New results are in from the Fermi Space Telescope, which settled into orbit in the summer of 2008, and the findings seem to prove Albert Einstein right once again. Man, that guy was good.
The telescope detected and studied a gamma ray burst, one of the massively bright and powerful explosions that occurs when stars go supernova in distant galaxies. Astronomers were interested in the gamma rays of differing energies and wavelengths that were generated by the explosion, and that raced each other across the universe. After a journey of 7.3 billion light-years, they all arrived within nine-tenths of a second of one another in a detector on NASA’s Fermi Gamma-Ray Space Telescope, at 8:22 p.m., Eastern time, on May 9 [The New York Times].
The researchers were wondering if certain gamma rays with both high energies and short wavelengths would arrive last, at the back of the pack. That would suggest that they had violated one of the principles set out in Einstein’s theory of relativity: that the speed of light is always constant. If researchers could detect a significant lag in some gamma rays, it would also give fresh hope to those ambitious researchers searching for a theory of everything.
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In a lab in Nanjing, China, two researchers are mucking about with what could be called the world’s first artificial black hole–but there’s no reason for alarm. The researchers, Qiang Cheng and Tie Jun Cui, haven’t created a doomsday device, but rather a nifty experiment that harnesses the strange properties of metamaterials. Physicists have already learned how to steer light around an object within a metamaterial to create an invisibility cloak…. Now Qiang and Tie have created a metamaterial that distorts space so severely that light entering it (in this case microwaves) cannot escape [Technology Review].
The lab experiment simulates a cosmological black hole, where the intense gravity curves space-time, sucking in any matter or radiation that gets too close. Not even light can escape a black hole (hence the name). The researchers couldn’t duplicate the intense gravity, but they could build a metamaterial with a physical structure that would make light curve into its central core, never to return. The device they built works only with microwaves so far, but the researchers say a visible light black hole is the next step.
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Three scientists who mastered light through technology have been awarded this year’s Nobel Prize for physics, for breakthroughs that the prize committee said “helped to shape the foundations of today’s networked societies.” Half of the $1.4 million prize goes to Charles Kao (pictured), for his work on fiber optics, while the other half will be divided between Willard Boyle and George Smith, two retired researchers from Bell Labs who invented the first imaging technology using a digital sensor instead of film, paving the way for the creation of digital cameras.
Kao’s discovery in fiber optics set the stage for the technological revolution that underpins today’s global communication systems, powering broadband internet connections and carrying data transmissions around the world. In 1966, he figured out how to transmit light for more than 100 kilometers using optical glass fibers, five times the length of the most advanced fibers then available [Bloomberg]. Fiber optics have become ubiquitous in today’s wired, networked world; the Nobel committee noted that if all the optical cables in use today were unraveled, it would equal a single thread more than a billion kilometers long, enough to circle the globe 25,000 times.
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A $40 price tag for a single light bulb may seem ridiculous to most consumers. But the Dutch company Lemnis Lighting hopes people will listen to all the arguments for their high-tech LED bulb, and consider it a bargain. [W]hat if it used 90% less electricity than a standard incandescent bulb, cut greenhouse gas emissions and saved you about $280 over its 25-year life span? [Los Angeles Times].
LEDs — light-emitting diodes — are semiconductors that glow and are considered one of the great hopes for slashing carbon emissions from lighting, which consumes about 19% of energy production worldwide [Los Angeles Times]. LEDs are already used in commercial lighting and electronic displays, but the cold, invariable glow has not caught on for household fixtures. Lemnis says its Pharox60 bulb, which just came on the market in the United States, is a major improvement, as it casts a warm glow similar to that of a standard 60-watt incandescent bulb and works in any normal light socket. The company also says this bulb is the first that’s compatible with dimmer switches. Finally, unlike curly compact fluorescent bulbs, LED bulbs don’t contain toxic mercury and can be recycled.
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Scientists now know how the iridescent green scarab beetle’s shell get its iridescent hue: A molecular arrangement that reflects light, with the reflected light’s magnetic field oriented like a corkscrew, according to a study published in Science.
The beetles don’t appear green due to pigments, which give flowers and plants their colors. Instead, they get their hue from structural color, or molecular structures that reflect light in a certain manner–the same way birds and butterflies do. Light hitting the shell is reflected by the microstructures, and these reflections create an electric field that forms a clockwise helix. Humans cannot see this property — known as left-handed circular polarization — but can see a green hue [ScienceNews]; some organisms, however, can actually see circular polarization itself. The molecular structure consists of three shapes: pentagons, hexagons, and seven-sided heptagons.
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Researchers have created a fabric that acts like a camera, made of tiny light-sensitive fibers that turn light waves into images. Says lead researcher Yoel Fink: “While the current version of these fabrics can only image nearby objects, it can still see much farther than most shirts can” [LiveScience].
Fink notes that the technology does away with one of the most basic camera components: the lens. Just like in an eye, cameras use a curved lens to focus the light waves reflected off an object, but the system contains an Achilles’ heel: Damage the lens, and you lose or diminish the ability to see [ScienceNOW Daily News]. By getting rid of the lens, researchers say they can develop a technology that is less vulnerable to damage–if one part of the fabric gets damaged, the rest can still function. “We are saying, ‘instead of a tiny, sensitive object [for capturing images], let’s construct a large, distributed system,’” Fink said [LiveScience].
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The European Space Agency’s Planck observatory has reached its operating temperature of a mere tenth of a degree above the lowest temperature theoretically possible given the laws of physics, known as absolute zero. That means it’s ready for its mission: Observing the oldest light in the universe, known as the cosmic microwave background, or CMB, to create the clearest picture yet of what the young universe looked like.
Although scientists have achieved temperatures closer than this to absolute zero in the laboratory, the spacecraft is likely the coldest object in space. Such low temperatures are necessary for Planck’s detectors to study the Cosmic Microwave Background by measuring its temperature across the sky. Over the next few weeks, mission operators will fine-tune the spacecraft’s instruments. Planck will begin to survey the sky in mid-August [SPACE.com], and the first batch of data is expected to be released next year. Planck was launched May 14 and will observe the CMB from a spot more than 930,000 miles from Earth.
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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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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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Just because Albert Einstein said that the faster-than-light travel is impossible isn’t any reason to stop trying for it, a number of Star Trek-loving theoretical physicists have declared. To achieve the starship Enterprise’s fabled warp speed, they propose simply bending the rules of physics a bit.
The speed-of-light speed limit, they argue, only applies within space-time (the continuum of three dimensions of space plus one of time that we live in). While any given object can’t travel faster than light speed within space-time, theory holds, perhaps space-time itself could travel. “The idea is that you take a chunk of space-time and move it,” said Marc Millis, former head of NASA’s Breakthrough Propulsion Physics Project. “The vehicle inside that bubble thinks that it’s not moving at all. It’s the space-time that’s moving” [SPACE.com].
But how do you move a bubble of space time around the universe? For an answer, researchers Gerald Cleaver expands on a theory first proposed in 1994 by Mexican physicist, Michael Alcubierre. It might be possible to expand space behind a vehicle, say the Enterprise, and shrink space in front of it, thereby creating a bubble that could move through Einstein’s space-time fabric at speeds much greater than the speed of light…. Cleaver, who earned his doctorate at the California Institute of Technology, in the heart of surfing country, likens it to “surfing a wave” [ABC News].
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Optics researchers have invented a camera that uses infrared lasers to bounce light off an object, and say the result should leave shutterbugs with a serious case of technology envy. Their device can take 6.1 million pictures in a single second, at a shutter speed of 440 trillionths of a second. Light itself moves just a fraction of a centimeter in that time…. “It’s the world’s fastest camera” [Wired], says study coauthor Keisuke Goda.
Conventional digital cameras use charge-coupled devices (CCDs) to take a picture. The devices contain semiconducting chips that … produce electrons in response to light. The electrons are read off the chip and their signals are then electronically amplified and encoded as a digital image [Nature News]. But that process has its limits. Top-notch conventional cameras top out at about 30 frames per second, while the fanciest scientific instruments can take about one million frames per second. For Goda and his colleagues, that just wasn’t fast enough.
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Researchers who created the first so-called invisibility cloak in 2006, have made significant advances that could lead to an invisibility cloak for visible light in as little as six months. “A large number of folks are looking at it, and I think it’s a matter of coupling the right material to the right device,” [Discovery News] said researcher David Smith. His team has developed an algorithm that speeds up the design of materials that can bend light around an object. Using the new algorithm, they were able to create an invisibility cloak that can bend much wider spectrum of microwaves than previous versions.
Invisibility cloaks rely on metamaterials, ones with unique properties that derive from [their] physical structure, not [their] chemical make up [Discovery News]. Smith compares the effect of metamaterials on light to mirages that appear over a road on sweltering days. “You see what looks like water hovering over the road, but it is in reality a reflection from the sky,” Smith said. “In that example, the mirage you see is cloaking the road below. In effect, we are creating an engineered mirage with this latest cloak design” [AFP].
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Encryption systems that rely on the “spooky” properties of quantum mechanics have long been hyped as the ultimate in spy- and hack-proof communication, and recently governments and large companies have begun sampling early examples of the technology. Now, scientists in Vienna have demonstrated a commercial telecommunications network protected by quantum cryptography, and say the system could be generally available in less than 10 years.
One of the researchers who worked out the basic idea behind quantum cryptography 25 years ago, Gilles Brassard, was on hand in Vienna to explain the mechanism. “All quantum security schemes are based on the Heisenberg Uncertainty Principle, on the fact that you cannot measure quantum information without disturbing it,” he explained. “Because of that, one can have a communications channel between two users on which it’s impossible to eavesdrop without creating a disturbance. An eavesdropper would create a mark on it. That was the key idea” [BBC News].
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Researchers at the University of California, Berkeley, announced yesterday that they were able to construct a prism that bent light “the wrong way” and so would make an object appear to vanish [Times UK]. Details of the two different experiments will be published separately later this week in Nature and Science.
To bend the light, the scientists used “metamaterials,” mixtures of metal and circuit board materials such as ceramic, Teflon or fiber composite [AP]. One group built what they called a metal “fishnet” of alternating silver and magnesium fluoride; the other used tiny silver nanowires. Both created negative refraction: Light is neither absorbed nor reflected by the objects, passing “like water flowing around a rock,” according to the researchers. As a result, only the light from behind the objects can be seen [BBC].
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The exact mechanism that triggers the colorful auroras that dance across the night sky near the Earth’s two poles has been revealed by a quintet of NASA satellites. Scientists already knew that disturbances in the Earth’s magnetic field, called “substorms,” bring charged particles into the Earth’s upper atmosphere, where they collide with gas particles. Those gas particles then release energy as light, which flickers across the sky in waves of greens, reds, and blues.
Now, researchers with NASA’s THEMIS mission say they’ve discovered what sets off those magnetic disturbances. The substorms begin far out in space, roughly a third of the way to the Moon, where magnetic fields from the Earth are thrown together and reconnect to sling charged particles back toward the planet, they say [New Scientist].
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