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Some collected questions and answers by Stephen Wolfram
Questions may be edited for brevity; see links for full questions.
December 18, 2019
From: Interview by Guy Kawasaki, Remarkable People Podcast
Are we a simulation?
This whole simulation argument thing, it’s kind of charming how some of these theological, religious ideas and so on get reiterated in these very different, bizarre wrappings. It’s kind of like if we look at our universe. One thing about our universe… this is almost a theological fact about our universe… which is that it has definite laws, might not be the case. Might be the case that there are 10^90 particles in the universe. They might all do their own thing. There might be no order to the universe.
The first thing that is surprising, and that early theologians made a lot of hay out of was that the universe is an orderly place. It doesn’t need to be an orderly place. We don’t know why it should be an orderly place, but it is. When it comes to thinking about what would it mean if the universe was a simulation… It’s a philosophically wrong idea, but it takes a few steps to explain why that’s the case. Basically, if the universe has definite rules, then the universe is just doing what it does and running according to those rules. If you ask, “Where do those rules come from?”, well, the universe has the rules the universe has. You can say, “Why does it have those rules? For example, why doesn’t it have much more complicated rules?” We don’t actually know how simple the rules for the universe are. If we could write a program that would reproduce the universe, we don’t know if that program is a million lines long, a quintillion quintillion quintillion lines long, or three lines long. I think there’s a possibility that it’s three lines long.
I’m just about to launch a serious effort… I’ve been interested in this for decades, but I’m finally ready, plus I’m getting so old that I’ve got to do this now or never… to actually make a serious assault on can we find the fundamental theory of physics? Can we find the fundamental theory of our universe? Might be the wrong century to try this, but if it turns out the rule for the universe is simple, it’d be pretty embarrassing… if we have the technology now to find it… if we just hadn’t bothered to look for it. It might not be simple enough to find. It might be that there are things about validating whether it’s correct that are things we can’t do yet with the current state of science.
Imagine that we have the rules for the universe. Imagine that we succeeded. We’ve got the rules. We can write them down. I could tell you them in a few sentences. You say, “Okay, that’s the universe”. Now you say, “What do we conclude from that?” What would it mean for the universe to be a simulation? You say, “What are those rules running on?” They’re not running on anything. They’re just rules that describe how our universe works. It’s not like you have to take those rules and put them on a computer and run those rules. These are just rules that describe how the universe works. I told you this is philosophical and a bit complicated.
Essentially, the other side of it is to say… when we look at these rules… do these rules feel like they’re an artifact? Do they feel like they were produced by some intelligence on purpose making these rules, or are they just rules our universe happens to have? This then goes into the question of how can you tell if a thing was made for a purpose? That’s another huge can of worms. Even when we look at something like Stonehenge, for instance. We say, “What was Stonehenge for?” That’s not culturally that far away from modern times, but it’s still really hard for us to tell what it was for. If we found some extraterrestrial radio signal and we say, “Is this for a purpose? Is it an intended thing, or is it just some natural process that’s producing this thing?” Really hard to tell in the abstract. That’s one reason there isn’t even a meaning to saying, “The rules for the universe: Were they made on purpose? Were they made as a thing by some other entity and then we exist as a simulation with respect to that entity?” It doesn’t really make sense.
It’s a complicated area.