IntellectualNinja wrote:I don't know if neutrinos can travel faster than light, but I learned that you can detect a stream of neutrinos from a supernova a good deal of time before the star actually goes supernova. That's pretty cool.
Yeah, I learned that too. It's because the neutrino's are emitted at the speed of light the moment the stars core stops fusion-ing and collapses under it's own gravitational pull into a neutron core, but the resulting shockwave takes several hours to push its way up through the star, and isn't visible until it actually reaches the surface.
This is all accounted for, though. If neutrino's were really as much faster than the speed of light as this experiment indicates, you'd expect to see them arriving even earlier: more than ten minutes earlier per light-year, to be precise.
So for example, Supernova 1987A (the first in which the neutrino burst was seen before the supernova) happened 168,000 lightyears away. If all neutrinos really did travel 60 nanoseconds faster, we should have seen the burst more than three years
before the light from the supernova. Instead, we saw it a matter of hours before.
So either the ones we're producing in Italy are special somehow, there's still some experimental error we've missed, or something else entirely is going on.