A Cosmic Conversation with Kip Thorne

Summary

StarTalk Radio Episode Summary: "A Cosmic Conversation with Kip Thorne"

Release Date: November 26, 2024
Host: Neil deGrasse Tyson
Guest: Professor of Theoretical Physics Kip Thorne
Description: In this in-depth episode of StarTalk Radio, astrophysicist Neil deGrasse Tyson engages in a fascinating conversation with Nobel laureate Kip Thorne. They explore a wide array of topics, from the intricate science behind the film Interstellar to the groundbreaking discovery of gravitational waves with LIGO, and delve into profound debates in theoretical physics such as information loss in black holes.

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1. Introduction and Personal Connections ([01:26] – [07:46])

Neil deGrasse Tyson opens the conversation by reminiscing about his first interactions with Kip Thorne, highlighting their mutual respect and shared history through the seminal textbook Gravitation. They humorously discuss how carrying the hefty tome became a rite of passage for aspiring astrophysicists.

Notable Quote:
Neil deGrasse Tyson (02:56):
“...the only book where you learned about it just by carrying it around.”

Kip Thorne fondly recalls the collaborative environment with fellow physicists Charlie Misner and John Wheeler, emphasizing the organic growth of their joint projects.

---

2. Collaboration on Interstellar ([07:46] – [17:56])

The conversation shifts to Kip Thorne's pivotal role as the science advisor and executive producer for Christopher Nolan's film Interstellar. Thorne explains how his collaboration with Nolan ensured that the movie adhered closely to established physical laws, particularly concerning gravitational physics and wormholes.

Notable Quotes:
Kip Thorne (09:19):
“Interstellar was unlike almost any other film... science was baked into that film from the very beginning.”
Neil deGrasse Tyson (11:03):
“Admit it, you created a gateway film.”

They delve into specific scientific elements portrayed in the movie, such as the depiction of tidal waves on Miller's planet and the nature of wormholes, discussing both accuracies and artistic liberties taken for cinematic effect.

Notable Quote:
Kip Thorne (17:15):
“What's happening in the film... These issues were vetted by the world's best experts right in the process of the writing of the screenplay.”

---

3. Scientific Accuracy in Interstellar ([17:56] – [36:34])

Tyson challenges Thorne on specific scientific scenarios presented in Interstellar, particularly the solitary wave on Miller's planet. They dissect the plausibility of such a phenomenon, debating whether tidal forces could produce such a peaked wave without dispersing, as depicted in the film.

Notable Quote:
Neil deGrasse Tyson (21:06):
“Because one time tidal would be that peaky? And if it's any kind of wave, how could it still leave the water laying around its vicinity?”

Thorne explains the concept of solitary waves, referencing historical discoveries and the mathematical foundations that inspired their representation in the movie, while acknowledging some cinematic exaggeration.

Notable Quote:
Kip Thorne (22:15):
“This type of wave was discovered in the 1700s by a physicist in England... It was somewhat exaggerated in the movie.”

They also discuss the time dilation effects near the black hole Gargantua, with Thorne clarifying the scientific basis that allows for such phenomena without violating general relativity.

Notable Quote:
Kip Thorne (30:35):
“The last stable circular orbit... can have as high a redshift as you might wish... But it requires that this black hole spin extremely close to the maximum possible spin.”

---

4. Gravitational Waves and LIGO ([36:34] – [72:09])

Transitioning to his groundbreaking work, Thorne elaborates on the inception and development of the Laser Interferometer Gravitational-Wave Observatory (LIGO). He recounts the early skepticism surrounding gravitational wave detection, initiated by Joe Weber's pioneering but ultimately unverified experiments.

Notable Quote:
Kip Thorne (55:04):
“He began working on it in the late 60s, early 70s, and announced that he was seeing some possible evidence of gravitational waves... the bottom line was that others were not seeing gravitational waves.”

Thorne discusses the shift in gravitational wave detection methods, particularly Ray Weiss's innovative techniques, and the collaborative efforts between Caltech and MIT that led to the eventual success of LIGO in 2016. He emphasizes the technological marvels and immense precision required to detect waves equivalent to one-hundred-millionth the diameter of a proton.

Notable Quote:
Kip Thorne (62:45):
“We're trying to measure... 10 million times smaller than the atoms of which the mirrors are made... it's equivalent to 1/100 the diameter of a proton.”

He highlights the monumental achievement of LIGO, culminating in the first detection of gravitational waves, which confirmed Einstein's century-old predictions and earned the team the Nobel Prize in 2017.

Notable Quote:
Kip Thorne (71:16):
“Einstein was kind of smart and so... and 100 years later, his gravitational waves are found with lasers.”

---

5. The Information Loss Paradox and the Bet with Stephen Hawking ([72:09] – [91:54])

One of the most intellectually stimulating segments revolves around the famed bet between Kip Thorne, Stephen Hawking, and John Preskill concerning the black hole information loss paradox. Thorne explains the core of the debate: whether information that falls into a black hole is irretrievably lost, which would violate the principles of quantum mechanics.

Notable Quote:
Kip Thorne (75:36):
“The bet was between Stephen Hawking and me... over whether or not information does get lost in black holes.”

Thorne details Hawking's initial stance advocating for information loss, influenced by his discovery of Hawking radiation, and how Preskill championed the quantum mechanics perspective that information must be preserved. The dialogue captures the intense scientific discourse that led to Hawking eventually conceding the bet, acknowledging the preservation of information.

Notable Quotes:
Neil deGrasse Tyson (75:21):
“So the bet was between Stephen Hawking and me on one side and John Preskill on the other side, and it was over whether or not information does get lost in black holes.”
Kip Thorne (85:28):
“So Stephen Hawking conceded the bet at a big international conference on general relativity and gravitation in Dublin, Ireland, in early 2000.”

They explore the implications of this resolution for the compatibility of general relativity and quantum mechanics, touching upon advanced theoretical concepts and the ongoing quest for a unified theory of quantum gravity.

Notable Quote:
Kip Thorne (89:55):
“The real holdup is that they are logically incompatible with each other. And so something has to give.”

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6. Current and Future Projects ([91:54] – [105:51])

As the conversation winds down, Thorne reflects on his transition from active scientific research to creative endeavors. He discusses his ongoing projects, including collaborations on poetry and art that bridge science and the humanities, and his work on a comprehensive history of the LIGO project.

Notable Quote:
Kip Thorne (96:17):
“So I decided that I would like to spend a few decades doing creative work at the interface between science and the arts.”

He also humorously touches upon myths surrounding Nobel Prizes at Caltech and shares anecdotes from his extensive career, highlighting the collaborative spirit essential to scientific breakthroughs.

Notable Quote:
Kip Thorne (95:37):
“We have to trend. This had to make the transformation happen otherwise...”

Thorne expresses optimism about the future of theoretical physics, particularly regarding string theory and the quest to reconcile quantum mechanics with general relativity, while acknowledging the field's complexities and the contributions of successive generations of physicists.

Notable Quote:
Kip Thorne (94:27):
“And that's the nature of science. And the struggles that our colleagues have been having with string theory and M theory and quantum gravity, we've learned an enormous amount.”

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7. Closing Remarks ([105:51] – End)

Neil deGrasse Tyson concludes the episode by lauding Thorne's monumental contributions to science and his humility regarding collaborative achievements. Thorne expresses gratitude for the discussion and reiterates his appreciation for the blend of science and art.

Notable Quote:
Kip Thorne (105:48):
“That was such a fun rumor, though.”

Tyson wraps up by encouraging listeners to continue their pursuit of knowledge and curiosity about the universe.

Notable Quote:
Neil deGrasse Tyson (106:55):
“As always, I bid you to keep looking up.”

---

Conclusion

This episode of StarTalk Radio offers listeners a profound glimpse into the mind of one of modern physics' leading figures, Kip Thorne. Through engaging dialogue, the conversation not only demystifies complex scientific concepts but also underscores the collaborative and often tumultuous journey of scientific discovery. From the silver screen to the depths of spacetime, Thorne's insights illuminate the intricate dance between theory, experimentation, and creativity that propels our understanding of the cosmos forward.

Transcript

[Neil DeGrasse Tyson]

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[Kip Thorne]

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[Neil DeGrasse Tyson]

StarTalk welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now. This is StarTalk. I'm your host, Neil Degrasse Tyson, your personal astrophysicist. And today we're featuring one of our one on one conversations, this time with professor of theoretical physics Kip Thorne. Kip Thorne, welcome to StarTalk.

[Kip Thorne]

A pleasure to be with you. Neil.

[Neil DeGrasse Tyson]

Oh my gosh. We are coming from your home office in Pasadena, California.

[Kip Thorne]

It's a wonderful office. My son designed this part of the house and built it and my brother designed and built all the furniture.

[Neil DeGrasse Tyson]

These are really useful people to have in the family.

[Kip Thorne]

It's a wonderful family to be in. They're the practical ones.

[Neil DeGrasse Tyson]

I've actually known you for some. Not that we were beer drinking buddies.

[Kip Thorne]

But I think we've drunk beers together in the Canary Islands.

[Neil DeGrasse Tyson]

Yes, we did. Okay, okay, I stand corrected. But my first exposure to you was you were one of the three authors of this book called Gravitation and we used to joke, of course it was the only book where you learned about it just by carrying it around.

[Kip Thorne]

And I think we probably wrote it before you were born.

[Neil DeGrasse Tyson]

Possibly, possibly. Although I'm older than you might think, this book is a graduate level treatise on basically Einstein's general theory of relativity. At the time I acquired the paperback of it, which this is. It's tough making a paperback this thick, but this has the exact proportions of what was then the Manhattan Yellow Pages. So we used to call it the phone book.

[Kip Thorne]

Yes.

[Neil DeGrasse Tyson]

Just affectionately, may I add. It was brilliantly conceived because I don't know if you can notice on camera, there are tabs, are different colors, there's white and black, and they represent two different paths through the book. One is sort of the elementary path and one the more advanced path, except it all looked advanced to me at the time. So whose idea was this to come up with this book?

[Kip Thorne]

Coming up with a book, I think it was, sort of grew out of discussions that Charlie Misner, John Wheeler, my PhD advisor and I had a few years after.

[Neil DeGrasse Tyson]

Those are the three co authors.

[Kip Thorne]

Those are the three co authors. And so it sort of grew organically and they.

[Neil DeGrasse Tyson]

That's the best kind of projects to have.

[Kip Thorne]

1960S and early 1970s.

[Neil DeGrasse Tyson]

Yes. I was born before the 60s.

[Kip Thorne]

Oh, really?

[Neil DeGrasse Tyson]

So on here is Charlie Misner, who was at the University of Maryland.

[Kip Thorne]

Yes.

[Neil DeGrasse Tyson]

And so my copy of this, I had you sign it. And then I spent a year teaching at the University of Maryland. So I quickly went over to his office and had him sign it. But before then, I started out in graduate school at the University of Texas where John Archibald Wheeler had. They stole him from Princeton, I think, is what that. Or lured him from Princeton, I think.

[Kip Thorne]

Yeah, that's an accurate statement.

[Neil DeGrasse Tyson]

And so I had all three of them sign it. In fact, John Wheeler's course that he taught in general relativity is where I met my wife.

[Kip Thorne]

Wow.

[Neil DeGrasse Tyson]

She has a PhD in mathematical physics, so we met in relativity class. Just thought I'd say that.

[Kip Thorne]

Very romantic place to meet, Neil. Very romantic.

[Neil DeGrasse Tyson]

Very romantic. And John Wheeler used to give out a penny if you caught an error that he committed on the front board. So I have one of his pennies. I don't remember. It was not a big thing. It was like it was a typo or something or whatever. The written version of a typo. But so anyhow, it's just delight to meet again with you. And what prompted this was our. You know, you have a lot of accolades, of course, including a Nobel Prize. Okay. But more importantly than that, you were science advisor on the film Interstellar.

[Kip Thorne]

Well, I was more than science advisor.

[Neil DeGrasse Tyson]

Yes, you were. You were executive producer.

[Kip Thorne]

I was more than executive producer. It grew out of a treatment that Linda Ops, an ex girlfriend of mine.

[Neil DeGrasse Tyson]

Oh. And I. Linda's a big producer of sci fi films.

[Kip Thorne]

Yeah. A big producer of films of a wide variety But Linda and I dated in 1979. 80. And she was too high strung for me and I was too nerdy for her. But we became close friends.

[Neil DeGrasse Tyson]

Wow. Who knows that? Why didn't I know this?

[Kip Thorne]

Why didn't.

[Neil DeGrasse Tyson]

No, stop. Where would one learn this? We need a gossip. A physicist gossip column. Is that right?

[Kip Thorne]

Yeah. It was some years later, after Carl Sagan, who set us up on a blind date, by the way. That's how we met.

[Neil DeGrasse Tyson]

Okay.

[Kip Thorne]

Some years later, Linda called me up and said, would you like to brainstorm with me for a movie?

[Neil DeGrasse Tyson]

Wow.

[Kip Thorne]

And we did. And that's how Interstellar was born.

[Neil DeGrasse Tyson]

So was that at the time?

[Kip Thorne]

It really was the creation of the Nolan brothers because they took what we had given them, which was basically a structure and a venue for the movie, the Warped side of the Universe. And they ran with it and changed our story almost completely and made it into a great film. But all the seeds came out of.

[Neil DeGrasse Tyson]

Linda and me at the time. I mean, you're a professor at Caltech. The Richard Feynman professor at Caltech, now Emeritus. Caltech is a pretty high level place. How was it viewed for you to say, guys, hold on. I'm going to make a movie. Now, how is that received by your colleagues?

[Kip Thorne]

I think they were all enthusiastic. Caltech is a different kind of a place than some other more stuffy university.

[Neil DeGrasse Tyson]

Oh, okay, Okay. I never hung out much at Caltech, so I couldn't judge the mood or the tone.

[Kip Thorne]

Yeah, no, look, we're on the edge of Hollywood. The Hollywood folks come over and you know Big Bang Theory was based on Caltech, Right.

[Neil DeGrasse Tyson]

They didn't call it Caltech. What did they call it?

[Kip Thorne]

They did call it Caltech in the first few episodes.

[Neil DeGrasse Tyson]

Okay.

[Kip Thorne]

And then they stopped using the Caltech name because the shirts, that's Hollywood speak for the attorneys.

[Neil DeGrasse Tyson]

Oh, yeah. Stiff shirts. Yes, yes.

[Kip Thorne]

Up in the office, the shirts got scared that they might do something on screen that the Caltech shirts wouldn't like. And the Caltech shirts might sue the Hollywood shirts. So they stopped using Caltech name.

[Neil DeGrasse Tyson]

And in the film which I adored, was it called Real Genius? Real Genius. They were at Pacific Tech, all right. That was where all the smart kids were. So of course, Pasadena is in like, I can't say foothills of Hollywood, but you have a proximal awareness of this huge industry and you know that science fiction matters as a genre.

[Kip Thorne]

Well. And some of us love it.

[Neil DeGrasse Tyson]

I love it. I sign up every time. And so Interstellar, I think it introduced many people to authentic gravitational Physics for the very first time.

[Kip Thorne]

Well, Interstellar was unlike almost any other film. I think there were precursors in 2001. And in contact.

[Neil DeGrasse Tyson]

Yeah. Carl Sagan's Contact.

[Kip Thorne]

Carl Sagan's Contact. And the point is that science, lots of science, was baked into that film from the very beginning because of the way it was born and because of close collaboration I had with the Nolan brothers and build in right from the very beginning.

[Neil DeGrasse Tyson]

Baked in.

[Kip Thorne]

Baked in. And a science in which the guideline that we worked from is that nothing in the movie would violate well established physical laws, and all the wild things would at least spring from science in.

[Neil DeGrasse Tyson]

Some manner, as any good science fiction story should be. But there's not enough.

[Kip Thorne]

Well, there's nothing wrong with fantasy films. The Harry Potter style, for example, that's just a different genre.

[Neil DeGrasse Tyson]

By the way, that film, you must have known. You said, okay, we're gonna have to help people out. Give a guy a break, okay? They're trying to see the movie. They're trying to follow what's going on. What the hell's happening? Why did the guy get old? Why is he younger than his mother? What's going on? And you upped and said, let's help a person out.

[Kip Thorne]

Yeah. Well, I would put it a little differently. I saw it as a superb opportunity to use this film as a motivator to get people interested or intrigued in science. And then there would be a bridge to the science through this book.

[Neil DeGrasse Tyson]

Admit it, you created a gateway film.

[Kip Thorne]

It was a gateway film. Yes.

[Neil DeGrasse Tyson]

So the Science of Interstellar, New York Times bestseller Kip Thorne, with a foreword written by, of course, Christopher Nolan. And it says, spoiler alert. This book explains the fantastic climax and ending of Interstellar.

[Kip Thorne]

And so let me tell you how that this issue came about. Chris said to me early on, I would like.

[Neil DeGrasse Tyson]

Chris Nolan.

[Kip Thorne]

Chris Nolan. I would like to make a film where the ending is as mysterious as the ending of 2001 the Space Odyssey.

[Neil DeGrasse Tyson]

That's a high bar.

[Kip Thorne]

That's a high bar. But he greatly admires Stanley Kubrick and that film. And so somewhat later on, as we were talking about the ending and we had lots of conversations about the ending, he said, well, you can explain the ending in this book that you're planning to write.

[Neil DeGrasse Tyson]

So he volunteered you to write the book?

[Kip Thorne]

Well, no, I was already planning to write the book. But he identified that as the place where the ending will get explained. He was not going to explain the ending. He would leave it mysterious.

[Neil DeGrasse Tyson]

In his film tease, he was pulling a Kubrick on us.

[Kip Thorne]

That's right.

[Neil DeGrasse Tyson]

In fact, we interviewed Christopher Nolan. If you're an archive diver. We've got a whole episode with Christopher Nolan even before Interstellar was produced. And as we know so many of his movies, he plays with time in some kind of interesting way. If I remember correctly, he talks about how influential 2001 A Space Odyssey was to him back in 1968. That would have been.

[Kip Thorne]

Yes.

[Neil DeGrasse Tyson]

So let me ask you just a couple of things about the storyline. And I have. I have an issue with it, if I may, but I don't know if I ever went public on this, but I figure I'm in front of the man himself, so if I have an issue, they would be here.

[Kip Thorne]

And now you're gonna get turned into a journalist who's challenging me.

[Neil DeGrasse Tyson]

I know.

[Kip Thorne]

Gonna give me a tough time.

[Neil DeGrasse Tyson]

Yeah, I gotta. This can't be just all, okay, softball. Let's play a little hardball. So I guess my issue. We're looking for a planet. Again, this is in the themes of the movie. We're looking for a planet like Earth, similar enough to Earth that we can send people there to continue our civilization and our species. Is that a fair characterization of a plotline? Of the plotline. Okay. And it turns out there's like a wormhole that can make that happen a little faster because otherwise you don't live long enough to travel the distances with the rockets available to hit those destinations. Okay. I'm just thinking this blight on the crops that was starving everyone on Earth, requiring that we jump ship, literally jump ship to go find another ship, another spaceship planet. It seems to me that whatever effort it takes to find another Earth, travel through a wormhole, ship a billion terraform it, ship a billion people there, whatever that effort is seems to me to be a bigger effort than just telling the biologist come up with a serum that could fix the crops. Even today, we have full knowledge of crop genomes. Just fix it. Whatever is. Just go in there, nip tuck the DNA, fix it. Isn't that cheaper, easier, faster than wormholing your way off this planet? That's where I'm coming from.

[Kip Thorne]

So you think that all problems can be solved by humans with human technology on timescale. You have such faith in humans. Come on.

[Neil DeGrasse Tyson]

So I'm the optimist here.

[Kip Thorne]

Okay, so let me describe this characterizes how this movie was done. So when it was Jonah Nolan, Chris's brother, who came up with the idea that he wanted a blight or something like that. And so we said, okay, we will bring together the Best biologists we can who are experts on these kinds of things put together mostly Caltech biologists. And we had a dinner and we brought out very expensive wine for them to drink, and we set up a.

[Neil DeGrasse Tyson]

Recording in vino veritas. Okay. In truth, there is wine.

[Kip Thorne]

Yes.

[Neil DeGrasse Tyson]

In wine there is truth. Yes.

[Kip Thorne]

And so we had a conversation that lasted about three or four hours at the Caltech faculty club, the Athenaeum, about what could we. What would be the best backstory here? There are two types of blights. There are generalized blights that attack lots of crops, and there are lots of.

[Neil DeGrasse Tyson]

Different species of crops.

[Kip Thorne]

Lots of different species of crops. But they are generally fairly benign blights. And then there are blights that are very specific to a particular crop and they can be very lethal blights that may totally wipe out that species on Earth even. But basically, for Earth and life on Earth to survive, you better not have a vicious generalized light. But according to the biologists that I discussed this with, they didn't know of anything that would prevent the development of a very vicious generalized light. So that's what occurs in this movie. And it's something that biologists have never seen, but they cannot rule it out. Rule it out.

[Neil DeGrasse Tyson]

Okay, so let me repeat what I think you said. They have vicious, lethal blights that attack a species, less lethal generalized blights that cross species boundaries and they can't rule out a lethal blight that would cross species.

[Kip Thorne]

That's right.

[Neil DeGrasse Tyson]

And so that's what's happening in the film.

[Kip Thorne]

What's happening in the film. And that's what they just. The biologists. All right, unearth in this in the back. So there's a back.

[Neil DeGrasse Tyson]

I'll give you that. Okay.

[Kip Thorne]

Okay. So anyway, this film is full of backstories because of the way we did it. As I say again, it's unlike almost any other film and that these issues were like that were vetted by the world's best experts right in the process of the writing of the screenplay.

[Neil DeGrasse Tyson]

Okay.

[Nicholas Costello]

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[Neil DeGrasse Tyson]

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[Kip Thorne]

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[Neil DeGrasse Tyson]

Supporter of StarTalk on Patreon. This is StarTalk with Neil DeGrasse Tyson. I got another one. Okay, you're one for one. All right. When they're on the black hole planet, okay, and then they see this wave.

[Kip Thorne]

Coming, okay, It's Miller's planet. Miller's planet. The water planet.

[Neil DeGrasse Tyson]

The planet orbiting gargantuan. Gargantua.

[Kip Thorne]

Okay.

[Neil DeGrasse Tyson]

The strength of tidal forces are highly sensitive to the distance you are to that which is causing the tides. Highly sensitive, okay. But every illustration I've drawn or taught about tides, they're not so peaky, they're much broader in their representation on a planet. And so there they are wading in water, but then they see this single wave come. And if it is a single wave, as we've seen with tsunamis, it actually takes water away from what's ahead of it, because it can't just be water out of nowhere. It's drawing water from its vicinity. So my two issues was, if it's tidal, would it be that peaky? And if it's any kind of wave, how could it still leave the water laying around its vicinity and then just be that big as it came by?

[Kip Thorne]

So there is a type of wave called a solitary wave on water that was.

[Neil DeGrasse Tyson]

Are you going to tell me you brought wave people together and had that lunch?

[Kip Thorne]

Is that what you. No. This particular kind of wave was discovered in the 1700s by. I've forgotten who, a physicist in England who saw a boat that was being pulled by horses, and it was just starting up, and it created this wave that traveled down a channel, a canal. And it was peaked, like the wave. And interstellar, though the wave. And interstellar. I have to admit it was exaggerated. There was.

[Neil DeGrasse Tyson]

I don't mind exaggeration.

[Kip Thorne]

There was some exaggeration in the peak, but it traveled down the channel. It never broke. Most waves at the ocean, they break.

[Neil DeGrasse Tyson]

Okay, just so we can get the picture, because we're talking about centuries ago, when you say a channel, that would be a channel or a canal.

[Kip Thorne]

A canal.

[Neil DeGrasse Tyson]

And then there's a towpath on the side. And then. And then people, and more likely beasts of burden would drag things through the canal because themselves don't typically have currents.

[Kip Thorne]

Drag a barge down the canal.

[Neil DeGrasse Tyson]

A barge, exactly.

[Kip Thorne]

And so this barge was dragged down the canal and it was just starting up, and it created this wave that.

[Neil DeGrasse Tyson]

On the startup.

[Kip Thorne]

On the startup. And it just headed out and just took off and went down the channel. And this. This guy got. Got on his horse and he followed down the channel, and it went down the channel.

[Neil DeGrasse Tyson]

I'm curious, physicists. Nothing gets by.

[Kip Thorne]

It went and went down the channel for, I don't know, a mile or two without changing its shape, without breaking.

[Neil DeGrasse Tyson]

Without breaking.

[Kip Thorne]

And so the theory of these waves is, is that there are two different effects that cause a wave to steepen or disperse, and the two can balance each other out in a stable sort.

[Neil DeGrasse Tyson]

Of a way and give it longer.

[Kip Thorne]

Life and give it long life. And so aside from the issue of friction, if there were no friction, it would just live forever and keep propagating in a very stable way. There's mathematics behind it, something called the Cordovac de Vries equation that this is a solution of. But anyway, these waves then.

[Neil DeGrasse Tyson]

So that equation, I presume, has both kinds of waves in equilibrium somehow represented. It's a static wave.

[Kip Thorne]

The dispersion and the steepening. The steepening is due to non linearities. The dispersion is due to the fact that. That the higher parts of the water travel faster than the lower parts of the water. If you're at the ocean, you see a little tiny wave, it travels quite slowly. You see a big wave, it travels quite fast.

[Neil DeGrasse Tyson]

And that's why the crest of the wave will actually break before the rest of the wave gets there. Is that part of the reason?

[Kip Thorne]

That's right. Unless that's being balanced out by dispersion, which is.

[Neil DeGrasse Tyson]

Anyway, I love it. No, it's good. Good. I'm loving it.

[Kip Thorne]

I'm getting this slightly confused. But anyway, the two effects balance each other and to produce this very stable solitary wave. And so in the movie, but for this stable, solitary wave, the height of the wave is. And I've forgotten the number, but it's something like six times higher than the depth of the water.

[Neil DeGrasse Tyson]

Got it.

[Kip Thorne]

So there's a problem now in the movie, because they're walking around in shallow water and this wave is high, and so it's got to be deep water.

[Neil DeGrasse Tyson]

Okay.

[Kip Thorne]

But they're. But they're on an island. This is the backstory again. There's always a backstory.

[Neil DeGrasse Tyson]

So they're on a subterranean. A subsurface island.

[Kip Thorne]

Yeah, you got to read it in my book. They're on. They're on an island. And this wave diffracts around the island. They hardly notice the island at all. So, again, it's all explainable, except there is a bit of exaggeration. The CGI wave was made somewhat more peaked. Somewhat Hollywood, we'll give you that.

[Neil DeGrasse Tyson]

It's a movie and it's Hollywood. But what you're saying is this wave might have been caused by some effect other than the tidal forces of the black hole.

[Kip Thorne]

Yeah. Yeah. Well, this wave is caused, in fact, by the fact that this time is much slowed. On this.

[Neil DeGrasse Tyson]

Yes.

[Kip Thorne]

On this planet. So the planet has been put into the orbit around Gargantuan, not that long ago is seen on the planet, though it's a long, long time ago, as seen from far away. And it's like Mercury. Like the Moon keeps one face toward Earth, or Mercury keeps one face toward the sun due to tidal effects. This planet is distorted by tidal effects, and it's Swinging back and forth. It has not yet settled down to one face toward the planet. And that swinging back and forth is generating this wave. That's all in the book.

[Neil DeGrasse Tyson]

He weaseled out of another one. Okay.

[Kip Thorne]

There's an enormous amount of science in that book.

[Neil DeGrasse Tyson]

I must have missed that when I. The book. And one last point.

[Kip Thorne]

You didn't study it carefully enough. Neil.

[Neil DeGrasse Tyson]

One last point. We took our show to Oxford recently, and I interviewed at Oxford, I think it was a postdoc. And I was named Andrew Mummery, postdoc. And he showed us a recent paper he published. I don't know if you've seen it recently, like within the past 18 months. And he's a theoretical physicist, and he alerted me, something I'd never knew. I love the field, but it's not my active professional field that in the vicinity of a black hole, there is an innermost orbit. Because, of course, you can orbit any source of gravity, even if it's a black hole. But for black holes in particular, there's an orbit within which the orbit is no longer stable and it will spiral into the black hole itself. And according to his calculation, to get the time dilation necessary in the scene with the black hole planet, which was huge, remember, they were on the planet for, like, 15 minutes or whatever. How long?

[Kip Thorne]

One hour on the planet is seven years up at high altitude.

[Neil DeGrasse Tyson]

Seven years up in their spaceship. Okay. And the guy who they left there, he's like, gray and unshaven and everything. And we're like, oh, my God. Gosh, there's some serious Einsteinian physics going on here. His calculation showed that for that difference, for that extreme difference in time dilation requires that planet orbit so close to the black hole, that would be in the unstable zone. And so I just thought I'd tell.

[Kip Thorne]

You that my calculation says otherwise.

[Neil DeGrasse Tyson]

And where's his Nobel Prize? The other guy.

[Kip Thorne]

The formula is in the book.

[Neil DeGrasse Tyson]

In this one.

[Kip Thorne]

Yeah. So. So.

[Neil DeGrasse Tyson]

So we don't have to go to your graduate textbook for that.

[Kip Thorne]

No, no. Well, not for the answer. Okay. If you want to derive the formula, that's a lot of work. So let me tell you the story behind this.

[Neil DeGrasse Tyson]

Oh, so the story. Okay.

[Kip Thorne]

So Christopher Nolan says to me one day, he says, I want the hero and Cooper, the hero in this movie, to go down onto this planet.

[Neil DeGrasse Tyson]

Cooper, played by Matthew McConaughey.

[Kip Thorne]

That's right. Professor Brand's daughter is played by Je. Jessica Chastain. Christopher Nolan says to me, he says, I want, in this movie, that one hour on Miller's Planet is seven years up at very high orbit or back on Earth.

[Neil DeGrasse Tyson]

He prescribed that?

[Kip Thorne]

Yes. And I said to him, that's impossible because the planet will fall into the black hole. He said, go do a real calculation. I've already learned that your off the cuff reactions can be wrong and I should not trust you unless you do a real calculation.

[Neil DeGrasse Tyson]

There's a good Hollywood producer. Go back and give me the answer I'm looking for.

[Kip Thorne]

Well, well. And so I went back home and I did a real calculation and I was amazed that the last stable circular orbit, which is what we're talking about, is if the planet spins fast enough, last circular stable orbit can have as high a, a high, a redshift, as high a time difference as you might wish. But that requires. It requires that this black hole spin extremely close to the maximum possible spin. And so in the book I give the formula for what is the spin of the black hole that is required to produce a given amount of slowing of time.

[Neil DeGrasse Tyson]

I did not know that.

[Kip Thorne]

And so. And that it's an approximate formula, but it's a formula that can be derived though it takes a fair bit of algebra.

[Neil DeGrasse Tyson]

Okay. So the one one would just learn about would probably be that's the lowest stable orbit around a non rotating black hole.

[Kip Thorne]

That's right.

[Neil DeGrasse Tyson]

And that's a clean.

[Kip Thorne]

That's a clean problem. And that. Clean problem. That's what I was thinking when Chris said I want this. When I knew that if I made the black hole spin that it would get closer. But I couldn't imagine, I cannot imagine that nature would provide a orbit for a black hole that spins fast enough that they could provide this much of a slowing of time. But it does. It does. At least unless I made a mathematical error. But I don't think that's likely because I used Mathematica.

[Neil DeGrasse Tyson]

Okay. You had tools to help you do this. I could check my calculations because it was. It's not just an analytic solution.

[Kip Thorne]

Well, it is an analytic solution, but it's very complicated. But it's very complicated. Yeah.

[Neil DeGrasse Tyson]

Okay.

[Kip Thorne]

Well, it's a power series solution.

[Neil DeGrasse Tyson]

In the end, I think our hero character is inside the black hole. We come to understand this and he has access to a timeline that wouldn't otherwise be available to him. And he sees his daughter's bookshelf.

[Kip Thorne]

Well, he's no longer inside the black hole.

[Neil DeGrasse Tyson]

Where is he when he's doing this?

[Kip Thorne]

So this is the key thing that's not explicit, that you only understand if you read my book. You didn't read it. Well, Enough. Okay.

[Neil DeGrasse Tyson]

Busted. No, I read a lot of it. Let me say. I read some of the biology.

[Kip Thorne]

Yeah, it was a long time ago too.

[Neil DeGrasse Tyson]

Yes. Okay.

[Kip Thorne]

So when he gets inside the black hole, he is scooped up by a spacecraft that was built by this advanced civilization that provided the wormhole to him, to humanity. And it's called the Tesseract. And the Tesseract is a four dimensional cube, four spatial dimensions.

[Neil DeGrasse Tyson]

And that's why in there you saw, I guess, the past and future all.

[Kip Thorne]

Kind of simultaneously, all related to the.

[Neil DeGrasse Tyson]

It felt very higher dimensional.

[Kip Thorne]

Yeah, that's right. Anyway, this Tesseract, he. So, so, so let me back up, I'll tell you a story. So early on in, when we were working on the film, Christopher Nolan said to me he wanted to take his hero back to Earth. Cooper back to Earth by a different route than the wormhole. 10 billion light years away from the Earth. How's he going to do it if it doesn't go through a wormhole? He said, well, I want to take him back faster than the speed of light. And of course I say to Chris, you can't do that. It violates the laws of physics. He says, go do a real calculation. I said, I don't have to do a real calculation. And so we discussed this for a week and then he threw in the towel. He said, okay, I believe you. And so what do we do? And so I said, well, you put him, he goes inside the black hole, he gets deposited on the three dimensional surface of a four dimensional sphere. And this four dimensional sphere is a spacecraft that can go into the bulk, into the higher dimension, and it goes out of the black hole, not through the horizon. It can't do that. It goes up through the fourth dimension, up through the fourth space dimension, or what's called the fifth dimension in the movie. This time is the fourth dimension and goes back to Earth. And the distance back to the Earth is less than the distance between the Earth and the sun. Even though it's 10 billion light years inside of our universe, up in the bulk, it's a very short distance and so he can get back quickly.

[Neil DeGrasse Tyson]

This is the higher dimensional space time in which we are now having this.

[Kip Thorne]

So he gets back very quickly riding on the surface of this four dimensional sphere. He said, I like it all entirely, except I'm going to use a four dimensional cube instead of a four dimensional sphere. That's a tesseract. And so that's what happens. And when you see Cooper out there sort of flailing around at the beginning of the Tesseract scene. He's being carried by the Tesseract back to Earth. But you don't know that's what happened until you read my book. By agreement, between Chris and me, that's the only way anyone's ever going to know. So anyway, he's carried back to Earth, and then everything is happening when the Tesseract is docked in the higher dimension.

[Neil DeGrasse Tyson]

Beside his, giving access to his life in that past time.

[Kip Thorne]

That's right. So it's docked in his home, in his daughter's bedroom.

[Neil DeGrasse Tyson]

Okay, so now he's pushing books off the shelves that land on the floor. And through some clever cryptographic judgment, he's spelling out words with the first letter of the title of each book. Okay, here's my issue. I had no problems with Tesseract, Black hole, fourth dimension, five dimensions. How does he know the title of each book from the other side of the book?

[Kip Thorne]

So I don't remember. That's how he's actually.

[Neil DeGrasse Tyson]

He's pushing books out.

[Kip Thorne]

No, I know he's pushing. I know he's pushing.

[Neil DeGrasse Tyson]

He's pushing books out from this side.

[Kip Thorne]

Yeah, yeah.

[Neil DeGrasse Tyson]

And all he sees is the other side of the library shelves.

[Kip Thorne]

I guess I had forgotten that he was spelling things out based on the first word.

[Neil DeGrasse Tyson]

Oh, you forgot.

[Kip Thorne]

I forgot. Or I didn't know. Or you're wrong.

[Neil DeGrasse Tyson]

So that was one of my.

[Kip Thorne]

That one. I don't know.

[Neil DeGrasse Tyson]

Oh, okay. Okay.

[Kip Thorne]

I don't know.

[Neil DeGrasse Tyson]

Okay, so you're three for four.

[Kip Thorne]

He probably has a photographic memory.

[Neil DeGrasse Tyson]

Perfect memory of the other side of the book.

[Kip Thorne]

Yeah.

[Neil DeGrasse Tyson]

What's this I hear that you can use a wormhole to travel backwards in time? Does the math check out? Does the Einsteinian physics check out? And does that mean I will just show up a younger version of myself and shake my own hand? Is that what you mean by that? Or do I no longer exist in the time that I left for my younger version of myself to see that and wasn't there? Didn't Hawking put forth a time travel prevention conjecture or something? What's going on there?

[Kip Thorne]

So this is all an outgrowth of my phone conversation with Carl Sagan when he was working on the novel for Contact, where he triggered me to start thinking about wormholes. And then having started to think about wormholes, it became pretty obvious to me rather quickly that if I give my wife Carolee, one mouth of a wormhole and she carries it at high speed in a rocket ship out into space and then back, and I keep the other worm mouth at home, and if she Sees me age by 50 years back on Earth while she ages only one year, going out and coming back. But if we look through the wormhole at each other, we see each other aging at the same rate. Just imagine we hold hands and we look at each other's wristwatches. It's ticking away at the same rate. So through the wormhole we faced at the same rate. We're the same age, but looking outward through, outside the wormhole, through a normal universe, she's aged one year and I've aged 50 years. Something weird has happened. The wormhole has become a time machine. If I just go over and go into her mouth, wormhole mouth, and come out, I'll meet my younger self.

[Neil DeGrasse Tyson]

Okay, Now, Hawking said, this is no, we're not going to allow this. There's some conjecture yet to be discovered that'll tell you you can't do that.

[Kip Thorne]

Well, so this story we get there. You're going too fast.

[Neil DeGrasse Tyson]

I'm going too fast. Sorry.

[Kip Thorne]

So then I talked to friends at the University of Chicago. Physics. It's crucial to talk to friends. They tell you where you're all at. They tell you when you made a mistake, they straighten you out. And they pointed out to me that it might be that when the time machine is turned on, it'll self destruct. Basically they said. And I said, I don't understand. They said, go do a calculation. So I went and did a calculation. And the issue is they had guessed and basically that's oversimplified. But they. Bob Garroach and Robert Wald at Chicago. Anyway, it turns out that at the moment that you can first time travel, the first thing that goes through it can be vacuum fluctuations of light. Say that enter her mouth of the wormhole, come out of my mouth and go back and arrive back at her mouth at the very moment they started out. Now you have twice as much at the same place in space and time.

[Neil DeGrasse Tyson]

So this is a runaway.

[Kip Thorne]

So it's a runaway. And so you now have twice as much and then it goes around again. Now you have four times as much, goes around again. So this runaway builds up just like.

[Neil DeGrasse Tyson]

The feedback between a microphone and a speaker.

[Kip Thorne]

Precisely.

[Neil DeGrasse Tyson]

And it just runs away.

[Kip Thorne]

It just runs away. And it runs away. And this runaway shows up in the quantum mechanical calculation that I did. You're bumming me out together with Sang Hwan Kim, a Korean postdoc of mine.

[Neil DeGrasse Tyson]

Okay, I want to be a movie director and say, go Kip, go home and figure out how to do this. Give me another pull, another Rabbit out of the hat here.

[Kip Thorne]

Well, anyway, we discovered this Stephen, I think, and one of his, Stephen Hawking and a student of his, I think, had more or less the same discovery at the same time. Except Stephen probably just did it all in his head, because that's the way Stephen is. Anyway, so then Stephen and I started corresponding about it by email and talking on the phone about it and so forth. It appeared to me, looking at the details of the calculation, that in fact the explosion, if I designed the time machine just right, the details of the explosion, the explosion would not be strong enough to destroy the wormhole. And Stephen then showed me that I was wrong. And we argued back and forth for a while and finally we came to agree that the explosion becomes strong enough that quantum gravity enters in and then holds the answer tightly in its grip. And so we won't know whether the time machine self destructs until we understand the laws of quantum gravity.

[Neil DeGrasse Tyson]

Let me be fond of obscure here.

[Kip Thorne]

But then we come to the Hawking cosmic censorship conjecture.

[Neil DeGrasse Tyson]

That's what it's called.

[Kip Thorne]

Yeah, the conjecture that in fact, in the end, the laws of quantum gravity won't save the day. The wormhole will be destroyed and any time machine that any advanced civilization makes will be destroyed when they try to turn it on by these vacuum fluctuations. And thereby, as Hawking says, keeping the universe safe for historians of all species.

[Neil DeGrasse Tyson]

It reminds me of the ultraviolet catastrophe where you run the calculation, this is going to blow up. How does this even work? And then out comes the discovery of the quantum which saves the day. Right. And this is. It could be a calculation waiting for another branch of physics to open, or another progress in the known branches of physics to resolve.

[Kip Thorne]

We and LIGO and our gravity wave project. But I'll just make the remark that the LIGO team has perfected a technique called quantum precision measurement, which is based on manipulating vacuum fluctuations in order to circumvent the uncertainty principle. And so this business of manipulating vacuum fluctuations is something we do in modern physics.

[Neil DeGrasse Tyson]

If memory serves, Carl Sagan came up to you and said for contact, I want to go far distances quickly. How am I going to do it? Can you cook up a wormhole for me?

[Kip Thorne]

Carl phoned me back in the 80s.

[Neil DeGrasse Tyson]

When he's writing the novel, because obviously he predated the movie.

[Kip Thorne]

That's right. And he said that he wanted. That he has written. He'd already written the book, the novel. It was already in page proofs. And he said, I've got this novel, it's in page proof. The Publisher is not going to be happy if I change it, but I really need some help to see what the truth is. And then we'll figure out how to deal with this. And he said that I have my heroin traveling through a black hole to get to the star Vega. And I said, that's rather dangerous. There's a singularity in there. Okay? There's a singularity in there, and you can't get through to get to the star Vega. So what you actually need is a wormhole. But there is an issue that wormholes implode. They collapse so quick that nothing can get through. But I'll see if I can figure out how to hold the wormhole open just for you, Carl. And so I was going with, it's.

[Neil DeGrasse Tyson]

Like rent a physicist, right? It's like, whatever your needs are.

[Kip Thorne]

So I was getting in a car that morning to ride with my former wife to our daughter's graduation up at Santa Cruz. And so Linda said, I'll drive, and you calculate. So she drove and I calculated and I fiddled around. And then it became fairly obvious. Turns out somebody other. Some other physicist would figure this out sooner. But that's the usual thing with me. I figure it out, and then I go, see, did people know this before or not? So, anyway, I figured out that if you had what I like to call exotic matter that repels gravitationally, and you put it inside the throat of a wormhole that can hold the wormhole, it'd.

[Neil DeGrasse Tyson]

Be like pushing it outward.

[Kip Thorne]

That's right. It basically repels the walls of wormhole to hold them open. And it turns out that that will do it. But you have to have enough exotic matter to hold the wormhole open. And I deduced a formula for how much you had to have. And it basically says the following. If you move through the wormhole.

[Neil DeGrasse Tyson]

Let the record show he's about to describe how to make a wormhole.

[Kip Thorne]

No, no, only how to hold it. Only how much exotic matter you have to hold it open.

[Neil DeGrasse Tyson]

This sounds like a recipe to me.

[Kip Thorne]

So you travel through the wormhole as close to the speed of light as you possibly can. Just close to the speed of light and add up all the energy density all the way through the wormhole of stuff that's in the wormhole. The net has to be negative, and then you can hold the wormhole open. So it basically means you've got more negative energy in there than positive energy.

[Neil DeGrasse Tyson]

Because we have nothing known as exotic matter.

[Kip Thorne]

Oh, yes, we do.

[Neil DeGrasse Tyson]

What?

[Kip Thorne]

Yeah. And so they.

[Neil DeGrasse Tyson]

Oh, is this in your basement? What do you mean. What do you mean? Oh, yes, we do. Okay. What is our exotic matter that would fulfill this purpose?

[Kip Thorne]

So if you.

[Neil DeGrasse Tyson]

Should we turn off the camera now? Is the government going to show up in your driveway? Okay, go.

[Kip Thorne]

Well, I learned about this from Yakov Boris Zeldovich in Moscow.

[Neil DeGrasse Tyson]

Zeldovich.

[Kip Thorne]

Zeldovich was one of the inventors of the Russian hydrogen bomb.

[Neil DeGrasse Tyson]

Okay.

[Kip Thorne]

And I learned this from him.

[Neil DeGrasse Tyson]

All right?

[Kip Thorne]

He was really brilliant. I learned about vacuum fluctuations and how important they can be and how powerful it can be if you can manipulate them. And so if you take a box and you remove everything that can possibly be removed from the box, you're left in the end with tiny fluctuations of everything that cost possibly could have been in the box. So electric fields, you have fluctuating electric fields, fluctuating magnetic fields, fluctuating protons, electrons fluctuating. Neil Tyson, Degrasse Tyson's.

[Neil DeGrasse Tyson]

So this creates a form of pressure inside the box.

[Kip Thorne]

Well, so the next, there's vanishing pressure and that vanishing energy due to renormalization. That's a nasty word in physics.

[Neil DeGrasse Tyson]

But.

[Kip Thorne]

You can measure energy by whether it produces gravity or not. And although these fluctuations that are there, you can think of them as particles, say particles of light flashing in and out of existence randomly.

[Neil DeGrasse Tyson]

So why isn't this not the virtual particles that people speak of?

[Kip Thorne]

So it's virtual particles.

[Neil DeGrasse Tyson]

It is that. Okay, We've spoken about those on our show before.

[Kip Thorne]

Okay.

[Neil DeGrasse Tyson]

So you have virtual green, in fact.

[Kip Thorne]

So you have virtual particles in the.

[Neil DeGrasse Tyson]

Vacuum popping in and out of existence.

[Kip Thorne]

Popping in and out. And you can't stop it, you can't prevent it. However, you can take fluctuations from one region and borrow them and put them in another adjacent region for a little while. Or if you put an electrically conducting sheet, say a sheet of superconducting metal here, then that will suppress the fluctuating electric fields parallel to the metal, because they would create an infinite current flowing in that metal, and that would wipe out the electric field parallel to the metal. And so you have.

[Neil DeGrasse Tyson]

Is that an element of the Casimir effect?

[Kip Thorne]

Yes, that's the Casimir effect.

[Neil DeGrasse Tyson]

It is, yeah. Where you have two parallel plates evacuated between them.

[Kip Thorne]

That's right.

[Neil DeGrasse Tyson]

And there's a point where they actually feel a whole other force attracting them.

[Kip Thorne]

And so what that force really is in the region between them. The vacuum fluctuations are suppressed. And so you have negative energy in between that energy. Negative energy is sucking them together. And they can do work on you. If you're holding onto these plates and they attract each other, you Put energy in as they go together. They do work on you. The electromagnetic field between two plates in the Casimir effect is exotic. Okay, and so.

[Neil DeGrasse Tyson]

So you have this in your basement is what you're telling me?

[Kip Thorne]

Yeah, Well, I don't have it in my basement, but. But physicists do this. Let me just say, as a side remark, having learned a lot about vacuum fluctuations, we and LIGO and our gravity wave project. I'll just. Just make the remark that we have. We, the LIGO team has. Has perfected a technique called quantum precision measurement, which is based on manipulating vacuum fluctuations in order to circumvent the uncertainty principle. And so this business of manipulating vacuum fluctuations is something we do in modern physics. And it is something then that you can imagine. You can ask, can a very advanced civilization manipulate vacuum fluctuations adequately in order to make enough exotic matter inside a wormhole to hold the wormhole open? And so I posed this as a question to my physicist colleagues, stimulated by Carl Sagan and him wanting to send his heroin through a black hole. I said, no, use a wormhole. And so we got to hold it open. And so, physic colleagues, please help Carl and figure out, can an advanced civilization do this? And the answer is, we still don't know. Forty years later, now we still don't know.

[Neil DeGrasse Tyson]

Right. Well, we're doing magic compared to what anyone thought was possible 50 years ago, certainly the dawn of quantum physics. We're on the centennial of the decade of quantum discovery back in the 1920s.

[Kip Thorne]

Well, I was very close friends with Carl Sagan, and I've developed close friendship with Christopher Nolan. Chris has a very different background than me. He knows a lot of science, but he's learned it all by browsing the Web. And he. And he knows it well enough to ask me hard questions, just like you do, but he asked them first. So I have the answers now and have inspired me to ask questions that then I sort of translate to and give to colleagues, because my colleagues are smarter than I am. My role is to pass on interesting questions.

[Neil DeGrasse Tyson]

You're the conduit for this conduit for.

[Kip Thorne]

Interesting questions for my colleagues to work on.

[Neil DeGrasse Tyson]

So, dude, you can't leave well enough alone. Einstein says maybe there are gravitational waves emanating from major gravitational disturbances in the universe, and you got to go up and find them. But you're not the first to have attempted this, right? At the University of Maryland, there was Weber, I think. What's his first name?

[Kip Thorne]

Joe.

[Neil DeGrasse Tyson]

Joe Weber, who had a cylinder, if I remember correctly, where he was trying to measure whether If a gravitational wave washed over it, he could detect a distortion in the shape of the cylinder, I think was the goal.

[Kip Thorne]

Yeah, the gravitational wave would drive vibrations of the cylinder end to end vibrations. And so he instrumented it to search for changes in the amplitude and phase of vibrations of the cylinder. Cylinder is at a finite temperature, so it's always vibrating a little bit because it's a finite temperature. And so he instrumented it with what's called phoelectric transducers. Transducers that he. That he glued around the middle of the cylinder that when they were squeezed, they would generate an electrical voltage that he could measure. And they're amazing things. This piezoelectric transducer is just absolutely amazing. You squeeze them a tiny, tiny bit and you get a big voltage out. And I mean, Joe Weber was tremendously creative. He was the.

[Neil DeGrasse Tyson]

I think he was working on that while I was at the University of Maryland. I was there in the 80s. I think he was still working on it.

[Kip Thorne]

Yeah, that's right. So he began working on it in the late 60s, early 70s, and announced that he was seeing possible evidence for gravitational waves in.

[Neil DeGrasse Tyson]

There's a lot of skepticism at the.

[Kip Thorne]

Time, if I remember. I'm sorry. He started working out in the late 50s, early 60s, announced in 69 that he was seeing some possible evidence of gravitational waves. And a number of other physicists around the world built similar detectors. And the bottom line in the end, after a period of shaking out, was that others were not seeing gravitational waves.

[Neil DeGrasse Tyson]

And that's the only way science works. One person's result is not a result until somebody else, a competitor, somebody else who uses different wall current, somebody from another country. You need multiple verifications.

[Kip Thorne]

But on the other hand, Weber, Joe, he started the field. He triggered this work. The approach that he'd invented for searching for gravitational waves was the dominant approach from then until the 2000s. And a number of other research groups built similar detectors and improved them better and better and better over that period.

[Neil DeGrasse Tyson]

On that model.

[Kip Thorne]

On that model. The model. So. So, I mean, I have enormous respect for. For what he did.

[Neil DeGrasse Tyson]

Sure. Now you, now you decided to. You and others decided to look differently for them.

[Kip Thorne]

Yeah. Well, so Ray Weiss, Reiner Weiss, Ray, his friends call him at mit, was the primary inventor of an alternative technique that was the technique that ultimately succeeded. He invented. Well, he wrote. He wrote a technical paper about the technique that identified all the noise, kinds of noise that you would have to deal with and explained how you might deal with them and did analysis of how Good this detector could be. And he put it all in this paper. Oh my gosh. It was a recipe for how to go forward. And he wrote this in 1972. And Ray, being Ray, didn't publish this because I think he figured you don't publish until you have built one and seen a gravitational wave. So however, Ray sent copies of this around all his colleagues and he put it into quarterly reports of the MIT laboratory in which he worked. And so it is probably the most influential non published paper certainly that I know of in physics. I mean, it was a tour de force and it triggered the huge effort, the next generation that actually succeeded.

[Neil DeGrasse Tyson]

I was fortunate enough to visit the. Because there were two LIGO experiments. One in Louisiana and the other one is in Hanford, Washington. Why do you have two? Because you can't just have one result.

[Kip Thorne]

Yeah, you're looking for an effect that is so small that you wouldn't believe it unless you see it on two independent instruments.

[Neil DeGrasse Tyson]

There you go. So you've got these pathways, are they Kilometer long, 4km long, 4km long. Evacuated. You send a beam of light that is split from a sink, a beam laser that's split, it goes two. These are at 90 degree angles. And they go to the end, they get reflected back and you rejoin them. And you want to see if their waves line up. And if they line up, then each direction is identical. You can go home. If they're slightly different, then one of these legs experienced a different encounter with the fabric of the space time continuum than the other did. So that's audacious.

[Kip Thorne]

So actually what you want to do is you make them slightly different in the first place. But then, so that means you send your laser light in from this direction. There's a beam splitter where the light gets split in two to go down the two arms. So the laser light goes in like that. There's this beam splitter. So the light gets split in two into one arm in that direction, the other arm in this direction, and then it comes back and recombines in the beam splitter. The laser light was coming in from this direction, but when it recombines, a little bit of light goes out in a perpendicular direction. So you have a laser here and you have an output over there. And the output direction is the direction that has a signal. And if the length of one arm is shortened and the length of the other arm is lengthened.

[Neil DeGrasse Tyson]

And that would only happen because a gravitational wave washed over that arm.

[Kip Thorne]

That's right. Then you get a change in how much Light is coming out to the output.

[Neil DeGrasse Tyson]

All right, so you're trying to find a length difference. And if I remember the materials from the press releases, that is equivalent to one tenth the diameter of a proton.

[Kip Thorne]

No, it's equivalent to. It's 10 million times smaller than an atom and a hundred times smaller than a proton.

[Neil DeGrasse Tyson]

1/100 the diameter of a proton. Meanwhile, all the world is vibrating because everything is at a temperature. And you cool it as much as you want, there's still vibrations, and somebody is walking down the street. I remember being on campus there. Can I call it a campus? That's what it was. And you can detect cars on the road a mile away. You have to insulate this. That's half the science done for the experiment. You should get a Nobel Prize for that.

[Kip Thorne]

Well, that's what the Nobel Prize was going for, that. Yeah.

[Neil DeGrasse Tyson]

To have successfully isolated the effect, you're trying to measure.

[Kip Thorne]

So the way I like to describe it is you're trying to. You're bouncing light off of these mirrors and you're looking for a motion of the mirrors that is 10 million times smaller than the atoms of which the mirrors are made. And, well, the mirrors. The atoms in the mirrors themselves are vibrating because they're at finite temperature by an amount that is about the same as their size. So 10 million times smaller than the atoms and 10 million times smaller than the vibrations the atoms are undergoing.

[Neil DeGrasse Tyson]

So once again, in physics, there's a phenomenon we're trying to measure, but it's kind of buried and you need a way to get to it. And it seems like half, if not more than half of the effort is how brilliant is your engineer that you've brought onto the task to accomplish this? How good are your tools? It's not just the idea. It's. Now you gotta make the damn measurement. And it's not obvious. You need very talented people assembled for this.

[Kip Thorne]

Absolutely. And so that was the issue. How good a team can you put together? So when I learned of Ray Weiss's idea and I saw and I knew roughly how strong the strongest gravitational waves would be, I knew already then that it would be necessary to.

[Neil DeGrasse Tyson]

This would be the collision of two black holes.

[Kip Thorne]

Collision of two black holes.

[Neil DeGrasse Tyson]

And you can't just summon that up. There has to be real things in the universe that might produce that.

[Kip Thorne]

That's right. But based on what we knew about the universe at the time, I was estimating a wave strength that was roughly correct. And it was at that level that you would have to monitor the motion of these mirrors at 10 million times smaller than the atoms in the mirrors. And I thought to myself, that's crazy. So in this book, which was published in 1973, we went to press just after Ray Weiss wrote his seminal paper. I had not yet really studied that paper fully, but I just knew that this was crazy. And so it describes in a few words Ray's idea in here. And then it says, I think there's an exercise where it says, show why this is not very promising. Just a mild gentleman, because it is a textbook, right?

[Neil DeGrasse Tyson]

You get to know.

[Kip Thorne]

So it's the students challenge to show on stuff.

[Neil DeGrasse Tyson]

Well, it could not be a very good idea in 1973, but fast forward a half a century, right? So it is 1853. Flying is not a good idea. Write an essay on why flying isn't a good idea.

[Kip Thorne]

Yeah, but that was the central issue. If we worked for a few decades, did we have a shot at success in 1973? I thought, no, no way. But by 1975, I had turned around. I'd had long conversations with Ray. I'd had long conversations with Vladimir Braginsky, a colleague in Moscow. I'd done lots of calculations of my own. And I came to the conclusion that you had a real shot at success if you put together a superbly strong team and you worked at it for.

[Neil DeGrasse Tyson]

A few decades and you need money. And you were well supported, I think, by the National Science Foundation.

[Kip Thorne]

Well, not yet. So at that point, NSF had given Ray $60,000 to get started. And that's that. That's how much he had in the 1970s from the National Science Foundation. He also had some money from the Air Force Office of Scientific Research. I'm not sure how much he had or he had had that until in the Vietnam era, they stopped supporting science due to something called the Mansfield Amendment. American politics. And that's when NSF picked him up and gave him 60,000. That was a drop in the bucket compared to what was needed. And NSF wasn't about ready to put big money in.

[Neil DeGrasse Tyson]

This required some members of your team to, like, appear in front of Congress to defend this.

[Kip Thorne]

That's correct. But that was much later. The issue was getting started. And so how did we get started? Caltech is a very different kind of an institution than any other I've ever dealt with at Caltech. I was able to say to propose to my colleagues that we get into this field, that we build a experimental program in parallel with Ray Weiss's program at mit. So the chair of the Division of Physics Mathematics and astronomy at Caltech set up a committee to look at it. Committee looked at it for about six months, detailed study, came back and enthusiastic, said, let's go ahead. And so Caltech put private money, about $2 million of its own private money to get started. And that inflates about $12 million today of private money when. When nobody else is putting anything in.

[Neil DeGrasse Tyson]

No, you're right. That's a very different, a very different.

[Kip Thorne]

Culture and Caltech that had happened and we had brought Ron Drever from Scotland to start the experimental effort. Then NSF and NSF stood up and took notice. They did their own study of this and came up with the same conclusion and they started funding us and Ray Weiss and it became a Caltech MIT collaboration.

[Neil DeGrasse Tyson]

Let's fast forward to 2016 where you make the first detection.

[Kip Thorne]

You announce it in 16.

[Neil DeGrasse Tyson]

You announce it in 16. By the way, I would later learn that when I visited the facility in Louisiana, you already had made the detection. And you'd be happy to know that everyone was completely zip mouthed about it until it was officially, because I have this huge Internet following. Right. And people were totally zip mouthed. I swear I didn't know about it until the press release came.

[Kip Thorne]

Yeah, we were all sworn to see for.

[Neil DeGrasse Tyson]

Yes, yes. And so the confirmation of a first detection came from the second facility built in Hanford. And at that point you have a time delay because gravitational waves move at the speed of light. Correct. And Earth is a finite size. And so all that worked out.

[Kip Thorne]

Yeah, yeah. And so it was just 7 milliseconds 71 second time difference because the waves came up from the south, they entered the Earth around the tip of the Antarctic Peninsula, traveled through the Earth, came up through the Earth in Louisiana first and in Washington State second, seven milliseconds later.

[Neil DeGrasse Tyson]

This is.

[Kip Thorne]

And then the waves were unaffected by all the matter of the Earth. They just. And they couldn't see the difference between Earth and no Earth, and they couldn't see the difference between detector and no detector. They were very hard to detect.

[Neil DeGrasse Tyson]

They're doing their thing. So what impresses me greatly is here we have a prediction made by Albert Einstein when in 1916 or 15, whenever Albert Einstein, in a little known fact, I mean, physicists know this, but I don't think the public knows. Einstein laid out the equations for the stimulated emission of radiation, which is the physical foundation of a laser. He wrote that down first. And a laser would take a few decades to actually be built into the 1950s. And I'm just saying, here's Einstein predicting gravitational waves, laying the foundation for a laser. And 100 years later, his gravitational waves are found with lasers.

[Kip Thorne]

Yes.

[Neil DeGrasse Tyson]

So these are crumbs spilling off his plate.

[Kip Thorne]

Einstein was kind of smart and lo.

[Neil DeGrasse Tyson]

And behold, nobody's surprised. The Nobel Prize goes to this project and you, along with Ray Weiss and Barry Barish share the Nobel Prize. What year was that? 2017.

[Kip Thorne]

They apologized to us that they didn't give us in 16 because we didn't announce it until past their deadline for nominations.

[Neil DeGrasse Tyson]

They delay anyway. They're never.

[Kip Thorne]

Yeah, well, no, they. They said it. Obviously it was obvious the prize was going for this. It was just obvious.

[Neil DeGrasse Tyson]

Yeah.

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[Neil DeGrasse Tyson]

You can't be a general relativity Einstein guy without being a black hole guy. So forgive me for asking you to retell a story you've probably told a thousand times. But there's some famous bet you made. Was it with Preskill? With some other physicist.

[Kip Thorne]

Preskill and Hawking.

[Neil DeGrasse Tyson]

And Stephen Hawking, by the way. I was at the University of Texas when preschool was there. I think he was like a Postdoc or something. He was just starting out because that's how old I am. I'm an old guy.

[Kip Thorne]

I'm an old guy. You're a young kid.

[Neil DeGrasse Tyson]

I'm an old man. So you made a bet. And let me see if I can set the table here. A black hole. Once we all agree that they exist, we can ask other questions. When you have something outside the black hole and it falls in, what happens to that information that was contained in that object? Is it gone forever? And is that okay? Because information theory was a whole branch of science, shall I call it science, that was rising up at around the same time, and entropy became a buzzword among many. So what was the bet, and how did it. And how was it ultimately resolved?

[Kip Thorne]

So the bet was between Stephen Hawking and me on one side and John Preskill on the other side, and it was over whether or not information does get lost in black holes. The background of that.

[Neil DeGrasse Tyson]

And why is that so bad?

[Kip Thorne]

Okay, so it's bad because the fundamental laws of quantum mechanics as they are normally formulated, physicists are widely agreed that quantum physics is fundamental and that quantum physics underlies all of physics.

[Neil DeGrasse Tyson]

It's the most successful theory ever put.

[Kip Thorne]

Forth of the universe. And classical physics, where there are not these quantum fluctuations, there are not these probabilities that arises from quantum physics as an approximation under ordinary, everyday circumstances.

[Neil DeGrasse Tyson]

There are many people who caricature science, physics in particular, by saying, well, we used to think classical physics was it, but now we discard it in favor of quantum physics. But that's not true. No. Quantum physics absorbed as well as relativity, general relativity, absorbing Newtonian gravity. It's not discarded. It's a bigger understanding, a deeper understanding. Just want to emphasize that many people get that confused.

[Kip Thorne]

And so quantum physics is normally formulated, is almost universally viewed, has built right into it from the very beginning the fact that information cannot be lost. Now, these words, information cannot be lost are a translation into everyday language of something else, which is not everyday language, which says that the evolution of everything in the universe is unitary. So those are buzzwords that are not part of the normal lexicon. But I want to just to say that, to indicate that there's some very extremely precise version of this, of which information is being lost is a colloquial way of saying it.

[Neil DeGrasse Tyson]

Okay, okay. But it would represent a violation of some fundamental tenets of quantum theory.

[Kip Thorne]

That's right. Stephen Hawking, back when he was visiting.

[Neil DeGrasse Tyson]

Caltech, who, by the way, we've interviewed for StarTalk in our archives.

[Kip Thorne]

Check it out In 1974, 74, 75, he spent a year in my research group at Caltech. We were very close friends. And he. During that period, he having discovered something called Hawking radiation, which is a very slow evaporation of a black hole that emits radiation, slowly evaporates. He then, while he was here, began to look much more deeply at quantum theory in black holes. And he came up with a prediction that information really is lost. And when black holes evaporate, you could form a black hole if you waited long enough, much longer than the age of the universe for normal black holes, the black hole would evaporate, and all the information that went into the black hole would be gone. The black hole would be gone. You just simply lost the information. It no longer is there. And that was complete violation of the normal tenets of quantum mechanics. And yet he was claiming that that was true. He wrote a paper on this with all the technical details. He couldn't get it published because it was so obvious it had to be wrong. But nobody could see anything wrong in his calculation. And so he had to fight for more than a year to get it published. If you look at this paper, you.

[Neil DeGrasse Tyson]

See the submission date as all research papers give you.

[Kip Thorne]

Yeah, they give you a submission date, and then you usually have a revised date, and then it's published. There's no revised date. There's a submission date, and the publication date is, like, nearly a year and a half later because he fought for a whole year, more than a year, to get this thing published. And physicists struggled with this ever since. So those of us whose roots are in relativity tended to believe Hawking. And those of us whose roots were in who grew up with quantum mechanics instead of relativity first, those of us who were enamored of relativity tended to believe Hawking. And so Hawking and I made this bet with Preskill, whose roots were in quantum physics.

[Neil DeGrasse Tyson]

And he's the junior of you both, right?

[Kip Thorne]

He's the junior young whippersnapper coming up. He is now the Richard P. Feymer professor of Theoretical Physics at Caltech. I'm the Richard P. Feyer professor of Theatrical Physics. Emeritus.

[Neil DeGrasse Tyson]

Emeritus. Okay, them young whippersnappers. Oh, man, they'll take your job in a minute.

[Kip Thorne]

So I just turned the chair over to John. I mean, John is brilliant. He's a hell of a lot smarter than I am. A hell of a lot smarter. Anyway, so we made this bet, and this was in a period when Hawking was starting to visit Caltech for typically three to Six weeks every year.

[Neil DeGrasse Tyson]

Was he yet wheelchair bound?

[Kip Thorne]

Oh, yeah, he'd been wheeled. He was wheelchair bound, going way back to about 1970. And this is 1990.

[Neil DeGrasse Tyson]

Oh, whoa.

[Kip Thorne]

We made the bet around 1990.

[Neil DeGrasse Tyson]

So the stage is set. Okay. The cage match is set. You and Stephen Hawking, titans in your field, in your subject, conclude, yeah, information is lost, especially if Hawking radiation, you could evaporate the black hole and everything is gone. There's no memory of what was there. Presquel is declaring that information is not lost. And his roots are deep in quantum physics, which we know has never been shown to be wrong.

[Kip Thorne]

And they're both smarter than I am, and they both know a lot more about quantum physics than I do, because we'll return to this, but let me just explain. Explain that through my whole career, I've thought that the quantum gravity, combining general relativity with quantum physics was the most important area of physics of all. But I also made a decision when I was very young. I will never work in quantum gravity because the field is too crowded. There are too many smart people there. I'm smart enough to pick really important problems that I can solve that nobody else is working on, and they'll only figure out later that I'm right, that those problems are important. But I won't touch a problem wherever.

[Neil DeGrasse Tyson]

You got a million people in the room.

[Kip Thorne]

Just too many smart people.

[Neil DeGrasse Tyson]

Too many smart people in the room.

[Kip Thorne]

So anyway, so they have now agreed that information is not lost.

[Neil DeGrasse Tyson]

So Hawking conceded. And by association with you. Or have you still a holdout on this?

[Kip Thorne]

No, I'm still a holdout.

[Neil DeGrasse Tyson]

Okay. And what led to this concession, if I understand correctly?

[Kip Thorne]

So Stephen, together with a student, was working on an idea for how the information might be recovered. And he basically said that in quantum physics, if you form a black hole and then it evaporates, there's also. It's a tiny probability the black hole never formed in the first place, and the information sneaks out through the root where it didn't form in the first place. And I'm sorry, that sounds like a cop out. Yeah, it does sound like a cop out, but it's very clever and it's in keeping with how physics works. But it's not obvious that it's right, but it's conceivable that this is. This is what about the idea?

[Neil DeGrasse Tyson]

So maybe I've misunderstood. So I got to go back to see where I've said this even publicly. I thought, as the black hole evaporates because the energy, the gravitational energy in the vicinity of a black hole can spontaneously make a pair of particles. And one particle escapes, the other one falls into the black hole. And this just keeps going until there's no black hole left. But the particle that escapes, if you inventory those particles, they're real particles. And don't you recover all the particles that went in in the first place?

[Kip Thorne]

Well, you recover all the energy, but they don't recover the inventory of particles. You don't get the same particles necessarily.

[Neil DeGrasse Tyson]

Okay, then I misunderstood that. I think I've been wrong. I thought you get particle for particle, they come out, which blew my mind.

[Kip Thorne]

I don't think. Certainly there's no proof that that's the case.

[Neil DeGrasse Tyson]

Well, of course.

[Kip Thorne]

Certainly no proof. And I don't think it is the case.

[Neil DeGrasse Tyson]

Okay, so you guys lost the bet?

[Kip Thorne]

Well, no, I.

[Neil DeGrasse Tyson]

Okay, Hawking concedes the bet.

[Kip Thorne]

Hocking concedes the bet.

[Neil DeGrasse Tyson]

And what was at stake for this?

[Kip Thorne]

The loser will give the winner an encyclopedia filled with information that somehow escaped the black hole. And so.

[Neil DeGrasse Tyson]

Information is the penalty gift.

[Kip Thorne]

That's right. So Stephen Hawking conceded the bet at a big international conference on general relativity and gravitation in Dublin, Ireland, in early 2000.

[Neil DeGrasse Tyson]

Were there gasps in the audience?

[Kip Thorne]

There were rumors that he was going to concede. And so there was a big ceremony. I played some role in the ceremony, but I didn't concede myself. And so Stephen gave Preskill, who's a big baseball fan, Encyclopedia of American Baseball.

[Neil DeGrasse Tyson]

Oh, any kind of encyclopedia.

[Kip Thorne]

Yeah. Well, that was his idea.

[Neil DeGrasse Tyson]

That's clever.

[Kip Thorne]

So anyway.

[Neil DeGrasse Tyson]

And less expensive.

[Kip Thorne]

Yeah. I didn't concede for a peculiar reason that there is an alternative formulation of quantum mechanics in which information could be lost. It's due to Feynman. It's called a sum over histories formulation. And as I say, I don't work in quantum theory in any deep sort of way. I do in terms of quantum technology, which we needed for ligo, but that's a separate story. But two of the very deepest physicists working in quantum theory of my lifetime were Murray Gell Mann and Jim Hartle. Jim Hartle at Santa Barbara, Gell Mann at Caltech, and then he moved to the Santa Fe Institute and retirement.

[Neil DeGrasse Tyson]

Gel man is credited with proposing quarks.

[Kip Thorne]

As the fundamental particle of the giants of theoretical physics. When I was a young physicist at Caltech were Gelman and Feynman and two colleagues of mine that I enormously respect. So Gell, Mann and Hartl took Feynman's path interval or some over history's approach to quantum mechanics. And they developed it further in a form that they could apply it to cosmology, to the universe. And then they. Hartel has used that to study quantum cosmology, the quantum mechanical description of how the birth of the universe and how it has evolved. That particular approach to quantum mechanics, Harle took it and he showed how that approach can deal perfectly well with information loss. And it deals with. It rises because of what we call closed time, like curves. There's a certain probability for backward time travel in quantum physics. In this Feynman, Gell, Mann, Hartl approach, there's a certain probability for backward time travel. And if you can have backward time travel at the quantum level, then you lose information. And there's. So there's an elegant mathematical formulation here.

[Neil DeGrasse Tyson]

Quantum physics is so weaselly this way.

[Kip Thorne]

Well, that's. That. That's not the standard version of quantum mechanics, but that was the version that. That. That Feynman and that Hardland Gell man needed in order to do the quantum mechanics of the entire universe and the birth of the universe. So that we're getting into this issue of the birth of the universe and quantum gravity here. And I am rather enamored of this approach, Although I don't do it. I just look on the sidelines and admire these people who are smarter than I am and who have the courage to work in a crowded field. But I'm just so impressed with this and with the fact that within that formulation, you can lose information.

[Neil DeGrasse Tyson]

Is that the start of a formulation that will one day marry general relativity and quantum physics?

[Kip Thorne]

It does do that.

[Neil DeGrasse Tyson]

It's knocking on the door.

[Kip Thorne]

It's knocking on the door.

[Neil DeGrasse Tyson]

Remind me now, you're Professor Thorn in this question. What is the problem with general relativity not melding together with quantum physics? What is the real holdup there?

[Kip Thorne]

Well, the real holdup is that they are logically incompatible with each other. And so something has to give.

[Neil DeGrasse Tyson]

And that's because of the. General relativity requires space to be a continuous.

[Kip Thorne]

You have a continuum space, and it's a very definite space. It's not a space where you have a certain probability that space is warped in this way and another probability is warped in that way.

[Neil DeGrasse Tyson]

In fact, there are no probabilities at all.

[Kip Thorne]

Yeah, there are classical probabilities, but not quantum. Not quantum probabilities.

[Neil DeGrasse Tyson]

And so at the smallest scale, they're incompatible.

[Kip Thorne]

The smallest scale, they're incompatible. In any place where gravity becomes extremely strong, they're incompatible. So the smallest scale, they're incompatible even here in this room. But also they're incompatible in the birth of the universe when gravity was extremely strong. They're incompatible in the core of a black hole, where gravity is extremely strong. They're incompatible if you try to make a time machine. Hockey and I independently, with our students, sort of identified a process whereby if a very advanced civilization tries to make a time machine, it will quite possibly explode at the moment you try to turn it on. And that's also controlled by these laws of quantum gravity.

[Neil DeGrasse Tyson]

So that's why we haven't seen any time travelers yet.

[Kip Thorne]

Well, that may be the.

[Neil DeGrasse Tyson]

It would explain it. They're all dead trying to turn on the machine.

[Kip Thorne]

That's right.

[Neil DeGrasse Tyson]

What you're saying is Einstein puts forth the general theory of relativity, which is so successful in so many realms, and it picked up where Newtonian gravity failed. Yet we must confess or concede that there's a limit to how far general relativity goes, although we've yet to find a limit to quantum physics. So the betting. The betting pool will say general relativity is going to succumb to quantum physics in some way.

[Kip Thorne]

Yeah, that's one way to say it. Certainly there is this incompatibility between the.

[Neil DeGrasse Tyson]

Two, and string theorists are trying to be. They're like performing the shotgun wedding between the two branches of physics somehow.

[Kip Thorne]

Yeah. And I do think, again, looking in from the outside, since I've chosen not to work in this field, that string theory is likely to be a successful route into the correct laws of quantum gravity. Yeah.

[Neil DeGrasse Tyson]

You haven't had it for 50 years.

[Kip Thorne]

Oh, yeah, 40 years. Larry Long, come on. I'm 84 years old. Come on, that's just a drop in the bucket. Come on.

[Neil DeGrasse Tyson]

Wait, but Einstein went from special relativity to general relativity in 10 years. Kepler went from weird nested solids to the Kepler's three laws of motion in 10 years. And that's lone scientists.

[Kip Thorne]

We've been working to try to do controlled fusion for 50 years. More than 50 years. LIGO took 50 years from the time I first started working on gravitational waves until we succeeded. It was 50 years. Some things take a long time.

[Neil DeGrasse Tyson]

Yeah, but LIGO is a machine. The merging of quantum physics and general relativity are ideas. Could it be. And I've said this, I don't want to say this to you because you're Kip Thorne, but I've said this to Brian Green, okay? Because Brian Green is like my generation. I said to Brian Greene, I said, brian, you've been working on string theory for decades. Maybe all of you are just too stupid to figure it out. And we're waiting for someone else to be born into this field to then solve it and went the ways none of the rest of you can. None of them are saying, I'm too stupid to figure this out. Let me choose another profession. No, they're saying, the problem is too hard. And if you go 40 years of really smart people not figuring something out, that tells me either they're barking up the wrong tree or none of them are smart enough. Am I overreacting here?

[Kip Thorne]

I think you have to remember that we do build on each other. None of them by themselves are smart enough. Okay, but the community, again, it's like this Nobel Prize really belongs to a thousand people. It doesn't belong to me.

[Neil DeGrasse Tyson]

With a genesis in Joe Weber.

[Kip Thorne]

With a genesis in Joe Weber, we build. Newton spoke of standing on the shoulders of giants, and that really is true.

[Neil DeGrasse Tyson]

If I can see farther than others, it's because I've stood on the shoulders of giants who have come before me.

[Kip Thorne]

And that's the nature of science. And the struggles that our colleagues have been having with string theory and M theory and quantum gravity, we've learned an enormous amount. It shows it's very promising, but it's going to continue on into the next generation before the ultimate success is had. Very, very probably.

[Neil DeGrasse Tyson]

Those are like, final words right there. Those are like, kip, I've heard rumor that whichever faculty of Caltech gets a Nobel Prize, they get a parking spot with their name on it. Is that true?

[Kip Thorne]

If I. When at Caltech, a Nobel Prize does not get you a parking spot with your name on it. You have to pay for this parking spot just as much as you do without Nobel Prize.

[Neil DeGrasse Tyson]

Okay. That was such a fun rumor, though.

[Kip Thorne]

I heard that that's true at usc, but it's not true at Caltech.

[Neil DeGrasse Tyson]

Okay. Cause there's just too many of you all running around with Nobel Prizes, then the parking spots are too valuable. So true at USC. Okay.

[Kip Thorne]

Just true at USC.

[Neil DeGrasse Tyson]

All right, so you're 84. You have 84 years of wisdom coursing in your veins and arteries. Are there any projects you're working on in the next several years?

[Kip Thorne]

So I made a gradual transition. Conscious away from science, away from scientific research, beginning around 15 years ago.

[Neil DeGrasse Tyson]

Oh.

[Kip Thorne]

I would like to believe I can live to 110. That's my intended goal. And so for the next remaining decades, I wanted to do things that I really enjoyed. And I've enjoyed science. I've been a conventional Caltech professor for half a century. Enormously enjoyed it. Enormously enjoyed working with Students. I trained over 50 PhD students who did far more important research than I did and been there, done that. And I have worked in all these areas of science and I've had enormous fun. But I've turned them over to the younger generation and they're smarter than I am.

[Neil DeGrasse Tyson]

Okay, so what are you. You surfing now or skydiving? Okay, you're taking up other.

[Kip Thorne]

So I decided that I would like to spend a few decades doing creative work at the interface between science and the arts.

[Neil DeGrasse Tyson]

Oh.

[Kip Thorne]

So Interstellar is an example that was.

[Neil DeGrasse Tyson]

Going to be released in September and then they delayed it to the holiday season in December.

[Kip Thorne]

So the re release of Interview, the.

[Neil DeGrasse Tyson]

Re release to December 2024.

[Kip Thorne]

That's right, that's right. That was enormously enjoyable for me. I learned how great it can be to collaborate with somebody as brilliant and is completely different than I am. Christopher Nolan. So my most recent collaboration has been a book of poetry and paintings with Leah Halloran and about the warp side of the universe and my poetry, my attempts at poetry and her paintings, but just trying to see whether it's possible by tightly integrating paintings with verse to convey the essence of issues in science, the spirit, the essential features, without conveying the precise details. No, that's not the right genre for precise details, but anyway. So I've been enjoying that, by the way.

[Neil DeGrasse Tyson]

I've always felt that way about Van Gogh's Starry Night.

[Kip Thorne]

Yes.

[Neil DeGrasse Tyson]

Where you look at that painting, you say this is clearly not what he saw, but it's definitely what he felt.

[Kip Thorne]

Yes, yes.

[Neil DeGrasse Tyson]

And you get to experience the universe through his own lens.

[Kip Thorne]

Yes.

[Neil DeGrasse Tyson]

And so I've always appreciated art when it plays that role.

[Kip Thorne]

I have a second movie that's been in the works for more than a decade.

[Neil DeGrasse Tyson]

Can you tell? Can you?

[Kip Thorne]

Well, it's just something that I started with Stephen Hawking and Linda Opst, who is my partner on starting Interstellar and is wonderful to work with. But that movie might never get made. I'm not going to tell you what it's about, aside from the fact that it's sci fi and it's solid sci fi science built in from the outset. So if that does not work out in the end, then I may turn it into. Try turning it into a novel. I've never tried to write a novel. I don't know whether I can, but it would be fun to try. And actually the thing that I have put almost a large fraction of my effort in, the lion's share of my effort in since the beginning of the Pandemic is a history of the LIGO project, The LIGO Gravitational Wave Project. Because that is, I think, pretty clearly the technically most difficult thing that's ever been done by physicists.

[Neil DeGrasse Tyson]

By anybody. By anybody.

[Kip Thorne]

Yeah, probably by anybody.

[Neil DeGrasse Tyson]

And 1/100th the diameter of a proton. That's anybody.

[Kip Thorne]

And success required both amazing. Developing amazing technology, new technologies required developing computer simulations of colliding black holes required developing quantum precision measurement technology that is now in LIGO and playing a major role where you circumvent the. What's called the Heisenberg Uncertainty Principle.

[Neil DeGrasse Tyson]

My mind is still partly blown by you. Having said that, you are bypassing Heisenberg's uncertainty principle.

[Kip Thorne]

That's right. By manipulating vacuum fluctuations, just like advanced civilizations might do as a routine thing. So we developed this new area of technology for Lyle, but it was also a very political thing. How do you get a billion dollars of taxpayer money for a field that didn't exist when you began?

[Neil DeGrasse Tyson]

And should they bet on you and not someone else?

[Kip Thorne]

That's right.

[Neil DeGrasse Tyson]

Plus, I think you even had naysayers. If I remember correctly. Colleagues would say this is a pipe dream.

[Kip Thorne]

We had political battles in Washington.

[Neil DeGrasse Tyson]

Tell me who the naysayers were. I got people.

[Kip Thorne]

They were some of the leading astronomers.

[Neil DeGrasse Tyson]

I got people taking. You want my people to.

[Kip Thorne]

No, they've come around. And you think, okay, they've come around because this is so exciting now that LIGO succeeded. But the sociology of the transition from small science to big science is a very rocky process.

[Neil DeGrasse Tyson]

And that's the right word, sociology, because that's what it is.

[Kip Thorne]

I don't like working in a big science project. It's not for me. Just like working in a crowded field is not for me. But we had to trend. This had to make the trans.

[Neil DeGrasse Tyson]

It wouldn't have happened otherwise.

[Kip Thorne]

Transformation wouldn't have happened otherwise. And the genius of Barry Barish in making that happen was. And the genius of Rob Evoked in getting us partway there. At the very beginning is our initial director, who was the one that sold it to Congress, and. And it really got us going. It's a very complicated story. And I have a set of five collaborators that I've been working on with this history. We just finished draft six and sent it out to LIHU colleagues to comment on. And I have getting back huge numbers of comments, and it'll take me two more years, I think, to. So anyway, this history, because of the nature of this project, it's a very interesting and complex history that is quite important for the future, for the history.

[Neil DeGrasse Tyson]

Of Science, especially when you consider most people knew nothing of LIGO until they see the headline that it discovered gravitational waves. And why would they have any thought of what challenges preceded that? You know, they just read the result. Oh, scientists discover this. Well, how about the. Like you said, the politics, the sociology, the genesis, the who's standing on whose shoulders, Who. The naysayers, all that has to be overcome.

[Kip Thorne]

The international collaboration, key input from the Soviet Union in the depths of the Cold War. And it's just a fascinating story and enormous fun.

[Neil DeGrasse Tyson]

You know what Arthur C. Clarke said? He said, in space, where there is no air, a flag will not wave. So maybe the universe is not a place where we should be waving flags. Collaboration is what gets you there.

[Kip Thorne]

I like that.

[Neil DeGrasse Tyson]

So, Kip, this has been a delight. Thanks for making time. A lot of fun for StarTalk. I look forward to the release of the re release of Interstellar. We were recording this before that has come out and you already know this, but let me reaffirm that that film just took people on a ride far beyond anything they had imagined. It had kind of an impact on people in the Way 2001 A Space Odyssey did. It was mysterious, it was modern, it was the future, but it was still relevant. But it left you with more questions to ask than questions answered. And you want that? I think.

[Kip Thorne]

Yeah. And that was really the genius of Christopher Nolan, taking some science that he and I had put together, but combining it with a human story. That it was powerful and.

[Neil DeGrasse Tyson]

And with marquee director and marquee actors that made sure it would get noticed.

[Kip Thorne]

And music.

[Neil DeGrasse Tyson]

Yes.

[Kip Thorne]

I went to a concert by Hans Zimmer who was here.

[Neil DeGrasse Tyson]

That was Hans Zimmer?

[Kip Thorne]

Yes. Just I think the night before last. And he let loose. But I didn't know there that he basically said that the Muse, certain pieces of the music in Interstellar were as close to perfection as he has achieved.

[Neil DeGrasse Tyson]

Wow. I'm going to give it another listen because there is no 2001 without its musical track with the Strauss waltzes. The.

[Kip Thorne]

This is very different. I mean it's all Zimmer's original music and it's a remarkable score. Just amazing.

[Neil DeGrasse Tyson]

I look forward to your next 25 years when you live to 110. Maybe we can do a reprise of this conversation. We'll check in on you.

[Kip Thorne]

We'll plan on that.

[Neil DeGrasse Tyson]

See how you been coming along, dude.

[Kip Thorne]

Okay, thanks a lot.

[Neil DeGrasse Tyson]

Thanks.

[Kip Thorne]

Great to see you again.

[Neil DeGrasse Tyson]

Thanks. This has been a special conversation, exclusive one on one between StarTalk and Kip Thorne Nobel laureate even let me touch his medal. First time I've ever touched the Nobel Prize.

[Kip Thorne]

Well, the medal that really belongs to a thousand.

[Neil DeGrasse Tyson]

The medal earned by a huge team, as he humbly declares. And as we enter a new era of science where collaborations are really how this works, especially where you have international collaborations, you have scientists getting along even at times when the leaders of their countries are in conflict. That's just messed up. That's messed up. I'm Neil Degrasse Tyson, your personal astrophysicist for StarTalk. As always, I bid you to keep looking up.

[Kip Thorne]

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