At Long Last: IceCube Spots 28 High-Energy Neutrinos

Wired reports that IceCube, the detection facility built just to detect such things, has seen just what it was looking for, even though the researchers involved didn't know it at the time. High-energy neutrinos, the target that IceCube was seeking, weren't showing up as had been hoped, but it turns out that there were quite a few (nearly 30 already, with 2013's data still being recorded) in the three years that the detector has been operating — they just weren't obvious until the data was combed for it. "Most of the 28 high-energy neutrinos so far detected originate from parts of the night sky that don’t include the Milky Way, making it quite likely that they are arriving from a distant source. There are still too few neutrinos to make any specific conclusions about AGNs or gamma-ray bursts, but the IceCube team will continue gathering new data."

Re:Ugh

[Anonymous Coward]

The project consists of a huge 3D grid of light detectors in ice, such that when any high energy particle hits something in the ice, it creates a spray of particles, which also creates a spray of photons from Cerenkov radiation. At the basic level, you can think of conservation of momentum meaning most of the spray needs to be going in the direction of the incoming particle. So they can see which way all of the secondary particles are going and tell with pretty good accuracy which way the original particle came from. Really good timing measurements also gives some time of flight info helping pin point the direction. The shape and type of spray of particles really narrows down what type of particle they are seeing, although neutrinos are most obvious when they are coming upward having traveling through the Earth which would block other kinds of cosmic rays.