The Fundamental Assumptions of Relativity
Jerry Hynecek
The paper discusses in detail the fundamental assumptions that are necessary for the derivation of special relativity theory and in particular for the derivation of Lorentz coordinate transformation. It is shown that the usual postulate of the constancy of speed of light is not needed. This is a generalization that is useful for studying the space-times with gravitational fields present in them, including the space-time of the Universe, since it is well known that the gravitational potential affects not only the clock rates but also the speed of light.
