Question

What does the effective mass of a photon describe

A) Photons only have a rest mass of zero
B) It has mass-like properties because photons move at the speed of light
C) Effective mass occurs because photons warp the space-time continuum
D) Photons have no effective mass as they are massless

Answer 1

Does the photon have mass? After all, it has energy and energy is equivalent to mass. Photons are traditionally said to be massless. This is a figure of speech that physicists use to describe something about how a photon's particle-like properties are described by the language of special relativity.