If the acceleration due to gravity is velocity dependent at some point, that would solve the problem. But note that one doesn't need a black hole to cause acceleration past C (using the Newtonian force law, and the weak equivalence principle, which obviously must fail somehow, but I don't know...
That's why I said "from an inertial frame observing the spaceship." But I'm really just quoting the heuristic explanation all kinds of people (including Feynman) give for why one can't accelerate to the speed of light. Actually, he (and others) use it as a lead-in to relativistic mass; the...
I probably need a more qualitative explanation. :-) The "weak equivalence principle" is that gravitational mass = inertial mass. Eg, this is the reason why heavy bodies fall as fast as light bodies. So far as I understand it, Einstein explained this "weak equivalence principle" with a much...
Obviously, I'm missing a great deal, but it's commonly stated (including by Feynman in those old books of his) that while the structure of bMInkowski space itself demonstrates that a moving object can't reach the speed of light, this has to work out in a practical way for a spaceship trying to...
The fact that it is impossible to accelerate an object to (or past) the speed of light is typically explained as connected to the relativistic increase in inertial mass that occurs with increasing velocity; eg., for any given force, the acceleration produced by that force will decline as the the...