Pod Insights StarTalk Podcast Cosmic Queries – Bits of Spacetime with Janna Levin About this episode Is gravity fundamental to the universe? Neil deGrasse Tyson and Chuck Nice explore quantum physics, the fourth dimension, whether H2O is water, and the many-worlds interpretation with theoretical cosmologist Janna Levin, PhD.
Transcript Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.
0:00 Neil deGrasse Tyson? Coming up on StarTalk Cosmic Queries with our friend Jan Levin. Yeah, it's gonna be relativistic, cosmological, higher dimensions, lower dimensions, Big Bang, end of the universe, edge of black holes, everything that blows your freaking mind.
0:21 Neil deGrasse Tyson? Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now. This is StarTalk, Neil deGrasse Tyson, your personal astrophysicist. We've got a StarTalk Cosmic Queries today with one of our favorites, or Chuck, is she our very favorite?
0:46 Chuck Nice? Uh, she's our very favorite theoretical physicist.
0:50 Neil deGrasse Tyson? Oh, that's a good one.
0:52 Chuck Nice? That is for sure.
0:53 Janna Levin? I wanna know who's on this list.
0:58 Neil deGrasse Tyson? So, Jan Levin, welcome back to StarTalk.
1:00 Janna Levin? Always fun to be here.
1:01 Neil deGrasse Tyson? Yeah.
1:02 Janna Levin? Very glad. As Chuck was saying, we're getting closer and closer together here. Love it.
1:05 Neil deGrasse Tyson? Just for the...
1:06 Chuck Nice? Just for the video.
1:07 Neil deGrasse Tyson? For the video. You know why? Because we spent three years Zooming away.
1:11 Janna Levin? I love it, I know.
1:16 Neil deGrasse Tyson? So, you're a theoretical physicist and you're a professor, a TOE professor? That's the founder of your endowed chair, I guess?
1:24 Janna Levin? Yes, yes. I think we say Tao.
1:27 Neil deGrasse Tyson? Tao?
1:27 Janna Levin? Yes.
1:28 Neil deGrasse Tyson? Tao professor, not T A U.
1:29 Janna Levin? I'd get in trouble if I don't say it right.
1:30 Neil deGrasse Tyson? Yeah, not T A U, just T O W.
1:32 Janna Levin? T O W.
1:32 Neil deGrasse Tyson? The Tao professor of astronomy and physics at Barnard and at Columbia.
1:37 Janna Levin? Yeah.
1:37 Neil deGrasse Tyson? University, which is up the street here in New York City. And you've written several books, and forgive me, but all the titles of your three books have merged into one flow of words.
1:50 Janna Levin? You say them better than anybody else on the planet.
1:53 Neil deGrasse Tyson? So, one of them is How the Universe Got Its Spots?
1:55 Janna Levin? How the Universe Got Its Spots.
1:56 Neil deGrasse Tyson? Okay. The other one was Black Hole Survival Guide.
2:00 Janna Levin? Yes.
2:01 Neil deGrasse Tyson? And a third one was?
2:02 Chuck Nice? Black Hole Blues.
2:03 Neil deGrasse Tyson? The Black Hole Blues.
2:04 Janna Levin? Excellent. There's one more. I wrote a novel.
2:08 Neil deGrasse Tyson? What?
2:08 Janna Levin? Yeah.
2:09 Neil deGrasse Tyson? What?
2:09 Janna Levin? I won like a PEN Award for fiction.
2:12 Neil deGrasse Tyson? What?
2:13 Janna Levin? Yeah, you guys, you guys know 1% about me.
2:15 Neil deGrasse Tyson? I'm sorry.
2:16 Janna Levin? I am going to be your favorite by the end of today.
2:20 Chuck Nice? Wow, what's the novel?
2:21 Neil deGrasse Tyson? So what's the novel?
2:22 Janna Levin? A madman dreams of turing machines. Maybe the title's too long.
2:25 Chuck Nice? Wow, a madman dreams of turing machines.
2:27 Janna Levin? It's about Alan Turing.
2:29 Chuck Nice? Alan.
2:31 Neil deGrasse Tyson? Okay.
2:32 Janna Levin? It's a little trippy. Yeah.
2:34 Chuck Nice? Wow.
2:34 Janna Levin? It was a long time ago.
2:36 Chuck Nice? Oh, wow, so it's, it's, it's, uh, it's, it's, I thought it was something that was relatively new.
2:40 Janna Levin? No, it's not.
2:41 Chuck Nice? It's where you started, so that's where your heart is.
2:43 Janna Levin? Yeah, well, every once in a while, I dabble with unfinished fiction.
2:48 Neil deGrasse Tyson? What a sentence that is. Oh, my gosh. How many people get to say that?
2:53 Chuck Nice? Very cool, very cool.
2:55 Neil deGrasse Tyson? Well, all right, it's a, it's a cosmic queries where our fanbase knows you, and we left it wide open.
3:02 Janna Levin? Fun.
3:03 Neil deGrasse Tyson? Just to have to be, in your bailiwick is theoretical, cosmological, relativistic physics.
3:09 Janna Levin? Love it.
3:10 Neil deGrasse Tyson? And she's ready for it.
3:12 Janna Levin? Bring it on.
3:12 Neil deGrasse Tyson? Ready to throw down. But before we do that, I just want to catch up on a few things. You are also very active in Pioneer Works. Just remind people briefly what that is.
3:22 Janna Levin? Pioneer Works is a cultural center. It's pretty new. It's for arts and sciences. It was founded by artist Dustin Yellen and the founding artistic director is Gabriel Florentz. And then I came in as the founding director of sciences. We're kind of a triad. And we really have science and art really rubbing together. So we have exhibitions for artists.
3:39 Neil deGrasse Tyson? Rubbing in a good way.
3:40 Janna Levin? In a good way.
3:41 Neil deGrasse Tyson? If it's rubbed together in a bad way, you want to stop that.
3:44 Janna Levin? You chase, you chase.
3:45 Neil deGrasse Tyson? You chase. Get some WD-40. But this one is rubbing so that they can influence.
3:50 Janna Levin? Yeah, and we're, you know, we're not crowbar-ing things together in a, I, I hope not a fake way. It's very genuine and spirited. It's a real labor of love.
3:59 Neil deGrasse Tyson? You can say organic.
3:59 Janna Levin? Organic. We've had you, Neil, we've had you, Chuck, in our space.
4:05 Neil deGrasse Tyson? We performed a live StarTalk at your space in Brooklyn.
4:08 Chuck Nice? No, I wasn't there for that.
4:09 Janna Levin? Yeah, we're not there for that, at least.
4:11 Chuck Nice? I did something totally different.
4:13 Janna Levin? Paul McCurry, I believe, was our.
4:14 Neil deGrasse Tyson? Paul, we have Paul.
4:15 Chuck Nice? Very funny.
4:16 Neil deGrasse Tyson? Paul McCurry was our onstage comedian.
4:18 Janna Levin? Yeah, we do, uh, like, we'll have an exhibition about, we had one for the Hiroshima panels, which were made in 1945. And then we had conversations with scientists about.
4:31 Janna Levin? Nuclear energy and nuclear weaponry and the history of things like containment. And so we riff off each other.
4:37 Neil deGrasse Tyson? And you have a social conscience.
4:40 Janna Levin? Yes, definitely.
4:42 Chuck Nice? Well, how so?
4:45 Janna Levin? We're not, we don't prescribe anything politically, morally, socially. It's radical as all art spaces have to be and challenging, challenging even to our own ideas. But it very much is a place for community. I really believe that science is part of culture. It's at the forefront of culture along with art, music. It doesn't have to be hidden like a wall inside the walnut of those other things. That we have a community around that.
5:10 Chuck Nice? Inside the walnut.
5:12 Janna Levin? So I believe like people need a place to gather and to be together and to break bread and to talk about things and think about things. So very much central to sort of our thinking around the place. If you come to an event, you'll stay after, you'll hang out in our garden. We often have telescopes. Scientists will mill around, you can ask them questions.
5:32 Neil deGrasse Tyson? And the telescopes because you have a relationship with the amateur astronomers?
5:36 Janna Levin? Yes.
5:36 Neil deGrasse Tyson? The New York City amateurs?
5:38 Janna Levin? Yes, the Amateur Astronomers Association of New York are tried and true. They're wonderful.
5:42 Neil deGrasse Tyson? I was a member of them since I was 10 years old.
5:45 Janna Levin? Yeah, they bring out the telescopes, rain or shine, they're always there. They're terrifics for a while.
5:50 Neil deGrasse Tyson? Not in the rain.
5:52 Janna Levin? Well, they come out in the rain because even so they'll be like, I'll show you what a telescope looks like or how it operates. Like they're really devoted.
5:58 Neil deGrasse Tyson? They're not observing rain or shine, but they're there.
6:00 Janna Levin? Not observing rain or shine, right, but they'll, they rarely drop out.
6:04 Chuck Nice? Around the city too.
6:04 Neil deGrasse Tyson? Yeah, yeah.
6:05 Chuck Nice? If you join, like if you just want to look through a telescope and see, you know, celestial bodies, like they set up on the High Line and.
6:13 Janna Levin? Amazing.
6:13 Chuck Nice? And you just go there and look.
6:15 Janna Levin? Now, you know, we're trying to build an observatory on top of Pioneer.
6:18 Neil deGrasse Tyson? I caught wind of it.
6:19 Janna Levin? This is our big aspiration.
6:21 Neil deGrasse Tyson? Oh, yeah.
6:22 Janna Levin? Yes, and you know, I know you and I were talking about it and there is a sense like, ah, I could buy a telescope for a couple of grand and it'll be great, right? And that is true. But we have this old telescope from 18.
6:35 Janna Levin? Uh, 93, 95, that is being refurbished and it's just a stunning museum quality piece. And it's very inspiring to have that. And of course, we'll have modern telescopes available. But that kind of central piece is gonna be part of arts and performances around it.
6:54 Neil deGrasse Tyson? It'll anchor the ethos of what you're about.
6:57 Janna Levin? Yes, it's romance.
6:58 Chuck Nice? When you refurbish it, would you put in like new glass and better?
7:02 Janna Levin? Actually, no, the glass is so excellent. We know the provenance of the lenses and they're incredible. They were made by kind of people at the peak of that kind of engineering and craftsmanship.
7:15 Chuck Nice? Cool.
7:16 Janna Levin? Yeah, it's very neat.
7:17 Chuck Nice? That's amazing stuff.
7:18 Janna Levin? Yeah, that's amazing.
7:19 Neil deGrasse Tyson? All right.
7:20 Janna Levin? Let's hope we hoist it up on the building without incident.
7:24 Neil deGrasse Tyson? So Janet, your field of study is, I bet, most people would say would be the most mind-blowing science that anyone does.
7:34 Chuck Nice? Wow.
7:34 Neil deGrasse Tyson? Because it's just out, it's out there.
7:37 Janna Levin? Yeah.
7:38 Neil deGrasse Tyson? You know, I could talk about stars and planets and there's a tangibility to that. Even the size, even the expanding universe, it's a little weird, but it's not, it doesn't blow your mind.
7:51 Janna Levin? Yeah.
7:51 Neil deGrasse Tyson? You think about stuff that's like, what?
7:55 Janna Levin? One of my favorite experiences when I'm doing research is when I have a huge shift, when I'm shocked by something and I realize I've had some kind of preconceived notion that has just been shattered.
8:07 Neil deGrasse Tyson? Right.
8:08 Janna Levin? And it's really amazing. I'm following the science. I'm not dragging it along.
8:13 Neil deGrasse Tyson? Right, right, right.
8:14 Janna Levin? And, um, yeah, it literally blows your mind.
8:17 Neil deGrasse Tyson? Many people who don't know the moving frontier of science think, and I think, want to believe that somehow we all sit around wanting to agree with one another.
8:26 Janna Levin? Right.
8:26 Neil deGrasse Tyson? But in fact, the advance has come when someone says, I have an idea. Was it, uh, Isaac Asimov said... That true scientific discovery is never eureka.
8:38 Chuck Nice? Right.
8:38 Neil deGrasse Tyson? It's, that's odd.
8:40 Janna Levin? Yes, yes.
8:42 Neil deGrasse Tyson? Just a little thing.
8:43 Janna Levin? Totally, absolutely.
8:44 Neil deGrasse Tyson? That doesn't fit that.
8:45 Janna Levin? Yeah, and I love, I really appreciate what you're saying. I really feel that debate is not actually how scientists operate. They don't sit there trying to win an argument. That would be so unscientific.
8:56 Chuck Nice? It doesn't make any sense to do that.
8:56 Janna Levin? No, not at all. You want to say, wait, what are you, what are you talking about?
9:00 Chuck Nice? Basically, it's, I call BS.
9:03 Janna Levin? Yeah.
9:03 Chuck Nice? That's really a nutshell.
9:05 Janna Levin? Right, and that's how.
9:05 Chuck Nice? I call BS, and then, and then you got to set about to prove it.
9:09 Janna Levin? Absolutely.
9:09 Neil deGrasse Tyson? Well, so Jenna, what I think you're saying is, the way I've described it is two scientists in an argument, there's an unwritten contract between them.
9:19 Chuck Nice? Okay.
9:19 Neil deGrasse Tyson? Okay? Either I'm right and you're wrong, you're right and I'm wrong, or we're both wrong.
9:25 Janna Levin? Right, yeah.
9:26 Neil deGrasse Tyson? And if we can't agree at the end of that conversation, we do agree that more or better data will resolve it.
9:33 Janna Levin? Absolutely.
9:34 Chuck Nice? In which case, you could both be right.
9:36 Neil deGrasse Tyson? Well, so, yes, so there are the rarer case where we're both right.
9:39 Chuck Nice? Right.
9:40 Neil deGrasse Tyson? If, in the, in the, in the classical example of the, the blind people touching an elephant, they give completely disparate accounts.
9:49 Chuck Nice? Right.
9:50 Neil deGrasse Tyson? Okay, one is the trunk, one is the leg.
9:52 Janna Levin? Right.
9:52 Neil deGrasse Tyson? One is the toenails, one is the tail.
9:54 Janna Levin? They each have a piece.
9:54 Neil deGrasse Tyson? One is the tusk, and we can argue what the actual nature of that animal is, but at the end of the day, we're all correct, because it's all part of the same animal.
10:05 Janna Levin? And then there's a bigger vision.
10:06 Neil deGrasse Tyson? There's a bigger vision, so the bigger visions are often very hard to reach, but that can happen, and it, it does, it can and does happen.
10:13 Janna Levin? I totally agree with you. One thing that drives me a little crazy is when people say, oh, science is always overturning what came before completely and rewriting, so why should I believe in? And that's not true.
10:23 Neil deGrasse Tyson? It's, it's not only not true, it's very false.
10:25 Janna Levin? It's very false.
10:27 Chuck Nice? Very false.
10:27 Janna Levin? So, so if we were logicians, we would, we would care about that distinction. So if I look back at what Newton did, it is absolutely a part of the elephant, an excellent description of a part of the elephant that he was able to palpate at the time. Einstein comes along and it's bigger.
10:42 Chuck Nice? That's the one.
10:43 Janna Levin? See, that's, that's the novelist.
10:45 Neil deGrasse Tyson? Okay.
10:47 Janna Levin? So, you know, Einstein comes along and has a bigger vision, but he absolutely requires of his work that it match Newton, right? Not that it has nothing to do with Newton. Suddenly, when I pour my coffee, it doesn't go upward, right? So, um, so it's cumulative.
11:01 Neil deGrasse Tyson? So Einstein enclosed Newton as a special case.
11:03 Janna Levin? A bigger view.
11:04 Neil deGrasse Tyson? Within a larger understanding of the world. But it was not overthrown. It was, uh...
11:10 Janna Levin? Extended.
11:11 Neil deGrasse Tyson? Extended, right. Cool. Right. We don't always... Anything that was experimentally determined to be true previously does not all of a sudden become false. Right. It becomes embedded in a deeper truth. And that's true even, even when you look at continental drift, which famously was delayed, had delayed acceptance among geologists. All the while, they're still trying to understand volcanoes and, and, and they're still trying and, and, and so they're coming up with local accounts for what would happen in a volcano.
11:43 Janna Levin? Right.
11:44 Neil deGrasse Tyson? When they had continental drift, that just attached to the continental drift. And there's a lot of that science that was completely portable into the new idea that the surface of the earth moves within itself.
12:02 Speaker 03 I'm Nicholas Costella, and I'm a proud supporter of StarTalk on Patreon. This is StarTalk with Neil deGrasse Tyson.
12:18 Neil deGrasse Tyson? I wonder if we have any mind blowing questions that await us?
12:21 Chuck Nice? Well, we have questions. Now, whether or not they're mind blowing, that remains to be seen.
12:26 Neil deGrasse Tyson? We're not gonna blow Jana's mind.
12:27 Janna Levin? Oh, I hope so.
12:28 Chuck Nice? Maybe that's what we'll find, see if we can find a...
12:30 Janna Levin? I'm susceptible, you know? I'm vulnerable to that.
12:33 Chuck Nice? Find a question that blows Jana's mind and, uh...
12:35 Neil deGrasse Tyson? Oh, right.
12:36 Chuck Nice? And we'll send you a special gift, which will...
12:39 Janna Levin? A piece of my...
12:42 Janna Levin? Debris from the explosion.
12:44 Chuck Nice? There you go. All right, this is David Garvin, and David says, hello, Lady Levin, Dr. Tyson, Lord Nice. I'm David, a mechanical engineer in Seattle. Now, we know that spacetime can stretch. Is there anything within known physics which requires that spacetime be infinitely elastic? Could dark matter observations be plastic deformation of spacetime? Dimples, as you will, in spacetime, which would be non-interactive but are in two things we now call galaxies. Wow.
13:17 Neil deGrasse Tyson? Okay, so, yeah, tell me about the stretchability.
13:21 Chuck Nice? Yeah.
13:22 Janna Levin? Yeah.
13:23 Chuck Nice? Start there.
13:24 Janna Levin? Well, let's start there. Really, I think it's more of a dark energy tie-in than a dark matter tie-in. So, is there anything that requires space is infinitely elastic that can be stretched forever? Probably not. Just like when I look at the continuum of water, as I get closer and closer and higher energy and more microscopic, I realize it's actually not a continuous medium, it's made up of discrete pieces.
13:48 Chuck Nice? Right.
13:49 Janna Levin? Molecules. And so it's not infinitely smooth.
13:52 Neil deGrasse Tyson? But there's a big, big debate, I don't know if it's still raging, but it was for a while, in deep philosophy literature, is H2O water?
14:03 Chuck Nice? Really?
14:04 Janna Levin? Fascinating.
14:05 Neil deGrasse Tyson? Okay. Right? Because everything we know and understand and love about water requires an ensemble of H2Os.
14:10 Chuck Nice? Right.
14:11 Neil deGrasse Tyson? If you pull out one of them, you get to call that water.
14:14 Janna Levin? Right.
14:15 Neil deGrasse Tyson? Yeah, so it's interesting philosophical challenge, that's where they're going there.
14:18 Janna Levin? Yeah.
14:19 Neil deGrasse Tyson? So, you know water is not infinitely stretchable in that sense.
14:22 Janna Levin? Right, in that sense, right. And so, if I looked at spacetime at higher and higher energies and smaller and smaller scales, much, much smaller than what I need to look at for water, like... Trillions and trillions and trillions of times smaller or something we will never reach even in the most powerful accelerators on earth, but probably was reached in the big bang.
14:41 Neil deGrasse Tyson? So smaller than the atoms, smaller than the nucleus.
14:43 Janna Levin? Absolutely, and probing energies we really haven't seen since the big bang.
14:48 Neil deGrasse Tyson? Because it takes high energy to get to those regimes.
14:52 Janna Levin? That's right, absolutely.
14:53 Neil deGrasse Tyson? Because that's not always made obvious when people talk about, why do you need a bigger accelerator?
14:58 Janna Levin? Right, why do you need high energy to look small?
15:00 Neil deGrasse Tyson? Right.
15:01 Janna Levin? But you do, because you need to get really in there, you need to get really high energies to probe into the tiniest regions.
15:09 Neil deGrasse Tyson? You gotta bust in.
15:10 Janna Levin? Otherwise, you're just like kind of big and lumbering and low energy, you're not sufficiently powerful to do so. At those scales, we do think it's completely conceivable that spacetime will start to come in individual quanta, just like particles, and that we will find there are little bits of spacetime.
15:26 Neil deGrasse Tyson? So could it be that-
15:27 Janna Levin? Like almost like little manifolds, it could be all big origamis that kind of connect together.
15:32 Chuck Nice? So that would mean that there's space in between spacetime?
15:33 Janna Levin? Well, then you have a hard time, see that's a very interesting question, because then you can't really talk about space and time between. If there's space and time between, then that is part of the universe that we're talking about. So now you're just talking relationally in like an abstract space, that they relate to each other, but I can no longer think of the distance between them in any realistic way.
15:57 Neil deGrasse Tyson? So isn't it true that quantum physics requires that space be quantized?
16:01 Janna Levin? Quantum, excellent question too. Quantum gravity requires that spacetime be quantized, but there might not be a theory of quantum gravity. We might look deeper and deeper, and instead of finding quantum bits of spacetime, we will only find pure quantum mechanics with no gravity in it whatsoever, and that gravity emerges only out of the collective of tons and tons of these quantum interactions.
16:30 Chuck Nice? That's crazy.
16:31 Janna Levin? So that just like water, it's like, yeah, it's crazy.
16:34 Neil deGrasse Tyson? So the quantum interactions manifests as what we call gravity, the way the ensemble of H2O-
16:40 Chuck Nice? Manifests as water.
16:42 Janna Levin? Exactly.
16:43 Chuck Nice? Right, and the same way you would pull out a single molecule, you're not necessarily looking at water at that point.
16:51 Janna Levin? You can't pull out a quantum and say, is this gravity? Is this spacetime anymore? Exactly.
16:59 Chuck Nice? Janet, you're saying gravity might not exist as a fundamental thing in the universe?
17:03 Janna Levin? I'm saying gravity might not exist as a fundamental thing in the universe.
17:06 Chuck Nice? Wow. Man, Janet. Let's keep that between us.
17:08 Janna Levin? Yeah.
17:09 Chuck Nice? Everybody else.
17:10 Janna Levin? I don't want to...
17:11 Chuck Nice? Didn't hear that? You didn't hear that because I don't want to turn on the internet? You know there's no such thing as gravity now.
17:15 Janna Levin? Right, and now we're all floating.
17:17 Chuck Nice? Well, there's no such thing as gravity. I heard it. Janna Levin told me. There's no such thing as gravity. Okay, I'm floating right now. You're floating too? We don't even know that we're floating.
17:26 Janna Levin? So, I would say, you know, there is such a thing as gravity. It's just a... it only emerges out of the collective ensemble. And just like the temperature in this room only emerges out of the collective ensemble of bunches of particles. But another analogy I like to give is if we imagine quantum interactions, or even quantum entanglement, complex things like that, as like threads sewn between quantum interactions. Out of those threads, like embroidery, from a macroscopic distance, it might look like there's a black hole event horizon, for instance, out in spacetime. But if I look very closely, I realize, oh, it's just sewn together quantum entangled threads. And it's not fundamentally spacetime, it's really quantum mechanics.
18:06 Chuck Nice? Is love real?
18:09 Janna Levin? Yeah, yeah, well...
18:11 Chuck Nice? Love is real, but it's a thread that goes around your neck and slowly chokes you.
18:15 Janna Levin? It's a black hole horizon.
18:17 Chuck Nice? It's a black hole in your heart that can never be filled. It's a branch of string theory, that.
18:22 Janna Levin? So, as somebody said to me recently, um, reality isn't overrated, but realism is.
18:29 Chuck Nice? Wow.
18:31 Janna Levin? So, there's a reality out there, but our attachment philosophically to realism is misplaced.
18:37 Chuck Nice? All right, I have to digest this. Man, I'm telling you right now, this should be the end of the show, right?
18:42 Janna Levin? I know.
18:43 Chuck Nice? Because that's enough...
18:44 Janna Levin? We should all be lying down.
18:45 Chuck Nice? Seriously, that's enough to think about for the next, like, years. I gotta digest this. It's insane. Wait, so Janet?
18:50 Neil deGrasse Tyson? So why isn't, or might it be, why the Planck length? Why isn't that the quantum of spacetime? Because I've read, because I've tried to trail behind you guys as you think about this, that I've heard that there's nothing in principle asserting that that is a quantization of space and time. It's just a convenient metric for us to talk about things that small.
19:14 Chuck Nice? And once I found out what it actually is, I'm like, that ain't even real. Like, let's be honest.
19:21 Janna Levin? Well, I think what the Planck length tells you is the scale at which we really have to be concerned about these things. Where the universe is behaving in a way that these questions are revealed. And until then, it's really hard to say what's going on because it's...
19:39 Neil deGrasse Tyson? Okay, but that itself is not the limit of your stretchability.
19:42 Janna Levin? Well, yes, I think in some sense it will tell you the scale at which these ideas break down.
19:47 Chuck Nice? See, you make it sound like it's setting the perspective. But, so, once you set the perspective, okay, and now we know, can we then say, alright, half a Planck length?
19:57 Janna Levin? Well, what we can say is when we, if we were looking...
20:00 Neil deGrasse Tyson? If you get there, and then you might be able to...
20:02 Chuck Nice? If you get there.
20:03 Neil deGrasse Tyson? You know what I'm saying?
20:03 Janna Levin? If you're in the Big Bang, unhappily, and that happens at the Planck energy scale, where the energies can probe Planck lengths, you will either probably, as far as we can understand, find individual bits of spacetime that are quantized via a quantum gravity description would be correct for that. Or you will only find, for instance, little loops of string from string theory, and they're all, they're not yet, spacetime hasn't yet emerged. So I'm saying it's setting the scale at which we would have, the answer to that question is relevant.
20:39 Neil deGrasse Tyson? Spacetime's not even real.
20:39 Chuck Nice? I'm telling you.
20:40 Neil deGrasse Tyson? Gravity's not real, spacetime's not real.
20:43 Janna Levin? I don't know what to believe anymore. Well, to make it worse, even in Einstein's description...
20:51 Neil deGrasse Tyson? To make it work. No. I'll cover my ears.
20:55 Janna Levin? I'm even looking at books on your shelf that might even talk about this. So even at the scales of big astrophysics where spacetime seems to be doing really well as a description, you can rewrite the entire theory of general relativity just in terms of particle interactions. You don't have to resort to the geometry of spacetime. It's my preferred language, but as we say, there's a lot of extras that are required in that description that aren't necessary. I can simply look at it like I would any particle interaction. Two particles exchange a graviton, something happens. I don't ever need to resort to the whole beautiful geometry. I like to, I prefer it, but I can cast it as what we would call a field theory just as easily.
21:36 Neil deGrasse Tyson? Oh, wow. So curved spacetime is not a field theory? Because there's no field.
21:41 Janna Levin? Well, the gravitational field would be, you know, it has a spin two particle associated with it, just like there's an electromagnetic field with a spin one particle.
21:49 Neil deGrasse Tyson? Einstein had none of that.
21:50 Janna Levin? No, he did not have it.
21:52 Neil deGrasse Tyson? He's saying we have curved spacetime. And so, and it worked.
21:56 Janna Levin? And it worked beautifully.
21:57 Neil deGrasse Tyson? It worked. What you're saying, even that is a manifestation, is a macroscopic manifestation of something more fundamental.
22:03 Janna Levin? Yeah, you can think of that as a quantum field theory in a sense. And if you look at Steven Weinberg and the great geniuses like Feynman from that era that were developing a quantum description of matter.
22:13 Neil deGrasse Tyson? He went to my high school.
22:14 Janna Levin? Get out. Really? Amazing person. An amazing, amazing person.
22:21 Janna Levin? I mean, you can brag about Steven. That's a nice association. So he, you know, showed that you can rewrite Einstein's theory of general relativity strictly in a field theory language.
22:31 Neil deGrasse Tyson? Okay.
22:32 Janna Levin? It's very nice. And so then like photons are replaced by gravitons, particle charges, electric charges are replaced by mass charges, and it works.
22:43 Neil deGrasse Tyson? Chuck, what's next up?
22:44 Chuck Nice? All right, thank you, David Darby.
22:46 Neil deGrasse Tyson? I don't just, if I brain left for any.
22:51 Chuck Nice? This is Judy. Sade, I'll say, or Sade, okay, whatever, Judy. Hey Judy, she says.
23:00 Neil deGrasse Tyson? You can't say whatever about someone's name. It's their name.
23:04 Chuck Nice? I gave her a new last name, it's called whatever.
23:09 Chuck Nice? No, S A A D E H, so Sade, I will say. She says, hi, my name is Judy, I'm a second year Ohio State student with an inquiry. What are your residual thoughts on Clauser entanglement experiment? And how it disproves our local universe? Do you still believe we exist? And does this theory change how physicists can view topology of the observable universe?
23:38 Neil deGrasse Tyson? That question's so easy, even my driver knows the answer. You know that story with Einstein? So back in, Einstein was getting famous around the day. Right. When relativity was published, but there weren't many photos of people. Cause the newspapers, you couldn't put photos in a paper yet, really, not really. So no one really knew what he looked like. He didn't have that classic wiry hair, yeah, plus he was very young, he was 20, he was 30 years old. And so he went around to give his tour. And this is probably just apocryphal, but it's fun nonetheless. And the driver sits in every one of his talks. And, and the driver, they come to some new location, the driver says, you know, I've heard, I've heard your talk. I think I can deliver your talk.
24:24 Neil deGrasse Tyson? And give you a day off, okay? And so you, you come, you sit in the back, I'll give your talk, no one will know the difference. He gives the talk to some resounding. No way. And then someone says, Dr. Einstein, could you comment on the topological deformation in the field of the high density matter? He says. That's such an easy question. My driver can answer that question. The driver in the background.
24:52 Janna Levin? Who's Einstein?
24:53 Neil deGrasse Tyson? Who's Einstein?
24:55 Janna Levin? That's classic. While you're mentioning Einstein, it reminds me that what catapulted his fame in the English-speaking world was the eclipse of 1919. And, you know, less than six months after World War I, Europe's devastated, Germany and England were at war, and Eddington, as a pacifist, made this...
25:15 Neil deGrasse Tyson? The first astrophysicist, really, of the century.
25:19 Janna Levin? Yeah, and a British scientist went, took an expedition off the coast of Africa, off the coast of Principe, not Principe, that's Newton's, but Princeipe, Princeipe. Off the coast of Newton's giant dome. So they're off the coast of Princeipe, and they're observing the eclipse, and what Eddington's trying to do is look for a star cluster behind the sun, because the light will be bent by the curved spacetime of the sun. But you need to block out the blinding solar rays to do so, so you need a total eclipse to make this measurement. And, in fact, he sees that a cluster that should be behind the sun, in fact, is visible,
26:04 Janna Levin? meaning that the rays have made it around and into their telescopes, and it catapults Einstein's fame in the English-speaking world. And I always think of it as like, you know, a shadow of war, and I really feel like Eddington did this intentionally as a pacifist. A British person confirming a German scientist's work because that transcends all. It's a good story. I don't know if it'll make it into our cosmic queries.
26:29 Neil deGrasse Tyson? And by the way, there was a total solar eclipse in 1918, where they could have done this a year earlier, but the war conditions prevented it. It wasn't safe to travel.
26:40 Janna Levin? Crazy.
26:41 Chuck Nice? All right, well.
26:42 Janna Levin? I feel like, yeah.
26:43 Chuck Nice? I was gonna say, basically, what Judy is saying is, do you have any thoughts on the Clauser experiment and how it disproves the local universe? And do you believe that this theory would change how physics can view the topology of the observable universe?
27:01 Janna Levin? So, I'm not gonna speak directly to that particular experiment, but there was a kind of thought experiment that it, I know that it must be referring to, which is the Einstein, Podolsky, Rosen argument that quantum mechanics is absurd with those three names, and often called EPR. And their argument, really Einstein was very much trying to show that quantum mechanics was absurd. And an argument he gave for the absurdity of quantum mechanics is that it wasn't local. Because, let's say, I entangle two particles. Think of it as the quantum version of a wishbone.
27:39 Chuck Nice? Right.
27:40 Janna Levin? It's wishing bone.
27:41 Chuck Nice? Right.
27:41 Janna Levin? Experiment.
27:42 Chuck Nice? A wishbone.
27:42 Janna Levin? A wishbone?
27:44 Chuck Nice? It's a wishing well.
27:45 Janna Levin? Right.
27:46 Chuck Nice? It's a wishbone.
27:46 Janna Levin? Right.
27:47 Chuck Nice? Right, right.
27:47 Janna Levin? And two people break it apart, one person has the big piece, wins, one person has the little piece. But the quantum version, you, they're permanently entangled. I put my particle, my part in my pocket, but yours in your pocket, but they're still entangled. They're neither in either state yet.
28:04 Chuck Nice? So.
28:05 Janna Levin? There's still the potential for both.
28:06 Chuck Nice? You haven't looked at it yet.
28:07 Janna Levin? Right. Haven't disturbed it, they're entangled, there's two possibilities, I've got the big piece.
28:12 Chuck Nice? You got the little piece.
28:13 Janna Levin? Vice versa, but it hasn't assumed either of those two possibilities yet.
28:17 Chuck Nice? And we don't know.
28:17 Janna Levin? Right. I travel to Andromeda, and it's still like that. Now, the absurdity, they said, is, now, let's say I look at my experiment and I find out I have the big piece.
28:27 Chuck Nice? Then you automatically have the little piece, or the other person.
28:29 Janna Levin? Exactly.
28:30 Chuck Nice? You know this.
28:30 Janna Levin? And right.
28:31 Chuck Nice? We all, we know this.
28:32 Janna Levin? We know this with certainty, and that's highly unlocal. It seems like information traveling fast in the speed of light.
28:37 Chuck Nice? Right, because that would mean that you're breaking the speed of light law.
28:40 Janna Levin? Now, Bell came along, and I assume that this experiment is in that spirit, and showed that, in fact, Einstein was right and wrong, they were right, that experiment shows that it's non-local. And all the statistics of the experiment are consistent with the non-locality of quantum mechanics.
28:57 Neil deGrasse Tyson? So if it's not local, what does that say about anything that we think of as local?
29:01 Janna Levin? You know, most of the stuff we think of as local is because it's big lumbering lots of particles, and that experiment's impossible because it requires such delicacy. And even the temperature in this room, the particles bouncing around would collapse any attempts.
29:16 Neil deGrasse Tyson? But you can imagine a world where we are not these lumbering macroscopic things. We are particles that are entangled with something else at a distance, so that in that way, the entire universe would be holding hands with itself.
29:31 Janna Levin? Yeah, I mean, there's lots of great science fiction plots that hinge on these simultaneous things existing at once, seemingly in conflict. And of course, this goes back to Schrodinger's famous cat, which is simultaneously alive and dead. So I think that the question about how does it affect the topology of the universe, I don't think it's going to affect the observable topology for all the same reasons. Topology is the connectedness of the spacetime, not just its local curves, but like if I panned out, would I find that the universe wraps back onto itself? And it has handles and holes, it's like a little origami.
30:08 Neil deGrasse Tyson? You step away, but you see the local region. But if we're connected to another local region, you're not seeing the whole picture.
30:17 Janna Levin? Yeah, you can't see the whole picture. So it's like looking at a little patch of the Earth and not realizing, oh, if I walk in a straight line, I'm going to actually come all the way back to where I started. Lots of people saw a little patch of the Earth and didn't know it was round.
30:27 Neil deGrasse Tyson? Yeah, correct.
30:28 Janna Levin? So its topology is simply connected but compact and finite. The Earth's surface isn't infinite, and no, it is not flat. And no, you will not sail off the edge. So that is the topology of the Earth.
30:40 Neil deGrasse Tyson? Because you were arguing it was flat. I still stand by that.
30:47 Janna Levin? So what I will say is that if you looked at the topology of possibly small extra dimensions, we might see some curious quantum effects there. So it's possible that there's a whole bunch of other dimensions, which is really teeny tiny, wrapped up real small.
31:15 Chuck Nice? That takes us to our next question.
31:17 Janna Levin? Awesome.
31:17 Chuck Nice? You just walked right into William Walker's question. And he says hello to you all: Lord Nice, Dr. Tyson, Dr. Levin. I've read that the consensus among professionals is that the math supports a universe of 11 dimensions.
31:31 Janna Levin? Ah, perfect.
31:32 Chuck Nice? Assuming this is generally accepted, even if we cannot observe these other dimensions, have they been described or labeled? I've always been confused about how a tesseract is supposedly a fourth-dimensional object when we also describe time as the fourth dimension. Thanks for all you do.
31:51 Neil deGrasse Tyson? Yeah, I love that. So, not to repeat his question, but I want to sharpen it in a different way. When we talk about a hypercube, those are four spatial dimensions. Time is not one of those dimensions.
32:04 Chuck Nice? Mm-hmm.
32:04 Neil deGrasse Tyson? But if time is a dimension, the fourth dimension, can you make a hypercube where time is the fourth dimension? Or do you need four spatial dimensions for that?
32:14 Janna Levin? Uh, well, that's a tricky question, so...
32:16 Neil deGrasse Tyson? And just to clarify, in the Marvel series, the tesseract that they describe and they look at and they bring out...
32:22 Janna Levin? It's a mathematical object.
32:24 Neil deGrasse Tyson? Is a mathematically real object.
32:26 Janna Levin? Real object, yeah.
32:26 Neil deGrasse Tyson? Right.
32:27 Janna Levin? So, usually, we don't try to compactify time. I'm not saying no one's tried it. The problem with compactifying time is... So, when I compactify space...
32:35 Chuck Nice? We try not to compactify time.
32:38 Janna Levin? It's frowned upon.
32:39 Chuck Nice? Yes.
32:41 Janna Levin? So, you know, if space...
32:42 Chuck Nice? We sometimes fail.
32:43 Janna Levin? Right. So, you know, on the Earth, I can talk about my local left and right, but there's no global left and right, right? Like, if I go to the right, I'll just come back on the left again. So, left is really, really far to my right.
32:55 Neil deGrasse Tyson? Because two longs don't make a right, but three rights make a left.
33:00 Janna Levin? So, in time, you don't want to be able to come back to where you started. You don't want to be able to travel forward and that it's wrapped back into your past and connected.
33:12 Neil deGrasse Tyson? They did that in the movie Arrival.
33:14 Janna Levin? Yeah, they do that in movies.
33:16 Chuck Nice? It was so weird.
33:18 Janna Levin? It has been tried and sometimes it has some very cool implications, but...
33:24 Neil deGrasse Tyson? So you're saying it's fundamentally a different kind of dimension?
33:27 Janna Levin? Yes, it is fundamentally a different kind of dimension. You can compactify...
33:31 Neil deGrasse Tyson? Even though you tell us, and all my relativity professors told me, it's just another dimension. You calculate with it.
33:36 Janna Levin? Right, still a little different. I know exactly what you mean. It is another dimension, but one way to say it is, is sometimes we call Euclidean space to be space. It means all the dimensions are on equal footing. I can rotate between them just by doing a normal rotation that we're used to doing. I can rotate my left into your left, just by physically rotating, right? But in...
33:59 Neil deGrasse Tyson? So in other words, you're facing him and if we put these two hands together, it's my left hand against his right hand, but I can turn around and now my right hand is lined up with his right hand.
34:07 Janna Levin? So we know a spatial rotation aligns things, and that's great. With time, you can't do a spatial rotation. I can't spatially rotate into time. I have to do something called, um, sometimes a Lorentz boost. It's a kind of a rotation in spacetime.
34:24 Neil deGrasse Tyson? Lorentz boost.
34:25 Janna Levin? A Lorentz boost, and it's similar...
34:27 Neil deGrasse Tyson? In the health store, it's next to the testosterone boost.
34:30 Chuck Nice? Right, Lorentz boost. And if you're at a restaurant, it's right before the abuse boost.
34:38 Janna Levin? Well, if you do one of these, you can rotate space and time into space and different spacetimes. And we can, you know, if you're traveling past me and I say your, your clock is running slowly relative to mine, etc., I can realign us by doing a boost. It's equivalent to me coming up to your speed in some sense.
34:56 Chuck Nice? I got you.
34:56 Janna Levin? Now, there's different, but anyway, what, all that to say is, is it's much harder to compactify spaces that have this spacetime difference. You can do it mathematically, but the question is, will physics allow it? Can I, can I make sense of physics on a space that also has a compact time? I can certainly make the mathematical object, but, but, um, you know, of course, the problem... Is the famous grandfather paradox where I could go back and murder my grandfather before my parent was born and thereby
35:32 Neil deGrasse Tyson? That's so violent.
35:33 Janna Levin? Right, so.
35:35 Neil deGrasse Tyson? Have them not meet each other.
35:37 Janna Levin? So, well, actually, that's actually part of the resolution is that, well, what would be consistent with that compact time would be if I tried to go back in time and I tried to murder my grandfather.
35:49 Neil deGrasse Tyson? Right.
35:49 Janna Levin? But I just injured him severely so that he was neurologically damaged and had terrible children and I therefore was so deranged that I went back and tried to injure him.
36:02 Neil deGrasse Tyson? It's odd that it's not the grandmother because you could still kill the grandfather and have it make no change in you having been born.
36:09 Chuck Nice? That's right. And that's the truth.
36:11 Janna Levin? You could store.
36:13 Chuck Nice? So you end up still being born, you're just like, oh my God, my grandmother cheated on my.
36:16 Neil deGrasse Tyson? That's what I'm saying. It's the milkman.
36:18 Chuck Nice? Oh my God.
36:20 Neil deGrasse Tyson? All right, keep going.
36:21 Chuck Nice? Okay. This is Morgan Fisher. He says, hi, Dr. Tyson, Dr. Levin, Lord Nice. Morgan, he/him here from Waterloo, Ontario, where Dr. Levin gave a brief talk at the Perimeter Institute back in 2017, and I was honored to attend. Wow, look at that.
36:37 Janna Levin? How nice.
36:37 Chuck Nice? Impression.
36:38 Neil deGrasse Tyson? Fanbase out there.
36:39 Chuck Nice? 2017 and he's still like, I'm still thinking about saying talk.
36:42 Neil deGrasse Tyson? Still a fan, still a fan.
36:44 Chuck Nice? Can you please explain in Lehman's terms the fundamentals of Hugh Everett's many-worlds interpretation? From what I understand, every quantum fluctuation could mean the spawning of an entire new universe. While the universes are under no obligation to us, as Dr. Tyson says, makes sense, this seems so bizarre, so peculiar, so outlandish. Wow, that was very, uh, William Shatner of me. That it seems to
37:07 Neil deGrasse Tyson? Very Captain Kirk.
37:09 Chuck Nice? That it seems to defy every bit of both common sense and physical reality. For instance, where does all this new mass come from when the new universe is created?
37:24 Janna Levin? Wow. Yeah, I
37:26 Neil deGrasse Tyson? So there.
37:27 Janna Levin? So there. I will say I am not an avid proponent of the many-worlds interpretation of quantum mechanics.
37:34 Chuck Nice? Well, there you go.
37:35 Neil deGrasse Tyson? Neither am I.
37:35 Janna Levin? But I am surprised at how many of my peers are. And I did a kind of anecdotal. Survey amongst friends and I was surprised how many said, "Oh yeah, yeah, I really think it's the many worlds interpretation." I do not think that, but let's just quickly describe the many worlds interpretation. It says, it doesn't even have to be as fancy as quantum entanglement. It just says a particle can be in more than one state. So the analogy I like to give, I don't know if I've done it here before, is chords in music versus individual notes in music.
38:08 Chuck Nice? Okay.
38:09 Janna Levin? So let's say I play a chord and it's a definite chord.
38:11 Chuck Nice? Right.
38:12 Janna Levin? That is a superposition of certain notes. So I can't simultaneously be in a single state of one note and in the state of the chords.
38:21 Chuck Nice? Correct.
38:22 Janna Levin? Right, so particles can be like this. If they're in a particular place...
38:25 Chuck Nice? What an eloquent depiction.
38:28 Janna Levin? That's because I live with musicians.
38:29 Chuck Nice? That is amazing what you just said there.
38:32 Janna Levin? Thank you, I appreciate that.
38:33 Chuck Nice? I mean, that is beautiful.
38:34 Janna Levin? I love it.
38:35 Chuck Nice? It's almost painterly the way, because when you, you don't think of a musical chord as something physical, but it is indeed physical.
38:45 Janna Levin? Yeah.
38:46 Chuck Nice? It is the reverberation of the sound and at the same time, they coexist as one. However, you can identify every note in the chord at the same time. That is frickin' amazing!
39:00 Janna Levin? Yeah, is that amazing?
39:01 Chuck Nice? That's great.
39:02 Janna Levin? Because I am surrounded by musicians. I myself can't play, but, but in, in the universe, it's just like this. If I have a particle in a particular state, it's in, it's like a chord where there's superposition of momentum states. I no longer have a precise definitive state of, of its motion.
39:20 Chuck Nice? Right.
39:21 Janna Levin? And so it's like positions are chords where momentum are the notes or vice versa. I can have an exact location on its momentum, but now I don't know where it is in space. It's like a chord. It has a superposition of positions.
39:35 Chuck Nice? Pretty crazy, man.
39:36 Janna Levin? It's pretty nice.
39:37 Chuck Nice? That is, that's, that's...
39:38 Janna Levin? So the many worlds interpretation says, okay...
39:42 Janna Levin? Now, let's say it assumes a definite position state. It's in like this superposition of locations, this particle. But now I get it to assume a specific state. And it could have assumed any one. Let's pretend with equal weighting, it doesn't really matter. The many world says, well, every one of those things happened. It's just there's a you in one world, which found the particle over here to the left, let's say. And there's a you in another world, which found the particle to the right. And they branched off. And now there's just two worlds.
40:16 Chuck Nice? Isn't this their attempt to try to make sense? Classical sense of something?
40:19 Janna Levin? Yeah.
40:20 Chuck Nice? That is inherently non-classical?
40:21 Janna Levin? I think that that's true. I think there is a deeper thinking to it that is intriguing, which is to say, if we really believe Schrodinger's equation, which describes these superpositions. If we really believe quantum mechanics, as it is now with no added ingredients. It is actually the barest interpretation. It's the most minimal interpretation of quantum mechanics. Now, these questions are great about what does that mean? About all the mass of the entire universe reproduced? It doesn't, it's, it's hard to talk about it in that way.
40:55 Chuck Nice? But see, if you're, from the way you just explained. If this is, we'll call it a superstate, where these positions are already assumed. You're not really creating a new universe. You're just realizing a universe at that particular point where you
41:13 Janna Levin? It's a nice way of saying it.
41:14 Chuck Nice? Where you actually may take the position. So when you assume the position.
41:21 Chuck Nice? When you do, that state now becomes solidified, we'll say.
41:25 Janna Levin? Yeah.
41:25 Chuck Nice? That's all.
41:25 Janna Levin? Right.
41:26 Chuck Nice? So you didn't create a new universe.
41:27 Janna Levin? No, you didn't, you didn't, you didn't do anything. You were always in a superposition yourself.
41:32 Chuck Nice? Right.
41:33 Janna Levin? Of finding it here and there.
41:34 Chuck Nice? Exactly.
41:35 Janna Levin? So, again, this is a kind of Schrodinger's cat argument. But it's not as though part of the mass of the particles over here and part of the mass of the particles over there. That's not it. The whole particle is either here or there.
41:46 Chuck Nice? Right.
41:47 Janna Levin? And in fact, the particle isn't real, back to realism, in the way that we used to think. The only thing that's real and deterministic and has all the properties we used to assign to particles is the probability, what we call the wave function in Schrodinger's.
42:02 Chuck Nice? Well, remind me the next time we have Janet in here to make sure I take an edible.
42:09 Chuck Nice? Because I can't smoke in this office. But I can doggo a store, swallow a gummy before I come in. That is something else, man.
42:18 Janna Levin? Well, one more small thing about this, if I could. It means that if you're doing this with a coin toss, like a particle's heads up or heads down. It means that there is factually a world, if this were true, in which somebody, every single coin toss gets heads. And they have to walk away and say, oh, I'm just that unlucky guy in the multiverse who happens to get heads every time.
42:41 Chuck Nice? Right.
42:42 Neil deGrasse Tyson? Because that would be harder to swallow.
42:45 Janna Levin? That doesn't sound great. But then again, I don't think nature cares about our plans for understanding the world. So I don't use that as my argument for why I don't think it's true. But it certainly would be peculiar.
42:59 Chuck Nice? Cool.
43:00 Neil deGrasse Tyson? Chuck, we hardly have any time left. Let's see if it's possible for us to answer two questions in half the time.
43:07 Janna Levin? Yeah.
43:07 Neil deGrasse Tyson? Do the math right, two questions in half the time.
43:10 Janna Levin? It works. Number two in two locations.
43:12 Chuck Nice? Well, then, it'll be a little more than that because Logan Davis has a two-parter. He says, greetings from Alabama. I have two questions that are somewhat related. One, if you were the mass of a black hole, would your gravity affect your flow of time? And two, does the speed of an object's vibration affect its flow of time?
43:33 Neil deGrasse Tyson? Ooh, I love that.
43:34 Chuck Nice? Look at that.
43:38 Janna Levin? Well, this is an intriguing question. Different observers around a black hole experience a different passage of time. It's not as though the black hole sets an absolute notion of time. So let's say I'm hovering right outside the event horizon of a black hole, and I'm firing my engines like crazy and I'm trying to escape. I will measure a very, very different time than somebody who's passing right by me. We can look each other in the eye and it's like, I'm just going to succumb to the fall. And I'm going to go right through the event horizon. We will not agree on the passage of time. So it's not as though at a particular spacetime point, the black hole fixes the passage of time. So it certainly affects the passage of time
44:22 Janna Levin? of anyone trying to navigate or explore. But how they navigate and explore matters.
44:29 Chuck Nice? Okay.
44:29 Janna Levin? So that's maybe a partial answer to that one. And does the speed of an object's vibration-
44:36 Chuck Nice? Vibration affect its flow of time?
44:38 Janna Levin? That's interesting.
44:40 Neil deGrasse Tyson? Because it seems to me if you have a vibrating membrane or drum or something, then the middle is moving faster than the outer edges.
44:48 Janna Levin? So, yeah.
44:48 Neil deGrasse Tyson? So whatever is the relativistic effects will affect the middle of the drum more than the edges of the drum.
44:54 Janna Levin? I agree. So I would, yeah, I would say, you know, it's always relative to something. As Neil, you just cautiously laid out because it's not as though the person with the clock in the middle is gonna say, "Hey, my time's funky." Everyone always thinks their time's fine.
45:11 Neil deGrasse Tyson? Yeah.
45:11 Janna Levin? Right?
45:12 Neil deGrasse Tyson? Your time is messed up.
45:12 Janna Levin? It's your time, it's messed up. So it's the relative vibration to some other part will, yes, for sure be affected by any motion.
45:19 Chuck Nice? Mm-hmm. Wow. That's great stuff. All right, last question. This is Lynn Newton. Lynn says, "Hello, Dr. Levin, Dr. Tyson, your lordship. I saw Dr. Levin post on Twitter recently about quantum teleporting of a molecule that was achieved, and I'm wondering if you can tell us a bit more about what that is in layperson's terms."
45:44 Janna Levin? Oof. Well, this is related to quantum entanglement.
45:47 Chuck Nice? Okay.
45:48 Janna Levin? So in quantum teleportation, what they're trying to do is entangle two particles. And then it gives you a mechanism by which you can throw information from one particle to the other without, you know, clomping in between. And the non-locality that we were talking about in the previous question. So in those entanglement, you still have to sometimes communicate information ahead of time. So it's a little bit sneaky. Like, you have to send, you have to send plans, you know, through the mail, which is slower than light travel. But you don't have to send 100% of the information.
46:30 Janna Levin? You just have to have a plan, and you send it across, and then you kind of have to- Break, crush some of the information on one side to get it out, and it gets tossed or reappears in some senses, though the molecule itself was teleported.
46:48 Chuck Nice? Hmm.
46:49 Janna Levin? So if you were talking about this with a person, you basically have to destroy Chuck and Neil here to reproduce them on the planet's surface.
46:58 Neil deGrasse Tyson? And you're allowed to say it was teleported?
46:59 Janna Levin? Yeah, that would be quantum teleportation. I mean, if it's exactly, you know, if you give me an electron, I can't tell you which electron it is in the universe. It's, it's, it's just, there's no experiment I can perform. It's identical to every other electron. And so it's, it's, might as well be exactly the same electron. I don't know what it means to say, no, this one's not the same electron.
47:22 Chuck Nice? Wow.
47:22 Janna Levin? So if I quantum teleport it, I have no logical way of saying it's not exactly the same particle.
47:30 Neil deGrasse Tyson? Did you hear about the idea where the universe repeats, but there's a sole electron that is going forward and then backwards through time? It flushes out the existence of every other electron? So that, the reason why the electrons are identical is because it's the same electron.
47:50 Neil deGrasse Tyson? And it's gone through the universe this many times to then populate.
47:55 Chuck Nice? Right.
47:56 Neil deGrasse Tyson? Yeah.
47:57 Chuck Nice? Yes, it's just...
47:58 Janna Levin? It's doing a lot, it's doing a lot here.
48:00 Chuck Nice? So everything... So basically, everything we hear... There's just one electron all around us.
48:06 Neil deGrasse Tyson? There's a whole chapter in my quantum physics book called "Identical Particles."
48:10 Chuck Nice? Right.
48:11 Neil deGrasse Tyson? Just to get you to understand what that means.
48:13 Janna Levin? Oh, and in the context of this conversation, the reason why black holes are so odd, and you were talking about this earlier, you talk about stars and planets and things, black holes are peculiar because they are like fundamental particles. They have something in common with fundamental particles, and that is that they are flawless and indistinguishable. So once a black hole is, you can throw things on it and it can be active, but once it settles down to a pure bare black hole with nothing else going on, it is indistinguishable. There's no experiment I can perform to tell me which one it is from every other black hole with that mass, charge, or spin.
48:48 Janna Levin? And in that sense, it shares more in common with fundamental particles than it does with with matter.
48:53 Neil deGrasse Tyson? Look at that.
48:53 Janna Levin? I mean, I'm sorry, with physical things like stars and planets.
48:56 Neil deGrasse Tyson? Look at that.
48:57 Janna Levin? Yeah.
48:57 Neil deGrasse Tyson? That's pretty wild.
48:59 Janna Levin? Yeah, it's pretty weird. So we think black holes were created as quantum particles in the Big Bang. Very, very small, Planck scale, black holes.
49:08 Neil deGrasse Tyson? They would evaporate quickly.
49:09 Janna Levin? They would evaporate very quickly. Yeah, so through Hawking radiation, the smaller the black hole, the hotter they are. So they actually explode.
49:16 Neil deGrasse Tyson? Mm-hmm.
49:17 Janna Levin? Yeah.
49:18 Neil deGrasse Tyson? Wow.
49:18 Janna Levin? Yeah.
49:19 Neil deGrasse Tyson? In fact, I think his original paper was...
49:21 Janna Levin? Primordial Black Holes?
49:22 Neil deGrasse Tyson? No, the...I don't know what the original paper is. One of his papers described the search for evaporating black holes as bursts of gamma rays. Hmm. That's the last gasp of a black hole as it dies. And I think the wavelength of the light that it emits is the diameter of the event horizon.
49:40 Janna Levin? That's right.
49:40 Neil deGrasse Tyson? As it gets smaller and smaller, the wavelength gets smaller and smaller, and the energy of the light gets higher and higher.
49:45 Janna Levin? Exactly.
49:46 Neil deGrasse Tyson? Wow. Yeah.
49:47 Janna Levin? Yeah, exactly.
49:48 Neil deGrasse Tyson? That's all the time we have. That's it. Damn.
49:50 Janna Levin? How you guys feeling?
49:51 Neil deGrasse Tyson? I'm exhausted. I'm so tired. My God. So I should stock some Gummy Bear for you. Yeah. Edibles. So Janice, you don't come by often enough, I think.
50:04 Janna Levin? Oh, yeah, it's always fun to be here. I love it.
50:06 Neil deGrasse Tyson? We don't have to make it all that far away.
50:07 Janna Levin? Yeah.
50:07 Neil deGrasse Tyson? We gotta make sure.
50:08 Janna Levin? Yeah.
50:08 Neil deGrasse Tyson? And we were delighted to do that event at Pioneer Works.
50:12 Janna Levin? Oh, I'm so glad. Yeah, that was amazing for us. Absolutely. Love it.
50:18 Neil deGrasse Tyson? All right.
50:19 Janna Levin? All right, guys.
50:20 Neil deGrasse Tyson? So let me just reflect on this for a moment. When we think about life and everything that matters to us, we think about tangible objects. I'm speaking into a microphone, I'm wearing clothing, I'm...but there's some people among us who think way deeper thoughts than that. Like, how does it all work? And why does it work in that way? And it's...much of it sounds completely irrelevant. It'll probably forever be irrelevant. However, let's remind ourselves what it is to be human. We are comfortable sleeping on our backs, and we sleep at night.
51:03 Neil deGrasse Tyson? We wake up at night, what are you looking at? You're looking at the night sky. Looking at objects that are there one night and move the next night. There's a curiosity that we can natively embrace, that other animals have no access to, because they never look up. Does a beetle ever look up? Do it? I don't know. I've never asked one, but I don't think so. We look up, and we see things change, and it stimulates our curiosity. A curiosity about things that have nothing to do with life on Earth, not directly, or maybe not ever. But that curiosity is fundamental to what it is to be human.
51:48 Neil deGrasse Tyson? And when we study cosmology and the origin of the universe, the birth, the death, that is a fulfillment of what it is to be human in the first place. I wouldn't trade that for anything. That's a cosmic perspective. Neil deGrasse Tyson, coming to you from my office at the Hayden Planetarium, right here at the American Museum of Natural History. I thank Chuck, Dana for being on. A pleasure. And as always, I bid you to keep looking up.
Previous Cosmic Queries – Physics All Around Us Next The Science of MDMA with Ben Rein Page updated October 26, 2026 · transcript and summary are machine-generated
