# Photon mass and life time

In this article, the author tried to explain that, Einstein's theory may not valid because he says "photon can decay because it may have minute amount of mass". I'm totally in a conundrum state that how to take this article? Anyone can explain a bit please.

• The current text of this questions is deeply misleading. The article assumes the correctness of relativity which investigating a theory in which the photon has mass. – dmckee Aug 4 '13 at 18:58
• Dear Raisa - just scanning the text, I can't find mention of relativity. I presume then you mean that a photon mass would imply variable lightspeed, thus overturning SR and GR. Not so. $c$ is simply the speed of a massless particle - whether or not light has mass has no impact on relativity - there are still very basic symmetry reasons for SR that have nothing to do with light - see a description of relativity without consideration of light of mine. – WetSavannaAnimal Aug 4 '13 at 22:29