Cosmic Queries: Gravity

The pull of gravity (the force, not the movie) is irresistible as Neil deGrasse Tyson and Leighann Lord grapple with weighty fan questions about matter and the curvature of spacetime. Read more and listen to the full episode at http://www.startalkradio.net/show/cosmic-queries-gravity/

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, your personal astrophysicist. I'm also the director of New York City's Hayden Planetarium at the American Museum of Natural History, right here in the Big Apple. I've got with me co-host Leanne Lord. Leanne, welcome back to StarTalk.

• 0:41Speaker 01

  Thank you. Good to be back.

• 0:42Neil deGrasse Tyson?

  We don't get enough of you here.

• 0:43Speaker 01

  No, no.

• 0:43Neil deGrasse Tyson?

  Where are you? You don't call, you don't write, you don't text.

• 0:46Speaker 01

  I do tweet.

• 0:48Neil deGrasse Tyson?

  But not to me, which how do we know you're there?

• 0:50Speaker 01

  I do tweet to you, but you're so busy with your millions of followers. Millions and billions of followers.

• 0:57Neil deGrasse Tyson?

  So with this is a Cosmic Queries edition of StarTalk, and you know how, you know the drill. I've not seen any of these questions.

• 1:05Speaker 01

  You have not.

• 1:05Neil deGrasse Tyson?

  They're solicited by our social media folks, and a topic is tossed up, and then everyone sends in their questions, and they know that it's gonna come to me. But I haven't seen them, so if I don't know the answer, I'll say, I don't know, go get on the next one.

• 1:18Speaker 01

  Wow.

• 1:19Neil deGrasse Tyson?

  I will be very candid if I don't know something.

• 1:21Speaker 01

  Okay, okay, fair enough.

• 1:22Neil deGrasse Tyson?

  Or I will say, I don't know it, but here's the answer I think it should be, if that's the case. And so let's just start right out.

• 1:29Speaker 01

  Well, you know, the subject is gravity, and I had a chance to briefly look through some of these questions, and nobody...

• 1:34Neil deGrasse Tyson?

  Gravity, not the movie, specifically, but just gravity as a physics thing.

• 1:39Speaker 01

  Right, gravity as a force.

• 1:40Neil deGrasse Tyson?

  Okay, I know a few things about gravity, so I feel comfortable in this particular Cosmic Queries.

• 1:45Speaker 01

  Oh, good, good, because of all the questions that I looked at, not one of them is, what is gravity?

• 1:51Neil deGrasse Tyson?

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

• 1:54Speaker 01

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

• 1:57Neil deGrasse Tyson?

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

• 1:59Speaker 01

  Yes.

• 1:59Neil deGrasse Tyson?

  You're taking co-host privileges.

• 2:01Speaker 01

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

• 2:05Neil deGrasse Tyson?

  You have no idea. Okay, next question.

• 2:07Speaker 01

  Wow.

• 2:07Neil deGrasse Tyson?

  Here's the difference. We can describe gravity. We can say what it does to other things. We can measure it, predict with it, but when you start asking, like, what it is? I, I, I don't know.

• 2:21Speaker 01

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

• 2:24Neil deGrasse Tyson?

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

• 2:27Speaker 01

  Apparently, I was.

• 2:27Neil 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, that's a good start. And I can also say that Einstein noted that the gra- matter tells space how to curve. Space tells matter how to move.

• 3:09Speaker 01

  Say that again.

• 3:11Neil deGrasse Tyson?

  Isn't that beautiful?

• 3:12Speaker 01

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

• 3:14Neil deGrasse Tyson?

  Matter, and it, matter and energy will curve the fabric of space.

• 3:18Speaker 01

  Okay.

• 3:18Neil deGrasse Tyson?

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

• 3:35Speaker 01

  I wouldn't know.

• 3:35Neil deGrasse Tyson?

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

• 3:39Speaker 01

  Not, that is beautiful.

• 3:40Neil deGrasse Tyson?

  It is beautiful.

• 3:42Speaker 01

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

• 3:46Neil deGrasse Tyson?

  So, that is your, that is your co-host privileges.

• 3:48Speaker 01

  Thank you.

• 3:49Neil deGrasse Tyson?

  For a first question.

• 3:49Speaker 01

  So much.

• 3:50Neil deGrasse Tyson?

  That warmed up the crowd.

• 3:52Speaker 01

  It did, I hope so. And now, some more intense questions. Uh, this one is from Rostin Rodriguez, or Rostan, and it is...

• 4:01Neil deGrasse Tyson?

  Can I add before you begin?

• 4:03Speaker 01

  Yes.

• 4:03Neil deGrasse Tyson?

  That, uh, you know, as I majored in physics in college and in graduate school, my PhD is in astrophysics. But there's a course I never took. That I regret. It was a little too hard for me at the time. It's probably still too hard for me.

• 4:17Speaker 01

  Poetry?

• 4:17Neil deGrasse Tyson?

  And I rely, no, I love poetry. And I rely on others who are familiar in these areas to tell me what is and what isn't. I've never taken a grad, taken a graduate course in field theory. And graduate field theory is the full analysis of the forces of nature at their deepest and most mathematical levels. And so, I read about them, but I've never calculated with them.

• 4:44Speaker 01

  Okay.

• 4:45Neil deGrasse Tyson?

  And so, if any of these questions go there, I'll just say I didn't, I didn't take that class.

• 4:49Speaker 01

  Well, that is something you and I have in common. Because with my degree in journalism and creative writing, I too did not take, uh, field theory.

• 4:59Neil deGrasse Tyson?

  Okay, proceed.

• 5:00Speaker 01

  Yes. From Rostin Rodriguez. The question is, what is gravity fundamentally made up of? Is it a result of some quantum phenomena, or is there any particle responsible for gravity? How fast do the gravitational waves travel through space, and what decides the limit of that speed? Lot of questions.

• 5:18Neil deGrasse Tyson?

  I love it when people, because that sounds like they were burning within him and he couldn't get to sleep.

• 5:24Speaker 01

  He can't sleep at night.

• 5:25Neil deGrasse Tyson?

  Get him off his chest.

• 5:26Speaker 01

  He's like pacing.

• 5:27Neil deGrasse Tyson?

  I love it. So, uh, so gravity, before quantum, by the way, Einsteinian gravity was conceived before quantum mechanics was discovered. So Einsteinian gravity is 1916. This is where matter curves space and objects respond to that curvature. That's what we call gravity. When quantum physics came in, where everything was accountable as a particle-wave duality. If you have something that are gravity waves, Einstein predicts the existence of gravity waves, then there ought to be a particle counterpart to that gravity wave. We then we said we'll call it gravitons. Just the same way, any particles, any matter at all, will have a wave version of it.

• 6:12Neil deGrasse Tyson?

  From a quantum mechanical point of view. So, a gravity waves were predicted to move at the speed of light in Einstein's equations. And if you have a graviton, the propagator of gravity, of gravity, that would also move at the speed of light. So, there you have it. But now, we've never detected a graviton. We, or directly have we detect, nor have we directly detected gravity waves. But we have top people working on it.

• 6:39Speaker 01

  Wow.

• 6:41Neil deGrasse Tyson?

  The Laser Interferometric Gravitational Wave Observatory, shortened to LIGO, is a multi-location observatory that uses high technology, lasers and interferometers, where it, it knows the distances between two points in long tunnels, accurate to like the width of the nucleus of an atom. So that if a gravity wave comes across, and it slightly jiggles the space between these two measured points, it will measure it. It will know it. And that will be, would become the first detection of a gravity wave passing across us. So what makes gravity waves? When gravity changes somewhere in the galaxy.

• 7:24Neil deGrasse Tyson?

  So if you have two stars orbiting and then they collide, then there's a ripple in the gravitational wave continuum that's out there. And that's what you would then see. If, if, if a star plunges into a black hole, these are disturbances in the gravitational field. And those disturbances are the gravity waves that get measured. So we got top people working on it. We've never measured them, but they're predicted to exist. Not only from Einstein's special, uh, grav, uh, uh, general theory of relativity, his theory of gravity, but also from quantum physics.

• 7:55Speaker 01

  So we can detect, but not measure? Did I understand that?

• 7:58Neil deGrasse Tyson?

  No, we can detect the existence of gravity.

• 8:00Speaker 01

  Okay.

• 8:00Neil deGrasse Tyson?

  But the graviton that propagates it, to know that that is a particle, the gravity wave that tells us when something got disturbed in the universe, those have yet to be directly detected. We have indirectly detected gravitational energy by two pulsars orbiting one another. They have such high gravities at their surfaces, and you orbit them near one another, that they're, that system is unstable. It radiates gravitational energy.

• 8:27Speaker 01

  Okay.

• 8:28Neil deGrasse Tyson?

  And if you're reading gravitational energy, then the system orbits closer today than it did yesterday. And as it keeps doing it, they orbit closer and closer and closer, and they eventually just collide. The measurement of binary pulsars giving up the gravitational ghost led to a Nobel Prize in Physics. Joe Taylor and Russell Hulse, Russell Hulse was one of the Bronx High School of Sciences eight Nobel laureates.

• 8:54Speaker 01

  Nice.

• 8:55Neil deGrasse Tyson?

  Yes. That's as many as the country of Spain, by the way. I know, that's, that's crazy.

• 9:03Speaker 01

  Wow. And I now feel more prepared for that category on Jeopardy.

• 9:06Neil deGrasse Tyson?

  Okay. All right. What else you got?

• 9:10Speaker 01

  I have a question from Tristan Brooks. Some theorize that gravity is a side effect of the multi-dimensional geometry of space. But I've also heard talk of a graviton particle, which we just talked about. Is it possible it could be both? If not, what is the more likely candidate for explaining gravity, in your opinion?

• 9:29Neil deGrasse Tyson?

  Yeah. I think the, the big challenge now, by the way, as I understand what is going on in, behind the string theory door, which is occasionally closed, they try to open it, and then if you're not a string theorist, you have no idea what they're doing behind there.

• 9:44Speaker 01

  Right. You think there's a cat in a box somewhere, and that's a whole different experiment.

• 9:48Neil deGrasse Tyson?

  But they're smart people, and you, you know, you give them the room to think. And so.

• 9:52Speaker 01

  I like that. Give them room to think. I like that.

• 9:57Neil deGrasse Tyson?

  Well, because they're not actually very expensive. They.

• 10:00Speaker 01

  These rooms where people think?

• 10:01Neil deGrasse Tyson?

  Exactly. Rooms, rooms are cheap. Your brain, you got for free. Throw in a pad, a pencil, and, and a laptop to hand it to a string theorist, and let him go to town. I don't have any problems with that. So, it, so in the world of string theory, there, there's, gravity comes out of some of their calculations, as I've come to understand it. So that's a good thing, because we know gravity exists. And as a minimum, you want your theory to explain at least what you already know, but then come up with predictions to then test, uh, test it even more deeply. So here's the point. There is no reason to think that gravity does not also have a quantum manifestation of itself, because everything

• 10:45Neil deGrasse Tyson?

  else has a quantum manifestation of itself.

• 10:47Speaker 01

  I have a quantum.

• 10:48Neil deGrasse Tyson?

  Yes, you do, but it's very averaged out because you're a macroscopic entity.

• 10:51Speaker 01

  Did you just call me average? I'm sorry, I misheard.

• 10:54Neil deGrasse Tyson?

  No, I called you macroscopic entity.

• 10:57Speaker 01

  Alright.

• 10:57Neil deGrasse Tyson?

  That was the name calling that I engaged in.

• 11:00Speaker 01

  I'm not sure how to respond to that.

• 11:01Neil deGrasse Tyson?

  And we know from small, how matter manifests in small sizes, that it can reveal itself as a wave, as a particle, depending on how you measure it, and on the circumstances under which you conduct the experiment. So, it's not, it's a very human thing to say, is it this or is it that? Is it a planet, is it not a planet? Is it, is it less filling or is it great taste? Is it, is it gum or is it candy? These are sort of false dichotomies. Something can be both. But our language forces us, forces us to require that it fit into one word or another.

• 11:40Speaker 01

  Okay.

• 11:41Neil deGrasse Tyson?

  What we're not recognizing is that it's not a fault of the object or the concept. It's a defect in our language. And if our thoughts follow language, we have trouble thinking of things that fit more than one category.

• 11:52Speaker 01

  We do.

• 11:53Neil deGrasse Tyson?

  I think that's the source of most human ailments in the world.

• 11:56Speaker 01

  Yes, it is.

• 11:56Neil deGrasse Tyson?

  Cultural ailments. Are you gay or are you not gay?

• 12:00Speaker 01

  Right.

• 12:01Neil deGrasse Tyson?

  Are you black or you're not? Are you this, are you that?

• 12:02Speaker 01

  Are you male or female?

• 12:04Neil deGrasse Tyson?

  Are you, and it's like chill out, just let it, let, you know, just let things be what they are. Allow there to be a spectrum in all that you see.

• 12:13Speaker 01

  So, does that, that doesn't necessarily just mean a broadening of language, but a broadening of the, the way the human mind thinks?

• 12:19Neil deGrasse Tyson?

  I think that, once you learn language, the language shapes how you think, more than your thoughts shape what language does. It takes a very creative person to start inventing words for thoughts that they had, for which no words applied.

• 12:34Neil deGrasse Tyson?

  There's an age after which your thoughts are-

• 12:36Speaker 01

  That's the word icky.

• 12:37Neil deGrasse Tyson?

  Your thoughts are constructed from the vocabulary available to you. And you have to be very creative to have a thought for which there's no vocabulary to account. And when you do, that's how you invent new words. And Shakespeare put tons of words into the English language. That man had thoughts beyond all.

• 12:55Speaker 01

  Or, it could start with just saying, "I don't know how I feel." And then there comes the exploration of finding that word.

• 13:02Neil deGrasse Tyson?

  Yeah, but typically, that's not what people do. They find a word that exists.

• 13:05Speaker 01

  Right.

• 13:06Neil deGrasse Tyson?

  And then they force it into the words that exist, and then that becomes-

• 13:08Speaker 01

  That's true.

• 13:09Neil deGrasse Tyson?

  The manifestation of their thoughts. So, so, I think, most of the world comes in flavors, and not just, is it A or B, or black or white, or up or down, and so-

• 13:20Speaker 01

  There's a swirl.

• 13:20Neil deGrasse Tyson?

  Yeah, even gravity.

• 13:23Neil deGrasse Tyson?

  Well, quantum physics.

• 13:25Speaker 01

  Wow.

• 13:25Neil deGrasse Tyson?

  That got way more philosophical than I don't think.

• 13:27Speaker 01

  It did, but I liked it. I liked it. Um, I have a question, which I think is, you almost touched on, uh, from Daniel Owen, excuse me, from Dan Owens. How closely related is the Higgs boson to gravity? Would a further understanding of the Higgs give us some more, give us more insight into gravity?

• 13:44Neil deGrasse Tyson?

  I don't know any direct connection between the Higgs boson and gravity. 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.

• 14:04Speaker 01

  Annoyingly so, yes.

• 14:05Neil deGrasse Tyson?

  Right. You, do 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, the Jesus spider. Have you ever seen the Jesus spider? It's called the Jesus spider. It's cute. It walks on water.

• 14:30Speaker 01

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

• 14:32Neil deGrasse Tyson?

  No.

• 14:34Neil deGrasse Tyson?

  Was it the third day? On the third day he wrote, yeah.

• 14:36Speaker 01

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

• 14:42Neil deGrasse Tyson?

  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. Entirely. That's why, so the world of the insect is very different from the world of us. And that, 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.

• 15:10Speaker 01

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

• 15:12Neil deGrasse Tyson?

  100% of them get it wrong. Okay. Giant ants, giant spiders. There's a reason why there are no giant spiders.

• 15:21Speaker 01

  Thank goodness.

• 15:21Neil deGrasse Tyson?

  They have to have really thick rhinoceros legs and we'd call them a rhinocerous. 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.

• 15:33Speaker 01

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

• 15:41Neil deGrasse Tyson?

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

• 15:45Speaker 01

  Really?

• 15:46Neil 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 forty orders of magnitude stronger than gravity. Forty orders of ma- forty powers of ten 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 are of opposite electrical charge. Write down that number. The electrical charge force of attraction is ten to the fortieth power stronger than gravity. So if you're a particle, you would never discover that gravity exists.

• 16:30Neil deGrasse Tyson?

  Unless you had an experiment that can measure to the accuracy, to the precision of forty powers of ten. And that ain't happening.

• 16:36Speaker 01

  Not on my account.

• 16:37Neil deGrasse Tyson?

  Not on my- so, so, so I don't see any connection. There could be some subtle particle physics correspondence that I don't know. But generally, when you talk about particles and particle physics, you're not thinking about any large-scale gravitational phenomenon. Yeah.

• 16:56Speaker 01

  Okay. Uh, moving on.

• 16:58Neil deGrasse Tyson?

  Yeah.

• 16:58Speaker 01

  We have, oh, we have so many questions. Oh, my gosh. This one is from Ben Bonafent. And it says, if you were in deep space and there were no stars or planets or spaceships around, or spaceships, just there in spaceships, that's awesome. Would items of small mass accelerate toward you noticeably, or would the gravitational force be too small?

• 17:18Neil deGrasse Tyson?

  Ooh.

• 17:20Speaker 01

  You like that?

• 17:20Neil deGrasse Tyson?

  What he's asking is, if I'm alone in space and nothing's competing with me for my gravitational attraction, would I start seeing everything drift towards me? The answer is, yes. Everything drifts. The gravity doesn't stop. And while my force of gravity as a human being is not very large, doesn't matter. The little paper clip that floated out of my pocket, there it is, it'll start drifting towards me. And so it'll be slow and not very interesting, but yes.

• 17:50Speaker 01

  So this is the cute single guy that walks into the bar. Everything then starts to gravitate toward him, or the single woman.

• 17:56Neil deGrasse Tyson?

  Yeah.

• 17:57Speaker 01

  Because...

• 17:58Neil deGrasse Tyson?

  This is the bar analogy.

• 18:00Speaker 01

  The bar analogy.

• 18:00Neil deGrasse Tyson?

  To the cosmos.

• 18:01Speaker 01

  It is. Trying to keep it, keep it real for the little people.

• 18:04Neil deGrasse Tyson?

  So this is your, your upcoming book, Everything I Learned About the Cosmos, I Learned From the Bar.

• 18:10Speaker 01

  Cheers.

• 18:11Neil deGrasse Tyson?

  Yeah, yeah. A comedian, Leanne walks into a bar. The cosmos, according to Leanne. We gotta, we'll come back for the next segment. You got more questions for me?

• 18:20Speaker 01

  I do, I have a ton of questions.

• 18:20Neil deGrasse Tyson?

  This is StarTalk Radio. We'll be right back.

• 18:41Neil deGrasse Tyson?

  We're back, StarTalk Radio. You know, we're on the net, on the internet, starTalkRadio.net. You can download archival shows there, everything. And you can find us on iTunes. We're all over the place.

• 18:52Speaker 01

  Uh, what's the other one? Stitcher. On Stitcher Radio.

• 18:54Neil deGrasse Tyson?

  Stitcher, yeah, yeah, very cool. And StarTalk has a Twitter handle?

• 18:58Speaker 01

  Yes.

• 18:59Neil deGrasse Tyson?

  StarTalk Radio.

• 18:59Speaker 01

  Yes, uh, I, I interact with it, uh, very frequently.

• 19:02Neil deGrasse Tyson?

  Interact?

• 19:03Speaker 01

  Yes. You guys tweet, I retweet.

• 19:06Neil deGrasse Tyson?

  Oh, nice, nice.

• 19:07Speaker 01

  I at you guys.

• 19:08Neil deGrasse Tyson?

  And you are Leanne Lord on Twitter?

• 19:09Speaker 01

  Yes, I'm, I'm Leanne Lord on Twitter.

• 19:11Neil deGrasse Tyson?

  Good, good. Can I say what my Twitter handle is?

• 19:13Speaker 01

  Uh, please do.

• 19:15Neil deGrasse Tyson?

  It's Neil Tyson.

• 19:16Speaker 01

  And who doesn't know that? Just everybody.

• 19:20Neil deGrasse Tyson?

  But people, you know, people come to me and say, will you be tweeting, like, cosmic? No, I, I suppose I could, but then I would just be your news source. They, you know, they want me to tweet current events in the universe, but that's not what I do.

• 19:31Speaker 01

  Current events in the universe?

• 19:33Neil deGrasse Tyson?

  Yes, we get some of that, too, in the cosmos.

• 19:35Speaker 01

  I like that.

• 19:36Neil deGrasse Tyson?

  Cosmos is immune to current events, but it's really just, when I have random crazy thoughts, I just put them down on, on page. So, so anyhow, we are a Cosmic Queries edition of StarTalk.

• 19:45Speaker 01

  Yes, my favorite.

• 19:46Neil deGrasse Tyson?

  And today's topic is?

• 19:47Speaker 01

  Gravity.

• 19:48Neil deGrasse Tyson?

  Gravity, and I've not seen these questions.

• 19:50Speaker 01

  No, you have not.

• 19:50Neil deGrasse Tyson?

  Called from our social media.

• 19:51Speaker 01

  Mm-hmm.

• 19:52Neil deGrasse Tyson?

  And I'd love to hear them. So, and if I don't know the answer, I'm just gonna come out and tell you. Okay, go.

• 19:55Speaker 01

  Well, I have a question, and I love this person's name. It's Fitz, oh, McFitz. I'm sorry, Fritz, oh, McFitz.

• 20:03Neil deGrasse Tyson?

  Wow. I would have to assume it's real, 'cause our, our fanbase doesn't lie to us.

• 20:08Speaker 01

  No, never.

• 20:09Neil deGrasse Tyson?

  Right, they're pretty cool. Okay. Fitz, oh, McFitz, okay?

• 20:13Speaker 01

  Even though gravity is the weakest of the four fundamental forces.

• 20:16Neil deGrasse Tyson?

  See, he knew that. Remember from the last segment, I told you how weak it was. The, the man is on the case.

• 20:20Speaker 01

  Yes.

• 20:21Neil deGrasse Tyson?

  Fritz, you, you happen in here. Okay, go on.

• 20:24Speaker 01

  Uh, yes, since it's the weakest of the four fundamental forces.

• 20:27Neil deGrasse Tyson?

  It's not just the weakest, it's the stupidly weakest force.

• 20:30Speaker 01

  Stupidly weakest?

• 20:31Neil deGrasse Tyson?

  It is not just weaker. It's not like you are weaker than I am, 'cause I can bench press 200 and you can bench press 100. No, it is, you're weaker than I am, 'cause I can bench press 200 and you can't lift anything. All right?

• 20:44Speaker 01

  Well, maybe gravity is smart enough to get people to do the work for it. Maybe that's what's going on. Although I will say the four fundamental forces, sounds like a rap group from the seventies.

• 20:52Neil deGrasse Tyson?

  Oh, the four forces. No one ever named their album. You can see them coming out dressed the same. Back then, people used to dress the same. The four tops, the temptations, the supremes. So, yeah, so that's, that is a Motown group from the sixties that was never, never.

• 21:07Speaker 01

  Never done, the four fundamental forces. Love it.

• 21:12Neil deGrasse Tyson?

  So what's, what's the question?

• 21:13Speaker 01

  Okay, um, even though gravity is the weakest of the four fundamental forces, does it act on a larger scale than, say, the weak nuclear force? In other words, is gravity the only force that keeps a planet orbiting a sun? Or do the other fundamental forces have a large role in that?

• 21:28Neil deGrasse Tyson?

  So he assumes everybody knows what the other fundamental forces are.

• 21:30Speaker 01

  Well, y'all.

• 21:32Neil deGrasse Tyson?

  I shouldn't, I wouldn't even have to mention that, but they are.

• 21:35Speaker 01

  But for the, for the purposes of maybe a co-host who doesn't know.

• 21:39Neil deGrasse Tyson?

  So, we've got gravity.

• 21:40Speaker 01

  Okay.

• 21:41Neil deGrasse Tyson?

  That with which we are most familiar. The next most familiar force to us humans is the electromagnetic force. That's what holds your flesh together.

• 21:50Speaker 01

  Oh, thank goodness.

• 21:51Neil deGrasse Tyson?

  That's what makes magnets repel and stick. That's why we have material objects in the world. Another force is the weak nuclear force. And another force is the force within the nucleus of the atom that holds particles together, like protons, it holds them together. Even though two protons of the same charge would want to do what? They're like charges, so what, what'd they do? Like charges.

• 22:18Speaker 01

  Hang out together?

• 22:19Neil deGrasse Tyson?

  Opposite charges attract, like charges repel.

• 22:23Speaker 01

  Oh, I'm sorry, I'm thinking of a dating sense that I would like to be with someone who had similar interests. So, no, it's the opposite.

• 22:29Neil deGrasse Tyson?

  So, opposite charges attract, like charges repel. To cram two protons into a nucleus, you need something to make that happen. Cause they want to repel each other awesomely. And so, we need a really strong force to do that. It's called the strong nuclear force.

• 22:44Speaker 01

  So there's the strong nuclear force, the weak nuclear force, electromagnetism?

• 22:50Neil deGrasse Tyson?

  Electromagnetic force.

• 22:51Speaker 01

  Electromagnetic force, and then gravity.

• 22:54Neil deGrasse Tyson?

  Gravity.

• 22:54Speaker 01

  Which you say with disdain.

• 22:56Neil deGrasse Tyson?

  No, it's funny.

• 22:57Speaker 01

  Because it's the weak.

• 22:57Neil deGrasse Tyson?

  It just occurred to me, electromagnetism. It's just electromagnetic force, but if you say electromagnetism, it sounds like a political or cultural movement.

• 23:08Speaker 01

  Yeah.

• 23:08Neil deGrasse Tyson?

  Like there's vegetarianism. I'm into electromagnetism. That's, we just started a movement. We are the electromagnetisms.

• 23:16Speaker 01

  Yes, and our opening act.

• 23:17Neil deGrasse Tyson?

  It's electromagnetics.

• 23:18Speaker 01

  To be the four fundamental forces.

• 23:20Neil deGrasse Tyson?

  So those are the four fundamental forces.

• 23:22Speaker 01

  Okay.

• 23:22Neil deGrasse Tyson?

  And two of them actually, in the 1970s, were merged into one. They were learned to be different sides of the same coin. If you, if you go back into high temperature, high, high density, two of those forces come together and they become one, and the name of that force is the electro-weak force. So electromagnetism and the weak nuclear force are manifestations of the same force. So technically, there's only three forces, three known forces, distinct forces in the universe. But, but this merging together, stapling together of forces?

• 23:51Speaker 01

  Mm-hmm.

• 23:51Neil deGrasse Tyson?

  That has set people on a path to try to merge all the forces. They're saying, if it worked for two of them, and before we knew about electromagnetism, there was electricity and there was magnetism. And research in the 19th century said, hey, these are...

• 24:04Speaker 01

  Direct quote, that's exactly what they said. They said, hey!

• 24:09Neil deGrasse Tyson?

  Hey! So, that magnetism and electricity were discovered by Faraday and others to be the same phenomenon, but just measured in different ways. So hence came the word electromagnetism. So now electromagnetism merged with the weak nuclear force, you have the electro-weak force. There you have it. So we really only have three forces. So, after saying all that, I forgot the question.

• 24:32Speaker 01

  I know, I was about to say, do you remember the question?

• 24:34Neil deGrasse Tyson?

  Was it?

• 24:35Speaker 01

  Um, okay, does it act on a larger scale than say, weak nuclear force? Or in other words, is gravity the only force that keeps a planet orbiting the sun? Or do other fundamental forces have a large role?

• 24:44Neil deGrasse Tyson?

  Yes, the strong and weak nuclear forces have very short range. Oh. Yeah, the short nuclear force drops off precipitously as you move. You go too far away from the nucleus. It has no, it does not manifest at all. Okay. You can describe the force, you can describe the strength of the force as it, as you move away. And it goes to zero very quickly. So, so you don't have a universe of planets guided by the strong nuclear force. Okay. All right, so now, how about the electromagnetism? If matter were not neutral, you would never noticed gravity in its presence. If a planet were made of negative charges and the star in orbit was made of positive charges,

• 25:28Neil deGrasse Tyson?

  you would never even know that gravity existed. That's how overwhelming the electromagnetic force would be on the operations of matter in the universe. It just so happens that matter does not like staying separately charged. It will do all it can to recombine negative charges with positive charges. That's why we have lightning strikes, thousands of strikes. Was it every minute? But you could count up all the lightning discharges in the world. Mm hmm. I forgot the number, but it's some huge number. It's going on all the time. All right, rebalancing this, this, this, going out of equilibrium between positive and negative charges. It does not like staying out of, out of balance.

• 26:11Neil deGrasse Tyson?

  So, whole planets will not just exist as a negative charged thing. It's going to find a positive charge, merge, and you've got a neutral planet. It'll do that instantly. Do you realize you could take the electrons, the negative charged particles, out of one cubic centimeter of the nose cone of the space shuttle? Space shuttle is something we used to use to get to orbit. Yes, I've, I've heard tell. For our younger listeners out there, this is how the United States used to get to orbit. Yes, okay, so if you took out the negative charges, put it at the base of the launch pad, which means that cubic centimeter at the tip of the shuttle is entirely positive charged now. Okay?

• 26:55Neil deGrasse Tyson?

  You remove the negative charges from their positive charge. Put it at the base of the space shuttle, ignite the solid rocket boosters and the main engine. It will not be able to take off.

• 27:06Speaker 01

  Because it's missing a piece?

• 27:07Neil deGrasse Tyson?

  No, because it's the attractive force of those negative and positive charges will overwhelm the strength of those of those rocket engines.

• 27:16Speaker 01

  So you kind of put a, what do you, those LoJack? No, it's not a LoJack, but you, you, you locked it by?

• 27:23Neil deGrasse Tyson?

  Yeah, yeah, yeah, yeah. It's, you prevented anyone from stealing it.

• 27:27Speaker 01

  Nice. Is anybody out there working on this car technology?

• 27:30Neil deGrasse Tyson?

  Yeah, yeah. LoJack for the space shuttle. Yeah. Cause that, there's such a high fencible item out there.

• 27:35Speaker 01

  Well, I'm automatically seeing, you know, regular market, you know? How can I adapt this to my Honda? I just take something out of the front fender, put it on the back and my car's not moving.

• 27:45Neil deGrasse Tyson?

  I can't stop laughing because I'm picturing the space shuttle up on blocks.

• 27:51Neil deGrasse Tyson?

  The space shuttle's up on blocks where someone stole the hubcaps or something.

• 27:55Speaker 01

  I love it. I love it.

• 27:56Neil deGrasse Tyson?

  But they couldn't drive it away, so they could only strip it down. So what would have happened while you did that is they would immediately reconnect with one another through electrical currents moving through the space shuttle. Or a lightning strike would bring them together and then that neutralizes it and then it would take off. So the only reason why gravity dominates the universe is because electromagnetism finds itself neutral nearly all the time. That's the only reason why. Otherwise you wouldn't even know gravity existed and we would be dominated by electromagnetic force.

• 28:26Speaker 01

  So maybe gravity's not so weak after all.

• 28:28Neil deGrasse Tyson?

  Which leads me to wonder, is there some force forty orders of magnitude weaker than gravity that cannot manifest in our lives because we are swamped by the force of gravity itself?

• 28:40Neil deGrasse Tyson?

  I lay awake at night wondering about that.

• 28:43Speaker 01

  And now so will I.

• 28:44Neil deGrasse Tyson?

  Okay. That's my, that's my job so that you will lose sleep based on cosmic distractions.

• 28:50Speaker 01

  I appreciate it. Uh, I have more questions though.

• 28:53Neil deGrasse Tyson?

  Go!

• 28:54Speaker 01

  Okay. From Dan Parenti, uh, other than Mr. Tyson himself, what is quote, "the great attractor"? Does its force affect us and if so, how? I love that.

• 29:05Neil 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.

• 29:35Speaker 01

  Yes.

• 29:36Neil 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.

• 29:55Speaker 01

  Okay.

• 29:56Neil 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 gravitational field of the

• 30:41Neil deGrasse Tyson?

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

• 30:52Speaker 01

  Oh dear.

• 30:53Neil deGrasse Tyson?

  Oh yeah.

• 30:55Speaker 01

  Feeling more insignificant every day.

• 30:57Neil deGrasse Tyson?

  That's my job. That the job of the cosmic perspective is to convey to all of us that we are a small part of a much larger universe.

• 31:07Speaker 01

  Well, that's I love the the visual in cosmos, the last minute of the last hour of the last day of the calendar, last second, like, wow, I'm not, I'm not even here yet.

• 31:19Neil deGrasse Tyson?

  Yeah, you're not even here yet. Yeah, you haven't even been thought up yet in the universe.

• 31:22Speaker 01

  Not really. You sneeze and I'm gone. Uh, I have a question. Uh, well, actually, this question isn't mine. It's from Mary Kathleen, who is from Newark, Delaware. Yay, Delaware.

• 31:33Neil deGrasse Tyson?

  How many women have two first names? It's usually the guys, right?

• 31:37Speaker 01

  Oh, oh, I thought you wanted it.

• 31:38Neil deGrasse Tyson?

  Jesse James.

• 31:39Speaker 01

  I thought you wanted an actual count.

• 31:40Neil deGrasse Tyson?

  Oh, you were gonna count them.

• 31:42Speaker 01

  No, no, no, there are one million, two hundred and seventy five.

• 31:46Neil deGrasse Tyson?

  Thousand.

• 31:48Speaker 01

  Five hundred and two, oh, three.

• 31:51Neil deGrasse Tyson?

  Three, there you go.

• 31:52Speaker 01

  There we go.

• 31:52Neil deGrasse Tyson?

  All right. So what do you have?

• 31:54Speaker 01

  So for Mary Kathleen, why is the Milky Way going to collide with the Andromeda Galaxy?

• 31:58Neil deGrasse Tyson?

  Oh.

• 31:59Speaker 01

  Yeah, she wants to know why, because she knew we were just gonna have this conversation.

• 32:03Neil deGrasse Tyson?

  Well, we, it turns out, we're, we're falling towards one another. So that's kind of when you.

• 32:08Speaker 01

  It's love.

• 32:09Neil deGrasse Tyson?

  It's love at first sight. Uh, we've probably, probably been falling towards one another from the very earliest times in the universe.

• 32:17Speaker 01

  So it was meant to be.

• 32:18Neil deGrasse Tyson?

  And we think it was meant to be. And by the way, it'll be a spectacular train wreck, but we will survive it for sure. Unless there's a fly.

• 32:26Speaker 01

  We, meaning?

• 32:26Neil deGrasse Tyson?

  We, the solar system.

• 32:28Speaker 01

  Okay.

• 32:28Neil deGrasse Tyson?

  Unless there's a sort of a fly by looting of our planets, the stars are so far away from one another that they will just pass through. Our stars of our galaxy will pass through the stars of the other. What won't pass through one another are huge gas clouds where stars are born. If one gas cloud collides with another, they will stick together like two heart marshmallows passing in the night. And when they stick, they will ignite huge waves of star, of the birth of stars. And so colliding galaxies tend to be regions of heavy duty births of star formation, births of stars. And while the rest of the stars sort of slide back and forth until they achieve a new equilibrium in a larger galaxy

• 33:09Neil deGrasse Tyson?

  that would be in need of a new name, because the two galaxies from which it came would exist no longer.

• 33:17Speaker 01

  Because they've merged.

• 33:18Neil deGrasse Tyson?

  Because they've merged.

• 33:19Speaker 01

  Wow, awesome.

• 33:20Neil deGrasse Tyson?

  Yeah, so we've been that way since the beginning. And we're close enough to one another that the expansion of the universe is not interfering with the fact that we are falling. And Andromeda is one of the few galaxies where we have motion towards one another. Instead of all the rest of the galaxies out there that are far away, where the manifestation of the expanding universe overrides any local motion they might have with their neighbor.

• 33:45Speaker 01

  Got it.

• 33:45Neil deGrasse Tyson?

  You got it. You got one more question. We got a few seconds left in this segment.

• 33:48Speaker 01

  Well, she had another part to her question. How does gravity override the expansion of the universe?

• 33:52Neil deGrasse Tyson?

  Well, she's right on the case here.

• 33:54Speaker 01

  She really is.

• 33:54Neil deGrasse Tyson?

  Okay, gravity wouldn't unless you're very close to one another, where the strength of gravity is strong enough.

• 33:59Speaker 01

  Right.

• 33:59Neil deGrasse Tyson?

  When you're close, you feel the force of gravity to be very high. And when you are a bound system, planets orbiting stars, stars orbiting a galaxy, galaxies orbiting one another, then the expansion of the universe will not override you. And so that's why nearby things, you don't have to worry about the expansion, you don't have to think about the expansion of the universe when you're describing their motion relative to one another. So it's an excellent question. We're listening to StarTalk Cosmic Queries. I'm with Leanne Lord. We'll be right back.

• 34:48Neil deGrasse Tyson?

  We're back. StarTalk Radio. Leanne Lord, my co-host. Leanne, you do stand-up, right?

• 34:53Speaker 01

  I do.

• 34:54Neil deGrasse Tyson?

  Yeah, that's very cool. It's one of my favorite genres of art.

• 34:57Speaker 01

  I know. I tell people that you're a huge stand-up comedy fan.

• 35:00Neil deGrasse Tyson?

  Completely. And when I give public talks, I use a handheld microphone, just like you guys do.

• 35:04Speaker 01

  And you're very funny.

• 35:05Neil deGrasse Tyson?

  No, they say, "Do you want to use a lavalier?" No. "Do you want a pin mic?" No. I want to have a relationship with my acoustic device.

• 35:15Speaker 01

  And now I'm frightened. But now, but now, interestingly enough, I, why do you do that? What does that do for you?

• 35:21Neil deGrasse Tyson?

  Because I want to, I'd like having it implement. I've pretended it was a spacecraft docking with me and I was in wayward asteroid. And I get to show that to the audience. If I don't, if my, if nothing's in my hands, my hands cannot be as useful to the delivery of content as it, they otherwise would be. So that's why.

• 35:39Speaker 01

  Okay.

• 35:39Neil deGrasse Tyson?

  That's why. So, we are in Cosmic Queries Edition.

• 35:42Speaker 01

  Cosmic Queries.

• 35:43Neil deGrasse Tyson?

  Of StarTalk topic.

• 35:45Speaker 01

  Gravity.

• 35:46Neil deGrasse Tyson?

  Right.

• 35:46Speaker 01

  Not the movie.

• 35:47Neil deGrasse Tyson?

  I haven't seen the question, so just have them, send them at me. And by the way, in this segment, if, if we don't get through all of them, we switch over to the lightning round.

• 35:55Speaker 01

  Yes.

• 35:56Neil deGrasse Tyson?

  Just warning you upfront.

• 35:57Speaker 01

  Okay.

• 35:57Neil deGrasse Tyson?

  And we have a bell, just for that purpose.

• 35:59Speaker 01

  Not the bell!

• 36:01Neil deGrasse Tyson?

  Alright, go.

• 36:02Speaker 01

  Alright, I have a question from Luke Dickinson, or Dickerson. Uh, does gravity repel antimatter? Does gravity exist? Oh, excuse me, does anti-gravity exist? And where are the hoverboards?

• 36:15Neil deGrasse Tyson?

  That's funny, because people born in the era of Back to the Future, they want the hoverboards.

• 36:20Speaker 01

  Mm-hmm.

• 36:20Neil deGrasse Tyson?

  I'm old enough to have seen the 1960s, I want the flying cars.

• 36:25Speaker 01

  Wow.

• 36:25Neil deGrasse Tyson?

  See?

• 36:26Speaker 01

  You need to downscale your expectations. That's what that is.

• 36:29Neil deGrasse Tyson?

  Is that what that was?

• 36:30Speaker 01

  Yes.

• 36:30Neil deGrasse Tyson?

  No, it was a Back to the Future thing. You think they, no, I don't believe that they downgraded their expectations. They just had something else that looked cool that they could do.

• 36:38Speaker 01

  Uh-huh, and what do kids today want? Exactly. They, they've downscaled to rollerblades.

• 36:44Neil deGrasse Tyson?

  Nobody thinks of flying cars to go joyriding in them. They think of them so that they would have less traffic. But anyone who's thinking of a hoverboard is, is ready to just rock the, rock the slopes.

• 36:54Speaker 01

  Yes.

• 36:54Neil deGrasse Tyson?

  Right? Okay. So, couple of things. Gravity attracts anything. The way the equations of gravity work, by the way, when antimatter was first predicted and then discovered, by the way, the physicists got that before the sci-fi people got ahold of it, just so you know, let's set the records right. Antimatter is real. We've had it since, what, the 1940s, 1930s, when it was predicted and then discovered. And, so, we, we, we got that, that, we got that one.

• 37:23Speaker 01

  Wow.

• 37:24Neil deGrasse Tyson?

  Just so you know. And in the movie, what's the Dan Brown story? Movie Angels and Demons. The Vatican apparently had some vial of antimatter and it was rare. Look, we get that all the time. We it's like that's not it would destroy the world and the church had to control it. Dan, he could have called me up and I could have said, call it unobtanium or something that we don't know about.

• 37:46Speaker 01

  Oh, don't even say unobtanium. You that will send me into an hour long rant. You do not have time for that.

• 37:51Neil deGrasse Tyson?

  That's another show.

• 37:52Speaker 01

  It is.

• 37:52Neil deGrasse Tyson?

  So, so, so all I'm saying is if you run the equations of gravity, they are such that it does not matter what the thing is that's falling. Or even what its mass is. It will fall at the same rate as anything else. That's why heavy things fall at the same rate to earth as light things do. Because the mass of the object divides out from the equation. That tells you how how earth attracts things to it. So it's a it's a fascinating feature of the mathematics of gravity and the equations that describe it. Now, if you want to get super geeky.

• 38:36Speaker 01

  And I do.

• 38:37Neil deGrasse Tyson?

  Do you? Are you ready for this?

• 38:39Speaker 01

  I'm not saying I'm ready, but I want to do it anyway.

• 38:41Neil deGrasse Tyson?

  You ready? This for geeks only, okay? Everyone else, cover your ears. Geeks only, you ready? You ready, Leanne?

• 38:48Speaker 01

  I'm ready.

• 38:49Neil deGrasse Tyson?

  Okay. Isaac Newton's equation for the force of gravity is mass of the first object times the mass of the second object divided by the distance between them squared. That gives you the force of gravity between the those two massive objects.

• 39:04Speaker 01

  Okay.

• 39:04Neil deGrasse Tyson?

  M one times M two divided by the distance between their centers squared. Okay, got that?

• 39:09Speaker 01

  Got it.

• 39:10Neil deGrasse Tyson?

  For us, one of those masses is earth. The other one is the mass of you. Got that? Okay. That is the force of gravity. That is your weight. That's how much you that equation gives you your weight. How do you lose weight? You can either remove mass from the earth. Or remove mass from your body.

• 39:28Speaker 01

  Uh, how, how plausible is that first option? Cause I'm having a difficult time with option two.

• 39:34Neil deGrasse Tyson?

  There you go. So that is gravitational mass. Now, I want to ask, how

• 39:40Speaker 01

  How much I weigh?

• 39:41Neil deGrasse Tyson?

  How quickly will that object accelerate me? So this is second equation we attribute to Newton. F equals ma, force equals mass times acceleration. Everybody should have learned that in high school. Even if not physics class, physical science class. F equals ma. So I want to know what my acceleration will be in the presence of the gravity. I take mm over r squared, set it equal to m times a. And the a is the acceleration I experienced in the face of that gravity. But I have an m on both sides of the equation. Guess whose m that is? That's your m. Your m is on the right hand side and on the left hand side of the same equation. And in algebra,

• 40:24Speaker 01

  They cancel each other out.

• 40:25Neil deGrasse Tyson?

  They cancel each other out.

• 40:26Speaker 01

  I knew that.

• 40:27Neil deGrasse Tyson?

  So the acceleration of gravity on earth depends only, only on the mass of the earth and the distance between the center of you and the center of the earth. And has nothing to do with your mass. That's why everything fall at the same rate as light things. So if you come up with antimatter, antimatter goes in one side of the equation and in the other side of the equation and it cancels out.

• 40:51Speaker 01

  It doesn't matter.

• 40:52Neil deGrasse Tyson?

  So even if something had anti-gravity, it's going to be accelerated to the object at the same rate as everything else.

• 41:01Speaker 01

  I love it.

• 41:02Neil deGrasse Tyson?

  As long as it has a mass that shows up on both, even if it has anti-mass. Even if that m is a negative number, whatever that means, it's negative that cancels on both sides.

• 41:12Speaker 01

  Got it.

• 41:13Neil deGrasse Tyson?

  There you have it.

• 41:14Speaker 01

  So me and a girl twice my size both get shoved off the top of a building. We're hitting the ground at the same time.

• 41:21Neil deGrasse Tyson?

  Basically, unless she's really large. And then she'll have more air resistance and she'll be, uh, yeah, she'll, she'll, she'll have a terminal velocity. If you, if you get shoved off a 12-story building, your air ain't gonna help you.

• 41:38Speaker 01

  I was about to say, get me a donut.

• 41:39Neil deGrasse Tyson?

  Right, right.

• 41:41Speaker 01

  Alrighty.

• 41:42Neil deGrasse Tyson?

  So, you know, I just ate half of that segment talking about giving you that one answer. And we already, like, we only have like seven minutes left, I'm afraid, Leon.

• 41:51Speaker 01

  No, no.

• 41:52Neil deGrasse Tyson?

  It is time for

• 41:53Speaker 01

  Uh oh.

• 41:54Neil deGrasse Tyson?

  The lightning round.

• 41:55Speaker 01

  The lightning round.

• 41:57Neil deGrasse Tyson?

  Did you hear it? There we go, okay.

• 41:59Speaker 01

  Alright, lightning round.

• 42:00Neil deGrasse Tyson?

  Lightning round, so you'll ask me questions, I will give you soundbite answers, which are, I maintain soundbite answers in me, because anytime I'm interviewed on the evening news, they can't listen to a lecture, there's no time.

• 42:10Speaker 01

  No.

• 42:10Neil deGrasse Tyson?

  I gotta give them a 30 second reply, and that's all they want. If I give them more, they're gonna edit it to that. So here, I'm gonna hand you pre-edited morsels of cosmic content.

• 42:19Speaker 01

  For questions you have not heard.

• 42:20Neil deGrasse Tyson?

  Go.

• 42:21Speaker 01

  Question from Jason Carey.

• 42:22Neil deGrasse Tyson?

  Yes.

• 42:22Speaker 01

  What could we achieve with the new propulsion technology that would come from the hypothetical element z equals 45 that possesses anti-gravity properties? Oh!

• 42:35Neil deGrasse Tyson?

  Yeah, if you had, if you actually had some anti-gravity propulsion device, it would always have to be sort of in front of you somehow, right? And then you'd be falling towards it, but then you have to be constantly moving this thing for you to fall towards it. So you run into the problem of the sailboat, where a person brings an electric fan onto the sailboat to blow air into the billowed sail to move forward.

• 43:02Speaker 01

  Okay.

• 43:04Neil deGrasse Tyson?

  Nature doesn't work that way, because the fan has a recoil force, plus where would you plug it in, in your sailboat? But if you could, if it was battery operated, the fan has a recoil force that exactly will cancel anything it's doing to your sail. So if you try to travel with some anti-gravity attraction device in front of you, I don't know how you would keep moving it in front of you. That takes the same energy it would have taken for you to fall towards it in the first place, you end up going nowhere. So I don't fully know how you would make an anti-gravity element pull you across the galaxy, much less to the Piggly Wiggly.

• 43:40Speaker 01

  From Alexander B. Kowalski.

• 43:44Neil deGrasse Tyson?

  Lightning round, read fast.

• 43:45Speaker 01

  All right, how realistic is the idea of a gravity gun? That was fast, that was short. How realistic is the idea of a gravity gun?

• 43:52Neil deGrasse Tyson?

  I don't know, forgive my ignorance, I wouldn't know what you would want a gravity gun to do. What would it do to you?

• 44:03Speaker 01

  I don't know, make you feel heavier? I don't know.

• 44:07Neil deGrasse Tyson?

  Yeah, you aim it at someone, they could become so heavy, their muscles can't move their body, and they're sluggish in place, and then you go cuff them. So maybe the gravity gun, I got it, the gravity gun has Higgs boson fields in it. And I aim, because the Higgs boson grants mass to particles that are, that, that's what it is. It's a very, it's called the God particle, because it's, if you were a particle, that's the particle you'd want to be. You grant, the Higgs field grants mass to other particles. So, a Higgs gun would influence the mass of what it is you pointed at. And you can make, basically, have them have no mass at all, or have so much mass, they can't even lift their own weapon. There you go.

• 44:50Speaker 01

  There we go.

• 44:51Neil deGrasse Tyson?

  I think we're a long way away from such a gun.

• 44:53Speaker 01

  Which answers this question.

• 44:54Neil deGrasse Tyson?

  Yeah, try to make peace, and then you don't have to kill the person with the gravity gun. Next.

• 44:58Speaker 01

  All right, from Jacob Martin, from Plano, Texas, if we were able to create and accumulate enough-

• 45:02Neil deGrasse Tyson?

  It's flat in Plano, Texas.

• 45:03Speaker 01

  It's very flat. If we were to able, if we were able to create and accumulate enough of an extremely heavy material, something like element 118, but heavier, could we create a gravitational force strong enough to affect tides, orbits, etc.?

• 45:16Neil deGrasse Tyson?

  Good question. So, just because you have a heavy element, doesn't mean when you make a solid object out of that element, that that is heavy?

• 45:23Speaker 01

  Oh.

• 45:23Neil deGrasse Tyson?

  Because the element decides how close to its neighbor it's going to exist, in whatever is the lattice that you have constructed. So that, in fact, the densest elements on the periodic table are not at the heavy end, they're kind of in the middle. In fact, my favorite dense element is osmium. A cubic foot of osmium, cubic foot, just take, a cubic foot of osmium would make the world's best paperweight. It weighs about 1,800 pounds.

• 45:50Neil deGrasse Tyson?

  It weighs more than than small cars.

• 45:52Speaker 01

  A little chunky.

• 45:53Neil deGrasse Tyson?

  A cubic foot. So we do have heavy things. What matters here is not what the mass is, but what, what, yes, mass matters and density matters. But for stuff that's going to fit in your lab, no, you know, the gravity is not going to have that effect. You have to make a whole lot of it. And do we have enough material? Do you know how much total gold has ever been mined? Gold is very dense as well. Much denser than lead.

• 46:17Speaker 01

  Hmm.

• 46:17Neil deGrasse Tyson?

  In fact, it makes a better analogy to something being heavy than lead does. You say, I got a, got a lead foot when you're driving a car. You say, I have a gold foot. You say, oh, it's worth a lot. No, it's heavier than lead. Right? So, gold, gold is the total amount of gold ever mined in the history of the world would fill a barn.

• 46:37Speaker 01

  That's it?

• 46:37Neil deGrasse Tyson?

  That's it. So you don't have that much of these rare elements to try to create so much of it to then try to affect tides or do other gravitational things to the earth. So give up on that one. That was, I didn't answer that fast. Damn. Okay, go.

• 46:50Speaker 01

  From my-

• 46:51Neil deGrasse Tyson?

  We've got two minutes left.

• 46:51Speaker 01

  Michael Jesus Shores. Okay, two minutes left?

• 46:53Neil deGrasse Tyson?

  Yes, go.

• 46:54Speaker 01

  All right, all right. Oh, go this one. I love this one. This is from Twitter. How close does my-

• 46:58Neil deGrasse Tyson?

  Who's the person?

• 46:58Speaker 01

  Hmm?

• 46:59Neil deGrasse Tyson?

  Who's, who's-

• 46:59Speaker 01

  No name. I don't see a name.

• 47:01Neil deGrasse Tyson?

  Twitter him!

• 47:01Speaker 01

  Oh, there we go. I'm sorry, it was on another page. It's Dave Steele. Dave underscore Steele.

• 47:05Neil deGrasse Tyson?

  Good.

• 47:06Speaker 01

  Okay. And the question is, how close does my girlfriend have to be so that her force of gravity is equal to the force of gravity of the closest star?

• 47:14Neil deGrasse Tyson?

  Ooh.

• 47:15Speaker 01

  Science and romance.

• 47:16Neil deGrasse Tyson?

  I'd have to calculate that. But I can tell you, we have done this calculation for, I think I'm going to end on this.

• 47:23Speaker 01

  Uh oh.

• 47:23Neil deGrasse Tyson?

  Because I, I won't be able to follow it with what I'm about to tell you.

• 47:27Speaker 01

  Okay.

• 47:28Neil deGrasse Tyson?

  Okay. We have done the, I have done, and others have done the calculation for the gravity of the obstetrician who birthed you and its effect on you. And when you do the math, the gravitational force of the obstetrician on you, the brand new fetus who just emerged, is greater than the gravitational force exerted on you by the planet Mars.

• 47:55Speaker 01

  Okay.

• 47:56Neil deGrasse Tyson?

  But no one talks about, in astrological circles, the effects of the obstetrician

• 48:03Speaker 01

  No.

• 48:03Neil deGrasse Tyson?

  on your personality, or on your sex life, or social life, or financial life.

• 48:07Speaker 01

  No.

• 48:07Neil deGrasse Tyson?

  Why not? And suppose you were born with an open window and Mars was in the sky, so you felt the light of Mars. How about that? But now ask, what is the wattage of the birthing lamps relative to the brightness of Mars? Compare these, and then you realize the folly of such proclamations.

• 48:26Speaker 01

  But you're interjecting logic where people just want feelings.

• 48:31Neil deGrasse Tyson?

  Sometimes logic wins the day. That's all the time we have. Lee Antlort, thank you.

• 48:35Speaker 01

  Thank you.

• 48:36Neil deGrasse Tyson?

  For being my co-host. 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, your host. As always, bidding you to keep looking up.