- The strings kind of inspire a view, as did atoms and particles and quarks, but especially strings inspire a view of the universe as a kind of information processing system, as a computer of sorts. Do you see the universe in this way? - No. Some people think, in fact, the whole universe is a computer of some sort.

And they believe that perhaps everything, therefore, is a simulation. - Yes. - I don't think so. I don't think that there is a super video game where we are nothing but puppets dancing on the screen and somebody hit the play button and here we are talking about simulations. No, even Newtonian mechanics says that the weather, the simple weather, is so complicated with trillions upon trillions of atoms that it cannot be simulated in a finite amount of time.

In other words, the smallest object which can describe the weather and simulate the weather is the weather itself. The smallest object that can simulate a human is the human itself. And if you had quantum mechanics, it becomes almost impossible to simulate it with a conventional computer. This quantum mechanics deals with all possible universes, parallel universes, a multiverse of universes.

And so the calculation just spirals out of control. Now, at so far, there's only one way where you might be able to argue that the universe is a simulation. And this is still being debated by quantum physicists. It turns out that if you throw the encyclopedia into a black hole, the information is not lost.

Eventually, it winds up on the surface of the black hole. Now, the surface of the black hole is finite. In fact, you can calculate the maximum amount of information you can store in a black hole. It's a finite number. It's a calculable number, believe it or not. Now, if the universe were made out of black holes, which is the maximum universe you can conceive of, each universe, each black hole has a finite amount of information.

Therefore, ergo, ta-da, ergo, the total amount of information in a universe is finite. This is mind-boggling. This, I consider mind-boggling, that all possible universes are countable, and all possible universes can be summarized in a number, a number you can write on a sheet of paper, all possible universes, and it's a finite number.

Now, it's huge. It's a number beyond human imagination. It's a number based on what is called a Planck length, but it's a number. And so if a computer could ever simulate that number, then the universe would be a simulation. - So theoretically, because the amount of information is finite, there necessarily must be able to exist a computer.

It's just, from an engineering perspective, maybe impossible to build. - Yes, no computer can build a universe capable of simulating the entire universe, except the universe itself. - So that's your intuition, that our universe is very efficient, and so there's no shortcuts. - Right, two reasons why I believe the universe is not a simulation.

First, the calculational numbers are just incredible. No finite Turing machine can simulate the universe. And second, why would any super intelligent being simulate humans? If you think about it, most humans are kind of stupid. I mean, we do all sorts of crazy, stupid things, right? And we call it art, we call it humor, we call it human civilization.

So why should an advanced civilization go through all that effort just to simulate a Saturday Night Live? - Well, that's a funny idea, but it's also, do you think it's possible that the act of creation cannot anticipate humans? You simply set the initial conditions and set a bunch of physical laws, and just for the fun of it, see what happens.

You launch the thing, so you're not necessarily simulating everything. You're not simulating every little bit in the sense that you could predict what's going to happen, but you set the initial conditions, set the laws, and see what kind of fun stuff happens. - Well, in some sense, that's how life got started.

In the 1950s, Stanley did what is called the Miller experiment. He put a bunch of hydrogen gas, methane, toxic gases with liquid and a spark in a small glass beaker, and then he just walked away for a few weeks, came back a few weeks later, and bingo, out of nothing and chaos came amino acids.

If he had left it there for a few years, he might've gotten protein, protein molecules for free. That's probably how life got started, as a accident. And if he had left it there for perhaps a few million years, DNA might have formed in that beaker. And so we think that, yeah, DNA, life, all that could have been an accident if you wait long enough.

And remember, our universe is roughly 13.8 billion years old. That's plenty of time for lots of random things to happen, including life itself. - Yeah, we could be just a beautiful little random moment and there could be an infinite number of those throughout the history of the universe, many creatures like us.

We perhaps are not the epitome of what the universe was created for. - Thank God. (both laughing) Let's hope not. Just look around. - Yeah. - Look to your left, look to your right. (both laughing) (upbeat music) (upbeat music) (upbeat music) (upbeat music) (upbeat music)