Computers powered by frickin’ laser beams just came a step closer. Light-based, or photonic, computers would theoretically be much faster and smaller than the electronic computers we use today, but researchers have had a hard time putting theory into action. Now, a new study has shown that two laser beams can be harnassed to turn a single molecule into a transistor. However, the specialized conditions necessary for the trick to work mean that computer stores won’t have photonic sections anytime soon.
Conventional computers are based on transistors, which allow one electrode to control the current moving through the device and are combined to form logic gates and processors. The new component achieves the same thing, but for laser beams, not electric currents. A green laser beam is used to control the power of an orange laser beam passing through the device [New Scientist]. In the study, published in Nature, the green beam could make the orange beam either weak or strong, which is analagous to an electronic transistor turning a current on or off.
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In a rare victory for freedom of information in China, the government has abruptly reversed course on its mandate that Internet filtering software be installed on every computer sold in China after July 1.
Yesterday, the Ministry of Industry and Information Technology announced that mandatory installation of the software, called Green Dam Youth Escort, would be delayed indefinitely. The software caused a torrent of protests from both Chinese computer users and global computer makers…. China has said the software is designed to filter out pornography and violence to protect minors, but many experts say it can also block any other content that the authorities deem subversive [The New York Times].
While some experts suggested that the Chinese government might be delaying the program’s roll-out simply to give computer makers more time to test the software and comply with the policy, others believe that the government was forced to bow to the pressure from outraged citizens. “This shows that social pressure can’t be ignored,” said Zhou Ze, a Beijing lawyer who challenged the legality of the plan. “They tried to control public opinion to back the plan by creating a fuss about pornography, but that failed, and they will have learnt to be more careful next time” [Reuters]. Analyst Edward Yu of Beijing says that while protests from foreign computer companies probably influenced the government’s decision, “we think public opinion played an even more important role” [AP].
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When Chicago’s Sears Tower was completed in 1973 the 110-story building was the tallest in the world, and it offered a bold example of the human potential to build towards the clouds. Now, although the tower lost the title of tallest building to other skyscrapers in the 1990s, the tower hopes to dazzle the world anew with a fresh vision of urban architecture: The building will soon receive a $350 million environmental retrofit, with wind turbines, solar panels, and gardens all added to the building’s staggered rooftops.
The 5-year project would reduce the tower’s electricity use by 80 percent and save 24 million gallons of water a year, building owners and architects said…. “Our plans are very ambitious,” said John Huston of American Landmark Properties, who represents the building ownership. “Our plans to modernize and transform this icon will re-establish Sears Tower as a leader, a pioneer” [AP].
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The Department of Energy is handing out nearly $8 billion in loans today, and $465 million of the funds will go to Tesla Motors to produce its Model S electric sedan, the company’s first attempt at a mass-market car. The company already manufactures the Roadster, a high-performance electric sports car. Nissan and Ford Motor Company will receive the other loans; they’ll get $1.6 billion and $5.9 billion, respectively, to help produce fuel-efficient cars.
Nissan will use the funds updating a plant in Tennessee to produce the company’s upcoming electric sedan, and Ford’s loan will help expedite production of cars that go farther on less fuel. Tesla was perhaps the wild card in the funding equation because it is a small startup. The company has delivered slightly more than 500 Roadsters to customers, and the government loan will help pay for a Southern California manufacturing plant for the Model S sedan, due in 2011. A second plant in the Bay Area will make battery packs and electric drivetrains [The New York Times].
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Apple chief executive and all-around tech visionary Steve Jobs reportedly received a liver transplant two months ago in Tennessee, and is on track to return to work by the end of the month. Jobs presumably underwent the procedure to treat a reappearance of the cancer he was diagnosed with several years ago. In 2004 Jobs had surgery to remove a rare, slow-growing type of pancreatic cancer, called a islet cell neuroendocrine tumor, but he was thought to be in remission until last year, when a period of drastic weight loss last year led to frenzied speculation that the cancer had returned [The Guardian].
Jobs’s health has been a matter of intense interest to Apple investors, who feel that his leadership is key to the company’s continuing success, and questions have been raised about the company’s handling of the matter. In January, the notoriously secretive Jobs made a rare public statement attributing his weight loss to a “hormone imbalance”. Just a few days later, however, he was forced to admit that the situation was “more complex” than first thought, before announcing his intention to step down from day to day activities at Apple for six months [The Guardian].
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Curious how much carbon the atmosphere contains at this moment? Look no further than a giant “carbon counter” first switched on yesterday morning near New York City’s Pennsylvania Station. The 70-foot-tall screen, lit by digital low-energy LED, displays in real time the amount of greenhouse gases present in the atmosphere–and therefore gives some indication of how much trouble humanity is facing from global warming.
People outside of New York, don’t despair: The constantly scrolling numbers can be viewed at the project’s Web site as well. The numbers shown are based on measurements developed at the Massachusetts Institute of Technology and include all the long-lasting greenhouse gases in the 1997 Kyoto Protocol, which was established at the United Nations Framework Convention on Climate change [Bloomberg].
The clock, which is illuminated 24 hours a day, is also environmentally friendly. It uses low-risk carbon credits to offset its energy use, while illuminating digital numbers with 40,960 low-energy light-emitting diodes [Bloomberg]. The counter is a project Deutsche Asset Management, a branch of Deutsche Bank that invests in industries that mitigate or adapt to climate change.
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In several labs around the world, sound waves are doing things they’ve never done before. Teams working in England and the Ukraine have made a sonic laser, or “saser,” which operates in the terahertz range, with sound waves oscillating more than a trillion times per second. Meanwhile, in an Israeli lab, researchers say they’ve created the first ever sonic black hole that traps sound waves and won’t let them escape.
The saser uses packets of sonic vibrations called “phonons” much like a regular laser uses photons. Specifically, the acoustic laser device consists of a sonic beam traveling through a “superlattice” constructed of 50 sheets of material each only atoms thick that are alternately made of gallium arsenide and aluminium arsenide, two materials found in semiconductor [CNET]. The phonons bounce back and forth inside the lattice, which causes more phonons to be released and amplifies the overall signal. The result is the formation of an intense series of synchronised phonons inside the stack, which leaves the device as a narrow saser beam of high-frequency ultrasound [New Scientist].
At the moment the terahertz saser, described in a paper published in the journal Physical Review B, is mainly a neat trick, but it may find practical applications down the line, says lead researcher Tony Kent. “Fifty years ago many eminent scientists said that light amplification by the stimulated emission of radiation [lasers] was no more than a scientific curiosity,” says Kent, but lasers are now used for everything from digital storage and cancer treatment to weaponry [New Scientist]. Kent says the new saser technology could lead to breakthroughs in imaging for tiny, nanoscale objects.
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When North Korea announced on May 25th that it had conducted its second underground test of a nuclear weapon, scientists weren’t surprised: They had already picked up seismic readings indicating a subterranean explosion. While seismologists say the readings carried subtle signatures that strongly suggest that the blast was caused by a nuclear device rather than conventional explosives, scientists were still waiting for one more piece of evidence–detecting radionuclide evidence in the form of radioactive gas is the “smoking gun”. And the big news here is that they have not found that signal [BBC Two].
Unlike other nuclear debris, xenon, an unreactive noble gas, can filter out through fissures in the rock after an underground test. Once in the atmosphere, plumes of xenon isotopes can be blown for thousands of miles. In 2006, for example, a [nuclear monitoring] station in Yellowknife, Canada, detected traces of xenon-133 two weeks after North Korea’s first test [Nature News]. But monitoring stations set up by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) have failed to detect any trace of xenon following the May blast, and now it may be too late. Researcher Lassina Zerbo of the CTBTO notes that these xenon isotopes rapidly decay in the atmosphere. This long after the blast, he says, “there is very little chance that we will pick up anything” [Nature News].
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The street protests in Iran will be not be televised–how passé. Instead, they are being tweeted.
The microblog service Twitter has become a critical way to get out information about the tumult in Iran’s capital, Tehran, where people have poured into the street to protest the disputed results of last Friday’s presidential election. And the whole world is watching. The U.S. State Department has confirmed that over the weekend officials reached out to Twitter and asked them to delay a network upgrade that was scheduled for Monday night. The reason? To protect the interests of Iranians using the service [Time].
The vast majority of Twitter messages support the leading opposition candidate, Mir Hussein Moussavi, and argue that he was the true winner of the presidential election. Twitter users are posting messages, known as tweets, with the term #IranElection, which allows users to search for all tweets on the subject. On Monday evening, Twitter was registering about 30 new posts a minute with that tag. One read, “We have no national press coverage in Iran, everyone should help spread Moussavi’s message. One Person = One Broadcaster. #IranElection” [The New York Times]. Since then, the Iranian government has restricted the movements of foreign journalists and has cracked down on blogs and Web sites within the country, but the flow of information on Twitter has only increased.
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The newest attempt at a viable hydrogen-powered car is a tiny two-seater that should have early adopters tootling around the United Kingdom next year, according its manufacturer, a startup company named Riversimple. While momentum has recently shifted away from hydrogen cars and back towards electric vehicles, company executives say their Riversimple Urban Car meets the challenges posed by hydrogen fuel cell technology. Its makers claim that by starting from scratch to build a small, efficient car they can make it commercially viable more quickly than the major auto manufacturers experimenting with adapting more conventional cars to hydrogen [New Scientist].
A prototype of the light-weight city car was unveiled today in London. Riversimple executives drove up in the vehicle, which has a top speed of 50 miles an hour and can travel about 200 miles before refueling with liquid hydrogen. The car is packed with novel approaches to car design, but company founder Hugo Spowers says it’s the business model that really sets Riversimple apart. Users willl lease the car for an estimated $315 per month, a price that includes the cost of hydrogen fuel and any repairs. The company asserts that in the leasing model, the vested interest for the manufacturer is in producing long-lasting, fuel-efficient, high-quality products [BBC News]. The company will first try a small pilot program in one (to be determined) city in England, where a gas supply company will partner with Riversimple to build fuel stations.
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NASA is turning its attention back on a familiar target–the moon–but in service of a unprecedented goal. Two new spacecraft are expected to launch this week on a robotic mission aimed at finding the best site for Earth’s first off-world colony, the centuries-old dream of science fiction writers and utopians…. “We’re going to provide NASA with what is needed to get human beings back to the moon and to stay there for an extended duration” [Los Angeles Times], explains NASA’s Craig Tooley. However, whether such a lunar outpost will ever be built is still an open question.
The spacecraft duo comprises an orbiter and a crash-lander; the two spacecraft will take off for the moon aboard a single Atlas V rocket, but once in space they’ll separate and take different routes. The Lunar Reconnaissance Orbiter (LRO) will make a four-day journey to the moon’s orbit where it will begin mapping the moon’s surface, looking for potential moon base sites in polar locations that are bathed in near-constant sunlight (which would be useful for solar panels). The orbiter will also carry pieces of plastic designed to simulate the density and chemical proportions of human skin and muscle…. The LRO’s particle detectors will measure how this plastic interacts with cosmic rays - a form of space radiation made up of particles such as protons that can lead to cancer by damaging DNA [New Scientist].
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A French nuclear submarine has joined the search for the “black box” of Air France Flight 447, which disappeared over the Atlantic last week with all of its 228 passengers. The “black box” is actually an orange cylinder — about 13 pounds of metal wrapped around a stack of memory chips and designed to withstand the force of being slammed high-speed into a brick wall. Actually a pair of devices — the flight data recorder and a voice and audio recorder — the equipment records virtually everything about how an airplane is working [CNN].
Aviation experts hope that the black box, if it can be located on the seafloor, will provide an explanation for what went wrong on the flight, which vanished so mysteriously. On board the French sub, the Emeraude, crewmen called “golden ears” were straining to pick up in their headsets the acoustic pings aircraft black boxes are supposed to transmit for 30 days under water. Nothing is better equipped for such faint sounds than an attack submarine with sophisticated sonar gear for detecting vessels deep in the ocean, naval officers said [Times Online].
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The battle of the light bulb may not be quite over. While traditional incandescents will soon be phased out in the United States and abroad, researchers are plugging away to create more efficient versions that comply with looming new standards — while also providing an alternative for consumers who find compact fluorescents objectionable [The New York Times, blog]. In one new study, researchers have demonstrated how an incandescent bulb can be modified to give out much more light without requiring more power.
Lead researcher Chunlei Guo and his colleagues were experimenting with the effect of ultrafast laser pulses on metals when they noticed that pulses lasting only a few femtoseconds–quadrillionths of a second–could fundamentally change the molecular arrangement of metals without melting them [ScienceNOW Daily News]. The laser blasts caused the metal to turn black, which boosted its ability to absorb light. Because the law of thermal radiation state that materials that can absorb a great deal of energy will also emit large amounts of energy, the researchers decided to see if their laser treatment would boost the light output of the metal filament in an ordinary light bulb.
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The electric car under development at General Motors has been heralded as a potential savior of both the American car industry and the environment, but in aftermath of the automaker’s bankruptcy filing many questions are being raised about the Chevy Volt’s future. GM executives swear that the cutting edge vehicle is still on track to reach auto dealerships late next year: GM executive Jon Lauckner says that the bankruptcy filing “has no bearing on the Volt, quite frankly…. We’re not anticipating any changes. November 2010 remains our date with destiny” [Wired.com]. Lauckner added that engineers have already begun assembly of the pre-production Volts that will be used to test handling and durability, and for crash tests. But some outside experts wonder whether bankruptcy courts will permit the expensive Volt program to continue.
The Volt could revolutionize driving for many commuters, allowing them to cruise to and from work without ever stopping by a gas station to fill up. Different than traditional hybrid or plug-in hybrid vehicles, the Volt can go 40 miles on a single charge on the electric engine and then a smaller, gasoline-powered combustion engine generates electricity for the motor, acting as a range extender [GreenBiz.com]. GM has said that the Volt should be able to drive 400 miles on a full charge and a full tank. The car is expected to sell for around $40,000.
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Last week’s official dedication of the National Ignition Facility, the massive experiment in nuclear fusion, has set some physicists to plotting ways in which nuclear fusion could be put to work in a new generation of nuclear power plants. Although doubters say that NIF may not even be able to produce a controlled fusion reaction, the same reaction that occurs in the heart of the sun and in thermonuclear weapons, boosters such as U.S. Energy Secretary Steven Chu are already discussing how fusion energy could best be harnessed.
Chu notes that the Obama administration’s decision to halt construction of the Yucca Mountain repository for nuclear waste has renewed interest in reactors that could actually reduce the nuclear waste produced by traditional nuclear power plants. There are “a resurgence of hybrid solutions of fusion fission where the fusion would impart not only energy, but again creates high-energy neutrons that can burn down the long-lived actinides” [Technology Review], says Chu. Actinides are a group of radioactive chemical elements, including plutonium and uranium, which compose some of the radioactive waste from traditional fission reactors.
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