10 Craziest Facts You Didn't Know About Black Holes

2. We May Be Inside One

Never mind falling into a black hole, there is some evidence that we may already be inside one.

If stuff falls into a black hole, it's entirely possible that that stuff is ejected from an opposite white hole, which could be exactly what the big bang was.

Although this seems like a wildly abstract theory, there could actually be ways to test it. First, you need to establish what the universe actually looks like, something that scientists are already trying to figure out. If the universe turns out to be "closed", then the whole born-in-a-black-hole theory looks a lot more likely. In a closed universe, you could set off in one direction and eventually arrive back where you started, much like on our spherical Earth.

Another way to test this would be to look at how the things in our universe rotate. Black holes spin pretty rapidly, so you would expect a universe on the inside to be whirling around like one of those dodgy looking horses on a carousel. If we can find out if the universe is spinning in one direction, we might be one step closer to finding out where we really are.

Who knows, in the centre of every black hole could in fact be another universe, with another version of you trying to find out exactly the same thing.