This is probably a bizarre question, and I`m not trying to go off into woo-woo-land, but maybe someone could help me out with the following (and of course, disabuse me of any misconceptions I may be harboring). Photons have no mass, and travel at c, which is the fastest possible speed. Objects with mass are prohibited from ever reaching c, but would any massless particle (assuming others are found) necessarily move at c, or could massless particles possibly move slower in their own frame? (I understand that photons can be made to go slower than c in our frame, but in their own, they are still moving at c, right?) If so, do we have any idea why some massless particles would move at different speeds than others?