Jerry Stuckle wrote in news:m17bvm$cm0$1@dont-
email.me:

But by definition, anything moving at the speed of light must be
massless, because it takes an infinite amount of energy to accelerate
even an electron to that speed. Which means a photon cannot have mass.


Agreed, (though mass-energy it does have), Not why I posted though, I find
that the interestign thing is this term 'speed'. A 'speed' is something that
CAN be reached, so what interests me is that the timing of light's travel
seems to have other things to be known, starting with why it even appears to
be a 'speed' and why it has the value it has. Studies of refractive index
don't seem to have cracked this, but Bose-Einstein condensates seem to be
doing dramatic things that might.