2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/115767De Broglie believed that the photon has a mass, a view shared by a few others. Quite recently, the author has argued that the photon has a mass which is consistent with the latest experimental limits. In the present paper we point out that there is experimental evidence for this mass and also give a theoretical demonstration of the photon mass.8 pages, texGeneral Physicstext