My recent article
on the relationship between Einstein's Theory of Relativity and superluminal neutrinos has triggered a series of comments. Some of them were reasonable, some others not. Among the reasonable doubts on this topic, there is a possible concern about the meaning of "limiting velocity", i.e. velocity that cannot be exceeded in the context of the theory. Could it be that we have found a new limiting velocity- the one of neutrinos- and the theory still stands up with a new value for a fundamental constant c? Could it be that the speed of light is not well measured?
There is a certain amount of confusion on the relationship between Einstein's Theory of Relativity and the recent experimental results that seem to point towards neutrinos that are faster than light by an amount of about 7 km/s. So let me try to clarify things by answering to the following question:
If neutrinos travel faster than light by 7 km/s, do we need to modify Relativity?
The answer is a clear-cut "Yes"; let me explain why.
Lorentz invariance, which is embodied in the theory of Relativity, has the unescapable consequence that there exists a precise relationship between a free particle's energy E, its momentum p and its mass m: