Quantum Science Satellite (QSS)
China’s Quantum Science Satellite, nicknamed Micius, is the world’s first satellite mission testing quantum communications technology which is likely to become the cornerstone of uncrackable communications systems of the future.
The Quantum Science Satellite (QSS) provides the first space-based platform with long-distance satellite and ground quantum channel, carrying out a series of tests to examine fundamental quantum principles and communications protocols in a full-sized space-to-ground architecture. Completing a two-year mission from a 600-Kilometer orbit, QSS will test long-range quantum communications to evaluate the technology readiness level for a Global Scale Quantum Communications Network.
QSS is a project of the China Academy of Sciences with participation of the Austrian Academy of Sciences for a total project value of around $100 million.
Space-based quantum communications represent a kind of modern-day space race given the technology will uncover any tinkering and eavesdropping in the exchange of information between two parties – making it attractive for national security needs and intelligence agencies.
A number of projects are currently being worked on by teams in China, Canada, Japan and Singapore and some progress was made in the field of exchanging information via entangled photons. The U.S. is likely developing quantum communications technology as part of classified national defence projects.
Quantum communications between space and Earth are accomplished by establishing a long-distance quantum channel.
Data sent between the transmitting and receiving stations can not be copied, stolen or spied on – illustrating why quantum communications have been identified as a criticality in times when attacks on sensitive information have become a threat to the world’s governments and private endeavors.
Quantum entanglement is a physical phenomenon in which pairs or groups of particles interact in ways such that the quantum state can only be described for the system as a whole and not for the individual particles part of that system.
The measurement of a property of a particle can be seen as acting on that particle and will change its original quantum property which – in case of entangled particles – will cause the system’s quantum state to change. It appears that one particle of an entangled pair “knows” the measurement conducted on the other particle in an exchange of information that can cover any distance.
Entanglement is one of the most counter-intuitive features of quantum mechanics because the perfect correlations between entangled systems are in direct conflict with the concepts of classical physics. There are proposed theories that predict quantum entanglement is limited to certain scales concerning mass and length or can be altered in certain gravitational environments.
To exploit quantum mechanics for communications, the validity of these theories has to be investigated beyond distances and velocities achievable in ground-based experimentation and in environments were effects of quantum physics and relativity begin to interplay to reveal quantum interference effects that could occur with distances of thousands of Kilometers and speeds closer to relativistic velocities.
Quantum encryption can take advantage of quantum entanglement, utilizing it to detect any eavesdroppers entering the communications loop as their presence would automatically cause quantum states to collapse, ending the flow of information and revealing their spying to the operators of the system. The inherit complexity of quantum mechanics makes it impossible to reverse engineer the quantum key encoded in the polarization of a string of photons, providing an ultra-secure means of communication. Classical cryptography does not allow a provable, unconditionally secure key to be generated simultaneously by two separate communicating parties.
While the exchange of information through quantum entanglement is perfectly secure, quantum networks are still vulnerable to denial of service attacks, physical tampering with hardware, and typical issues arising with operational security.
The primary goal of the QSS mission is to implement a series of communications experiments between the Quantum Science Satellite and quantum communications stations on the ground. The mission will aim to set up an ultra-long-range quantum channel between the ground and satellite, implementing a quantum key distribution for secure quantum experiments. Another experiment will use the satellite as a repeater to connect two quantum ground stations on Earth.
QSS will test quantum entanglement over large distances, distributing quantum entangled photons from the satellite to a pair of distant ground stations. This will also put the principles of the non-locality of quantum mechanics to the test.
The QSS mission is hoped to demonstrate Quantum Teleportation, a fundamental process needed in quantum communications and quantum computing. This experiment will use a high-quality quantum entanglement source on the ground to achieve ground-to-satellite teleportation.
The QSS satellite is a 600-Kilogram spacecraft outfitted with a quantum key communicator, a quantum entanglement emitter, quantum entanglement source, quantum experiment controller and processor, and high-speed coherent laser communicator.
Ground-based quantum communications using optical fibers have been demonstrated over distances of a few hundred Kilometers. Photons traveling through optical fibers or Earth’s air-filled atmosphere are scattered and absorbed – requiring amplifiers to extend a signal’s reach which is extremely difficult while maintaining a photon’s quantum state. Transmitting signals through the vacuum of space should enable communications over much greater distances.
The basic working principle of QSS revolves around a crystal that generates pairs of entangled photons whose properties remain coupled to one another however far apart they are. A high-fidelity optical communications system is then responsible for delivering the partners of the entangled pairs to optical ground stations in Vienna, Austria and Beijing, China where their polarization properties will be used to generate a secret encryption key.
QSS is really the first mission to put to the test whether entanglement can indeed exist between particles separated by very large distances as the laws of quantum mechanics stipulate.
Teleportation of quantum states will be attempted by using entangled photons plus data on their quantum states to reconstruct the photons in an identical quantum state in a new location.
The QSS spacecraft is based on a microsatellite bus that can host payloads of around 200 Kilograms, providing a stable platform with precise pointing capability for ground stations to lock onto the optical carriers from the satellite and vice versa.
The basic design work of QSS was finished by the end of 2011, allowing the project to head into mission definition and technology research in 2012. By mid-2013, the first prototypes of QSS payloads were completed and underwent electronics characteristic testing. A ground test model of the satellite structure was finished by October 2013 for mechanical environment simulations followed by thermal testing. The joint payload systems headed into testing in 2014 before the flight units were manufactured for integration on the satellite bus.
Because quantum communications are a sensitive new technology, information on the design of the QSS payload are not available.
The two-year primary mission is expected to deliver the data needed for an assessment of the feasibility of establishing a constellation of up to 20 satellites to generate a quantum communications network with global space-to-ground communications coverage – a major step towards establishing a quantum internet.
The quantum internet, or a quantum computing cloud, would likely consist of a combination of a satellite and terrestrial network. However, a system of this type requires entangled photons to be created by different sources and inter-satellite quantum communications that are still in the more distant future. Also, data rates – currently expected to be in the megabit range – will have to be boosted to several gigabits per second to compete with traditional space-to-ground data links and optical communications using lasers.
QSS, if successful, may become a trigger for other nations to invest in the development of quantum communications systems for the government and private sector.


The first Wiki was known as WikiWikiWeb and was started in 1994. Wikipedia was launched in 2001. During this period, the technology gestated, waiting for just the right factors to make it relevant and widespread. There are a number of technologies that we come across, that are overhyped, and promise too much on what they can deliver, while still in the early phases of deployment. This deals with the future, and we could get stunning breakthroughs. As with the other articles in this issue, take everything below with a pinch of salt.
Quantum computing promises to speed up computing power, because of the various quantum states available, instead of just simple binary. While the term may be common, we are very far away from having quantum computers everywhere. We don’t even know what the quantum bit, or the qubit will be made up of, atoms, electrons, photons or some other subatomic particle. The materials needed to build the circuits and measure these particles are also currently under development. The few quantum computers that exist today are run in lab environments, at near sub zero temperatures. They have a high error rate, and they cannot process the number of qubits yet that would take their capabilities well beyond the scope of conventional computers. Then, there is the question of creating standards and protocols for quantum computers. A lot of progress will be done over the next decade, but don’t expect a consumer grade quantum computer. Even if a consumer ready quantum computer is invented tomorrow, there remains the question of roll out, and even ten years are not enough to make the transition from one computing paradigm to another.
SpaceX Mars base
The first Red Dragon mission to Mars is expected to take off a little after 2018. This is a pathfinding mission with the specific purpose of finding an ideal place to start building a Mars colony. After this, the first cargo missions to Mars on the Big Falcon Rocket is expected to start off in 2022. So far so good, but this will only happen if the new rocket is developed, successfully tested, and works as expected. SpaceX has not even sent a probe to the red planet yet. The first mission will be called the Heart of Gold, and will deliver a propellant plant to the planet. SpaceX has not yet outlined how it plans to mine the resources as raw material for this fuel planet. It will require carbon dioxide and water locally. It is beyond this stage that things get increasingly improbable. SpaceX is planning a manned mission to Mars with a crew of 12 to make sure the propellant plant is running properly. The earliest pioneering missions by NASA is also beyond the 2030 horizon. We are not saying the SpaceX missions will not happen, but expect some delays.
Artificial General Intelligence
There is no question about it, Artificial Intelligence will own the next decade. According to Sundar Pichai, the next decade belongs to AI. In the mid 80s, desktop computers changed everything, in the mid 90s, it was the internet, and in the mid 2000s, we saw the advent of smartphones. It is the mid 2010s now, and according to Google, this will totally be AI. IBM, Microsoft, Baidu and other tech majors are banking on AI as well. Artificial general intelligence, is however the point at which an AI can do the entire range of tasks that a human can. The problem here is not a specific task, which AI is already better at in many areas. The challenge here is a single AI being able to understand, adapt, and provide a superior response to a human, every single time, when faced with a wide variety of tasks. This kind of AI is called “strong AI” or “full AI”. The incipient field of neuromorphic computing will have to mature first, which are computers built in the same way that human brains are. We still do not have the raw computing power that artificial general intelligences will require. The machines may take our jobs, but they will not be replacing everything that we can do, just yet.
Cross species communication
Species already communicate between themselves. This is about technological interventions to enable cross species communication. While there are already technological solutions to better understand what pets want, or make more accurate guesses, we are a far way away from true cross species communication. This is because, our brains are all wired differently, and our understanding of the world is considerably different. For example, dogs depend far more on the sense of smell than humans do. There is evidence to suggest that pets can understand human body language better than other humans. It would be hilarious, and useful to directly understand what your pet is thinking when it is introduced to novel environments and people. To realise cross species communication, we need to get neural implants that understand all the signals in the brain. Then we need machine learning algorithms to translate the intentions and desires of one species, and make them comprehensible to another species. This is just to communicate with humans. Getting your pet parrot to communicate with your pet cat in a meaningful manner, is nowhere close to realisation over the course of the next decade. A cross species communication system is a far cry.
3D printing, or additive manufacturing has been around for a long time. The first systems were actually created in the 1980s. Even after almost 40 years, it is nowhere close to becoming a consumer grade technology. This is because the end products are not very useful or durable. It also takes a long time to create stuff, and it is expensive as well. Additive manufacturing will continue to grow, but is more likely to be used by services that cater to very specific markets. This could be a 3D printing studio for sundry tasks for artists, architects, and cosplayers. It could also be garages that produce custom spare parts for cars. The actual 3D printers are themselves prohibitively expensive, and do not really offer value for money in terms of the types of items they can produce. The techniques for additive manufacturing will continue to improve, and we see some implementation on the production line. But consumer level 3D printing has not happened for the last 40 years, and we don’t see why it should happen in the next 10.
Multipurpose Household Robots
The challenges with building multipurpose household robots is everything facing artificial general intelligence, plus the robotic implementation. For example, it is very simple to make a robot drive a car, open a door, walk a gangway, or turn a valve. In fact, this can be done just by having robotic cars, doors, and valves. The problem is a single robot that can perform all of these tasks. That would require a roughly human form factor, which robots are very bad at. These robots would be required to use the same appliances and devices that are designed to be used by humans. An android robot cannot even open a door or smash an axe through one, without toppling over. Boston Dynamics is one of the leading companies in this field. The thing is, we might not even need a general purpose household automaton, such as Rosie the Robot in Jetsons. Household automation, IoT, smart speakers can together accomplish separately, what a household robot could possibly do. Forget not happening over the next decade, this one we are chalking down to not even necessary.
Of all the things in the list, this is actually the most likely to come true. Both Amazon and UPS are testing out products that use drones to deliver parcels. The problem is scaling up the service, to build a worldwide network. There are many different variables that autonomous drones will have to handle, and they might not be ready to tackle all these situations within the next ten years. There are limitations on the weight and the distance for which a drone can make a delivery. Landing and taking off is a tricky process, and companies are exploring options such as using parachutes and specially marked drop zones. To allow drone delivery at scale, they will need to be proven safe enough, and pass a number of regulatory hurdles. The on board cameras and sensors on board, for example, will have to prove that they do not invade the privacy of the people. Then there is the question of security, when dispatching high value items such as mobile phones. While drone deliveries will certainly implemented in certain pockets, we don’t see a global implementation within the next decade.


To understand the function of nanoscale materials we need to dip our toes into a discussion of quantum physics. One of the key precepts of quantum physics is that particles and energy waves called photons (like light) can only have distinct amounts of energy, as opposed to having any value of energy along a continuum. The differences between the energy states are called quanta. Quantum physics also tells us that fundamental particles, such as electrons or quarks, have a spin state, described as up or down. Spinning particles exist in pairs, one with up spin and one with down. It’s as though the nanoscale world is digital rather than analog. The most spectacular, everyday manifestation of quantum physics is the rainbow. The hot hydrogen and helium atoms in the sun give off photons of light of precise and specific energy values characteristic of their atomic structure. When refracted by raindrops we see these photons of light arrayed in the colors of the rainbow.
Other aspects of quantum physics are much harder to both understand and explain. Perhaps the most exotic is quantum entanglement, which stumped even Albert Einstein. Quantum entanglement works as follows: let electrons A and B be a spin pair with A spinning up and B spinning down. If energy is applied to A to flip its spin to down, B will immediately flip its spin to up. The amazing part of this process is that B’s spin will flip sooner than the time it would take for light to travel from A to B. This was at odds with Einstein’s view that no information or energy in the universe could travel faster than the speed of light. The mechanism responsible for quantum entanglement remains a mystery to this day.
The appeal of nanotechnology stems from the fact that the physical and chemical properties of materials less than 100 nanometers exhibit behavior based on quantum physics that are not apparent in larger objects. For example, at the nanometer scale copper turns from opaque to transparent, aluminum becomes flammable (even explosive), and carbon atoms can be assembled into nanotubes which are 100 times stronger than steel while having only one sixth of its weight. These changes in properties, of which we are only in our infancy of discovering, are what drive the interest in nanoscale devices.
While quantum physics calculations had long suggested that potentially useful, even revolutionary, devices could be made at the nanoscale level, construction of them was not really possible until the invention of the Scanning Tunneling Microscope (STM) in 1981. The STM works on another fascinating principle in quantum physics called quantum tunneling which, for the sake of brevity and to spare myself the challenge, I will leave unexplained. The beauty of the invention of the STM was the ability to image materials at the nanoscale level so you can see the individual atoms. Without this ability you could not “see” the nanomaterials you were attempting to construct.
With the STM in hand, research and entrepreneurship in nanotechnology took off. Current applications of nanomaterials include titanium dioxide particles in your sunscreen which are dramatically better at blocking UV rays compared to larger titanium dioxide particles, and the silver, bacteria-killing nanotubes which have been added to Band-Aids® to promote healing and socks to cut down on foot odor. You might think that silver is a rather expensive material to use for something as mundane as foot odor control. However, since the effectiveness of the silver nanotubes is directly dependent on their extraordinarily small size, a minute amount goes a long way. We’ll touch on silver nanotubes again later.
The potential for new inventions based on nanotechnology is hard to exaggerate. I like to think of it this way. Since the origin of our species millions of years ago, we have been utilizing the macro-scale (>100 nm) materials available to us on Earth to spectacular effect. Think rockets, iPads®, artificial joints and Cheez Whiz®. But with the advent of nanomaterials and their surprising and unique properties, it’s almost as though we have an entire new planet of materials to work with.
There are far too many potential applications of nanotechnology to include a comprehensive review, so here are several that I find intriguing.
- Nanoscale devices may result in dramatically improved solar cells. An improvement of solar cell efficiency from the current level of 20% to 40-50% would transform global electricity production.
- Quantum computers based on instantaneous quantum entanglement could result in machines that make today’s supercomputers look like the Model T.
- Nano-robots could be launched in the upper atmosphere to rebuild the ozone layer.
- Nanotechnology could provide dramatic improvements in fighting cancer. One approach I find promising is the construction of gold, chemoactive agent containing that have receptors which can bind to cancer cells. With this approach, chemotherapy could be delivered directly to tumors while sparing patients the ravages of having these toxic drugs coursing through their entire bodies.
Unfortunately, the same properties that make nanomaterials attractive, their small size and physical and chemical reactivity, make them potentially dangerous. Remember the socks with the silver, antibacterial nanotubes? When you run them through the laundry, some of the tubes wash off and enter local water-ways where they kill beneficial bacteria. The production and use of nanomaterials also presents significant respiratory risks. We already know that inhaling particulates from coal mining, smoking, or asbestos can cause lung cancer. Breathing in tiny, chemically-active nanoparticles would likely be far worse, a concern which is supported by laboratory studies with mice.
In the final analysis, nanotechnology shares the same characteristics as most new scientific developments, the potential to result in both great benefit and significant harm. Our challenge as a society will be to utilize them responsibly. Undoubtedly, we will make some mistakes along the way, but in the end the results are likely to amaze.
Have a comment, question, or prediction about nanotechnology? Use the comment interface below or send me an e-mail to email@example.com.


Researchers from the European Space Agency and Simon Fraser University in British Columbia have been working to develop a robot sticky enough to cling safely to the outside of a spacecraft while also remaining mobile.
At this point, the robot, dubbed Abigaille, is able to climb walls on Earth.
“This approach is an example of ‘biomimicry,’ taking engineering solutions from the natural world,” said Michael Henrey, a graduate student in engineering at Simon Fraser and a researcher on the project. “Our Abigaille climbing robot is therefore quite dexterous, with six legs each having four degrees of freedom [or joints], so it should be able to handle environments that a wheeled robot could not.”
He added that the robot can transition from a vertical position to horizontal, which could be useful for navigating around the surface of a satellite or maneuvering around obstacles.
For the lizard-like robot, the European Space Agency said it’s taking a lesson from the hairs on the bottom of the gecko’s feet that enable it to stick to surfaces.
“We’ve borrowed techniques from the microelectronics industry to make our own footpad terminators,” Henrey said in a statement. “Technical limitations mean these are around 100 times larger than a gecko’s hairs, but they are sufficient to support our robot’s weight.”
The agency has tested the robot to see if it could work in the rigors of a space environment.
“The reason we’re interested in dry adhesives is that other adhesive methods wouldn’t suit the space environment,” said Henrey. “Scotch, duct or pressure-sensitive tape would collect dust, reducing their stickiness over time… Velcro requires a mating surface, and broken hooks could contaminate the robot’s working environment. Magnets can’t stick to composites, for example, and magnetic fields might affect sensitive instruments.”
It’s not uncommon for robotics researchers to build machines based on animals or even insects. In November, scientists at New York University said they had built a small, flying robot to move like the boneless, pulsating, water-dwelling jellyfish.
Last spring, Harvard University researchers announced that they had built an insect-like robot that flies by flapping its wings. The robot is so small it has about 1/30th the weight of a U.S. penny.
In the fall of 2012, scientists at the University of Sheffield and the University of Sussex in England teamed up to study the brains of honey bees in an attempt to build an autonomous flying robot.
Seasonally adjusted, that would be down 1-2 per cent on a monthly basis and mean that actual chip sales will likely fall 15-16 per cent on a yearly basis. The reason for the fall, the analysts say, is due to disk drive shortages in Thailand which have forced costs to rise. The PC market is likely to be more back-loaded this year, the report notes.
Handset chip sales were likely also soft in January. Chips for cars were softer after a strong December. Other quirks, such as an early Chinese New Year also contributed the low figures in January. Although several chip makers indicated the inventory problems in fourth quarter had ended, Carnegie thinks that the indicator shows that the trend will continue into this year.
PC’s are the biggest chip users, followed by cell phones. Cars, appliances, base stations, and instruments are other significant users, the analyst said.
The latest fad of using SoC (System-o-Chip) processor will be incorporated into the new Slim Xbox 360 according to Microsoft, which cuts down on two processors. According to Microsoft the chip was designed by IBM/Global Foundries is using a 45nm process and combines the tri-core CPU, AMD/ATI GPU, dual channel memory controller, and I/O onto a single chip with a new front side bus. This technological design is similar to the methods used by AMD’s Fusion and Intel’s Sandy Bridge offerings.
As you the true reason for Microsoft to use SoC is to reduce cost. That said, it also reduces heat and increases power efficiency; these are two areas that Microsoft has improved upon with each generation of Xbox 360 that has been released.
The new SoC will have 372 million transistors that took Microsoft development team 5 years of research to bring to life. It is said that Microsoft wanted to pay special attention to guaranteeing compatibility, implemented precision latency and bandwidth throttling that perfectly impersonates the older Xbox systems which used separate chips to make up older XBOX 360s. Now I wonder if Microsoft will drop the Xbox 360 price even more in the Fall.
The tiny computer is being called the Phoenix chip, its size is 1 cubic millimeter and was made to be used in the human eye. The little computer does not have a lot on its plate. The Phoenix has the job of monitoring the intraocular pressure of glaucoma patients, do not be fooled by the assumed simple task, the device is considered a computer by all technical standards.
Researcher Dennis Sylvester, a professor at the University of Michigan says the Phoenix computer comprised of an ultra-low-power microprocessor, a pressure sensor, memory, a ultra slim battery, a solar cell and a wireless radio with an antenna that can transmit data to an external device.
The Phoenix amazingly uses only 5.3 nanowatts while in use, otherwise it sleeps. The researchers profess that such tiny computers will one day be utilized to track pollution, monitor structural integrity, perform surveillance, or make virtually any object smart and track-able.
We are always glad to see Universities lead with amazing research to make our lives better.
IBM is breathing new life into a quantum computing research division at its Thomas J. Watson Research Center, reports New York Times. The computer giant has hired alumni from promising quantum computing programs at Yale and the University of California-Santa Barbara, both of which made quantum leaps in the past year using standard superconducting material.
Groups at both universities have been using rhenium or niobium on a semiconductor surface and cooling the system to absolute zero so that it exhibits quantum behavior. As the Times reports, the method relies on standard microelectronics manufacturing tech, which could make quantum computers easier and cheaper to make.
The Santa Barbara researchers told the Times they believe they can double the computational power of their quantum computers by next year.
Rather than using transistors to crunch the ones and zeroes of binary code, quantum computers store data as qubits, which can represent one and zero simultaneously. This superposition enables the computers to solve multiple problems at once, providing quick answers to tough questions. But observing a qubit strips it of this duality — you can only see one state at a time — so physicists must figure out how to extract data from a qubit without directly observing it. That’s where quantum entanglement comes in handy; two qubits can be connected by an invisible wave so that they share each other’s properties. You could then watch one qubit to see what its twin is computing.
None of this is simple, however; there are several competing methods for making the qubits, including laser-entangled ions, LED-powered entangled photons, and more. Google is working with a Canadian firm called D-Wave that has claimed 50-qubit computers, although skeptics have questioned that number. In most systems, the number of entangled qubits remains small, but Yale researchers believe they will increase in the next few years, the Times says.
Even better: with all this practice, physicists are getting a lot better at controlling quantum interactions. Their precision has increased a thousand-fold, one researcher said. That’s good news for anyone studying quantum mechanics.


For a scientist whose career was made by his work on black holes, it might seem a little confusing to read that Stephen Hawking now thinks that they don’t exist. But that’s what “Information Preservation and Weather Forecasting for Black Holes,” the study Hawking published last week on arXiv, says: “there are no black holes.”
While this might seem surprising–after all, there’s a huge amount of (indirect) evidence that black holes exist, including a massive one several million times the mass of our Sun at the centre of the Milky Way—it’s really not. It’s Hawking’s latest attempt to solve a paradox that he, and other astrophysicists, have been grappling with for a couple of years.
So what’s he talking about? Here’s the background: black holes are objects which are so massive, with such strong gravity, that even light can’t escape. The distance from the black hole, beyond which nothing gets out, is the event horizon. However, Hawking made his name in the 1970s when he published a paper showing that black holes don’t just suck stuff up, endlessly—they spew out a beam of so-called “Hawking radiation” as they absorb other matter. That means black holes actually lose mass over time, eventually whittling away to nothing.
Black holes are frustrating, though, because their extreme gravity exposes the major inadequacy in our current scientific understanding of the universe - we don’t know how to reconcile quantum mechanics and general relativity. With general relativity, we can make accurate predictions about objects with certainty, but on the tiny scale of quantum mechanics it’s only possible to talk about the behaviour of objects in terms of probability. When we do the maths on what happens to things that fall into black holes, using relativity gives results that break quantum mechanics; the same goes vice versa.
One of the key things about quantum mechanics is that it tells us information can’t be destroyed–that is, if you measure the radiation given off by a black hole, you should be able to build up a picture of what matter fell into the hole to create it. However, if general relativity holds, and nothing can escape from inside the event horizon, then that should apply to that quantum information–any radiation that’s coming out is, Hawking showed, random. It’s the black hole “information paradox.” Either give up quantum mechanics, or accept that information can die.
Hawking was in the “information can die” camp, until 2004, when it became clear—thanks to string theory—that quantum mechanics held up (and there’s an excellent in-depth explanation of this in Nature that explores this story more fully if interested). There was just one problem—nobody could work out *how* information was getting out of black holes, even if it was happening mathematically.
And, just in case this wasn’t all entirely confusing, it turns out that our best post-2004 theory about what’s been going on gives rise to an entirely new paradox—the “firewall.”
It’s to do with quantum entanglement, where two particles are created that are identical on the quantum level. The way it works isn’t exactly clear yet—it could be something to do with string theory and wormholes—but it means that measuring the properties of one particle will give readings that mirror those found on its entangled particle. It might lead to teleportation technology, but scientists aren’t sure yet.
Joseph Polchinski from the Kavli Institute for Theoretical Physics in Santa Barbara, California published a paper in 2012 that worked out the information paradox could be solved if Hawking radiation was quantum entangled with the stuff falling in. But, due to the limitations of entanglement, if this is true, that would mean that at the event horizon a massive amount of energy was given off by particles entering and leaving.
Hence “firewall”—anything crossing the event horizon would be burnt to a crisp. And even though most scientists, including Polchinski, thought this couldn’t possibly be right—it completely contradicts a lot of the stuff underlying general relativity, for example—nobody’s yet managed to disprove it.
The choice for physicists, once again, was to: a) accept the firewall, and throw out general relativity, or b) accept that information dies in black holes, and quantum mechanics is wrong.
Still with me? Here’s where Hawking’s latest paper comes in.
(That title—“Information Preservation and Weather Forecasting for Black Holes”—might make some more sense too, hopefully.)
Hawking’s proposed solution, building on an idea first floated in 2005, is that the event horizon isn’t as defined as we’ve come to imagine it. He instead proposes something called an “apparent horizon,” which light and other stuff can escape from:
"The absence of event horizons mean that there are no black holes—in the sense of regimes from which light can't escape to infinnity. There are however apparent horizons which persist for a period of time."
Black holes should be treated more like massive galactic washing machines. Stuff falls in and starts getting tossed around, mixed up with other stuff in there, and only eventually is allowed to escape out again when ready. This happens because the quantum effects around a black hole, like weather on Earth, churn so violently and unpredictably that it’s just impossible to either predict the position of an event horizon or expect uniform effects for stuff crossing it. While the theoretical basis, that information is preserved, remains, in practice it's so difficult as to be impractical.
It’s a fudge of an idea, which tries to have its general relativity and quantum mechanics cakes, and eat them, too. Possible weaknesses, as Nature points out, are that it could imply that escaping from black holes is easier than it is in reality. It could also be the apparent horizons are just as much of a firewall as the traditional conception of an event horizon. Hawking's peers have yet to have a go at assessing his idea, so we'll have to wait to see whether the idea has merit—or whether it merely gives rise to yet more paradoxes.
This piece first appeared on newstatesman.com.
Image via Shutterstock.


The latest news from academia, regulators
research labs and other things of interest
Posted: Dec 23, 2013
Graphene can host exotic new quantum electronic states at its edges
(Nanowerk News) Graphene has become an all-purpose wonder material, spurring armies of researchers to explore new possibilities for this two-dimensional lattice of pure carbon. But new research at MIT has found additional potential for the material by uncovering unexpected features that show up under some extreme conditions — features that could render graphene suitable for exotic uses such as quantum computing.
On a piece of graphene (the horizontal surface with a hexagonal pattern of carbon atoms), in a strong magnetic field, electrons can move only along the edges, and are blocked from moving in the interior. In addition, only electrons with one direction of spin can move in only one direction along the edges (indicated by the blue arrows), while electrons with the opposite spin are blocked (as shown by the red arrows).
Under typical conditions, sheets of graphene behave as normal conductors: Apply a voltage, and current flows throughout the two-dimensional flake. If you turn on a magnetic field perpendicular to the graphene flake, however, the behavior changes: Current flows only along the edge, while the bulk remains insulating. Moreover, this current flows only in one direction — clockwise or counterclockwise, depending on the orientation of the magnetic field — in a phenomenon known as the quantum Hall effect.
In the new work, the researchers found that if they applied a second powerful magnetic field — this time in the same plane as the graphene flake — the material’s behavior changes yet again: Electrons can move around the conducting edge in either direction, with electrons that have one kind of spin moving clockwise while those with the opposite spin move counterclockwise.
“We created an unusual kind of conductor along the edge,” says Young, a Pappalardo Postdoctoral Fellow in MIT’s physics department and the paper’s lead author, “virtually a one-dimensional wire.” The segregation of electrons according to spin is “a normal feature of topological insulators,” he says, “but graphene is not normally a topological insulator. We’re getting the same effect in a very different material system.”
What’s more, by varying the magnetic field, “we can turn these edge states on and off,” Young says. That switching capability means that, in principle, “we can make circuits and transistors out of these,” he says, which has not been realized before in conventional topological insulators.
There is another benefit of this spin selectivity, Young says: It prevents a phenomenon called “backscattering,” which could disrupt the motion of the electrons. As a result, imperfections that would ordinarily ruin the electronic properties of the material have little effect. “Even if the edges are ‘dirty,’ electrons are transmitted along this edge nearly perfectly,” he says.
Jarillo-Herrero, the Mitsui Career Development Associate Professor of Physics at MIT, says the behavior seen in these graphene flakes was predicted, but never seen before. This work, he says, is the first time such spin-selective behavior has been demonstrated in a single sheet of graphene, and also the first time anyone has demonstrated the ability “to transition between these two regimes.”
That could ultimately lead to a novel way of making a kind of quantum computer, Jarillo-Herrero says, something that researchers have tried to do, without success, for decades. But because of the extreme conditions required, Young says, “this would be a very specialized machine” used only for high-priority computational tasks, such as in national laboratories.
Ashoori, a professor of physics, points out that the newly discovered edge states have a number of surprising properties. For example, although gold is an exceptionally good electrical conductor, when dabs of gold are added to the edge of the graphene flakes, they cause the electrical resistance to increase. The gold dabs allow the electrons to backscatter into the oppositely traveling state by mixing the electron spins; the more gold is added, the more the resistance goes up.
This research represents “a new direction” in topological insulators, Young says. “We don’t really know what it might lead to, but it opens our thinking about the kind of electrical devices we can make.”
The experiments required the use of a magnetic field with a strength of 35 tesla — “about 10 times more than in an MRI machine,” Jarillo-Herrero says — and a temperature of just 0.3 degrees Celsius above absolute zero. However, the team is already pursuing ways of observing a similar effect at magnetic fields of just one tesla — similar to a strong kitchen magnet — and at higher temperatures.
Philip Kim, a professor of physics at Columbia University who was not involved in this work, says, “The authors here have beautifully demonstrated excellent quantization of the conductance,” as predicted by theory. He adds, “This is very nice work that may connect topological insulator physics to the physics of graphene with interactions. This work is a good example how the two most popular topics in condensed matter physics are connected each other.”
Source: By David L. Chandler, MIT
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A crucial step in a procedure that could enable future quantum computers to break todayâ€™s most commonly used encryption codes has been demonstrated by physicists at the U.S. Commerce Departmentâ€™s National Institute of Standards and Technology (NIST).
Image: This colorized image shows the fluorescence from three trapped beryllium ions illuminated with an ultraviolet laser beam. Black and blue areas indicate lower intensity, and red and white higher intensity.
As reported in the May 13 issue of the journal Science,* the NIST team showed that it is possible to identify repeating patterns in quantum information stored in ions (charged atoms). The NIST work used three ions as quantum bits (qubits) to represent 1s or 0sâ€”or, under the unusual rules of quantum physics, both 1 and 0 at the same time. Scientists believe that much larger arrays of such ions could process data in a powerful quantum computer. Previous demonstrations of similar processes were performed with qubits made of molecules in a liquid, a system that cannot be expanded to large numbers of qubits.
â€œOur demonstration is important, because it helps pave the way toward building a large-scale quantum computer,â€? says John Chiaverini, lead author of the paper. â€œOur approach also requires fewer steps and is more efficient than those demonstrated previously.â€?
The NIST team used electromagnetically trapped beryllium ions as qubits to demonstrate a quantum version of the â€œFourier transformâ€? process, a widely used method for finding repeating patterns in data. The quantum version is the crucial final step in Shorâ€™s algorithm, a series of steps for finding the â€œprime factorsâ€? of large numbersâ€”the prime numbers that when multiplied together produce a given number.
Developed by Peter Shor of Bell Labs in 1994, the factoring algorithm sparked burgeoning interest in quantum computing. Modern cryptography techniques, which rely on the fact that even the fastest supercomputers require very long times to factor large numbers, are used to encode everything from military communications to bank transactions. But a quantum computer using Shorâ€™s algorithm could factor a number several hundred digits long in a reasonably short time. This algorithm made code breaking the most important application for quantum computing.
Quantum computing, which harnesses the unusual behavior of quantum systems, offers the possibility of parallel processing on a grand scale. Unlike switches that are either fully on or fully off in todayâ€™s computer chips, quantum bits can be on, off, or on and off at the same time. The availability of such â€œsuperpositions,â€? in addition to other strange quantum properties, means that a quantum computer could solve certain problems in an exponentially shorter time than a conventional computer with the same number of bits. Researchers often point out that, for specific classes of problems, a quantum computer with 300 qubits has potentially more processing power than a classical computer containing as many bits as there are particles in the universe.
Harnessing all this potential for practical use is extremely difficult. One problem is that measuring a qubit causes its delicate quantum state to collapse, producing an output of an ordinary 1 or 0, without a record of what happened during the computation. Nevertheless, Shorâ€™s algorithm uses these properties to perform a useful task. It enables scientists to analyze the final quantum state after the computation to find repeating patterns in the original input, and to use this information to determine the prime factors of a number.
The work described in the Science paper demonstrated the pattern-finding step of Shorâ€™s algorithm. This demonstration involves fewer and simpler operations than those previously implemented, a significant benefit in designing practical quantum computers.
In the experiments, NIST researchers performed the same series of operations on a set of three beryllium qubits thousands of times. Each set of operations lasted less than 4 milliseconds, and consisted of using ultraviolet laser pulses to manipulate individual ions in sequence, based on measurements of the other ions. Each run produced an output consisting of measurements of each of the three ions. The NIST team has the capability to measure ionsâ€™ quantum states precisely and use the results to manipulate other ions in a controlled way, before the delicate quantum information is lost.
The same NIST team has previously demonstrated all the basic components for a quantum computer using ions as qubits, arguably a leading candidate for a large-scale quantum processor. About a dozen different types of quantum systems are under investigation around the world for use in quantum processing, including the approach of using ions as qubits.
The new work was supported in part by the Advanced Research and Development Activity/National Security Agency.
As a non-regulatory agency, NIST develops and promotes measurement, standards and technology to enhance productivity, facilitate trade and improve the quality of life.
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First Electronic Quantum Processor Created
2009 07 01
A team led by Yale University researchers has created the first rudimentary solid-state quantum processor, taking another step toward the ultimate dream of building a quantum computer.
The two-qubit processor is the first solid-state quantum processor that resembles a conventional computer chip and is able to run simple algorithms. (Credit: Blake Johnson/Yale University)
They also used the two-qubit superconducting chip to successfully run elementary algorithms, such as a simple search, demonstrating quantum information processing with a solid-state device for the first time. Their findings appeared in Nature's advanced online publication June 28.
"Our processor can perform only a few very simple quantum tasks, which have been demonstrated before with single nuclei, atoms and photons," said Robert Schoelkopf, the William A. Norton Professor of Applied Physics & Physics at Yale. "But this is the first time they've been possible in an all-electronic device that looks and feels much more like a regular microprocessor."
Working with a group of theoretical physicists led by Steven Girvin, the Eugene Higgins Professor of Physics & Applied Physics, the team manufactured two artificial atoms, or qubits ("quantum bits"). While each qubit is actually made up of a billion aluminum atoms, it acts like a single atom that can occupy two different energy states. These states are akin to the "1" and "0" or "on" and "off" states of regular bits employed by conventional computers. Because of the counterintuitive laws of quantum mechanics, however, scientists can effectively place qubits in a "superposition" of multiple states at the same time, allowing for greater information storage and processing power.
For example, imagine having four phone numbers, including one for a friend, but not knowing which number belonged to that friend. You would typically have to try two to three numbers before you dialed the right one. A quantum processor, on the other hand, can find the right number in only one try.
"Instead of having to place a phone call to one number, then another number, you use quantum mechanics to speed up the process," Schoelkopf said. "It's like being able to place one phone call that simultaneously tests all four numbers, but only goes through to the right one."
These sorts of computations, though simple, have not been possible using solid-state qubits until now in part because scientists could not get the qubits to last long enough. While the first qubits of a decade ago were able to maintain specific quantum states for about a nanosecond, Schoelkopf and his team are now able to maintain theirs for a microsecond—a thousand times longer, which is enough to run the simple algorithms.
To perform their operations, the qubits communicate with one another using a "quantum bus"—photons that transmit information through wires connecting the qubits—previously developed by the Yale group.
The key that made the two-qubit processor possible was getting the qubits to switch "on" and "off" abruptly, so that they exchanged information quickly and only when the researchers wanted them to, said Leonardo DiCarlo, a postdoctoral associate in applied physics at Yale's School of Engineering & Applied Science and lead author of the paper.
Next, the team will work to increase the amount of time the qubits maintain their quantum states so they can run more complex algorithms. They will also work to connect more qubits to the quantum bus. The processing power increases exponentially with each qubit added, Schoelkopf said, so the potential for more advanced quantum computing is enormous. But he cautions it will still be some time before quantum computers are being used to solve complex problems.
"We're still far away from building a practical quantum computer, but this is a major step forward."
Authors of the paper include Leonardo DiCarlo, Jerry M. Chow, Lev S. Bishop, Blake Johnson, David Schuster, Luigi Frunzio, Steven Girvin and Robert Schoelkopf (all of Yale University), Jay M. Gambetta (University of Waterloo), Johannes Majer (Atominstitut der Österreichischen Universitäten) and Alexandre Blais (Université de Sherbrooke).
Article source: ScienceDaily.com
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(PhysOrg.com) -- Until now, scientists have thought that the process of erasing information requires energy. But a new study shows that, theoretically, information can be erased without using any energy at all. Instead, the cost of erasure can be paid in terms of another conserved quantity, such as spin angular momentum.
In the study, physicists Joan Vaccaro from Griffith University in Queensland, Australia, and Stephen Barnett from the University of Strathclyde in Glasgow, UK, have quantitatively described how information can be erased without any energy, and they also explain why the result is not as contentious as it first appears. Their paper is published in a recent issue of the Proceedings of the Royal Society A.
Traditionally, the process of erasing information requires a cost that is calculated in terms of energy more specifically, heat dissipation. In 1961, Rolf Landauer argued that there was a minimum amount of energy required to erase one bit of information, i.e. to put a bit in the logical zero state. The energy required is positively related to the temperature of the systems thermal reservoir, and can be thought of as the systems thermodynamic entropy. As such, this entropy is considered to be a fundamental cost of erasing a bit of information.
However, Vaccaro and Barnett have shown that an energy cost can be fully avoided by using a reservoir based on something other than energy, such as spin angular momentum. Subatomic particles have spin angular momentum, a quantity that, like energy, must be conserved. Basically, instead of heat being exchanged between a qubit and thermal reservoir, discrete quanta of angular momentum are exchanged between a qubit and spin reservoir. The scientists described how repeated logic operations between the qubits spin and a secondary spin in the zero state eventually result in both spins reaching the logical zero state. Most importantly, the scientists showed that the cost of erasing the qubits memory is given in terms of the quantity defining the logic states, which in this case is spin angular momentum and not energy.
The scientists explained that experimentally realizing this scheme would be very difficult. Nevertheless, their results show that physical laws do not forbid information erasure with a zero energy cost, which is contrary to previous studies. The researchers noted that, in practice, it will be especially difficult to ensure the systems energy degeneracy (that different spin states of the qubit and reservoir have the exact same energy level). But even if imperfect conditions cause some energy loss, there is no fundamental reason to assume that the cost will be as large as that predicted by Landauers formula.
The possibility of erasing information without using energy has implications for a variety of areas. One example is the paradox of Maxwells demon, which appears to offer a way of violating the second law of thermodynamics. By opening and closing a door to separate hot and cold molecules, the demon supposedly extracts work from the reservoir, converting all heat into useful mechanical energy. Bennetts resolution of the paradox in 1982 argues that the demons memory has to be erased to complete the cycle, and the cost of erasure is at least as much as the liberated energy. However, Vaccaro and Barnetts results suggest that the demons memory can be erased at no energy cost by using a different kind of reservoir, where the cost would be in terms of spin angular momentum. In this scheme, the demon can extract all the energy from a heat reservoir as useful energy at a cost of another resource.
As the scientists explained, this result doesn't contradict historical statements of the second law of thermodynamics, which are exclusively within the context of heat and thermal reservoirs and do not allow for a broader class of reservoirs. Moreover, even though the example with Maxwells demon suggests that mechanical work can be extracted at zero energy cost, this extraction is associated with an increase in the information-theoretic entropy of the overall system.
The maximization of entropy subject to a constraint need apply not only to heat reservoirs and the conservation of energy, Vaccaro explained to PhysOrg.com.
The results could also apply to hypothetical Carnot heat engines, which operate at maximum efficiency. If these engines use angular momentum reservoirs instead of thermal reservoirs, they could generate angular momentum effort instead of mechanical work.
As for demonstrating the concept of erasing information at zero energy cost, the scientists said that it would take more research and time.
We are currently looking at an idea to perform information erasure in atomic and optical systems, but it needs much more development to see if it would actually work in practice, Vaccaro said.
She added that the result is of fundamental significance, and its not likely to have practical applications for memory devices.
We don't see this as having a direct impact in terms of practical applications, because the current energy cost of information erasure is nowhere near Landauer's theoretical bound, she said. It's more a case of what it says about fundamental concepts. For example, Landauer said that information is physical because it takes energy to erase it. We are saying that the reason it is physical has a broader context than that.
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More information: Joan A. Vaccaro and Stephen M. Barnett. Information erasure without an energy cost. Proceedings of the Royal Society A. DOI:10.1098/rspa.2010.0577


Entangled photons are the tools of choice for testing the foundations of quantum physics and demonstrating the teleportation of quantum states. They are also a resource in quantum information protocols. So far, most work has focused on entangled photons at optical frequencies. But for several decades, researchers have been developing a quantum information technology based on superconducting circuits, which have quantized excitations in the form of microwave photons. These circuits are attractive for generating, processing, and storing quantum information because they can be lithographically patterned on a small chip, allowing a good design to be replicated many times over. Now, in Physical Review Letters, Emmanuel Flurin and colleagues at École Normale Supérieure in Paris report they can generate, and then spatially separate, entangled microwave fields in a superconducting circuit , enabling quantum teleportation schemes that utilize microwave technology.
Entangled objects (such as two photons) are described by a common, nonseparable quantum-mechanical state. Measuring one object instantly changes the common state and therefore instantly affects the other object, even if it is far away—a phenomenon that seems to fly in the face of special relativity.
As a concept, entanglement got off to a rocky start. In 1935, Einstein, Podolsky, and Rosen (EPR) concluded that the “action at a distance” allowed by entanglement was so bizarre that quantum mechanics must be an incomplete theory . They and others proposed the alternate theory of local hidden variables, which (loosely speaking) assumes entangled objects decide on a set of variables before they separate. A clear resolution didn’t emerge until 1964, when John Bell showed that the hidden variable theory set an upper bound on the degree of correlation between particles in an entangled state . In contrast, quantum mechanics predicted that correlations for certain states exceeded, or “violated”, this upper bound. Violations of Bell’s inequality emerged again and again in quantum optics experiments, confirming that quantum entanglement was real. Still, the quest to find a loophole has continued to this day.
Even though it started as a suspicious property, by the nineties, entanglement was considered a technologically important resource for quantum cryptography and quantum computation. Other applications grew out of the fact that entangled photons can behave like an effective wave with half the photons’ wavelength, a feature that can be used to perform interferometry at sub-shot noise levels.
One advantage of using microwave superconducting circuits to test quantum physics and explore its applications is that the interaction between microwave photons is large compared to that found in optical photon technologies. These lithographically defined circuits are made from metals, like aluminum, which become superconducting when cooled to low temperatures. A central component within the circuit is the Josephson junction, a thin barrier that separates two superconducting stretches of metal. On either side of a Josephson junction, the Cooper-pair condensate is described by a macroscopic quantum mechanical wave function with an amplitude and a phase. The current through the junction is a sinusoidal function of the phase difference across the junction, which is in turn proportional to the time-integral of the voltage across the junction. As a result, unlike capacitors and inductors, Josephson junctions have a nonlinear response to currents, which makes it possible to engineer circuits that amplify or change the frequency of signals.
Even though they are macroscopic objects, superconducting circuits support quantized excitations of the electromagnetic field . Researchers at NEC in Japan have used superconducting circuits to make a quantum bit  that could remain in a superposition of two charge states for a few nanoseconds. In the last few years, experimentalists at the University of California, Santa Barbara , have demonstrated a nine-element solid-state quantum processor that can factor the number , while researchers at IBM have observed coherent life times of a single superconducting qubit of up to microseconds .
Building on this superconducting technology for quantum information processing, Flurin et al. take a first step towards engineering the circuits for quantum communication. The circuit they use for generating the entanglement is essentially a parametric amplifier, an ultralow-noise device that amplifies a quantum signal. In this case, they use it to amplify vacuum fluctuations (fluctuations that exist because the circuit is a quantum object) to create a so-called squeezed state.
To do this, the team fabricated a chip (Fig. 1) that consists of two thin, serpentine aluminum channels that act as microwave resonators with different resonant frequencies (). These resonators are coupled by a nonlinear circuit element consisting of several Josephson junctions. A third aluminum channel pumps coherent microwaves with frequency into the nonlinear crossing, which converts a pumped photon into a pair of photons, one in each resonator, whose frequencies and add up to the pump frequency. Since both photons originate from the same pump photon, they are correlated in a specific way, called two-mode squeezing , with the phase reference coming from the pump. The entanglement is then detected using a second device, similar to the one used to entangle the photons. With their device, Flurin et al. are able to produce pairs of entangled photons at a rate corresponding to six million entangled bits per second.
Two-mode squeezing of microwaves has been observed before , but it was at two different frequencies in a single transmission line. Flurin et al. are the first to create a two-mode squeezed microwave field where the two modes are spatially separated, thus showing entanglement in the original EPR sense. Taking a different approach, researchers in Germany, Spain, and Japan are now reporting on the arXiv that they can produce spatially separated entangled microwave photons  at a single frequency.
By demonstrating an efficient way to produce a flow of spatially separated entangled microwave photons, Flurin et al. have opened the door towards a new set of on-chip experiments in quantum information and measurement. One of the next steps will certainly be to demonstrate quantum teleportation with microwaves. Long term, researchers will look to interface microwave circuits, which are efficient at generating strongly interacting photons, with the fiber optic technology that works so well for sending light over long distances.
- E. Flurin, N. Roch, F. Mallet, M. H. Devoret, and B. Huard, “Generating Entangled Microwave Radiation Over Two Transmission Lines,” Phys. Rev. Lett. 109, 183901 (2012).
- A. Einstein, B. Podolsky, and N. Rosen, “Can Quantum-Mechanical Description of Physical Reality Be Considered Complete?,” Phys. Rev. 47, 777 (1935).
- J. Bell, “On the Einstein Podolsky Rosen Paradox,” Physics 1, 195 (1964).
- M. Devoret et al., “Measurements of Macroscopic Quantum Tunneling out of the Zero-Voltage State of a Current-Biased Josephson Junction,” Phys. Rev. Lett. 55, 1908 (1985).
- Y. Nakamura, Yu. A. Pashkin, and J. S. Tsai, “Coherent Control of Macroscopic Quantum States in a Single-Cooper-Pair Box,” Nature 398, 786 (1999).
- E. Lucero et al., “Computing prime factors with a Josephson phase qubit quantum processor,” Nature Phys. 8, 719 (2012).
- C. Rigetti et al., “Superconducting Qubit in a Waveguide Cavity with a Coherence Time Approaching 0.1 ms,” Phys. Rev. B 86, 100506 (2012).
- C. M. Caves and B. L. Schumaker “New Formalism for Two-Photon Quantum Optics. I. Quadrature Phases and Squeezed States,” Phys. Rev. A 31, 3068 (1985).
- C. Eichler, D. Bozyigit, C. Lang, M. Baur, L. Steffen, J. M. Fink, S. Filipp, and A. Wallraff, “Observation of Two-Mode Squeezing in the Microwave Frequency Domain,” Phys. Rev. Lett. 107, 113601 (2011).
- E. P. Menzel et al., “Path Entanglement of Continuous-Variable Quantum Microwaves,” arXiv:1210.4413 (cond-mat.mes-hall).


First Generation (1941-1956)
World War gave rise to numerous developments and started off the computer age. Electronic Numerical Integrator and Computer (ENIAC) was produced by a partnership between University of Pennsylvania and the US government. It consisted of 18,000 vacuum tubes and 7000 resistors. It was developed by John Presper Eckert and John W. Mauchly and was a general purpose computer. "Von Neumann designed the Electronic Discrete Variable Automatic Computer (EDVAC) in 1945 with a memory to hold both a stored program as well as data." Von Neumann's computer allowed for all the computer functions to be controlled by a single source.
Then in 1951 came the Universal Automatic Computer (UNIVAC I), designed by Remington rand and collectively owned by US census bureau and General Electric. UNIVAC amazingly predicted the winner of 1952, presidential elections, Dwight D. Eisenhower.
In first generation computers, the operating instructions or programs were specifically built for the task for which computer was manufactured. The Machine language was the only way to tell these machines to perform the operations. There was great difficulty to program these computers and more when there were some malfunctions. First Generation computers used Vacuum tubes and magnetic drums (for data storage).
The IBM 650 Magnetic Drum Calculator
Second Generation Computers (1956-1963)
The invention of Transistors marked the start of the second generation. These transistors took place of the vacuum tubes used in the first generation computers. First large scale machines were made using these technologies to meet the requirements of atomic energy laboratories. One of the other benefits to the programming group was that the second generation replaced Machine language with the assembly language. Even though complex in itself Assembly language was much easier than the binary code.
Second generation computers also started showing the characteristics of modern day computers with utilities such as printers, disk storage and operating systems. Many financial information was processed using these computers.
In Second Generation computers, the instructions (program) could be stored inside the computer's memory. High-level languages such as COBOL (Common Business-Oriented Language) and FORTRAN (Formula Translator) were used, and they are still used for some applications nowadays.
The IBM 7090 Console in the Columbia Computer Center machine room, 1966. Pictured: A group of particle physicists who discovered the violation of charge-conjugation invariance in interactions of intermediate strength: Charles Baltay and Lawrence Kirsch of Nevis Lab (back row); Juliet Lee-Franzini of SUNY Stony Brook and team leader Paulo Franzini of Nevis Lab [V1#7].
Photo: Columbia Computer Center Newsletter, V1#7, Aug 1966, Columbiana Archive.
Although transistors were great deal of improvement over the vacuum tubes, they generated heat and damaged the sensitive areas of the computer. The Integrated Circuit(IC) was invented in 1958 by Jack Kilby. It combined electronic components onto a small silicon disc, made from quartz. More advancement made possible the fittings of even more components on a small chip or a semi conductor. Also in third generation computers, the operating systems allowed the machines to run many different applications. These applications were monitored and coordinated by the computer's memory.
The IBM 360/91
Fourth Generation (1971-Present)
Fourth Generation computers are the modern day computers. The Size started to go down with the improvement in the integrated circuits. Very Large Scale (VLSI) and Ultra Large scale (ULSI) ensured that millions of components could be fit into a small chip. It reduced the size and price of the computers at the same time increasing power, efficiency and reliability. "The Intel 4004 chip, developed in 1971, took the integrated circuit one step further by locating all the components of a computer (central processing unit, memory, and input and output controls) on a minuscule chip."
Due to the reduction of cost and the availability of the computers power at a small place allowed everyday user to benefit. First, the minicomputers which offered users different applications, most famous of these are the word processors and spreadsheets, which could be used by non-technical users. Video game systems like Atari 2600 generated the interest of general populace in the computers.
In 1981, IBM introduced personal computers for home and office use. "The number of personal computers in use more than doubled from 2 million in 1981 to 5.5 million in 1982. Ten years later, 65 million PCs were being used." Computer size kept getting reduced during the years. It went down from Desktop to laptops to Palmtops. Mackintosh introduced Graphic User Interface in which the users don’t have to type instructions but could use Mouse for the purpose.
The continued improvement allowed the networking of computers for the sharing of data. Local Area Networks (LAN) and Wide Area Network (WAN) were potential benefits, in that they could be implemented in corporations and everybody could share data over it. Soon the internet and World Wide Web appeared on the computer scene and fomented the Hi-Tech revolution of 90's.
Fifth generation computers
Fifth generation computers are mainly future computers. Of course some modern computers also belong to this generation. The aim of these computers is to develop devices that respond to natural language input and are capable of learning and self-organization. In these computers massive numbers of CPUs are used for more efficient performance. Voice recognition is a special feature in these computers. By using superconductors and parallel processing computer geeks are trying to make artificial intelligence a reality. Quantum computing, molecular and nanotechnology will change the face of computers in the coming years.Fifth generation computer.


Today's quantum computers are no more than experiments. Researchers can string together a handful of quantum bits - seemingly magical bits that store a "1″ and "0″ at the same time - and these ephemeral creations can run relatively simple algorithms. But new research from IBM indicates that far more complex quantum computers aren't that far away.
On Tuesday, IBM revealed that physicists at its Watson Research Center in Yorktown Heights, New York have made significant advances in the creation of "superconducting qubits," one of several research fields that could eventually lead to a quantum computer that's exponentially more powerful than today's classical computers.
According to Matthias Steffen - who oversees Big Blue's experimental quantum computing group - he and his team have improved the performance of superconducting qubits by a factor of two to four. "What this means is that we can really start thinking about much larger systems," he tells Wired, "putting several of these quantum bits together and performing much larger error correction."
David DiVincenzo - a professor at the Jülich Research Center‘s Institute of Quantum Information in western Germany and a former colleague if Steffen - agrees that IBM's new research is more than just a milestone. "These metrics have now - for the first time - attained the levels necessary to begin scaling up quantum computation to greater complexity," he says. "I think that we will soon see whole quantum computing modules, rather than just two- or three-qubit experiments."
Whereas the computer on your desk obeys the laws of classical physics - the physics of the everyday world - a quantum computer taps the mind bending properties of quantum mechanics. In a classic computer, a transistor stores a single "bit" of information. If the transistor is "on," for instance, it holds a "1." If it's "off," it holds a "0." But with quantum computer, information is represented by a system that can an exist in two states at the same time, thanks to the superposition principle of quantum mechanics. Such a qubit can store a "0″ and "1″ simultaneously.
Information might be stored in the spin of electron, for instance. An "up" spin represents a "1." A "down" spin represent a "0." And at any given time, this spin can be both up and down. "The concept has almost no analog in the classical world," Steffan says. "It would be almost like me saying I could be over here and over there where you are at the same time."
If you then put two qubits together, they can hold four values at once: 00, 01, 10, and 11. And as you add more and more qubits, you can build a system that's exponentially more powerful than a classic computer. You could, say, crack the world's strongest encryption algorithms in a matter of seconds. As IBM points out, a 250-qubit quantum computer would contain more bits that there are particles in the universe.
But building a quantum computer isn't easy. The idea was first proposed in the mid-80s, and we're still at the experimental stage. The trouble is that quantum systems so easily "decohere," dropping from two simultaneous states into just a single state. Your quantum bit can very quickly become an ordinary classical bit.
Researchers such as Matthias Steffen and David DiVincenzo aim to build systems that can solve this decoherence problem. At IBM, Steffen and his team base their research on a phenomenon known as superconductivity. In essence, if you cool certain substances to very low temperatures, they exhibit zero electrical resistance. Steffen describes this as something akin to a loop where current flows in two directions at the same time. A clockwise current represents a "1," and counter clockwise represents a "0."
IBM's qubits are built atop a silicon substrate using aluminum and niobium superconductors. Essentially, two superconducting electrodes sit between an insulator - or Josephson junction - of aluminum oxide. The trick is keep this quantum system from decohering for as long as possible. If you can keep the qubits in a quantum state for long enough, Steffen says, you can build the error correction schemes you need to operate a reliable quantum computer.
The threshold is about 10 to 100 microseconds, and according to Steffen, his team has now reached this point with a "three-dimensional" qubit based on a method originally introduced by researchers at Yale University. Ten years ago, decoherence times were closer to a nanosecond. In other words, over the last ten years, researchers have improved the performance of superconducting qubits by a factor of more than 10,000.
IBM's team has also built a "controlled NOT gate" with traditional two-dimensional qubits, meaning they can flip the state of one qubit depending on the state of the other. This too is essential to building a practical quantum computer, and Steffen says his team can successfully flip that state 95 percent of the time - thanks to a decoherence time of about 10 microseconds.
"So, not just is our single device performance remarkably good," he explains, "our demonstration of a two-qubit device - an elementary logic gate - is also good enough to get at least close to the threshold needed for a practical quantum computer. We're not quite there yet, but we're getting there."
The result is that the researchers are now ready to build a system that spans several qubits. "The next bottleneck is now how to make these devices betters. The bottleneck is how to put five or ten of these on a chip," Steffen says. "The device performance is good enough to do that right now. The question is just: ‘How do you put it all together?'"
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Quantum mechanics is, mathematically, quite simple. But it has implications that require people to think differently about the world. One particularly hard-to-grasp idea is that, on the surface, some knowledge precludes obtaining other knowledge. This is a consequence of how we obtain it.
In an innovative experiment, researchers from Austria have demonstrated how to recover that lost information. Before you get the wrong impression, though, this is completely in agreement with the rules of quantum mechanics—it is simply a very clever way of playing with quantum states.
Before looking at the experiment, note what makes this interesting. The keywords that turn up in these sorts of articles are superposition states and measurement. Imagine that we have 100 electrons, sitting in a magnetic field. Their individual magnetic fields are all, thanks to the applied field, pointing in the same direction. Now, we turn on a microwave for a specific period of time. Chosen correctly, all 100 electrons flip their fields so that they point in exactly the opposite direction. If we make a measurement, all electrons report the same spin. If we cut the time of the microwave pulse in half, however, something very strange happens: all the electrons end up with their fields pointing in both directions at once. This is called a superposition state.
Once we make a measurement, though, we find half the electrons have their fields pointing in one direction and half have their fields pointing in the opposite direction—the superposition state vanishes. You might immediately think it was never there in the first place: we simply put in half the energy, so only half the electrons responded.
But this is incorrect. We know that we get superposition states because we've looked. We can create a situation where, if the electrons were not in superposition state, we observe one result, and if they're in a superposition state, we observe something different. Even though we know it is a superposition state, every measurement on a single electron reports that its field is either pointing with the applied field or against the applied field.
This behavior tells us that, when we make a measurement, we destroy the superposition state and place the electron in a single pure state. We can't tell anything about the superposition state other than that it included the state that we measured.
Why should we care?
This property of quantum mechanics has made quantum computing a little bit more difficult. If everything goes well, at the end of a calculation, a qubit (quantum bit) will be in a superposition of the right answer and the wrong answer. Although the probability of the right answer should be much higher than that of the wrong answer, there is always a chance of getting the wrong answer. In very fast quantum computers, we would just run the calculation a few times and take the most frequent answer as the correct answer. But what if your computer is slow?
The ideal situation is to be able to take a measurement, then reconstruct the original superposition state so that repeated measurements could be used (ensuring that the most probable state can be determined). However, for a single particle, that is impossible. To overcome this problem, researchers have done the obvious: they spread their qubit over three particles. Even with three particles, however, measuring all three then taking a majority vote on the answer may not be good enough.
So the researchers decided to be clever. In their scheme, the qubit is encoded between two states of an ionized calcium atom. To provide redundancy, the qubit is then entangled with two other qubits. (You can think of this as creating two mirror images of the quantum state of the qubit in two other particles. This isn't a technically correct description, but it should help you get the point). Now, we have our three qubits, each of which encodes a single quantum bit of information.
But, unlike our electron in the magnetic field where there are only two possible states, the calcium ion has many, many states available to it. The researchers make use of a total of four states. One state corresponds to a logical zero, while a second corresponds to a logical one. (I'll call the other two states the measurement state and the hidden state.)
One laser connects the measurement state to the logical one state, while a second laser connects the logical one state to the hidden state. To measure a state, we turn on the first laser. The qubit falls into either the logical one or logical zero, based on the probabilities of the superposition state. If it ends up in logical one, the laser light is scattered by the ion and is detected. Hence a pulse on the photodetector indicates a logic one, while the absence of light signals a logical zero. That is the measurement process.
The second laser simply changes the definition of the qubit. Initially, a qubit is a superposition of the logical one and logical zero states. After the laser pulse, the qubit is a superposition between the hidden state and the logical zero state. In this case, the qubit cannot be evaluated by the measurement process.
The researchers take advantage of this by placing two of the three qubits into the hidden state, then measuring the remaining qubit to get an answer (logical one or zero). Then, after the measurement process, the hidden qubits are returned to their original states (a superposition of logical one and zero) and re-entangled with the original qubit. In doing so, the qubit is placed back in its original superposition state.
By repeating this process, the researchers can measure the state as many times as required to ensure that they know which logical state was the most frequent. Indeed, through multiple measurements, the researcher can obtain the relative probabilities of logical one and logical zero of the original superposition state.
In terms of advances for practical quantum computers, this may not mean a huge amount. However, it demonstrates a technique that will be critical for a working quantum computer. So in this sense, it is a very important step. But the issue may be with the implementation; the work was done with trapped ions, and it's hard to believe that trapped ions, floating in a vacuum, are the future of quantum computing.
Physical Review Letters, 2013, DOI: 10.1103/PhysRevLett.110.070403
Listing image by David Singleton


Climate events drive a high-arctic vertebrate community into synchrony
Climate change is known to affect the population dynamics of single species, such as reindeer or caribou, but the effect of climate at the community level has been much more difficult to document. Now, a group of Norwegian scientists has found that extreme climate events cause synchronized population fluctuations among all vertebrate species in a relatively simple high arctic community. These findings may be a bellwether of the radical changes in ecosystem stability that could result from anticipated future increases in extreme events. The findings are published in the 18 January issue of Science.
The Norwegian scientists, with lead authors from the Centre for Conservation Biology at the Norwegian University of Science and Technology (NTNU), wanted to know how climate and weather events influenced an overwintering vertebrate community on the high arctic island of Spitsbergen, Svalbard, at 78 degrees N latitude.
They chose this simple ecosystem because it is composed of just three herbivores in the winter -- the wild Svalbard reindeer (Rangifer tarandus platyrhynchus), the Svalbard rock ptarmigan (Lagopus muta hyperborea), and the sibling vole (Microtus levis), and one shared consumer, the arctic fox (Vulpes lagopus).
The community's population fluctuations were mainly driven by rain-on-snow events, the researchers found. Rain-on-snow is an extreme climatic occurrence that causes icing on the deep-frozen arctic tundra. The ice keeps reindeer from grazing on their winter pastures and also reduces food accessibility for the rock ptarmigan and sibling vole populations, causing extensive simultaneous population crashes in all three species in the winter and spring after the extreme weather.
However, the arctic fox, which mainly relies on reindeer carcasses as its terrestrial winter food source, didn't see a decline in its population size until a year after the herbivore die-offs. Even though the synchronized die-offs decrease the number of live prey available for foxes to eat, the high number of reindeer carcasses generates an abundance of food for foxes during icy winters and the subsequent spring and summer. This leads to high fox reproduction.
But almost no reindeer carcasses will be available during the following winter, mainly because those reindeer that survived the previous winter are more robust and also subject to reduced competition for food resources. At the same time, none of the other herbivores is able to recover in the summer after the icing. The net result is low fox reproduction and a strong reduction in the arctic fox population size one year after the herbivore die-offs.
"We have known for a long time that climate can synchronize populations of the same species, but these findings suggest that climate and particularly extreme weather events may also synchronize entire communities of species," says lead author Brage Bremset Hansen, from NTNU's Centre for Conservation Biology. "Svalbard's relatively simple ecosystem, which lacks specialist predators, combined with large weather fluctuations from year to year and strong climate signals in the population dynamics of herbivores, are the likely explanations for how such clear climate effects can be observed at the ecosystem level."
In other, more complex systems, he says, community-level effects of climate can be present but are likely masked by other factors that tend to obscure the synchronizing effects of climate, which thus complicates the picture.
Extreme rain-on-snow events are rare in most of the Arctic compared with Svalbard, where the climate is oceanic and mild for the latitude. However, because the frequency of such rain-on-snow events leading to icing is closely linked to a rapidly warming arctic climate, the authors warn that changes in winter climate and extreme events may have important implications for ecosystem functioning and stability in the circumpolar Arctic in the future.
"Previous studies have shown that rain-on-snow and icing can also cause vegetation damage and reduce survival of soil microbiota," says Hansen. "But more importantly, we suspect that the strong effects of icing on the overwintering vertebrate community have the potential to indirectly influence other species and cascade throughout the food web. The die-offs among resident herbivores shape predator abundance, which could in turn affect the migratory prey that reside in the area in the summer, such as sea birds and barnacle geese."
- How Extreme Weather Links The Fates Of Four Adorable Arctic Speciesfrom PopSciThu, 17 Jan 2013, 17:30:58 EST
- Extreme weather events a potent force for arctic overwintering populationsfrom PhysorgThu, 17 Jan 2013, 14:01:26 EST
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Diamonds have long been available in pairs—say, mounted in a nice set of earrings. But physicists have now taken that pairing to a new level, linking two diamonds on the quantum level.
A group of researchers report in the December 2 issue of Science that they managed to entangle the quantum states of two diamonds separated by 15 centimeters. Quantum entanglement is a phenomenon by which two or more objects share an unseen link bridging the space between them—a hypothetical pair of entangled dice, for instance, would always land on matching numbers, even if they were rolled in different places simultaneously.
But that link is fragile, and it can be disrupted by any number of outside influences. For that reason entanglement experiments on physical systems usually take place in highly controlled laboratory setups—entangling, say, a pair of isolated atoms cooled to nearly absolute zero.
In the new study, researchers from the University of Oxford, the National Research Council of Canada and the National University of Singapore (NUS) showed that entanglement can also be achieved in macroscopic objects at room temperature. "What we have done is demonstrate that it's possible with more standard, everyday objects—if diamond can be considered an everyday object," says study co-author Ian Walmsley, an experimental physicist at Oxford. "It's possible to put them into these quantum states that you often associate with these engineered objects, if you like—these closely managed objects."
To entangle relatively large objects, Walmsley and his colleagues harnessed a collective property of diamonds: the vibrational state of their crystal lattices. By targeting a diamond with an optical pulse, the researchers can induce a vibration in the diamond, creating an excitation called a phonon—a quantum of vibrational energy. Researchers can tell when a diamond contains a phonon by checking the light of the pulse as it exits. Because the pulse has deposited a tiny bit of its energy in the crystal, one of the outbound photons is of lower energy, and hence longer wavelength, than the photons of the incoming pulse.
Walmsley and his colleagues set up an experiment that would attempt to entangle two different diamonds using phonons. They used two squares of synthetically produced diamond, each three millimeters across. A laser pulse, bisected by a beam splitter, passes through the diamonds; any photons that scatter off of the diamond to generate a phonon are funneled into a photon detector. One such photon reaching the detector signals the presence of a phonon in the diamonds.
But because of the experimental design, there is no way of knowing which diamond is vibrating. "We know that somewhere in that apparatus, there is one phonon," Walmsley says. "But we cannot tell, even in principle, whether that came from the left-hand diamond or the right-hand diamond." In quantum-mechanical terms, in fact, the phonon is not confined to either diamond. Instead the two diamonds enter an entangled state in which they share one phonon between them.
To verify the presence of entanglement, the researchers carried out a test to check that the diamonds were not acting independently. In the absence of entanglement, after all, half the laser pulses could set the left-hand diamond vibrating and the other half could act on the right-hand diamond, with no quantum correlation between the two objects. If that were the case, then the phonon would be fully confined to one diamond.
If, on the other hand, the phonon were indeed shared by the two entangled diamonds, then any detectable effect of the phonon could bear the imprint of both objects. So the researchers fired a second optical pulse into the diamonds, with the intent of de-exciting the vibration and producing a signal photon that indicates that the phonon has been removed from the system. The phonon's vibrational energy gives the optical pulse a boost, producing a photon with higher energy, or shorter wavelength, than the incoming photons and eliminating the phonon in the process.
Once again, there is no way of knowing which diamond produced the photon, because the paths leading from each diamond to the detectors are merged, so there is no way of knowing where the phonon was. But the researchers found that each of the photon paths leading from the diamonds to the detectors had an interfering effect on the other—adjusting how the two paths were joined affected the photon counts in the detectors. In essence, a single photon reaching the detectors carried information about both paths. So it cannot be said to have traveled down one path from one diamond: the photon, as with the vibrational phonon that produced it, came from both diamonds.
After running the experiment over and over again to gather statistically significant results, the researchers concluded with confidence that entanglement had indeed been achieved. "We can't be 100 percent certain that they're entangled, but our statistical analysis shows that we're 98 percent confident in that, and we think that's a pretty good outcome," Walmsley says.
The catch to using phonons for macroscopic entanglement is that they do not last long—only seven picoseconds, or seven trillionths of a second, in diamond. So the experimenters had to rely on extremely fast optical pulses to carry out their experiment, creating entangled states with phonons and then damping the phonons with the second pulse to test that entanglement just 0.35 picoseconds later.
Because of this brevity, such entanglement schemes may not take over for more established techniques using photons or single atoms, but Walmsley hopes that researchers will consider the possibilities of using fairly ordinary, room-temperature materials in quantum technologies. "I think it gives a new scenario and a new instantiation of something that helps point in that direction," he says.
Indeed, the new study is just the latest to show how quantum mechanics applies in real-world, macroscopic systems. Oxford and NUS physicist Vlatko Vedral, who was not involved in the new research, says it "beautifully illustrates" the point of Austrian physicist Erwin Schrödinger's famous thought experiment in which a hypothetical cat is simultaneously alive and dead. "It can't be that entanglement exists at the micro level (say of photons) but not at the macro level (say of diamonds)," because those worlds interact, Vedral wrote in an email. "Schrödinger used atoms instead of photons and cats instead of diamonds, but the point is the same."