Light Signals in Galilean Relativity
Adolphe Martin
In invariant Galilean space-time, the Einstein postulate of the constancy of light speed is replaced by the postulate of space and time invariance. The Doppler factor is used to determine the time of light reception by the observer moving relative to the source. The requirement that velocity addition be vectorial in three space dimensions or arithmetical on each space dimension is met. Finally, we compare four viewpoints: one in Einstein Relativity, three in Galilean Relativity, with Einstein speed v, with Proper speed v/L and with Galilean speed V.
