2011 Science News of the Year: Atom & Cosmos
By Science News
Not so fast, neutrinos
News of particles zipping along faster than light (SN: 10/22/11, p. 18) was met with universal skepticism — including from the physicists in Italy who reported the results. But the Gran Sasso National Laboratory’s OPERA team hasn’t found any source of error that could explain how the neutrinos appeared to shave 60 nanoseconds off of light-speed travel time while covering the 730 kilometers from the CERN physics laboratory near Geneva to Gran Sasso.
Einstein’s special theory of relativity says such speeds shouldn’t be attainable. And even if they were, the neutrinos would have shed observable energy during flight, report physicists at Boston University (SN: 11/5/11, p. 10). Critics suggest that at the different locales gravity may have pulled on the clocks with different strengths, causing the timekeepers to tick at different rates. Or some of the particles in the neutrino bunches could have started the trip earlier than thought.
Faced with these criticisms, the OPERA team has used shorter, sharper pulses of particles to check the results. The researchers say the findings still stand, but other large neutrino projects plan to repeat the experiment. — Devin Powell