How do black holes form?
They form from massive stars that become supernovae. Their core regions implode, and no known force can withstand the force of gravity once the imploding mass gets close to its eventual size as a black hole-a size determined by the so-called Schwarzschild radius of the mass. Large supermassive black holes probably from by simply eating vast quantities of stars and gas every year for billion of years. Black holes that form in our universe from the collapse of very massive stars actually form objects that do not become true black holes until an infinite amount of time passes for those of us outside watching. This is because the mathematical black hole condition only describes the so-called asymptotic end state of such objects after they have settled down. Because of the gravitational time dilation effect, we will see this process take thousands and even millions of years, although someone riding on the surface of a collapsing body will judge this to take less than a second. To someone wa
