A black hole an extremely dense concentration of matter equal in mass to millions or billions of suns.

It's an industry that's willing to donate millions. It doesn't matter that much when they can reap billions.

This galaxy is a rare find -- a tiny galaxy that is still building up the mass of its black hole. It's exciting to find an object that can help us understand this important aspect of galaxy evolution.

The problem with ash is it's so dense. The tables are extremely heavy.

There seems to be this sense among even well-meaning Americans that Africa is this black hole of murder and mutilation that can never be fixed, no matter what aid is brought in.

One of the big mysteries about the black hole at the center of the galaxy is, 'Why don't we see emission from matter falling onto the black hole, or, rather, the black hole eating up its surroundings?'