David Chalmer: The Matrix is REAL!

Speaker:

The human brain is a big complex machine. It’s an amazing machine. It’s a creative machine, but it’s still made up of these neurons which are appear to be computational units hooked up in amazing ways. The imagination, as far as we can tell, is itself a kind of simulation when we imagine things. When Einstein was imagining things in free fall, he was running a kind of simulation himself running on this incredible computer, which is far more sophisticated than any computer that we ourselves have developed to date. But, you know, AI is moving fast. I can’t believe where it is now compared to where it was 10 years ago. I am

Brian Keating:

your fearful host, professor Brian Keating of the Arthur c Clark Center For Human Imagination, talking with a renowned Intellect. And this is a rear, a real treat. When I found out that his new book was coming out, I just had to get them. And it is none other than professor David Chalmers, who first formulated the problem of the hard problem of consciousness, which we’re gonna get to in a paper facing up to the problem Consciousness in way back in 1995, expanded upon it in his, wonderful book, the conscious mind 96, his works are provocative, influential And and, some of the greatest luminaries of all time, including past guest Steven Pinker have, called it, so praiseworthy and his acclaim and renown no no bounds. And so first, I wanna welcome you today, Dave. How are you doing today all the way in New York?

Speaker:

Thanks, Brian. Yeah. Great to great to be here. It’s kinda kinda rainy out here, but, I hope it’s hope it’s sunnier where you are.

Brian Keating:

Yeah. La Jolla, that’s a fair game. You know? I I usually say, you know, the hardest job in the world is being a San Diego sportscaster because we’ve never won a championship in any sport. But the easiest job is being San Diego’s meteorologist because 72 and sunny, 71a half and sun. You know, it’s it’s, it makes up for, its lack of of variance by its, a consistency of beauty. So, yes, it is quite lovely. But I am a native New Yorker. I’m a a born and bred in New York, so sometimes the accent will come out.

Brian Keating:

And, Dave, as I told you right before we started, my audience loves it when I play the game, which we call judging books by their covers and titles and subtitles. So this book has a butterfly, very provocative and beautiful butterfly, which is kind of the only character that makes its way through dream sequences throughout the book. The title’s reality plus. The subtitle’s virtual worlds and the problems of philosophy. Dave, explain to us what is the title, the meaning of the title, and that mischievous butterfly doing on it.

Speaker:

The title is, is reality plus. Actually, I started I had a working title for a long time that was reality 2.0 because this is about you know, the book is in large part about virtual an artificial realities. These could be the, the, the 2nd class of realities. 1st reality, physical reality. But then we start creating our own artificial realities. That’s reality 2 point o. Another idea is it could turn out that we ourselves might be in simulated artificial reality, so that our reality is reality 2.0. Now the only trouble is there’s a fatal flaw with this title, which has probably occurred to all of your listeners already, which is, you know, reality 2.0 suggests to people AOL 19 nineties, You’ve Got Mail.

Brian Keating:

Dial up.

Speaker:

Yeah. It’s it’s so retro that it sounds like it’s a step the step backwards rather than a step forwards. Was it yeah. Even our colleague Max Tegmark went to life 3.0 to avoid this problem. I thought reality 4.0, maybe not. But someone had the great idea of, yeah, well, reality plus. Mhmm. Because although putting a plus, on the, on the end of a title may be becoming a ubiquitous cliche too, at least in, at least in streaming services, you know, Disney plus Right.

Speaker:

Hulu. Apple TV plus, Paramount plus, and so on. At least, it’s a 20 twenties cliche and not a, and not a 19 nineties cliche. And it kinda suggests this idea. There’s more to reality than you think. There’s physical reality, there’s virtual reality, there’s simulated realities. And, yeah, if in the future somebody comes up with a reality streaming service, where you’re able to choose between the virtual realities and you wanna live in, then reality plus might be a, might be an appropriate name for it. So in the end, I thought, okay.

Speaker:

Gotta go with reality plus, gotta go with the plus sign.

Brian Keating:

And that gives a hint that the enhancement that we’re going to be, experiencing in the Maybe augmentation and supplementation, but maybe even full scale replacement of our notions of reality. And I’ve had on, as I said, Don Hoffman So it believes reality does not exist and that’s sort of a, an avatarish, scenario, desktop scenario, which is which is provocative, and you refer to him towards the end of the book, when we may get a chance to get into that. I neglected to mention that you are the codirector of NYU Center For mind and brain consciousness. So oh, no. Brain consciousness. You know, my mom named me, you know, Brian so that people would make that mistake, and it happens about 2 times a day. And you were elected a fellow of both the American Academy of arts and sciences, but in your native land down under of Australia, you were elected The Australian Academy of Humanities as well. And I want to start by, because I can’t resist.

Brian Keating

It’s like if we were to hear, Go to a concert by your countrymen ACDC, and they don’t play. You shook me all night long. There’s just, you know, you’re going to leave unsatisfied. I have to take it from the master. I want you to define the hard problem of consciousness.

Speaker:

Yeah. So the hard problem of consciousness is the problem of explaining how physical processes in the brain give rise to subjective experience, to the subjective experience of the mind and the world. So for me, the core of consciousness, that word means many things to many people, but the core of consciousness is subjective experience the perceiving, of feeling, of thinking, of acting. It’s anything that feels like something from the inside. And the easy problems of consciousness are things like explaining behaviors which are associated. How can we walk? How can we talk? I get a stimulus. I can point to it. I can act on it.

Speaker:

I can report it. I can say, yeah, there’s a red object over there. We got a beat on how to playing those things in terms of physical processes in the brain. Specify a mechanism, show how it does the job, but those were the easy problems. A hard problem is why is all that accompanied by subjective experience? Why doesn’t it all go on in the dark without any subjective experience at all. I mean, it doesn’t. At least in me, I know that I’m conscious. I experience all this, and I assume it does for you as well.

Speaker:

But why does it? Right now right now, we don’t know. That’s the hard problem.

Brian Keating:

Yeah. And you further work done, by Thomas Nagel and and others. And I wanna write a book. You know, my dream, Dave, maybe with your help, I wanna write a book. What is it like to be Thomas Nagel? And the author would be ABAT, because, you know, I think a lot of these things, you know, to physicists tend to be a little bit unsatisfying. In other words, We, we kind of really tie into the physical, the Boltzmann brain aspects. We’ll get into that. The it from bit, and I think the more interesting, you know, bit From it.

Brian Keating:

But, but, you know, how do we how do we understand at a core grasp, you know, and reconcile things that Are kind of this, yeah, sub subjective. And I wanna maybe begin the the core conversation by talking about this kind of Maybe, fitful tension between physicists and, and philosophers. So famous quote by Galileo when he invented Not the telescope, but he perfected the Galilean telescope. Here’s an example of one. He didn’t invent it, but he used it for the first time astronomically. And what he said he did with it is resolve questions that had vexed philosophers for many generations And cause them unending suffering. In other words, he was kind of, like, pejoratively putting down, philosophers. And nowadays, we see it in people like Lawrence Krauss and others and and talking about the utility or lack thereof.

Brian Keating:

Why is there a tension between physics and philosophy? And and do philosophers have antipathy towards, those of my ilk physicists.

Speaker:

I don’t think so, and I don’t think there has to be a tension here at all. I mean, the great physicists of the past, many of them were great philosophers. You know, Isaac Newton considered himself a philosopher. He was professor of natural philosophy. But, I mean, along the way and when he was born, the problems of space and time were problems for a philosopher. Now, Newton was a good enough philosopher, that he managed to make progress on this on this problem with new methods, formal methods, experimental methods that would basically turned this problem of philosophy into something we could make progress on, and thereby kind of birthed the core of the science of physics. And this happens in philosophy all along, so many times, you know, disciplines like economics, psychology, linguistics, parts of logic kind of started as philosophy. Some philosopher made progress on it, and then we okay.

Speaker:

Then we spin off the science. Okay. So now what’s happened is that a number of these a lot of philosophers have been successful enough that we now have the successful spin off going in physics, in psychology, in linguistics, and so on. And what’s left in philosophy, almost by nature, is the too hard basket, the stuff that we haven’t figured out how to turn into a science yet. But on the other hand, there’s quite a lot of things which are just at the interface. And I would like to think the science of consciousness is precisely one of those, starting with a very core philosophical question, how could there be consciousness in a physical universe? And we’re managing to, to at least bite bits and pieces of it off. So we now have a thriving science of consciousness that involves neuroscientists, psychologists, and also philosophers right around right around that that borderline. And there there’s still bits of the science of of the study of consciousness, which are in the philosophy camp, but bits in the science camp.

Speaker:

And, actually, my experience is I’ve had a lot of of great experience interacting with neuroscientists, psychologists. Right now, I’ve got a big project with a number of neuroscientists where we’re trying to design experiments to test some of the leading philosophical theories of consciousness and come up with, with experiments that will that will do that. So, yeah, historically, look at all the physicists who were great philosophers. Heisenberg, Schrodinger, Bohr, Einstein, early first half of the twentyth century. They were all great philosophers. One thing that happens over time is that things get a bit more professionalized. Maybe, you know, physicists have to focus a little bit more these days and some philosophers focus a bit more, so there’s less room for for maybe there’s a bit less of that kind of crossover, but still there’s so many physicists who are who are, brilliant philosophers too. You know, John Wheeler was a brilliant philosopher.

Speaker:

Look now at someone like Max Tegmark wrote, you know, the mathematical universe. That’s a great work of philosophy. People like David Deutsch who are at the interface between the 2, philosophers like David Albert and Tim Modlin, who know who know physics forward and backwards. So I still think there’s a real productive core there.

Brian Keating:

Yeah. I would agree. And, I mean, if they look at the root of the word’s meaning, you know, love of wisdom, love of knowledge, I think that’s, That’s something that physicists should aspire to. Of course. Yeah. As you say, we have to focus. We have to niche down. We have to choose a, you know, a profession And so forth.

Brian Keating:

So, typically, those questions, I call them the 3 AM dorm room couch questions. You know, those kinda dissipate as we mature, and then people look back with somewhat of disdain, you know, or just like, oh, you know, David, the 1st exposure I had in college of philosophy was, you know, philosophy 101, my 1st day of freshman year at Case Western Reserve University. And then the, professor was this guy who looked like, you know, the guy the professor and welcome back Kotter. His name, I think was even caught or something like that. And, he’d never taught before. And we would just have these, you know, infinitely long exams, on a on a quarter you know, on a on a bimonthly basis. And they were all true, false. It was like, you know, the The categorical imperative is something that can then subsume the ontological.

Brian Keating:

It’s true. I don’t know. And I would get less than a 58% on each. I don’t understand how that’s possible. It was only, it was only 5050 choice. My thumb’s rather occupied right now holding up good old Carl Sagan, but yours is free to push that like button. And don’t forget to subscribe. It really helps us with the algorithm.

Brian Keating:

Now back to the episode. But to recapitulate, one thing you said is that, I mean, some of these things are coming back And really providing a sound basis for physics research. In other words, they’re encountering aspects of the multiverse of alien worlds in this in this book, certainly of the substrate dependence or lack thereof, all topics we’re gonna get into. And I wanna start with this, kind of, really amusing section of the book where you you go through kind of what I call, the well, I’m gonna call I’m gonna hope this trends, but I’m gonna call it the Chalmers equation. And it’s kind of the Drake equation, but for the probability of of simulation to exist and virtual worlds to exist. And you go through all the different kinda steps in exactly the way that Frank Drake 60 years ago this year came up with his eponymous Drake equation, which is to settle on the number of, you know, alien, civilizations that could potentially have extraterrestrial intelligence. And, of course, that’s still an open question. You know? And Paul Davies, who was on the show recently, Caught wrote a book called The Eerie Silence, you know, the Fermi Paradox.

Brian Keating:

Why don’t we see them? I wondered, was that kind of an inspiration for the you know, I you don’t call it the Chalmers equation, But it’s sort of, of the same vein, is it not?

Speaker:

Yeah. It is a kind of a similar statistical equation here, I guess, and thinking about the number of simulations. I should say that here I got a lot of inspiration from the philosopher Nick Bostrom, who’s thought about the simulation himself. And he comes up with his own equation for, what fraction of beings in the universe we should expect will be simulated. And, he ties it to some complicated things like the number of beings who become posthuman and so on. I don’t fully agree with, with how Bostrom does it, which is why I come up with with my own way of of coming out of it. But the but the equation takes a fairly similar form. 1st, we need to take the probability there’s this background assumption which is, you know, the question is, if you had to simulate how many universes, how many beings, how many simulated beings are gonna have consciousness just like mine in the history of the universe.

Speaker:

Well, one assumption there is that simulated beings can be conscious at all. I don’t know. How likely is that? Not everyone is going to to grant that. But I say, okay, let’s grant that. I think it’s at least 50% probability that, simulated beings can be conscious at all, put your own, put your own probability there. Then conditional on simulated conscious beings being possible, or what I call simulated human like conscious beings being possible, beings with experience like us, what is the probability that there will be many of them, that they will greatly outnumber humans. And, well, again, that depends on some assumptions, it depends on beings getting to the point where they can have the capacity to build these beings, and that they will choose to build them. Least, whatever whatever probability you get for that, I say, let’s give it at least 50%, multiply those out, you then get a 25% chance that most beings with conscious experiences like mine, are themselves simulated being, and then running running the probabilities a little bit further, you basically get just under 25% chance that I’m in I’m myself in a simulation.

Speaker:

Fun. Okay. That’s, that’s just a back of the envelope case, but it’s a back of the envelope case for 25% chance where in a simulation. If you wanted to be more conservative, you could dial some of those back to 1 in 10 and and you still get a 1 in a 100 chance, that’s at least interesting. Yeah.

Brian Keating:

As I always say, though, when I gave a talk on, you know, maybe enemy territory, I spoke at the SETI Institute 6 years ago now maybe, and I Laid out a case for, you know, my my complaints against the Drake equation. And this is at the institute that Frank Drake and Jill Tarrin, you know, built, so I had a tread kinda carefully, but I said, you know, to scientists like like myself, the number is is interesting, interesting, but the error bars are much more important because the error bars subsume all your ignorance, all your uncertainties, all the model dependencies, all the calibration biases, Etcetera, etcetera. And I went through an example where I calculated let’s do the Drake equation for how many people are in the world famous San Diego Zoo down the road from me At this very moment. I go through the calculation. People can see it on YouTube, at SETI Institute’s website YouTube channel. And I come up with a number, and I come up with a number of people there. It’s like eight Thousand, but the uncertainty was plus or minus 12,000. There could be negative people.

Brian Keating:

There could be holes and virtual people, you know, and and kind of Suffusing the void there. So the point being that the error bars are, you know, in some cases, more important than the number itself. So what would you ascribe the error bar on either the 25% or the 100% or the 1%? You know, some people say it’s even much higher, than than either one of those 2 number, you know, The 25%. So talk about the errors in that calculation, which is what really matters to scientists in the end.

Speaker:

Yeah. And in fact, in this case, the error bars, in a way, play in my favor. Because the conclusion I wanna argue for here is that we don’t know that we’re not in a simulation, that we can’t rule it out. So to the extent that there’s a whole lot of uncertainty here, well, that just increases the likelihood that, yeah, we don’t know whether possibilities here we can’t exclude. But I agree that there’s all kinds of uncertainty here. One one source of uncertainty is just on the the consciousness side, right? We don’t understand consciousness, so we don’t know whether a simulated being could be conscious at all. I go 5050, but someone might say, come on. Why I believe that.

Speaker:

Maybe that’s, maybe that’s that’s under 10%. Another source of uncertainty is whether simulated universes will be possible. Will the laws of physics ultimately be be computational? Of course, Roger Penrose thinks that the laws of physics were not computable, so we’ll never have a simulation of the universe, at least on a classical computer. I mean, at this point, I’d like to think that even if a classical computer can’t do it can’t do it. Just say, you know, Penrose is right that the true theory of quantum gravity will have some non computable element in it. I’d like to think that whatever that element is, we could then, you know, we could then capture that element and use that to build new computers, quantum gravity computers that would thereby exploit this this non computable element, and we could get universe simulations that way. But okay. There’s a big source of uncertainty there.

Speaker:

And the 3rd is less is maybe tied to the sociology, tied to the future. Is it the case that we will actually have beings even though these simulations could exist, is it the case we’ll get to the point where we have beings who can build them and do build them? Maybe all the beings of the future will be will be, self protective enough maybe that they choose not to create advanced general artificial general intelligence thinking that this is just too dangerous. Or maybe they’ll be ethical enough to say, man, we can’t create these simulated universes that would be playing God. So, yeah, maybe this sociological part is probably the most uncertain of them all. I mean, I’m just thinking that the naively, these populations will be gung ho. Someone’s gonna do it eventually. It’s gonna be useful for all these purposes, help predict the future, help understand the world. Scientists love to run simulations now.

Speaker:

So much science is simulation based. Once we can simulate the whole universe, of course, scientists are gonna wanna run some universe simulations to see what happens. But who knows? Maybe maybe the the institutional review boards will come in with The grants

Brian Keating:

will be cut off. Yeah. Only get a very good, not an excellent, you know, from the Galactic Science Foundation. Right? But in the of the Drake equation, what a lot of people point to is excessive things like the Kepler mission and calculating the number and observing, actually, real data, unlike, you know, some some branches of of, really theoretical physics, like string theory or whatever, or or very little data actually exists. And it’s all retrodictive and not predictive. But but in any case, let I’m not gonna go off on a polemic about string theory right now. But on the other hand, we’ve reduced Some of these terms in the, in the Drake equation to basically what I call the only thing that’s remaining are the sociological terms and then the the lifetime. Mhmm.

Brian Keating:

You go through this really, and it’s just such a great book. I I can’t recommend highly enough, especially for my fellow physicists and those nerds, like me out there because Dave goes through in great detail, but it’s so entertaining, this notion of, well, what is the brain viewed as a supercomputer? And, You know, we had this notion, that the brain the human brain is so far surpassing. It’s got more neurons and connections between neurons than there are, you know, galaxies and the observed bold universe, etcetera, etcetera. And yet you make a very convincing calculation that the human brain is sort of equivalent to a 10 petaflop computer right now. And there are computers that we use to analyze data from the universe, the cosmic microwave background owned by the Department of Energy That are 10 petaflop computers, you know, or, you know, that scale. And that’s, what, 60 years after general, you know, Turing machines were kinda first conjectured By Alan Turing and and and so forth by Neumann and and others. So in such a short amount of time, we’re already surpassing in raw computation power. And that’s one of the terms I think that would have to go into a Chalmers equation for calculating the number of simulates.

Brian Keating:

So what other things Remain. As I said, the sociological term, the lifetime of intelligent civilizations before they blow themselves apart, create some runaway AI, create some virus or whatever. Those that’s the limiting factor in our understanding and the maximum contributor to our error bars. What is in the Chalmers equation? Again, you don’t call it that, but I can call it that. What is what is the the limiting factor? And what have we learned most, most recently, you know, from analogs of, you know, consciousness Kepler’s or or so forth. Like, what are the current experimental And theoretical computer science or sociological, terms that have shrunk the error bars in that equation.

Speaker:

That’s interesting. Yeah. I guess on the, the first factor, there’s, like, a simulated conscious as possible, a simulated physics possible, and the limiting factors there are gonna be tied to our knowledge of consciousness and of physics. On the sociological side, there’s gonna be, will we get to the point where we can make these and will we choose to, to make them? But maybe, yeah, the technology side is interesting. I mean, yeah, the exact number of petaflops required to simulate a brain or a universe. I mean, in certain respects, you might say the simulation argument doesn’t need overly strong arguments here. Just say it’s a vast amount that’s required because we don’t need to hypothesize that the universe in which a simulation is run is the same as ours. Yeah.

Speaker:

It seems actually very likely it might be quite different, might be quite different from ours. And, I mean, obviously, if the universe is finite, there’s pretty good reason to think no no finite universe can run a perfect simulation of itself. But much oh, some people say, therefore, the simulation hypothesis is bunk. But, of course, the relevant hypothesis is the complex universes can run simulations of simple universes or parts of themselves and so on. We also should hold open the possibility that the simulating universe is infinite. That’s quite different laws of physics from ours, perhaps, and that is somehow trivial in these infinite these universes with infinite resources to, to create universes with even with with finite resources such as, such as our own appears to be, at least in the known universe. So from that perspective, it’s like even if those resource bounds don’t hold, then all we need to do is move to, say, for example, the infinite simulation hypothesis, and we should still give some probability to that. But it is interesting that, actually, simulation technology has been moving along very, very fast in recent years, both on the you know, people actually build cosmic simulations and, and, yeah, every every few years, the cosmic simulations get a whole lot more, get a whole lot more detailed and more fine grained.

Speaker:

And, yeah, there are multi scale simulations are becoming more and more more and more of a thing. And then from the bottom up, it’s like, well, virtual reality technology is also developing. For me, that’s It’s very relevant that, actually, we now have these simulations that we can enter and experience immersively. Those are not yet VR is not yet a copy of the physical world. But if VR just gets better and better for 50 years or a 100 years, we’ll probably have the version of VR which is indistinguishable from the physical world. Once we have that technology in front of us, we will actually be able to put people into simulations that feel like the simulations of physical reality. At that point, no one’s gonna be able to say, hey, this is just way out. This is science fiction.

Speaker:

We’re actually gonna have the technology in front of us. It’ll be happening to some people, and we can then raise the question. Maybe just that is happening to us. Now some people say, oh, isn’t the simulation hypothesis meaningless because it’s unverifiable or undetectable? Once we can actually put people into these simulations, no one can say it’s meaningless anymore. It’s like we’ve got our red here.

Brian Keating:

Got it right here. So I’m gonna now strap on my my Oculus. You have 1 there too, Dave. We can, we can Enter into VR. You did a VR interview with, Cassandra Etienne here in, UC San Diego for the Arthur c Clark Center. And Arthur c Clark makes an appearance in, In your book as well, one of his books, The Childhood End, I believe, you you quote from, which presaged as an ocean of VR and and, and and computer simulation and so forth. But now this isn’t super realistic, you know, when I’m when I put these on. In fact, I’ve tried to use it for, you know, to to do exercise.

Brian Keating:

And then as you get all these cookies, and I tried to use it for meditation, and it’s, like, blindingly bright. And I’m taking you have a more recent, version than I do. Mine is the Oculus. It’s just the Oculus Go, I think, from 3 years ago, which is totally outdated. Mhmm. I see. The Quest. Yeah.

Brian Keating:

I mean, they’re prominent. Yeah. My kids are on the there’s There’s the fundamental problem with them and and that you know that you’re wearing this giant thing. And as we know now, I don’t know if you’ve checked, you know, your your, IRA or or whatever. But, you know, Facebook, which is now known as Meta, you know, for the metaverse is is cratering and and going, you know, going down, is making a lot of people really happy. But, that’s sort of a virtual where you could put this on. You could talk to your Facebook friends maybe, But it’s it’s so cumbersome. And even if you use your voice, it’s kinda cumbersome.

Brian Keating:

Now I mentioned Galileo before. It turns out Galileo may have been the 1st person to invent a VR or Or maybe an AR headset, because he there was a problem of computing time as you know in the in the 16 1700, and there was this longitude prize that was offered for the first kinda clock. And Galileo said, well, hey. Wait a second. I’ve got this telescope, and I can see the moons of Jupiter, and they’re as periodic as you would like them to be. And in fact, you can see them, You know, all over the Earth. And so he invented this helmet with 2 telescope or 1 telescope attached called, like, a chronoscope or something like that. And, he used it to you know, trying to claim the longitude wise.

Brian Keating:

And, of course, it was rejected because people’s, oh, you can only see the moons, you know, 9 months out of the year. And what do you do those other months? He’s like, well, you could, you know, calculate tables and interpolate. But, but, you know, back then, if you look at, well, how much has really changed in augmented reality. Now I could, you know, go to IKEA’s website. I can take a picture of my, you know, carpet, and then it’ll suggest that how a chair will look. It’s kind of being used as Facebook’s using it for, like, advertising. And I wonder when we scale up these digital computers, as I understand it, Moore’s Law Starts to, deteriorate because as the power of the computer grows, and it does grow at this exponential rate, the number of use cases, the number of users and the demands that they’re putting on are always scratching, you know, the upper bound of the envelope. So you in other words, you’re you’re almost like The the utility of them becomes so much higher in addition to their raw power, and it and it’s growing at a rate that’s, You know, sort of causing their bounds to saturate when it comes to the actual number of, say, output.

Brian Keating:

And you could distill that into any term, you know, not just petaflops, but into how many papers get written, how many, You know, full simulations come to conclusion. And those are actually tapering off for these large supercomputers. And so we have to keep building more and more so that the plateau gets higher and higher. Can you see that as a term in the Chalmers equation that would eventually limit the, you know, kind of optimistic Prospects of a, you know, world in which we are already living in such a simulation?

Speaker:

Especially if we’re talking about, yeah, building ultimate full simulations of the human brain, full ground level simulations of physics. Yeah. In the book, I give some calculations that require that rely on something like Moore’s Law continuing. So, yeah, every decade we get this multiplication factor. And given that, it’s not too hard to say, okay, I’m a philosopher. Or I take the long view. I don’t care what happens in the next 10 years. I care what happens what happens eventually.

Speaker:

If it’s a 100 years, 200 years, I’m fine as long as it continues. But, yeah, is it if it asymptotes at some point, then obviously there are serious, there are serious potential limitations there. I mean, I kinda hope then, at a certain point, we get to harness the power of the sun and the amazing things we, things that we couldn’t do before. But, yeah, if it turns out there are principled limits, then I mean, we know we know their current physics has principled limits like the speed of light and the Planck scale and so on. So either we eventually if we eventually hit them, then I think we need to get more creative on the, on the software side, so to speak. If we have ultimate hardware limitations, then we do things on the on the software side. For example, we find speed ups and shortcuts in our simulation as people do already. Maybe people will find ways where, okay, we’re only going to simulate local parts of the universe.

Speaker:

Okay. Simulating the whole universe out of reach. Let’s just simulate the solar system in detail, and everything else is just kind of a sketchy background copy. It’ll obey, a few basic principles of cosmology and not too much, hey, that could have been what messed up those experiments a few years ago.

Brian Keating:

Exactly. In addition to the dust you talk about at the end of the book.

Speaker:

We’ll get into that.

Brian Keating:

So, you mentioned, you know, sir Roger Penrose is a 3 or 4 time, guest on, Into the Impossible. And, yeah, you’re right. He does talk about the limits of computability and his a book, The Emperor’s New Mind, which is the 1st science book I ever read. And it was kind of a treat to have him endorse my first book, way back when Before he won a Nobel Prize, and, and and it’s quite interesting. And he and I have talked and others have have talked about this notion of AI physicists. So, Yeah. What is the limitation of and our friend Max Tegmark, who’s also a guest and friend, you know, he is very sanguine about AI Feynman, AI Galileo, AI. But I always remind folks.

Brian Keating:

I say, you know what? I don’t know if you’re familiar, with this, Dave, but, Einstein called the happiest thought of his life. And I’ve got a little Einstein, a virtual Einstein. Here he is. My god. My, audience always loves when I break out the the virtual, areas. So yeah. I only have one of these that has, actually been on the show, and that’s Noam Chomsky. But maybe someday there’ll be a Chalmers finger puppet from the unemployed philosophers’ guild.

Speaker:

This is this is this is called the unemployed philosophers’ guild. Yeah. Who knew that Einstein was

Brian Keating:

Einstein. Speaking about, the equivalence principle, which undergirds all of general relativity. And he said, He described what he called the happiest thought of his life. And that was that an observer, you know, freely falling in space would experience no gravitational field, Meaning that, you know, gravity and acceleration are, you know, 1, and the same and that geodesics are manifestations of the shortest paths in a curvature free space time in their moniadon, curvature due to gravitating mass, then it changes and alters the perception of both spatial intervals and time. But, I posit to you that I don’t believe it’s possible for an AI, Einstein to exist because, I mean, first of all, how do you how do you, visualize the notion of free fall as a silicon based entity? And then, 2, what does it mean to be happy? Like, What what does an an AI mean when when he or she or it or z or whatever feels happy? So Isn’t that, you know, kind of a a counter, you know, proof that we could ever come up with the a computer, you know, simulator could come up with such laws that the human brain Has done over and over again.

Speaker:

I think the human brain is a big, complex machine. It’s an amazing machine. It’s a creative machine, but it’s still made up of these neurons, which are appear to be computational units hooked up in amazing ways. It can learn in amazing ways. The imagination, as far as we can tell, is itself a kind of simulation when we imagine things. When Einstein was imagining things in free full. He was running a kind of simulation himself, running on this incredible this incredible computer, which is far more sophisticated than any computer that we ourselves have developed to date. But, you know, AI is moving fast.

Speaker:

I can’t believe where it is now compared to where it was 10 years ago. I did my PhD in an AI lab in the 19 nineties with, with Doug Hofstadter. Back then, people used to say a year spent working in AI. A year spent working in AI is enough to make you believe in God because AI is so hard. It’s so hard to get machines to do human level sophisticated things. But suddenly, in the last 10 years, yeah, machines doing image recognition, they’re doing speech recognition, they’re doing speech generation, they’re doing game playing, they’re doing navigation, they’re writing their own code, they’re suddenly all these hurdles are, hurdles are falling. And yeah. I mean, we don’t we don’t remotely have an AI Einstein yet, but I’m not gonna be the one who bets against it in 20 or 30 years’ time.

Speaker:

And, yeah, we do have emotion is certainly a limiting factor in AI right now. But we do have computational models of emotion, at least treating happiness and sadness as forms of valence. And don’t think anyone would claim that we yet have AI systems that experience genuine emotion, but I don’t see the principal limit towards AI’s, ultimately. There are what they call affective computing as a field, and people are working on this. Machines can be made to behave in certain ways, which at least seem to reflect irritation, satisfaction, frustration. Question, are they really experiencing it? Well, that’s a question about consciousness. Right. So may

Brian Keating:

I my late father used to say, well, if you want to simulate, you know, pleasure and pain response, which is, You know, some psychologists and social philosophers claim that’s, you know, all we’re responding to is is a conscious entities. He used to my father used to say, yeah, well, just like When it does something wrong, you know, you blow a transistor or you, you know, you you know, collapse a wave function if it’s a quantum key. You know, do something that is a painful, you know, cost function for that computer. It’s still not clear how to, you know, simulate, you know, happiness and and freefall. Is it really the the sum totality of of only pleasure with no pain. I mean, obviously, we can have superpositions. You know, right now, I’m really happy, but I could be, you know, unhappy very easily, And I could be much happier very easily too. So it’s not is it clear that I have to be in the ultimate state of happiness to experience it? You mentioned God.

Brian Keating:

You mentioned, you know, believing in God is kind of off off. But but I do feel like, you know, it’s pretty remarkable that these, you know, bronze age, you know, itinerant Semitic wanderers, you know, 3000 years ago, you know, came up with a a notion of, you know, pleasure, pain, experience, reality, free will, commandments, moral and ethical imperatives. You know, 3000 years ago, were they creating, the, you know, the earliest version of the sim hypothesis?

Speaker:

I don’t know how how far back some of these simulation ideas go, but you can find elements of it, ancient Chinese philosophy, the idea of Zhuangzi and his butterfly. How do I know I’m not a butterfly dreaming that he’s drunk that that is where, by the way, that’s where the butterfly on the, on the cover came from that is meant to be a virtual reality version of Dvwangsa’s butterfly. I could be a butterfly dreaming he’s he’s Dwanje. You find it in Indian philosophy of ideas about, ideas about illusion. So many, the Hindu tradition has God’s mind supporting all of reality and maybe this also connects to what you find in the, in the Abrahamic traditions, where yeah. Basically, God is so powerful. God supports, God supports reality. And, of course, the question is how did God create reality? I guess, I I always remember let there be light, and there was, and there was light.

Speaker:

In the book, I I, I speculated a bit about maybe what actually went on was let there be bits. And, yeah, god creates some, god creates some bits. The difference between Exactly. So so in the Hebrew tradition

Brian Keating:

and the Talmudic tradition that I’m more familiar with, the what god does in the 1st 6 days of creation is separate. So the 2nd line after let there be light or information, however you wanna say it, Is, and the world was chaos and void, and he created order. So in other words, there’s chaos, which could be a state, like a one, And there’s order, which would be lower entropy, could be a 0. And and he separates between man and animal, between vegetation, water and land. And so it’s not at all a stretch to to hypothesize that that is yeah. There you go. Yeah. Show that.

Brian Keating:

That’s

Speaker:

I got a great illustration of this in the, in the book. On one side we have there is a traditional God creating the universe by, creating some bits, and then the, the tables and chairs and animals and everything else come from there. On the on the other side, we have a simulator, a simulator god who here is like a teenage girl on the next universe up. She’s creating reality while programming her computer to create bits that that create the trees and Right. Dolphins and and

Brian Keating:

the oceans. Yeah. We’ll keep it. I believe. So you only need zeros and ones. And and you talk about, The Leibniz who also, yeah, came up with the primitive Boolean construction. So, yeah, you only need these, you know, fundamental units, chaos and order, If you like. And so it’s not altogether, you know, impossible even to be in, you know, some sort of resonance with a traditional religious, you know, conception.

Brian Keating:

And so I saw a funny thing in one of these, like, onion type magazines. It was like, you know, scientists praise God for creating an ultra realistic metaverse that calls the universe. But, I wanna ask you if there’s a very, very provocative, middle section in the book where you start talking you basically make the Claim that a creator plus it from bit equals a simulation. And yet you still personally don’t Believe that such a god is worthy of worship, nor do you worship an ordinary Abrahamic or other, faith creator. You also don’t believe that is necessary or worthy of worship potentially. So but before we go there, Dave, I wanna ask you, what is It From Bit? And why is it so central? It’s a Wheelerism, like many things. But, how do you instantiate, you know, a computer program, from the absence of a computer program. I’ve had on and I’ll ask you to kind of, steelman my opponent or maybe your opponent’s ideas, but if you’re if you’re game.

Brian Keating:

But, you know, I’ve had on intelligent designers. I’ve had on people that believe in God, believe in, you know, creation. And and even people like Michio Kaku is your, you know, fellow New York professor down there somewhere in New York City. But this notion that, that There’s nothing we’ve ever discovered that can’t be traced in some way to something with a design, well, that contains information. In other words, there’s life and you could say, well, life didn’t come, but something that has an information content a bit that is not associated with, the, you know, a mind in some sense. A computer program written by itself doesn’t exist. Hieroglyphic on a cave doesn’t exist without a person. But first, despite that long preamble, what is it from bit? Then we’ll get into the creation aspects of it.

Speaker:

Yeah. Well, it from bit is a slogan from the physicist John Wheeler, who basically said, maybe, you know, the fundamental level of reality. What there is is the difference between, yeah, 2 different answers to a question. Yes or no? 1 or 0? And Wheeler took this in a certain direction towards the participatory universe where observation plays a central role. That kind of gets you into the role of the mind and the foundations of physics. But the direction that I wanna take it and which a lot of people wanna take it is just the idea that at the bottom level of physics, that could be something digital like, ones and zeros, binary states. We have this wonderful example of this that so many people know, which is John Conway’s Game of Life, which is a cellular automaton. It’s basically a two dimensional universe with a whole bunch of cells, each of which can be in 1 of 2 states.

Speaker:

They can be on, they can be off. And we’ve got these very simple rules that, you know, a cell turns on if 3 of its neighbors are on, and it turns off if, if there are too few or too many neighbors. And from those basic laws of binary physics, of digital physics. We can generate all kinds of behavior. And from this, you know, many people have speculated that, okay, there’s so many forms digital physics could take. Maybe even our world has a level of digital physics underneath standard physics. And my My sense of this is that most physicists don’t take this terribly seriously as a as a working hypothesis. It goes way beyond any evidence we have now.

Speaker:

There are people like Stephen Wolfram who are developing ideas in the vicinity. But I don’t need it to be true. I just need it to be kind of a coherent a coherent hypothesis. Most importantly, you know, these digital worlds, they’re not worlds where nothing is real. They’re not worlds where things are an illusion. Their worlds where things are ultimately digital. This is important for me because it means at the very least that just because something is digital doesn’t mean we should say it isn’t real. A big central theme in this book as a digital objects can be real too.

Speaker:

And if we’re in a simulate so if so one thing I wanna say is if we’re in a simulation, we shouldn’t say the objects around us aren’t real, rather we should say they’re digital, which is to say, you know, if we’re in a simulation we’ve got tables, We’ve got chairs, we’ve got molecules, atoms, quarks underneath them. And underneath those, we have bits. This is to say that if we’re in a simulation universe, we’re really in a kind of it from bit universe with some digital level underlying all these analog levels that we experience. Bits underneath physics. So that’s how the that’s the it from bit idea and how it connects to the simulation idea. And then, yeah, the next question, of course, is how it connects to the creation idea.

Brian Keating:

Right. So in the book, you say, like, creation plus if from bit equals the simulation hypothesis. So where does that, how can we, reconcile that that statement, equation, so to speak?

Speaker:

Yeah. It’s interesting. I was always a bit skeptical about, about creators and creation. Most of my life, I’ve considered myself an atheist. Not particularly religious. Don’t believe in God. The whole God idea seems somewhat supernatural to me. But once you start thinking about simulations and the simulation hypothesis, suddenly there’s a route to thinking about gods or at least creators.

Speaker:

They no longer seem so supernatural. Just an entirely natural way of thinking about gods just as the creator of a simulation. You know, we can create simulations in our own world now without needing any supernatural powers. So we thought it will maybe somebody in some universe created this universe as a simulation. I mean, if you have a simulation and it looks like you need a simulator, you need some kind of agent to to create it. And then that simulators well, I don’t wanna call the simulator a god or a god, but simulator the simulator has at least some of the traditional properties of a god. They created this world. Presumably, they can affect all kinds of things and potentially all knowing about this world.

Speaker:

Those are 3 of the central properties of a traditional god, traditional god. Now there are some other properties the simulator might not have. Being all good or all wise. No particular reason to think the simulator has to be especially good or especially wise. Maybe they didn’t create the entire cosmos either. They created this bit of the cosmos. In some ways, that’s more like what’s sometimes called a demiurge in some religious traditions, like a sub god that created at least this part of reality for us. They fashioned it as a kind of, as a kind of constructive creator.

Speaker:

So most importantly, I would not recommend that we that we erect a religion around the simulator. I don’t think this being is somebody we should worship. I don’t think we should expect this being to have any special moral insight. So for reasons like that, I’m uncomfortable describing the simulator. Even if I believed we were in a simulation, I’d be comfortable describing the simulator as a god. But, nevertheless, you know, it’s a way of getting some of the properties of a traditional god. And, yeah, it combines with it from bit idea because, after all, how does the simulator set up the simulation? By arranging a computer program, by arranging the bits. So what I wanna say is if we’re in a simulation, then, yeah, the it from bit hypothesis is true, it’s all made of bits, and all that was put there by a simulator, by a creator.

Speaker:

So, basically, the simulation hypothesis equals the it from bit hypothesis plus the creation hypothesis. Yeah. We can go about the Chama’s equation.

Brian Keating:

Pretty pretty simple. I like it, the elegance and simplicity. So to push back with a little respect, as you know, I have for you. If you think about, you know, a a god as being worthy of worship, what would it take for such a Simulator or Abrahamic deity. In other words, what would it take for you personally to define such an entity worthy, or is there no combination of traits, properties, behaviors that would make any simulated or actual god worthy of David Chalmers’ respect or worship rather.

Speaker:

I would greatly there are beings I would greatly respect, I would have awe for, you know, whether it’s a simulator or a non simulator, someone who created the universe and understood so many things that have knowledge and understanding and power that goes far beyond earth. I would have the most enormous respect, admiration and awe. But I don’t think I would worship them. Maybe I guess I just don’t really understand worship and why it’s ever appropriate. This is an amazing being that, that I would find, yeah, fully, fully awesome. But worshiping them is like a special why would I worship them? Is it like another source of all moral truth? I guess, I don’t I don’t really see why that would be true. I’d it’s a bit like my attitude to god would be like my attitude to Einstein, but squared cube to the minute of our So I built one of them. It has

Brian Keating:

to be something of benevolence. And and there’s oftentimes, you know, there is no commandment, in the Hebrew Bible, which is the root of the Christian Bible. Obviously, you know that. There’s no commandment to to worship God. There’s no commandment to believe in God. There’s a commandment to love God. And I always say, you know, you don’t get commanded to do things that are natural. Like, I don’t have to command you, you know, Dave, to to eat whatever kind of burger, vegan, or meat that you like because you like to do it.

Brian Keating:

It’s fun. Right? It’s it tastes good, or for people that have children. I don’t have to be commanded to love my kids. It’s totally natural. On the other hand, you have to be commanded to love something that’s inherently unlovable. So in the in the biblical tradition, God recognizes that he is not lovable, that he is there are things about what he’s doing, and there is authority That by its nature is not you know, it’s anathema to some aspects of creatures such as we who have free will. And I think that is the divine thing that we are endowed with free will, unlike animals. We’re the only creatures that are mentioned creations that are mentioned that no good from evil, no life from death, know that we will die.

Brian Keating:

In fact, that’s what, you know, homo sapien really is referring to. So I think worship is the wrong word, and I think it’s a miss let’s let’s like the translation of the, you know, the 6th commandment. Most people say, thou shall not kill. Right? I mean, You might you might have been familiar with it. It’s not thou shall not kill. Of course, their god does a lot of killing. Weren’t instructed to kill all sorts of people, but thou shall not murder, Which is stealing of a life. So there’s a lot of King James translations.

Brian Keating:

One of them is worship. And I think the real term should be awe. And it’s sort of you know, in the way I have conceived of it as coming later in life back to Judaism, which was my roots, is that God should be visualized kind of like a parent, a father, You know, unlike the graduate student girl that’s, the, the hero of your book, the god goddess of your book. But, but it’s it’s sort of like your father, something a paternalistic figure, that is worthy of awe, but a little bit of fear. So it’s like your father’s the king, and, And you’re close to him, and he cares about you. And it is a personal god, which I have issues with, you know, just believing in the supernatural suspension of all the laws of physics for Brian Keating. But there’s something one of my rabbis once said. He’s like, you know, well, if you were God, I’ll ask you, Dave.

Brian Keating:

You know? But he said, you know, if you were God, what would you be doing? And I asked him, I don’t know. I said, what would you be doing? He said he said the exact same thing that’s happening right now. You think I know more than God? You know? It’s like things are are are behaving in a certain way. And for us, you know, it’s a little bit of of hubris. And you don’t have to respond to this if you don’t want to, but but the notion that, you know, we should believe in God, like, oh, wait. God’s waiting for Brian Keating or David Chalmers, you know, if he exists if it exists, you know, he really no. It’s it’s more does god, you know, believe in us, so to speak. Are we acting in accord with with those principles that will create flourishing or minimize harm and cause the greatest amount of pleasure.

Brian Keating:

So I think that’s the more term. The word in Hebrew is kaveid. It means to respect or make heavy, and that’s also what you must do to your parents. So you can respond if you like. I I don’t you know, we don’t need to continue on this, Maine.

Speaker:

I have attitudes of respect and awe to many human beings. I’ve got respect and awe for Einstein. I’ve got respect and awe for, you know, Nelson Mandela. Respect and all for Beyonce. It’s like in in in very different ways. And it’s like totally if if I believed that there was this God who created the universe and showed themselves to have amazing wisdom and amazing power, then I would have I would have respect and all for that being, something something not something short of worship. I mean and if our simulators turn out to have those properties, maybe they’re gonna turn out to be super intelligent AIs or something. I could I’d have respect and all for that as well.

Speaker:

But if they stop behaving like, you know, they start raining down death and destruction, then I’m gonna well, actually, I got into this when I probably got into this idea when I came across my 5 year old nephew playing a game like, like SimCity. And he would he would show he would build up these worlds and these cities and these forests and everything. And then he said, now’s the fun part, sensible and fire. You kill all those people. They’re gone. They’re gone. You know, that is kinda curiously reminiscent to the old testament god. Right.

Speaker:

Yeah. Yep. So I thought yeah. That’s so I’m thinking my god is not gonna, if I’m if I’m gonna if I’m gonna have respect at all for a for a god, I hope that, yeah, they’re gonna be they’re gonna be much more the way that you were describing, the god. They’re not gonna care whether we worship them. They’re not gonna, they get they made it they’re gonna rain down death and destruction, but they’re gonna try and set Right. Yeah. Exactly.

Speaker:

So there was, there’s a lot of that.

Brian Keating:

And, also, I I often, you know, point out to people. They say, oh, you know, scientists should run the world. You know? Scientists embody, you know, the best aspects of of humanity and, you know, you’re so childlike, and and it’s wonderful to see something. And I say, yeah. You know, scientists are like children. We’re very inquisitive. We’re very curious. We’re very, you know, kind of, you know, e egotistical in a certain good way.

Brian Keating:

And we also don’t play well with others. We don’t share our toys with others. We compete. Like, you know, it’s like, we’re selfish. We’re jealous. We’re petty. Yeah. So it’s like, there’s no single I always say, there’s no single edged swords out there.

Brian Keating:

All they’re all double edged sword. Every blessing comes with a curse. And one of the curses of of of such a god is, yeah, is that temptation, that involuntary volition or or otherwise. You know, like, what happens if I, you know, take away or put this little tiny virus out there, and we’ll see what happens. And we could talk theodicy some other time, but I wanna get back to the book. You know, when I’m reading the book, thinking, let’s say there is the simulation. I know my audit and we’re gonna take audience questions. I have stored up, from, you know, over a 100, responses to you generously sharing your time on the podcast.

Brian Keating:

But one thing that, you know, they wanna know, They’re screaming out to us. Why? And I know it’s not a kosher scientific question to ask why, but why would there why would they simulate anything? In other words, You know, the Talmudic rabbis of 2000 years ago, you know, came to a conclusion that God shouldn’t have created the world. Like, it caused more problems than than itself. So Why why is there a simulation? Why? What what is the is there, you know, is there a teleological purpose for such a universe?

Speaker:

I don’t know, why do we create simulations? I mean, we create a lot of simulations, like simulated worlds now already. I guess, right now, there are maybe 2 overarching purposes. One is entertainment, simulations of video game worlds, and so on. There’s a vast entertainment industry, and the other one is science. People like running scientists like running simulations now to understand the systems that they’re working with, whether it’s the, the cosmos or traffic patterns in a city or water flow. Everyone is doing science with simulations. It’s easy to imagine that both reasons could be reasons why people might eventually create simulated universes. Do science, run the simulation many times, pick up the statistics, see how often life develops.

Speaker:

Hey, you wanna study that those Drake equation issues? Let’s see how often life actually develops given certain laws of physics and how often intelligence develops and so on. So that’s one good reason. Yeah. Entertainment is another. Or the 3rd is predicting the future. You know, we run simulations to predict what will happen, whether it’s, say, a military simulation or a financial simulation or this or that that episode of Black Mirror where a couple there’s an app that a couple can run, run a whole bunch of simulation of that simulations of their relationships to see if they’re, to see if they’re compatible. Actually, it’s the sidebar on this is I’ve come to think that using simulation technology for predictive purposes is actually very difficult, especially for social predictive purposes because do you simulate the simulation technology or not? Like do the people in that Black Mirror episode when they run then when they go out on dates, do the I actually call

Brian Keating:

it simulations all the way down.

Speaker:

I think you mentioned something in the world where they’re running. Right? Yeah. But if you do that, then, of course, you know, the simulations they’re running themselves gonna have to have simulations, and you’re gonna basically have an infinite regress. The the alternative is at some point, just simulate worlds where they don’t have simulation technology. Well, that’s gonna be totally unreliable. 2 people could be totally compatible in a world without the technology, but the technology will ruin it for them. And more generally, I think this is this is gonna be a regress for any any use any social uses of simulation technology for predictive It brings up a lot of, of little Maybe there’ll be some buttons.

Brian Keating:

Go down. Maybe I’ll I’ll I’ll start with 1. You know? There’s the old joke, you know, if you can, if you can, simulate being authentic, then you’ve got it made. You know? Like, You know, on the surface, he’s deep, but, you know, superficially, he’s very shallow. Right? So, you know

Speaker:

Deep down, he’s shallow.

Brian Keating:

Only it from bit. You know, there is a certain kernel of of, and as you mentioned, skepticism among the physics community. Likewise, Stephen Wolfram, past guests, multiple guests on this show. There’s skepticism. Great skepticism. In other words, there’s just direct criticism. There’s nothing that’s practically relevant to theories of everything, to unification. They’re these these things tend the cellular automata tend to be really good at simulating the properties of cellular automata.

Brian Keating:

Just in the same way that string theory is the best theory ever invented to study the properties of string theory. In other words, it’s it’s very much siloed. And I wonder, you know, is that because of this, you know, this This substrate dependency versus, you know, you could get things irreducibly down to information. But, again, all instantiations of computability, even if you claim the human brain is a computer, it’s still running on a substrate. How do we get the substrate? Where does the substrate come from? Or can you have a truly substrate free? And I don’t wanna have any spot. I hate when authors would or podcasters would have me on their show and say, Describe your entire book so my audience doesn’t have to butt no. I’m not gonna do that. But at the end of reality plus, you talk about the dust cloud and and and so forth and and this fundamental primitive computer, The conclusion tends to be towards that.

Brian Keating:

Well, it can contain enough bits, you know, and theoretically that it could support a computational system of, you know, not infinite complexity, but some limited, but large complexity. How do you get the substrate independence? We still need a substrate.

Speaker:

Yeah, well, the substrate could just be something like like bits, pure bits. Yeah. I mean, I don’t really actually need the it from bit hypothesis to make to make this idea around. I think it provides a very vivid illustration. Certainly, I don’t need, like, the bits to be serious physics required for a unification, for a grand unified theory. But it would be enough if we could have, say, a grand unified theory physics, and then, you know, in the simulation, maybe, the bits don’t ever actually show up in the equations, because, you know, when you run it I run a simulation of Newtonian physics, And if it works well, you’ll just see Newtonian physics. You won’t see the bits. Right.

Brian Keating:

But they’re they’re instigated in silicon or in a qubit. I mean, there still is matter That has to exist to run the computer.

Speaker:

So here we have 2 versions of the it from bit idea. 1 is what I call the pure it from bit idea, where the basic level is bits. And they’re not you got zeros and ones, and there’s nothing more basic. Yeah. The zeros and ones we all know about, they’re made of something more basic. They’re, you know, they’re instantiated in voltages on transistors within circuits. So that so that was what we might call the bits from it idea. The bits the bits that we actually have on our computers going to the underlying it.

Speaker:

And that could be hap you could combine the it from bit idea

Brian Keating:

From it.

Speaker:

With that. Then you get what I call the it from bit from it idea. Objects in our world made of bits, but at the underlying level, those bits are made of something more basic. Maybe, for example, there’s a computer in in the next universe up, that’s, instantiating those bits with some analog of voltages in their world, and that’ll be it from bit from it. And then the substrate will be the its and that well. Okay. Then we go to ask the question of the its and that well made of bits, which are made of further its, and then we’ll get it from bit from it from bit from it, and on you, and on you go. But, also, one thing is also worth saying is you don’t actually need classical bits to make this work.

Speaker:

You can make this work with, with cubits, you know, the kind of the kind of the analog of bits you find in quantum computing. And I think you can also make it work with, with Mhmm. Continuous bits. So what I sometimes call reals in the book. Actually doesn’t have to be binary physics. It could be continuous physics. The key idea is just kind of a level of information underneath everything, which could be binary information, it could be quantum information, or it could even be a kind of continuous information. It’s just I use bits because that’s by far the simplest version of this idea, but I’m not sure that binariness per se is so important.

Speaker:

But the issue you raise of is there a substrate beneath the information? That’s super important because, yeah, I think there’s 2 very different ideas here in the world of pure information. It’s a beautiful vision, but it’s yeah.

Brian Keating:

It’s not totally clear. It makes sense. That’s right. You know?

Speaker:

I don’t know what you make of it.

Brian Keating:

Like to steel man my own, arguments from time to time. So one of the things that I point because I’m, you know, more in the materialist that you do need a substrate. It’s a fundamental issue. Even the qubits are actual matter, material particles, etcetera, and those and the forces and fields that interact between them. But I also will push back on my own thinking and say, well, You know, the 1st operating system, by definition, was written without an operating system. The, you know, assembly language is written without assembly language. You know, the first, the first modern, you know, goes up, and and you do bootstrap recursively. But, you know, it’s to me, it’s it’s it’s it’s difficult to envision without some fundamental layer of a substrate, which, you know, comes from physics.

Brian Keating:

And the the issue that I think presents a serious challenge that you you do address in the book and and you Partially alluded to it now, but, is the notion of what we believe at least is noncomputable. Like so Turing’s original 19, you know, 56 or whatever paper or the 48 paper, whatever, computable it was on computable numbers. And it was on numbers, that could be programmed and actually executed by a universal machine, a generalized, you know, computing machine. And that excluded things like transcendental numbers or irrational numbers. And you just mentioned continuous real numbers, but, of course, all the numbers are you know, include transcendental numbers. And the most 2 most important numbers seem to be, you know, numbers that computers have a very difficult time with. In other words, the number 0 and the number infinity, if it’s a number. A pie and e.

Brian Keating:

Yes. No. I talk about that. But I I always say, you know, the middle 4 digits of pie are my PIN number. So don’t tell anyone because I could lose a lot in my My University of California savings account. But, but yeah. So those are yeah. So, they are irrational numbers.

Brian Keating:

We can’t we can’t or, you know, square root of 2, etcetera. There’s no program that can can calculate them or for for transcendental numbers. And so they failed that the a Turing type machine cannot produce them. But similarly, infinity cannot be really represented on a on a computer. We can we can, you know, approximate it to arbitrary precision. But, you know, if you truly do things that the human mind is totally capable of finding, you know, the, the logarithm of, of negative infinity, you know, we can we can think about those numbers, and we can use those numbers even to construct calculus. But how can a computer of any kind, you know, Capture this notion of infinity. Is that something that’s uniquely relevant to this, yeah, squishy wet supercomputer, or do you think that notion will exist Even in a simulated universe, and and therefore, the continuum is true.

Brian Keating:

In other words, there’ll be an infinite number of of bits required to represent the actual universe.

Speaker:

Yeah, well, we can maybe we can yeah. Infinity is tricky, but we can axiomatize infinity. We can kinda get our grasp. We can try to articulate our grasp of infinity via axioms. And, yeah, in traditional set theory, there is this axiom of infinity, which is a finite string of symbols that we lay out

Brian Keating:

different levels of infinity. Exactly.

Speaker:

Our understanding of infinity. Yeah. Actually, of course, what we find actually is is that these axioms for infinity actually underdetermine its, its nature. It’s, like, how many levels of infinity are there? Is the continuum hypothesis true or false? Is the one after the integers the reals? Or is there a whole bunch in between? I mean, you can add axioms to try and, to try and determine these matters, but then there’s always gonna be stuff left underdetermined for reasons in the foundations of of mathematics. So it may be that we will never get a precise grasp of infinity through a finite set of axioms. On the other hand, who says that humans have such a precise grasp of infinity anyway? Maybe we can lay out enough axioms that capture the elements of our own understanding of infinity. It won’t articulate everything, but maybe it will articulate everything in the human conception Mhmm. Of infinity and So, switching gears again.

Brian Keating:

Maybe we’ll go back to steelmanning. Now I’m gonna ask you to steelman. In part 3 of the book, the wonderful section, you, you end part 3 by saying, very carefully, And you say we can’t know that we are not in a simulation. Why did you phrase it like that? And what’s the best argument against that. In other words, against what would you say to some if what would you say on behalf of somebody who says, no. We can know that we are not in a simulation?

Speaker:

How do they know? What is the evidence? They’ll presumably try and come up with some evidence, they say, conclusive evidence that we can’t be in a simulation. The basic reason I think that’s impossible. Unimulated. It looks like any evidence could itself be simulated. So if the evidence can be simulated, then we’ll never know for sure. In principle, we can have simulations indistinguishable from unsimulated reality. So to defeat that, someone’s gonna need to come up with something. And maybe, you know, maybe, who’s to say, like, a Penrose style argument.

Speaker:

Look. Human beings can do things that no classical computer could do. I mean, I’m dubious about that, but even if it were true, I’d think, okay, let’s just move to quantum computers or quantum gravity computers and build our simulations build our simulations like that. I mean, maybe the biggest challenge is consciousness. Could consciousness be simulated? And many people say, you’re crazy if you think a simulation could have consciousness. And I haven’t thought about this a fair amount, and I don’t see any bar to, consciousness in principle being had by myself. I don’t wanna say we know we are in a simulation because I think that’s false. I don’t think I know that for sure.

Speaker:

I think there’s some probability, but we might not be in a simulation. So I wanna say but we might so the most important thesis for me is we might be. And when you when you translate, we might be into, like, epistemic logic, but not logic of knowledge. It just comes out as Right. Not k naught. You can’t know you’re not in a simulation. But in in order language Yeah. We might be in a simulation.

Speaker:

Is that any number?

Brian Keating:

So I appreciate that. It’s I think it’s always important to, to describe these things. So I want to, turn in the remaining, 15 minutes. If you can spare another 15 minutes there. Okay. Great. So I’m gonna ask you first, would you take the red pill?

Speaker:

It lets me out of the matrix. It gives me access to all of reality. I think I would totally take the red pill because it’s gonna enable me to second, I grew up in Australia, and Australia was great. But then I discovered there was this whole wide world out there, and I wanted to explore the whole wide world. If I grew up in the matrix, I think in my view is the matrix is real. It’s not like it needn’t be a dystopia, depends on how it’s run, needn’t be an illusion. If I discover that I’m in reality and out there is reality plus, if I get the opportunity to explore reality plus, then fantastic. No.

Speaker:

I’m gonna wanna be able to come back to the matrix, you know, all my friend all my family, all my friends are gonna be in the, are gonna be in the matrix. I don’t wanna lose touch of them entirely. And for me, the matrix will be part of reality, but insofar as the red pill represents knowledge, understanding, exploration.

Brian Keating:

Okay. Next, totally unbroken. From the audience. So, what do you think is the ultimate and final machines that human beings Create. This is from a man by the name or a woman by the name of high reality sensorium, which I was gonna call my 2nd child. So What’s the ultimate machine that humans Homo sapiens could create?

Speaker:

Oh, that’s easy. The ultimate machines that Homo sapiens Homo sapiens create is the first machine which is smarter than Homo sapiens. After that, we will leave the creation after that, we will leave the creation to

Brian Keating:

the machine. Question for a point next. Better at design machine enough. David Chalmers thinks the delayed choice quantum erasure experiment results support the simulation hypothesis, by observing error correction codes in process Where the prior state of quantum entangled photon has changed to match its entangled counterpart. So does this does the delayed choice quantum erasure results, which are not fully definitively support, I suppose. Do you believe that that has any bearing say on the, support of the simulation hypothesis.

Speaker:

Yeah. In general, I’m dubious. I haven’t really worked worked carefully through those, those results in general, and there are various things in physics that people have pointed to as potential supports for simulation hypothesis, whether it’s error correcting codes, possible glitches and, and approximations. Well, some people think that, you know, the collapse of the wave that the collapse of the wave function might be potential support for, for the simulation hypothesis because it shows, like, a a bit of rendering efficiency. Okay. Well, in in VR, people often say, don’t render the world until you know, for the for the observer until you need to. So some people say in quantum mechanics, we’re we’re gonna yeah. For efficiency purposes, we’ll never collapse the wave function until we need to.

Speaker:

But as far as I can tell, the world with, yeah, the world with an uncollapsed wave function is just as hard to simulate as the one with the collapsed wave function. And, yeah, world with a whole lot of error correcting codes. That’s gonna add to the overhead

Brian Keating:

stuff. I’m

Speaker:

not totally clear o

Brian Keating:

how the

Speaker:

reasoning is.

Brian Keating:

A, fellow philosopher, by the name of Bernardo Castroop or Castroop, I guess, maybe. Do you have any thoughts or feelings on his work? I’m trying to eventually get him on the show because he has the same initials as BK. So yeah. Emerge yeah. What do you think about his notion of analytic idealism?

Speaker:

Oh, BK. Specific question. This is a view with a long tradition in philosophy. Many of the ancient Indian philosophers were idealists, George Berkeley, in the, in the 17th, 18th century was a was an idealist. In the 19th century, everyone was an idealist. Hegel, Kant was the kind of idealist that got very unpopular for a long time. But lately, it’s had a bit of a comeback. And, yeah, in analytic philosophy, in the scientifically oriented philosophy, a few people are advocating the idea that underneath the world might be a level of, of mind.

Speaker:

One way of getting there actually is via the it from bit idea. Then you say, what are the bits made of? We need a substrate. Some people say, consciousness. It from bit from consciousness. At the underlying level, reality is the interplay of consciousness. There are some people the panpsychists also put forward this idea. Anyway, Bernardo, I don’t understand his view fully, but he certainly has the idea that underneath physics is a level of mind, perhaps a single cosmic mind. This corresponds to what’s sometimes called cosmo psychism.

Speaker:

It’s like the whole universe has a mind, and we’re just aspects of that mind that, hey. Take this view. Look. It’s extremely speculative, and I think it’s got many big issues that needs to address. One big question is how does our mind emerge from the cosmic mind or from the bit mind? No one’s answered that question yet. But, he I I view him as someone that’s doing really interesting some days. Speculative pet physics, and jet vehicle that we have on your show.

Brian Keating:

Asked me, is it true you told your kids That if it is still not solved in your lifetime, you are to put, quote, still hard on his tombstone. True or false?

Speaker:

I’m hoping for, I’m hoping that if not, I don’t have kids, but I’m hoping that maybe, maybe that our AI successes will one day solve the hard problem for us. It’s like, if it’s too hard for just too hot for humans. Let’s just program superintelligent AIs to create ever more intelligent superintelligent AIs. Hopefully, they’ll be better

Brian Keating:

than before. Kids video for graduate students.

Speaker:

Counting on them.

Brian Keating:

And by the way, what was Douglas Hofstadter like as a graduate advisor?

Speaker:

Oh, boy. He’s amazing. He was full of, you know, full of ideas and passions and interest and everything under the sun. We’d have a workshop 1 weekend on on humor, another one on creativity, another one on analogy, another one on sexist language, and so on. But he’s also passionate about one thing you don’t quite get from his books, in his books, he’s such an enthusiast for so many things. In the in the real world. He’s actually a disenthusiast for most things. He hates 90% of AI, 90% of philosophy, 90% of of cognitive science.

Speaker:

And that comes out also a little bit in in person, but the breadth of of his interest is amazing. I love being in his, in his AI lab as a graduate student, so many smart other graduate students around from psychology and AI and following up with a scale of a little hard

Brian Keating:

to explain. Surprise. Just quickly on the notion that because I can’t resist, like, I asked you to, you know, if you’re ACDC to play, Back in Black, I I can’t resist you asking you about Popper and and, falsification as I claim it’s sort of a physicist version of Godel’s incompleteness theorem. It’s kind of the best we have, but not quite as complete or good as as what Godel did for mathematicians. What do you make of the, of of pauperism? Is it Are we too, in inured to the, to the paparazzi as Leonard Susskind calls them?

Speaker:

I don’t know. Paparazzi kind of went out of fashion and philosophy a while ago now. Most people who think about the philosophy of science and philosophy, the dominant tradition is Bayesian. We think about this in terms of probabilities, higher probabilities, lower probabilities, prior probabilities, and their interaction with evidence. But this this, this total concentration on falsification I mean, yeah, sure. Falsification is important, but in general, updating of probabilities by evidence is the more important thing. By the way, yeah, some people worry about the simulation hypothesis, that it’s not falsifiable. Some versions of it might be falsifiable, imperfect simulation hypothesis.

Speaker:

The perfect simulation hypothesis maybe not falsifiable in principle. But that’s just to say, okay, the perfect simulation hypothesis. I’m happy to say it’s not exactly a scientific hypothesis. Still a philosophical hypothesis. Popper himself put forward many philosophical hypotheses the one in scientific hypotheses. So I think it can still be meaningful.

Brian Keating:

Come to the end when I ask my thrilling 3 existential questions about the meaning of life, your past world line, your future history, your gifts to the universe. But to watch this, you’re gonna have to subscribe to my YouTube channel. Not you, Dave. You’re gonna watch it in real time because you’re gonna participate in it. Cool. But, you have Subscribe to my mailing list, brianketing.com. And there, I update, and I provide all the links to David’s wonderful work and his, and his book, of course, that you should buy. I listened to it and read it.

Brian Keating:

I think it’s just one of the I I guess your best to date, and I I can’t wait to see how successful it becomes. So if you wanna hear Dave answer the thrilling 3 final questions. You’ll have to subscribe to the channel and to my mailing list, briankeeting.com. I’ll send you the link. So for now, signing off of this main portion of the episode of Into the Impossible with Dave Cholmond’s NYU and author of Reality Plus, a, God, philosopher philosophy’s problems and, the ultimate answer to that to the, perhaps the most important questions of the modern age. Dave, thank you so much.