All the stuff in orbit around a black hole keeps bumping in to each other. With each collision, some energy is lost to heat and so the "stuff" falls into a lower orbit. Eventually, MANY thousand years later, the gas and other cosmic debris either falls across the event horizon or gets blasted away from the black hole in an entirely seperate process. But that's another story.
Slashdot Mirror
All the stuff in orbit around a black hole keeps bumping in to each other. With each collision, some energy is lost to heat and so the "stuff" falls into a lower orbit. Eventually, MANY thousand years later, the gas and other cosmic debris either falls across the event horizon or gets blasted away from the black hole in an entirely seperate process. But that's another story.