All this stuff about parallel universes that we've talked about so far is pretty mind-blowing, but here's an idea that is even stranger.
In 2003, philosopher Nick Bostrom, director of the Future of Humanity Institute at the University of Oxford, raised the question of whether what we think of as reality — that is, our particular parallel universe — is simply a digital simulation of another universe. In Bostrom's conception, it would take 10 to the 36th power calculations to create a lifelike, detailed replica of the entirety of human history.
A really advanced alien civilization — we're talking beings whose technological sophistication would make us look like Paleolithic flint carvers — conceivably might have enough computing power to pull it off. In fact, simulating every human who ever lived might not even gobble up that much of their electronic resources, so that there might be more computer-generated beings in existence than real ones [source: Choi and Kestin].
And that might mean that we're living in an actual version of the digital world in "The Matrix" movies.
But wait, it gets even weirder. What if the civilization that's simulating us is itself a simulation?