WEBVTT 00:00:02.080 --> 00:00:08.960 Welcome to StarTalk, your place in the universe where science and pop culture collide. 00:00:10.380 --> 00:00:12.740 StarTalk begins right now. 00:00:22.296 --> 00:00:23.556 This is StarTalk. 00:00:24.116 --> 00:00:30.176 I'm your host, Neil deGrasse Tyson, and I have with me in studio, my cohost, Chuck Nice. 00:00:30.196 --> 00:00:30.996 Hey, Neil. 00:00:31.016 --> 00:00:32.196 We love it when you're here, Chuck. 00:00:32.216 --> 00:00:33.016 I love being here. 00:00:33.016 --> 00:00:35.736 I feel like we go way back, but we don't. 00:00:35.836 --> 00:00:39.776 It just feels that way, I don't know. 00:00:39.896 --> 00:00:41.476 Yes, I have that effect on people. 00:00:41.496 --> 00:00:42.516 I'm like a rash. 00:00:42.996 --> 00:00:44.196 You feel very familiar. 00:00:45.596 --> 00:00:52.056 So this is StarTalk, the Cosmic Queries edition, and today we are themed, we've solicited questions. 00:00:52.616 --> 00:00:59.016 Some come in unsolicited, and we hold those aside, and then we call for others, and when they fit, we match them up. 00:00:59.416 --> 00:01:03.536 And so today, it's our son and other stars. 00:01:03.656 --> 00:01:07.536 Yes, and not like Tom Cruise or Meryl Streep, not those other stars. 00:01:07.556 --> 00:01:11.476 Unless one of those slipped in, but we had stars in the universe before there were stars in Hollywood. 00:01:11.816 --> 00:01:12.896 Just an FYI. 00:01:12.916 --> 00:01:13.596 Just to let the people know. 00:01:13.616 --> 00:01:14.716 They took the name from us. 00:01:14.856 --> 00:01:16.196 Not according to People Magazine. 00:01:16.516 --> 00:01:19.976 That's why on Hollywood Boulevard, the shape is a star. 00:01:20.656 --> 00:01:21.316 That's what we got. 00:01:21.336 --> 00:01:21.836 That's correct. 00:01:21.856 --> 00:01:22.296 That is correct. 00:01:22.316 --> 00:01:23.776 They're borrowing our word. 00:01:23.796 --> 00:01:25.076 Shine bright like a diamond. 00:01:25.096 --> 00:01:26.056 You know what else borrowed our word? 00:01:26.076 --> 00:01:27.856 Pulsar watches borrowed our word. 00:01:27.876 --> 00:01:28.736 That's right, Pulsar. 00:01:28.756 --> 00:01:30.056 Quasar, remember Quasar? 00:01:30.616 --> 00:01:32.756 Yes, they borrowed, we got that first. 00:01:32.776 --> 00:01:34.236 That's right, that's right. 00:01:34.256 --> 00:01:36.616 I'm trying to think of any other cosmic branding. 00:01:36.696 --> 00:01:39.876 Well, there's like Star Kiss oranges. 00:01:39.896 --> 00:01:40.356 Star Kiss. 00:01:40.376 --> 00:01:42.016 It goes on, and don't get me started on that. 00:01:42.036 --> 00:01:42.476 Okay. 00:01:42.496 --> 00:01:43.236 No, no, there's like- 00:01:43.256 --> 00:01:44.296 And there's Sun Kissed? 00:01:44.316 --> 00:01:46.996 Sun Kissed, Star Kissed, Moon Glow Bath Beads. 00:01:47.016 --> 00:01:47.696 Moon Pies. 00:01:47.716 --> 00:01:51.936 Celestial Seasonings, Moon Pie, Milky Way Candy Bar, Mars. 00:01:51.996 --> 00:01:52.876 You got me started. 00:01:52.896 --> 00:01:53.836 Milky Way Candy Bar. 00:01:53.856 --> 00:01:54.436 Mars Bar. 00:01:54.456 --> 00:01:58.276 The Chevy Nova, except had they known that was a star that just blew up, they might not have. 00:01:58.296 --> 00:01:59.776 Right, not a good name for the car. 00:02:00.416 --> 00:02:01.136 Please get into this. 00:02:01.316 --> 00:02:01.896 So anyway. 00:02:02.016 --> 00:02:04.056 All right, so you got questions for me. 00:02:04.076 --> 00:02:04.616 I haven't seen these. 00:02:04.856 --> 00:02:07.736 You haven't seen any of these questions, nor do you know what they are going to say. 00:02:08.376 --> 00:02:10.016 Culled from the internet and other sources. 00:02:10.036 --> 00:02:10.816 All from different sources. 00:02:10.836 --> 00:02:12.336 Might even have a couple of callers, that's good. 00:02:12.436 --> 00:02:13.016 Oh, that's great. 00:02:13.036 --> 00:02:13.736 So what do you got? 00:02:13.756 --> 00:02:16.896 Let's jump right into it, and let's kick it off at the beginning, okay? 00:02:17.116 --> 00:02:18.936 And this is from Christopher Lloyd on Facebook. 00:02:18.956 --> 00:02:19.576 He says, let's start- 00:02:19.596 --> 00:02:20.076 Christopher Lloyd. 00:02:20.096 --> 00:02:22.456 Christopher Lloyd, as in an actor. 00:02:22.676 --> 00:02:23.156 All right. 00:02:23.236 --> 00:02:25.676 Christopher Lloyd wants to know, let's start at the beginning. 00:02:25.696 --> 00:02:31.436 How does something like the sun even form or come into being the way that it is? 00:02:31.456 --> 00:02:34.896 So in the current incarnation, how does that happen? 00:02:34.916 --> 00:02:35.356 Yeah, cool. 00:02:35.376 --> 00:02:36.876 Of course, this happens all the time. 00:02:37.196 --> 00:02:41.156 Our galaxy has hundreds of billions of these things called stars. 00:02:41.536 --> 00:02:43.796 So nature has no problem making these things. 00:02:43.796 --> 00:02:49.356 And the star is made of gas, 100% of gas, and it comes from a gas cloud. 00:02:49.456 --> 00:02:54.996 Now, if we look through the galaxy and didn't find gas clouds, we would wonder, where are these things born? 00:02:55.176 --> 00:02:56.436 But we find gas clouds. 00:02:56.556 --> 00:03:01.116 It's like looking around society and never seeing a pregnant woman, but you see babies all over. 00:03:01.516 --> 00:03:03.436 You'd have to wonder where do babies come from. 00:03:03.456 --> 00:03:05.196 Do you know I feel the same way about pigeons? 00:03:05.536 --> 00:03:06.036 But anyway. 00:03:06.056 --> 00:03:07.116 Oh, you don't see baby pigeons. 00:03:07.136 --> 00:03:08.036 I've never seen baby pigeons. 00:03:08.056 --> 00:03:08.756 Yeah, you're not alone. 00:03:08.836 --> 00:03:10.336 It's one of the big mysteries of life. 00:03:10.356 --> 00:03:11.456 Where's the little pigeon? 00:03:11.456 --> 00:03:12.756 Where's the little pigeon? 00:03:12.976 --> 00:03:14.036 They're just born whole. 00:03:15.656 --> 00:03:17.036 Out of the egg, it's a big pigeon. 00:03:17.376 --> 00:03:27.676 So either they're born quickly or, so you have to ask these questions, but society does have pregnant women and you can judge how long they're pregnant if you take snapshots of the culture. 00:03:28.016 --> 00:03:29.516 So that's what we do in the universe. 00:03:29.536 --> 00:03:36.076 We take snapshots of the galaxy at different times and we find out there are places where there are huge gas clouds. 00:03:36.516 --> 00:03:46.636 Gravity is gathering the gas clouds into, it nucleates, and if you get one part of a gas cloud that's slightly more dense than another, it wins. 00:03:47.256 --> 00:03:52.316 It's got more gravity than anywhere else and then it attracts more gas, then it has even more gravity. 00:03:52.356 --> 00:03:53.876 So it's like Mexican food. 00:03:54.276 --> 00:03:57.396 I can't, I don't follow the analogy, I'm sorry. 00:03:57.416 --> 00:03:59.336 Help me out on that one. 00:03:59.936 --> 00:04:04.796 Well, you eat Mexican food and it causes gas, which leads to more gas. 00:04:04.916 --> 00:04:05.776 I see, there you go. 00:04:05.896 --> 00:04:06.916 I missed that one, sorry. 00:04:06.936 --> 00:04:08.936 That would be the bean part of the Mexican food. 00:04:08.956 --> 00:04:22.456 Exactly, so yeah, so if you have slightly more mass, slightly more density in your region of a gas cloud than another, you are more likely to condense first and then you win that contest and all the matter comes to you. 00:04:22.796 --> 00:04:28.076 Eventually in the center, as the matter accumulates, it gets hotter and hotter and hotter, it's under pressure. 00:04:28.756 --> 00:04:35.796 Gas clouds under pressure get hotter and eventually it triggers thermonuclear fusion and a star is born. 00:04:35.816 --> 00:04:37.916 Look at that, thermonuclear fusion. 00:04:37.936 --> 00:04:38.436 There you got it. 00:04:38.456 --> 00:04:40.776 So it just gets hot, it bursts into flames. 00:04:40.796 --> 00:04:41.416 Busts open. 00:04:41.436 --> 00:04:44.016 I am so hot, I'm just gonna bust into flames. 00:04:44.036 --> 00:04:46.396 Yeah, and it's thermonuclear fusion energy. 00:04:46.416 --> 00:04:48.136 It's not like fire energy. 00:04:48.236 --> 00:04:55.596 It's another kind of energy that you derive from the nucleus of an atom rather than from sort of molecules breaking apart. 00:04:55.776 --> 00:05:00.616 Normal fire is just molecules breaking apart that have stored energy that releases it as fire. 00:05:00.636 --> 00:05:02.076 Right, this is different. 00:05:02.096 --> 00:05:04.276 We say stars burn, but we don't mean burn. 00:05:04.736 --> 00:05:05.656 They're not on fire. 00:05:05.676 --> 00:05:06.576 They're thermonucleating. 00:05:07.336 --> 00:05:08.076 Exactly, exactly. 00:05:08.096 --> 00:05:09.296 That's fascinating. 00:05:09.476 --> 00:05:11.116 All right, man, way to go. 00:05:11.136 --> 00:05:11.916 And that was Christopher Lloyd? 00:05:11.936 --> 00:05:12.556 That was Christopher Lloyd. 00:05:12.576 --> 00:05:13.776 Was that their actor, Christopher Lloyd? 00:05:13.836 --> 00:05:15.736 You know it doesn't say, but let's just say it is. 00:05:15.756 --> 00:05:17.176 You know my favorite acting role of his? 00:05:17.196 --> 00:05:18.936 Most adults don't know this. 00:05:18.976 --> 00:05:23.096 He was the hacker on Cyberchase on PBS. 00:05:23.116 --> 00:05:23.596 That's right. 00:05:23.616 --> 00:05:25.056 But he had to have kids to know that. 00:05:25.056 --> 00:05:29.496 Christopher Lloyd is hacker, and let's see, Gilbert Gottfried is the parrot. 00:05:29.516 --> 00:05:31.776 Yes, no, no, he's the little duck. 00:05:31.796 --> 00:05:32.716 Yeah, the little bird. 00:05:32.816 --> 00:05:35.496 Yes, of course Gilbert Gottfried would be the duck. 00:05:39.016 --> 00:05:42.796 So yeah, it's a show that teaches mathematics and science to kids. 00:05:43.716 --> 00:05:47.436 That's how I know it, because I'm a child who needs to know about mathematics. 00:05:47.936 --> 00:05:48.556 Hey, let's move on. 00:05:49.536 --> 00:05:50.536 Jason Clow. 00:05:51.216 --> 00:05:52.836 This is also from Facebook. 00:05:52.896 --> 00:05:53.876 This is Jason from Facebook. 00:05:53.896 --> 00:05:54.616 Did they say where they're from? 00:05:54.636 --> 00:05:55.236 I like knowing what city. 00:05:55.256 --> 00:05:55.896 Yeah, they do. 00:05:55.916 --> 00:05:56.236 What city? 00:05:56.856 --> 00:05:58.976 Oh, no, he did not say where he is from, just from Facebook. 00:05:58.996 --> 00:05:59.956 The city of Facebook. 00:06:00.076 --> 00:06:00.876 Yes, exactly. 00:06:01.196 --> 00:06:02.316 Okay, this is what he wants to know. 00:06:02.596 --> 00:06:11.836 What technological advances would be needed to prevent our sun from expanding, and how close are we to obtaining that technology? 00:06:12.656 --> 00:06:13.796 And he has an example. 00:06:13.816 --> 00:06:16.556 Dude, we're still pulling oil out of the ground. 00:06:17.696 --> 00:06:18.136 Dude. 00:06:18.756 --> 00:06:19.496 Oh, snap. 00:06:19.516 --> 00:06:20.496 Dude, give that hope up. 00:06:20.936 --> 00:06:22.196 Yeah, you better think. 00:06:22.216 --> 00:06:23.116 Was there a follow-up? 00:06:23.556 --> 00:06:32.676 No, no, no, he was like, okay, like the Gravity Satellite in Doctor Who, episode SO1EO2, end of the world. 00:06:32.696 --> 00:06:33.176 Oh, that one. 00:06:33.316 --> 00:06:33.696 Yes. 00:06:34.896 --> 00:06:36.836 I'm gonna say that this guy's a real ladies man. 00:06:36.856 --> 00:06:38.976 Just saying. 00:06:39.476 --> 00:06:41.556 He knows episode numbers from Doctor Who. 00:06:41.576 --> 00:06:43.216 You know he is slaying the ladies. 00:06:43.396 --> 00:06:45.716 All right, there is a way to prolong the life of a star. 00:06:46.136 --> 00:06:53.056 And if we were ever to do that for the sun, because our civilization would somehow outlive the life expectancy of most mammals. 00:06:53.536 --> 00:06:56.016 The mammal life expectancy is about three million years. 00:06:56.696 --> 00:07:05.916 And on average, and we're a mammal, so unless we figure out a way to beat those odds, we're toast for one reason or another after, on average, three million years. 00:07:05.936 --> 00:07:07.676 That's why I love talking to you, always so uplifting. 00:07:07.996 --> 00:07:10.536 The sun's got another five billion years left. 00:07:10.776 --> 00:07:15.396 So we'd have to prolong our lives until the sun is ready to die and then prolong the life of the sun. 00:07:15.856 --> 00:07:19.516 So one way to do that is, it's got hydrogen in the center converting it to helium. 00:07:19.536 --> 00:07:20.856 That's the thermonuclear fusion. 00:07:21.176 --> 00:07:24.416 There's a lot of hydrogen in the outer layers that never makes it to the center. 00:07:24.976 --> 00:07:28.596 So when the sun runs out of helium, it only runs out of helium in the center. 00:07:29.196 --> 00:07:36.256 And so what you need is a way to channel helium from the outer layers deep down into the center to give it fresh supply. 00:07:36.376 --> 00:07:38.636 You do that, the sun could live a hundred billion years. 00:07:38.696 --> 00:07:39.316 Oh my God. 00:07:39.336 --> 00:07:40.316 No question about it. 00:07:40.336 --> 00:07:43.596 So you would basically just have to funnel helium back to the sun. 00:07:44.016 --> 00:07:44.456 Did I say helium? 00:07:44.476 --> 00:07:44.816 I meant hydrogen. 00:07:45.716 --> 00:07:46.816 Hydrogen in the outer layers. 00:07:47.016 --> 00:07:48.836 Because it's converting hydrogen into helium. 00:07:49.416 --> 00:07:52.816 All these outer layers, you bring it back in, you prolong the life of the sun. 00:07:52.836 --> 00:07:53.316 Fascinating. 00:07:53.316 --> 00:07:54.816 More after this break. 00:07:54.836 --> 00:07:56.216 You're listening to Cosmic Queries. 00:07:57.056 --> 00:07:57.756 StarTalk. 00:07:57.776 --> 00:07:58.656 We'll see you in a moment. 00:08:16.816 --> 00:08:18.816 We're back on StarTalk Radio. 00:08:18.836 --> 00:08:20.336 I'm your host, Neil deGrasse Tyson. 00:08:20.736 --> 00:08:25.536 I'm an astrophysicist with the American Museum of Natural History, right here in New York City. 00:08:25.556 --> 00:08:28.436 I got with me in studio, Chuck Nice Comic. 00:08:28.576 --> 00:08:30.876 That's right, at Chuck Nice Comic, on Twitter, that's me. 00:08:31.136 --> 00:08:32.216 I'm supposed to plug you. 00:08:32.616 --> 00:08:33.236 All right. 00:08:34.056 --> 00:08:36.716 Just before the break, we talk about prolonging the life of the sun. 00:08:36.736 --> 00:08:41.936 And all you have to do is churn fresh fuel, which lives in the outer layers down into the center. 00:08:42.456 --> 00:08:48.736 And we know this works because there are stars that collide with one another, and when you collide, you mix your materials. 00:08:49.036 --> 00:09:01.716 And stars have a fresh birth, simply because all the helium that it collected in the center as leftover byproduct all gets mixed back into the star and fresh hydrogen shows up in the middle. 00:09:01.836 --> 00:09:04.376 And that's how, and then you have a new life to the star. 00:09:04.396 --> 00:09:11.636 Now, it just seems to me, if we have the power to prolong the life of the sun by churning its contents, we have the power to just move to another damn solar system. 00:09:13.036 --> 00:09:16.596 If we can do that, move to Mars or to Jupiter or to Jupiter's moons, you know what I mean? 00:09:16.856 --> 00:09:19.936 So, there might be other options available than messing with the sun. 00:09:19.996 --> 00:09:22.896 Like making the earth a spaceship and just actually leaving. 00:09:22.916 --> 00:09:24.196 Yeah, keep the whole earth intact. 00:09:24.496 --> 00:09:25.216 I hadn't thought about that. 00:09:25.236 --> 00:09:26.216 And just take it someplace else. 00:09:26.236 --> 00:09:26.456 Cool. 00:09:26.476 --> 00:09:28.676 I mean, hey, if we can manipulate the sun, we can do that, right? 00:09:28.696 --> 00:09:30.836 You can do that, but you need an energy source en route. 00:09:30.936 --> 00:09:31.236 Gotcha. 00:09:31.256 --> 00:09:35.616 So, you gotta get cozy until you get to another solar system. 00:09:35.636 --> 00:09:37.076 To that, I don't think that far ahead of me. 00:09:37.476 --> 00:09:38.376 So, we got another question. 00:09:38.396 --> 00:09:43.716 Yeah, let's go to the phones, actually, and we have on the phone with us, Jared, who is a 16-year-old student. 00:09:43.796 --> 00:09:44.936 Jared, how are you? 00:09:45.016 --> 00:09:45.796 Jared on the line? 00:09:45.816 --> 00:09:46.776 Yeah, it's on the line. 00:09:47.216 --> 00:09:47.936 Jared, hello. 00:09:48.056 --> 00:09:55.636 Now, Chuck introduced you as a student, but as at age 16, I would assume you're a student somewhere, or otherwise you're a truant dropout. 00:09:56.256 --> 00:09:56.556 Yeah. 00:09:57.636 --> 00:10:01.536 Well, I'm a student at North Quinette High School in Sawani, Georgia. 00:10:01.636 --> 00:10:02.256 Okay, cool. 00:10:02.276 --> 00:10:03.376 Well, welcome to StarTalk. 00:10:03.396 --> 00:10:04.176 Yeah, so what do you got? 00:10:04.196 --> 00:10:22.116 So, my question is, in five billion years, when our sun begins to run out of hydrogen to fuse into helium, do you think that we will be able to prolong its life by somehow adding the planet Jupiter or any of the gas giants for that matter into the sun? 00:10:23.076 --> 00:10:23.676 Okay, yes. 00:10:24.756 --> 00:10:25.896 That's an excellent question. 00:10:25.896 --> 00:10:32.236 So, like in the previous segment, we talked about churning the sun, giving it a fresh supply of fuel. 00:10:32.516 --> 00:10:35.876 Of course, Jupiter and or Saturn are mostly hydrogen and helium. 00:10:35.996 --> 00:10:38.396 They have a similar composition to the sun itself. 00:10:38.416 --> 00:10:38.676 Really? 00:10:39.676 --> 00:10:47.336 So, if you had a way to cram Jupiter down into the core, yes, you could prolong the sun even further. 00:10:47.376 --> 00:10:51.176 So, Jared, what do you have against Jupiter, man, if you want to sacrifice it to the sun? 00:10:51.196 --> 00:10:53.296 Yeah, it would be a sacrifice, wouldn't it? 00:10:53.316 --> 00:10:58.336 No, no, I like Jupiter, especially its moons and their potential for life. 00:10:58.436 --> 00:10:59.936 Yeah, the moons are where the action is. 00:10:59.956 --> 00:11:05.876 Like Europa and Io, all of these are kept warm by the stress of Jupiter's gravity. 00:11:06.336 --> 00:11:11.996 Its tidal forces are keeping those moons warm well outside of the habitable zone. 00:11:12.496 --> 00:11:16.436 There's that zone where it's just the right temperature for your liquid water to stay liquid. 00:11:16.456 --> 00:11:16.736 Stay liquid. 00:11:16.976 --> 00:11:19.056 Yeah, not too close, you freeze, not too far away. 00:11:19.076 --> 00:11:23.816 Jupiter's far enough to freeze, but it's got another energy source not dependent on the sun. 00:11:23.836 --> 00:11:27.016 So, Jared, I'm glad you recognize Jupiter's moons in this. 00:11:27.736 --> 00:11:42.636 So the general solution to prolonging the sun is try to get some fuel down into the center, and you wouldn't have to bring a whole planet there because most of the sun's mass never participates in the thermonuclear fusion going on in the core. 00:11:42.916 --> 00:11:57.336 So Jupiter itself could work, but I'm betting that if we're really powerful at solar and geoengineering, that it would be easier to sort of churn the sun's outer layers down into the middle. 00:11:57.636 --> 00:12:06.436 Then it would be to readjust Jupiter's orbit, lose a nighttime planet, lose the beautiful moons around it, just to prolong the sun a little longer. 00:12:06.456 --> 00:12:08.236 There you go. 00:12:08.256 --> 00:12:09.956 So we're gonna keep the neighborhood the same. 00:12:09.976 --> 00:12:10.416 Keep the hood. 00:12:10.436 --> 00:12:11.816 We're gonna keep the hood the same, Jared. 00:12:11.916 --> 00:12:12.776 That's what we're gonna do. 00:12:13.256 --> 00:12:14.856 All right, hey, thanks for calling. 00:12:14.876 --> 00:12:15.136 All righty. 00:12:15.156 --> 00:12:15.656 Thanks, Jared. 00:12:15.776 --> 00:12:16.236 All right. 00:12:16.616 --> 00:12:19.136 And remember, nerds rule, okay? 00:12:20.056 --> 00:12:21.136 All right, buddy, take care. 00:12:22.196 --> 00:12:22.556 All right. 00:12:23.136 --> 00:12:24.276 All right, good. 00:12:24.516 --> 00:12:25.016 Yeah. 00:12:25.036 --> 00:12:25.976 So there's some hope. 00:12:26.556 --> 00:12:27.976 There is hope, I love that. 00:12:27.996 --> 00:12:29.676 We've got high schoolers asking questions like that. 00:12:29.696 --> 00:12:30.596 We got hope for the world. 00:12:30.616 --> 00:12:32.336 Oh, without a doubt, that makes me happy. 00:12:33.416 --> 00:12:34.316 Oh, what else you got there? 00:12:34.336 --> 00:12:39.656 Okay, hey, let's go to Twitter right now, and this comes from at Vincenzo. 00:12:39.676 --> 00:12:42.096 These are people who tweeted at StarTalk Radio. 00:12:42.116 --> 00:12:46.076 They tweeted at StarTalk Radio and asked a question, and this is at Vincenzo. 00:12:46.096 --> 00:12:48.136 Vincenzo, 1023 at Vincenzo. 00:12:48.756 --> 00:12:52.116 I bet he's born October 23rd, that's my guess. 00:12:52.436 --> 00:12:54.316 You know, that's a, I would never think that. 00:12:54.396 --> 00:12:59.976 See, my, I would say there are 1022 other Vincenzo's. 00:12:59.996 --> 00:13:02.716 Okay, all right, here we go. 00:13:02.956 --> 00:13:09.376 How, or could you describe how big the sun would look in the skies of Mercury? 00:13:09.396 --> 00:13:12.656 So the way we see the sun, how would it look from another planet? 00:13:12.676 --> 00:13:15.576 Yeah, I don't have that off the top of my head, but I can calculate it, okay? 00:13:15.936 --> 00:13:20.696 So we are, the Earth-Sun distance is one unit. 00:13:21.056 --> 00:13:22.036 Let's call it one unit. 00:13:22.056 --> 00:13:22.596 Call it one unit. 00:13:22.616 --> 00:13:25.636 We call it one astronomical unit, right? 00:13:25.716 --> 00:13:27.916 That's how you get your way around the solar system, right? 00:13:28.236 --> 00:13:32.616 So Earth is by definition one astronomical unit. 00:13:33.596 --> 00:13:37.196 Venus is.7 astronomical units. 00:13:37.596 --> 00:13:41.076 Mercury is.4 astronomical units. 00:13:41.336 --> 00:13:45.616 So Mercury is like half, basically half the distance. 00:13:46.156 --> 00:13:49.956 If you're half the distance to something, the thing is twice as big. 00:13:49.976 --> 00:13:50.496 Twice as big. 00:13:50.856 --> 00:13:55.016 Yes, so the vantage point would be a huge yellow ball. 00:13:55.036 --> 00:13:57.316 Well, huge, twice as big. 00:13:57.776 --> 00:13:59.756 When we can quantify it, you don't need adjectives. 00:14:00.976 --> 00:14:01.636 It's twice as big. 00:14:03.016 --> 00:14:03.716 I'm just saying. 00:14:03.736 --> 00:14:04.976 Thanks for making me feel smart. 00:14:05.076 --> 00:14:07.836 We got adjectives because we can't quantify, right? 00:14:07.856 --> 00:14:08.456 This is true. 00:14:08.476 --> 00:14:10.416 I felt awesomely huge about that. 00:14:10.436 --> 00:14:12.596 Well, numerically, what was, I can't go there. 00:14:12.636 --> 00:14:14.556 So it would literally be twice as big. 00:14:14.576 --> 00:14:17.356 Yeah, a little bit more than twice as big, but here's what's devastating. 00:14:18.296 --> 00:14:26.316 Light, the intensity of light goes up not as the factor closer, but as the factor closer squared. 00:14:26.976 --> 00:14:30.876 So if you're twice as close, then the intensity of sunlight will be four times as great. 00:14:31.096 --> 00:14:36.436 So the sun would be twice as big in the sky, but you'd never be able to see it. 00:14:36.456 --> 00:14:40.756 It'll be four times, yeah, I mean, you'd be vaporized in the heat. 00:14:41.156 --> 00:14:44.816 Yeah, you'd have other issues than just wondering how big the sun is in the sky. 00:14:45.036 --> 00:14:46.816 Gosh, that is fascinating. 00:14:46.836 --> 00:14:48.756 Well, there you go, Vincenzo, there's your answer. 00:14:49.276 --> 00:14:52.216 That is, the answer is don't look at the sun when you're on Mercury. 00:14:52.516 --> 00:15:03.016 And another issue is you can ask how far away do you have to be for the daytime sky to be so dim that you can see the stars of night in the daytime? 00:15:04.176 --> 00:15:06.176 That question wasn't asked, but this reminds me of that. 00:15:06.196 --> 00:15:07.016 I've thought about this. 00:15:07.016 --> 00:15:07.436 All right. 00:15:07.456 --> 00:15:13.676 And if you get to like around Neptune, that's far enough away so that if Earth were at Neptune, you'd see stars in the daytime. 00:15:14.036 --> 00:15:14.576 Oh, really? 00:15:14.596 --> 00:15:14.916 Yeah, yeah. 00:15:14.936 --> 00:15:15.496 That's kind of cool. 00:15:15.516 --> 00:15:17.296 The full sun would be so dim and so far away. 00:15:17.316 --> 00:15:23.216 Is that the same, I'm sorry, is that the same premise as the moon being visible by day? 00:15:23.236 --> 00:15:26.976 Like sometimes by day you see like a full moon or a half moon in the sky. 00:15:26.996 --> 00:15:27.956 Okay, so two things, Chuck. 00:15:27.976 --> 00:15:28.376 Go ahead. 00:15:28.376 --> 00:15:29.956 You've never seen the full moon in the daytime? 00:15:31.216 --> 00:15:31.656 I have. 00:15:31.696 --> 00:15:31.936 No. 00:15:32.396 --> 00:15:33.916 My vision is that good, Neil. 00:15:34.676 --> 00:15:35.316 Seriously. 00:15:35.336 --> 00:15:35.816 You may have seen. 00:15:36.676 --> 00:15:38.076 I've had Lasik surgery, sir. 00:15:38.176 --> 00:15:39.976 You may have been mooned in the daytime. 00:15:39.996 --> 00:15:41.396 It wasn't like the war. 00:15:41.456 --> 00:15:42.616 All right. 00:15:42.796 --> 00:15:50.036 So here's the thing, but apart from the full moon, which only comes out at night, every other phase of the moon appears at some time during the day. 00:15:50.316 --> 00:15:53.476 The moon is out in the day as often as it's out at night, basically. 00:15:54.096 --> 00:15:58.056 So, contrary to what many people think is what's going on. 00:15:58.256 --> 00:16:01.196 But yeah, you'd be able to see, the moon comes out in the day, but it's not nighttime. 00:16:03.436 --> 00:16:10.136 Neptune is 30 times as far away from the sun as Earth is, 30 AUs, the astronomical units. 00:16:10.376 --> 00:16:16.636 So the sun would be 1 thirtieth the size, and 1 nine hundredth as bright. 00:16:17.176 --> 00:16:17.576 What? 00:16:17.596 --> 00:16:18.316 30 squares. 00:16:18.336 --> 00:16:20.096 So basically 1 one thousandth as bright. 00:16:20.196 --> 00:16:22.196 Yeah, and it's just another, it's just a dim light. 00:16:22.216 --> 00:16:22.956 It's a blip. 00:16:23.016 --> 00:16:23.836 It's a pin. 00:16:23.856 --> 00:16:25.096 It's a pin hole in the sky. 00:16:25.096 --> 00:16:25.436 Blip. 00:16:25.556 --> 00:16:30.216 So now let me ask you a piece of trivia, and you'll tell, you say this full moon never comes out during the day. 00:16:30.616 --> 00:16:30.956 Never. 00:16:31.396 --> 00:16:32.036 Ever. 00:16:32.276 --> 00:16:33.956 So how about a solar eclipse? 00:16:34.316 --> 00:16:34.976 Would that be? 00:16:34.996 --> 00:16:37.396 A total solar eclipse is new moon. 00:16:37.776 --> 00:16:38.416 That's a new moon. 00:16:38.916 --> 00:16:44.416 You're looking at the backside of the moon, which is completely dark, because it's the other side that's lit up, that's coming between you and the sun. 00:16:44.536 --> 00:16:46.276 You always have an answer, don't you? 00:16:46.296 --> 00:16:46.516 No. 00:16:49.816 --> 00:16:52.776 Just because my answers sound like they need a snap at the end. 00:16:52.796 --> 00:16:53.736 All right, go. 00:16:53.756 --> 00:16:54.816 We got like 90 seconds before. 00:16:54.836 --> 00:16:55.776 We got 90 seconds, here we go. 00:16:55.796 --> 00:16:56.276 We got another one. 00:16:56.436 --> 00:16:57.896 You know what, let me find a quick one. 00:16:58.376 --> 00:17:02.716 Are we just incredibly lucky to have a sun 400 times bigger than our moon and 400 times farther away? 00:17:03.236 --> 00:17:08.036 What are the odds of another star planet moon system out there having this same exact setup? 00:17:08.256 --> 00:17:08.716 It's luck. 00:17:09.456 --> 00:17:09.996 Oh my God. 00:17:10.016 --> 00:17:22.656 What he's asking is, during a total solar eclipse, the size of the moon is basically exactly the same size as the sun, so it makes for a beautiful eclipse watching, but it has very little other meaning or value. 00:17:22.936 --> 00:17:25.196 Early in the history of the earth, the moon was closer. 00:17:25.216 --> 00:17:28.796 Do you know the moon is spiraling away from earth at about two inches per year? 00:17:29.036 --> 00:17:30.996 You told me that before, that's the only reason I know it. 00:17:30.996 --> 00:17:35.216 Okay, so in the past, the moon was closer and bigger. 00:17:35.596 --> 00:17:39.256 So for most of earth's history, the moon was much larger than the sun. 00:17:39.716 --> 00:17:46.456 You still get eclipses, but you wouldn't get that beautiful sort of corona edge atmosphere of the sun glowing around the out there. 00:17:46.476 --> 00:17:47.916 Setting that mood lighting for the earth. 00:17:47.936 --> 00:17:50.576 It's so mood lighting for four minutes at a time. 00:17:50.796 --> 00:17:54.176 So it is complete coincidence that that's the case. 00:17:54.676 --> 00:17:56.096 And it won't forever be that way. 00:17:57.436 --> 00:18:02.216 As the moon continues to spiral away, one day it'll become smaller than the sun in all cases. 00:18:02.516 --> 00:18:05.496 So you'll get what's called an annular eclipse. 00:18:05.516 --> 00:18:06.376 An annular eclipse. 00:18:06.396 --> 00:18:09.156 Yes, which is Latin is it for a ring. 00:18:09.176 --> 00:18:10.996 An annulus is a ring. 00:18:11.436 --> 00:18:16.756 And so what happens is the moon doesn't completely cover the sun and it leaves a ring of sunlight around the edge. 00:18:16.996 --> 00:18:18.556 It's also a beautiful thing to behold. 00:18:18.676 --> 00:18:18.996 Awesome. 00:18:19.016 --> 00:18:20.516 But you need filters and things to watch it. 00:18:21.196 --> 00:18:22.316 There you go. 00:18:22.596 --> 00:18:26.176 We'll be back on Star Talk Radio, for the Cosmic Queries edition. 00:18:45.328 --> 00:18:48.048 This is StarTalk Radio, we're back. 00:18:48.688 --> 00:18:50.988 I'm Neil deGrasse Tyson with Chuck Nice. 00:18:52.428 --> 00:18:54.988 I just heard you just co-hosted The View. 00:18:55.408 --> 00:18:57.908 Does this give you like, women credit? 00:18:57.928 --> 00:18:58.428 Like, what do you? 00:18:59.128 --> 00:19:05.088 You know, I gotta tell you, Neil, I don't believe anything will ever give me women credit, to be honest. 00:19:05.408 --> 00:19:10.748 Gloria Steinem could actually breastfeed me, and I wouldn't have women credit. 00:19:11.508 --> 00:19:13.848 I know that loud men to co-host is a special thing. 00:19:14.168 --> 00:19:17.648 Well, they do it on Fridays, and so they had a Guide Day Friday, and I was the co-host for that. 00:19:17.668 --> 00:19:18.188 Guide Day Friday. 00:19:18.208 --> 00:19:19.348 For that particular Guide Day Friday. 00:19:19.368 --> 00:19:20.188 All right, I'll look for you. 00:19:20.208 --> 00:19:21.248 Yeah, yeah, it's fun. 00:19:21.628 --> 00:19:23.228 All right, so these are Cosmic Queries. 00:19:23.248 --> 00:19:23.548 Yes. 00:19:23.568 --> 00:19:24.648