| “ú–{Œê |

As has drawing at the last figure, the light's source is reflected in the mirror and attain
the count, that mark 1 count.
If this count represent 1 second, this 'clock' is called 'light clock'.
Putting this clock in a rocket, and see them by the earth, how the light's trajectory set up?

A tube has seen by a person that is stopping, wil see a angular trajectory, because "The
Principle of light's constant speed". Thus the time for the light go and back became more
slowly. This setup of the 'walking of the light' is showed in the next Java's Simulation.