What is a Black Hole? Does it suck even energy? When a black hole sucks something, what happens to that substance? When a black hole appears, does it even suck empty space?(<-Sorry, if this last question sounds stupid and absurd to the reader. But, hey! No scientific question is foolish for the questioner!) Does a black hole have mass and energy? We all Know that a good absorber is also a good emitter... Can a black hole be a good emitter of heat too? Does it have a magnetic field around it like earth? What is its density? What is its composition?