(February 26, 2015 at 9:25 pm)bennyboy Wrote:(February 26, 2015 at 8:28 pm)Surgenator Wrote: I guess they're more postulates than axioms. The second one is what I'm referring to, i.e. speed of light is constant in all inertial reference frames.What's the speed of something traveling 0 distance? Infinity? Zero? Any arbitrary value? I don't think a photon can be said to have inertia if it has zero mass, can it?
Measurement aside, instantaneous speed is still something.
Also, I think your mixing the 'inertial' in inertial reference frame with actual inertia. Inertial reference frame means it is not accelerating. Plus, the photon has inertia since it has momentum.