Einstein’s Crumbs with Janna Levin

How did Einstein’s work influence the world we know today? Neil deGrasse Tyson and Harrison Greenbaum team up with astrophysicist Janna Levin, PhD, to explore Einstein’s physics and its resulting discoveries, from Walmart laser pointers to black holes and wormholes.

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Neil deGrasse Tyson?

  So Harrison, if you loved Einstein before, how do you love the man now?

• 0:02Harrison Greenbaum?

  Oh my gosh, so much. And I already loved him. I had a T-shirt when I was a kid of Albert Einstein on a surfboard.

• 0:07Neil deGrasse Tyson?

  So you were a geek kid?

• 0:08Harrison Greenbaum?

  Oh, 100%.

• 0:09Neil deGrasse Tyson?

  And was that like a backhanded reference to gravitational waves?

• 0:12Harrison Greenbaum?

  I think I didn't know that at the time, but now I do.

• 0:15Neil deGrasse Tyson?

  Who knew that Einstein's smorgasbord left crumbs for the rest of us to discover and win Nobel prizes on? Oh my gosh, all that and more, coming up on StarTalk.

• 0:29Neil deGrasse Tyson?

  Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now.

• 0:42Neil deGrasse Tyson?

  This is StarTalk. Neil deGrasse Tyson, your personal astrophysicist. Got with me is my co-host Harrison Greenbaum. Harrison, how you doing, dude?

• 0:50Harrison Greenbaum?

  Good to be here.

• 0:51Neil deGrasse Tyson?

  All right.

• 0:52Harrison Greenbaum?

  Yeah, I'm excited.

• 0:52Neil deGrasse Tyson?

  And not your first StarTalk rodeo?

• 0:55Harrison Greenbaum?

  Nope, not at all.

• 0:56Neil deGrasse Tyson?

  All right.

• 0:56Harrison Greenbaum?

  Maybe it would be my first rodeo. I've never done a rodeo. I think I would die immediately.

• 1:01Neil deGrasse Tyson?

  That's not happening here, I promise. We're gonna talk about Einstein today.

• 1:05Harrison Greenbaum?

  Love it.

• 1:05Neil deGrasse Tyson?

  You gonna help me out on that?

• 1:06Harrison Greenbaum?

  I've heard of him.

• 1:07Neil deGrasse Tyson?

  I need more help than that.

• 1:08Harrison Greenbaum?

  He married his cousin, I know that.

• 1:10Neil deGrasse Tyson?

  Every time we talk about Einstein and related subjects, we have our go-to person at large. Janna Levin, Janet, welcome back to StarTalk.

• 1:19Janna Levin?

  I'm always glad to be here.

• 1:21Neil deGrasse Tyson?

  You're like a regular practically.

• 1:22Janna Levin?

  I know.

• 1:22Neil deGrasse Tyson?

  Because Einstein's a regular.

• 1:24Janna Levin?

  I know. I feel like I just want to hang around here all the time.

• 1:28Neil deGrasse Tyson?

  So Janet, you are the Tao Professor of Physics and Astronomy at Barnard College of Columbia University. Theoretical cosmologist.

• 1:38Janna Levin?

  Yeah, I mean, I say astrophysicist these days.

• 1:41Neil deGrasse Tyson?

  Yeah, okay.

• 1:41Janna Levin?

  Or theoretical physicist, only because people think cosmology is like cosmetology and stuff.

• 1:45Neil deGrasse Tyson?

  Oh, okay, right, right.

• 1:46Janna Levin?

  They wanted me to do their makeup.

• 1:48Harrison Greenbaum?

  I want a fancy title. Fine, I'm not a comedian, I'm a punchline engineer. Specializing in ha-ha building and giggle construction.

• 1:55Neil deGrasse Tyson?

  So you're Director of Sciences at the Pioneer Works in Brooklyn, one of my favorite places.

• 2:01Janna Levin?

  Yeah, I know.

• 2:02Neil deGrasse Tyson?

  This is quite the juxtaposition of science, creativity, and art. And it's just, we're creative people on both sides of that fence, if there really is one.

• 2:12Janna Levin?

  Yeah.

• 2:12Neil deGrasse Tyson?

  Come together and express themselves.

• 2:14Janna Levin?

  I really feel like Pioneer Works is a sanctuary because science is part of culture. We're not trying to hide it in something else. We're not packaging it in something else. It just exists out there and it's a big appetite for it. People want to know.

• 2:26Neil deGrasse Tyson?

  And you've also written a bunch of books. I have two with me like right now. The Black Hole Survival Guide.

• 2:33Janna Levin?

  It's like.

• 2:34Harrison Greenbaum?

  It looks tiny, but it's dense, like a black hole.

• 2:38Janna Levin?

  Spoiler alert, it does not end well.

• 2:39Neil deGrasse Tyson?

  It does not end well. I could have guessed that, I think. Black Hole Death Guide, not a Black Hole Survival Guide.

• 2:47Janna Levin?

  Exactly.

• 2:47Harrison Greenbaum?

  The book is normal size. Neil's hand is gigantic.

• 2:51Janna Levin?

  There's an element of truth to that.

• 2:53Neil deGrasse Tyson?

  And my favorite book I like to pronounce, The Black Hole Blues.

• 2:58Janna Levin?

  I love that.

• 3:00Harrison Greenbaum?

  Nana, nana.

• 3:01Janna Levin?

  That's the British cover. That's very nice.

• 3:02Neil deGrasse Tyson?

  Oh, yeah. So, yeah, I get around. I get around.

• 3:05Harrison Greenbaum?

  What's the difference between the British and the, is there an extra U?

• 3:08Janna Levin?

  Yeah, right. Well, actually, they're completely different covers.

• 3:13Neil deGrasse Tyson?

  Yeah, they decide, yeah, different countries, they have issues with each other's.

• 3:18Harrison Greenbaum?

  They change the Albert Einstein's teeth to make them feel less bad.

• 3:20Janna Levin?

  That's what I was explaining. In one language and translation, they changed my last name.

• 3:24Harrison Greenbaum?

  To what?

• 3:24Janna Levin?

  Levanova. I think it was Czech. I thought that was some serious license.

• 3:32Harrison Greenbaum?

  We'll help you out. We'll make it less Jewy.

• 3:35Janna Levin?

  I kind of, I kind of liked it.

• 3:38Harrison Greenbaum?

  Yeah, because it made it like Italian almost.

• 3:40Janna Levin?

  It's just a thing. Women are Levanova.

• 3:43Neil deGrasse Tyson?

  The Ova, okay.

• 3:44Janna Levin?

  Yeah. It was a female thing.

• 3:46Neil deGrasse Tyson?

  So, we're here to talk about what I intermittently reference as Einstein's crumbs. You know, when you're eating a meal that you enjoy and something spills over the edge, you don't even notice. Because the meal is so good. And then you walk away with your plate and other people see what spilled off of your plate. Hey, that's tasty. I want that. I can build, I can work with that.

• 4:10Harrison Greenbaum?

  So in this analogy, the other scientists are my dog.

• 4:14Harrison Greenbaum?

  Comes in and is like, crumbs, this is the best. So these Nobel Prize winning scientists are Rufus.

• 4:22Neil deGrasse Tyson?

  Thank you.

• 4:22Harrison Greenbaum?

  My terrorist.

• 4:24Neil deGrasse Tyson?

  Thought about it that, just that way. Let's benchmark ourselves, Jana, to, do I pronounce this right? Anis merabilis?

• 4:33Janna Levin?

  It's Latin. I'll take it.

• 4:36Neil deGrasse Tyson?

  1905.

• 4:37Janna Levin?

  Yes, quite a year.

• 4:38Neil deGrasse Tyson?

  Just list for me, what did Einstein do in 1905? And the dude was 26 years old when this happened. Go for it.

• 4:45Janna Levin?

  So he writes a series of papers, all of which completely knock the world on its proverbial arse. Yes, each one.

• 4:53Harrison Greenbaum?

  On its Anis, if you will.

• 4:56Janna Levin?

  I'm sure there's Latin for that.

• 4:58Neil deGrasse Tyson?

  Mirabulous.

• 5:00Janna Levin?

  Yes, that's my dating profile there. So let's see, what are they, photoelectric effect?

• 5:05Neil deGrasse Tyson?

  Yes, which?

• 5:06Janna Levin?

  The photoelectric effect was the idea that sometimes light behaved like a particle and not a wave. And so sometimes when you bombard a surface with light, it will knock it like a basketball might dislodge something from place, as opposed to accumulating energy like a wave might. And so it really was very shocking.

• 5:27Neil deGrasse Tyson?

  Was that the first demonstration that light could be also referenced as particles?

• 5:32Janna Levin?

  Yeah, it was the first observation, connection between theory and observation, that it is actually behaving like a particle sometimes.

• 5:39Neil deGrasse Tyson?

  Gotcha.

• 5:39Janna Levin?

  Very shocking, because 1800s, we thought of light as a wave, and we often still do, because it's very convenient to do so sometimes, and sometimes it's acting like a wave.

• 5:48Neil deGrasse Tyson?

  Yeah, yeah.

• 5:49Janna Levin?

  But here was an instance where it really acted more like you threw a basketball at something.

• 5:54Neil deGrasse Tyson?

  A really tiny basketball.

• 5:55Janna Levin?

  A really tiny basketball. Which was incredible for Einstein to observe, because basketball hadn't been invented yet. Right, and I somehow don't see him, I don't know, jiving with the sports analogy, but anyway, so photoelectric effect, shocker.

• 6:07Neil deGrasse Tyson?

  Paper one, paper two.

• 6:08Janna Levin?

  Paper two, special relativity, where he has...

• 6:12Neil deGrasse Tyson?

  Oh, just that.

• 6:13Janna Levin?

  Just that. So a lot of times, so the theory of relativity became this real colloquial thing, everything's relative, and it became, invest in society, I often say it could have been called the theory of absolutism, because what Einstein really had done is he had adhered to the absolute limit of the speed of light. He took that more seriously than anybody else was taking it at the time. In fact, people were struggling to get rid of it, this idea that the speed of light was a constant, and they were doing everything they can to dethrone that concept, which really wasn't taking hold.

• 6:43Neil deGrasse Tyson?

  It's not just that it's a constant, it's that it's a constant no matter how, when, or where you measure it.

• 6:49Janna Levin?

  Absolutely.

• 6:49Neil deGrasse Tyson?

  You're getting the same answer.

• 6:51Janna Levin?

  That's right.

• 6:51Neil deGrasse Tyson?

  Even if you're moving, and the light is moving relative, you measure the same speed of light.

• 6:55Janna Levin?

  Right.

• 6:56Neil deGrasse Tyson?

  Which doesn't exist for anything else.

• 6:57Janna Levin?

  That's insane. That was an insane concept. Two cars coming at each other are coming at each other faster than if one of the cars stops.

• 7:05Neil deGrasse Tyson?

  Right.

• 7:06Janna Levin?

  Okay, but that is not true at the speed of light. You run at the speed of light. Maybe you're running slowly, maybe you're running near the speed of light yourself. It's still coming at you at the speed of light.

• 7:15Neil deGrasse Tyson?

  Right.

• 7:15Janna Levin?

  It is chilling, strange, seems impossible.

• 7:18Neil deGrasse Tyson?

  So I think a simpler example is I'm on the front of a train, let's say the train goes 60 miles an hour, and I throw a ball 40 miles an hour. Can I throw that fast? Probably not.

• 7:27Harrison Greenbaum?

  I know, I definitely can.

• 7:28Janna Levin?

  I think you can do anything, Neil.

• 7:30Neil deGrasse Tyson?

  I can do anything.

• 7:31Janna Levin?

  I think you can do anything.

• 7:31Neil deGrasse Tyson?

  I throw it 40 miles an hour in front of the train. You're standing on, at the platform. How fast is the ball passing you? Ding ding.

• 7:39Harrison Greenbaum?

  Right, is it not adding the two up?

• 7:41Neil deGrasse Tyson?

  Yeah.

• 7:42Harrison Greenbaum?

  It's a hundred miles an hour.

• 7:43Neil deGrasse Tyson?

  A hundred miles an hour.

• 7:43Janna Levin?

  Should be, I'm not with common experience.

• 7:45Neil deGrasse Tyson?

  But if I'm on the front of a train...

• 7:46Harrison Greenbaum?

  I mean, I'm not calculating this speed. I'm worried that Neil Grasik is on the top of a train throwing the ball. I'm very confused.

• 7:53Neil deGrasse Tyson?

  So, so now I'm on the same 60 mile an hour train, I shine a beam of light, and you measure the beam of light going by you. It is the same speed of light.

• 8:00Harrison Greenbaum?

  It does, we don't add the train.

• 8:01Neil deGrasse Tyson?

  We don't add the train.

• 8:02Janna Levin?

  We don't add the train.

• 8:03Neil deGrasse Tyson?

  That's cra- that, that's batshit crazy.

• 8:05Janna Levin?

  It is crazy, and Einstein meditated on this for so long, and there's kind of a simple way to see. He, he said, "Well, you know, what is speed? It's, it's the distance you cover in space divided by the time elapsed." So it has to do with space and time. I mean, I mean, that's a huge leap already, and he said, "I'd rather that your measures of space and time are relative than give up the absolute nature of the speed of light."

• 8:31Neil deGrasse Tyson?

  Wow.

• 8:32Janna Levin?

  So two of the...

• 8:33Neil deGrasse Tyson?

  So your very measuring stick changes.

• 8:35Janna Levin?

  Changes.

• 8:35Harrison Greenbaum?

  Right.

• 8:36Janna Levin?

  Relative to the other...

• 8:37Neil deGrasse Tyson?

  So that you get the same answer.

• 8:38Janna Levin?

  So that you get the same answer.

• 8:39Neil deGrasse Tyson?

  That's, that's, that's...

• 8:42Janna Levin?

  Yeah.

• 8:42Neil deGrasse Tyson?

  Not the measuring stick and your rate that time ticks. That, that's crazy.

• 8:46Janna Levin?

  I mean, I still get chills a little bit.

• 8:48Harrison Greenbaum?

  So he's, which drug is he on?

• 8:49Neil deGrasse Tyson?

  I know.

• 8:50Harrison Greenbaum?

  Is it opium?

• 8:51Neil deGrasse Tyson?

  What was available at the time?

• 8:53Harrison Greenbaum?

  Ether?

• 8:53Janna Levin?

  He's not doing ketamine shots.

• 8:56Neil deGrasse Tyson?

  Okay, give me more. So that's two.

• 8:57Janna Levin?

  Um, Brownie in Motion?

• 8:59Neil deGrasse Tyson?

  Talk about, give me some Brownie in Motion.

• 9:00Janna Levin?

  So if you...

• 9:02Harrison Greenbaum?

  I mean, I think that feels like a dirty topic. I don't know if that's appropriate for this.

• 9:06Janna Levin?

  Actually, I'm not. I bet Neil knows why it was called Brownie.

• 9:09Neil deGrasse Tyson?

  There's a guy.

• 9:10Janna Levin?

  There's a guy who first talked about the statistical, right.

• 9:13Neil deGrasse Tyson?

  Observed it, but didn't fully understand it.

• 9:16Harrison Greenbaum?

  Right. Mr. Brown.

• 9:17Janna Levin?

  We've all observed it. So you go to a window, the dastier the house, the better. You pull the curtains aside, and you start to see all the particles move around. They don't fall like rain, they bounce around.

• 9:28Neil deGrasse Tyson?

  Dust particles.

• 9:29Janna Levin?

  The dust particles, and you can see the reflection of the dust in the air, you know, it's kind of a beautiful image, the sunlight hitting, reflecting off the dust particles.

• 9:37Neil deGrasse Tyson?

  Of an undusted apartment.

• 9:37Harrison Greenbaum?

  I was gonna say.

• 9:38Janna Levin?

  Of grandma's.

• 9:39Harrison Greenbaum?

  My OCD is like, yeah. Clean map, yeah, why have you let it go so far?

• 9:44Janna Levin?

  So, but we all have had that observation, and we all know it doesn't fall like rain. So Einstein also relates this to the quantum nature of matter. He says fundamentally, air is not a continuum. If I look at it at the microscopic level, I'm gonna realize it's made up of individual molecules, and the molecules are moving randomly because they're knocking into each other. They're bouncing around, he called that Brownian motion. So they bounce around randomly because they're kind of constantly knocking and banging into each other as they move around. And it was more evidence for the quantum nature of reality in very early years.

• 10:15Neil deGrasse Tyson?

  In fact, I think it was one of the first supportive bits of evidence that atoms even exist.

• 10:21Janna Levin?

  That's right.

• 10:21Neil deGrasse Tyson?

  Because you can, if you, in other words, you can have a big, you use the air, dust analogy, but in a, in a, in a liquid solution, if you have a suspended particle that's larger than the molecules themselves, the particle sort of moves around in response to the collective energy of all the particles that are around it. And you can calculate what should happen if this liquid is composed of these tiny particles. And then you only get this motion when you have atoms doing the constant.

• 10:55Janna Levin?

  Yeah, absolutely. And, and we talk about.

• 10:57Neil deGrasse Tyson?

  Jostling, that's a better word.

• 10:57Janna Levin?

  We, we talk about the temperature in the room all the time, but what that really is, is the average of the thermal motions of an awful lot of particles.

• 11:04Neil deGrasse Tyson?

  Yeah.

• 11:04Janna Levin?

  And the statistical behavior later very well predicted by Planck. And so this was all part of that early era of starting to understand that if I look at a glass of water, it is not a continuum. If I get small enough, it is actually made up of individual molecules.

• 11:19Neil deGrasse Tyson?

  So, and it was in the fourth paper, wasn't there?

• 11:21Janna Levin?

  Um, E equals mc squared.

• 11:23Neil deGrasse Tyson?

  Oh.

• 11:24Harrison Greenbaum?

  That's a pretty good one.

• 11:26Neil deGrasse Tyson?

  Okay, yeah, how can I forget about that one? Yeah, yeah.

• 11:28Janna Levin?

  Which, to some extent.

• 11:29Harrison Greenbaum?

  That was the whole paper, he just wrote E equals mc squared.

• 11:31Janna Levin?

  E equals mc squared.

• 11:32Neil deGrasse Tyson?

  Mic drop.

• 11:33Harrison Greenbaum?

  This has been a busy year.

• 11:34Neil deGrasse Tyson?

  Except they didn't have mics then.

• 11:35Janna Levin?

  Yeah.

• 11:35Neil deGrasse Tyson?

  Drop.

• 11:36Janna Levin?

  Totally.

• 11:36Harrison Greenbaum?

  Find something to drop. Speaker.

• 11:38Janna Levin?

  Right. Refrigerator drop, he was working in a patent office, right? Refining things like refrigerator coolants and refrigerator cooling mechanisms. And at the bottom drawer of his desk, he had what he called the physics department. And in the physics department, he was working. On these papers between refining people's patents and E equals mc squared is one of the most gorgeous results, obviously, most famous equation. Obviously, we all love this result and the implications of it went so far beyond his initial motivation for thinking about it.

• 12:07Neil deGrasse Tyson?

  That's the point of his whole episode.

• 12:09Janna Levin?

  It's so far beyond. I mean, it's changed the world as we know it in so many ways, but.

• 12:13Neil deGrasse Tyson?

  Okay, so of those four.

• 12:14Janna Levin?

  Yeah.

• 12:15Neil deGrasse Tyson?

  Results.

• 12:16Janna Levin?

  Yeah.

• 12:16Neil deGrasse Tyson?

  Two of them.

• 12:17Janna Levin?

  Mm hmm.

• 12:17Neil deGrasse Tyson?

  Were stapled together for the one Nobel Prize that he got.

• 12:22Janna Levin?

  Brownian and photoelectric.

• 12:23Neil deGrasse Tyson?

  Correct.

• 12:24Janna Levin?

  Mm hmm.

• 12:24Neil deGrasse Tyson?

  Right?

• 12:24Janna Levin?

  Yeah.

• 12:25Neil deGrasse Tyson?

  And so he's got one Nobel Prize.

• 12:27Janna Levin?

  Mm hmm.

• 12:28Neil deGrasse Tyson?

  For two things that.

• 12:29Harrison Greenbaum?

  And not for eagles.

• 12:29Neil deGrasse Tyson?

  And not for eagles. Not for scratch. Not for relativity.

• 12:32Janna Levin?

  Let alone general relativity, which comes 11 years later.

• 12:35Neil deGrasse Tyson?

  So for me, what's intriguing is his Nobel Prize is some of the least interesting work that he's done.

• 12:43Harrison Greenbaum?

  If somebody wins a Grammy for their worst album.

• 12:46Janna Levin?

  Well, it was practical. It was practical. The Nobel was always very attached to verifiable results. So it was very hard for Stephen Hawking to get nominated for a Nobel Prize. It was surprising to me that even Roger Penrose not only was nominated, but was awarded the Nobel Prize because they were so theoretical. And the Nobel Prize is often awarded for things that have been verified by experiment, not a minute before.

• 13:07Neil deGrasse Tyson?

  Certainly in the day.

• 13:08Janna Levin?

  That's the intention.

• 13:08Neil deGrasse Tyson?

  That's correct. That's correct. Because it was the idea that if you're, if it's a theoretical result, could, could go with the winds.

• 13:15Harrison Greenbaum?

  Right.

• 13:15Neil deGrasse Tyson?

  You know? Whereas you have, if you anchor it in an experiment, then we got, we got legit. You become legit. So.

• 13:22Harrison Greenbaum?

  He did this all at 26.

• 13:24Neil deGrasse Tyson?

  By the time he turned 26, yeah.

• 13:26Harrison Greenbaum?

  I'm 38, so this is very demotivated.

• 13:28Neil deGrasse Tyson?

  Sorry.

• 13:30Janna Levin?

  What is your mommy saying? Look at us both consoling.

• 13:36Neil deGrasse Tyson?

  Okay. So you're 38?

• 13:38Harrison Greenbaum?

  38.

• 13:38Neil deGrasse Tyson?

  Okay. So when Mozart was your age, he was already dead for a year. Okay? So I don't mean to tell your mom this.

• 13:44Harrison Greenbaum?

  Oh, no. It's not gonna happen.

• 13:46Neil deGrasse Tyson?

  You are such a disappointment.

• 13:59Speaker 03

  Hello, I'm Alexander Harvey and I support StarTalk on Patreon. This is StarTalk with Dr. Neil deGrasse Tyson.

• 14:15Neil deGrasse Tyson?

  So, let's pick up some of the crumbs now.

• 14:18Janna Levin?

  Alright.

• 14:18Neil deGrasse Tyson?

  So, let's talk about his cosmological constant.

• 14:22Janna Levin?

  Okay.

• 14:22Neil deGrasse Tyson?

  What's up with that?

• 14:24Janna Levin?

  I love the cosmological constants, like the guy couldn't be wrong. It's like he couldn't be wrong even when he was terribly wrong.

• 14:29Neil deGrasse Tyson?

  Even when he was terribly wrong, he was right.

• 14:31Janna Levin?

  He was somehow later would turn out to be right.

• 14:33Neil deGrasse Tyson?

  Yeah, so, one of the crumbs, a crumb you don't even know it's gonna grow into an interesting crumb later. So, your dog would need to give it a chance before it laps it up. He put it in his bed and he's saving it.

• 14:44Janna Levin?

  Yeah. I should go look up some more Einstein crumbs, actually, now that he's... Maybe this will give me some.

• 14:50Neil deGrasse Tyson?

  I gotta...

• 14:50Janna Levin?

  Infigurate some, yeah. Well, so, Einstein writes down the general theory of relativity, which goes beyond special relativity.

• 14:57Neil deGrasse Tyson?

  This is later, 10 years later, okay?

• 14:59Janna Levin?

  Yeah, it takes him a...

• 14:59Neil deGrasse Tyson?

  36, alright, now we're talking.

• 15:01Janna Levin?

  He's feeling it. He's feeling that there's something there that he wants to describe, not just that space and time are relative, not just that I can rotate space into time, that they're one kind of spacetime. But also, that spacetime itself could maybe curve, stretch, be mutable, respond to matter and energy, that around the Earth, the reason why the apple falls from the tree is because it's following the natural curve in space, created by the mass of the Earth. This is general relativity now. He generalizes the theory away from flat spacetime to curved spacetime. Now, once he does this, he still cannot predict everything that this theory suggests. It's just abundant. It's so abundant that today, people are still trying to find solutions for the theory

• 15:46Janna Levin?

  to describe universes. And people came to him, a number of different scientists from around the world, very international experiment, and over, very quickly and over the next couple of years, said, you know, your theory predicts that the universe is expanding. So other people are studying his theory, they're imagining, what if I have an average distribution of galaxies in there, all this stuff now, but I smoothed it out, I imagine it's pretty smooth out there, and they say, how is spacetime mutable in response to this distribution of energy? And you would sort of think, well, a lot of gravity means things are gonna re-collapse.

• 16:19Neil deGrasse Tyson?

  Yeah, everything is mass.

• 16:20Janna Levin?

  Everything is mass, and so, you know, it's all gonna pull towards each other, and it's gonna cause a collapse of the universe, in which case, the universe shouldn't be static, stable, or permanent. And Einstein really is resistant to this idea, he does not like it, and he says to himself, I must have made a mistake in my fundamental equations of general relativity, that describe every possible scenario in the universe, and he adds something called the cosmological constant, because technically, mathematically, it was consistent with Einstein's laws, and if you're being completely thorough, you would have included this term, called this cosmological constant, and it's this magic term, doesn't know what it is physically, doesn't know what it refers to in terms of known forms of matter.

• 17:03Neil deGrasse Tyson?

  So you can have a math representation of an idea, not all of which actually applies to reality.

• 17:09Janna Levin?

  Yeah.

• 17:09Harrison Greenbaum?

  I also like that you can just like, throw that in and be like, I don't know if my theory is right, but I, there's this magical extra thing.

• 17:15Janna Levin?

  Right.

• 17:15Harrison Greenbaum?

  And now it's right.

• 17:16Janna Levin?

  He knew it was mathematically consistent, that's exactly what he did.

• 17:19Harrison Greenbaum?

  That's what I wanna know.

• 17:20Janna Levin?

  That's exactly what he did.

• 17:21Neil deGrasse Tyson?

  Mathematically legit.

• 17:22Janna Levin?

  He said, look, maybe nature produces an energy density that's uniform across space and time, and it is an absolute constant, and it has this very different property, that it actually pushes the universe outward, and if I tune it to exactly the right value, I'm going to balance things, and the universe will not collapse, and it will be permanent. And it will, it will exist that way forever.

• 17:42Neil deGrasse Tyson?

  Because why think the universe is doing anything at all?

• 17:44Harrison Greenbaum?

  Right.

• 17:44Neil deGrasse Tyson?

  But the universe...

• 17:45Harrison Greenbaum?

  Doesn't owe you anything.

• 17:46Neil deGrasse Tyson?

  Right, right, the universe is just there, and if it's just there, you gotta somehow stabilize it.

• 17:50Janna Levin?

  Yeah, so he stabilized the universe with the cosmological constant.

• 17:53Neil deGrasse Tyson?

  There you go.

• 17:54Janna Levin?

  There, now he has a universe that's permanent, has lived forever, will last forever, but not so fast, because very quickly, people study the mathematics of this, and they say it's very unstable. You basically have stood a pencil on its tip on the top of a hill and said it's stable. I mean, you can do it for a second. But it very quickly wants to fall over and begin to do something.

• 18:16Neil deGrasse Tyson?

  It'll fall in one direction or the other.

• 18:17Janna Levin?

  Or the other, and the two directions, in this case, collapse or expansion.

• 18:20Neil deGrasse Tyson?

  Yes, there you go.

• 18:21Janna Levin?

  So either the universe is collapsing, or it's expanding. It does not want to stay static. And he called it his greatest blunder. Now, he made a lot of kind of mathematical mistakes, so he was not afraid of that. And he was really so experimental and so daring. So the idea that he even called it a blunder, I think, was because it was a blunder of intuition.

• 18:42Neil deGrasse Tyson?

  Wait, wait, wait.

• 18:43Janna Levin?

  Or resistance.

• 18:44Neil deGrasse Tyson?

  Wait, but wait. It's not a blunder until it's a blunder. So he puts it in reluctantly, and then Hubble comes along. Telescope guy. Later, later in the...

• 18:56Janna Levin?

  Oh, that's true, yeah.

• 18:57Neil deGrasse Tyson?

  Yeah, yeah, yeah. A telescope thing. Telescope came first, yes.

• 19:02Neil deGrasse Tyson?

  Edwin Hubble Yes. Comes along in the same decade, discovers that the universe is not static, it's expanding. So now we're okay, because that's one of the signs of hell. That's one of the signs, and so you don't even need the cosmological constant.

• 19:16Janna Levin?

  You don't even need the cosmological constant. So he comes along and says, "Look, the universe is not dominated by the cosmological constant from what he could measure. It's dominated by the galaxies, and the galaxies are in fact expanding away from each other. The universe is in fact expanding." And it was a real shock.

• 19:32Neil deGrasse Tyson?

  Because we had no physical way to understand a force or a pressure in the universe going opposite gravity. There was no, there was no way, there was no... And then philosophically, what is it expanding in time? I know, that's the point that we haven't gotten there, yeah.

• 19:47Janna Levin?

  We'll get there, yeah. But, you know, at the time Einstein was first doing this, especially 1905, I mean, he didn't know there were other galaxies out there.

• 19:55Neil deGrasse Tyson?

  Oh, yeah.

• 19:55Janna Levin?

  I mean, imagine that.

• 19:56Neil deGrasse Tyson?

  Yeah.

• 19:56Janna Levin?

  We knew about the Milky Way, our little island of hundreds of billions of stars.

• 20:00Neil deGrasse Tyson?

  The whole universe is just the stars in the night sky.

• 20:01Janna Levin?

  And that was that. And, I mean, he imagined, I mean, but, but it wasn't until Hubble that we identified that some of those objects out there really were, first of all, other galaxies, and that they were all moving away essentially on average, and that it looked like the universe was in fact expanding.

• 20:17Neil deGrasse Tyson?

  So at that point, he doesn't need the cosmological constant, and then he declares...

• 20:21Janna Levin?

  His greatest blunder?

• 20:21Neil deGrasse Tyson?

  And then, fast forward to 1998.

• 20:24Janna Levin?

  Right, and there it is.

• 20:25Neil deGrasse Tyson?

  And we discover the cosmological constant operating in the universe. It's measured, and it wins a Nobel Prize. For him? No!

• 20:37Janna Levin?

  No, gosh.

• 20:37Neil deGrasse Tyson?

  God damn it.

• 20:40Neil deGrasse Tyson?

  Plus, they don't give it to you if you're dead. All right. They don't, they don't announce.

• 20:45Janna Levin?

  It might have happened once.

• 20:46Neil deGrasse Tyson?

  Unless you're alive. But if you die between the announcement and the award ceremony.

• 20:49Harrison Greenbaum?

  Okay, then you're okay.

• 20:50Neil deGrasse Tyson?

  Then you're.

• 20:51Janna Levin?

  You still gotta hold on.

• 20:52Neil deGrasse Tyson?

  You're still dead.

• 20:53Harrison Greenbaum?

  But we gotta hold on. You gotta hold on till the announcement.

• 20:56Neil deGrasse Tyson?

  Yeah, if you die, you still get the award, but you're dead. All right. So in this sense. What he rejects as a blunder. Yes. Becomes an actual measurement. And they get the Nobel Prize for making that measurement.

• 21:09Janna Levin?

  So now, the reason why they can measure it, even though it's not static. You might think, oh, they could only measure it if it made the universe static or something. It actually was very unstable. What it really wants to do is kind of dominate. So as all the energy density in the universe kind of slowly wanes. This constant is eventually there to peak above all the others. As they dilute away, it just doesn't go away. And so eventually.

• 21:33Neil deGrasse Tyson?

  It's a permanent feature of the vacuum of space.

• 21:35Janna Levin?

  It's a permanent feature.

• 21:36Neil deGrasse Tyson?

  It's crazy.

• 21:37Janna Levin?

  Of empty space.

• 21:38Neil deGrasse Tyson?

  Right, there's no way that could.

• 21:39Janna Levin?

  It is the energy of empty space.

• 21:41Neil deGrasse Tyson?

  Energy of empty space.

• 21:42Janna Levin?

  So eventually, it will dominate the property of the universe. And what it does when it dominates is it drives the universe not only to expand, but to expand at an accelerated rate. It's getting faster and faster. Dark energy.

• 21:54Harrison Greenbaum?

  I've heard about the energy of empty space from my realtor.

• 21:56Neil deGrasse Tyson?

  Is that right?

• 21:57Harrison Greenbaum?

  They walk around and say, you should feel the, there's nothing in here yet. But you should feel this energy of this empty space.

• 22:03Janna Levin?

  Did they sell you air rights? Maybe they should charge you extra for the dark energy.

• 22:07Harrison Greenbaum?

  Yeah.

• 22:08Janna Levin?

  And the air rights.

• 22:08Harrison Greenbaum?

  Don't give them that idea.

• 22:10Neil deGrasse Tyson?

  And in 10 to the 22 years, which is a long time from now.

• 22:14Janna Levin?

  It's a pretty long time.

• 22:15Neil deGrasse Tyson?

  Pretty long time, but I have it on my calendar. The dark energy will become so dominant. And the expansion will become so accelerated. That the fabric of spacetime cannot keep up with it. And it will rip.

• 22:31Harrison Greenbaum?

  Well, that's not, you don't want to be alive with that.

• 22:34Neil deGrasse Tyson?

  It's called the big rip. That's if it goes unchecked, the big rip.

• 22:39Harrison Greenbaum?

  So there are still humans that far out. They have to figure a way to.

• 22:42Neil deGrasse Tyson?

  To not have it rip. Right. It'll rip the very structure of the fabric of spacetime.

• 22:47Janna Levin?

  Cosmological climate change. Like they'll have, you know, like.

• 22:51Harrison Greenbaum?

  Does it happen instantaneously? Or do they feel it slowly start to happen? Or is it like they're, they're just, they just know at a certain time it's all over?

• 22:57Neil deGrasse Tyson?

  You start seeing it all around you. Stuff starts flying apart. Oh, yeah. That bad place like is gonna happen in your lifetime. So now, here's a good one. Great, great, great, great, great grandchildren problem. Maybe you don't know this one.

• 23:07Janna Levin?

  Oh, yeah.

• 23:08Neil deGrasse Tyson?

  Okay.

• 23:08Janna Levin?

  Yeah.

• 23:08Neil deGrasse Tyson?

  He predicts, based on general relativity, that if you have an alignment of two objects, one of them will get lensed around it.

• 23:16Janna Levin?

  Oh.

• 23:17Neil deGrasse Tyson?

  And you get what is called an Einstein ring.

• 23:19Janna Levin?

  Hmm.

• 23:19Neil deGrasse Tyson?

  Because if two objects are perfectly aligned together, the curvature of space will take that light and spread it into a perfect ring.

• 23:28Janna Levin?

  Hmm.

• 23:28Neil deGrasse Tyson?

  And so you would see rings around

• 23:30Janna Levin?

  Right.

• 23:30Neil deGrasse Tyson?

  stars in the night sky. From another star that's exactly aligned behind it. Here's the problem. Back then, the universe was composed only of stars. And stars are so small at those distances, you would never get an exact alignment. So he said, "This will probably never get observed." Until we discover whole galaxies Right. out in the universe. And so it's no longer a point of light.

• 23:54Janna Levin?

  Right.

• 23:54Neil deGrasse Tyson?

  The galaxy has a whole field. So there are many places you can be behind a galaxy and still have this phenomenon. So we see gravitational lenses all the time.

• 24:03Janna Levin?

  Yeah. And we, we, we see it around black holes. That's how we detected a black hole. We took a picture of a black hole because of the light from behind it went above and below and cast the shadow of the black hole.

• 24:15Neil deGrasse Tyson?

  There's no above or below in space. Went around. You in my office.

• 24:20Janna Levin?

  Went around. Went around.

• 24:24Neil deGrasse Tyson?

  She got there with a compass. It's all north. So that was one that he predicted, assumed it would never be found. And then, in my lifetime, like while I'm in graduate school, we'd discover gravitational lenses. Because people found these objects hanging off the side. They said, "What is that? Why is it a little distorted?"

• 24:43Janna Levin?

  A whole arc.

• 24:44Neil deGrasse Tyson?

  It's a whole arc. And then he took a spectrum of it and exactly matched the spectrum of the object on the other side. And that's the splitting of the light around the object. So that's another little crumb that fell off the dude's plate. Okay. So, tell me about black holes themselves.

• 24:58Janna Levin?

  Yeah, well, black holes also predicted from his mathematical theory.

• 25:02Neil deGrasse Tyson?

  But did he predict?

• 25:03Janna Levin?

  But not by Einstein.

• 25:03Neil deGrasse Tyson?

  Why not?

• 25:04Janna Levin?

  He did not predict. Well, you know, there's, it's, as I said, abundant. It's endlessly productive.

• 25:09Neil deGrasse Tyson?

  So black holes are crumbs.

• 25:10Janna Levin?

  Black holes.

• 25:11Neil deGrasse Tyson?

  Yet to be shaped crumbs.

• 25:13Janna Levin?

  Yeah, you have to go at the equations to decide what you want to think about.

• 25:16Neil deGrasse Tyson?

  Yeah.

• 25:17Janna Levin?

  Because it describes every possibility imaginable. Once you put matter and energy in, how will space and time curve? So I could, how does that couch curve spacetime? Not a great question. Scientifically, not one most people aren't gonna spend their time on. But one guy decided, you know, it's, he's on the Russian front during World War I. Uh, Carl Schwarzschild.

• 25:35Neil deGrasse Tyson?

  Oh, Carl Schwarzschild, yes. Did he die on the front?

• 25:37Janna Levin?

  He did. He died like six months after, I think, this correspondence with Einstein where he sends him. He said, "I found a very simple solution to your equation."

• 25:44Harrison Greenbaum?

  Did he die on the front because he was busy writing letters to Einstein?

• 25:47Neil deGrasse Tyson?

  I know, but not paying attention to the bullets.

• 25:49Harrison Greenbaum?

  Hey buddy, you're on the front.

• 25:51Janna Levin?

  Yeah, um, yeah, I think he contracted some infection.

• 25:54Harrison Greenbaum?

  Oh.

• 25:55Janna Levin?

  It was quite dire.

• 25:55Neil deGrasse Tyson?

  A lot of people back then died of non-bullet injuries.

• 25:58Janna Levin?

  Related, yeah. So, but he said, imagine, it was a thought experiment, imagine you took all the mass of a star and you crushed it to a point. And, or it could have been a planet, or it could have been anything. So you're imagining that all the mass is at the center in a point. You don't ask how nature would do such a thing. I don't even think Schwarzschild believed that there was a way nature would do such a thing. Certainly Einstein didn't, but the math was sound. It described the curvature of spacetime. If you're far away, around a star or the earth, but as you get closer and closer and all the mass is still in front of you, eventually you form this event horizon where not even light can escape. That's really what we mean by the black hole.

• 26:33Neil deGrasse Tyson?

  Surface gravity gets higher and higher and higher.

• 26:34Janna Levin?

  Yeah, just because the mass is always in front of you, if you think about it.

• 26:36Neil deGrasse Tyson?

  Yeah.

• 26:37Janna Levin?

  Like if I go inside the sun, the, the gravity drops off because I'm leaving some of the mass behind.

• 26:41Neil deGrasse Tyson?

  So you're vaporized.

• 26:42Janna Levin?

  And I'm vaporized.

• 26:43Neil deGrasse Tyson?

  Ruining that complication.

• 26:44Janna Levin?

  Right. It's, right, I always say, you know, black holes are much more benign than people give them credit for.

• 26:48Neil deGrasse Tyson?

  Oh, yeah, you could just die.

• 26:49Janna Levin?

  The star is incendiary, right? But, but the black hole, you can get real close.

• 26:54Neil deGrasse Tyson?

  So this is You just can't get out. So we call this the Schwarzschild solution to Einstein's equations.

• 26:59Janna Levin?

  Yes.

• 26:59Neil deGrasse Tyson?

  So Schwarzschild does this.

• 27:01Janna Levin?

  Yes.

• 27:01Neil deGrasse Tyson?

  And, but he dies, so no Nobel Prize for him. But it's still an amazing result.

• 27:06Janna Levin?

  And Einstein doesn't think they're real. Says it's beautiful. He helps get it published. And he couldn't believe that, that such a simple solution came out so quickly. It was within six months.

• 27:15Neil deGrasse Tyson?

  Or that nature would even allow it.

• 27:17Janna Levin?

  Yes, he, he thought nature would not allow it.

• 27:19Neil deGrasse Tyson?

  Yeah, that there could be some, something that arises.

• 27:22Janna Levin?

  Yeah.

• 27:22Neil deGrasse Tyson?

  That prevents such a catastrophic collapse.

• 27:25Janna Levin?

  Well, that makes sense.

• 27:26Neil deGrasse Tyson?

  Of matter itself. Just staring at this guy, no.

• 27:29Janna Levin?

  Yeah. Well, try to crush a soda can. It's, it's nearly impossible to get past a certain point. It's hard to do. It's hard to crush things because there's matter forces that resist.

• 27:36Neil deGrasse Tyson?

  Wait, that's a soda can with soda in it.

• 27:40Neil deGrasse Tyson?

  I could otherwise totally crush a soda can, okay? Can I be clear about this?

• 27:44Janna Levin?

  That'll be like a demo that I want to see added, but only to a point. You can't make a black hole.

• 27:48Neil deGrasse Tyson?

  No, not a black hole. Right, right, right.

• 27:49Janna Levin?

  Because the, the atomic forces will resist.

• 27:51Neil deGrasse Tyson?

  Now, so I have to share this quick story with you. I'm having dinner with Stephen Hawking and Nice flex.

• 27:59Neil deGrasse Tyson?

  And so I was talking about Isaac Newton.

• 28:02Janna Levin?

  Mm-hmm.

• 28:03Neil deGrasse Tyson?

  Where he did not figure out that the solar system was stable using his own equations. Okay? It turns out in the solar system, here's the sun and here's like Earth going around. You're Jupiter. Every time I go between the sun and Jupiter. You're saying I'm very big? Yeah.

• 28:23Neil deGrasse Tyson?

  No, I'm saying you're gaseous. I've been, I've been working, I've been working to get to Mars. I'm saying you're, you're bulbous and gaseous. So Earth comes around and it feels you a tug a little because you're closer here, right? And then over here and it comes back around, it feels a little tug. So all these little tugs, he knew that if this continued, Earth would just fly out of its orbit. For thousands, millions of years, this would just be this runaway destabilizing force going on in the solar system. And so know what he said? He said, "God must step in and fix things."

• 28:56Janna Levin?

  No.

• 28:57Neil deGrasse Tyson?

  That's how badass he is. He said, "My, I know my equations work."

• 29:00Janna Levin?

  I can't do it.

• 29:01Neil deGrasse Tyson?

  So the only thing, because we see a stable solar system. Okay. But, late, 100 years later, 100 years later, Laplace comes up with a formalism, a branch of, he develops with others, but he develops a branch of calculus that can demonstrate that these little tugs, which are multiple little tugs on a major system, all cancel out. It's called perturbation theory. But it's just a branch of calculus. The dude invented calculus. Right. So you can't, you can't figure that out? So I asked Hawking. I said, "How come he didn't figure it out?" Because who else are you gonna ask? If not Stephen Hawking? Right. So...

• 29:45Janna Levin?

  And you waited a very, very long time for a reply?

• 29:47Neil deGrasse Tyson?

  Yes, I did. So, so I went on to other conversations, right?

• 29:51Janna Levin?

  And when he was ready.

• 29:52Neil deGrasse Tyson?

  Like I thought it was my entire mail. With his eye blinks, he's assembling the answer. Wow. And it must have been 20 minutes.

• 29:59Janna Levin?

  Oh, yeah.

• 29:59Neil deGrasse Tyson?

  20 minutes later, he said something simple and brilliant. He said, "You can't think of everything."

• 30:07Neil deGrasse Tyson?

  That's like, that's like 20 minutes at a time? No, no. "You can't think of everything." And I said, "That is so beautiful." That, and then he went on to say, to follow that with, Einstein did not come up with black holes.

• 30:20Janna Levin?

  That's right.

• 30:20Neil deGrasse Tyson?

  Because you can't think of everything.

• 30:22Janna Levin?

  Can't think of everything.

• 30:23Neil deGrasse Tyson?

  And I said, "That, that, that's comforting, actually."

• 30:26Janna Levin?

  Yeah. I mean, an entire industry of scientists have been since still working on Einstein's equations.

• 30:32Neil deGrasse Tyson?

  I got another one for you.

• 30:33Janna Levin?

  Okay.

• 30:33Neil deGrasse Tyson?

  He wrote a research paper on the stimulated emission of radiation. This is an extraordinary result that you have to kind of be on the inside to appreciate. Okay, I'll tell you what it is. Ready? So you have an atom with these energy levels where the electron hangs out. It's in discrete energy levels. It can't hang out anywhere. This is quantum. A quantum is units of anything. Okay? So it's quantized. Even solace. Quantum. Think about it, if you have a quantum of solace.

• 31:05Janna Levin?

  Very Marquez somehow.

• 31:07Neil deGrasse Tyson?

  Yes, it is. So the electron can only be in any one of these discrete levels at any given time. And if it's at a higher level, left to itself, it'll wanna de-excite back to a lower level. And it shoots out a photon in so doing. So this is what atoms just want to do. If you excite them, they wanna de-excite. We got this. Okay. So, let's go back to our atom, and we have an electron hanging out in an energy level. Now, I send in light photons that are exactly the energy level that'll boost this up. So it's gonna absorb those and take 'em up, okay? It's gonna do that. However. Oh no.

• 31:50Neil deGrasse Tyson?

  Here's what he discovers. That if you bathe an atom with an electron at a given level of photons that would boost it, it will also spontaneously trigger it to de-excite. At the same time? Yes! Exciting and de-excite. No, no, no. I mean, it will, it will, not all the, all the photons will not go to just boost it. Gotcha. Being in that bath will also de-excite it. For, for, there's no, there's no classical understanding of that, okay? So it's the stimulated emission of radiation. Normally, when you stimulate it, it absorbs it. This one, you shine on it, it de-excites. Okay, that's a weird result. Yeah.

• 32:33Neil deGrasse Tyson?

  It's a quantum result that he deduces using math and quantum physics, okay? And what do we get out of this?

• 32:42Janna Levin?

  Well, we got lasers.

• 32:43Neil deGrasse Tyson?

  Lasers!

• 32:46Neil deGrasse Tyson?

  You say that so calmly.

• 32:47Janna Levin?

  We got lasers.

• 32:48Neil deGrasse Tyson?

  We get lasers.

• 32:51Neil deGrasse Tyson?

  Pull some, grab some more.

• 32:54Janna Levin?

  So, it's really an interesting history, because there were also masers before lasers, which were microwave versions of this. And Joe Weber, who wanted to study gravitational waves, was working on masers, and they were, they were completely overrun by the laser.

• 33:06Neil deGrasse Tyson?

  Give us the full acronym.

• 33:08Janna Levin?

  Microwave amplitude stimulated emission resonance.

• 33:14Harrison Greenbaum?

  Laser stands for.

• 33:16Neil deGrasse Tyson?

  You got a C minus on that one.

• 33:19Harrison Greenbaum?

  Laser stands for look and stare, experience regret.

• 33:23Neil deGrasse Tyson?

  Oh, very good on the spot.

• 33:25Harrison Greenbaum?

  Or it's like, remember George Costanza with the laser pointer? So it's like, look, a Seinfeld episode reference.

• 33:32Neil deGrasse Tyson?

  Oh, hey, this guy's good.

• 33:34Janna Levin?

  That's very good.

• 33:35Neil deGrasse Tyson?

  That's very good. Let's, from here on, let us call it.

• 33:40Neil deGrasse Tyson?

  So, so, so the laser is an acronym, like scuba and all these fun acronyms.

• 33:44Janna Levin?

  Laser.

• 33:45Neil deGrasse Tyson?

  Light amplification.

• 33:46Janna Levin?

  Amplification.

• 33:47Neil deGrasse Tyson?

  By the stimulated emission of radiation. And those are the three words.

• 33:50Janna Levin?

  I did a real bad job.

• 33:52Neil deGrasse Tyson?

  So light would be. He has a sir of laser. So it'd be visible light. But you can, it works with any kind of photons. Microwaves, it turns out it's easier to make a microwave laser. Microwave amplification by the stimulated emission of radiation. So this was, this is just some paper. He does, like, while he's taking a crap, right? And publishes it and then.

• 34:12Harrison Greenbaum?

  His poop paper.

• 34:14Neil deGrasse Tyson?

  I don't know if he was actually on the toilet.

• 34:15Harrison Greenbaum?

  He was experiencing some Brownian motion, if you will.

• 34:20Neil deGrasse Tyson?

  Some Brownian movement, yes.

• 34:24Neil deGrasse Tyson?

  So that, for me, that's my favorite.

• 34:26Janna Levin?

  Is it?

• 34:27Neil deGrasse Tyson?

  Of his.

• 34:27Janna Levin?

  Of his crumbs.

• 34:28Neil deGrasse Tyson?

  Of his crumbs.

• 34:29Janna Levin?

  Interesting. I mean, it's, it's an unbelievable technological advance. It's incredible, it's everywhere.

• 34:33Neil deGrasse Tyson?

  Yeah, because, because the amplification is, if you emit light in this bath of light, and that light you emit is the same light when brought around that will deexcite it and emit a photon. So the, so it's, it's almost self-feeding. The light that it emits is the same light that it then absorbs. So this, this loop is, you can, you can pump light that way with the right number of molecules in the right cavity. Oh, my gosh.

• 35:05Janna Levin?

  And it becomes very coherent and very tight beam and very intense.

• 35:08Neil deGrasse Tyson?

  Yes.

• 35:08Janna Levin?

  So it's a way of getting like this incredible intensity at this one very narrow frequency range or light range.

• 35:15Neil deGrasse Tyson?

  Yeah. And so at the time, I'm sure he was saying to himself. Skin peel.

• 35:20Janna Levin?

  Right, it's like, I'm gonna have a little laser.

• 35:24Neil deGrasse Tyson?

  Yeah, I mean, the application of laser were, oh my god, so the people who invented the laser, I think it was Charlie Townes, got a Nobel Prize for that. Wow, did he expect it to be in like a Walmart? Yeah, I know, at the checkout line, yeah, no, the first lasers were huge. And so, just the idea that here's a paper that thirty years later becomes a device, and the device gets the Nobel Prize. Incredible.

• 35:48Janna Levin?

  Do you know when Townes got the Nobel Prize?

• 35:50Neil deGrasse Tyson?

  So the laser was invented in nineteen fifty-six, fifty-seven, and Einstein died in nineteen fifty-five. He was so close to seeing the laser. So close, so close, and they were gonna operate on him, because he had some element that was... No, no, stop. And he said, he was already in his seventies or something, he said, "My work is done."

• 36:10Janna Levin?

  Did he really?

• 36:11Neil deGrasse Tyson?

  Yes, I thought that was classy. He was just scared of medical care.

• 36:15Janna Levin?

  Wow, I mean, he was still so combative with quantum mechanics, I'm...

• 36:19Neil deGrasse Tyson?

  Yeah, he did, yeah, give me the quote.

• 36:21Janna Levin?

  Which one, the God does not play dice?

• 36:23Neil deGrasse Tyson?

  God does not play dice.

• 36:24Janna Levin?

  There are others?

• 36:25Neil deGrasse Tyson?

  Was it Niels Bohr, who said back to him, another physicist, "Einstein, stop telling God what to do." It was one of several times he talked about God and God's intentions, because quantum physics is fundamentally statistical. It's not, does not describe a unique, objective reality, it only describes a statistical reality. And this felt very bad to Einstein, even though he made significant contributions to quantum physics. This feels like a trend though, because Newton also was like, "I don't know, God."

• 37:15Neil deGrasse Tyson?

  So a couple of fast other ones, so, he predicts out of general relativity that certain phenomena should produce ripples in

• 37:24Janna Levin?

  Oh yeah.

• 37:25Neil deGrasse Tyson?

  spacetime continuum, gravitational waves.

• 37:28Janna Levin?

  Gravitational waves. So he says, look, if the earth can curve spacetime, if the, if the sun can curve spacetime so that the earth falls around the sun, then if these systems move around, the curves have to move too. So the curves themselves have to modulate like waves. And he predicted something called gravitational waves, which are these silent waves in the shape of spacetime. And they are not visible. It's not light. It's pure gravity. It's not light. But if you saw something, you could see it bobbing on the wave as its path changed. Around and moving on. So if the sun decides to, you know, do something crazy, we would know eight minutes later when the wave got to us.

• 38:05Neil deGrasse Tyson?

  So I, I think I have this right. There is a cottage industry rising up in astrophysics, where they're looking at the pulsars in the galaxy. Pulsars are very fast rotating stars that have extremely precise timing. Precise. So if there's a gravitational wave not coming towards us, but passing across our field of view, we can see the effect of the turbulent spacetime wave on the timing of the pulsar as it goes through the wave. And then you can see them move across the universe.

• 38:43Janna Levin?

  They'll bobble around. They're like buoys on, on the ocean.

• 38:46Neil deGrasse Tyson?

  Yes, they'll just, you'll see this effect as that happens. And so it's like, whoa.

• 38:51Janna Levin?

  Now, he wrote many papers where he thought they didn't exist. So he really struggled with whether or not these.

• 39:00Harrison Greenbaum?

  I don't know if black holes exist, but maybe.

• 39:03Janna Levin?

  Well, gravitational waves were really confounding, whether they carried energy or were real in a substantive way, or it was just, oh, I'm just changing my coordinates. It's just, it's not physically real. There's no physical impact. This was confounding for decades. He once would write, he, he wrote papers where he said they do not exist. They would be accepted for publication. And in the space between publication and sending it to press, he would change the entire paper. And say they do exist.

• 39:27Neil deGrasse Tyson?

  In the space between it being accepted.

• 39:28Janna Levin?

  Yes, between it being accepted and going into print. He would change the entire conclusion, rewrite the paper and say they do exist.

• 39:34Neil deGrasse Tyson?

  He wants to be right no matter what. Right, right, right, right. So then, we decide maybe we can detect some of these. And Kip Thorne, who was a guest on our show, we took StarTalk to him, because he's Kip Thorne. We moved the mountain to Kip Thorne. We went to his home office in Pasadena. He's a professor at, he's at Emeritus now, I think, at Caltech. And we talked about Interstellar, because he was a executive producer on Interstellar.

• 39:58Janna Levin?

  He wrote the original treatment. It's like his dream idea.

• 40:01Neil deGrasse Tyson?

  He did write the original treatment. He brought on Christopher Nolan to realize those views. It wasn't the other way around. So, he petitions Congress and the National Science Foundation and other agencies to, and with a lot of support from other physicists and the like.

• 40:18Janna Levin?

  Ray Weiss, yeah.

• 40:19Neil deGrasse Tyson?

  To build the first gravitational wave detector. And it's built, it's called LIGO, Laser Interferometer Gravitational Observatory. LIGO, sensibly abbreviated, LIGO. And they made it really sensitive to this. They have two lasers that go off at right angles. And if a wave washes over Earth, the length of one laser path will change relative to the other. They make this measurement. Ba-da-bing! They found the first colliding black holes, which deposited so much energy into the spacetime continuum that it would have, we'd have a chance of measuring it.

• 40:57Janna Levin?

  Yeah, I mean, it was the most powerful event humanity's ever observed since the observation of the Big Bang itself. More energy came out of this.

• 41:04Neil deGrasse Tyson?

  All in gravitational waves.

• 41:06Janna Levin?

  In utter darkness.

• 41:07Neil deGrasse Tyson?

  Utter darkness.

• 41:08Janna Levin?

  And yet, and that the power was greater than all the stars in the observable universe combined at that moment. So, but it all came out just in ringing space, literally. So darkness could not see it with a telescope.

• 41:19Neil deGrasse Tyson?

  And so, think about it.

• 41:21Janna Levin?

  I love the look on your face, thank you for that.

• 41:23Neil deGrasse Tyson?

  Yeah, he's looking back and forth like, whoa, whoa.

• 41:27Harrison Greenbaum?

  I'm trying to think of anything else that would be more powerful than those stars combining. I'm stuck at Taylor Swift and Travis Kelce. When those stars came together, we all felt it.

• 41:36Neil deGrasse Tyson?

  That was a moment. It was a tectonic shift. So, we discover gravitational waves that won a Nobel Prize. But, more so, we discover gravitational waves using lasers.

• 41:54Neil deGrasse Tyson?

  His crumbs connected. His crumbs came together and made a big smorgasbord of science and physics and Nobel prizes for everybody on board. So, can you get more amazing than that? I mean, I don't.

• 42:10Janna Levin?

  The detection was essentially in the centenary, too.

• 42:14Neil deGrasse Tyson?

  Yes, it was in 2015.

• 42:16Janna Levin?

  A hundred years. A hundred years after his gravitational wave papers.

• 42:18Neil deGrasse Tyson?

  Oh, man.

• 42:19Janna Levin?

  Yeah.

• 42:20Neil deGrasse Tyson?

  That's Einstein had something to do with that.

• 42:21Janna Levin?

  I mean, he's magic.

• 42:22Neil deGrasse Tyson?

  Einstein totally had something to do with that. Now, Jana, memory serves, Einstein was a big proponent of a unified field theory. And when I first heard that, I was a kid, field? What do you mean by field? I didn't know that field was synonymous with forces. Right? So, we have gravitational force, electromagnetic force, which in its day was the electric force and the magnetic force. And then the force.

• 42:50Neil deGrasse Tyson?

  I've seen Star Wars. Maybe they, maybe they figured it out. They got the one force, you know? So, with the work of Heinrich Hertz and others, we figured out how to combine electricity and magnetism to make one force. And we take that word for granted, but they used to be two whole separate words. Electromagnetic force. So, Einstein, why did he fail at this? Or what, what was motivating him?

• 43:17Janna Levin?

  Well, we've all failed at this. So, there is great success in unifying all of the matter forces, all of the quantum matter forces, electromagnetism with the weak nuclear force and the strong nuclear force. That's the whole story of matter. Done. Completely sealed.

• 43:32Neil deGrasse Tyson?

  Yeah, but they're not combined.

• 43:33Janna Levin?

  Well, so the electro-weak theory is combined. Weak and electromagnetic.

• 43:37Neil deGrasse Tyson?

  So, we went from electro, electricity, magnetism, and the weak nuclear force. Then we got electromagnetism, and then with my guy from my high school.

• 43:44Janna Levin?

  Right. Which guy from your high school?

• 43:47Neil deGrasse Tyson?

  What? Steve Weinberg and Sheldon Glashaw.

• 43:52Janna Levin?

  Yeah.

• 43:52Neil deGrasse Tyson?

  They and- What was this high school?

• 43:54Janna Levin?

  Oh, no, yeah.

• 43:55Neil deGrasse Tyson?

  This was the third one in there?

• 43:57Janna Levin?

  Uh, Salam, Abdul Salam.

• 43:58Neil deGrasse Tyson?

  Abdul Salam, right, that's correct. So the three of them, two of them were classmates in my high school before me, but in my high school. Anyhow, they-

• 44:05Janna Levin?

  There was something in the water there.

• 44:05Neil deGrasse Tyson?

  They managed to conjoin the electromagnetic force and the weak force, and they called it what?

• 44:12Janna Levin?

  Electro weak.

• 44:12Neil deGrasse Tyson?

  Okay, that's not very creative, but all right, we'll go with it.

• 44:15Janna Levin?

  But it is pretty magical. It says that those are really one force, which is magical, something that is at nuclear ranges that we do not-

• 44:21Neil deGrasse Tyson?

  That's manifesting as separate forces today.

• 44:24Janna Levin?

  Right.

• 44:24Neil deGrasse Tyson?

  You go back in time, there's a point where they were just one expressed force in the universe. So that gives us electro weak, strong force, and gravitation.

• 44:32Janna Levin?

  Yeah, now the strong easily can get in there, even though we don't talk about it very much anymore.

• 44:35Neil deGrasse Tyson?

  What do you mean easily? If you did that, you'd have a Nobel Prize now, so-

• 44:38Janna Levin?

  Well, there's something called the grand unified theories, and they have certain failures. There isn't like an ideal grand unified theory, but, but really, there's nothing barring the possibility of it. I mean, it's, it's not-

• 44:49Neil deGrasse Tyson?

  No obvious obstacle.

• 44:50Janna Levin?

  There's no fundamental obstacle to a grand unified theory. Most people think it's gonna come along for the ride when we do the full unification.

• 44:56Neil deGrasse Tyson?

  So when Einstein said a unified field theory, was he thinking just that, or was he also want to include gravity?

• 45:02Janna Levin?

  He wants gravity.

• 45:03Neil deGrasse Tyson?

  He wants gravity.

• 45:04Janna Levin?

  He wants gravity, and it's the same thing he did when he went from special to general. When he started thinking about quantum mechanics, he wants a quantum theory of gravity.

• 45:10Neil deGrasse Tyson?

  But gravity behaves so differently from the other forces. Because, because you can think of gravity not even as a force, but as the, just falling down the curvature of space and time.

• 45:19Janna Levin?

  That's geometry.

• 45:20Neil deGrasse Tyson?

  It's geometry, it's not really a force. So, so that could be a barrier to summing these together.

• 45:26Janna Levin?

  Well, it's, nobody's ever succeeded at even-

• 45:28Neil deGrasse Tyson?

  So how about Kip Thorne? Does he have some ideas here? Does he?

• 45:30Janna Levin?

  Oh, well, I mean, Kip has endless ideas.

• 45:33Neil deGrasse Tyson?

  Yeah, he does.

• 45:33Janna Levin?

  And I, and I think-

• 45:35Neil deGrasse Tyson?

  Interstellar 2.

• 45:35Janna Levin?

  Yes. I, I think Kip's ambition is for- Yes, a universe that would be completely comprehensible, which would mean we either understand quantum gravity or we understand that gravity is not fundamental. Those are the two kind of choices.

• 45:49Neil deGrasse Tyson?

  Oh, yeah.

• 45:50Janna Levin?

  That everything's quantum mechanics. Now, I don't know that--

• 45:52Neil deGrasse Tyson?

  Yeah, quantum mechanics is the most successful idea we've ever had about anything in the universe. I don't think any prediction has ever failed.

• 45:59Janna Levin?

  No, and to the largest number of decimal points of any scientific theory in the history of time.

• 46:02Neil deGrasse Tyson?

  Whereas, general relativity, as badass as it is, we know where its limits are. Like, at the center of a black hole is a singularity. It gives you a singularity in the equations.

• 46:12Janna Levin?

  Mm-hmm.

• 46:12Neil deGrasse Tyson?

  And I don't know what-- that's what we say, where God is dividing by zero.

• 46:16Janna Levin?

  Right.

• 46:16Neil deGrasse Tyson?

  I mean, I'm supposed to divide by zero. Yes. Bad.

• 46:19Janna Levin?

  Well, even Roger Penrose, who talked about the singularity in his Nobel Prize-winning paper--

• 46:22Neil deGrasse Tyson?

  Nobel laureate of recent years.

• 46:23Janna Levin?

  Even in that paper, he says, "I don't really think this part's gonna survive." He really says, "Ah, quantum mechanics will probably get rid of the singularity."

• 46:30Neil deGrasse Tyson?

  But it hasn't.

• 46:31Janna Levin?

  But it hasn't, but it hasn't done any of the things it was supposed to do around gravity.

• 46:35Neil deGrasse Tyson?

  Point is, more crumbs--

• 46:37Janna Levin?

  More crumbs, yes.

• 46:38Neil deGrasse Tyson?

  --await the attention of brilliant people--

• 46:40Janna Levin?

  Yes.

• 46:41Neil deGrasse Tyson?

  Either--

• 46:41Janna Levin?

  Wormholes.

• 46:42Neil deGrasse Tyson?

  --who walk among us or are yet to be born.

• 46:44Janna Levin?

  I'm just gonna throw in, because this is very relevant to this, wormholes, which Einstein talked about, the Einstein-Rosen bridges--

• 46:50Neil deGrasse Tyson?

  Okay.

• 46:50Janna Levin?

  --which ultimately give rise to wormholes, might be involved in understanding that things like black holes and gravity aren't fundamentally real. They're just sort of embroidered out of quantum wormholes. And so it might really be another one of Einstein's crumbs.

• 47:04Neil deGrasse Tyson?

  Embroidered out of quantum wormholes.

• 47:06Harrison Greenbaum?

  And not real.

• 47:08Janna Levin?

  So, more crumbs from Einstein to come.

• 47:11Neil deGrasse Tyson?

  Wow.

• 47:11Harrison Greenbaum?

  Is anybody--

• 47:12Janna Levin?

  Keep your eyes on wormholes.

• 47:13Harrison Greenbaum?

  Is there any other scientist that is that a messy eater, so to speak? Has anybody else left?

• 47:18Neil deGrasse Tyson?

  Isaac Newton was badass, too.

• 47:19Harrison Greenbaum?

  Okay.

• 47:20Neil deGrasse Tyson?

  In fact, I think if Isaac Newton were a contemporary of Einstein, he would have done everything Einstein did, and more.

• 47:25Harrison Greenbaum?

  Whoa.

• 47:25Neil deGrasse Tyson?

  I'm a Newton guy.

• 47:26Janna Levin?

  Yeah, you're a real Newton guy.

• 47:28Neil deGrasse Tyson?

  Yeah, yeah, you gotta give me something here.

• 47:30Janna Levin?

  Yeah.

• 47:30Neil deGrasse Tyson?

  Yeah, I'm a Newton guy.

• 47:32Janna Levin?

  I mean, calculus is pretty impressive.

• 47:33Harrison Greenbaum?

  That's pretty good.

• 47:34Neil deGrasse Tyson?

  Yeah, just like on a dare. Like, Isaac, why are your orbits moving in ellipses rather than circles? He said, "I don't know, let me get back to you on that."

• 47:44Harrison Greenbaum?

  I'm gonna eat an apple.

• 47:45Janna Levin?

  Yeah.

• 47:45Neil deGrasse Tyson?

  "Let me go back, and here's why." And, "Well, how did you do it? Well, I had to invent integral and differential calculus to show that." "Okay, Isaac." So, if you'll indulge me just for a moment, I need to reflect on our conversation.

• 48:02Neil deGrasse Tyson?

  Love me some mathematics. Why? It was early on when I learned, when I wanted to be an astrophysicist, that the language of the universe is mathematics. Now, that's an extraordinary fact, because we just invented mathematics out of our heads. The history of math is filled with examples of, "I don't know how that works. Let me invent a way to calculate with it, so that I can figure out how it works." Thus is the rise of arithmetic, and algebra, and trigonometry, and calculus. All of this

• 48:43Neil deGrasse Tyson?

  helps us commune with the cosmos.

• 48:48Neil deGrasse Tyson?

  But what makes it even more extraordinary is, you start out with an idea of how the universe works, but you can't manipulate that idea, because you're stuck with using only words. If you make a mathematical representation of that idea, then you can manipulate that idea using the perfect logic of mathematics. And by doing so, you can extend the idea in places you didn't even know the idea could go. Because you're extending it with perfectly logical steps from the map of that idea into the world of mathematics. The fact that that works for us at all leaves me in awe

• 49:32Neil deGrasse Tyson?

  of not only the existence of mathematics, but of the human mind that took us there. And here we have, in the likes of Albert Einstein, laying down a physical idea of how the universe works, attaching a mathematical model to it, and the rest of us run with that mathematical model.

• 49:55Neil deGrasse Tyson?

  Crumbs from Einstein's plate, leading to Nobel prizes that at some level should have all gone to him. My boy should have had eight, nine, 10 Nobel prizes. But he's sharing his genius with the rest of us in these, the 20th and 21st centuries. More to come from Einstein's Crumbs. And that is a cosmic perspective. So Jenna, thank you for helping out here.

• 50:22Janna Levin?

  Thanks, I'm always glad to be here.

• 50:24Neil deGrasse Tyson?

  And you have a podcast. Tell me.

• 50:25Janna Levin?

  Oh, right. Joy of Y.

• 50:27Neil deGrasse Tyson?

  I love that. The Joy of Y. That is, that's a beautiful title.

• 50:32Janna Levin?

  Yeah, Quantum Magazine. So the story is, my friend Steve Stroghatz, who's the original host of the show, it's by Quantum Magazine from the Simons Foundation, wonderful science magazine. His book was called The Joy of X, Mathematician. And I thought it was a brilliant title. And so the show was originally called Joy of X.

• 50:49Neil deGrasse Tyson?

  Called The Joy of Lex, which is all about language and words.

• 50:52Harrison Greenbaum?

  There's another one, I think, called The Joy of Sex.

• 50:54Neil deGrasse Tyson?

  That started it all. Yes, okay. Yeah.

• 50:57Janna Levin?

  Yes, that was the original. So Steve and I co-host a show. It's a lot of fun. We deep dive hardcore physics.

• 51:04Neil deGrasse Tyson?

  Excellent.

• 51:04Janna Levin?

  Biology, computer science.

• 51:06Neil deGrasse Tyson?

  Good. And the Simons Foundation, from Jim Simons, the very successful Wall Street trader. I think he's the most successful Wall Street trader there ever was. And

• 51:15Janna Levin?

  He's the original quant.

• 51:16Neil deGrasse Tyson?

  His background in math and physics.

• 51:19Janna Levin?

  A brilliant mathematician and an accomplished mathematician. We still use his mathematical results in theoretical physics.

• 51:25Neil deGrasse Tyson?

  I took a ride on his yacht. It was called The Archimedes.

• 51:29Harrison Greenbaum?

  Nice.

• 51:30Neil deGrasse Tyson?

  That's classy.

• 51:31Janna Levin?

  Jim was the best.

• 51:32Neil deGrasse Tyson?

  All right. I think we did justice to his crumbs here.

• 51:35Janna Levin?

  Thanks so much, guys. Always fun.

• 51:37Neil deGrasse Tyson?

  Yeah. Thanks for filling in those gaps and taking us to the next step. And Harrison, you're on the road with your, your routine.

• 51:45Harrison Greenbaum?

  Yes, I have my comedy magic show. We've been off Broadway. I'm taking it on the road and I'm doing a stand-up all over the country.

• 51:51Neil deGrasse Tyson?

  Harrison.

• 51:51Harrison Greenbaum?

  HarrisonGreenbaum.com.

• 51:52Neil deGrasse Tyson?

  Dot com. We'll look for it. All right. This has been StarTalk, the Einstein Crumbs edition. Neil deGrasse Tyson here. As always, I bid you keep looking up.