I have a question on speed of light in vacuum as measured in accelerating reference frames: is it less than c (as measured from an inertial reference frame)?
I'd like to have an analogy which would make this idea (provided it is correct, of course) more clear in the same way as an upwardly accelerating elevator elegantly illustrates the bending of light. Then the equivalence principle says that this is equivalent to a downward gravitational field. Could you come up with the same kind of analogy showing why the speed of light is less if it is measured in an accelerating frame? Would it make difference if the acceleration would be due to change in the magnitude of velocity (tangential acceelration) or due to change in the direction of velocity (normal acceleration)?