How come x-rays can escape from a black hole when visible light can not?

Asked by: Ed Bonjokian

Your question may stem from reports that black holes have been found due to x-rays emitted by them. However the x-rays which can be used as a signature of super dense bodies are actuallu emitted from a ring of material which orbits outside the Schwartzchild radius, something like the rings orbiting around Saturn and other planets. As material falls into this disk, and then into the black hole itself, energy is given off which can be detected in the form of x-rays.

Answered by: Rob Landolfi, Science Teacher, Washington, DC