Q&A: Black Holes
What it looks like when black holes are made, how long it takes to make them, and how do they mess with the stream of time?
Black holes, because of their very intense gravity will cause light to bend around them, which will cause the
appearance of background objects (like stars) to be distorted. It isn't known how long it takes for a supermassive black hole to form (this is a type of black hole found at the center of galaxies that weighs
millions or billions of times the mass of the Sun). We do know it can take less
than a billion years for one to reach a very large size:
A stellar-mass black hole, on the other hand, can likely form in seconds, after the collapse of a massive star. Finally, if you were to approach a black hole, the powerful gravity would cause time to slow down.