Janna Levin
Appearances
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Oh, that I can do.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And they might not have cracked it.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Now, I'm not going to say sometimes I take too long to come to that conclusion, but I will proudly say, as most theoretical physicists should, that I kill most of my ideas myself.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I am absolutely able to say, oh, that's just not... I mean, I'm not going to deny that sometimes I maybe take a while to come to that conclusion, longer than I should, but I will. I absolutely will. I will drop it. And that is... Any self-respecting physicist should be able to do that. The problem is with somebody like Andrew Wiles, you were describing, who...
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
to prove Fermat's last theorem, it took him seven years. Was that the number? Something like that. He went up into his mother's attic or something and did not emerge for seven years. Is that maybe he did. He was on the right track. He wasn't wrong. But that's so, it could have been interminable. He still might not have gotten there in the end.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And so that's the really difficult space to be in where you're not wrong. You are onto something, but it's just asymptotically approaching that solution and you're never actually going to land it. That happens. Yeah.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yes.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Right.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I mean, it's taking a year for people to check it. It's not the kind of thing you look over in an afternoon. Yeah.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's a great story.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah. That's a very different psychology. That's why you're differently.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yep.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Well, if you look at someone like Turing, his... his eccentricities were completely different, right? It's not as though there's some mold, and I really don't like it when it's portrayed that way. These are really individuals who were still lost in their own minds, but in very different ways. And Turing was openly gay, really, during this time.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
You know, he was working during the war, World War VI, understand the era, and it was illegal in Britain. at the time, and he kind of refused to conceal himself. There was a time when the kind of attitude was, well, we're just going to ignore it. But he had been robbed by somebody that he had picked up somewhere. I think it was in Manchester. And it was such a small thing.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I don't know what they took. It took like nothing. You know, it was nothing. But he couldn't tolerate. He goes to the police and he tells them. And then he's arrested. He's the criminal. because it involved this homosexual act. Now, here you have somebody who made a major contribution to the Allies winning the war. I mean, it's just unbelievable, not to mention the genius, mathematical genius.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I mean, he saved the lives of the people that were doing this to him. And they essentially chemically castrated him as a punishment. That was his sentence. And he became very depressed and suicidal. And the story is he was obsessed with Snow White, which was recently released. And he used to chant one of the little, I don't know if you would call them poem songs, hymns.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
dip the apple in the brew, let the sleeping death seep through." It was a chant from Snow White. The belief is that he dipped an apple in cyanide and bit from the poison apple. Now, I don't know if this is apocryphal, but people think that the apple on the Macintosh with the bite out of it is a reference to Turing. Now, some people deny this.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But some people say he did that so his mother could believe that maybe it was an accident. But yeah, quite a terrible end.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I think the reason why I tie them together, not just because ultimately their work is so connected, but because there's this sort of impossibility of understanding them. There's this sort of... impossibility of proving something about their lives, that even if you try to write factual biography, there's something that eludes you.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And I felt like that's kind of fundamental to the mathematics, the incompleteness, the undecidable, the uncomputable. So structurally, it was about what we can kind of know and what we can believe to be true, but can't ever really know.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I do like to say that black holes are no thing.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Biography, limitations of fiction and nonfiction.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
No thing. They're nothing.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah, I can start with Pioneer Works. Pioneer Works, in some sense, it was inevitable that I would land at Pioneer Works. It felt like I was marching there forever. for many years, and just it came together again, like this collision. It was founded by this artist, Dustin Yellen, very utopian idea. He bought this building, this old ironworks factory called Pioneer Ironworks in Brooklyn.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It was in complete disrepair, but a beautiful old building from the late 1800s. And He wanted to make this kind of collage. Dustin's definitely a collage artist, works in glass, very big pieces, very imaginative and wild and narrative and into nature and consciousness. And I think he wanted to do that with people. He wanted a place of a collage, a living example of artists and scientists.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
That's what I mean. That's the more profound aspect of the black hole. So you asked originally, how do they form? And I think that even when you try to form them in messy astrophysical systems, there's still nothing at the end of the day left behind. This was a very big surprise, even though Einstein accepted that this was a true prediction. He didn't think that they'd be made.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And it was founded by Dustin and Gabriel Florence was the founding artistic director. It was started just before Hurricane Sandy. I don't know if people feel as strongly about Hurricane Sandy as New Yorkers do, but... It was a real moment around 2012, 2013. Sort of paused the project and you can even see the kind of water line on the brick of where Sandy was.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I came in and collided with these two shortly after that. And it really was like a collision. I'm science, you know. They're art. Gabe makes everything, builds everything with his bare hands. Dustin's a dreamer. They love science. They really wanted science, but science is hard to access. I have always loved the translation of science in literature, in art.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I love fiction writers, like really literary fiction writers who dabble thinking about science. And I very firmly believe science is part of culture. I just, I know it to be true. I don't think of myself as doing outreach or education. I don't like those labels. I'm doing culture. And artists in their...
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
studio working out problems understanding materials building a body of work nobody says to them when they exhibit why are you doing outreach or are you doing education you know it's the logical extension so I feel that if you've had the privilege of knowing some of these people of seeing a little bit from the summit if you've had a little glimpse yourself that you bring it back to the world so we
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
boom, exploded, Pinerix became science and art. It's not artists who all do science or scientists who do art. It's real hardcore scientists talking about science in a lot of live events. We have a magazine called Broadcast where we feature all of the disciplines rubbing together, artists working on all kinds of things.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
When I first started doing events there, my first guest, like you, I was talking to people. And this was like, I know how to talk to people because I know these guys. And I've been on the interviewee side so much. I know exactly. It was like fully formed for me how to do those conversations.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah, thank you. I appreciate that. You learn how to do it too, though. I mean, I don't think the first one I did. I think I've learned, right? And you acquire, you get better, which is really interesting. And I love to study. I think you do too. I really look into it. And I love science. I really do. I want to talk to a CRISPR biologist because I don't understand it and I want to understand it.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yes. We have a really fascinating variety of humans. That's a good way of putting it.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yes. You have to come see us. I think you would love it.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
You're giving me an opportunity to give a shout-out to Andrea Lauer, who's a designer who makes these amazing jumpsuits that I often wear in a lot of my events. She has a jumpsuit design line called Risen Division, and she just makes these incredible—they're fantastic— We also design patches for all of our events. So there are these string theory patches and consciousness patches.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
We should show this as overlays. Right.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So, you know, I think all of this is just... I just like to experiment with life, I think. Making the magazine was a big, wild experiment.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And it was quite astounding that that people like Oppenheimer, actually it's probably Oppenheimer's most important theoretical work, who are thinking about nuclear physics and quantum mechanics, but in the context of these kind of utopian questions. Why do stars shine? Why is the sun radiant and hot? this amazing source of light.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
With life.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah. This kind of idea that we were just describing is I find it hard to stop the momentum if I think... something can, I can make something. I have to try to make it. And to me, this is the closest I come to experimentation and collaboration, because even though I collaborate theoretically, I have great collaborators, Brian Green, Massimo Perotti, Dan Cabot.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
These are my really close collaborators. A lot of theoretical physics is alone and You're in your mind a lot. This is something that really was built, this triad of Dustin, Gabe, and I, and all the amazing people who work there on our amazing board. We really are doing it together. You take one element out and it starts to change shape. And that's a very interesting experience, I think.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And making things is an interesting experience.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I love fiction, which I think people expect me to read a lot of sort of sci-fi or nonfiction. I mostly read fiction. I had a syllabus of great fiction writers that had science in it, and I love that syllabus.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah, I suppose I could, but I can tell you some of them as they come to mind. Katsuo Ishiguro, who won the Nobel Prize, wrote Remains of the Day, probably most famously. His book Never Let Me Go, It's unbelievable. Totally devastating. Stunning. I say I really love literature. So when people can do that with these very abstract themes, it's sort of my favorite space for literature.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Martin Amis wrote a book that runs backwards, Times Arrow. I love some of his other books even more, but Times Arrow is pretty clever.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And the beauty of the language. I really appreciate that. Even Orwell is amazing. You know, Hitchens' writing on Orwell is amazing. There were some plays on the syllabus. I have to think of what else was in there. But there was one book that I think was kind of surprising that I think is an absolute masterpiece, which is The Road. And you might say, in what sense is The Road a science?
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Well, first of all, Cormac McCarthy absolutely loved scientists and science. And you can feel this very subtle influence, and that book is... It's a really remarkable, precise, stunning, ethereal, all of these things at once. And there's no who, what, where, when, or how. You might guess it's a nuclear event that kicks off the book.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
A lot of people know the road, I think, from the movie, but really the book is magnificent. And it's very, very abstract, but there's a sense to me in which it is, science is structuring it.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And it was people like Oppenheimer who began to ask the question, well, could stars collapse to form black holes? Could they become so dense that eventually not even light would escape? And that's why I think people think that black holes are these dense objects. That's often how it's described. But actually what happens, these very massive stars, they're burning thermonuclear fuel.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Mm-hmm.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Mm-hmm. Oh, animal form's incredible. In fact, some of the, I've kind of played with, you know, some animals are more equal than others. There are, in Godel Turing's work, there were some infinities that are bigger than others. Yeah.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
You know, it's funny. I should say the obvious thing, but I almost feel like it would be greedy. I think of a complicated response to this. The obvious thing for me to say would be I want to understand quantum gravity or if gravity is emergent. It's not even something I work on day to day. I mostly just... look with interest at what others are doing.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And if I think I can jump in, I would, but I'm not jumping into the fray. But obviously, that's the big one. And there is a sort of sense that with that will come the answers to all these other things. My complicated relationship is that, well, you know, part of the scientific disposition isn't having stuff you don't know the answer to.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I mean, we're not going to have all the answers, I hope, because then sort of, then what? It's sort of dystopian.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
They will lead to more. In the same way that relativity led to black holes, black holes led to the information loss paradox or the Big Bang or what happened before or the multiverse. It's because we learned so much, we were able to escalate to the next level of abstraction.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And then you say, well, wait.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I mean, it's been a hundred years more since relativity and we're still picking it apart.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah, it's a tough thought. But again, I think there's a way in which we can come to terms with that, that that's kind of poetic. You know, you build something in the sand and then you erase it. So I think it's just a reminder that we have to be concerned about our immediate experience too, right? How we are to those around us, how they are to us.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
what we leave behind in the near term, what we leave behind in the long term. Have we contributed and did we contribute overall net positive? Eventually, I think it's kind of hard to imagine, but yes, all of these Nobel Prizes, all of these mathematical proofs, all of these conversations, all of these ideas, all the influence we have on each other, even the AI eventually, Will expire.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
You know, they're earthfuls of thermonuclear fuel they're burning. And emitting energy in E equals mc squared energy. So it's fusing. It's a fusion bomb. It's a constantly going thermonuclear bomb. And eventually it's going to run out of fuel. It's going to run out of hydrogen, helium stuff to fuse. It hits an iron core. Iron to go past iron with fusion is actually energetically expensive.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And me for your work. Thanks so much for having me.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah. Lots of fun.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So it's no longer... going to do that so easily. So suddenly it's run out of fuel. And if the star is very, very, very massive, much more massive than our sun, maybe 20, 30 times the mass of our sun, it'll collapse under its own weight. And that collapse is incredibly fast and dramatic, and it creates a shockwave. So that's the supernova explosion.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So a lot of these, they rebound because once they crunch, they've reached a new critical capacity where they can reignite to higher elements, heavier elements, and that sets off a bomb, essentially. So the star explodes, helpfully, because that's why you and I are here, because stars send their material back out into space, and you and I get to be made of carbon and oxygen and all this good stuff.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
We're not just hydrogen. So the suns do that for us. And then what's left sometimes ends at a neutron star, which is a very cool object, very fascinating object, super dense, but bigger than a black hole, meaning it's not compact enough to become a black hole. It's an actual thing. A neutron star is a real thing. It's like a giant neutron.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Literally, electrons get jammed into the protons and make this giant nucleus and this superconducting matter. Very strange, amazing objects. But if it's heavier than that, the core, and that's heavier than twice the mass of the sun... It will become a black hole.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And Oppenheimer wrote this beautiful paper in 1939 with his student saying that they believed that the end state of gravitational collapse is actually a black hole. This is stunning and really a visionary conclusion. Now, the paper is published the same day the Nazis advance on Poland. And so it does not get a lot of fanfare in the newspapers.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
What I also love about that lesson is how agnostic science is. because he was asking these utopian questions, as were other people of the time, about the nuclear physics and stars. You might know this play, Copenhagen, by Michael Frayn. There's this line that he attributes to Bohr.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Bohr was the great thinker of early foundations of quantum mechanics, Danish physicist, where Bohr says to his wife, nobody's thought of a way to kill people using quantum mechanics. Now, of course, then there's the nuclear bomb. And what I love about this was the pressure scientists were under to do something with this nuclear physics and to enter this race over a nuclear weapon.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But really, at the same time, 1939, really, Oppenheimer's thinking about black holes. There's even a small line in Chris Nolan's film It's very hard to catch. There's a reference to it in the film where they're sort of joking, well, I guess nobody's going to pay attention to your paper now, you know, because of the Nazi advance on Poland.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Right.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Exactly. So, of course, Oppenheimer, now known as the father of the atomic bomb, he talks about destroyers of worlds. But it's the same technology. And that's what I mean by science is agnostic, right? It's the same technology, overcoming a critical mass, igniting thermonuclear fusion. Eventually, there was a fission. The original bomb was a fission bomb.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And fission was first shown by Lise Meitner, who showed that a certain uranium, when you bombarded it with protons, broke into smaller pieces that were less than the uranium, right? So some of that mass that E equals MC squared energy had escaped. And it was the first kind of concrete demonstration of this, Einstein's most famous equation.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So all of this comes together, but the story of, they still weren't called black holes. This is 1939. And they had these very long-winded ways of describing the end state, the catastrophic end state of gravitational collapse. But what you have to imagine is as this star collapses, so now, so what's the sun? The sun's a million and a half kilometers across.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So imagine a star much bigger than the sun, much bigger radius. And it's so heavy, it collapses, it supernovas. What's left is still maybe 10 times the mass of the sun, just what's left in that core. And it continues to collapse. And when that reaches about 60 kilometers across, Like, just imagine, 10 times the mass of the sun, city-sized. That is a really dense object.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And now the black hole essentially has begun to form, meaning the curve in spacetime is so tremendous that not even light can escape. The event horizon forms, but the event horizon is almost imprinted on the spacetime because the star can't sit there in that dense state any more than it can race outward at the speed of light. Because even light is forced to rain inwards.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So the star continues to fall. And that's the magic part. The star leaves the event horizon behind. And it continues to fall. And it falls into the interior of the black hole. Where it goes, nobody really knows. But it's gone from sight. It goes dark. There's this quote by John Wheeler, who's like granddaddy of American relativity, and he has a line that's something to the effect.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
The star, like the Cheshire cat, fades from view. One leaves behind only its grin, the other only its gravitational attraction. And he was giving a lecture. It's actually above Tom's restaurant, you know, from Seinfeld near Columbia in New York. There was a place, or there still is a place there, where people were giving lectures about astrophysics. And it's 1967.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Wheeler is exhaustively saying this loaded term, the End state of catastrophic gravitational collapse. And rumor is that someone shouts from the back row, well, how about black hole? And apparently he then foists this term on the world. Wheeler had a way of doing that.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Oh, yeah, it's gorgeous.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah. Now, I have to say, Wheeler, who actually coins the term black hole, gives Oppenheimer quite a terrible time about this. He thinks he's wrong. And they entered what has sometimes been described as kind of a bitter, I don't know if you would actually say feud, but there were bad feelings. And Wheeler actually spent decades saying Oppenheimer was wrong.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And eventually, with his computer work, that early work that Wheeler was doing with computers when he was also trying to understand nuclear weapons, and in peacetime, found themselves returning again to these astrophysical questions, decided that actually Oppenheimer had been right.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
He thought it was too simplistic, too idealized a setup that they had used, and that if you looked at something that was more realistic and more complicated, that it just simply, it just would go away. And in fact, he draws the opposite conclusion. And
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
There's a story that Oppenheimer was sitting outside of the auditorium when Wheeler was coming forth with his declaration that, in fact, black holes were the likely end state of gravitational collapse for very, very heavy stars. And when asked about it, Oppenheimer sort of said, well, I've moved on to other things.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I think it's an excruciating moment in the history of science. People talk about Heisenberg, who stayed in Germany and worked for the Nazis in their own attempt to build the bomb. There was this kind of hopeful talk that maybe Heisenberg had intentionally derailed the nuclear weapons program, but I think that's been largely discredited, that he would have made the bomb, could he?
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Had he not made some really kind of simple... errors in his original estimates about how much material would be required or how they would get over the energy barriers. And that's a terrifying thought.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I don't know that any of us can really put ourselves in that position of imagining that we're faced with that quandary, having to take the initiative to participate in thinking of a way that quantum mechanics can kill people and then making the bomb. I think overwhelmingly physicists today feel we should not continue in the proliferation of nuclear weapons.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Very few theoretical physicists want to see this continue.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
In the game theory version, this was the least harmful outcome. Yes. Yes. But there is no outcome with an Obam that any game theorist would, I think, would play. Right.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
They don't have control, right. Once it's made, it's no longer scientific reasoning that dictates the use or it's restraint. But I will say that I do believe that it wasn't a 31 third down the line because science America was different. And I think that's something we have to think about right now in this particular climate. So many scientists fled here. They fled to here.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Americans weren't fleeing to Nazi Germany. They came here and they were motivated. It's more than a patriotism. I mean, it was a patriotism, obviously, but it was sort of more than that. It was really understanding the threat of Europe, what was going on in Europe, and how quickly it turned.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
How quickly this free-spirited Berlin culture, you know, was suddenly in this repressive and terrifying regime. So I think that it was a much higher chance that it happened here in America.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Absolutely, the world flocked here, and that won't be the case if we no longer have intellectual freedom.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Oh, yeah. I don't have the number, but it's disproportionately so. In fact, a lot of them from particle physics came from the Bronx. And they were European immigrants.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
They fled Europe precisely because of the geopolitics we're describing. And so instead of being Nobel Prize winners from the Soviet Union or from the Eastern Bloc, they were from the Bronx. Yes.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
The star is collapsing.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah. So if I were falling into a black hole and I tried really fast, right as I crossed this empty region, but this demarcation, I happened to know where it was. I calculated because there's no line there. There's no sign that it's there. There's no signpost. I could... emit a little light pulse and try to send it outward exactly at the event horizon. So it's racing outward at the speed of light.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It can hover there because from my perspective, it's very strange. The space-time is like a waterfall raining in, and I'm being dragged in with that waterfall. I can't stop at the event horizon. It comes, it goes. It's behind me really quickly. That light beam can try to sit there because it's like a fish swimming against the Niagara, you know, swimming against a waterfall.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But it's like stuck there. And so that's one way you can have a little signpost. You know, if you fly by, you think it's moving at the speed of light. It flies past you at the speed of light, but it's sitting right there at the event horizon.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yes.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It just gets stuck there. Now, it's very unstable. So the star can't sit there is the point. It just can't. So it rains inward with this waterfall. But from the outside, all we should ever really care about is the event horizon because I can't know what happens to it.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It could be pure matter and antimatter thrown together, which annihilates into photons on the inside and loses all its mass into the energy of light. Won't matter to me because I can't know anything about what happened on the inside. Wow.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I don't mind being incautious about thinking about what the math tells us. I'm not such an observer. I'm very theoretical in my work. It's really pen on paper a lot. These are thought experiments that I think we can perform and contemplate. Whether or not we'll ever know is another question.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And so one of the most beautiful things that we suspect happens on the inside of a black hole is that space and time, in some sense, swap places. So while I'm on the outside of the black hole, let's say I'm in a nice, comfortable space station, this black hole may be 10 times the mass of the sun, 60 kilometers across. I could be 100 kilometers out. That's very, very close. Orbiting quite safely.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
No big deal. You know, hanging out. I don't bug the black hole. Black hole doesn't bug me. It won't suck me up like a vacuum or anything crazy. But my astronaut friend jumps in. As they cross the event horizon, what I'm calling space, I'm looking on the outside at this... spherical shadow of the black hole cast by maybe light around it. It's a shadow because everything gets too close, falls in.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's just this contrast against a bright sky. I think, oh, there's a center of a sphere. And in the center of the sphere is the singularity. It's a point in space from my perspective. But from the perspective of the astronaut who falls in, it's actually a point in time.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So their notions of space and time have rotated so completely that what I'm calling a direction in space towards the center of the black hole, like the center of a physical sphere, they're going to tell me what they can't tell me, but they're going to come to the conclusion, oh, no, that's not a location in space. That's a location in time.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
In other words, the singularity ends up in their future, and they can no more avoid the singularity than they can avoid time coming their way. So there's no shenanigans you can do once you're inside the black hole to try to skirt it, the singularity. You can't set yourself up in orbit around it. You can't try to fire rockets and stay away from it because it's in your future.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And there's an inevitable moment when you will hit it. Usually for a stellar mass black hole, we think it's microseconds.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yes, from their perspective, the singularities in their future.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So one way to think about this is to think that as you're approaching the black hole, the astronaut's space-time is rotating relative to your space-time. So let's say right now my left is your right. We're not shocked by the fact that there's this relativity in left and right. It's completely understood. And I can perform a spatial rotation to align my left with your left.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Right now, I've completely rotated left out. If I just want to draw a compass diagram, not a compass diagram, but at the top of maps, there's a north, south, east, west, but now time is up, down, and one direction of space is, let's say, east, west. As you approach the black hole, it's as though you're rotating in space-time, is one way of thinking about it. What is the effect of that?
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
The effect of that is as this astronaut gets closer and closer to the event horizon, Part of their space is rotated into my time and part of their time is rotated into my space. So in other words, their clocks seem to be less aligned with my time. And the overall effect is that their time seems to dilate.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
The spacing between ticks on the clock of their watch, let's say, on the face of their watch, is elongated, dilated. relative to mine. And it seems to me that their watches are running slowly, even though they were made in the same factory as mine, they were both synchronized beautifully, and they're excellent Swiss watches. It seems as though time is elapsing more slowly for my companion.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And likewise, for them, it seems like mine's going really fast. So years could elapse In my space station, my plants come and go. They die. I age faster. I've got gray hair. And they're falling in, and it's been minutes in their frame of reference. Flowers and their little rocket ship haven't rotted. They don't have gray hair. Their biological clocks have slown down relative to ours.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Eventually, at the event horizon, it's so extreme, it's so slow, it's as though their clocks have stopped altogether from my point of view. And that's to say that it's as though their time has completely rotated into my space. And this is connected with the idea that inside the black hole, space and time have switched places. So I might see them hover there for millennia.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Other astronauts could be born on my space station. Generations could be populated there watching this poor astronaut never fall in.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Right. They do fall in eventually. Now that's because they have some mass of their own.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So they're not a perfectly light particle. And so they deform the event horizon a little bit. You will actually see the event horizon bobble and absorb. The astronaut. So in some finite time, the astronaut will actually fall in.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Eventually you'll fall in. Any perturbation will only go one way. It's unstable in one direction, in one direction only. But it's really important to remember that from the point of view of the astronaut, not much time has passed at all. You just sail right across as far as you're concerned and nothing dramatic happens or you might not even realize you've come to the event horizon.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
You might not even realize you've crossed the event horizon because there's nothing there. This is an empty region of spacetime. There's no marker to tell you you've reached this very dangerous point of no return. You can fire your rockets like hell when you're on the outside and maybe even escape. But once you get to that point, there's no amount of energy.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
All the energy in the universe will not save you from this demise.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah, that might surprise people. The bigger it is, the less noticeable it is that you've crossed the event horizon. One way to think about it is curvature is less noticeable the bigger it is. So if I'm standing on a basketball, I'm very aware I'm balancing on a curved surface. My two feet are in different locations and I really notice.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But on the Earth, you actually have to be kind of clever to deduce that the Earth is curved. The bigger the planet, the less you're going to notice the curvature, the global curvature. And it's the same thing with a black hole, a huge, huge black hole. It just kind of feels like just flat. You don't really notice.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
In your frame of reference.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Well, so another cool thing. So I like to dispel myths.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Do you need a minute? You're holding your head.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah. At first, at least, you might not realize what's happened. There are some hints. For instance, black holes are dark from the outside, but they're not necessarily dark on the inside. So this is a kind of fascinating that your experience could be that it's quite bright inside the black hole because all the light from the galaxy is can be shining in behind you.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And it's focusing down because you're all approaching this really focused region in the interior. And so you actually see a bright white flash of light as you approach the singularity. I joke that it's like a near-death experience. We see the light at the end of the tunnel. So you would see millennia pass on Earth. You could see the evolution of
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
the entire galaxy, you know, one big bright flash of light. So it's like a near-death experience, but it's definitely a total death experience.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah. The clocks on the Earth, on the space station, seem to be progressing very rapidly relative to yours. The light can catch up to you, and you get this bright beam of light as you see the evolution of the galaxy unfold. I mean, it sort of depends on the size of the black hole and how long you have to hang around. The bigger the black hole, the longer it takes you to expire in the center.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Right. It would be a microsecond, and that would be too fast.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But a big black hole, you could actually hang around for some months.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
No. So this is also why it's important to think of black holes more abstractly. They are something very profound in the universe, and there are probably multiple ways to make black holes. Making them with stars is most plentiful. There could be hundreds of millions, maybe even a billion black holes in our Milky Way galaxy alone. That many stars.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's only about 1% of stars that will end their lives in a death state that is a black hole. But we now see, and this was really quite a surprise, that there are supermassive black holes. They're billions or even hundreds of billions of times the mass of the sun. millions to tens of billions, maybe even hundreds of billions. So extremely massive.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
We don't think that the universe has had enough time to make them from stars that just merge. We know that two black holes can merge and make a bigger black hole, and then those can merge and make a bigger black hole. We don't think there's been enough time for that. So it's suspected that they're formed very early, maybe even a few hundred million years,
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
after the Big Bang, and that they're formed directly by collapsing out of primordial stuff, that there's a direct collapse right into the black hole.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Right. So it's odd, but it's weirdly easier to make a big black hole out of something that's just the density of air, if it's really, really as big as what we're talking about. So in some sense, if they're just allowed to directly collapse very early in the universe's history, they can do that more easily.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And it's so much so that we think that there's one of these supermassive black holes in the center of every galaxy. So they're not rare, and we know where they are. They're in the nuclei of galaxies. So they're bound to the very early formation of entire galaxies in a really surprising and deeply connected way.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah. I mean, it's ongoing, right? It's ongoing. Which came first, the black hole or the galaxy? Probably big early stars, which were just made out of hydrogen and helium from the Big Bang. There wasn't anything else, not much of anything else. Those early stars were forming and then maybe the black holes and kind of the galaxies were like these gassy clouds around them.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But there's probably a deep relationship between the black hole powering jets, these jets blowing material out of the galaxy that shaped galaxies, maybe kind of curbed their growth. And so I think the mechanisms are still ongoing attempts to understand exactly the ordering of these things.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
There are different ways we can think about it. We can imagine drawing a map of space and treating time as another direction in that map. But we're limited because as three-dimensional beings, we can't really draw four dimensions, which is what I'd require. Three spatial, because I'm pretty sure there's at least three. I think there's probably more.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But I'm happy just talking about the large dimensions, the three we see everywhere. Up, down, east, west, north, south, three spatial dimensions, and time is the fourth. Nobody can really visualize it, but we know mathematically how to unpack it on paper. I can mathematically suppress one of the spatial dimensions and then I can draw it pretty well.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Now, the problem is that we'd call it a Euclidean spacetime. A Euclidean spacetime is when all the dimensions are orthogonal and are treated equally. Time is not another Euclidean dimension. It's actually a Minkowskian spacetime. But it means that the space-time, we're misrepresenting it when we draw it, but we're misrepresenting it in a way that we deeply understand. I can give you an example.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
The Earth, I can project onto a flat sheet of paper. I am now misrepresenting a map of the Earth. And I know that, but I understand the rules for how to add distances on this misrepresentation, because the Earth is not a flat sheet of paper. It's a sphere.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And as long as I understand the rules for how I get from the North Pole to the South Pole, that I'm moving along really a great arc, and I understand that the distance is not the distance I would measure on a flat sheet of paper... then I can do a really great job with a map and understanding the rules of addition, multiplication, and the geometries, not the geometry of a flat sheet of paper.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I can do the same thing with spacetime. I can draw it on a flat sheet of paper, but I know that it's not actually a flat Euclidean space. And so my rules for measuring distances are different than the rules I would use that, for instance, Cartesian rules of geometry. I would know to use the correct rules for Minkowski spacetime and
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And that will allow me to calculate how long time has elapsed, which is now a kind of a length, a space-time length on my map, between two relative observers, and I will get the correct answer. But only if I use these different rules.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Right, exactly. So Einstein struggled for this completely general theory, not a specific solution like a black hole or an expanding space-time or galaxies make lenses. Those are all solutions. That's why what he did was so enormous. It's an entire paradigm that says, over here is matter and energy. I'm going to call that the right-hand side of the equation.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Everything on the right-hand side of Einstein's equations is how matter and energy are distributed in spacetime. On the left-hand side tells you how space and time deform in response to that matter and energy. And it can be impossible to solve some of those equations.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
What was so amazing about what Churchill did is he found this very elegant, simple solution within like a month of reading this final formulation. But Einstein didn't go through and try to find all the solutions. He sort of gave it to us, right?
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
He shared this, and then lots of people since have been scrambling to try to, ah, I can predict the curvature of the spacetime if I tell you how the matter and energy is laid out. If it's all compact in a spherical system like a sun or even a black hole, I can understand the curves in the spacetime around it. I can solve for the shape of the spacetime.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I can also say, well, what if the universe is full of gas or light and it's all kind of uniform everywhere? And I'll find a different, equally surprising solution, which is that the universe would expand. In response to that, that it's not static, that the distances between galaxies would grow. This was a huge surprise to Einstein. So all of these consequences of his theory, you know,
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
came with revelations that were not at all obvious when he first wrote down the general theory.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So if you think about 1905, when he's writing these sequence of unbelievable papers as a 25-year-old who can't get a job as a physicist, and he writes all of these remarkable papers on relativity and quantum mechanics. And then even in 1915-16, he does not know that there are other galaxies out there. This was not known. People had mused about it.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
There were these kind of smudges on the sky that people... They contemplated what if there are other island universes, you know, going back to Kant thought about this, but it wasn't until Hubble, it really wasn't until the late 20s, that it's confirmed that there are other galaxies.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But these are all connected.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Very little information. That's absolutely true. Actually, one of the things I like to point out is the idea of relativity was foisted on people in this kind of cultural way. But there's many ways in which you could call it a theory of absolutism. And the way Einstein got there...
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
with so little information, is by adhering to certain very strict absolutes, like the absolute limit of the speed of light and the absolute constancy of the speed of light, which was completely bizarre when it was first discovered, really. That was observed through experiments trying to figure out, you know, What would the relative speed of light be?
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's really only massless particles have this property that they have an absolute speed. And if you think about it, it's incredibly strange.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
he takes it very seriously and everyone else is trying to come up with models to make it go away, to make the speed of light be a little bit more reasonable, like everything else in the universe. You know, if I run at a car, two cars coming at each other, they're coming at each other faster than if one of them stops. It's really a basic observation of reality, right?
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Here, this is saying that if I'm racing at a light beam and you're standing still relative to the source, will measure the same exact speed of light. Very strange. And he gets to relativity by saying, well, what's speed? Speed is distance. It's space over time. It's how far you travel. It's the space you travel in a certain duration of time.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And he said, well, I bet something must be wrong then with space and time. So this is an enormous leap. He's willing to give up the absolute character of space and time in favor of keeping the speed of light constant.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I'll tell you, it took me, I think, a long time to... I can't say this is how he got there exactly. It's not as though I studied the historical accounts or his description of his internal states. This is more... having learned the subject, how I try to tell people how to get there in a few short steps.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
One is to start with the equivalence principle, which he called the happiest thought of his life. And the equivalence principle comes pretty early on in his thinking. And it starts with something like this. Like right now, I think I'm feeling gravity because I'm sitting in this chair and I feel the pressure of the chair and it's stopping me from falling. And
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I lie down in a bed and I feel heavy on the bed and I think of that as gravity. Einstein has a beautiful ability to remove all of these extraneous factors, including atoms. So let's imagine instead that you're in an elevator and you feel heavy on your feet because the floor of the elevator is resisting your fall. But I want to remove the elevator.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
What does the elevator have to do with fundamental properties of gravity? So I cut the cable. Now I'm falling, but the elevator is falling at the same rate as me. So now I'm floating in the elevator. And if this happened to me, if I woke up in this state of falling or floating in the elevator, I might not know if I was in empty space, just floating, or if I was falling around the earth.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
They're equivalent situations. I would not be able to tell the difference. Actually, when I get rid of the elevator in this way by cutting the cable, I'm actually experiencing weightlessness. And that weightlessness is the purest experience of gravity. And so this idea of falling is actually fundamental. It's how we talk about it all the time. The earth is in a free fall around the sun.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's actually falling. It's not firing engines, right? It's just falling all the time, but it's just cruising so fast.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
To be falling. That is the purest experience of gravity. The experience of gravity, unfettered, uninterrupted by atoms, is weightlessness. That observation, no, it has an unhappy ending, the elevator story, because of atoms again. That's the fault of the atoms in your body interacting electromagnetically with the crust of the earth or the bottom of the building or whatever it is.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But this period of free fall, so the first observation is that that is the purest experience of gravity. Now I can convince you that things fall along curved paths because I could take a pen and if I throw it, we both know it's going to follow an arc. And it's going to follow an arc until atoms interfere again and it hits the ground.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But while it's in free fall, experiencing gravity at its purest, what the Einsteinian description would say is it is following the natural curve in space-time. inscribed by the earth. So the earth's mass and shape curves the paths in space, and then those curvatures tell you how to fall, the paths along which you should fall when you're falling freely.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And so the Earth has found itself on a free fall that happens to be a closed circle. But it's actually falling. The International Space Station uses this principle all the time. They get the space station up there, and then they turn off the engines. Can you imagine how expensive it would be if they had to fuel that thing at all times, right? They turn off the engines. They're just falling.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And they're not that far up. There are certainly people sometimes say, oh, they're so far away, they don't feel gravity. Oh, absolutely. If you stopped the space station, it's going like 17,500 miles an hour, something like that. If you were to stop that, it would drop like a stone right to the Earth. So they're in a state of constant freefall. And they're falling along a curved path.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And that curved path is a result of curving space-time.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Right. So it has to be cruising at a certain speed. So once you get it at that cruising speed, you turn off the engines.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
A weird neighbor, yeah.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's like a watershed moment. Yeah.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Well, this, it was obvious to no one that space-time was curved, but even Newton understood something wasn't right. So he knew there was something missing. And I think that's always fascinating when we're in... a situation where we're pressure testing our own ideas.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
He did something remarkable, Newton did with his theory of gravity, just understanding that the same phenomenon was at work with the earth around the sun as the apple falling from the tree. That's insane. That's a huge leap. Understanding that mass, inertial mass, what makes something hard to push around, is the same thing that feels gravity, at least in the Newtonian picture, in that simple way.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Unbelievable leap. Absolutely genius. But he didn't like that the apple fell from the tree, even though the Earth wasn't touching it.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
The action at a distance.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's really weird. But see, Einstein solves that. Relativity solves that. Because it says the Earth created the curve in space. The apple wants to fall freely along it. The problem is the tree's in the way. The tree's the problem. The tree's actually accelerating the apple. It's keeping it away from its natural state of weightlessness in a gravitational field.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And as soon as the tree lets go of it, the apple will simply fall along the curve that exists.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And told him all this?
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's too out of context.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I heard that Newton used that as an unkind remark to his competitor, Hook.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Right. I know.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I know.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
The one woman in the department.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Well, you know the expression, I'm sure, the battles are so bitter in academia because the stakes are so low.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Children.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
The best scientists I know often ask the simplest questions. First of all, there's probably some confidence there, but also they're never going to lie to themselves that they understand something that they don't understand.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So even this idea that Newton didn't understand the apple falling from the tree, had he lived another couple hundred of years, he would have invented relativity because he never would have lied to himself that he understood it. He would have kept asking this very simple question. And I think that there is this childlike beauty to that. Absolutely. Yeah.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I'll talk about those.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah, absolutely. The discovery is going to come because somebody couldn't sleep at night and couldn't rest.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah, I think it's important to separate the idea that there are these astrophysical states that become black holes from being synonymous with black holes. Because black holes are kind of this larger... and they might've been made primordially when the Big Bang happened. There's something flawless about black holes that makes them fundamental, unlike anything else.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So they're flawless in the sense that you can completely understand a black hole by looking at just its charge, electric charge, its mass, and its spin. And every black hole with that charge, mass, and spin is identical to every other black hole. You can't be like, oh, that one's mine, I recognize it. It has this little feature, and that's how I know it's mine. They're featureless.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
You try to put Mount Everest on a black hole and it will shake it off in these gravitational waves. It will radiate away this imperfection until it settles down to be a perfect black hole again. So there's something about them that is unlike, and another reason why I don't like to call them objects in a traditional sense, unlike anything else in the universe that's macroscopic.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's kind of a little bit more like a fundamental particle. So an electron is described by a certain short list of properties, charge, mass, spin, maybe some other quantum numbers. That's what it means to to be an electron. There's no electron that's a little bit different. You can't recognize your electron. They're all identical in that sense.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And so in some very abstract way, black holes share something in common with microscopic fundamental particles. And so what they tell us about the fundamental laws of physics can be very profound. And it's why even theoretical physicists, mathematical physicists, not just astronomers who use telescopes, they rely on the black hole as a terrain to perform their thought experiments.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And it's because there's something fundamental about them.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's in reach for thought experiments.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Which are quite beautiful.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So this is what catapulted Hawking's fame. When he was a young researcher, he was thinking about black holes and wanted to just add a little smidge of quantum mechanics. Just a little smidge. You know, I wasn't going for full-blown quantum gravity, but kind of just asking, well, what if I allowed...
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
This nothing, this vacuum, this empty space around the event horizon, the star is gone, there's nothing there. What if I allowed it to possess sort of ordinary quantum properties, just a little tiny bit, you know, nothing dramatic? don't go crazy. And one of the properties of the vacuum that is intriguing is this idea that you can never say the vacuum's actually completely empty.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
We talked about Heisenberg. The Heisenberg uncertainty principle really kicked off a lot of quantum mechanical thinking. It says that you can never exactly know a particle's position simultaneously with its motion, with its momentum. You can know one or the other pretty precisely, but not both precisely. And the uncertainty isn't a lack of ability that we'll technologically overcome.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's foundational. In some sense, when it's in a precise location, it is fundamentally no longer in a precise motion. And that uncertainty principle means I can't precisely say a particle is exactly here, but it also means I can't say it's not. Right. Okay, and so it led to this idea that what do I mean by a vacuum? Because I can't 100% precisely know.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
In fact, there's not really meaningful to say that there's zero particles here. And so what you can say, however, is you can say, well, maybe particles kind of froth around in this seething quantum sea of the vacuum. Maybe two particles come into existence and they're entangled in such a way that they cancel out each other's properties so they have the properties of the vacuum.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
They don't destroy the kind of properties of the vacuum because they cancel out each other's spin maybe, each other's charge maybe, things like that. But they kind of froth around. They come, they go, they come, they go. And that's what we really think is the best that empty space can do in a quantum mechanical universe.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Now, if you add an event horizon, which, as we said, is really fundamentally what a black hole is, that's the most important feature of a black hole. The event horizon, if the particles are created slightly... on either side of that event horizon, now you have a real problem. Now the pair has been separated by this event horizon. Now they can both fall in, that's okay.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But if one falls in and the other doesn't, It's stuck. It can't go back into the vacuum because now it has a charge or it has a spin or it has something that is no longer the property of that vacuum it came from. It needs its pair to disappear. Now it's stuck. It exists. It's like you've made it real. So in a sense, the black hole steals one of these virtual particles and forces the other to
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
to live. And if it'll escape, radiate out to infinity, and look like to an observer far away that the black hole has actually radiated a particle. And the particle did not emanate from inside. It came from the vacuum. It stole it from empty space, from the nothingness that is the black hole.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Now, the reason why this is very tricky is because in the process, because of this separation on either side of the event horizon, the particle it absorbs, it has to do with the switching of space and time that we talked about, but the particle it absorbs, well, from the outside, you might say, oh, it had negative momentum. It was falling in.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
From the inside, you say, well, this is actually motion and time. This is energy. It has negative energy. And it absorbs negative energy. Its mass goes down. Black hole gets a little lighter. And as it continues to do this, the black hole really begins to evaporate. It does more than just radiate. It evaporates away.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And it's intriguing because Hawking said, look, this is going to look thermal, meaning featureless. It's going to have no information in it. It's going to be the most informationless possibility you could possibly come up with when you're radiating particles. It's just going to look like a thermal distribution of particles, like a hot body.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And the temperature is going to only tell you about the mass, which you could tell from outside the black hole anyway. You know the mass of the black hole from the outside. So it's not telling you anything about the black hole. It's got no information about the black hole. Now you have a real problem.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And when he first said it, a lot of people describe that not everyone understood how really naughty he was being. He did. But some people who love quantum mechanics were really annoyed. People like Lenny Susskind, Gerard Zuft, Nobel Prize winner, they were mad because it suggested something was fundamentally wrong with quantum mechanics, if it was right.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And the reason why it says there's something fundamentally wrong with quantum mechanics is because quantum mechanics does not allow this. It does not allow quantum information to simply evaporate away and poof out of the universe and cease to exist. It's a violation of something called unitarity, but really the idea is it's the loss of quantum information that's intolerable.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Quantum mechanics was built to preserve information. It's one of the sacred principles. As sacred as conservation of energy, in this example, more sacred, because you can violate conservation of energy with Heisenberg's uncertainty principle a little tiny bit, but so sacred that
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
it created what became coined as the Black Hole Wars, where people were saying, look, general relativity's wrong, something's wrong with our thinking about the event horizon, or quantum mechanics isn't what we think it is, but the two are not getting along anymore.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And just to tell you how dramatic it is, so the temperature goes down with the mass of the black hole, heavier a black hole, the cooler it is, so we don't see black holes evaporate, they're way too big. But as they get smaller and smaller, they get hotter and hotter.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So as the black hole nears the end of this cycle of evaporating away, it takes a very long time, much longer than the age of the universe, it will be as though the curtain, the event horizon, is yanked up. Like it'll literally explode away. Just boom. And the event horizon, in principle, would be yanked up. Everything's gone.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
All that information that went into the black hole, all that sacred quantum stuff, gone, poof, okay, because it's not in the radiation, because the radiation has no information. And so it was an incredibly productive debate because in it are the signs of what will make gravity and quantum mechanics play nice together, you know, some quantum theory of gravity.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Whatever these clues are, and they're hard to assemble, If you want a quantum gravity theory, it has to correctly predict the temperature of a black hole, the entropy of a black hole. It has to have all of these correct features. The black hole is the place on which we can test quantum gravity.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It has not been fully resolved.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I'm unhappy with that. I would not be happy with information loss. I love that it's telling us that there's this crisis, because I do think it's giving us the clues. And we have to take them seriously.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
We have to come to the rescue. As Lenny Susskind in his book, Black Hole Wars, his subtitle is, My Battle with Stephen Hawking to Make the World Safe for Quantum Mechanics. Yeah.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Something to that effect.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
In some sense, it says there's no interior to the black hole, nothing ever crosses. So I gave you this very nice story that there's no drama. Sometimes that's how it's described at the event horizon and you fall through and there's nothing there. This other idea says, well, hold on a second.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
If it's really strings, as I get close to this magnifying quality and the slowing time down near the event horizon, it is as though I put a magnifying glass on things and now the strings aren't so microscopic. They kind of smear around and then they get caught like a tangle around the event horizon and they just actually never fall through. I don't think that either, but it was interesting.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
There are no teeny tiny marbles to fall through.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Nothing falls in. So the information gets out because it never went in in the first place.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
There's a strong statement there, yeah.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Worth trying, but I also don't think that that's the case. So the no hair theorems are formal proofs that the black hole is this featureless perfect fundamental particle that we talked about, that all you can ever tell about the black hole is its electrical charge, its mass, and its spin, and that it cannot possess other features. It has no hair, is one way of describing it.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And those are proven mathematical proofs in the context of general relativity. So the idea is, well, therefore I can know nothing about what goes into the black hole, so the information is lost. But if they could have hair, I could say that's my black hole, because it'd have features that I could distinguish, and it could encode the information that went in in this way.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And the event horizon isn't so serious. There isn't such a stark demarcation between events inside and outside, where I can't know what happened inside or outside. I don't think that's the resolution either, but it was worth a try.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
This is probably it, though.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I can say that this is not a situation where we can follow the chalk. We can't start at the end. So it's still a conjecture. I think it's very profound, though. I kind of imagine Juan Maldacena, who's part of this, with Lenny Suskin, they were kind of like, oh, it's like ER equals EPR. They couldn't even formulate it properly. It was like an intuition that they had kind of
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
landed on and now are trying to formalize. But to take a step back, one way of thinking about ER equals EPR, you have to talk about holography first. And holography, both Juan Maldacena really formalized it, Lenny Susskind suggested it.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
The idea of a black hole hologram is that all of the information in the black hole, whatever it is, whatever entropy as a measure of information, whatever the entropy of the black hole is, which is telling you how much information is hidden in there, how much information you don't have direct access to in some sense, is completely encoded in the area of the black hole.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Meaning, as the area grows, the entropy grows. It does not grow as the volume. This actually turns out to be really, really important. If I tried to pack a lot of information into a volume, more information than I could pack, let's say, on the surface of a black hole, I would simply make a black hole. And I would find out, oh, I can't have more information than I can fit on the surface.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So Lenny coined this a hologram. People who take it very seriously say, well, again, maybe the interior of the black hole just doesn't exist. It's a holographic projection of this two-dimensional surface. In fact, maybe I should take it all the way and say, so are we. The whole universe is a holographic projection of a lower dimensional surface.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And so people have struggled, nobody's really landed it, to find a universe version of it. Oh, maybe there's a boundary to the universe where all the information is encoded and this entire three-dimensional reality that's so compelling and so convincing is actually just a holographic projection. Juan Maldacena did something absolutely brilliant.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's the most highly cited paper in the history of physics. It was published in the late 90s. It has a very opaque title that would not lead you to believe it's as revelatory as it is. But he was able to show that a universe like in a box with gravity in it, it's not the same universe we observe, doesn't matter. It's just a hypothetical called an anti-de Sitter space.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
This universe in a box, it has gravity, it has black holes, it has everything gravity can do in it. On its boundary, is a theory with no gravity, a universe that can be described with no gravity at all, so no black holes, and no information loss problem. And they're equivalent. That the interior universe in a box is a holographic projection of this quantum mechanics on the boundary.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Pure quantum mechanics, purely unitary, no loss of information. None of this stuff could possibly be true. There can't be loss of information if this dictionary really works, if the interior is a hologram, a projection of the boundary. I know that's a lot.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Well, what it would mean for us is that information can't be lost even if we don't know how to show it in the description in which there are black holes. It means it can't possibly be lost because it's equivalent to this description with no gravity in it at all, no event horizons, no black holes, just quantum mechanics.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So it really strongly suggested that quantum mechanics was going to win in this battle, but it didn't show exactly how it was going to win. So then comes ER equals EPR. A visual way to imagine what this means. So ER has to do with little wormholes. EPR, Einstein, Podolsky, Rosen, has to do with quantum entanglement.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
The idea was, well, maybe the stuff that's interior to the black hole is quantum entangled, like EPR, quantum entangled, with the Hawking radiation outside the black hole that's escaping. And that quantum entanglement is what allows you to extract the information because it's not actually physically moving from the interior to the exterior. It's just subtle quantum entanglement.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And in fact, I can kind of think of The entire black hole, if I look at it, it looks like a solid shadow cast on the sky, some region of space-time. If I look at it very closely, I will see, oh no, it's actually sewn from these quantum wormholes, like embroidered. And so when I get up close, it's almost as though the event horizon isn't the fundamental thing. feature on the spacetime.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
The fundamental feature is the quantum entanglement, embroidering the event horizon.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And they're connected by a wormhole.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So the reason why that's helpful, it helps you connect the interior to the exterior without trying to pass through the event horizon.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
True. We do what we can do in baby steps.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I would say the firewall papers were fascinating and were very provocative and very important in making progress. I don't even think the authors of those papers thought firewalls were real. I think they were saying, look, we've been brushing too much under the rug. And if you look at the evaporation process, it's even worse than what you thought previously.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's so bad that I can't get away with some of these prior solutions that I thought I could get away with. There was a kind of duality idea or a complementarity idea that, oh, well, maybe one person thinks they fell in, one person thinks they never fell in, and that's okay. You know, no big deal.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
They sort of exposed flaws in these kind of approaches, and it actually reinvigorated the campaign to find a solution. So it stopped it from stalling. I don't think anyone really believes that at the Event Horizon you'll find a firewall. But it did lead to things like the entangled wormholes embroidering a black hole, which was born out of an attempt to address the concerns that Amps raised.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So it did lead to progress.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
The empty space, the beautiful event horizon. I'll give up locality, meaning that I will allow things to be connected non-locally by a wormhole.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah, classic. Sidney was beloved.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I'll entertain pretty weird things, but I think that's the one that sounds promising. The implications are so dramatic because this is why you start to hear things like, wait a minute, if the event horizon only exists when it's sewn out of these quantum threads, does that mean that gravity is fundamentally quantum mechanics?
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Not that gravity and quantum mechanics get along and I have a quantum gravity theory and I now know how to quantize gravity. Actually, something much more dramatic. Gravity is just kind of emerging from this quantum description that gravity isn't fundamental. And what is the only thing that we have when we go rock bottom, when we go deeper and deeper, smaller and smaller, is quantum mechanics.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So all of this, like space-time looks nice and smooth and continuous, but if I look at the quantum realm, I'll see everything sewn together out of quantum threads. And that space-time is not a smooth continuum all the way down. Now, people already thought that, but they thought it kind of came in chunks of space-time. Instead, maybe it's just quantum mechanics all the way down.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But when you zoom in a lot... When you zoom in a lot to the quantum mechanical scale at which you're seeing the Hawking radiation, you would be noticing that there's some entanglement between the radiation that I could not explain before and the interior of the black hole. So it's now no longer a perfectly...
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
thermal spectrum with no features that only depends on the mass, it actually has a way to have an imprint of the information interior to the black hole. in the particles that escape.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And so now, in principle, I could sit there for a very long time, it might take longer than the age of the universe, and collect all the Hawking radiation and see that it actually had details in it that are going to explain to me what was interior to the black hole so the information is no longer lost.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Now, I can't do that any more than I can recover the words on that piece of paper once it's been burnt. But that's a practical limitation, not a fundamental one. It's just too hard. But when I burn a piece of paper, technically, the information is all there somewhere. It's in the smoke. It's in the currents. It's in the molecules. It's in the ink molecules. But in principle, if I had...
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
took the age of the universe, I should be able to, in principle, reconstruct the piece of paper and all the words on it.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah, we're skirting around it. I think that this is the way to find that out. It's going to be on the train of black holes that we figure out if that's possible. I think that this is suggesting that there might not be a theory of quantum gravity, that gravity will emerge at a macroscopic level out of quantum phenomena. Now, we don't know how to do that yet.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
There are examples of emergent phenomena which are very simple and clean. Like I can just take electromagnetic scattering, which is law of physics where particles scatter just by electromagnetically. And I have a lot of them and I have a lot of them in this room and they come to some average. Well, I call that temperature.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And that one number, the fact that there's one number describing all of these gazillions of particles is an emergent quantity. There's no particle that carries around this fundamental property called temperature. It emerges from the collective behavior of tons and tons of particles. In some sense, temperature is not a fundamental quantity. It's not a fundamental law of nature.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's just what happens... from the collective behavior. And that's what we'd be saying. We'd be saying, oh, this emerges from the collective behavior of lots and lots and lots of quantum interactions.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah, we could discover dark matter, dark energy. We could discover extraspatial dimensions. We could discover that those three things are linked, that there's like a dark sector to the universe that's hiding in these extra dimensions. And that's something that I love to work on. I think it's really fascinating.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Okay.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
All of those would also be clues about this question, but they wouldn't solve this problem. I think it's impossible to predict. There has been real progress. And the progress, as we've said, comes from the childlike curiosity of saying, well, I don't actually understand this. I'm going to keep leaning on it because I don't understand it. And then suddenly you realize nobody really understood it.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So I don't know. Do I think it's a harder problem than the problem of the origin of life? I think it's technically a harder problem, but I don't know. Maybe the breakthrough will come.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Well, we know that there are three spatial dimensions. We like to talk about time as a dimension. We can argue about whether that's the right thing to do. But we don't know why there are only three. It very well could be that there are extra spatial dimensions, that there's like a little origami of these tightly rolled up dimensions. Not all the models require that they're small, but most do.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
String theory requires extra dimensions to make sense, but even if you feel very hostile towards string theory, there are lots of reasons to consider the viability of extra dimensions. And we think that they can trap little quantum energies in such a way that might align with the dark energy. The numerology is not perfect. It's a little bit subtle. It's hard to stabilize them.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's possible that there are these kind of quantum excitations that look a lot like dark matter. It's kind of an interesting idea that in the Big Bang, the universe was born with lots of these dimensions. They were all kind of wrapped up in the early universe. And what we're really trying to understand is why did three get so big? Yeah. And why did the others stay so small?
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah, there is, actually. And people have worked on that. Is there a reason why it's easier to unravel three dimensions? Some people think about strings and brains wrapping up in the extra dimensions, causing a kind of constriction, but preferentially loosening up in three.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah. In a way, people often confuse how they're formed with the concept of the black hole in the first place. So when black holes were first proposed, Einstein was very surprised that such a solution could be found so quickly, but really thought nature would protect us from their formation. Then nature thinks of a way.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Sometimes we look at exactly models like that, which have to do with the origami being resistant to change in a certain way that only allows three to unravel and keeps the others really taut. But then there are other ideas that we're actually living on a three-dimensional membrane that moves through these higher dimensions. And so the reason we don't notice them isn't because they're small.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Maybe they're not small at all. But it's because we're stuck to this membrane. So we're unaware of these extra directions.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I think it is certainly mathematically possible on paper to imagine a higher dimensional universe with more than one membrane. If things are mathematically possible, I often wonder if nature will try it out. Yeah. Just how people get into the strange territory of talking about a multiverse.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Because if you start to say... One of the aspirations was, in the same way that we identified the law of electroweak theory of... matter, that it was a single description and exactly landed on the description that matched observations. People were hoping the same thing would happen for a kind of theory that also incorporated gravity.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
There would be this one beautiful law, but instead they got a proliferation, all of which did okay or did equally badly. They suddenly had trouble finding, not only finding a single one, but sort of That would just beg a new question, which is, well, why that one? And if nature can do something, won't she do anything she can try?
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And so maybe we really are just one example in an infinite sea of possible universes with slightly different laws of physics. So if I can do some of these things on paper, like imagine a higher dimensional space in which I'm confined to a brain and there's another brain or maybe a whole array of them, maybe nature's tried that out somewhere. Maybe that's been tried out here.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And then, yes, is it possible that there's life and civilizations on those other brains? Yeah, but we can't communicate with them. They'd be like in a shadow space.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
No, that's fair. I'm limited in my communication because I'm glued to the brain, but some things can move. We call the bulk through the bulk. Gravity, for instance, a gravitational wave. So I could design a gravitational communicator, communication system, and I could send gravitational waves through the bulk. And how SETI is doing with light into space, I could send signals into the bulk.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Telling them where we are and what we do and singing songs. Of course.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Very expensive. Very hard to localize. They tend to be long wavelength and very hard to do. A lot of energy moving around. A lot of energy.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Nature thinks of a way to make these crazy objects, which is to kill off a few stars. But then I think that there's a confusion that dead stars, these very, very massive stars that die, are synonymous with the phenomenon of black hole. And it's really not the case. Black holes are more general and more fundamental than just the death state of a star.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It is possible that there's other things that live in the bulk. I mean, last night I was calculating away, looking at something that lives in the bulk.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah, nature's an experimenter.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Right, yeah. We don't even have to go to something as crazy as extra dimensions and brain worlds and all of that. What's happening right now in the past 30 years in astronomy, looking at real objects, is that the number of planets, exoplanets, outside our solar system has absolutely proliferated. There are probably more planets in the Milky Way galaxy than there are stars.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And now we have a real quandary. I don't think it's a quandary. I think it's really exciting. It becomes impossible. What you just said, I totally agree with. It becomes impossible to imagine that life was not sparked somewhere else in our Milky Way galaxy and maybe even in our local neighborhood of the Milky Way galaxy, maybe within a few hundred light years of our solar system.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Well, isn't that kind of appalling? I mean, just take that statement. We've only been around for like, I mean, a couple hundred thousand years tops, you know, that is not very long. And we're at a 50-50. I mean, that's unbelievable. I mean, it's indisputable that we have created the means, at least potentially, for our own destruction. Will we learn from our mistakes?
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But even the history of how people realized that stars could form black holes is quite fascinating because the entire idea really just started as a thought experiment. If you think of, it's 1915, 1916, when Einstein fully describes relativity in a way that's the canonical formulation. It was a lot of changing back and forth before then. And it's World War I, and he gets a message
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Will we avert course and save ourselves? One hopes so, right? But even the concept that it's conceivable, whales have not invented a way to kill themselves, to wipe out all whales and Earth and life on Earth.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
You mean all these civilizations?
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Right. You could use a kind of evolutionary Darwinian natural selection on that, where survival isn't just in a harsh, naturally-induced climate change, but it's because of a nuclear holocaust. And then something will... be created that is now impervious to that, that now knows how to survive.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Right. Well, because that's a pretty big bar. So if you look at the, just to say, for comparison, dinosaurs, you know, 250 million years. I mean, maybe not very bright. Didn't invent fire, didn't write sonnets. They didn't contemplate the origin of the universe, but they lived. And in a benign situation without confronting their own demise at their own hands, paws, hooves.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So it's just a sheer numbers game. That's a long time, 250 million years. I do think, though, that life can flourish without wanting to manipulate its environment and that we do see many examples of species on Earth that are very long-lived, very, very long-lived, and have very different states of consciousness. They have the jellyfish, does not even have a localized brain.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I don't think they have a heart or blood. I mean, they're really different from us. And that's what I think we have to start thinking about when we think about aliens. Those species have lived for a very, very long time. They even show some evidence of immortality. You can wound one badly, and there are certain jellyfish that will go back into a kind of pre-state and start over.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So I think we're very attached to imagining creatures like us that manipulate technology. And I think we have to be way more imaginative if we're going to really take seriously life in the universe.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
They might not be violent.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
They might be solitary. They might not be social. They might not move in groups. They might not want to leave records. They might, again, not have a localized brain or have a completely different kind of nervous system. I think all we can say about life is it has something to do with moving electrons around. And neurologically, we move electrons through our nervous system.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Our brain has electrical configurations. We metabolize food, and that has to do with getting energy, electrical energy in some sense, out of what we're eating. We have organisms on the earth that can eat rocks. It's quite amazing. Minerals. I mean, talk about extremophiles. They can metabolize things that were impossible to metabolize.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And so, again, I think we have to kind of open our minds to how strange that could be and how different from us. And we are the only example, even here on Earth, that does manipulate its environment in that extreme way.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
From the Eastern Front, from a friend of his, Karl Schorchild, who solved Einstein's equations, you know, between sitting in the trenches and like cannon fire. It was joked that he was calculating ballistic trajectories. He's also perusing the proceedings of the Prussian Academy of Sciences, as you do. Interesting. He was an astronomer who had enlisted in his 40s.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I think there are arguments like that. How entropy is changing from the beginning of the universe to today. How life lowers entropy by organizing things, but it costs more as a whole system. So the whole entropy of the whole system goes up. But of course, I organized things today and reduced the entropy of certain things in order to get up and get here.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And even having this conversation, organizing thoughts. out of the cloud of information, but it comes at the cost of the entire system increasing entropy. So I do think there's probably a very interesting way to talk about life in this way. I'm sure somebody has.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah. I mean, people have tried to make arguments like that. Like, can I look for entropic arguments that might suggest we've done this before? The Big Bang has happened before. Yeah.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I don't think membranes is going to explain why we don't see them in the Milky Way. I think that is just a problem we're stuck with. Whether or not there are extra dimensions or whether or not there's life in another membrane, I think we know that even just in our galaxy, which is a very small part of the universe, 300 billion stars, something like that,
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
A whole kind of variety of possibilities to be explored by nature in the same way that we're describing. And I think you're absolutely right. When life was kicked off, first sparked here on Earth, it was voracious. Now, it took a really long time, though, to get to multicellularity. I think that's interesting.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's weird. It took a really, really long time to become multicellular. But it did not take long just to start.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I would say multicellularity, which is strictly an energy problem, I think. Again, it's just like, can electrons flow the right way? And is it energetically favorable for multicellularity to exist? Because if it's energetically expensive, it's not going to succeed. And if it's energetically favorable, it's going to take off.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's really just... And that's why I also think that going from inanimate to animate is probably gray, right? Like the transition is gray. At what point we call something fully alive? Famously, it's hard to make a nice list of bullet points that need to be met in order to declare something alive. Is a virus alive? I mean, I don't know. Is a prion alive?
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
They seem to do some things, but they kind of rely on stealing other DNA and replicating and I don't know. I guess they're not alive. But I mean, the point is, is that it really, at the end of the day, I really think it's just, you asked if it's just physics. I mean, I think it's just this, these rules of energetics.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And he finds this really remarkable solution to Einstein's equations. And it's the first exact solution. He doesn't call it a black hole. It's not called a black hole for decades. But what I love about what Churchill did is it's a thought experiment. It's not about observations. It's not about making these things in nature. It's really just about the idea.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Carbon is really cool and really useful because it finds a lot. It's nice. It finds a lot of ways to combine with other things. And that's complexity. And complexity is the kind of thing you need for life. You can't have a very simple linear chain and expect to get life. But I don't know. Maybe sulfur would do okay.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I think wormholes are a perfectly valid construction to consider. They're just a curve in space-time. Topologically, which has to do with the connectedness of the space, is a little tricky because we know that Einstein's description is completely in terms of local curves and distortions, expansion, contraction, but it doesn't say anything about the global connectedness of the space.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Because he knew that it could be globally connected on the largest scales.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
This kind of origami that we're talking about, that you could travel in a straight line through the universe, leave our galaxy behind, watch the Virgo cluster drift behind us and travel in a straight line as possible and find ourselves coming back again to the Virgo cluster and eventually the Milky Way and eventually the Earth, that we could find ourselves on a connected, compact space-time.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But topologically, there's something we know for sure, something beyond Einstein's theory that has to explain that to us. Now, wormholes are a little funky because they're topological. You know, they create these handles and holes in these sneaky, by topological, I mean these connected spaces and structures.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Like Swiss cheese, right. So I could have two flat sheets that are connected by a wormhole, but then wrap around on the largest scale, all this cool stuff. There's nothing wrong with it, as far as I can see. There's nothing... abusive towards the laws about a wormhole, but we can reverse engineer.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
We were saying, oh, look, if I know how matter and energy are distributed, I can predict how spacetime is curved. I can reverse engineer. I can say, I want to build a curved spacetime like a wormhole. What matter and energy do I need to do that? It's a simple process. And it's kind of thing Kip Thorne worked on, very imaginative, creative person.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And the problem was that he said, oh, you know, here's the bummer. The matter and energy you need doesn't seem to be like anything we've ever seen before. It has to have like negative energy. That's not great. There are some conjectures that we shouldn't allow things that have that kind of a property, that have negative energies.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
He sets up this completely untenable situation. He says, imagine. I crush all the mass of a star to a point. Don't ask how that's done, because that's really absurd. But let's just pretend, and let's just imagine that that's a scenario. And then he wants to decide what happens to spacetime if I set up this confounding but somehow very simple scenario.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Only things that have positive energies are going to be stable and long-lived. But we actually know of quantum examples of negative energy. It's not that crazy. There's something called the Casimir effect. You have two metal plates, and you put them really close together, you can see this kind of quantum fluctuation between the plates.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's called a Casimir energy, and that can have a negative energy. It can actually... cause the place to attract or repel depending on how they're configured. And so you could kind of imagine doing something like that, like having wormholes propped up by these kinds of quantum energies. And people have thought of imaginative configurations to try to keep them propped up.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Are we at the point of me saying, oh, this is an engineering problem? I'm not saying that quite yet. But it's certainly plausible.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
You need a lot of this weird matter to send a person through.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
That's going to be really challenging. So I'm not saying it's simply an engineering problem, but it's all within the realm of plausible physics, I think.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
People have looked at that. They tend to be non-traversable wormholes. They're not trying to prop them open. But yeah, I mean, some of this ER equals EPR quantum entanglement, they're trying to connect black holes. Yeah. You know, it's really cool. Again, it's not quite following the chalk. And by that, I mean, we can't exactly start at a concrete place, calculate all the way to the end yet.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
An omniscient being.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Right.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's a hyperbolic manifold that's identified across.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
You need to be able to ask a follow-up question.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
In ways we don't understand.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But I can tell you, I'm pretty sure all of them have in common the feature that they're saying, here's what I want my wormhole to look like first. So it's like saying, I want to build a building first. So they construct, there's an architecture of the space-time that they're after. And then they reverse the Einstein equations to say, what must matter in energy first?
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
What are the conditions that I impose on matter and energy to build this architecture?
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But it's important because it's how they realized, oh, wow, they have to have these negative energies. They have to violate certain energy conditions that we often assume are true. And then you either say, oh, well, then all bets are off. They'll never exist. Or you look a little harder and you say, well, I can violate that energy condition without it being that big a deal.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And really what Einstein's equations were telling everybody at the time was that matter and energy curve space and time. And then curved space-time tells matter and energy how to fall once the space-time is shaped. So he finds this beautiful solution.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And again, quantum mechanics often does violate those energy conditions.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah, I mean, sometimes I assign in an advanced general relativity class the assignment of inventing a warp drive. And it's kind of similar. So the idea is, here's a place you want to get to. And can you contract the space-time between you with something antithetical to dark energy, the opposite, and skip across and then push it back out again? You can do that in the context of general relativity.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Now, I can't find the energy that has these properties, but I also can't find dark energy. So we've already been confronted with something that we look at the space-time. The space-time is expanding ever faster. We say, what could possibly do that? We don't know what it is, but I can tell you about its pressure. I can tell you certain features about it.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And I just call it dark energy, but I actually have no idea. It's just, that name's just a proxy for what this, it should be called invisible because it's not actually dark. It's in this room. It's not hard to see through. It's not dark. It's literally invisible. So maybe that was a misnomer. But the point being, I still don't fundamentally know what it is. That's not so terrible.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
That's the state of the world that we're actually in. So maybe warp drive is just kind of like a version of that. I don't know. I don't know what form of matter can do that yet, but at least I can identify the features that are needed.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah, actually it might. It is positive energy and a negative pressure, which is like a rubber band quality. We think of pressure as pushing things outward and dark energy has a very strange quality that as things move outward, you feel more energy as opposed to less energy. The energy doesn't get lower, it gets more.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And the most amazing thing about his solution is he finds this demarcation, which is the event horizon, which is the region beyond which not even light can escape. And if you were to ask me today, all these decades, over 100 years later, I would say that is the black hole. The black hole is not the mass crushed to a point. The black hole is the event horizon.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It doesn't have the right features for the wormhole, but those are some pretty surprising features. We, again, can conjecture like, oh, hey, you know, the quantum energy of the vacuum kind of behaves that way. That would be a great resolution to the dark energy problem. It's just the energy of empty space, and it's the quantum energy of empty space. That's an excellent answer.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
The problem is, is by all our methods and all the understanding we have, that energy's either really, really huge, huge energy, way bigger than what we see today, or it's like zero. So that's a numbers problem. We can't naturally fine-tune the energy of empty space to give us this really weird value so that we just happen to be seeing it today.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But again, we can think of a kind of dark energy that exists. So the question is just why is it such a weird value? not how is this conceivable, because we can't conceive of it.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yes, there's absolutely a phenomenon. Nobody's going to say they're happy with that. We're all going to say there's something we don't understand, which is why we look to the extra dimensions. Because then you can say, oh, maybe it has to do with the size of the extra dimensions or the way that they're wrapped up.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And so maybe it's foisted on us because of the topology, the connectedness of the higher dimensional space. These are all things that we're exploring. Nobody's landed one that's so compelling that your friends like it as much as you do.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I think dark matter might be less peculiar than dark energy. My hope is that they're all tied together. That would be very gratifying. These aren't just separate problems coming from different sectors, but that they're actually connected. That the reason the dark matter is where it is
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
in terms of how much it's contributing to the universe, is connected with why the dark energy is showing up right now. I would love that. That would be a solution like no other, right? And like I said, if it revealed something about dark dimensions, you know, that would be a happy day.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah. Dark matter is localized in space. So it clumps. I mean, it doesn't clump a lot, you know, but I mean, it's around the galaxy, right? It's in a halo around the galaxy.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Oh, it's really compelling.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I mean, you see these images of galaxies, clusters that pass through each other. And you can see where the light is, the luminous matter is distributed. And then by looking at the gravitational lensing, which...
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
shows you where the actual mass is distributed so that light bends around the most massive parts in a particular way so you can reconstruct where the mass is gravitationally quite separate from looking at the luminous matter, which is not dark, and they are separate.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Because the stuff, as they pass through each other, the interacting stuff, the luminous stuff collides and gets stuck, and you can see it colliding and lighting up. The dark stuff, which by definition it's dark because it doesn't interact, passes right through each other, right? And this is, I mean, it's so compelling.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And there's lots of other observations, but that one is just, before you just look at it, you can see that the mass is distributed differently than the interacting luminous matter.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And the event horizon is really just a point in spacetime or a region in spacetime. It's actually, in this case, a surface in spacetime. And it marks a separation in events, which is why it's called an event horizon. Everything outside is causally separated from the inside insofar as what's inside the event horizon can't affect events outside. What's outside can affect events inside.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Dark energy is much harder to get a hold of. I mean, the Higgs field could have also explained dark energy, if you've heard of the God particle. I don't know if you know, originally Leon Letterman co-authored a book and he wanted to call it the goddamn particle because they couldn't find it.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
His publisher convinced him to call it the God particle.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And he said they managed to offend two groups, those that believed in God and those that didn't.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
He was very funny. He was very witty.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I mean, unbelievable. There it was. Build this massive collider in CERN in Switzerland. And there it is. Unbelievable. Kind of where you expect it to be. Now, the reason I say it could be dark energy is because the Higgs particle, like a particle of light, also has a field, like an electromagnetic field.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So light can have this field that's distributed through all space, electromagnetic field, and you shake it around and it creates little particles. So the Higgs field... is actually more important than the Higgs particle, the complement to the Higgs particle, because that's what you and I connect with to get mass in our atoms.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So the idea is that our atoms are interacting with this gooey field that's everywhere. Mm-hmm. And that's what's giving us this experience of inertial mass. But we don't actually... There's not a lot of quanta lying around. There's not a lot of Higgs particles lying around because they decay. So it's the field that's really important. And that field could act like a dark energy. It's just not...
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
In the right place, meaning it's not at the right, the energy is too high to explain this tiny, tiny value today. And again, we're back to this mismatch. It's not that we can't conceive of forms of dark energy. It's that we can't make one where we're finding it.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
There's some truth to it, but it's really missing a huge point, which is that if we did not understand the universe as incredibly precisely as we do, it's stunning that there's modern precision cosmology. It's Absolutely incredible. When COBE, which is an experiment that measured the light left over from the Big Bang in the 80s, first revealed its observations, I mean, there was applause.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
People were cheering. It was unbelievable. We had predicted and measured the light left over from the Big Bang. And because of all the precision that's happened since then, that's how we're able to confront that there's things that we don't know.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And that's how we're able to confront like, wow, this is really everything everybody has ever seen and ever will see, as far as we understand, makes up less than 5% of what's out there. And so I would say, yes, we're just giving proxy names to things we don't understand. But to dismiss that as some kind of Oh, they just don't know. It is actually quite the opposite.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It is a stunning achievement to be able to stare that down and to have that so precise and so compelling that we're able to know that there's dark energy and dark matter. I don't think those are disputed anymore. And they were up until recently. They were still disputed.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Well, I can think of examples of dark matter that exist that we really know for sure are real versions of dark matter, like neutrinos. Right now, they're radiating through us. That's very well confirmed. And they're technically dark. They don't interact with light. And so we can't see them. Right now they're raining through us.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I can throw a probe into a black hole and cause something to happen on the inside. But the opposite isn't true. Somebody who fell in can't send a probe out. And this one-way aspect really is what's profound about the black hole. Sometimes we talk about the black holes being nothing because at the event horizon, there's really nothing there.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
If we could see the dark matter in this room and we absolutely know it's coming from the sun, it would be wild. It would be a rainstorm. But they're just invisible to us. Mostly they pass through our bodies. Mostly they pass through the earth. Occasionally they get caught in some fancy detector experiment that somebody built specifically to catch solar neutrinos. So dark matter is known to exist.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's just, again, there's not enough of it. It's not the right mass to be the dark matter that makes up this missing component.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Wow. Well, good for them.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Really? That's fascinating. Did somebody film that? That would be a great documentary.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah, and why do they want to believe a thing? What's very interesting is trying to use rational arguments. That makes it even more confounding to me. I would understand more somebody who just said, look, I have faith and I believe these things and it's not about reason and it's not about logic. Okay. I mean, I don't relate to it, but okay. But to say I'm going to use reason and logic
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And to prove to you this completely orthogonal conclusion, that I find really interesting. So there's some kind of romance about reason and logic?
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Well, I mean, I actually appreciate the skeptic's stance. I don't... Scientists also have to be skeptics. We have to be childlike, naive, and somewhat, in some sense, really open to anything. Right? Otherwise, you're not going to be a flexible. You're not going to be at the forefront. But... but also to be skeptical. So I have respect for it.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I guess that's exactly what I'm saying is more confusing because to invoke skepticism and then to want to use rational argument, what is the other component that's going into this? Because as you said, this is something that's easily verified. I mean, we have people in space. So you have to believe a lot more machinery arguments That's a lot more difficult to justify, explain as a wild conspiracy.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So there's something about the conspiracy that stirs a positive emotion.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Sometimes when we think about black holes, we want to imagine a really dense dead star. But if you go up to the event horizon, it's an empty region of spacetime. It's more of a place than it is a thing. And Einstein found this fascinating. He helped get the work published, but he really didn't think these would form in nature. I doubt Karl Schwarzschild did either.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Let's just start with the idea of gravitational waves here. I have to move around a lot of mass to make anything interesting happening in gravity. I mean, if you think about it, gravity is incredibly weak. I mean, right now the whole earth is pulling on me and I can still get out of this chair and walk around. Like that's insane. The whole earth, you know, gravity's weak.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So to get something going on in gravity, I need big objects and things like black holes. So the idea is if black holes curve space and time around them in the way that we've been describing, things fall along the curves in space. If the black holes move around, the curves have to follow them. But they can't travel faster than the speed of light either.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So what happens is these black holes, let's say, move around. Maybe I've got two black holes in orbit around each other. That can happen. It takes a while. A wave is created in the actual shape of space. And that wave follows the black holes. Those black holes are undulating. Eventually, those two black holes will merge.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And as we were talking about, it doesn't take an infinite time, even though there's time dilation, because they're both so big. They're really deforming space-time a lot. I don't have a little tidy marble falling across an event horizon. I have two event horizons. And in the simulations, you can see it bobble and expand.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
They merge together and they make one bigger black hole and then it radiates in the gravitational waves. It radiates away all those imperfections and it settles down to one quiescent, perfectly silent black hole that's spinning. Beautiful stuff. And it emits E equals mc squared energy. So the mass of the final black hole will be less than the sum of the two starter black holes.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And that energy is radiated away in this ringing of space-time. It's really important to emphasize that it's not light. None of this has to do literally with light. that we can detect with normal things that detect light. X-rays form a light, gamma rays are a form of light, infrared, optical, this whole electromagnetic spectrum, none of it is emitted as light. It's completely dark.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's only emitted in the rippling of the shape of space. A lot of times it's likened closer to sound. Technically, we've kind of argued, I mean, I haven't done an anatomical calculation, But if you're near enough to two colliding black holes, they actually ring spacetime in the human auditory range.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
The frequency is actually in the human auditory range that the shape of space could squeeze and stretch your eardrum, even in vacuum. And you could hear, literally hear these waves ringing. So the idea is that they're closer to something that you would want to map as a sound than it's something as a picture.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It would literally bob around like your orbit would change. If you were orbiting these black holes, two black holes, you'd be on a kind of complicated orbit, but your orbit would get tossed about.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yes, I see. So the black hole is experienced within spacetime as a squeezing and stretching. So you would feel it as a sort of squeezing and stretching, and you would also find your location change. Where you would fall would be redirected. So it's literally like a squeezing and stretching. That's the way to think about it. And it's very detailed, the sort of nature of this.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I think they thought they were solving theoretical, mathematical problems, but not describing what turned out to be the end state of gravitational collapse.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But for many years, people thought, well, these gravitational waves kind of have to exist for these intuitive reasons I've described. As space-time's curved, I move the curve, the wave has to propagate through that curved space-time. But people didn't know if they really carried energy. The arguments went on and back and forth and papers written and decades, right?
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But I like this sound more than an analogy because I liken the black holes as like mallets on the drum. The drum is space-time. As they move, they bang on the drum of space-time, and it rings. Remarkably, those gravitational waves, things don't interfere with them very much.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So they can travel for two billion years, light years, you know, in distance, two billion years in time, and get to us kind of as they were when they were emitted. quieter, more diffuse, maybe they've stretched out a little bit from the expansion of the universe, but they're pretty preserved. The idea of LIGO, this instrument, is to build a gigantic musical instrument.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's like building an electric guitar where the electric guitar is recording the shape of the string and it plays it back to you through an amplifier. LIGO is trying to record the shape of the ringing drum. And they literally listen to it in the control room. Just sort of hums and wobbles. And they're like trying to play this recording drum back to you.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
As opposed to taking a snapshot, it's like in time.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yes, this gigantic instrument.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's unbelievable. I can't believe they succeeded. Honestly, I can't believe they succeeded. It was so insane. It was such a crazy thing to even attempt. It took them 50 years. Really, it's people who started in their 30s and 40s who were in their 80s when it succeeded. I mean, imagine that tenacity, the unbelievable commitment. But the sensitivity that we're talking about as we have it now.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
this musical instrument, four kilometers, spanning four kilometers in a kind of L shape with these tunnels where there's the largest holes in the Earth's atmosphere because they pulled a vacuum in these tunnels to build this instrument.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And they're measuring, they're trying to record the wobbling of space-time, right, as it passes, this sort of undulation that amounts to less than one ten-thousandth the variation in a proton over the four kilometers. It's an insane, insane achievement.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I don't know how they did it. I followed them around just for fun. I'm very theoretical. I don't build things. I'm always super impressed that people can translate something on the page and And it looks like wires. And I don't know how, I'm always surprised at what it looks like.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But I walked the tunnels with Ray Weiss, who won the Nobel Prize along with Kip Thorne and Barry Barish, one of the project managers. And I walked the tunnels with Ray. It was a delight. I mean, Ray's one of the most delightful people. Kip is one of the most wonderful people I've ever known.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And Ray said to me, you know, the reason why it was called Black Hole Blues is because about a month before they succeeded in He said to me, if we don't detect black holes, this whole thing's a failure. And we've led this country down this wrong path. And he really felt like this tremendous responsibility for this project to succeed. And it weighed on him.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It was just quite tremendous what the integrity, the scientific integrity was. And the first instruments he built, he was building outside of MIT and on a tabletop. And his colleagues said, you're not going to get tenure. You're never going to succeed. And they just kept going.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Oh, yeah.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It does both. So it also describes the sun from far away. So the same solution does a great job helping us understand the Earth's orbit around the sun. It's incredible. It does a great job. It's almost overkill. You don't really need to be that precise as relativity. And yes, it predicts phenomenon of black holes, but it doesn't really explain how nature would form them.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah, it really is. You see so many moments when they could have stumbled. Yeah. And they built a first-generation machine just after 2000, and it wasn't a surprise to them, but it detected nothing. Crickets. Crickets. And they just, you know, they have the wherewithal to keep going. Second-generation machines. They're about to turn the machine on, quote unquote.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's a little bit of a simplification, but do their first science run. And they decide to postpone because they feel they're not ready yet. September 14th in 2015. And the experimentalists are out there. They're in the middle of the night. You know, they're working all night long and they're banging on the thing, literally driving trucks, slamming the brakes on to see the noise that it creates. And
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So they're really messing with the machine, really interfering with it just to kind of calibrate how much noise can this thing tolerate. And I guess the story is, is they get tired. There's an instrument in Louisiana and there's one in Washington state and they go home, put their tools down, they go home. They leave the instrument locked though, mercifully.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And it's something like within the span of an hour of them driving back to their humble abodes that they have in these remote regions where they built these instruments. This gravitational wave washes over, I think it hits Louisiana first. It travels across the U.S., brings the instrument in Washington state.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It began, you know, over a billion and a half years ago before multicellular organisms had emerged on the earth. Just imagine this from like a distant view, this collision course, right? And it's the centenary. It's the year Einstein published general relativity. Yes. So it was this, you know, a hundred years.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I mean, just think about where that signal was when Einstein in 1915 wrote down the general theory of relativity. It was on its way here. It was almost here.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Well, I can't disparage my friends, but of course relativity is just so all-encompassing.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I don't know, man.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah. I mean, I just, as I said, my admiration for Ray and Kip and the entire team is enormous. And, you know, just imagining Ray had been out there on site. He had just left to go back home, wakes up in the middle of night and sees it. You know, can you imagine? And there's a signal, you know, there's something in the log. He's like, what the hell is that?
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah, I was really mesmerized by these two characters. People know of Alan Turing for having ideated about the computer, being the person to really imagine that. But his work began with thinking about Gödel's work. That's where it began. And it began with this phenomenon of undecidable propositions or unprovable propositions. So there was something huge that happened in mathematics.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But then it also, on top of that, does signal the breakdown of the theory. I mean, you're quite right about that. It actually says, oh man, but you go all the way towards the center and yeah, this doesn't sound right anymore. Sometimes I liken it to, you know, it's like a dying man marking in the dirt that something's gone wrong here.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
People imagined that any problem in math could technically be proven to be true. It doesn't mean human beings are going to prove every fact about everything in mathematics, but you know, it should be provable, right? I mean, it seemed kind of It's not that wild supposition. And everyone believed this. All the great mathematicians.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Hilbert was a call of his to prove that and go to a very strange character. Very unusual. He was a Platonist. He literally believed that mathematical objects had an existential reality. He wasn't so sure about this reality, this reality he struggled with. He was distrustful of physical reality, but he absolutely took very seriously Platonic reality.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And often his own way of thinking, and he proved that there were facts, even among the numbers, that could never be proven to be true. to think about that, how wild that is, that even a fact about numbers seems very simple, could be true and unprovable, could never exist as a theorem, for instance, in mathematics, unreachable. This incompleteness result was very disturbing.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Essentially, it's equivalent to saying there's no theory of everything for mathematics. Mm-hmm. It was very disturbing to people, but it was very profound. And Alan Turing got involved in this because he was thinking about uncomputable numbers. And that led him... What's an uncomputable number? A number like 0.175. It just goes on forever with no pattern and
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I can't even figure out how to generate it. There's no rule for making that number. And he was able to prove that there were such things as these uncomputable, effectively unknowable numbers. That might not sound like a big deal. It was actually really quite profound. He was relating to Gödel intellectually, right, in the space of ideas.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But he goes a very different path, almost philosophically the opposite direction. He starts to think about machines. He starts to think about mechanizing thought. He starts to think, what is a proof? How does a mathematician reason? What does it mean to reason at all? What does it mean to think? And he begins to imagine inventing a machine.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
that will execute certain orders, mechanize thought in a specific way. Well, maybe I can get a machine. I can imagine a machine that does this kind of thinking and that he can prove that even a machine could not compute these uncomputable numbers. But where he ends up is the idea of a universal machine that computes, essentially can take different software and execute different jobs.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
We don't have a different computer to connect to the internet than we do to write papers. It's one machine and one piece of hardware, but it can do all of these, this huge variety. And so he really does invent the computer, essentially.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And famously, he uses that thinking in a very primitive form in the war effort where he's recruited to help break the German Enigma Code, which is heavily encrypted and largely believed to be uncrackable code. And people believe that Turing and his very small group actually turned the tide of the war in favor of the Allies precisely.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
It's signaling that there's some culprit, there's something wrong in the theory. And even Roger Penrose, who did this general work trying to understand the formation of black holes from gravitational collapse, He thought, oh yeah, there's a singularity that's inevitable. There's no way around it once you form a black hole.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
By using a combination of this thinking and just sheer ingenuity and some luck. But the other profound revelation that Turing has is that, well, maybe we're just machines. Right? And just biological machines. And this is a huge shift for him. It feels very different from Gödel, who doesn't really believe in reality and thinks numbers are platonic realities.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
And Turing kind of thinking, we're kind of like, we're actually machines and we could be replicated. So, of course, Turing's influence is still widely felt.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
On many levels, yeah.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Yeah, I think they were very tormented.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I mean, I think so much. I don't want to promote the kind of trite trope of the mad genius. You know, if you're brilliant, you are insane. I don't think that. I don't think if you're insane, you're brilliant. But I do think if somebody who's very brilliant, who also chooses not to go for regular gratification in life, They don't go for money. They don't necessarily value creature comforts.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
They're not leveraging for fame. I mean, they're really after something different. I think that can lead to a kind of runaway instability, actually, sometimes. Yeah. They're already outside of kind of social norms. They're already outside of normal connections with people. They've already made that break. And I think that makes them more vulnerable.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
So Gödel did have a wife and a strong relationship, as far as I understand, and had a husband. was a successful mathematician and ended up at the Institute for Advanced Study, where he walked with Einstein to the institute every day. They talked about how he proved certain really unusual things in relativity. You made reference to these rotating galaxies we were talking about.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Actually, Gödel had a model of a rotating universe that you could travel backwards in time. It was mathematically correct. Show to Einstein that within relativity, you could time travel. Just an unbelievably influential and brilliant man. But he was probably a paranoid schizophrenic. He did have breaks with reality.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
He was, I think, quite distrustful and feared the government, feared his food was being poisoned. And ultimately literally starved himself to death. And it's such an extreme outcome for such a facile mind, for such a brilliant mind.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Oh, yeah.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But he said this is probably just a shortcoming of the fact that we've forgotten to include quantum mechanics and that when we do, we'll understand this differently.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Psychosomatic or psychophysical.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I'm a big believer in the tragic flaw, actually. I think the Greeks really had that right. You're describing it. What makes us great is ultimately our downfall. Maybe that's just inevitable. The choice could be not to be great. And I guess that's sort of what I mean by they had already broken from a traditional path because they decided to pursue something.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
so elusive and that would isolate them to some extent inevitably. and that could fail, right? And whose rewards were hard to predict even. And I do think that that, all the character traits that went into their accomplishments were the same traits that went into their demise. And I think you're right. You could say, well, you know, Lex, maybe you should not be so empathetic.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Hold yourself, cut yourself off a little bit, protect yourself, right? But isn't that exactly what you're bringing, one of the elements that you're bringing that makes something extraordinary in a space that lots of people try to break through?
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I think everybody would say that. I think everybody would say the closer you get to the singularity, for sure you have to include quantum mechanics. You just can't consistently talk about magnifying such small scales, having such enormous ruptures and curvatures and energy scales and not include quantum mechanics. That's just inconsistent with the world as we understand it.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
I would find it impossible to not pursue a discovery that I could imagine my way through, if I can really see how to get there. I cannot imagine abandoning it for some other reason, fear that it would be misused. It's just a real fear, right? I mean, it's a real concern. I don't think in my work, since I'm doing extra dimensions in the early universe or black holes, you know, I feel pretty safe.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
But, I mean, who knows, right? Bohr couldn't think of a way to use quantum mechanics to kill people. I cannot imagine pulling back and saying, nope, I'm not going to finish this.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Brilliant.
Lex Fridman Podcast
#468 – Janna Levin: Black Holes, Wormholes, Aliens, Paradoxes & Extra Dimensions
Brilliant.