Are we Living in a Simulation?

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Speaker 1: Have you ever woken up from a dream, walked around and then realize you're still dreaming? Yes, And it's made me wonder like, is reality actually part of a dream? Like an inception or the matrix? How do we know if we are living in a dream or even in someone else's dream, or like a low resolution A bit video game. Hi, I'm Daniel and I'm Jorge, and this is Daniel and Jorge explain the universe, ex playing the universe, the whole entire universe, all of it. Now you might be wondering, who are these guys who are gonna explain the universe to you? Yeah? Who are we? Daniel? Who are we? Anyway? That's a good question. Well, I'm a particle physicist. I do my research at the Large Hadron Collider in Geneva, where we smash particles together and trying to figure out what is the universe made out of and how does this all work? And mostly enjoy getting to play with enormous ten billion dollar taxpayer funded toys. Nice, And I'm a former robotics researcher. And now I'm a cartoonist. And where do you do most of your work or is it a fancy government lab. Yes, I do most of my work in my pajamas in my garage. Um, usually starting late in the morning. And how does a roboticist end up becoming a cartoonist? That is a really great question. And I have to tell you that, Um, my parents are also very worried about that whole career trajectory. But now, yeah, they're worried about their investment in your in your education. There. I think they're just concerned about my financial well being. But now I used to be uh, I used to be I have a PhD in robotics. I used to do research on legged robots and robots and could run and like jump around. Um. But then at some point I started drawing comics and I really like that and it kind of became more popular than my research, and so I draw something called PhD comics, which is how we met because I used to be a huge fan of PhD comics. Yeah, and um, and I used to be a big fan of of like the universe and so so until you know, it's almost all of the universe now, and but the universe is sort of where we overlap, right. I do research about the universe, and you try to explain the universe in your science, communication and all that stuff, and so I feel like we have a significant overlap there. Yeah. I just really like talking to people who know a lot of stuff about something and just kind of learning new things, you know. I always I always get my mind blown when I talked to someone who's a researcher on something, because it's just kind of amazing, like how much we don't know about stuff. You know, you sort of walk around feeling like, hey, we got everything figured out. Um. But I always love finding out what people are still like wondering about, and I love pretending to know stuff about stuff and blowing people's minds. So it's a perfect setup right now. I think that some of these questions are really interesting and they're really accessible, and my hope is that people out there will be listening to this stuff and think, oh, man, I wish I could have done physics in high school, or some kid who's who's listening to it out there it gets inspired and thinks about, um potentially going into physics, because there's a huge number of really deep, fascinating questions that we still have to answer. Like the topic of today's podcast Yeah Today on the program is the universe a simulation the whole universe. I love the size of these questions we're asking. Is the whole universe simulation? Yeah? That's uh so, that's a crazy question. It's basically the question like are we living in the matrix? Well, first of all, the matrix is ridiculous because at its basic premise it didn't work at all, you know, like batteries what I mean, come on, humans consume and or they don't produce energy. So the whole fundamental underlying assumption of the matrix boom, toss it out the window. But the core idea there that did we could be immersed in a deeply realistic virtual reality that we're not aware of, right, that we think reality, that what we're experiencing is reality, when when actually it's something simulated. That's the fascinating way, Like what we see and what we hear and what we touch is not like actually real, it's just like a a computer feeding as these sensations to us. Yeah, and only I think recently has this possibility even arisen because we do now have virtual reality, right, you can't have fairly immersive experiences and people extrapolate from that. It's getting more real and real the simulated things we can the things we can simulate. Absolutely. I had a virtual reality experience a couple of weeks ago. I went to a go kart place with my son and I went into a virtual reality go kart racing thing where you sit in a chair and the chair shakes in your car bumps into stuff, and um, it's totally immersive. And you know, every time I was about to crash into the wall, which was a lot of times, I found myself like throwing my arms up to protect myself and ducking and stuff like that, because it really it felt realistic. It definitely triggered all of my instincts and absolutely, I mean I would have wet myself ahead and pid just beforehand. Well. I had a very intense virtual reality experience too recently. I I am. I read the news and you think, I hope that because this is crazy. Um, but yeah, so that's that's the idea, is that that's the question. Is the universe a simulation, Like is what we see around is real? Or is it Are we like sitting in a vat of liquids floating somewhere in some alien beings um factory, being fed all of these sensations and sights and sounds just kind of keep us happy. For some reason, you make it sound so sinister. Why can't it be like a cozy, warm, cuddly environment where we're like nestled in a sunny garden somewhere and being fed this beautiful, wonderful universe of simulations. Right, But you just have to be like, we're experiments in some you know, we're subjects in some sinister experiments somewhere. Well, why else would somebody do that? So let's take a step back. So this question has been kind of very recently come. I mean, it's always sort of been around in science fiction, but it's sort of become serious, lady, right, like Elon Musk is wondering about it. Right, And so we went out in the street. We asked people if they thought they were living in a simulation. So think for a moment yourself, listener, do you think the universe could be a simulation? Here's what people on the street had to say. We're like my trich or somewhere that it could be. But I doubt it. I doubt it, you know. But it's because I don't want to tell myself that everything I do is the universe seems so let's normal. It doesn't seem like that could be fossible. So most people thought maybe it was a possibility, but nobody really firmly believed it. Nobody thought absolutely, I'm convinced. Yeah, most people seem very skeptical, but a lot of them allowed the possibility. Right, Well, you never know, but maybe sort of a thing. Yeah, And I have to mean I fall into like Kemp, I'm pretty skeptical about this idea. Uh. And I like one of the answers that they said, which is like, I don't know if that's possible. Everything seems really realistic. Yeah, that's a nice argument, and it's just because the universe around you feel so detailed. I mean you look at the tiniest little water droplets and the light sparkling off of it. It seems like an impossible problem to write a simulation that it's this realistic. It seems impossible, right, Yeah, But I don't know if that that's really very persuasive argument, because computers are getting faster and faster, and you just extrapolate from what we can do now to what we can do in twenty years. I mean, look at how video games have improved from like Super Mario two super realistic racing games. Now it's incredible how much more realistic they are, from like Pong to like, uh yeah, like World of Warcraft. There's so realistic now. Absolutely, So I don't really think the it's impossible argument is very strong also because you have to imagine if somebody is running our universe as a simulation, who knows what kind of computational powers they have, right, um, and and if they are their universe, the one that our universe is running as a simulation inside of doesn't have to follow the same laws as our universe. Right If we're in a video game inside somebody else's universe, our video game can have rules that don't exist outside the video game. Right, So they like F equals m A or general relativity that could have been something they just made up because they thought they would be fun or interesting, you know, like like we like we create video games with crazy physical rules. You know, Mario can jump half of the screen, he can jump twenty feet up in the air. Um, so maybe that's that's why our physical laws are. They're just kind of like, hey, let's make this fun universe where efquals are a kind of the idea that's exactly right. Yeah, that's exactly right. And I think that's partially the origin of this idea. You know, what is physics doing? Ask yourself that physics is trying to figure out what are the rules of this universe? Right, what are the underlying code that runs this universe? And so now that we actually have pretty powerful computer programs, people wonder, well, if you were in a computer program and you were trying to figure out what the rules of that simulated universe were, you'd essentially be trying to understand what was the physics coded into that universe. So in some sense, yeah, you'd be a physicist exactly. Physicists are trying to reverse engineer the source code of the universe. Right, regardless of whether you believe the universe is real or a simulation, it does seem to follow some rules, right. So it's like when you first it's amazing that we can even discover those. So it's kind of like when you first play Super Mario or something and you're you're just jumping around and move around trying to figure out how Mari moves. You're essentially like being a physicist in that world. That's exactly right. Everybody who plays a video game for the first time is being I think that's exactly everybody who plays video games. That's right. That you just gave a whole generation of listeners a reason to stop doing their physics homework and turn on their video Thank you. The PC is only valued inside the video game, that's right. But you know, I think that there's a natural curiosity there, right. The reason video games are fun is because you get to explore a new world and figure out it's rules and learn to master it. Also, the best science fiction is the same way. The best science fiction. You're thrown into a fictional universe and the rules could be different. Usually they are, and you have to figure them out. You know, bad science fiction they tell you in boring narration overtones exactly how things work. But in good science fiction, you have to puzzle it out for yourself. You have to deduce what the history is and what the rules are, and how things work in this fictional universe. Have to be like an explorer, like an experiment er. Yeah. I love how we're describing physicists as these like avant gode explorers as the couch potatoes who play video games. That's that's basically not that not that different from reality built couch potatoes. Well, you know, I find it really interesting that you so you're a serious physicist. I mean, like, um, you know, you you're like a professor, and you you've you don't sort of scoff at this idea immediately, you know, like I feel like it's a crazy idea, but it's like something physicists uh uh, actually sort of, they say, are forced to say, yeah, it's possible. Right. Well, I think part of the job of being a physicist, and I would take exception with being called too serious. Seriously, part of the job of being a physicist is being prepared for making mind blowing discoveries. You know, I think best kind of physics discoveries are the ones that completely change your view of the universe. You know that discover where you discover the universe works really differently from the way you did, And so you have to be open to crazy new ideas if you even have a chance to make a crazy discovery. I guess by serious physicist, I mean an employed physicist. That's right, I still have a job that makes me a physicist. On that note, let's take a quick break I like what you said earlier, which is that you know our universe right now, the one where even if it was not a simulation, it's sort of like a simulation in that that's kind of what a simulation is. It's like there's laws and then uh, you figure out what's going to happen in the next time instant based on those laws. That's I mean, that's basically what a simulation is, right, right, But is the universe like a simulation or is a simulation like the universe? I mean we can think simulations I know, or Ay says whoa. I mean, we invented simulations in order to model example universes, right, We said, what would happen if the universe was like this, Well, let's see, and then we build a little simulation and we test it out. So simulations are built to mirror the universe on purpose, and and we code in the rules of the universe in that simulation because we think there are rules of the universe, and we could have a whole other conversation about like why does the universe have rules? Why do those rules seem to be fairly constant, and why can we discover them and express them in terms of mathematics, like enormous philosophy questions we haven't even scratched the surface of. And I thought, I really like thinking about, like what is the computer of the universe except for a moment? The universe follows some laws, real or simulation. Right, they're like imprinted in the way things are. Yeah, they're set somewhere, right, they're fixed somehow. How are those laws enacted? Like when a particle bounces off of another particle, how is that calculation done? You know what determines what is going to happen? There? It takes no time, right, it's instantaneous, no lag or delay in our universe that says, oh you know, um no, there's no spinning ball of death when something complicated happens, right, No matter how complicated it is, the calculation is done instantly. Like how does that little particle know to follow the rules? That's right, that's right, It's just it's just done. Yeah, And like, what what is there to enforce those rules? Right? If a particle was like, yeah, I'm not gonna follow the rules. I like how you try to give attitude to everything like personalities. Yeah, maybe that's why I got um fired from my robotics too. Um um, yeah, but like what what what enforces the laws of physics in our universe? Right? That's right? Well, if you if you like the simulation model, right, then member that inside the simulation the rules are followed, but the calculations are done outside the simulation. Right. If we build a simulated universe, right, you and me sit down de side when they would build a little mini universe in which cartoonists and roboticists or kings or something, and we can set the rules of that universe, but the calculations for that universe are not done inside that universe, are done in our universe. Right, in our computers, like in a simulation or a video game, you would say, all right, here's a mass of Mario, and this is the force that's being applied to Mario. Therefore he should be accelerating. You crunch the numbers and you say he should be accelerating this much, right, and then you apply that to the video games. Say we're in universe zero, right, and we're simulating universe one. And then as you said, things that happened in universe one are calculated in universe zero right outside of our universe. That's the thing I find compelling about this is the universe of simulation question because it touches on that question, where are the calculations done for our universe universe zero? Is there a universe minus one with some giant computer that's doing these calculations blindingly fast or is it just magically done? So, like, if if we're in a simulation and everyone listening to this is an assimulation, what is computing the calculations in the upper universe, in the outside universe, that's right? What is that computer? Like it doesn't have to follow the same rules as our universe, And how is it possibly doing all these calculations um to describe our universe? And this is a question that's fair to ask even if the universe is real, even if it's not a simulation, you have to wonder how is this done? How is this um? How is this universe run? You know, I think that's a really fun way. It doesn't It doesn't go away. That's the interesting thing. It's like, even if we are a simulation, then you still have to answer the question about the aliens is universe, you know, like what how how does it work for them? Yeah, that's right, it's an endlessly recursive question. And you can owe is ask are we in the stimulation or not? And you know, basic things that we assume, like the universe has rules. Those rules don't change with time. That could be different in other simulations or in the you know this the universe that's running our simulation. That could be different. It could be in their universe. The laws of physics change with time, the speed of light is variable with time, all sorts of other stuff. So they were like, hey, let's have some fun. Let's create a video game where the rules don't change. Yeah, for example, I mean, that's just one hypothetical, not one that I believe, but just it's a possibility. Um. And and that that touches on other really fascinating stuff like say you have some calculation you want to do. It's really complicated. It would take one of our computers a billion years, right, If you can arrange our universe in such a way so that it does that calculation for you, Well, our universe appears to be able to do these calculations instantly, right, So so you might be thinking, well, that's absurd. Well let me give you a concrete example. So you have a ball that has like ten to the ten atoms in it, and you want to understand how it drops right, how it falls right, Well, you could either do that calculation, which would take you a billion years, or you could actually just drop a ball right. So in that sense, we can use our universe as a computer if what you wanted to know was something that was going to happen naturally in our universe exactly. And that is what experimental physics is, is arranging physical systems to do instantaneous calculations of things we otherwise couldn't figure out. Right. For example, I kind of said it in a derisive way I can. I said it is like, that's a silly idea, but you're saying it's the basis of your entire research field. That's right, That's what it experimental physics. That's why we do experimental physics because the universe is faster calculating this stuff than we are. Sometimes in particle physics, we don't know how to do a calculation. We're like, well, what happens when this and this hits that? Well, we can't calcul it. Well, let's just go measure it, because the universe can do the calculation without us. If you had as a miraculous computer. You wouldn't need to do experiments because you could just simulate every possibility in this magical computer and you would know the answer that's right, And the universe is that computer. Oh that's that's wild. Yeah, but you know it's it's not infinitely configurable. Like on your simulation that you write on your laptop, you can control everything, you can do everything you want. In the case of the universe, we can't necessarily do any arbitrary calculation because you can't arrange the universe to do it for you. Like if you want to just know what's going to weather going to be like tomorrow in Australia, that's a really hard calculation. How would we set that up. Well, we'd have an earth, right, and we'd run it forward for a day, But you wouldn't have the answer in advance, right, you'd have the answer tomorrow when it's tomorrow in Australia. So it's not it's not I'm not saying that the universe is a perfect infinite computer that we can use to answer any question. I'm saying that's kind of the model. Yeah, exactly. On that note, let's take a quick break. Well, I find it really fascinating that physicists have come up with ways to maybe check to see if we are in a simulated universe. Right, Like, there's actually there might be experiments we can do to test whether we are neo in the matrix or not exactly. And that's step two, right for Step one is have crazy idea. Step two is how could we test this idea? Step two get money for the crazy idea, apply for grant fundings. Are crazy idea? Um, it's pretty hard because you have to make some assumptions about how that simulation is done right, and those assumptions are just guesses really, But that's fine. Like a lot of times in science, we don't know how to approach a problem, so we just make a bunch of guesses so that we can at least try to answer the question. And then maybe later we re evaluate those guesses and try to widen the scope or whatever, but just so we can get somewhere. Right, Well, what are some of these ways that physicists think that maybe we could figure out if we're in a simulation. Well, one way is to look for things that move super duper fast. And the reason is that if we were to simulate a universe. The way we would do it is to slice space up into huge cubes and simulate each cube. Because you can't simulate the whole universe at once. You'd want like a bank of computers. You would only simulate the parts that are sort of relevant to the video game players, that's right. And also you would want to have a bunch of computers working in parallel. You wouldn't want a single computer operating on the whole universe. You just want to slice it up and say this cube light year cube of space is handled by this computer, and this light year cube handle them by that computer, and when things cross the boundaries, they have to talk to each other. But that's the way we simulate. For example, you know an ice cube forming you have you have a bunch of calculations of these water molecules, but you do them in little cubes um and then you interface them. And so people think, what happens when something is going super fast through the universe. It could cross a bunch of these cubes really quickly, and that would be difficult for this simulation to do correctly, and so we'd have to look for little glitches like that, like you would have to look for cases that are really kind of pushing the limits of the computer that's simulating us potentially to see if there are any like like if if the simulation breaks them out exactly and that's you put it exactly right. But we have to assume we know something about what's hard for those kind of universe simulators, right, which is like so presumptuous to even know. But if what's hard for the universe simulators is the same thing as what's hard for us when we simulate a little mini universes, then one thing that's hard is things across that go really fast. And so there are things out there in space that's that zoom around super quickly and that can potentially give us clues. So we have to assume that a it's hard to simulate the entire universe at the same time, so we have to break it up and be we have to assume that, um, things going really really really fast across these different chunks of the universe. Um, that's a hard problem, that's right. And so one thing we look at our super fast cosmic rays cosmic grains are just particles in space zooming around, and it's a whole other interesting mystery about why those particles are there and why they're going so fast. But they're going incredibly fast, like ridiculously fast, much faster than particles we make here on Earth, even at our fancy ten billion dollar accelerators, and those are going so fast that they might reveal these glitches. So if we look to see if those particles are coming at the same rate in every direction and this kind of stuff, we might be able to get hints that there might be little glitches in the simulation. Cool. So are there any other ideas for testing this? I don't think there are any ideas that have much widespread support. I mean, we're already talking about crazy theories here, but I mean an idea I have is communicate with the simulators, right, Like, let's send the message, you know, like like I know, like I know what's going on. We figured it out, right, Like, say you are running a simulation of a universe, right, and you don't tell the beings inside that universe that it's a simulation because that would spoil your experiments somehow, right, Right, Well, if they discover it, then you kind of want to know and maybe you be interested in talking to them, right, So I think let's try to send a message, you know, let's write something on it. It's the equivalent running s OS on the beach or or something. But they would because they're overseeing our our universe, so they would know that we're actually bluffing. We say, ha ha, we found out, and they'd be like, no, you didn't. They haven't talked to us so far. Why would they start out we started bluffing. Mmm. That's a good point. But you're assuming we are bluffing, right, What if we sincerely, honestly believe the universe is a simulation. You're right, we don't have any evidence for it, so we can't so we can't scientifically sincerely believe that. Well, I think the biggest sign that we're in a simulation is the fact that Kenna Reeves has an age to day. Surely that's that is a glitch in the matrix right there, the matrix. Yeah, well, um, what would it be like to be in a simulation? Like? What implications with that? It might be just like this, It might not be any different. Yeah, I mean, if we are in a simulation, then we already know the answer. What's it like to be in a simulation? But you probably meant something else you probably meant like you mean, oh, I see, Like are we simulated minds? Like maybe we're not um humans in a vat in a warehouse, in an alien warehouse. Maybe we're like actually like pieces of coding. We're like artificial intelligences. Oh my god. Like maybe we're like the fodder in a video game. We're like the mushrooms in Super Mario. You know we're here form right, sort of two levels there, right, Like one level is you are a brain, and your brain exists in the real universe, but you're being fed information about a fake universe, right, But your brain exists in the real universe. That's sort of level one. Level two is you don't exist in the real universe at all except in that simulation, right, a piece of code that describes a virtual person. Right, you could just exist in that simulation until the question is like basically that are we real, are we conscious? Are we actually something? Or are we like completely fake or right? Which is right now an open question in philosophy, Like say, for example, I could perfectly simulate Jorge's brain and Horee's body, right, and I had that inside a computer, and it's a completely faithful reproduction right, and just like you, it's spent most of its day in pajamas and taking naps in the afternoon. Right, Totally accurate. The question is would that, Jorge feel anything? Would it be a where would it be self conscious? Right? Because really we're sort of computer ourselves, right, Like if we are real, we're just a bunch of like neurons, which are really just like little computers. We're just a massive computers in our brain. So maybe maybe there's no difference. Maybe there's no difference, right exactly. Maybe the thing that makes us us is just the arrangement of these bits, right, just the information stored in the physical computer that is me, of the physical computer that is you. That's a little hard to grasp. It's a little hard to feel comfortable with thinking I am just this representation, right, because that means that you could translate me into a totally different representation. Right, bits inside a computer which are also a physical system, or a computer is a physical system with switches and and bits and stuff, and that that could be somehow equivalent to me. The problem is, I don't think we could ever know. And what I mean by that is, say I have a computer simulation which is a perfect reproduction of Jorge, Right, I mean not that I'm not perfect already. But um, I'm not saying I wouldn't make a few tweaks. You want to make a few tweaks? Oh um, But say we had the simulated version before hey, and we asked it, are you real? Well, if I ask you if you're real, you'll say yes. So if the stimulation is a perfect reproduction of you, it will also say it's real. How do we distinguish between something that says it's real, seems real, and but isn't actually aware? Wow, we can't. That's a that's a topic known as a philosophical zombie in philosophy circles. Yeah, well, the whole reason we're talking about this is basically, um is that the computers are getting so advanced now that it's actually kind of a possibility A and B. Physicists can't categorically say no, that's impossible, and so that's why we're talking about it. That's right, And there are even some people that make the argument that it's likely, okay likely. Some people even say that's not just like a crazy idea, that's not impossible. It's like there's there's strong evidence for it. Not strong evidence. But here here's the argument. You can judge for yourself how strong it is. The idea goes like this, say this one real universe, and inside that real universe, somebody invents a simulated universe. Inside that simulated universe, somebody invents a simulated universe. So now imagine a whole set of nested universes, right, each of which is very realistic and high fidelity, and his beings in it to feel alive and love and hate and and all this kind of stuff. Um, then if there are this whole nested set of universes and only one is real, then what is the probability that ours is that real one? So they argue that, therefore the probability that our universe is real is small. Right, It turns the question on its head, is you see universe is simulation two? Is the universe real? And it suggests that that's unlikely? Oh, meaning that it is it is possible to simulate a universe. Therefore, in the infinity of a time him in space. Um, what's the likelihood that we are real? Not a stimulation? Um, It's it's like non zero, yeah, exactly. It's like if you're in an infinite crowd and only one person is real and everybody else is fake. What are the chances that you're the real one? Pretty small? Um. I think that's not a very strong argument because it makes a lot of assumptions. You know, it assumes that universes will always simulate another universe, and those universes would be high fidelity, and that all of them would be like ours, um and that kind of stuff. But you know, it does have that cosmic context. I like the sender, the fact that it reminds us that we don't really know where we are and what the context is, and that is important. As we think we are sometimes it could just be that we are Super Mario brothers bouncing around inside a video game. That's that's I think a useful reminder. I've always identified more with LEGI, to be honest, because he's the taller one. He's I think he's a yeah, he's just kind of the alert, the clearer brother. He doesn't care about getting all the spotlight right. He's he's over that, he's above it. Well, whether we are in a simulation or not. Um, it's really fun to kind of question the nature of the universe. Right, absolutely, And it's only in asking these crazy questions that we're going to make crazy discoveries. Right, the universe might not be a simulation, but in thinking about ways to test it, we might discover other weird stuff that that gives us another crazy idea, and that one might actually be true. So this is we're all physicists in the sense that we'd like to all think about big questions about the universe. It's like in trying to break the video game, that's when you discover the hitting easter eggs. That's right, the easter eggs of the universe. That's where we're all hoping for. Cool. Well, I hope you guys are keeping it real out there, and I enjoyed this discussion. I hope you're keeping it simulated. And have a great day until next time.