Hi, Welcome to Science Stuff, a production of iHeartRadio. My name is Jorge cham and today we're asking the question are we living in a simulation? Are you and I real people? Or are we characters in a fake video game put on by an advanced alien civilization. Believe it or not, this is a possibility that is actually being
considered and discussed by really smart philosophers and scientists. We're going to talk to the man who first proposed this philosophical argument, and we'll talk to a quantum information scientist who thinks he knows how to tell if we're living in a computer or not. So whether you're simulated or real, join us as we break the code and answer the question are we living in a simulation?
Hi?
Everyone, Okay, we're going to do something different today, and that is we're going to give you a choice. In this episode, there's an argument that none of this and none of us us are real. But as Morphius said in the Matrix movies, not everyone is ready to hear the truth. So we're going to offer you a red
pill and a blue pill. If you take the red pill, you will hear the argument for the idea that we're living in a simulation, and if you're convinced, as many smart people are, it's going to turn your world upside down. But if you take the blue pill, then you'll hear the argument against the idea we're all living in a simulation, and you can go back to the life you've been living, even if it's all a lie. And then later on we're going to offer you a third pill, a purple pill,
but that's going to come later. So here's your choice for now. To take the red pill, skip to the next chapter and hopefully your podcast player recognizes chapter markers, or just keep listening and you'll hear why some scholars think we're living inside a computer. Or to take the blue pill and be reassured you're a real person. Kip ahead two chapters. We go to after the first ad break at about the middle of the episode, and you'll jump straight to the argument against the idea we're living
in a simulation. All right, pause the episode if you have to. I'll give you a second to make your choice, And here we go the red pill, Why we are probably living in a simulation. One of the first mentions of this idea is in a nineteen sixty four science fiction novel called Simulacron three. In the book, a man named Douglas Hall helps create a computer simulation of a city filled with simulated people who think they are real
people as a platform to do marketing research. But when strange events happen to him and his coworkers, he starts to realize that he is living in a computer simulation. He's a computer program and the simulation he was working on is a simulation inside of another simulation. But the reason this idea has been so talked about in recent
years is due to a man named Nick Bostrom. Doctor Boston is a philosopher and former professor at Oxford University who published the paper in the Philosophical Quarterly in two thousand and three titled Are We Living in a Computer Simulation? In which he presented his argument that the most rational thing for humans to do is to assume that we are living in a simulation created by an advanced species of humans or aliens. The argument is so persuasive that
it's been hotly debated for the last twenty years. Of this argument, Neil Degrassi Tyson, the famous astrophysicist, said, quote, I wish I had a good argument against that, but I do not end quote, even he is partially convinced. Okay, so what is this argument? To find out, I went straight to the source and talked to doctor Nick Bostrom. Thank you doctor Boston for joining us here today could be with George. Can you please tell us who you are and what do you do.
I'm a Nick Bostrom, I'm a philosopher. Have been thinking for a long time about the future of technology AI in particular, and the implications for the big picture situation for humanity.
So for those of us that are not familiar, what is the simulation?
Well, in the context of the simulation argument, which I published back in two thousand and one, a simulation refers to a detailed computer simulation run by some technologically advanced civilization, which includes brains, simulations of brains simulated at the sufficient level of detail that these simulated brains are conscious and have experiences similar to the experiences that we have. It's a computer program, Yeah, an implementation of a computer program. Okay,
here's the scenario. Imagine a computer the size of a planet, and this giant computer is running a computer program that's simulating a virtual world in which you, you, me, and everyone you know is not real, which is part of the simulation. So you don't really have a brain. Your brain is just code being simulated inside the program. And this program is being run by a super advanced civilization, which could be humans in the future, or it could be aliens. Yes, it's a wild scenario. So what could
possibly make us think it's true? Now you've famously said that there's an argument to be made that we are currently living in a simulation. What is that argument? The simulation argument argues that one of three possibilities is true. The first possibility is that almost all civilizations at our current stage of technological development go extinct before they reach
technological maturity. The second possibility is that out of all civilizations throughout the universe or the multiverse that do reach technolgical maturity, a strong convergence in that they all basically all of them lose interest in creating ancestors simulations.
All right, The argument for the idea that we're living in a simulation comes down to three possibilities about the universe. The first possibility is that most civilizations in the universe snuff themselves out before they become the kind of super advanced species that can create these massive simulations. This would imply that there are no advanced civilizations in the universe and there never will be, because none of them ever
make it that far. Maybe they wipe themselves out with nuclear war or environmental disaster, or maybe they deplete all their resources, or maybe bad luck just catches up to them and an asteroid or a comet eventually kills them. The second possibility is that there are civilizations that do become super advanced, to the point where they have nearly infinite resources, and they could make these massive planet sized similations,
but for some reason they don't. Maybe they'll think it's a waste of time, or they find it morally objectionable to create sentient beings. And then there's a third possibility.
And then the third remaining possibility is suppose it's not the case that almost all civilizations fail to reach technolgical maturity, so that means that like some significant fraction of them get through. Then let's suppose that at least some non trivial fraction of these civilizations that do become technolgically mature are still interested in using some non negligible fraction of
the resources for this purpose of creating simulations. You can then show that there would be many, many more people like us living inside simulations than that would be people like us living in the original history. Because even using a small fraction of the resources of a technolically advanced civilization, you could run millions and millions and millions simulations of all of human history. Then it would be the case that most people like us would be in simulations, the overwhelming majority.
Okay, here's the core of the argument. It's basically a betting argument. If the other two possibilities are not true, meaning that there are advanced civilizations out there and at least some of them think it's cool to create massive, planet sized computer simulations, then the odds are that we are in one of those simulations. That is because these advance civilizations, doctor Boston argues wouldn't just create one simulation, they would create millions of them.
Just like when.
Millions of kids here on Earth play say Minecraft, each kid is creating a world with thousands or millions of artificial beings in it, And so the argument goes, in the whole universe there would be many more simulated beings than real ones. So if you're a conscious being, meaning some kind of entity that thinks they're real. Then the odds that you are real are small.
So what that that means is, if you're the first two alternatives, you have to accept the third one. And then I argue that conditional that we should think we are probably one of the simulated ones rather than one of the exceptional non simulated ones. That we are almost certainly living inside a computer simulation created by some technolically advanced civilization.
So that is the main argument for the idea that we're living in a simulation. It's a logical argument and it's a betting argument. There are three possibilities. The first two are not true, the third one must be true, and that one says that there are advance civilizations out there that are simulating millions and millions of virtual lives, which means to us that you are one of them.
Is really high. Like if there are a million real people out there, but there are trillions of simulated people who think they are real, then the most likely thing is that you are one of the simulated ones. Now, as you can imagine, there are several big assumptions here. The first one is that we could ever have the technology to make these planet size relations of billions of brains. And the second is that anyone would want to do this. Here's how doctor Boston talks about the first assumption.
So a key premise here, which is that a technolgical matricivilization would have enough computing power to run gazillions of these simulations. Now, we currently don't have the ability to create these simulations because we don't have that technological wherewithal yet, but a technolgical mature civilization would have this capability. In fact, you could say that even just using the resources of a single planet, using only computational architectures that we already know,
would be possible. For one minute, they could run like millions of simulations of all of the brains that have
existed throughout human history. If you can roughly estimate the processing power of the human brain, you can count the number of synopsies, the frequency with which they fire, et cetera, and you still get the conclusion that, even if they are only very slowly interested in this application, the number of simulations one of these interested technologically matri civilization could run over the course of its lifespan would be in the trillions and trillions and trillions.
Okay, what doctor Boston is saying here is that if a civilization is really advanced, and we're talking super futuristic humans or aliens that have figured out things like fusion energy and can build spaceships, mind asteroids, and conquer other planets, then simulating a few billion or a few trillion human brains would be easy for them. And you can sort of see that even now, we have a huge amount of computing power and we can simulate ais that can solve most problems humans can.
And in this argument, you don't need.
All civilizations to reach this advanced point. If only a few do, say one in one hundred or one in a thousand, then that would be enough to simulate trillions of fake people and outnumber the real ones. And the second biggest emgine is why would anyone do this? Do you see humanity making these simulations? Is there evidence right now that we would make these if.
We were given the ability right now? If somehow some scientists figured out how to just create vastly more powerful computers, and if we had the ability to program them appropriately, a lot of people would do it for all kinds of reasons, like historical researchers would find it interesting to run counterfactual runs of history. Game developers might have a game setting where there are like real historical people. You
might want to visit an earlier era. You can't build a time machine, so the second best you could do would be to create a detailed simulation of this epoch in the past, and then you could sort of visited as a as a tourist. That might be many other reasons as well, or for no reason, just for you know, for the heck of it. So right now, yeah, we would be running a lot of simulations if it was cheap enough to do it easily.
Doctor Boston's point is that there are lots of reasons to create such a massive simulation. It could be like a video game, for that advanced revilization, or for research or curiosity. And you don't need all futuristic civilizations to do it. You just need one or two.
Now, we don't know that much about technogically mature civilizations, so maybe there is this strong convergence, like they all realize that it's like morally bad to do this, and they all converge on the right ethic. But this second alternative,
it's hard to rule it out completely. But even if most civilizations, say would somehow converge that they would not run any of these simulations, like wouldn't one in a thousand, one in a million somewhere in the universe do it, then that would be not to generate enough of these simulations that most people like us would be in the simulations now.
In doctor Boston's original paper, he envisioned future humans running a simulation of the past, meaning we think we're in the year twenty twenty five right now, but really we're in a computer running in the year ten thousand or one hundred thousand that is built by one of our descendants. But the argument in general also works with aliens.
Yeah, you could mutter a technodically mature civilization. One type of simulation they could do would be simulations of people like their ancestors or variations thereof Maybe they would simulate people like us. You could also run simulations of potential aliens. Right, you don't only have to simulate people you thought inhabited
your planet before, but you could. So all of those are possible, and there would be this population of different simulations and simulated creatures of potentially many different kinds like the idea of Earth could be simulated and fake. Yeah, yeah, that could be the case.
Yeah. Now what is your personal opinion? Do you think that we are living in simulation? Or is your judge just to think about these possibilities.
So I tend to pond on I've often asked, what, like the probability is. I tend to like refrain from giving a precise num. I do think it's a serious hypothesis. I would assign it significant credence, but I haven't given a particular specific number. And the simulation argument in and of itself doesn't tell us that. It only tells us that at least one of these three alternatives is true.
So if you wanted to conclude that the third alternative is true, that is that we are in a simulation, you wouldn't have to bring in some additional evidence to rule out the other two. All right.
So that is the red pill, the argument that we are living in a simulation, and it's compelling because it's hard to rule out all other possibilities, or is it. When we come back, we'll take the blue pill and talk to a quantum scientist who's going to make the case that we are not living in a simulation. And then at the end, I'll offer you a third option that gets even crazier. So stay with us. You're listening
to sign stuff. Welcome back the Bluepill. Here's the argument for why we are probably not living inside a simulation. If you skip ahead, here's the proposed scenario. You and I and all eight billion people on the planet right now are not real.
We are all.
Simulated beings living inside a computer program running on a planet sized computer built by a super advanced future human or alien civilization. And believe it or not, there is a very compelling argument that this is true. But to give us the counter argument that we are not living in a simulation, I reached out to a couple of quantum scientists who wrote a paper titled Probability and Consequences of Living Inside a Computer Simulation, in which they argue
that we are probably not simulated. The authors, Alexander Bibou and Guiz brazaar we're working on quantum cryptography when they realize that quantum mechanics pretty much throws a big French into the whole simulation argument. So here's my conversation with the main author of that paper, doctor Alexander Bibo. All right, doctor Bibo, thank you so much for joining us.
It's my pleasure.
The first thing I want to check is this is you right, I'm talking to the real you, not a simulation.
As far as I know.
Well, we're talking today about this question of whether we're living in a simulation. This is a pretty wild idea, because you know, I go through my everyday life and feels like I'm in a real place. It feels like I'm in actual reality. You wrote a paper arguing against this idea. Yeah, now, please spend the next ten minutes trying to convince me we are not in a simulation.
The big thing that in Bostrom's paper and what people have this argument discount is the fact that you don't need to only simulate the brains of the people living in the simulations, but you need to simulate their whole world. For instance, this idea that you could build a bunch of brains with just a small amount of matter optimize according to all the laws of physics, the number of brains that could simulate is really really high. That initially like,
it's very much in favor of their being more simulated beings. Okay, but building all this world around these simulated beings will require that same level of power, and physics can get very complicated, especially quantum physics can be very complicated to simulate. So it ends up canceling out, and it ends up not being such an argument in favor of there being
so many more simulated beings. Mathematically speaking, okay, the first argument against the idea that we're living in a simulation is the fact that it's really hard to make a simulation of reality. According to doctor Bibo, you not only.
Have to simulate a human brain, which is the most complex arrangement of matter we know about, but you also have to simulate the physical world around that brain, and it's especially hard if you make your simulation accurate to the level of quantum physics. So whereas before you might say that it would be very easy for an advanced alien or humans flization to simulate trillions of sentient beings.
And therefore make it more likely that we are.
Simulated beings, doctor People argues, it's not that easy.
It's very hard computationally speaking, to simulate whole worlds, okay, especially cold worlds in which there is quantum physics. Okay, because quantum computations are inefficient.
Like if someone were to make a video game and we're in that video game, most of their computer, most of their PlayStation thirteen would have to be spent running quantum physics on.
It, exactly, exactly, especially if inside the video game they don't know they're in a video game and they're starting to be curious about their world and they're trying to perform like quantum physics experiments, like these scientists are at work trying to verify that quantum mechanics is being respected as some of our quantum scientists are. It would require all the computing power of their advanced PlayStation and the game would slow down to a crawl. This is the argument.
So that's one of the arguments against the idea that we are living in a simulation. It's very hard to simulate quantum physics. You either need a quantum computer, which are really hard to make, or you end up spending most of your computing power calculating all of the different probabilities that happen all at once in quantum systems. And if you want to know more about this, check out
our episode on quantum computers. Now some people have argued, including doctor Bostram himself that a simulated reality doesn't need to simulate quantum physics, at least not all the time. They could use something called procedural generation. Here's how doctor Bostrom describes it.
In these simulations, you would need a simulation of the environment to generate the experiences that these simulated brains have, but you wouldn't have to simulate the environment in perfect detail. You would only need to simulate the aspects of the environment that the simulated brains person eve at a given point in time. So it's not the case that every single atom in the desk in front of you would be simulated continuously, let alone the quarks and stuff. Right.
I think that that would add massive demands on how much computing power it would take, and it would soon become infeasible even with like really advanced technology. But all that would be required is that the surface appearances of your desk are simulated sufficiently that it looks to you fully realistic.
Right.
And then let's say some physicists in a lab like took an electron microscope and looked at a piece of your desk, right that they could see potentially individual molecules, right, than atoms. So at that point more detail would have to be filled in in the simulation, but only in the particular piece that they were looking at, so it would be sort of procedurally generated.
This is what's done in a lot of video games today, like Minecraft or the Legend of Zelda, where a character is free to walk around a huge virtual environment. The computer doesn't need to simulate the entire world, just the parts that the character sees, and just at the level that matters to them. So if a mountain is far away, you don't need to simulate every atom or quantum particle of that mountain. You can just simulate it as a big block or even the table in front of you
to tap it or put your hand on it. You don't actually have to simulate it at the atomic level. This would make it easier to simulate a whole reality, and therefore make it more likely we are in a simulation, But as doctor Bibaut counter argues, it has its limits, and.
The people who argue for this high probability that we are in a simulation, we don't need such higher rate of input in order for it to feel real. You know, you can play a video game which is fully immersive with not much better technology than what we have now. You could have like a screen which shows you something
which to your eyes is indistinguishable for reality. This is true, but in order for that world to be coherent and for it to like show no inconsistencies in the laws of physics everywhere, it has a very very high cost.
Like right now in our reality. In our world, there are physicists running the Large Hadron Collider in Geneva. They have atomic microscopes looking down at Adams. If someone is simulating our reality, they would also have to simulate like every physicist poking around at the atomic level.
Yeah, exactly, all this stuff in a completely coherent way, in a way that no one would find contradictions in and all that stuff. Yeah, that would be crazy to do. I'm not saying it's impossible. What I'm saying maybe one day we will do this, but we will not be able to do it on such a scale that we're able to drive the number of simulated consciousness higher than what there is in reality as far as I can talk.
Okay, Now, the second argument against the idea we're in a simulation is that while a futuristic civilization might be interested in simulating reality. They may not be that interested. It might not be that much fun for anyone.
When you have advanced computer the second factor that remains is how much of it do you spend on these simulations versus on other things?
What do you mean?
What I mean is that even if you have these advanced computers and someone somewhere like is running all that stuff, you need to run other things too, presumably right, and you're not just using your computers for simulating brains right now? What proportion of all the computing power in the world is used to simulate brains? A very small amount. Everything else is used to show ads again whatever, for like blockchain, or for for a bunch of other purposes. We use
computing power for everything else. What proportion of all the computing power that you do have in your real civilization do you use to simulate a world which is indistinguishable from reality. So let's say even if your simulation was perfectly efficient, then it only used one quantum bit in the simulation, which is impossible. But let's say you could you spend more computing power on other things, more computing
power on cryptography than on simulations, for instance. Okay, you would still have fewer simulated people than real people.
So if it was easy and everybody was trying to play God in their home computers, then the number of simulated realities is huge. Yeah, and we're very likely to live in a simulation. But you're saying no, it's a really hard and b from what we know over the world around us, not everyone is playing PlayStation at the same time.
And sometimes even if we had a very advanced civilization, you would not necessarily play games in which the other characters are conscious. And see a world that looks like this, you might still prefer to play like Super Mario two, you know, which, like the Little Turtle guys are clearly not conscious.
The aliens prefer retro games. Maybe all right, that was the blue pill. When we come back, we're going to ask our two experts how we might settle this debate. Could we ever tell if we are living in a simulation? And then at the end, I'm going to offer you a purple pill, which I have to warn you might blow your mind, whether it's simulated or not.
So stay with us. We'll be right back.
And we're back, all right, Whether you took the red pill or the blue pill, or maybe both. You might be wondering if we could ever tell that we are living in a simulation, How can we know if we're living in the matrix. I asked both our experts this question, and this is what they said, Could we ever tell if we were one of those simulated consciousness?
So that would depend on the simulation. So if the simulators wanted to reveal this curtly to do that, you could imagine like a window popping up in front of your visual field saying here, you're in a simulation. Click here for more information. Right, that would be a pretty conclusive proof. Short of that, I think there are indicators that the closer we get to technological maturity, the less
likely the first alternative becomes. Right, Like, if we look like we're almost there, then it doesn't seem the case that almost all civilizations that our current level will go extinct before reaching technogical maturity. I see, And if we at that point remain interested in creating ancestors simulations ourselves, just like we right now run a lot of computer grames and three D virtual realities and scientific simulations for
all kinds of purposes. Right, if that remains the case as we get really close to being able to do this ourselves. That would really start to roll out the first two alternatives, and it would then force us to infer that we are almost certainly simulated ourselves.
Let's say we were looking for evidence that we are not or that we are living in simulations. What are some of the things we could be looking out for.
One of the things I do mention in the paper is that if you're looking for violations of these laws of physics, they could be very subtle. They could just be errors in quantum correlations. So some of the experiments we perform to understand how quantum mechanics work, they could have noise that we're not able to explain. And same thing when we're doing quantum cryptography. In quantum cryptography, your piece to p people at the end, they're exchanging information
on something which is a quantum channel. And if there is noise in this experiment in this communication, usually you say, oh, the noise is there because someone is puying on the information. Someone is trying to intercept part of these photons to
get information out of them. If this was happening, if you do see noise and no one can explain away, this could be an indication, for instance, that we are in a simulation and that these correlations in physics are violated because there is either a bug in the simulation or they're using part of this information to look into what's happening in our world.
I see, like, if we test the lots of physics and we find errors or weird things happening, then that might be a clue.
That we're in a simulation.
Yeah, I believe so.
But do they have to be at the quantum level?
This is probably where they would happen, because it's much harder to get quantum computations correctly without noise than it is that anything else to happen. You cannot observe it without disturbing it. In that sense, if the laws of physics are truly quantum, and we have good reason to believe that they are, then even from outside the simulation, trying to observe them in that way could disturb them in a way which we could measure.
Okay, So to tell if we are in a simulation, you can do one of two things. You can look at the world around us and see how it affects the philosophical argument. For example, if it looks like our civilization is about to crash and burn, then maybe that's common and there aren't any advanced civilizations out there. Or if we find that playing video games or running realistic simulations is not a high priority for us, then maybe
it's not for any civilizations out there either. The other thing you can do to tell if we're in a simulation is you can look for glitches in the matrix. If you run quantum experiments and find that things don't quite add up, then that may be a sign that we are simulated. Or as doctor Bobo said, you could try to break the simulation. You could overtax it, maybe by doing a lot of quantum experiments or running your own simulations within the simulation, although that could be dangerous.
So poking at the loss of physics is one way to test whether we're in a box or not.
There are other ways, which could be trying to make our own simulation, so trying to keep acquiring technology and increasing our computational power and trying to make our own simulated worlds. If we use too much, I mean, we could be slowing down their simulation and they could be tempted to turn it off or to do something about it. Which maybe is not so smart if we think we are in a simulation.
So yeah, if we are in a simulation, maybe we don't want to do anything that might make whoever is running the simulation stop because it may not matter. Here's the last question I asked, doctor Buster. Do you think there's a difference between a simulated reality and a real reality?
Well, that depends that on the simulation. I think that could be very close. If the simulators wanted to make it as accurate as possible, I think that could make it pretty accurate. And if ever there were like some glitch or some anomaly, then they could sort of edit the memories of whoever detected that or sort of patch things up. You imagine these simulators as being super intolent. One of the things that could do with our advanced technology would be to make themselves smarter.
Well, I really appreciate your time here, and it's been a real experience to talk with you, hopefully not a simulated one.
The experience is real now, the implementation of it is more hidden in a shroud of uncertainty.
I guess all right. The last thing I'm going to do is offer you a purple pill. This is an idea that might be even crazier than the idea that we're all living in a simulation put on by some alien civilization out there in space, an idea that came up when I was talking to doctor Bubo about how he got interested in the idea of a simulated universe.
So basically I was working on seeing physics as a potentially computation no thing, saying like, okay, like could physics at its most base level be a computation?
What do you mean physics being a computation?
So saying that if you're trying to understand the laws of physics, a good way to understand it is from the perspective of what is the informational content of physics and what we perceive as time evolution of systems. How could this represent a type of computation? You would say that at some point this would mean that on the most microscopic level, space and time are discrete.
And I think you're saying that maybe the laws of physics are just a program.
Yeah, any physical system, because it's state changes with time, and it's taking like an input state, doing something and getting an output state at the end, it's performing a computation. So in some sense, the laws of physics as a whole could also do that.
Maybe, like the laws of physics were a program, but they weren't running in a computer. They were just running on the.
Universe exactly exactly. The universe is kind of like a natural computer that just happens to be there.
In other words, the real actual universe itself could be a simulation, which means the answer to the question are we living in a simulation could be yes, but it's a simulation that is being run by no one. As Neo famously said in The Matrix WHOA. Thanks for joining us, see you next Wednesday. You've been listening to Science Stuff production of iHeartRadio, written and produced by me or Hm, candited by Rose Seguda, executive producer Jerry Rowland, and audio
engineer and mixer Kasey Pegram. And you can follow me on social media to search for PhD comics and the name of your favorite platform. Be sure to subscribe to Sign Stuff on the iHeartRadio app, Apple Podcasts, or wherever you get your podcasts, and please tell your friends We'll be back next Wednesday with another episode.