vierlights answered: What propels light? Light (photons) were at the sun about eight minutes ago, and now they’re here. What makes them “go?”

Great question! It’s due, in part, because photons are the gauge bosons of the electromagnetic field, and the field “propels them,” but mainly because the photons seek areas of lower energy density. Much like diffusion, the high concentration of photons wants to go to places of lower concentration.