Science Friday - If ‘Interstellar’ Were Made Today, What Would Be Different?

Episode Date: December 23, 2024

For its 10th anniversary, the science advisor for “Interstellar” discusses the film’s impact and how new information about gravitational waves could have changed it.The science fiction film “Interstellar” turns 10 years old this month. For many of us, it was our first encounter with some pretty advanced astrophysics, taking sci-fi concepts like wormholes and time warping, and backing them up with actual science. Now, we’re revisiting the impact that movie’s science had on pop culture, and how astrophysics has advanced in the past decade. If it were made today, what would be different?Ira Flatow sits down with “Interstellar” science advisor Dr. Kip Thorne, a professor of theoretical physics at the California Institute of Technology. Since the film’s release, he has won a Nobel Prize for his contributions to the detection of gravitational waves generated from black holes. They discuss how the film inspired people to pursue scientific careers and how recent astrophysics discoveries, like gravitational waves, could’ve made it into the movie.Transcripts for each segment will be available after the show airs on sciencefriday.com.  Subscribe to this podcast. Plus, to stay updated on all things science, sign up for Science Friday's newsletters.

If the movie Interstellar was made today, what would be different? Christopher Nolan was describing the wonderful things he could have done with gravitational waves if only he had kept them in the movie and then said, well, there's no turning back time. It's Monday, December 23rd, and you're listening to Science Friday. I'm SciFry producer Kathleen Davis. The sci-fi film Interstellar turns 10 years old this month. For a lot of us, it was our first. encounter with some pretty advanced astrophysics, taking sci-fi concepts like wormholes and time-warping

and backing them up with actual science. Now we're revisiting the impact that movie science had on pop culture and how astrophysics has advanced in the past decade. If it was made today, what would be different? Here's Ira Flato with the movie's science advisor, Dr. Kip Thorne. He's also professor of a theoretical physics at Caltech. And since the film's released, least he won a Nobel Prize for his contributions for the detection of gravitational waves generated from black holes. Welcome back to Science Friday. Good to have you. Great to be here, Ira. Thank you for inviting me. Yeah, you were the, as I say, the science advisor for the movie. Remind us how the movie came about because you played a pretty big role in that, too, right? Yes. Well, the movie began when a former

girlfriend of mine, Linda Oakes, called me up and said, would you like to brainstorm with me for a movie? I had helped her and Carl Sagan a little bit with the movie Contact, on which Carlisle that played a role similar to mine on Interstellar in the end. And so I said, yes, of course. I thought, how better to reach a very large audience with the beauties of astrophysics than through a movie like this? And so we brainstormed, and Stephen Spielberg's assistant

came around to visit Linda a few weeks after we started brainstorming and asked her what movies she was thinking of doing and she described the movie we were thinking about and he went back talked to Stephen and Stephen called her up and said can you have a

treatment on my desk by Monday so we drew up a treatment a very short treatment about eight pages long just described the movie, the characters and a little bit of the science in the movie and Stephen called back and said I would like to direct I've never heard of a movie moving that fast.

So they brought on Jonah Nolan, Jonathan Nolan, Christopher Nolan's brother to write the screenplay. And Jonah went through three drafts of the screenplay under the oversight of Steven Spielberg. And in interaction with me, a lot of brainstorming with me about additional science that would be on what Linda Opson and I started with. But then along in that process,

Christopher Nolan, Jonah's brother, said to him, if Spielberg drops out, I might be interested in directing this movie. What Chris knew was that Spielberg carries along more movies in the early creative phase than he could possibly make. And indeed, that was the way it was when he chose to do Lincoln. And so after two and a half years of Chris thinking about it, but working on the Dark Night Rises, Chris came around. and said, yes, I would like to direct it. So Chris took over as director, and the first half of the movie,

Jonah Nolan had almost completely changed the story from what Linda and I began. But the second half of the movie, Chris almost completely changed the story. So the basic outline of going through a wormhole and visiting a black hole, and some of that was all already there in what Linda and I began with. But the human story was completely changed. So this really was the Nolan Brothers movie with the science that Linda and I began with, an additional science that came out of brainstorming between me and the two Nolan brothers. Right, right.

And speaking of the science, the movie, has had a huge impact, not just on the pop culture, but on science as well. Did you hope that it would open up this mind-bending world of astrophysics to the public when you were working on it? Well, that was my hope, yes. That was a large part of my motivation. And I feel so pleased with how effectively it did that. The number of people who have come up to me, having heard my role in this, around the world,

and said, I decided I wanted to be a scientist from going to this movie. It's been a huge number of young people. And it's really been very, very satisfying. That has. That's really interesting. And you were actually involved in some official research that came out of the movie. And that was the visual depiction of the black. hole. You gave the visual effects team your equations for how a black hole should behave. And you and the

team published a paper on that, right? Right. And we actually had to develop a whole new way of doing the visualizations, different from the way that they have normally been done in the past, because black holes so radically distort light when the light goes near the black hole that in order to get high resolution images. It was necessary to use a whole new technique. Instead of propagating light rays past the black hole, we propagated light beams, the finite size past the black hole, overlapping light beams, and that's rather more complicated in a new way to do it. And our technical paper described that and then described some of the things we discovered about gravitational lensing that is the influence of the black hole on the light. That paper is now,

Now, I'm told by far the most downloaded paper in the history of the journal in which we published. No kidding. If you were to, you know, with what we know about black holes in the last 10 years, would that black hole look any different today? Would your equations that you fed into the computer be any different? No, they wouldn't. We made a choice that the black hole is illuminated by a disk of gas that's orbiting around the black hole, but it's a thin disk, rather like Saturn's ring. things. And the images you see are precisely what you would see with an IMAX camera if you were in the vicinity of that disk around the black hole. There has been since then, of course,

a scientific project called the Event Horizon Telescope that takes data from radio telescopes, a number of them scattered across the world, and combines them so that you get images that are as the kind of image you would normally get from a telescope that is as big as the Earth. And with such a big telescope, you can actually, the team that has done this made images of two black holes lighted up by gas that is not in a thin disk as we see it in the moving interstellar, but rather gas that is swirling around in three dimensions around the black holes. One of those black holes that's in a nearby galaxy called M-80s. a giant galaxy and the others at the center of our own Milky Way galaxy, those images are a little

different from what you see in interstellar because the gas is behaving differently, but the similarity is quite striking. You know, when we last talked in 2014, you said there had to be a balance between established science versus speculative science and interstellar. Is there any speculative science in the movie that has been moving closer to established science since then? There was a speculative science in the movie as in the screenplay that Jonah Nolan was working on that has moved into the mainstream of established science. That has to do with gravitational waves. But Christopher Nolan, when he came on board, he said, look, we're not using gravitational waves

very much in this movie, and there's so much other science that I'd like to add to the movie. Maybe we were better just remove the gravitational waves, so he removed them. And so when LIGO, the project I worked on that my colleagues and I got the Nobel Prize for, when it saw gravitational waves and we announced the result, I let Chris know that it was going to be announced. And the day after it was announced, Chris called me up and said, would you come over to my house, let's talk. So I went over and he spent about 90 minutes describing the wonderful things he could have done with gravitational waves if only he had kept them in the movie and then said, well,

there's no turning back time. So he went on to talk about the future movies. Did he say what he would do with them with gravitational waves? Not explicitly. Well, the way the gravitational the waves were in the movie originally was the humans on Earth with Leligo, gravity wave detectors, discover gravitational waves from a neutron star that's being torn apart by a black hole, discover those gravitational waves that have traveled through the wormhole, where the mouth of the wormhole is near Saturn. The wormhole in the movie then Cooper and his crew travel the other direction through to get to a distant galaxy. So the gravitational waves come through the wormhole there, seen, they're observed, and it is quite startling that the source of the gravitational waves is near Saturn.

And that's how they discover the wormhole. So that's the way it was used originally in the movie. And there are a variety of other things could have been done with it. I have forgotten what Chris was saying they could have been done. But the thing that is really interesting to me as a physicist, and what I would have advocated doing with the gravitational waves is interstellars, when two black holes collide, they actually create a storm in the fabric,

in the shape of space, and the storm of the rate of flow of time. So the rate of flow of time near the black hole oscillates, speeds up and slows down in a crashing sort of a way like crashing waves in an ocean storm. The shape of space slushes like crashing waves in an ocean storm. And it's just fantastic how wildly spacetime behaved during that collision. And I would have loved to have seen that and seen how the visual effects team dealt with that in Interstellar. After the break, why astronomers are excited to learn more. about the black hole at the center of our galaxy.

Stay with us. Hi, Ira here, reminding you that Science Friday has a dollar-for-dollar donation match, which means that any donation made through December 31st will be doubled. So now is the time to head over to ScienceFriday.com slash support and make a gift. Our 2025 programming depends on the generosity of our fans and listeners. Again, that's ScienceFriday.com slash support. and thanks. Let's talk about what's happening now with astrophysics research. What has your attention right now been? Now with the new black hole science, where's the interesting area here?

Well, the remarkable thing is that now gravitational waves have now been seen by LIGO from about approximately 300 collisions of black holes. The gravity wave detectors have become more and more sophisticated and more and more sensitive, thanks to, in part, to introducing what is called quantum precision measurement. It's a cousin, basically, of quantum computing and quantum cryptography. Anyway, so the key thing then is that with this new technology,

we've taken off and are seeing so many more black hole collisions than we could see before. In addition, gravitational waves have been discovered by a whole different technique. They've been discovered by radio astronomers who are looking at radio waves from pulsars. Pulsars are sort of like clocks and they have a ticking

that is associated with a spin of a neutron star. And if gravity waves passes across the earth, it may speed up or slow down those signals by influencing the radio signals as they're passing over the Earth, influencing basically the rate of flow of time of the clocks we use on Earth. So it's sort of like radio astronomy and optical astronomy. So it's really quite marvelous that we now have two different frequency bands for observing gravitational waves.

You know, we talk about black holes so far away. And what about the black hole in the center of our Milky Way? Have we lost interest in that? Or is there still interest in it? Oh, that's a very interesting black hole. What I want there is to see a movie of the flow of gas around that black hole. Because the process by which the black hole interacts with the gas around it, we think involves magnetic fields that thread through the black hole.

And as the black hole spins, it whirls the magnetic fields around. as they whirl around, they generate electric fields that accelerate particles to very high speeds. And I would like to be able to observe a movie of this flow of gas around the black hole. And through that movie, begin to observe this fantastic process. And in fact, the Event Horizon Telescope team is in the process of trying to make those kinds of movies. and I expect we're only a few years away from having them. This is Science Friday from WNYC Studios. You've said movie at least three times in this last sentence.

Have you been bitten by the movie bug? I mean, you've been a science advisor for Carl Sagan's contact and other Christopher Nolan films. Are you going to keep doing that kind of work? I mean, any projects you're excited about? Well, I had another Hollywood movie that I was working. that was conceived by Linda Oakes, my dear Hollywood friend, Stephen Hawking and me, the three of us together. About 15 years ago, we conceived it. It has never gotten fully off the ground.

And it's tragically, Linda died a few weeks ago. There's a huge loss in Hollywood, her death. And I suspect that movie may never in the end get made. If it doesn't get made, if it doesn't get made, maybe I'll try turning it into a novel. It may still take off, but on the other hand, you know, I'm in my mid-80s. I would, I am enjoying doing different kinds of things, such as the movies, but I've not ever tried to write a novel yet. And so, yeah, so that, that would be what I may do with this. Tell me how the fame from these movies has affected your career, besides thinking about being a novelist now? Well, it means that I get several requests to lecture somewhere or online a day,

and I say no to almost all of them. And that's how it's affected my life. I'm very self-protective. I love the creative process. It just published with a wonderful painter, via Hallor, about a year ago, a book of her paintings and my poet. And so I'm just having great fun being creative in ways that I never imagined I'd be creative.

I realize that the whole purpose of the Nobel Prize, from the point of view, the Nobel Committee, is to create icons who can promote science. And so I have, as an icon, I feel uncomfortable as an icon, but I have sort of come to terms with it. I feel some obligation to help promote science. but only to the extent that it doesn't get seriously in the way of continuing to do creative work, but of new types. Do you think science needs a little more promotion now that it seems to be under attack in many fields? Yes, this is a particularly scary time, I think,

when we see a man being pushed to become the Secretary of Health and Human Services who promotes the idea that vaccines are dangerous, when the science says that's simply not true, it's really a scary time for the human race and for the dangers that can come as a result of not paying attention to science. So, yes, I worry a lot about that in this era. Well, I'm glad you're not worrying too much to talk with us

and to be optimistic about the future. it sounds like you still are. I am. I am. Yeah. Dr. Thorne, thank you for your work, for your career, and everything you've given us. And we hope to have you back on the show not quite 10 years from now again. Okay. Well, thank you. And try to remember to call me Kip. Okay, Kip. Thank you, Ira.

You're welcome. Dr. Kip Thorne, professor of theoretical physics at Caltech. That's it for today's episode. Tomorrow, NASA's Parker Solar Probe is getting closer to the sun than any other human-made object. Join us tomorrow for the how and the why. Lots of folks help make the show happen, including... Dee Petersman. Sandy Roberts. Beth Ramey. John Dan Kosky. I'm Cyfry producer Kathleen Davis. Thanks for listening.