I heard Neil deGrasse Tyson talk about the life of a photon that was emitted from the Sun and hit oneself. He said that its entire life was an instant. I hope I'm not misquoting or misunderstanding what he said. With that in mind, does that instant take into account the thousand of years (relative to us) it spends trapped in the mantle and core of the Sun, trying to get out? Also, how would one describe the life of a photon that is emitted from the Sun, or any Star for that matter, and travels indefinitely throughout the Universe, never coming into contact with anything? Is this an indefinite instant?