What is black whole? does it really exist?
Despite its invisible interior, a black hole can be observed through its interaction with other matter. A black hole can be inferred by tracking the movement of a group of stars that orbit a region in space. Alternatively, when gas falls into a stellar black hole from a companion star, the gas spirals inward, heating to very high temperatures and emitting large amounts of radiation that can be detected from earthbound and Earth-orbi ...more
it can be explained by theory of relativity......for more infohttp://en.wikipedia.org/wiki/Black_hole