Black holes are supposedly invisible because light does not deflect off of it, rather being sucked into it. Black holes, in theory, are the only known way to "travel back in time" but they cannot be survived. If there was a way to survive a black hole, anyway, what would happen if you tried to go out the other end? Yes, you'd have theoretically traveled back in time, but you're stuck being thrown around faster than the speed of light, backing between the future and the past.
There are more theories about black holes, about HOW you would have died. Fried, cut, destroyed piece by piece. Even theoretical WHITE HOLES! Post what you think would happen!