One problem is that the CERN result busts the apparent speed limit of neutrinos seen when radiation from a supernova explosion reached Earth in February 1987.
Supernovae are exploding stars that are so bright they can briefly outshine their host galaxies. However, most of their energy actually streams out as neutrinos. Because neutrinos scarcely interact with matter, they should escape an exploding star almost immediately, while photons of light will take about 3 hours to get out. And in 1987, trillions of neutrinos arrived 3 hours before the dying star’s light caught up, just as physicists would have expected.
The recent claim of a much higher neutrino speed just doesn’t fit with this earlier measurement. “If neutrinos were that much faster than light, they would have arrived [from the supernova] five years sooner, which is crazy,” says Sher. “They didn’t. The supernova contradicts this [new finding] by huge factors.”
It’s possible that the neutrinos that sped to the Italian mine were a different type of neutrino from the ones streaming from the supernova, or had a different energy. Either of those could explain the difference, Sher admits. “But it’s quite unlikely.” [bron]