: The answer to this lies in the manner in which gravitational forces are computed, ie. from the center of the mass. The density of the matter doesn't enter into the equation. That is to say: at a given distance, 100 solar masses would have the same gravitational effect regardless of the SIZE the mass occupies. To steal someone else's analogy (Kipp's), were the sun to implode into a black hole (which it can't, but pretend it were to), the Earth's orbit would not change because neither the sun's mass, nor our distance from the center of that mass, nor our orbital speed about the mass has changed. Inside a black hole's apparent horizion, it is conjectured that there is an infinite curvature of space-time (infinite density, singularity, all that), but the gravitation forces outside the apparent horizion are no different than the moment the mass decreased in area to the size of the black hole. Black holes do not "eat" everything in the universe, just those things that they would have attracted eventually even before they became black holes. : No, a singularity does not have infinite mass. It is a finite amount of matter compressed into a mathematical point. i.e. it's density is infinite. It is believed that inside a black hole, all matter is compressed into a singularity because there is no known force that is strong enough to prevent matter from compressing down to the singularity.

: : Okay, a singularity is a single point of infinite mass, if its : : were infinite wouldn't all the matter in the universe then : : gravitate towards it at an infinite speed? Some info please?