I haven't studied a lot about these topics to put it that way. But I wonder if there is a connection between spontaneous symmetry breaking and the fact that photons are massless?
The spontaneous symmetry breaking breaks the symmetry of the universe predicted by the force and particle equations and thus, makes other particles acquire mass. Is that right? Then, is this symmetry breaking that causes mass to be in some way related to the at speed of light traveling photons that do not have mass?