Black holes are the most enigmatic and exotic objects in the universe. They're also the most powerful, with gravity so strong it can actually trap light. And they're destructive. Anything that falls into them vanishes…gone forever. But now, astrophysicists are realizing that black holes may be essential to understanding how our universe unfolded—possibly leading to life on Earth and us.Tune in Wednesday, July 3, at 8 p.m.