Pod Insights StarTalk Podcast Things You Thought You Knew – Somewhere Over the Rainbow About this episode Is anything at the end of the rainbow? On this episode, Neil deGrasse Tyson and comic co-host Chuck Nice break down how rainbows work, the history behind zero, and what Zoom calls and Einstein’s Theory of Relativity have in common.
Transcript Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.
0:01 Neil deGrasse Tyson? Welcome to StarTalk. Your place in the universe where science and pop culture collide. StarTalk begins right now. This is StarTalk. A Things You Thought You Knew edition. Chuck, is that your favorite format?
0:20 Chuck Nice? It's, no, explainers are my favorite, but Things You Thought You Knew is my second favorite because I am aware, thanks to working with you for almost 12 years, that I don't know jack crack.
0:34 Neil deGrasse Tyson? I don't know.
0:35 Chuck Nice? That is what I have learned. And all this time we have spent together is that I don't, I used to think, I thought at one point I knew something. I thought I knew something. And then the universe sent a man named Neil deGrasse Tyson into my life. And then the universe said, boy, you don't know shit. You don't know shit about even. You don't know nothing, dude.
1:02 Neil deGrasse Tyson? Okay, so Things You Thought You Knew is like a superset of explainers?
1:06 Chuck Nice? Yes.
1:06 Neil deGrasse Tyson? Okay, you ready?
1:07 Chuck Nice? Go ahead.
1:08 Neil deGrasse Tyson? First one is gonna be rainbow.
1:10 Chuck Nice? Okay, that, that sounds delightful.
1:11 Neil deGrasse Tyson? Nobody doesn't love rainbows.
1:12 Chuck Nice? That's right. Sounds delightful. I love it.
1:15 Neil deGrasse Tyson? Okay, nobody doesn't love rainbows. Okay, I have a quick rainbow story. Ready? I knew a couple, they were dating, and the guy was a little high strung and, and she was sort of like normal, right? And she pointed, we were driving, I happened to be in the car with them, and there was a beautiful rainbow out the window. And I, and, and the guy was speaking about something else. And I said, oh, look at the rainbow. And she said, oh, that's a beautiful rainbow. And he says, no, shut up, I'm talking about something else. And I said, what? Who doesn't like rainbows? And she turned to him, and, and two months later they broke up.
1:50 Chuck Nice? Yeah.
1:51 Neil deGrasse Tyson? So, I don't know.
1:53 Chuck Nice? He didn't know it, but they were already broken up.
1:58 Neil deGrasse Tyson? Chuck has seen some therapist, he knows the signs.
2:01 Chuck Nice? That's it, buddy. Let me tell you.
2:05 Chuck Nice? So what's number two?
2:07 Neil deGrasse Tyson? Second segment is just gonna be about zero.
2:10 Chuck Nice? All right.
2:10 Neil deGrasse Tyson? The nu- the number zero.
2:12 Chuck Nice? The number zero.
2:14 Neil deGrasse Tyson? Yeah, numbers is, zero's a number, just get over it.
2:16 Chuck Nice? Okay, yeah, you never think of zero as a number.
2:18 Neil deGrasse Tyson? Yeah, yeah, yeah, but it is. And we need it, it turns out, for most of what we do in mathematics. So, is that, and the third one is, what do Zoom calls and Einstein's theory of relativity have in common?
2:31 Chuck Nice? All right, you've gone too far, Neil.
2:32 Neil deGrasse Tyson? I know, have I stepped off the ledge?
2:34 Chuck Nice? Seriously, bro. You are over the cliff, that's it. That's, give it a chance, Chuck.
2:40 Neil deGrasse Tyson? Oh my god. Let me try.
2:44 Chuck Nice? I don't know, how you gonna pull that rabbit out of your hat?
2:48 Neil deGrasse Tyson? All right, let's get to our first one in this first segment. So, Chuck, we're gonna talk about rainbows.
2:55 Chuck Nice? My eight-year-old daughter loves rainbows.
2:58 Neil deGrasse Tyson? Okay, well, make sure she listens to this, all right, so.
3:01 Chuck Nice? That's cool, yeah.
3:02 Neil deGrasse Tyson? So, it was not until Isaac Newton, my man.
3:06 Chuck Nice? That's your boy.
3:08 Neil deGrasse Tyson? Okay, early seventeen hundreds, he wrote a book in, was seventeen oh four, it was just called Optics. One of these rare books that he actually wrote in English. All his other books were in Latin, which was the, the.
3:20 Chuck Nice? Wow, he really was a nerd.
3:23 Neil deGrasse Tyson? Okay. But, in there, he figured something out.
3:28 Chuck Nice? Okay.
3:29 Neil deGrasse Tyson? Everyone, of course, had known about the colors of the rainbow. Red, orange, yellow, green, blue, violet, every, okay? And people have seen, you know, chandelier, light will come through the chandelier and you'd see rainbow colors come out one side or another. Everybody until Newton presumed that those colors were somehow getting generated inside the chandelier glass.
3:55 Chuck Nice? Okay.
3:56 Neil deGrasse Tyson? Or, inside the raindrop.
3:58 Chuck Nice? Right.
3:59 Neil deGrasse Tyson? That it was some property of the medium itself. Nobody was thinking that pure white light is composed of those colors.
4:09 Chuck Nice? Oh, if only we could learn that lesson in our society.
4:17 Neil deGrasse Tyson? Chuck getting all sociological.
4:23 Neil deGrasse Tyson? So imagine if Martin Luther King were more physics fluent. That would have been a whole different I have a dream.
4:27 Chuck Nice? Yeah, it would. I have a dream. That one day we will recognize that white, black, red or brown, we're all white.
4:42 Chuck Nice? It's okay. It's okay.
4:46 Neil deGrasse Tyson? Everybody would have tipped their head and said, what?
4:48 Chuck Nice? What? I may not get there with you. I may not get there with you, but we'll all be white one day.
5:05 Neil deGrasse Tyson? So here's how he did it. Okay, so he puts the white light through a prism. Okay, and out the other side comes the colors of the rainbow. Much as what we all remember from Pink Floyd's Dark Side of the Moon album cover.
5:20 Chuck Nice? One of the best ever.
5:22 Neil deGrasse Tyson? All right, so he then, and this is what makes Newton Newton. He said, let me take another prism. And put it upside down next to it.
5:33 Chuck Nice? Ooh.
5:34 Neil deGrasse Tyson? Okay, and this would kind of reverse what had just happened. And when he did that out, the second prism came white light.
5:43 Chuck Nice? Okay, how did I not hear? In all the time we've been working together, this is the first time I've ever heard this story.
5:51 Neil deGrasse Tyson? Yes.
5:52 Chuck Nice? This is brilliant.
5:54 Neil deGrasse Tyson? Yes.
5:55 Chuck Nice? Because in doing so, he proves that it has nothing to do with the actual medium itself. That the light coming in was merely separated. And then by coming out and going back into another medium. It combines, it's the light. It's just the light.
6:19 Neil deGrasse Tyson? That's why he is Isaac Newton and the rest of us aren't.
6:22 Chuck Nice? Wow.
6:23 Neil deGrasse Tyson? It's that simple.
6:23 Chuck Nice? That is brilliant.
6:25 Neil deGrasse Tyson? And it's simple and brilliant.
6:27 Chuck Nice? Yes, yeah, exactly.
6:28 Neil deGrasse Tyson? That's what makes it extra brilliant is how simple it is. Okay, so.
6:34 Neil deGrasse Tyson? So at that point, it's easy to sort of extrapolate that a rainbow is just sunlight broken up into those same colors that the prism did for you. Right. Okay. So now, what's going on inside a raindrop? So sunlight enters the raindrop at a particular angle. All right, actually comes in at all angles, but only one of those angles will internally reflect off the boundary between the raindrop and the air. Okay, this is, this is the, one of the most fascinating features of optics. Okay. In other words, if I'm underwater and I, let's say I have a laser, so we get a nice sharp point.
7:18 Neil deGrasse Tyson? And I point it upwards, not straight up, but at an angle. At a slight angle. When that laser beam exits into the air, it bends. Okay, it's bent. Right. It's bent. Okay, you can picture this. Yes. You can try it yourself if you have a pocket laser. Okay. So it's easy then to expect that a similar thing is happening between sunlight and raindrops that was happening between your sunlight and your prism. Okay. But the fun part is, the sunlight goes inside the raindrop and bounces around a couple of times before it exits again. And by the time it exits,
8:01 Neil deGrasse Tyson? all of those colors have been separated out from the white light. And thus, you have this participatory rainbow where all of these dots of, uh, all these droplets of water participate in one coherent rainbow. Now, the, the, the, the angle the light exits creates a rainbow that you see.
8:29 Neil deGrasse Tyson? Okay.
8:29 Chuck Nice? Right, okay.
8:30 Neil deGrasse Tyson? Right, you only see what enters your eye. You can't see what doesn't enter your eye, correct?
8:34 Chuck Nice? Right.
8:35 Neil deGrasse Tyson? That makes sense.
8:36 Chuck Nice? Makes sense.
8:36 Neil deGrasse Tyson? Okay. By the way, that itself was a discovery from a thousand years ago. Ibn al Haytham was a Muslim scientist back in the Golden Age of Islam. He was the first to deduce that sight is not you beaming stuff out of your eyes. It's completely passive. Your eyeballs are just sitting there waiting for light to enter and for your brain to then make an image. This is profound because before then you had these legends like Medusa.
9:08 Chuck Nice? Yeah.
9:09 Neil deGrasse Tyson? All right. How does Medusa work? How does that work?
9:11 Chuck Nice? Well, when you look her in the eyes, she turns you to stone, basically.
9:15 Neil deGrasse Tyson? She turns you
9:17 Chuck Nice? Right.
9:17 Neil deGrasse Tyson? into stone.
9:18 Chuck Nice? Because she's casting whatever from her eyes.
9:20 Neil deGrasse Tyson? From her eyes, correct. You could only think that if you have no idea how vision works.
9:25 Chuck Nice? Right. Or if you're creating X-Men, but that's a different story.
9:31 Neil deGrasse Tyson? Oh, he's got, yeah, he's got his little visor thing that can send out the beams. So what that means is all of the rainbow light that's coming to you is exiting those raindrops at the precise angle that enters your eyeballs. Okay? Okay. That means your rainbow is unique to you.
9:57 Chuck Nice? Wow.
10:00 Neil deGrasse Tyson? If I stand to your left or right or above, doesn't matter. If I stand somewhere else and we're looking at, quote, "the same rainbow," we tell ourselves. We're not.
10:10 Chuck Nice? Interesting.
10:11 Neil deGrasse Tyson? We are each looking at our own private rainbow.
10:14 Chuck Nice? Oh, my God, my own private rainbow.
10:16 Neil deGrasse Tyson? Now, watch. If you keep, if you keep moving to the side, you'll reach a point where they do not see the rainbow because there's no rainbow light coming to them.
10:26 Chuck Nice? Right.
10:27 Neil deGrasse Tyson? So Chuck, this, you know what this fact means?
10:30 Chuck Nice? I do not.
10:31 Neil deGrasse Tyson? Every rainbow you have ever seen has been exactly face on to you.
10:38 Chuck Nice? Uh huh. And so I am, every rainbow.
10:43 Chuck Nice? Actually was made just for me.
10:45 Neil deGrasse Tyson? Just for you. You have never witnessed a rainbow at an angle.
10:50 Chuck Nice? Angle, right.
10:52 Neil deGrasse Tyson? So think about that because if your rainbow was a real thing in the sky, I could move to another location and look at it from a different angle.
11:03 Chuck Nice? Right.
11:04 Neil deGrasse Tyson? If it was an actual thing that was there.
11:06 Chuck Nice? Like anything else, right, like a mountain, a tree, or whatever.
11:09 Neil deGrasse Tyson? Like anything else, okay. So,
11:14 Neil deGrasse Tyson? if you wanted to go to the base of the rainbow, you can't.
11:22 Chuck Nice? Ah.
11:23 Neil deGrasse Tyson? Because that would be taking a different angle of view on a thing that does not really exist as a physical entity.
11:32 Chuck Nice? And, and now you have just explained how I have wasted a significant portion of my life trying to find that pot of gold.
11:43 Neil deGrasse Tyson? If you're gonna hide a pot of gold, put it at the bottom of a rainbow, nobody will ever find it.
11:50 Chuck Nice? Nobody's.
11:52 Neil deGrasse Tyson? Ever, ever. Yeah, so, so just a little known fact now. The light that's inside the raindrop, this is like inside baseball here. You ready for this? This is like.
12:04 Chuck Nice? Go ahead.
12:04 Neil deGrasse Tyson? This is for, this is, this is rainbow 201, not 101. So, the light inside the raindrop sends out not only one rainbow, but multiple rainbows, but each next one is a little weaker than the previous one.
12:21 Chuck Nice? Okay, okay.
12:22 Neil deGrasse Tyson? Okay, and because the second rainbow that comes out had an extra, extra reflection to it, if you ever see a double rainbow.
12:34 Chuck Nice? Oh, it means that you, you're tripping on mushrooms.
12:37 Neil deGrasse Tyson? Oh, no, if you see.
12:39 Chuck Nice? Oh, double rainbow.
12:41 Neil deGrasse Tyson? Chuck, it's just physics. Sometimes it's actually just physics, not the mushrooms you'll be consuming.
12:46 Chuck Nice? But go ahead, the double rainbow.
12:48 Neil deGrasse Tyson? So with that, two properties of that second rainbow is, one, it's much dimmer than the first.
12:55 Chuck Nice? Got you.
12:55 Neil deGrasse Tyson? It's always there, but generally it's very hard to detect because it's so dim. So it's much dimmer and the sequence of colors is reversed.
13:04 Chuck Nice? Oh no!
13:05 Neil deGrasse Tyson? From the original.
13:06 Chuck Nice? That's, okay, that is, first of all, that's dope. Secondly, who knew? So the double rainbow is kind of like the reverse rainbow.
13:18 Neil deGrasse Tyson? It's an inverted rainbow to the first rainbow and it's dimmer. There's actually a third and fourth and fifth. They're called the orders of the rainbow, first order, second order, third order. But they're so dim, if the sky is bright, you just will never see them. So, and there's a famous YouTube video some years back. I think they just call it the double rainbow guy. He's hiking.
13:39 Chuck Nice? Yeah, that's what I'm saying. He's tripping on mushrooms, that guy.
13:42 Neil deGrasse Tyson? And he sees two rainbows and he falls prostrate to the ground. And said, there is a God.
13:49 Chuck Nice? Double rainbow.
13:50 Neil deGrasse Tyson? Double rainbow. And that's how you behave if you don't know physics, right?
13:55 Chuck Nice? Right.
13:56 Neil deGrasse Tyson? It's just physics, really.
13:58 Chuck Nice? That's all it is. It's just physics. Yeah, once again, Neil, way to ruin rainbows.
14:03 Neil deGrasse Tyson? No, just saying.
14:06 Neil deGrasse Tyson? I want you to reserve your sense of wonder for things for which we still do not understand. And not apply it for things that are completely understood.
14:18 Chuck Nice? You know?
14:19 Neil deGrasse Tyson? There will always be a moving frontier of science. Where our area of knowledge grows, so too does the perimeter of our ignorance. Leaving us with no end of this universe to stand in wonder as we gaze.
14:34 Chuck Nice? Wow. Okay. Thank you, people. That's the show. Ain't nothing left to say. Nothing left to say. That's it. That's it.
14:49 Neil deGrasse Tyson? So Chuck, we gotta take a break. When we come back, we'll do a little bit more of this. We'll find some other subject, if you're game.
14:55 Chuck Nice? Sounds great.
14:55 Neil deGrasse Tyson? Let's do it. Okay, StarTalk, Stuff You Thought You Knew.
15:08 Speaker 02 Hey, I'm Roy Hill Percival and I support StarTalk on Patreon. Bringing the universe down to earth. This is StarTalk with Neil deGrasse Tyson.
15:28 Neil deGrasse Tyson? We're back, Chuck.
15:29 Chuck Nice? Yes.
15:29 Neil deGrasse Tyson? Things you thought you knew. You ready for another one?
15:31 Chuck Nice? I'm ready. Let's do it.
15:33 Neil deGrasse Tyson? Let's go there. And by the way, I picked these based on how familiar we think we are about the subject. And then throw in some things that you never knew.
15:45 Chuck Nice? Which is why they work. I mean, if we were just gonna talk about like gravitational waves, of course, we know we don't know none. You know what I mean? Like, who's an astrophysicist? There's like, what, 20 of you? You know what I mean? There's, you know, like, seven of you sitting around, you know, drinking tea.
16:00 Neil deGrasse Tyson? Yeah, so this is not just, let me explain stuff that you can get on a wiki page.
16:03 Chuck Nice? Right.
16:03 Neil deGrasse Tyson? It's like, just cool, fun stuff you never thought.
16:06 Chuck Nice? No, it's the twist. The twist that gets you, man. Like, the inverted rainbow. Who knew that? The orders of rainbow. Who knew that?
16:15 Neil deGrasse Tyson? Yeah, yeah.
16:16 Chuck Nice? Like, I mean, that's stuff that you honestly, but everybody knows rainbows. So, yeah, you're right. It's the twist. It's the twist that gets you.
16:23 Neil deGrasse Tyson? So today, so for this segment, we're gonna talk about zero.
16:27 Chuck Nice? All right, here we go again.
16:33 Chuck Nice? Okay, now I'm gonna be honest. It's, this is a, this is gonna be tough for you, man. Come on.
16:38 Neil deGrasse Tyson? Are you ready?
16:39 Chuck Nice? Seriously. All right, here we go. Zero.
16:42 Neil deGrasse Tyson? So, zero is a number, but it wasn't always a number.
16:49 Neil deGrasse Tyson? In fact, no one ever imagined it could be a number. In fact, no one even imagined how to imagine it. Why would you?
16:59 Chuck Nice? Right.
17:00 Neil deGrasse Tyson? What were numbers for?
17:02 Chuck Nice? Right. Who counts nothing?
17:04 Neil deGrasse Tyson? Right. Numbers are for counting.
17:06 Chuck Nice? Right.
17:06 Neil deGrasse Tyson? Okay, how many chickens do you have? Three. How many cattle do you have? You count things. So, nobody had any use to count zero. It just was not there. For most of civilization, this was the case.
17:24 Chuck Nice? Right.
17:25 Neil deGrasse Tyson? Even through the Roman Empire.
17:31 Chuck Nice? Wow.
17:31 Neil deGrasse Tyson? We think of them as highly civilized, the whole cities and hot baths and armies and if that
17:38 Chuck Nice? Equidux and
17:40 Neil deGrasse Tyson? Equidux, right?
17:41 Chuck Nice? And they were, they're so sophisticated, their numbers were letters.
17:47 Neil deGrasse Tyson? So, Roman Empire, they can count, they used Roman numerals, right? We learn Roman numerals in elementary school, don't we? Still, I think, right? And the reason why we learn Roman numerals is so that we know how to count Super Bowl games.
18:04 Chuck Nice? That is kind of the only application left, right?
18:07 Neil deGrasse Tyson? No, one more, one other for some movie sequels.
18:10 Chuck Nice? True, true.
18:11 Neil deGrasse Tyson? That's it, that's it. I don't, I don't know any other application.
18:15 Chuck Nice? Okay, yeah.
18:16 Neil deGrasse Tyson? Oh, I know also lowercase Roman numerals are the page numbers in books before you get to the actual chapters of the book.
18:28 Chuck Nice? Okay, yeah, that's true.
18:29 Neil deGrasse Tyson? Look at the bottom of the pages, those are usually Roman numerals. And then they restart from, from one at the beginning of the book.
18:35 Chuck Nice? Page one, yeah.
18:35 Neil deGrasse Tyson? So, I don't know if you've ever thought about this, Chuck?
18:38 Chuck Nice? Uh huh.
18:38 Neil deGrasse Tyson? You can't write zero with Roman numerals.
18:40 Chuck Nice? No, you can't, right?
18:42 Neil deGrasse Tyson? There is no symbol for zero. It's not because they didn't come up with it, it's that the concept of zero was not yet invented.
18:53 Chuck Nice? Wow.
18:54 Neil deGrasse Tyson? So, when they made the Julian calendar, that's the one that has a leap day every four years, and because they knew enough to know that the calendar needed it, that calendar, the Julian calendar, which anchored its starter date on the birth of Jesus. Okay, so this obviously came later after Constantine. I, I think that Constantine brought Christianity to the Roman Empire, so that they stopped feeding the Christians to the lions, that all turned around, right? So-
19:26 Chuck Nice? Very bad development for the lions.
19:30 Chuck Nice? They were like, damn, we, you know, we, we liked that.
19:35 Neil deGrasse Tyson? Chuck.
19:35 Chuck Nice? I know. Don't write people.
19:41 Neil deGrasse Tyson? So, so in the Julian calendar, they went from 1 B.C., B.C. of course stands for before Christ,
19:48 Chuck Nice? Before Christ.
19:48 Neil deGrasse Tyson? to A.D. 1, and A.D. is in Latin, anno domini, the year of our Lord, 1. And there was no year zero in that transition. So, so when would Jesus have been born? All right? And, you know, in the mythical year between the two? He can't be born in A.D. 1, because that's after. And he can't be born in B.C., because that's before. So where was, so this is, this is an issue.
20:15 Chuck Nice? Oh, I got the answer. It's a miracle.
20:19 Neil deGrasse Tyson? Okay.
20:24 Neil deGrasse Tyson? Well, later biblical research would show that Jesus was probably born closer to 3 or 4 B.C. And so, but the calendar was already in place. So you're stuck with that. There's a mismatch there. Three or four year mismatch.
20:37 Chuck Nice? We gotta play this hand. We gotta play this hand, bro.
20:39 Neil deGrasse Tyson? We've got to play, okay. So now, move time forward. Going, um, is it in the 600s, 700s? I forgot exactly when. Uh, in India, there were great advances in mathematics there. Where they even developed the numerals, early versions of the numerals we now use.
21:03 Chuck Nice? Okay.
21:04 Neil deGrasse Tyson? Rather than Roman numerals.
21:06 Chuck Nice? Right.
21:07 Neil deGrasse Tyson? Roman numerals were letters. These are now sort of symbolic shapes that would then represent the numbers. And in this effort, where was the hint that maybe you might want a zero in there? Okay.
21:23 Chuck Nice? Okay.
21:23 Neil deGrasse Tyson? So we're crawling now before we can walk, but the seeds are planted. This, these new mathematics work their way to the Middle East. Okay? And Baghdad specifically, a big trading post. And there it was, ideas were put across the table. This is the golden age of Islam. All right, where major advances were made in all, in engineering and astronomy and biology, physiology and, and, and vision. That's where the discovery that in, in vision is a passive phenomenon, not active. And so all of this is going on and then the zero was perfected.
22:02 Chuck Nice? Oh.
22:03 Neil deGrasse Tyson? The zero is perfected and they call those numerals Hindu numerals.
22:08 Chuck Nice? Okay.
22:08 Neil deGrasse Tyson? But we today call those numerals Arabic numerals.
22:12 Chuck Nice? Right, yeah.
22:13 Neil deGrasse Tyson? Okay? So this is the full tracking there. Because in the Middle East, an entire algebra rose up. And arithmetic and algebra rose up invoking zero. Uh, and you have negative numbers. Uh, and so mathematics is off to the races. Algebra is one of very common words in English that has its roots in Arabic. A lot of the AL words, uh, AL is the in Arabic.
22:39 Chuck Nice? Yeah.
22:39 Neil deGrasse Tyson? As I understand it.
22:40 Chuck Nice? Yeah.
22:41 Neil deGrasse Tyson? Yeah, so, uh, so algebra, algorithm.
22:44 Chuck Nice? Right.
22:44 Neil deGrasse Tyson? Is another one, alcohol. Uh, these are all traceable to that period. But all I'm trying to say.
22:49 Chuck Nice? The best of which is alcohol.
22:51 Neil deGrasse Tyson? Alcohol.
22:56 Neil deGrasse Tyson? Good going, guys.
22:57 Chuck Nice? There you go, way to, way to do it.
23:01 Neil deGrasse Tyson? So, so I'm just saying zero, all, just consider how late zero came. In civilization, the Egyptians knew nothing of zero.
23:11 Chuck Nice? Right.
23:12 Neil deGrasse Tyson? The, but it's there and, and we've got it and so now.
23:15 Chuck Nice? So what is this, what is this I hear about the Mayans? Uh, and zero, that they somehow had something to do.
23:22 Neil deGrasse Tyson? I don't fully know my Mayan history, other than that their calendar was, uh, they really worshipped Venus in the sky.
23:29 Chuck Nice? Oh.
23:29 Neil deGrasse Tyson? And so their calendar was sort of Venus based. Uh, the, the calendar in ancient Egypt was based on the star Sirius. When, I mean, I'm talking about the new year.
23:41 Chuck Nice? Yeah, yeah, yeah, yeah.
23:42 Neil deGrasse Tyson? Cause it's completely arbitrary when you say the, here, the new year just began, you know? Completely arbitrary, just pick a date and whatever matters in your culture, call it the beginning of the year. It's not, you know, and to this day, when, when is the Chinese New Year? It's in like late January, February, right?
23:55 Chuck Nice? Right.
23:56 Neil deGrasse Tyson? Everybody's got a different starter date and so that we.
23:58 Chuck Nice? The Jewish New Year is another new year that, yeah.
24:01 Neil deGrasse Tyson? Yeah, everybody's got their new year.
24:02 Chuck Nice? Everybody's got their own new year.
24:03 Neil deGrasse Tyson? Uh, the academic calendar has a new year, it's, it's September 1st, even though they don't say it, it really is that. Uh, you know, all the academic folks come back from summer vacation, children buy their school supplies. That's in a way a New Year's Day for school. Alright. So anyway, so that's, I just wanted to just round out what zero was all about. And by the way, so you know, wait, one quick thing.
24:25 Chuck Nice? Go ahead.
24:26 Neil deGrasse Tyson? One quick thing, you got a hundred dollars in your bank account and you go withdraw a hundred dollars from the cash machine? And the bank tells you what?
24:34 Chuck Nice? Um, don't do this again, man, because, uh, by the way, you think you have a hundred dollars and you don't. What you forgot was the electoral bill came through yesterday.
24:47 Neil deGrasse Tyson? Before you withdrew the hundred.
24:48 Chuck Nice? Before you withdrew this hundred dollars.
24:49 Neil deGrasse Tyson? You sound like this has happened to you, Chuck. Right, so here's the thing, you, you have no money left in the bank and that's bad. But what's worse is to have negative money.
25:00 Chuck Nice? Yes.
25:00 Neil deGrasse Tyson? In the bank. And so this whole concept of negative numbers arose and made complete sense. Once you pass through zero and now instead of something coming your way, you now owe it.
25:14 Chuck Nice? Right.
25:15 Neil deGrasse Tyson? And so the mathematics began to mirror commerce and the needs of civilization. As we move forward, because we're doing much more than just counting things.
25:25 Chuck Nice? You know, so this is like the birth of modern accounting. Once you find zero, that's when you're able to actually have, you know, a ledger sheet that shows you minuses and pluses and all that kind of stuff.
25:36 Neil deGrasse Tyson? Yeah, it's one of the few places in the world where it's really good to be in the black.
25:43 Neil deGrasse Tyson? Apparently, no other way is it good to be in the black, except on the accounting sheet.
25:48 Chuck Nice? Oh, that's great.
25:50 Neil deGrasse Tyson? So, so now you can go into negatives, and this keeps going with math, and you find other needs of culture and civilization and science where whole other branches of math have to be developed. And so this just went on and on, and we got trigonometry, all the stuff that you thought the teacher was just being angry with you, giving you these assignments. These are entire branches of math, the zero started it all, where it gives you deeper insights into the operations of nature.
26:19 Chuck Nice? Absolutely. Wow, that's, that's pretty cool. I mean, all this just from, from nothing.
26:27 Neil deGrasse Tyson? Yeah.
26:28 Chuck Nice? All this came from nothing.
26:30 Neil deGrasse Tyson? And so in this way, nothing means something.
26:33 Chuck Nice? Right.
26:33 Neil deGrasse Tyson? It means something, and what's that, what's that song from the 80s?
26:37 Chuck Nice? Nothing from nothing leaves nothing. You gotta have something if you won't be with me.
26:47 Neil deGrasse Tyson? From nothing, leaves nothing. I think that's a legit equation. I have to think about that. Zero minus zero, you just can't start dividing, right? Because then you end up dividing by zero, and that's, that's illegal.
27:01 Chuck Nice? Right. That's a, you've broken the law of the universe or something, but...
27:07 Neil deGrasse Tyson? If you do that too many times, Beetlejuice shows up and it explodes.
27:10 Chuck Nice? Yeah, exactly.
27:13 Neil deGrasse Tyson? So Chuck, I just want to bring you up to speed on zero, that's all.
27:16 Chuck Nice? Yeah, yeah, I gotta tell you, I've never been more impressed with nothing. So, this is cool. This is very cool.
27:22 Neil deGrasse Tyson? So Chuck, we gotta take a break. When we come back, one more stuff you thought you knew, we can fit it in. All right, we'll be right back.
27:43 Neil deGrasse Tyson? Chuck, we're back.
27:44 Chuck Nice? Yes. What do we got?
27:47 Neil deGrasse Tyson? Yeah, I got another topic for you.
27:49 Chuck Nice? All right.
27:49 Neil deGrasse Tyson? Okay.
27:52 Neil deGrasse Tyson? What the Zoom calls? And Einstein's theory of relativity haven't come?
28:00 Chuck Nice? Um, no one knows how either of them actually work. I'm gonna say that's gotta be the answer.
28:11 Neil deGrasse Tyson? That's a good, that's a good answer. So, here you go. You ready?
28:15 Chuck Nice? Okay, let's do it.
28:16 Neil deGrasse Tyson? Uh, what we learned, what we affirmed in Einstein's theories of relativity is that space cannot be thought of just as space. Time is a fundamental coordinate right alongside space.
28:32 Chuck Nice? Right.
28:33 Neil deGrasse Tyson? So that when you ever wanna think about events, phenomena, past, present, future, you have to think of spacetime.
28:40 Chuck Nice? Right.
28:41 Neil deGrasse Tyson? You can't just think of space or time as separate things. And there's an entire set of equations that fold the two together.
28:48 Chuck Nice? That's, see now, that's, the first part I am so cool with, I like literally get it, you know? But when you talk about proving it mathematically, I'm still just flabbergasted.
29:03 Neil deGrasse Tyson? That's how you know it's gonna be tight.
29:04 Chuck Nice? Yeah, of course, yeah, cuz it keeps moving, it keeps working. When it, when the math works, it works. Yeah, that's cool, man.
29:10 Neil deGrasse Tyson? It works, right, okay. So, um, let us, for those who might still be uncomfortable with the spacetime concept, what you don't know perhaps is that you live that way. There's no other way you, you live. It's so intuitive, you think it's complicated, but it's easy. So if I say to you, Chuck, you ready?
29:32 Chuck Nice? Yep.
29:33 Neil deGrasse Tyson? Okay, I say, uh, Chuck.
29:38 Neil deGrasse Tyson? Uh, let's have lunch tomorrow at noon.
29:41 Chuck Nice? I would say, oh my god, as long as you're paying. That is such a wonderful offer.
29:48 Neil deGrasse Tyson? Okay, Chuck, it's on me. Let's have lunch tomorrow at noon. What is your next comment back to me?
29:54 Chuck Nice? Where? Where you wanna eat? Where do you wanna eat?
29:56 Neil deGrasse Tyson? Because the time alone was insufficient.
30:00 Chuck Nice? Of cour- yeah.
30:01 Neil deGrasse Tyson? For your life and my life to intersect, time is alone will not make that happen. You also have to give a spatial coordinate.
30:13 Chuck Nice? Right.
30:13 Neil deGrasse Tyson? Is it the diner on the corner of, you know, Hollywood and Vine at 12 noon?
30:20 Chuck Nice? Right.
30:20 Neil deGrasse Tyson? So you have a space coordinate and time coordinate so that we can both meet.
30:25 Chuck Nice? Right.
30:26 Neil deGrasse Tyson? Okay?
30:26 Chuck Nice? Leave it to you to give me a coordinate where you know I can't get to.
30:34 Neil deGrasse Tyson? So watch, if you go to the diner at the corner of Hollywood and Vine, yesterday, and I go there tomorrow, we were in the same place.
30:43 Chuck Nice? We were.
30:45 Neil deGrasse Tyson? But not at the same time.
30:46 Chuck Nice? Okay.
30:48 Neil deGrasse Tyson? Doesn't work, okay? Let's keep going. You were at the diner yesterday, and I'm at the diner tomorrow. We're both in the same place, but not at the same time.
30:58 Chuck Nice? Right.
31:00 Neil deGrasse Tyson? Okay.
31:01 Chuck Nice? Which is what I call Neil's favorite lunch.
31:07 Chuck Nice? Chuck, you were here yesterday, good.
31:09 Neil deGrasse Tyson? Okay, so now watch, so now, you're at the diner in the corner, and I'm at, this works with Starbucks. You're in that Starbucks, I'm in a different Starbucks. We're at the same time, but not at the same place.
31:24 Chuck Nice? Right.
31:25 Neil deGrasse Tyson? Okay, so you need to be at the same place and at the same time. For anything to happen where you have two things that want to coordinate together. Okay, all right. So how does this manifest? Let's go in the universe, and there's an asteroid headed towards Earth. You could do the Bruce Willis thing, and what?
31:42 Chuck Nice? Blow it up.
31:43 Neil deGrasse Tyson? Blow it out of the sky, which it takes a lot of wasted energy. Or you can deflect it.
31:50 Chuck Nice? Not a good movie. Not a good movie.
31:54 Neil deGrasse Tyson? How do you deflect an asteroid? So, here it is. If you left it alone, it will collide with Earth. Which means it will be in the same place at the same time that Earth is sometime in the future, at some point in the future, okay? So what I can do is, I can speed up the asteroid.
32:13 Chuck Nice? Oh, I love that.
32:16 Neil deGrasse Tyson? Which you're on, then, oh. You speed it up.
32:20 Chuck Nice? Yeah.
32:21 Neil deGrasse Tyson? Then it gets to that location in my orbit before I do.
32:24 Chuck Nice? Exactly.
32:25 Neil deGrasse Tyson? So it's at the, we're exist at the same time, but we're not in the same place.
32:30 Chuck Nice? That's a whole, that's a whole nother way to look at deflecting an asteroid.
32:34 Neil deGrasse Tyson? That's what's going on when you deflect an asteroid.
32:37 Chuck Nice? That's awesome.
32:39 Neil deGrasse Tyson? Or you could slow it down.
32:41 Chuck Nice? Right.
32:41 Neil deGrasse Tyson? Then we get to that point before it does, we keep moving and it goes right on by behind.
32:47 Chuck Nice? Oh man, it's the proverbial, um, mental, uh, uh, exercise that everyone does when they have a car accident. If only I hadn't forgotten my keys. If only I had left a little bit earlier, I would have never had.
33:04 Neil deGrasse Tyson? And they wouldn't have been in that spot at that time for the, for the drunk driver.
33:09 Chuck Nice? Exactly, right, yeah.
33:10 Neil deGrasse Tyson? It's a mental calculation you do. Right, right. And, and it works in simple ways that we don't even talk about, but it's so simple. You cross the street, five minutes later, a bus drives down the street. You just say, oh my gosh, I was ol, I was almost hit. No, you didn't, you didn't.
33:27 Chuck Nice? Oh, you're a bit of a drama queen, you know that, right? My God, I was almost hit by a bus, did you see that? What? No, it came by here five minutes ago, it was just barreling, just barreling down the street.
33:39 Neil deGrasse Tyson? It was in the same spot.
33:40 Chuck Nice? I was right there. I could have died.
33:43 Neil deGrasse Tyson? Right, you would not have died, and by the way, in relativity, we call these world lines.
33:50 Chuck Nice? World lines.
33:51 Neil deGrasse Tyson? Your world line is where you are in space and time.
33:56 Neil deGrasse Tyson? Which is always in motion. Right. Because time as a, even if you're sitting there on your butt. Right. You're moving forward in time. Right.
34:07 Neil deGrasse Tyson? By the way, this affects time machines. All right, so I give you a time machine and you say, okay, you want to go into the future, how far do you want to go in the future? Oh, I'm gonna go at least 200 years, just to see if we're still here. Okay, but suppose you say, all right, I don't want to land in the winter, let me land in the summer. So I want to go 200 years in six months. Okay. Okay, let's say, because we're recording this, it's cold outside right now. So you do that, all right, so you go, we'll go in your time machine, go 200 years, and then you walk out of the time machine, you will suffocate in the vacuum of space.
34:39 Neil deGrasse Tyson? Oh. Because Earth is not just spinning, it's moving while it's spinning. Okay, so you will land in the same spot that Earth was in its orbit, which is a different place than where it is six months from now. Oh, man. Which tells you a time machine can only work if it's a space-time machine. That's right. That's pretty awesome. You want to move to a location in time and a location in space. Correct. Right. All right, so. Oh, wow, that is really cool, because. Okay, so now watch, watch how this plays out. Right. Are we, are we on the same page? I don't know. I don't want to move forward until I hear Neil, I'm with you.
35:23 Neil deGrasse Tyson? I am riding this wave with you, buddy. Okay, okay, so, under normal circumstances, I'm in my office three or four days a week, I travel a lot. There are seminars and colloquia, scientists come through the department and they give talks. You know, if I'm around, I'm gonna attend those talks, because they're good, they learn about the latest breaking discoveries made by my colleagues. Okay. So we get, we have maybe three or four talks a week in our division at the American Museum of Natural History. I used to make maybe one of those a week. All righty. However, during COVID, I was making four out of four talks a week. Okay. Why? Because Zoom calls
36:07 Neil deGrasse Tyson? broke the space-time alliance.
36:12 Neil deGrasse Tyson? So that now you only have to be at the same time and you do not have to be at the same place.
36:22 Chuck Nice? Interesting.
36:23 Neil deGrasse Tyson? As a result, world lines can split and only conjoin on the time coordinate, rendering the space coordinate irrelevant.
36:34 Chuck Nice? Hmm.
36:35 Neil deGrasse Tyson? That is why probably more people attending more conferences, seeing more meetings than ever before. You can no longer use an excuse, "Oh, I'm on a business trip. I can't come in." Zoom in. We have you on the Zoom call.
36:53 Chuck Nice? I know. It's an electronic leash is what it is for most people.
36:57 Neil deGrasse Tyson? And that's how, Chuck, you spent how many months you were filming Brain Games for National Geographic?
37:03 Chuck Nice? Yes.
37:03 Neil deGrasse Tyson? You're their new host in their new season, yet you didn't lose a bit of the schedule. Your background was different because you were recording with us via Zoom through your hotel rooms and other setups.
37:14 Chuck Nice? That's right.
37:15 Neil deGrasse Tyson? And so, so you were still participating because your world line didn't need the space coordinate.
37:22 Chuck Nice? That's true. Yeah.
37:23 Neil deGrasse Tyson? And so this is the relationship between Zoom calls and Einstein's theory of relativity.
37:31 Chuck Nice? That is, uh, that's pretty wild. And, um, in a way I have a new respect for Zoom now. Uh, I gotta tell you.
37:40 Neil deGrasse Tyson? For breaking the space-time continuum?
37:41 Chuck Nice? Yes, exactly. It's like, who knew Zoom was so damn sci-fi?
37:50 Chuck Nice? No, that's pretty, that's, yeah. I love it. I love it.
37:54 Neil deGrasse Tyson? Chuck, in all fairness to the history of communication that predates Zoom, the telephone was kind of like that. All right. And by the way, do you know what the word caller meant? Before there was a telephone? It was a visitor to you front.
38:11 Chuck Nice? I was gonna say, um, a handsome gentleman, perhaps?
38:15 Neil deGrasse Tyson? Yes, you have a gentleman caller.
38:17 Chuck Nice? Oh, I do believe you have a gentleman caller.
38:19 Neil deGrasse Tyson? Yes, exactly. That's the meaning of that with the original meaning of that word. And then Alexander Bell invents a telephone. And so what word are you gonna use when you show up at the front door of the telephone line? It's a caller.
38:33 Chuck Nice? It's a caller.
38:34 Neil deGrasse Tyson? And now that's we've been that way for 130 years or whatever. So we, no, 150 years now. So 1876 was the demonstration of the patent for the first telephone. Um, and so that put people together in time without having to be together in space.
38:51 Chuck Nice? Wow.
38:52 Neil deGrasse Tyson? So this is what, this is one of the great achievements and advances in modern civilization. Uh, and Zoom just did it full up with voice and sound and audio quality and saved files and everything.
39:04 Chuck Nice? It's, it's really funny because the video call was reported to be the thing that would change everything in society. And
39:13 Neil deGrasse Tyson? I, I remember seeing a video phone in 1964 World's Fair in New York.
39:18 Chuck Nice? Wow.
39:18 Neil deGrasse Tyson? It was like, wow, that's the future. Then you realize you call someone at six in the morning. They don't want you looking at their.
39:24 Chuck Nice? Yeah, exactly.
39:27 Neil deGrasse Tyson? The people don't always want you looking at them anytime you happen to call them.
39:30 Chuck Nice? What is that on your face? Don't look at my face.
39:34 Chuck Nice? Let's just have a call. Stop looking at my face.
39:39 Neil deGrasse Tyson? So now you can pre-schedule Zoom calls and now you can get all dolled up and call Purdy. You can Zoom Purdy.
39:46 Chuck Nice? Yeah, you got to. That's pretty, yeah, that's great, though. I mean, it's, it's, uh, who knew that you could link this back to Einstein? I said you had a, a tough one, but you did it. You linked it back to Einstein somehow.
39:59 Neil deGrasse Tyson? And now you know with asteroids, we're just changing its world line.
40:02 Chuck Nice? Yeah, which by the way, that is the coolest thing ever. The fact that, I mean, and the idea is you don't even have to knock it off course. You can just speed it up or slow it down. That's because you always think of deflection as a change in
40:17 Neil deGrasse Tyson? Going sideways.
40:18 Chuck Nice? In the vector, right?
40:19 Neil deGrasse Tyson? Well, a vector is direction and speed.
40:22 Chuck Nice? And speed.
40:22 Neil deGrasse Tyson? Technically, a vector has both of those components. So if you change its direction or you change its speed, you have changed its velocity. The velocity is the combination of those two.
40:32 Chuck Nice? Nice.
40:32 Neil deGrasse Tyson? So it's exactly right.
40:33 Chuck Nice? That's great. It's like, I mean, I am less scared of asteroids now.
40:39 Neil deGrasse Tyson? I don't want, that was not the point of this explanation.
40:42 Chuck Nice? Oh, okay.
40:44 Neil deGrasse Tyson? No, you are heartened, oh, by the way, a velocity vector is motion that has direction and, and, and speed as part of it, like the asteroid, right? So you can change its direction or change its speed or both. Either of those are changing the velocity of the asteroid. Okay, so now watch. You can do that, so with a car, there are three ways to change its velocity.
41:10 Chuck Nice? Right. You can slow it down, you can speed it up, and you can hit a wall.
41:17 Neil deGrasse Tyson? Ideally not.
41:18 Chuck Nice? Okay.
41:19 Neil deGrasse Tyson? You can slow down, it reduces its speed, you can accelerate, increase its speed, or you can change direction.
41:28 Chuck Nice? Okay.
41:28 Neil deGrasse Tyson? All three of those can help you avoid an accident.
41:33 Chuck Nice? Right.
41:34 Neil deGrasse Tyson? It's not just how good your brakes are. Do you have a place to steer so that your world line does not fully intersect with the one that would cause the accident?
41:44 Chuck Nice? You know what? As a person who rides a motorcycle, you just explained how you stay alive on a bike. Those are the three things that are your friend, that they teach you all the time. The first is acceleration. Get up and get out of the way. The second is being able to brake properly, but now motorcycles have anti-lock brakes, so that used to be a big deal, not so much. But the most important is being able to maneuver. So you know, to, to, to be able to
42:12 Neil deGrasse Tyson? And motorcycles are particularly nimble in that regard, right?
42:15 Chuck Nice? Exactly, yeah. Super cool!
42:17 Neil deGrasse Tyson? So Chuck, we got to bring this to a close. This was stuff you thought you knew.
42:21 Chuck Nice? And now I do!
42:26 Neil deGrasse Tyson? And the inventory was rainbows, zero, and Zoom calls and relativity.
42:31 Chuck Nice? Yeah.
42:31 Neil deGrasse Tyson? There it is. That's as, that's as motley a crew as you'll find. All right, Chuck, we're gonna land this plane, and I'm gonna get out, and so are you.
42:41 Neil deGrasse Tyson? Neil deGrasse Tyson here, your personal astrophysic. Wait a minute, wait, wait, before I end, I did say it, didn't I? Chuck, your show premiered for, with National Geographic.
42:52 Chuck Nice? Yes, sir.
42:52 Neil deGrasse Tyson? Brain Games.
42:53 Chuck Nice? Thank you.
42:53 Neil deGrasse Tyson? The new host. Oh, my God.
42:55 Chuck Nice? Yes, yes, please watch it, people.
42:58 Neil deGrasse Tyson? I'm gonna find, don't sound that desperate.
43:01 Chuck Nice? Oh, yeah, that's right. That's not the way. You're not supposed to, uh, not supposed to, um, promote a show by going, hey, man, please watch it. I got kids.
43:11 Chuck Nice? That's not the way you're supposed to.
43:13 Neil deGrasse Tyson? I got hungry kids.
43:14 Chuck Nice? Hey, man, these kids eat so much, please watch my show.
43:21 Neil deGrasse Tyson? No, Brain Games, it's a new season, 20 episodes, just dropped on National Geographic. You can get it through the Disney portal.
43:28 Chuck Nice? That's correct.
43:28 Neil deGrasse Tyson? And, uh, check out our very own Chuck Nice. We, we take, we take ownership of you, Chuck. We feel like you're ours.
43:35 Chuck Nice? That's right. Yeah. Well, that's what, I know, I don't, I feel that way, too.
43:38 Neil deGrasse Tyson? Okay.
43:41 Chuck Nice? Thank you. Yeah, thanks, Neil.
43:42 Neil deGrasse Tyson? All right, all right. This has been StarTalk. Neil deGrasse Tyson here, as always. Keep looking up.
Previous Cosmic Queries – Stoner Edition with Janna Levin Next Equations in Motion – Bowling with Dr. Dave Alciatore Page updated September 29, 2026 · transcript and summary are machine-generated
