I've just learned the very basics of Black Holes, and it left me with this question: a Black Hole becomes more massive (hence more 'gravitational' pull) the more matter it 'sucks up', does that mean a Black Hole keeps growing in mass forever? Is there any way in which a Black Hole can weaken or cease to exist?
If Black Holes can't 'die' then the number of them should keep growing. I know that the pull of a Black Hole is only very large at a short distance to the Hole itself, but I suppose this short distance becomes larger when the Black Hole grows more massive. Could it be true that at some point there are so many Black Holes that "the universe" is ripped apart by them, or maybe even contracts?