The discovery of a "black hole" in space, 13 billion light-years away, has astronomers pretty excited. Previously, only mathematicians and astrophysicists could see black holes in their theoretical formulas.
What's implied by this discovery is a chance to test the theories against hard, observable facts. For instance, note the definition scientists like to give of "black holes": rips in the fabric of space-time. Sounds great, until you fasten on the concept of a "rip." Einstein proved that space and time were part of the same thing early in this century. So if their interrelationship is really a "fabric" described by mathematical equations, what's underneath?
Another concept open to investigation is the idea of collapsed, super-massive matter. If the burned-out centers of overworked gas giants really are able to be compressed beyond the observable limits of ordinary, not-highly-stressed atoms -- so much so that a big enough version could "fall" out of this universe -- where could it go? A hole massive enough to gobble up a galaxy, over millions of years, must surely be on its way out.