Why is it that people are insisting that photons have mass when all available evidence and theory are contrary to that? I just don't understand it.
SJ, nice try

, but that calculation shows how much mass would be generated if the photon was completely anihilated. It does not show how much mass a photon has. This has been observed, by the way, in a process called "pair production". A photon (gamma) of at least 1.02 MeV can be transformed (E=mc^2) into an electron and a positron. There must be 2 particles due to conservation laws (momentum, spin, charge, etc.) beyond the scope of this discussion.
Slick.