Search Results

Huor: For this discussion light = electromagnetic radiation, so when OP talk about light it's from low wavelength radio wave to gamma radiation. It's all light, all photons. As for black hole, they emit nothing (except for hawking radiation). You can't get energy out of them, tho you can extract a lot of energy out of the mater falling in the black hole.

No Huor, they do not. The matter falling into the black hole emit lots of radiation but not the black hole them selves. Once something go past the event horizon nothing can get out (except very slowly by a quantum effect know as hawking radiation). A good way to visualize what the event horizon is to think of it as a sphere around the singularity at witch point the orbital speed is the speed of light. Since nothing can go faster then light nothing can get out past that limit.