YouSaid · the spoken record

Andrew Strominger

lines on the record: 128
first: 2023-02-15
most recent: 2023-02-15
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

“Yeah, yeah, yeah. And it was all based on something called, let me not explain what it is. Let me just throw out the buzzword Renormalizable quantum field theory. They all fall in the category of renormalizable quantum field theory.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“So much fun has been happening, and so that's all. That's all pretty well understood. There are some things that might or might not around the edges of that dark matter, neutrino masses, some sort of fine points or things we Haven't quite measured perfectly, and so on, but it's largely a very complete theory, and we don't expect Anything very new Conceptually, in the completion of that.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“The standard model. Everything in the standard model has been observed, its properties have been measured, the final particle to be observed was the Higgs particle. Served like over a decade ago.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“It's a theory that describes Everything with astonishing accuracy, it's the most. Accurate theory in the history of human thought, theory and experiment have been successfully compared to sixteen decimal plates. We have that stenciled on the door where I work. It's an amazing feat of the human mind. It describes the electromagnetic interaction, unifies the electromagnetic interaction with the so-called weak interaction, which you need some good tools to even view the weak interaction. And then there's the strong interaction. which binds the quarks into protons and the forces between them are mediated by something called Yang-Mills theory, which is a beautiful mathematical generalization of electromagnetism In which the analogues of the photons themselves carry charge. And so the final piece of this”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“Yes, because that one has been understood since the 50s. Polly was the First person to notice it. And Hawking in the early 70s gave it a really much more visceral form. And people have been. Hurling themselves at it, trying to reduce it to some technicality, but nobody has succeeded. And the efforts to understand it have led to All kinds of interesting relations between quantum systems and applications to other fields and so on.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“It was exactly in resolving those contradictions that Einstein came up with the general theory of relativity. And it's fascinating how this contradiction, which seems like maybe it's kind of technical thing. Led to a whole new vision of the universe. Now, let's not get fooled because Lots of contradictions are technical things. We haven't set up We run into other kinds of contradictions that are technical and they don't seem to, we understood something wrong, we made a mistake, we set up our equations in the wrong way, we didn't translate the formalisms.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, yeah, yeah. It was all sort of wonderful century. I mean, the seed of general relativity was the incompatibility of Maxwell's theory of the electromagnetic field. With Newton's laws of gravity, they were incompatible. Because if you look at Maxwell's theory, There's a contradiction, if anything goes faster than the speed of light. Newton's theory of gravity Gravitational field, the gravitational force, is instantaneously transmitted across the entire universe. So you could, you know, if you had a A frandon in another galaxy with a very sensitive measuring device that could measure the gravitational field. It could just take this cup of coffee and move it up and down and Morse code and they could. Get the message instantaneously over another galaxy. That leads to all kinds of contradictions. It's not self-consistent.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“Contradictions that create discovery. There's no question in my mind. Course, many people would disagree with me that now is the most Wonderful time to be a physicist. So people look back At It's a classical thing to say among physicists, I wish it were nineteen twenty. Quantum mechanics had been just understood. There was the periodic table. But in fact, that was such a rich thing. That Well, so that went a lot of exciting stuff happened around 1920. It took It took a whole century to sort out the new insights that we got.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“Newton's gravity had its demise. There were regimes in which it wasn't valid. Maxwell's electromagnetism had its demise. There was regimes in which quantum effects greatly modified the equations. General relativity all on its own. Drove a system which originally was fine would perversely wander off into a configuration in which Einstein's equations no longer applied”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“So when you hit the singularity, you know that you need some improvement to Einstein's theory of gravity and that improvement, we understand what kind of things that improvement should involve. It should involve quantum mechanics, quantum effects become important there. It's a small thing. We don't understand exactly what the theory is, but we know there's no reason to think Einstein's theory was invented to describe weakly curved things, the solar system and so on. It's incredibly robust that we now see that it works very well near the horizons around black holes and so on. So it's a good thing. The theory drives itself It predicts its own demise.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“That's true, but I would phrase it as saying when it's super accurate. You know, if you look at the bore atom, Maxwell Electromagnetism is not a very good approximation to the force between the proton and the electron. The quantum mechanics, if you didn't have quantum mechanics, the electron would spiral into the proton and the atom would collapse. So that's a huge correction there So every theory gets corrected as we learn more. Just be no reason to suppose that it should be otherwise.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“But of course he made one of the greatest discoveries in the history of science without even knowing what good it was going to be. So that's how small that was the first sign that there was something wrong with Newton. So the corrections to Newton's law are very, very small, but they're definitely there. The corrections to electromagnetism They're mostly the ones that we see are mostly coming from quantum effects.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“The internet is going to be very messy. We could discuss that, but that's a different thing. We wouldn't say Newton's theory was wrong. It had very, very small corrections, incredibly small corrections. It's actually a puzzle why they're so small. So if you watch the precession of Mercury's perihelion, this was the first indication of something going wrong. According to Newton's theory, Mercury has an elliptical orbit. The long part of it moves around as other planets come by and perturb it and so on. And so this was measured by Le Verrier in 1859, and he compared theory and experiment, and he found out that the perihelion process moves around the sun once every 23 centuries instead of every two hundred. Now, this is the wonderful thing about science. Why was this guy? We don't have any idea how much.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“It's an odd thing that Maxwell's theory Newton's theory Never exhibit this phenomenon. You write them down, you can solve them exactly. They're really Newton's theory of gravity. They're really very simple theories. You can solve them. Well, you can't solve the three-body problem. Can certainly solve a lot of things about them. Nevertheless, There was never any reason. Even though Maxwell and Newton perhaps Fell for this trap, there were never any reason to think that these equations were exact. And there's no equation. There's some equations that we've written down that we still think are exact. Some people still think they are exact. My view is that there's no exact equation”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“Well, something very interesting happens in Shoreshield's solution of the Einstein equation. Think his reasoning was ultimately wrong, but let me Explain to you what it was. The center of the black hole behind the horizon. A region that nobody can see and live to tell about it. The center of the black hole, there's a singularity, and if you pass the horizon, you go into the singularity, you get crushed, and that's the end of everything. Now, the word singularity Means that It just means that Einstein's equations break down. They become infinite, you write them down, you put them on the computer, when the computer hits that singularity, it crashes. Everything becomes infinite. There's two. Equations are just no good there. That's actually. Not a bad thing. It's a really good thing. And let me explain why. So”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“Either one, space or time. That gets very tricky. And Einstein didn't. Didn't have it right. And in fact, he had an earlier version of general relativity. In nineteen fourteen, which he was very excited about, Which was wrong Gave it wasn't fully coordinate invariant, it was only partially coordinate invariant. It was wrong. It gave the wrong answer for bending light to the sun. Factor of two. There was an expedition sent out to measure it during World War I. They were captured. For they could measure it. And that gave Einstein four more years to clean his act up, by which time he'd gotten it right. So it's a very tricky business. But once it's all laid out, it seems. It's clear.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“Yeah, yeah, there's some very delicate subtleties to that. Began to be noticed in the 50s. It's mostly true, but when you have a space-time with edges, Gets very tricky how you label the edges.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“No matter which weather stations we use or how we, you know, it's a very trivial, the labeling of points is an artifact and not in the real physics. So it turns out that Almost true. but not quite. There's some subtleties to it.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“Let's imagine I want to draw a map with pictures of all the states and the mountains. And then I want to draw the weather forecast, what the temperatures are going to be all over the country. And I do that using one set of weather stations, and I number the weather stations, and you have some other set of Weather stations and you do the same thing. So the coordinates are the locations of the weather stations They're how we describe where the things are. At the end of the day, We should draw the same map. That is coordinate invariance. And if we're telling somebody, we're going to tell somebody at a real physical operation, we want you to stay as dry as possible on your drive from here to California. We should give them exactly the same route.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“He went back and forth, but he wrote a paper in, I think, 34 saying that gravity waves didn't exist because people were very confused about what a coordinate transformation is. And in fact, this confusion about what a coordinate transformation is has persisted. And we actually think we were on the edge of solving it. Hundred years later Hundred years later.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“And 25 years later, Einstein wrote a paper. So with 25 years to think about what this solution means Wrote a paper in which he said that black holes didn't exist. And I'm like, whoa, if one of my students in my general relativity course wrote this. I wouldn't pass them.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“Einstein was before he started thinking about the issues. I can't even reconstruct my own confusion from two weeks ago. So the really beautiful ideas that physics have this very hard to get yourself back into the mindset. Of course, Einstein was confused. About many, many things. It doesn't matter if you're physicists. It's not how many things you got wrong. It's not the ratio of how many you got wrong, how many you got right. It's the number that you got right. So Einstein didn't believe black holes existed, even though he predicted them. And I went and I read that paper, which he wrote, you know, Einstein wrote down his field equations in 1915. And Schwartz-Hild solved them and discovered the black hole solution three or four months later, in very early 1916.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“No, no, it's a very funny thing in physics, the best discoveries seem completely obvious and retrospect Even my own discoveries, which of course are far lesser than Einstein's, but many of my papers, many of my collaborators get all confused, will try to understand something and say, we've got to solve this problem. We'll get all confused. Finally, we'll solve it. We'll get it all together. Then we'll all of a sudden everything will fall into place. We'll explain it, and then we'll look back at our discussions for the precedings of months. And literally be unable to reconstruct. Confused we were And how we could ever have thought of it any other way. So not only can I not fathom How confused.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“If you shine light straight up away from the earth, it doesn't have too much trouble. It's going way above the escape velocity. But if you have enough mass there, even light can't escape this escape velocity. And according to... Einstein's theory of relativity, there is an absolute speed limit in the universe, the speed of light, and nothing makes any sense. Nothing could be self-consistent if there were objects that could exceed light speed. And so in these very, very massive regions of space-time, even light cannot escape.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“Now it turns out that the gravitational pull exerted by an object is proportional to its mass. And so if you get enough mass in a small enough region, Um... you can prevent light from escaping. And let me flesh that out a little more. If you're On the earth and you're on a rocket ship leaving the surface of the earth, and if we ignore the friction from the air, If your rocket accelerates up to 11 kilometers per second, that's escape velocity. And if there were no friction, it could just continue forever to the next galaxy. On the moon, which has less mass, it's only seven kilometers per second. So, but going in the other direction, if you have Enough mass in one place, the escape velocity can become the speed of light.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“Think you were alluding to is why doesn't light get out or how is it that there can be a region of space-time from which light can't escape? It definitely happens. We've seen those regions. We have spectacular pictures, especially in the last several years of those regions. They're there. In fact, they're up in the sky. thousands or millions of them. We don't yet know how many. But the proper explanation of why light doesn't escape from Black hole is still Matter of some debate. One explanation. Which perhaps Einstein might have given. Is that light carries energy? You know it carries energy because we have photo cells and we can take the light from the sun and collect it, turn it into electricity. So there's energy and light. And anything that carries energy is subject to a gravitational pull. Gravity will pull at anything with energy.”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“Well, light is the stuff that comes out of the sun, the stuff that goes into your eyes. Light is one of the stuff that disappears when the lights go off. This is stuff that appears when the lights come on. Of course, I could give you a bathymedical definition or a physical mathematical definition, but I think it's something that we Understand very intuitively what is light. Black holes, on the other hand, we don't understand intuitively. They're very weird. What are the questions?”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source
“So, a black hole is defined theoretically as a region of spacetime from which light can never escape, therefore it's black. Now that's just the starting point. Many weird things follow from that basic definition, but that is Is the basic definition They can't”
2023-02-15 · Lex Fridman Podcast · #359 – Andrew Strominger: Black Holes, Quantum Gravity, and Theoretical Physics · IDENTIFIED FROM THE TRANSCRIPT · source