The hunt for fusion energy is one that has been plagued by false starts and overly-optimistic announcements. This week, however, researchers at the National Ignition Facility in California announced a major new step: firing all of its 192 lasers together for the first time, and channeling the beam into an area no bigger than a pencil eraser.
That tiny target is called the hohlraum. It’s a gold-plated cylinder intended to contain the hydrogen isotopes deuterium and tritium, which would fuse together during a potential fusion reaction. In this test, documented in the journal Science this week, the 192 lasers heated up the hohlraum to “only” about 6 million degrees Fahrenheit. But, team member Jeffrey Atherton says, the NIF is working its way up to the really powerful reactions. “The point is that we were doing it at a scale that’s about 20 times larger than has been done, with a laser power that accordingly is about 20 times higher than has been done, with a precision and efficiency that hasn’t been done before,” he said [MSNBC].
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Scientists have figured out a way to switch brain cells on and off like light bulbs, but instead of using a clapper, they’re using microbial proteins and lasers. Ed Boyden, a neuroscientist at the Massachusetts Institute of Technology, has developed a way to shut down parts of a brain just by shining light on them. When the light is turned off, the brain switches back on [Forbes].
The research team says their technology will help neuroscientists probe the brain’s circuitry by silencing certain regions and studying the effects. The technique, which was described in the journal Nature, could one day be used to shut down overactive regions of the brain often found in people with epilepsy, depression, Parkinson’s disease, and blindness.
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There’s nothing like the round number at the start of a new decade to get everyone prognosticating (yes, we know some of you are in the crowd that says the new decade doesn’t begin until 2011; OK, fine). To predict what the scientific scene will be like in 2020, the journal Nature brought in experts from 18 fields. Though the collection doesn’t encapsulate the “world of tomorrow” feel of, say, the old Omni magazine, it’s still packed with sunny (and scary) forecasts. Some show lingering uncertainty, some unbridled optimism, and some give warnings to the world to make a much-needed course correction. Here are five we thought were particularly telling.
1. In 2020, Google defines your reality (even more than it does already).
Peter Norvig, Google’s director of research, tackles the question of where search will be a decade hence. Advanced, he says, but also troublesome: Most searches will be spoken rather than typed, and designers will be experimenting with search systems that read your brain waves. “Users will decide how much of their lives they want to share with search engines, and in what ways”—such is Norvig’s polite description of a world with even less digital privacy than today’s.
What search engines give you back will change, too. Particularly, he says, they will come up with a way to judge relevance and quality that doesn’t rely on popularity: “Thus, a site that claims that the Moon landings were a hoax and seems to have a coherent argument structure will be judged to be lower quality than a legitimate astronomy site, because the premises of the hoax argument are at odds with reality.”
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A laser-powered robot took a climb up a cable in the Mohave Desert in Wednesday, and pushed ahead the sci-fi inspired notion of a space elevator capable of lifting astronauts, cargo, and even tourists up into orbit. The robot, built by LaserMotive of Seattle, whizzed up 2,953 feet (nearly 1 kilometer) in about four minutes, which qualifies the team for at least $900,000 of the $2 million in prizes offered in the NASA-backed Space Elevator Games.
Theorized in the 1960s and then popularized by Arthur C. Clarke’s 1979 novel “The Fountains of Paradise,” space elevators are envisioned as a way to gain access to space without the risk and expense of rockets. Instead, electrically powered vehicles would run up and down a cable anchored to a ground structure and extending thousands of miles up to a mass in geosynchronous orbit — the kind of orbit communications satellites are placed in to stay over a fixed spot on the Earth [AP].
The LaserMotive vehicle that climbed up the cable (held by a hovering helicopter) was powered by a system that resembles an upside-down solar power mechanism. Laser beams on the ground were fired up at the ascending craft and hit its photovoltaic cells–like those used in solar panels–in a process known as “power beaming.” LaserMotive will have a chance to improve its vehicle’s speed at another trial today, and other teams will also be vying for prizes.
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Image: Space Elevator Games. The LaserMotive vehicle gets weighed in.
It sounds like a scene from an insect version of Total Recall: Using genetically engineered fruit flies and laser beams, researchers have found a way to embed false, fearful memories in the flies.
Researchers first tested normal flies in a chamber where a jets of air on either side brought two different odors into the container. The researchers delivered an electric shock each time a fly strayed into a particular odour stream, which taught the flies to prefer the other one: the flies learned to move in the direction of the shock-related odour 30 per cent less often [New Scientist].
Next, the researchers created a strain of genetically engineered flies with certain neurons that would be activated by a laser blast. Lead researcher Gero Miesenböck explains that with this technique, called optogenetics, researchers can use light to activate particular cell types that have been genetically engineered to express a light-responsive protein. When laser pulses hit the brain, cells expressing the light-sensitive protein activate. “It’s like sending a radio signal to a city but only those houses with a radios set to the right frequency will get the signal,” says Miesenböck [Nature News].
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Nissan is looking to schools of fish to learn about how to help people reduce car crashes and traffic jams. The car company developed tiny robots that move in fish-like groups of up to 7 without bumping into each other. Each uses a laser range-finder to measure the distance between obstacles. The data is constantly shared between peers via radio, allowing the group to travel as a “shoal” without bumping into each other. The technique allows the cars to travel side-by-side or quickly switch direction as a group [BBC News]. The robot is dubbed Eporo, which stands for Episode O (Zero) Robot, meaning zero episodes, or accidents, and zero emissions.
This is Nissan’s second attempt at designing a crash avoidance system based on animal behavior. Their last attempt was the BR23C robot, modeled after the anti-collision behavior of bumblebees (check out a video of the bee based bot here). The Eporo, however, imitates three rules of fish movement: avoiding crashes, traveling side by side, and keeping close to other members of the school [CNET]. Nissan plans to unveil the Eporo at the Ceatec conference in Tokyo on October 6.
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Image: Nissan
In future military operations, aircraft and submarines may be able to stay in contact by firing up the laser comm. Researchers have devised a new way to communicate with submarines by using high-energy laser beams to create bubbles of steam in the water, which then pop in little explosions that generate a 220-decibel pulse of sound. By controlling the frequency of explosions, researchers could make a kind of underwater Morse code.
According to a press release from the U.S. Naval Research Laboratory, one of the peculiar effects of high-intensity laser beams is that they can actually focus themselves when passing through some materials, like water. As the laser focuses, it rips electrons off water molecules, which then become superheated and create a powerful “pop”. Because different colours of light travel at markedly different speeds underwater, the precise location where different colours focus together could be manipulated by the suitable design of a many-coloured input pulse [BBC News].
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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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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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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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Luminaries gathered today at a lab in Livermore, California to toast the opening of the National Ignition Facility, a massive physics experiment aiming to recreate the reaction that takes place in the hearts of stars: nuclear fusion. “Bringing Star Power to Earth” reads a giant banner that was recently unfurled across a building the size of a football stadium [The New York Times]. Scientists are now ready to begin firing the world’s most powerful laser, comprised of 192 separate beams, at a target the size of a match head. Yet for all the celebration and hoopla, doubters note that there’s no guarantee that the fusion researchers will achieve their goal.
The project’s director, Ed Moses, said that getting to the cusp of ignition (defined as the successful achievement of fusion) had taken some 7,000 workers and 3,000 contractors a dozen years, their labors creating a precision colossus of millions of parts and 60,000 points of control, 30 times as many as on the space shuttle. “It’s the cathedral story,” Dr. Moses said…. “We put together the best physicists, the best engineers, the best of industry and academia” [The New York Times]. The project has also cost at least $3.5 billion. NIF’s researchers will spend the next year gradually increasing the energy of the laser beams, and say serious ignition experiments will begin next year.
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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 in California are preparing to fire 192 lasers at a minuscule pellet of fuel to create their first nuclear fusion reaction, the same reaction that takes place in the center of the sun. Within two to three years, the researchers at the National Ignition Facility (NIF) expect to be creating fusion reactions that release more energy than it takes to produce them. If they’re successful, it will be the first time this has been done in a controlled way–in a lab rather than a nuclear bomb, that is–and could eventually lead to fusion power plants [Technology Review].
Earlier this month, technicians test fired all 192 lasers at once, concentrating their beams on a single focal point in the middle of the chamber. For the test, the chamber was empty. But when real experiments begin within the next few months, the target will be a tiny gold capsule the size of an extra-strength Advil. The goal is to mash the contents of the capsule, a BB-size pellet of hydrogen frozen to nearly absolute zero, until the hydrogen atoms fuse into helium and release a gush of energy [Forbes Magazine].
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In a preview of possible high-tech battles to come, Boeing has announced the successful test of a laser weapon designed to shoot down unmanned aerial vehicles (UAVs). Robotic spy and combat planes are a hot field of military research because their use doesn’t endanger pilots, and because they can be smaller and harder to detect than conventional planes. But Boeing vice-president Gary Fitzmire argues that the military should be investing not just in UAVs, but also in devices that can destroy them. “Small UAVs armed with explosives or equipped with surveillance sensors are a growing threat on the battlefield,” he insists. “Laser Avenger, unlike a conventional weapon, can fire its laser beam without creating missile exhaust or gun flashes that would reveal its position. As a result, Laser Avenger can neutralize these UAV threats while keeping our troops safe” [The Register].
The weapon was tested at the White Sands Missile Range in New Mexico, where the Laser Avenger tracked three UAVs flying “against a complex background of mountains and desert”, shooting down one of the UAVs [Gizmodo]. The device got its sci-fi tinged name because it’s a modified version of the Army’s existing Avenger air defense system, which had two missile launchers mounted on a Humvee. To build the Laser Avenger, Boeing swapped its ray gun and a target tracker for one of those missile launchers.
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In several years police officers may have laser or microwave guns to point at miscreants, according to the Justice Department’s research and development agency. These nonlethal weapons build on knowledge gained from the Pentagon’s controversial Active Denial System (ADS) – first demonstrated in public last year, which uses a 2-metre-[wide] beam of short microwaves to heat up the outer layer of a person’s skin and cause pain. Like the ADS, the new portable devices will also heat the skin, but will have beams only a few centimetres across. They are designed to elicit what the Pentagon calls a “repel response” – a strong urge to escape from the beam [New Scientist]. But the idea of giving cops a tool capable of instantly inflicting pain from across a town square is raising protests from human rights advocates.
The Justice Department is working on two separate weapons. One, the Personnel Halting and Stimulation Response, or PHaSR, uses an infra-red laser to heat a patch of skin about 4 inches in diameter, and pairs that heat with another bright laser that dazzles the eyes. The PHaSR looks like a bulky rifle, and law enforcement officials say that a cheap, portable version could be very useful to police and prison guards. Sid Heal, formerly a Commander in the Los Angeles Sheriff’s Department (and before that a Marine) , has long been an advocate of non-lethal weapons and thinks the new devices might have potential. “Needless to say, the “market” is so vacant with alternatives that ANYTHING is going to be appealing at this point” [Wired News], says Heal.
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