Into the Impossible With Brian Keating - Part 2: John Preskill – Quantum Computing, Artificial Intelligence, and Encountering Richard Feynman (#111)

Episode Date: January 19, 2021

Learn about the exciting promise of quantum computing and how it may solve problems in fundamental physics. Join my mailing list to get slides from this conversation: briankeating.com. We went deep��discussing Artificial Intelligence, the simulation hypothesis, lessons from Richard Feynman and more! You don’t want to miss his answers to my patented Thrilling Three final questions! John Preskill is the Richard P. Feynman Professor of Theoretical Physics at the California Institute of Technology, where he is also the Director of the Institute for Quantum Information and Matter. He is one of the most prolific and influential scientists of our time. Preskill is a leading scientist in the field of quantum information science and quantum computation, and he is known for coining the term “quantum supremacy.” Preskill studied magnetic monopoles in Grand Unified Theories. This work pointed out serious flaws in the then-current cosmological models, a problem which was later addressed by Alan Guth and others by proposing the idea of cosmic inflation. He’s the Director of the Institute for Quantum Information at Caltech. He is known for coining the term “Quantum Supremacy” in a 2012 paper. Preskill has achieved some notoriety in the popular press as a party to a number of bets involving fellow theoretical physicists Stephen Hawking and Kip Thorne. Preskill was elected a member of the National Academy of Sciences in 2014. Watch my most popular videos: Jim Simons, the World’s Smartest Billionaire  Bill Perkins: DIE WITH ZERO:  Patrick Bet-David YOUR NEXT FIVE MOVES  Sheldon Glashow Sir Roger Penrose, Nobel Prize winner  Frank Wilczek Jill Tarter  Eric Weinstein Sir Roger Penrose  Juan Maldacena’s First Podcast Interview Sara Seager Venus Life Noam Chomsky Sabine Hossenfelder Sarah Scoles Stephen Wolfram ‍♂️ Find me on Twitter at https://twitter.com/DrBrianKeating Find me on Instagram at https://instagram.com/DrBrianKeating Buy my book LOSING THE NOBEL PRIZE: http://amzn.to/2sa5UpA Subscribe for more great content https://www.youtube.com/DrBrianKeating?sub_confirmation=1 ✍️Detailed Blog posts here: https://briankeating.com/blog.php Learn more about your ad choices. Visit megaphone.fm/adchoices

Hi, everybody. Welcome to this episode of the Into the Impossible podcast. I'm your fearful host, Dr. Brian Keating of the University of California, San Diego. And I am enjoying these pandemic podcasts tremendously and never more so. Then when I get to interview one of my friends, one of my heroes, one of my inspirations and mentors, such as today's podcast, you'll hear really an exclusive interview with none other than John Preskill, who is the Richard Feynman professor of physics. at Caltech. Today you're going to learn about Richard Feynman. You're going to learn how he inspired a nine-year-old John Preskill, who later took the name of the very person who inspired him, namely Richard Feynman. You're going to learn about Feynman's blunders, if there were any. You're going to learn about quantum computing, the simulation hypothesis, artificial intelligence, and even impact on things like cryptography, blockchain, etc. This is really, to my knowledge, the first podcast of this type, not purely about scientific contributions made by John and his group. John's been an inspiration to me since I met him in the year 2000 when I was up at that little

technical college up in Pasadena known as Caltech. And ever since, he's been so generous and gracious with his time and his energy. He's working on a lot of things. I want you to stay in touch with me so that you can get these resources like get notified when his book on quantum computing comes out. This is a book you will not want to miss. He's one of the founders of this field. He'll talk about how Feynman influenced him as well as answering the thrilling three questions

that we always talk about on The Into the Impossible podcast relating to his ethical will, his monolithic wisdom that he would leave on a monolith, and also his advice to his younger self. You don't want to miss it. So please subscribe to my mailing list at bryankeating.com. You'll get resources from John, from Frank Will. from Michael Saylor. We've been doing so many phenomenal interviews. But for now, sit back, enjoy.

And please, before you go, take a second to go down to the app reviewing section of, or the podcast reviewing section of this app. And please do leave a tiny constellation, asterism of stars, ranging from one to five. I hope five, but maybe one. Let me know what you think of these episodes of the Into the Impossible podcast. We're getting so much great feedback from you, my listening audience, that I just love so much. And I hope that you will do me that honor. It's really the only thing I'm asking for.

And I do read every single one of them. Here's one that just came in just today from Jason Werner. Professor Keating manages to bring an impressive mix of brilliance to bear within this podcast through vocal and bleeding edge guests from countless sectors and philosophical realms. The podcast is a must subscribe, but definitely check out the series on YouTube for, It's live and event-based programming. Cheers. Yeah, so please do that. Another review.

I can't believe this. I can't read this. A horrible podcast is on the air. He's a terrible... Barbara Keating. That's my mom. Oh, my God. How could she do it?

No, she didn't do that. But anyway, please do subscribe and leave a comment because it will really help me out. Thank you so much. Now, enjoy this podcast. Any sufficiently advanced technology is indistinguishable. from magic. And with respect, that the namesake for which your chaired professorship is named is, of course, Richard Feynman, who said the first principle is that you should not fool yourself. No one ever says the second principle, but I think you're the easiest person to fool, to which I added a third

one, John, you'll be interested to know I'm unveiling it here for the first time. The third principle is that you must never fool Richard Feynman, because that would just be mean to fool Richard. First of all, did you know him well? Did you guys overlap much at all? We overlap for five years on the Caltech faculty. I arrived in 1983 and I'm a passed away in 1988. And we did interact. We had a shared interest in quantum chromodynamics,

the theory of the strong interaction. And in particular, it's so-called non-perturbitive aspects. that is the things that we can understand, ironically enough, just using Feynman diagrams. How do we explain things like court confinement, for example? Feynman was very interested in that. So was I. We often discussed those issues. I, you know, I just, as an aside, my first encounter with Feynman was not a face-to-face encounter.

It occurred when I was nine years old, and I acquired a book which was called The World of Science. This was a big golden book about science, and there was a chapter called Theoretical Physics. If I was a fourth grader, I got this book at a book fair, and I read the whole book. It was fascinating in many ways, but the thing that resonated with me the most at the time was the chapter on theoretical physics. which discussed the discovery that parody is violated, that physics in a mirror is different than physics in real life. And that was just, I just found that totally amazing. And in this chapter, incidentally, there was also a story about a little boy who had a ball in a wagon,

and he asked his father why the ball goes to the back of the wagon when he starts pulling it, and it goes to the front of the wagon when he stops pulling it. And his father told him, well, that's called inertia, but nobody knows why. And then years later, when Feyman did the BBC interview with Christopher Sykes, he told that story. And I thought, what's going on here? Feynman stole that story from that little golden book, well, wasn't a big golden book, that I read when I was nine years old. But I still have the book, so I looked back and I saw that, in fact, all the chapters, the author's book was named Jane Warner Watson, and she had gotten every chapter from interviews with Caltech faculty.

You wouldn't have known this unless you looked at the very fine print in the notes. So, of course, she had based that chapter on conversations with Feynman and Gelman, who just, the book was just really rather amazing. The book was published in 1958. Parity violation had just been discovered two years earlier. That was the year that Feynman and Galman collaborated on a famous paper about the theory of the weak interaction that accounted for parity violation. And that got into this golden book about science. And it actually was described very cogently what the experimental evidence was for the violation of parity. And so that really did have an influence on me, I think, that I encountered that book at that age.

But anyway, Feynman, at the time that I was at Caltech, he was getting very interested in quantum computing, and I can tell you why. It was because of our shared interest in quantum chromodynamics, and his recognition that with the methods that were then just starting out for studying QCD using classical computers, which are what we call Monte Carlo methods, that they had limitations. And there were some problems you just wouldn't be able to solve. Using that type of technology, that type of algorithm, he also thought it was going to be a long time before we'd have accurate data from those simulations. He was right about that too.

But this was part of what stimulated him to think about the idea of a quantum computer because he appreciated that it would be too hard to simulate something like a collision between two protons at very high energy, to understand from first principles in QCD, for which we know the right equations, but they're just too hard to solve, what comes out when you bang two protons together. And that, I think, was a key feature in guiding him towards proposing the idea of a quantum computer to solve problems that would be too hard to solve otherwise.

When I think about that, his prescience in all things, and gravity and nanotechnology, is famous, plenty of room at the bottom lecture, but also that, you know, kind of principle against confirmation bias and the notion of, you know, you're the easiest person to fool, and that scientists often give off this aura of invincibility, which I think, you know, I talked at this conversation with Caltech postdoc alum, Jim Gates, who I know you know very well, He's a good friend of mine and a mentor to me and millions of other people. And Jim was saying, look, there's this notion that Einstein is some, you know, unapproachable genius. And he's like Einstein wasn't always Einstein.

And, you know, but I feel like Feynman might have always been Feynman. He had this kind of, you know, otherworldly, almost magical ability to both communicate science, but also to develop and innovate in science in a very artistic showman-like way. And the only reason I bring up that famous quote against confirmation biases, because you said, you know, I hope that you'll be successful in discovering it. Lately, I've been thinking a lot about that and how it, of course, led to the famous episode in my book, behind me losing the Nobel Prize, which you can get. Wherever books are sold, I'm waiting for John's book to come out so I can also hawk his book

when that does appear in quantum computing. But the point being that, you know, oftentimes you see what you want to see. And as Feynman was saying, that scientists have this extra special duty because the layperson sees us as these very special people doing very special things with very special equipment and that maybe they don't have access to it, but they're certainly interested in it. But, you know, I'm not sure I could ask somebody like Richard Feynman in this question, but it's just amazing to hear the story of you as a nine-year-old, this through line carrying through to the little boy becoming the Feynman professor at Caltech. It's just astounding to me. The serendipity of it all. And I think that is kind of a basis for a lot of good science, is that you see where your curiosity takes you.

But getting back to this notion of quantum matter and quark matter, et cetera. So I asked this of Frank Wilczak earlier this week. I would like to get your impression. I said to me, one of the most beautiful experiments ever done is the Aharonov-Bome effect. Because it really does this magical kind of connection. between the classical world and the quantum world, and it also connects things that we thought had no physical import, namely the vector potential, and it makes it manifest in an actual classical physical experiment, which again can be manifest in quantum scales, too. That to me is one of the most beautiful experiments, the CS Wu, Madame Wu experiment that revealed parity violation that you just talked about as a young child that you read about. What to you, I'll tell you what Frank said, but I want to know, what, what, what, John, is your most beautiful experiment coming from the perspective of a renowned theorist? What makes an experiment beautiful and what experiments do you particularly find important and beautiful?

Well, just to follow up on the Aharnah foam example, which is, of course, a wonderful example. One of the things that I think is really cool about that is that you can observe the Aharnah foam effect in a solid state device in which, an electron follows one of two paths, even though it's kind of dirty. And the electron gets scattered in the device because of the dirt. But because it gets scattered elastically, because by being scattered, it doesn't leave any footprints in the material, there's no record of which way it went. And so you have to consider the quantum mechanical superposition of two paths, even though that electron was not perfectly isolated from other stuff,

it was getting bumped around, but in getting bumped around, it didn't leave any record, and therefore that quantum mechanical interference was possible. I'm not sure what I think is the most beautiful experiment, but, well, I already made reference to the fact, which, you know, I think is quite amazing. that we can manipulate single atoms now with extraordinary precision thanks to laser technology. Yeah.

So, you know, it's often the case that in order to make scientific progress, we need new ideas, but we also need new technology. And in order to do the things that people do nowadays, manipulating single atoms or interactions between pairs of atoms with laser light, for example, it requires, you know, very sophisticated laser technology. You need very quiet, stable lasers to do that. And, you know, it's just a single atom, for Christ's sake. And yet, you can make it very, you know, very palpable.

You can make it do what you wanted to do, because we have the technology for that. I think that if you step back and think about it, it is pretty amazing. Yeah, it certainly is. I want to segue into something related to what Frank answered, which was the not physically beautiful necessarily, but the fact that QCD can be revealed, or asymptotic freedom, et cetera,

can be revealed by these quark jets that come out that reveal the internal composition of the structural, of the nucleon, which I think is, which is quite amazing. I want to take a break and then I'm going to come right back to that. I don't know, how much more time do you have today, John? Well, I'm still having fun. Yeah, me too. I want to keep going if we can.

So the question that I have, well, first let me just take a break. Please like and subscribe and comment, et cetera, on this video, on this podcast, on iTunes. It really helps us in our mission to connect the multiverse of minds around these very high-level, deep conversations that hopefully are accessible. to people too. So exercise your finger regularly, push the like, push to subscribe, give a rating, etc. Also, please note, I am taking all your donations. My friend in moderator, Jacob Cune, who's just hilarious and helpful Sprite, who's doing such a good job. He's keeping track of every donation. I am going to double it. It's going to the foothill center in Pasadena, which is a cause near and dear to my heart and to Johns as well. So please keep the superchats coming. I'll try to get

as many of them as I can. And, you know, and we'll hopefully raise a lot of great resources for this wonderful charity. So, and that can be held. Can I follow up on what you were saying about Jets and QCT? Because, I mean, there's a Feynman story here, too, right? Which goes back to about 1968 when there were these miscellaneous. mysterious scaling results seen in the slack electro-production experiments. And in trying to figure out what was going on,

Feynman developed what he called the Parton model. It infuriated Murray Gelman, by the way, that he called them. Partons, yes. But at any rate, he anticipated that in a high-energy collision of protons, if you hit a quark, he called it a part-ton, if you hit it really hard, you could produce a pair of leading quarks going in opposite directions, which, although you wouldn't be able to detect the single quark, would produce a spray of strongly interacting particles, which could be detected. Now, this was actually an absurd idea because there are very strong interactions inside the proton and the quark. can't get out and he was pretending they were just like free particles. And there were some people who ridiculed the idea for that example.

I might as well name names. Marie Gallagher. I thought it was, you know, amazingly unsophisticated to treat those quarks as though they were free particles, whereas obviously they couldn't be because they were trapped inside the proton. And yet, as experiments validated, validated, the picture is pretty accurate. Now, of course, the reason the picture makes sense is because of asymptotic freedom. In 1968 or nine, Feynman didn't know that, but nevertheless, he had the boldness and intuition to propose that for some purposes, the things rattling around inside a proton would behave like they were nearly free.

And of course, later on, we understood the theoretical foundation of that picture. That's right. I'm getting a quote from one of my good friends and very devoted followers, Brett Harris, who makes a joke that those were, of course, fine men being the womanizer, he was, named those after Dolly Parton. So the next comment I want to make about relevant to Jets and Frank Wilchek's statement that that's the most beautiful experiment to him, of course, you know, he had to also associate it with his gilden medallion that he achieved as well.

But to me, I want to connect it to something which is tangentially perhaps related to quantum computing. And I know you're going to get mad at me, but I have to say it, the simulation hypothesis. So there is this notion that quantum computing will become so powerful. It will be way beyond supremacy, and it will be something that we can hardly envision today just as, you know, Einstein could not have envisioned an iPhone, us having this conversation essentially at the speed of light, taking questions from Pakistan and Uganda at the same time as in La Jollaia and Pasadena. But the concept of the simulation hypothesis is, as Nick Ballstrom and others have popularized it, that eventually will reach this incredible power of AI.

And so it might even have occurred already in that you and I, as you said before, We might be inside a black hole's event horizon now plummeting furiously towards the singularity, but in the notion that we would be unaware of it. And so in that same sense, as Descartes would say, you know, we could be brains in jars. We could be brains in a computer and a quantum computer. So first, I want to ask you, what do you think about this simulation hypothesis? Do you put any stock in it? And then if you're willing to, I'd love to talk about some of the implications, the moral and ethical implications,

of artificial intelligence, if such a scenario is at all plausible in John Preskill's mind? Well, I have limited interest in it unless we can somehow validate it. You know, if we had a way of doing an experiment, which would yield a result that would say, aha, we are in a simulation or we are not, that would certainly be interesting. and there have been some suggestions along those lines, although rather crude ones, when we try to simulate an imaginary world on our computers, we can't do it perfectly. So, for example, if I wanted to do it, if you wanted to simulate quantum chromodynamics, it's a quantum field theory, and that means you have an infinite number of degrees of freedom for unit volume,

and you've never put that on a computer. So you approximate it. And you approximated by just introducing some lattice in space or doing some other, what we call regularization, some truncation of the problem. And that means that the results don't exactly agree with the target that we're trying to simulate.

So if our hypothetical higher beings who might be simulating our world have similar limitations, if we could somehow find evidence for the imperfections in their simulations, I'm not sure how, but that would be interesting. So, in fact, you can, what people have, tried to get limits on the possibility that space isn't a continuum, but is really an approximation, some kind of lattice structure, how can we probe that in an experiment? Well, that's somewhat interesting to think about.

Yeah, I'm showing. But if it's purely hypothetical and then we don't have a way of testing it, then I just can't get that interesting. Yeah, I'm showing on the screen now a paper by Silas Bean, Zorae Davudi, and Martin Savage called Constraints on the Universe as a numerical simulation, and they're examining these consequences of a cubic space-time lattice or grid being explored in the QCD lattice simulations. So using historical development of lattice gauge theory technology as a guide,

we assume our universe is an early numerical simulation with unimproved Wilson-Fermion discretization. I don't know if that means, but we investigate potentially observable consequences. Among the observables that are considered is G-minus 2 and the spectrum of cosmic rays and so forth. So there are forays into it. I wonder always how fruitful this will be, but eventually I think this can be in our manifestation. of perhaps deeper questions, maybe that go outside of science, even into perhaps religion, because if you think about the universe as a simulation, maybe there are simulators,

maybe there's artificial life out there, as Max Tegmark calls it, as Life 3.0. And then my question is, what obligation do we humans have to these artificial intelligence? Can we turn them off? Can we blow up one of their capacitors? So I want to turn to artificial intelligence for a little bit. and ask about the prospects for improvements in AI. And also, you've talked about this before. I always say it's not surprising, so surprising to me that computers can beat humans at chess.

Even the alpha zero results where it basically learns the rules of chess from millions and trillions of games watched played by humans and then playing itself and even learn the pieces and how they move and that a knight moves a different way than a bishop. But what would really surprise me and convince me that computers have artificial wisdom is if they could create the game of chess itself. Or, you know, if there's a lot of art now that I'm told exist on the blockchain. There's actually blockchain art that exists, that you can buy it and it exists and you get it on a USB key if you want it, 50 megabytes worth of beautiful hand-creator computer-created art. I want to ask you these notions of artificial intelligence.

Do you think a computer can ever create a game like chess or even chess itself? And then I want to ask you a follow-up about the laws of physics. Can a computer, can an artificial intelligence eventually, just given the laws of Newton, derive the laws of Einstein? But first, tell me, what are your thoughts about artificial intelligence and its future and the limitations possibly thereof? Well, I don't see any reason why not, in answer to your question, Can artificial intelligence be creative?

Can it discover things that have escaped the astute humans? That seems likely to me as artificial intelligence continues to advance. And part of the reason I say that is I think you and I are ourselves, just sophisticated machines. I don't believe that there is magic in human cognition. I think it's a kind of emergent phenomenon that occurs in a sufficiently complicated network of neurons. And if it can happen in our brains, I don't see why it can't happen in devices that engineers fill. Sorry, what was that rest of the question?

Well, can a computer, yeah, create the game of chess? or a game. You know, what I'd like to see them do is, it's, uh, be funny.

You know, why can't they create a great sitcom? That's art for, uh, that we all would need right now. I think, you know, as much of a joke as I am,

but still would be great to have to, you know, people have, have fooled around, uh, getting, um, AI systems to,

uh, to create, uh, visual art and to write poetry. And, uh, you know, so far,

I'm not really impressed, but that'll get better and better. So again, we're talking to John Preskill, Feynman, Professor of Physics, California Institute of Technology, Caltech Go Beavers, spent many wonderful lectures listening to John, both up at Caltech and here at UC San Diego, where he's given some of our prize lectures. Speaking on the theme of artificial intelligence, as you know, my friend Max Tagmark has done a lot of work, in this. He's a guest on the show, frequent guest on the show, and that reminds me to ask you all out there to please

subscribe, because Max is coming back again on the end of the Impossible podcast. But he talks about creating artificial physicists. And my question to you is, let's say now I've got my voodoo doll out, this is Galileo. So, you know, Galileo did something, and

then Newton came along and did something even better. But there's something different in my mind between what Newton did to Galileo, and his laws of motion and what Einstein did. It's a fundamentally different characteristic class. So I can almost imagine a computer program with the laws of Newtonian physics,

or the laws of Galilean relativity, coming up with Newtonian mechanics. But it's harder for me to think about a computer coming up just with the lacuna in the data that general relativity patched up, the perihelian anomaly of mercury, et cetera, that a computer could come up with GR as an AR artificial physicist. What do you think about this? Because I have some desires in pedagogy that I want to talk to you about right after this. But tell me, what are your thoughts about the nature of physics?

Is it like coming up with good stand-up comedy? Or is it something that computers couldn't do? Where do you get those Einstein and get a layer to us? Don't worry. Yes. I have a team of little servants at home. No, no. I buy them from a place called the Unemployed Philosopher's Guild. They're called Magnetic Person. I've got one of everyone. I've got Carl Sagan here. I've got Noam Chomsky, who's also been a guest on the show.

I've got Kurt Gordel, who has not been a guest on the show. That would be quite a get. I will send you some, John. I'll send you an Einstein, and we've got to get one of Feynman and one of you. Those really come in handy, don't they? Good pun. Good pun, John. Come in handy.

I like it. Yeah, exactly. You know, it's interesting. Goodell, is sort of relevant to your question, perhaps. You know, the notion that there's a distinction to be made between things that we can easily verify through thought or computation and the things that we can discover what the computer scientists call the conjecture that p is not equal to n p. Goetal thought about this quite some time ago, like in the 1950s.

And he was very curious about what it would mean if p is equal to np. That would mean that anything that, you know, you could buy some feasible computation check would be something that you could discover. and he found this idea rather distressing because it indicated to him that there was no role for the creativity of the mathematician who somehow, by some mysterious process, was able to discover a theorem for which a proof could be given and it was possible for any diligent party to check that the proof was correct, but to come up with the theorem in the first place required a leap of creativity. And so, you know, some might believe, maybe, did you discuss this with Roger? Because he has interesting views on this kind of thing. Roger Fulner. Yeah, we certainly did. And I talked about it with Namchomsky as well, this notion of, you know, kind of incompleteness. And I feel, you know, the, you know,

There's an old joke that most sciences have physics envy. But I actually think physicists have mathematician envy in a sense that we don't have a law that tells us whether or not something is physics. I mean, most of us use popper. I think I have a popper doll somewhere. But your friend Lenny Susskin said, don't be overwhelmed by the paparazzi. You know, basically these unfalsifiable kind of cudgels that physicists get hit with are not as useful as girdles. incompleteness theorem is to mathematics. So I joke that, yeah, we have mathematician envy in the sense. And I think Roger, to some extent, agrees.

Sorry to interrupt you during your enjoyment of the Into the Impossible podcast with my friend, my hero, my mentor, John Preskill in his first interview of its kind. I hope you're enjoying this unique opportunity to learn from a great physics titan, one who's deeply connected to physics past and its future. Richard Feynman, up to Murray Gelman, up to Murray, to Lenny Suskind, Sabina Hasenfelds, and beyond. So please do me a tiny favor. Please like this or subscribe to the podcast first and foremost. If you're listening to this, and if you're on iTunes, please leave a review.

Please leave a quick rating, which could be take you one second to leave a one star to five star review. You'll hear reviews that I will then read to you like this one by Benderbilt. Dr. Keating is a fantastic interviewer. and he interviews many fascinating guests. You do not hear from elsewhere. 11 out of 10. Wow, 11 out of 10. That really makes up for my mother, giving it the 0 out of 10.

Just kidding, Mom. Anyway, please do subscribe and leave a short, quick review. I read everyone. I'll read yours on the air next time on the Into the Impossible podcast. Thank you. Now, back to our regularly scheduled programming with Professor John Preskill. Well, anyway, to come back to your question, it's my belief that the leap that, say, an Einstein made by discovering a general relativity on the basis of rather paltry experimental evidence at the time is something that an artificial intelligence system should eventually be able to do, because I don't think. Einstein or other human physicists and mathematicians are superhuman, I think they are machines too.

So I think they're just very sophisticated and effective machines. Now, incidentally, the discovery of general relativity was not something that sprung from Einstein's mind in its full glory instantaneously. It was the result of a struggle that went on for years. and in which there were many wrong turns. Yeah. But, you know, he was able just on theoretical grounds to find the way because various things that he tried seemed not to work. And so, you know, the circumstances were such that it was possible to find one's way

to that discovery through, of course, an enormous... a creative genius, but also a kind of process of trial and error until he hit on the right thing. Yeah, it is, Quint kind of, and it wasn't ever, it took, you know, five years to come up with, to come up with the final formulation. And then even in its final formulation, he had the cosmological term, which he, you know, apocryphally called a blunder, but he really didn't. But still, it was a blunder to even think it was a blunder because, of course, in 97, 98, We realized we needed dark energy or some cosmological like acceleration to explain the anomalous acceleration of expansion of the universe that former guest Adam Reese talked about on the show earlier this summer. It's funny because I get a lot of emails.

I'm sure you do too. I'm actually getting some right now that say, you know, Professor Keating, Einstein was wrong. You know, I can prove it. I'm not so good at math. But if you help me, I will share the Nobel Prize with you, at least a third of the Nobel Prize. I'll share that with you, but you've got to help me do it. But he was wrong. And I told that to Adam Reese, and he said, yeah, how do you think I won my Nobel Prize?

Yeah. Well, you know, Einstein did make blunders. And in the case of the cosmological constant, I mean, I've always felt that the blunder was not that he proposed it, which was a perfectly reasonable thing to do. it's a perfectly sensible thing to add to the equations. In fact, from our modern point of view, it's very hard to understand why it wouldn't be there, or even why it would be as small as it's observed to be.

The blunder was that his motivation for doing so was to make the universe static, and it's unstable, and he never bothered to check. His family family has not mentioned in his paper that he was balancing the universe like a pencil on its point and it wouldn't you know you give it a little nudge and it would not stay so uh mario you may know has written uh many many books uh the golden ratio is got a mathematician i think or maybe someone else wrote that but he wrote a book recently brilliant blunders and also a book about creativity

uh we talk about you know even darwin had blunders galileo certainly had some huge whoppers you know He missed the discovery of the planet Neptune. He thought the Earth's tides. I don't know if you've ever seen this book or read this book, John. I had not read it until very recently. This is a book that is called The Dialogue on the Two Chief World Systems. And there's a forward by Stephen Jay Gould and so forth. There's a forward by Albert Einstein who calls it one of the greatest books in science history,

much better than even Newton's Principia, which is almost unreadable, even for a lay person, but certainly, even for a physicist, certainly for many lay people. But in that book, the original title for the book called The Dialogue was, I don't know if you, do you know what the original title that Galileo wanted for this book? I do not. It was on the flux and reflux of tides in oceans, rivers, and ferns. I don't know what a fern is. Maybe you do, but, but.

That was really burying the league, wasn't it? But actually, that was what he thought was the most pronounced evidence for the Copernican theory. And of course, it's totally wrong. The tides are caused by the Earth's moon, not the Earth's motion. And so the Catholic Church did him a favor. They prohibit him to use that title. Maybe they thought the evidence was overwhelming. But it really goes to show great men and great women are capable of making great mistakes.

I wonder we have this image of Richard Feynman as ineffable, as unfailing, as prescient beyond human, mortal comprehension. Is there a blunder that he made? I have eight different blunders that Einstein made, ranging from, you know, spooky action at a distance to the cosmological constant. Even the, his original paper on relativity contained a misassociation of energy and mass. I mean, he went on to have an okay career, okay? I'm not really going to assail him too much. But did Feynman have any blunders? I'm not, I'm not particularly aware. He didn't, he didn't, you know, get credit for things like quarks, but that was not a blunder per se. Do you know of any, like, mistakes or whoppers that he might have made? Not in his publications that come to mind. He was fallible, and I think he was

certainly capable of being wrong in physics discussions that I recall. Now, I should add the qualifier that I started to have scientific discussions with Feynman when he was, in the 60s, and the fine men of earlier decades might have given a different impression. But he would sometimes surprise me because he had some ideas about renormalization, for example, that I thought were a little behind the times and unsophisticated.

you know, Feynman often said, it would give the advice that, you know, don't pay attention to what other people say, you know, put their papers away and work it out for yourself. And there's something to be said for that, of course, you know, when you really work it out, you own it. But it's not very good advice. It's bad advice. It wouldn't be very good advice for me. And it's not very good advice for most students. You know, the people who worked on problems ahead of you are not all idiots, and you can learn a lot by studying their work. Of course, you want to be able to internalize it to the extent that you can reproduce it.

And I think Feynman, in the years that I knew him, suffered a bit from his attitude that, you know, he wasn't so interested in what others working on similar problems had to say. As I mentioned earlier, we worked, well, we discussed, we never wrote a paper or anything, but we used to discuss court confinement and how to think about it. And there were very insightful papers on the topic by, for example, Polyakov and Doof, two of my physics heroes. and which, you know, Feynman, well, I, in discussions, he thought I was brilliant because I was able to share the insights I had learned by reading those papers. But, you know, he would have benefited if he had been more open to following the literature at that stage. Yeah, and he could have had a good career. I want to take a couple of questions from the audience. If you'll indulge me on this, this is a very technical.

question. Again, I have a brilliant audience of fellow geeks, nerds, and dweeps all around the world. And this one is going to come from another one from Brett Harris. This is an Aussie dollars, which I think are miniature dollars, I'm not sure. But Brett asks, loop quantum gravity implies the horizon of a black hole contains the information in area eigenstates. Could there be literally nothing inside the event horizon? including the absence of space-time itself. It's a very interesting question, and it has been a topic of some controversy

in recent years. I think, well, you asked about the singularity earlier, and it's true we don't have anything close to a satisfying theoretical understanding of what happens at singularity. that singularity inside a black hole, the horizon itself is also very interesting from the point of view of quantum gravity. And in fact, you mentioned the bet earlier that I had with Stephen about what happens to information that falls into a black hole. And his intuition that a black hole would destroy information.

was not, well, in the singularity had something to do with it, but one could understand where he was coming from, just thinking about the event horizon, that stuff would fall into a black hole, and it didn't have any way of getting out. And he had to, now that wouldn't itself necessarily mean that information gets destroyed, were it not for the fact of hawking radiation,

which he discovered, which means that a black hole, radiates away its mass and eventually could disappear entirely. So if you throw some precious information encoded in your diary or something like that into a black hole, then if that black hole evaporates and disappears, it seems that that information is from then on permanently concealed from any possible observer. and it was that kind of picture that led to him to argue that information is lost. Our current understanding, and I would not claim that we have at all a complete understanding of how it works,

is that the information encoded in that diary does get revealed by the Hawking radiation itself, but in a very, very highly scrambled form, which is hard to read. and in order to understand how that works, we don't necessarily have to contemplate what happens at the singularity. And in fact, that's part of the reason that addressing the question of information lost by black holes hasn't taught us much about the singularity. I think we have gotten a lot of insight into how information can leak out of a black hole by understanding more deeply what's happening in the vicinity of the event horizon. So just to, so I've taken on a new. a new component of the Into the Impossible podcast. Again, everybody, stretch your fingers.

It's been a nice long 94 minutes so far. We're going to keep going for a few more minutes until I get overwhelmed with hunger and start to eat one of these finger puppets on my desk. But please do subscribe, like, and leave a comment what you're learning from this episode. And hopefully we can get John back for a part two someday. But one of my components of the Into the Impossible podcast, I ask authors, if they're willing to do the following, to read the highest and lowest reviews

that they've gotten on their book or project on Amazon. A lot of people like to do that. Some people are scared to do that. They don't want to hear the one-star reviews. And so, yeah, I sometimes will not press the issue. Since your book is not out yet, when is your book on quantum computing coming out, John? I don't know.

I have infinitely patient editors. Cambridge University, correct. Well, whenever it comes out, I'm sorry for delaying it for almost two hours now, but we'll continue. But anyway, getting to this, you know, Erdos apparently said he was incredibly productive, but once his students got very concerned because he was basically doing amphetamines. Every day he would take some form of caffeine and amphetamines, and they implored him. They said, you have to stop. You're addicted.

He said, I'm not addicted. I can stop any time. He stopped, and they said, stop for a month. So he stopped for a month. At the end of the month, he came back, and he said, you have congratulations. I've done it, but you have set mathematics back exactly one month. So this conversation is setting back quantum computing textbooks exactly two hours, hopefully. But I want to push back from a colleague by the name of Sabine Hassenfelder. I don't know if you know Sabina, but she claims the black hole information loss paradox is one of the biggest hyped problems and a waste of time in all of physics. It's been solved multiple times. It's not been solved. It can't be solved because existing technology, she says, I'm reading from some of her tweets, because the hawking temperature of the known black holes is too low to see them evaporating. And even if we did see them evaporating, it wouldn't tell us anything about information laws. So how do you respond to that, given that, you know, a lot of this kind of notoriety, at least that Hawking got was based on, you know, in part this bet that the two of you wagered together. Well, I think Sabina was too pessimistic. I mean, I understand where she's coming from, I think. Physics advances by the interplay of theory and experiment,

and she's expressing the concern that we're speculating about phenomena that we don't have a means of exploring experimentally. And so we're limited, we're constrained to try to the problem just by pure thought, and she just doesn't believe we can make progress that way. Yeah. I think we actually have made a lot of progress, and in fact, I'm hopeful that we can accelerate that progress eventually, coming back to the topic at the beginning of this discussion, by simulating phenomena like the formation and evaporation of the black hole

using quantum computers. And we understand, I think, and this is one of the signals of progress in recent years, what that would mean, how we would do it. And what has been the foundation of much of our progress on understanding quantum gravity for over 20 years is what we call holographic duality. One of your earlier guests

actually, did you have Juan Maldesano on your case? Yes, I did, and Lenny Susskin, which I'll get to understand. So you had Lenny and Juan and Leone and a foote really conceived the holographic principle, and Juan discovered in 1997

a manifestation of it, which we continued to pursue and think about and I think it's led to quite remarkable insights, and it concerns the importance of quantum entanglement. In fact, what this holographic duality is about in the form that Maldesana formulated is that we can, in a particular type of space time,

which unfortunately isn't the one we live in, so it's kind of a model, anti-de-sitter space, but we can explore gravitational phenomena in which quantum effects are important by using ordinary quantum mechanics describing behavior at the boundary of that space time, in fact a space of one lower dimension. And so somehow this bulk evolution of geometry

is encoded in that boundary. And how is it encoded? It's encoded in the structure of the quantum entanglement. in that boundary description. So we have these two different ways of describing the same physical phenomena. They look very different, but there's a dictionary that relates the description in one formulation with the description on the other, and that's very empowering, because you can make use of that dictionary to get insights, which would otherwise be very elusive.

And what we are learning from that is that we should think of the geometry of the geometry of space itself in the context of quantum gravity is a kind of emergent phenomenon. It's really a manifestation of quantum entanglement in a sense, which we partially understand. And what we haven't understood very well so far is how to think about what happens to Brian Keating when he daringly enters a black hole and crosses the event horizon and what he experiences in the black hole. interior. We still have a limited understanding of that, and in particular of what happens at the singularity, as we discussed earlier. But I think really amazing insights are occurring. And when it comes to experiment, since we now understand that in a way this quantum gravity can be described

by ordinary quantum mechanics, that's something we can simulate with quantum computers. And I'm hopeful, although it's not going to happen in the next 10 years, in a few days. In a few decades, I'm hopeful that we'll get real insights into quantum gravity by doing such experiments. And we wouldn't have thought of doing those experiments if we had followed Sabina's instructions to not bother to think about it because we'll never figure it out. Yeah, I had that discussion with Lenny exactly about this very topic. And it surprised me. I asked him, what is the most quantum aspect of a black hole in totality?

Is it the singularity? And he said, no, it's this stretched horizon that he sort of, I believe, coined the term about and that how much we're learning about quantum gravity and the potential for quantum gravity from it. Of course, yeah, that dovetailed in nicely with the conversation with Kammer and Bafa as well, that essentially that we're learning more and more about concepts like quantum gravity like even string theory, potentially from observations of black holes, even with your colleagues at Caltech and LIGO instrumentation.

I've had Ray Weiss on and Barry Barish, and they think there might be clues that we could get to the nature, quantum nature of black holes, even from instruments, maybe successors to LIGO, if not LIGO itself. So I think, and there are people working on current generation gravitational wave instrumentation to detect quantum properties of black holes. So let me put in a word for my friend, Kip Thorne. Have you tried to have Kip on your show? Yes, Kip is amazing.

He's blown me off three times, but always as a gentleman, and he has a great reason for it, which I'll summarize in and by just saying he's never been so productive, he claims, as during COVID and that the COVID emergency, which is tragic and awful, has afforded him the opportunity to say no to, you know, Schmendricks like me. So he's declining everything. I guess he and Ray and Barry are working on a book about LIGO. So he's occupied by that. I was just going to say the notion of a stretched horizon is sort of a living, breathing thing. This was Kipp's idea. Oh, wow. That he developed with his students, I guess in the 1980s. They wrote a book about it, in fact. But they were thinking about black holes as classical objects for the most part of

they had some ideas about their quantum behavior as well, and pointed out, you know, you can think of the horizon as having physical properties like viscosity and electrical conductivity. And I think that helped to inspire Lenny's quantum version of the stretched horizon. And incidentally, you know, since you mentioned LIGO, and I'm from Caltech, of course, maybe that should have been my answer to the most beautiful experiment. Golly, just think about it, you know. a couple of black holes merge billions and billions of years ago. And today, a wave washes over the earth that stretches and contracts the earth by about the size of an atomic nucleus.

And an instrument can detect that. I mean, that's just such a wonderful story. Oh, yes, it is quite phenomenal. And especially the technological challenges and the story behind it, almost getting canceled many times and kind of emerging from an unlikely team of rival. between rival beavers, as we described earlier. So I have a quick question for you from Ernesto Eduardo de Barginez again. Thank you so much, Ernesto. He's asking a very simple question.

What happens to a Lagrange point, such as L1, when two black holes merge? Nice. So I guess it's a question about the orbits around the black holes. I don't think it's really a general relativity question. It's a question about, you know, orbital mechanics. Well, okay, maybe it's a question about general relativity because you can't ignore curvature for the orbits he's talking about. Well, it's already complicated when you have two black holes, right?

Well, I guess I should confess I don't really know exactly. Yeah, I assume your colleague, Sterl, Finney could present some approach. I'll try to get Sterl on to answer that question, Ernesto. Thank you. A question as we kind of wrap up that I've always wanted to ask you. I've asked this of Sean Carroll, who's your Caltech colleague. He's been on the show multiple times. And that is whether or not these mathematical objects are real in the sense that we talk about reality, materialism, et cetera.

You know, Sean's given many talks about concepts like God, religion, et cetera, that they are less likely to be true because there are simpler entities and universes that could be imagined and are not instantiated, such as a Hilbert space with no objects within it. Before we get to like, you know, maybe the politics and God, a section of this podcast, I want to ask you, is, is Hilbert space real? Does it exist? Does it predate the universe? What's your notion of the reality? Which came first? The Hilbert space or the egg universe? Well, I guess that's a pretty deep question. I should say when it comes to mathematics,

my view is that maybe this is a little bit iconiclasic, I'm not sure, is that what's true and false in mathematics is in a sense a question about physics? What do I mean by that? I mean mathematicians are interested in what they can prove, and a proof is something that you can verify, and the verification is some kind of physical process. So you can always formulate it in the form of some experiment that you do by manipulating objects,

it's running a computer program, and you can check all the steps and see if they follow within the logical system that you formulate. Now, you know, the set theorists have these wild imaginative, nations and invent incredible trans finite worlds that seem far beyond the world we can ever experience. But nevertheless, they make statements about those which are logically verifiable.

And that verification is something I would think of as in the domain of physics, because it's some machine or something. the checks that the steps are really consistent with the rules. As for, does Gilbert space really exist? Well, yeah, that's a good question. We have a growing prejudice, which I sort of referred to, among those who study quantum gravity, that space is an effective concept,

not, it's emergent. It's not, you know, really at the, at the bottom of things, that under the right conditions, something that we can describe as space as we study it in ordinary particle physics, in particular with a finite speed of light, you know, that that emerges as an approximation from some more fundamental description. And I mentioned the idea of holographic duality. That's sort of a manifestation of that in a certain setting, that there really are things. things that happen there, which are non-local, which you might think of as, you know, information traveling faster than light, but it's still a very, very good approximation under

the right conditions to use our usual rules of Einstein's space time. I don't, I'm not aware of a similar, deeper description in which Hilbert space is emergent that I have found leads to useful insights. So I certainly can't rule it out. But as of now, I'm not aware of a good incentive to think of Hilbert space as emerging.

Maybe Sean would disagree with it. Yes, he does put a lot of stock in Hilbert space as I've come to realize over time. So we are going to wrap up soon. I want to make one last plea to please be generous with your donations to the Foothill Community Center. I'll put this back up on the screen so that you may gaze upon this wonderful organization that John and I are raising funds for. We've had almost $100 that will be donated so far. I'd love to even up that, maybe even double it.

Thank you so much for your generosity to just my cherished audience. I love you guys. And stay tuned for many more wonderful interviews with intellects. We didn't get to any of the quantum computing fundamental physics links, John. I hope we'll be able to do a part two at some point. Maybe with Gerard or maybe we'll do it with Lenny. We'll get a live stream cage match between friends. Maybe Sabina.

I'll get Sabina in here. That'll be fun. I know my audience would like to see that. She doesn't like to debate anymore. We did do a debate this summer. about theories of everything with Max Tagmark, Lee Smolin, Stefan Alexander, Lisa Randall, Sabina, Eric Weinstein, and I believe I didn't miss anybody out.

And that was really fun, but she said that's basically the last time she's going to do a live chat like that, not because she had a bad time, but just she feels her energy is best used elsewhere. But anyway, I'd love to get you back to actually talk about the fundamental physics implications and opportunities that quantum computing could provide. So maybe on the, you know, before your book comes out,

I'll use it as a marketing tool to get more attention to your book, which I can't wait to get my hands on, get a signed copy, like I gave you a signed copy of losing the Nobel Prize not too long ago. All right, so John, the last three questions I ask my cherished guests involve basically Arthur C. Clark in one form or another. and that is really thinking about the future and thinking about the past, advice to your former self. But I'll ask you the first one, which actually comes from my religion of Judaism, which is known originally as an ethical will or a Zava-a.

And it's not too dissimilar from what good old Alfred Nobel did when he endowed this golden medallion that Frank Wilczek left on my couch earlier this week. And that was that the Nobel Prize had to be given to those who had these gold. great inventions or discoveries in physics, that caused the greatest benefit to humanity. In other words, the will was not just about money and giving away attention. It was to advocate for the improvement of the human condition. So it was an ethical will in addition to being a material will. And it kind of encapsulated his wisdom and his hopes for the future. He had no children. He was not married, so this is really his ideological air. I want to ask you, John, for both your biological

progeny and your ideological progeny, which I count myself as one influenced by you, what ethical or piece of wisdom do you want to leave for the future so that people can benefit perhaps in the way they live their life, maybe not related to physics at all, but in terms of the wisdom that you've developed during your time on this spinning blue marble that we call home. Well, that's a big question. I guess it would just be keep a sense of humor. Don't take yourself too seriously. It's okay to be self-confident and arrogant sometimes, but recognize your own boybils and limitations and, you know, appreciate that, you know, one's indiosyncrasies can be kind of funny. It's okay to make funny yourself.

And, you know, actually, you know, you quote, you mentioned one of my, one of my favorite Feynman quotes, too, which is related wisdom. You're the easiest person to fool. Try to be honest. It's hard because, you know, we do have biases. And, but we have to do our best to make judgments that are sound even about our society. Yeah, very, very, very sage advice. Okay, the next question also goes into the future, and that is related to the movie 2001, a Space Odyssey,

based on the Arthur C. Clark book. I don't know if you've ever seen the movie, but it opens. Oh, I saw it when it first came out. I was 16, I think. Wasn't it in 1960? Yeah. And my brother and I, it was in limited engagement in downtown Chicago. We were living in the suburbs.

we took the train in because we were so excited to see it. And, you know, we spent countless hours afterwards trying to figure out what it was about. Yeah. But it was an amazing cinematic experience. It was. Yeah, Kubrick is just the highlight of basically pinnacle of science fiction movies, in my opinion. But that movie opens with these hominid-like creatures on the plains of Africa, presumably, you know, millions of years ago, hundreds of thousands of years ago.

and they come upon this monolith, this mysterious object on the savannah, and they hit it with a bone, and they do all sorts of crazy stuff to it. And then later astronauts encounter the same menacing monolith on the moon and space, etc. And it's clearly meant to be some sort of time capsule for what purpose we don't really know. I asked Avi Loeb last week what he would put on it, and he thinks we've been visited by one of these monoliths. but stay tuned. Two weeks from now, I'll have Avi Loeb on my podcast for the release of his new book called Extraterrestrial. That's just a plug.

So make sure you subscribe. But I want to ask you, if you had a monolith, it sort of remind me of Richard Feynman, his again making an appearance on this show. He said that if in some cataclysm, all scientific knowledge were to be destroyed, and only one sentence passed on to the next generation of creatures, What statement would contain the most information in the fewest words? I'm sure you know what he said, but I want to ask you, scientific or otherwise, I don't care what you put on it.

It could be a quote. It could be your tattoo. It could be the tattoo you have on your backside. No, I'm just kidding. You don't have one of those. But John, what would you put on a billion-year lasting, enduring time capsule, wisdom, knowledge, scientific, or otherwise? Right.

Well, the supplyment said everything's made of atoms. And of course that's a very good answer. And he meant that you can understand a lot of things, just starting from that principle. I guess maybe I would be trying to convey not necessary the content of science, but how to do science, the method of science. And, well, actually, finally, said something good about that, too, right? In the character of physical law, he said, when you're trying to guess or understand the laws of nature, it doesn't matter how smart you are. You know, it doesn't matter how important you are if it disagrees with experiment in its role. And so I think the idea that we have to look at the world with objectivity, we have to evaluate the evidence.

And if we have pet ideas that we favor, we have to, you know, be willing to test them. And if they fail, we move on. And in the case of a situation where we can't get experimental evidence, say, for the singularity at the core of a black hole or the origin of the universe in a singularity event, you know, I actually revealed, you know, which I didn't know, but, you know, Stephen Hawking's brief history of time. was really an advocacy of this hard old hawking, you know, no boundary condition. And he used that for a particular purpose. In his case, I'll talk about it on my podcast with Leonard Maladna, which comes out this coming Tuesday. But nevertheless, you know, it's kind of an advocacy against a supernatural creator's necessity because one of the jobs of a supernatural creator would be to create the universe. And if the universe can emerge from nothing, essentially, in this no

boundary or in time itself can emerge from nothing, maybe such an entity is not. not necessary. But nevertheless, getting back to Feynman, if it disagrees with the experiment it's wrong, what if you can't do the experiment? What do you do? Keep trying, keep thinking about it. You, I mean, unless you have some entirely convincing argument that it's impossible to test the idea, keep trying. Great. Okay, John, last question. Now we're going to go backwards in time, and we're going to use the famous three laws of Arthur C. Clark, the opening one of which opens the podcast, and that is any sufficiently advanced technology is indistinguishable from magic. I love that quote.

I love his second law of Arthur C. Clark is, for every expert, there is an equal and opposite expert. And I think Feynman said science is the belief in the ignorance of experts, something like that. But the third law is the name of this podcast, and it involves basically, the following sentence, the only way of discovering the limits of the possible is to venture a little way past them into the impossible. So that's where I got the name of the podcast. So I want to ask you, Joan, what aspect of life seemed impossible to a 20-year-old, 30-year-old John Preskill, but because of your courage, because of your integrity, because of your

strength of character, whatever, you made it possible. What advice would you give to the young John Preskill to venture beyond his comfort zone into the impossible. Well, there are several questions. They're all rolled up into one, it seems. Well, this doesn't directly answer your question about advice to the young John Preskill,

but we did encounter in the early days of quantum computing, and to some degree even today, the objection or the viewpoint that scaling up quantum computing is impossible.

And the basis for that, well, different people might have different reasons for raising that objection. But I remember in the mid-90s, very, very good physicists, like Bill Unroy, he'd be a good guest. Yes, I'd love to have him on. Yeah, I talk to Lenny about that, yeah. And also Rolf Landauer and Sergio Rosh and others argued, you know, we'll never be able to get a quantum computer to work, and it's because of decoherence. Well, in particular for Unroy and Oroche, that was the reason. And Horoche knew very well because he'd worked very hard for a long time to study decoherence in the lab. It's just too pervasive, it's too unavoidable, and it's impossible to get around it.

But, you know, we developed this idea of quantum air correction, which I think in its long-term implications is as important as the idea that there are quantum algorithms that can greatly outperform classical ones. And so now, most people who think seriously about it, believe we will have large-scale quantum computers and will protect them against decoherence using this idea. And that was interesting to see that unfold. As far as advice, I might give to myself, I'm sure I wouldn't have paid attention to my own advice, by the way. but I probably, when I was a young theorist, maybe starting graduate school, you know, there were certain things I was interested in and many things that I thought just aren't that interesting.

And one thing that might have been good advice for me at the time was pay more attention to experiments, and I don't just mean the results of them, but experimental techniques, you know, what people actually do in the lab to make stuff work. I didn't learn much about that in my PhD, education and I think if I had, you know, I would have a better understanding even today of practice of doing really hard experiments, which of course is very relevant to trying to develop

quantum computers. Absolutely. And that brings up my last imprecation for the future that people should not be so siloed. I always say to my students who are experimentalists that they don't need to be theorists. They don't need to come up with new theorists. They don't need to come up with new theories and so forth, but they need to understand the theory. Otherwise, they're just kind of mindlessly applying the principles of electronics and plumbing and so forth. And they're really not fulfilling their potentiality to become merchants of truth and understand the essence of what they're doing rather than just doing it to get a PhD, et cetera. I'd love to talk to you because you are such an inspiring teacher and mind and so forth. I love to talk to you someday about pedagogy and

especially as I said when your book comes out, but maybe even before that, because I think I've learned so much from you. You didn't maybe ever hear it before now, but you're one of my mentors in a remote sense. I look up to you. I use you as sort of a filter. You won't like that,

but if it's interesting to Preskill, it's got to be interesting enough for Keating. So I want to thank you, John, for going into The Impossible with me, and I hope you stay well. I hope we see each other. Barry Barish is offering to interview, me for my podcast. He has some questions to ask me. So I might come up to Pasadena. I'd love to see you

and just get a socially distance, you know, fist bump from you. I don't know. John, stay well. Thank you for going into the impossible. Everybody, thank you. I hope you enjoyed this as much as I did. Thank you for all your donations. You can still give to the Foothill Unity Center. It's a phenomenal organization. And we raised about $100, maybe a little bit more, to tally it up afterwards from around the world. I mean, you'll tell them, John, that they got money from Australia and from the UK as well as from San Diego. John, thank you so much. This has been fun, Brian. I'd be happy to do it again sometime. Thank you so much. Bye, everybody. Stay tuned for more episodes of Into the Impossible, Leonard Maladna, Avi Loeb. We have Deepak Chopra in a solo episode, and hopefully we'll get people

like Jor Toof and others back on the show. That would be such a treat. John, thank you so much. well. If you enjoyed this episode of Into the Impossible with Professor Brian Keating, please subscribe, comment, share, and review. Watch on YouTube, listen on iTunes, Spotify, Google Player, Stitcher. We appreciate hearing from you and are always open to your suggestions for future episodes. For more information, and to sign up for Professor Keating's mailing list, go to Brian Keating.com. Follow Professor Keating on Medium and Twitter at Dr. Brian Heating, DR. Brian Heating.

For more information on the Clark Center, go to Imagination.ucsd.edu. Into the Impossible is a production of the Arthur C. Clark Center for Human Imagination at the University of California, San Diego, in the Division of Physical Sciences. Eric Vary, director, Brian Heating, co-director, Produced by Ryan Keating and Stuart Volko.