Season 5 Time Capsule (Part 2)

You asked the questions, you chose the episodes: Join us for your favorite Cosmic Queries of Season 5, answered by your own personal astrophysicist, Neil deGrasse Tyson, and guest hosts Bill Nye and Dr. Amy Mainzer.

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

• 0:01Neil deGrasse Tyson?

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

• 0:21Neil deGrasse Tyson?

  Welcome to StarTalk Radio. I'm your host, Neil deGrasse Tyson. I'm an astrophysicist and director of New York City's Hayden Planetarium at the American Museum of Natural History. The following show is a Cosmic Queries time capsule, a collection of our fifth season of StarTalk Cosmic Queries shows that were selected by you, our fans, as your favorites of the year. First up, comedian Leigh Anne Lord reads your pressing questions about one of the four fundamental forces of the universe: gravity.

• 0:55Speaker 01

  Of all the questions that I looked at, not one of them is, "What is gravity?"

• 0:59Neil deGrasse Tyson?

  Okay, well, that's good, because I have no hell idea what gravity is.

• 1:02Speaker 01

  Yeah, folks ask some really intricate stuff, and I'm like, "Mm-mm, I need more basics."

• 1:05Neil deGrasse Tyson?

  Well, you could start with one. What is gravity?

• 1:07Speaker 01

  Yes, I'm opening the field. Yes.

• 1:11Neil deGrasse Tyson?

  You're taking co-host privileges.

• 1:12Speaker 01

  I am, and I'm putting my question out there first. What is gravity?

• 1:16Neil deGrasse Tyson?

  You have no idea. Okay, next question.

• 1:18Speaker 01

  Wow.

• 1:19Neil deGrasse Tyson?

  No, here's the difference. We can describe gravity. We can say what it does to other things. We can, we can measure it, predict with it. But when you start asking, like, "What it is?", I don't know.

• 1:35Speaker 01

  So did I accidentally ask a deeper question than I meant to?

• 1:38Neil deGrasse Tyson?

  Yeah, no, you were meant to ask these questions.

• 1:40Speaker 01

  Apparently, I was.

• 1:41Neil deGrasse Tyson?

  In life. So, to say, "What is it?", I think Einstein, in an Einsteinian answer, we would say gravity is the curvature of space and time. And that, and objects will follow the curvature of spacetime, and we, we interpret that as a force of gravity. That's probably the best answer I can give to a "What is gravity?" question, or "Why is there gravity?". That's the best I can do there. I think that's a good start. And I can also say that Einstein noted that matter tells space how to curve, space tells matter how to move.

• 2:24Speaker 01

  Say that again.

• 2:25Neil deGrasse Tyson?

  Isn't that beautiful?

• 2:26Speaker 01

  It is. No, no, I want to get that. I like that. That's a t-shirt.

• 2:28Neil deGrasse Tyson?

  Matter and energy will curve the fabric of space. And it's that curvature that tells other matter how to move in the curvature of space itself. And so Einstein juxtaposed those in a poetic phrase where he said, "Matter tells space how to curve. Space tell..." Did I get that right?

• 2:52Speaker 01

  I wouldn't know.

• 2:52Neil deGrasse Tyson?

  "Matter tells space how to curve. Space tells matter how to move." It's beautiful.

• 2:57Speaker 01

  That is beautiful.

• 2:58Neil deGrasse Tyson?

  It is beautiful.

• 2:59Speaker 01

  It sounds like the opening to a dance lesson. And we begin.

• 3:03Neil deGrasse Tyson?

  So, that is your co-host privileges.

• 3:06Speaker 01

  Thank you so much.

• 3:08Neil deGrasse Tyson?

  That warmed up the crowd.

• 3:09Speaker 01

  It did. I hope so. Other than Mr. Tyson himself, what is, quote, "The Great Attractor"?

• 3:18Speaker 01

  Does its force affect us and if so, how? I love that.

• 3:21Neil deGrasse Tyson?

  The Great Attractor. I haven't been up on the latest research on the Great Attractor, but I was around when it was discovered. And the Great Attractor, if you look out into the universe beyond our own galaxy, we live in the Milky Way, and there's the Andromeda Galaxy, and there are galaxies in the Virgo Cluster. That's what defines the Virgo Cluster. There's a bunch of other galaxies there. And there's the general expansion of the universe, which we measure in the speed signatures of these galaxies. We got that.

• 3:51Speaker 01

  Yes.

• 3:51Neil deGrasse Tyson?

  But you can also measure other movements of these galaxies by secondary methods. And when you do this, this research showed that there was a whole field of galaxies, all with an extra bit of motion in one particular direction. It was called the Great Attractor.

• 4:11Speaker 01

  Okay.

• 4:11Neil deGrasse Tyson?

  It was mysterious, and so hence it had this mysterious name. We didn't call it the great, you know, sun god or great galaxy. It was just the Great Attractor. And so, no, it doesn't affect us at all. I mean, it's just stuff moving in the universe according to the gravitational fields in which they are embedded. We are on Earth, moving in the gravitational field of the sun. The sun is moving. Dragging the entire solar system with it in the gravitational field established by the galaxy, the galaxy and Andromeda are moving within our own mutual gravitational field, we will one day collide, and the Andromeda and the Milky Way are moving within a general

• 4:55Neil deGrasse Tyson?

  gravitational field of the Virgo supercluster of galaxies. And just recently, a larger system of galaxies was discovered, of which the Virgo supercluster is just a part.

• 5:07Speaker 01

  Oh dear.

• 5:08Neil deGrasse Tyson?

  Oh yeah.

• 5:10Speaker 01

  Feeling more insignificant every day.

• 5:13Neil deGrasse Tyson?

  That's my job. That's the job of the cosmic perspective is to convey to all of us that we are a small part of a much larger universe. What's interesting about particle physics is that gravity is essentially irrelevant to everything that's going on down there. It is as irrelevant to particle physics as gravity is irrelevant to most insects. You see insects just crawl up the wall or crawl on the ceiling?

• 5:39Speaker 01

  Annoyingly so, yes.

• 5:40Neil deGrasse Tyson?

  Right. You say, yo, there's gravity, you should be falling, you should be, you know, so others, you know, at different size scales in the universe, different manifestations of the laws of physics will predominate. So for an insect, surface tension of liquid matters more than anything. That's why you have the Jesus spider. Have you ever seen the Jesus? It's called the Jesus spider. It's cute. It walks on water.

• 6:05Speaker 01

  Oh, I thought because it died and then came back in three days.

• 6:07Neil deGrasse Tyson?

  No. Was it the third day? On the third day he wrote, yeah.

• 6:11Speaker 01

  Well, there's arguments about what constitutes a day and, you know, was it just a bad weekend?

• 6:16Neil deGrasse Tyson?

  Okay. So that it can walk on water and you say, well, if I try to walk on water, if I'm not Jesus, I will fall through the surface of the water because the insect is responding to the surface tension of the water, which overrides the forces of gravity entirely.

• 6:31Neil deGrasse Tyson?

  Entirely. That's why, so the world of the insect is very different from the world of us. And that's, that's why you can't take an insect and make a human-sized version of it and have it have any success doing what it was as an insect.

• 6:46Speaker 01

  So a lot of sci-fi movies get that wrong?

• 6:48Neil deGrasse Tyson?

  100% of them get it wrong. Okay? Giant ants, giant spiders. There's a reason why there are no giant spiders. They'd have to have really thick rhinoceros legs and we'd call them a rhinoceros. You know, you, you can't, you can't just scale it up. The laws of physics, it's all the same laws of physics, but it manifests differently depending on your scale.

• 7:08Speaker 01

  See, I was gonna ask that. Does that mean insects have a different physics? Like are there insects in little lab coats with different, different, you know, results than we get?

• 7:16Neil deGrasse Tyson?

  Their lab scientists would, probably would not yet have discovered gravity.

• 7:21Speaker 01

  Really?

• 7:22Neil deGrasse Tyson?

  Yes, yes. So now you're a particle responding to, are you a positive charge or negative charge? Now you've got electromagnetic forces, which are 40 orders of magnitude stronger than gravity. Forty orders of mag, 40 powers of 10 stronger. So in other words, you take an electron and a proton and say, well, their mass, right? How much do they attract each other gravitationally? You can calculate that. Write down that number. Now you do your equation for how much they attract one another because they're of opposite electrical charge. Write down that number. The electrical charge force of attraction is 10 to the 40th power stronger than gravity. So if you're a particle, you would never discover that gravity exists.

• 8:07Neil deGrasse Tyson?

  Two of your favorite guests on StarTalk Radio, Bill Nye the Science Guy and NASA astronaut Mike Massimino, took control of the show in this next segment. They were helped out in the studio by comedian co-host Eugene Mirman.

• 8:23Speaker 02

  What's new on the subject of high temperature or even room temperature superconductors? Are we getting any closer to grasping how it works? And will this knowledge in conjunction with 3D printing create a new industrial age?

• 8:37Bill Nye?

  Sounds like he's making a prediction of his own, doesn't it?

• 8:40Speaker 02

  He's like, am I right? What do you think?

• 8:42Speaker 04

  He's a sage.

• 8:43Speaker 02

  Yeah.

• 8:43Bill Nye?

  We'll see.

• 8:44Speaker 04

  Or maybe she's a sage.

• 8:46Bill Nye?

  3D printing is fabulous and uh...

• 8:48Speaker 02

  What's this, what's the state of uh, superconductors in room temperature?

• 8:51Bill Nye?

  Well, I don't know that uh, we have superconductors that work at sort of liquid helium temperatures.

• 8:57Speaker 02

  Mm-hmm.

• 8:57Bill Nye?

  Everybody wants to get into...

• 8:58Speaker 04

  It's kinda cold though.

• 8:59Bill Nye?

  Yeah.

• 8:59Speaker 02

  Yeah.

• 8:59Bill Nye?

  Four Kelvin.

• 9:01Speaker 04

  Yeah, it's pretty cold.

• 9:01Speaker 02

  Yeah, four Kelvin sounds cold.

• 9:02Bill Nye?

  It is cold.

• 9:03Speaker 04

  It's even colder than like, Canada.

• 9:05Speaker 02

  Yeah, so it's like, super Canada.

• 9:07Speaker 04

  Yeah.

• 9:09Bill Nye?

  But wouldn't it be good if they worked with liquid nitrogen? Wouldn't they work, good if they worked with with frozen water?

• 9:15Speaker 02

  Yeah.

• 9:15Bill Nye?

  But it's a long way off as far as I know, but that doesn't mean it can't be done. What I would do, where I, king of the forest, is invest again in these nano tubes, in the um, getting carbon atoms to arrange themselves in these extraordinary tubes where they have very, very low electrical resistance.

• 9:31Speaker 02

  Alright. Let's do it.

• 9:33Speaker 04

  The 3D printing thing is here.

• 9:35Bill Nye?

  Suppose we 3D printed carbon tubes? Wahahaha!

• 9:39Speaker 02

  Oh, could we ever do that? Is that a thing in the future?

• 9:41Bill Nye?

  It seems very reasonable to me, but I'm not a carbon tube printer.

• 9:44Speaker 04

  But it's quite, it's quite amazing.

• 9:45Speaker 02

  Have you guys ever 3D printed? I've never done that.

• 9:47Bill Nye?

  Oh, it's cool.

• 9:47Speaker 04

  They have them and, and you know, they're affordable now, sort of.

• 9:50Bill Nye?

  You can get them at Staples.

• 9:51Speaker 02

  Really?

• 9:52Bill Nye?

  Yeah.

• 9:52Speaker 02

  Wait, how, so, how much are, like, meaning a few thousand dollars?

• 9:56Bill Nye?

  Yeah, less than $2,000.

• 9:57Speaker 02

  Oh, wow.

• 9:58Bill Nye?

  And then you can make your own salt shakers.

• 9:59Speaker 02

  I can't wait to go home and make salt shakers! And plastic swords!

• 10:03Speaker 04

  Too bad we can't, people can't see this because it's radio, but Eugene's eyes have just lit up.

• 10:08Speaker 02

  Yeah, I was like, that is...

• 10:08Speaker 04

  He's ready to get out of here and go buy a 3D printer.

• 10:10Speaker 02

  Yeah. If one were to warp space to travel a vast distance, would people existing in the space that is being warped between takeoff and destination and destination notice anything unusual?

• 10:24Bill Nye?

  Well, they don't in the movies.

• 10:26Speaker 04

  The people in between.

• 10:27Bill Nye?

  The in-betweeners.

• 10:28Speaker 04

  Who's like, someone's hanging out, so some people on some planet.

• 10:31Speaker 02

  So, so if someone's-

• 10:32Speaker 04

  We're assuming there's someone else out there that's gonna, you're just gonna get-

• 10:34Bill Nye?

  I'm charmed by the idea that, of course, since, you know, you're going through a space warp, then of course, you can see whether-

• 10:39Speaker 04

  It will happen.

• 10:40Bill Nye?

  You gotta understand that these things are big fun when you're trying to create a science fiction television show where you really don't have time to have people not speaking English, and you gotta get up and down from a planet and travel around various quadrants in the galaxy, or galaxies.

• 10:55Speaker 02

  Mm-hmm.

• 10:56Bill Nye?

  But these things are more theoretical than they are. And so, uh, we will see how people do as they go between extraordinary destinations, uh, through unproven theoretical spaces in space.

• 11:11Speaker 04

  Would they notice, I think this person suspects they might have seen something.

• 11:15Speaker 02

  Yeah.

• 11:15Speaker 04

  Would we notice anything unusual?

• 11:17Speaker 02

  Right, right. This person is like, "I saw something weird at my house."

• 11:20Speaker 04

  I saw something unusual.

• 11:22Speaker 02

  All right.

• 11:23Speaker 04

  My hamburger special looked a little bit different today than it did the other day. Is it, since someone warped speed through the diner, something like that?

• 11:30Bill Nye?

  Well, it's the government.

• 11:30Speaker 04

  Something funny's going on here, I think.

• 11:32Speaker 02

  Yeah. Is there a theoretical limit to the size of a sun? I keep seeing graphics comparing our sun to larger and larger solar giants. Just how big can they get?

• 11:43Bill Nye?

  Well, but you get to be a few hundred solar, uh, sun diameters, you become a black hole.

• 11:49Speaker 02

  Really?

• 11:49Bill Nye?

  Yeah, you become a star that has so much gravity, light doesn't escape. A black hole is, in a sense, a star-

• 11:54Speaker 02

  So would you describe it as over a million whales?

• 11:58Bill Nye?

  Uh, yeah.

• 11:59Speaker 04

  Big whales!

• 12:00Speaker 02

  That wouldn't be inaccurate, but it wouldn't be the most accurate way to describe it.

• 12:03Speaker 04

  A big whale, you're talking about a big whale.

• 12:04Bill Nye?

  Well, but over a million, by a factor of, I guess, ten to the nineteenth or something, yeah.

• 12:10Speaker 04

  Like the whale that's hanging from, uh, Neil's museum.

• 12:13Speaker 02

  Exactly.

• 12:13Speaker 04

  For those of you who've been to New York City, to American Museum of Natural History.

• 12:15Speaker 02

  So a sun that was too big would just become a black hole, it would collapse?

• 12:18Bill Nye?

  Yeah. Well, that's what, apparently, it does. They do.

• 12:22Speaker 02

  Oh, great. Now, well, that's all, now I know how to make a black hole. Thanks.

• 12:26Speaker 04

  Look out, world.

• 12:28Neil deGrasse Tyson?

  Most of the questions sent to us are about scientific theories and discoveries. But in this Cosmic Queries, we tackle the intersection between science and art with comedian co-host Chuck Nice.

• 12:42Neil deGrasse Tyson?

  I would definitely like to hear Neil's thoughts on the golden ratio and the role of mathematics in aesthetics in general. Thanks. That's an awesome question. Oh, my gosh. Right. So it has been suggested since antiquity that certain proportions are pleasing to the eye. Right. No matter what your upbringing is, perhaps no matter even, no matter your upbringing within a culture, and perhaps no matter even what culture you derive from, and one of them is the golden ratio. Golden ratio. Yeah, and I think it's one plus the square root of five over two. So some, I'll look it up over the break, but I don't carry it in my head. But what it does is it tells you how wide something should be for how tall it is. Right.

• 13:27Neil deGrasse Tyson?

  And that's why certain paintings, certain pictures in their frame, just feel a little awkward. Mm-hmm. They don't feel pleasing, and you can't even put your finger on it. It's kind of an emotional force operating on you, and a hidden intellectual force that's telling you, I like this picture better than that, and you might not even know why. I know why, because I'm looking at porn at that point. For me personally, I'm just saying. So you have other ratios that apply to porn. There's the porn ratio. We've got to check out that one. Oh, my God. Where my mind just went. Go ahead. So I like geometry. Geometry, in fact, literally means earth measurement, geometry. Geometry.

• 14:12Neil deGrasse Tyson?

  And it was applied to measuring distances and along earth's surface, and earth is curved, so you get some interesting mathematical discussions when you bring mathematics to bear on earth measurement. But math, I think, is overvalued as a force in art. Okay. Because in math, there is no room for emotion.

• 14:38Speaker 05

  True.

• 14:39Neil deGrasse Tyson?

  That just isn't. And so the question is, is there something that's mathematically pure? That is also emotionally, uh, rich or satisfying? And by the way, people have been thinking about this since forever. And it started with the music of the spheres. They saw planets in orbit around the sun. Well, that's a, there's a rhythm to that. And the different orbits of different times. Is there a ratio of those that means something mathematically that, for, out of which you can make music?

• 15:12Speaker 05

  Hmm.

• 15:12Neil deGrasse Tyson?

  And it was imagined that music, you can make awesome music from the universe. And for all the music I've heard that came from the universe, it's not. I'm sorry.

• 15:23Speaker 05

  If art influences science, how come the International Space Station is so ugly?

• 15:32Neil deGrasse Tyson?

  It's because art does.

• 15:35Neil deGrasse Tyson?

  It's because art does not influence science. Art influences design of architecture and hardware. But it does not influence science. So those were engineers that had an opportunity to make the baddest looking thing there ever was, orbiting the earth, and out came something that looked like some, you know, a rector set. Uh, and so, yeah, I'm a little disappointed now that you mention it. Uh, but I, I, we want to bring in some art, art and designers for when we go to Mars. Cause I want that to be the badass looking thing that's ever come off the earth.

• 16:08Speaker 05

  Was there ever a painting or sculpture during the Renaissance? Or any other historical time that captured an accurate depiction of the cosmos at that time?

• 16:19Neil deGrasse Tyson?

  Yes, there is Giacomo's painting of the Birth of Jesus. A very famous painting in which he puts a comet.

• 16:34Neil deGrasse Tyson?

  We don't put comets to signify good things? The whole history of civilization, where people have looked up and seen a comet, if you look at how they reacted, they said, "Oh, something bad is about to happen." And so, he took a leap and said, "Well, the birth of Jesus is a good thing," to Christians. And a comet is just something in the sky. And that comet is likely Halley's comet that he had seen in the sky at the time that he painted it. Because if you date back the appearance of Halley's comet every 76 years, it lines up with when he made that painting. Wow. So, that is real science in a real painting. Not only that, 1066, the Bayou Tapestry.

• 17:16Neil deGrasse Tyson?

  There is a dude pointing up at a comet. The comet came in 1066, and it coincided with William the Conqueror. Look at that.

• 17:44Neil deGrasse Tyson?

  Welcome back to StarTalk Radio. I'm Neil deGrasse Tyson. In this time capsule show, we're featuring our fans' favorite cosmic queries from season five. Appropriately for a time capsule, you selected our time travel cosmic queries, which featured the comedian and Saturday Night Live Weekend Update host, Colin Jost.

• 18:06Speaker 06

  Doesn't the fact that there are no time travelers now prove that time travel will never be invented in the future?

• 18:12Neil deGrasse Tyson?

  Yeah, that's an excellent point. And I've always thought about that, because I said to myself, in fact, if you watch the TV, the CBS sitcom, The Big Bang Theory, in the roommate contract of...

• 18:26Neil deGrasse Tyson?

  I know you gotta be totally in the show for this.

• 18:28Speaker 06

  Yeah, no, no, no.

• 18:29Neil deGrasse Tyson?

  But in the roommate contract, it stipulated that if any one of them invents a time machine in the future, they have to go back to that moment that they're reading that phrase in the roommate contract to show up in the room. And so, so they're going through the contract, and then they pause for a moment.

• 18:45Speaker 06

  That's great.

• 18:46Neil deGrasse Tyson?

  Nope, okay, we have, you know, you're not the one who invents the time machine in the future.

• 18:49Speaker 06

  That's the ultimate, like, let's agree to meet back here 10 years from now, but it's at the same time.

• 18:53Neil deGrasse Tyson?

  Exactly. And so, I think that's a, that's a pretty good argument, and I don't have a rebuttal to that.

• 19:00Speaker 06

  But, you know, what if people are hiding it? What if people have come back but are not telling people for some reason because they don't want to give something away?

• 19:06Neil deGrasse Tyson?

  There's a quote, I think it was from Raoul Dahl, but others perhaps have said it, that "The only secret that can be kept between two people is when one of them is dead." So, I'm pretty sure that if a time machine were out there, people would have figured that one out. It's been rumored that the, the reason why the Titanic sank is because in the future they invented a time machine, and everyone wanted to go back to the Titanic to see the iceberg when it hits, and then it overloaded the Titanic and it sank.

• 19:37Speaker 06

  Oh, that's great.

• 19:38Neil deGrasse Tyson?

  Right.

• 19:39Speaker 06

  Oh, well, now I'm convinced.

• 19:40Neil deGrasse Tyson?

  So, here's the evidence. You're looking for evidence?

• 19:42Speaker 06

  There we go.

• 19:43Neil deGrasse Tyson?

  That's hardcore evidence. So, that's a pretty good one.

• 19:45Speaker 06

  Yeah.

• 19:46Neil deGrasse Tyson?

  And it may, it might be that your time travel machine can only take you into the future, and then you don't have these paradoxes of killing your grandmother and then you're never born to go back in the-

• 19:56Speaker 06

  Yeah, weird Back to the Future stuff.

• 19:58Neil deGrasse Tyson?

  Yeah, yeah, exactly.

• 19:59Speaker 06

  And the question is, if we could fold two points of spacetime together, what would happen to the matter that was between those two points?

• 20:07Neil deGrasse Tyson?

  Fold two points in spacetime, oh, so, ooh, so, well, you can't, because the two points in time will not correspond. They're two different places on the time axis. So, you can't have time t equals zero in the same place as time t equals five, because they're different places on the axis. If you folded them, you're folding them in a higher dimension, and so they're kinda near each other. If you stepped above them in a higher dimension-

• 20:34Speaker 06

  But they're not actually the same.

• 20:36Neil deGrasse Tyson?

  They're not actually in the same place. And so, just to make that clearer, if you took a sheet of paper, and I've got one right here, even though it's radio, you can, you can listen to it. And I've got a sheet of paper, eight and a half by 11, and I'm curling the two edges. And I have the two edges sort of touching each other now.

• 20:53Speaker 06

  Yeah.

• 20:53Neil deGrasse Tyson?

  And I can say they're in the same place, but no, they're not.

• 20:55Speaker 06

  They're not actually.

• 20:56Neil deGrasse Tyson?

  They're not actually. Now, what I'll do is I'll punch a hole through one to get to the other, a little wormhole, and I've just warped the fabric of space, traveled through a wormhole, landed on the other side. Now I unfold a sheet of paper, and I just crossed the sheet of paper instantly in what might have otherwise taken me some, some unacceptably long period of time, such as what they do in Star Trek.

• 21:18Speaker 06

  Wow.

• 21:18Neil deGrasse Tyson?

  They invoke their warp drives, they take their destination, warp their location close to it, they travel through this warp in the fabric of space and time, they unfold it, and they cross the galaxy during the TV commercial. That's how that works.

• 21:32Speaker 06

  That sounds awesome. That's a great commute.

• 21:33Neil deGrasse Tyson?

  In what would have otherwise taken a course the galaxy hundreds of thousands of years, even at the speed of light. So it's a legitimate way to cheat the laws of relativity.

• 21:42Speaker 06

  So the D train going uptown is like the exact opposite of that.

• 21:45Neil deGrasse Tyson?

  So he'd asked about the Star Trek: The Voyage Home.

• 21:50Speaker 06

  Mm-hmm.

• 21:51Neil deGrasse Tyson?

  Star Trek IV.

• 21:52Speaker 06

  Mm-hmm.

• 21:52Neil deGrasse Tyson?

  Which has been dubbed Save the Whales.

• 21:54Speaker 06

  That's right.

• 21:55Neil deGrasse Tyson?

  Right, that's the subtitle of that show.

• 21:57Speaker 06

  That's right.

• 21:57Neil deGrasse Tyson?

  Where they go back in time to the present day of the time of the film. So it was 1984, I think it was, or 85. And so he wants to know, is there an actual speed with which you can swing by slingshot past the sun, such as what they did in that show.

• 22:12Speaker 06

  Right.

• 22:12Neil deGrasse Tyson?

  In that movie, in order to go back in time.

• 22:15Speaker 06

  Right, and it says, can you use the sun's pull, but is there a safe enough distance that it wouldn't just pull you in?

• 22:21Neil deGrasse Tyson?

  Yeah, so first of all, you cannot do what they did in the show, in the movie.

• 22:24Speaker 06

  Regardless of.

• 22:25Neil deGrasse Tyson?

  Regardless, right. So, so just would nip that one in the bud.

• 22:28Speaker 06

  Yes.

• 22:29Neil deGrasse Tyson?

  Okay, so, and the only way you could do something like that is if you had vastly more powerful gravity than the sun. And you needed a, the fabric of space and time has to be so warped that, in fact, there's a colleague of mine who studies this, his name is Rich Gott, in fact, he's been on StarTalk before, he wrote a book called Time Travel in Einstein's Universe, and he found a solution to Einstein's equations that allows backwards time travel with a kind of a slingshot trajectory, but not around the sun. The sun does not disturb the fabric of space and time nearly enough. What's a kind of thing that would? Two black holes that are in orbit around each other, and so you'd have to do

• 23:11Neil deGrasse Tyson?

  a kind of a wiggly path around these black holes, and you can end up in the past of your own world line before you had left to go on that trip. Whoa. Yeah, it's a very whoa moment. And so Star Trek, it was more exciting to do it around the edge of the sun. Of course. Because visually, rather than just two black things in space, which is already black. This season on StarTalk, we had a few guest hosts take over the show. One such host was Dr. Amy Mainzer, an astrophysicist from NASA's Jet Propulsion Laboratory. She answered questions about comets and asteroids with comedian Chuck Nice.

• 23:50Speaker 05

  I have heard some theorize that the water on Earth could have been deposited here by comets, which is what you just said. These comets have to come from somewhere. So do you think they orig- so where do you think they originated from? And what is the source of their water? And that's a really involved question there, and that's a tough one for you to tell.

• 24:13Speaker 07

  Right. Well, it's certainly not the Tap, clearly. They definitely have to come from somewhere far away.

• 24:19Speaker 05

  It ain't Avion.

• 24:20Speaker 07

  No, it is not Avion, definitely not. So we know that the comets come from a couple different sources in our solar system. They are, some of them are way out there, and we think they might even be halfway to the nearest star.

• 24:31Speaker 05

  Wow.

• 24:32Speaker 07

  Yeah, really far, really cold, super cold, deep freeze. And that stuff that's been out there is very, very old. It is ancient.

• 24:39Speaker 05

  Right.

• 24:40Speaker 07

  And it is, again, billions.

• 24:41Speaker 05

  Billions.

• 24:42Speaker 07

  Billions.

• 24:43Speaker 05

  Billions of years old.

• 24:45Speaker 07

  It's extremely old. So when it gets here, every now and again... We don't even know exactly how, but sometimes these objects get kind of shuffled loose from that cloud that surrounds our solar system. We call it the Oort Cloud. And occasionally, one will get flung inward and bring all of that ice and volatile material inwards. And when it gets to the sun, what happens?

• 25:04Speaker 05

  It starts to melt, because our sun's, from what I hear, kind of hot.

• 25:06Speaker 07

  Uh, yes.

• 25:07Speaker 05

  Yes.

• 25:08Speaker 07

  Exactly. So the sun basically does a number on the comet, starts to vaporize it, and it can form a big, long tail. And eventually, some of them actually make their way to Earth. We think that that may have been how a lot of the Earth's oceans actually formed.

• 25:22Speaker 05

  Wow, are you serious? Like, it was that much ice?

• 25:26Speaker 07

  Could have been, yeah.

• 25:27Speaker 05

  So, wow. So the tail of the comet is actually expelling that much ice that if it were to get caught in the Earth's gravitational pull, pulled down, it creates oceans?

• 25:38Speaker 07

  Imagine lots of comets.

• 25:40Speaker 05

  Lots of them.

• 25:40Speaker 07

  Lots of comets. I mean, right now, this is kind of a quiet time in our solar system's history.

• 25:45Speaker 05

  Oh, God, you're scaring me.

• 25:46Speaker 07

  And now, we're kind of glad, we're glad for that, right?

• 25:48Speaker 05

  Yes, we are.

• 25:49Speaker 07

  Because life here on Earth does not really like it when things get too interesting.

• 25:51Speaker 05

  No, exactly.

• 25:52Speaker 07

  So, but early on, when the solar system was first forming, we do think there was a period when the Earth pretty much just got pelted by asteroids and comets.

• 25:59Speaker 05

  Right.

• 25:59Speaker 07

  And that could have been when the water got here.

• 26:02Speaker 05

  Wow. That is fascinating.

• 26:06Speaker 05

  Do you, Amy, have a favorite asteroid or comet? If so, why? Which one do you think is the most interesting?

• 26:14Speaker 07

  Oh, this is just, this is, no, I can't answer this question. This is like Sophie's Choice.

• 26:19Speaker 05

  Is that like asking you to pick a kid?

• 26:20Speaker 07

  I love them all. They're all my favorites. I love them all.

• 26:24Speaker 05

  Come on now.

• 26:25Speaker 07

  Okay, well, all right. I like the ones that I discovered.

• 26:31Speaker 05

  You really do like your own children.

• 26:33Speaker 07

  I do like my own children. It's kind of bad. Actually, there is one particular weirdo thing that we found with our survey when we were out looking for asteroids. And it's called the first known Earth Trojan. And this is an asteroid that actually is stuck to the Earth in a peculiar way.

• 26:50Speaker 05

  Okay, really?

• 26:51Speaker 07

  Yeah.

• 26:53Speaker 05

  It's stuck to the Earth.

• 26:56Speaker 07

  It is actually trapped in a gravitational resonance with the Earth, which sounds really cool, and this actually is a really cool asteroid.

• 27:03Speaker 05

  Yeah.

• 27:03Speaker 07

  It's basically, Earth is following it around in its orbit around the sun.

• 27:08Speaker 05

  Sweet.

• 27:09Speaker 07

  And it's kind of trapped there. And what's going to happen is, after a while, eventually it's going to pop its way out.

• 27:15Speaker 05

  Right, but right now it's like a little mama's boy.

• 27:17Speaker 07

  Oh, yes.

• 27:18Speaker 05

  Just trapped, can't get out.

• 27:19Speaker 07

  Can't get out, won't leave.

• 27:21Speaker 05

  Won't leave. And Earth is like, no, you come with me. No, I can't see my baby go.

• 27:27Speaker 07

  She's like, no, no, don't leave me. So.

• 27:30Speaker 05

  So that's, that's, okay.

• 27:31Speaker 07

  That's one of my favorites.

• 27:32Speaker 05

  That's one of your favorites.

• 27:33Speaker 07

  If I had to pick.

• 27:35Speaker 05

  Can an asteroid consisting of gold or silver be out there? And if it hit the Earth, who would own it?

• 27:42Speaker 07

  Well, I say, I would love to find a gold or silver asteroid if I could, but the ones we find that are metallic tend to be nickel-iron.

• 27:49Speaker 05

  Nickel-iron.

• 27:50Speaker 07

  Yeah.

• 27:51Speaker 05

  Not nearly worth as much.

• 27:52Speaker 07

  No, not nearly as much fun.

• 27:54Speaker 05

  And the answer to the second part of the question is, if it does exist, I own it. Okay, Richie? Okay, so just back up off my asteroid. Get off my ass-roid. Okay.

• 28:06Speaker 05

  How scientifically accurate is the 1979 Atari game Asteroids?

• 28:12Speaker 07

  Okay, I spent way too much of my childhood playing that game.

• 28:16Speaker 05

  Me and you both.

• 28:17Speaker 07

  Yes, and so when I became an asteroid scientist, it turns out the game is actually not that bad. If you hit an asteroid that is big in the game, it breaks into a lot of little pieces. And sure enough, that is exactly what happens to the asteroids.

• 28:29Speaker 05

  Wow. That is awesome. All right, here's a very quick one. What role do you think plasma physics plays in the landscape of comets?

• 28:38Speaker 07

  Oh, my goodness, a confusing one.

• 28:43Neil deGrasse Tyson?

  Science in the movies is always a popular topic with our audience. And in this show, comedian co-host Eugene Mirman asks you questions about Star Trek, Star Wars, and so much more.

• 28:56Speaker 02

  If you were an astronaut tumbling through space like in the movie Gravity, could you change your rotation or trajectory, say through twisting your body? Thank you. Love the show.

• 29:07Neil deGrasse Tyson?

  No.

• 29:07Speaker 02

  No?

• 29:08Neil deGrasse Tyson?

  Unless you unless you're in contact with some other thing.

• 29:11Speaker 02

  Mm hmm.

• 29:12Neil deGrasse Tyson?

  Or unless you lose mass. If you do not lose mass or come in contact with anything else, you will tumble in that same way at that same speed.

• 29:22Speaker 02

  Wait, but you.

• 29:23Neil deGrasse Tyson?

  Forever.

• 29:24Speaker 02

  But you actually will lose mass in the sense that you'll grow hungry and die.

• 29:27Neil deGrasse Tyson?

  Uh, uh, it depends. You, well, okay.

• 29:31Speaker 02

  Thirsty?

• 29:32Neil deGrasse Tyson?

  That's a really slow, as people who have tried to lose weight will attest, that is a slow way to lose. There are much faster ways to lose mass.

• 29:39Speaker 02

  Yeah, but if you're tumbling through space and you don't have access to any restaurants or anything.

• 29:43Neil deGrasse Tyson?

  No, what you can do is if you open up certain hatches of your spacesuit, you could like pee in one direction or another.

• 29:51Speaker 02

  Oh.

• 29:51Neil deGrasse Tyson?

  This will send your mass out another direction, opposite presumably the way you're tumbling and you don't want to go. That will slow you down.

• 29:59Speaker 02

  So I do like the idea of someone spinning and peeing and then just it would just they'd be spinning in the other direction. They'd still spin.

• 30:06Neil deGrasse Tyson?

  So you'd have to know some angular angular momentum physics before you went about.

• 30:11Speaker 02

  Started peeing.

• 30:12Neil deGrasse Tyson?

  Started peeing or spitting or.

• 30:14Speaker 02

  Yeah, yeah.

• 30:14Neil deGrasse Tyson?

  Pooping or or or or.

• 30:17Speaker 02

  Do you think that's the end of gravity is just someone peeing themselves back to earth?

• 30:20Neil deGrasse Tyson?

  I'm just saying, oh, by the way, you can't be inside the suit. It has to actually leave your body.

• 30:24Speaker 02

  Oh, of course, of course.

• 30:25Neil deGrasse Tyson?

  Into space, right?

• 30:25Speaker 02

  Yeah.

• 30:26Neil deGrasse Tyson?

  If you do this, you can then control to some level that your your wayward trajectory. This is no different.

• 30:32Speaker 02

  Would you die? Like, say you open the suit, there'd be, your skin wouldn't be able to contact. You would.

• 30:37Neil deGrasse Tyson?

  Oh, it's just a vacuum. I mean, yeah, it's not, it won't be comfortable, but you can do it temporarily in order to adjust your. Oh, yeah.

• 30:42Speaker 02

  For how long?

• 30:43Neil deGrasse Tyson?

  A couple, few minutes.

• 30:44Speaker 02

  Oh, really?

• 30:44Neil deGrasse Tyson?

  Yeah.

• 30:44Speaker 02

  That sounds great.

• 30:45Neil deGrasse Tyson?

  Yeah.

• 30:45Speaker 02

  Now I have a new goal. Tumble through space for a few minutes in no suit.

• 30:49Neil deGrasse Tyson?

  So so the point is that when you lose, if you look at spacecraft when they make adjustments, if they're in free open space, they're little sort of what they call these nozzles, these rocket nozzles that are strategically positioned around the body of the ship to make it rotate one direction or another, to change the attitude, the angle, or to slow down or to speed up. It is losing mass.

• 31:12Speaker 02

  Okay.

• 31:12Neil deGrasse Tyson?

  By the act of burning fuel that sends gases out in one direction or another.

• 31:16Speaker 02

  Oh, wow.

• 31:17Neil deGrasse Tyson?

  Yeah. So anything that comes up, burp, any other flatulent activity.

• 31:21Speaker 02

  I understand.

• 31:21Neil deGrasse Tyson?

  Okay?

• 31:22Speaker 02

  Yes. Here's a question from Alex Robinson about the Death Star. In the movie Star Wars, thanks for clarifying, we see the Death Star blow up the planet Alderaan. Setting aside the question of how a thing would be possible, what would happen to our solar system if the Empire blew up, say Mars?

• 31:44Neil deGrasse Tyson?

  Yeah, so that's a great question. So it's really simple. First, how would you want to go about blowing up a planet? You ask yourself, how much energy is keeping it together?

• 31:51Speaker 02

  Mm-hmm.

• 31:52Neil deGrasse Tyson?

  Then you put more than that amount of energy into the object.

• 31:55Speaker 02

  Mm-hmm.

• 31:55Neil deGrasse Tyson?

  It will explode.

• 31:56Speaker 02

  So more than whatever, so more than the gravitational?

• 31:59Neil deGrasse Tyson?

  Yeah, so you find out, you can calculate that. That's Physics 102.

• 32:02Speaker 02

  Right.

• 32:02Neil deGrasse Tyson?

  Not Physics 101, 102.

• 32:04Speaker 02

  Is how to blow up Mars. That's a pretty, that's quite an accelerated sciences.

• 32:10Neil deGrasse Tyson?

  So you calculate what's called the binding energy of the planet.

• 32:14Speaker 02

  Mm-hmm.

• 32:15Neil deGrasse Tyson?

  All right, and it's a gravitational binding. It's gravity keeps it together. You want to overcome the gravity that's holding it together. Calculate that. How much energy is it? Now you have a device that can pump that energy into your planet and have that planet absorb the energy rather than have the energy come out the other side. It will completely destroy the planet to smithereens.

• 32:36Speaker 02

  Uh-huh.

• 32:36Neil deGrasse Tyson?

  Entirely. So that's how one would go about it. If you did it to Mars, we'd lose our Curiosity Rover that's finding, discovering science there now.

• 32:44Speaker 02

  But it wouldn't affect us that much.

• 32:46Neil deGrasse Tyson?

  I would affect our rover.

• 32:48Speaker 02

  No, no, of course.

• 32:49Neil deGrasse Tyson?

  Tax money, excuse me.

• 32:50Speaker 02

  I mean, I mean our physical well-being, not our mental, emotional, and knowledge well-being.

• 32:55Neil deGrasse Tyson?

  Uh, we will continue to orbit the sun and Mars will have essentially no effect on us.

• 33:19Neil deGrasse Tyson?

  Welcome back to StarTalk Radio. I'm Neil deGrasse Tyson. This Cosmic Craters Time Capsule Show is a collection of fan favorites from season five. And one of your top picks was when Bill Nye the Science Guy hosted in my stead, answering questions about space and science with comedian co-host Chuck Nice.

• 33:39Speaker 05

  If a planet had a slower axis rotation allowing the star in its orbiting, that it's orbiting, to heat the planet over a longer day, could a planet be further out of what we consider the habitable zone? And still sustain life at similar temperatures as Earth? So, bigger planet, farther out, longer day. Do all those things factor into?

• 34:05Bill Nye?

  Let's back up. The Earth day used to be, before we had clocks, as far as it used to be 18 hours, in the ancient dinosaur days. So, that's a fact, that's like 30%. That the Earth is going a third slower than it used to.

• 34:18Speaker 05

  I did not know that!

• 34:20Bill Nye?

  And we're here, we're alive. So, you gotta figure if you're farther out and turning slowly, if conditions are right, you could be a living thing. You've got to, why not? Who's to stop you? Wait, wait, there's more. The planet Mercury spins two-thirds of a time for every orbit. And I don't think there are any Mercurians, because it's too close to the sun, from what we understand.

• 34:40Speaker 05

  Right.

• 34:41Bill Nye?

  But there's ice in the craters of Mercury. Is there some place on some other world? That's turning slowly? That has some slush? And there's living things in it? I don't know.

• 34:55Speaker 05

  Right.

• 34:56Bill Nye?

  One way to find, to make sure we never find out.

• 35:00Speaker 05

  Is to stay here.

• 35:01Bill Nye?

  Not go looking.

• 35:02Speaker 05

  And not go looking.

• 35:03Bill Nye?

  Exactly.

• 35:03Speaker 05

  Wow, that is very cool. That is, hey, hey JD, number one, great question. And number two, who knew that the Earth day used to be 18 hours?

• 35:15Bill Nye?

  Well, that's when you talk to the ancient dinosaurs, take a meeting with them. Well, really, they're the fossil ferns that are extant, that are along with their fossils.

• 35:24Speaker 05

  Okay.

• 35:24Bill Nye?

  You can infer a lot about the ancient environment. And then you look at silts and ice.

• 35:32Speaker 05

  Right.

• 35:33Bill Nye?

  And things, and you can infer a lot about the, how the Earth is slowing down now, caused by tidal friction with the moon. And you can work backwards to how fast it must have been spinning in ancient times.

• 35:45Speaker 05

  Since people at the equator go faster relative to people closer to the poles.

• 35:50Bill Nye?

  Yeah.

• 35:51Speaker 05

  Do they age more slowly?

• 35:53Bill Nye?

  It seems to me, I've done this calculation in physics class.

• 35:57Speaker 05

  For real?

• 35:57Bill Nye?

  Yeah.

• 35:57Speaker 05

  Okay.

• 35:58Bill Nye?

  They do, but it's not, it's not much.

• 36:00Speaker 05

  So it's insignificant?

• 36:02Bill Nye?

  Oh, it's insignificant for sure, but when you get into these thousands of billionths, things do not add up.

• 36:09Speaker 05

  Right. Gotcha.

• 36:11Bill Nye?

  But it's a cool question, and astronauts age ever so slightly more slowly than you and I do.

• 36:17Speaker 05

  Just by being up there?

• 36:18Bill Nye?

  By being in orbit.

• 36:19Speaker 05

  By being in orbit. Okay, fantastic.

• 36:21Bill Nye?

  Now, the astronauts of the very near future, if we can use this term, who will go into where the sky is dark, 100 kilometers, the, uh, Karman limit, the Karman limit, uh, they're gonna go up and down without going in orbit. They will be slightly younger. Oh, by the way, when you're in a jet airplane flying around the continent around the world, you're going, your time is passing ever so slightly more slowly.

• 36:45Speaker 05

  Slightly more slowly.

• 36:46Bill Nye?

  And for those of you who take physics and have not computed that, I encourage you to do that, cause it's fun. And then the other thing that's just used to rivet me was, there was a question, what is the attraction, but, uh, and then in parentheses, gravitational, between a 70 kilogram boy and a 60 kilogram girl, in parentheses, gravitational?

• 37:07Speaker 05

  Yeah.

• 37:08Bill Nye?

  Boy, that was a titillating science problem right there. The gravitational constant times mass one, mass two, over the distance between them squared.

• 37:19Speaker 05

  And that's gravitational, because the other computation is boobs.

• 37:24Bill Nye?

  I am shocked. Absolutely shocked.

• 37:30Speaker 05

  Will the Earth ever increase or decrease in its size over life?

• 37:35Bill Nye?

  Over its life.

• 37:36Speaker 05

  Over its life, not our life.

• 37:38Bill Nye?

  Well, I gotta think, yeah. Now, geologists, I'm sure, have pondered this question deeply. It's a question of ti- ti- timing, ti- timing. Will the sun expand and heat the earth before the earth has a chance to cool off? See, when you cool the metal of the inside of the earth, your nickel, your iron, your molten earth core.

• 37:58Speaker 05

  Right.

• 37:59Bill Nye?

  Are you going to, uh, you're gonna shrink? But will the sun, uh, come out here and hook and cook things up before that hap-? I think the sun's gonna beat us. As far as, uh, cooling the earth off, I wouldn't worry about it. And let me remind you, one of the tremendous insights, uh, into the nature of geology, the nature of our place in space. People wondered, quite reasonably, how could you have evolution happen over three billion years? How could the earth stay hot as it seems to have, uh, all this time? And you can tell the earth's hot inside when you have a volcano.

• 38:32Speaker 05

  Absolutely.

• 38:32Bill Nye?

  Which we have, now and then.

• 38:34Speaker 05

  That and the way Venus looks at us lets us know we're hot. I'm sorry, go ahead.

• 38:40Bill Nye?

  Uh, I'm, I'm sure you're right, Chuck. I, I'm sure you're right. I've always kinda had a thing for Venus myself.

• 38:46Speaker 05

  I don't blame you.

• 38:47Bill Nye?

  But that said, uh, Venus stays really hot for other reasons. Anyway, the inside of the earth has fission going on, nuclear fission, and that keeps it really hot. But eventually, you would think hypothetically, theoretically, things would cool off. But I think the sun's gonna heat up and cook us before then. Venus stays hot because of all its carbon dioxide in the atmosphere, which has run away with the greenhouse effect.

• 39:09Speaker 05

  So Venus, please, could, could that be our future? Is, wh- when you talk about the greenhouse effect, it's, could it be?

• 39:20Bill Nye?

  No, I don't think so. Venus is so hot.

• 39:24Speaker 05

  How hot is it?

• 39:25Bill Nye?

  Thank you. It's so hot that, uh... The ground, you would melt lead on the ground. You take your fishing weights. What? They would melt. Oh my goodness. Your stainless steel cutlery would just, just bend, yield. So furthermore- Like a Salvador Dali painting. It would be. Really? Uh, but you'd be dead to, before you could appreciate it, probably. I mean, instantly. And then furthermore, it, not only, wait, wait, there's more. It rains acid rain. Wow. This sounds like an environmental disaster, this place. Venus is like hell. And the guys who did the first, in the modern era, not the people from the seventeen hundreds and the early eighteen, early nineteen hundreds. Mm-hmm. In the modern era, the people who discovered climate change on Earth, James Hansen. Okay.

• 40:09Bill Nye?

  June of nineteen eighty-three. Oh, right. Testified in front of Congress. It was studying Venus, the atmosphere of Venus with telescopes, that people discovered the real, the real effect- The deleterious effects of greenhouse gases. Too much carbon dioxide. Wow. Wow. And by too much, we're talking about just a little bit too much. Just a little- Just a little bit. And that's all we need here, is just a little bit too much. That's right, yes. And it's game over. Yes. But I think it's gonna happen, even if I whisper about it.

• 40:38Neil deGrasse Tyson?

  We're wrapping up our season five Cosmic Queries Time Capsule with the paleoanthropologist, Dr. Ian Tattersall. He and I are based at the same institution, the American Museum of Natural History in New York City. Along with the comedian Eugene Mirman, we asked him your questions about primate evolution.

• 40:57Speaker 02

  Does selective breeding do the same as evolution faster, or not at all? And if it does cause evolution faster, could we possibly selectively breed chimps until they reach intelligence?

• 41:09Neil deGrasse Tyson?

  Ooh, yeah, why, why aren't we doing to chimps what we're doing to dogs?

• 41:12Speaker 02

  Yeah, and creating super chimps that we can murder us.

• 41:16Speaker 08

  Yeah, we already have ourselves. And that, I think that's probably enough for us to have to deal with right there. Um, why you would want to turn a chimpanzee into a human being when human beings are already out there, really, uh, you know, messing up the world, I, I can't imagine.

• 41:32Speaker 02

  What's the difference between buying a cake and making a cake? You can see the fun.

• 41:36Speaker 08

  Well, I suppose.

• 41:37Neil deGrasse Tyson?

  No, we're not turning chimps into humans, we're turning chimps into smart chimps.

• 41:41Speaker 02

  Yeah.

• 41:42Speaker 08

  Turning chimps into smart chimps. Uh, you know, people have been trying to do things to, uh, to, to, to, to teach chimpanzees language. Turns out that chimpanzees can learn a lot of signs. They can manipulate symbols in their minds. They can add them up anyway. Uh, but they just don't, uh, don't.

• 42:02Speaker 02

  They don't love doing it.

• 42:03Speaker 08

  Manipulate information the way we do.

• 42:05Neil deGrasse Tyson?

  Well, excuse me, Ian. Wait, wait, Ian, Ian.

• 42:07Speaker 08

  Mm-hmm.

• 42:08Neil deGrasse Tyson?

  Neither are wolves cuddly lap creatures, but we turn them into, we turned wolves into cuddly city dogs that sit on your lap during dinner. So why can't, why aren't we doing that to other animals, to chimps, to?

• 42:24Speaker 08

  You know, I think dogs basically domesticated us, you know, dogs, uh, dogs, dogs are basically, uh, the, uh, the victims of their own, their own personal kind of relationship with human beings. Uh, chimpanzees aren't that way.

• 42:39Speaker 02

  Meaning dogs decided they could get food easier if they just hung out with us than hunted it.

• 42:43Neil deGrasse Tyson?

  And didn't bite us.

• 42:44Speaker 02

  And didn't bite us.

• 42:45Speaker 08

  That's basically it.

• 42:46Speaker 02

  And chimps are like, we can get food easier if we stay away from people.

• 42:49Speaker 08

  Exactly, exactly.

• 42:51Speaker 02

  In current human populations, a clear selection pressure isn't observed for certain geotypes, genotypes over others. Most people can leave offspring. How will this affect human evolution?

• 43:04Speaker 08

  Well, as I was just saying, I think it means that we're not going anywhere biologically, that essentially that we're, we're static biologically until demographic circumstances change. But meanwhile, there's a lot going on in the cultural sphere to keep us amused.

• 43:17Speaker 02

  So you're saying the X-Men franchise isn't totally realistic?

• 43:22Speaker 08

  Totally. Unrealistic.

• 43:24Neil deGrasse Tyson?

  Wait, wait, wait, wait. So it, what that says is because we all interbreed and we have airplanes to do it all around the world, the next time we.

• 43:33Speaker 02

  That's why we made airplanes, to fly around having sex.

• 43:36Neil deGrasse Tyson?

  We didn't want, there was no branch of the human species unmated with.

• 43:40Speaker 02

  Exactly.

• 43:41Speaker 08

  Yes, as soon as you have the airplane, everything possible happens.

• 43:45Neil deGrasse Tyson?

  Exactly, but you also spread disease faster and.

• 43:48Speaker 08

  Absolutely, yeah.

• 43:49Neil deGrasse Tyson?

  At jet speed. But, uh, but so it means if we speciate, it's going to be because we send colonies to Mars or on generational ships to other star systems.

• 44:00Speaker 08

  Well, you're not gonna like this because I think, yes, theoretically, you could send a colony on Mars, which was small and genetically unstable, could incorporate innovations and could speciate. But they'd be so far away that they would have no relevance at all to what was going on on Earth.

• 44:16Speaker 02

  What do you mean? They would be-

• 44:18Speaker 08

  Mars is a long way away.

• 44:19Speaker 02

  Yeah, but what if they came back?

• 44:20Neil deGrasse Tyson?

  Wait, wait, wait, Ian, that's no different from Australia breaking away from its other mother continent and generating these weird marsupial creatures that you don't find anywhere else on Earth. Same difference.

• 44:33Speaker 08

  Yeah. We weren't around to see those strange marsupials either until, of course, the Aboriginal Australians got there and made them all extinct in a hurry. The fact is that we are here on Earth and we are on this planet and, as you say, we're all in it together. You send out a colony on Mars, it's so far away.

• 44:51Neil deGrasse Tyson?

  That's what they said about Australia.

• 44:55Speaker 08

  Australia.

• 44:55Neil deGrasse Tyson?

  Okay, so in a hundred years, as a wormhole, I get to Mars for lunch. It's not a convincing point to me.

• 45:02Speaker 08

  When Mars, when you can get to Mars for lunch, that'll change the rules. But right now, how long does it take to get to Mars?

• 45:09Neil deGrasse Tyson?

  A long time.

• 45:10Speaker 02

  How long, how long in a-

• 45:12Neil deGrasse Tyson?

  The fastest, nine months is the fastest.

• 45:15Speaker 02

  Nine months? So you could totally go there and have sex. In fact, if you had sex and food there, you'd have a kid.

• 45:19Speaker 08

  You'd have nothing much else to do on the way there.

• 45:22Speaker 02

  It's true. Well, you could bring a Vektrix, you could bring video games.

• 45:27Neil deGrasse Tyson?

  I got a question. I got a question. We have so much DNA in common with all the other life, starting with chimpanzees, going down the list. Presumably, we have, we're vertebrates, so we have DNA in common with all vertebrates at some level, correct?

• 45:39Speaker 08

  You've got 60% of your DNA in common with a banana.

• 45:42Neil deGrasse Tyson?

  With a banana.

• 45:43Speaker 02

  Really?

• 45:43Neil deGrasse Tyson?

  So therefore-

• 45:44Speaker 02

  So why am I not as delicious?

• 45:46Neil deGrasse Tyson?

  I mean, why are you not appealing?

• 45:49Speaker 02

  Actually, I take it back. I am as delicious as a banana.

• 45:51Neil deGrasse Tyson?

  Yeah, and appealing. So, can I get some props for coming up with that?

• 45:57Speaker 02

  That was very good. That was very good.

• 45:59Neil deGrasse Tyson?

  Thank you.

• 45:59Speaker 02

  That was, I will-

• 46:02Neil deGrasse Tyson?

  So, Ian, what I ask is, can't you just go into our genome, flick a switch? That it excites or turns on or off, so whatever combination necessary to have your offspring, have your arms have become wings.

• 46:18Speaker 02

  Yeah, or have people.

• 46:19Neil deGrasse Tyson?

  If it's all there.

• 46:20Speaker 08

  If you knew what to do, you'd have to do it in seven billion people.

• 46:23Neil deGrasse Tyson?

  No, no, not in the lab.

• 46:25Speaker 02

  I would be happy with five people with wings and four that were bananas. Why do you change everyone?

• 46:30Speaker 08

  Where would you keep them?

• 46:31Speaker 02

  Where would I keep four people with bananas?

• 46:33Neil deGrasse Tyson?

  You want to turn people back into bananas?

• 46:35Speaker 02

  I don't want to turn people a little. I mean, I only found out recently it was possible. So I'd like to try it just on one person.

• 46:43Speaker 08

  Holy moly, this is interesting.

• 46:46Speaker 02

  Well, one person that hasn't been born yet has that.

• 46:48Neil deGrasse Tyson?

  I'm assuming nobody wants to turn their offspring into bananas. I want to know.

• 46:52Speaker 02

  We would force them.

• 46:53Neil deGrasse Tyson?

  If they're just, so Ian, in the old days, we had computers and it was called dip switches, where you can change the parameters of the calculation. Right, if you're old enough, you remember that. So if such switches exist in our genes, it's not that you have or don't have the gene. The gene is manifested or not manifested in its operation within you. So in principle, let's turn on the gene that can regenerate limbs, that as newts do. Let's, you know, newts got that. And here we are, thinking we're evolved in some special way and we can't do stuff that other animals can do.

• 47:26Speaker 08

  You know, you don't have a technology to do that right now. We have to worry about this and this one down the line. But right now, you can repair genes, you can insert genes, you can do all sorts of things, but you're not going to get a separate population going on its own evolutionary trajectory without isolating it somehow. And that would be probably unacceptable to the majority of people.

• 47:48Speaker 02

  Yes, let's not enslave a banana people. And make them have wings and regrow limbs until they destroy us.

• 47:56Neil deGrasse Tyson?

  No, I want a flying banana. That's what I want.

• 47:58Speaker 02

  I kind of want a flying banana.

• 48:00Speaker 08

  Flying banana, I see how we could do that.

• 48:02Speaker 02

  That can regrow. We really have solved a lot of stuff here. It could fly, people would eat it, it would regrow another banana.

• 48:09Neil deGrasse Tyson?

  Did we only get to one question in this segment?

• 48:11Speaker 02

  Yeah, but it was a long, solid question.

• 48:14Speaker 08

  Bananas need help.

• 48:18Neil deGrasse Tyson?

  You've been listening to StarTalk Radio, brought to you in part by a grant from the Alfred P. Sloan Foundation. I'm Neil deGrasse Tyson, compelling you, as always, until next time, to keep looking up.