Things You Thought You Knew - Windows to the Universe

Is it possible to make something invisible? Neil deGrasse Tyson and comedian Chuck Nice explore transparency, how we measure time on Earth, and how airplanes have changed.

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

• 0:01Neil deGrasse Tyson?

  Welcome to StarTalk. Your place in the universe where science and pop culture collide. StarTalk begins right now. This is StarTalk. Neil deGrasse Tyson here, your personal astrophysicist. I got with me Chuck Nice. Chuck?

• 0:22Chuck Nice?

  What's up Neil?

• 0:23Neil deGrasse Tyson?

  All right, this is another installment of Things You Thought You Knew.

• 0:28Chuck Nice?

  Yes.

• 0:28Neil deGrasse Tyson?

  With each segment goes someplace where you thought you knew and maybe you didn't.

• 0:35Chuck Nice?

  And you didn't. Yeah, no, let's be honest.

• 0:37Neil deGrasse Tyson?

  You're gonna confirm that?

• 0:38Chuck Nice?

  And don't be one of these people that says, "I knew that. I knew that. I did. I knew that." No, no you didn't. So just relax.

• 0:51Neil deGrasse Tyson?

  All right, we're gonna lead off with a first segment on the topic of transparency.

• 0:57Chuck Nice?

  Ooh.

• 0:58Neil deGrasse Tyson?

  I just want a general discussion about transparency because I think it's fascinating. Okay, so if we're in the same room and I see you, you know, there's a day when it's said, "Well, there's nothing there, so that's why I can see you." Except, of course, there's air there.

• 1:15Chuck Nice?

  Of course.

• 1:16Neil deGrasse Tyson?

  All right, so it's not that there's nothing between me and you blocking the view. Air is blocking the view, except that air happens to be transparent to the light that we are detecting.

• 1:31Chuck Nice?

  Okay.

• 1:32Neil deGrasse Tyson?

  Okay, it is transparent air. All right, so now, when we build domiciles, homes and whatever, you want to be able to look outside. You can just cut a hole in the wall and look outside because air is transparent. But we don't. We want to protect ourselves from the elements.

• 1:56Neil deGrasse Tyson?

  So instead of having air in the window, we put something else in the opening on the side of the wall that is itself transparent to visible light.

• 2:08Chuck Nice?

  Mm hmm.

• 2:08Neil deGrasse Tyson?

  Okay, and that's what we call windows.

• 2:11Chuck Nice?

  Yes.

• 2:11Neil deGrasse Tyson?

  Which are variations on SiO2, silicon dioxide. Okay, so that's transparent.

• 2:18Chuck Nice?

  Right.

• 2:19Neil deGrasse Tyson?

  Okay, the sun is peaks in the energy that it sends to Earth. It peaks in the red, orange, yellow, green, blue, violet part of the spectrum, the visible light part of the spectrum. And within that, it peaks right at the green, yellow boundary. Okay, so the sun gives more green, yellow light than any other kind of light that's out there. All right, that's part of why we say the sun is yellow, except it's also giving just as much green, and no one says the sun is green.

• 2:50Chuck Nice?

  The sun is green.

• 2:50Neil deGrasse Tyson?

  So you're right, but it's the mixture of all of those gives us the color of the sun, which is basically white. All right, my point is, how does sunlight reach us here on Earth? Because the atmosphere is transparent. Okay, but occasionally, a cloud moves in.

• 3:13Neil deGrasse Tyson?

  Clouds are not transparent to visible light. So they block the sun. Right, this sounds all very basic and simple. Agreed?

• 3:23Chuck Nice?

  I'm, I'm, right now, I'm with you on every step.

• 3:27Neil deGrasse Tyson?

  Okay, so now, now, what else is transparent? All right, you are in your home. You have glass in the windows, you have walls.

• 3:38Chuck Nice?

  I do.

• 3:38Neil deGrasse Tyson?

  You have a roof and a floor.

• 3:41Chuck Nice?

  Okay, that's true.

• 3:42Neil deGrasse Tyson?

  And then your, and then your cellphone rings.

• 3:46Neil deGrasse Tyson?

  Well, is your cellphone using visible light? No.

• 3:50Chuck Nice?

  No, it isn't.

• 3:51Neil deGrasse Tyson?

  No, it's using microwaves.

• 3:53Chuck Nice?

  Right. By the way, I have a, I have a really crappy carrier, so my cellphone doesn't break.

• 3:58Neil deGrasse Tyson?

  It's not working, it's not working. So, the microwaves, the microwaves have no hesitation penetrating your walls. With or without the window.

• 4:11Chuck Nice?

  Okay.

• 4:12Neil deGrasse Tyson?

  You could, you could use your cellphone in a windowless bathroom. So, two microwaves, which are part of the electromagnetic spectrum, your home is transparent.

• 4:25Chuck Nice?

  Nice.

• 4:26Neil deGrasse Tyson?

  So if you had microwave vision, your home basically disappears. You might see the, the door frames, you know, depending on how it's framed out. You might see some metal wiring and things, but overall, the house disappears.

• 4:44Neil deGrasse Tyson?

  In the same way, when you look out a window, you're not looking at glass. The glass disappears to you.

• 4:50Chuck Nice?

  Right.

• 4:50Neil deGrasse Tyson?

  And, and you know it does when people walk into that stuff in, in stores.

• 4:55Chuck Nice?

  Actually, I'm, I'm looking out my window right now and I'm like, maybe I need to clean these because this glass is not disappearing.

• 5:03Chuck Nice?

  This is straight up safety glass that I'm looking at right now.

• 5:07Neil deGrasse Tyson?

  It's safety glass.

• 5:08Chuck Nice?

  No, no one is walking through this glass.

• 5:12Neil deGrasse Tyson?

  Yeah, so you know what safety glass is? It's glass that breaks into a zillion tiny pieces.

• 5:16Chuck Nice?

  I didn't know that.

• 5:17Neil deGrasse Tyson?

  You thought it was what?

• 5:18Chuck Nice?

  I thought it was glass that didn't break, like, you know, basically.

• 5:21Neil deGrasse Tyson?

  No, no, no, no. Well, that, that could be a variant on safety glass, but in cars where they say safety glass.

• 5:27Chuck Nice?

  Right.

• 5:27Neil deGrasse Tyson?

  When the car windshield breaks, it completely shatters into tiny little bits of glass.

• 5:33Chuck Nice?

  I, I know.

• 5:34Neil deGrasse Tyson?

  So the question is.

• 5:34Chuck Nice?

  That, that doesn't make me feel safe.

• 5:37Neil deGrasse Tyson?

  No, no, no, but you ask, how deep into you can a tiny piece of glass go? Like, the depth of the tiny piece of glass. Whereas, if the windshield broke in these huge shards.

• 5:50Chuck Nice?

  Yeah.

• 5:51Neil deGrasse Tyson?

  It could penetrate you and, and get into your heart, break your jugular, or whatever. The worst you need is a bag of Band-Aids at the end of the broken glass, of safety glass, that's all. It's designed to be completely shattered, alright?

• 6:04Chuck Nice?

  Alright.

• 6:04Neil deGrasse Tyson?

  And that version of, that variety of safety glass is designed for that.

• 6:07Chuck Nice?

  I got you, I got you.

• 6:09Neil deGrasse Tyson?

  Alright, so, but that's not what we're talking about. We're talking about the fact that to microwaves, your home is transparent.

• 6:15Chuck Nice?

  Right.

• 6:16Neil deGrasse Tyson?

  Your home is also transparent to, largely to radio waves. Now, if you're old school, some of our listeners are old school.

• 6:26Chuck Nice?

  Mm-hmm, and know what a ra- and know what radio is?

• 6:29Neil deGrasse Tyson?

  Radio is, you'd go into a tunnel. If you were listening to FM, the FM signal would drop out.

• 6:36Chuck Nice?

  Mm-hmm.

• 6:37Neil deGrasse Tyson?

  If you're listening to AM, it would stay.

• 6:39Chuck Nice?

  Yes.

• 6:40Neil deGrasse Tyson?

  Okay? AM has greater penetration through the surroundings of tunnels than FM does. Alright, so it's all a matter of who is transparent to whom. Now, let's say you, let's tune our eyes, so, so you have, uh, there's red, orange, yellow, green, blue, violet. Below red, we have infrared. Okay, and below infrared, we had microwaves. So, microwaves get through stuff, okay? But microwaves have a hard time getting through metal.

• 7:06Chuck Nice?

  Okay, right.

• 7:07Neil deGrasse Tyson?

  Okay, the metal interacts with them, it prevents that.

• 7:09Chuck Nice?

  I learned that the hard way in my oven, but, go ahead.

• 7:12Neil deGrasse Tyson?

  In your microwave.

• 7:13Chuck Nice?

  That's a whole nother story.

• 7:15Neil deGrasse Tyson?

  In your microwave oven, you have a metal, so there's, the, the door is made of glass.

• 7:21Chuck Nice?

  Right.

• 7:22Neil deGrasse Tyson?

  Okay? Microwave goes right through glass.

• 7:25Chuck Nice?

  No problem.

• 7:26Neil deGrasse Tyson?

  But it's not pure gla- it's not only glass, your door has this mesh on the inside.

• 7:31Chuck Nice?

  Right.

• 7:32Neil deGrasse Tyson?

  Okay? And the wavelength of microwaves is like a few millimeters up to maybe a couple of centimeters, in that zone.

• 7:39Chuck Nice?

  Wow.

• 7:39Neil deGrasse Tyson?

  So, that mesh has holes.

• 7:43Neil deGrasse Tyson?

  That are smaller than the size of the microwave, so they can't come through.

• 7:47Chuck Nice?

  So I can see in, but the waves bounce back.

• 7:50Neil deGrasse Tyson?

  You can see in because you're not, you're not using microwaves to see.

• 7:53Chuck Nice?

  Right.

• 7:54Neil deGrasse Tyson?

  Using visible light, which goes through the holes.

• 7:56Chuck Nice?

  Right.

• 7:57Neil deGrasse Tyson?

  Visible light's way smaller than those holes.

• 7:59Chuck Nice?

  So I'm not getting irradiated because the waves can't get through the holes, so they bounce back into the microwave?

• 8:04Neil deGrasse Tyson?

  Back into the microwave, correct.

• 8:06Chuck Nice?

  Okay.

• 8:06Neil deGrasse Tyson?

  Correct. So now let's look at infrared, which is.

• 8:09Chuck Nice?

  That's brilliant. What a simple thing. That's freaking brilliant.

• 8:13Neil deGrasse Tyson?

  This is why, science and engineering, this is what we, this is, these are the foundations of civilization, right?

• 8:19Chuck Nice?

  I can't believe I got a science oven. Oh, that's so cool.

• 8:23Neil deGrasse Tyson?

  So, now let's go to infrared. So, now let's look around us in infrared. You'll see things that are, infrared is a good measure of temperature. Because things will glow if they're glow, we know this.

• 8:39Chuck Nice?

  From Predator. We know it from Predator. Let's be honest.

• 8:41Neil deGrasse Tyson?

  From Predator, yes.

• 8:42Chuck Nice?

  Let's be honest. That's how we know about infrared, okay? We didn't pay attention in school, but then we saw the alien monster up in the tree and it was making that gurgling sound like

• 8:53Chuck Nice?

  and it was looking at Arnold Schwarzenegger like you know, and, and we saw him, you know.

• 9:00Neil deGrasse Tyson?

  Damn, you remember the sound effects too?

• 9:02Chuck Nice?

  Yeah, man.

• 9:04Neil deGrasse Tyson?

  If it, if it bleeds, we can kill it, which is brilliant.

• 9:07Chuck Nice?

  Yeah, but that's it. That's, that's true.

• 9:10Neil deGrasse Tyson?

  That's the most brilliant line in the movie. So.

• 9:12Chuck Nice?

  He was wrong, by the way.

• 9:18Neil deGrasse Tyson?

  If it bleeds, we can nuke it. Yes, okay.

• 9:19Chuck Nice?

  Exactly, because that's, that's how it died. It nuked itself. So he was wrong.

• 9:25Neil deGrasse Tyson?

  It didn't bleed to death.

• 9:26Chuck Nice?

  It did not bleed to death. He blew up half the Dagor jungle, okay, because he lost. First, and the Predator is a bad loser. Let me just tell you that right now. I ain't never lost no game and been like, that's it, I'm nuking this whole place. This whole place is going up, mushroom cloud and all.

• 9:46Neil deGrasse Tyson?

  Screw you humans. That has nothing to do with what I'm trying to say. I know, I'm sorry.

• 9:54Neil deGrasse Tyson?

  You're going off on a Predator tangent? All right, so, but you are correct. Predator has vision, uh, has infrared vision. By the way, so too did Terminator, interestingly. Also played by. That same guy.

• 10:11Neil deGrasse Tyson?

  So, all right, so infrared, I look around and I see things glowing. Then I try to look out the window and I can't. It's opaque.

• 10:25Neil deGrasse Tyson?

  It is opaque.

• 10:29Neil deGrasse Tyson?

  And you can test this yourself. You ready? Okay. So put someone on one side of the window and have them turn on a flashlight. On the other side, they can see the flashlight. Now have someone turn on a, something that turns red hot. Like an iron. Like an iron, you know, a red hot. And have them go on the other side of the window and ask if you feel the heat of the iron. You do not feel it at all. That's so cool because glass is like an insulator. Glass prevents the transmission of heat. Yes. Wow. Okay. So infr- so glass, transparent glass is opaque to infrared light.

• 11:14Neil deGrasse Tyson?

  Yes. Nice. Okay, well, let's keep going. Um, how about, uh, radio waves? Well, like, radio waves are what you get when you go beyond microwaves. They have excellent penetration depth through everything, basically. That's why it works as communication. Otherwise, you say, I'll call you at 3:03, 10, but get out in the street and face the radio tower when we're talking. That, if, you know, that's not what it is. Wherever you are, we can find you and we can communicate with you. Right. So, uh, so I'm just trying to have people broadly think about the fact that when you say something is transparent,

• 11:55Neil deGrasse Tyson?

  technically, you should be specifying transparent for what wavelength of light? Right. For what wavelength, correct. By the way, you know what else is opaque to, uh, what glass blocks? UV.

• 12:11Neil deGrasse Tyson?

  Glass blocks UV. Gl-. Glass out of the box will absorb ninety-seven percent of UV that hits it. And I've done this experiment using in a laboratory, okay? Out of the box, it's a UV filter. When you buy special sunglasses that say UV.

• 12:29Chuck Nice?

  UV blockers?

• 12:31Neil deGrasse Tyson?

  Protections, right? They're getting you from the ninety, if it's, they're made of glass. They'd get you from the ninety-seven percent it gets for free up to like ninety-nine percent. Okay?

• 12:41Chuck Nice?

  Wow.

• 12:42Neil deGrasse Tyson?

  Now, um, there were physicists when they were testing atomic bombs and there had high energy radiation there. What they would do is they would dip behind the windshield of the Jeep that drove them out there.

• 12:54Chuck Nice?

  Oh.

• 12:54Neil deGrasse Tyson?

  It would still be bright, visually bright, but the high energy radiation would be blocked by the transparent glass. So glass blocks infrared on one side of this visible spectrum and ultraviolet on the other side of the spectrum, which is beyond violet, and it transmits by definition what we call visible light. And that's what makes glass quite a fascinating thing. In our, in our, in our culture and in our civilization.

• 13:24Chuck Nice?

  So, so, so that's, that's why Wonder Woman never gets a tan. Cause she's riding around in her invisible glass ship or, you know, plane.

• 13:36Neil deGrasse Tyson?

  I forgot about that.

• 13:37Chuck Nice?

  Which by the way.

• 13:38Neil deGrasse Tyson?

  It's some flying thing.

• 13:39Chuck Nice?

  It's a flying thing, but it's, we don't know.

• 13:41Neil deGrasse Tyson?

  It's a transparent flying thing.

• 13:42Chuck Nice?

  It's a, yeah, cause we call it a plane, but the truth is we, we can't see it. So we don't know what it is, to be honest.

• 13:49Neil deGrasse Tyson?

  Right, right.

• 13:50Chuck Nice?

  Cause it's invisible. By the way, she only flew it once and that was, you know.

• 13:54Neil deGrasse Tyson?

  Okay, all right, all right.

• 13:55Chuck Nice?

  Yeah, she got out of it and then she couldn't find it.

• 13:59Neil deGrasse Tyson?

  So in Harry Potter, they had the invisibility cloak.

• 14:02Chuck Nice?

  Oh, that thing is cool.

• 14:04Neil deGrasse Tyson?

  Okay, so here's what you do is, since you are in the way between me and what's behind you. Okay, I can't all of a sudden make you transparent. But you, if you, but we, we have research such as what they had in Harry Potter. Whereas you put on this invisibility cloak and what happens is the light from behind you hits the back of your cloak and is channeled around the front and then comes straight back out from the front of you.

• 14:34Chuck Nice?

  Wow.

• 14:34Neil deGrasse Tyson?

  This is a very complicated optical pathways that the light has to take. If it does that, then my pathway goes to your chest, around you, and to the wall behind you, and I don't even know you're standing there, because I don't know the light took that circuitous route, because it comes straight to my eye.

• 14:51Chuck Nice?

  Wow.

• 14:52Neil deGrasse Tyson?

  So I can make you transparent if the light behind you is brought around to the front of you. This was also shown in a James Bond film, I forgot which, he can make his, his, his Aston Martin disappear.

• 15:03Chuck Nice?

  Disappear, but really you're just, just diverting, bending the light to the front.

• 15:07Neil deGrasse Tyson?

  You're bending the light around it. Correct, correct. And it means you should still be able to shoot it.

• 15:15Neil deGrasse Tyson?

  It's not, the bullet's not gonna say, "Hey, where'd the car go?" I don't know what to do.

• 15:20Chuck Nice?

  That's funny.

• 15:20Neil deGrasse Tyson?

  The bullet still has its trajectory and it's gonna be right to the target. So just, that was just a little, I thought I'd spend a couple of minutes talking about transparency.

• 15:30Chuck Nice?

  I liked it.

• 15:31Neil deGrasse Tyson?

  Chuck, we gotta take a quick break.

• 15:32Chuck Nice?

  Okay.

• 15:33Neil deGrasse Tyson?

  But when we come back, more things you thought you knew on StarTalk.

• 15:48Speaker 02

  I'm Joel Cherico and I make pottery. You can see my pottery on my website, cosmicmugs.com. Cosmic Mugs, art that lets you taste the universe every day. And I support StarTalk on Patreon. This is StarTalk with Neil deGrasse Tyson.

• 16:13Neil deGrasse Tyson?

  Welcome back to StarTalks, Things You Thought You Knew. Chuck, you know what I'm gonna talk about now?

• 16:18Chuck Nice?

  I do not. That's the thing I thought I knew, but clearly I don't.

• 16:24Neil deGrasse Tyson?

  Things You Thought You Knew. We're gonna talk about the International Dateline. There might be some stuff in there you didn't know about.

• 16:31Chuck Nice?

  Oh, believe me. I'm letting you know right now, I don't care what you say about the International Dateline. I did not know it.

• 16:42Neil deGrasse Tyson?

  Well, it's kind of a weird place, you know? You cross just one spot on Earth's surface and it's then it's yesterday or tomorrow, right? And it's the same time, but a different day.

• 16:55Chuck Nice?

  Yeah, that's true.

• 16:56Neil deGrasse Tyson?

  That's a little creepy, right? It's a little weird.

• 16:59Chuck Nice?

  It is.

• 17:00Neil deGrasse Tyson?

  I just wonder, you never thought about that?

• 17:01Chuck Nice?

  I, you know, because to me, I mean, I get it that we're in motion and so that's why there's gotta be different times, but I'm gonna be honest. It's one of those things that I never get right.

• 17:17Neil deGrasse Tyson?

  Okay.

• 17:18Chuck Nice?

  And I'm talking about here on this continent, North America. I'm not even talking about leaving our shores.

• 17:27Neil deGrasse Tyson?

  Okay, you're talking about you don't get time zones right.

• 17:30Chuck Nice?

  I get them. I screw every single time zone up, no matter what email, no, even when they explain it to me. And then I still screw it up.

• 17:40Neil deGrasse Tyson?

  For what it's worth, what prevents me from screwing it up is I re-derive time zones from first principles almost every time I think of them. So I say, okay, Earth is rotating west to east. The sun therefore rises first for everyone east of us. So everyone east of us has to be, has to be later than us than the ones west of us. So I reconstruct that in my head so that I get it right every time.

• 18:06Chuck Nice?

  See, you, I am too busy for that.

• 18:13Neil deGrasse Tyson?

  Time is valuable too.

• 18:15Chuck Nice?

  Time is valuable, man. That is too much time thinking about time.

• 18:22Chuck Nice?

  However, that's a, that's a very good, uh, that's a good way to do it. You know what I mean? If you're, if, if you're in that discipline to do it that quickly.

• 18:29Neil deGrasse Tyson?

  Yeah, okay, so here's the thing. So you say, well, how do we even know you need one?

• 18:34Chuck Nice?

  Yeah.

• 18:35Neil deGrasse Tyson?

  Who, okay, so watch this, so watch. Uh, do you remember who was the first to circumnavigate the globe?

• 18:40Chuck Nice?

  Um, that was the man who went around the world in 80 days in that balloon.

• 18:49Neil deGrasse Tyson?

  That's the, that's exactly not the person I'm talking about.

• 18:53Neil deGrasse Tyson?

  So Ferdinand Magellan.

• 18:56Chuck Nice?

  Right.

• 18:56Neil deGrasse Tyson?

  Okay. Uh, this is after Columbus and after a bunch of other voyages to the new world from Europe.

• 19:02Chuck Nice?

  Right.

• 19:02Neil deGrasse Tyson?

  Uh, he goes around the world and returns to the port that they sailed from.

• 19:11Chuck Nice?

  Wow.

• 19:11Neil deGrasse Tyson?

  Okay, and I think it was actually port in Portugal. But it doesn't matter for what I'm about to describe. So anyway, so they, they, they leave Europe and they head west.

• 19:22Chuck Nice?

  Mm-hmm.

• 19:22Neil deGrasse Tyson?

  There's a scribe on board named Antonio Pigafetta. Okay?

• 19:27Chuck Nice?

  Wow.

• 19:27Neil deGrasse Tyson?

  I think he was a wealthy, I think he was a wealthy nobleman, was not part of the crew, not, he was just went along joyriding, basically.

• 19:34Chuck Nice?

  Okay.

• 19:35Neil deGrasse Tyson?

  But he kept, but he kept very good records of what was going on.

• 19:39Chuck Nice?

  Well, it's, it's easy to do when you don't have any work to do on the ship.

• 19:44Neil deGrasse Tyson?

  Exactly.

• 19:45Chuck Nice?

  Everybody else is lowering the boom and hoisting a mizzen mast and you over there writing, writing it down. Isn't that lovely the way you did that? Oh, that was wonderful.

• 19:55Chuck Nice?

  The men.

• 19:57Neil deGrasse Tyson?

  Can you show me that again? That was so.

• 20:00Chuck Nice?

  What a knot, what a great knot. What do you call that knot? I'd like. I'd like very much to make a notation of that particular knot.

• 20:09Neil deGrasse Tyson?

  That was basically what this guy did. And he kept track of who died on board because disease would go through the crew. And at some point Magellan was killed by natives on an island that they arrived at. And so Magellan did not complete the voyage because he died. Okay, en route. But the ship made it, as so did Antonio Pigafetta.

• 20:35Chuck Nice?

  Of course, you know Antonio gonna make it, you know?

• 20:42Neil deGrasse Tyson?

  Alright, so, so here's what happened. So he goes west and you keep track of what's called local noon. Alright, so when is noon? It's when the sun is at its highest point in the sky.

• 20:54Chuck Nice?

  Okay.

• 20:55Neil deGrasse Tyson?

  Okay, and that's the middle of your day. And that whatever day that is, and he's marking these days on his calendar. Okay? And as they keep traveling and he's got, we have another day upon us. And there's the sunrise and sunset, there's quote local noon, alright? And he does this and he keeps track. And he's good at this, okay? He's a wealthy, educated Italian nobleman. And he's good at it, okay?

• 21:27Neil deGrasse Tyson?

  They come around the world and come back. And he thinks it's Wednesday and everyone there thinks it's Tuesday.

• 21:38Chuck Nice?

  Ah.

• 21:39Neil deGrasse Tyson?

  He can't believe it. He's, and he's writing, I think they're pulling a trick on me. That they want to fool me, that they want to fool me. Then he went to check other people and everyone says it's Tuesday, whatever day of the month it was. And he's still thinking it's Wednesday. And again, whichever days it is, but he has a different day.

• 22:01Chuck Nice?

  He has a different day, he's off.

• 22:02Neil deGrasse Tyson?

  He's got a different day, he's off.

• 22:04Chuck Nice?

  He's off by a day, he's off by a day.

• 22:06Neil deGrasse Tyson?

  He's off by a day and he can't figure it out. And he said, I kept very good notes. I don't know what happened here. And it's just sitting there in his notebook. The confusion of a nobleman's scribe.

• 22:21Neil deGrasse Tyson?

  And it is laid bare, the discovery of the need for an international dateline.

• 22:26Chuck Nice?

  That is.

• 22:27Neil deGrasse Tyson?

  That was the discovery.

• 22:28Chuck Nice?

  Fascinating.

• 22:29Neil deGrasse Tyson?

  Yes.

• 22:30Chuck Nice?

  That's fascinating, because there's no need for it unless you're actually going to make the trip.

• 22:36Neil deGrasse Tyson?

  Yes, that's exactly right. Do you and I give a rat's ass what's in the center of the Pacific Ocean?

• 22:43Chuck Nice?

  Exactly.

• 22:44Neil deGrasse Tyson?

  It doesn't matter, but if you're gonna make the next trip, you're gonna make that trip, you need to know it. And he discovered it by accident, which I thought was just so, it's the kind of things you discover when you're very good at, when you're very careful in your observations and in your data recording.

• 23:02Chuck Nice?

  Yeah.

• 23:03Neil deGrasse Tyson?

  He was being a scientist without even knowing.

• 23:04Chuck Nice?

  Without even knowing it, yeah. And then, of course, for weeks, he still walked around like, come on, man, seriously, what the? Come on. Come on, you can tell me.

• 23:15Neil deGrasse Tyson?

  Stop messing with me.

• 23:15Chuck Nice?

  You can tell me now. It's just us here, come on, seriously. It's Wednesday, right? It's Wed- come on. How'd y'all all get in on this? How did, come on, who was? Was it, was it the king? Was it the king? Cause he said, he said, we'll not get back, right? Come on.

• 23:32Neil deGrasse Tyson?

  He told it to everybody.

• 23:35Neil deGrasse Tyson?

  He pinned up a broadsheet in the center of town and said, don't tell anybody.

• 23:41Chuck Nice?

  Exactly. Oh, man, that's funny.

• 23:45Neil deGrasse Tyson?

  So anyway, and of course, if you go the other way around the earth, you would be, you'd be a day behind. So, so the point is, if you go west, you're chasing the sun, because the sun sets in the west.

• 23:55Chuck Nice?

  Right.

• 23:56Neil deGrasse Tyson?

  Right, so if you're going in the direction the sun is, and so you are adding a whole day to your life as you go around that other people are not enjoying. And so, and so I'm just, I put it out there, I don't know how many people know that story.

• 24:11Chuck Nice?

  That is.

• 24:12Neil deGrasse Tyson?

  But it's, it's, it's in the notes of Magellan's voyage, kept by Anton Pigafetta, yeah.

• 24:17Chuck Nice?

  Pigafetta, that's one.

• 24:19Neil deGrasse Tyson?

  Pigafetta.

• 24:20Chuck Nice?

  Pigafetta, what a great name.

• 24:21Neil deGrasse Tyson?

  Oh, by the way, if, um, his, clearly, there was no reason for there to be bias in those observations that he made. He's just checking local noon, sunrise, sunset, and he's counting days. But in other places in his writings, he talks about, there was a disease that afflicted the crew, and many of them died, and they had some natives from the island that they befriended and came on board. And when they die, if you die on a ship, you know, you know what to do with the body?

• 24:46Chuck Nice?

  Uh, I would say bury it at sea, cause you know, dead bodies are not, yeah, they're not very pleasant to be around, dead bodies.

• 24:54Neil deGrasse Tyson?

  Yeah, not on your ship.

• 24:55Chuck Nice?

  As, not on the ship, as they're rotting next to your food supply.

• 24:58Neil deGrasse Tyson?

  Right, exactly. So you toss it overboard. And there he writes carefully, and he says, oh, and natives and other non-Christians floated face down, and all the Christians floated face up.

• 25:14Chuck Nice?

  Mmm.

• 25:15Neil deGrasse Tyson?

  Towards heaven.

• 25:16Chuck Nice?

  That's cause they were going at, they're going at, first of all, how do you know what's in their heart? Ha ha, you don't know this, but guess what? I was actually a Jewish person. There you go. Mister Pig Feta, ah.

• 25:31Chuck Nice?

  Yeah, I converted. Yeah, now why am I floating face up?

• 25:38Neil deGrasse Tyson?

  So, you know, statistically, I guess that could have happened that way, or would the clothing do that? But he was deeply religious, as were so many European explorers back then, wanting to convert the world to not simply Christianity, but Catholicism specifically. And, and so this was a, this is also in his writings. So, basically, if you're gonna evaluate the work of someone who's an acute observer, you wanna ask, could they have a bias of any kind before you go into what it is they write?

• 26:11Chuck Nice?

  Right.

• 26:11Neil deGrasse Tyson?

  And if he's deeply religious, there could be a religious bias, you have to watch for that. But he's not gonna have a Tuesday, Wednesday bias, you don't expect that.

• 26:19Chuck Nice?

  Exactly. And by the way, I'm just saying, it's really not very much of an accomplishment for your particular deity to allow your dead corpse, uh, there's no other kind of corpse, to float one way. See, the real deal would be like, we threw the Christians overboard, and they started to swim.

• 26:43Neil deGrasse Tyson?

  Well, they popped back up and landed on the deck.

• 26:46Chuck Nice?

  Praise Jesus.

• 26:47Neil deGrasse Tyson?

  Wait, or they never got sick in the first place?

• 26:50Chuck Nice?

  There you go. That's even better. You gotta be kidding me. Yeah, anyway.

• 26:56Neil deGrasse Tyson?

  I'm pretty sure they would have thrown you overboard. Whether or not you were dead.

• 27:00Chuck Nice?

  Let me tell you something, before we left port, my ass would have been thrown.

• 27:07Neil deGrasse Tyson?

  The kind of humor not accepted by, at, at, by, at the court gesture level, right?

• 27:11Chuck Nice?

  Let me tell you something, off with his head.

• 27:14Neil deGrasse Tyson?

  Alright, so that's everything you ever knew, wanted to know about the international dateline.

• 27:18Chuck Nice?

  That is so cool.

• 27:19Neil deGrasse Tyson?

  By the way, we, by the way, we could have put it anywhere in the world. But we had this convenient Pacific Ocean, which is one-third of all the world's longitude.

• 27:29Chuck Nice?

  Wow.

• 27:30Neil deGrasse Tyson?

  And we just said, well, let's put it there, but it has to line up with the prime meridian. So that, because it's the opposite of the prime meridian. And that all worked out because Greenwich, England, alright, if you extend the line around the other side of the earth, it goes right down the middle of the Pacific Ocean. And you gotta avoid some islands that are, oh, you, you don't want part of your country to be on a different day. So if you watch, you look at the, if you look at it, it, I think it has to accommodate Hawaii. It bends a little over to the side and comes back.

• 28:00Chuck Nice?

  It's got a little, okay.

• 28:01Neil deGrasse Tyson?

  It's got a little, a little, little, you know, some movement. Because it's, at the end of the day, do you really care what, you know, the precise location on earth?

• 28:11Chuck Nice?

  Yeah, especially if you.

• 28:12Neil deGrasse Tyson?

  The 24 time zones, the 24 time zones are highly fungible.

• 28:15Chuck Nice?

  Right.

• 28:16Neil deGrasse Tyson?

  I mean, the, the eastern time zone is not exactly where the line would be. You include the states that want to be part of that club.

• 28:22Chuck Nice?

  That want to be part of that, yeah.

• 28:23Neil deGrasse Tyson?

  Right, right, and hardly anybody lives in the mountain time zone.

• 28:26Chuck Nice?

  And, and why do we have it? Why, why do we have mountain time?

• 28:29Neil deGrasse Tyson?

  Look, the people have their mountains.

• 28:31Chuck Nice?

  Colorado, I'm sorry, but why do we have mountain time?

• 28:35Neil deGrasse Tyson?

  Stop, stop.

• 28:36Chuck Nice?

  You just.

• 28:36Neil deGrasse Tyson?

  Okay, so what, what I'm saying is that has the lowest population, right? And so, uh, it's also very narrow. So I, I, I don't know if it's a TV, uh, schedulers, whatever.

• 28:49Chuck Nice?

  That, that's.

• 28:49Neil deGrasse Tyson?

  You know, they give the time, a- and then the slash central time, right?

• 28:53Chuck Nice?

  Right.

• 28:53Neil deGrasse Tyson?

  So that main time is east coast, west coast, and then central time, they don't get, they, nobody reports mountain time.

• 28:59Chuck Nice?

  Nobody reports mountain, that's why I wonder why they have it. No, because.

• 29:03Neil deGrasse Tyson?

  Did you notice they don't report mountain time? They, they, they, they have to adjust on their own.

• 29:08Chuck Nice?

  Who's there? No one's there, that's why.

• 29:10Neil deGrasse Tyson?

  Yes, there are a few people live in mountain time.

• 29:13Chuck Nice?

  Yeah.

• 29:13Neil deGrasse Tyson?

  There are a few people, I know, the same as like the 20 mile radius of Manhattan, right? But still, people live in mountain time, the same, Montana. Utah, Colorado, Arizona, New Mexico. All right.

• 29:28Chuck Nice?

  Whatever.

• 29:29Neil deGrasse Tyson?

  There it is.

• 29:33Neil deGrasse Tyson?

  Mountain Time people, send all your hate mail to Chuck.

• 29:36Chuck Nice?

  How about this, Mountain Time people? Get a new time zone. There you go, and then we won't have to have this conversation. You won't be mad at me. I'm doing you a favor.

• 29:48Neil deGrasse Tyson?

  Thank you, Chuck. All right, that's the, we're done here with the international dateline. Oh, by the way, a quick one. There was a TV show, I forgot what network it was on, Zack and Cody. Okay, it was like a-

• 30:01Chuck Nice?

  It was like Nickelodeon or Disney or something like that.

• 30:04Neil deGrasse Tyson?

  One of those, Disney or Nickelodeon, they had an episode where they,

• 30:10Neil deGrasse Tyson?

  they were on an ocean liner that crossed the international dateline. And they turned it into like a, like a Groundhog Day, reliving the incident. So every time it went across, it's like the-

• 30:22Chuck Nice?

  It would reset.

• 30:23Neil deGrasse Tyson?

  Ship flipped back and forth, it reset, and then they, all the events are happening again and they got to replay it. So people think magical things happening there, but it's a completely arbitrary place where we put it.

• 30:33Chuck Nice?

  Nice.

• 30:34Neil deGrasse Tyson?

  We could have put it right down the middle of Manhattan if we wanted, but that would have just been weird. I'll see you next Tuesday, yeah.

• 30:42Chuck Nice?

  That's a whole nother dateline.

• 30:45Neil deGrasse Tyson?

  I guess so. Very good, Chuck. All right. We gotta take a quick break, but when we come back, the third and final installment of this episode of StarTalk, Things You Thought You Knew.

• 31:12Neil deGrasse Tyson?

  We're back for the third and final segment of Things You Thought You Knew. So Chuck, I'm an acute observer of airplanes, air traffic, airports.

• 31:25Chuck Nice?

  Okay.

• 31:27Neil deGrasse Tyson?

  I just think it's one of the great, beautiful things of civilization that we can fly.

• 31:33Chuck Nice?

  Yeah.

• 31:33Neil deGrasse Tyson?

  And I bet if you ever seen a 747 take off, you're thinking to yourself.

• 31:37Chuck Nice?

  I have.

• 31:38Neil deGrasse Tyson?

  Oh, my gosh. This thing flies.

• 31:40Chuck Nice?

  Oh, God, yes.

• 31:41Neil deGrasse Tyson?

  Right. The 300-ton aluminum, or however much it weighs, the thing flies. And it looks like it's in slow motion when it's flying. That's even more.

• 31:49Chuck Nice?

  It does.

• 31:50Neil deGrasse Tyson?

  Stunning, right?

• 31:50Chuck Nice?

  Amazing.

• 31:51Neil deGrasse Tyson?

  Amazing. Okay.

• 31:52Chuck Nice?

  And the fact that it's like, looks like it's three stories tall.

• 31:56Neil deGrasse Tyson?

  Right, right. Inside, yeah, yeah, yeah.

• 31:58Chuck Nice?

  Inside, yeah, it's crazy. I mean, it's just crazy.

• 32:00Neil deGrasse Tyson?

  Right. So, I just wanted to update you on some things that have happened slowly that you might not have noticed. All right. So, airplanes today, when they leave the runway, typically take off at a steeper angle into the air than they once did many decades ago.

• 32:22Chuck Nice?

  Well, I didn't know that.

• 32:24Neil deGrasse Tyson?

  But so, the engines have enough power so they can accelerate at a steep angle without getting more horizontal velocity to try to get the lift, okay? If you take off at a steep angle, the air can hit the wing and push it up with your engine. And so you get a lift that is, if the fuselage and the engines are done correctly for this, it can take off at a steep angle. What that does is reduce the acoustic footprint of the airport.

• 32:54Chuck Nice?

  That makes sense because you're not spreading it out over a larger period, larger distance.

• 33:00Neil deGrasse Tyson?

  Correct. Correct. So, it gets higher faster so that the sound is not disrupting whatever's going on on the ground. So you can sell real estate closer to the airport without the airport badly influencing those real estate values.

• 33:18Neil deGrasse Tyson?

  So that's one little thing that has changed over the years. The engines are more powerful to enable that. Not only that, the engines are quieter than they ever were. When I grew up, and I'm not that much older than you Chuck. This would have overlapped some of your day. If a plane flew overhead, you had to stop your conversation, let the plane continue flying, and then you continued your conversation. You could not speak over the sound of the engines. If a plane was flying overhead.

• 33:51Chuck Nice?

  Now, are you sure you didn't grow up next door to an airport? Cause that could have been the problem.

• 34:01Neil deGrasse Tyson?

  I distinctly remember this, okay? I can't impress upon you how much quieter jet engines are relative to even just a few decades ago. So you combine how much-

• 34:13Chuck Nice?

  I'm trying to figure out how that happens, though. It's still a jet engine, you're still sucking in a bunch of air.

• 34:19Neil deGrasse Tyson?

  Yes, yes, yes, yes, yes. No, no, you designed the cap, these engineers do this, okay? This is like, it's reducing noise pollution, alright? As we slowly reduced air pollution and water pollution and all these things that were big buzz terms in the 1960s and 70s, we made great progress across the board in all of these categories, okay? Did you know that in 1969, when the Mets were in the World Series, Mayor Lindsay redirected traffic from LaGuardia to not fly over the stadium? Because when planes flew over the stadium, everything stopped. The announcers couldn't speak. I remember this, that's how old I am, okay? I'm just saying.

• 35:02Chuck Nice?

  That's pretty damn loud. Now that, anytime a roaring, a stadium full of roaring people can be drowned out by a plane. And LaGuardia is very, very close to the, uh, that's, that's, that's, that's insane.

• 35:15Neil deGrasse Tyson?

  So, other, other little things you might not have noticed. Um, when was the last time you saw someone throw up on an airplane?

• 35:27Chuck Nice?

  Um, well, you know, every time I fly.

• 35:30Neil deGrasse Tyson?

  No, you're the one, okay, oh, except for you.

• 35:37Neil deGrasse Tyson?

  No, here's the point. Here's the point. There was a day when it was the duty of the pilot to sort of do what they can as they fly it to maintain the stability. And you'd have turbulence and you'd have things like that. There are control surfaces on the airplane controlled by computers that make micro-adjustments in the flaps that maintain a level of stability, the likes of which planes have never seen before.

• 36:07Chuck Nice?

  I know, yeah, yeah.

• 36:08Neil deGrasse Tyson?

  And so-

• 36:09Chuck Nice?

  That's funny. It's funny you say that, because the last time I flew, which was very, very short time ago, I was sitting in the chair thinking, "God, it is almost peaceful up here."

• 36:23Neil deGrasse Tyson?

  This is my point.

• 36:24Chuck Nice?

  This is my point.

• 36:26Neil deGrasse Tyson?

  Okay, but that's not my favorite part of this, of this, the airplanes. My favorite part is-

• 36:33Chuck Nice?

  Okay, okay.

• 36:34Neil deGrasse Tyson?

  And I might have said this in another, because I don't, this all just jumbles in my head. Here it is. You ready?

• 36:38Chuck Nice?

  Go ahead.

• 36:39Neil deGrasse Tyson?

  Okay. Have you ridden modern roller coasters lately?

• 36:43Chuck Nice?

  Oh, yeah.

• 36:43Neil deGrasse Tyson?

  So, a modern roller coaster, it's not, you're not in a, in a, in a cart with, with a thing.

• 36:49Chuck Nice?

  You're actually in an open airtight cockpit with just a harness over top of you, and that's it.

• 36:57Neil deGrasse Tyson?

  You're basically dangling there, okay? And when the thing makes the turn, your gondola swings out.

• 37:04Chuck Nice?

  Swings out.

• 37:05Neil deGrasse Tyson?

  To bank that turn. Have you, do you ever notice that?

• 37:07Chuck Nice?

  Oh, yeah, yeah, yeah, yeah.

• 37:09Neil deGrasse Tyson?

  Okay. Well, what's going on there? Oh, well, at the speed you're going, and the radius of curvature of that turn, the free-floating, uh, gondola, whatever you want to call this thing you're in- Will swing out to the precise angle where your effective gravity is still into your pants, into your seat.

• 37:35Chuck Nice?

  Okay.

• 37:36Neil deGrasse Tyson?

  Okay. All right.

• 37:38Chuck Nice?

  Okay, I, oh, oh, oh, oh.

• 37:39Neil deGrasse Tyson?

  This is important. Okay, so you're tipped at an angle, but you don't feel the angle because the combination of gravity and centrifugal force is such that you, your up or down is still straight into your seat and up above your head.

• 37:55Chuck Nice?

  Right.

• 37:56Neil deGrasse Tyson?

  Even if that's at an angle. Okay.

• 37:59Chuck Nice?

  That's true.

• 37:59Neil deGrasse Tyson?

  Okay, so whereas in the old roller coasters, they would occasionally bank the turn, but usually when you're making a turn,

• 38:06Chuck Nice?

  No.

• 38:06Neil deGrasse Tyson?

  you end up leaning into the person next to you. Like this.

• 38:10Chuck Nice?

  Yeah.

• 38:11Neil deGrasse Tyson?

  Okay.

• 38:11Chuck Nice?

  Yeah, which is, which is why often you needed a neck brace when you got off of the roller coaster.

• 38:17Neil deGrasse Tyson?

  Yeah, okay. Yeah, because it would totally disrupt your musculoskeletal structure because you're getting knocked around like this. If you ever noticed, even in the people who film themselves on these high-speed roller coasters, everyone is always in a straight line. There's none of this going on there, okay? So now, that's because the speed of the roller coaster and the bank of the roller coaster and the radius of curvature conspire so that you always have your net gravity vector straight into the chair. What I'm telling you is, on an airplane, they solve that equation. They solve that equation on an airplane. So, when the airplane banks a turn,

• 39:00Neil deGrasse Tyson?

  it does it at the speed and the bank angle such that you don't even know you're turning. Because everything is just vertical to you. You can have a glass of wine sitting there and the level of the liquid is perfectly horizontal to you and to the sides of the glass. Yet you open the window to the left or right and the ground is down here and the clouds are up there and then it does this and the ground is down there and the clouds are up there and your liquid in your glass of water, wine, or vodka is completely level.

• 39:34Neil deGrasse Tyson?

  That is, that the computer does that. Computers know how to combine that, so you don't even know you're turning. And so no longer do you lean into one way or another when the, when the plane is banking. So this adds to the stability of your entire plane flying experience.

• 39:50Chuck Nice?

  This is very cool. Um, what I am gaining from this discussion is a brand new appreciation for computers.

• 40:00Neil deGrasse Tyson?

  Okay.

• 40:04Chuck Nice?

  Planes aren't really that cool. It's the computers that are cool, man.

• 40:08Neil deGrasse Tyson?

  They're figuring all this out to give you the smooth ride.

• 40:12Chuck Nice?

  Smooth ride, quieter ride, less, you know.

• 40:15Neil deGrasse Tyson?

  So all I'm saying, so the way to do this is try to get the people to your left and to your right to open, when you're nearing the airport, um, cause when you're more likely to turn to line up for the runway, have both sides lift up their, their windows and put a glass of water right in front of you. Okay. If you can still have it at that, unless they, they didn't take it.

• 40:34Chuck Nice?

  They're not gonna let you do that.

• 40:35Neil deGrasse Tyson?

  But yeah, it's right in front of you.

• 40:37Chuck Nice?

  Then again, wait a minute, I'm, I forgot you fly first class.

• 40:40Neil deGrasse Tyson?

  No.

• 40:40Chuck Nice?

  So you still, you still might be able to get a glass of water.

• 40:44Neil deGrasse Tyson?

  Okay. So it's there and it's just watch the level around the rim. And then look to the left and right, and as the plane turns, nothing happens to that water level. Even though the plane is tilting to bank the turn that it needs to come in for a landing. This is a, this is, this is a, and by the way, you do this in a physics class. You can ask, what is the speed? This is how you determine what the bank of a track is. All right? If you're gonna bank a track for something you know is going 150 miles an hour, then you can know what bank and what radius of curvature and all those numbers come together. So that if you're in the car, you don't feel yourself being pushed to the left or right. So I, this is all in airplanes. I mean, it's, I love airplanes.

• 41:28Neil deGrasse Tyson?

  They're, they're brilliant and beautiful things.

• 41:31Chuck Nice?

  I, I, I, I listen, I, I, I, I don't disagree. I just love computers more now. That's all I think.

• 41:39Neil deGrasse Tyson?

  I'll tell you something else. One last thing here before we land this plane. See what I did there? So there was a day when computers were still new, you know?

• 41:50Chuck Nice?

  Yeah.

• 41:50Neil deGrasse Tyson?

  There was an old saying, they say, to air is human. To really foul things up requires a computer.

• 41:58Chuck Nice?

  Well, that makes sense.

• 41:59Neil deGrasse Tyson?

  So in the day, yeah, you'd make a mistake, but a computer will make the mistake a thousand times before you caught it, right? So to really foul things up. In that mindset, they ask people, do you want a computer flying your airplane? Suppose something happens to the airplane and something bad happens and, and you have to land the airplane. Who do you want? What do you want to land the airplane? A computer or a trained Navy pilot? Okay? And almost everybody said a trained Navy pilot.

• 42:30Chuck Nice?

  Of course.

• 42:30Neil deGrasse Tyson?

  But I was early out of the box and I said, the computer.

• 42:35Neil deGrasse Tyson?

  But, but back then that might've been a controversial answer. Today, the computer's already doing it, all right?

• 42:40Chuck Nice?

  Yeah, that's for sure. Some airline is gonna try to tap you to be a spokesperson, bro. I'm letting you know that right now. Some, United, American, somebody's coming after you. JetBlue, you know. It won't, it won't, it won't be Spirit because you, you know, everything you just said, none of that happens.

• 43:01Chuck Nice?

  On Spirit. None of what you just said happens.

• 43:05Neil deGrasse Tyson?

  All right. This has been StarTalk, Things You Thought You Knew Edition. Chuck, always good to have you.

• 43:10Chuck Nice?

  Always a pleasure.

• 43:12Neil deGrasse Tyson?

  Neil deGrasse Tyson, keep looking up.