YouSaid · the spoken record

Leonard Susskind

lines on the record: 70
first: 2019-09-26
most recent: 2019-09-26
sittings or episodes: 1
sources: podcast

Every line below is reproduced as it was said and linked to the record it came from. Nothing here is summarised or generated. Directory · Search · Corrections

“The other thing, big systems can be composed of lots of little systems, materials, the materials that we work with and so forth are Be large systems, a large piece of material, but they're made out of quantum systems. Now, one of the things that's been happening over the last good number of years is we're discovering materials and quantum systems which function much more quantum mechanically than we imagine. Topological insulators, this kind of thing, that kind of thing, those are macroscopic systems, but just superconductors. Superconductors have a lot of quantum mechanics in them. Can have a large chunk of superconductor. So it's a big piece of material. On the other hand, it's functioning and its properties depend very, very strongly on quantum mechanics. And to analyze them, you need the tools of quantum mechanics.”
2019-09-26 · Lex Fridman Podcast · Leonard Susskind: Quantum Mechanics, String Theory, and Black Holes · IDENTIFIED FROM THE TRANSCRIPT · source
“Yes. And they also function in a very quantum mechanical way. It is, first of all, unclear to me, but of course it's unclear to me. I'm not a neuroscientist. I don't even have very many friends who are neuroscientists. I would like to have more friends who are neuroscientists. I just don't run into them very often Among the few neuroscientists I've ever talked about about this, they are pretty convinced that the brain functions classically. That is not intrinsically a quantum mechanical system or doesn't make use of the special features, entanglement, coherent superposition. Are they right? I don't know. I sort of hope they're wrong just because I like the romantic idea that the brain is a quantum system But I think probably not.”
2019-09-26 · Lex Fridman Podcast · Leonard Susskind: Quantum Mechanics, String Theory, and Black Holes · IDENTIFIED FROM THE TRANSCRIPT · source
“With all the excitement, among the people that I interact with is understanding black holes. Black holes are big things. There are many, many degrees of freedom Is another kind of quantum system that is big. It's a large quantum computer. And one of the things we've learned is that the physics of large quantum computers is in some ways similar to the physics of large quantum black holes. And we're using that relationship. Now you asked, you didn't ask about quantum computers or systems. You didn't ask about black holes. You asked about brains.”
2019-09-26 · Lex Fridman Podcast · Leonard Susskind: Quantum Mechanics, String Theory, and Black Holes · IDENTIFIED FROM THE TRANSCRIPT · source
“So we probably will run out of the ability to solve equations for these things, solve equations by the standard methods of pencil and paper. Solve the equations by the method of classical computers. And so, what we'll do is we'll build versions of these systems. Run them and run them under controlled circumstances where we can change them, manipulate them, make measurements on them, and find out all the things we want to know.”
2019-09-26 · Lex Fridman Podcast · Leonard Susskind: Quantum Mechanics, String Theory, and Black Holes · IDENTIFIED FROM THE TRANSCRIPT · source
“They're actually satisfying the same laws as the systems that they're simulating. Okay, so on the one hand, you have things like factoring. Factoring is the great thing of quantum computers, factoring large numbers. That doesn't seem that much to do with quantum mechanics It seems to be almost a fluke That a quantum computer can solve the factoring problem in a short time. And those problems seem to be extremely special, rare, and it's not clear to me that there's going to be a lot of them. On the other hand, there are a lot of quantum systems, chemistry, there's solid state physics, there's material science, there's quantum gravity, there's all kinds of quantum field theory. Some of these are actually turning out to be applied sciences as well as very fundamental sciences.”
2019-09-26 · Lex Fridman Podcast · Leonard Susskind: Quantum Mechanics, String Theory, and Black Holes · IDENTIFIED FROM THE TRANSCRIPT · source
“Simply build a version of the same system. You build a version of it, you build a model of it that's actually functioning as the system, you run it, and then you do the same thing you would do to the quantum system, you make measurements on it, quantum measurements on it. Advantages, you can run it much slower. You could say, why bother? Why not just use the real system? Why not just do experiments on the real system? Well, real systems are kind of limited. You can't change them. You can't manipulate them. You can't slow them down so that you can poke into them. You can't modify them in arbitrary kinds of ways to see what would happen if I changed the system a little bit. So I think that quantum computers Will be extremely valuable in In understanding quantum systems.”
2019-09-26 · Lex Fridman Podcast · Leonard Susskind: Quantum Mechanics, String Theory, and Black Holes · IDENTIFIED FROM THE TRANSCRIPT · source
“Okay, so we know that there are a handful of algorithms that can seriously be classical computers and which can have exponentially more power. This is a mathematical statement. Nobody's exhibited this in the laboratory. It's a mathematical statement. We know that's true, but it also seems more and more that the number of such things is very limited, only very, very special. Problems exhibit that much advantage for a quantum computer. Of standard problems. To my mind, as far as I can tell, the great power of quantum computers will actually be to simulate quantum systems You're interested in a certain quantum system and it's too hard to simulate classically.”
2019-09-26 · Lex Fridman Podcast · Leonard Susskind: Quantum Mechanics, String Theory, and Black Holes · IDENTIFIED FROM THE TRANSCRIPT · source
“400 spins, that's not very many. 400 I can put in my pocket, 400 pennies in my pocket. Be able to simulate the quantum state of 400 elementary quantum systems, qubits we call them, to do that would take more information than can possibly be stored in the entire universe if it were packed so tightly that you couldn't pack any more in. 400 qubits. On the other hand, if your quantum computer is composed of 400 qubits, it can do everything 400 qubits can do.”
2019-09-26 · Lex Fridman Podcast · Leonard Susskind: Quantum Mechanics, String Theory, and Black Holes · IDENTIFIED FROM THE TRANSCRIPT · source
“Physically, it's not doing the things that the quantum system would do. The quantum computer is really a quantum mechanical system which is actually carrying out the quantum operations. You can measure it at the end. It intrinsically satisfies the uncertainty principle. It is limited in the same way that quantum systems are limited by uncertainty and so forth. And it really is a quantum system. That means that what you're doing when you program something for a quantum system is you're actually building a real version of the system. The limits of a classical computer, classical computers are enormously limited when it comes to Quantum systems. They're enormously limited because you probably heard this before, but in order to store the amount of information that's in the quantum state of”
2019-09-26 · Lex Fridman Podcast · Leonard Susskind: Quantum Mechanics, String Theory, and Black Holes · IDENTIFIED FROM THE TRANSCRIPT · source
“It's not just leveraging quantum mechanical ideas. You can simulate quantum systems on a classical computer. Simulate them means solve the Schr ⁇ dinger equation for them or solve the equations of quantum mechanics on a computer, on a classical computer. But the classical computer is not doing a quantum mechanical system itself. Of course it is. Everything's made of quantum mechanics, but it's not functioning. It's not functioning as a quantum system. It's just solving equations. The quantum computer is truly a quantum system which is actually doing the things. You're programming it to do. You want to program a quantum field theory. Do it in classical physics, that program is not actually functioning in the computer as a quantum field theory. It's just solving some equations.”
2019-09-26 · Lex Fridman Podcast · Leonard Susskind: Quantum Mechanics, String Theory, and Black Holes · IDENTIFIED FROM THE TRANSCRIPT · source
“Oh, both, both. Very definitely both. The younger time I spent more time with myself. Now, because I'm at Stanford, because I Have a lot of ex students and people who are interested in the same thing I am. I spend a good deal of time almost on a daily basis interacting, brainstorming, as you said It's a very important part. Spend less time probably completely self focused in A piece of paper and just sitting there staring at it.”
2019-09-26 · Lex Fridman Podcast · Leonard Susskind: Quantum Mechanics, String Theory, and Black Holes · IDENTIFIED FROM THE TRANSCRIPT · source
“That's right. I wasn't. I always felt a little bit of an outsider in the beginning a lot an outsider. Way of thinking was different. My approach to mathematics was different, but also my social background that I came from was different. Now, these days, half the young people I meet, their parents or professors That was not my case. But then all of a sudden, at some point I found myself at the very much the center of maybe not the only one at the center, but certainly one of the people in the center of a certain kind of physics. And all that went away. I mean, it went away in a flash.”
2019-09-26 · Lex Fridman Podcast · Leonard Susskind: Quantum Mechanics, String Theory, and Black Holes · IDENTIFIED FROM THE TRANSCRIPT · source
“I don't know that I thought about it as much as I just felt it. Thinking is one thing, feeling is another thing. I felt like an outsider until a certain age when I suddenly found myself the ultimate insider in academic physics. That was a sharp transition. I wasn't a young man. I was probably 50 years old.”
2019-09-26 · Lex Fridman Podcast · Leonard Susskind: Quantum Mechanics, String Theory, and Black Holes · IDENTIFIED FROM THE TRANSCRIPT · source
“No, I had different kind of doubts. I came from a very working class background and I was uncomfortable in academia for, oh, for a long time. But there weren't doubts about my ability or my... They were just the discomfort in being in an environment that Family hadn't participated in. I knew nothing about as a young person. I didn't learn that there was such a thing called physics until I was almost 20 years old. So I did have certain kind of doubts, but not about my ability. I don't think I was too worried about whether I was succeed or not. I never felt this insecurity. Am I ever going to get a job? That had never occurred to me that I wouldn't.”
2019-09-26 · Lex Fridman Podcast · Leonard Susskind: Quantum Mechanics, String Theory, and Black Holes · IDENTIFIED FROM THE TRANSCRIPT · source
“I think both. Both. Both. I think you have to have both arrogance and humility. You have to have the arrogance to say, I can do this. Nature is difficult. Nature is very, very hard. I'm smart enough. I can do it. I can win the battle with nature. On the other hand, I think you also have to have the humility to know that you're very likely to be wrong on any given occasion. Everything you're thinking could suddenly change. Young people can come along and say things you won't understand and you'll be lost and flabbergasted. So, I think it's a combination of both. You You're very limited and you better be able to say to yourself, I'm not so limited that I can't win this battle with nature. Takes a special kind of. Who can manage both of those, I would say.”
2019-09-26 · Lex Fridman Podcast · Leonard Susskind: Quantum Mechanics, String Theory, and Black Holes · IDENTIFIED FROM THE TRANSCRIPT · source
“visualized in my head the one dimension, the two dimension, the four dimensions, the five dimensions, and I don't think that's ever going to happen. The reason is, I think, neural wiring is just set up for that. On the other hand, we do learn ways to think about five, six, seven dimensions. We learn ways, we learn mathematical ways, and we learn ways to visualize them, but they're different. And so, yeah, I think we do rewire ourselves whether we can ever completely rewire ourselves to be completely comfortable with these concepts. I doubt.”
2019-09-26 · Lex Fridman Podcast · Leonard Susskind: Quantum Mechanics, String Theory, and Black Holes · IDENTIFIED FROM THE TRANSCRIPT · source
“I'm not sure. I think many of us have evolved. The ability to think quantum mechanically to some extent, but that doesn't mean you can think like an electron Don't mean another example, forget for a minute quantum mechanics, just visualizing four-dimensional space or five-dimensional space or six-dimensional space. I think we're fundamentally wired to visualize three dimensions. I can't even visualize two dimensions or one dimension without thinking about it as embedded in three dimensions. If I want to visualize a line, I think of the line as being a line in three dimensions. I think of the line as being a line on a piece of paper with a piece of paper being in three dimensions. I never seem to be able to, in some abstract and pure way,”
2019-09-26 · Lex Fridman Podcast · Leonard Susskind: Quantum Mechanics, String Theory, and Black Holes · IDENTIFIED FROM THE TRANSCRIPT · source
“Rewiring your brain in new ways. Quantum mechanics is not intuitive. Very little of modern physics is intuitive. Intuitive, or what does intuitive mean? It means the ability to think about it with basic classical physics, the physics that we evolved with throwing stones, splashing water, whatever it happens to be. Quantum physics, general relativity, quantum field theory are deeply unintuitive in that way. But after time and getting familiar with these things, you develop new intuitions. I always said you rewire. And it's to the point where me and many of my friends, I and many of my friends, Think more easily quantum mechanically than we can classically. We've gotten so used to it.”
2019-09-26 · Lex Fridman Podcast · Leonard Susskind: Quantum Mechanics, String Theory, and Black Holes · IDENTIFIED FROM THE TRANSCRIPT · source
“Very much so. Very much so. I tend not to think about the equations. I tend not to think about the symbols. I tend to try to visualize the phenomena themselves. And then when I get an insight that I think is valid, I might try to convert it to mathematics. But I'm not a natural mathematician or I'm good enough at it. I'm good enough at it, but I'm not a great mathematician. So for me The way of thinking about physics is first intuitive, first visualization. Scribble a few equations, maybe, but then try to convert it to mathematics. Experiences that other people are better at converting it to mathematics than I am.”
2019-09-26 · Lex Fridman Podcast · Leonard Susskind: Quantum Mechanics, String Theory, and Black Holes · IDENTIFIED FROM THE TRANSCRIPT · source
“I saw. I think what I saw was somebody who could do physics in this deeply intuitive way. His style was almost a close eyes and visualize the phenomena that he was thinking about and through visualization. Outflank the mathematical, the highly mathematical and very, very sophisticated technical arguments that people would use. I think that was also natural to me. I saw somebody who was actually successful at it, who could do physics in a way that I regarded as Simpler, more direct, more intuitive. And while I don't think he changed my way of thinking, I do think he validated it. He made me look at it and say, yeah, that's something you can do and get away with. Practically you can get away with it.”
2019-09-26 · Lex Fridman Podcast · Leonard Susskind: Quantum Mechanics, String Theory, and Black Holes · IDENTIFIED FROM THE TRANSCRIPT · source