Gravity Bends Light

Light being a particle, that's an interesting calculation to try to make. Well, you can actually get very close to the right answer if you assume light is a particle. If you go back to pre-relativity, imagine you have a particle traveling very quickly past a source and just run through standard gravitational calculations on this. If you get to almost the correct answer, you just have to multiply by a factor of two and you get what we now have as the correct answer.