Neutrino experiment sees them apparently moving faster than light
Tomorrow, researchers from CERN will be releasing experiment results that suggest neutrinos, the lightest particles we're aware of, may be moving slightly faster than the speed of light. Although the results have not yet been made public (a webcast will accompany the release of the paper), rumors of the finding have spread far and wide, leading to coverage by the BBC and the AP. Still, because the findings would seem to violate relativity, the authors are being very cautious about their results, and many in the physics community are expressing skepticism.
Neutrinos have generally made the news because they engage in what are called flavor oscillations, in which (to give one example) an experiment that creates only muon neutrinos will see some of them behave as electron neutrinos when they hit a detector. These oscillations confirmed that neutrinos must have mass, although they are orders of magnitude lighter than any of the other fundamental particles. That extremely low mass means that it doesn't take much energy to get them moving very quickly, which allows physicists who work on neutrino detectors to simply treat them as if they are moving at the speed of light when calculating their expected behavior.
As far as we could tell, this was a pretty good approximation. Neutrinos are produced in copious quantities in supernovae, and despite the enormous distances, they arrive at about the same time as the photons generated in the explosion. (The neutrinos actually get here a bit more quickly because they so rarely interact with matter, meaning they can escape the core of the star without incident. The photons, in contrast, get held up by interacting with the outer layers of the star, and typically appear a short time afterwards.)
