport-style Merchant Mariner Credential. Mariners receive the new credential when they apply for a new document or renew their current one. Current MMDs remain valid until their expiration date.
Law of the sea
Merchant navy
Professional titles and certifications
International travel documents |
2864015 | https://en.wikipedia.org/wiki/Sir%20Twardowski | Sir Twardowski | Sir Twardowski (Polish: Pan Twardowski, ), also known as Master Twardowski (Polish: Mistrz Twardowski), is a sorcerer from Polish folklore and literature who made a deal with the Devil. Pan Twardowski sold his soul in exchange for special powers – such as summoning up the spirit of King Sigismund Augustus' deceased wife – but he eventually met a tragic fate.
The tale of Pan Twardowski exists in various diverging versions and forms the basis for many works of fiction, including one by Adam Mickiewicz, although the folklore is commonly assumed to have been heavily inspired by a similar German story of Faust, as there are many parallels in both stories.
Legend
According to an old legend, Twardowski was a nobleman (szlachcic) who lived in Kraków in the 16th century. He sold his soul to the devil in exchange for great knowledge and magical powers. However, Twardowski wanted to outwit the devil by including a special clause in the contract, stating that the devil could only take Twardowski's soul to Hell during his visit to Rome – a place the sorcerer never intended to go. Other variants of the story have Twardowski being sold to the devil as a child by his father.
With the devil's aid, Twardowski quickly rose to wealth and fame, eventually becoming a courtier of King Sigismund Augustus, who sought consolation in magic and astrology after the death of his beloved wife, Barbara Radziwiłł. He was said to have summoned the ghost of the late queen to comfort the grieving monarch, using a magic mirror. The sorcerer also wrote two books, both dictated to him by the devil – a book on magic and an encyclopedia.
After years of evading his fate, Twardowski was eventually tricked by the devil and caught not in the city, but at an inn called Rzym (Rome in Polish). While being spirited away, Twardowski started to pray to the Virgin Mary, who made the devil drop his victim midway to hell. Twardowski fell on the Moon where he lives to this day. His only companion is his sidekick whom he once turned into a spider; from time to time Twardowski lets the spider descend to Earth on a thread and bring him news from the world below.
Historical Twardowski
Dr Jan Kuchta in his 1935 doctoral thesis "Cracovian Warlock of XVI Century. Master Twardowski" suggested that Twardowski may have been a German nobleman who was born in Nuremberg and studied in Wittenberg before coming to Kraków. His name Lorenz Dhur was Latinised to Laurentius Durus and in turn rendered as Twardowski in Polish; durus and twardy mean "hard" in Latin and Polish respectively. There is also some speculation that this legend was inspired by the life of either John Dee or his associate Edward Kelley, both of whom lived in Kraków for a time.
The title Pan, used as a universal honorific and polite form of address in modern Polish, was reserved for members of nobility (szlachta) at the time the tale developed and was roughly equivalent to the English Sir (see Polish name). Twardowski's forename is sometimes given as Jan (John), although most versions of his tale do not mention a forename at all. This, however, may have resulted as a confusion between Pan Twardowski and a Polish Catholic priest writer, Jan Twardowski.
Twardowski in literature, music, film and gaming
The legend of Pan Twardowski inspired a great number of Polish, Czech, Ukrainian, Russian and German poets, novelists, composers, directors and other artists.
One of the best known literary works featuring Pan Twardowski is the humorous ballad Pani Twardowska by Adam Mickiewicz (1822). In this version of the story, Twardowski agrees to be taken to hell on the condition that the devil spends one year living with his wife, Pani (Lady) Twardowska. The devil, however, prefers to run away and thus Pan Twardowski is saved. Stanisław Moniuszko wrote music for the ballad in 1869.
Other works based on the legend include:
Pan Tvardovsky, an opera by Alexey Verstovsky, libretto by Mikhail Zagoskin (1828);
Pan Tvardovsky, Zagoskin's short story from the collection An Evening on the Khopyor (1834);
Mistrz Twardowski [Master Twardowski], a novel by Józef Ignacy Kraszewski (1840);
Tvardovsky, a ballad by Semen Hulak-Artemovsky;
Pan Twardowski, a ballet by Adolf Gustaw Sonnenfeld (1874);
Pan Tvardovski, an opera by Ivan Zajc (1880);
Twardowski, a poem by Jaroslav Vrchlický (1885);
Mistrz Twardowski, a poem by Leopold Staff (1902);
Pan Twardowski, a ballad by Lucjan Rydel (1906);
Pan Tvardovsky, a film by Ladislas Starevich (1917);
Pan Twardowski, a ballet by Ludomir Różycki (1921);
Pan Twardowski, a film by Wiktor Biegański (1921);
Pan Twardowski, czarnoksiężnik polski [Pan Twardowski, a Polish sorcerer], a novel by Wacław Sieroszewski (1930);
Pan Twardowski, a film by Henryk Szaro, screenplay by Wacław Gąsiorowski (1936);
Pan Twardowski oder Der Polnische Faust [Pan Twardowski or The Polish Faust], a novel by Matthias Werner Kruse (1981);
Dzieje Mistrza Twardowskiego (The Story of Master Twardowski), a film by Krzysztof Gradowski (1995).
Twardowsky, a short sci-fi film from Polish Legends series directed by Tomasz Bagiński (2015)
Hearts of Stone, an expansion to RPG game The Witcher 3: Wild Hunt (2015), has a main storyline heavily inspired by the legend.
Mr. Twardowski is also a popular character in the folk art of the Kraków region. He may be found, for example, in some of the famous Cracovian cribs (szopki). He is typically depicted as a Polish noble either riding a rooster or standing on the Moon.
Places associated with Pan Twardowski
Pan Twardowski is said to have lived in or near Kraków, the capital of Poland at the time. Different places in Kraków claim to be the exact location of Twardowski's house. The sorcerer might have lived either somewhere in the city center, near the Rynek Główny or Ulica Grodzka, or across the River Vistula in the village of Krzemionki (now part of Kraków).
Across Poland, there are a number of inns and pubs called Rzym ("Rome"), all of which claim to be the one where Pan Twardowski met the devil. The oldest of these inns date back to only the late 17th century, about 100 years after Twardowski's time. The one in Sucha is probably the best known of these inns.
In the sacristy of a church in Węgrów, hangs a polished metal plate claimed to be the magic mirror which once belonged to Pan Twardowski. According to a legend, it was possible to see future events reflected in the mirror until it was broken in 1812 by Emperor Napoléon Bonaparte of France when he saw in it his future retreat from Russia and collapse of his empire.
It is also said that Pan Twardowski spent some time in the city of Bydgoszcz, where, in his memory, a figure was recently mounted in a window of a tenement, overseeing the Old Town. At 1:13 p.m. and 9:13 p.m. the window opens and Pan Twardowski appears, to the accompaniment of weird music and devilish laughter. He takes a bow, waves his hand, and then disappears. This little show gathers crowds of amused spectators.
See also
Faust
Theophilus of Adana
Simon Magus
The Smith and the Devil
References
European folklore characters
Legendary Polish people
Supernatural legends
Polish folklore
Fictional Polish people
Fictional characters who have made pacts with devils
Moon myths
Deal with the Devil
Fictional characters from the 16th century |
2864740 | https://en.wikipedia.org/wiki/List%20of%20lunar%20meteorites | List of lunar meteorites | This is a list of lunar meteorites. That is, meteorites that have been identified as having originated from Earth's Moon.
Notes
Where multiple meteorites are listed (e.g. NWA 4472/4485), they are believed to be pieces of the same original body. The mass shown is the total.
AaU -
ALH – Allan Hills, Antarctica
Asuka – Antarctica
Calcalong Creek – Australia
Dar al Gani – Libya
Dho - Dhofar, Oman
EET – Elephant Moraine, Antarctica
Kalahari – Botswana
LAP – LaPaz Icefield, Antarctica
MAC – MacAlpine Hills, Antarctica
MET – Meteorite Hills, Antarctica
MIL – Miller Range, Antarctica
NEA – Northeast Africa: Sudan
NWA – Northwest Africa: Morocco, Algeria
PCA – Pecora Escarpment, Antarctica
QUE – Queen Alexandra Range, Antarctica
SaU – Sayh al Uhaymir, Oman
Yamato – Antarctica
Source: Washington University in St. Louis, Department of Earth and Planetary Science.
See also
Glossary of meteoritics
List of Martian meteorites
References
External links
An Up-to-Date List of Lunar Meteorites — Washington University in St. Louis.
Lunar meteorites — Washington University in St. Louis.
Taylor, G. J. (Oct., 2004) New Lunar Meteorite Provides its Lunar Address and Some Clues about Early Bombardment of the Moon. Planetary Science Research Discoveries.
Lunar meteorites — Meteoritical Bulletin Database.
-
Meteorites |
2866360 | https://en.wikipedia.org/wiki/Meanings%20of%20minor%20planet%20names%3A%2094001%E2%80%9395000 | Meanings of minor planet names: 94001–95000 |
94001–94100
|-bgcolor=#f2f2f2
| colspan=4 align=center |
|}
94101–94200
|-bgcolor=#f2f2f2
| colspan=4 align=center |
|}
94201–94300
|-id=228
| 94228 Leesuikwan || || Lee Sui Kwan (born 1968), Chinese former vice president of the Hong Kong Astronomical Society, has been putting sustained efforts into astronomical popularization and education to the general public in Hong Kong. He has given several hundred astronomical talks to teenagers to stimulate their interest in astronomy. ||
|-id=291
| 94291 Django || || Django Reinhardt (1910–1953), a legendary Belgian Sinto Gypsy jazz guitarist composer, became renowned as a member of the famous ensemble "Quintette du Hot Club de France" in 1934. Despite limited use of his injured fretting hand, Reinhardt pushed guitar technique to new virtuosic heights. ||
|}
94301–94400
|-id=356
| 94356 Naruto || || Naruto Strait (Naruto Kaikyō) is a strait between the Japanese islands of Shikoku and Awaji. ||
|-id=400
| 94400 Hongdaeyong || || Hong Daeyong (1731–1783), a Korean astronomer of the late Chosun Dynasty, worked to overcome old, conventional cosmology in Korea and advocated new concepts introduced through China. He also invented numerous astronomical instruments. ||
|}
94401–94500
|-bgcolor=#f2f2f2
| colspan=4 align=center |
|}
94501–94600
|-id=556
| 94556 Janstarý || || Jan Starý (born 1950) has worked as an observer at Ondřejov Observatory of the Astronomical Institute of the Czech Academy of Sciences. He was involved in operations of fireball photographing cameras there for more than 10 years. Name suggested by P. Spurný. ||
|}
94601–94700
|-bgcolor=#f2f2f2
| colspan=4 align=center |
|}
94701–94800
|-bgcolor=#f2f2f2
| colspan=4 align=center |
|}
94801–94900
|-id=884
| 94884 Takuya || || Takuya Matsuda (born 1943), a Japanese astrophysicist and professor in the department of Earth and planetary sciences at Kobe University, is a recognised authority on computer simulations, particularly of accretion disks and wind accretion. Also a relativitist, he has served as president of the Astronomical Society of Japan. ||
|}
94901–95000
|-bgcolor=#f2f2f2
| colspan=4 align=center |
|}
References
094001-095000 |
2866421 | https://en.wikipedia.org/wiki/Meanings%20of%20minor%20planet%20names%3A%2098001%E2%80%9399000 | Meanings of minor planet names: 98001–99000 |
98001–98100
|-bgcolor=#f2f2f2
| colspan=4 align=center |
|}
98101–98200
|-id=127
| 98127 Vilgusová || || (1946–2007) was a Czech illustrator of books of tales that have been published in several European countries. Her great empathy for a child's soul has resulted in her illustrations having a very positive charge of humanity. ||
|}
98201–98300
|-bgcolor=#f2f2f2
| colspan=4 align=center |
|}
98301–98400
|-bgcolor=#f2f2f2
| colspan=4 align=center |
|}
98401–98500
|-id=494
| 98494 Marsupilami || || Marsupilami, comic-strip character created by the Belgian cartoonist André Franquin. A playful, gluttonous wag, the Marsupilami first appeared in January 1952 in Spirou and Fantasio magazine, where it shouted out its first "Houba!" ||
|}
98501–98600
|-bgcolor=#f2f2f2
| colspan=4 align=center |
|}
98601–98700
|-bgcolor=#f2f2f2
| colspan=4 align=center |
|}
98701–98800
|-id=722
| 98722 Elenaumberto || || Elena Persichilli (born 1940) and Umberto Masi (born 1926) are the parents of the Italian discoverer, Gianluca Masi, who expresses eternal gratitude to them. This citation celebrates the great importance they had in supporting him over the last 26 years, since the beginning of his interest in astronomy, up to his professional involvement with this science. ||
|}
98801–98900
|-id=825
| 98825 Maryellen || || Mary Ellen Craven, companion and partner of American astronomer Edwin E. Sheridan, who discovered this minor planet ||
|-id=866
| 98866 Giannabussolari || || Gianna Bussolari (born 1943) has been a beloved teacher for three decades. Mother of three, she is very much appreciated by a worldwide community of astronomers as a charming guest and hostess, deserving substantial credit for the success of several astronomical conferences organized in Padova. ||
|}
98901–99000
|-bgcolor=#f2f2f2
| colspan=4 align=center |
|}
References
098001-099000 |
2868301 | https://en.wikipedia.org/wiki/Acoustic%20Doppler%20current%20profiler | Acoustic Doppler current profiler | An acoustic doppler current profiler (ADCP) is a hydroacoustic current meter similar to a sonar, used to measure water current velocities over a depth range using the Doppler effect of sound waves scattered back from particles within the water column. The term ADCP is a generic term for all acoustic current profilers, although the abbreviation originates from an instrument series introduced by RD Instruments in the 1980s. The working frequencies range of ADCPs range from 38 kHz to several megahertz.
A similar device is a SODAR, which works in the air and uses the same principles for wind speed profiling.
Working principle
ADCPs contain piezoelectric transducers to transmit and receive sound signals. The traveling time of sound waves gives an estimate of the distance. The frequency shift of the echo is proportional to the water velocity along the acoustic path. To measure 3D velocities, at least three beams are required. In rivers, only the 2D velocity is relevant and ADCPs typically have two beams. In recent years, more functionality has been added to ADCPs (notably wave and turbulence measurements) and systems can be found with 2,3,4,5 or even 9 beams.
Further components of an ADCP are an electronic amplifier, a receiver, a clock to measure the traveling time, a temperature sensor, a compass to know the heading, and a pitch/roll sensor to know the orientation. An analog-to-digital converter and a digital signal processor are required to sample the returning signal in order to determine the Doppler shift. A temperature sensor is used to estimate the sound velocity at the instrument position using the seawater equation of state, and uses this to estimate scale the frequency shift to water velocities. This procedure assumes that the salinity has a preconfigured constant value. Finally, the results are saved to internal memory or output online to an external display software.
Processing methods
Three common methods are used to calculate the Doppler shift and thus the water velocity along the acoustic beams. The first method uses a monochromatic transmit pulse and is referred to as "incoherent" or "narrowband". The method is robust and provides good quality mean current profiles but has limited space-time resolution. When the transmit pulse consists of coded elements that are repeated, the method is referred to as "repeat sequence coding" or "broadband". This method improves the space-time resolution by a factor of 5 (typical). Commercially, this method was protected by US patent 5615173 until 2011. The pulse-to-pulse coherent method relies on a sequence of transmit pulses where the echo from subsequent pulses are assumed not to interfere with each other. This method is only applicable for very short profiling ranges but the corresponding improvement in space time resolution is of order 1000.
Applications
Depending on the mounting, one can distinguish between side-looking, downward- and upward-looking ADCPs. A bottom-mounted ADCP can measure the speed and direction of currents at equal intervals all the way to the surface. Mounted sideways on a wall or bridge piling in rivers or canals, it can measure the current profile from bank to bank. In very deep water they can be lowered on cables from the surface.
The primary usage is for oceanography. The instruments can also be used in rivers and canals to continuously measure the discharge.
Mounted on moorings within the water column or directly at the seabed, water current and wave studies may be performed. They can stay underwater for years at a time, the limiting factor is the lifetime of the battery pack. Depending on the nature of the deployment the instrument usually has the ability to be powered from shore, using the same umbilical cable for data communication. Deployment duration can be extended by a factor of three by substituting lithium battery packs for the standard alkaline packs.
Bottom tracking
By adjusting the window where the Doppler shift is calculated, it is possible to measure the relative velocity between the instrument and the bottom. This feature is referred to as bottom-track. The process has two parts; first identify the position of the bottom from the acoustic echo, then calculating the velocity from a window centered around the bottom position. When an ADCP is mounted on a moving ship, the bottom track velocity may be subtracted from the measured water velocity. The result is the net current profile. Bottom track provides the foundation for surveys of the water currents in coastal areas. In deep water where the acoustic signals cannot reach the bottom, the ship velocity is estimated from a more complex combination of velocity and heading information from GPS, gyro, etc.
Discharge measurements
In rivers, the ADCP is used to measure the total water transport. The method requires a vessel with an ADCP mounted over the side to cross from one bank to another while measuring continuously. Using the bottom track feature, the track of the boat as well as the cross sectional area is estimated after adjustment for left and right bank areas. The discharge can then be calculated as the dot product between the vector track and the current velocity. The method is in use by hydrographic survey organisations across the world and forms an important component in the stage-discharge curves used in many places to continuously monitor river discharge.
Doppler velocity log (DVL)
For underwater vehicles, the bottom tracking feature can be used as an important component in the navigation systems. In this case the velocity of the vehicle is combined with an initial position fix, compass or gyro heading, and data from the acceleration sensor. The sensor suite is combined (typically by use of a Kalman filter) to estimate the position of the vehicle. This may help to navigate submarines, autonomous, and remotely operated underwater vehicles.
Wave measurements
Some ADCPs can be configured to measure surface wave height and direction. The wave height is estimated with a vertical beam that measures the distance to the surface using the echo from short pulses and simple peak estimation algorithms. The wave direction is found by cross correlating the along-beam velocity estimates and the wave height measurement from the vertical beam. Wave measurements are typically available for seafloor-mounted instruments but recent improvements permit the instrument to be mounted also on rotating subsurface buoys.
Turbulence
ADCPs with pulse-to-pulse coherent processing can estimate the velocity with the precision required to resolve small scale motion. As a consequence, it is possible to estimate turbulent parameters from properly configured ADCPs. A typical approach is to fit the along beam velocity to the Kolmogorov structure configuration and thereby estimate the dissipation rate. The application of ADCPs to turbulence measurement is possible from stationary deployments but can also be done from moving underwater structures like gliders or from subsurface buoys.
Advantages and disadvantages
The two major advantages of ADCPs is the absence of moving parts that are subject to biofouling and the remote sensing aspect, where a single, stationary instrument can measure the current profile over ranges exceeding 1000 m. These features allow for long term measurements of the ocean currents over a significant portion of the water column. Since the start in the mid-1980s, many thousand ADCPs have been used in the world oceans and the instrument has played a significant role in our understanding of the world ocean circulation.
The main disadvantage of the ADCPs is the loss of data close to the boundary. This mechanism, often referred to as a sidelobe interference, covers 6–12% of the water column and, for instruments looking up toward the surface, the loss of velocity information close to the surface is a real disadvantage. Cost is also a concern but is normally dwarfed by the cost of the ship required to ensure a safe and professional deployment.
As any acoustical instrument, the ADCP contributes to noise pollution in the ocean which may interfere with cetacean navigation and echolocation. The effect depends on the frequency and the power of the instrument but most ADCPs operate in a frequency range where noise pollution has not been identified to be a serious problem.
References
Sonar
Physical oceanography
Oceanographic instrumentation
Ocean currents
Watercraft components |
2868397 | https://en.wikipedia.org/wiki/RSM-56%20Bulava | RSM-56 Bulava | The RSM-56 Bulava (, lit. "mace", NATO reporting name SS-NX-30 or SS-N-32, GRAU index 3M30, 3K30) is a submarine-launched ballistic missile (SLBM) developed for the Russian Navy and deployed in 2013 on the new of ballistic missile nuclear submarines. It is intended as the future cornerstone of Russia's nuclear triad, and is the most expensive weapons project in the country. The weapon takes its name from bulava, a Russian word for mace.
Designed by Moscow Institute of Thermal Technology, development of the missile was launched in the late 1990s as a replacement for the R-39 Rif solid-fuel SLBM. The Project 955/955A Borei-class submarines carry 16 missiles per vessel. Development and deployment of the Bulava missile within the Russian Navy is not affected by the enforcement of the new START treaty.
A source in the Russian defense industry told TASS on June 29, 2018, that the D-30 missile system with the R-30 Bulava intercontinental ballistic missile had been accepted for service in the Russian Navy after its successful four-missile salvo launch tests in 2018.
Description
The Bulava missile was developed by Moscow Institute of Thermal Technology under the leadership of chief designer . Although it utilizes some engineering solutions used for the recent RT-2PM2 Topol-M ICBM, the new missile has been developed virtually from scratch. The Bulava is the submarine version of the Topol-M, and is both lighter and thinner than the Volna. The two missiles are expected to have comparable ranges, and similar CEP and warhead configurations. Bulava has a declared START throw weight of 1150 kg to 9,500 kilometers.
The missile has three stages; the first and second stages use solid fuel propellant, while the third stage uses a liquid fuel to allow high maneuverability during warhead separation. The missile can be launched from an inclined position, allowing a submarine to fire them while moving. It has a low flight trajectory, and due to this could be classified as a quasi-ballistic missile. It is rumored to possess advanced missile defense evasion capabilities and can maneuver at its boost stage.
Borei-class submarines carrying Bulava missiles are expected to be an integral part of the Russian nuclear triad until 2040.
Bulava can be loaded on TEL road mobile launchers, on railway BZhRK trains and other various launchers.
Development history
Inception
In the 1990s, Russia had two submarine-launched ICBMs, the solid-fuel R-39 and the liquid-fuel R-29 Vysota family, both developed by the Makeyev Design Bureau. A new missile, designated R-39UTTH Bark was under development to replace the R-39. The Bark was planned to become the only submarine-launched ballistic missile of the Russian nuclear arsenal. However, its development was plagued with problems, and after three test failures the Bark programme was canceled in 1998. Moscow Institute of Thermal Technology was now tasked with developing a new advanced missile. The institute promised that it would be able to quickly develop a new naval missile based on its recent Topol-M land-based ICBM.
The new missile would be deployed per 16 missiles on the Borei I (Project 955) and Borei II (Project 955A) class submarines. As the new submarines would not be ready in time for flight tests, the Typhoon-class submarine Dmitry Donskoy was upgraded to carry Bulavas.
Key people involved in the decision to develop Bulava included the institute director and Bulava's chief designer Yury Solomonov; director of the Defense Ministry's Fourth Central Research Institute, Major-General Vladimir Dvorkin; Navy Commander, Fleet Admiral Vladimir Kuroyedov; Defense Minister, Marshal Igor Sergeyev; Economics Minister Yakov Urinson and Prime Minister Viktor Chernomyrdin.
First tests
The missile completed the first stage launch-tests at the end of 2004. Although it was initially planned to base the Bulava design on the Topol-M, the first tests showed that the new missile was completely different in terms of appearance, dimensions and warhead lay-out. It was later acknowledged that the Moscow Institute of Thermal Technology had developed Bulava virtually from scratch, reusing only a few engineering solutions from the Topol-M.
Troubles
The missile's flight test programme was problematic. Until 2009, there were 6 failures in 13 flight tests and one failure during ground test, blamed mostly on substandard components. This led to the missile's chief designer, Yury Solomonov resigning from his post in July 2009. Aleksandr Sukhodolskiy was appointed as the new general designer of sea-based ballistic missiles at the Moscow Institute of Thermal Technology; Solomonov however retained his post of general designer of land-based missiles.
After a failure in December 2009, further tests were put on hold and a probe was conducted to find out the reasons for the failures. Testing was resumed on 7 October 2010 with a launch from the in the White Sea; the warheads successfully hit their targets at the Kura Test Range in the Russian Far East. Seven launches have been conducted since the probe, all successful. On 28 June 2011, the missile was launched for the first time from its standard carrier, Borei-class submarine , and on 27 August 2011 the first full-range (over ) flight test was conducted. After this successful launch, the start of serial production of Bulava missiles in the same configuration was announced on 28 June 2011. A successful salvo launch on 23 December 2011 concluded the flight test programme. The missile was officially approved for service on 27 December 2011, and was reported to be commissioned aboard Yuri Dolgorukiy on 10 January 2013. The missile did however continue to fail in the summer of 2013 and was not operational as of November 2013. The Bulava became operational aboard Yury Dolgorukiy as of October 2015. However, recent developments put this in question. In November 2015, the submarine fired two missiles while submerged. One of the missiles self-destructed during the boost phase and the other failed to deliver its warheads to the specified target. After being sent back to the manufacturer, it was determined that the missiles failed due to manufacturing defects.
After two successful tests in June 2017 and May 2018, a source in the Russian defense industry told TASS on June 29, 2018, that the D-30 missile system with the R-30 Bulava intercontinental ballistic missile had been accepted for service in the Russian Navy.
Explanations for the failures
Chief designer Solomonov blamed the failures on the poor state of the Russian defense industry and problems in the design-technology-production chain.
"Sometimes [the problem] is poor-quality materials, sometimes it is the lack of necessary equipment to exclude the 'human' factor in production, sometimes it is inefficient quality control"
According to Solomonov, the industry is unable to manufacture 50 of the necessary components for the missile, forcing designers to improvise and look for alternative solutions, which seriously complicates the testing process. Solomonov further said that despite the failures, there was no need for changes in the design.
Sergei Kovalyov, the designer of three generations of Russian strategic submarines said that due to lack of funding, the developers had been unable to conduct test launches from a floating pad to test the underwater segment of the missile's trajectory. He also said that there were insufficient funds to conduct ground-based test launches. Both types of testing had been standard procedure during Soviet times. Kovalyov also criticised the poor quality of missile components provided by a large number of sub-contractors and the absence of military representatives at manufacturing plants.
The 2009 Norwegian spiral anomalies, a temporary strange light phenomenon over vast areas of northern Norway have been explained with a failed stage of a Bulava missile test.
According to a spokesman, "The missile's first two stages worked as normal, but there was a technical malfunction at the next, third, stage of the trajectory".
Effects on the military
Due to the delays in Bulava's development, the launch of the fourth Borei-class submarine, Svyatitel Nikolay, was pushed back. Russia was planning to build eight Borei-class submarines by 2015.
Only one Typhoon-class submarine, Dmitry Donskoy, was modified to launch Bulavas. The Bulava program is the most expensive weapons project in Russia.
Debate about the program
Despite continued test failures, the Russian defense minister, Anatoliy Serdyukov, has stated that the project will not be abandoned. "We will certainly not give up the Bulava. I think that despite all the failures, the missile will fly," he said in an interview in late December 2009. The Russian military has been adamant that there is no alternative to Bulava.
There has been discussions among analysts about the possibility of re-equipping the Borei-class submarines with the more reliable liquid-propellant R-29RMU Sineva missiles. The Sineva is an upgrade of the R-29RM Shtil and entered service in 2007. According to RIA Novosti military analyst Ilya Kramnik, this would have been an attractive option, given that the less advanced Sineva missiles already have "virtually the same impressive specifications as the Trident II (D5) SLBMs wielded by the U.S. Navy and the Royal Navy." However, the work needed to redesign and modify the Borei-class submarines to carry Sinevas is regarded as too expensive.
Probe
After a launch failure in December 2009 caused by a defective engine nozzle and which led to the 2009 Norwegian spiral anomaly, further tests were put on hold and a review of the missile program was initiated. The results of the probe were delivered to the Russian government in May 2010.
2010 tests
Testing was resumed for the first time after the probe on 7 October 2010. The missile was launched from the submerged Dmitry Donskoy, in the White Sea, and the warheads successfully hit their targets at the Kura testing range, to the north of Petropavlovsk-Kamchatsky in the Russian Far East. The launch reportedly took place at 07:15 UTC. The missile travelled over , and the rocket's trajectory was within the normal parameters, according to a Navy official.
The second test launch in 2010 from Dmitry Donskoy was set to 29 October and was successful.
The next test to be performed from Yuriy Dolgorukiy was initially planned to December 2010, but was postponed to mid-summer 2011 due to ice conditions in White Sea.
2011 tests and deployment
According to the Russian Vice Premier Sergei Ivanov another six successful launches (one planned in 2010, other five in 2011) will be required before the missile could be commissioned.
2012 tests and deployment
In August 2012 a high-ranking official of Russia's United Shipbuilding Corporation said in 2012 Russia will test fire its Bulava missile only once, in November, specifically from the nuclear-powered submarine .
2013 deployment
Bulava was finally commissioned with its lead carrier Yuri Dolgorukiy on 10 January 2013. The official ceremony of raising the Russian Navy colors on the submarine was led by Russian Defense Minister Sergey Shoigu. After another failed launch in September, Shoigu announced a pause in the state trials of the next two submarines and five more test launches. The entire production run of the missiles was then recalled for factory inspections.
Timetable
Service
In October 2010 it was reported that 150-170 operational missiles would be built (124 active + reserve for training and tests). After the successful launch on 27 June 2011, the Russian government announced the start of serial production of Bulava missiles. On 10 January 2013, Bulava was adopted into experimental service with its lead carrier submarine Yuri Dolgorukiy. It was reported in June 2018 that the missile has been accepted for service by the Russian Navy after its successful test firings conducted in 2018.
Operators
The Russian Navy is the only operator of the RSM-56 Bulava. As of January 2023, 96 missiles were deployed on 6 Borei-class ballistic missile submarines:
K-535
K-550
K-551
K-549
K-552
K-553
Specifications
See also
R-29 Vysota
R-29RM Shtil
R-29RMU Sineva
R-29RMU2 Layner
Kanyon
UGM-133 Trident II
M45 (missile)
M51 (missile)
JL-1
JL-2
JL-3
K Missile family
Pukkuksong-1
R-39 Rif
R-39M
References
External links
CSIS Missile Threat - SS-N-32 "Bulava"
Russia's Bulava undergoes fast-track test programme, May 2006.
Technical data in PDF, DTIG.
Technical data from CNews.ru.
Technical data from warfare.ru.
Nuclear weapons of Russia
Submarine-launched ballistic missiles of Russia
Intercontinental ballistic missiles of Russia
Votkinsk Machine Building Plant products
MIRV capable missiles
Military equipment introduced in the 2010s |
2868872 | https://en.wikipedia.org/wiki/476%20Hedwig | 476 Hedwig | Hedwig (minor planet designation: 476 Hedwig) (1901 GQ) is a main-belt asteroid discovered on August 17, 1901, by Luigi Carnera at Heidelberg. Named in honour of the wife of Swedish-Danish astronomer Elis Strömgren.
See also
List of Solar System objects by size
References
External links
Background asteroids
Hedwig
Hedwig
P-type asteroids (Tholen)
X-type asteroids (SMASS)
19010817 |
2868875 | https://en.wikipedia.org/wiki/477%20Italia | 477 Italia | Italia (minor planet designation: 477 Italia) (1901 GR) is a main-belt asteroid that was discovered on 23 August 1901 by Italian astronomer Luigi Carnera at Heidelberg.
Photometric observations of this asteroid collected in 2005 gave a provisional rotation period of 19.4189 hours and a brightness variation of about 0.2 in magnitude.
References
External links
Background asteroids
Italia
Italia
T-type asteroids
S-type asteroids (Tholen)
S-type asteroids (SMASS)
19010823 |
2869570 | https://en.wikipedia.org/wiki/Chaoite | Chaoite | Chaoite, or white carbon, is a mineral described as an allotrope of carbon whose existence is disputed. It was discovered in shock-fused graphite gneiss from the Ries crater in Bavaria. It has been described as slightly harder than graphite, with a reflection colour of grey to white. From its electron diffraction pattern, the mineral has been considered to have a carbyne structure, the linear acetylenic carbon allotrope of carbon. A later report has called this identification, and the very existence of carbyne phases, into question, arguing that the new reflections in the diffraction pattern are due to clay impurities.
Synthetic material
It has been claimed that an identical form can be prepared from graphite by sublimation at 2700-3000 K or by irradiating it with a laser in high vacuum. This substance has been termed ceraphite.
A review cautions that "in spite of these seemingly definitive reports … several other groups have tried unsuccessfully to reproduce these experiments. Independent confirmatory work is obviously needed … and at the present time white graphite appears to be the carbon analog of polywater".
Occurrence and discovery
Chaoite was first described from Möttingen, Ries Crater, Nördlingen, Bavaria, Germany and approved by the IMA in 1969. The mineral was named for USGS petrologist Edward C. T. Chao (1919-2008). At the type locality in Bavaria chaoite occurs in graphite bearing gneiss that has undergone shock metamorphism. It has also been reported from meteorites including the Goalpara meteorite in Assam, the Dyalpur meteorite in Uttar Pradesh in India and the Popigai impact structure in the Anabarskii massif of Eastern Siberia. Minerals associated with chaoite include: graphite, zircon, rutile, pseudobrookite, magnetite, nickeliferous pyrrhotite and baddeleyite.
See also
Glossary of meteoritics
References
Further reading
Frans J. M. Rietmeijer and Alessandra Rotundi, Chapter 16. Natural Carbynes, Including Chaoite, on Earth, in Meteorites, Comets, Circumstellar and Interstellar Dust, in Polyynes: Synthesis, Properties, and Applications, Edited by Franco Cataldo, CRC Press 2005, Pages 339–370, Print eBook Contents link
Allotropes of carbon
Native element minerals
Meteorite minerals
Hexagonal minerals
Minerals in space group 191 |
2869896 | https://en.wikipedia.org/wiki/List%20of%20craters%20on%20the%20Moon%3A%20R%E2%80%93S | List of craters on the Moon: R–S | The list of approved names in the Gazetteer of Planetary Nomenclature maintained by the International Astronomical Union includes the diameter of the crater and the person the crater is named for. Where a crater formation has associated satellite craters, these are detailed on the main crater description pages.
R
back to top
S
back to top
References
R |
2870417 | https://en.wikipedia.org/wiki/Mons%20Penck | Mons Penck | Mons Penck is a mountain promontory on the near side of the Moon. It lies just to the northeast of the crater Kant, to the north of Ibn-Rushd and the Rupes Altai scarp. Southeast of Mons Penck are the prominent craters Theophilus and Cyrillus.
The selenographic coordinates of this peak are 10.0° S, 21.6° E. It has a diameter of about 30 km at the base and climbs to an altitude of over 4 km (13,000 feet). It was named after Albrecht Penck (1858–1945), a German geographer and geologist.
References
External links
LTO-78C1 Kant — L&PI topographic orthophotomap map.
Penck, Mons |
2873257 | https://en.wikipedia.org/wiki/April%20Morning | April Morning | April Morning is a 1961 novel by Howard Fast, about Adam Cooper's coming of age during the Battle of Lexington. One critic notes that in the beginning of the novel he is "dressed down by his father, Moses, misunderstood by his mother, Sarah, and plagued by his brother, Levi." In the backdrop are the peaceful people of Lexington, forced "to go into a way of war that they abhorred."
While the novel was not originally written as a young adult story, it has increasingly been assigned in middle school English and social studies classes, due to the age of the protagonist and Fast's meticulous efforts to recreate the texture of daily life in colonial America and the political currents on the eve of the American Revolution.
In 1988, a film version was made for television starring Chad Lowe as Adam and Tommy Lee Jones as Moses.
Plot
The novel begins in the afternoon of April 18, 1775, when Adam's father, Moses, sends him out to draw water from the well for his mother, Sarah. After completing this task, he heads upstairs to talk with Granny. During it, they engage in a debate on religion. Afterwards, they head downstairs for dinner. Then they pray and the meal, consisting of bread pudding and donkers, begins. In the middle of it, Moses confronts Adam about a "spell" to be said while drawing water. As a result, the confrontation starts an argument, which is interrupted by Cousin Simmons arriving. He, chosen to draft a letter on the rights of man, comes to Moses with his draft seeking criticism. Another debate arises over his description of rights as "god-given." Moses asserts that rights come from the people backing them, not God.
After dinner is over and Adam finishes some evening chores, he heads over to the Simmons' house to meet with Ruth, his love interest, and go on a walk. Before he is able to see her, however, Aunt Simmons makes conversation with him and feeds him pie. Then Ruth comes downstairs, and she and Adam leave on a walk. During it, they talk about various things, including their futures and what they want to be in the world. After a kiss he walks her home and then he himself heads home. Upon arrival, he spots his brother, Levi, cleaning his gun. He does not like this but Sarah insists that he let him do it. Then he heads upstairs and goes to bed. Before falling asleep he overhears his parents talking about the committee meeting. Finally he falls asleep.
Suddenly, Adam is awakened by Levi, who draws attention to a speedy rider that stops in the center of town. Now all the Coopers are awake and curious. People gather around the rider on the green, who informs them that the British are coming and may be marching through their town. He then rides off. Because of this news, arguments stir in the crowd on whether to muster the militia. The people of Lexington agree to muster it. Adam signs up and is then tasked to take Ruth home. After doing so, he comes home to overhear his parents designating him a man. As he walks in Moses chastises him. He then has him load his gun and go to the muster.
After Adam and all the other men arrive at the green, the militia muster falls into order and the women and children are sent inside. They stand there for a few hours until the redcoats march into town. The British fix bayonets, then fire upon the militia. Moses falls and Adam runs away. He hides in a smokehouse until Levi comes in. Levi tells him to leave town because the British are searching. He leaves, jumps over a wall, and meets Solomon Chandler. He feeds and comforts Adam on the events he just witnessed. Then they walk until they meet Cousin Dover, Cousin Simmons, and the Reverend. They continue to walk until they arrive at the militia encampment. There the militia plans several ambushes and Adam shares his story of the massacre on the Lexington green. Then the militia sends a horseman to scout ahead while the others lie in wait by the road. He returns, then the British come. The militia releases a few volleys before retreating over the hill. The militia, not pursued by the British, stop to rest and plan the next ambush.
During the next ambush Adam falls asleep under some brush. He is awakened by Cousin Simmons and the Reverend searching for his body and talking about him. He calls to them, to their relief, and they send him home. He returns home and is greeted by Levi, who walks him into the house. It is occupied by mourners, Ruth, Granny, and Sarah. The latter sends him to get Moses a coffin and take it to the church. After a brief conversation with the coffin-maker he returns home. He eats dinner, then Sarah sends him to light candles by Moses' coffin. Ruth accompanies him and they talk for a while, until he walks her home. Then he himself goes home and to bed.
Themes
Several major themes arise in the novel. Although the most common theme picked up on is coming of age, several others have been noted. These others are non-violence, the rights of man, and the truth.
The first theme, coming of age, deals with Adam's becoming a man during the Battle of Lexington. After Moses is killed on the green, Adam is thrust into manhood. Vomiting and sobbing after the battle, he then returns home to be treated as the man of the house, against his wishes.
The theme of nonviolence is based on Moses' belief in solving problems through arguments, rather than warfare. This theme is also supported by Adam's later saying "I don't hate anyone enough to kill him." The rights of man appears several times through Moses' speeches. Also, the colonists are drafting a statement on the rights of man to send to Boston.
For the truth theme, several conflicts have been noted in the first chapter, such as Moses' talking against superstition yet birching Adam seven times.
Background
York has said that Fast's view on the revolution (that aligns with his political beliefs) is exhibited in the novel. He says "[Fast] believed the essence of the revolution was with the faceless and nameless people who fought it." Also, The New York Times says that "[Fast] proposes that Solomon Chandler organized the Battle of Lexington.
Reception
The novel received many positive reviews. Hunter praised Fast for writing it for "demonstrat[ing] a more mature vision." Desrosiers agreed, saying that April Morning "[is] a well written work which knits together the events of the 19th of April 1775." Macdonald also praised Fast for "A virtually perfect relationship between literary character and research."
Adaptations
The novel was adapted for TV in the Hallmark Hall of Fame in 1988 by James Lee Barrett. It was directed by Delbert Mann. It stars Chad Lowe as Adam and Tommy Lee Jones as Moses. Although it is set at the very beginning of the American Revolution it is more about Adam's journey to manhood and his relationship with his parents.
Publication information
April Morning, by Howard Fast. Originally published 1961. Mass Market Paperback: Bantam, 1983.
See also
List of films about the American Revolution
List of television series and miniseries about the American Revolution
References
Novels by Howard Fast
American historical novels
Novels set during the American Revolutionary War
American young adult novels
Works about children in war
1961 American novels
Fiction set in 1775
Lexington, Massachusetts
Novels set in one day
Novels set in the 1770s |
2875713 | https://en.wikipedia.org/wiki/Tsegihi | Tsegihi | Tsegihi is a bright region in Titan's southern mid-latitudes. It is centered at
Tsegihi is named for a sacred place of the Navajo. The first line in the Navajo Nightsong Tsegihi, The House Made of Dawn runs:
In Tsegihi, oh you who dwell
In the house made of the dawn...
References
Surface features of Titan (moon) |
2876862 | https://en.wikipedia.org/wiki/Mons%20Huygens | Mons Huygens | Mons Huygens is the Moon's tallest mountain (but not its highest point, which is Selenean Summit). It is about high and is located in the Montes Apenninus. Adjacent to the west is Mons Ampère. The Montes Apenninus were formed by the impact that created Mare Imbrium. The mountain was named after the Dutch astronomer, mathematician and physician Christiaan Huygens.
Surroundings
See also
List of tallest mountains in the Solar System
Astrogeology
References
External links
Mons Huygens at the Moon Wiki
Annotated map (source)
Mountains on the Moon
Mons Huygens |
2877892 | https://en.wikipedia.org/wiki/Space%20Race%20%28TV%20series%29 | Space Race (TV series) | Space Race is a BBC docudrama series first shown in Britain on BBC2 between 14 September and 5 October 2005, chronicling the major events and characters in the American/Soviet space race up to the first landing of a man on the Moon. It focuses on Sergei Korolev, the Soviet chief rocket designer, and Wernher von Braun, his American counterpart. The series was a joint effort between British, German, American and Russian production teams.
Reception
Awards
Royal Television Society 2006
Nominated: RTS Television Award for Best Production Design (Drama): Alan Spalding
Sir Arthur Clarke Award 2006
Won: Sir Arthur Clarke Award for Best Presentation (TV & Radio)
Episodes
Episode 1: "Race For Rockets" (1944–1949)
The results of Wernher von Braun's work on the V-2 for the Nazis at Mittelwerk and Peenemünde is shown, and his final activities within Germany during the last years of the Second World War, as both American and Soviet forces race to capture German rocket technology. However, when the Americans gain the upper hand by recovering von Braun and most of his senior staff, along with all their technical documents and much other materiel. Sergei Korolev's is released from the Gulag to act as the Soviets' rocketry expert alongside former colleague Valentin Glushko, and how he is set to work bringing Soviet rocket technology up to date with that of von Braun, working with what material and personnel are left after von Braun's escape to the US.
Episode 2: "Race For Satellites" (1953–1958)
As the Cold War intensifies, Korolev is asked to build a rocket capable of carrying a five-ton warhead to America; he designs and constructs the R-7 Semyorka, the first ICBM, and is later allowed to use it to launch the first satellite, Sputnik 1, quickly following up with the rushed Sputnik 2. Meanwhile, von Braun struggles to persuade the US government to allow him to launch his own satellite; after Sputnik's launch and the failure of the US Navy to launch a Vanguard satellite, he is finally allowed to launch the first American satellite, Explorer 1. Korolev announces that the Americans have evened the score and that they are in a space race, which they intend to win. At the end of the episode, two men are shown walking down a corridor, one of them wearing a spacesuit.
Episode 3: "Race For Survival" (1959–1961)
Both the Americans and Soviets are planning crewed space flights, and we see both sides preparing to do so with the development of the Vostok programme (USSR) and Project Mercury (USA). As well as basic details about the capsules and their delivery vehicles, we also see some of the selection and training of the Russian cosmonauts, and rather less of that of their counterparts in the US. After difficulties and failures on both sides, including a side story about a catastrophic failure of one of the first Russian ballistic missiles, the Soviets succeed in putting Yuri Gagarin into space first, with the Americans putting Alan Shepard up shortly afterwards.
Episode 4: "Race for the Moon" (1964–1969)
Both countries now plan to put a man on the Moon; the Americans pull ahead in the space race with Project Gemini, but then suffer a disaster with the Apollo 1 fire. Meanwhile, despite a notable successes such as the first space walk by Alexei Leonov, the Soviet space programme struggles to keep up amid internal strife. Glushko and Korolev permanently fall out in an argument about fuel; Korolev turns to Nikolai Kuznetsov to develop engines instead. Kuznetsov delivers the NK-33, very efficient but much less powerful than the Americans' F-1. The Soviet program suffers further blows when Korolev dies during surgery, Gagarin dies in a jet crash, Soyuz 1 crashes and kills Vladimir Komarov, and the prototype booster for the Moon shot, the N-1 rocket, fails to successfully launch. In America, von Braun has continuing difficulties with the Saturn V, especially combustion instability in the large F-1 engine, but these are ultimately overcome almost by brute force at great expense, and the rocket successfully launches the first crewed lunar mission, Apollo 8, and the first crewed lunar landing, Apollo 11. The final episode finishes with brief text summaries of the remaining careers of the various people involved.
Production details
The BBC filmed Space Race in and around the town of Sibiu, Transylvania in Romania. Romania has signed the EU co-production treaty which allows for EU co-productions. Compared to other locations, Romania attracted the BBC with unspoiled natural locations, experienced crews and moderately priced production facilities.
The series was filmed with the Panasonic SDX 900 DVCPro50 professional camcorder. This allowed keeping to the speedy shooting schedule and provided the 'gritty' look appropriate to the time period. Shot in widescreen 25fps progressive mode, the series deliver rich, filmic feel, which compares favourably with high definition.
Cast
Richard Dillane – Wernher von Braun
Steve Nicolson – Sergei Korolev
John Warnaby – Vasily Mishin
Ravil Isyanov – Valentin Glushko
Rupert Wickham – Kurt H. Debus
Tim Woodward – Marshal Mitrofan Nedelin
Eric Loren – Castenholz
Chris Robson – Dieter Huzel
Mark Dexter – Staver
Oliver de la Fosse – Staver's Lieutenant
Vitalie Ursu – Yuri Gagarin
Oleg Stefan – Alexei Leonov
Mariya Mironova – Nina
Jeffry Wickham – Nikolai Kuznetsov
Robert Jezek – Robert R. Gilruth
Robert Lindsay – Narrator
Stuart Bunce – Lev Gaidukov
David Barrass – Helmut Gröttrup
Constantine Gregory – Nikita Khrushchev
Simon Day – Kammler
Nicholas Rowe – R. V. Jones
Mikhail Gorevoy – Ivan Serov
Stephen Greif – Colonel Holger Toftoy
Anna Barkan – Ksenia Koroleva
Max Bollinger – Russian cosmonaut (VO)
Todd Boyce – Alan Shepard
Emil Măndănac – Viacheslav Lapo, Russian sound technician
Mihai Dinvale – German Scientist
Anthony Edridge – Chris Kraft
Inaccuracies and errors
Most of the historical and technological data presented in the series are heavily simplified, and sometimes contain outright untruths or errors. The series would best be described and interpreted as giving a general impression of the subject matter, rather than rigorous factual account.
Factual errors
An early scene shows Serov executing Polish resistance fighters who discovered a V-2. This did not happen. A team of British and Polish soldiers and scientists formed a mission to retrieve a fallen V-2 near the Blizna V-2 missile launch site in Poland.
Footage showing early rocket club activity of von Braun actually shows Reinhold Tiling's rockets, a rival to the VfR club that von Braun belonged to. The VfR rockets were crude engines attached to sticks.
Key figures are missing from the presented history. Andrei Tupolev, Vladimir Chelomei and Mikhail Yangel are also conspicuously absent, for example, even in the sequence depicting the disastrous explosion of Yangel's prototype R-16 ICBM. In the series, Glushko is generally identified with all rocket projects competing with Korolev within the USSR, even those for which he had only partial responsibility or was a subcontractor.
The narrator said twice that the Mercury-Redstone could put an astronaut into orbit. In reality, the best the Redstone rocket could do was put an astronaut into a 15-minute "suborbital" ballistic trajectory, which peaked out around 120 miles up. The first orbital flight of an American astronaut did not occur until 20 February 1962, when the Mercury capsule was put into orbit with a more powerful Atlas rocket. Indeed, NASA report TMX-53107 called Mercury-Redstone "a prelude to an orbital flight program" (pg 1–2). However, Episode 3, "Race for Survival", is at pains to disclaim orbital capability. The narrator says (from 8'46" to 8' 51") only that the V-derived Redstone "has only a tenth of the power of Korolev's rocket. Barely enough to put a man into space." This of course is why Freedom 7, Alan Shepard's Redstone-launched capsule, was suborbital.
The narrator states that Gagarin flies "over a sleeping America" even though Vostok's flightpath did not take the craft anywhere near North America, except the Aleutian Islands. Gagarin did say "I'm over America", though. America includes South America and Vostok 1's flight path did just touch America in that sense. Gagarin spoke at night, while still over the Pacific, but only three minutes from the Straits of Magellan; a little earlier he was near Hawaii, which had become one of the US less than two years earlier.
Episode 1 features a map of Europe with wrongly indicated countries. Switzerland is labeled Austria, Austria is labelled Yugoslavia and the Czech Republic is labelled Hungary.
Episode 1 features the surrender of Wernher von Braun to the Americans; at that time, he had a badly fractured arm, which was not mentioned in the series.
In Episode 2 the narrator states twice that the R-7 rocket has 32 engines. This is not entirely correct. The R-7 and its successors have four side boosters and a core booster. Each side booster has a single rocket engine with four combustion chambers, two vernier combustion chambers, and one set of turbopumps. The central core has a similar engine but with four vernier combustion chambers instead of two. This makes total of 32 chambers, not engines. In the scene where Glushko is supposedly testing the clustering scheme, only one engine is shown.
One of the cosmonauts, after seeing the Vostok's cockpit for the first time (Episode 3), asks where the controls are. Also the Gagarin flight scene indicates that there were no controls inside. In fact controls were present on board the Vostoks, but they were blocked to prevent the cosmonauts from manipulating them. A set of codes was placed aboard, so that the cosmonaut could unlock the controls if necessary.
When the Mission Control is shown for the first time in Episode 3 it shows that all the flight controllers have a TV screen showing the launch pad. In reality only the flight director had a TV screen. The other consoles had only meters to measure the various systems.
In Episode 4 the narrator states that "if they (Apollo 8) fail to lock into the Moon's orbit they will fly on, forever lost in space". In fact, Apollo 8 used a free return trajectory that would have taken them back to Earth had the engine performing lunar orbit injection failed.
Unconfirmed statements
The series repeats the claim Korolev was denounced by Glushko several times. There are no known documents substantiating this statement. Glushko had been imprisoned himself before Korolev was arrested and had been sentenced to eight years in a prison camp "for participating in sabotage organization". He was retained to work for the NKVD to develop aircraft jet boosters. In 1942, at Glushko's request, NKVD transferred Korolev from another prison to Glushko's OKB.
Filming inaccuracies
American soldier who meet Von Braun carry a SKS carbine instead of the standard us M1.
Usage of period footage is inconsistent, in particular with regard to the R-7 and its variants.
The scene that depicts transporting a V-2 missile to firing position uses a different missile pulled by the Soviet ZIL-157 truck.
In the sequence with the train leaving the German station with scientists one can read "CFR" on the locomotive, which stands for Căile Ferate Române (Romanian Railways).
The scene depicting a launch from Kapustin Yar, which is dated by 1948, includes vehicles that were not produced at that time, in particular the ZIL-157 (1958), the ZIL-131 (1967) and the UAZ-469 (1971).
Notes
While Korolev's last name often appears to be mispronounced as "Korolyov" in the film, this is closer to its pronunciation in the Russian language.
While both Glushko and Korolev were civilian engineers, they were correctly depicted as wearing military uniform during their stay in Germany, as both had been given commissions in the Red Army.
Companion book
A companion book to the series was written by Deborah Cadbury.
Selected editions
Notes
The National Geographic Channel broadcast the series as a two-part mini-series in 2006.
See also
From the Earth to the Moon
When We Left Earth: The NASA Missions
References
External links
2005 British television series debuts
2005 British television series endings
2000s British documentary television series
BBC television docudramas
Science docudramas
2000s British television miniseries
English-language television shows
Cultural depictions of Yuri Gagarin
Cultural depictions of Nikita Khrushchev
Cultural depictions of Wernher von Braun
Alexei Leonov
Alan Shepard
BBC television documentaries about history during the 20th Century
Works about V-weapons |
2877923 | https://en.wikipedia.org/wiki/Department%20of%20Aerospace%20Science%20and%20Technology | Department of Aerospace Science and Technology | The Brazilian Department of Science and Aerospace Technology (; DCTA) is the national military research center for aviation and space flight. It is subordinated to the Brazilian Air Force (FAB).
It coordinates all technical and scientific activities related to the aerospace sector in which there are interests by the Ministry of Defense. It was established in 1953. It currently employs several thousand civilian and military personnel.
Institutes
The DCTA has four institutes within its campus.
Aeronautics and Space Institute (IAE)
Aeronautics and Space Institute (). It develops projects in the aeronautical, airspace and defense sectors, co-responsible for the execution of the Brazilian Space Mission.
Aeronautics Institute of Technology (ITA)
Aeronautics Institute of Technology () is one of the main educational colleges of the Brazilian Air Force.
Institute for Advanced Studies (IEAv)
Institute for Advanced Studies (). Responsible for the development of pure and applied sciences: photonics, nuclear energy, applied physics, remote sensor systems and decision support systems. In 2006, the IEAv inaugurated the T3 Hypersonic wind tunnel, the largest in Latin America.
Industrial Promotion and Coordination Institute (IFI)
Industrial Promotion and Coordination Institute (). It provides military aeronautical certification and aerospace equipment approval, acting as an interface between the institutes and the industry. Until 2006, it carried out the civil aircraft certification activities, today under the National Civil Aviation Agency responsibilities.
Flight Testing and Research Institute (IPEV)
Flight Testing and Research Institute (). This institute is responsible for the instruction and fulfillment of flight testing campaigns (founded 1953). IPEV has a dedicated Air Force Squadron, based at CTA using the A-29A Super Tucano, C-95BM & CM Bandeirante, and the C-97 Brasília.
Museum
The DCTA is also responsible managing for the Brazilian Aerospace Memorial (Memorial Aerospacial Brasileiro - MAB). It is located in São José dos Campos, São Paulo, Brazil.
See also
Brazilian Organization for the Development of Aeronautical Certification
Brazilian Space Agency
Brazilian space program
Brazilian National Institute for Space Research
Instituto Tecnológico de Aeronáutica
Institute of Aeronautics and Space
List of aerospace flight test centres
Marcos Pontes, the first Brazilian in space
References
External links
CTA homepage
IAE homepage
IFI homepage
Commands of the Brazilian Armed Forces
Research institutes in Brazil
Brazilian Air Force
Organisations based in São José dos Campos
Aerospace |
2880210 | https://en.wikipedia.org/wiki/Lionheart%3A%20Legacy%20of%20the%20Crusader | Lionheart: Legacy of the Crusader | Lionheart: Legacy of the Crusader is an action role-playing game, developed for Microsoft Windows by Reflexive Entertainment and published by Interplay Entertainment and subsidiary Black Isle Studios for Microsoft Windows, released in August 2003. The game is viewed from a 3/4 isometric camera angle. It focuses on a protagonist, controlled by the player, as he travels on a quest that constitutes the central focus of the game. The plot stipulates a rift in reality that drastically altered medieval history by allowing demons and other similar beings to enter the mortal realm. During the game, the protagonist encounters and interacts with numerous historical figures such as Joan of Arc, Leonardo da Vinci and Galileo Galilei who are represented as non-player characters.
Lionheart utilizes the SPECIAL role-playing system, which was first used in the Fallout series, and in this game functions primarily in adding points to specific skills in separate trees to strengthen a character's "Spiritkind", which has a personality and nature chosen by the player at the start of the game.
Gameplay
As Lionheart implements the SPECIAL system, the character creation is similar to that of the Fallout series. Players begin by setting the values of their characters' strength, perception, endurance, charisma, intelligence, agility and luck, and selecting "traits", which alter a character's inherent abilities for either better or worse, for the duration of the game. In addition, the player must distribute points to "skills" – abilities which a character uses to achieve various effects. One skill, "diplomacy," allows the player to talk their way out of situations gone awry, while another, "sneak", allows the player to move undetected by enemies. Unlike the Fallout series, Lionheart also allows the player to select magical skills – an example being "discord", which turns hostile enemies against one another.
Players also select "perks" during the course of the game – abilities similar to traits, which affect a character's abilities in some form. For example, the ability "Superior Senses" grants the player character a +1 bonus to his or her perception and +15 skill points in the "find traps/secret doors" skill.
Another element newly introduced by Lionheart is the player's selection of a "Spiritkind" for their character, which is done during character generation at the game's start. A Spiritkind is a spirit, which is either demonic, elemental or bestial, that resides in the player character and occasionally rouses to explain happenings or gameplay mechanics, or advance the plot.
The character generated by the player is the only character a player has direct control over, and though characters will occasionally join a player's adventuring party, they are AI-controlled without exception.
Plot
The setting of Lionheart is an alternate history created by the occurrence of the Disjunction, a rip in the fabric of time that introduces magic into the world. This event occurred when Richard the Lionheart massacred prisoners at the Siege of Acre during the Third Crusade, a decision exploited by a mysterious source to fuel a ritual that tore the fabric of reality and caused magic to enter the world from other dimensions.
The game takes place in 1588 and initially set in an alternate history version of Barcelona. In this time, the Spanish Armada is almost set to invade England, and the Inquisition is rampant. Lionheart features several Renaissance figures who make ahistorical appearances in the game, including Miguel de Cervantes, William Shakespeare, Galileo Galilei, Niccolò Machiavelli, and Leonardo da Vinci.
The plot of Lionheart sees the player character, discovered to be a descendent of Richard the Lionheart, inherit the powers obtained during the Disjunction. Players follow the story through aligning with one of the four main factions in the game – the Knights Templar, the Inquisition, the Knights of Saladin and the Wielders – and are tasked with stopping an attempt to permanently open the dimensional rift, and alter the course of European history.
Development
Reflexive Entertainment was approached by Black Isle Studios to develop a game after playing their previous title Zax: The Alien Hunter, an isometric game using the same engine. Ion Hardie states Black Isle originally wanted Reflexive Entertainment to develop a game in the vein of Fallout using the SPECIAL system. Chris Avellone recalls the decision to use SPECIAL was an attempt to "try and help boost sales by leveraging Fallout fan interest".
Production of Lionheart was strained, with both developer and publisher in financial stress. Ion Hardie notes Reflexive Entertainment was "literally one day away from making hard choices that might have shut us down for good when we got the contract (for Lionheart)". Interplay also bore significant financial issues that prevented them from providing the developer with milestone payments, with Hardie stating "(Interplay) had issues getting us the initial payment.
Release
The game went gold on July 16, 2003. As with other Interplay titles at the time, Vivendi Universal Games handled North American distribution while Avalon Interactive handled European distribution.
Reception
Lionheart received "mixed" reviews according to the review aggregation website Metacritic. GameSpot's Greg Kasavin noted that although Lionheart seems to promote diverse character creation, the significant focus on monster-infested areas "all but forces you to play as some sort of combat-oriented character." The game was also criticised for its attempts at promoting "Diablo-style," hack-and-slash gameplay after a more dialogue-driven approach in the earlier stages of the game. IGN's Barry Brenesal wrote, "the problem of deciding what kind of game it really wants to be, RPG or Diablo clone, is probably the most serious problem it's got." He continued that Lionheart "feels like a good game got lost somewhere en route, and ended up being pushed out the door with some basic features missing." RPGamer's Steven Bellotti assessed that the game "starts out so promising," but "once you get out of Barcelona and into the wider world, [it] falls flat on its face."
Conversely the game was praised for both its musical score, which was described as "excellent," and voice-acting, which was exclaimed to be "top-notch." The SPECIAL system-fueled character creation was called "great."
References
External links
2003 video games
Action role-playing video games
Alternate history video games
Fantasy video games set in the Middle Ages
Reflexive Entertainment games
Role-playing video games
Video games scored by Inon Zur
Video games developed in the United States
Video games with gender-selectable protagonists
Video games set in the 16th century
Video games with historical settings
Windows games
Windows-only games
Cultural depictions of Leonardo da Vinci
Cultural depictions of Joan of Arc
Cultural depictions of Nostradamus
Cultural depictions of Niccolò Machiavelli
Cultural depictions of Guy Fawkes
Cultural depictions of Galileo Galilei
Cultural depictions of Saladin
Multiplayer and single-player video games |
2883449 | https://en.wikipedia.org/wiki/Imilac | Imilac | Imilac is a pallasite meteorite found in the Atacama Desert of Northern Chile in 1822.
Classification
Imilac is classified as a stony–iron pallasite. Imilac specimens are highly prized by meteorite collectors due to its high concentration of beautiful olivine grains.
Strewn field
Numerous masses were found in a valley to the SW of Imilac. The total weight of the Imilac fall is estimated to be around . The primary strewn field is long about .
Specimens
Due to weathering, intact olivine grains are present only on large specimens (over ). Smaller samples contain darker altered olivine crystals. On the market there are also a lot of very small (few grams) Imilac individuals called metal skeletons: they are severely weathered and lack olivine grains.
Notes
See also
Glossary of meteoritics
Meteorites found in Chile
Atacama Region
Stony-iron meteorites |
2885124 | https://en.wikipedia.org/wiki/Agonalia | Agonalia | An Agonalia or Agonia was an obscure archaic religious observance celebrated in ancient Rome several times a year, in honor of various divinities. Its institution, like that of other religious rites and ceremonies, was attributed to Numa Pompilius, the semi-legendary second king of Rome. Ancient calendars indicate that it was celebrated regularly on January 9, May 21, and December 11.
A festival called Agonia or Agonium Martiale, in honor of Mars, was celebrated March 17, the same day as the Liberalia, during a prolonged "war festival" that marked the beginning of the season for military campaigning and agriculture.
Purpose
The offering was a ram (aries), the usual victim sacrificed to the guardian gods of the state. The presiding priest was the rex sacrificulus, and the site was the Regia, both of which could be employed only for ceremonies connected with the highest gods that affected the wellbeing of the whole state. But the purpose of this festival was disputed even among the ancients themselves.
Etymology
The etymology of the name was also a subject of much dispute among the ancients. The various etymologies proposed are given at length by Ovid. None of these, however, is satisfactory. One possibility is that the sacrifice in its earliest form was offered on the Quirinal Hill, which was originally called Agonus, at the Colline gate, Agonensis. The sacrifice is explicitly located at the Regia, or the domus regis ("house of the king"), which in the historical period was at the top of the Via Sacra, near the arch of Titus, though one ancient source states that in earliest times, the Regia was on the Quirinal.
The Circus Agonensis, as it is called, is supposed by some to have occupied the place of the present Piazza Navona, and to have been built by the emperor Alexander Severus on the spot where the victims were sacrificed at the Agonalia. It may not, however, have been a circus at all, and Humphrey omits the site in his work on Roman circuses.
January 9
An Agonium occurs on January 9 in the Fasti Praenestini, albeit in mutilated form. In Ovid's poem on the Roman calendar, he calls it once the dies agonalis ("agonal day") and elsewhere the Agonalia, and offers a number of etymologies of varied plausibility. Festus explains the word agonia as an archaic Latin term for hostia, a sacrificial victim. Augustine of Hippo thought the Romans had a god named Agonius, who might then have been the god of the Colline part of the city (see "Etymology" above).
December 11
This third occurrence of the Agonia or Agonalia shares the date of December 11 with the Septimontium or Septimontiale sacrum, which only very late Roman calendars take note of and which depends on a textual conjecture. The relation between the two observances, if any exists, is unknown. A fragmentary inscription found at Ostia that reads: "Agonind" testifies that this festival was dedicated to Sol Indiges. It was indeed the second festival celebrating this deity, after that of August 10.
Agonium Martiale
The Agonia to Mars occurs during a period of festivals in March (Latin Martius), the namesake month of Mars. These were the chariot races of the Equirria February 27, a feria on the Kalends of March (a day sacred also to his mother Juno), a second Equirria on March 14, his Agonalia March 17, and the Tubilustrium March 23.
A note on the holiday from Varro indicates that this Agonia was of more recondite significance than the Liberalia held on the same day. Varro's source is the books of the Salian priests surnamed Agonenses, who call it the Agonia instead. According to Masurius Sabinus, the Liberalia was called the Agonium Martiale by the pontiffs. Modern scholars are inclined to think that the sharing of the date was a coincidence, and that the two festivals were unrelated.
Notes
References
Ancient Roman festivals
January observances
May observances
December observances
Festivals of Mars |
2886349 | https://en.wikipedia.org/wiki/Mount%20Mandara | Mount Mandara | Mandara (; ) is the name of the mountain that appears in the Samudra Manthana episode in the Hindu Puranas, where it was used as a churning rod to churn the ocean of milk. Shiva's serpent, Vasuki, offered to serve as the rope pulled on one side by a team of asuras, and on the other, by a team of devas. The Puranas refer to various sacred places on the hill that are also believed to be the abode of the avatar Krishna as Madhusudana or the destroyer of the asura called Madhu, who was killed by Krishna and then covered by the Mount Mandara.
Literature
Kalidasa's Kumarasambhava refers to foot marks of Vishnu on the slopes of Mandara. The hill is replete with relics of bygone ages. Besides inscriptions and statues there are numerous rock cut sculptures depicting various Brahmanical images. The hill is equally revered by the Jains who believe that their 12th Tirthankara Shri Vasupujya attained nirvana here on the summit of the hill.
Depictions
The depiction of the Churning of the Ocean of Milk became very popular in Khmer art, perhaps because their creation myth involved a Nāga ancestor. It is a popular motif in both Khmer and Thai art; one of the most dramatic depictions is one of the eight friezes that can be seen around the inner wall of Angkor Wat—the others being the Battle of Kurukshetra, Suryavarman's Military Review, scenes from Heaven and Hell, the battle between Vishnu and the asuras, the Battle between Krishna and Banasura, a battle between the gods and asuras, and the Battle of Lanka.
References
Dictionary of Hindu Lore and Legend () by Anna Dallapiccola
Locations in Hindu mythology
Mythological mountains |
2887126 | https://en.wikipedia.org/wiki/Paragould%20meteorite | Paragould meteorite | The Paragould Meteorite at by by and weighing is the second largest witnessed meteorite fall ever recovered in North America (after the Norton County meteorite) and the largest stony meteorite chondrite. It fell to Earth at approximately 4:08 a.m. on February 17, 1930.
The fireball could be seen as far away as Illinois, Indiana, Missouri, Kansas, and Arkansas. Initially, observers thought it was an airplane crashing.
The meteorite split into many pieces. The largest piece was discovered by W. H. Hodges in an 8-foot (2 m) hole on a farm south of Bethel Church, off Highway 358, a few miles south of Paragould, Arkansas. A smaller piece was found by George W. Hyde in Finch, Arkansas.
It was purchased by Harvey H. Nininger, who in 1930 sold it to Chicago's Field Museum of Natural History. It has been on loan to the University of Arkansas since 1988, initially to the University Museum and then after November 2003 to the Arkansas Center for Space and Planetary Sciences. It was on display in Mullins Library, at the University of Arkansas in Fayetteville till April 11, 2008, when it was moved to the Arkansas Center for Space and Planetary Sciences building.
Two other pieces were found, one weighing (presently stored in Washington, D.C.) and another piece presently resides in New York.
See also
Glossary of meteoritics
References
External links
Article at MeteoriteStudies.com
Ency Arkansas
Chondrite meteorites
University of Arkansas
1930 in the United States
1930 in science
Meteorites found in the United States
Geology of Arkansas
1930 in Arkansas |
2890675 | https://en.wikipedia.org/wiki/FalconSAT | FalconSAT | FalconSAT is the United States Air Force Academy's (USAFA) small satellite engineering program. Satellites are designed, built, tested, and operated by Academy cadets. The project is administered by the USAFA Space Systems Research Center under the direction of the Department of Astronautics. Most of the cadets who work on the project are pursuing a bachelor of science degree in astronautical engineering, although students from other disciplines (typically electrical engineering, mechanical engineering, or computer science) join the project.
Compared to most commercial satellite projects, FalconSAT is considerably lower budget, and follows a very accelerated development cycle. Because of the near total personnel turnover every year (the program is generally a senior cadet project, and graduating cadets must be replaced yearly) it forces the cadet engineers to very quickly learn and become familiar with the satellite systems to which they are assigned.
FalconSAT used to have a sister project, FalconLaunch, to design and develop sounding rocket class vehicles.
Satellites
FalconGOLD (COSPAR 1997-065B) – was launched on 25 October 1997 on an Atlas rocket. Tested and proved the feasibility of using GPS to determine orbit position when outside the extent of the GPS constellation. Various web pages document FalconGOLD telemetry, a USAF Academy award, and an AIAA award. The design and launch team is documented on the AIAA award plaque. GPSWorld.com's October 1999 article declared "The results of this low-cost, off-the-shelf experiment were quite encouraging for the use of GPS at high altitudes". This work accelerated enthusiasm for GPS side lobe exploitation. The mission operated from 3 to 9 November 1997, after which the batteries of the device were depleted and the device along with the rocket upper stage to which it was solidly bolted on became derelict objects in orbit.
FalconSAT-1 (FS 1, COSPAR 2000-004D) – was launched on 27 January 2000 on a converted Minuteman II missile (that is, Minotaur 1 rocket). It carried the CHAWS (Charging Hazards and Wake Studies) experiment developed by the Physics Department at the Academy. The satellite was successfully placed into orbit but was lost about a month later due to an electrical power system failure. No useful science data was returned, despite repeated recovery attempts. The mission was declared a loss after about a month in orbit. A USAF press statement of June 2002 said: "While FalconSat-1 was a technical failure, it was a resounding academic success".
FalconSAT-2 (FS 2, COSPAR 2006-F01) – Significantly damaged when Falcon 1 launch vehicle failed seconds after launch on 24 March 2006. Despite the loss of the launch vehicle, the satellite landed, mostly intact in a support building for the launch vehicle. It was originally scheduled for launch on STS-114 with the Space Shuttle Atlantis in January 2003. Its payload was the MESA instrument (Miniaturized electrostatic Analyzer), which would have been used to sample plasma in the upper atmosphere. The data would have been used to correlate the effect of ionospheric plasma on trans-ionospheric radio communications.
FalconSAT-3 (FS 3, COSPAR 2007-006E) – contains 5 experiments, including a gravity gradient boom, launch adapter shock ring, and several AFRL sponsored payloads, including MPACS (Micro Propulsion Attitude Control System), FLAPS (Flat Plasma Spectrometer), and PLANE (Plasma Local Anomalous Noise Experiment). The launch, aboard an Atlas V 401 from SLC-41 at Cape Canaveral Air Force Station, was scheduled to occur on 8 December 2006, however as this was on the same day as the scheduled launch of STS-116, and a 48-hour turnaround was required, it was delayed. Launch took place on 9 March 2007 at 03:10 UTC, alongside MidSTAR-1. While the FalconSAT-3 software architecture at launch limited access to all ADCS sensors, all scientific mission objectives were achieved. Bus software updates are ongoing, enabling enhanced visibility into satellite bus operations and payload performance. In addition to providing both a ground and space based training platform, FalconSAT-3 was used as a trainer for cadets at West Point, student officers at the Air Force Institute of Technology, and a ground station is in work at Vandenberg AFB, California to support the Air Force's Space 100 course. In late September 2017, the Air Force transferred control of FalconSAT-3 to AMSAT for use by the amateur radio service for the 5–6 years of expected life remaining. Non-amateur radio frequencies were disabled. The satellite can be used as a packet radio bulletin board and as a digipeater. FalconSAT-3 decayed from orbit on 21 January 2023.
FalconSAT-5 (FS 5, USA 221, COSPAR 2010-062E) – was launched on 20 November 2010 at 01:25 UTC on board a Minotaur IV. Though the US$12,000,000 mission is listed on a NASA website, data are not being made available to the public through that portal. Instead, all satellite information and data are maintained internally at USAFA, with no public information being released regarding the status of this mission.
FalconSAT-6 (FS 6, COSPAR 2018-099BK) – was launched on 3 December 2018 on board a Falcon 9. The satellite test various thrusters and measure the local plasma.
Falcon Orbital Debris Experiment (Falcon ODE, also known as AFOTEC 1 (Air Force Operational Test and Evaluation Center 1), COSPAR 2019-026A) - was launched 5 May 2019 on an Electron rocket on the STP-27RD mission. which is intended to evaluate ground-based tracking of space objects.
FalconSat-7 (FS 7, also known as Peregrine or DOTSI, COSPAR 2019-036) – was launched on 25 June 2019 aboard a Falcon Heavy. The primary objective is to demonstrate solar space telescope technology utilizing a membrane photon sieve.
FalconSAT-8 was launched on 17 May 2020 at 13:14 UTC on board an Atlas V rocket. The spacecraft will test a novel electromagnetic propulsion system, low-weight antenna technology, a star tracker, a carbon nanotube radio frequency experiment, a commercial reaction wheel to provide attitude control in orbit. The FalconSAT-8 was deployed from the Boeing X-37B spacecraft around 28 May 2020 and is being used by cadets at the Air Force Academy in Colorado Springs, CO.
In addition to the above, there were plans to construct FalconSAT-4 (FS 4) satellite, but the mission planned for this satellite was deemed too ambitious and funding could not be found for the satellite, leading to cancellation early on in the development. The satellite was replaced with the simpler FalconSAT-5.
References
External links
Program summary and FalconSAT-2 launch video
FalconSAT-2 press release
FalconSAT-3 on Gunter's Space Page
Satellites orbiting Earth
Satellites of the United States Air Force
United States Air Force Academy
Amateur radio satellites |
2892975 | https://en.wikipedia.org/wiki/Religious%20views%20of%20Isaac%20Newton | Religious views of Isaac Newton | Isaac Newton (4 January 1643 – 31 March 1727) was considered an insightful and erudite theologian by his Protestant contemporaries. He wrote many works that would now be classified as occult studies, and he wrote religious tracts that dealt with the literal interpretation of the Bible.
He kept his heretical beliefs private.
Newton's conception of the physical world provided a model of the natural world that would reinforce stability and harmony in the civic world. Newton saw a monotheistic God as the masterful creator whose existence could not be denied in the face of the grandeur of all creation. Although born into an Anglican family, and a devout but heterodox Christian, by his thirties Newton held a Christian faith that, had it been made public, would not have been considered orthodox by mainstream Christians. Scholars now consider him a Nontrinitarian Arian.
He may have been influenced by Socinian christology.
Early history
Newton was born into an Anglican family three months after the death of his father, a prosperous farmer also named Isaac Newton. When Newton was three, his mother married the rector of the neighbouring parish of North Witham and went to live with her new husband, the Reverend Barnabas Smith, leaving her son in the care of his maternal grandmother, Margery Ayscough. Isaac apparently hated his step-father, and had nothing to do with Smith during his childhood. His maternal uncle, the rector serving the parish of Burton Coggles, was involved to some extent in the care of Isaac.
In 1667, Newton became a Fellow of Trinity College, Cambridge, making necessary his commitment to taking Holy Orders within seven years of completing his MA, which he did the following year. He was also required to take a vow of celibacy and recognize the Thirty-Nine Articles of the Church of England. Newton considered ceasing his studies prior to completion to avoid the ordination made necessary by law of King Charles II. He was eventually successful in avoiding the statute, assisted in this by the efforts of Isaac Barrow, as in 1676 the then Secretary of State for the Northern Department, Joseph Williamson, changed the relevant statute of Trinity College to provide dispensation from this duty. Newton then embarked on an investigative study of the early history of the Church, which developed, during the 1680s, into inquiries about the origins of religion. At around the same time, he developed a scientific view on motion and matter. Of Philosophiæ Naturalis Principia Mathematica he stated:
Christian heresy
According to most scholars, Newton was Arian, not holding to Trinitarianism. Scholars have generally concluded that Newton's heretical beliefs were self-taught, but he may have been influenced by then-current heretical writings; controversies over unitarianism were raging at the time.
As well as rejecting the Trinity, Newton's studies led him to reject belief in the immortal soul. Despite his unorthodox beliefs, Sir Isaac Newton affirmed infant baptism, in keeping with his Anglican upbringing, writing, "The Declaration by imposition of hands is a Iewish ceremony. We call it confirmation, meaning a confirmation of what was done by the Godfathers in baptizing the Infant."
Although he was not a Socinian, he shared many similar beliefs with them. They were a unitarian Reformation movement in Poland. A manuscript he sent to John Locke in which he disputed the existence of the Trinity was never published. In 2019, John Rogers stated, "Heretics both, John Milton and Isaac Newton were, as most scholars now agree, Arians."
Newton refused the sacrament of the Anglican church offered before his death.
After his death, Deists sometimes claimed him as one of their own, as have Trinitarians. In fact, he was a fundamentalist Christian who opposed both orthodox teachings and religious skepticism.
God as masterful creator
Newton saw God as the masterful creator whose existence could not be denied in the face of the grandeur of all creation. Nevertheless, he rejected Leibniz's thesis that God would necessarily make a perfect world which requires no intervention from the creator. In Query 31 of the Opticks, Newton simultaneously made an argument from design and for the necessity of intervention:
This passage prompted an attack by Leibniz in a letter to his friend Caroline of Ansbach:
Leibniz's letter initiated the Leibniz-Clarke correspondence, ostensibly with Newton's friend and disciple Samuel Clarke, although as Caroline wrote, Clarke's letters "are not written without the advice of the Chev. Newton".
Clarke complained that Leibniz's concept of God as a "supra-mundane intelligence" who set up a "pre-established harmony" was but a step from atheism: "And as those men, who pretend that in an earthly government things may go on perfectly well without the king himself ordering or disposing of any thing, may reasonably be suspected that they would like very well to set the king aside: so, whosoever contends, that the beings of the world can go on without the continual direction of God...his doctrine does in effect tend to exclude God out of the world".
In addition to stepping in to re-form the Solar System, Newton invoked God's active intervention to prevent the stars falling in on each other, and perhaps in preventing the amount of motion in the universe from decaying due to viscosity and friction. In private correspondence, Newton sometimes hinted that the force of gravity was due to an immaterial influence:
Leibniz said that such an immaterial influence would be a continual miracle; this was another strand of his debate with Clarke.
Newton's view has been considered to be close to deism, and several biographers and scholars labelled him as a deist who is strongly influenced by Christianity. However, he differed from strict adherents of deism in that he invoked God as a special physical cause to keep the planets in orbits. He warned against using the law of gravity to view the universe as a mere machine, like a great clock, saying:
On the other hand, latitudinarian and Newtonian ideas taken too far resulted in the millenarians, a religious faction dedicated to the concept of a mechanical universe, but finding in it the same enthusiasm and mysticism that the Enlightenment had fought so hard to extinguish. Newton may have had some interest in millenarianism, as he wrote about both the Book of Daniel and the Book of Revelation in his Observations Upon the Prophecies.
Newton's concept of the physical world provided a model of the natural world that would reinforce stability and harmony in the civic world.
Bible
Newton spent a great deal of time trying to discover hidden messages within the Bible. After 1690, Newton wrote a number of religious tracts dealing with the literal interpretation of the Bible. In a manuscript Newton wrote in 1704, he describes his attempts to extract scientific information from the Bible. He estimated that the world would end no earlier than 2060. In predicting this, he said, "This I mention not to assert when the time of the end shall be, but to put a stop to the rash conjectures of fanciful men who are frequently predicting the time of the end, and by doing so bring the sacred prophesies into discredit as often as their predictions fail."
The Library of Trinity College, Cambridge, holds in its collections Newton's personal copy of the King James Version, which exhibits numerous marginal notes in his hand as well as about 500 reader's marks pointing to passages of particular interest to him. A note is attached to the Bible, indicating that it "was given by Sir Isaac Newton in his last illness to the woman who nursed him". The book was eventually bequeathed to the Library in 1878. The places Newton marked or annotated in his Bible bear witness to his investigations into theology, chronology, alchemy, and natural philosophy; and some of these relate to passages of the General Scholium to the second edition of the Principia. Some other passages he marked offer glimpses of his devotional practices and reveal distinct tensions in his personality. Newton's Bible appears to have been first and foremost a customized reference tool in the hands of a biblical scholar and critic.
The Trinity
Newton's work of New Testament textual criticism, An Historical Account of Two Notable Corruptions of Scripture, was sent in a letter to John Locke on 14 November 1690. In it, he reviews evidence that the earliest Christians did not believe in the Trinity.
Prophecy
Newton relied upon the existing Scripture for prophecy, believing his interpretations would set the record straight in the face of what he considered to be, "so little understood". Though he would never write a cohesive body of work on prophecy, Newton's beliefs would lead him to write several treatises on the subject, including an unpublished guide for prophetic interpretation titled Rules for interpreting the words & language in Scripture. In this manuscript, he details the requirements for what he considered to be the proper interpretation of the Bible.
End of the world vs. Start of the millennial kingdom
In his posthumously-published Observations upon the Prophecies of Daniel, and the Apocalypse of St. John, Newton expressed his belief that Bible prophecy would not be understood "until the time of the end", and that even then "none of the wicked shall understand". Referring to that as a future time ("the last age, the age of opening these things, be now approaching"), Newton also anticipated "the general preaching of the Gospel be approaching" and "the Gospel must first be preached in all nations before the great tribulation, and end of the world".
Over the years, a large amount of media attention and public interest has circulated regarding largely unknown and unpublished documents, evidently written by Isaac Newton, that indicate he believed the world could end in 2060. While Newton also had many other possible dates (e.g. 2034), he did not believe that the end of the world would take place specifically in 2060.
Like most Protestant theologians of his time, Newton believed that the Papal Office and not any one particular Pope was the fulfillment of the Biblical predictions about Antichrist, whose rule was predicted to last for 1,260 years. They applied the day-year principle (in which a day represents a year in prophecy) to certain key verses in the books of Daniel and Revelation (also known as the Apocalypse), and looked for significant dates in the Papacy's rise to power to begin this timeline. Newton's calculation ending in 2060 is based on the 1,260-year timeline commencing in 800 AD when Charlemagne became the first Holy Roman Emperor and reconfirmed the earlier (756 AD) Donation of Pepin to the Papacy.
2016 vs. 2060
Between the time he wrote his 2060 prediction (about 1704) until his death in 1727, Newton conversed, both first-hand and by correspondence, with other theologians of his time. Those contemporaries who knew him during the remaining 23 years of his life appear to be in agreement that Newton, and the "best interpreters" including Jonathan Edwards, Robert Fleming, Moses Lowman, Phillip Doddridge, and Bishop Thomas Newton, were eventually "pretty well agreed" that the 1,260-year timeline should be calculated from the year 756 AD.
F. A. Cox also confirmed that this was the view of Newton and others, including himself:
Thomas Williams stated that this timeline had become the predominant view among the leading Protestant theologians of his time:
In April of 756 AD, Pepin, King of France, accompanied by Pope Stephen II entered northern Italy, forcing the Lombard King Aistulf to lift his siege of Rome and return to Pavia. Following Aistulf's capitulation, Pepin gave the newly conquered territories to the Papacy through the Donation of Pepin, thereby elevating the Pope from being a subject of the Byzantine Empire to the head of state, with temporal power over the newly constituted Papal States.
The end of the timeline is based on Daniel 8:25, which reads "he shall be broken without hand" and is understood to mean that the end of the Papacy will not be caused by any human action. Volcanic activity is described as the means by which Rome will be overthrown.
In 1870, the newly formed Kingdom of Italy annexed the remaining Papal States, depriving the Popes of any temporal rule for the next 59 years. Unaware that Papal rule would be restored (albeit on a greatly diminished scale) in 1929 as head of the Vatican City state, the historicist view that the Papacy is the Antichrist and the associated timelines delineating his rule rapidly declined in popularity as one of the defining characteristics of the Antichrist (i.e. that he would also be a political temporal power at the time of the return of Jesus) were no longer met.
Eventually, the prediction was largely forgotten and no major Protestant denomination currently subscribes to this timeline.
Despite the dramatic nature of a prediction of the end of the world, Newton may not have been referring to the 2060 date as a destructive act resulting in the annihilation of the earth and its inhabitants, but rather one in which he believed the world was to be replaced with a new one based upon a transition to an era of divinely inspired peace. In Christian theology, this concept is often referred to as The Second Coming of Jesus Christ and the establishment of Paradise by The Kingdom of God on Earth.
Other beliefs
Henry More's belief in the universe and rejection of Cartesian dualism may have influenced Newton's religious ideas. Later works—The Chronology of Ancient Kingdoms Amended (1728) and Observations Upon the Prophecies of Daniel and the Apocalypse of St. John (1733)—were published after his death.
Newton and Boyle's mechanical philosophy was promoted by rationalist pamphleteers as a viable alternative to the pantheists and enthusiasts, and was accepted hesitantly by orthodox clergy as well as dissident preachers like the latitudinarians. The clarity and simplicity of science was seen as a way in which to combat the emotional and mystical superlatives of superstitious enthusiasm, as well as the threat of atheism.
The attacks made against pre-Enlightenment magical thinking, and the mystical elements of Christianity, were given their foundation with Boyle's mechanical conception of the universe. Newton gave Boyle's ideas their completion through mathematical proofs, and more importantly was very successful in popularizing them. Newton refashioned the world governed by an interventionist God into a world crafted by a God that designs along rational and universal principles. These principles were available for all people to discover, allowed man to pursue his own aims fruitfully in this life, not the next, and to perfect himself with his own rational powers.
Writings
His first writing on the subject of religion was Introductio. Continens Apocalypseos rationem generalem (Introduction. Containing an explanation of the Apocalypse), which has an unnumbered leaf between folios 1 and 2 with the subheading De prophetia prima, written in Latin some time prior to 1670. Written subsequently in English was Notes on early Church history and the moral superiority of the 'barbarians' to the Romans. His last writing, published in 1737 with the miscellaneous works of John Greaves, was entitled A Dissertation upon the Sacred Cubit of the Jews and the Cubits of the several Nations.
Newton did not publish any of his works of biblical study during his lifetime. All of Newton's writings on corruption in biblical scripture and the church took place after the late 1670s and prior to the middle of 1690.
See also
Classical mechanics
Clockwork universe theory
Religious and philosophical views of Albert Einstein
References
Further reading
Eamon Duffy, "Far from the Tree" The New York Review of Books, vol. LXV, no. 4 (8 March 2018), pp. 28–29; a review of Rob Iliffe, Priest of Nature: the Religious Worlds of Isaac Newton, (Oxford University Press, 2017).
Feingold, Mordechai. "Isaac Newton, Heretic? Some Eighteenth-Century Perceptions." in Reading Newton in Early Modern Europe (Brill, 2017) pp. 328-345.
Feingold, Mordechai. "The religion of the young Isaac Newton." Annals of science 76.2 (2019): 210-218.
Greenham, Paul. "Clarifying divine discourse in early modern science: divinity, physico-theology, and divine metaphysics in Isaac Newton’s chymistry." The Seventeenth Century 32.2 (2017): 191-215 online.
Iliffe, Rob. Priest of Nature: The Religious Worlds of Isaac Newton. Oxford University Press: 2017, 536 pp. online review
Joalland, Michael. "Isaac Newton Reads the King James Version: The Marginal Notes and Reading Marks of a Natural Philosopher". Papers of the Bibliographical Society of America, vol. 113, no. 3 (2019): 297–339 (https://www.journals.uchicago.edu/doi/abs/10.1086/704518?journalCode=pbsa)
Manuel, Frank. E. The Religion of Isaac Newton. Oxford: Clarendon Press, 1974.
Rogers, John. "Newton's Arian Epistemology and the Cosmogony of Paradise Lost." ELH: English Literary History 86.1 (2019): 77-106 online.
Snobelen, Stephen D. "Isaac Newton, heretic: the strategies of a Nicodemite." British journal for the history of science'' 32.4 (1999): 381–419. online
External links
Isaac Newton Theology, Prophecy, Science and Religion – writings on Newton by Stephen Snobelen
The Newton Manuscripts at the National Library of Israel – the collection of all his religious writings
Newton, Isaac
Religious Views
Nontrinitarianism
Criticism of atheism
Criticism of religion
Apocalypticism |
2893507 | https://en.wikipedia.org/wiki/Aradia%2C%20or%20the%20Gospel%20of%20the%20Witches | Aradia, or the Gospel of the Witches | Aradia, or the Gospel of the Witches is a book composed by the American folklorist Charles Godfrey Leland that was published in 1899. It contains what he believed was the religious text of a group of pagan witches in Tuscany, Italy that documented their beliefs and rituals, although various historians and folklorists have disputed the existence of such a group. In the 20th century, the book was very influential in the development of the contemporary Pagan religion of Wicca.
The text is a composite. Some of it is Leland's translation into English of an original Italian manuscript, the Vangelo (gospel). Leland reported receiving the manuscript from his primary informant on Italian witchcraft beliefs, a woman Leland referred to as "Maddalena" and whom he called his "witch informant" in Italy. The rest of the material comes from Leland's research on Italian folklore and traditions, including other related material from Maddalena. Leland had been informed of the Vangelos existence in 1886, but it took Maddalena eleven years to provide him with a copy. After translating and editing the material, it took another two years for the book to be published. Its fifteen chapters portray the origins, beliefs, rituals, and spells of an Italian pagan witchcraft tradition. The central figure of that religion is the goddess Aradia, who came to Earth to teach the practice of witchcraft to peasants in order for them to oppose their feudal oppressors and the Roman Catholic Church.
Leland's work remained obscure until the 1950s, when other theories about, and claims of, "pagan witchcraft" survivals began to be widely discussed. Aradia began to be examined within the wider context of such claims. Scholars are divided, with some dismissing Leland's assertion regarding the origins of the manuscript, and others arguing for its authenticity as a unique documentation of folk beliefs. Along with increased scholarly attention, Aradia came to play a special role in the history of Gardnerian Wicca and its offshoots, being used as evidence that pagan witchcraft survivals existed in Europe, and because a passage from the book's first chapter was used as a part of the religion's liturgy. After the increase in interest in the text, it became widely available through numerous reprints from a variety of publishers, including a 1999 critical edition with a new translation by Mario and Dina Pazzaglini.
Origins
Charles Godfrey Leland was an American author and folklorist, and spent much of the 1890s in Florence researching Italian folklore. Aradia was one of the products of Leland's research. While Leland's name is the one principally associated with Aradia, the manuscript that makes up the bulk of it is attributed to the research of an Italian woman whom Leland and Leland's biographer, his niece Elizabeth Robins Pennell, referred to as "Maddalena". According to folklorist Roma Lister, a contemporary and friend of Leland's, Maddalena's real name was Margherita, and she was a "witch" from Florence who claimed a family lineage from the Etruscans and knowledge of ancient rituals. Professor Robert Mathiesen, as a contributor to the Pazzaglini translation of Aradia, mentions a letter from Maddalena to Leland, which he states is signed "Maddalena Talenti" (the last name being a guess, as the handwriting is difficult to decipher).
Leland reports meeting Maddalena in 1886, and she became the primary source for his Italian folklore collecting for several years. Leland describes her as belonging to a vanishing tradition of sorcery. He writes that "by long practice [she] has perfectly learned ... just what I want, and how to extract it from those of her kind." He received several hundred pages worth of material from her, which was incorporated into his books Etruscan Roman Remains in Popular Tradition, Legends of Florence Collected From the People, and eventually Aradia. Leland wrote that he had "learned that there was in existence a manuscript setting forth the doctrines of Italian witchcraft" in 1886, and had urged Maddalena to find it. Eleven years later, on 1 January 1897, Leland received the Vangelo by post. The manuscript was written in Maddalena's handwriting. Leland understood it to be an authentic document of the "Old Religion" of the witches, but explains that he did not know if the text came from written or oral sources.
Leland's translation and editing was completed in early 1897 and submitted to David Nutt for publication. Two years passed, until Leland wrote requesting the return of the manuscript in order to submit it to a different publishing house. This request spurred Nutt to accept the book, and it was published in July 1899 in a small print run. Wiccan author Raymond Buckland claims to have been the first to reprint the book in 1968 through his "Buckland Museum of Witchcraft" press, but a British reprint was made by "Wiccens" Charles "Rex Nemorensis" and Mary Cardell in the early 1960s. Since then the text has been repeatedly reprinted by a variety of different publishers, including as a 1998 retranslation by Mario and Dina Pazzaglini with essays and commentary.
Contents
After the eleven-year search, Leland writes that he was unsurprised by the contents of the Vangelo. It was largely what he was expecting, with the exception that he did not predict passages in "prose-poetry". "I also believe that in this Gospel of the Witches", comments Leland in the appendix, "we have a trustworthy outline at least of the doctrine and rites observed at [the witches' Sabbat]. They adored forbidden deities and practised forbidden deeds, inspired as much by rebellion against Society as by their own passions."
Leland's final draft was a slim volume. He organised the material to be included into fifteen chapters, and added a brief preface and an appendix. The published version also included footnotes and, in many places, the original Italian that Leland had translated. Most of the content of Leland's Aradia is made up of spells, blessings, and rituals, but the text also contains stories and myths which suggest influences from both the ancient Roman religion and Roman Catholicism. Major characters in the myths include the Roman goddess Diana, a sun god called Lucifer, the Biblical Cain as a lunar figure, and the messianic Aradia. The witchcraft of "The Gospel of the Witches" is both a method for casting spells and an anti-hierarchical "counter-religion" to the Catholic church.
Themes
Entire chapters of Aradia are devoted to rituals and magic spells. These include enchantments to win love (Chapter VI), a conjuration to perform when finding a stone with a hole or a round stone in order to turn it into an amulet for Diana's favour (Chapter IV), and the consecration of a ritual feast for Diana, Aradia, and Cain (Chapter II). The narrative material makes up less of the text, and is composed of short stories and legends about the birth of the witchcraft religion and the actions of their gods. Leland summarises the mythic material in the book in its appendix, writing "Diana is Queen of the Witches; an associate of Herodias (Aradia) in her relations to sorcery; that she bore a child to her brother the Sun (here Lucifer); that as a moon-goddess she is in some relation to Cain, who dwells as prisoner in the moon, and that the witches of old were people oppressed by feudal lands, the former revenging themselves in every way, and holding orgies to Diana which the Church represented as being the worship of Satan". Diana is not only the witches' goddess, but is presented as the primordial creatrix in Chapter III, dividing herself into darkness and light. After giving birth to Lucifer, Diana seduces him while in the form of a cat, eventually giving birth to Aradia, their daughter. Diana demonstrates the power of her witchcraft by creating "the heavens, the stars and the rain", becoming "Queen of the Witches". Chapter I presents the original witches as slaves that escaped from their masters, beginning new lives as "thieves and evil folk". Diana sends her daughter Aradia to them to teach these former serfs witchcraft, the power of which they can use to "destroy the evil race (of oppressors)". Aradia's students thus became the first witches, who would then continue the worship of Diana. Leland was struck by this cosmogony: "In all other Scriptures of all races, it is the male ... who creates the universe; in Witch Sorcery it is the female who is the primitive principle".
Structure
Aradia is composed of fifteen chapters, the first ten of which are presented as being Leland's translation of the Vangelo manuscript given to him by Maddalena. This section, while predominantly made up of spells and rituals, is also the source of most of the myths and folktales contained in the text. At the end of Chapter I is the text in which Aradia gives instructions to her followers on how to practice witchcraft.
The first ten chapters are not entirely a direct translation of the Vangelo; Leland offers his own commentary and notes on a number of passages, and Chapter VII is Leland's incorporation of other Italian folklore material. Medievalist Robert Mathiesen contends that the Vangelo manuscript actually represents even less of Aradia, arguing that only Chapters I, II, and the first half of Chapter IV match Leland's description of the manuscript's contents, and suggests that the other material came from different texts collected by Leland through Maddalena.
The remaining five chapters are clearly identified in the text as representing other material Leland believed to be relevant to the Vangelo, acquired during his research into Italian witchcraft, and especially while working on his Etruscan Roman Remains and Legends of Florence. The themes in these additional chapters vary in some details from the first ten, and Leland included them partly to "[confirm] the fact that the worship of Diana existed for a long time contemporary with Christianity". Chapter XV, for example, gives an incantation to Laverna, through the use of a deck of playing cards. Leland explains its inclusion by a note that Diana, as portrayed in Aradia, is worshipped by outlaws, and Laverna was the Roman goddess of thievery. Other examples of Leland's thoughts about the text are given in the book's preface, appendix, and numerous footnotes.
In several places Leland provides the Italian he was translating. According to Mario Pazzaglini, author of the 1999 translation, the Italian contains misspellings, missing words, and grammatical errors, and is in a standardised Italian rather than the local dialect one might expect. Pazzaglini concludes that Aradia represents material translated from dialect to basic Italian and then into English, creating a summary of texts, some of which were mis-recorded. Leland himself called the text a "collection of ceremonies, 'cantrips,' incantations, and traditions" and described it as an attempt to gather material, "valuable and curious remains of ancient Latin or Etruscan lore" that he feared would be lost. There is no cohesive narrative even in the sections that Leland attributes to the Vangelo. This lack of cohesion, or "inconsistency", is an argument for the text's authenticity, according to religious scholar Chas S. Clifton, since the text shows no signs of being "massaged ... for future book buyers."
Claims questioned
Leland wrote that "the witches even yet form a fragmentary secret society or sect, that they call it that of the Old Religion, and that there are in the Romagna entire villages in which the people are completely heathen". Accepting this, Leland supposed that "the existence of a religion supposes a Scripture, and in this case it may be admitted, almost without severe verification, that the Evangel of the Witches is really a very old work ... in all probability the translation of some early or later Latin work."
Leland's claim that the manuscript was genuine, and even his assertion that he received such a manuscript, have been called into question. After the 1921 publication of Margaret Murray's The Witch-cult in Western Europe, which hypothesised that the European witch trials were actually a persecution of a pagan religious survival, American sensationalist author Theda Kenyon's 1929 book Witches Still Live connected Murray's thesis with the witchcraft religion in Aradia. Arguments against Murray's thesis would eventually include arguments against Leland. Witchcraft scholar Jeffrey Russell devoted some of his 1980 book A History of Witchcraft: Sorcerers, Heretics and Pagans to arguing against the claims in Aradia, Murray's thesis, and Jules Michelet's 1862 La Sorcière, which also theorised that witchcraft represented an underground religion. Historian Elliot Rose's A Razor for a Goat dismissed Aradia as a collection of incantations unsuccessfully attempting to portray a religion. In his Triumph of the Moon, historian Ronald Hutton summarises the controversy as having three possible extremes:
The Vangelo manuscript represents a genuine text from an otherwise undiscovered religion.
Maddalena wrote the text, either with or without Leland's assistance, possibly drawing from her own background with folklore or witchcraft.
The entire document was forged by Leland.
Hutton himself is a sceptic, not only of the existence of the religion that Aradia claims to represent, but also of the existence of Maddalena, arguing that it is more likely that Leland created the entire story than that Leland could be so easily "duped" by an Italian fortune-teller. Clifton takes exception to Hutton's position, writing that it amounts to an accusation of "serious literary fraud" made by an "argument from absence"; one of Hutton's main objections is that Aradia is unlike anything found in medieval literature.
Mathiesen also dismisses this "option three", arguing that while Leland's English drafts for the book were heavily edited and revised in the process of writing, the Italian sections, in contrast, were almost untouched except for corrections of "precisely the sort that a proofreader would make as he compared his copy to the original". This leads Mathiesen to conclude that Leland was working from an extant Italian-language original that he describes as "authentic, but not representative" of any larger folk tradition. Anthropologist Sabina Magliocco examines the "option one" possibility, that Leland's manuscript represented a folk tradition involving Diana and the Cult of Herodias, in her article Who Was Aradia? The History and Development of a Legend. Magliocco writes that Aradia "may represent a 19th-century version of [the legend of the Cult of Herodias] that incorporated later materials influenced by medieval diabolism: the presence of 'Lucifero,' the Christian devil; the practice of sorcery; the naked dances under the full moon."
Influence on Wicca and Stregheria
Magliocco calls Aradia "the first real text of the 20th century Witchcraft revival", and it is repeatedly cited as being profoundly influential on the development of Wicca. The text apparently corroborates the thesis of Margaret Murray that early modern and Renaissance witchcraft represented a survival of ancient pagan beliefs, and after Gerald Gardner's claim to have encountered religious witchcraft in 20th-century England, the works of Michelet, Murray, and Leland helped support at least the possibility that such a survival could exist.
The Charge of the Goddess, an important piece of liturgy used in Wiccan rituals, was inspired by Aradia's speech in the first chapter of the book. Parts of the speech appeared in an early version of Gardnerian Wicca ritual. According to Doreen Valiente, one of Gardner's priestesses, Gardner was surprised by Valiente's recognising the material as having come from Leland's book. Valiente subsequently rewrote the passage in both prose and verse, retaining the "traditional" Aradia lines. Some Wiccan traditions use the name Aradia, or Diana, to refer to the Goddess or Queen of the Witches, and Hutton writes that the earliest Gardnerian rituals used the name Airdia, a "garbled" form of Aradia. Hutton further suggests that the reason that Wicca includes skyclad practice, or ritual nudity, is because of a line spoken by Aradia:
And as the sign that ye are truly free,
Ye shall be naked in your rites, both men
And women also: this shall last until
The last of your oppressors shall be dead;
Accepting Aradia as the source of this practice, Robert Chartowich points to the 1998 Pazzaglini translation of these lines, which read "Men and Women / You will all be naked, until / Yet he shall be dead, the last / Of your oppressors is dead." Chartowich argues that the ritual nudity of Wicca was based upon Leland's mistranslation of these lines by incorporating the clause "in your rites". There are, however, earlier mentions of ritual nudity among Italian witches. Historian Ruth Martin states that it was a common practice for witches of Italy to be "naked with their hair loose around their shoulders" while reciting conjurations. Jeffrey Burton Russell notes that "A woman named Marta was tortured in Florence about 1375: she was alleged to have placed candles round a dish and to have taken off her clothes and stood above the dish in the nude, making magical signs". Historian Franco Mormando refers to an Italian witch: "Lo and behold: in the first hours of sleep, this woman opens the door to her vegetable garden and comes out completely naked and her hair all undone, and she begins to do and say her various signs and conjurations ...".
The reception of Aradia amongst Neopagans has not been entirely positive. Clifton suggests that modern claims of revealing an Italian pagan witchcraft tradition, for example those of Leo Martello and Raven Grimassi, must be "match[ed] against", and compared with the claims in Aradia. He further suggests that a lack of comfort with Aradia may be due to an "insecurity" within Neopaganism about the movement's claim to authenticity as a religious revival. Valiente offers another explanation for the negative reaction of some neopagans; that the identification of Lucifer as the God of the witches in Aradia was "too strong meat" for Wiccans who were used to the gentler, romantic paganism of Gerald Gardner and were especially quick to reject any relationship between witchcraft and Satanism.
Clifton writes that Aradia was especially influential for leaders of the Wiccan religious movement in the 1950s and 1960s, but that the book no longer appears on the "reading lists" given by members to newcomers, nor is it extensively cited in more recent Neopagan books. The new translation of the book released in 1998 was introduced by Wiccan author Stewart Farrar, who affirms the importance of Aradia, writing that "Leland's gifted research into a 'dying' tradition has made a significant contribution to a living and growing one."
Author Raven Grimassi has written extensively about Aradia in his popularization of Stregheria, presenting what he admits is his own personal rendering of her story. He differs from Leland in many ways, particularly in portraying her as a witch who lived and taught in 14th-century Italy, rather than a goddess.
In response to Clifton, he states that similarity or dissimilarity to Leland's Aradia material cannot be a measure of authenticity, since Leland's material itself is disputed.
Therefore it cannot effectively be used to discredit other writings or views on Italian witchcraft, nor is it a representative ethnographic foundation against which other writings or views "must" be compared. The Aradia material is, unfortunately, a disputed text with problems of its own when compared to the usually accepted folklore, folk traditions, and folk magic practices of Italy.
He agrees with Valiente that the major objection of Neopagans to this material is its "inclusion of negative stereotypes related to witches and witchcraft", and suggests that comparisons between this material and religious witchcraft are "regarded as an insult by many neo-pagans".
Influence on culture
Classical music
The Norwegian classical composer Martin Romberg wrote a Mass for mixed choir in seven parts after a selection of poems from Leland's text. This Witch Mass was premiered at the Vestfold International Festival in 2012 with Grex Vocalis. In order to create the right atmosphere for the music, the festival blocked off an entire road tunnel in Tønsberg to use it as a venue. The work was released on CD through Lawo Classics in 2014.
See also
Etruscan mythology
Tages, a prophet of Etruscan religion
Vegoia, a prophet of Etruscan religion
Usil, Etruscan sun god
References
External links
Aradia, or the Gospel of Witches at Internet Archive (scanned books illustrated)
Aradia, or the Gospel of Witches at Internet Sacred Text Archive (HTML)
Aradia , article at an Italian witchcraft website.
1899 non-fiction books
Grimoires
Modern paganism in Italy
Witchcraft in Italy
Diana (mythology)
Lucifer
1890s in modern paganism
si:අරඩියා |
2893610 | https://en.wikipedia.org/wiki/Wind%20%28spacecraft%29 | Wind (spacecraft) | The Global Geospace Science (GGS) Wind satellite is a NASA science spacecraft designed to study radio waves and plasma that occur in the solar wind and in the Earth's magnetosphere. It was launched on 1 November 1994, at 09:31:00 UTC, from launch pad LC-17B at Cape Canaveral Air Force Station (CCAFS) in Merritt Island, Florida, aboard a McDonnell Douglas Delta II 7925-10 rocket. Wind was designed and manufactured by Martin Marietta Astro Space Division in East Windsor Township, New Jersey. The satellite is a spin-stabilized cylindrical satellite with a diameter of and a height of .
The spacecraft's original mission was to orbit the Sun at the Lagrangian point, but this was delayed to study the magnetosphere and near lunar environment when the Solar and Heliospheric Observatory (SOHO) and Advanced Composition Explorer (ACE) spacecraft were sent to the same location. Wind has been at continuously since May 2004, and is still operating . , Wind currently has enough fuel to last over 50 more years at , until at least 2070. Wind continues to collect data, and by the end of 2022 had contributed data to over 6,780 scientific publications.
Mission operations are conducted from the Multi-Mission Operations Center (MMOC) in Building 14 at Goddard Space Flight Center in Greenbelt, Maryland. Wind data can be accessed using the SPEDAS software. Wind is the sister ship to GGS Polar.
Science objectives
The aim of the International Solar-Terrestrial Physics Science Initiative is to understand the behaviour of the solar-terrestrial plasma environment, in order to predict how the Earth's atmosphere will respond to changes in solar wind conditions. Wind objective is to measure the properties of the solar wind before it reaches the Earth.
Provide complete plasma, energetic particle, and magnetic field input for magnetospheric and ionospheric studies.
Determine the magnetospheric output to interplanetary space in the up-stream region.
Investigate basic plasma processes occurring in the near-Earth solar wind.
Provide baseline ecliptic plane observations to be used in heliospheric latitudes by the Ulysses mission.
Instruments
The Wind spacecraft has an array of instruments including: KONUS, the Magnetic Field Investigation (MFI), the Solar Wind and Suprathermal Ion Composition Experiment (SMS), The Energetic Particles: Acceleration, Composition, and Transport (EPACT) investigation, the Solar Wind Experiment (SWE), a Three-Dimensional Plasma and Energetic Particle Investigation (3DP), the Transient Gamma-Ray Spectrometer (TGRS), and the Radio and Plasma Wave Investigation (WAVES). The KONUS and TGRS instruments are primarily for gamma-ray and high energy photon observations of solar flares or gamma-ray bursts and part of the Gamma-ray Coordinates Network. The SMS experiment measures the mass and mass-to-charge ratios of heavy ions. The SWE and 3DP experiments are meant to measure/analyze the lower energy (below 10 MeV) solar wind protons and electrons. The WAVES and MFI experiments were designed to measure the electric and magnetic fields observed in the solar wind. All together, the Wind spacecraft's suite of instruments allows for a complete description of plasma phenomena in the solar wind plane of the ecliptic.
Wind/WAVES
Time domain sampler
The electric field detectors of the Wind WAVES instrument are composed of three orthogonal electric field dipole antennas, two in the spin plane (roughly the plane of the ecliptic) of the spacecraft and one along the spin axis. The complete WAVES suite of instruments includes five total receivers including: Low Frequency FFT receiver called FFT (0.3 Hz to 11 kHz), Thermal Noise Receiver called TNR (4–256 kHz), Radio receiver band 1 called RAD1 (20–1040 kHz), Radio receiver band 2 called RAD2 (1.075–13.825 MHz), and the Time Domain Sampler called TDS (designed and built by the University of Minnesota). The longer of the two spin plane antenna, defined as Ex, is tip-to-tip while the shorter, defined as Ey, is tip-to-tip. The spin axis dipole, defined as Ez, is roughly tip-to-tip. When accounting for spacecraft potential, these antenna lengths are adjusted to ~, ~, and ~ [Note: these are subject to change and only estimates and not necessarily accurate to two decimal places]. The Wind WAVES instrument also detects magnetic fields using three orthogonal search coil magnetometers (designed and built by the University of Iowa). The XY search coils are oriented to be parallel to the XY dipole antenna. The search coils allow for high-frequency magnetic field measurements (defined as Bx, By, and Bz). The WAVES Z-axis is anti-parallel to the Z-GSE (Geocentric Solar Ecliptic) direction. Thus, any rotations can be done about the Z-axis in the normal Eulerian sense followed by a change of sign in the Z-component of any GSE vector rotated into WAVES coordinates.
Electric (and magnetic) field waveform captures can be obtained from the Time Domain Sampler (TDS) receiver. TDS samples are a waveform capture of 2048 points (16384 points on the STEREO spacecraft) per field component. The waveforms are measures of electric field versus time. In the highest sampling rates, the Fast (TDSF) sampler runs at ~120,000 samples per second (sps) and the Slow (TDSS) sampler runs at ~7,500 sps. TDSF samples are composed of two electric field components (typically Ex and Ey) while TDSS samples are composed of four vectors, either three electric and one magnetic field or three magnetic and one electric field. The TDSF receiver has little to no gain below about ~120 Hz and the search coil magnetometers roll off around ~3.3 Hz.
Thermal Noise Receiver
The TNR measures ~4–256 kHz electric fields in up to 5 logarithmically spaced frequency bands, though typically only set at 3 bands, from 32 or 16 channels per band, with a 7 nV/(Hz)1/2 sensitivity, 400 Hz to 6.4 kHz bandwidth, and total dynamic range in excess of 100 dB. The data are taken by two multi-channel receivers which nominally sample for 20 ms at a 1 MHz sampling rate (see Bougeret 1995 for more information). The TNR is often used to determine the local plasma density by observing the plasma line, an emission at the local upper hybrid frequency due to a thermal noise response of the wire dipole antenna. One should note that observation of the plasma line requires the dipole antenna to be longer than the local Debye length, λDe. For typical conditions in the solar wind λDe ~, much shorter than the wire dipole antenna on Wind. The majority of this section was taken from.
Wind / 3DP
The Wind / 3DP instrument (designed and built at the Berkeley Space Sciences Laboratory) was designed to make full three-dimensional measurements of the distributions of suprathermal electrons and ions in the solar wind. The instrument includes three arrays, each consisting of a pair of double-ended semiconductor telescopes each with two or three closely sandwiched passivated ion implanted silicon detectors, which measure electrons and ions above ~20 keV. The instrument also has top-hat symmetrical spherical section electrostatic analyzers (ES) with microchannel plate detectors (MCPs) are used to measure ions and electrons from ~3 eV to 30 eV. The two types of detectors have energy resolutions ranging from ΔE/E ≈0.3 for the solid state telescopes (SST) and ΔE/E ≈ 0.2 for the top-hat ES analyzers. The angular resolutions are 22.5° × 36° for the SST and 5.6° (near the ecliptic) to 22.5° for the top-hat ES analyzers. The particle detectors can obtain a full 4π steradian coverage in one full(half) spin (~3 seconds) for the SST (top-hat ES analyzers). The majority of this section was taken from.
Electrostatic analyzers
The arrays of detectors are mounted on two opposing booms, each in length. The top-hat ES analyzers are composed of four separate detectors, each with different geometry factors to cover different ranges of energies. The electron detectors, EESA, and ion detectors, PESA, are each separated into low (L) and high (H) energy detectors. The H and L analyzers contain 24 and 16 discrete anodes, respectively. The anode layout provides a 5.6° angular resolution within ± 22.5° of the ecliptic plane (increases to 22.5° at normal incidence to ecliptic plane). The analyzers are swept logarithmically in energy and counters sample at 1024 samples/spin (~3 ms sample period). Thus the analyzers can be set to sample 64 energy samples per sweep at 16 sweeps per spin or 32 energy samples per sweep at 32 sweeps per spin, etc. The detectors are defined as follows:
EESA Low (EL): covers electrons from ~3 eV to ~1 keV (These values vary from moment structure to moment structure depending on duration of data sampling, spacecraft potential, and whether in burst or survey mode. The typical range is ~5 eV to ~1.11 keV.) with an 11.25° spin phase resolution. EL has a total geometric factor of 1.3 × 10−2 E cm2-sr (where E is energy in eV) with a nearly identical 180° field of view (FOV), radial to the spacecraft, to that of PESA-L.
EESA High (EH): covers electrons from ~200 eV to ~30 keV (though typical values vary from a minimum of ~137 eV to a maximum of ~28 keV) in a 32 sample energy sweep each 11.25° of spacecraft spin. EH has a total geometric factor of 2.0 × 10−1 E cm2-sr, MCP efficiency of about 70% and grid transmission of about 73%. EH has a 360° planar FOV tangent to the spacecraft surface which can be electro statically deflected into a cone up to ±45° out of its normal plane.
PESA Low (PL): covers ions with a 14 sample energy sweep (Note that in survey mode the data structures typically take 25 data points at 14 different energies while in burst mode they take 64 data points at 14 different energies.) from ~100 eV to ~10 keV (often energies range from ~700 eV to ~6 keV) each 5.6° of spacecraft spin. PL has a total geometric factor of only 1.6 × 10−4 E cm2-sr but an identical energy-angle response to that of PESA-H. While in the solar wind, PL reorients itself along the bulk flow direction to capture the solar wind flow which results in a narrow range of pitch-angle coverage.
PESA High (PH): covers ions with a 15 sample energy sweep from as low as ~80 eV to as high as ~30 keV (typical energy range is ~500 eV to ~28 keV) each 11.25° of spacecraft (Note that PH has multiple data modes where the number of data points per energy bin can be any of the following: 121, 97, 88, 65, or 56). PH has a total geometric factor of 1.5 × 10−2 E cm2-sr with a MCP efficiency of about 50% and grid entrance post transmission of about 75%.
The majority of this section was taken from Wilson III (2010).
Solid-state telescopes
The SST detectors consist of three arrays of double-ended telescopes, each of which is composed of either a pair or triplet of closely sandwiched semiconductor detectors. The center detector (Thick or T) of the triplet is in area, 500 μm thick, while the other detectors, foil (F) and open (O), are the same area but only 300 μm thick. One direction of the telescopes is covered in a thin lexan foil, ~1500 Angstrom (Å) of aluminum evaporated on each side to eliminate sunlight, (SST-Foil) where the thickness was chosen to stop protons up to the energy of electrons (~400 keV). Electrons are essentially unaffected by the foil. On the opposite side (SST-Open), a common broom magnet is used to refuse electrons below ~400 keV from entering but leaves the ions essentially unaffected. Thus, if no higher energy particles penetrate the detector walls, the SST-Foil should only measure electrons and the SST-Open only ions. Each double-ended telescope has two 36° × 20° FWHM FOV, thus each end of the five telescopes can cover a 180° × 20° piece of space. Telescope 6 views the same angle to spin axis as telescope 2, but both ends of telescope 2 have a drilled tantalum cover to reduce the geometric factor by a factor of 10 to measure the most intense fluxes. The SST-Foil data structures typically have 7 energy bins each with 48 data points while the SST-Open has 9 energy bins each with 48 data points. Both detectors have energy resolutions of ΔE/E ≈ 30%. The majority of this section was taken from.
Wind / MFI
The Magnetic Field Instrument (MFI) on board Wind is composed of dual triaxial fluxgate magnetometers. The MFI has a dynamic range of ±4 nT to ±65,536 nT, digital resolution ranging from ±0.001 nT to ±16 nT, sensor noise level of < 0.006 nT (R.M.S.) for 0–10 Hz signals, and sample rates varying from 44 samples per second (sps) in snapshot memory to 10.87 sps in standard mode. The data are also available in averages at 3 seconds, 1 minute, and 1 hour. The data sampled at higher rates (i.e. >10 sps) is referred to as High Time Resolution (HTR) data in some studies.
Wind / SWE
The Wind spacecraft has two Faraday Cup (FC) ion instruments. The SWE FCs can produce reduced ion distribution functions with up to 20 angular and 30 energy per charge bins every 92 seconds. Each sensor has a ~15° tilt above or below the spin plane and an energy range from ~150 eV to ~8 keV. A circular aperture limits the effects of aberration near the modulator grid and defines the collecting area of the collector plates in each FC. The FCs sample at a set energy for each spacecraft rotation, then step up the energy for the next rotation. Since there are up to 30 energy bins for these detectors, a full reduced distribution function requires 30 rotations or slightly more than 90 seconds.
Wind / KONUS and TGRS
KONUS remains a very active partner in the Gamma-ray Coordinates Network (GCN) and the Interplanetary Network. Notifications of astrophysical transients are sent worldwide instantly from KONUS, and are of importance in the subsequent positioning of telescopes everywhere. Thus, the instrument remains an active contributor to the astrophysical community, for instance, with the Neil Gehrels Swift Observatory (Swift mission).
The TGRS instrument was shut off early in the mission due to the planned expiration of coolant.
Wind / EPACT
The Energetic Particles: Acceleration, Composition and Transport (EPACT) investigation consists of multiple telescopes including: the Low Energy Matrix Telescope (LEMT); SupraThermal Energetic Particle telescope (STEP); and ELectron-Isotope TElescope system (ELITE). ELITE is composed of two Alpha-Proton-Electron (APE) telescopes and an Isotope Telescope (IT).
The highest energy telescopes (APE and IT) failed early in the mission, though APE does two channels of ~5 and ~20 MeV protons but IT was turned off. However, LEMT (covering energies in the 1–10 MeV/nucl range) and STEP (measuring ions heavier than protons in the 20 keV–1 MeV/nucl range) still continue to provide valuable data.
Wind / SMS
The Solar Wind and Suprathermal Ion Composition Experiment (SMS) on Wind is composed of three separate instruments: SupraThermal Ion Composition Spectrometer (STICS); high-resolution mass spectrometer (MASS); and Solar Wind Ion Composition Spectrometer (SWICS). STICS determines the mass, mass per charge, and energy for ions in the energy range of 6–230 keV/e. MASS determines elemental and isotopic abundances from 0.5 to 12 keV/e. SWICS determines mass, charge, and energy for ions in the energy range of 0.5 to 30 keV/e. The SWICS "stop" microchannel plate detector (MCP) experienced a failure resulting in reduced capabilities for this instrument and was eventually turned off in May 2000. The SMS data processing unit (DPU) experienced a latch-up reset on 26 June 2009, that placed the MASS acceleration/deceleration power supply into a fixed voltage mode, rather than stepping through a set of voltages. In 2010, MASS experienced a small degradation in the acceleration/deceleration power supply which reduced the efficiency of the instrument, though this does not seriously affect science data analysis.
Discoveries
Observation of relationship between large-scale solar wind-magnetosphere interactions and magnetic reconnection at the terrestrial magnetopause.
First statistical study of high frequency (≥1 kHz) electric field fluctuations in the ramp of interplanetary (IP) shocks. The study found that the amplitude of ion acoustic waves (IAWs) increased with increasing fast mode Mach number and shock compression ratio. They also found that the IAWs had the highest probability of occurrence in the ramp region.
Observation of the largest whistler wave using a search coil magnetometer in the radiation belts.
First observation of shocklets upstream of a quasi-perpendicular IP shock.
First simultaneous observations of whistler mode waves with electron distributions unstable to the whistler heat flux instability.
First observation of an electrostatic solitary wave at an IP shock with an amplitude exceeding 100 mV/m.
First observation of electron-Berstein-like waves at an IP shock.
First observation of the source region of an IP Type II radio burst.
First evidence for Langmuir wave coupling to Z-mode waves.
First evidence to suggest that the observed bi-polar ES structures in the shock transition region are consistent with BGK modes or electron phase space holes.
First evidence of a correlation between the amplitude of electron phase space holes and the change in electron temperature.
First evidence of three-wave interactions in the terrestrial foreshock using bi-coherence.
First evidence of proton temperature anisotropy constraints due to mirror, firehose, and ion cyclotron instabilities.
First evidence of Alfvén-cyclotron dissipation.
First (shared with STEREO spacecraft) observation of electron trapping by a very large amplitude whistler wave in the radiation belts (also seen in STEREO observations).
First observation of Langmuir and whistler waves in the lunar wake.
First evidence of direct evidence of electron cyclotron resonance with whistler mode waves driven by a heat flux instability in the solar wind.
First evidence of local field-aligned ion beam generation by foreshock electromagnetic waves called short large amplitude magnetic structures or SLAMS, which are soliton-like waves in the magnetosonic mode.
Observation of interplanetary and interstellar dust particle impacts, with over 100,000 impacts recorded as of 2019.
First evidence of connection between a fast radio burst and a magnetar with the Milky Way galaxy. The press release can be found at Fast Radio Bursts. This work led to at least six papers published in Nature.
First observation of a giant flare — emission of greater apparent intensity than gamma ray bursts with an average occurrence rate of once per decade — within the nearby Sculptor Galaxy. The press release can be found at Giant Flare in Nearby Galaxy. This work led to at least six papers published in Nature.
A comprehensive review of the contributions made by Wind to science was published in Reviews of Geophysics by and highlighted by the journal in an Editors' Vox on the Eos (magazine) website.
List of refereed publications for Wind
For a complete list of refereed publications directly or indirectly using data from the Wind spacecraft, see https://wind.nasa.gov/bibliographies.php.
Wind continues to produce relevant research, with its data having contributed to over 4300 publications since 1 January 2010 and over 2480 publications prior. As of 26 April 2023 (not including 2023 publications), the total number of publications either directly or indirectly using Wind data is ~6786, or an average of ~242 publications/year (the average since 2018 is ~428 publications/year or ~2141 publications since 2018).Wind data has been used in over 110 high impact refereed publications with ~12 in Science, ~64 in Nature Publishing Group (includes Nature, Nature Physics, Nature Communications, Scientific Reports, and Scientific American), and ~37 in Physical Review Letters. Many of these publications utilized Wind data directly and indirectly by citing the OMNI dataset at CDAWeb, which relies heavily upon Wind measurements.
Science highlights in the news
An April 2012 paper makes NASA's homepage news.
A March 2013 paper using data from the Wind spacecraft was highlighted as a Physical Review Letters Spotlight article and a NASA Feature Article.
An April 2013 paper was highlighted on the NASA website.
A September 2014 paper was highlighted on the NASA website and at Popular Science.
Wind celebrated the 20th anniversary of its launch on November 1, 2014, highlighted on NASA's homepage.
A November 2016 paper primarily using THEMIS observations and utilizing data from the Wind spacecraft was published in Physical Review Letters and selected as an Editors' Suggestion article, and was highlighted on the NASA and THEMIS Science Nuggest sites.
Wind data was used in a June 2019 paper showing that ions are heated in a preferential zone close to the solar surface, at altitudes that will be visited by Parker Solar Probe in roughly two years.
Wind celebrated the 25th anniversary of its launch on 1 November 2019, highlighted in a NASA feature article.
Wind/ KONUS data was used to show, for the first time, that fast radio bursts may originate from magnetars, highlighted by NASA at Fast Radio Bursts on 4 November 2020.
Wind/ KONUS data helped provide evidence of the first giant flare in the nearby Sculptor Galaxy, highlighted by NASA at Giant Flare in Nearby Galaxy on 13 January 2021.
Wind/ LEMT data helped to pinpoint the source region of solar energetic particles, highlighted by NASA at Scientists Trace Fastest Solar Particles to Their Roots on 10 March 2021.
Wind/ KONUS data helped to detect one of the strongest/brightest gamma-ray burst (GRB) events on record, with a total energy output of 1054 ergs (or 1047 J). The story is highlighted on 13 October 2022 at Exceptional Cosmic Blast.
Wind celebrated the 28th anniversary of its launch on 1 November 2022.
On 21 February 2023 the Wind review paper published in Reviews of Geophysics was awarded as a Top Cited Article 2021-2022 by the journal.
Awards
The Wind Operations Team at NASA's Goddard Space Flight Center received the NASA Group Achievement Award in June 2015 for recovery of the Wind spacecraft's command and attitude processor.
The Wind Operations Team at NASA's Goddard Space Flight Center received the AIAA Space Operations & Support Award on 2 September 2015. The award honors the team's "exceptional ingenuity and personal sacrifice in the recovery of NASA's Wind spacecraft". Jacqueline Snell, engineering manager for the Wind, Geotail, and Advanced Composition Explorer (ACE) missions, accepted the award on behalf of the team.
In 2019, Lynn B. Wilson III, the project scientist for Wind, was awarded NASA's Exceptional Scientific Achievement Medal.
See also
List of active Solar System probes
List of heliophysics missions
Timeline of Solar System exploration
Advanced Composition Explorer (ACE), launched 1997, still operational
Cassini–Huygens
Cluster
Helios
Magnetospheric Multiscale Mission (MMS)
MESSENGER (Mercury Surface, Space Environment, Geochemistry and Ranging), launched 2004, decommissioned April 30, 2015
Solar Dynamics Observatory (SDO), launched 2010, still operational
Solar and Heliospheric Observatory (SOHO), launched 1995, still operational
Solar Maximum Mission (SMM), launched 1980, decommissioned 1989
Solar Orbiter (SOLO), launched in February 2020
Parker Solar Probe, launched in 2018
STEREO (Solar Terrestrial Relations Observatory), launched 2006, one of two spacecraft still operational
Time History of Events and Macroscale Interactions during Substorms (THEMIS), launched 2007, still operational
TRACE (Transition Region and Coronal Explorer), launched 1998, decommissioned 2010
Van Allen Probes (formerly called Radiation Belt Storm Probes), launched 2012, decommissioned 2019
References
External links
Wind website at NASA.gov
Old Wind website at NASA.gov
3-D Plasma and Energetic Particles Experiment at Washington.edu
Radio and Plasma Wave Experiment at NASA.gov
NASA space probes
Spacecraft launched in 1994
Spacecraft launched by Delta II rockets
Artificial satellites at Earth-Sun Lagrange points
Geospace monitoring satellites |
2893681 | https://en.wikipedia.org/wiki/International%20Solar-Terrestrial%20Physics%20Science%20Initiative | International Solar-Terrestrial Physics Science Initiative | The International Solar-Terrestrial Physics Science Initiative (or ISTP for short) is an international research collaboration between NASA, the ESA, and ISAS. Its goal is to study physical phenomena related to the Sun, solar wind and its effects on Earth.
See also
List of heliophysics missions
References
External links
NASA's ISTP web site
Sun |
2893723 | https://en.wikipedia.org/wiki/Lectisternium | Lectisternium | The lectisternium was an ancient Roman propitiatory ceremony, consisting of a meal offered to gods and goddesses. The word derives from lectum sternere, "to spread (or "drape") a couch." The deities were represented by their busts or statues, or by portable figures of wood, with heads of bronze, wax or marble. It has also been suggested that the divine images were bundles of sacred herbs tied together in the form of a head, covered by a waxen mask so as to resemble a kind of bust, rather like the straw figures called Argei. A couch (lectus) was prepared by draping it with fabric. The figures or sacred objects pertaining to the deity (such as the wreath awarded in a triumph) were laid upon it. Each couch held a pair of deities, sometimes male with female equivalent. If the image was anthropomorphic, the left arms were rested on a cushion (pulvinus) in the attitude of reclining to eat, whence the couch itself was often called pulvinar) The couches were set out in the open street, or a temple forecourt, or in the case of ludi, in the pulvinar or viewing box, and a meal was served on a table before the couch.
History
Livy says that the ceremony took place "for the first time" in Rome in the year 399 BC, after a pestilence had caused the Sibylline Books to be consulted by the duumviri sacris faciundis, the two (later 10, and later 15) priestly officials who maintained the archive. Three couches were prepared for three pairs of gods — Apollo and Latona, Hercules and Diana, Mercury and Neptune. The feast lasted for eight (or seven) days, and was also celebrated by private individuals. The citizens kept open house, quarrels were forgotten, debtors and prisoners were released, and everything done to banish sorrow.
Similar honors were paid to other divinities in subsequent times: Fortuna, Saturnus, Juno Regina of the Aventine, the three Capitoline deities (Jupiter, Juno, Minerva). In 217 BC, after the Roman defeat at Lake Trasimene, a lectisternium was held for three days to six pairs of gods, corresponding to the Twelve Olympians of ancient Greek religion: Jupiter, Juno, Neptune, Minerva, Mars, Venus, Apollo, Diana, Vulcan, Vesta, Mercury, Ceres.
In 205 BC, alarmed by unfavorable prodigies, the Romans were ordered to fetch the Great Mother of the gods from Pessinus in Phrygia; in the following year the image was brought to Rome, and a lectisternium held. In later times, the lectisternium became a constant or even daily occurrence, celebrated in the different temples. Occasionally the "Draping of Couches" was part of Roman Triumph celebrations. Aulus Hirtius reports that Julius Caesar was greeted with "draped dining couches" following his victory in Gaul, in anticipation of a forthcoming triumph. Such celebrations must be distinguished from those which were ordered, like the earlier lectisternia, by the Sibylline Books in special emergencies.
In the Imperial era, chairs were substituted for couches in the case of goddesses, and the lectisternium in their case became a sellisternium. This was in accordance with Roman custom, since in the earliest times all the members of a family sat at meals, and in later times at least the women and children. This is a point of distinction between the original practice at the lectisternium and the epulum Jovis, the goddesses at the latter being provided with chairs, whereas in the lectisternium they reclined.
In Christian times the word was used for a feast in memory of the dead.
Origins
Offerings of food were made to the gods in very early Roman times on such occasions as the ceremony of confarreatio, and the epulum Jovis (often conflated with the lectisternium). The lectisternia, however, are likely of Greek origin. The Greek theoxenia (Θεοξένια) is similar, except that the gods played the part of host. The gods associated with it were either previously unknown to Roman religion, though often concealed under Roman names, or were provided with a new cult. Thus Hercules was not worshipped as at the Ara Maxima, where, according to Servius and Cornelius Balbus a lectisternium was forbidden. The Sibylline Books, which decided whether a lectisternium was to be held or not, were of Greek origin; the custom of reclining at meals was Greek.
Some, however, assign an Etruscan origin to the ceremony, the Sibylline Books themselves being looked upon as old Italian "black books." It may be that as the lectisternia became an almost everyday occurrence in Rome, people forgot their foreign origin and the circumstances in which they were first introduced, and then the word pulvinar with its associations was transferred to times in which it had no existence.
Sources
Taylor, Lily Ross. “The Sellisternium and the Theatrical Pompa.” Classical Philology, vol. 30, no. 2, 1935, pp. 122–30. JSTOR, http://www.jstor.org/stable/263926. Accessed 9 Dec. 2022.
Article by A. Bouché-Leclercq in Daremberg and Saglio, Dictionnaire des antiquités;
Marquardt, Römische Staatsverwaltung, iii. 45, 187 (1885);
G. Wissowa, Religion und Kultus der Römer, p. 355 seq.;
Monograph by Wackermann (Hanau, 1888);
C. Pascal, Studii di antichità e mitologia (1896).
Notes
External links
Lectisternium (article in Smith's Dictionary of Greek and Roman Antiquities)
4th-century BC establishments in the Roman Republic
Ancient Roman religion
Neptune (mythology)
Hercules
Cult of Apollo
Leto
Diana (mythology)
Mercury (mythology)
Ceremonies |
2895407 | https://en.wikipedia.org/wiki/Forbush%20decrease | Forbush decrease | A Forbush decrease is a rapid decrease in the observed galactic cosmic ray intensity following a coronal mass ejection (CME). It occurs due to the magnetic field of the plasma solar wind sweeping some of the galactic cosmic rays away from Earth. The term Forbush decrease was named after the American physicist Scott E. Forbush, who studied cosmic rays in the 1930s and 1940s.
Observation
The Forbush decrease is usually observable by particle detectors on Earth within a few days after the CME, and the decrease takes place over the course of a few hours. Over the following several days, the galactic cosmic ray intensity returns to normal. Forbush decreases have also been observed by humans on Mir and the International Space Station (ISS), at other locations in the inner heliosphere such as the Solar Orbiter spacecraft, and at Mars with the Mars Science Laboratory rover's Radiation assessment detector and the MAVEN orbiter, as well as in the outer solar system by instruments onboard Pioneer 10 and 11 and Voyager 1 and 2, even past the orbit of Neptune.
The magnitude of a Forbush decrease depends on three factors:
the size of the CME
the strength of the magnetic fields in the CME
the proximity of the CME to the Earth
A Forbush decrease is sometimes defined as being a decrease of at least 10% of galactic cosmic rays on Earth, but ranges from about 3% to 20%. The amplitude is also highly dependent on the energy of cosmic rays that is observed by the specific instrument, where lower energies typically show larger decreases. Reductions of 30% or more have been recorded aboard the ISS.
The overall rate of Forbush decreases tends to follow the 11-year sunspot cycle. It is more difficult to shield astronauts from galactic cosmic rays than from solar wind, so future astronauts might benefit most from radiation shielding during solar minima, when the suppressive effect of CMEs is less frequent.
Effects on the atmosphere
A 2009 peer reviewed article found that low clouds contain less liquid water following Forbush decreases, and for the most influential events the liquid water in the oceanic atmosphere can diminish by as much as 7%. Further peer-reviewed work found no connection between Forbush decreases and cloud properties until the connection was found in diurnal temperature range, and since confirmed in satellite data.
See also
Ionizing radiation
References
External links
Who's Afraid of a Solar Flare? from Science@NASA
Cosmic Ray Data Applications to Space Weather Forecasting
Cosmic rays
Solar phenomena |
2898771 | https://en.wikipedia.org/wiki/Lambda%20Aurigae | Lambda Aurigae | Lambda Aurigae, Latinized from λ Aurigae, is the Bayer designation for a solar analog star in the northern constellation of Auriga. It is visible to the naked eye with an apparent visual magnitude of 4.71. Based upon parallax measurements, it is approximately distant from the Earth. The star is drifting further away with a high radial velocity of +66.5 km/s, having come to within some 117,300 years ago. It has a high proper motion, traversing the celestial sphere at the rate of per year.
Properties
This is a G-type main sequence star with a stellar classification of G1 V. It is sometimes listed with a class of G1.5 IV-V Fe-1, which indicates the spectrum is showing some features of a more evolved subgiant star along with a noticeable underabundance of iron. In terms of composition it is similar to the Sun, while the mass and radius are slightly larger. It is 73% more luminous than the Sun and radiates this energy from its outer atmosphere at an effective temperature of . At this heat, the star glows with the yellow hue of a G-type star. It has a low level of surface activity and is a candidate Maunder minimum analog.
Lambda Aurigae has been examined for the presence of excess infrared emission that may indicate the presence of a circumstellar disk of dust, but no significant surplus has been observed. It is a possible member of the Epsilon Indi Moving Group of stars that share a common motion through space. The space velocity components of this star are = .
Name
This star may have been called by the name Al Hurr, meaning the fawn in Arabic. Lambda Aurigae, along with μ Aur and σ Aur, were Kazwini's Al Ḣibāʽ (ألحباع), the Tent. According to the catalogue of stars in the Technical Memorandum 33-507 - A Reduced Star Catalog Containing 537 Named Stars, Al Ḣibāʽ were the title for three stars : λ Aur as Al Ḣibāʽ I, μ Aur as Al Ḣibāʽ II and σ Aur as Al Ḣibāʽ III.
In Chinese, (), meaning Pool of Harmony, refers to an asterism consisting of λ Aurigae, ρ Aurigae and HD 36041. Consequently, the Chinese name for λ Aurigae itself is (, .)
Observation
From Earth, Lambda Aurigae has an apparent magnitude of 4.71. The closest large neighboring star to Lambda Aurigae is Capella, located away. Hypothetically viewed from Lambda Aurigae, Capella's quadruple star system would have an apparent magnitude of approximately -5.48, about 40 times brighter than Sirius can be seen at maximum brightness from Earth.
References
External links
Image Lambda Aurigae
G-type main-sequence stars
G-type subgiants
Aurigae, Lambda
Maunder Minimum
Auriga (constellation)
Aurigae, Lambda
BD+39 1248
Aurigae, 15
0197
034411
024813
1729 |
2906879 | https://en.wikipedia.org/wiki/Air%20current | Air current | In meteorology, air currents are concentrated areas of winds. They are mainly due to differences in atmospheric pressure or temperature. They are divided into horizontal and vertical currents; both are present at mesoscale while horizontal ones dominate at synoptic scale. Air currents are not only found in the troposphere, but extend to the stratosphere and mesosphere.
Horizontal currents
A difference in air pressure causes an air displacement and generates the wind. The Coriolis Force deflects the air movement to the right in the northern hemisphere and the left in the southern one, which makes the winds parallel to the isobars on an elevation in pressure card. It's called the geostrophic wind.
Pressure differences depend, in turn, on the average temperature in the air column. As the sun does not heat the Earth evenly, there is a temperature difference between the poles and the equator, creating air masses with more or less homogeneous temperature with latitude. Differences in atmospheric pressure are also at the origin of the general atmospheric circulation while the air masses are separated by ribbons where temperature changes rapidly. These are the fronts. Along these areas, higher winds aloft form. These horizontal jets (jet streams) can reach speeds of several hundred kilometers per hour and can span thousands of kilometers in length, but can only have a few tens or hundreds of kilometers of width.
On the surface, the friction due to the terrain and other obstacles (buildings, trees, etc.) may contribute to a slowdown and/or a wind deflection. Thus, a more turbulent wind in the atmospheric boundary layer. This wind can be channeled through narrows, like valleys. The wind will also be raised along the slopes of the mountains to give local air currents.
Vertical currents
Mechanically induced
In an air mass moving, vertical movements occur when there is convergence and divergence at different levels of the atmosphere. For example, when we are near the jet stream, winds increase when approaching its most intense region and decreases when it moves away. So there are areas where the air accumulates and must come down, while in other areas there is a loss and an updraft from lower layers. These upward or downward flows will be relatively diffused.
On the other hand, barriers such as mountains force air up or down, sometimes rapidly. As the barriers are very localized, these currents will affect very limited areas and therefore will form corridors.
Thermically induced
Thermals are caused by local differences in temperature, pressure, or impurity concentration in the vertical. Temperature differences can cause air currents because warmer air is less dense than cooler air, causing the warmer air to appear "lighter." Thus, if the warm air is under the cool air, air currents will form as they exchange places. Air currents are caused because of the uneven heating of Earth's surface.
See also
Air flow
References
Atmospheric dynamics
Gliding technology |
2907112 | https://en.wikipedia.org/wiki/Equation%20of%20the%20center | Equation of the center | In two-body, Keplerian orbital mechanics, the equation of the center is the angular difference between the actual position of a body in its elliptical orbit and the position it would occupy if its motion were uniform, in a circular orbit of the same period. It is defined as the difference true anomaly, , minus mean anomaly, , and is typically expressed a function of mean anomaly, , and orbital eccentricity, .
Discussion
Since antiquity, the problem of predicting the motions of the heavenly bodies has been simplified by reducing it to one of a single body in orbit about another. In calculating the position of the body around its orbit, it is often convenient to begin by assuming circular motion. This first approximation is then simply a constant angular rate multiplied by an amount of time. There are various methods of proceeding to correct the approximate circular position to that produced by elliptical motion, many of them complex, and many involving solution of Kepler's equation. In contrast, the equation of the center is one of the easiest methods to apply.
In cases of small eccentricity, the position given by the equation of the center can be nearly as accurate as any other method of solving the problem. Many orbits of interest, such as those of bodies in the Solar System or of artificial Earth satellites, have these nearly-circular orbits. As eccentricity becomes greater, and orbits more elliptical, the equation's accuracy declines, failing completely at the highest values, hence it is not used for such orbits.
The equation in its modern form can be truncated at any arbitrary level of accuracy, and when limited to just the most important terms, it can produce an easily calculated approximation of the true position when full accuracy is not important. Such approximations can be used, for instance, as starting values for iterative solutions of Kepler's equation, or in calculating rise or set times, which due to atmospheric effects cannot be predicted with much precision.
The ancient Greeks, in particular Hipparchus, knew the equation of the center as prostaphaeresis, although their understanding of the geometry of the planets' motion was not the same. The word equation (Latin, aequatio, -onis) in the present sense comes from astronomy. It was specified and used by Kepler, as that variable quantity determined by calculation which must be added or subtracted from the mean motion to obtain the true motion. In astronomy, the term equation of time has a similar meaning. The equation of the center in modern form was developed as part of perturbation analysis, that is, the study of the effects of a third body on two-body motion.
Series expansion
In Keplerian motion, the coordinates of the body retrace the same values with each orbit, which is the definition of a periodic function. Such functions can be expressed as periodic series of any continuously increasing angular variable, and the variable of most interest is the mean anomaly, . Because it increases uniformly with time, expressing any other variable as a series in mean anomaly is essentially the same as expressing it in terms of time. Because the eccentricity, , of the orbit is small in value, the coefficients of the series can be developed in terms of powers of . Note that while these series can be presented in truncated form, they represent a sum of an infinite number of terms.
The series for , the true anomaly can be expressed most conveniently in terms of , and Bessel functions of the first kind,
where
are the Bessel functions and
The result is in radians.
The Bessel functions can be expanded in powers of by,
and by,
Substituting and reducing, the equation for becomes (truncated at order ),
and by the definition, moving to the left-hand side,
gives the equation of the center.
This equation is sometimes derived in an alternate way and presented in terms of powers of with coefficients in functions of (truncated at order ),
which is identical to the above form.
For small , the series converges rapidly. If exceeds 0.6627..., it diverges for some values of , first discovered by Pierre-Simon Laplace.
Examples
See also
Celestial mechanics
Gravitational two-body problem
Kepler orbit
Kepler problem
Two-body problem
References
Further reading
Marth, A. (1890). On the computation of the equation of the centre in elliptical orbits of moderate eccentricities. Monthly Notices of the Royal Astronomical Society, Vol. 50, p. 502. Gives the equation of the center to order e10.
Morrison, J. (1883). On the computation of the eccentric anomaly, equation of the centre and radius vector of a planet, in terms of the mean anomaly and eccentricity. Monthly Notices of the Royal Astronomical Society, Vol. 43, p. 345. Gives the equation of the center to order e12.
Morrison, J. (1883). Errata. Monthly Notices of the Royal Astronomical Society, Vol. 43, p. 494.
Orbits |
2907660 | https://en.wikipedia.org/wiki/Ludovisi%20Ares | Ludovisi Ares | The Ludovisi Ares is an Antonine Roman marble sculpture of Mars, a fine 2nd-century copy of a late 4th-century BCE Greek original, associated with Scopas or Lysippus: thus the Roman god of war receives his Greek name, Ares.
Ares/Mars is portrayed as young and beardless and seated on a trophy of arms, while an Eros plays about his feet, drawing attention to the fact that the god of war, in a moment of repose, is presented as a love object. The 18th-century connoisseur Johann Joachim Winckelmann, a man with a practiced eye for male beauty, found the Ludovisi Ares the most beautiful Mars that had been preserved from Antiquity, when he wrote the catalogue of the Ludovisi collection.
Rediscovered in 1622, the sculpture was apparently originally part of the temple of Mars (founded in 132 BCE in the southern part of the Campus Martius), of which few traces remain, for it was recovered near the site of the church of San Salvatore in Campo. Pietro Santi Bartoli recorded in his notes that it had been found near the Palazzo Santa Croce in Rione Campitelli during the digging of a drain. (Haskell and Penny 1981:260) The sculpture found its way into the collection formed by Cardinal Ludovico Ludovisi (1595–1632) the nephew of Pope Gregory XV at the splendid villa and gardens he built near Porta Pinciana, on the site where Julius Caesar and his heir, Octavian (Caesar Augustus), had had their villa. The sculpture was lightly restored by the young Bernini, who refinished its surfaces and discreetly provided a right foot; he was probably largely responsible for the cupid, which Haskell and Penny note was omitted from G.F. Susini's bronze replica and from the prints of the sculpture in Maffei's anthology.
The sculpture was a sensational find. A small-scale bronze replica of it was executed by G.F. Susini, heir and assistant to his more famous uncle Antonio Susini, when he visited Rome in the 1630s and copied several marbles from Ludovisi's collection; a bronze of the Ludovisi Ares is in the Ashmolean Museum, Oxford. Later, the Ludovisi Ares was one of the featured antiquities to be seen on the "grand tour". For example, the portrait of English tourist John Talbot (later first Earl Talbot) by Pompeo Batoni depicts him next to the statue to display his culture and showing his familiarity with great works of art. Less expensive representations could be found: Giambattista Piranesi's son Francesco made an engraving of it at the Villa Ludovisi in 1783 . Casts of the Ludovisi Ares found their way into early museum collections, such as the Copenhagen Glyptotek and were influential to several generations of Neoclassical and academic students.
In 1901, the eventual heir, prince Boncompagni-Ludovisi, brought the Ludovisi antiquities to auction. The Italian state purchased 96 of the objects, and the rest have been dispersed among the museums of Europe and the US. The Ares is conserved in the section of the National Museum of the Terme that is housed in Palazzo Altemps, Rome.
A depiction of the statue is used as an emblem for the Greek athletic club Aris Thessaloniki.
See also
List of works by Gian Lorenzo Bernini
References
Francis Haskell and Nicholas Penny, 1981. Taste and the Antique: the Lure of Classical Sculpture 1500–1900. (Yale University Press) cat. no. 58.
External links
Altemps Palace and the Ludovisi collection
Collections of the National Roman Museum
Ludovisi collection
Roman copies of 4th-century BC Greek sculptures
Ares
Sculptures of Greek gods |
2909308 | https://en.wikipedia.org/wiki/Pressure%20gradient | Pressure gradient | In atmospheric science, the pressure gradient (typically of air but more generally of any fluid) is a physical quantity that describes in which direction and at what rate the pressure increases the most rapidly around a particular location. The pressure gradient is a dimensional quantity expressed in units of pascals per metre (Pa/m). Mathematically, it is the gradient of pressure as a function of position. The negative gradient of pressure is known as the force density.
In petroleum geology and the petrochemical sciences pertaining to oil wells, and more specifically within hydrostatics, pressure gradients refer to the gradient of vertical pressure in a column of fluid within a wellbore and are generally expressed in pounds per square inch per foot (psi/ft). This column of fluid is subject to the compound pressure gradient of the overlying fluids. The path and geometry of the column is totally irrelevant; only the vertical depth of the column has any relevance to the vertical pressure of any point within its column and the pressure gradient for any given true vertical depth.
Physical interpretation
The concept of a pressure gradient is a local characterisation of the air (more generally of the fluid under investigation). The pressure gradient is defined only at these spatial scales at which pressure (more generally fluid dynamics) itself is defined.
Within planetary atmospheres (including the Earth's), the pressure gradient is a vector pointing roughly downwards, because the pressure changes most rapidly vertically, increasing downwards (see vertical pressure variation). The value of the strength (or norm) of the pressure gradient in the troposphere is typically of the order of 9 Pa/m (or 90 hPa/km).
The pressure gradient often has a small but critical horizontal component, which is largely responsible for wind circulation in the atmosphere. The horizontal pressure gradient is a two-dimensional vector resulting from the projection of the pressure gradient onto a local horizontal plane. Near the Earth's surface, this horizontal pressure gradient force is directed from higher toward lower pressure. Its particular orientation at any one time and place depends strongly on the weather situation. At mid-latitudes, the typical horizontal pressure gradient may take on values of the order of 10−2 Pa/m (or 10 Pa/km), although rather higher values occur within meteorological fronts.
Weather and climate relevance
Interpreting differences in air pressure between different locations is a fundamental component of many meteorological and climatological disciplines, including weather forecasting. As indicated above, the pressure gradient constitutes one of the main forces acting on the air to make it move as wind. Note that the pressure gradient force points from high towards low pressure zones. It is thus oriented in the opposite direction from the pressure gradient itself.
In acoustics
In acoustics, the pressure gradient is proportional to the sound particle acceleration according to Euler's equation. Sound waves and shock waves can induce very large pressure gradients, but these are oscillatory, and often transitory disturbances.
See also
Adverse pressure gradient
Force density
Isobar
Geopotential height
Geostrophic wind
Primitive equations
Temperature gradient
Citations
References
Conner A. Perrine (1967) The nature and theory of the general circulation of atmosphere, World Meteorological Organization, Publication No. 218, Geneva, Switzerland.
Robert G. Fleagle and Joost A. Businger (1980) An Introduction to Atmospheric Physics, Second Edition, Academic Press, International Geophysics Series, Volume 25, .
John S. Wallace and Peter V. Hobbs (2006) Atmospheric Science: An Introductory Survey, Second Edition, Academic Press, International Geophysics Series, .
External links
IPCC Third Assessment Report
Atmospheric dynamics
Pressure
Spatial gradient |
2913315 | https://en.wikipedia.org/wiki/Global%20Atmosphere%20Watch | Global Atmosphere Watch | The Global Atmosphere Watch (GAW) is a worldwide system established by the World Meteorological Organizationa United Nations agencyto monitor trends in the Earth's atmosphere. It arose out of concerns for the state of the atmosphere in the 1960s.
Mission
The Global Atmosphere Watch's mission is quite straightforward, consisting of three concise points:
To make reliable, comprehensive observations of the chemical composition and selected physical characteristics of the atmosphere on global and regional scales;
To provide the scientific community with the means to predict future atmospheric states;
To organize assessments in support of formulating environmental policy.
Goals
The GAW program is guided by 8 strategic goals:
To improve the measurements programme for better geographical and temporal coverage and for near real-time monitoring capability;
To complete the quality assurance/quality control system;
To improve availability of data and promote their use;
To improve communication and cooperation between all GAW components and with the scientific community;
To identify and clarify changing roles of GAW components;
To maintain present and solicit new support and collaborations for the GAW programme;
To intensify capacity-building in developing countries;
To enhance the capabilities of National Meteorological and Hydrological Services in providing urban environmental air quality services.
Moreover, the programme seeks not only to understand changes in the Earth's atmosphere, but also to forecast them, and perhaps control the human activities that cause them.
Genesis
The original reason for testing the atmosphere for trace chemicals was mere scientific interest, but of course, many scientists eventually wondered what effects these trace chemicals could have on the atmosphere, and on life.
The GAW's genesis began as far back as the 1950s when the World Meteorological Organization began a programme of monitoring the atmosphere for trace chemicals, and also researching air pollution from a meteorological point of view. They were also responsible for monitoring ozone, establishing the Global Ozone Observing System (GO3OS) in 1957, in the International Geophysical Year.
In 1968, the United Nations called for an international conference to address world environmental problems caused by rapid industrialization. At about this time, the World Meteorological Organization set up another environmental research body, the Background Air Pollution Monitoring Network. The conference was held in Stockholm in 1972, and addressed several environmental concerns, namely:
The threat posed to the atmosphere by chlorofluorocarbons (CFCs);
Acidification of lakes and forests in North America and Europe due to acid rain;
Global warming caused by build-up of greenhouse gases.
Indeed, it was the World Meteorological Organization's readings and observations that figured prominently at this conference. They had little good news to offer.
The GAW itself was eventually created in 1989 by combining the GO3OS and the Background Air Pollution Monitoring Network. The GAW consists of a worldwide system of observing stations and supporting facilities providing data for atmospheric assessments, and also serving as an early warning system for chemical or physical changes in the Earth's atmosphere which could be cause for environmental concern. Such changes might involve a change in ozone, and therefore ultraviolet, levels, levels of greenhouse gases, or precipitation chemistry, the culprit in the world's acid rain woes.
Organization
The GAW consists of a coordinated system of various components, prominent among which are:
measurement stations;
calibration and data quality centres;
data centres;
external scientific groups.
Measurement stations
More than 65 countries currently host and operate the GAW's global or regional measurement stations. There are also "contributing stations" that furnish additional data. Lately, satellite programmes have also become important to the GAW, providing atmospheric data that complement ground measurements.
Calibration and data quality centres
These have the job of ensuring that all data produced by the system measure up to international standards. This is achieved by assuring a rigorous adherence to standards established by scientific advisory groups and a strict enforcement of world calibration standards. A number of programmes such as education, workshops, calibration station visits and so on are provided within the GAW programme to enhance the performance of the human component of the GAW. This has become particularly important in recent years as quite a number of stations are now operating in developing countries where further education is often a luxury enjoyed only by a small élite.
Data centres
The Global Atmosphere Watch currently has six World Data Centres, each administered by its host nation, and each responsible for gathering and storing atmospheric data from measurement stations worldwide, and making it freely available to scientists in a number of different forms.
The six data centres are:
The World Ozone and UV radiation Data Centre (WOUDC), hosted by Environment Canada.
The World Data Centre for Greenhouse Gases (WDCGG), hosted by the Japan Meteorological Agency.
The World Data Centre for Aerosols (WDCA), hosted by the Norwegian Institute for Air Research (NILU).
The World Radiation Data Centre (WRDC), hosted by the Voeikov Main Geophysical Observatory, St Petersburg
The World Data Centre for Precipitation Chemistry (WDCPC) hosted by the Illinois State Water Survey
The World Data Centre for Remote Sensing of the Atmosphere (WDC-RSAT), hosted by the German Aerospace Centre (DLR).
External scientific groups
Scientific Advisory Groups (SAGs) have the job of managing and implementing the GAW programme. This includes establishing data quality objectives and standard operating procedures, and also providing guidelines and recommendations for achieving these things. Measurement methods and procedures also fall within the SAGs' domain. They are also charged with promoting twinning and training in developing countries.
References
External links
GAW Station Information System
Atmosphere of Earth
International climate change organizations
Meteorological data and networks
World Meteorological Organization |
2914911 | https://en.wikipedia.org/wiki/Modra%20Observatory | Modra Observatory | The Astronomical Observatory of Modra (), also known as Modra Observatory or the Astronomical and Geophysical observatory in Modra, is an astronomical observatory located in Modra, Slovakia. It is owned and operated by the Comenius University in Bratislava. The scientific research at the observatory is led by the Department of Astronomy, Physics of the Earth and Meteorology, Faculty of Mathematics, Physics and Informatics.
The asteroid 11118 Modra discovered at this observatory is named in the honor of the town.
About
The Astronomical and Geophysical observatory of Comenius University is located near the town of Modra and in the mountain range of Little Carpathians. The 3.5-hectare area contains several buildings and scientific instruments surrounded by beech forest. It lies on the middle trias quartzitic bedrock. It is accessible via a tourist trail or by the private paved road from Zochova chata. The main administrative building with the dome on the top contains the 0.60-metre Zeiss telescope with CCD camera and the 0.20-metre solar telescope with H-alpha filter. Within walking distance there are several buildings and pavilions with scientific devices, such as the magnetic pavilion (measurement of the Earth's magnetic field), the seismic cell with the seismograph, the solar telescope dome, the dome with the Schumann resonances registration device and the meteor pavilion of photographic and video meteor detection. The upper building with the 5-metre dome has a 0.70-metre reflecting telescope with CCD primarily for space debris research and registration devices for GPS and forward scatter meteor radar of the Bologna-Lecce-Modra network (transceiver-receiver-receiver). The lower building, standing next to the pond, consists of a small conference room and housing facility for guests. Since 1988, continuous weather and meteorological observations are done, therefore, the data provide a unique and homogeneous climate record of the site.
In 2012 open-air amphitheater with seating, screen, projector and sound system was built for the public outreach purposes.
Education and research
As a part of the Comenius University, the observatory provides research opportunity for students, and the staff offers guidance for the Master and PhD theses. The research is mainly aimed at the interplanetary matter. Until January 2014, 175 numbered and 34 unnumbered asteroids were discovered at the observatory including two Near Earth Objects 2005 GB34 and 2008 UW5. The observing time is mostly assigned for the photometry of asteroids and comets and astrometry. The first observation of a transiting extrasolar planet in Slovakia was performed at the observatory. The solar physics researchers perform solar prominence and chromosphere features observations in the H-alpha line.
The observatory is also a member of the European bolide network and it has been developing its own TV meteor detection grid. Besides photographic all-sky cameras, fish-eye all-sky semi-automated meteor detection devices are located at Modra observatory, near Tesárske Mlyňany and in Kysucké Nové Mesto. In addition to meteor detection, real time all-sky cameras detect other phenomena, such as atmospheric sprites and elves (TLE).
Proposed Wide Field Survey (ADAM-WFS)
Based on the study on detecting close approaching Near-Earth Asteroids scientists of the department proposed a wide-field survey called "Automated Detection of Asteroids and Meteoroids - Wide Field Survey" (ADAM-WFS) aimed at discovery of small asteroids in the Earth vicinity and orbital debris.
In contrast to current asteroid surveys that are based on narrower field of view but deeper limiting magnitude, ADAM-WFS will observe entire visible night sky three times per night and identify moving targets. This survey is also considered as a low-cost project. It will use existing and verified methods and techniques, such as Moving Object Processing Pipeline (used by Pan-STARRS, NEOWISE, LSST). The proposed survey is similar to Asteroid Terrestrial-impact Last Alert System. If funded, the telescope will be housed in the Solar dome.
References
External links
Astronomical and Geophysical Observatory in Modra
Department of Astronomy, Physics of the Earth and Meteorology, Comenius University
Automated Detection of Asteroids and Meteoroids - Wide Field Survey
Dušan Kalmančok and Juraj Tóth at Modra Observatory (Gallery)
Asteroid surveys
Astronomical observatories in Slovakia
Comenius University
Minor-planet discovering observatories
1988 establishments in Czechoslovakia |
2920924 | https://en.wikipedia.org/wiki/Room%20Temperature%20%28novel%29 | Room Temperature (novel) | Room Temperature is Nicholson Baker's second book, and continues the genre established in his first novel The Mezzanine, though this time the action spans a few minutes at the narrator's home (in Quincy, Massachusetts).
Mike is feeding his baby daughter, "the Bug", as her head rests in the crook of his arm. He blows in the direction of a mobile; twenty seconds and two dozen pages later, he is surprised to see the mobile move. Mike's thoughts wander as he contemplates, for example, the possibility of admitting to one's wife that one has been picking one's nose, or the juxtaposition of Debussy and Skippy peanut butter jars in a symphonic poem. The novel was received warmly but without great enthusiasm, as an enjoyable if slightly demure domestic follow-up to The Mezzanine.
External links
Room Temperature Quotes
Room Temperature on J-Walk
1990 American novels
Novels by Nicholson Baker
Novels set in Massachusetts
Quincy, Massachusetts
Novels set in one day |
2921783 | https://en.wikipedia.org/wiki/Royal%20Observatory%2C%20Edinburgh | Royal Observatory, Edinburgh | The Royal Observatory, Edinburgh (ROE) is an astronomical institution located on Blackford Hill in Edinburgh. The site is owned by the Science and Technology Facilities Council (STFC). The ROE comprises the UK Astronomy Technology Centre (UK ATC) of STFC, the Institute for Astronomy of the School of Physics and Astronomy of the University of Edinburgh, and the ROE Visitor Centre.
The observatory carries out astronomical research and university teaching; design, project management, and construction of instruments and telescopes for astronomical observatories; and teacher training in astronomy and outreach to the public. The ROE Library includes the Crawford Collection of books and manuscripts gifted in 1888 by James Ludovic Lindsay, 26th Earl of Crawford. Before it moved to the present site in 1896, the Royal Observatory was located on Calton Hill, close to the centre of Edinburgh, at what is now known as the City Observatory.
History
Calton Hill
The University of Edinburgh in 1785 and by Royal Warrant of George III created the Regius Chair of Astronomy and appointed Robert Blair first Regius Professor of Astronomy. After his death in 1828 the position remained vacant until 1834. In 1811 private citizens had founded the Astronomical Institution of Edinburgh with John Playfair – professor of natural philosophy – as its president. The Institution acquired grounds on Calton Hill to build an observatory, which was designed by John's nephew William Henry Playfair; it remains to this day as the Playfair building of the City Observatory.
During his visit of Edinburgh in 1822, George IV bestowed upon the observatory the title of "Royal Observatory of King George the Fourth". In 1834 – with Government funding – the instrumentation of the observatory was completed. This cleared the way to uniting the observatory with the Regius Chair, and Thomas Henderson was appointed the first Astronomer Royal for Scotland and second Regius Professor of Astronomy. The main instruments of the new observatory were a 6.4-inch (16 cm) transit telescope and a 3.5-inch (9 cm) azimuth circle.
In 1852 Charles Piazzi Smyth – second Astronomer Royal for Scotland – came up with the idea of building astronomical observatories on high mountains with good weather. He travelled to Tenerife a few years later for site testing. Nothing came of it until about 100 years later, when this mode of operation became common practice the world over. A time service was established in 1858. Timings of star transits were used to keep the observatory clock accurate. The clock was wired up to control the drop of a time ball on Nelson's Monument. This is visible from the port of Leith, thus providing accurate time for shipping. Another wire led to a time gun on Edinburgh Castle.
Chronic underfunding by the Government eventually led to Smyth's resignation in 1888. The Government then intended to close the Royal Observatory and to abolish the post of Astronomer Royal for Scotland.
Blackford Hill
When the Earl of Crawford learned of the plans to close the Royal Observatory, he offered to give the instruments of his own Dunecht observatory and his unique astronomical library to the nation on condition that the Government build and maintain a new Royal Observatory to replace the one on Calton Hill. Ralph Copeland was appointed third Astronomer Royal for Scotland and oversaw the move of the two observatories from Dunecht and Calton Hill to Blackford Hill. The new site was opened in April 1896.
The instruments to move into the domes were a 15-inch (38 cm) refractor (East Dome) and a 24-inch (0.6 m) reflector (West Dome). An 8.5-inch (22 cm) transit circle was housed in a separate building further west. The time service continued to control the time ball on Calton Hill and the time gun on Edinburgh Castle by telegraph wire. It also controlled a time gun in Dundee and a clock at Rosyth dockyard. In the 1910s and 1920s research at the ROE led to more accurate pendulum clocks, which remained in service until they had to give way to quartz clocks in the 1960s.
On May 21st, 1913, at 01:00, a bomb planted by suffragettes detonated No one was inside the building but was damage to floors and stone walls.
During the first half of the 20th century the ROE pursued the new fields of photographic and photoelectric recording of stellar positions, brightnesses and spectra. From the 1950s onwards the ROE has concentrated even more on instrumentation and automation. In 1965 the ROE moved from the responsibility of the Scottish Office into the new Science Research Council (SRC), which in 1981 became the Science and Engineering Research Council (SERC).
Outstations and national facilities
From 1961 to 1973 the ROE's Earlyburn Outstation some 20 miles (30 km) south of Edinburgh was used for optical tracking of artificial satellites. From 1967 to 1976 the observatory operated a 16/24-inch (0.4/0.6 m) Schmidt camera – matching the one in Edinburgh – at its Monte Porzio Catone observing station near Rome. A division of labour developed: By 1976 the ROE as an SRC/SERC establishment spent most of its resources on running and supporting national facilities, while astronomical research was left to the university's Department of Astronomy.
The ROE operated the UK Schmidt Telescope (UKST) since it was opened in 1973. This took photographic plates in blue light of the entire southern sky. Together with red-light plates taken by the European Southern Observatory (ESO) they form the ESO/SERC Southern Sky Survey, which in turn extends the Palomar Observatory Sky Survey beyond its southern limit. In 1988 the telescope was handed over to the Anglo-Australian Observatory, which until 2010 operated it for Australia and the United Kingdom (UK); in July 2010, the Australian Astronomical Observatory was formed, to operate the telescope as part of a facility entirely under Australian control. The photographic laboratory and plate library for the UKST remained at the ROE in Edinburgh.
Since 1967 the ROE had been operating a machine (GALAXY – General Automatic Luminosity And X-Y) to digitise photographic plates. After the opening of the UKST, this was upgraded to become the COSMOS (COordinates, Sizes, Magnitudes, Orientations and Shapes) machine in 1975. It operated until 1993 and was replaced by a new SuperCOSMOS machine. When in 1980 the Starlink Project was formed to support astronomical image processing in the UK, the ROE became one of the six original nodes of the Starlink network.
Over the years 1973–1979 the ROE built the 3.8-metre UK Infrared Telescope (UKIRT) on Mauna Kea in Hawaii. This is an early example of the use of thin mirrors in large telescopes. The ROE operated UKIRT in cooperation with the University of Hawaii and built instruments for it, including the first ever common-user infrared camera. In 1987 the James Clerk Maxwell Telescope (JCMT) – also on Mauna Kea – was handed over to the ROE after the Rutherford Appleton Laboratory had completed its construction. The JCMT is a 15-metre diameter, millimetre- and sub-millimetre-wavelength telescope, which was run by a partnership of the UK, the Netherlands and Canada until 2014.
Reviews and international involvement
After Malcolm Longair – ninth Astronomer Royal for Scotland – left in 1990, astronomy in Edinburgh underwent a period of re-organisation and uncertainty. Andrew Lawrence became Regius Professor of Astronomy in the University of Edinburgh, whereas the title of Astronomer Royal for Scotland went to John Brown of the University of Glasgow. For a while Paul Murdin was acting director of the ROE. In 1993 the observatories of the UK – the Royal Greenwich Observatory (RGO), the Royal Observatory Edinburgh, the Isaac Newton Group of Telescopes, and the Joint Astronomy Centre in Hawaii (operating UKIRT and JCMT) – came under the single directorship of Alec Boksenberg, until then director of the RGO.
In 1994 the SERC was split up and the ROE became part of the Particle Physics and Astronomy Research Council (PPARC). In 1995 the merged observatories were dissolved into four independent entities. Having lost the UKST in 1988 – the ROE now also lost the UKIRT and the JCMT, operated by the independent Joint Astronomy Centre. ROE retained its role of building instruments for telescopes and satellites. It also became the UK project office for the construction of the Gemini Observatory, a pair of 8.1-metre telescopes run by seven countries.
A review of the Royal Observatories in 1996 concluded that the running of observatories and building of instruments should be put out to competitive tender, raising the fear of privatisation or closure. In 1997 this came to a halt and instead it was decided to reduce the RGO and the ROE into a smaller single astronomy technology centre. In 1998 the RGO was closed, while the ROE escaped lightly: The Plate Library and SuperCOSMOS machine were handed over to the University of Edinburgh, while the technology and project management expertise of the ROE – and to a lesser degree of the RGO – was retained by the newly formed UK Astronomy Technology Centre, which superseded the ROE as the Edinburgh establishment of the PPARC. (The ROE name remains as an umbrella term for UKATC; IfA, Edinburgh University; and the Visitor Centre).
Following the work on Gemini, the UK ATC was put in charge of managing the construction of the 4-metre f/1 VISTA (Visible and Infrared Survey Telescope for Astronomy). In the tradition of the UKST this is a survey telescope with a wide field of view. It works in the infrared and uses an array of 16 large infrared detectors. The telescope is located at the Paranal Observatory of the European Southern Observatory (ESO). In 1962 five European countries had founded the ESO; the UK joined in 2002 as the tenth member country. VISTA was handed over to ESO in 2009 as part of the UK's joining fee.
Directors
Also Astronomer Royal for Scotland and Regius Professor of Astronomy in the University of Edinburgh:
1834–1844, Thomas Henderson
1846–1888, Charles Piazzi Smyth
1889–1905, Ralph Copeland
1905–1910, Frank Dyson
1910–1937, Ralph Sampson
1938–1955, W.M.H. Greaves
1957–1975, Hermann Brück
1975–1980, Vincent Reddish
1980–1990, Malcolm Longair
Directors of ROE or UK ATC after amalgamation and dissolution of "The Royal Observatories":
1995–1997, Stuart Pitt
1998–2004, Adrian Russell
2005–2012, Ian Robson
2012–present, Gillian Wright
Present day
Telescopes
The original 1894 building includes two cylindrical copper domes on top of the East and West Towers. These were refurbished in 2010. The East Dome still shelters a 36-inch (0.9 m) Cassegrain reflector that was installed in 1930. This is part of the visitor centre exhibition, but is not operational any more. A 16/24-inch (0.4/0.6 m) Schmidt camera was installed in the West Dome in 1951. In 2010 this was removed to the National Museum of Scotland. The only working telescope is a Meade MAX 20in ACF (0.5 m) reflector in a hemispherical dome on top of the teaching laboratories. This telescope is used for undergraduate teaching. As of April 2012, the 1967 telescope and mount have been removed to Mid-Kent Astronomical Society; a replacement telescope will be installed later in 2012.
Crawford Collection
The Crawford Collection has first editions of most books relevant to the history of astronomy. This includes many works by the likes of Brahe, Copernicus, Galileo, Kepler and Newton. For the most part, Lord Lindsay collected this library in the 1870s and 1880s. An early addition was that of over 2500 items from Charles Babbage's library after his death in 1871.
Visitor Centre
The Visitor Centre hosts public events, including astronomy lectures and public open nights. The Observatory also holds classes, professional development courses, and other educational events for primary and secondary schools.
Gallery
See also
List of astronomical observatories
List of astronomical societies
References
Reddish, V.C. (1976). Royal Observatory Edinburgh, annual report for the year ended 30 September 1976. Science Research Council. . .
Brück, H.A. (1983). The story of astronomy in Edinburgh from its beginnings until 1975. Edinburgh University Press. .
Longair, M.S. (1983). Royal Observatory Edinburgh, research and facilities 1983. Royal Observatory, Edinburgh.
Longair, M.S. (1987). Royal Observatory Edinburgh, research and facilities 1987. Royal Observatory, Edinburgh. .
Pounds, K. (1995). "Alec Boksenberg moves to Cambridge University". Spectrum, Newsletter of the Royal Observatories, 9. p. 20. .
Wall, J. (1996). Spectrum, Newsletter of the Royal Greenwich Observatory, 16. .
Pitt, S. (1997). Royal Observatory Edinburgh, astronomy and technology. Royal Observatory, Edinburgh.
External links
Astronomical observatories in Scotland
Buildings and structures in Edinburgh
Category A listed buildings in Edinburgh
Minor-planet discovering observatories
1896 establishments in Scotland
Science and Technology Facilities Council
Science and technology in Edinburgh
University of Edinburgh |
2924177 | https://en.wikipedia.org/wiki/Ridge%20%28meteorology%29 | Ridge (meteorology) | In meteorology a ridge or barometric ridge is an elongated area of relatively high atmospheric pressure compared to the surrounding environment, without being a closed circulation. It is associated with an area of maximum anticyclonic curvature of wind flow. The ridge originates in the center of an anticyclone and sandwiched between two low-pressure areas, and the locus of the maximum curvature is called the ridge line. This phenomenon is the opposite of a trough.
Description
Ridges can be represented in two ways:
On surface weather maps, the pressure isobars form contours where the maximum pressure is found along the axis of the ridge.
In upper-air maps, geopotential height isohypses form similar contours where the maximum defines the ridge.
Related weather
Given the direction of the winds around an anticyclonic circulation and the fact that weather systems move from west to east:
ahead of an upper-ridge, the airflow that comes from the polar regions and brings cold air.
behind the upper-ridge line, the flow that comes from the equator and brings mild air.
Surface ridges, just like highs, generate fair weather because they develop under wind convergence in the negative vorticity advection zone ahead of the upper-level ridge. The vertical downward air motion then gives a divergence of the winds near the surface. The subsidence of the air causes a warming in the column compared to the previous environment and therefore a drying of it because its relative humidity decreases, which has the effect of clearing the sky.
Subtropical ridge
An important atmospheric ridge is the subtropical ridge. It is a series of ridges near the horse latitude characterized by mostly calm winds, which act to reduce air quality under its axis by causing fog overnight, and haze during daylight hours as a result of the stable atmosphere found near its location. The air descending from the upper troposphere flows out from its center at surface level toward the upper and lower latitudes of each hemisphere, creating both the trade winds and the westerlies. It helps steer tropical cyclones and the monsoon.
Ridge blocking
Blocks in meteorology are large-scale patterns in the atmospheric pressure field that are nearly stationary, effectively "blocking" or redirecting migratory cyclones. These blocks can remain in place for several days or even weeks, causing the areas affected by them to have the same kind of weather for an extended period of time (e.g. precipitation for some areas, clear skies for others). Upper ridges are often associated with such blocks, particularly in Omega blocks.
References
Atmospheric dynamics
Atmospheric circulation
Synoptic meteorology and weather |
2924238 | https://en.wikipedia.org/wiki/Consell%20Observatory | Consell Observatory | Consell Observatory ( and ; observatory code: 176) is an astronomical observatory owned and operated by the Latin American League of Astronomy. It is located at an altitude of in Consell on Majorca island, which is part of Spain.
Discoveries
The discovery of asteroid in 2004, is credited to the observatory. Other discoveries made at the observatory include the asteroids , , and which are credited to astronomer Rafael Pacheco and, in one case, to his collaborator Ángel López Jiménez.
See also
Astronomical Observatory of Mallorca (OAM)
External links
Consell Observatory (Spanish)
Astronomical observatories in Spain
Buildings and structures in Mallorca
Minor-planet discovering observatories |
2925371 | https://en.wikipedia.org/wiki/Radiative%20transfer | Radiative transfer | Radiative transfer (also called radiation transport) is the physical phenomenon of energy transfer in the form of electromagnetic radiation. The propagation of radiation through a medium is affected by absorption, emission, and scattering processes. The equation of radiative transfer describes these interactions mathematically. Equations of radiative transfer have application in a wide variety of subjects including optics, astrophysics, atmospheric science, and remote sensing. Analytic solutions to the radiative transfer equation (RTE) exist for simple cases but for more realistic media, with complex multiple scattering effects, numerical methods are required.
The present article is largely focused on the condition of radiative equilibrium.
Definitions
The fundamental quantity that describes a field of radiation is called spectral radiance in radiometric terms (in other fields it is often called specific intensity). For a very small area element in the radiation field, there can be electromagnetic radiation passing in both senses in every spatial direction through it. In radiometric terms, the passage can be completely characterized by the amount of energy radiated in each of the two senses in each spatial direction, per unit time, per unit area of surface of sourcing passage, per unit solid angle of reception at a distance, per unit wavelength interval being considered (polarization will be ignored for the moment).
In terms of the spectral radiance, , the energy flowing across an area element of area located at in time in the solid angle about the direction in the frequency interval to is
where is the angle that the unit direction vector makes with a normal to the area element. The units of the spectral radiance are seen to be energy/time/area/solid angle/frequency. In MKS units this would be W·m−2·sr−1·Hz−1 (watts per square-metre-steradian-hertz).
The equation of radiative transfer
The equation of radiative transfer simply says that as a beam of radiation travels, it loses energy to absorption, gains energy by emission processes, and redistributes energy by scattering. The differential form of the equation for radiative transfer is:
where is the speed of light, is the emission coefficient, is the scattering opacity, is the absorption opacity, is the mass density and the term represents radiation scattered from other directions onto a surface.
Solutions to the equation of radiative transfer
Solutions to the equation of radiative transfer form an enormous body of work. The differences however, are essentially due to the various forms for the emission and absorption coefficients. If scattering is ignored, then a general steady state solution in terms of the emission and absorption coefficients may be written:
where is the optical depth of the medium between positions and :
Local thermodynamic equilibrium
A particularly useful simplification of the equation of radiative transfer occurs under the conditions of local thermodynamic equilibrium (LTE). It is important to note that local equilibrium may apply only to a certain subset of particles in the system. For example, LTE is usually applied only to massive particles. In a radiating gas, the photons being emitted and absorbed by the gas do not need to be in a thermodynamic equilibrium with each other or with the massive particles of the gas in order for LTE to exist.
In this situation, the absorbing/emitting medium consists of massive particles which are locally in equilibrium with each other, and therefore have a definable temperature (Zeroth Law of Thermodynamics). The radiation field is not, however in equilibrium and is being entirely driven by the presence of the massive particles. For a medium in LTE, the emission coefficient and absorption coefficient are functions of temperature and density only, and are related by:
where is the black body spectral radiance at temperature T. The solution to the equation of radiative transfer is then:
Knowing the temperature profile and the density profile of the medium is sufficient to calculate a solution to the equation of radiative transfer.
The Eddington approximation
The Eddington approximation is a special case of the two stream approximation. It can be used to obtain the spectral radiance in a "plane-parallel" medium (one in which properties only vary in the perpendicular direction) with isotropic frequency-independent scattering. It assumes that the intensity is a linear function of , i.e.
where is the normal direction to the slab-like medium. Note that expressing angular integrals in terms of simplifies things because appears in the Jacobian of integrals in spherical coordinates.
Extracting the first few moments of the spectral radiance with respect to yields
Thus the Eddington approximation is equivalent to setting . Higher order versions of the Eddington approximation also exist, and consist of more complicated linear relations of the intensity moments. This extra equation can be used as a closure relation for the truncated system of moments.
Note that the first two moments have simple physical meanings. is the isotropic intensity at a point, and is the flux through that point in the direction.
The radiative transfer through an isotropically scattering medium with scattering coefficient at local thermodynamic equilibrium is given by
Integrating over all angles yields
Premultiplying by , and then integrating over all angles gives
Substituting in the closure relation, and differentiating with respect to allows the two above equations to be combined to form the radiative diffusion equation
This equation shows how the effective optical depth in scattering-dominated systems may be significantly different from that given by the scattering opacity if the absorptive opacity is small.
See also
Absorption (electromagnetic radiation)
Atomic line spectra
Beer-Lambert law
Emission
List of atmospheric radiative transfer codes
Scattering
Radiative transfer equation and diffusion theory for photon transport in biological tissue
Spectral radiance
Specific intensity
Vector radiative transfer
References
Further reading
Radiometry
Electromagnetic radiation
Atmospheric radiation |
2926577 | https://en.wikipedia.org/wiki/Land%20terrier | Land terrier | A land terrier is a record system for an institution's land and property holdings. It differs from a land register in that it is maintained for the organisation's own needs and may not be publicly accessible.
Typically, it consists of written records related to a map. Modern practice involves the use of Geographic Information Systems.
In France the term "terrier" refers to feudal records associated with the Ancien Régime.
See also
Manorial roll
Urbarium
References
R P Croom-Johnson and G F L Bridgman. Taylor on Evidence. Twelfth Edition. 1931. Section 622 at page 1772.
"Ancient terriers, maps, etc". Archbold Criminal Pleading, Evidence and Practice, 1999 Edition, paragraph 9–44 at pages 1095 to 1096.
Thomas Starkie. "Terrier". A Practical Treatise of the Law of Evidence, and Digest of Proofs, in Civil and Criminal Proceedings. Third Edition. V and R Stevens and G S Norton. London. A Milliken. Dublin. 1842. Volume 1. Pages 238 to 241 and 251. Volume 2. Pages 1090 and 1091.
Robert Joseph Pothier. Translated by William David Evans. A Treatise on the Law of Obligations, or Contracts. Second American Edition. Robert H Small. Minor Street, Philadelphia. 1839. Volume 2. Page 125.
Samuel March Phillipps and Thomas James Arnold. "Terriers". A Treatise on the Law of Evidence. Tenth English Edition. Fourth American Edition. With notes by Cowen and Hill. By Isaac Edwards. Banks and Brothers. New York. 1859. Volume 2. Page 292 et seq.
Mark Bailey. The English Manor c 1200 to c 1500. Manchester University Press. Manchester and New York. 2002. Pages 18, 21, 42, 75, 76, 79.
Property management
Land tenure |
2927890 | https://en.wikipedia.org/wiki/Omega%20Speedmaster | Omega Speedmaster | Omega Speedmaster is a line of chronograph wristwatches produced by Omega SA. While chronographs have been around since the late 1800s, Omega first introduced this line of chronographs in 1957. Since then, many different chronograph movements have been marketed under the Speedmaster name. Astronaut Walter Schirra was the first person to wear one in space in 1962 during his Mercury-Atlas 8 mission. The manual winding Speedmaster Professional or "Moonwatch" is the best-known and longest-produced; it was worn during the first American spacewalk as part of NASA's Gemini 4 mission, and was the first watch worn by an astronaut walking on the Moon during the Apollo 11 mission. The Speedmaster Professional remains one of several watches qualified by NASA for spaceflight, and is still the only one so qualified for EVA. The Speedmaster line also includes other models, including analog-digital and automatic mechanical watches.
Early development
The Speedmaster was not originally designed for space exploration. Instead, it was introduced in 1957 as a sport and racing chronograph following on from the early chronographs of the 1920s and 1930s, including the Omega 28.9 chronograph, which was Omega's first small wrist chronograph, complementing Omega's position as the official timekeeper for the Olympic Games. The first Speedmaster model, the reference CK 2915, was powered by the Omega Calibre 321 movement. This movement was developed in 1946 by Albert Piguet of Lemania, which had been acquired in 1932 by Omega's parent company, Société Suisse pour l'Industrie Horlogère, (SSIH). The "Speedmaster" name was coined from the model's novel tachymeter scale bezel (in brushed stainless steel) and by the convention set by prior Omega brands Seamaster and Railmaster. The model established the series's hallmark 12-hour, triple-register chronograph layout, domed Plexiglas crystal (named Hésalite), and simple, high-contrast index markers; but, unlike most subsequent Speedmaster models, it used Omega's broad arrow hand set. In 1959, a second version, CK 2998, was released with a black aluminum base 1000 bezel and later in 2998-2, tachymeter 500 bezel and alpha hands. This was again updated in 1963 by references ST 105.002, which kept the alpha hands and then less than one year later ST 105.003 with straight baton hands and ST 105.012, the first Speedmaster with the "Professional" appellation on the dial, with an asymmetrical case to protect the chronograph pushers and crown. All of the early Speedmasters used the same Calibre 321 movement, which was only replaced in 1968/1969 with the introduction of the Calibre 861 movement, used in the "Moon watch". The watches used for Apollo 11's mission were the 1967 "pre-Moon" 321 versions.
Pilots
Chronographs were first developed for use in artillery for battle, but soon came to be indispensable for use in high performance machinery, specifically by pilots, but later also by race car drivers. Submariners, who also relied heavily on split second timing for what was essentially blind travel, were known for the use of chronographs. The ability to time, and therefore calibrate, fuel consumption, trajectory and other variables allowed for both more efficient travel as well as better pilots and race car drivers. When President Eisenhower decreed that test pilots would be the only permissible option for Project Mercury, the inclusion of a chronograph of some sort was virtually assured.
Use in space
Qualification tests
Three years before the Speedmaster's official qualification for space flight, astronaut Wally Schirra took his personal CK 2998 aboard Mercury-Atlas 8 (Sigma 7) on October 3, 1962. That same year, according to an apocryphal anecdote repeated by Omega press materials and trade publications, a number of commercial chronograph wristwatches were furtively purchased from Corrigan's, a Houston jeweler, to evaluate their use for the Gemini and Apollo Programs. James Ragan, a former NASA engineer responsible for Apollo flight hardware testing, contradicted this story, calling it a "complete invention". Instead, bids were officially solicited of several brands already familiar to the pilots who were joining the growing astronaut corps. Brands under official consideration included Breitling, Rolex, and Omega, as well as others that produced mechanical chronographs. Hamilton submitted a pocket watch and was disqualified from consideration, leaving three contenders: Rolex, Longines-Wittnauer, and Omega. These watches were all subjected to tests under extreme conditions:
High temperature: 48 hours at followed by 30 minutes at
Low temperature: Four hours at
Temperature cycling in near-vacuum: Fifteen cycles of heating to for 45 minutes, followed by cooling to for 45 minutes at 10−6 atm
Humidity: 250 hours at temperatures between and at relative humidity of 95%
Oxygen environment: 100% oxygen at 0.35 atm and 71 °C for 48 hours
Shock: Six 11 ms 40 g shocks from different directions
Linear acceleration: from 1 to 7.25 g within 333 seconds
Low pressure: 90 minutes at 10−6 atm at , followed by 30 minutes at
High pressure: 1.6 atm for one hour
Vibration: three cycles of 30 minutes vibration varying from 5 to 2000 Hz with minimum 8.8 g impulse
Acoustic noise: 30 minutes at 130 dB from 40 to 10,000 Hz
All chronographs tested were mechanical hand-wound models. Neither the first automatic chronograph nor the first quartz watch would be available until 1969, well after the space program was underway. The evaluation concluded in March 1965 with the selection of the Speedmaster, which survived the tests while remaining largely within 5 seconds per day rate.
Gemini program
Gus Grissom and John Young wore the first officially qualified Speedmasters on Gemini 3 on March 23, 1965. In June of that year, Ed White made the first American space walk during Gemini 4 with a Speedmaster 105.003 strapped to the outside of the left-side sleeve of his G4C space suit. In order to accommodate the space suit, the watch was attached via a long nylon strap secured with Velcro. When worn on the wrist, the strap could be wound around several times to shorten its length. According to Omega, the company was surprised to learn of the Speedmaster’s role upon seeing a photograph of the EVA; however, ordering forms sent by NASA's Gemini 4 Flight Support Procurement Office to Omega's American agents in 1964 suggest that this anecdote may be exaggerated. These images would be widely used in Omega marketing materials from 1965 to 1967, establishing the popular connection between the Speedmaster and space exploration. Speedmasters were issued to all subsequent Gemini crews until the end of the program in 1966.
Apollo program
In 1966, Speedmaster reference 105.012 was updated to reference 145.012. These two models would be the two Speedmaster references known to have been worn on the Moon by Apollo astronauts, the original "Moon watches." Speedmasters were used throughout the early crewed Apollo program, and reached the Moon with Apollo 11. Ironically, these and prior models are informally known as "pre-Moon" Speedmasters, since their manufacture predate the Moon landings and lack the inscription subsequent models carry: "The First Watch Worn on the Moon".
Although Apollo 11 commander Neil Armstrong was first to set foot on the Moon, he left his 105.012 Speedmaster inside the lunar module as a backup, because the LM's electronic timer had malfunctioned. Buzz Aldrin elected to wear his, and so his Speedmaster became the first watch to be worn on the Moon. Later, he wrote of his decision:
Aldrin's Speedmaster was lost during shipping when he sent it to the Smithsonian Institution, its reference number being ST105.012, although it is sometimes erroneously reported as a 145.012.
To commemorate the success of the Apollo 11 mission, then-president Richard Nixon was presented with a gold Omega Speedmaster ref. BA 145.022 as gift. These were the first ever gold Omega Speedmasters, and only 1,014 of these Omega Speedmasters were ever made. Nixon's was engraved: “RICHARD M. NIXON”, “to mark man’s conquest of space with time, through time, on time”, and “PRESIDENT OF THE UNITED STATES”. He famously refused the gift citing its high value.
In 1970, after Apollo 13 was crippled by the rupture of a service module oxygen tank, Jack Swigert's Speedmaster was used to time the critical 14-second burn using the lunar module's descent propulsion system, which allowed for the crew's safe return. In recognition of this, Omega was awarded the Snoopy Award by the Apollo 13 astronauts for "dedication, professionalism, and outstanding contributions in support of the first United States Manned Lunar Landing Project."
In 1971, Apollo 15 commander Dave Scott's Speedmaster lost its Plexiglas crystal during EVA-2. For EVA-3, the final lunar surface EVA, he wore a Bulova Chronograph (model number 88510/01 with velcro-strap part number SEB12100030-202) that was not part of the normal mission equipment and that he had agreed to evaluate for the company at the request of a friend. Because of the commercial interests involved and the revelation of the Apollo 15 postage stamp incident, NASA withheld Bulova's name for years afterward. There is also evidence that Rolex GMTs were used as personal backup watches on the Apollo 13 & 14 missions.
In addition to issued crew watches, Apollo 17 carried an additional Speedmaster to lunar orbit as part of the heat flow and convection experiment conducted by Command Module Pilot Ronald Evans. This watch was sold for $23,000 at a Heritage auction in 2009.
Later models
In 1968, American insurance salesman Ralph Plaisted and three companions were the first confirmed expedition to reach the North Pole on snowmobiles. The team successfully used the same reference 145.012 Omega Speedmasters as the Apollo program along with sextants for navigation.
Also in 1968, Omega transitioned the caliber 321 movement to the new caliber 861, also designed by Albert Piguet, with the introduction of the reference 145.022 Speedmaster. The 861 was very similar to the 321, but replaced its column wheel switching mechanism with a cam and increased the beat rate from 18,000 to 21,600 vibrations per hour. Most Speedmaster Professional watches from 1968 to the present have used variants of this movement, including the modern rhodium-plated caliber 1861 and decorated exhibition calibers 863 and 1863. A standard Speedmaster Professional model with Plexiglas crystal, solid caseback with anti-vibration and anti-magnetic dust cover, tachymeter scale, without date or day complications, and powered by a caliber 861-based movement has been continuously produced since. The tritium-powered phosphorescent lume on the hands and index markers of the original watches were replaced at the end of the 1990s with non-radioactive pigments, but the fundamental design, dimensions, and mechanism of these watches have remained unchanged however one thing Omega comes under fire for is the none identical renders of there professional chronograph configuration appears more bold in advertisement unlike the final product which feature shortened chronograph configurations. In this form, the basic Speedmaster line has remained flight-qualified for NASA space missions and EVAs, after re-evaluation by NASA in 1972 and for use in the Space Shuttle program in 1978. The current such model is reference 311.30.42.30.01.005 (since 2014).
Omega has produced a large number of commemorative and limited edition variants of the basic "Moon watch" design, celebrating important anniversaries and events, emblazoned with the different patches for the space missions it was issued for, or evoking its motor sport roots with various racing patterns. It has also released many models made with various precious metals, jewels, and alternative dial colors for the luxury market.
Over the years, Omega has also sought to improve functional aspects of the basic Speedmaster Professional. In 1969, it produced the Speedmaster Professional Mk II, with shrouded lugs and a flat, anti-reflective mineral glass crystal. In 1970, Omega launched the Alaska Project under Pierre Chopard, which changed the dial of the original Speedmaster Professional from black to white and created a removable anodized aluminum housing to shield the watch from a wider range of temperatures. In 1971 and 1973, Omega turned to automatic mechanisms on the Speedmaster Automatic MkIII and MkIV models alongside Speedsonic Electronic Chronometer Chronograph (marketing as a Speedmaster) other non-Speedmaster Chronographs such as the Omega Bullhead. However none of these proved as popular or long-lasting as the basic Speedmaster Professional "Moon watch". A variety of other types of watches have used the Speedmaster brand, including many different automatic day and day-date models, the tuning fork movement Speedsonic line, and the digital LCD Speedmaster Quartz (the Speedsonic and LCD Speedmaster where also prototyped in ten examples each under the Alaska project but not taken up by NASA). The digital-analog Speedmaster X-33 was produced in 1998; it was qualified for space missions by NASA and flown on the Mir space station and Space Shuttle Columbia during STS-90 later that year.
In September 2019, Omega introduced a reissue of the calibre 321. The new calibre 321 was designed to replicate the same mechanism and design as the original 321. The new calibre was manufactured with modern metals and computer-aided manufacturing in a designated workshop.
Most recently, in January 2021, Omega announced it would update the standard-production Speedmaster Professional with a new movement and a subtle design refresh, including a step dial and dot-over-90 bezel. Calibre 1861 has been officially discontinued, replaced with calibre 3861, featuring a co-axial escapement and Master Chronometer certification.
Omega Speedmaster Automatic
Omega Speedmaster Automatic (informally known as the Speedmaster Reduced) is a line of chronograph wristwatches based on the Omega Speedmaster and produced by Omega SA. The Speedmaster Reduced was first introduced in 1988 as a smaller, cheaper version of the Omega Speedmaster. With a case that measures 39mm in diameter it is smaller than its big brother the Speedmaster Professional which has a case size of 42mm. The Speedmaster Reduced went out of production in 2009.
Starting with a base movement of the Omega 3220, a Dubois Depraz chronograph module is mounted on top.
Automatic Racing models
The Speedmaster has also seen iterations within motor racing, in particular the Automatic 'Racing' models. This differ from the Professional models by having a slightly smaller case (38mm as opposed to 42mm). Michael Schumacher was one of the brand's key representatives during the early 2000s and had his own dedicated line of models.
Omega did produce at least one Racing model with the 42mm Speedmaster Professional case in 2003. The watch has the exclusive Omega calibre 3301 movement, a carbon fibre dial, and was given the model number 3552.59.
Notable wearers
Joe Biden, 46th President of the United States of America
Wally Schirra, one of the first Americans in space; also the first astronaut to wear a Speedmaster on a space mission in 1962
Neil Armstrong, first man on the Moon as an Apollo 11 astronaut
Buzz Aldrin, second man on the Moon as an Apollo 11 astronaut
Ed White, first American to walk in space as a Gemini 4 astronaut; later perished in the ill-fated Apollo 1 mission
Tom Hanks, actor; famously wore a Speedmaster Professional while portraying Jim Lovell in Apollo 13
Ron Howard, director
Ralph Ellison, author of Invisible Man
Daniel Craig, actor
George Clooney, actor
Steve Carell, actor
Ryan Reynolds, actor
Eddie Redmayne, actor
James Corden, actor and late night talk show host
Ed O'Neill, actor
Dennis Quaid, actor
Richard Hammond, presenter from Top Gear and The Grand Tour
Adam Savage, presenter on the American TV series MythBusters
Rory McIlroy, professional golfer
Willem-Alexander, King of the Netherlands
Mark Knopfler, musician
Antoni Porowski, presenter of Queer Eye
Jeff Bezos, Founder of Amazon
Gallery
See also
Science and technology in Switzerland
Swiss Space Office
COSC
Dive watch
Omega Seamaster
References
Bibliography
.
.
Grégoire Rossier and Anthony Marquié (2014), Moonwatch Only, 60 years of Omega Speedmasters
External links
, a detailed table of Speedmaster models
.
Omega Speedmaster Professional Chronographs, NASA History page.
speedmaster-mission.net, by Jean-Michel
NASA blueprint SEB12100030 for velcro watchbands (sheet 1 of 2) Material specifications, notes and revisions.
NASA blueprint SEB12100030 for velcro watchbands (sheet 2 of 2) Assembly diagrams.
The Right Stuff: Inside the Omega Speedmaster Professional - Part 1, by Jack Forster
The Right Stuff: Inside the Omega Speedmaster Professional - Part 2, by Jack Forster
Legendary Watches: The Omega Speedmaster, by Matthew Boston
Legend of The Moon Watch: Omega Speedmaster
The truth about the real Armstrong’s and Aldrin’s Speedmaster references and how the Omega Speedmaster became the Moonwatch by Monochrome-Watches
The history of the Omega Speedmaster - Part 1, the early Pre-Moons by Monochrome-Watches
Moonwatch Only by Grégoire Rossier and Anthony Marquié
Omega watches
Products introduced in 1957
Apollo program hardware |
2929349 | https://en.wikipedia.org/wiki/The%20Penultimate%20Peril | The Penultimate Peril | The Penultimate Peril is the twelfth novel in the children's novel series A Series of Unfortunate Events by Lemony Snicket.
Plot
The Baudelaire orphans, Violet, Klaus and Sunny are travelling with pregnant V.F.D. member Kit Snicket to Hotel Denouement, the last safe place for volunteers to gather. She tells them that, prior to V.F.D.’s gathering in two days, they will be disguised as concierges to observe the mysterious 'J.S.,’ in order to identify him as a volunteer or a villain of V.F.D. The hotel's managers are identical triplets Frank, Dewey and Ernest - Frank is a volunteer, while Ernest is on the opposing side as a villain, and Dewey is someone of legend who many do not believe exists. He has created a book cataloging all information of the V.F.D.
During their first day of disguised employment, the Baudelaires split up to assist the hotel's guests - Violet assists Esmé Squalor and Carmelita Spats by bringing them a harpoon gun, Klaus assists Charles and Sir (the owners of the Lucky Smells Lumbermill) by escorting them to the sauna while also hanging flypaper outside a window for one of the managers, and Sunny assists Hal (an employee at Heimlich Hospital), Vice-Principal Nero, Ms. Bass and Mr. Remora (teachers at Prufrock Preparatory School) while locking a V.F.D device onto a door of the laundry room, converting it into a Vernacularly Fastened Door - all the guests discuss the mysterious J.S. and together the siblings discuss who asked for what, as each of them run into a separate manager.
Klaus concludes that Carmelita Spats requested the harpoon gun to shoot down a bird carrying the sugar bowl, as Sunny mentioned that Hal and a manager were discussing the sugar bowl (an object both volunteers and villains are seeking for unknown reasons) and the Medusoid Mycelium (a deadly fungus parasite they encounter in the previous book) - the flypaper would retrieve the bird's body, and the sugar bowl would fall into the laundry room, in which the room's door was converted into a Vernacularly Fastened Door.
Shortly after his proposal, a man encounters them and reveals himself as Dewey Denouement, the third of the secretly three brothers. He also tells them that a pool reflection of the hotel is the actual safe place, as the hotel's words and structure were designed backward to reflect the actual words onto the pool - beneath the pool is an underwater catalog containing crucial information concerning V.F.D. They are then encountered by Jerome Squalor and Justice Strauss, who have joined V.F.D. after believing messages being sent to J.S were being addressed to them.
While the four re-enter the hotel, Count Olaf intercepts them, and threatens Dewey with a harpoon gun for the code needed to access the door. While the children attempt to prevent the killing, Mr. Poe suddenly enters, causing Olaf to shove the weapon into the Baudelaires' hands — surprised, they drop the gun, causing it to discharge and kill Dewey. As a crowd arrives, the Baudelaires and Olaf are sent to court; however, everyone except for the judges must be blindfolded for it to be legal. The other two judges are later revealed to be The Man with a Beard But No Hair and The Woman With Hair But No Beard. During the hearing, however, the Baudelaires realize that it was a trick for Olaf to kidnap Justice Strauss, pursue the sugar bowl, and burn the hotel and its inhabitants. Klaus, realizing that the sugar bowl was actually underneath the pool, reveals the door code to Olaf. Violet gains access to a boat for all of them to escape the authorities, while Sunny assists in burning the hotel as a signal to V.F.D. that the gathering has been canceled due to the invasion of enemies. The Baudelaires, along with Justice Strauss, attempt to alert everyone about the fire; it is unknown whether anyone escapes.
Shortly after the authorities arrive, the orphans, along with Olaf, are about to disembark by sea; however, Justice attempts to intervene. Sunny apologetically bites her hand, and the four sail away from the area, and out to sea.
Foreshadowing
In the last picture of The Penultimate Peril, Count Olaf and the Baudelaire children sail away from the smoking shore aboard a large ship.
Unlike the other novels, there are no hints or foreshadowing to the next book.
Translations
Dutch: "" (The Penultimate Peril)
Finnish: "" (At the Borders of Solution), WSOY, 2006,
French: "" (The Penultimate Peril)
German: ”” (The Outlandish Hotel)
Japanese: "終わりから二番目の危機" (The Second-to-Last Crisis), Soshisha, 2007,
Norwegian: ”Den tolvte trussel” (The Twelfth Threat), Tor Edvin Dahl, Cappelen Damm, 2006,
Persian: “خطر ما قبل اخر" (The Penultimate Risk)
Polish: ”” (The Penultimate Trap)
Russian: "" (Penultimate Scrape), Azbuka, 2007,
Thai: "หายนะก่อนปิดฉาก", Nanmeebooks Teen, 2006,
Adaptation
The book was adapted into the fifth and sixth episodes of the third season of the television series adaptation produced by Netflix.
References
2005 American novels
Books in A Series of Unfortunate Events
HarperCollins books
Sequel novels
2005 children's books
American novels adapted into television shows
Novels set in hotels
Novels set in one day
Children's books set in hotels |
2930200 | https://en.wikipedia.org/wiki/Santa%20Catarina%20%28ship%29 | Santa Catarina (ship) | Santa Catarina was a Portuguese merchant ship, a 1500-ton carrack, that was seized by the Dutch East India Company (also known as VOC) on 25 February 1603 off Singapore. She was such a rich prize that her sale proceeds increased the capital of the VOC by more than 50%. From the large amounts of Ming Chinese porcelain captured in this ship, Chinese pottery became known in Holland as Kraakporselein, or "carrack-porcelain" for many years.
The capture of Santa Catarina
At dawn on 25 February 1603 three Dutch ships under the command of Admiral Jacob van Heemskerck spotted the carrack at anchor off the Eastern coast of Singapore. The Portuguese ship, captained by Sebastian Serrão, was travelling from Macau to Malacca, loaded with products from China and Japan, including 1200 bales of Chinese raw silk, worth 2.2 million guilders. The cargo was particularly valuable because it contained several hundred ounces of musk. After a couple of hours of fighting, the Dutch managed to subdue the crew who forfeited the cargo and the ship, in return for the safety of their lives.
The Admiralty of Amsterdam's subsequent decision to take the ship and her cargo as a prize, despite Portugal's demands, became the casus belli for the Dutch–Portuguese War that lasted until 1663, and eventually ended the Portuguese monopoly on trade in the East Indies. The Dutch, who in previous years had learnt about the lucrative trade routes in the East, were now attempting to appropriate some of that wealth for themselves.
Santa Catarina and Mare Clausum versus Mare Liberum controversy
Though Heemskerk did not have authorization from the company or the government to initiate the use of force, many shareholders were eager to accept the riches that he brought back to them. Not only was the legality of keeping the prize questionable under Dutch statute, but a faction of shareholders (mostly Mennonite) in the Company also objected to the forceful seizure on moral grounds, and of course, the Portuguese demanded the return of their cargo. The scandal led to a public judicial hearing and a wider campaign to sway public (and international) opinion. It was in this wider contexst that representatives of the Company called upon jurist Hugo Grotius to draft a polemical defence of the seizure.
Grotius sought to ground his defense of the seizure in terms of the natural principles of justice. One chapter of his long theory-laden treatise entitled De Jure Prædæ made it to the press in the form of the influential pamphlet, Mare Liberum (The Free Sea).
In Mare Liberum, published in 1609, Grotius adapted the principle originally formulated by Francisco de Vitoria and further developed by Fernando Vázquez de Menchaca (cf. the School of Salamanca), that the sea was international territory, against the Portuguese Mare Clausum (closed sea) policy, and all nations were free to use it for seafaring trade. Grotius, by claiming 'free seas', provided suitable ideological justification for the Dutch breaking up of various trade monopolies through its formidable naval power.
England, competing fiercely with the Dutch for domination of world trade, opposed this idea, redefining the Mare Clausum principles. As conflicting claims grew out of the controversy, maritime states came to moderate their demands and base their maritime claims on the principle that it extended seawards from land. A workable formula was found by Cornelius Bynkershoek in his De dominio maris (1702), restricting maritime dominion to the actual distance within which cannon range could effectively protect it. This became universally adopted and developed into the three-mile limit.
See also
List of longest wooden ships
Cinco Chagas
Henry Grace à Dieu
Baochuan
Rahīmī
Ganj-i-Sawai
Javanese jong
Notes
References
Further reading
Age of Sail merchant ships of Portugal
Ships of the Dutch East India Company
Santa Catarina (1603)
1603
1604 in law
1604 in Europe
Maritime incidents in 1603
Law of the sea
Carracks
Hugo Grotius |
2930872 | https://en.wikipedia.org/wiki/LoJack | LoJack | LoJack is a stolen vehicle recovery and IoT connected car system that utilizes GPS and cellular technology to locate users' vehicles, view trip history, see battery levels, track speeding, and maintain vehicle health via a native app. Prior to selling a vehicle, LoJack dealers can use the system to manage and locate inventory, view and manage battery health, and recover stolen inventory.
Previous generation of the system utilized radio tracking signal. The system used a hidden mounted transceiver and a tracking computer installed in police cars and aircraft.
History
The original LoJack system was created and patented in 1979 by William Reagan, a former Medfield, Massachusetts police commissioner, who went on to establish LoJack Corporation in Medfield. Reagan served as the company's first CEO and Chairman. The name "LoJack" was coined to be the "antithesis of hijack", wherein "hijack" refers to the theft of a vehicle through force.
Legacy radio based system
The original LoJack was a hardware and radio based system designed to prevent theft of a vehicle and aid in the vehicle’s recovery by transmitting vehicle location to the LoJack receiver.
It was installed in the vehicle and connected to the starting mechanism such that only the original key would start the vehicle. It could also include the incorporation of a scheme whereby an additional step was required to activate the ignition. Prior to starting, it would require the activation of any number of the usual vehicle features such as the radio, headlight switch, or other switched device. Without knowledge of the proper procedure, it would be almost impossible to activate the ignition.
The core of the legacy LoJack system is a small, silent radio transceiver that is discreetly installed in a vehicle. Once installed, the unit and the vehicle's VIN are registered in a database that interfaces with the National Crime Information Center (NCIC) system used by federal, state and local law enforcement agencies throughout the United States. In the event of a theft, a customer reports the incident to the police, who make a routine entry into the state police crime computer, including the stolen vehicle's VIN. This theft report is automatically processed by LoJack network computers, triggering a remote command to the specific LoJack unit in the stolen vehicle.
The command activates the LoJack unit to start sending out signals to LoJack police tracking computers on board some police cars. Every police car so-equipped within a 3-5 mile radius of the signal source will be alerted. The tracking units will display an alphanumeric reply code and an indication of the approximate direction and distance to the stolen vehicle. Based on the reply code, the police can obtain a physical description of the vehicle, including make (brand), model, color, VIN and license plate number. Police aircraft can also be equipped with tracking computers; airborne units can receive the (line-of-sight) signals from further away than ground-based units. The signal is received in equipped police vehicles, utilizing a phased array antenna system, hence the four distinctive antennas on the roof. This provides the directional location tracking capabilities of the system.
In addition to automobile theft recovery, LoJack systems are used to recover stolen construction equipment and motorcycles.
In 1998, the company began offering its tracking system to the heavy machinery and construction industry, including entering into an agreement with Caterpillar.
By 2013, the LoJack system was reportedly operating in 28 states and the District of Columbia and in more than 30 countries. The company reported that more than 1,800 U.S. law enforcement agencies had LoJack tracking computers in their police vehicles. In November 2013, the company announced they were expanding tracking capabilities to parents, auto makers and insurance companies.
In March 2016, the company was acquired for $134 million by CalAmp, an Irvine, California-based provider of Internet of things (IoT) software applications, cloud services, data intelligence and telematics products and services.
Frequency
LoJack transmits on a radio (RF) carrier frequency of 173.075 MHz. Vehicles with the system installed send a 200 millisecond (ms) chirp every fifteen seconds on this frequency. When being tracked after reported stolen, the devices send out a 200 ms signal once per second. The radio frequency transmitted by LoJack is near the VHF spectrum used in North America by digital television channel 7, although there is said to be minimal interference due to the low power of radiation, brief chirp duration, and long interval between chirps.
Modern system
Modern transponder key based systems made the original LoJack starting system obsolete. The system marketed under the LoJack brand since 2021 is a cell phone/GPS based stolen vehicle tracking and recovery system. the device transmits data to the LoJack base and includes speed, location, and other data to aid in the vehicle’s recovery. Such information is also simultaneously sent to the vehicle owner’s computer or cell phone.
In March 2021, the vehicle intelligence company Spireon announced it had acquired the LoJack U.S. Stolen Vehicle Recovery business from CalAmp, joining LoJack users with "nearly 4 million active subscribers from over 20,000 current Spireon customers". CalAmp would still retain and continue to expand LoJack International, which operates as a subscription-based SaaS business, while also retaining ownership of the LoJack patents and trademarks. Under Spireon, LoJack technology moved from RF-based location to GPS and cellular-based technology, growing availability of the solution throughout the U.S. and Hawaii and expanding the solution from only stolen vehicle recovery into connected car technology for both dealers and consumers.
In 2023, a group of security researchers announced discovery of multiple software bugs affecting vehicles from nearly all major car brands, potentially enabling hackers to take full control of the affected cars. The most serious vulnerabilities were found in Spireon's fleet management software, which spans 15 million connected vehicles, and could have allowed remote control over a wide range of fleet vehicles, including those used by law enforcement. All identified bugs have since been fixed.
See also
Carjacking
Comparison of device tracking software
Connected car
LoJack for Laptops
Motor vehicle theft
Radio direction finder
Vehicle tracking system
References
Further reading
Automotive accessories
Companies based in Massachusetts
Motor vehicle theft
Security technology
Wireless locating
Geopositioning
Technology companies based in Massachusetts |
2931010 | https://en.wikipedia.org/wiki/Simplified%20perturbations%20models | Simplified perturbations models | Simplified perturbations models are a set of five mathematical models (SGP, SGP4, SDP4, SGP8 and SDP8) used to calculate orbital state vectors of satellites and space debris relative to the Earth-centered inertial coordinate system. This set of models is often referred to collectively as SGP4 due to the frequency of use of that model particularly with two-line element sets produced by NORAD and NASA.
These models predict the effect of perturbations caused by the Earth’s shape, drag, radiation, and gravitation effects from other bodies such as the sun and moon. Simplified General Perturbations (SGP) models apply to near earth objects with an orbital period of less than 225 minutes. Simplified Deep Space Perturbations (SDP) models apply to objects with an orbital period greater than 225 minutes, which corresponds to an altitude of 5,877.5 km, assuming a circular orbit.
The SGP4 and SDP4 models were published along with sample code in FORTRAN IV in 1988 with refinements over the original model to handle the larger number of objects in orbit since. SGP8/SDP8 introduced additional improvements for handling orbital decay.
The SGP4 model has an error ~1 km at epoch and grows at ~1–3 km per day. This data is updated frequently in NASA and NORAD sources due to this error. The original SGP model was developed by Kozai in 1959, refined by Hilton & Kuhlman in 1966 and was originally used by the National Space Surveillance Control Center (and later the United States Space Surveillance Network) for tracking of objects in orbit. The SDP4 model has an error of 10 km at epoch.
Deep space models SDP4 and SDP8 use only 'simplified drag' equations. Accuracy is not a great concern here as high drag satellite cases do not remain in "deep space" for very long as the orbit quickly becomes lower and near circular. SDP4 also adds Lunar–Solar gravity perturbations to all orbits, and Earth resonance terms specifically for 24-hour geostationary and 12-hour Molniya orbits.
Additional revisions of the model were developed and published by 2010 by the NASA Goddard Space Flight Center in support of tracking of the SeaWiFS mission and the Navigation and Ancillary Information Facility at the Jet Propulsion Laboratory in support of Planetary Data System for navigational purposes of numerous, mostly deep space, missions. Current code libraries use SGP4 and SDP4 algorithms merged into a single codebase in 1990 handling the range of orbital periods which are usually referred to generically as SGP4.
References
External links
Source code for algorithm implementations, and TLE interpretation in some cases:
python-sgp4 A Python Implementation of the sgp4 model with automatic downloading of TLE Elements from NORAD database.
PHP5 based on Gpredict
Java: SDP4 and predict4java
C++, FORTRAN, Pascal, and MATLAB.
go-satellite GoLang implementation of SGP4 model and helper utilities.
Orbital perturbations
North American Aerospace Defense Command
Computational physics
Japanese inventions |
2932854 | https://en.wikipedia.org/wiki/High%20Earth%20orbit | High Earth orbit | High Earth orbit (HEO) is a region of space around the Earth where satellites and other spacecraft are placed in orbits that are very high above the planet's atmosphere. This area is defined as an altitude higher than 35,786 km (22,236 mi) above sea level, which is the radius of a circular geosynchronous orbit. HEO extends to end of the Earth's sphere of influence. Satellites in HEO are primarily used for communication, navigation, scientific research, and military applications. A variety of satellites, such as TESS, have been placed in HEO.
One of the main benefits of HEO is that it provides a nearly unobstructed view of the Earth and deep space. This makes it an ideal location for astronomical observations and Earth monitoring. In addition, satellites in HEO can provide a continuous coverage of the Earth's surface, making it very useful for communication and navigation purposes.
There are four main reasons that most satellite are placed in lower orbits. First, a HEO can take a month or more per orbit. This is because HEOs are very large orbits and move at only 7000 mph. Meanwhile, a LEO (low Earth orbit) can take less than 90 minutes. So, for satellites that need to orbit quickly, HEO is not a good fit. Second, HEOs take far more energy to place a satellite into than LEOs. To place a satellite into HEO takes nearly as much energy as to place it into a heliocentric orbit. For example, an expended Falcon 9 can carry 50,000 pounds to LEO. However, it can only carry around 10,000 pounds to HEO. This means that it costs 5 times more to place a payload in HEO versus placing it in LEO. Third, HEOs are incredibly far from Earth. This means that there is a constant communication delay when sending signals to and from the satellite. This is actually because the signals can only travel at the speed of light. This means that it can take around 0.1 to 4.5 seconds in delay time each way. This makes it useless for internet, and hard to use for other things as well. The fourth reason is radiation. HEO is outside of the magnetic field of Earth. This means that there is far more radiation in HEO. As a result, spacecraft in HEO require specialized equipment and shielding to protect them from radiation. As a result, only satellites that require the unique characteristics of HEO use this orbit.
The development of HEO technology has had a significant impact on space exploration and has paved the way for future missions to deep space. The ability to place satellites in HEO has allowed scientists to make groundbreaking discoveries in astronomy and Earth science, while also enabling global communication and navigation systems.
Examples of satellites in high Earth orbit
See also
Ukrainian Optical Facilities for Near-Earth Space Surveillance Network
References
Earth orbits |
2935012 | https://en.wikipedia.org/wiki/Nekyia | Nekyia | In ancient Greek cult-practice and literature, a nekyia or nekya () is a "rite by which ghosts were called up and questioned about the future," i.e., necromancy. A nekyia is not necessarily the same thing as a katabasis. While they both afford the opportunity to converse with the dead, only a katabasis is the actual, physical journey to the underworld undertaken by several heroes in Greek and Roman myth.
In common parlance, however, the term "nekyia" is often used to subsume both types of event, so that by Late Antiquity for example "Olympiodorus ... claimed that three [Platonic] myths were classified as nekyia (an underworld story, as in Homer's Odyssey book 11)".
Questioning ghosts
A number of sites in Greece and Italy were dedicated wholly or in part to this practice. "The Underworld communicated with the earth by direct channels. These were caverns whose depths were unplumbed, like that of Heraclea Pontica." The most notable was the Necromanteion in the northwestern Greek town of Ephyra. Other oracles of the dead could be found at Taenaron and Avernus. Such specialized locations, however, were not the only places where necromancy was performed. One could also perform the rite at a tomb, for example. Among the gods associated with the nekyia rite are Hades, his wife Persephone, Hecate, and Hermes (in his capacity as psychopompus – one who escorted souls to Hades).
The Odyssey
The earliest reference to this cult practice comes from Book 11 of the Odyssey, which was called the Nekyia in Classical antiquity. Odysseus was instructed to "make a journey of a very different kind, and find your way to the Halls of Hades ... across the River of Ocean". There he consults the soul of the priest and prophet Teiresias about the means to return home to Ithaca, in a setting of "ghosts and dark blood and eerie noises, like a canvas of Hieronymous Bosch". He sacrifices a ram and an ewe so that "the countless shades of the dead and gone" would "surge around" him and then he meets and talks to the souls of the dead.
"The story of Odysseus's journey to Hades ... was followed ... by further accounts of such journeys undertaken by other heroes", although it is clear that, for example, "the [katabasis, "descent"] of Herakles in its traditional form must have differed noticeably from the Nekyia".
The Athenian playwright Aeschylus features the use of tombside nekyiai in his Persians and Libation Bearers.
Returning from the Underworld, from the House of Hades, alive represents the monumental feat a mere mortal could accomplish. In this, Aeneas surpasses Odysseus who merely journeys to the entrance of the Underworld to perform the ritual sacrifice needed to summon the spirits of the dead, the ghosts whose knowledge he seeks. Aeneas actually descends into the House of Hades and travels through the world of the dead.
Menippus and Lucian of Samosata
Lucian of Samosata is the author of a satirical dialogue titled Μένιππος ἢ Νεκυομαντεία, dating from 161–162 CE, which, as German classical philologist Rudolf Helm (1872-1966) argues, may be an epitome of the lost Nekyia of cynic philosopher Menippus. In The Lives of the Philosophers, Diogenes Laërtius lists the Nekyia among the thirteen works composed by Menippus (Vitae philosophorum, VI, 101). In Lucian's dialogue, Menippus, perplexed by the conflicting accounts of the afterlife put forward by Homer, Hesiod, the philosophers, and the tragic poets, decides to discover the truth for himself. He therefore enlists the help of a Babylonian Magus, named Mithrobarzanes, in order to visit the underworld. Mithrobarzanes performs a necromantic ritual, and the two descend to Hades, where they see Pyriphlegethon, Cerberus, the palace of Pluto, Charon, and the rest of the mythological machinery of the Greek underworld. Ultimately, the underworld setting serves Lucian as a vehicle for satire on not only the rich and powerful, but also the philosophers.
Jung
C. G. Jung used the concept of Nekyia as an integral part of his analytical psychology: "Nekyia ... introversion of the conscious mind into the deeper layers of the unconscious psyche". For Jung, "the Nekyia is no aimless or destructive fall into the abyss, but a meaningful katabasis ... its object the restoration of the whole man".
Jolande Jacobi added that "this 'great Nekyia' ... is interwoven with innumerable lesser Nekyia experiences".
Night sea-journey
Jung used the images of the Nekyia, of "the night journey on the sea ... descend[ing] into the belly of the monster (journey to hell)", and of Katabasis' (descent into the lower world)" almost interchangeably. His closest followers also saw them as indistinguishable metaphors for "a descent into the dark, hot depths of the unconscious ... a journey to hell and 'death – emphasising for example that "the great arc of the night sea journey comprises many lesser rhythms, lesser arcs on the same 'primordial pattern, just like the nekyia.
The post-Jungian James Hillman however made some clear distinctions among them:
Cultural references
"Thomas Mann's conception of the nekyia draws extensively from 'the doctrines of the East...Gnosticism, and Hellenism'".
Jung viewed Picasso's "early Blue Period ... as the symbol of 'Nekya', a descent into hell and darkness".
In 1937, English composer Michael Tippett planned a large choral work based on Jungian concepts, titled Nekyia. The work would become the basis of his secular oratorio, A Child of Our Time.
See also
Odyssey
Geography of the Odyssey
References
Death in Greek mythology
Odyssey
Necromancy
Hecate
Katabasis |
2936161 | https://en.wikipedia.org/wiki/Local%20search%20%28Internet%29 | Local search (Internet) | Local search is the use of specialized Internet search engines that allow users to submit geographically constrained searches against a structured database of local business listings. Typical local search queries include not only information about "what" the site visitor is searching for (such as keywords, a business category, or the name of a consumer product) but also "where" information, such as a street address, city name, postal code, or geographic coordinates like latitude and longitude. Examples of local searches include "Hong Kong hotels", "Manhattan restaurants", and "Dublin car rental". Local searches exhibit explicit or implicit local intent. A search that includes a location modifier, such as "Bellevue, WA" or "14th arrondissement", is an explicit local search. A search that references a product or service that is typically consumed locally, such as "restaurant" or "nail salon", is an implicit local search.
Local searches on Google Search typically return organic results prefaced with a 'local 3-pack', a list of three local results. More local results can be obtained by clicking on “more places” under the 3-pack. The list of results one obtains is also called the Local Finder.
Search engines and directories are primarily supported by advertising from businesses that wish to be prominently featured when users search for specific products and services in specific locations. Google for instance, has developed local inventory ads and features ads in the local pack. Local search advertising can be highly effective because it allows ads to be targeted very precisely to the search terms and location provided by the user.
Evolution
Local search is the natural evolution of traditional off-line advertising, typically distributed by newspaper publishers and TV and radio broadcasters, to the Web. Historically, consumers relied on local newspapers and local TV and radio stations to find local product and services. With the advent of the Web, consumers are increasingly using search engines to find these local products and services online. In recent years, the number of local searches online has grown rapidly while off-line information searches, such as print Yellow Page lookups, have declined. As a natural consequence of this shift in consumer behavior, local product and service providers are slowly shifting their advertising investments from traditional off-line media to local search engines.
Of directories, search engines and maps
One can search local information via search engines. These often return local search results from directories and maps. Google for instance, will present results from its directory (called Google Business Profile) in Google Maps and also in the search engine results pages in the form of a local pack. One can also look for local information by searching Apple Maps Search engines offer local businesses the possibility to upload their business data to their respective local search databases.
Other local search engines adjunct to major web search portals include general Windows Live Local, Yahoo! Local, and ask.com's AskCity. Yahoo!, for example, separates its local search engine features into Yahoo! Local and Yahoo! Maps, the former being focused on business data and correlating it with web data, the latter focused primarily on the map features (e.g. directions, larger map, navigation).
Local search, like ordinary search, can be applied in two ways. As John Battelle coined it in his book "The Search," search can be either recovery search or discovery search.
This perfect search also has perfect recall – it knows what you’ve seen, and can discern between a journey of discovery – where you want to find something new – and recovery – where you want to find something you’ve seen before.
This applies especially to local search. Recovery search implies, for example, that a consumer knows who she is looking for (i.e., Main Street Pizza Parlor) but she does not know where they are, or needs their phone number. Discovery search implies that the searcher knows, for example, what she wants but not who she needs it from (i.e., pizza on Main Street in Springfield).
In February 2012, Google announced that they made 40 changes to their search algorithm, including one codenamed "Venice" which Google states will improve local search results by "relying more on the ranking of (Google's) main search results as a signal", meaning local search will now rely more on organic SERPs (Search Engine Result Pages).
Local search results
Google can show a business's information in mobile or desktop google search results, or/and in mobile and desktop google maps results. Local search results displayed by google often include a local pack, that currently displays three listings.
Ranking factors
Major search engines have algorithms that determine which local businesses rank in local search. Primary factors that impact a local business's chance of appearing in local search are proper categorization in business directories, a business's name, address, and phone number (NAP) being crawlable on the website, and citations (mentions of the small business on other relevant websites like a chamber of commerce website).
In 2016, a study using statistical analysis assessed how and why businesses ranked in the local packs and identified positive correlations between local rankings and 100+ ranking factors. Although the study can’t replicate Google’s algorithm, it did deliver several interesting findings:
backlinks showed the most important correlation (and also Google’s Toolbar PageRank, suggesting that older links are an advantage since the Toolbar has not been updated in a long time)
Sites with more content (hence more keywords) tended to fare better (as expected), especially when the page has the local cities name within the text content and meta data
Quality of citations such as low number of duplicates, consistency and also a fair number of citations, mattered for a business to show in local packs. However, for businesses within the pack, citations did not influence their ranking: “citations appear to be foundational but not a competitive advantage."
Having a verified Google Business Profile Page with reviews and photos also showed a positive correlation (with ranking)
The authors were instead surprised that geotargeting elements (city and state) in the title of the Google Business Profile landing page did not have any impact on Google Business Profile rankings. Hence they suggest to use them only if it makes sense for usability reasons.
Keywords in a business name carry significant weight in local search algorithms, and have led to a rise in business name spam. Google's December 2021 Vicinity Update placed more importance on proximity as a ranking factor and decreased the significance of adding keywords in a business name on Google Business Profile.
Private label local search
Traditional local media companies, including newspaper publishers and television and radio broadcasters, are starting to add local search to their local websites in an effort to attract their share of local search traffic and advertising revenues in the markets they serve. These local media companies either develop their own technology or license "private label" or "white label" local search solutions from third-party local search solution providers. In either case, local media companies base their solution on business listings databases developed in-house or licensed from a third-party data publisher.
Social local search
Local search that incorporates internal or external social signals could be considered social local search-driven. The first site to incorporate this type of search was Explore To Yellow Pages. Explore To uses Facebook Likes as one of the signals to increase the ranking of listings where other factors may be equal or almost equal. Typical ranking signals in local searches, such as keyword relevancy and distance from centroid can, therefore, be layered with these social signals to give a better crowdsourced experience for users. More recently, social media sites Facebook, Foursquare, LocalMate and Zappenin have become more directly involved in local search by updating their mobile apps with features to help people discover new businesses to visit.
Mobile local search
Several providers experimented with providing local search for mobile devices, but on March 5, 2020, Google was the first to announce mobile-first indexing by default shifting the focus of optimization from desktop to mobile. Some of these are location aware. In the United States, Google previously operated an experimental voice-based locative service (1-800-GOOG-411) but terminated the service in November, 2010. Many mobile web portals require the subscriber to download a small Java application, however, the recently added .mobi top level domain has given impetus to the development of mobile targeted search sites are based upon a standard mobile-specific XML protocol that all modern mobile browsers understand. The advantage of mobile responsive website development is that no software needs to be downloaded and installed, plus these sites may be designed to simultaneously provide conventional content to traditional PC users by means of automatic browser detection.
Business owners and local search
Electronic publishers (such as businesses or individuals) who would like information such as their name, address, phone number, website, business description and business hours to appear on local search engines have several options. The most reliable way to include accurate local business information is to start claiming business listings through Google's, Yahoo!'s, or Bings's respective local business centers.
Business listing information can also be distributed via the traditional Yellow Pages, electronic Yellow Page-style data aggregators, and search engine optimization services. Some search engines will pick up on web pages that contain regular street addresses displayed in machine-readable text (rather than a picture of text, which is more difficult to interpret). Web pages can also use geotagging techniques.
Google Business Profile
On May 30, 2012 Google launched Google+ Local, a simple way to discover and share local information featuring Zagat scores and recommendations from the people you trust on Google+.
On June 11, 2014 Google launched Google Business Profile which replaced Google+ Local. Google Business Profile has more features and connects with AdWords to make an all-in-one small business online management center.
Reviews on Google Business Profile can be written by anyone regardless of whether they have actually had experience with the business. It's not uncommon for less honorable "reputation management" companies to post fraudulent negative reviews and then call the business offering to remove the fake reviews for a fee. Google has a posted policy that states all reviews "should accurately represent the location in question. Where contributions distort the truth, we will remove content." In reality, the Google Business Profile support staff almost never removes fraudulent reviews and appears to be more interested in encouraging business owners to spend money on Adwords than in actually ensuring the accuracy of the Google Business Profile information.
See also
hCard (protocol for adding local info to web pages)
Local advertising
References
External links
Internet search engines
Internet geolocation |
2936643 | https://en.wikipedia.org/wiki/Moon%20dog | Moon dog | A moon dog (or moondog) or mock moon, also called a paraselene (plural paraselenae) in meteorology, is an atmospheric optical phenomenon that consists of a bright spot to one or both sides of the Moon. They are exactly analogous to sun dogs.
A member of the halo family, moon dogs are caused by the refraction of moonlight by hexagonal-plate-shaped ice crystals in cirrus or cirrostratus clouds. They typically appear as a pair of faint patches of light, at around 22° to the left and right of the Moon, and at the same altitude above the horizon as the Moon. They may also appear alongside 22° halos.
Moon dogs are rarer than sun dogs because the Moon must be bright, about quarter moon or more, for the moon dogs to be observed. Moon dogs show little color to the unaided human eye because their light is not bright enough to activate the eye's cone cells.
See also
Halo (optical phenomenon)
Circumhorizontal arc
Circumzenithal arc
Gegenschein
Zodiacal light
References
Atmospheric optical phenomena |
2937772 | https://en.wikipedia.org/wiki/Thermophotovoltaic%20energy%20conversion | Thermophotovoltaic energy conversion | Thermophotovoltaic (TPV) energy conversion is a direct conversion process from heat to electricity via photons. A basic thermophotovoltaic system consists of a hot object emitting thermal radiation and a photovoltaic cell similar to a solar cell but tuned to the spectrum being admitted from the hot object.
As TPV systems generally work at lower temperatures than solar cells, their efficiencies tend to be low. Offsetting this through the use of multi-junction cells based on non-silicon materials is common, but generally very expensive. This currently limits TPV to niche roles like spacecraft power and waste heat collection from larger systems like steam turbines.
General concept
PV
Typical photovoltaics work by creating a p–n junction near the front surface of a thin semiconductor material. When photons above the bandgap energy of the material hit atoms within the bulk lower layer, below the junction, an electron is photoexcited and becomes free of its atom. The junction creates an electric field that accelerates the electron forward within the cell until it passes the junction and is free to move to the thin electrodes patterned on the surface. Connecting a wire from the front to the rear allows the electrons to flow back into the bulk and complete the circuit.
Photons with less energy than the bandgap do not eject electrons. Photons with energy above the bandgap will eject higher-energy electrons which tend to thermalize within the material and lose their extra energy as heat. If the cell's bandgap is raised, the electrons that are emitted will have higher energy when they reach the junction and thus result in a higher voltage, but this will reduce the number of electrons emitted as more photons will be below the bandgap energy and thus generate a lower current. As electrical power is the product of voltage and current, there is a sweet spot where the total output is maximized.
Terrestrial solar radiation is typically characterized by a standard known as Air Mass 1.5, or AM1.5. This is very close to 1,000 W of energy per square meter at an apparent temperature of 5780 K. At this temperature, about half of all the energy reaching the surface is in the infrared. Based on this temperature, energy production is maximized when the bandgap is about 1.4 eV, in the near infrared. This just happens to be very close to the bandgap in doped silicon, at 1.1 eV, which makes solar PV inexpensive to produce.
This means that all of the energy in the infrared and lower, about half of AM1.5, goes to waste. There has been continuing research into cells that are made of several different layers, each with a different bandgap, and thus tuned to a different part of the solar spectrum. , cells with overall efficiencies in the range of 40% are commercially available, although they are extremely expensive and have not seen widespread use outside of specific roles like powering spacecraft, where cost is not a significant consideration.
TPV
The same process of photoemission can be used to produce electricity from any spectrum, although the number of semiconductor materials that will have just the right bandgap for an arbitrary hot object is limited. Instead, semiconductors that have tuneable bandgaps are needed. It is also difficult to produce solar-like thermal output; an oxyacetylene torch is about 3400 K (~3126 °C), and more common commercial heat sources like coal and natural gas burn at much lower temperatures around 900 °C to about 1300 °C. This further limits the suitable materials. In the case of TPV most research has focused on gallium antimonide (GaSb), although germanium (Ge) is also suitable.
Another problem with lower-temperature sources is that their energy is more spread out, according to Wien's displacement law. While one can make a practical solar cell with a single bandgap tuned to the peak of the spectrum and just ignore the losses in the IR region, doing the same with a lower temperature source will lose much more of the potential energy and result in very low overall efficiency. This means TPV systems almost always use multi-junction cells in order to reach reasonable double-digit efficiencies. Current research in the area aims at increasing system efficiencies while keeping the system cost low, but even then their roles tend to be niches similar to those of multi-junction solar cells.
Actual designs
TPV systems generally consist of a heat source, an emitter, and a waste heat rejection system. The TPV cells are placed between the emitter, often a block of metal or similar, and the cooling system, often a passive radiator. PV systems in general operate at lower efficiency as the temperature increases, and in TPV systems, keeping the photovoltaic cool is a significant challenge.
This contrasts with a somewhat related concept, the "thermoradiative" or "negative emission" cells, in which the photodiode is on the hot side of the heat engine. Systems have also been proposed that use a thermoradiative device as an emitter in a TPV system, theoretically allowing power to be extracted from both a hot photodiode and a cold photodiode.
Applications
RTGs
Conventional radioisotope thermoelectric generators (RTGs) used to power spacecraft use a radioactive material whose radiation is used to heat a block of material and then converted to electricity using a thermocouple. Thermocouples are very inefficient and their replacement with TPV could offer significant improvements in efficiency and thus require a smaller and lighter RTG for any given mission. Experimental systems developed by Emcore (a multi-junction solar cell provider), Creare, Oak Ridge and NASA's Glenn Research Center demonstrated 15 to 20% efficiency. A similar concept was developed by the University of Houston which reached 30% efficiency, a 3 to 4-fold improvement over existing systems.
Thermoelectric storage
Another area of active research is using TPV as the basis of a thermal storage system. In this concept, electricity being generated in off-peak times is used to heat a large block of material, typically carbon or a phase-change material. The material is surrounded by TPV cells which are in turn backed by a reflector and insulation. During storage, the TPV cells are turned off and the photons pass through them and reflect back into the high-temperature source. When power is needed, the TPV is connected to a load.
Waste heat collection
TPV cells have been proposed as auxiliary power conversion devices for capture of otherwise lost heat in other power generation systems, such as steam turbine systems or solar cells.
History
Henry Kolm constructed an elementary TPV system at MIT in 1956. However, Pierre Aigrain is widely cited as the inventor based on lectures he gave at MIT between 1960–1961 which, unlike Kolm's system, led to research and development.
In the 1980s, efficiency reached around 30%.
In 1997 a prototype TPV hybrid car was built, the "Viking 29" (TPV) powered automobile, designed and built by the Vehicle Research Institute (VRI) at Western Washington University.
In 2022, MIT/NREL announced a device with 41% efficiency. The absorber employed multiple III-V semiconductor layers tuned to absorb variously, ultraviolet, visible, and infrared photons. A gold reflector recycled unabsorbed photons. The device operated at 2400 °C, at which temperature the tungsten emitter reaches maximum brightness.
Details
Efficiency
The upper limit for efficiency in TPVs (and all systems that convert heat energy to work) is the Carnot efficiency, that of an ideal heat engine. This efficiency is given by:
where Tcell is the temperature of the PV converter. Practical systems can achieve Tcell= ~300 K and Temit= ~1800 K, giving a maximum possible efficiency of ~83%. This assumes the PV converts the radiation into electrical energy without losses, such as thermalization or Joule heating, though in reality the photovoltaic inefficiency is quite significant. In real devices, as of 2021, the maximum demonstrated efficiency in the laboratory was 35% with an emitter temperature of 1,773 K. This is the efficiency in terms of heat input being converted to electrical power. In complete TPV systems, a necessarily lower total system efficiency may be cited including the source of heat, so for example, fuel-based TPV systems may report efficiencies in terms of fuel-energy to electrical energy, in which case 5% is considered a "world record" level of efficiency. Real-world efficiencies are reduced by such effects as heat transfer losses, electrical conversion efficiency (TPV voltage outputs are often quite low), and losses due to active cooling of the PV cell.
Emitters
Deviations from perfect absorption and perfect black body behavior lead to light losses. For selective emitters, any light emitted at wavelengths not matched to the bandgap energy of the photovoltaic may not be efficiently converted, reducing efficiency. In particular, emissions associated with phonon resonances are difficult to avoid for wavelengths in the deep infrared, which cannot be practically converted. An ideal emitter would emit no light at wavelengths other than at the bandgap energy, and much TPV research is devoted to developing emitters that better approximate this narrow emission spectrum.
Filters
For black body emitters or imperfect selective emitters, filters reflect non-ideal wavelengths back to the emitter. These filters are imperfect. Any light that is absorbed or scattered and not redirected to the emitter or the converter is lost, generally as heat. Conversely, practical filters often reflect a small percentage of light in desired wavelength ranges. Both are inefficiencies. The absorption of suboptimal wavelengths by the photovoltaic device also contributes inefficiency and has the added effect of heating it, which also decreases efficiency.
Converters
Even for systems where only light of optimal wavelengths is passed to the photovoltaic converter, inefficiencies associated with non-radiative recombination and Ohmic losses exist. There are also losses from Fresnel reflections at the PV surface, optimal-wavelength light that passes through the cell unabsorbed, and the energy difference between higher-energy photons and the bandgap energy (though this tends to be less significant than with solar PVs). Non-radiative recombination losses tend to become less significant as the light intensity increases, while they increase with increasing temperature, so real systems must consider the intensity produced by a given design and operating temperature.
Geometry
In an ideal system, the emitter is surrounded by converters so no light is lost. Realistically, geometries must accommodate the input energy (fuel injection or input light) used to heat the emitter. Additionally, costs have prohibited surrounding the filter with converters. When the emitter reemits light, anything that does not travel to the converters is lost. Mirrors can be used to redirect some of this light back to the emitter; however, the mirrors may have their own losses.
Black body radiation
For black body emitters where photon recirculation is achieved via filters, Planck's law states that a black body emits light with a spectrum given by:
where I′ is the light flux of a specific wavelength, λ, given in units of 1 m–3⋅s–1. h is the Planck constant, k is the Boltzmann constant, c is the speed of light, and Temit is the emitter temperature. Thus, the light flux with wavelengths in a specific range can be found by integrating over the range. The peak wavelength is determined by the temperature, Temit based on Wien's displacement law:
where b is Wien's displacement constant. For most materials, the maximum temperature an emitter can stably operate at is about 1800 °C. This corresponds to an intensity that peaks at or an energy of ~0.75 eV. For more reasonable operating temperatures of 1200 °C, this drops to ~0.5 eV. These energies dictate the range of bandgaps that are needed for practical TPV converters (though the peak spectral power is slightly higher). Traditional PV materials such as Si (1.1 eV) and GaAs (1.4 eV) are substantially less practical for TPV systems, as the intensity of the black body spectrum is low at these energies for emitters at realistic temperatures.
Active components and materials selection
Emitters
Efficiency, temperature resistance and cost are the three major factors for choosing a TPV emitter. Efficiency is determined by energy absorbed relative to incoming radiation. High temperature operation is crucial because efficiency increases with operating temperature. As emitter temperature increases, black-body radiation shifts to shorter wavelengths, allowing for more efficient absorption by photovoltaic cells.
Polycrystalline silicon carbide
Polycrystalline silicon carbide (SiC) is the most commonly used emitter for burner TPVs. SiC is thermally stable to ~1700 °C. However, SiC radiates much of its energy in the long wavelength regime, far lower in energy than even the narrowest bandgap photovoltaic. Such radiation is not converted into electrical energy. However, non-absorbing selective filters in front of the PV, or mirrors deposited on the back side of the PV can be used to reflect the long wavelengths back to the emitter, thereby recycling the unconverted energy. In addition, polycrystalline SiC is inexpensive.
Tungsten
Tungsten is the most common refractory metal that can be used as a selective emitter. It has higher emissivity in the visible and near-IR range of 0.45 to 0.47 and a low emissivity of 0.1 to 0.2 in the IR region. The emitter is usually in the shape of a cylinder with a sealed bottom, which can be considered a cavity. The emitter is attached to the back of a thermal absorber such as SiC and maintains the same temperature. Emission occurs in the visible and near IR range, which can be readily converted by the PV to electrical energy. However, compared to other metals, tungsten oxidizes more easily.
Rare-earth oxides
Rare-earth oxides such as ytterbium oxide (Yb2O3) and erbium oxide (Er2O3) are the most commonly used selective emitters. These oxides emit a narrow band of wavelengths in the near-infrared region, allowing the emission spectra to be tailored to better fit the absorbance characteristics of a particular PV material. The peak of the emission spectrum occurs at 1.29 eV for Yb2O3 and 0.827 eV for Er2O3. As a result, Yb2O3 can be used a selective emitter for silicon cells and Er2O3, for GaSb or InGaAs. However, the slight mismatch between the emission peaks and band gap of the absorber costs significant efficiency. Selective emission only becomes significant at 1100 °C and increases with temperature. Below 1700 °C, selective emission of rare-earth oxides is fairly low, further decreasing efficiency. Currently, 13% efficiency has been achieved with Yb2O3 and silicon PV cells. In general selective emitters have had limited success. More often filters are used with black body emitters to pass wavelengths matched to the bandgap of the PV and reflect mismatched wavelengths back to the emitter.
Photonic crystals
Photonic crystals allow precise control of electromagnetic wave properties. These materials give rise to the photonic bandgap (PBG). In the spectral range of the PBG, electromagnetic waves cannot propagate. Engineering these materials allows some ability to tailor their emission and absorption properties, allowing for more effective emitter design. Selective emitters with peaks at higher energy than the black body peak (for practical TPV temperatures) allow for wider bandgap converters. These converters are traditionally cheaper to manufacture and less temperature sensitive. Researchers at Sandia Labs predicted a high-efficiency (34% of light emitted converted to electricity) based on TPV emitter demonstrated using tungsten photonic crystals. However, manufacturing of these devices is difficult and not commercially feasible.
Photovoltaic cells
Silicon
Early TPV work focused on the use of silicon. Silicon's commercial availability, low cost, scalability and ease of manufacture makes this material an appealing candidate. However, the relatively wide bandgap of Si (1.1eV) is not ideal for use with a black body emitter at lower operating temperatures. Calculations indicate that Si PVs are only feasible at temperatures much higher than 2000 K. No emitter has been demonstrated that can operate at these temperatures. These engineering difficulties led to the pursuit of lower-bandgap semiconductor PVs.
Using selective radiators with Si PVs is still a possibility. Selective radiators would eliminate high and low energy photons, reducing heat generated. Ideally, selective radiators would emit no radiation beyond the band edge of the PV converter, increasing conversion efficiency significantly. No efficient TPVs have been realized using Si PVs.
Germanium
Early investigations into low bandgap semiconductors focused on germanium (Ge). Ge has a bandgap of 0.66 eV, allowing for conversion of a much higher fraction of incoming radiation. However, poor performance was observed due to the high effective electron mass of Ge. Compared to III-V semiconductors, Ge's high electron effective mass leads to a high density of states in the conduction band and therefore a high intrinsic carrier concentration. As a result, Ge diodes have fast decaying "dark" current and therefore, a low open-circuit voltage. In addition, surface passivation of germanium has proven difficult.
Gallium antimonide
The gallium antimonide (GaSb) PV cell, invented in 1989, is the basis of most PV cells in modern TPV systems. GaSb is a III-V semiconductor with the zinc blende crystal structure. The GaSb cell is a key development owing to its narrow bandgap of 0.72 eV. This allows GaSb to respond to light at longer wavelengths than silicon solar cell, enabling higher power densities in conjunction with manmade emission sources. A solar cell with 35% efficiency was demonstrated using a bilayer PV with GaAs and GaSb, setting the solar cell efficiency record.
Manufacturing a GaSb PV cell is quite simple. Czochralski tellurium-doped n-type GaSb wafers are commercially available. Vapor-based zinc diffusion is carried out at elevated temperatures (~450 °C) to allow for p-type doping. Front and back electrical contacts are patterned using traditional photolithography techniques and an anti-reflective coating is deposited. Efficiencies are estimated at ~20% using a 1000 °C black body spectrum. The radiative limit for efficiency of the GaSb cell in this setup is 52%.
Indium gallium arsenide antimonide
Indium gallium arsenide antimonide (InGaAsSb) is a compound III-V semiconductor. (InxGa1−xAsySb1−y) The addition of GaAs allows for a narrower bandgap (0.5 to 0.6 eV), and therefore better absorption of long wavelengths. Specifically, the bandgap was engineered to 0.55 eV. With this bandgap, the compound achieved a photon-weighted internal quantum efficiency of 79% with a fill factor of 65% for a black body at 1100 °C. This was for a device grown on a GaSb substrate by organometallic vapour phase epitaxy (OMVPE). Devices have been grown by molecular beam epitaxy (MBE) and liquid phase epitaxy (LPE). The internal quantum efficiencies (IQE) of these devices approach 90%, while devices grown by the other two techniques exceed 95%. The largest problem with InGaAsSb cells is phase separation. Compositional inconsistencies throughout the device degrade its performance. When phase separation can be avoided, the IQE and fill factor of InGaAsSb approach theoretical limits in wavelength ranges near the bandgap energy. However, the Voc/Eg ratio is far from the ideal. Current methods to manufacture InGaAsSb PVs are expensive and not commercially viable.
Indium gallium arsenide
Indium gallium arsenide (InGaAs) is a compound III-V semiconductor. It can be applied in two ways for use in TPVs. When lattice-matched to an InP substrate, InGaAs has a bandgap of 0.74 eV, no better than GaSb. Devices of this configuration have been produced with a fill factor of 69% and an efficiency of 15%. However, to absorb higher wavelength photons, the bandgap may be engineered by changing the ratio of In to Ga. The range of bandgaps for this system is from about 0.4 to 1.4 eV. However, these different structures cause strain with the InP substrate. This can be controlled with graded layers of InGaAs with different compositions. This was done to develop of device with a quantum efficiency of 68% and a fill factor of 68%, grown by MBE. This device had a bandgap of 0.55 eV, achieved in the compound In0.68Ga0.33As. It is a well-developed material. InGaAs can be made to lattice match perfectly with Ge resulting in low defect densities. Ge as a substrate is a significant advantage over more expensive or harder-to-produce substrates.
Indium phosphide arsenide antimonide
The InPAsSb quaternary alloy has been grown by both OMVPE and LPE. When lattice-matched to InAs, it has a bandgap in the range 0.3–0.55 eV. The benefits of such a low band gap have not been studied in depth. Therefore, cells incorporating InPAsSb have not been optimized and do not yet have competitive performance. The longest spectral response from an InPAsSb cell studied was 4.3 μm with a maximum response at 3 μm. For this and other low-bandgap materials, high IQE for long wavelengths is hard to achieve due to an increase in Auger recombination.
Lead tin selenide/Lead strontium selenide quantum wells
PbSnSe/PbSrSe quantum well materials, which can be grown by MBE on silicon substrates, have been proposed for low cost TPV device fabrication. These IV-VI semiconductor materials can have bandgaps between 0.3 and 0.6 eV. Their symmetric band structure and lack of valence band degeneracy result in low Auger recombination rates, typically more than an order of magnitude smaller than those of comparable bandgap III-V semiconductor materials.
Applications
TPVs promise efficient and economically viable power systems for both military and commercial applications. Compared to traditional nonrenewable energy sources, burner TPVs have little NOx emissions and are virtually silent. Solar TPVs are a source of emission-free renewable energy. TPVs can be more efficient than PV systems owing to recycling of unabsorbed photons. However, losses at each energy conversion step lower efficiency. When TPVs are used with a burner source, they provide on-demand energy. As a result, energy storage may not be needed. In addition, owing to the PV's proximity to the radiative source, TPVs can generate current densities 300 times that of conventional PVs.
Energy storage
Man-portable power
Battlefield dynamics require portable power. Conventional diesel generators are too heavy for use in the field. Scalability allows TPVs to be smaller and lighter than conventional generators. Also, TPVs have few emissions and are silent. Multifuel operation is another potential benefit.
Investigations in the 1970s failed due to PV limitations. However, the GaSb photocell led to a renewed effort in the 1990s with improved results. In early 2001, JX Crystals delivered a TPV based battery charger to the US Army that produced 230 W fueled by propane. This prototype utilized an SiC emitter operating at 1250 °C and GaSb photocells and was approximately 0.5 m tall. The power source had an efficiency of 2.5%, calculated as the ratio of the power generated to the thermal energy of the fuel burned. This is too low for practical battlefield use. No portable TPV power sources have reached troop testing.
Grid storage
Converting spare electricity into heat for high-volume, long-term storage is under research at various companies, who claim that costs could be much lower than lithium-ion batteries.
Spacecraft
Space power generation systems must provide consistent and reliable power without large amounts of fuel. As a result, solar and radioisotope fuels (extremely high power density and long lifetime) are ideal. TPVs have been proposed for each. In the case of solar energy, orbital spacecraft may be better locations for the large and potentially cumbersome concentrators required for practical TPVs. However, weight considerations and inefficiencies associated with the more complicated design of TPVs, protected conventional PVs continue to dominate.
The output of isotopes is thermal energy. In the past thermoelectricity (direct thermal to electrical conversion with no moving parts) has been used because TPV efficiency is less than the ~10% of thermoelectric converters. Stirling engines have been deemed too unreliable, despite conversion efficiencies >20%. However, with the recent advances in small-bandgap PVs, TPVs are becoming more promising. A TPV radioisotope converter with 20% efficiency was demonstrated that uses a tungsten emitter heated to 1350 K, with tandem filters and a 0.6 eV bandgap InGaAs PV converter (cooled to room temperature). About 30% of the lost energy was due to the optical cavity and filters. The remainder was due to the efficiency of the PV converter.
Low-temperature operation of the converter is critical to the efficiency of TPV. Heating PV converters increases their dark current, thereby reducing efficiency. The converter is heated by the radiation from the emitter. In terrestrial systems it is reasonable to dissipate this heat without using additional energy with a heat sink. However, space is an isolated system, where heat sinks are impractical. Therefore, it is critical to develop innovative solutions to efficiently remove that heat. Both represent substantial challenges.
Commercial applications
Off-grid generators
TPVs can provide continuous power to off-grid homes. Traditional PVs do not provide power during winter months and nighttime, while TPVs can utilize alternative fuels to augment solar-only production.
The greatest advantage for TPV generators is cogeneration of heat and power. In cold climates, it can function as both a heater/stove and a power generator. JX Crystals developed a prototype TPV heating stove/generator that burns natural gas and uses a SiC source emitter operating at 1250 °C and GaSb photocell to output 25,000 BTU/hr (7.3kW of heat) simultaneously generating 100W (1.4% efficiency). However, costs render it impractical.
Combining a heater and a generator is called combined heat and power (CHP). Many TPV CHP scenarios have been theorized, but a study found that generator using boiling coolant was most cost efficient. The proposed CHP would utilize a SiC IR emitter operating at 1425 °C and GaSb photocells cooled by boiling coolant. The TPV CHP would output 85,000 BTU/hr (25kW of heat) and generate 1.5 kW. The estimated efficiency would be 12.3% (?)(1.5kW/25kW = 0.06 = 6%) requiring investment or 0.08 €/kWh assuming a 20 year lifetime. The estimated cost of other non-TPV CHPs are 0.12 €/kWh for gas engine CHP and 0.16 €/kWh for fuel cell CHP. This furnace was not commercialized because the market was not thought to be large enough.
Recreational vehicles
TPVs have been proposed for use in recreational vehicles. Their ability to use multiple fuel sources makes them interesting as more sustainable fuels emerge. TPVs silent operation allows them to replace noisy conventional generators (i.e. during "quiet hours" in national park campgrounds). However, the emitter temperatures required for practical efficiencies make TPVs on this scale unlikely.
References
External links
6th International Conference on Thermophotovoltaic Generation of Electricity
NASA Radioisotope Power Conversion Technology NRA Overview
New thermophotovoltaic materials could replace alternators in cars and save fuel
Photovoltaics
Thermodynamics |
2938357 | https://en.wikipedia.org/wiki/Emergency%20Response%20Information%20Network | Emergency Response Information Network | The Emergency Response Information Network (ERIN), is a 24-hour hurricane TV channel set up by the Dish Network. It was formerly called the Katrina Information Network. Dish network set up the channel to provide information on missing people from Hurricane Katrina, but then changed the name before Hurricane Rita came ashore. Dish Network provides the channel free of charge to all Dish customers. Important phone numbers and other updates provided by hurricane relief agencies are shown in addition to the names of missing or dislocated children and adults.
ERIN is currently shown on channel 206, and was developed by Flying Colors Broadcasts, a Washington, D.C.-based company.
References
Disaster preparedness in the United States
Dish Network |
2939202 | https://en.wikipedia.org/wiki/Earth%27s%20inner%20core | Earth's inner core | Earth's inner core is the innermost geologic layer of planet Earth. It is primarily a solid ball with a radius of about , which is about 20% of Earth's radius or 70% of the Moon's radius.
There are no samples of Earth's core accessible for direct measurement, as there are for Earth's mantle. Information about Earth's core mostly comes from analysis of seismic waves and Earth's magnetic field. The inner core is believed to be composed of an iron–nickel alloy with some other elements. The temperature at the inner core's surface is estimated to be approximately , which is about the temperature at the surface of the Sun.
Scientific history
Earth was discovered to have a solid inner core distinct from its molten outer core in 1936, by the Danish seismologist Inge Lehmann, who deduced its presence by studying seismograms from earthquakes in New Zealand. She observed that the seismic waves reflect off the boundary of the inner core and can be detected by sensitive seismographs on the Earth's surface. She inferred a radius of for the inner core, not far from the currently accepted value of . In 1938, Beno Gutenberg and Charles Richter analyzed a more extensive set of data and estimated the thickness of the outer core as with a steep but continuous thick transition to the inner core; implying a radius between for the inner core.
A few years later, in 1940, it was hypothesized that this inner core was made of solid iron. In 1952, Francis Birch published a detailed analysis of the available data and concluded that the inner core was probably crystalline iron.
The boundary between the inner and outer cores is sometimes called the "Lehmann discontinuity", although the name usually refers to another discontinuity. The name "Bullen" or "Lehmann-Bullen discontinuity", after Keith Edward Bullen has been proposed, but its use seems to be rare. The rigidity of the inner core was confirmed in 1971.
Adam Dziewonski and James Freeman Gilbert established that measurements of normal modes of vibration of Earth caused by large earthquakes were consistent with a liquid outer core. In 2005, shear waves were detected passing through the inner core; these claims were initially controversial, but are now gaining acceptance.
Data sources
Seismic waves
Almost all direct measurements that scientists have about the physical properties of the inner core are the seismic waves that pass through it. The most informative waves are generated by deep earthquakes, 30 km or more below the surface of the Earth (where the mantle is relatively more homogeneous) and recorded by seismographs as they reach the surface, all over the globe.
Seismic waves include "P" (primary or pressure) waves, compressional waves that can travel through solid or liquid materials, and "S" (secondary or shear) shear waves that can only propagate through rigid elastic solids. The two waves have different velocities and are damped at different rates as they travel through the same material.
Of particular interest are the so-called "PKiKP" waves—pressure waves (P) that start near the surface, cross the mantle-core boundary, travel through the core (K), are reflected at the inner core boundary (i), cross again the liquid core (K), cross back into the mantle, and are detected as pressure waves (P) at the surface. Also of interest are the "PKIKP" waves, that travel through the inner core (I) instead of being reflected at its surface (i). Those signals are easier to interpret when the path from source to detector is close to a straight line—namely, when the receiver is just above the source for the reflected PKiKP waves, and antipodal to it for the transmitted PKIKP waves.
While S waves cannot reach or leave the inner core as such, P waves can be converted into S waves, and vice versa, as they hit the boundary between the inner and outer core at an oblique angle. The "PKJKP" waves are similar to the PKIKP waves, but are converted into S waves when they enter the inner core, travel through it as S waves (J), and are converted again into P waves when they exit the inner core. Thanks to this phenomenon, it is known that the inner core can propagate S waves, and therefore must be solid.
Other sources
Other sources of information about the inner core include
The magnetic field of the Earth. While it seems to be generated mostly by fluid and electric currents in the outer core, those currents are strongly affected by the presence of the solid inner core and by the heat that flows out of it. (Although made of iron, the core is not ferromagnetic, due to being above the Curie temperature.)
The Earth's mass, its gravitational field, and its angular inertia. These are all affected by the density and dimensions of the inner layers.
The natural oscillation frequencies and modes of the whole Earth oscillations, when large earthquakes make the planet "ring" like a bell. These oscillations also depend strongly on the density, size, and shape of the inner layers.
Physical properties
Seismic wave velocity
The velocity of the S waves in the core varies smoothly from about 3.7 km/s at the center to about 3.5 km/s at the surface. That is considerably less than the velocity of S waves in the lower crust (about 4.5 km/s) and less than half the velocity in the deep mantle, just above the outer core (about 7.3 km/s).
The velocity of the P-waves in the core also varies smoothly through the inner core, from about 11.4 km/s at the center to about 11.1 km/s at the surface. Then the speed drops abruptly at the inner-outer core boundary to about 10.4 km/s.
Size and shape
On the basis of the seismic data, the inner core is estimated to be about 1221 km in radius (2442 km in diameter), which is about 19% of the radius of the Earth and 70% of the radius of the Moon.
Its volume is about 7.6 billion cubic km (), which is about (0.69%) of the volume of the whole Earth.
Its shape is believed to be close to an oblate ellipsoid of revolution, like the surface of the Earth, only more spherical: the flattening is estimated to be between and , meaning that the radius along the Earth's axis is estimated to be about 3 km shorter than the radius at the equator. In comparison, the flattening of the Earth as a whole is close to , and the polar radius is 21 km shorter than the equatorial one.
Pressure and gravity
The pressure in the Earth's inner core is slightly higher than it is at the boundary between the outer and inner cores: It ranges from about .
The acceleration of gravity at the surface of the inner core can be computed to be 4.3 m/s2; which is less than half the value at the surface of the Earth (9.8 m/s2).
Density and mass
The density of the inner core is believed to vary smoothly from about 13.0 kg/L (= g/cm3 = t/m3) at the center to about 12.8 kg/L at the surface. As it happens with other material properties, the density drops suddenly at that surface: The liquid just above the inner core is believed to be significantly less dense, at about 12.1 kg/L. For comparison, the average density in the upper 100 km of the Earth is about 3.4 kg/L.
That density implies a mass of about 1023 kg for the inner core, which is (1.7%) of the mass of the whole Earth.
Temperature
The temperature of the inner core can be estimated from the melting temperature of impure iron at the pressure which iron is under at the boundary of the inner core (about 330 GPa). From these considerations, in 2002 D. Alfè and others estimated its temperature as between and . However, in 2013 S. Anzellini and others obtained experimentally a substantially higher temperature for the melting point of iron, .
Iron can be solid at such high temperatures only because its melting temperature increases dramatically at pressures of that magnitude (see the Clausius–Clapeyron relation).
Magnetic field
In 2010, Bruce Buffett determined that the average magnetic field in the liquid outer core is about 2.5 milliteslas (25 gauss), which is about 40 times the maximum strength at the surface. He started from the known fact that the Moon and Sun cause tides in the liquid outer core, just as they do on the oceans on the surface. He observed that motion of the liquid through the local magnetic field creates electric currents, that dissipate energy as heat according to Ohm's law. This dissipation, in turn, damps the tidal motions and explains previously detected anomalies in Earth's nutation. From the magnitude of the latter effect he could calculate the magnetic field. The field inside the inner core presumably has a similar strength. While indirect, this measurement does not depend significantly on any assumptions about the evolution of the Earth or the composition of the core.
Viscosity
Although seismic waves propagate through the core as if it were solid, the measurements cannot distinguish between a solid material from an extremely viscous one. Some scientists have therefore considered whether there may be slow convection in the inner core (as is believed to exist in the mantle). That could be an explanation for the anisotropy detected in seismic studies. In 2009, B. Buffett estimated the viscosity of the inner core at 1018 Pa·s, which is a sextillion times the viscosity of water, and more than a billion times that of pitch.
Composition
There is still no direct evidence about the composition of the inner core. However, based on the relative prevalence of various chemical elements in the Solar System, the theory of planetary formation, and constraints imposed or implied by the chemistry of the rest of the Earth's volume, the inner core is believed to consist primarily of an iron–nickel alloy.
At the known pressures and estimated temperatures of the core, it is predicted that pure iron could be solid, but its density would exceed the known density of the core by approximately 3%. That result implies the presence of lighter elements in the core, such as silicon, oxygen, or sulfur, in addition to the probable presence of nickel. Recent estimates (2007) allow for up to 10% nickel and 2–3% of unidentified lighter elements.
According to computations by D. Alfè and others, the liquid outer core contains 8–13% of oxygen, but as the iron crystallizes out to form the inner core the oxygen is mostly left in the liquid.
Laboratory experiments and analysis of seismic wave velocities seem to indicate that the inner core consists specifically of ε-iron, a crystalline form of the metal with the hexagonal close-packed () structure. That structure can still admit the inclusion of small amounts of nickel and other elements.
Structure
Many scientists had initially expected that the inner core would be found to be homogeneous, because that same process should have proceeded uniformly during its entire formation. It was even suggested that Earth's inner core might be a single crystal of iron.
Axis-aligned anisotropy
In 1983, G. Poupinet and others observed that the travel time of PKIKP waves (P waves that travel through the inner core) was about 2 seconds less for straight north–south paths than straight paths on the equatorial plane. Even taking into account the flattening of the Earth at the poles (about 0.33% for the whole Earth, 0.25% for the inner core) and crust and upper mantle heterogeneities, this difference implied that P waves (of a broad range of wavelengths) travel through the inner core about 1% faster in the north–south direction than along directions perpendicular to that.
This P wave speed anisotropy has been confirmed by later studies, including more seismic data and study of the free oscillations of the whole Earth. Some authors have claimed higher values for the difference, up to 4.8%; however, in 2017 Daniel Frost and Barbara Romanowicz confirmed that the value is between 0.5% and 1.5%.
Non-axial anisotropy
Some authors have claimed that P wave speed is faster in directions that are oblique or perpendicular to the N−S axis, at least in some regions of the inner core. However, these claims have been disputed by Frost and Romanowicz, who instead claim that the direction of maximum speed is as close to the Earth's rotation axis as can be determined.
Causes of anisotropy
Laboratory data and theoretical computations indicate that the propagation of pressure waves in the crystals of ε-iron are strongly anisotropic, too, with one "fast" axis and two equally "slow" ones. A preference for the crystals in the core to align in the north–south direction could account for the observed seismic anomaly.
One phenomenon that could cause such partial alignment is slow flow ("creep") inside the inner core, from the equator towards the poles or vice versa. That flow would cause the crystals to partially reorient themselves according to the direction of the flow. In 1996, S. Yoshida and others proposed that such a flow could be caused by higher rate of freezing at the equator than at polar latitudes. An equator-to-pole flow then would set up in the inner core, tending to restore the isostatic equilibrium of its surface.
Others suggested that the required flow could be caused by slow thermal convection inside the inner core. T. Yukutake claimed in 1998 that such convective motions were unlikely. However, B. Buffet in 2009 estimated the viscosity of the inner core and found that such convection could have happened, especially when the core was smaller.
On the other hand, M. Bergman in 1997 proposed that the anisotropy was due to an observed tendency of iron crystals to grow faster when their crystallographic axes are aligned with the direction of the cooling heat flow. He, therefore, proposed that the heat flow out of the inner core would be biased towards the radial direction.
In 1998, S. Karato proposed that changes in the magnetic field might also deform the inner core slowly over time.
Multiple layers
In 2002, M. Ishii and A. Dziewoński presented evidence that the solid inner core contained an "innermost inner core" (IMIC) with somewhat different properties than the shell around it. The nature of the differences and radius of the IMIC are still unresolved as of 2019, with proposals for the latter ranging from 300 km to 750 km.
A. Wang and X. Song proposed, in 2018, a three-layer model, with an "inner inner core" (IIC) with about 500 km radius, an "outer inner core" (OIC) layer about 600 km thick, and an isotropic shell 100 km thick. In this model, the "faster P wave" direction would be parallel to the Earth's axis in the OIC, but perpendicular to that axis in the IIC. However, the conclusion has been disputed by claims that there need not be sharp discontinuities in the inner core, only a gradual change of properties with depth.
In 2023, a study reported new evidence "for an anisotropically-distinctive innermost inner core" – a ~650-km thick innermost ball – "and its transition to a weakly anisotropic outer shell, which could be a fossilized record of a significant global event from the past." They suggest that atoms in the IIC atoms are [packed] slightly differently than its outer layer, causing seismic waves to pass through the IIC at different speeds than through the surrounding core (P-wave speeds ~4% slower at ~50° from the Earth’s rotation axis).
Lateral variation
In 1997, S. Tanaka and H. Hamaguchi claimed, on the basis of seismic data, that the anisotropy of the inner core material, while oriented N−S, was more pronounced in "eastern" hemisphere of the inner core (at about 110 °E longitude, roughly under Borneo) than in the "western" hemisphere (at about 70 °W, roughly under Colombia).
Alboussère and others proposed that this asymmetry could be due to melting in the Eastern hemisphere and re-crystallization in the Western one. C. Finlay conjectured that this process could explain the asymmetry in the Earth's magnetic field.
However, in 2017 Frost and Romanowicz disputed those earlier inferences, claiming that the data shows only a weak anisotropy, with the speed in the N−S direction being only 0.5% to 1.5% faster than in equatorial directions, and no clear signs of E−W variation.
Other structure
Other researchers claim that the properties of the inner core's surface vary from place to place across distances as small as 1 km. This variation is surprising since lateral temperature variations along the inner-core boundary are known to be extremely small (this conclusion is confidently constrained by magnetic field observations).
Growth
The Earth's inner core is thought to be slowly growing as the liquid outer core at the boundary with the inner core cools and solidifies due to the gradual cooling of the Earth's interior (about 100 degrees Celsius per billion years).
According to calculations by Alfé and others, as the iron crystallizes onto the inner core, the liquid just above it becomes enriched in oxygen, and therefore less dense than the rest of the outer core. This process creates convection currents in the outer core, which are thought to be the prime driver for the currents that create the Earth's magnetic field.
The existence of the inner core also affects the dynamic motions of liquid in the outer core, and thus may help fix the magnetic field.
Dynamics
Because the inner core is not rigidly connected to the Earth's solid mantle, the possibility that it rotates slightly more quickly or slowly than the rest of Earth has long been entertained. In the 1990s, seismologists made various claims about detecting this kind of super-rotation by observing changes in the characteristics of seismic waves passing through the inner core over several decades, using the aforementioned property that it transmits waves more quickly in some directions. In 1996, X. Song and P. Richards estimated this "super-rotation" of the inner core relative to the mantle as about one degree per year. In 2005, they and J. Zhang compared recordings of "seismic doublets" (recordings by the same station of earthquakes occurring in the same location on the opposite side of the Earth, years apart), and revised that estimate to 0.3 to 0.5 degree per year. In 2023, it was reported that the core's spin has stopped spinning faster than the planet's surface around 2009 and likely is now rotating slower than it. This is not thought to have major effects and one cycle of the oscillation is thought to be about seven decades, coinciding with several other geophysical periodicities, "especially the length of day and magnetic field".
In 1999, M. Greff-Lefftz and H. Legros noted that the gravitational fields of the Sun and Moon that are responsible for ocean tides also apply torques to the Earth, affecting its axis of rotation and a slowing down of its rotation rate. Those torques are felt mainly by the crust and mantle, so that their rotation axis and speed may differ from overall rotation of the fluid in the outer core and the rotation of the inner core. The dynamics is complicated because of the currents and magnetic fields in the inner core. They find that the axis of the inner core wobbles (nutates) slightly with a period of about 1 day. With some assumptions on the evolution of the Earth, they conclude that the fluid motions in the outer core would have entered resonance with the tidal forces at several times in the past (3.0, 1.8, and 0.3 billion years ago). During those epochs, which lasted 200–300 million years each, the extra heat generated by stronger fluid motions might have stopped the growth of the inner core.
Age
Theories about the age of the core are necessarily part of theories of the history of Earth as a whole. This has been a long-debated topic and is still under discussion at the present time. It is widely believed that the Earth's solid inner core formed out of an initially completely liquid core as the Earth cooled down. However, there is still no firm evidence about the time when this process started.
Two main approaches have been used to infer the age of the inner core: thermodynamic modeling of the cooling of the Earth, and analysis of paleomagnetic evidence. The estimates yielded by these methods still vary over a large range, from 0.5 to 2 billion years old.
Thermodynamic evidence
One of the ways to estimate the age of the inner core is by modeling the cooling of the Earth, constrained by a minimum value for the heat flux at the core–mantle boundary (CMB). That estimate is based on the prevailing theory that the Earth's magnetic field is primarily triggered by convection currents in the liquid part of the core, and the fact that a minimum heat flux is required to sustain those currents. The heat flux at the CMB at present time can be reliably estimated because it is related to the measured heat flux at Earth's surface and to the measured rate of mantle convection.
In 2001, S. Labrosse and others, assuming that there were no radioactive elements in the core, gave an estimate of 1±0.5 billion years for the age of the inner core — considerably less than the estimated age of the Earth and of its liquid core (about 4.5 billion years) In 2003, the same group concluded that, if the core contained a reasonable amount of radioactive elements, the inner core's age could be a few hundred million years older.
In 2012, theoretical computations by M. Pozzo and others indicated that the electrical conductivity of iron and other hypothetical core materials, at the high pressures and temperatures expected there, were two or three times higher than assumed in previous research. These predictions were confirmed in 2013 by measurements by Gomi and others. The higher values for electrical conductivity led to increased estimates of the thermal conductivity, to 90 W/m·K; which, in turn, lowered estimates of its age to less than 700 million years old.
However, in 2016 Konôpková and others directly measured the thermal conductivity of solid iron at inner core conditions, and obtained a much lower value, 18–44 W/m·K. With those values, they obtained an upper bound of 4.2 billion years for the age of the inner core, compatible with the paleomagnetic evidence.
In 2014, Driscoll and Bercovici published a thermal history of the Earth that avoided the so-called mantle thermal catastrophe and new core paradox by invoking 3 TW of radiogenic heating by the decay of in the core. Such high abundances of K in the core are not supported by experimental partitioning studies, so such a thermal history remains highly debatable.
Paleomagnetic evidence
Another way to estimate the age of the Earth is to analyze changes in the magnetic field of Earth during its history, as trapped in rocks that formed at various times (the "paleomagnetic record"). The presence or absence of the solid inner core could result in different dynamic processes in the core that could lead to noticeable changes in the magnetic field.
In 2011, Smirnov and others published an analysis of the paleomagnetism in a large sample of rocks that formed in the Neoarchean (2.8–2.5 billion years ago) and the Proterozoic (2.5–0.541 billion). They found that the geomagnetic field was closer to that of a magnetic dipole during the Neoarchean than after it. They interpreted that change as evidence that the dynamo effect was more deeply seated in the core during that epoch, whereas in the later time currents closer to the core-mantle boundary grew in importance. They further speculate that the change may have been due to growth of the solid inner core between 3.5–2.0 billion years ago.
In 2015, Biggin and others published the analysis of an extensive and carefully selected set of Precambrian samples and observed a prominent increase in the Earth's magnetic field strength and variance around 1.0–1.5 billion years ago. This change had not been noticed before due to the lack of sufficient robust measurements. They speculated that the change could be due to the birth of Earth's solid inner core. From their age estimate they derived a rather modest value for the thermal conductivity of the outer core, that allowed for simpler models of the Earth's thermal evolution.
In 2016, P. Driscoll published a numerical evolving dynamo model that made a detailed prediction of the paleomagnetic field evolution over 0.0–2.0 Ga. The evolving dynamo model was driven by time-variable boundary conditions produced by the thermal history solution in Driscoll and Bercovici (2014). The evolving dynamo model predicted a strong-field dynamo prior to 1.7 Ga that is multipolar, a strong-field dynamo from 1.0–1.7 Ga that is predominantly dipolar, a weak-field dynamo from 0.6–1.0 Ga that is a non-axial dipole, and a strong-field dynamo after inner core nucleation from 0.0–0.6 Ga that is predominantly dipolar.
An analysis of rock samples from the Ediacaran epoch (formed about 565 million years ago), published by Bono and others in 2019, revealed unusually low intensity and two distinct directions for the geomagnetic field during that time that provides support for the predictions by Driscoll (2016). Considering other evidence of high frequency of magnetic field reversals around that time, they speculate that those anomalies could be due to the onset of formation of the inner core, which would then be 0.5 billion years old. A News and Views by P. Driscoll summarizes the state of the field following the Bono results.
See also
Geodynamics
Internal structure of Earth
Iron meteorite
Thermal history of Earth
Travel to the Earth's center
References
Further reading
Earth's inner core
Structure of the Earth |
2939621 | https://en.wikipedia.org/wiki/Callovian | Callovian | In the geologic timescale, the Callovian is an age and stage in the Middle Jurassic, lasting between 165.3 ± 1.1 Ma (million years ago) and 161.5 ± 1.0 Ma. It is the last stage of the Middle Jurassic, following the Bathonian and preceding the Oxfordian.
Stratigraphic definitions
The Callovian Stage was first described by French palaeontologist Alcide d'Orbigny in 1852. Its name derives from the latinized name for Kellaways Bridge, a small hamlet 3 km north-east of Chippenham, Wiltshire, England.
The base of the Callovian is defined as the place in the stratigraphic column where the ammonite genus Kepplerites first appears, which is the base of the biozone of Macrocephalites herveyi. A global reference profile (a GSSP) for the base had in 2009 not yet been assigned.
The top of the Callovian (the base of the Oxfordian) is at the first appearance of ammonite species Brightia thuouxensis.
Subdivision
The Callovian is often subdivided into three substages (or subages): Lower/Early, Middle and Upper/Late Callovian. In the Tethys domain, the Callovian encompasses six ammonite biozones:
zone of Quenstedtoceras lamberti
zone of Peltoceras athleta
zone of Erymnoceras coronatum
zone of Reineckeia anceps
zone of Macrocephalites gracilis
zone of Bullatimorphites bullatus
Palaeogeography
During the Callovian, Europe was an archipelago of a dozen or so large islands. Between them were extensive areas of continental shelf. Consequently, there are shallow marine Callovian deposits in Russia and from Belarus, through Poland and Germany, into France and eastern Spain and much of England. Around the former island coasts are frequently, land-derived sediments. These are to be found, for example, in western Scotland.
The Louann Salt and the southern Campeche Salt of the Gulf of Mexico are thought to have formed by an embayment of the Pacific Ocean across modern-day Mexico.
References
Literature
; 2002: Histoire de la Terre, Dunod, Paris (2nd ed.), .
; 2004: A Geologic Time Scale 2004, Cambridge University Press.
; 1842: Paléontologie française. 1. Terrains oolitiques ou jurassiques. 642 p, Bertrand, Paris.
External links
GeoWhen Database - Callovian
Jurassic-Cretaceous timescale, at the website of the subcommission for stratigraphic information of the ICS
Stratigraphic chart of the Upper Jurassic, at the website of Norges Network of offshore records of geology and stratigraphy
This contains a detailed description of the British and European strata as understood at the time.
04
Geological ages |
2939640 | https://en.wikipedia.org/wiki/Campanian | Campanian | The Campanian is the fifth of six ages of the Late Cretaceous Epoch on the geologic timescale of the International Commission on Stratigraphy (ICS). In chronostratigraphy, it is the fifth of six stages in the Upper Cretaceous Series. Campanian spans the time from 83.6 (± 0.2) to 72.1 (± 0.2) million years ago. It is preceded by the Santonian and it is followed by the Maastrichtian.
The Campanian was an age when a worldwide sea level rise covered many coastal areas. The morphology of some of these areas has been preserved: it is an unconformity beneath a cover of marine sedimentary rocks.
Etymology
The Campanian was introduced in scientific literature by Henri Coquand in 1857. It is named after the French village of Champagne in the department of Charente-Maritime. The original type locality was a series of outcrops near the village of Aubeterre-sur-Dronne in the same region.
Definition
The base of the Campanian Stage is defined as a place in the stratigraphic column where the extinction of crinoid species Marsupites testudinarius is located. A GSSP was ratified for the base of the Campanian in October 2022, having been placed in Bottaccione, Gubbio, Italy. The top of the Campanian stage is defined as the place in the stratigraphic column where the ammonite Pachydiscus neubergicus first appears.
Subdivisions
The Campanian can be subdivided into Lower, Middle and Upper Subages. In the western interior of the United States, the base of the Middle Campanian is defined as the first occurrence of the ammonite Baculites obtusus (80.97 Ma) and the base of the Upper Campanian defined as the first occurrence of the ammonite Didymoceras nebrascense. (76.27 Ma) In the Tethys domain, the Campanian encompasses six ammonite biozones. They are, from young to old:
zone of Nostoceras hyatti
zone of Didymoceras chayennense
zone of Bostrychoceras polyplocum
zone of Hoplitoplacenticeras marroti / Hoplitoplacenticeras vari
zone of Delawarella delawarensis
zone of Placenticeras bidorsatum
Paleontology
During the Campanian age, a radiation among dinosaur species occurred. In North America, for example, the number of known dinosaur genera rises from 4 at the base of the Campanian to 48 in the upper part. This development is sometimes referred to as the "Campanian Explosion". However, it is not yet clear if the event is artificial, i.e. the low number of genera in the lower Campanian can be caused by a lower preservation chance for fossils in deposits of that age. The generally warm climates and large continental area covered in shallow sea during the Campanian probably favoured the dinosaurs. In the following Maastrichtian stage, the number of North American dinosaur genera found is 30% less than in the upper Campanian.
References
Further reading
Varricchio, D. J. 2001. Late Cretaceous oviraptorosaur (Theropoda) dinosaurs from Montana. pp. 42–57 in D. H. Tanke and K. Carpenter (eds.), Mesozoic Vertebrate Life. Indiana University Press, Indianapolis, Indiana.
; 2004: Dinosaur distribution, in: (eds.): The Dinosauria, University of California Press, Berkeley (2nd ed.), , pp 517–606.
External links
GeoWhen Database – Campanian
Late Cretaceous timescale, at the website of the subcommission for stratigraphic information of the ICS
Stratigraphic chart of the Late Cretaceous, at the website of Norges Network of offshore records of geology and stratigraphy
Campanian Microfossils: 75+ images of Foraminifera
05
Geological ages
Cretaceous geochronology |
2939698 | https://en.wikipedia.org/wiki/Carnian | Carnian | The Carnian (less commonly, Karnian) is the lowermost stage of the Upper Triassic Series (or earliest age of the Late Triassic Epoch). It lasted from 237 to 227 million years ago (Ma). The Carnian is preceded by the Ladinian and is followed by the Norian. Its boundaries are not characterized by major extinctions or biotic turnovers, but a climatic event (known as the Carnian pluvial episode characterized by substantial rainfall) occurred during the Carnian and seems to be associated with important extinctions or biotic radiations. Another extinction occurred at the Carnian-Norian boundary, ending the Carnian age.
Stratigraphic definitions
The Carnian was named in 1869 by Mojsisovics. It is unclear if it was named after the Carnic Alps or after the Austrian region of Carinthia (Kärnten in German) or after the Carnia historical region in northeastern Italy. The name, however, was first used referring to a part of the Hallstatt Limestone cropping out in Austria.
The base of the Carnian Stage is defined as the place in the stratigraphic record where the ammonite species Daxatina canadensis first appears. The global reference profile for the base is located at the Stuores-Wiesen near Badia in the Val Badia in the region of South Tyrol, Italy.
The top of the Carnian (the base of the Norian) is at the bases of the ammonite biozones of Klamathites macrolobatus or Stikinoceras kerri and the conodont biozones of Metapolygnathus communisti or Metapolygnathus primitius.
Subdivisions
There is no established, standard usage for the Carnian subdivisions, thus, while in some regional stratigraphies a two-substage subdivision is common:
Julian
Tuvalian
others prefer a three-substage organization of the stage as follows:
Cordevolian
Julian
Tuvalian
Biostratigraphy
In the Tethys domain, the Carnian Stage contains six ammonite biozones:
zone of Anatropites spinosus
zone of Tropites subbullatus
zone of Tropites dilleri
zone of Austrotrachyceras austriacum
zone of Trachyceras
The Otischalkian land vertebrate faunachron corresponds to the early late Carnian, while the Adamanian land vertebrate faunachron corresponds to the latest Carnian.
Paleogeography and climate
The paleogeography of the Carnian was basically the same as for the rest of the Triassic. Most continents were merged into the supercontinent Pangaea, and there was a single global ocean, Panthalassa. The global ocean had a western branch at tropical latitudes called Paleo-Tethys. The sediments of Paleo-Tethys now crop out in southeastern Europe, in the Middle East, in the Himalayas, and up to the island of Timor.
The extreme land-sea distribution led to "mega-monsoons", i.e., an atmospheric monsoon regime more intense than the present one.
As for most of the Mesozoic, there were no ice caps. Climate was mostly arid in the tropics, but an episode of wet tropical climate is documented at least in the Paleo-Tethys. This putative climatic event is called the "Carnian Pluvial Event", its age being between latest early Carnian (Julian) and the beginning of late Carnian (Tuvalian).
Carnian life
In the marine realm, the Carnian saw the first abundant occurrences of calcareous nanoplankton, a morphological group including the coccolithophores.
Invertebrates
There are a few invertebrates which are typical and characteristic of the Carnian. Among molluscs, the ammonoid genus Trachyceras is exclusive to the lower Carnian (i.e., Julian of the two-substages subdivision, see above). The family Tropitidae and the genus Tropites appear at the base of the upper Carnian (Tuvalian). The bivalve genus Halobia, a bottom-dweller of deep sea environments, differentiated from Daonella at the beginning of this age. Scleractinian coral reefs, i.e., reefs with corals of the modern type, became relatively common for the first time in the Carnian.
Vertebrates
The earliest unequivocal dinosaurs, such as those from the Ischigualato Formation (e.g. Herrerasaurus and Eoraptor) and those from the Santa Maria Formation (e.g. Staurikosaurus and Buriolestes) originated during the Carnian, around 230 Ma.
In this stage the archosaurs became the dominant faunas in the world, evolving into groups such as the phytosaurs, rhynchosaurs, aetosaurs, and rauisuchians. The first dinosaurs (and the pterosaur Carniadactylus) also appeared in this stage, and though at the time they were small and insignificant, they diversified rapidly and would dominate the fauna for the rest of the Mesozoic. On the other hand, the therapsids, which included the ancestors of mammals, decreased in both size and diversity, and would remain relatively small until the extinction of the dinosaurs.
Conodonts were present in Triassic marine sediments. Paragondolella polygnathiformis appeared at the base of the Carnian Stage, and is considered a characteristic species. A partial list of Carnian vertebrates is given below. Many Carnian vertebrates are found in Santa Maria Formation rocks of the Paleorrota geopark.
Classic localities and Lagerstätten
The lower Carnian fauna of the San Cassiano Formation (Dolomites, northern Italy) has been studied since the 19th century. Fossiliferous localities are many, and are distributed mostly in the surroundings of Cortina d'Ampezzo and in the high Badia Valley, near the village of San Cassiano, after which the formation was named. This fauna is extremely diverse, including ammonoids, gastropods, bivalves, echinoderms, calcareous sponge, corals, brachiopods, and a variety of less common fossils. A collection of this fauna is exposed in the "Museo delle Regole", a museum in Cortina d'Ampezzo.
The Ischigualasto Formation of the Ischigualasto-Villa Unión Basin in northwestern Argentina yielded a very important vertebrate association, including the oldest dinosaurian assemblage.
The Lagerstätte of the Madygen Formation in Kyrgyzstan has provided over 20,000 fossil insects, vertebrates and flora.
Notable Formations
Chañares Formation (Argentina)
Denmark Hill Insect Bed (Queensland, Australia)
Dockum Group (Carnian - Norian)* (SW USA)
“Isalo II” (late Ladinian – early Carnian)* (Madagascar)
Ischigualasto Formation (Argentina)
Krasiejów* (Poland)
Los Rastros Formation (Argentina)
Lossiemouth Sandstone* (Scotland, UK)
Madygen Formation (Ladinian – Carnian)* (Kyrgyzstan)
Lower Maleri Formation* (India)
Molteno Formation (South Africa)
Popo Agie Formation* (Wyoming, USA)
Potrerillos Formation (Argentina)
Santa Maria Formation (Rio Grande do Sul, Brazil)
Stuttgart Formation (Germany)
Tiki Formation* (India)
Timezgadiouine Formation (Irohalene Member)* (Morocco)
Xiaowa Formation / Wayao Member of the Falang Formation (Guizhou and Yunnan, China)
Zhuganpo Formation / Zhuganpo Member of the Falang Formation (late Ladinian - early Carnian) (Guizhou and Yunnan, China)
* Tentatively assigned to the Carnian; age estimated primarily via terrestrial tetrapod biostratigraphy (see Triassic land vertebrate faunachrons)
References
Bibliography
; 2005: The Global boundary Stratotype Section and Point (GSSP) of the Ladinian Stage (Middle Triassic) at Bagolino (Southern Alps, Northern Italy) and its implications for the Triassic time scale, Episodes 28(4), pp. 233–244.
; 1999: The Prati di Stuores/Stuores Wiesen section (Dolomites, Italy): a candidate Global Stratotype section and Point for the base of the Carnian stage, Rivista Italiana di Paleontologia e Stratigrafia 105, pp. 37–78.
; 2006: High-precision U-Pb zircon age from the Triassic of Italy: Implications for the Triassic time scale and the Carnian origin of calcareous nannoplankton and dinosaurs, Geology 34, p. 1009–1012.
; 2004: A Geologic Time Scale 2004, Cambridge University Press.
; 2012: The Geologic Time Scale 2012, Elsevier.
; 1993: Adelobasileus from the upper Triassic of west Texas: the oldest mammal, J. Vert. Paleont. 13, pp. 309–334.
; 2012: The Global Boundary Stratotype Section and Point (GSSP) of the Carnian stage (Late Triassic) at Prati di Stuores/Stuores Wiesen section (Southern Alps, NE Italy), Episodes 35, pp. 414–430.
External links
GeoWhen Database – Carnian
Upper Triassic timescale, at the website of the subcommission for stratigraphic information of the ICS
Norges Network of offshore records of geology and stratigraphy: Stratigraphic charts for the Triassic, , and
Palaeos Mesozoic: Carnian Age
01
Geological ages
Triassic geochronology |
2941214 | https://en.wikipedia.org/wiki/Marion%20Power%20Shovel%20Company | Marion Power Shovel Company | Marion Power Shovel Company was an American firm that designed, manufactured and sold steam shovels, power shovels, blast hole drills, excavators, and dragline excavators for use in the construction and mining industries. The company was a major supplier of steam shovels for the construction of the Panama Canal. The company also built the two crawler-transporters used by NASA for transporting the Saturn V rocket and later the Space Shuttle to their launch pads. The company's shovels played a major role in excavation for Hoover Dam, the Holland Tunnel and the extension of the Number 7 subway line to Main Street in Flushing, Queens.
Founded in Marion, Ohio in August, 1884 by Henry Barnhart, Edward Huber and George W. King as the Marion Steam Shovel Company, the company grew through sales and acquisitions throughout the 20th century. The company changed its name to Marion Power Shovel Company in 1946 to reflect the industry's change from steam power to diesel power.
The company ceased to be independent when it was sold, becoming the Marion division of Dresser Industries in 1977. In 1992, Dresser spun off the Marion division and certain other assets into a holding company that eventually became the Global Industrial Technologies, Inc. Global sold the division to longtime rival Bucyrus International for US$40.1 million in 1997. Bucyrus integrated the Marion division's products into the Bucyrus product line, then closed the Marion, Ohio, facility. In 2010 Bucyrus was purchased by Caterpillar, Inc., the world’s largest equipment manufacturer.
History
Marion Steam Shovel Company
The Marion Steam Shovel Company was established by Henry Barnhart, George W. King and Edward Huber in August 1884. While steam shovels had been made prior to this date in the United States, Barnhart persuaded Huber to financially back his design, which incorporated a stronger bucket support than other makes. Barnhart and Huber patented Barnhart's changes under US Patent No. 285,100 on September 18, 1883. One element of Barnhart's design was the use of solid iron rods (hog rings) to support the boom of the shovel, which was stronger than simple chain.
This machine set the record in July 1908 for moving of earth in 25 eight-hour days after American project management began. Marion built large and small steam shovels for building contractors, railroads and the US Army Corps of Engineers who were building the Panama Canal at the time. The company, from between 1902 and 1911, shipped 24 shovels to Panama for the construction of the canal.
Marion excavators were used during construction of Magnitogorsk Iron and Steel Works in the Soviet Union in 1930s. Marion was the first fоreign machine there, in 1930. Poet Boris Ruchyov wrote the "Ballad of Excavator Marion" [Баллада об экскаваторе Марион] on this occasion.
By 1911 90% of all large bucket steam shovels and draglines were produced in Marion Ohio, which was also the headquarters of Osgood Steam Shovel, Fairbanks Steam Shovel and General Excavating Corporation. (Competitor Bucyrus Steam Shovel was founded from Marion in nearby Bucyrus, Ohio. The company soon relocated to Milwaukee, Wisconsin after Bucyrus city officials refused to approve expansion plans for the company.)
Towards the end of WWI the company assembled M1918 railway guns utilizing a repurposed M1895 12 inch 45 caliber coastal defense gun. The only remaining example was stored for testing purposes at Naval Surface Warfare Center Dahlgren VA until 2011 when it was moved to Fort Lee, VA for inclusion in the U.S. Army Ordnance Training and Heritage Center.
Marion Power Shovel
In April 1946, the company changed its name to the Marion Power Shovel Company to more closely reflect its products.
Marion built its first walking dragline in 1939 and became a key player in providing giant stripping shovels to the coal industry, being the first to put a long-boom revolving stripping shovel to work in North America in 1911. Marion’s succession of giant shovels, many breaking world size records, starting with The Mountaineer in 1956 which was 16 stories. One shovel load moved approximately 90 tons, which was then one of the world's largest power shovels. Marion's huge power shovel models eventually culminated in the world’s largest: the 1965 Marion 6360. The 6360 at the Captain Mine, Illinois, operated with a 180 cubic yard (138 cubic meter) dipper. With an estimated weight of 15,000 tons (13,600 tonnes), this machine is one of the heaviest mobile land machines ever built.
Marion designed and built the NASA Crawler-transporter used to transport both the Saturn V rocket, as well as the Space Shuttle.
Osgood Company acquisition
In 1955, Marion Power Shovel acquired its crosstown rival, the Osgood Company, which manufactured shovels under the Marion-Osgood and Osgood names. Osgood's product line complemented Marion Power Shovel's, with most of Osgood's product line focusing on shovels, cranes and draglines that were small capacity machines as opposed to Marion's line, which focused increasingly on high end strip mining draglines. Osgood also built road-ready mobile units that used Mack truck undercarriages.
Acquisition and end
The Marion Power Shovel Company was refinanced by management in the late 1960s with only the signature guarantee of the primary stockholder, billionaire Henry Hillman, of Pittsburgh, Pennsylvania and PNC Bank fame. In 1977 Dresser Industries, Inc. purchased Marion Power Shovel for approximately US$250 million. The company grew from 1,500 employees in 1974 to over 3,200 employees by 1978 under the direction of Putt McDowell during the massive growth in coal mining demand of the late 1970s.
By 1992, Dresser Industries decided to exit the production of industrial and mining equipment. The affected assets, including the Marion division, became part of Indresco, a holding company created by Dresser in 1992 and then spun off to Dresser shareholders. On November 1, 1995, Indresco changed its name to Global Industrial Technologies, Inc.
On January 23, 1997 Global Industrial Technologies announced that it was divesting certain assets, including the Marion division. Global Industrial Technologies sold the Marion Power Shovel Company, which had revenues of US$114.4 million in FY 1996, for US$40.1 million to Bucyrus International, Inc. on July 23, 1997. Following the acquisition, Bucyrus International closed Marion Power Shovel Company's Marion, Ohio facility.
Historical corporate files and archives for Marion Power Shovel were split between Bowling Green, Ohio's Historical Construction Equipment Association and the Marion County Historical Society in Marion, Ohio.
References & Sources
Sources
See also
Power shovel
Dragline
Big Muskie
Big Brutus
Marion Steam Shovel (Le Roy, New York)
External links
Bucyrus International, Marion Power Shovel
Historical Construction Equipment Association
Happy Birthday Crawlers, NASA page
NASA Moveable Launch Pad
Virtual Tour of the Crawler-Transporter 2 Upgrades, Sept 3, 2014
Apollo program
Construction equipment manufacturers of the United States
Defunct manufacturing companies based in Ohio
Articles containing video clips
Marion, Ohio
Panama Canal
Companies established in 1884
Companies disestablished in 1997
Bucyrus-Erie |
2943368 | https://en.wikipedia.org/wiki/Amphoterite | Amphoterite | Amphoterite is an obsolete classification of chondritic meteorites that are now classified as LL (Low Iron and Low total metal content) types.
Most of the iron in these types of meteorites is present as ironoxide in the minerals (e.g. olivine) rather than as free metal, as it is found in most other meteorites. Free metallic iron amounts to between 0.3% and 3.0% of the meteorite, and with a total iron content of 20% give or take a couple of percentage points.
There will be a number after the LL in a meteorites classification type, e.g. LL3, LL5, LL6. (Types range from 3 to 7) The number indicates the amount of alteration suffered by the chondrules in the meteorite.
A chondrule is a small mineral ball generally in diameter. An LL3 type is pristine with perfectly discernible chondrules, an LL7 type has been melted or altered by pressure or other force to almost completely obliterate the round chondrules.
Sources
Astrodigital Online Dictionary of Meteoritics
See also
Glossary of meteoritics
Meteorite mineralogy and petrology |
2945428 | https://en.wikipedia.org/wiki/Gerry%20Hughes%20%28sailor%29 | Gerry Hughes (sailor) | Gerry Hughes is a British sailor who became the first profoundly deaf man to sail single-handed across the Atlantic Ocean. He crossed the finishing line off Castle Hill, Newport at 11:30 am local time (4:30 pm UTC) on Saturday 3 July 2005 after 35 days of sailing. Hughes also became the world's first deaf yachtsman to sail single-handed around the world to pass the five great capes. He departed Troon, Scotland on 1 September 2012 and returned to Troon on 8 May 2013. Dr Hughes was added as number 202 on Sir Robin Knox-Johnston's list of elite solo circumnavigators - In 2019 Gerry Hughes published a book about his life called 'Bridging Our Differences'.
Biography
Gerry Hughes was born in Glasgow. He was profoundly deaf from birth. His father was a skilled sailor and Gerry enjoyed boating with him from around 2 years old in Largs, Rhu and Inverkip. At age 2 and a half, he was enrolled at St. Vincent's School for the Deaf. At thirteen Gerry began his schooling at St. John's School for the Deaf, Boston Spa, Yorkshire. He went on to attend Norfolk House College for the Deaf where he studied City and Guilds for London Institute Mechanical Engineering Part One Certificate, 'A' Level Technical Drawing, and ‘O’ Level Mathematics and Physics. During his time at Norfolk House, Gerry became captain for Surbiton Football Club. In his teenage years he was involved with a group of deaf sailors in the south of England and sailed across the English Channel. He became the first deaf skipper to sail around the British Isles, in 1981.
Gerry was a research associate for the British Sign Language Research Project (BSL) at Moray House College of Education working with Mary Brennan and Martin Colville.
Gerry went on to found a school for hearing and deaf people called ‘Quest for Language’ while at the same time studying towards a degree in mathematics from the Open University. In 1991, Gerry was offered a position as graduate instructor at St Vincent's School for the Deaf. After almost eighteen years from his first application to teacher training college, after being initially blocked from studying, and having to seek legal help, Gerry joined the PGCE course at St Andrew's College, Glasgow, to train as a secondary school teacher in mathematics. In 1995 he qualified as a teacher. He later became acting head of Donaldson's School for the Deaf in Edinburgh. Gerry later went on to teach at St Roch's Secondary School in Glasgow.
Single-handed trans-Atlantic race
In August 2004, Hughes bought a 23-year-old, 34-foot yacht. He named the yacht Quest II.
Hughes set off from Portsmouth in Quest II, but was forced to call at Cork in Ireland for repairs due to a failure of battery power. Out in the Atlantic, a few days later, the battery power failed again, resulting is the loss of use of his navigation lights, generator, laptop computer and mobile phone. He continued, making use of an oil lamp.
When he eventually reached USA waters he was able to ask directions from a passing speed-boat encountered in fog. He reached Newport successfully when the fog had cleared.
Sailing around the world
On 1 September 2012 Hughes left Troon, Scotland to start his eight-month journey across the world. Hughes travel around the world solo, sailed 32,000 miles and became the first deaf yachtsman to passed all five southernmost capes - Cape Agulhas, Cape Leeuwin, South East Cape, South West Cape and Cape Horn.
References
External links
Quest III Sailing Project
Bridging-Our-Differences-by Gerry-Hughes on Amazon
Single-handed sailors
Single-handed circumnavigating sailors
Living people
Educators of the deaf
Deaf sportspeople
Scottish deaf people
BSL users
Year of birth missing (living people)
Deaf educators |
2949297 | https://en.wikipedia.org/wiki/Loyola%20Residence%20Tower | Loyola Residence Tower | The Loyola Residence Tower (also known as the Ignatius Loyola Residence) in Halifax, Canada is a residence of Saint Mary's University completed in 1971. It is located on the main campus with a height of 67 metres accommodating up to 434 students on 22 floors.
It is notable as the home of the Burke-Gaffney Observatory, part of the university's Department of Astronomy and Physics. The building also houses the St. Mary's University Art Gallery, which is situated on the ground floor.
In early 2023, the south-facing concrete façade of the tower was replaced with solar panels in order to reduce the university's carbon footprint. Retrofitted at a cost of C$8.5 million, the installation is expected to generate around 100,000 kWh yearly, and makes the Loyola Residence the tallest solar-integrated building in North America.
See also
List of astronomical observatories
References
External links
Profile of The Ignatius Loyola Residence, St. Mary's University
Emporis
Astronomical observatories in Canada
Buildings and structures in Halifax, Nova Scotia
Saint Mary's University (Halifax)
Solar architecture |
2951341 | https://en.wikipedia.org/wiki/Sundance%20Sea | Sundance Sea | The Sundance Sea was an epeiric sea that existed in North America during the mid-to-late Jurassic Period of the Mesozoic Era. It was an arm of what is now the Arctic Ocean, and extended through what is now western Canada into the central western United States. The sea receded when highlands to the west began to rise.
Stratigraphy
The Sundance Sea did not occur at a single time; geological evidence suggests that the Sea was actually a series of five successive marine transgressions—each separated by an erosional hiatus—which advanced and receded from the middle Jurassic onward. The terrestrial sediments of the Morrison Formation—eroded from rising highlands to the west—were deposited on top of the marine Sundance sediments as the sea regressed for the last time late in the Jurassic.
Fauna
The Sundance Sea was rich in many types of animals. Gryphaea was extremely common, and shark teeth have been found. In addition to fish, belemnites and to an extent ammonites have been found in sediments from the Sundance Sea. Crinoids and bivalves would have dotted the seafloor. Ophthalmosaurus, a large long ichthyosaur, swam in the seas using its large, long jaws to catch belemnite 'squid'. Pantosaurus, a 15-20 foot (4.5-6 m) long cryptoclidid plesiosaur, went after the easier-to-catch fish. The largest marine reptile in the Sundance Sea was Megalneusaurus, a long pliosaur similar to Liopleurodon. Its fossils have been found in Alaska and Wyoming, which were both covered by the Sundance Sea when it was alive.
During the periods of recession, dinosaurs and other Jurassic terrestrial animals frequented the shores, as evidenced by the Red Gulch Dinosaur Tracksite near Shell, Wyoming.
See also
References
External links
Map of North America in the middle Jurassic, with the location of the Sundance Sea
Historical oceans
Late Jurassic North America
Jurassic paleogeography
Jurassic Canada
Jurassic United States
Geology of the Rocky Mountains
Jurassic Alberta
Jurassic Montana
Jurassic geology of Wyoming |
2951997 | https://en.wikipedia.org/wiki/The%20Loves%20of%20the%20Gods | The Loves of the Gods | The Loves of the Gods is a monumental fresco cycle, completed by the Bolognese artist Annibale Carracci and his studio, in the Farnese Gallery which is located in the west wing of the Palazzo Farnese, now the French Embassy, in Rome. The frescoes were greatly admired at the time, and were later considered to reflect a significant change in painting style away from sixteenth century Mannerism in anticipation of the development of Baroque and Classicism in Rome during the seventeenth century.
Production
Cardinal Odoardo Farnese (cardinal), Pope Paul III's great-great grandson, commissioned Annibale Carracci and his workshop to decorate the barrel-vaulted gallery on the piano nobile of the family palace. Work was started in 1597 and was not entirely finished until 1608, one year before Annibale's death.
His brother Agostino joined him from 1597 to 1600, and other artists in the workshop included Giovanni Lanfranco, Francesco Albani, Domenichino, and Sisto Badalocchio.
Scheme and interpretations
Annibale Carracci had first decorated a small room, the Camerino (1595-7), with scenes from the life of Hercules. The Herculean theme was probably selected because the Farnese Hercules was standing at the time in the Palazzo Farnese. This concept of art imitating ancient art seems to have been carried over to the large Gallery. While performing graduate research on the Gallery, Thomas Hoving, later director of the Metropolitan Museum of Art, pointed out many correspondences between the frescoes and items in the famous Farnese Collection of Roman sculpture. Much of the collection is now housed in the Capodimonte Museum and National Archaeological Museum in Naples but, in the sixteenth and seventeenth centuries, it was arranged according to themes within the Palazzo Farnese. Hoving's suggestion that many details of the frescoes were designed to complement the marbles below has been generally accepted.
In 1597, Carracci began to decorate the Gallery with scenes depicting the loves of the gods set within frames (quadri riportati) and faux bronze medallions painted on an illusionistic architectural framework referred to as quadratura. Ignudi, putti, satyrs, grotesques, and standing Atlas figures (Atlantes) help support the painted framework.
Gian Pietro Bellori, a biographer of seventeenth-century artists and Platonic apologist, called the cycle "Human Love Governed by Celestial Love". This observation was based principally on Carracci's depiction of putti representing Cupid (equated by Bellori with profane love) and Anteros (equated with sacred love) found at the four corners of the vault. For example, Bellori writes:
The painter wished to represent with various symbols the war and peace between heavenly and common love formulated by Plato. On one side he painted Heavenly Love wrestling with Common Love and pulling him by the hair: this is the philosophy and most sacred law that removes the soul from vice, raising it on high. Accordingly, a crown of immortal laurel is resplendent overhead amid brilliant light, demonstrating that victory over the irrational appetites raises men up to heaven.
Hoving saw it differently. In his memoir, he writes:
My lucky discovery destroyed the accepted interpretation of Annibale's fresco cycle as a "Neo-Platonic visual essay about celestial love's supremacy over physical passion." The paintings were actually both an entertaining celebration of a bunch of randy Olympians hitting on each other and also an up-scale mind game paying homage to Odoardo's fine antiquities collection.
Scenes on the vault
In addition to the putti shown at the four corners, The Loves of the Gods are depicted on the vault in thirteen narrative scenes. Complementing them, there are twelve medallions painted to appear as bronze reliefs. These medallions portray additional stories of love, abduction, and tragedy. The scenes are arranged as follows:
Central row (from left to right in the accompanying image): Pan and Diana, The Triumph of Bacchus and Ariadne, and Mercury and Paris.
Beginning in the lower left and proceeding counter-clockwise around the vault, the remaining scenes are:
West side (from left to right in the lower portion of the accompanying image): Jupiter and Juno, Marine scene (traditionally The Triumph of Galatea), and Diana and Endymion.
Medallions on the west side (from left to right): Apollo and Marsyas, Boreas and Orithyia, Orpheus and Euridice, and The Rape of Europa.
South side (on the right of the accompanying image): Apollo and Hyacinth above Polyphemus and Galatea.
Medallions on the south side: Possible scene of abduction and Jason and the Golden Fleece.
East side (from right to left in the upper portion of the accompanying image): Hercules and Iole, Aurora and Cephalus, and Venus and Anchises.
Medallions on the east side (from right to left): Hero and Leander, Pan and Syrinx, Salmacis and Hermaphroditus, and Cupid and Pan.
North side (on the left of the accompanying image): The Rape of Ganymede above Polyphemus and Acis.
Medallions on the north side: Judgement of Paris and Pan and Apollo.
The Triumph of Bacchus and Ariadne
Prominently displayed in the center panel, the Triumph of Bacchus and Ariadne depicts a both riotous and classically restrained procession which ferries Bacchus and Ariadne to their lovers' bed. Here, the underlying myth is that Bacchus, the god of wine, had gained the love of the abandoned princess, Ariadne. The procession recalls the triumphs of the Republican and Imperial Roman era, in which the parades of victorious leaders had the laurel-crowned ‘imperator’ in a white chariot with two white horses. In Carracci's procession, the two lovers are seated in chariots drawn by tigers and goats, and accompanied by a parade of nymphs, bacchanti, and trumpeting satyrs. At the fore, Bacchus' tutor, the paunchy, ugly, and leering drunk Silenus, rides an ass. The figures carefully cavort in order to hide most naked male genitals.
The program refers to Ovid's Metamorphoses (VIII; lines 160-182) and the spirit alludes to contemporary images voiced, for example, in a carnival song-poem written by Lorenzo de Medici in about 1475, that entreats:
{| style="width: 490px;"
|- style="vertical-align: top;"
| style="width: 46%;" |
Quest’è Bacco ed Arïanna,
belli, e l'un de l'altro ardenti:
perché ’l tempo fugge e inganna,
sempre insieme stan contenti.
Queste ninfe ed altre genti
sono allegre tuttavia.
Chi vuol esser lieto, sia:
di doman non c’è certezza.
| style="width: 54%;" |
Here are Bacchus and Ariadne,
Handsome, and burning for each other:
Because time flees and fools,
They stay together always content.
These nymphs and those others
Are ever full of joy.
Let those who wish to be happy, be:
Of tomorrow, we have no certainty.
|}
Additional scenes
Scenes on the walls
Legacy
Annibale Carracci's decorations in the Farnese Gallery demonstrated a new grand manner of monumental fresco painting. They exerted a powerful formative influence on both canvas and fresco painting in Rome during the seventeenth century. The dual classicizing and baroque tendencies in this work would fuel the debate by the next generation of fresco painters, between Sacchi and Pietro da Cortona, over the number of figures to be included in a painting. Carracci's treatment of the composition and the disposition and expression of the figures would influence painters such as Sacchi and Poussin, whereas his effervescent narrative manner influenced Cortona.
Annibale Carracci, in his day, was seen as one of the key painters to revive the classical style. In contrast, a few years later, artists such as Caravaggio and his followers would rebel against representing spatial depth in colour and light, and introduce tenebrous dramatic realism into their art instead. But it would be inappropriate to view Annibale Carracci as solely the continuation of an inherited tradition; in his day, his vigorous and dynamic style, and that of his studio assistants, changed the pre-eminent style of painting in Rome. His work would have been seen as liberating for artists of his day, touching on pagan themes with an unconstrained joy. It could be said that while Mannerism had mastered the art of formal strained contraposto and contorsion; Annibale Carracci had depicted dance and joy.
Later followers of Neoclassic formalism and severity frowned on the excesses of Annibale Carracci, but in his day, he would have been seen as masterful in achieving the supreme approximation to classic beauty in the tradition of Raphael and Giulio Romano's secular frescoes in the Loggia of the Villa Farnesina. Unlike Raphael, though, his figures can display a Michelangelo-esque muscularity, and depart from the often emotionless visages of High Renaissance painting.
References
Further reading
Cajano, Elvira, and Settimi, Emanuela (eds.) (trans. John Adamson and Victoria Constable) (2015), The Carracci Gallery: Its History and Restoration. Dijon: Éditions Faton .
External links
A paraphrased copy decorates the ceiling of the Blue Drawing Room at West Wycombe Park in England.
1608 paintings
Mythological paintings by Annibale Carracci
Fresco paintings in Rome
Paintings of Venus
Paintings of Pan (god)
Paintings of Cupid
Paintings of Apollo
Paintings of Roman goddesses
Paintings of Roman gods
Paintings of Jupiter (mythology)
Callisto (mythology)
Paintings depicting Diana (mythology) |
2954181 | https://en.wikipedia.org/wiki/Stokes%20%28Martian%20crater%29 | Stokes (Martian crater) | Stokes is an impact crater on Mars, located on the Martian Northern plains at 55.9°N latitude and 188.8°W longitude. It measures approximately in diameter and was named after Irish-born physicist George Gabriel Stokes (1819–1903). The crater's name was officially adopted by IAU's Working Group for Planetary System Nomenclature in 1973.
It is distinctive for its dark-toned sand dunes, which have been formed by the planet's strong winds. Research released in July 2010 showed that is one of at least nine craters in the northern lowlands that contains hydrated minerals. They are clay minerals, also called phyllosilicates.
References
Impact craters on Mars
Cebrenia quadrangle |
2958127 | https://en.wikipedia.org/wiki/Uttarayana | Uttarayana | The term Uttarāyaṇa (commonly Uttarayanam) is derived from two different Sanskrit words – "uttaram" (North) and "ayanam" (movement) – thus indicating the northward movement of the Sun. In the Gregorian calendar, this pertains to the "actual movement of the sun with respect to the earth." Also known as the six month period that occurs between the winter solstice and summer solstice (approximately 20 December - 20 January). According to the Indian solar calendar, it refers to the movement of the Sun through the zodiac. This difference is because the solstices continually precess at a rate of 50 arcseconds per year due to the precession of the equinoxes, i.e. this difference is the difference between the sidereal and tropical zodiacs. The Surya Siddhanta bridges this difference by juxtaposing the four solstitial and equinoctial points with four of the twelve boundaries of the rashis.
The complement of Uttarayana is Dakshinayana (the southward movement of the Sun). It is the period between Karka Sankranti and Makara Sankranti as per the sidereal zodiac and between the summer solstice and winter solstice as per the tropical zodiac.
Difference between Uttarayana and Makara Sankranti
There is a common misconception that Makara Sankranti marks the beginning of Uttarayana. This is because at one point in time Sayana and Nirayana zodiac were the same. Every year sidereal and tropical equinoxes slide by 50 seconds due to axial precession, giving birth to Ayanamsha and causing Makara Sankranti to slide further. When equinox slides it will increase ayanamsha and Makara Sankranti will also slide. This misconception continues as there is not much difference between actual Uttarayana date which occurs a day after winter solstice (of Dec 21) when the Sun makes the northward journey, and 14 January. However, the difference will be significant as equinoxes slide further. In 272 CE, Makara Sankranti was on 21 December. In 1000 CE, Makara Sankranti was on 31 December and now it falls on January 14. After 9000 years, Makara Sankranti will be in June. Then Makara Sankranti would mark the beginning of Dakshinayana. However Makara Sankranti still holds importance in Hindu rituals. All Drika Panchanga makers like mypanchang.com, datepanchang, janmabhumi panchang, rashtriya panchang and Vishuddha Siddhanta Panjika use the position of the tropical Sun to determine Uttarayana and Dakshinayana.
Uttarayana in various treatises
Surya Siddhanta
Mayasura, the composer of Surya Siddhanta, defines Uttarayana, at the time of composition, as the period between the Makara Sankranti (which currently occurs around January 14) and Karka Sankranti (which currently occurs around July 16). Lātadeva describes this as half revolutions of the Sun, using the terms Uttarayana and Dakshinayana to describe the "northern and southern progress" respectively. Bal Gangadhar Tilak, a scholar and mathematician, proposes an alternative, early vedic definition of Uttarayana as starting from Vernal Equinox and ending with Autumnal Equinox. This definition interprets the term "Uttara Ayana" as "northern movement" instead of "northward movement", i.e. as the movement of the Earth in the region North of the Equator. In support of this proposal, he points to another tradition that the Uttarayana is considered the daytime of the Gods residing at the North Pole which tradition makes sense only if we define Uttarayana as the period between the Vernal and Autumnal equinoxes (when there is Midnight Sun at the North Pole). Conversely, Dakshinaya is defined as the period between the Autumnal and Vernal Equinoxes, when there is midnight sun at the South Pole. This period is also referred to as Pitrayana (with the Pitrus (i.e. ancestors) being placed at the South Pole).
Drik Siddhanta
This festival is currently celebrated on the 14th or 15 January but due to axial precession of the Earth it will continue to shift away from the actual season. The season occurs based on tropical sun (without ayanamsha). The Earth revolves around Sun with a tilt of 23.44 degrees. When the tilt is facing the Sun it is defined as summer and when the tilt is away from the Sun it is called winter. That is the reason when there is summer north of the equator, it will be winter south of the equator. Because of this tilt, the Sun appears to travel north and south of the equator. This motion of the Sun transitioning from south to north is called Uttarayana (the Sun is moving towards north). Once the Sun reaches north, it begins moving south and is called Dakshinayana – the Sun is moving towards south. This causes seasons which are dependent on equinoxes and solstices.
Hindu Scriptures
Uttarayana is referred to as the day of new good healthy wealthy beginning. In the Mahabharata, this day marks the death of Bhishma. Bhishma had the ability to choose the time of his death and although mortally wounded in war, he chose to delay his death until uttarayan. According to the Bhagavad Gita, a Hindu scripture, those who die when the Sun is on its northward course (from south to north) attain nirvana. This explains the choice made by Bhishma to wait until Uttarayana to die.
According to the Hindu tradition the six month period of Uttarayana is equivalent to a single day of the Gods, while the six month period of Dakshinayana is equal to a single night of the Gods. Thus a year of twelve months is single day of the Gods. This refers to the six months of single day at the North pole and concurrent six months of night at the south pole.
Rituals
During the Uttarayana, devotees often undertake certain rituals to benefit during the auspicious time. Devotees often take part in pilgrimages to bathe in Prayag, where the Yamuna, Ganga and Saraswati rivers meet.
Pongal is celebrated as a harvest festival in the southern states of India like Tamil Nadu. Although rituals and customs may vary, it is generally celebrated as a four-day festival. On the first day, unwanted household items are discarded and burned in bonfires to symbolize starting anew. The second day, people dress in new clothes and prepare pongal, a sweet dish that is made of rice, milk and jaggery, and offer it to Surya, the Hindu sun deity. On the third day, cattle are worshipped because they are seen as a symbol of prosperity. And, on the last day, some regions host bull-fighting and farmers offer prayers for the new, fresh harvest.
Known as Lori in the northern states, children go door-to-door asking for sweets and money, and in the evening, people gather around huge bonfires to sing, dance, and make offerings to Agni, the fire deity, for future prosperity. Traditional dishes made from flatbread and mustard leaves are shared with offerings of sesame brittle, peanuts, popcorn, and jaggery. It is celebrated in other North Indian states like Haryana, Delhi, and Himachal Pradesh.
References
External links
Animated illustration of Uttarayana and Dakshinayana
Hindu astronomy
Hindu calendar
Articles containing video clips
Summer solstice
Winter solstice |
2958235 | https://en.wikipedia.org/wiki/Aphrodite%20Terra | Aphrodite Terra | Aphrodite Terra is one of the three continental regions on the planet Venus, the others being Ishtar Terra and Lada Terra. It is named for Aphrodite, the Greek equivalent of the goddess Venus, and is found near the equator of the planet. Aphrodite Terra is about half the size of Africa, making it the largest of the terrae.
Description
Aphrodite Terra was named by the International Astronomical Union, the governing body for planetary and satellite nomenclature, after Aphrodite, the goddess of love. The name was chosen because Aphrodite is the Greek equivalent of the Roman goddess Venus.
Located near the equator of Venus, Aphrodite Terra has an area about half the size of Africa, and is much larger than the rougher Ishtar Terra. It is covered with deep rift valleys. Like Ishtar Terra, Aphrodite Terra also has mountain ranges but they are only about half the size of the mountains on Ishtar.
Extending nearly two thirds around the planet, Aphrodite Terra's topography appears buckled and fractured which suggests large compressive forces. There are also numerous extensive lava flows across this terrain and some have an interesting bow shape to them due to atmospheric gravity waves.
Aphrodite Terra has two main regions: Ovda Regio in the west and Thetis Regio in the east. Ovda Regio has ridges running in two directions, suggesting that the compressive forces are acting in several directions. Certain dark regions appear to be solidified lava flows. A series of cracks appear where lava has welled up through the surface and flooded the surrounding terrain.
Gallery
See also
Geography of Venus
Ishtar Terra
Lada Terra
Vega 1
Vega 2
References
Bibliography
1. D. A. Senske, "Geology of the Venus equatorial region from Pioneer Venus radar imaging," Part 3 Regional Geology, Earth, Moon, and Planets, July 1990, Volume 50, Issue 1, Springer, pp 305–327.
2. L. S. Crumpler, "Eastern Aphrodite Terra on Venus: Characteristics, structure, and mode of origin," Part 3 Regional Geology, Earth, Moon, and Planets, July 1990, Volume 50, Issue 1, Springer, pp 343–388. (Page 1).
External links
NASA Map of Venus:
Surface features of Venus |
2958375 | https://en.wikipedia.org/wiki/Halibut%20Treaty | Halibut Treaty | The Halibut Treaty was a 1923 Canadian–American agreement concerning fishing rights in the northern Pacific Ocean. The treaty established the International Pacific Halibut Commission (IPHC) as a mechanism for the joint management of the Pacific halibut (Hippoglossus stenolepis) which, at that time, was in severe decline. The commission originally had four members but now has six, which are selected from industry and related government agencies. Half the members are Canadian and half are from the United States. The treaty also had a provision for a closed season, so halibut could not be fished during the more dangerous winter months. The treaty has been revised numerous times, often based on recommendations from the IPHC and its team of scientific researchers.
Background
In 1907, Canada began to negotiate its own commercial treaties. Prior to that, treaties had been negotiated on behalf of the Canadian government by the British government in London. However, those treaties negotiated since 1907 had all been signed into agreement by the British ambassador to Canada. In 1916, the British Columbia government was informed that halibut stocks were declining in the North Pacific Ocean. Large scale halibut fishing began after the opening of the Northern Pacific Railway to the Canadian Pacific Coast which allowed the transportation and sale of halibut in Eastern Canada. During World War I there was increasing cooperation between Canada and United States on trade issues. During the war, the value of halibut increased. Following the war in 1919, the United States and Canada agreed on a closed-season treaty that also included provisions for salmon fishing. The treaty failed to reach the United States Senate for approval.
The Canadian Prime Minister, William Lyon Mackenzie King, held the belief that only Canada through Parliament would determine its role within the British Empire. After negotiations over the Rush–Bagot Treaty failed due to British involvement, King intended to push for greater Canadian autonomy. King faced resistance to the treaty from the British Foreign Office. In 1921–22 some in the American halibut industry operated under a voluntary closed season.
1922 proposal
In 1922, Canada proposed a treaty that dealt only with halibut. Named, the Convention for the Preservation of Halibut Fishery of the Northern Pacific Ocean, this treaty created the International Fisheries Commission (IFC), which was initially intended just as a study institute, not for management. The treaty was birthed from Article VII of the previous salmon and halibut treaty. The treaty proposed a season closed to commercial fishing from 16 November to 15 February. Those that were caught during this period faced penalties up to and including seizure. By the 1920s, halibut stocks were noticeably lower to all parties and in 1923, the treaty was ratified by the United States Congress in 1923. The treaty went into effect in 1927.
In a break with standard empire practice at the time, in March 1923 King demanded to sign the treaty alone, without a British countersignature. The British initially refused but relented when King threatened to send an independent Canadian diplomatic representative to Washington, D.C. The treaty was signed by Ernest Lapointe, the Canadian Minister of Marine and Fisheries and Charles Evans Hughes, the United States Secretary of State on 23 March and intended to last five years.
Result
It was the first treaty negotiated by and signed only by Canada, independent of Britain. The British had relented as King's intention to send a delegation to Washington, D.C. would have bypassed British authority. The British had argued correctly, that what Canada had done had been illegal. However, at the 1923 Imperial Conference the British believed the Halibut Treaty set a new precedent for the role of the British Dominions, which had emerged following a series of events, among them the Chanak Crisis.
The ratification of the treaty paved the way for further British colony independence, including the Balfour Declaration at the Imperial Conference in 1926, which recognized that British Dominions were "autonomous communities within the British Empire, equal in status, in no way subordinate", and finally the Statute of Westminster in 1931 which repealed the Colonial Laws Validity Act and removed the last vestiges of the ability of the British government to create law which applied to its former colonies.
The lack of regulatory powers given to the IFC led to a continued decrease in halibut stocks. In 1930, the commission was expanded to include regulatory powers in a second convention. The treaty was reviewed and amended further in 1937, 1953 with a protocol created in 1979. The IFC was renamed the International Pacific Halibut Commission and expanded to six members. Following the emergence of the Quebec sovereignty movement, the Halibut Treaty was put forward as a method to be used by the provincial government of Quebec to earn independence from Canada.
Citations
Sources
1923 in the environment
Canada–United States treaties
Fisheries treaties
Pacific Ocean
Interwar-period treaties
Treaties concluded in 1923 |
2959462 | https://en.wikipedia.org/wiki/Ekran | Ekran | For the Soviet animation studio see page Studio Ekran
Ekran (, meaning "Screen") was a Soviet-Russian type of geostationary satellite, developed for a national system of Direct-To-Home television. The first satellite of Ekran series was launched on 26 October 1976. Each satellite in the Ekran series was designed to provide one TV and two radio program channels to cable TV systems throughout the USSR and to individual home receivers in northern Siberia. Ekran's downlink is in the Ultra high frequency (UHF) range.
Early Ekran satellites used orbital positions in the range from 48° East to 95° East, but recent Ekran, including the current Ekran 20, have been stationed at 99° East. These 3-axis stabilized satellites carry a single 24 MHz, 200 watts transponder, feeding a 28 dB gain antenna transmitting on right-hand circular polarization to produce in Siberia in the range 50 to 55 dBW at 714 MHz. The corresponding feeder link uses left-hand circular polarization at 6200 MHz. Therefore, almost every householder could receive the TV signal at home from Ekran's transponder using a simple Yagi–Uda antenna. There were also various kinds of collective or individual satellite receivers, such as Ekran-KR10 and Ekran-KR01. Latest version of receiver represents a simple individual TV set-top box itself. A modified version of Ekran was called Ekran-M. Ekran satellites have been replaced by improved geostationary craft for DBS, such as Gorizont, Gals, and Ekspress.
On 23 June 1978, the Ekran-2 spacecraft exploded due to a catastrophic discharge of its battery, contributing to the increase in space debris on the Geostationary orbit. On 1 February 2009, the last satellite from the Ekran series, Ekran-M at 99° East, stopped transmitting.
References
External links
Ekran satellite
Ekran satellite: a short history of development
Ekran-M
Communication satellites: Voices from Space - in Russian
Experiments of amateur Direct-To-Home reception of TV signal from Ekran satellite (included some photo)
Pacific Telecommunications Review
Communications satellites
Earth observation satellites of the Soviet Union
Television in the Soviet Union
Satellite television
Communications satellites of the Soviet Union
Satellites using the KAUR bus
Spacecraft that broke apart in space |