Nothing you're saying makes any sense. > since the mass of the photon acts exactly like mass in most things except when dealing with change in velocity Right:

Nothing you're saying makes any sense. > since the mass of the photon acts exactly like mass in most things except when dealing with change in velocity Right: inertia. Funny that. The fact that photons are affected by gravitational fields, even though they're massless, was a major victory for the theory of general relativity. It wouldn't be a big deal if you could just say the photon has mass. Because it doesn't. A photon is massless. Fullstop. To say otherwise is to use a nonstandard definition of "mass". At best, people won't know what you're talking about. At worst, they will assume you don't. You should be more specific next time.