From: Zardoz ®	04/11/2001 19:34:37
Subject: re: COSMOLOGY FAQ	post id: 484064
What colour is a Black Hole? What colour is the material inside a Black Hole? From: B.C. ®. A black hole is black, because there are no EMR reflected off it. Also they would be black inside. The only thing you would see inside the black hole, I think, is looking back out to the event horizon. There you would see what ever light was being reflected of other objects but in a distorted type of frame, all in a circular disk directly above you. Do they produce light? Do they produce energy? From: Robert ® They produce very small amounts of matter, energy (light) etc. via the Hawking Radiation effect. From: B.C. ®. The only light inside the black hole would be that capture from outside and this would quickly disappear into the singularity. If for example you fell inside the event horizon, anything before you, say a friend who also fell in would be highly red shifted on his way to the singularity, which you would never see him pass into. A black hole has gravitational energy and energy of momentum and some charge. From: Greg L ® A black hole wouldn't have a colour as such, and other than the Hawking radiation it emits, no EM radiation would come out of a black hole (and for black hole's with stellar mass or above, the temperature is so low they emit radiation far below the visible spectrum, so the question of colour is meaningless).