Changes
It is not difficult to demonstrate that it is impossible to reconcile these conditions with a Newtonian mechanics, in which the coordinates are formed in a three-dimensional space. In SRT, each object moving in its own inertial frame has its own time, which constitutes a fourth coordinate describing its state.
The three most prominent SRT effects are [[time dilation]], length contraction and the equivalence of mass and energy.
== Four Vectors and relativistic metric ==
