(Every day until Christmas, I’ll be posting a science-related image.)
Day 11
For this reason, the IceCube detector in Antarctica uses a huge volume of pure ice near the South Pole. The experimenters drilled 86 holes to a depth of 2 kilometers in the ice, and lowered strings consisting of 60 detectors into the holes. These 5,160 detectors can pick up faint blue flashes of light that are produced when a neutrino strikes an atom. The collision creates a muon, a more massive and unstable cousin to electrons (I’m sure we all have such a relative). The muon is produced such that it moves faster than the speed of light in ice, so it makes shock waves, akin to a sonic boom. However, the shock waves in this case are blue light known as Čerenkov (pronounced “CHAIR-en-koff”) radiation. That’s the stuff the IceCube detectors are looking for; when several detectors are triggered, the researchers can tell where the neutrino came from, and even how much energy it had when it hit the ice.