How is time changed in a black hole?
Well, in a certain sense it is not changed at all. If you were to enter a black hole, you would find you watch ticking along at the same rate as it always had (assuming both you and the watch survived the passage into the black hole). However, you would quickly fall toward the center where you would be killed by enormous tidal forces (e.g., the force of gravity at you feet, if you fell feet first, would be much larger than at you head, and you would be stretched apart). Although your watch as seen by you would not change its ticking rate, just as in special relativity (if you know anything about that), someone else would see a different ticking rate on your watch than the usual, and you would see their watch to be ticking at a different than normal rate. For example, if you were to station yourself just outside a black hole, while you would find your own watch ticking at the normal rate, you would see the watch of a friend at great distance from the hole to be ticking at a much faster
