Absolute and Relative Speeds of Light
Janusz Dyonizy Laski
It is shown that in particular case of photons, the Lorentz transform formulae for distance and time are simpler and take the same form as that of - corrected for relativity - Doppler formulae for the length and period of the wave. It means that considering light as particles and using Lorentz transform we obtained an unexpected result indicating that light is an electromagnetic wave which obeys the Doppler formulae. According to Doppler the length and period of the wave are relative and transform in such a way that their ratio does not change. The Doppler formulae show that the phase speed of the wave defined as the ratio of the length of the wave to its period is absolute. Should light be considered as a wave then the second Einstein postulate would automatically be given by Doppler formulae whether corrected for relativity or not. Light considered as a wave would have at least two speeds: the absolute phase speed and the relative speed of the wave front. Particles (photons) do not have two different speeds but the waves do. Instead of considering the light as photons and introducing the second Einstein postulate, we propose to accept the idea of particle-wave duality of light. In the case of waves it would automatically assure the existence of the absolute phase speed and would provide the relative speed of the light wave front. It is argued that introducing corrections for relativity into the Doppler formulae for electromagnetic waves we should also correct Doppler formulae for elastic waves. Otherwise the first Einstein postulate is violated.
