Neutrinos—faster than light?
According to the standard model, neutrinos are a type of lepton, which (along with quarks) are a fundamental building block of matter. Neutrinos have an incredibly tiny mass and are neutral, so they almost never interact with any other particles—most can simply stream straight through the earth without interacting with a single atom. Neutrinos come in three different flavours—electron, muon and tau—and experiments have observed them spontaneously changing from one type to another, so they’re basically shape shifters. In late 2011, CERN physicists claimed to measure neutrinos moving faster than the speed of light, which raised a serious challenge to Einstein’s theory of special relativity, which states that according to E=Mc^2, the speed of light is the universe’s ‘maximum speed limit’. However, other researchers failed to replicate the speeds of the initial experiment, and early this year, physicists admitted a wrong measurement due to faulty wiring in the experiment’s fibre-optic timing system, and the findings were subsequently overhauled. Recent experiments have indicated that neutrinos can travel at the same speed as light within a small error range, but they don’t actually break the speed limit—and so Einstein’s theory still stands the test of time.