The Science of Interstellar with Christopher Nolan: The Science of Interstellar with Christopher Nolan

Transcript DOWNLOAD SRT Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now. I’m your host, Neil deGrasse Tyson, an astrophysicist at the American Museum of Natural History’s Hayden Planetarium. And I’ve got with me my co-host, Eugene Mirman. Eugene, thanks for being here. Hello, it’s great to be here. Eugene, professional comedian and your voice on Bob’s Burgers. Yeah. Yeah. Yeah, you get around. I do. I do. I do at least two things, maybe more. So thanks for doing this. We’re like on TV now. I know. Very exciting. He fixed up. Normally, we do this on the radio and he’s on shaving, he’s a little sloppy. Yeah. I’ve never seen the guy this neat. I have a claw for a hand, but look, science. Today, you know what our topic is? Science fiction. Science fiction movies. You got any favorite movies? I do have. I love, well, one, I love science fiction, but I’d say a lot of superhero movies, Star Trek. Superhero? You want to be a superhero? I don’t know that I want to. I don’t want the responsibility. No. It is a big responsibility to be a superhero. If you believe even half, even if they have to do basically a quarter of the stuff they have to do in the movies, it’s exhausting. You said Star Trek too? Star Trek. Yeah. I love time travel. Because there are ways to do time travel that are astrophysically legitimate. Yes. Those are my favorite. Sometimes I’ll watch a time travel thing and be like pretty realistic. Tonight we’re featuring my interview with Christopher Nolan. Christopher Nolan. He came through town and I snared him, put him in my office and I milked him for 40 minutes of, well, you’re not going to see all 40 minutes here. Did you ever have him take it like a top and spin it? To find out which reality we’re in. Yeah. You watched all his movies, right? I have seen a bunch of his movies. It was Inception, right? To know whether you’re—Whether you’re dreaming or in the fifth world, I don’t know. Of course, we talked about how he thinks about time and space, and that would have been enough just to talk about Inception, but his most recent movie is—Interstellar. Interstellar, where it’s more of not only time and space, it’s especially relativity. Now, I know some relativity. Yeah. But I don’t know it—How much in comparison—I do some relativity. I can do that. However, I don’t count myself as an expert in relativity. I have to reach out into the ether to find such people, and we did just that with my special guest, Janna Levin. Janna, welcome to StarTalk. Janna Levin is professor of physics and astronomy at Barnard College, and Janna, you’d like all grown up because when I first met you, you were an undergraduate at Columbia. I was just telling somebody I didn’t think you remembered that. Oh, yeah. What you’re majoring in. You’re a professor, wrote books, and expert on relativity and cosmology. I looked up to you, Neil. You were writing your Ph.D. thesis at the time. Notice that was in past tense. I looked up to you back then. I still do. You’re a full-fledged cosmologist, and people pay you to do this. Yeah. I get paid to do relativity. To do relativity. You think about black holes and the birth of the universe. Yep. You were the right person to think about and talk about. Well, we’ll see how it goes. We’ll see. Janna, you have stars on your… I do. You know, I knew you were going to wear a thematic tie. I just knew you were, so I thought I would match the sort of… This is a black hole. I know no one…very… And it is spherical. With a horizon. With a… And I didn’t know where our conversation would go tonight, but I have every possible cosmic object of this tie, including a wormhole and black holes and galaxies. And this is the best tie to wear if you’re eating lasagna, because if something just falls on it, it’s just another nebula. Know from it. What we want to really talk about is the science of the film Interstellar. You’ve seen Interstellar. I did. Absolutely. And it’s quite an orgy of relativity. Yeah, would you say when Matthew McConaughey cries, would you be like, is that physically realistic? Is that physically plausible? Within the realm of physics, is that? Yeah, that was the part that I was not examining scientifically. So, what I did was, when I started talking to Christopher Nolan, he’s not himself a scientist, he’s a movie director and producer, but I always like knowing if there’s some influence, some teacher, somebody who sensitized you to this whole world of science. Let’s find out. I think a lot of my interest in physics is from when I was about 10, and I was really watching the original Cosmos. That was a huge impact on me. Oh, you’re so young. Oh my gosh. That was post-Star Wars, that late 70s, when the shuttle was about to go up for the first time. So it was in the air. It was absolutely everywhere. The original Cosmos was 1980 with Carl Sagan. And I remember watching that avidly. So you were feeling it. Oh yeah, feeling it in a big way. And I think, I mean, it’s a testament to the kinds of things that you’re doing and so many people are doing educationally. But I think really that 10, 11 year old, you get really fascinated by it. But what I found in school was I reached a point where the mathematics became a burden and I wasn’t as interested in mathematics as I was in English and writing and that kind of thing. And so it’s where physics starts to depend more on the math. I sort of lost at that point. That’s a fair point. I mean, there’s a lot of good physics that you can follow just because it’s really cool to think about. Exactly. Right. And after that, you’re kind of done, right? Go on with the rest of your life. But at least it was in there, percolating. Yeah, very much. I remember all those great experiments on Newton’s laws, you do with a little rolling little lead balls down the slides and things. Back when they made things out of lead. Before we knew they would make us stupid and kill us all. Christopher Nolan, so he studied English literature in college. And so one of my big things is to get more artists interested in science so that they can fold the science into their art and take us to new places. And you wrote a novel. Oh yeah. That you are a professor, a cosmologist, not to be confused with cosmetologist, just to be clear. But you wrote a novel, but that’s some artistic expression. I think that this idea that we have to choose at some stage in our lives is kind of silly. We go through this process where suddenly we have to decide we’re going to be one thing or the other, when actually most of us are really a combination of those things, right? Christopher Nolan is right. It’s the equations that really make science so dreary. Oh, no. The math is so beautiful. I do understand. It’s not saying it’s not beautiful. It just is pretty. It’s such a way in, and it’s such an exciting part of it. I love doing the mathematics, and I think that is exactly the fork in the road. You get to that fork in the road where you’re mesmerized by the universe. You discover the math. You either hate it or you love it. You get to the fork in the road and you pick it up. You pick up the fork? It’s like the old Yogi Berra. Sounds very meta. The mathematics, for you, apparently not for Eugene, is… Let’s just say not for artists. Let’s not single me out. One doesn’t need to be completely mathematically fluent to nonetheless bask in the majesty of the cosmos. I love logarithms. I’m not an idiot. You love logarithms to the base E. I love them to base 4, base 7 and 12. Boom! I might be saying a thing that’s right. But what the equations do, if you want to take that one step deeper, it’s like you part the curtains, this veil of the beauty of the universe, and there is the machinery operating. There is the language. Yeah, no, I get it. We wouldn’t have like stoves and electricity and fridges and stuff and cars. I’m very happy with science. But the math is actually a pleasure to do the math, and at some level, you know, there’s this confidence because one thing follows the other. You say following the chalk, and then you have this confidence when you’re at the end of the line. Following the what? The chalk. You know, you’re at the chalkboard and you follow the chalk. I still have one. You still have a chalkboard. Actually, I have one, too. I saved one from a demolition. Yeah, yeah, they’re historical relics. You know, with Christopher Nolan, he opened a new portal to moviemaking and storytelling. That scientists are people, too. Scientists are people, too. I mean, think about any sci-fi movie from the 50s. Who is the scientist? Is the crazy person behind in the lab coat, wiry hair? You don’t care if they’re in love. You don’t care if they have kids. It’s only in the 70s when scientists started to have feelings. And almost always, the scientist is like co-opted by a bad person or the scientists themselves are evil and want to take over the world or destroy the world. And scientists save the day. Not politicians, it’s not leaders, it’s just people who get the job done and who know their math and physics. And so, that was… And of course, you know, in the plot line, they visit an exoplanet. And we recently had the announcement of a whole boatload of exoplanets discovered by the Kepler Telescope. By the way, that was not an accidental discovery of the telescope. It was conceived, designed, and built to discover Earth-like planets around Sun-like stars. So the fact that this catalog exists with such richness of what could be twins to Earth is not itself a surprise. But the fact that so many planets do exist, I’m ready. Give me the list, you know? And the day we can travel through space, we know the order of planets that we might… Do we have an order now of planets we’d go to? Well, there are planets, that’s a great question. So, there are planets that you can say, well, okay, it’s about Earth sized. We’ll put a check in that box. Is there an atmosphere? We don’t fully know that just yet. But if it does, that would be a good thing. Can you breathe the atmosphere? Is the planet the right distance from its host star? So, Janna, do you have a way to get to one? No, we really don’t have a very good theoretical way. I mean, we know that even if you travel at the speed of light, the nearest exoplanets are a certain number of light years away. So, even traveling at the speed of light, you’re going pretty slowly. Well, I think, no, actually, I think really quite close to us. Maybe within a few hundred light years, we should be having a healthy number of exoplanets. Yeah, so if you draw a couple hundred year radius sphere, it would still be like a hundred years. Well, only if you’re going actually at the speed of light. And by comparison, Voyager, which has gone the furthest of any human-made objects, just breaking out of the Earth’s solar influence, it’ll be 10,000 years before it comes across another star system, because we’re not going anywhere near the speed of light. Right. In fact, when Voyager did its tour of the major planets, we discovered that the moons of those planets were more interesting than the planets themselves. The moon Io and Europa and all of these moons, they have volcanoes and some of them have atmospheres and lakes of methane. And so you’re right, we’re no longer restricted to planets. Excellent. So the net that we cast in the search for life as we know it has gotten larger. Yeah, they should have just gone to Jupiter’s moons. It would have been a shorter trip. Jupiter’s moons. All the way. Right, Jupiter’s got it all. Through a wormhole. If you got to live anywhere. Holding aside the radiation fields that would cook your gonads, it’s otherwise a really good place to start civilization. Jupiter has a very strong magnetic field and it traps dangerous particles. That’s why the movie, we didn’t go to Jupiter. Well, actually, I don’t know if you remember from your chemistry class. In your chemistry class, remember that mysterious chart of boxes in the front of the room? Yeah, the periodic table of elements. In there, did you remember that hydrogen appeared on the left and on the right? Did anybody remember that? It’s in two places. The left-hand side are metals and the right-hand side are non-metals. Hydrogen, depending on the conditions under which you find it, can behave as though it’s a metal as well as a gas. And hydrogen behaves as a metal in the core of the planet Jupiter, where it’s under so much pressure that the configuration of the atoms is such that it can move electrons around just the way a metal does, and it can conduct electricity. And if you can conduct electricity, you can create a dynamo. If you can create a dynamo, you can create an awesome magnetic field. What’s a dynamo? Dynamo, would you want to take this? No, no, please, I’m digging your explanation. So if you can, if you, in a rotating system, you can send up, you can create electrical currents inside wherever you conduct electricity. And wherever you have moving charges, you can create an electric field, and with the electric field you have an attendant magnetic field. And so you can drive magnetic forces with this. But if they didn’t have anything magnetic inside, you wouldn’t have a, you wouldn’t have poles, you wouldn’t have a magnetic field. In the center of the Earth, one of the bits of strong evidence, we had something metallic in the center was that we, Earth has a magnetic field. Yeah, exactly. But it’s a weak one. So there are things like, there are things like neutron stars, which have magnetic fields a trillion times the magnetic field of the Earth. A trillion times. A trillion or more or a thousand trillion times the magnetic field of the Earth. So it would be yanking nails out of your shoes and things. Oh, yeah. Yeah, you don’t want to go near them. But they can make you… You don’t want to go near… It’s a magnet. A neutron star is a dead star, a collapsed star. And because it would be too magnetic, that would be the main risk. And then it would be burning right away. Yeah. And yeah, you’d basically be liquefied on the surface because the gravity is so strong. Yeah, yeah. So ignoring the fact that the gravity is so strong, it would liquefy you. Right. It’s a really bad magnetic field, so you couldn’t… And it’s hot. It’s very hot. Yeah. Yeah, it depends on how old it is. They’re not hot like stars. But they’re hotter than a microwave. Well, yeah, that’s a weird comparison, I suppose. Wait, wait, Eugene, microwave ovens never get hot. It’s only the food. What kind of microwave ovens do you have? The worst example. Yes, it was. Convection ovens? No, but what they do beautifully is they act like a lighthouse because of that big magnetic field, so that you can see these neutron stars at great distances. As they rotate. It’s literally a lighthouse. It’s like a beacon, and there are these incredible plots. But in space, a lighthouse in space. In space, in our galaxy we see them. In fact, they’re key neutron stars in the galaxy, where you can uniquely triangulate on the solar system from where those spinning neutron stars are. We call them pulsars. When StarTalk returns, we’ll learn about matter and energy, which Relativity says distorts the fabric of space and time. It’s a fundamental element in the film Interstellar. Not only in where they go in the universe, but where he goes with his plot lines. When we come back to StarTalk! Right here in the Rose Center for Earth and Space, the hall of the universe. So many names for one giant room. Well, if it’s the center of the universe, you got to reference it somehow, I’m just saying. I’ve got Eugene Mirman, my co-host, Professor Janna Levin. Welcome to StarTalk. You are a cosmologist. This is your expertise. For today’s show, we’re talking about relativity, the universe, cosmology, everything that you are an expert in. On a daily basis. I just dabble in relativity. It is what you do. It is. It is. Well, we’re featuring my interview with Chris Nolan. And of course, we talked about just his, how he thinks about time and space. And I just wanted to know from him what’s going on in his head that leads him to creating such twisted realities. Let’s find out. I’m interested in, I call it sort of geometry or topology. You know, it’s those kind of things. Not the mathematics of it. That’s lost on me. But just the idea of, well, filmmaking itself, it’s this weird combination of two-dimensional images representing three dimensions. And then you add time and editing and camera blocking and structure the way all the things work. They just get you thinking about dimensions, really. Really, it’s about, I suppose, shapes and patterns and things. And that’s where the architecture of movies and movie craft is interestingly structured. And so as I started to make films, I got more and more interested in addressing that in the narrative itself. And it just pushes you to think of these things. If you put it in the narrative, it means it’s a deeper part of the story. Yeah. Rather than just some flashy razzmatazz. Yeah. And you start to think about what it means to you. You know, like why something, why you want to displace a chronology, why you want to tell a story with a beginning and middle and end, but not in that order, you know, that kind of thing. And it got me thinking about how we tell stories in real life. We don’t get it beginning, middle and end. You know, we read a newspaper, it gives us the headline version, you know, Man Bites Dog. Then it starts to fill in all the details. And then you get another version of the story the next day, and you get more details and everything. And I thought, you know, why make films that just give you the beginning, the middle and end in a linear form when that’s not really the way we experience life in a funny sort of way. And it’s way more intriguing that way. I think so. Now I have to think more deeply. I have to pay closer attention. Yeah, so he’s messing with time. Janna, what is time? Simple. Yeah, it is actually one of the most elusive aspects of physics. There’s this idea of life, psychologically. But even physically, we know that there is this sort of clock. The clock never stops. We never turn around and go back. We can never accidentally go the wrong direction in time. It’s always pushing us forward. And yet, we sort of imagine it almost spatially. We almost imagine it like a dimension. But I can’t look forward in that dimension the way I can look left. And I can’t turn around and look back in that dimension the way I can look right. And so that aspect of why time is different from a dimension remains sort of persistently confusing. So then, now we start twisting time. And no one thought to do that until Einstein, I guess, because is that a fair characterization? I mean, people may have imagined it culturally, but it wasn’t actually on the table as a viable possibility until Einstein. And it is a viable possibility. We know that my clock can run differently from your clock. And that there can be a difference between not only our psychological perception of time, but our biological perception of time. But our clocks are not going to run differently if we’re in the same place at the same time. No, they’re not. What if you’re in two different places? Then you have to ask what’s different about those two places. If I’m higher up in a building, if I’m in the space station, if I’m near a black hole, my clock will run differently than yours. The further away I am from the Earth, the faster my clock will appear to run relative to yours. So if I go to a black hole and have a sandwich and then come right back, how long will it have seemed? Civilization has come and gone. So if you fold relativity into a storytelling narrative, now time can be legitimately altered and warped for the purposes of your plot lines. So is Interstellar realistic, but Star Trek IV The Voyage Home a little unrealistic? Well, I honestly don’t remember The Voyage Home, but I can tell you. How could you not remember The Voyage Home? And they saved the whales, right? And humanity. It might be the one I never saw. I think I didn’t like that they came back to the present. It wasn’t the most exciting one in the canon, you know? Yeah, they did come back to the present. They traveled backwards in time. But the thing about going near a black hole, yes, you can absolutely go incredibly close to a black hole. I think I once asked how close they had to be in Interstellar. It was something like a millionth the size of the event horizon of the shadow. Like you had to be just really on top of it. What you’re saying is in the film, they go near a black hole, close enough to a black hole that the strength of gravity is so high that time goes so slowly that, what is it, one hour at this black hole planet, it’s like 20 years. It would be, that is the actual math of it. Yeah, you can calculate how close you’d have to get for that to happen. Now, the thing is that their experience of time is completely normal. Any time difference you want to write a story around, you can calculate what’s the strength of gravity that would give you that time difference. Yeah, so there you go. Their experience of time is completely normal. They have this very rushed hours to try to get back out away from the black hole, and many years have passed relative to the Earth. In fact, in the film, Anne Hathaway’s character said the most perceptive thing about it, that when there’s this difference in the rate of your clock ticking, time itself becomes a commodity. Yeah, exactly. It’s like a natural resource. A natural resource. You go down to the black hole, your time is ticking so slowly, you’re at risk of when you come back, that your kids are now dying in their deathbed. The things you care about that are motivating you to go near the black hole in the first place, because I don’t know why you would really want to do that. Right. All of that is gone. And that is actually a really powerful moment in the film. But what might not be as realistic is the question of whether or not they would have enough fuel to execute these things. This becomes very expensive to escape from a black hole. If I’m in a bookcase, is that realistic? Ask Neil. Neil, can you live behind a bookcase if you’re an astronaut? So, but it’s one thing to have time ticket different rates. It’s another thing to be able to visit your past. Yeah, that’s—Or to see your timeline writ large in front of you. Yeah. That’s taken yet an extra step here. It is an extra step. A lot of people think that somehow the physical laws will protect us from that, that there will be some barrier to being able to do that. In other words, you’re saying some people think there’s a yet to be discovered physical law that will declare in our revelation of this law that thou shalt not go back in time and prevent your parents from meeting. If your parents don’t meet, then you’re not born, then you can’t have gone back in time to prevent them from meeting. So, it’s actually technically possible in the context of relativity to do this. Like, there are mathematical proofs that if Einstein’s theory of relativity is the whole story, then there are certain situations in which you can absolutely go back in time, and this is really problematic, but you’re presuming that you have the will to go and stop your parents from meeting, and maybe you can’t do things like have will and volition that’s inconsistent with the laws of physics. Or maybe you can’t do that. It may be that you don’t purposefully stop them from meeting, and you do something else that changes all the history of the future of the world. You’re literally describing back to the future. But I understand we can pretend you’re not. But given that, you can get very interesting plot lines, such as what was in The Terminator, Terminator 1, 2 and 3, and all of these time travel movies. Well, coming up, we’ll learn about one of the most twisted plot lines imaginable. Traveling through a wormhole on StarTalk. We’re back, StarTalk, in the heart of New York City, the American Museum of Natural History. I’m your host, Neil deGrasse Tyson, of course. Janna, Professor Janna. Yeah, thanks. We’re talking about Interstellar, the film. And one of the most important plot elements, scientific elements, storytelling elements, is the existence of and their journey through a wormhole. And in fact, we’ve got an image of a wormhole. Let’s check it out right here. Oh, yeah. The wormhole is a portal through space and time, where in this particular case, we’re actually seeing what’s on the other side of the wormhole come through us, through the hole, through the channel optically. And that hole leads to another place. So we both know one of the advisors, one of the science advisors, the lead science advisor of the film, Interstellar, Kip Thorne. Kip Thorne, the wonderful, amazing, fascinating Kip Thorne. Yeah, he’s brilliant and a good- I like this Kip person already. So you should have said, wait, I found an error in one of his papers. That was your cue for that. I’ll find it. I’ll look through his notes. That’s where they hide the money. Christopher Nolan, so he studied English literature in college. And so one of my big things is to get more artists interested in science so that they can fold the science into their art and take us to new places. And you wrote a novel. Oh yeah. That you are a professor, a cosmologist, not to be confused with cosmetologist, just to be clear. But you wrote a novel, but that’s some artistic expression. I think that this idea that we have to choose at some stage in our lives is kind of silly. We go through this process where suddenly we have to decide we’re going to be one thing or the other, when actually most of us are really a combination of those things, right? Christopher Nolan is right. It’s the equations that really make science so dreary. Oh, no. The math is so beautiful. I do understand. It’s not saying it’s not beautiful. It just is pretty. It’s such a way in, and it’s such an exciting part of it. I love doing the mathematics, and I think that is exactly the fork in the road. You get to that fork in the road where you’re mesmerized by the universe. You discover the math. You either hate it or you love it. You get to the fork in the road and you pick it up. You pick up the fork? It’s like the old Yogi Berra. Sounds very meta. The mathematics, for you, apparently not for Eugene, is… Let’s just say not for artists. Let’s not single me out. One doesn’t need to be completely mathematically fluent to nonetheless bask in the majesty of the cosmos. I love logarithms. I’m not an idiot. You love logarithms to the base E. I love them to base 4, base 7 and 12. Boom! I might be saying a thing that’s right. But what the equations do, if you want to take that one step deeper, it’s like you part the curtains, this veil of the beauty of the universe, and there is the machinery operating. There is the language. Yeah, no, I get it. We wouldn’t have like stoves and electricity and fridges and stuff and cars. I’m very happy with science. But the math is actually a pleasure to do the math, and at some level, you know, there’s this confidence because one thing follows the other. You say following the chalk, and then you have this confidence when you’re at the end of the line. Following the what? The chalk. You know, you’re at the chalkboard and you follow the chalk. I still have one. You still have a chalkboard. Actually, I have one, too. I saved one from a demolition. Yeah, yeah, they’re historical relics. You know, with Christopher Nolan, he opened a new portal to moviemaking and storytelling. That scientists are people, too. Scientists are people, too. I mean, think about any sci-fi movie from the 50s. Who is the scientist? Is the crazy person behind in the lab coat, wiry hair? You don’t care if they’re in love. You don’t care if they have kids. It’s only in the 70s when scientists started to have feelings. And almost always, the scientist is like co-opted by a bad person or the scientists themselves are evil and want to take over the world or destroy the world. And scientists save the day. Not politicians, it’s not leaders, it’s just people who get the job done and who know their math and physics. And so, that was… And of course, you know, in the plot line, they visit an exoplanet. And we recently had the announcement of a whole boatload of exoplanets discovered by the Kepler Telescope. By the way, that was not an accidental discovery of the telescope. It was conceived, designed, and built to discover Earth-like planets around Sun-like stars. So the fact that this catalog exists with such richness of what could be twins to Earth is not itself a surprise. But the fact that so many planets do exist, I’m ready. Give me the list, you know? And the day we can travel through space, we know the order of planets that we might… Do we have an order now of planets we’d go to? Well, there are planets, that’s a great question. So, there are planets that you can say, well, okay, it’s about Earth sized. We’ll put a check in that box. Is there an atmosphere? We don’t fully know that just yet. But if it does, that would be a good thing. Can you breathe the atmosphere? Is the planet the right distance from its host star? So, Janna, do you have a way to get to one? No, we really don’t have a very good theoretical way. I mean, we know that even if you travel at the speed of light, the nearest exoplanets are a certain number of light years away. So, even traveling at the speed of light, you’re going pretty slowly. Well, I think, no, actually, I think really quite close to us. Maybe within a few hundred light years, we should be having a healthy number of exoplanets. Yeah, so if you draw a couple hundred year radius sphere, it would still be like a hundred years. Well, only if you’re going actually at the speed of light. And by comparison, Voyager, which has gone the furthest of any human-made objects, just breaking out of the Earth’s solar influence, it’ll be 10,000 years before it comes across another star system, because we’re not going anywhere near the speed of light. Right. In fact, when Voyager did its tour of the major planets, we discovered that the moons of those planets were more interesting than the planets themselves. The moon Io and Europa and all of these moons, they have volcanoes and some of them have atmospheres and lakes of methane. And so you’re right, we’re no longer restricted to planets. Excellent. So the net that we cast in the search for life as we know it has gotten larger. Yeah, they should have just gone to Jupiter’s moons. It would have been a shorter trip. Jupiter’s moons. All the way. Right, Jupiter’s got it all. Through a wormhole. If you got to live anywhere. Holding aside the radiation fields that would cook your gonads, it’s otherwise a really good place to start civilization. Jupiter has a very strong magnetic field and it traps dangerous particles. That’s why the movie, we didn’t go to Jupiter. Well, actually, I don’t know if you remember from your chemistry class. In your chemistry class, remember that mysterious chart of boxes in the front of the room? Yeah, the periodic table of elements. In there, did you remember that hydrogen appeared on the left and on the right? Did anybody remember that? It’s in two places. The left-hand side are metals and the right-hand side are non-metals. Hydrogen, depending on the conditions under which you find it, can behave as though it’s a metal as well as a gas. And hydrogen behaves as a metal in the core of the planet Jupiter, where it’s under so much pressure that the configuration of the atoms is such that it can move electrons around just the way a metal does, and it can conduct electricity. And if you can conduct electricity, you can create a dynamo. If you can create a dynamo, you can create an awesome magnetic field. What’s a dynamo? Dynamo, would you want to take this? No, no, please, I’m digging your explanation. So if you can, if you, in a rotating system, you can send up, you can create electrical currents inside wherever you conduct electricity. And wherever you have moving charges, you can create an electric field, and with the electric field you have an attendant magnetic field. And so you can drive magnetic forces with this. But if they didn’t have anything magnetic inside, you wouldn’t have a, you wouldn’t have poles, you wouldn’t have a magnetic field. In the center of the Earth, one of the bits of strong evidence, we had something metallic in the center was that we, Earth has a magnetic field. Yeah, exactly. But it’s a weak one. So there are things like, there are things like neutron stars, which have magnetic fields a trillion times the magnetic field of the Earth. A trillion times. A trillion or more or a thousand trillion times the magnetic field of the Earth. So it would be yanking nails out of your shoes and things. Oh, yeah. Yeah, you don’t want to go near them. But they can make you… You don’t want to go near… It’s a magnet. A neutron star is a dead star, a collapsed star. And because it would be too magnetic, that would be the main risk. And then it would be burning right away. Yeah. And yeah, you’d basically be liquefied on the surface because the gravity is so strong. Yeah, yeah. So ignoring the fact that the gravity is so strong, it would liquefy you. Right. It’s a really bad magnetic field, so you couldn’t… And it’s hot. It’s very hot. Yeah. Yeah, it depends on how old it is. They’re not hot like stars. But they’re hotter than a microwave. Well, yeah, that’s a weird comparison, I suppose. Wait, wait, Eugene, microwave ovens never get hot. It’s only the food. What kind of microwave ovens do you have? The worst example. Yes, it was. Convection ovens? No, but what they do beautifully is they act like a lighthouse because of that big magnetic field, so that you can see these neutron stars at great distances. As they rotate. It’s literally a lighthouse. It’s like a beacon, and there are these incredible plots. But in space, a lighthouse in space. In space, in our galaxy we see them. In fact, they’re key neutron stars in the galaxy, where you can uniquely triangulate on the solar system from where those spinning neutron stars are. We call them pulsars. When StarTalk returns, we’ll find out why Bill Nye, The Science Guy, is pretty sure that saving the world interstellar style is not in our future. On StarTalk. This is Star Talk. StarTalk is back. We’re talking about the movie Interstellar, featuring my interview with Christopher Nolan in my office at the Hayden Planetarium. And in that film, there’s a blight on Earth, we’re all gonna die, we need to find another planet, we find another planet, travel through a wormhole to get there. My good friend Bill Nye assesses this scenario in his Bill Nye rant. Space exploration brings out the best in us. You don’t believe me? How often have you heard somebody say, if they can put a man on the moon, why can’t they blank? And that blank can be filled with anything, like cell phone calls that don’t get dropped or better instant mashed potatoes. It all comes from the technology of space. So a movie that’s about space has got a lot of potential. But this idea that you can just ruin the place you live and go live somewhere else is unique to our time. I don’t think you’re going to really be able to do that when it comes to the Earth. This is where we make our stand. The Earth is only this big. We’re all stuck here. What about Mars? No. It hasn’t rained on Mars in three billion years. And as soon as that spacecraft door opens, you’ll notice you can’t breathe. See you down the track. Bill Nye, a man on the move. He brings up a very important point. No matter how bad Earth was, is there another place that’s better? Even after we mess it up as badly as we did? And in Interstellar, they go to a planet that didn’t look like the next planet I wanted to go to after Earth. And I also think that people want to terraform planets. After we mess up Earth, let’s terraform Mars. What’s terraforming? You turn it into Earth-like. Why don’t we just terraform Earth? Exactly. If you have the power to turn another planet into an Earth, you have the power to turn Earth back into Earth. Yeah. That’s how I see. I agree. It’s got to be easier than terraforming a planet and shipping a billion people there. But in any case, the movie Interstellar as well as some other films of recent years, Gravity among them, it got people talking about the universe, about space travel again, about science, about the value of science literacy in leading characters that maybe you want to be when you grow up. So I chatted with Chris Nolan in my office. I asked him, what effect does he think his movie has on the dreams of a nation and the world? I would love for kids today to see Interstellar and get inspired about some of this. It’s what you guys have been doing with Cosmos and whatever. I mean, it’s like if you can show people visually, that’s why you need such a lavish visual treatment. It’s like it’s about how exciting it is. It’s not about numbers on the page. It’s about flight of imaginations, about Einstein sitting there imagining sets of twins, one on a train going the speed of light, one at the station. All that stuff, it’s so visual and enormous. So anything you can do, either on television or in a movie or whatever, to try and get that scale and excitement across. Another thing, in fact, I’ve been telling this to, because people come to me now to comment on newly released science fiction films. I think it’s because I had some tweets for the movie Gravity. I heard. It went a little viral, which was not my intent. I was just putting it out there and I bump into them on the morning news, on the evening news and on and everyone said astrophysicist Neil Tyson says. And it’s like, my gosh, but that meant that there was an appetite. Why would anyone care unless the science in a film is now part of the dialogue? Oh my gosh. Science in the dialogue. In your defense, gravity got the gravity wrong. Listen, Janna, Professor Levin, thanks for coming. Anytime. And Eugene, it’s always great having you on StarTalk. Thank you. You’ve been watching StarTalk from the Hall of the Universe of the American Museum of Natural History in New York City. And as always, I bid you to keep looking up. See the full transcript