Space, time, and their transformations

We construct a set T of space-time transformations between inertial systems that are completely equivalent for explaining the experimental evidence, by starting from two empirically based assumptions: (1) The two-way velocity of light is c in all inertial systems and in all directions; (2) Time dilation effects take place with the usual relativistic factor. The Lorentz transformation is an element of T and any two elements of T differ only as to a convention regarding clock synchronization. The simplest choice is to transform time independently of space coordinates (absolute synchronization) and can be called “inertial transformation”. When accelerations are considered the equivalence is broken and the inertial transformation emerges as closest to physical reality.