Thanks. The equations give the answer in the end, I found this explanation the best [1]. The only way to get a zero mass is if the energy is zero, or the velo

Thanks. The equations give the answer in the end, I found this explanation the best [1]. The only way to get a zero mass is if the energy is zero, or the velocity is c. [1] https://profoundphysics.com/why-do-photons-have-no-mass-simple-proof/ https://profoundphysics.com/why-do-photons-have-no-mass-simp...