ABSTRACT
In special relativity, we saw that there is no distinction to be made between being at rest and travelling with a constant velocity. It was found that
“without looking outside,” it was not possible to determine whether we, performing experiments inside, were moving or not. That is, there is no preferred or fixed frame of reference required for physical laws. As a consequence of this, the velocity of light (in free space) had the same value no matter whether the source or the observer was moving.
