It is a necessity that for permitting oscillations between the three neutrinos, at least two of the three kinds of neutrinos must have a mass and not the same. One kind of neutrinos could have a zero rest mass. Only the three differences between two masses of the three kind of neutrinos are relevant in the oscillation phenomena. These differences must be non vanishing.

The logical contradiction lies in the necessity of at least two (and perhaps three) different masses AND the asserted observed velocity c of neutrinos.

On a logical point of view, it is impossible to simultaneously maintain that all neutrinos have a mass AND that neutrinos travel at velocity c. It is the same situation with the muons and with every other massive particles. Having a definite rest mass, as small as it is, they can not exactly travel at the velocity c. Even if the rest mass of neutrinos is very very low, at a velocity very very near of c, it would be big enough, or even huge enough, to be detected and measured, as mass increases with velocity, and sharply near c, according to the Einstein’s equation relating mass and velocity. It would become infinite at the velocity c, what is impossible.

In the case of the massless photon travelling at velocity c, the same equation gives 0 / 0, what is an undefined quantity…, not necessary nil, i.e. one can only say that the “mass” of the travelling photon is undefined, even if its rest mass is nil (One assumes that its mass continues to be nil). But, on the opposite, who knows what could be a resting photon ?

Nevertheless, I am one of those who are 99,999% certain that depending on neutrino generation conditions, there are classes of neutrinos that will travel faster than c.

good enough for now.
fluidic