Cosmic Queries – Alien Heist, Scimitars, & Time in a Bottle with Charles Liu

What if the laws of physics were different? Neil deGrasse Tyson and co-hosts Chuck Nice and Gary O’Reilly answer grab bag questions with astrophysicist Charles Liu about alien heists, gravity, and space exploration.

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

• 0:00Charles Liu?

  The constants of the universe, gravitational speed of light, whatever, were all tiny, tiny bit different, like different one part in a billion or something. Maybe in our daily lives we would not notice. But over the history of the universe, things would be so fundamentally changed that our existences would just not be the same.

• 0:20Neil deGrasse Tyson?

  Yeah, or we wouldn't exist at all.

• 0:23Neil deGrasse Tyson?

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

• 0:36Neil deGrasse Tyson?

  This is StarTalk Sports Edition. We're gonna do cosmic queries today. The grab bag version. I got with me my co-host, of course, Chuck Nice. Chuck?

• 0:48Chuck Nice?

  Hey, hey, hey, what's up, Neil?

• 0:49Neil deGrasse Tyson?

  All right, professional stand-up comedian and actor. Got Gary O'Reilly, former soccer pro. How you doing, Gary? I'm good, Neil. So this is, this is Cosmic Queries Grab Bag, which takes us to a broader stretch of the geekosphere than normally I can handle all by myself. And so, guys, we brought in the big guns for this. And who would that be? The one and only Charles Liu, my friend in college. Charles, welcome back. We need the crowd noise.

• 1:25Neil deGrasse Tyson?

  Charles, all hail the geek in chief. Our returning champion. Right, and still champion.

• 1:32Chuck Nice?

  You are all too kind, thank you. It's such a pleasure to be back. Thanks for having me.

• 1:36Neil deGrasse Tyson?

  The geek spectrum, the geekosphere knows no bounds in its extremities. So, yes, I'm card-carrying geek, and I'm proud of it, and I can hold my own on the street. But if Charles Liu walks in the house, in the room?

• 1:53Chuck Nice?

  Uh-oh. Now we just entered, we entered the multi-geekiverse.

• 2:00Chuck Nice?

  We have entered the multi gigaverse.

• 2:02Charles Liu?

  Alright, folks.

• 2:03Chuck Nice?

  We got Neo and Chuck Lou.

• 2:05Neil deGrasse Tyson?

  Oh my gosh, so Charles, you are a professor of astronomy and physics at City University of Staten Island in New York? Is that fair enough?

• 2:15Charles Liu?

  That's correct.

• 2:16Neil deGrasse Tyson?

  And do they still give you administrative duties now? Or are you back in?

• 2:20Charles Liu?

  Ah, yes, yes, regrettably or happily.

• 2:24Neil deGrasse Tyson?

  Oh, wow, yeah, sorry to hear that. Yeah, sorry about that.

• 2:26Charles Liu?

  Yeah. No, you know, it's a double edged sword. On the one hand, yes, there's a lot of paper, these days electrons, I guess, that one has to push that one wishes one does not have to push. But on the other hand, you get a chance to really enact change. You can help, you know, the 21st century classroom be what it is. You can design curriculum and move things along better. And so I really welcome the challenge and I'm very fortunate too that my colleagues are great. There's not a jerk or a jerk among us, which many departments, yeah, many times departments cannot boast that.

• 3:02Chuck Nice?

  I really want to look up the origin of the double edged sword analogy metaphor because, you know, when it comes to killing people, I want a double edged sword. But we use it.

• 3:17Charles Liu?

  Not necessarily.

• 3:17Chuck Nice?

  Why wouldn't you?

• 3:18Charles Liu?

  No, think about the scimitar.

• 3:21Chuck Nice?

  I know what they're.

• 3:22Charles Liu?

  It's a curved blade. It's heavy on one side and as a result, the front side can be very, very sharp. And meanwhile, you have much more force going that way and then you poke in the other direction. So not having the blade actually gives you an advantage because you have a strength of striking in one direction. There is a story that goes that during the Crusades, Richard the Lionhearted tried to demonstrate to the Saracen prince that he was going to just how powerful the Crusaders were. He took his two sided sword and severed an iron bar with a single stroke because of his great power. And the Saracen prince then came back and brought his scimitar, took a feather pillow.

• 4:07Chuck Nice?

  Sliced it.

• 4:08Charles Liu?

  And sliced the pillow exactly in half.

• 4:12Chuck Nice?

  That's.

• 4:12Charles Liu?

  With the scimitar. You can't do that with a double edged sword.

• 4:15Chuck Nice?

  With a Ginsu knife, so screwed up, Chris. That prince is not that impressive.

• 4:23Chuck Nice?

  And it wasn't a my pillow pillow because, I mean, let's be real.

• 4:29Neil deGrasse Tyson?

  Why can't a double edged sword cut a pillow in half?

• 4:32Charles Liu?

  The double edged sword could cut a pillow in half, but it was not built to cut a pillow in half. And as a result, it was built for strength and power, but there was no subtlety to it.

• 4:41Chuck Nice?

  Not precision, no precision.

• 4:43Gary O'Reilly?

  No, it was the broadsword and it was meant to, it was meant to be used to fight against soldiers or knights in chain mail armor. So therefore the scimitar's not gonna poke a hole through the metal.

• 4:55Chuck Nice?

  If I can't, if I can't cut through the armor, I'll just break your arm.

• 4:59Gary O'Reilly?

  Pretty much, pretty much what it was.

• 5:01Charles Liu?

  But, but what, but what the scimitar can do is basically scalpel things, surgically remove limbs and things, digits, in such a way that you can be as armored as you want, but you still can't do what you want to do.

• 5:17Chuck Nice?

  See, but here's where I, where I go back to my point. Why not just have a double edged scimitar? Now I'm.

• 5:25Charles Liu?

  Because the second edge, because the second edge reduces the ability of the first edge. It's a trade off between one side and the other.

• 5:33Chuck Nice?

  Hmm, okay. Well, you're a real know it all, ain't you?

• 5:36Gary O'Reilly?

  I know.

• 5:44Charles Liu?

  Guilty as charged, Sir Lord Nice.

• 5:47Neil deGrasse Tyson?

  You know, you should be on our podcast, you know?

• 5:49Gary O'Reilly?

  You think?

• 5:49Chuck Nice?

  Oh, that was fast, that was good shit.

• 5:51Charles Liu?

  Sure.

• 5:52Neil deGrasse Tyson?

  Alright, so we got, we got questions from our Patreon members. And this is a grab bag, so it's anything in sports, right? Sciencey and sporting.

• 6:00Gary O'Reilly?

  I'd say, I think it's, I think you just end that sentence that it's anything.

• 6:04Neil deGrasse Tyson?

  It's anything, okay. Let, let's go with it. This is sports edition though. So we can put a sports spin on it. So Chuck and Gary, you got the questions, but bring it on. And I'll help out like when it's my turn or when I think I can help, but generally.

• 6:19Gary O'Reilly?

  You'll be involved, guaranteed.

• 6:21Neil deGrasse Tyson?

  Generally, I am unnecessary in the presence of Charles.

• 6:24Gary O'Reilly?

  No, no, no, no. Alright, well, let's, let's kick off the first one. Dan Rez, and thank you to all our Patreon patrons for involving themselves in our requests for questions. So here we go. I have another question, because this is one of several that Dan decided he'd drop into our inbox. If time is a constant but is affected in a way by gravity, is there theoretically a way to manipulate time? If gravity waves can affect how time moves and speed can make time move either faster or slower, depending on vantage, and he says in brackets, I guess. Is there a way, obviously theoretically, to manipulate time? Also, is there a correlation in size and time?

• 7:05Gary O'Reilly?

  Let's say hypothetically, there's an object or being that is bigger than the universe itself. Would time act differently due to the larger mass? And would this thing experience time as we do? And does the fact that the size difference allows for faster movement also perception of time to said thing or being? Now, that's the end of the show because that question's particularly...

• 7:27Chuck Nice?

  Exactly.

• 7:29Neil deGrasse Tyson?

  There's no more time left.

• 7:30Chuck Nice?

  There's no more time. We're out of time. Out of time. And by the way, just out of curiosity, is time a constant? The way the speed of light is a constant? Because that's how he started.

• 7:40Neil deGrasse Tyson?

  Well, here's what I'm gonna do. I'm gonna reshape the question into something that's one and a half sentences long. I don't get handed to Charles. Charles, as Dan knows, different factors affect the rate of passage of time. We know this. Sources of gravity, how fast you're moving, how much mass you are. So, might there be a future time where we can manipulate these factors? And make time, make time do, we become the time overlords? And make time do what we want?

• 8:12Gary O'Reilly?

  Doctor Who.

• 8:12Chuck Nice?

  Dan, hey Dan, that was a no question, Dan.

• 8:17Neil deGrasse Tyson?

  I just, I think that's what he's after, but I've said it in full words.

• 8:20Chuck Nice?

  I don't care if that's what he's after or not. That's what he's asking now.

• 8:23Neil deGrasse Tyson?

  Right.

• 8:24Chuck Nice?

  That's a great question. That's amazing.

• 8:27Neil deGrasse Tyson?

  Right.

• 8:27Charles Liu?

  Well, this is a great question. It's very complicated. Lots of great stuff involved. Here's how I think about it. Here's how I approach something like this. Time is a dimension, right? You go back to the general theory of relativity. Time, manipulating time is like talking about manipulating length, width, or height. In other words, we don't manipulate the dimensions itself. We manipulate where we are in that dimension, how we travel in that dimension, which direction we move, how, speed at which we move, things like that. So, the answer really, you're... Combining two different things. One is the idea of time as a dimension. And the idea, and the second idea is time as we experience it as humans

• 9:12Charles Liu?

  or as individual organisms or things in the universe. So the answer is, yes, we can absolutely manipulate how we experience time in the future. We, if we could, for example, go near a black hole, we would change our time experience. We can manipulate how we, fast we move through space, you know, length, width and height. In the same way, we can manipulate how fast we move through time. Just by picking up our speed, getting close to the speed of light. We know that there's this phenomenon called time dilation. The important thing to think about is, what are you trying to do? Are you trying to change the dimension of time itself? Or are you trying to change what we are experiencing? Or what others are experiencing in the form of time?

• 9:55Charles Liu?

  This laughter thing is certainly doable, given the right technology. But boy, does a technology have to be pretty darn advanced.

• 10:03Neil deGrasse Tyson?

  So what would happen is if we do master it, you could have a whole other set of people that we might call time bandits. Oh. That I did there.

• 10:13Charles Liu?

  Name's really been taken, Neil. Sorry about that. Yeah, yeah, I know. Maybe, yeah, some other time.

• 10:19Neil deGrasse Tyson?

  Or what was that movie where time was a commodity? And you could take it or give it to people. Do you remember that movie? Starring Justin Timberlake. Yeah, he was in it, and so was the guy from, from

• 10:30Charles Liu?

  Was it?

• 10:30Neil deGrasse Tyson?

  The Big Bang Theory. Um, he was in it too.

• 10:34Charles Liu?

  Oh.

• 10:34Neil deGrasse Tyson?

  The, I, I.

• 10:36Charles Liu?

  Well, is this the one where, where everyone had the set amount of time to live? And the moment your time ran out, you would just tip over and die? But until then, you would never age?

• 10:46Neil deGrasse Tyson?

  Yeah, and you could just hand the time, you could buy it or sell it, commoditize it, get it on the, on the black market. Yeah.

• 10:53Charles Liu?

  Right, that's a classic idea of time, you know, take it to the extreme, of course, of time as a resource, right? If you talk to, say, human resource managers or people who wish to optimize a corporation or an individual's ability to get stuff done, they think of time as a resource and say, you have 24 hours each day, how do you apportion it to all the different things you do? How do you make it more efficient? Things like that, right? As a physicist, you might think more about time as a dimension, which is what Einstein considered as the right way to think about it.

• 11:28Chuck Nice?

  If only we could put it in a bottle.

• 11:29Charles Liu?

  Yeah, there are many different ways.

• 11:30Neil deGrasse Tyson?

  Time in a bottle.

• 11:31Charles Liu?

  The first thing that I'd like to do.

• 11:34Chuck Nice?

  What would you do? What would you do, that first thing?

• 11:37Neil deGrasse Tyson?

  I would sing it.

• 11:38Charles Liu?

  But there never seems to be enough time.

• 11:40Chuck Nice?

  That's right.

• 11:41Charles Liu?

  To do the things, right?

• 11:43Chuck Nice?

  Well, well, time has come today!

• 11:46Charles Liu?

  At least time is on my side.

• 11:51Gary O'Reilly?

  And time for another question.

• 11:54Chuck Nice?

  Look at that, Annie win! That's why he's the champion, look at that, goes out with a little dagger on us, can't beat that.

• 12:01Neil deGrasse Tyson?

  Gary, what else you got?

• 12:02Gary O'Reilly?

  All right, Samuel Barnett, greetings from London. That's London, England.

• 12:07Chuck Nice?

  Oh, look at that.

• 12:08Neil deGrasse Tyson?

  London, Connecticut, okay.

• 12:09Gary O'Reilly?

  No, not to be mistaken. A bit of a hypothetical question, given enough advanced technology, would it be possible, I think you're gonna like this, would it be possible for an advanced alien civilization to steal our sun before the other side of the world noticed it was missing?

• 12:25Charles Liu?

  Ah, great question.

• 12:27Chuck Nice?

  They have eight minutes to pull off the world's greatest heist.

• 12:30Neil deGrasse Tyson?

  There you go.

• 12:31Charles Liu?

  The solar system's greatest heist, right, Chuck? But you're exactly right. So, the thing is, it would take eight minutes plus to get...

• 12:43Charles Liu?

  The information to the earth that it's missing. But then the side that's facing away from the earth, uh, excuse me, the side of the earth that's facing away from the sun at that moment would still know right away, like within moments, that it was missing because of all the different things it does other than shine, right? Because of all the different things that the sun does to the earth other than shine. First of all, the shine is interesting enough, right? The each second, the amount of sunshine that hits the earth is equivalent to millions of atomic bombs, right? Uh, and as a result, you're, you're already removing that heat

• 13:25Charles Liu?

  and that heat's gonna flow completely differently than when the sun is shining. The equilibrium's completely messed up, right? Second of all, the gravitational effect is missing immediately. So the entire earth would start moving in a direction completely different from what it was doing when it was still in the sun's gravitational field, right? So, um, it might fly straight off into another direction, right? Just like if you let go of a lasso and you let the string go and then the thing just goes flying straight away, right? You have a brick on a string or something and you spin it. His moment you let go of the string, the brick heads off in a straight line. All of the earth would go at the same time in that direction.

• 14:09Charles Liu?

  And so there's all kinds of things that would immediately affect the entire earth the moment that the information that the sun was gone.

• 14:18Chuck Nice?

  Or maybe we just like finally get a chance to go make out with Mars.

• 14:24Charles Liu?

  Hmm, it would be fun, except Mars is heading off in its own direction at that point. Mars is like, I don't want anything to do with you, earth. I'm, I'm headed to Venus. All the planets, we'll fly off in a tangent. Yeah.

• 14:38Chuck Nice?

  Is there, what about, um, when you talk about that flying off in the tangent? Is there, since Jupiter has so much mass nowhere near the, of the sun, is it possible that we might one planet or two planet kind of follow after Jupiter? Because of the amount of gravity that it has?

• 14:57Charles Liu?

  Excellent question, Chuck. I would say that you would have to do the calculation at that precise moment, because the positions of the planets relative to one another keep varying on a second-by-second basis. They all orbit at different rates and at different distances from the Sun. But if, at the moment that the Sun disappeared, the planets were within Jupiter's sphere of influence, in other words, we weren't at escape velocity with respect to Jupiter, then indeed, we would start moving toward Jupiter, and there's a real possibility that we would wind up orbiting Jupiter after a long period of migration.

• 15:32Neil deGrasse Tyson?

  You can picture if we're on one side of the Sun, headed to the left, and Jupiter's on the other side of the Sun, headed the other way, and then we'd lose the gravity, Jupiter's in one direction, we're in the other, so we're not catching Jupiter at that point.

• 15:48Charles Liu?

  Exactly, right.

• 15:49Neil deGrasse Tyson?

  Yeah, so you're right, Charles, you'd have to really, you can probably do the math on that and see what planets would get together after that.

• 15:56Charles Liu?

  It would not be too hard. Yeah, it would not be too hard to do the math, but it would be really cool, actually. I'd love to. I don't want to try it.

• 16:06Neil deGrasse Tyson?

  It would be the Sun Bandits.

• 16:08Charles Liu?

  But I think it would be really neat. Nice.

• 16:10Neil deGrasse Tyson?

  Yeah. So guys, we've got to take a quick break. When we come back, more StarTalk Sports Edition Grab Bag, Cosmic Queries on StarTalk.

• 16:31Neil deGrasse Tyson?

  We're back, StarTalk Sports Edition, Cosmic Queries Grab Bag. And you know I need help with the grab bag, so we got Charles Lu, our geek-in-chief, with us.

• 16:43Charles Liu?

  Hey, hey.

• 16:44Neil deGrasse Tyson?

  And by the way, StarTalk fans, we retooled the categories of our Patreon membership.

• 16:52Neil deGrasse Tyson?

  And so I want to see what those new categories are that might entice you if you haven't been a Patreon member before. This new structure might resonate with you. And of course, you'd find that at patreon.com/stargradio. Check that out. Because all the questions we were responding to today are from Patreon members. That's one of the privileges and one of the perks.

• 17:14Chuck Nice?

  Alright, so stop sending them to me and join Patreon. Stop trying to, stop trying to game the system.

• 17:21Neil deGrasse Tyson?

  Game the system, right. And so Gary, this is, this is StarTalk Sports Edition. Why don't we get into the sports questions?

• 17:28Gary O'Reilly?

  Oh, you're so impatient. We're gonna get there.

• 17:32Chuck Nice?

  Sports, sports.

• 17:34Gary O'Reilly?

  Yeah, go sports. Segment three.

• 17:36Neil deGrasse Tyson?

  Segment three, I'll look forward to that.

• 17:38Gary O'Reilly?

  Yeah, but our Patreon audience are so inquisitive. Their cosmic curiosity is so deep and intense. I felt the need to just bring that forward and not just hog all those questions.

• 17:51Neil deGrasse Tyson?

  Get warmed up with the actual universe.

• 17:52Gary O'Reilly?

  Alright, we're gonna go off and do our stretches.

• 17:54Neil deGrasse Tyson?

  Alright, let's do it. Next question.

• 17:56Gary O'Reilly?

  Alright, next question up. Nefreti? Yeah. Okay, I might mangle that one. So which of the laws of, interesting question this. Which of the laws of physics could you change and have the least effect on everyday life?

• 18:12Charles Liu?

  Oh geez. Oh wow. Well, they're all so interconnected, right, Neil? I mean, I don't know if you can tweak any one thing and it not just like totally unravel the entire tapestry of the earth and the world and everything we do. I guess I-

• 18:31Neil deGrasse Tyson?

  Yeah, I gotta agree with, I gotta agree with you, Charles, on that. They're so interconnected.

• 18:35Charles Liu?

  Right.

• 18:36Neil deGrasse Tyson?

  That if you change one thing, that's the beginning of the end of everything you know and love in this world.

• 18:40Chuck Nice?

  Alright, how about this one? Let me give you guys my, my, my example. Just out of craps and giggles. Okay. For every action, there's an equal and opposite reaction. Suppose we made the reaction opposite, but not equal.

• 18:58Neil deGrasse Tyson?

  Yes.

• 18:58Charles Liu?

  Ah, well, already we, in, in, in reality, we have these things called friction and viscosity, right? They, they dissipate some of the action when it comes back. So to some extent, it is a lesser reaction, like by a tiny fraction, if you take these dissipative forces into account. So maybe if it were a tiny, tiny bit different, you know, that's a great point, Chuck. It's very possible that we would not notice. So it would have to be a very small change. But maybe, you know, if it were at the 99.99999% level true, and then you just had a tiny, tiny fraction of percent dissipating, we might not be able to tell on a daily basis,

• 19:40Charles Liu?

  because all of the rest of our, um, all the rest of our interactions are so large compared to that fraction. You know, that's a- Let me geek out a little.

• 19:49Gary O'Reilly?

  Are you saying, Neil, are you saying, Neil, and, and Charles, that there is a natural tolerance, albeit a small, very tiny one, in the laws of physics?

• 19:58Charles Liu?

  Possibly, right.

• 19:59Gary O'Reilly?

  Or are they, it's that and nothing else?

• 20:00Charles Liu?

  You know, and, and that may be the point, right, Neil? Uh, you're about to say something along those lines, but if the constants of the universe, gravitational, speed of light, whatever, were all tiny, tiny bit different, like different, one part in a billion or something, maybe in our daily lives we would not notice. But over the history of the universe, things would be so fundamentally changed that our existences would just not be the same.

• 20:27Neil deGrasse Tyson?

  Yeah, or we wouldn't exist at all. I'll give an example. There's a, there's a fun calculation you do in astrophysics graduate school. And I know the word fun and calculation are not always in the same sentence.

• 20:38Charles Liu?

  Bring it on.

• 20:39Neil deGrasse Tyson?

  So what you do is, you ask yourself, suppose the gravitational constant, this was predicted to exist by Isaac Newton, ultimately measured by a fellow named Cavendish, and this gravitational constant, if it was slightly different, what effect would it have on, for example, the luminosity of the sun? Okay, because the sun's, the, the, the, the, the weight of all the mass and the pressure and the temperature and the nuclear reactions, all of this. When you do that calculation, you find that the luminosity of the sun depends to the seventh power-

• 21:19Charles Liu?

  Yeah.

• 21:19Neil deGrasse Tyson?

  -on the gravitational constant.

• 21:21Charles Liu?

  Yeah. Damn. I, I remember doing that calculation.

• 21:24Neil deGrasse Tyson?

  So if the gravitational constant was, was a tiny bit higher? Then the luminosity of the sun would be unacceptably high for anything we enjoy and love here on Earth in our Goldilocks zone.

• 21:36Charles Liu?

  I remember that calculation, Neil. That's fun. I know we didn't go to grad school together, but it was, it's, it's that mental exercise. And, and I, I remember thinking, wow, if we just change the gravitational constant to the universe by a tenth of a percent, then the surface of the Earth would be uninhabitable.

• 21:53Neil deGrasse Tyson?

  Right, right, right. So, so, so it's not that everything is in delicate balance. Don't think about it in those terms. It's that we are what works with the properties that exist in this universe. Right? Yes, and if you change it, we're not here, but maybe something else would be here in those other, under those other conditions, but it wouldn't be anything we know and love.

• 22:18Charles Liu?

  Right.

• 22:18Chuck Nice?

  Oh, well, there you have it. So your answer is if it's, if, if some butts were candies and nuts, every day would be Christmas.

• 22:26Neil deGrasse Tyson?

  Yes, that's exactly what we said.

• 22:29Charles Liu?

  You know what? If you want to talk about the Big Bang Theory, that's a great point. You know what, Chuck? Because if the expansion rate of the universe were different, then it would not affect us as much during the lifetime of human beings on the Earth. Right, Neil? If, if the Hubble constant were, say, half of what it is now, or double what it is now, then it wouldn't make a big difference billions of years from now. But at this moment in the evolution of our society and of human civilization, it would not make that big of an effect.

• 23:03Neil deGrasse Tyson?

  I worry that if the Hubble constant were too high, then in the early universe, the matter would not have coalesced.

• 23:08Charles Liu?

  Right.

• 23:09Neil deGrasse Tyson?

  We would have expanded and then never formed stars and galaxies.

• 23:12Charles Liu?

  Yeah, yeah. It's a before thing instead of an after thing in that case.

• 23:15Neil deGrasse Tyson?

  Right. And I'm just saying, there are people who get religious about this and say, oh, you see, everything is perfectly tuned for us. No, we are perfectly tuned for it. That's the difference.

• 23:25Gary O'Reilly?

  All right.

• 23:25Neil deGrasse Tyson?

  Um. Oh, by the way, one other thing, quick, quick thing. You mentioned the Big Bang Theory and if butts were candy and nuts, what was that thing?

• 23:33Gary O'Reilly?

  Be Christmas every day.

• 23:34Charles Liu?

  Christmas every day.

• 23:34Neil deGrasse Tyson?

  My first of two cameos on the TV sitcom Big Bang Theory. Sheldon recited that very same poem to my face.

• 23:42Gary O'Reilly?

  Oh, really?

• 23:43Charles Liu?

  That's that's why I know it, Neil.

• 23:46Gary O'Reilly?

  That's very cool.

• 23:48Charles Liu?

  First time I ever heard that, actually. Yeah.

• 23:50Neil deGrasse Tyson?

  Yeah, yeah, yeah, yeah.

• 23:52Gary O'Reilly?

  All right, here we go. Let's dive in even deeper. Joey Medici has inquired. Could a body of mass have two different strengths of gravity? Think a giant meteor or a planet shaped like a cone? Would the end with more mass have more pull? And then finishes up with thanks.

• 24:12Charles Liu?

  Yes. The answer is yes.

• 24:14Neil deGrasse Tyson?

  Charles, let me take this one. I got this one. So, yes, first the answer is yes. Um, generally when we do calculations, we simplify it. And we talk about objects that are spherically symmetric. Not only in in radius, but in distance from the center. So that makes the calculations come out easy. But geologists, geophysicists, oil prospectors have gravimeters where they're looking for distortions in the overall average gravity of the earth that will tell them where something heavier than the normal gravity or lighter than the normal gravity might be found.

• 24:56Neil deGrasse Tyson?

  And that's how they found the undersea crater from 65 million years ago, which was the smoking gun that took out the dinosaurs from the asteroid that hit in the Yucatan Peninsula. So if you redistribute matter, the cone is an extreme example. But if you redistribute it any way, we have the power. To find out where the extra mass deposits are versus where they're not. And yeah, gravity is not always just coming quote from the center.

• 25:26Charles Liu?

  That's right. No, Joey's point is a very good one. And it shows up in other astronomical activities too. So for example, when we try to send spacecraft to orbit asteroids or other small bodies in the solar system, we have to take into account the fact that at every different point in that spacecraft's orbit, it is experiencing a slightly different gravitational acceleration from the asteroid because the asteroid's shape is not perfectly uniform and spherical. Yeah, so the gravitational constant of the universe stays the same no matter where you are, but the distribution of mass and how far away you are from that distribution affects the gravitational force you feel all the time.

• 26:08Neil deGrasse Tyson?

  You got it.

• 26:09Chuck Nice?

  Let me ask you this, is there any part of astrophysics where the answer is, eh, that's good enough?

• 26:18Charles Liu?

  Yes, yes. My, my.

• 26:21Chuck Nice?

  All your capital letters are synchrosized.

• 26:25Charles Liu?

  My, my thesis committee said precisely that on whether or not they wanted to give me my PhD. Ah, close enough.

• 26:33Chuck Nice?

  That's terrible. Stop it. You stop that now.

• 26:36Gary O'Reilly?

  All right, continuing with a kind of earthbound and slightly geophysical approach. David Williams has asked both Neil and Chuck, how far do you predict the tectonic plates will move or churn before tectonic activities stop on Earth? You'll be dead. That's the answer.

• 27:03Charles Liu?

  Yeah.

• 27:04Neil deGrasse Tyson?

  So Charles, let me offer you a fast back of the envelope.

• 27:07Charles Liu?

  Yeah, go for it, go for it.

• 27:08Neil deGrasse Tyson?

  Okay, so Mars.

• 27:11Neil deGrasse Tyson?

  Has, is it one eighth our surface area? Is that right?

• 27:15Charles Liu?

  Roughly, roughly.

• 27:17Neil deGrasse Tyson?

  I think roughly, one eighth our surface area. And generally, you radiate the heat through your surface.

• 27:22Charles Liu?

  Hmm.

• 27:23Neil deGrasse Tyson?

  Okay? Mars has no tectonic activity. We think it may have at one point, but it's completely cooled. So, I'm just wondering, maybe we have to be around eight times as long as Mars has been to reach the state that Mars is in right now.

• 27:38Charles Liu?

  Yep.

• 27:38Neil deGrasse Tyson?

  Or whenever Mars had stopped its activity. What do you think of that, back of the envelope?

• 27:41Charles Liu?

  I think that makes a lot of sense. Uh, the, the general consensus right now is that Mars' tectonic activity stopped about one to two billion years, I believe, after it formed.

• 27:53Neil deGrasse Tyson?

  Wow.

• 27:53Charles Liu?

  Which means that we have somewhere between, say, ten and twenty billion years' worth of tectonics going on, uh, in our Earth before we run out of internal heat. If we do that right now, we're at about four and a half billion. So, um, the tectonic plates currently move at about the rate at which your fingernails grow. That is, uh, an inch or two per year.

• 28:16Neil deGrasse Tyson?

  Wow.

• 28:17Charles Liu?

  If you go a couple inches a year, and you go for fifteen billion years...

• 28:21Neil deGrasse Tyson?

  Wait, Charles, you've never been to a black salon? Your nails grow way faster there.

• 28:25Chuck Nice?

  Yeah, they can grow in as quick as, uh, five to seven minutes.

• 28:29Neil deGrasse Tyson?

  Oh.

• 28:32Chuck Nice?

  Yes.

• 28:33Neil deGrasse Tyson?

  A little bit of glue, and you're all in.

• 28:35Chuck Nice?

  Yeah, that's right, you're right.

• 28:36Charles Liu?

  Thank you for providing me that extra context there.

• 28:39Chuck Nice?

  Walked in looking like Nubbs, walked out looking like Freddy Krueger.

• 28:42Charles Liu?

  Wow. Well, uh, yeah, so if you go in a couple inches a year for about fifteen billion years, uh, then that's a pretty fair distance you could travel. Now, the caveat, of course, a- as we all know, Neil, um, and Chuck and Gary, is that five billion years from now, uh, the Sun is going to go red giant, and the solar system and the entire Milky Way is going to crash into the Andromeda Galaxy, right? So, by then, I don't think tectonics will be an issue. Yeah, so...

• 29:16Chuck Nice?

  Yeah, there you go. So, how would you like to die?

• 29:20Neil deGrasse Tyson?

  But it also means, just to be clear, if you, if the tectonic, if Earth cools off, there's no volcanoes.

• 29:26Charles Liu?

  That's right.

• 29:26Neil deGrasse Tyson?

  There's no earthquakes, there's no, none of that.

• 29:29Charles Liu?

  That's right, there's none of that.

• 29:30Neil deGrasse Tyson?

  That whole ring of fire, all that ends.

• 29:31Charles Liu?

  That's right.

• 29:32Neil deGrasse Tyson?

  Yeah.

• 29:32Charles Liu?

  Yeah.

• 29:33Chuck Nice?

  And would mountains continue to grow?

• 29:35Neil deGrasse Tyson?

  No, they'd be an end. They'd be the end of mountain building.

• 29:38Chuck Nice?

  Right?

• 29:38Charles Liu?

  Mm-hmm.

• 29:39Chuck Nice?

  Okay.

• 29:39Charles Liu?

  Well, you could just look at Mars to sort of see what happens once there's no more plate tectonics, right? Or the moon, for example. Um, they have these things and they sit there and they're big and they just don't ever change.

• 29:52Neil deGrasse Tyson?

  Great.

• 29:52Gary O'Reilly?

  Oh, alright. Okay, on that cheerful note.

• 29:55Charles Liu?

  I was.

• 29:55Gary O'Reilly?

  Um.

• 29:56Charles Liu?

  Boring.

• 29:57Gary O'Reilly?

  The, the next question comes from Captain James Riley, so I'm, I'm guessing that's a title we should appreciate. Why don't we have a deep sea base yet? If we want to explore alien worlds, we've got some right here and that we just seem to be not interested. So he's, he's encouraging now, "Come on Elon, let's go to the bottom of the ocean." I'm saying Elon, it's more a James Cameron scene.

• 30:21Charles Liu?

  Mm-hmm.

• 30:22Neil deGrasse Tyson?

  So I bet Charles and I agree on this, but I'm gonna lead off and Charles, you, I'm gonna hand you the baton.

• 30:26Charles Liu?

  Please.

• 30:27Neil deGrasse Tyson?

  It is way easier to go into space than to the bottom of the ocean.

• 30:31Chuck Nice?

  Yeah.

• 30:32Gary O'Reilly?

  Chief.

• 30:32Neil deGrasse Tyson?

  Charles, that's my hand off to you.

• 30:34Charles Liu?

  It is not necessarily way easier. It is easier in some ways and harder in other ways to go into space compared to being the bottom of the ocean. But I believe that the main reason we haven't gone down as much as we've gone up is because there are, uh, shall we say, social and political advantages to going up as opposed to going down? If you want the high ground and companies and, and corporations and countries are always looking for the high ground, you don't go down to the bottom of the ocean, you go up into orbit, you go up into space.

• 31:09Neil deGrasse Tyson?

  Well, okay, but however, in, uh, the Second World War, the low ground was the realm of submarines.

• 31:17Charles Liu?

  Yes, but who do you think made a bigger difference, the submarines or the airplanes?

• 31:22Neil deGrasse Tyson?

  Yeah, the airplanes, for sure.

• 31:23Charles Liu?

  Yeah, right?

• 31:24Chuck Nice?

  Uh, depends on which movie you're watching.

• 31:27Chuck Nice?

  That's.

• 31:27Charles Liu?

  I, I did like, you know, Dust Boat was pretty awesome.

• 31:30Neil deGrasse Tyson?

  Red October and Crimson Tide.

• 31:34Chuck Nice?

  Crimson Tide, you know?

• 31:35Neil deGrasse Tyson?

  We got them all.

• 31:39Neil deGrasse Tyson?

  But so, Charles, what are the pressures at the Marianas Trench?

• 31:44Charles Liu?

  Well, let's see. Every time you go down about 32 feet is equivalent of one Earth atmosphere at the Earth's surface.

• 31:51Neil deGrasse Tyson?

  Oh my gosh.

• 31:51Charles Liu?

  So if you go down 35,000 feet, that's more than a thousand atmospheres. So that's 15,000 pounds per square inch, thereabouts.

• 32:00Neil deGrasse Tyson?

  Right. And the difference between one atmosphere in space is one atmosphere.

• 32:05Charles Liu?

  Mm-hmm. That's right.

• 32:07Chuck Nice?

  Right.

• 32:07Charles Liu?

  So there is a structural issue.

• 32:09Neil deGrasse Tyson?

  That's kind of my point about spaces structurally.

• 32:13Chuck Nice?

  Space is not trying to crush you like a grape.

• 32:18Charles Liu?

  And yet, we have sent things down into the Marianas Trench, and they have come back, right?

• 32:26Chuck Nice?

  They have.

• 32:26Charles Liu?

  So we have yet...

• 32:27Neil deGrasse Tyson?

  They're flatter when they come back.

• 32:29Charles Liu?

  Right.

• 32:29Neil deGrasse Tyson?

  Guys, we're going to take a quick break. Quick break. When we come back, StarTalk, Cosmic Queries, Sports Edition, and Gary promised us we're going to get to do some sports questions in the third season.

• 32:38Charles Liu?

  We will. Yes.

• 32:39Neil deGrasse Tyson?

  When we return on StarTalk.

• 32:54Neil deGrasse Tyson?

  We're back. StarTalk, Sports Edition, Cosmic Queries, grab that. I've got Charles Lu with me. Charles, what projects are you working on now?

• 33:02Charles Liu?

  Oh, this is quite a year for me. Thank you for asking. Scientifically, we're about to launch into a lot of work with my JWST, James Webb Space Telescope, and Rubin Observatory colleagues. Got some projects that are ramping up now.

• 33:16Neil deGrasse Tyson?

  Nice.

• 33:17Charles Liu?

  Yeah.

• 33:17Neil deGrasse Tyson?

  So you can talk to us as developments continue to roll off the, you know, roll off the assembly line?

• 33:24Charles Liu?

  It would be a pleasure. And I'll be talking a little bit about that, too, in season two of my podcast, The Lunarverse, with Dr. Charles Lu, which will be dropping soon.

• 33:34Neil deGrasse Tyson?

  Oh my god, alright, the the universe, I love it, love it.

• 33:38Charles Liu?

  I didn't come up with that name, but I liked it.

• 33:41Neil deGrasse Tyson?

  We're all fine podcaster fans.

• 33:43Charles Liu?

  Indeed.

• 33:44Neil deGrasse Tyson?

  Yeah, alright, alright, let's keep going, Gary, what do you got?

• 33:48Gary O'Reilly?

  Okay, I can't do this name as much justice as Chuck, but I'll I'll have a go at it. Alejandro Reynoso from Monterrey, Mexico. Sorry, Alejandro. I I just cannot cannot compete. I just can't compete with Lord Nice, not a chance. Alright, um, he wishes us well and has a question. How the weather affects a football match? For example, when it's snowing, is there anything players can do to compensate? So the the the natural elements of affecting an outdoor game?

• 34:23Charles Liu?

  Okay.

• 34:24Neil deGrasse Tyson?

  First of, the NFL has gotten wimpy because they they always put the Super Bowl, which takes place in January, February, in some southern climate. When it's the old days, I remember they'd be, they you couldn't even see the lines on the field and the and the the linesman would line up and you'd see smoke coming out of their noses.

• 34:41Charles Liu?

  Yeah. The Super Bowls were always held in warm climates before they had internal stadiums. That's true, but there are NFL championship games, right? The the very famous one, a long time ago, Green Bay Packers, uh, you know, the Art Star, he like crushed up and he looks old and stuff. There was a Super Bowl. There was a snowball. They they, there was a Super Bowl held in um, in New Jersey, uh, one time, not too long ago. They tried to do that, didn't work out so well, uh, and of course, uh, Peyton Manning was crushed thirty-four to eight, I'm so sorry to say. Although he did in fact eventually get a Super Bowl win later with the Devon Broncos. So, you know, he retired all. Anyway, too much, too much, too much. Okay, yes, if you have.

• 35:26Charles Liu?

  A problem with the weather, you have to adapt. If it's American football, right, you have to throw the ball a little bit shorter, a little bit faster. If you are running the ball, then you have to wear different shoes or you have to change your step a little bit. There's lots of things that you have to make adjustments for. As for-

• 35:47Neil deGrasse Tyson?

  So Charles, the ball's not as, not as sticky-

• 35:50Charles Liu?

  Correct.

• 35:50Neil deGrasse Tyson?

  When it's very cold.

• 35:52Charles Liu?

  Right, so the surface, yeah, it's harder to move. And it's almost as if it were, say, inflated a little bit extra.

• 35:58Neil deGrasse Tyson?

  Not let some of the air out.

• 36:00Chuck Nice?

  Let some of the air out, you know, why not?

• 36:03Neil deGrasse Tyson?

  It took you that long to get in.

• 36:05Chuck Nice?

  Why not?

• 36:07Neil deGrasse Tyson?

  Well, no, but, but Charles, in automotive-

• 36:10Charles Liu?

  Yes.

• 36:11Neil deGrasse Tyson?

  All right, in winter, whatever was the pressure in your tires-

• 36:15Charles Liu?

  Yes.

• 36:16Neil deGrasse Tyson?

  It drops just automatically because the-

• 36:19Charles Liu?

  Yes, it drops a little bit, that's right.

• 36:20Neil deGrasse Tyson?

  It drops a little bit, so you have to put extra air in your tires over the winter to maintain your standard tire pressure. I presume in the, in the football, they gotta put more air in to get the same, was it six to nine pounds of pressure per square inch or whatever that is?

• 36:34Charles Liu?

  You, you do, and, and as a result, you know, the way you inflate or deflate a football, depending on the temperature or whatnot, or whether the quarterback likes it this way or that.

• 36:47Neil deGrasse Tyson?

  And high altitude or low altitude.

• 36:49Chuck Nice?

  I need the ball to be just a little squishy.

• 36:51Charles Liu?

  Can in fact affect things, right, and, and that's not allowed, okay? It's not allowed, there's a range, and if you want to exceed that range, and, and because, you know, you want to have an advantage, or you feel better throwing the ball or catching the ball, you're not allowed to do that. That's just not part of the rules. But yes, you have to make adaptations as a player too. And if you're a, a non-US football player, I don't know how often you play in the snow. But I can only imagine how hard it is to play in the snow there. Uh, I remember I have.

• 37:22Gary O'Reilly?

  I mean, if it's fresh snow, Charles.

• 37:23Charles Liu?

  Yeah.

• 37:24Gary O'Reilly?

  Uh, what they do is they they clear the lines on the field.

• 37:27Charles Liu?

  Hmm.

• 37:27Gary O'Reilly?

  So as you can see, the lines, but they'll invariably leave the snow as long as it doesn't get too deep. But there is a kind of guideline. Can the ball roll?

• 37:36Charles Liu?

  Uh huh.

• 37:36Gary O'Reilly?

  Through the snow. So if it if the snow's compacted and it can roll over the top, then they'll play. If it's too deep, they won't play. If it, for instance, if it's really windy.

• 37:45Charles Liu?

  Yeah.

• 37:46Gary O'Reilly?

  You will not kick the ball too high in the air because it's more at the mercy of the prevailing winds.

• 37:52Charles Liu?

  Mm hmm.

• 37:52Gary O'Reilly?

  So the so if providing there's no snow involved, you would keep the ball on the surface and not get it up too much. If you think it's going to be like wet or snowy, then and it's not too windy, then you get it airborne more because then it doesn't get stuck, getting caught in the in the wet surface or the snow. It's totally you would it's adapt and survive. It's a it's a it's a simple principle. You change the style of game you have to accommodate for the the weather.

• 38:19Charles Liu?

  Hmm.

• 38:20Neil deGrasse Tyson?

  Uh, so so um, uh, one of our producers for this segment, Lane, uh, both she and I, not at the same time because I'm like way older, uh, we both rowed. And one of the things we know when we're rowing, uh, you've seen rowers on the river, perhaps, uh, the as the oar goes into the water, they do what's called they feather the blade. So the the blade goes into the water, comes out and it gets feathered so that when it moves backwards against the air, it reduces the air friction and then it feathers back and then goes in. So this rotation of the blade is to reduce air resistance. However, if you have a tailwind, you don't feather.

• 39:02Charles Liu?

  Mm hmm.

• 39:02Neil deGrasse Tyson?

  Because the blades then become your sail.

• 39:06Charles Liu?

  Mm hmm.

• 39:06Neil deGrasse Tyson?

  Yes, yes. So there are tactical, uh, changes that you invoke depending on on on how this works.

• 39:13Charles Liu?

  Oh, that's great.

• 39:14Chuck Nice?

  And if you're in a and if you're in Wisconsin on a lake, then you you don't go anywhere.

• 39:18Charles Liu?

  You run.

• 39:19Chuck Nice?

  It's frozen.

• 39:19Charles Liu?

  You run.

• 39:20Chuck Nice?

  Frozen solid.

• 39:22Gary O'Reilly?

  It just skates out.

• 39:23Charles Liu?

  That's right.

• 39:24Gary O'Reilly?

  So the other the other thing, Neil, is um, if you're a a track and field athlete and you're a thrower and there's a crosswind, you then use that, but you have to use it to throw into. So as it then brings you. Back into the centre of the art.

• 39:42Neil deGrasse Tyson?

  Possibly, but the discus actually famously goes farther into the wind than with the wind. So, because it becomes an airfoil and it coasts on the uplift.

• 39:55Gary O'Reilly?

  With javelins, no.

• 39:57Neil deGrasse Tyson?

  I don't think so. Yeah, I don't think so with javelins.

• 39:59Gary O'Reilly?

  No, I've had the experience of throwing javelins. So I got caught in a crosswind and it was just blowing the whole.

• 40:03Neil deGrasse Tyson?

  Listen to you, Mr. Olympic athlete. Listen to you.

• 40:05Gary O'Reilly?

  Not an Olympic athlete at all.

• 40:06Neil deGrasse Tyson?

  When I threw a javelin, yes, when I stepped out of the Grecian hearn, when I was modeling for the Grecian.

• 40:17Neil deGrasse Tyson?

  The Greek potters gave me a leave so that I could.

• 40:21Gary O'Reilly?

  That's right, to protect my modesty.

• 40:25Neil deGrasse Tyson?

  All right, give me some more here.

• 40:27Gary O'Reilly?

  Let's have another question here. All right, this is from Bill Williamson and greetings from Essexville, Michigan.

• 40:33Neil deGrasse Tyson?

  That means his name is William Williamson.

• 40:36Gary O'Reilly?

  Yes.

• 40:37Neil deGrasse Tyson?

  Just checking.

• 40:38Gary O'Reilly?

  Or Bill. All right, survival programs and competitions have occupied a special niche in American TV for a while. By survival here, I mean programs such as Alone, not Survivor.

• 40:46Neil deGrasse Tyson?

  Yeah.

• 40:47Gary O'Reilly?

  It's a rather long question. Let's see. I can't recall hearing anyone talk about how expertise in physics might shape a contestant's choices of survival gear. Once watched Les Stroud light a fire with a parabolic mirror that he fashioned from the bottom of an aluminium can.

• 41:06Charles Liu?

  That Les Stroud is superhuman. That guy, pretty amazing.

• 41:10Gary O'Reilly?

  Now, the curiosity now comes, what non-standard survival gear or preparations would us as gentlemen might take to demonstrate the value of scientific knowledge and know-how in the survival situation? So, okay, look at this. We're stuck somewhere we don't want to be, so we need to navigate. We quite need water for survival. We'll need food.

• 41:35Neil deGrasse Tyson?

  Wait, are we naked, like in Naked and Afraid?

• 41:40Gary O'Reilly?

  I hope not, but I'm ruling that.

• 41:43Neil deGrasse Tyson?

  It matters, right? Because you want to freeze, literally, freeze your gonads.

• 41:47Gary O'Reilly?

  So here we go. Be good if we had a sextant. We could navigate our way out of a bit of our knowledge of astronomy. So as we could possibly navigate our way out of there. Water. So could we?

• 42:03Gary O'Reilly?

  Then generate something from condensation.

• 42:06Chuck Nice?

  Sure, of course.

• 42:08Gary O'Reilly?

  No problem. So that way is there and then we've got to hunt and gather. We've got to go back to stay alive and go and find in nature what it is. So a knowledge of botany.

• 42:17Chuck Nice?

  Yeah.

• 42:18Gary O'Reilly?

  And or.

• 42:19Neil deGrasse Tyson?

  Botany so you know how to not die from your plants.

• 42:21Gary O'Reilly?

  Yeah, don't eat that, that'll kill you. That kind of basic stuff. So what do we think, gentlemen? What could we bring scientifically to survive in the great unknown?

• 42:32Neil deGrasse Tyson?

  I would bring my smartphone that has Uber Eats on it.

• 42:36Chuck Nice?

  Exactly.

• 42:37Gary O'Reilly?

  All right. Uh, that's great as long as you get a signal.

• 42:41Chuck Nice?

  I'll tell you what I'm bringing. Um, speaking of, oh, the long Neil's lines, a satellite phone. That's what I'm bringing.

• 42:48Gary O'Reilly?

  Okay.

• 42:49Chuck Nice?

  And I'm good, and I'm good to go. Come get me. That's it.

• 42:53Neil deGrasse Tyson?

  Did you see that FedEx commercial? That was a riff on the, on what's that movie that Tom Hanks was in?

• 43:01Gary O'Reilly?

  Wilson.

• 43:03Chuck Nice?

  Yeah.

• 43:04Neil deGrasse Tyson?

  What was the name of that movie?

• 43:05Chuck Nice?

  Um. Survivor, no.

• 43:06Neil deGrasse Tyson?

  No, no.

• 43:07Chuck Nice?

  What was called? Uh.

• 43:10Neil deGrasse Tyson?

  Cast Away.

• 43:11Gary O'Reilly?

  Cast Away.

• 43:12Chuck Nice?

  Cast Away.

• 43:12Neil deGrasse Tyson?

  Cast Away, Cast Away. So, so, so there's a TV commercial for FedEx, right?

• 43:19Gary O'Reilly?

  Yeah.

• 43:19Neil deGrasse Tyson?

  And they showed the Tom, Tom Hanks' character, right? Delivering this FedEx package years later to its address. Because they always deliver. Okay.

• 43:34Chuck Nice?

  Oh, my God.

• 43:35Neil deGrasse Tyson?

  And she said, and she said, oh, thank you. It's a little late, but thank you. And he turns away, but then he turns back and said, I just have to know. What was in that package? And she said, oh, a satellite phone, some seeds.

• 43:48Chuck Nice?

  Oh, my God.

• 43:51Chuck Nice?

  That's terrible. I love it. That's awesome.

• 43:55Neil deGrasse Tyson?

  Maps? Yeah, yeah, that's all that was in it. So thank you.

• 43:58Chuck Nice?

  That's great.

• 43:59Neil deGrasse Tyson?

  So I would.

• 44:02Neil deGrasse Tyson?

  I, I would say, um, I would take a cue from the movie, presumably it was in the book as well. Uh, Black Stallion. Okay. And in that, the, the little boy who survived, the, the, he learned from his father, he says.

• 44:19Neil deGrasse Tyson?

  You always want a pocket knife.

• 44:22Chuck Nice?

  Yep, I was gonna say, I want a giant knife and a magnifying glass.

• 44:26Neil deGrasse Tyson?

  Yeah. Yeah, a knife because there's nothing on our body that can do what a knife can do.

• 44:32Chuck Nice?

  Right.

• 44:33Neil deGrasse Tyson?

  Right? And teeth sort of, but not as well.

• 44:36Chuck Nice?

  Mm-hmm.

• 44:36Neil deGrasse Tyson?

  And so that would be the one tool that if you had to have a survival tool, uh, that would help. And a magnifying glass, certainly, you can make fire at any time. Otherwise, you gotta do it the caveman way, which is, you can still do it.

• 44:47Chuck Nice?

  Right. Yep. Screw that string and sticks crap.

• 44:51Charles Liu?

  Right, uh, you know.

• 44:53Chuck Nice?

  Forget that string and stick crap.

• 44:54Charles Liu?

  Remember that, right, remember.

• 44:56Chuck Nice?

  Giant knife.

• 44:57Charles Liu?

  Remember what a knife is, right? In physics, it's a simple machine. It's a wedge. It's a very, very sharp wedge. And so, uh, that is physics, right? Uh, and then the other thing I would say about.

• 45:09Neil deGrasse Tyson?

  Charles, tell us what the five machines are, just while you're going there.

• 45:11Charles Liu?

  Oh, there's the pulley thing, there's a wheel and axle thing, there's a wedge thing, there's a lever thing, and there's an inclined plane thing, right?

• 45:22Neil deGrasse Tyson?

  Yeah, yeah, these are the five basic machines in physics.

• 45:25Charles Liu?

  Yeah, so.

• 45:26Neil deGrasse Tyson?

  These are machines that will take energy invested at one rate, and it changes the rate on the other end at which it gets invested. So the screw, you left out the screw.

• 45:36Charles Liu?

  No, the screw is a wedge that's been coiled, right?

• 45:39Neil deGrasse Tyson?

  That's a wedge. So it's how you can crank a car, right? Because you're not stronger to lift the car, but you could move something, the equivalent of yards in distance, and then the car moves up an inch.

• 45:52Charles Liu?

  Yeah.

• 45:52Neil deGrasse Tyson?

  Right? So it took all that energy to move it, and then it packed it into that one inch. So it changes the ratio of invested energy.

• 46:00Charles Liu?

  That's right.

• 46:00Neil deGrasse Tyson?

  So, yeah.

• 46:01Chuck Nice?

  So cool, so cool, so cool. Yeah, the knife is the thing, man. And when you think, and think about it, think about how many, um, foods that grow wild that we can't eat because we don't have the strength or the teeth to cut them open. And a knife just allows you to go ahead, coconuts.

• 46:20Neil deGrasse Tyson?

  Right, right.

• 46:21Chuck Nice?

  You, you, you got a knife, man, you know, you're good to go.

• 46:24Neil deGrasse Tyson?

  Yeah.

• 46:25Charles Liu?

  Well, I would also want actually some sort of a blanket.

• 46:30Charles Liu?

  Uh, maybe one of those thermal Mylar-based blankets to keep myself warm.

• 46:35Chuck Nice?

  See, but with a knife.

• 46:36Charles Liu?

  Those are very small.

• 46:37Chuck Nice?

  With a knife, you can kill and skin a bear, and you got a coat. Now you got a coat.

• 46:44Charles Liu?

  Yeah, but it smells bad.

• 46:46Chuck Nice?

  And a shawl.

• 46:50Charles Liu?

  Yeah, the blanket, like these Mylar blankets, the space blankets things, right? They're very warm and they fit into a pocket. Once you fold them up, they're very, very small.

• 47:00Neil deGrasse Tyson?

  This is what they give to the marathon runners when they finish the race.

• 47:02Charles Liu?

  Right, exactly. Whereas, you know, bears are very large. They don't fit in your pocket all that easily, so it's gonna take a while. Not to mention you have to hunt it down.

• 47:10Gary O'Reilly?

  I'm not sure I wanna bring a knife to a bear fight.

• 47:15Gary O'Reilly?

  Can't see that working out well for me.

• 47:18Charles Liu?

  That's not so fair.

• 47:19Neil deGrasse Tyson?

  All right, let's try to fit in like one last question here.

• 47:22Gary O'Reilly?

  All right, James Parrish here, he's in Birmingham, Alabama. I have a baseball question, uh, if you will.

• 47:27Neil deGrasse Tyson?

  Well, I like the way you said that, Gary, because Birmingham is in the UK. He said Birmingham, Birmingham. Here's Birmingham.

• 47:34Gary O'Reilly?

  Birmingham.

• 47:35Neil deGrasse Tyson?

  Chuck, say it the way a southerner would say it.

• 47:36Chuck Nice?

  Birmingham.

• 47:39Gary O'Reilly?

  Okay.

• 47:40Chuck Nice?

  That's right.

• 47:40Gary O'Reilly?

  Alabama.

• 47:42Chuck Nice?

  Right.

• 47:42Charles Liu?

  Good one. Sweet home Alabama.

• 47:44Neil deGrasse Tyson?

  Birmingham.

• 47:44Gary O'Reilly?

  Here we go. Picture, if you will, a hitter that knows for their speed and proclivity to slide headfirst. Think about a Ricky Henderson or a Pete Rose, for example. And they're at bat. They hit a little dribbler down to third baseline. A third baseman charges in, bare hands the ball, and makes a throw to the first. It is going to be a close play. Will our speedster reach first base quicker by diving for the bag or running through the bag?

• 48:10Charles Liu?

  A classic, classic question.

• 48:12Gary O'Reilly?

  So here we go.

• 48:13Neil deGrasse Tyson?

  Charles.

• 48:14Gary O'Reilly?

  What is our physics?

• 48:15Neil deGrasse Tyson?

  Settle this, Charles.

• 48:17Charles Liu?

  All right, here's the physics of the situation. You will go faster if you are running than when you are diving. General. However. If you're trying to go a very short distance very fast, the dive can help if you launch yourself with both feet off the ground, giving yourself that extra little propulsion for that short distance that you're airborne before you hit the ground. So if you are, say, inches away and you want that last little extra bit, go ahead and dive. But if you are trying to make up a few feet, or even a foot or something like that, keep running.

• 48:53Neil deGrasse Tyson?

  Wait, but Charles, your two feet are never together when you're running.

• 48:57Charles Liu?

  That's the thing.

• 48:57Neil deGrasse Tyson?

  So that's not a realistic situation.

• 49:00Charles Liu?

  That's right. So you have to find a way, if you're gonna make your dive, you gotta put both feet into the final propelling push. And so that's why when normally...

• 49:09Neil deGrasse Tyson?

  So that you would go faster than you would have had you been only been pushed forward with one foot at any given time.

• 49:15Charles Liu?

  Correct. Now, here's the important caveat, right? When we are horizontal, we are a few feet longer than when we're vertical, right? So when Ricky Henderson used to dive, what he was gaining the advantage of was twofold. One, he would be ducking below the tag. And second of all...

• 49:33Neil deGrasse Tyson?

  That's why this is specifically for first base.

• 49:35Charles Liu?

  That's right. And second of all, right. Second of all, he's got that extra two or three feet horizontally to touch the bag with his hands that he otherwise would have had to do with his feet, because you have to stop, right? He used his belly to slow himself down without having to use the slide effect. I wonder if Ricky Henderson and some of these headfirst divers actually wear thicker uniforms to prevent themselves from getting scraped.

• 49:59Neil deGrasse Tyson?

  Charles, we're talking about first base. You don't have to slow down going into first base.

• 50:02Charles Liu?

  If you're talking about first base...

• 50:04Neil deGrasse Tyson?

  That's the question.

• 50:05Charles Liu?

  Right.

• 50:06Neil deGrasse Tyson?

  And our boy knew that in the question, right? This is not avoiding a tag. You're not slowing down so you don't overrun it. And so, well, how about this, Charles?

• 50:14Charles Liu?

  Yeah.

• 50:16Neil deGrasse Tyson?

  There's when my head would have reached the bag, but there's when my outstretched arm would have reached the bag. Because I can extend my arm faster than I can run.

• 50:25Charles Liu?

  That's right. So if you can coil yourself up in such a way that you give yourself that last two or three feet, right, going to first base, fine. But usually, it's not. Think also, most runners are still accelerating when they get to first base.

• 50:42Charles Liu?

  Right? If you're running 100-yard dash, you don't actually reach your maximum speed until, you know,

• 50:47Chuck Nice?

  Till later in the race.

• 50:48Charles Liu?

  Later in the race.

• 50:49Gary O'Reilly?

  About 30 meters.

• 50:50Charles Liu?

  So, uh, the distance from one base to another in Major League Baseball is 90 feet. Right? So you've got 30 yards.

• 50:57Neil deGrasse Tyson?

  That's only 30 yards.

• 50:58Charles Liu?

  That's right. So you're still speeding up. So you don't want to cut off your acceleration by diving. Once you leave your feet, you're not speeding up anymore. You have to use your body shape, right? Your reach, whatever, to compensate for the fact that you're no longer accelerating.

• 51:14Neil deGrasse Tyson?

  So Chuck, what Charles is saying is anyone who slides into first base is a physics idiot. That's what he's saying.

• 51:18Charles Liu?

  Right. Unless, unless they understand the concepts of rigid body motion and flexible body motion and moments of inertia, in which case they could actually gain a slight advantage.

• 51:31Chuck Nice?

  Okay.

• 51:31Gary O'Reilly?

  Would it be advantageous to go foot, feet first in a slide?

• 51:35Chuck Nice?

  Right.

• 51:35Gary O'Reilly?

  Rather than head first?

• 51:36Chuck Nice?

  And here's, here's what I'm gonna say. Anyone who understands, uh, moments of inertia and rigid body motion is not diving head first into first base.

• 51:45Charles Liu?

  Not.

• 51:45Gary O'Reilly?

  Yeah.

• 51:46Charles Liu?

  That most likely, they will have already done such a good job hitting the ball, that they would just be able to coast into first, round the base, and decide whether or not to take second.

• 51:59Gary O'Reilly?

  There you go.

• 52:00Neil deGrasse Tyson?

  All right. Well, thanks for this bit of insight here. And yes, it matters whether it's first base or second.

• 52:05Charles Liu?

  Yeah.

• 52:05Neil deGrasse Tyson?

  Uh, for this question, of course. But guys, that's all we have time.

• 52:09Charles Liu?

  Oh.

• 52:10Neil deGrasse Tyson?

  Today. It's been a delight, uh, Charles Liu, my friend and colleague, uh, to join us once again.

• 52:17Charles Liu?

  Always a pleasure.

• 52:18Neil deGrasse Tyson?

  As our geek, uh, as our geek in chief.

• 52:20Charles Liu?

  Thank you so much.

• 52:20Neil deGrasse Tyson?

  Chuck, Gary, always good to have you there.

• 52:22Charles Liu?

  Always.

• 52:23Neil deGrasse Tyson?

  As my co-hosts. This has been a StarTalk Sports Edition Cosmic Queries Grab Bag. Neil deGrasse Tyson, your personal astrophysicist. Keep working out.