Okay. As you accelerate particles up to the speed of light, they require exponentially more and more energy to make a significant difference in speed. If you had a marble and you made it go the speed of light, it would be infinitely dense, it would have an infinite amount of mass and therefore, it would have an infinite amount of kinetic energy. Take ANYTHING.. As long as it has some matter. If you accelerate it to the speed of light, it will have infinite energy. It's never been done before because it's theoretically impossible. But consider this. Light waves/particles have some mass. A very tiny and miniscule amount of matter. And because they are light, they're going the speed of light. So wouldn't one photon have an infinite amount of energy? Maybe the amount of matter ub a photon is so small that the rules don't apply to them. Urgh. What are your opinions?
Who says that light has mass? I believe that light is considered to be the "dividing line" between energy and matter. Therefore, looked at as energy, it is not bound by the infinite mass issue. Has anyone really "weighed" light?
Photons are affected by gravitational pull. Therefore it's thought by some to have matter. Same thing with electrons. Although the amount of mass is extremely minute.
Photons have no rest mass. This was covered in a recent thread in depth. I forget the exact title. Search for "light" and "mass".
Awaranowski Photons are affected by gravitational pull. Therefore it's thought by some to have matter. As James R points out, photons have no rest mass. They do however contain energy and it is the energy of the photon which is affected by gravitational fields. If photons contained matter, they would not be able to travel at c and they would be unable to be absorbed and re-emitted by atoms.