Comment: Re:what happens (Score 1) 56
Except that black holes radiate energy at a temperature that seems to be inversely proportional to its mass. Even a simple stellar mass black hole emits so little radiation that is is for all intents and purposes, black. A black hole will not become visible until it nears the end of its life, when its contents are rapidly radiating away and the rate of energy release brings its temperature into a detectable range. Right now they emit virtually nothing, so we literally can not see them.
We can, however, infer their existence through the effects of gravity on other nearby stars. We can also use this effect to infer their mass, which is exactly how we have figured out that at the very center of our own galaxy there is a black hole with 4.1-4.5 million times the mass of our Sun.
We can, however, infer their existence through the effects of gravity on other nearby stars. We can also use this effect to infer their mass, which is exactly how we have figured out that at the very center of our own galaxy there is a black hole with 4.1-4.5 million times the mass of our Sun.