Cosmic Queries: Answers at the Speed of Light

Join us for another episode of Cosmic Queries, where astrophysicist Neil deGrasse Tyson answers fan questions about light, energy and the universe as fast as comic co-host Leighann Lord can ask them.

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?

  This is StarTalk Radio. I'm your host Neil deGrasse Tyson. I'm your personal astrophysicist. I hail from New York City where I serve as Director of the Hayden Planetarium of the American Museum of Natural History and you're all invited. I got with me in studio here in New York, Leigh Anne Lord. Leigh Anne, welcome back.

• 0:41Speaker 01

  Thank you.

• 0:41Neil deGrasse Tyson?

  Love having you on the show.

• 0:43Speaker 01

  Good to be here.

• 0:44Neil deGrasse Tyson?

  And this is the cosmic queries part, the cosmic queries sector of the universe, I'd like to think. And we've called questions submitted to us on, in all of our social media.

• 0:57Speaker 01

  Yes.

• 0:57Neil deGrasse Tyson?

  Twitter, on our Facebook page.

• 0:59Speaker 01

  Email.

• 1:00Neil deGrasse Tyson?

  Email and on StarTalkRadio.com. And so this is a hodgepodge, I think.

• 1:05Speaker 01

  Yes.

• 1:05Neil deGrasse Tyson?

  And I haven't seen them and you've collected them and you're gonna hand them to me.

• 1:09Speaker 01

  Yes.

• 1:09Neil deGrasse Tyson?

  And if I don't know the answer, I'll just say, "I have no idea."

• 1:12Speaker 01

  Well, I can be honest right up front. I have no idea.

• 1:15Neil deGrasse Tyson?

  So let's do this.

• 1:16Speaker 01

  All right.

• 1:16Neil deGrasse Tyson?

  Go.

• 1:17Speaker 01

  We have a question and email that came from James Isaac Dagenhart. And he says, "I have read about something called Modified Newtonian Dynamics," he reads a lot, "that was introduced as being a possible model that doesn't presume the existence of dark matter. Does this have any credence or is this pseudoscience sensationalism?"

• 1:37Neil deGrasse Tyson?

  Man, what an erudite question.

• 1:40Speaker 01

  Yes.

• 1:40Neil deGrasse Tyson?

  Modified Newtonian Dynamics, that's otherwise known in the trade as MOND.

• 1:44Speaker 01

  Okay.

• 1:45Neil deGrasse Tyson?

  MOND, Modified Newtonian Dynamics.

• 1:48Speaker 01

  And would that be an acronym?

• 1:50Neil deGrasse Tyson?

  Yes, an acronym. When letters come together and you can pronounce them, right? But the CIA is not an acronym unless you said CIA. We actually spell out the letters.

• 2:01Speaker 01

  Okay.

• 2:01Neil deGrasse Tyson?

  Yeah, IBM, not an acronym. Just putting that on the table.

• 2:04Speaker 01

  Got it.

• 2:05Neil deGrasse Tyson?

  So, so what does he want to know? Oh, so... People don't like explaining things that we don't understand by other things that we understand less.

• 2:16Speaker 01

  Okay.

• 2:16Neil deGrasse Tyson?

  So the dark matter problem in the universe where there's six times as much gravity out there than matter enough to account for it.

• 2:26Speaker 01

  Right.

• 2:27Neil deGrasse Tyson?

  All right.

• 2:27Speaker 01

  I understand.

• 2:28Neil deGrasse Tyson?

  Where did it come from? And when this problem was discovered, this is now, you know, 80 years ago, it was called the missing mass problem. There's surely some mass out there, but we can't find it.

• 2:38Speaker 01

  Where is it?

• 2:38Neil deGrasse Tyson?

  Because I see gravity from it.

• 2:40Speaker 01

  Mm-hmm.

• 2:41Neil deGrasse Tyson?

  And so what's the solution? It is the longest standing unsolved problem in modern astrophysics, the dark matter problem. And so there are people who say, it's not a matter problem, you just don't understand gravity. Because why do I think there's too much gravity? Because I used an equation of gravity that told me that. An equation handed to me by Isaac Newton, his universal law of gravitation.

• 3:07Speaker 01

  Okay.

• 3:07Neil deGrasse Tyson?

  So I got his equation, I plug it in and I put in the numbers, it says, the matter that's out there is not giving me as much gravity as I see. So MAND takes, it starts out with Newton's gravity because it knows that works for most cases, but these extreme cases in galaxies and galaxy clusters, there's an extra term there, there's an extra acceleration to account for the extra gravity brought to you by the matter that we've all known and loved. That's MAND, modified Newtonian gravity. And it has some interesting, successful applications, but it doesn't explain everything.

• 3:44Speaker 01

  No.

• 3:45Neil deGrasse Tyson?

  For example, we need dark matter in the early universe to explain anything we know about the formation of everything in the cosmos. So this, so they're still duking it out. And if I were to vote, I would say MAND is on its way out.

• 3:58Speaker 01

  Really?

• 3:59Neil deGrasse Tyson?

  Yeah, but it was there fighting for a while.

• 4:01Speaker 01

  Well, I mean, isn't, doesn't that, that's what science does. You come up with what's a plausible explanation at the time and you test and you test and see if it stands up and if it doesn't, you throw it out.

• 4:09Neil deGrasse Tyson?

  There's nothing wrong with a wrong idea.

• 4:12Speaker 01

  Right.

• 4:12Neil deGrasse Tyson?

  The time you put it in, if it helps you try to solve a problem. One of the greatest wrong ideas ever was the geocentric universe with the earth in the middle.

• 4:20Speaker 01

  I thought you were gonna say leg warmers.

• 4:22Neil deGrasse Tyson?

  I used to have leg warmers.

• 4:24Speaker 01

  Oh, you better stop.

• 4:24Neil deGrasse Tyson?

  I used to wear leg warmers.

• 4:25Speaker 01

  You little flash dancer.

• 4:26Neil deGrasse Tyson?

  Well, I used to dance, so I, so it was, I wasn't just wearing them because it was like, you know.

• 4:31Speaker 01

  You were chilly? Wow.

• 4:34Neil deGrasse Tyson?

  Yeah, I still have them too.

• 4:35Speaker 01

  You are such a renaissance.

• 4:36Neil deGrasse Tyson?

  Put them on and I then I point my toe and raise my leg. Yeah, yeah.

• 4:39Speaker 01

  Wow, Renaissance man.

• 4:40Neil deGrasse Tyson?

  Well, not anymore. That was just like long ago. But anyhow, what else you got?

• 4:44Speaker 01

  In a galaxy far, far away. I have no question.

• 4:47Neil deGrasse Tyson?

  There's still people working on Mond.

• 4:49Speaker 01

  Okay, even though they they didn't get the memo, it's on the way out.

• 4:51Neil deGrasse Tyson?

  And we still don't have dark matter completely understood. So until that happens, you know, there'll be people still fighting the good fight and that's that's science at its best. Yeah.

• 5:00Speaker 01

  Love it.

• 5:01Neil deGrasse Tyson?

  All right.

• 5:01Speaker 01

  I have a question from Anil Virik.

• 5:04Neil deGrasse Tyson?

  Mm hmm.

• 5:04Speaker 01

  And it's about lightning.

• 5:05Neil deGrasse Tyson?

  Where are the these people? Do we know where they're from?

• 5:07Speaker 01

  You know, um, Anil did not say.

• 5:09Neil deGrasse Tyson?

  Okay.

• 5:09Speaker 01

  Oh, wait. Um, no, didn't say. They just sent the email.

• 5:13Neil deGrasse Tyson?

  Okay, just an email. All right.

• 5:14Speaker 01

  So, uh, right now they're from Gmail.

• 5:18Neil deGrasse Tyson?

  What country is that?

• 5:19Speaker 01

  That's everywhere.

• 5:20Neil deGrasse Tyson?

  Yeah.

• 5:21Speaker 01

  Gmail is dark matter.

• 5:22Neil deGrasse Tyson?

  Mm hmm.

• 5:22Speaker 01

  Uh, now I heard lately that lasers have been used to try to direct lightning strikes, strikes. Uh, the laser is shot into the thunderhead clouds and the plasma flows the laser back. Is there a way to harness this energy and make lightning farms?

• 5:37Neil deGrasse Tyson?

  Well, first of all, that's that's the first I've heard of this and I think it's amazing. And I can even explain how it works, even though I only just learned of it.

• 5:46Speaker 01

  Because you're that bad.

• 5:47Neil deGrasse Tyson?

  No.

• 5:49Speaker 01

  Cue music.

• 5:51Neil deGrasse Tyson?

  The idea, a theme, a theme.

• 5:53Speaker 01

  You do. You're like, you're the shaft of science. What you talk about?

• 5:58Neil deGrasse Tyson?

  Do you know, I was listening to, uh, uh, uh, XM radio, uh, seventies on seven, you know, because they have the sixties on six and seventies on seven. And on came the theme to Shaft. And I hadn't heard that in a long time. Who's the bad motherfucker, sex machine to all the chicks? And this goes on and on. And then immediately after that song, they didn't miss a beat. They played John Denver's Thank God I'm a Country Boy. It was like, no.

• 6:22Speaker 01

  Hey, Mr. DJ, did you not take your meds today?

• 6:27Neil deGrasse Tyson?

  Now, I happen to like both songs, but you don't play them. This is not a mixtape. We're gonna play "Thank God I'm a Country Boy" after Shaft.

• 6:35Speaker 01

  You could have hurt yourself on a dance floor with that.

• 6:37Neil deGrasse Tyson?

  Man, okay, now, sorry, I distracted myself. Where were we?

• 6:41Speaker 01

  Lightning farm, sir.

• 6:42Neil deGrasse Tyson?

  So, here's what happens. Lightning comes about because there's a difference in charge between a cloud and the ground beneath it.

• 6:51Speaker 01

  Yes.

• 6:51Neil deGrasse Tyson?

  And charges don't like being separate from one another. All right? The molecules reach an excited state because they've lost their electrons.

• 6:59Speaker 01

  Mm-hmm.

• 7:00Neil deGrasse Tyson?

  They don't like staying that way.

• 7:02Speaker 01

  Okay.

• 7:02Neil deGrasse Tyson?

  And all electrons are sitting on the ground, and those electrons want to get back to the cloud. And so, so the cloud comes over, the electrons gather, and they're ready to rise up and reach the cloud again. Thus is born a lightning strike, which tells you that lightning goes from the ground to the cloud, not the cloud to the ground.

• 7:21Speaker 01

  Really?

• 7:22Neil deGrasse Tyson?

  Now, so, if you take a laser that's very high power and you ionize gas at the atmosphere in one place versus another, you can build charges around where the cloud is and force a lightning bolt to go where you say so. Now, that's good.

• 7:41Speaker 01

  Yeah.

• 7:42Neil deGrasse Tyson?

  Now, the person wants to know if we can make a lightning farm out of that? I say, why not? More Cosmic Queries when we return.

• 8:09Neil deGrasse Tyson?

  We're back on StarTalk After Hours. Leanne, I shouldn't keep calling. It's Cosmic Queries.

• 8:16Speaker 01

  No, I like the After Dark.

• 8:17Neil deGrasse Tyson?

  You like that?

• 8:18Speaker 01

  Yes, it's part of the show's DNA now.

• 8:19Neil deGrasse Tyson?

  Oh, thank you.

• 8:20Speaker 01

  We keep it.

• 8:21Neil deGrasse Tyson?

  How bioliterate of you.

• 8:23Speaker 01

  Well, you know what? Hanging out with the folks of your ilk.

• 8:25Neil deGrasse Tyson?

  This, if you can't be... Bioliterate here, you know, where can that happen? You're reading me questions.

• 8:32Speaker 01

  Yes.

• 8:32Neil deGrasse Tyson?

  Call from the internet and right before the break, there was a question about lightning farms.

• 8:37Speaker 01

  Yes.

• 8:37Neil deGrasse Tyson?

  By creating spots where the lightning would strike using high powered lasers that would ionize the air. And it's a great idea. At first I learned of it was that question, but it sounds great.

• 8:46Speaker 01

  It does.

• 8:46Neil deGrasse Tyson?

  You just have to watch out that your lasers aren't so powerful to ionize the air in places so that you can force a lightning discharge that you're using more energy than you get back from the lightning itself.

• 8:56Speaker 01

  Because then that would be inefficient.

• 8:57Neil deGrasse Tyson?

  It would, then you're not making a light, you're not farming anything.

• 9:00Speaker 01

  Right now.

• 9:01Neil deGrasse Tyson?

  You're getting less than what you started with. Now, it turns out the act of forming a raindrop in a cloud takes some charge out of the cloud and brings it to the ground.

• 9:10Speaker 01

  Okay.

• 9:11Neil deGrasse Tyson?

  So you're relying on the sun, which evaporated the water in the first place to make the cloud, to then drop the water, bringing charges to the ground. You're relying on that in the first place. So if the lasers just to help it out, to direct the lightning where it would have struck anyway, but now you strike to, strike it to your spot, your sweet spot, then you got a good farm going.

• 9:33Speaker 01

  I'm sorry, my what?

• 9:34Neil deGrasse Tyson?

  I just had to say, I had to just clarify all of that. Yeah. Oh, sorry.

• 9:38Speaker 01

  I, I need a moment. I think I need a cigarette. The man said my sweet spot. I didn't hear anything after that. I'm gone. I'm just gone. I'm gone.

• 9:48Neil deGrasse Tyson?

  We gotta bring it back into the show.

• 9:49Speaker 01

  Okay.

• 9:50Neil deGrasse Tyson?

  Actually, I, I, I think we have a caller, actually.

• 9:52Speaker 01

  Do we really?

• 9:53Neil deGrasse Tyson?

  Yeah.

• 9:53Speaker 01

  I love it.

• 9:54Neil deGrasse Tyson?

  Yeah. So some people actually don't use the internet to bring in their questions. They actually use this old fashioned technology called a telephone.

• 10:01Speaker 01

  You're gonna have to explain that one.

• 10:02Neil deGrasse Tyson?

  Let's find out. Caller, are you there?

• 10:04Speaker 02

  Yes, I am.

• 10:05Neil deGrasse Tyson?

  Hello, caller.

• 10:06Speaker 02

  How are you today?

• 10:07Neil deGrasse Tyson?

  Okay, you know my name, but I don't know your name.

• 10:09Speaker 02

  Well, I'm not gonna tell you right away if that's okay.

• 10:12Neil deGrasse Tyson?

  Oh, okay.

• 10:13Speaker 02

  I, I actually called in to see if you could figure out what my name is.

• 10:17Neil deGrasse Tyson?

  Oh, okay. All right.

• 10:20Speaker 02

  My dad was a physicist, a lot like yourself. He did cosmology, black holes and all that stuff.

• 10:25Neil deGrasse Tyson?

  Mm-hmm.

• 10:26Speaker 02

  And so my mother named the first child, so she said that he could name the second child, which is me.

• 10:31Neil deGrasse Tyson?

  Uh-oh.

• 10:32Speaker 02

  Yeah.

• 10:33Neil deGrasse Tyson?

  You're giving naming rights to the physicist in the family.

• 10:36Speaker 02

  That's right.

• 10:36Neil deGrasse Tyson?

  These are the same people who named quarks, up, down, top, bottom, strange and charmed.

• 10:42Speaker 02

  Exactly.

• 10:42Neil deGrasse Tyson?

  These are the same, same people who couldn't come, come up with a more inventive name for their super collider, but super, the, the superconducting super collider. It's like, you know.

• 10:53Speaker 01

  Which I saw on the Super Friends.

• 10:56Neil deGrasse Tyson?

  If astrophoke had, I'd call it the super duper collider, right? The physicist, I don't know if the, so have you led a disturbed life because of this? What, what name did you end up with?

• 11:05Speaker 02

  Well, I'm gonna see if you can figure it out.

• 11:07Neil deGrasse Tyson?

  Okay.

• 11:08Speaker 02

  I think he did a little better than that.

• 11:10Neil deGrasse Tyson?

  Alright.

• 11:11Speaker 02

  Okay, so my name is Daco, D A C O.

• 11:16Neil deGrasse Tyson?

  D A C O.

• 11:18Speaker 02

  What do you think that stands for?

• 11:20Neil deGrasse Tyson?

  I have no idea. Dec- Deco.

• 11:24Speaker 02

  Deco, but think of each letter as

• 11:27Neil deGrasse Tyson?

  Okay, D.

• 11:28Speaker 02

  representing something in an equation.

• 11:30Neil deGrasse Tyson?

  Something that would come out of the brain of a physicist.

• 11:33Speaker 02

  Okay, give me a hint on the, on the D.

• 11:35Neil deGrasse Tyson?

  Well, let me try, well, D could be like delta, perhaps. Or D could be, the little d as when you're taking a derivative in calculus. Oh, it is.

• 11:43Speaker 02

  That's, you got the D?

• 11:44Neil deGrasse Tyson?

  Okay, so D A, alright, um, would be a derivative of the variable A. And A could be acceleration.

• 11:54Speaker 02

  That's it?

• 11:55Neil deGrasse Tyson?

  Oh, it is! I'm loving it! Oh my god! It's like a movie. Okay. It's like a Dan Brown movie, you're figuring out the However, the, the first derivative of acceleration is hardly ever talked about because it, it, it's called the jerk. Did you know, did you know that? It's called the jerk. It's called the Steve Martin?

• 12:14Neil deGrasse Tyson?

  So, if you, if you put on the brake in a car and then you start leaning forward, that's a constant lean. When, when a plane takes off on the runway, there's a constant pressure that you feel backwards. Alright, so under constant acceleration, you're leaning. Right. If you change the acceleration, you jerk. Yes. Okay? Okay. That's how you go. Got it. So, if you're slowing down constantly, but then you slam on the brake, you jerk forward rather than lean forward smoothly. Okay. So, the first derivative of acceleration will be the jerk, okay?

• 12:47Speaker 02

  Let me give you a little hint on the C. It has something to do with E equals M C squared.

• 12:52Neil deGrasse Tyson?

  Well, C is, would clearly be the speed of light, but I don't know what D A would be, though, relative to C as the speed of light. And then I thought, O could be like a little O, so, uh, I don't know, the speed of light in a vacuum, perhaps? But I could, uh, but, uh, other than that, I have no idea where he was going with this.

• 13:11Speaker 02

  Well, I, I think you, you answered the question, because I think it's the speed of light.

• 13:18Speaker 02

  So, the way I understand it is that D is derivative, A is acceleration, C is a constant at an E equals M C squared,

• 13:26Neil deGrasse Tyson?

  Yes.

• 13:27Speaker 02

  And O is zero. So, I'm thinking no change in acceleration at the speed of light and that just makes me the speed of light, but again, I'm not the physicist, I don't really know. I just have to go on faith here.

• 13:39Neil deGrasse Tyson?

  What, well, he didn't tell you?

• 13:41Speaker 02

  Well, he said it was an equation.

• 13:44Neil deGrasse Tyson?

  Oh, okay, I think we still could work on this.

• 13:47Speaker 02

  You think so?

• 13:48Neil deGrasse Tyson?

  Let me keep work, let me think about this some more. I'll give you the speed of light, but the DA, I don't know, it's, let me think this one through.

• 13:56Speaker 01

  I love it, that is such a great first date conversation.

• 14:00Speaker 02

  I know, it's, it's always been a topic of conversation, really.

• 14:03Speaker 01

  That's so built in and wonderful.

• 14:05Speaker 02

  And just think, if I was a physicist, I would, you know, have a great name, but I'm not, I can't get my head wrapped around all that math.

• 14:13Neil deGrasse Tyson?

  I'll hook you up.

• 14:14Speaker 02

  In fact, I'm a writer, and I actually just debuted with my first novel, it's a thriller, it's called The Libra Affair.

• 14:22Neil deGrasse Tyson?

  The Libra Affair.

• 14:23Speaker 02

  Yeah, and actually, it's relevant to you, because the, um, the heroine is a NASA scientist.

• 14:28Neil deGrasse Tyson?

  Uh huh.

• 14:29Speaker 01

  Love it.

• 14:30Speaker 02

  And the heroine targets him, she's a lady spy, because she wants to get a hold of his laser that's going up in space with SpaceX.

• 14:37Neil deGrasse Tyson?

  The chicks dig the lasers.

• 14:38Speaker 01

  They like the laser.

• 14:39Speaker 02

  He's sending it up to zap space debris, which is really relevant today, and she wants to get a hold of it to zap a missile, but, yeah, it's quite interesting, huh?

• 14:49Neil deGrasse Tyson?

  Wow, well, congratulations on that.

• 14:52Speaker 01

  Yes.

• 14:52Speaker 02

  Thank you, thank you, it came out and I'm, I'm really excited and, um, maybe I'll do well.

• 14:58Neil deGrasse Tyson?

  Well, and, and you're surely the only Deco in, uh, in the world, so.

• 15:03Speaker 02

  That's right.

• 15:03Neil deGrasse Tyson?

  One does, you could, you can start, you can start going solo name on this, who needs your last name when you have a unique first name?

• 15:10Speaker 02

  You know what, I'm publishing under only my first name, Deco. And my logo is thrillers at the speed of light.

• 15:18Neil deGrasse Tyson?

  Oh.

• 15:19Speaker 01

  You are so on it. What's the name of your book, hon?

• 15:21Speaker 02

  The Libra Affair.

• 15:23Speaker 01

  The Libra Affair.

• 15:23Neil deGrasse Tyson?

  The Libra Affair. Libra, of course, is a constellation, one of the twelve of the traditional zodiac.

• 15:28Speaker 01

  Traditional, because they did change last year.

• 15:29Neil deGrasse Tyson?

  Well, no, we've had thirteen constellations forever in it.

• 15:32Speaker 01

  Oh, they just didn't mention it to other people?

• 15:34Neil deGrasse Tyson?

  Every two years, people forget it, and someone announces it, and they think it's something new that got discovered.

• 15:39Speaker 01

  Wow.

• 15:39Neil deGrasse Tyson?

  And, in fact, the symbol for pound in our world is what?

• 15:43Speaker 01

  Hashtag?

• 15:44Neil deGrasse Tyson?

  No. Well, it can be that, but it's letters. It's what?

• 15:46Speaker 01

  L.B.

• 15:47Neil deGrasse Tyson?

  L.B., which is Libra. Did you know that?

• 15:49Speaker 01

  Uh.

• 15:49Neil deGrasse Tyson?

  Most people, like, write L.B. all their whole lives and don't know that means, uh, Libra.

• 15:55Speaker 01

  I had no idea.

• 15:55Neil deGrasse Tyson?

  Yeah. You never stopped and thought, why does L.B. stand for pound?

• 15:59Speaker 01

  Uh, no, dude, I really didn't. I had other fish to fry.

• 16:02Neil deGrasse Tyson?

  Libra is the scales. And Libra is the constellation in the sky that has the star names that are the longest of all the others.

• 16:09Speaker 02

  How about that?

• 16:10Neil deGrasse Tyson?

  Yeah.

• 16:10Speaker 01

  You would be hella great on Jeopardy.

• 16:12Neil deGrasse Tyson?

  No, no, so let me tell you. So, two of the stars in the constellation Libra, one is Zubel Janubi, and the other one is Zubel Shemali.

• 16:19Speaker 02

  Wow.

• 16:19Speaker 01

  Zubel Jalubi?

• 16:21Neil deGrasse Tyson?

  Zubel Janubi and Zubel Shemali.

• 16:24Speaker 01

  Someone who listens to this show is naming their twins this as we speak. And it's your fault.

• 16:31Neil deGrasse Tyson?

  So, did you, when you grew up, Deco, did you, like, were you beaten up by other girls who?

• 16:37Speaker 02

  Well, they didn't beat me up. They were afraid of me because I was so unique. I had this unique name.

• 16:42Speaker 01

  She's the speed of light. How could they catch her?

• 16:43Neil deGrasse Tyson?

  There you go.

• 16:44Speaker 02

  They couldn't catch me.

• 16:45Neil deGrasse Tyson?

  You got it. Well, I'm gonna keep working on your, on your thing. Now, did you have a question, or was your question, what was the meaning of your name?

• 16:51Speaker 02

  Well, I wanted to see if you could figure out what my name meant.

• 16:54Neil deGrasse Tyson?

  Okay, I can, I think I can do better than just representing them as single symbols, because maybe they come together in some important way.

• 17:01Speaker 02

  Well, that would be interesting, because I've, you know, I've got on my website this meaning, and if I'm wrong, boy, I need to correct that.

• 17:08Neil deGrasse Tyson?

  Let me see if I can.

• 17:08Speaker 02

  I've got the whole literary world believing that I'm the speed of light.

• 17:12Neil deGrasse Tyson?

  No, we can still get the speed of light in there, because C is the speed of light. We're not gonna argue that.

• 17:16Speaker 02

  Okay.

• 17:17Neil deGrasse Tyson?

  Let me work on it, and we'll get back to you.

• 17:19Speaker 02

  Okay, super. Thank you so much for taking my call. It's been so much fun.

• 17:23Neil deGrasse Tyson?

  Happy to have you on. Well, thanks for calling StarTalk, the Cosmic Queries Edition. So, so Leanne.

• 17:31Speaker 01

  Yes.

• 17:32Neil deGrasse Tyson?

  Yeah, so, so what was your mother smoking when she named you?

• 17:35Speaker 01

  Um, I had, listen, you ask what my dad was smoking, because this is what happens when you let fathers name their kids.

• 17:40Neil deGrasse Tyson?

  Oh, is that what that is?

• 17:41Speaker 01

  Yes, my dad was a big fan of Vivian Leigh.

• 17:43Neil deGrasse Tyson?

  Oh.

• 17:44Speaker 01

  That's how I got the L E I G H.

• 17:46Neil deGrasse Tyson?

  Uh huh.

• 17:46Speaker 01

  And then they just threw, tacked on the end, so where people think I'm from the South, and I'm not.

• 17:51Neil deGrasse Tyson?

  Yeah, Leanne, where's your accent? Yeah, but you're from Brooklyn or something, right?

• 17:54Speaker 01

  I'm from Queens.

• 17:56Neil deGrasse Tyson?

  Queens, excuse me.

• 17:58Speaker 01

  Yeah, come on, get it right now.

• 17:59Neil deGrasse Tyson?

  So I got like fifteen seconds, is there a fifteen second question there?

• 18:02Speaker 01

  No, man, there's really not. These, these people, these are emails, people did not feel constrained in any way.

• 18:07Neil deGrasse Tyson?

  Huh.

• 18:08Speaker 01

  We have novel sized questions here.

• 18:10Neil deGrasse Tyson?

  Oh, because if it came over Twitter, they, they'd contain it in a hundred and forty characters.

• 18:13Speaker 01

  Email, people are not containing themselves.

• 18:15Neil deGrasse Tyson?

  All right, well, we'll get back to a longer question on the cosmos in the Cosmic Queries edition, right after this.

• 18:40Neil deGrasse Tyson?

  We're back to the Cosmic Queries of StarTalk. I'm Neil deGrasse Tyson. Leanne.

• 18:46Speaker 01

  Leanne Lord is here.

• 18:48Neil deGrasse Tyson?

  Leanne Lord, how are you?

• 18:49Speaker 01

  I'm excellent, how are you?

• 18:50Neil deGrasse Tyson?

  All right, well, you were reading me questions before the break.

• 18:51Speaker 01

  I was.

• 18:52Neil deGrasse Tyson?

  Called from, in this case, email, right?

• 18:54Speaker 01

  Yes.

• 18:55Neil deGrasse Tyson?

  You know where they're from, sometimes they tell us where they're from?

• 18:56Speaker 01

  Well, actually, yes, I do have someone who has emailed us from Barcelona.

• 19:00Neil deGrasse Tyson?

  Barcelona.

• 19:00Speaker 01

  Barcelona.

• 19:01Neil deGrasse Tyson?

  Yeah.

• 19:02Speaker 01

  Yes, they have the lift.

• 19:03Neil deGrasse Tyson?

  Yes.

• 19:04Speaker 01

  Uh, and this is from Joan.

• 19:05Neil deGrasse Tyson?

  Beautiful, beautiful city, of course.

• 19:06Speaker 01

  Of course.

• 19:07Neil deGrasse Tyson?

  Yeah.

• 19:07Speaker 01

  I wouldn't know.

• 19:09Neil deGrasse Tyson?

  You gotta get out.

• 19:10Speaker 01

  I don't get out, well, no, I get out, I just haven't been there.

• 19:12Neil deGrasse Tyson?

  Okay.

• 19:13Speaker 01

  Um, this is from Joan, Joan, uh, Jean Perre, or Jean Perre, I'm not sure. And, uh, she says, congratulations on this great show, and it makes, uh, my daily two-hour train trips to work a lot easier, so we're helping people on their commute.

• 19:26Neil deGrasse Tyson?

  Wow, thank you.

• 19:29Speaker 01

  Uh, now she says that, uh, some time ago, Stephen Hawking said that in a contact, uh, with an advanced civilization, uh, it could turn very bad for us, uh, same as when Europeans went to America. So, can the potential risks of contacting an alien civilization, uh, somehow be evaluated? Um, I guess that according to the history of only advanced civilization that we know, uh, so far, it doesn't look pretty for us.

• 19:54Neil deGrasse Tyson?

  Yeah, so all of our worries derive entirely from the fact that anytime we did that, we totally messed over the folks that we came upon.

• 20:04Speaker 01

  Just a bit.

• 20:04Neil deGrasse Tyson?

  And the analogy here is that if anybody visits us, that means they cross the vast emptiness of space in some kind of vehicle that is beyond our capacity to accomplish.

• 20:19Speaker 01

  Right.

• 20:19Neil deGrasse Tyson?

  Because we're not doing that.

• 20:20Speaker 01

  Right.

• 20:21Neil deGrasse Tyson?

  Which would make them more advanced than we are.

• 20:23Speaker 01

  Mm-hmm. And coming over in Range Rovers is what they say.

• 20:27Neil deGrasse Tyson?

  A, B, now they come over, in all the cases where the Europeans went to the New World, they had greater technologies than the people they came upon.

• 20:35Speaker 01

  Mm-hmm.

• 20:36Neil deGrasse Tyson?

  And it's always been bad for the people with the lesser technologies. So the fear factor that Stephen Hawking is expressing is more a fear of how he knows we would treat other people than it is from any actual knowledge of how an actual alien would treat us. So in fact, he's holding up a mirror to our own cultures and our own motivations.

• 20:58Speaker 01

  So it's transference. We're assuming they're going to act like we.

• 21:01Neil deGrasse Tyson?

  I didn't know there's such a word. Sure, the psychology talk, transference?

• 21:04Speaker 01

  Just a little bit.

• 21:05Neil deGrasse Tyson?

  Yeah, transference. I'll go with that. That's what it was.

• 21:09Speaker 01

  I co-host a psychology show, so I learned some stuff over there and bring it here.

• 21:14Neil deGrasse Tyson?

  All right.

• 21:15Speaker 01

  Okay.

• 21:15Neil deGrasse Tyson?

  Next one.

• 21:16Speaker 01

  Our next question is from Emery. I hope I'm saying your name correctly. And she says, Dr. Tyson's explanation of how we could move.

• 21:24Neil deGrasse Tyson?

  How do you know it's a she?

• 21:25Speaker 01

  I don't.

• 21:26Neil deGrasse Tyson?

  You're assuming it.

• 21:26Speaker 01

  I am.

• 21:27Neil deGrasse Tyson?

  Just to make that clear. Go on.

• 21:28Speaker 01

  Okay. So it wants to know.

• 21:29Neil deGrasse Tyson?

  Yeah. It's okay.

• 21:33Speaker 01

  Dr. Tyson's explanation of how we could move incoming meteorites by parking a satellite next to it, lock them by gravity, then slowly tug them out of its trajectory got me to ask, what would it take to do something similar to planets? Like, could we move some of the planets to the Goldilocks zone? Would it mess up the orbits of Earth or Mars?

• 21:56Neil deGrasse Tyson?

  Excellent question. So that would be sort of planetary engineering.

• 22:00Speaker 01

  Yes.

• 22:01Neil deGrasse Tyson?

  Right. Oh, there's a planet we want to live on. If it's too close, or it's too far away, let's move it to the Goldilocks zone, where the temperature from the sun is just right for liquid water, as opposed to frozen water or evaporated water. We have words for those: ice and steam, right, or vapor.

• 22:17Speaker 01

  Wait, let me write that down. I learned so much here. Ice, how do you spell that?

• 22:21Neil deGrasse Tyson?

  So, so if the day that we can start shifting planetary bodies around, like asteroids and then large asteroids, start small, work big. I don't see any reason why we can't just shifting, start shifting planets around. You have to be careful, because if planets get too close to one another, they create what are called resonances. And when you have a resonance, it means one planet does not orbit freely, it's locked in place relative to another planet. And when that happens, or their orbital periods are locked relative to one another. And so there are these weird gravitational sort of resonances out there that you want to watch out for, because some of them are unstable, and you can be flung out of the solar system entirely. In fact, the early solar system, we've hypothesized,

• 23:06Neil deGrasse Tyson?

  justifiably, that we might have had 20, 30, 50 planets to start out in our solar system.

• 23:12Speaker 01

  Okay.

• 23:13Neil deGrasse Tyson?

  Because you know what happens? If you create a solar system on a computer, and give it 50 planets, and let it just fight it out, you get like, a few planets left after a billion years or so. And the rest are cast into interstellar space. And they're called, they're called rogue planets. And in fact, there may be more rogue planets, homeless planets in the galaxy than planets that actually orbit actual stars.

• 23:38Speaker 01

  Homeless planets?

• 23:39Neil deGrasse Tyson?

  Homeless planets. And so, yeah, I mean, nature does a lot of moving planets around. There are solar systems, star systems, where Jupiter's are close to the host star. Our Jupiter's far away, and we got Mercury, Venus, Earth, and Mars.

• 23:51Speaker 01

  Mm-hmm.

• 23:52Neil deGrasse Tyson?

  Uh, between Jupiter and our sun. The other solar system where their Jupiter-sized object is really close. We think that Jupiter migrated inward, flinging other planets out.

• 24:03Speaker 01

  Out of my way. I need to be near the star.

• 24:05Neil deGrasse Tyson?

  Exactly.

• 24:05Speaker 01

  It's a diva planet.

• 24:06Neil deGrasse Tyson?

  Exactly. Well, that's what we should call them, diva planets.

• 24:09Speaker 01

  Diva planets. You heard it here first.

• 24:11Neil deGrasse Tyson?

  We'll start it here first on StarTalk. Cosmic Queries. We've got time for one more question in this segment. What do you got?

• 24:17Speaker 01

  Uh, we know what? This is sort of comes off of, from the same person, off of the same theory. Um, could we move Mercury and Venus and how long would it take to cool them down sufficiently to terraform?

• 24:27Neil deGrasse Tyson?

  Oh, uh, things cool off pretty quickly.

• 24:30Speaker 01

  Oh.

• 24:30Neil deGrasse Tyson?

  Venus is nine hundred.

• 24:31Speaker 01

  Like a relationship.

• 24:32Neil deGrasse Tyson?

  Not, Venus is hot enough to like melt lead and zinc and I calculated it would cook nine seconds, take nine seconds to cook a pizza on your windowsill. But then a geekier person than I am corrected me and said, no, you left out the radiative effects of the atmospheric, uh, uh, the thermal and so it actually would take a fraction of a second to cook. We gotta, when we come back, more on cooking pizza on Venus. Cosmic Queries after hour.

• 25:17Neil deGrasse Tyson?

  We're back on StarTalk Radio. I'm Neil deGrasse Tyson. Leanne Lord is with me.

• 25:21Speaker 01

  Yes, I am.

• 25:22Neil deGrasse Tyson?

  Co-hosting.

• 25:23Speaker 01

  Co-hosting. My favorite job.

• 25:24Neil deGrasse Tyson?

  Comedian. That's my, were your favorite? You say that all your gigs.

• 25:27Speaker 01

  No, that's not true. I love you guys. You know, because we have the best fans. They tweet me so much. It's fantastic.

• 25:33Neil deGrasse Tyson?

  Excellent. Excellent. Cause you're, you're on, in your stream.

• 25:35Speaker 01

  Yes.

• 25:36Neil deGrasse Tyson?

  Yeah, good. So we left off talking about, uh, great question.

• 25:39Speaker 01

  Cooking pizza.

• 25:40Neil deGrasse Tyson?

  Uh, move Mercury and Venus, I presume farther away to make them habitable.

• 25:45Speaker 01

  Right, to terraform.

• 25:45Neil deGrasse Tyson?

  And they know Venus is very hot, Mercury is very hot. Bring them farther away from the sun, so the sun's rays are less intense.

• 25:52Speaker 01

  Mm-hmm.

• 25:53Neil deGrasse Tyson?

  And bring them into the Goldilocks zone. Here's a problem with Venus. Venus is hot only in part because it's near the sun. It's especially hot because it has a runaway greenhouse effect. You, there's something about the carbon dioxide you're gonna have to fix before you want to live on Venus.

• 26:09Speaker 01

  So it's a fixer-upper planet?

• 26:10Neil deGrasse Tyson?

  It's a total fixer-upper planet. Uh, CO2 is, it's 98% of the atmosphere and it's very dense, 100 times the atmospheric pressure on Venus as it is here on Earth. I guess it's probably closer to 90, but I rounded. To a hundred.

• 26:24Speaker 01

  Back of the envelope equation.

• 26:25Neil deGrasse Tyson?

  Back of the envelope, yeah. Just round it just because what the difference between ninety and hundred is not important for the point I'm making. So I just round it to a hundred. And so it's about a hundred times the the atmospheric pressure that we have here on Earth. So you step out on Venus, you'll be crushed and vaporized simultaneously.

• 26:44Speaker 01

  But I'll look good because I'll be a lot slimmer for like a half a second.

• 26:49Neil deGrasse Tyson?

  So you need to not only fix the CO2 problem, which is a greenhouse gas, as we all know. But also when you do that and then you let the planet cool down, that shouldn't take too long. Because it'll just radiate out into space. Look how fast Earth cools on a hot day after sunset in the desert.

• 27:08Speaker 01

  Okay.

• 27:08Neil deGrasse Tyson?

  If you go to the desert, right? If it's dry, because actually moisture is a greenhouse gas itself. That's why in wet places you don't get high temperature extremes, but in deserts you do. It warms up in the daytime.

• 27:23Speaker 01

  Right.

• 27:23Neil deGrasse Tyson?

  There's nothing to trap the heat. There's certainly no carbon dioxide and no water vapor. The heat escapes rapidly. Temperature dropped twenty, thirty degrees within a few hours.

• 27:32Speaker 01

  You know what? I always wondered that.

• 27:33Neil deGrasse Tyson?

  That's why the deserts have huge temperature extremes and other place Hawaii does not.

• 27:38Speaker 01

  Okay.

• 27:39Neil deGrasse Tyson?

  Completely surrounded by water.

• 27:40Speaker 01

  Now, is that because that the then the really hottest part of the day is really the end of the day? Because you still have that heat being released.

• 27:46Neil deGrasse Tyson?

  The hottest part of the day is hottest part of the day is when the sun's rays are its most intense.

• 27:50Speaker 01

  Mm hmm.

• 27:51Neil deGrasse Tyson?

  Well, that would be high noon. However, there's a time delay. That's when the sun's rays are most intense hitting Earth.

• 27:58Speaker 01

  Right.

• 27:59Neil deGrasse Tyson?

  But the sun does not heat the air. The sun heats the ground, the ground heats the air. So there's a.

• 28:05Speaker 01

  Okay.

• 28:05Neil deGrasse Tyson?

  And so there's a time delay between that that takes one or two hours. That's why the hottest time of day is two or three in the afternoon.

• 28:13Speaker 01

  Ah, that's what I was thinking of, okay.

• 28:15Neil deGrasse Tyson?

  Your most susceptible to like sunburn is at high noon when the sun is has its most direct rays on you. So that's this time delay. And that's why the hottest month of the year is not June.

• 28:28Speaker 01

  No.

• 28:28Neil deGrasse Tyson?

  Even though the sun is at its highest at any location on Earth, it's at its highest in that month. It takes a couple of months for the heat to hit the Earth and build up back and then warm the atmosphere. So visible light hits Earth, heats it. Earth re-radiates that same energy as infrared and it's the infrared that gets trapped by the greenhouse gases. If greenhouse trapped visible light, the visible light would never reach Earth's surface. It would trap it in midair.

• 28:56Speaker 01

  Oh.

• 28:56Neil deGrasse Tyson?

  This is why we receive energy from the sun and then keep it with the greenhouse effect. Because most of the energy that we that becomes the greenhouse started out as visible light. It's very cool.

• 29:08Speaker 01

  You're good.

• 29:08Neil deGrasse Tyson?

  That's right. No, no, it's the universe that's good.

• 29:11Speaker 01

  Well, no, I mean, the way you explain it, though.

• 29:14Neil deGrasse Tyson?

  Good.

• 29:15Speaker 01

  No, no, you're fantastic.

• 29:17Neil deGrasse Tyson?

  Yeah, so stuff cools pretty quickly. That's not the problem. Yeah. What else you got?

• 29:21Speaker 01

  All right, I have a question. I don't have a name. This person is shy.

• 29:26Neil deGrasse Tyson?

  An anonymous email.

• 29:27Speaker 01

  Well, I can say this, they're from a school because it's a .edu. So it's a student.

• 29:31Neil deGrasse Tyson?

  Institution.

• 29:32Speaker 01

  Yes, I'm just putting on my CSI cap here. And they want to know who was our most scientifically friendly president? Like, which one of our US presidents was the most friendly to the field of science?

• 29:42Neil deGrasse Tyson?

  Ever?

• 29:43Speaker 01

  Ever.

• 29:44Neil deGrasse Tyson?

  Yeah, it depends on what you mean by friendly. In Washington, friendly means how much money do you give the enterprise? That's what that's what in Washington, all that matters is money. What you say doesn't matter at all.

• 29:54Speaker 01

  Okay.

• 29:55Neil deGrasse Tyson?

  Okay.

• 29:55Speaker 01

  But then let's go.

• 29:56Neil deGrasse Tyson?

  Just an FYI.

• 29:57Speaker 01

  Got you.

• 29:58Neil deGrasse Tyson?

  Okay, all right. So a few things. Abe Lincoln began the National Academy of Sciences. Now, that's kind of cool.

• 30:09Speaker 01

  Very.

• 30:09Neil deGrasse Tyson?

  It was set up to establish an advisory board to Congress that was not itself politically motivated for any reason. And so Congress would call on the National Academy of Sciences to produce studies on scientific issues that befall the day. I got to put Lincoln at the top of that list.

• 30:29Speaker 01

  Okay.

• 30:29Neil deGrasse Tyson?

  As the most scientifically aware and literate.

• 30:32Speaker 01

  So he was not just a cat owner?

• 30:34Neil deGrasse Tyson?

  I didn't know he owned cats.

• 30:35Speaker 01

  He was the first president to have a cat?

• 30:37Neil deGrasse Tyson?

  I did not. Why do you even know that?

• 30:39Speaker 01

  Because I was getting tired of the slavery thing. Like, what else did he do?

• 30:42Neil deGrasse Tyson?

  When we come back, more of Cosmic Queries on StarTalk.

• 31:04Neil deGrasse Tyson?

  StarTalk, Cosmic Queries, Leanne Lord with me here in studio.

• 31:09Speaker 01

  You didn't say my favorite line.

• 31:11Neil deGrasse Tyson?

  What is that?

• 31:11Speaker 01

  StarTalk, Cosmic Queries after dark.

• 31:13Neil deGrasse Tyson?

  It exists in the dark. So, we left off talking about Lincoln. The question was, who's the most science-friendly president?

• 31:20Speaker 01

  Yes.

• 31:20Neil deGrasse Tyson?

  And I'd have to say, given all the things that presidents have done, you know, Jefferson was quite scientifically literate. President Obama has mentioned science in practically every speech he's given.

• 31:30Speaker 01

  Mentioned.

• 31:31Neil deGrasse Tyson?

  I know.

• 31:31Speaker 01

  I like the way, that's very political of you.

• 31:33Neil deGrasse Tyson?

  I'm still waiting for the money on that.

• 31:35Speaker 01

  Show me the money.

• 31:36Neil deGrasse Tyson?

  And Republicans, in the second half of the 20th century, tended to give more money to science, because science was viewed as an engine of our national security. So it wasn't so much that they were curious about the frontier, but just that science was good for war, essentially, and for winning wars. But Lincoln, there's another bit about Lincoln. You read the Gettysburg Address?

• 31:58Speaker 01

  Um, I read Abraham Lincoln.

• 31:59Neil deGrasse Tyson?

  Don't say "um," don't start that with an "um."

• 32:00Speaker 01

  I read Abraham Lincoln Vampire Hunter.

• 32:02Neil deGrasse Tyson?

  Okay.

• 32:03Speaker 01

  I think they covered it.

• 32:04Neil deGrasse Tyson?

  A Gettysburg Address, I don't memorize the whole thing, but fourscore and seven years ago, "Our four fathers brought forth a new nation, conceived in liberty," it goes on like that. If you feel the rhythm of it, it's five, six, seven words at a time.

• 32:16Speaker 01

  Mm-hmm.

• 32:17Neil deGrasse Tyson?

  And that's like the right number of words for an attention span if you're listening to someone speak. Think about that.

• 32:25Speaker 01

  Okay.

• 32:26Neil deGrasse Tyson?

  Yeah. And then I thought about it, and I said, why is this speech so effective? Of all the speeches given by all the politicians, this one is up on the wall, and there are no complex sentences within it. If you take a quill pen and dip it, you have about as much ink as will get you five, six, seven words.

• 32:47Speaker 01

  Yeah.

• 32:48Neil deGrasse Tyson?

  And it occurred to me that feather pen writing of speeches forces a rhythm in your communication that is the perfect marriage of words on a page and words to the ear. So to this day, when I'm preparing an important speech... I will write that speech with a quill pen.

• 33:07Speaker 01

  No.

• 33:08Neil deGrasse Tyson?

  Or I will dip my fountain pen unfilled. The fountain pens can store ink.

• 33:13Speaker 01

  Yes.

• 33:14Neil deGrasse Tyson?

  That doesn't count. It's unlimited ink until you run out. I will not fill it and I will dip it in a well and I will write it out that way. And it forces me to contain the ideas in morsels, in parcels of information, which then is my hope that the listener will embrace.

• 33:30Speaker 01

  Love it.

• 33:31Neil deGrasse Tyson?

  And so I have a collection of fountain pens and quill pens.

• 33:34Speaker 01

  I do too.

• 33:34Neil deGrasse Tyson?

  I just go there.

• 33:35Speaker 01

  I'm a pen person.

• 33:36Neil deGrasse Tyson?

  Just what I do.

• 33:36Speaker 01

  We've talked about this.

• 33:37Neil deGrasse Tyson?

  And sometimes I go all the way if I'm writing with a quill pen. I like candles because that's how.

• 33:42Speaker 01

  Well, that's how it should be done.

• 33:43Neil deGrasse Tyson?

  That's how, if you're gonna go there.

• 33:44Speaker 01

  Do you put on the powdered wig? I need a picture of you in the powdered wig. This is fantastic.

• 33:49Neil deGrasse Tyson?

  No, I don't do wig.

• 33:50Speaker 01

  Nothing yet. Come on now. You're not doing it the whole way. Ah, come on.

• 33:54Neil deGrasse Tyson?

  So now we're going on to Cosmic Query's lightning round.

• 33:57Speaker 01

  Lightning round.

• 33:58Neil deGrasse Tyson?

  Let me get the bell. Test it. There we go. All right, let's do this, Leanne.

• 34:04Speaker 01

  Lightning round, my favorite. All right. This is from Mike Hall. And he wants to know, are there valuable resources that are easier to obtain from space than drilling into the earth for?

• 34:13Neil deGrasse Tyson?

  Ah, they're not easier to get to, but oh, so you want them.

• 34:18Speaker 01

  Ooh.

• 34:18Neil deGrasse Tyson?

  Because on earth, we fight wars over resources that are underfoot.

• 34:22Speaker 01

  We do.

• 34:22Neil deGrasse Tyson?

  And the universe is an unlimited supply of all the resources that we fight each other to get down here on earth. So whether or not they're easier to get, they're better to get. Next.

• 34:31Speaker 01

  Got it. All right. Next question is from Chris Van Gundy. Uh, how can we determine the difference between a brown dwarf and a large rogue planet?

• 34:39Neil deGrasse Tyson?

  Oh, it's hard. Uh, brown dwarf is a star that didn't make it and a large rogue planet is just a big old chubby planet. There are astrophysical differences between the two, but they're very hard to notice from a distance. So it's very hard. It's one of the big challenges. And we got low mass star people and high mass planet people meeting in the dark of night trying to solve that problem.

• 35:00Speaker 01

  You said chubby planet. Next question is from Peter O'Hara, and he says, can you give us your take on parallel universes? They sound really cool.

• 35:08Neil deGrasse Tyson?

  I agree, parallel universes are awesome, but you should think of them not as parallel to one another, but as the consequence of the multiverse. In the multiverse, you have multiple universes popping out of some original distortion of the fabric of space and time. We are just one of multiple universes, hence the multiverse. And so there could be other universes adjacent to us in a higher dimension, and we would never know it. I think of them as parallel universes. Next.

• 35:35Speaker 01

  Nice. Joshua Jenkins wants to know, why does the Earth spin in the direction it does? And what if Earth started spinning twice as fast as it does now?

• 35:43Neil deGrasse Tyson?

  Ooh, okay, so we spin this direction because, I'm gonna say it exactly physically, you ready?

• 35:48Speaker 01

  Yes.

• 35:48Neil deGrasse Tyson?

  That is the direction of the angular momentum of the entire solar system.

• 35:52Speaker 01

  So we're going with the flow?

• 35:54Neil deGrasse Tyson?

  Beautiful. We're going with the flow. The sun spins that way. All planets orbit that way. The moons orbit that way. Everybody is going counterclockwise as viewed from the top. Now, why do they want to spin up Earth? I don't know. That would have the length of the day. There would be 12-hour days instead of 24-hour days.

• 36:13Speaker 01

  Oh, I can't get enough done.

• 36:14Neil deGrasse Tyson?

  And the act of spinning us up, okay, we'll feel that. That would not be a good day on Earth. Okay. You will know when Earth starts spinning faster. Well, you know what'll happen? Stuff behind you will run into you, and you'll be flattened against it, and you'll be a pile of goo on the wall behind you. Because you're, right now, you're moving 800 miles an hour with the rotation of the Earth. If you all of a sudden start going 1,600 miles an hour, something came in behind you to push you to do that, and that will flatten you into a pile of goo. Next.

• 36:41Speaker 01

  Yeah, not with it.

• 36:42Neil deGrasse Tyson?

  Fast.

• 36:43Speaker 01

  Ray Day, what would your opinion be on the seemingly regularity of mass extinctions on Earth?

• 36:48Neil deGrasse Tyson?

  They're not really regular. There's some analysis where you can see, oh, every 20 million years, things go extinct. But you have to cut the data in a way that makes it look that way. If you don't cut the data, the regularity is not really there.

• 37:01Speaker 01

  Okay.

• 37:01Neil deGrasse Tyson?

  So extinctions happen kind of randomly, and we're in the middle of what's called the sixth great extinction on Earth, and that extinction is caused by humans. We gotta run. Oh. Gotta go. That's it. Wow. StarTalk, brought to you in part by the National Science Foundation, Leanne Lord, Great Avenue. Thank you. I'm Neil deGrasse Tyson, as always, keep looking tough.