Postulates of special relativity

As Einstein's postulates two crucial assumptions are referred to by Albert Einstein in 1905 in his work met the Electrodynamics of Moving Bodies, in order to justify this, the special theory of relativity.

• The first postulate is the relativity principle and states that physical laws are invariant to the change of the inertial system, ie that they are the same in all inertial frames. For this reason, no absolute motion can in principle determine that all movements must be regarded as relative.
• The second principle is the constancy of the velocity of light. It states that in all inertial systems, the vacuum speed of light is the same.

These postulates form an axiomatic basis for the special theory of relativity and led to major principles of classical physics as the Galilean transformation and extended the concept of simultaneity had to be redefined.