![]() “I don’t think it will take twenty years, before we learn some very interesting things about the universe,” he says. But IceCube’s electronics were designed to survive for 20 years in the South Polar ice, and Halzen is convinced that the project’s scientists will find ways of upping the rate of needles they can pull from their haystack. With little more than two dozen neutrinos in hand so far, scientists can’t say much of anything about the violent events that created them. When you see one of these events on the display, you know you’ve never seen anything like it before.” “It sounds a bit like looking for a needle in a haystack,” says Halzen, “but it turns out to be amazingly easy. ( MORE: Just Right Black Hole Fills a Cosmic Void) But that’s just about the number theorists predicted. ![]() Only 28 turned out to be extragalactic, judging by their trajectory and the punch they packed. The new report in Science is based on IceCube’s first two years of operation in that time, the instrument picked up several hundred thousand such neutrinos. ![]() The vast majority of flashes come from neutrinos created right in Earth’s atmosphere, as cosmic-ray particles smash into air molecules in tiny, violent collisions. And those two details make all the difference. By measuring the intensity and direction of the flash, the scientists can calculate the energy level and flight path of the neutrino that caused it. What the scientists see with all those detectors isn’t the neutrinos themselves it’s tiny flashes of blue light, called Cherenkov radiation, triggered on those occasions when a neutrino slams into a hydrogen or oxygen atom in the frozen H2O that surrounds the detectors. “You know you’ll never get your hands on it again.” “It’s like launching a satellite,” says Francis Halzen, a University of Wisconsin physicist and IceCube’s lead scientist. The detector-studded cables were lowered into holes drilled with high-pressure hot-water hoses then the holes, filled with water, were allowed to re-freeze, sealing the cables permanently in place. It’s made up of more than 5,000 individual detectors, strung on 86 cables and sunk up to 1.5 mi (2.4 km) into the East Antarctic Ice Sheet. Other detectors have managed to pick up neutrinos created in the Sun’s core, and even from an exploding star, or supernova, just outside the Milky Way-the only neutrinos ever confirmed from beyond the Solar System.īut IceCube puts those earlier efforts to shame. That one, which confirmed the particle’s existence, was set up in the 1950’s just outside a nuclear reactor, where physicists suspected neutrinos were being churned out by the quadrillions. IceCube is not the first neutrino detector ever created. “This is a new window on the universe, and especially on the most ferocious, violent cosmic events.” When Jayawardhana says violent, he means it: events like jets of matter spewing from giant black holes at the cores of massive galaxies or gamma-ray bursts from the most powerful stellar explosions, both of which create neutrinos in droves. “This is quite a big deal,” says Ray Jayawardhana a University of Toronto astrophysicist and author of a new book called Neutrino Hunters, who wasn’t part of the research team. (MORE: Cosmic Fugeddaboudit: Dark Matter May Not Exist After All) Using a neutrino telescope known as IceCube, located appropriately enough at the South Pole, astronomers have detected 28 high-energy neutrinos that almost certainly came from the depths of the universe. So while they stream across the universe in vast numbers-literally trillions of them pass through your body every second-building a telescope to catch them is no mean trick.īut that’s what a team of scientists from 41 institutions in 12 countries has pulled off, and the first results have just come out in the Science. Trying to detect neutrinos, on the other hand, has proven hellishly difficult, and no wonder: these elementary particles are so elusive that the average neutrino could zip through a chunk of lead five trillion miles (8 trillion km) thick without the slightest problem. They’ve seen bursts of energy from black holes halfway across the universe, blips of radio noise from neutron stars spinning at hundreds of revolutions per second, and even the faint glow of microwaves emitted more than 13 billion years ago, in the immediate aftermath of the Big Bang itself. Follow have become incredibly skilled at detecting cosmic radiation in all its forms-not just ordinary, visible light, but also light we can’t see, everything from infrared to ultraviolet to gamma rays.
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