One very naïve question: Do we have sound experimental evidence for neutrinos travelling at subluminal speed?
Well, for a long time it was thought that neutrinos possibly, but not necessarily, traveled at light speed. That is that they had a zero rest mass. When they actually started detecting neutrinos they found that they were detecting about 1/3 of the number of neutrinos that they expected from the Sun. This caused all kinds of conjectures as to what was going on. Well, what their detector was catching was one particular type of neutrino, which was the type expected to be generated in the Sun. When they stared detecting other types they found that the number of detections went up to the expected number, but they came in 3 types. That was when they figured out that the neutrinos were oscillating among the 3 types as they traveled from the Sun. But that implies that the neutrino travels as less than light speed, so that they would have time to make the changes. Traveling at light speed the neutrinos internal clocks would be stopped with respect to our clocks and they would not have time to make the oscillations. So then we have pretty good evidence that neutrinos do travel at less than light speed.
Bill Gill
