This just serves as a short review of the special theory of
relativity(SR). The main concern here are some basic concepts
which will be used extensively later.
The physics statement in SR is the first postulate by Einstein.
"The laws of physics take the same form of in different inertia
frames". This is our belief. And the SR could be derived from
different approaches.
1.Started from 2nd postulate by Einstein, the speed of light is
a constant in different inertia frames. We always say 2nd postu-
