Fast moving observers, assuming whatever they observe is dictated by the Lorentz transformations, are unrealistic and impossible in certain cases.

Loretz transformations were made with the purpose to make the velocity of light constant, something that was achieved. However, ignoring unphysical situations may arise in some other cases, known as the S. Relativity paradoxes and contradictions. Some of these cases are shown in this paper, always involving a distance "x".

Moreover, the velocity of light seems to be constant on the surface of the Earth. We have no idea what happens with the velocity of light in other places of our Universe.