Originally Posted by **htam9876** the mass of a photon ,either the static mass is M0 and the released mass is ∞，or the released mass is hγ and the static mass is zero, (the detailed calculation with Special Relativity omitted),but both are meaningless in physics. If photon has no effective mass, how to explain the Campton efffect. what is the mass of a photon? |

Your mistake lies in this statement. The way that the velocity dependence of mass is derived is to require the conservation of the quantity of mv where m is the mass of a tardyon, i.e. a particle that always travels at a speed < c. It cannot be used for photons. I showed you how to get the mass of a photon. You use p = mv and with v = x and E = pc you get m = E/c^2.

So all your claims about the mass of a photon are wrong. The propr mass of any particle for v <= c is determined by E^2 - (pc)^2 = m_o^0 c^4

For a photon this gives m_o = 0.