Understanding Simulated Universes | StarTalk

Now, Brian Green, uh, he's best known to the public for popularizing string theory. His earliest book, "The Elegant Universe," was a mega bestseller back in 1999. It was followed up with a book called "The Fabric of the Cosmos: Space, Time, and the Texture of Reality." Now, that touches on so much, and it enables him to think about so many interesting branches of physics that intrigue us.

In 2003, there was a paper published by a philosopher from the University of Oxford on whether or not the universe is a simulation. I had to ask Brian Green if he thought this could actually be possible, just to get a professional opinion on this. Let's find out if it's the case that one day we can have computers that can recreate a reality in bits and bytes that has such veritude that their inhabitants of those simulations feel that it's real.

If that's possible, and I think many of us agree that it might be, we're getting closer already. Just let's assume that's possible. It's so much easier to create a simulation than it is to create a real universe. I mean, how are you going to create a real universe? So if you wait long enough, there are going to be many, many more simulated universes than there are real ones.

So, any sentient being, if they're rational, would think that the odds are that they're in one of those simulations because there are so many more of those compared to real ones. Statistically, you're in the simulated one, not the real one.

Yeah, yeah, exactly. So how do you know? It would be very hard. I mean, some have suggested, sort of like in "The Matrix," to look for glitches. Real universes don't have glitches, but computers can have them. But I say to that glitches, because, uh, presumably a fallible entity programmed that.

It could be that there could also be an electric current glitch that happens in the real universe and screws up what's happening inside the computer. But I don't buy that argument because if it's a really good simulation, it should be able to rewind, erase the memory of a glitch, fix it, and then the simulated beings have no memory of it ever happening.