Our universe began with a Big Bang some 13-15 billion years ago. On this, most physicists agree. But few theorists have ventured to explain what happened "before" the Big Bang, or how the Big Bang came to be. This is because the laws of physics break down at the point of a singularity, such as with the one that physicists claim composed pre-Big Bang reality.

But a few pioneering physicists are now positing a mind-blowing new theory that could forever change our perspective on the beginnings of the universe. Perhaps, they suggest, the entire universe — all the galaxies, stars, planets, everything — exists wholly inside a massive black hole, reports National Geographic.

This radical theory would imply that our universe is just one of many. It would suggest that our universe is ultimately contained within a much larger universe — a mother universe, if you will — which harbors the black hole we're currently living in. It's a wild theory, but it's one that is slowly but surely garnering consideration from physicists.

One such physicist is Dr. Nikodem Poplawski of the University of New Haven in Connecticut. He argues that singularities, like the ones that exist at the centers of black holes, have a physical limit, a point where they can be crunched no further. Such a point would have to be massive, perhaps the weight of a billion suns or more. But once that limit is reached, the immense compacting processes at the heart of all singularities must halt.

Then, like a tightly compressed can of springs, there's a bang; a very big bang. Perhaps the Big Bang.

According to Poplawski, the reason for such a limit (and, consequently, the universe-creating explosion that follows) is that black holes spin. They spin at near-light speeds. This, in turn, creates a huge amount of torsion. Thus, such massive black holes are not just incredibly tiny and immensely heavy, they are also twisted and compressed. The multitude of forces at work are so intense that a bursting point is eventually reached. This, Poplawski proposes, is how the Big Bang happened, though he prefers to call it "the big bounce."

Such a view, if true, would revolutionize how scientists think of black holes. Rather than being dark, foreboding chasms where the laws of physics break down, black holes could instead become conduits, "one-way doors," or passageways between universes.

As of now, Poplawski's theory remains unprovable — though it can't be ruled out either. At the very least, it's fun to think about. And it's a reminder of just how wide-open our current understanding of cosmology is.