the universe

What if the proton is already past the event horizon of a black hole and goes directly away from it. The proton has to stop because it can't escape from the black holes gravity but can't because the speed of light is constant.

...

The velocity of a moving particle has nothing to do with the speed of light. If the gravity of the black hole sucks it in, it's velocity moving away from the event horizon will accelerate (negatively, ok, decelerate if you want) until it's vector reverses and it accelerates towards the black hole. And technically, 'c' isn't always constant as it moves at different velocities through different media.

Bah, bow to my superior 10 weeks knowlege of introductory physics. :P