StarTalk Radio - Things You Thought You Knew - Timeline of the Universe

Episode Date: August 26, 2022

How far back in the universe’s timeline can the JWST see? Neil deGrasse Tyson and co-hosts Chuck Nice and Gary O’Reilly explore the Coriolis Effect, hurricanes, the gridiron timeline of the universe, the physics of spinning objects, and much more!NOTE: StarTalk+ Patrons can watch or listen to this entire episode commercial-free here: https://startalkmedia.com/show/things-you-thought-you-knew-timeline-of-the-universe/Photo Credit: NASA/GSFC, MODIS Rapid Response Team, Jacques Descloitres, Public domain, via Wikimedia Commons Subscribe to SiriusXM Podcasts+ on Apple Podcasts to listen to new episodes ad-free and a whole week early.

Welcome to StarTalk, your place in the universe where science and pop culture collide. StarTalk begins right now. This is StarTalk, the Things You Thought You Knew edition. I got Gary O'Reilly. Gary. Hi, Neil. All right, over from Sports Edition. And of course, Chuck. Hey, man. Chuck is my explain. Gary. Hi, Neil. All right. Over from Sports Edition. And, of course, Chuck. Hey, man.

Chuck is my explainer man. We got this. Yeah. We got this, Chuck. So, you guys called me into this, Gary. Yes. What do you want me to do? What are some things you thought you knew, but maybe you didn't, and so here I am.

Your assignment, Dr. Tyson, if you choose to accept it. That's what that is. And this tape will, etc. So, there are some very, very big scientific names attached to things. And then all of a sudden, you find they appear. Their theories, their principles appear in places. Well, you know what? I never knew that was the case.

Now, if we took the great and the good Coriolis and then said to you, field goal kick, I think you would have a thought. I indeed would and do. So, but we should talk about the Coriolis force. Yes. First of all, okay okay it's not really a force in fact we officially call it a fictitious force it feels like you're a force if you're in the middle of experiencing it okay but it's not actually a force okay pure and simple okay okay so it's what happens if you try to move in a straight line on something that's rotating.

Aha. Then your path on that rotating object is not a straight line, even though you swear you're moving in a straight line. Aha. Okay? So, take, for example, a spinning platter. We used to call those record players okay oh nice you could so spin it you know put it at 33 and a third rpm and take a little chalk and start at the edge and make a straight line to the spindle if you do that and then stop the thing and look at what your chalk line did, it will be this curve from the edge of the platter to the center. Right.

So if you are on that platter, you would say there's some force pushing this chalk in a direction that's to the side. Okay. This is how you would interpret what you saw. And so you would invoke, you'd say there must be a force. Okay. This is how you would interpret what you saw. And so you would invoke, you'd say there must be a force. Right. And in this case, we would call that the Coriolis force. Meanwhile, there's no such force acting on the system. So that's what's going on there. So this would happen to anybody trying to do a straight line or any kind of path on something that's in motion. If you try

to do it on a merry-go-round, okay, you could try to walk on a straight line, but it's not going to work relative to the merry-go-round. So that's all it is. No, you'll also look like a drunk person. Yes. I've tried it. I've tried it. You've tried it.

But wait, Chuck, it was stationary when you did it. Alright. drunk person yes i've tried it i've tried it you've tried it you've tried it but wait chuck it was stationary when you did all right so the perhaps the most common invocation of the coriolis force is that which forces winds on earth to curve into storms. Aha. Oh, no. Okay? So there's an air, you know, air moves, okay, on Earth's surface. Uh-huh. But Earth's surface is rotating with the solid Earth. So here I am, and I see a low-pressure system.

Right. And I'm a nice puffy cloud. Okay? And if I see a low-pressure system, I'm going to go towards the low-pressure system. Because that must mean there's a higher pressure behind me. And I get pushed into the low-pressure system. Okay? And I'm going to make a beeline for it. Or a cloud line for it.

Okay. So, there I am. But wait, if I'm going north to meet my low pressure system and I'm a cloud south of it, we're in the northern hemisphere now. Wait a minute. As I go north, I find myself overtaking the low-pressure system because my sideways motion is faster where I started from than where the low pressure is. And we've done this before.

The equator is moving 1,000 miles an hour sideways. And if you're up at northern Florida or D.C. or in New York, you're moving slower from west to east than the equator is. Yeah, you're all part of the same solid object, yes, but you complete one circle in the same amount of time as folks at the equator do, and they travel a longer distance to do it. So, therefore, you must be traveling more slowly.

They must be traveling faster than you. Here's the point. I'm a cloud birthed near the equator. I'm going sideways 1,000 miles an hour. Now I start marching north. I'm not touching the earth. I'm floating in the atmosphere. And I see the low-pressure system, and I find myself overtaking it,

and I end up veering to the right. And by the same token, a puff of cloud north of that low-pressure system, it too wants to reach the low-pressure system, except it's traveling slower than the low-pressure system. So it goes south, and it lags behind. So all the air migrating north ends up ahead of the storm, and all the air going south ends up behind the storm.

You put all this together, you get a counterclockwise circulation around the low-pressure system, otherwise known as a storm, because the cloud carries moisture. And if you're a cloud magnet, all right, and low-pressure systems nucleate storms for this reason. So what speed do I need to do, Neil, to overcome a Coriolis force?

45. You have to stop instead of 33 and a third. Oh, well played. I got you. I got you. I got you. That's cool. Oh, the 78? You don't want the 78?

You all have some old farts there on the other side of this call. So the point is the storms have so much weather going on in them because all the weather is trying to get to the low pressure system. And the low pressure system is the center of the storm. That's why there's rain at a hurricane. Okay. Oh, and by the way, do you know about the eye of the hurricane? Maybe.

Yeah. Yeah. Maybe. I'm not going to say something and have you tear me to pieces, am I? Chuck, that sounds like a no, right? Do you know what's happening? Well, I think I do. Nothing.

So the eye of the hurricane is completely clear. Right. No rain, and it's perfectly quiet. Okay? And I saw a movie called Marooned. It was a 1960s pre-moon landing movie, but we knew we were headed there. So we, Hollywood started making movies about this. So they're astronauts who were marooned in space. I don't

remember why. And we got to save them. All right. So there's another launch vehicle that this is in Florida. Florida likes hurricanes, don't they? Yeah. Okay? So they're ready to launch the rescue vessel because they're running out of oxygen, but they can't launch it because a hurricane is coming because then they'll put the other astronauts at risk. So everyone's giving up hope on this rescue mission until someone points out, wait a minute, the path of this hurricane

goes right over Cape Canaveral. Oh. So. How about that? How about that? So we can launch right over Cape Canaveral. Oh. So. How about that? How about that? So we can launch right over Cape Canaveral when all the weather dies down. So I was like nine years old or something. I said, that's kind of cool.

And so from then on, I was highly intrigued by hurricanes. Yeah. That this could happen. Here's the problem. The hurricane would have ripped apart the rocket before it got, you got to get it from the outside of the hurricane to the eye of the hurricane. Oh, no, no, no, no, no, no. So it's...

The spaceship is attached to the gantry. It's fine. Okay. It's fine. And it's round, so it's not like a... So it's not like a building

where it's going to be ripped apart. It's aerodynamic. It's fine. Okay? Okay. It's fine For that purpose We should all build houses Shaped like rockets

With gantries And we'll all be hurricane proof I'm not going to volunteer To test that theory There's probably some wind speed That would knock over a rocket Oh by the way The rocket that they worried Would get knocked over in the movie The Martian.

Right. Right. That's why they left Mark Watney on the ground. Right. So he's probably dead. We better take off now before this dust storm on Mars knocks us over. The storm's going to kill us, right? Ground us.

Kill us. So let's leave him, give him up for dead. And of course, he was alive. But the atmospheric pressure on Mars is one one-hundredth but but the atmospheric pressure on mars is one one hundredth that of the atmospheric pressure on earth one one hundredth oh so if you have a hundred mile an hour wind on mars there ain't much air there doing it yeah it's like an infant going yeah exactly yeah thank god that's it and so they could have so easily waited and then saved Mark's ass, but they didn't.

They just left that boy to die. Anyhow, so... And he was a scientist, so you know what he said. Y'all just left me. Because you don't think I know what the atmosphere pressure is here on Mars? You're not getting that by me. I'm not going for it.

I'm not going y'all left me and you know it. I'm going to try to play y'all know the atmospheric pressure wouldn't have toppled you over. Yeah, I don't want to hear it.

All right. So here's the thing. Because all of this air has sideways motion to the center of the low pressure system. It never actually reaches the center.

That's why it's clear in the center. It's a fascinating fact. Okay? That's why. It never actually gets there. So, where were we? So, that's how you get hurricanes. Yes.

If you repeat that scenario for the southern hemisphere, then what you find is that the forces operate such that the storm rotates in the opposite direction. So, storms in the southern hemisphere rotate clockwise. Storms in the northern hemisphere rotate counterclockwise.

When I say storms, I mean low-pressure storms. By the way, air circulates the opposite way for high-pressure centers. But because the air wants to leave, it will still circulate. But since high pressure systems repel clouds, no one thinks of them as a storm. But it's essentially a high pressure storm. Have you ever been completely cloudless days and it was very windy? Yeah. That's what you're experiencing.

Okay. Yeah. That's what you're experiencing. Okay? You're experiencing air escaping away from the high-pressure system, gaining speed relative to you on the rotating Earth. So, yes, you can have high winds with no clouds because the clouds are not collecting. If they're not collecting, you don't have rain or storms or hail or anything.

You call them windstorms when the winds are high enough. You can have them, right, and they'll knock stuff over, but not because it carries precipitation. That's all. Turns out, I'm watching a football game. I'm watching a football... It was like a quarter to six on a Sunday,

and I finished watching some show. I forgot. No, it was another football game, and I have a show coming on at 6. And I'm channel surfing. And I came upon the Cincinnati Bengals playing somebody. Was it, who are the Seattle folk? The Seahawks. Seahawks.

I think it was the Seahawks. It was definitely Cincinnati Bengals. Okay? And right at that time, I tuned in. It was a tie. And the game ended. So they went into a full period overtime. Okay. Now, you know the rules. I think they've even changed since I last memorized them, but each team gets possession. All right. And if they score a field goal, the other team gets a chance to score a field goal. If nobody scores with each possession,

other team gets a chance to score a field goal if nobody scores with each possession then it's sudden death okay that's the state of this game at the time in the 15 minutes that i watched so it's sudden death overtime at this point cincinnati has the ball they're at the 50 yard 45 yard line plus 10 yards or whatever whatever is the hike with the kick, they had to make a 55-yard field goal. And if they make it, it's for the win. If they don't, the game continues. But they could win it on this kick. So I'm watching this.

And the kick, it goes up. And it tumbles. This is where no one breathes, okay, in the stadium. Nobody breathes. And you see the stadium. Nobody breathes. And you see the ball tumble. And it's tumbling. And there it goes. And it hits the left upright and careens in for the score.

And the Cincinnati Bengals win. And I said, wait a minute. Hold on. And I did a fast calculation. It was airborne for like three and a half seconds, something like that. I did the math. I checked the orientation of the stadium.

The stadium is oriented north-south. And I said, oh my gosh. The Cincinnati Bengals for the win field goal kick was aided by a third of an inch deflection to the right. Yeah. Caused by the rotation of the earth. People lost their minds. I tweeted it.

People lost their mind. People wrote in and say, God help Cincinnati win. I know that kicker loves you. The kicker was just like, the earth hates me. Well, because you know from baseball, if you take a round object

and hit it with another round object, alright, a fraction of an inch can make all the difference in how the thing bounces away from it. Absolutely. Alright, so you have a round bat hitting a round ball, a cylindrical bat, but it's still round and it's cross-section,

hits a round ball, a fraction of an inch is a ground out, home run, or a pop out. Okay? Same is true with a round football hitting the cylindrical upright. So, I think that third of an inch made a difference,

and that's how much Coriolis force operated in the 55 yards of the field goal. Well, the Coriolis owes a lot of people some money. Because you know everybody who had money riding on that game. You're checking the bets. They were just like, how did we find this Coriolis? Now, just because I'm an educator,

I said the rotation of the earth, but I didn't mention Coriolis. Because if you label it, then people get distracted by the name and it prevents them from understanding the concept. Okay. So I said from the rotation of the earth. Well, how does that happen?

The next two tweets, I said this is like the Coriolis force and then I mentioned storms and this sort of thing. So now for all north-south oriented stadiums, I watch for this when that happens. So there you have it. Coriolis for us on storms and football games and putting chalk on old-fashioned record players playing at any speed at all, Chuck. Yes.

You got it. Cool. What that is. Yeah. All right. So is that enough for you there, Gary? That works. Thank you.

Okay. I just live enough for you there, Gary? That works. Thank you. Okay. I just, I live to please you, Gary. Don't put chalk on my records anymore. Okay. That's all I'm just going to say. I think when we come back, Gary's going to hand me another topic in the world of things you thought you knew on StarTalk. So let's see when we return. We're back.

StarTalk. Things You Thought You Knew. So here I want to talk about the gridiron timeline of the universe. All right. Okay. So, what's that about? It's really small because football started

in like 19 what? You know? Okay. So the gridiron timeline is only like what? 75, 80 years old? Yeah, that ain't what I'm talking about.

Oh. Plus you're in a fog. You're in a COVID fog. And the field's only 100 yards long. So I'm guessing we're going to stretch stuff here. Plus Chuck is in a COVID fog. in a covid and the fields the fields only 100 yards long so i'm guessing we're going to stretch stuff here plus chuck is in a covid yes all right so so here's how it goes you take the the age of the universe which is about 14 rounded to 14 billion years okay and

you can ask how do you think about that how do you yeah how do you measure ask, how do you think about that? How do you measure that? How do you? And so. Because honestly, you can't even think. Nobody can get their mind around 14 million. Much less. Much less than 14 billion. Correct.

Okay. Or 14,000. Yeah. Well, in years, we can never really think about what 14,000 years are. Right. Right. It's outside of, that's called deep time. And no one even thought anything in the universe was as old as that until relatively recently.

Right. Right. In the last 150 years or so. Yeah. So, think of all of the history of civilization and what our understanding was about time. Part of the problem is we think time intervals are, you know, somehow, cosmic time intervals somehow matter to human time intervals. Right. And they don't.

At all. The universe don't care. Nope. The universe don't care. Nope. The universe don't care. We have other indications of time scales that are different. For example, that of a dog. Right. You come home, the dog is jumping, licking you in the face, happy to see you.

And all you did was forget your keys. You were just there a minute and a half ago. Came back from the mailbox. So the dog is so fully living life. Think about that. Wow. No, humans don't carry on. Dogs do.

Yes. Yet every day a dog lives is like seven days to a human. Wow. Now I have another reason to be jealous of dogs. You can say that both ways. You can say one day unto a human is seven days unto the dog, right? Because we live seven times as long as a dog. But I'd rather think of it the other way,

that the dog lives seven days of life in one of your days. Wow. And that's why it'll sleep when you're not there. But when you're there, it is all up in your face, begging for your food, even though it just ate, looking all cute, wanting to get pet, get his tummy rubbed. So these are two very different time scales, and the life forms are reflecting that, I think.

That makes sense, because you go, you take them out for a walk in the morning, and then when you come home from work, they're just like, you know, let's go, let's go. Let's do it. Yeah, come on. Let's go, man. It's been three days since you lost me.

What is your problem? How could you leave me here for three days, man? Because that's half of one day. Right, right. The morning to evening. Chuck did the math on that one. See, the thing is, you've got insects that have a lifespan

of maybe 24, 48 hours. Yeah, I think they may fly. Yeah. At least legend has it. Right. Yeah, that's just unfortunate. There you go. Wait, did you see,

it was a Saturday Night Live skit of when it came out that Wilt Chamberlain had like thousands of lovers yeah okay in his biography and no one believed it but it's like but you're not wilt chamberlain right so who who you say it wasn't so saturday night live did a skit and it was called the love diaries of wilt chamberlain it's so funny so he's in a hotel room and a woman shows up. And it's like our eyes met and it was love at first sight. Where has she been my whole life?

I don't know. Our moments were so tender and so soft. And then it says six minutes later, we began to grow apart. That's funny. later we began to grow apart that's funny every every every five minute encounter had a full relationship yeah relationship that's pretty cool in and out of the yeah it was anyhow so time scales you want to try to get a sense of them and usually have to do that by putting them into another kind of reference frame so one way to do it is if you take 100 meters, let's say, right? It's a little longer than 100 yards. It won't make much of a

difference for what I'm about to describe. So take 100 meters. That's more international to think of it that way. And we can ask, if the timeline of the universe were placed onto those 100 meters, where would things happen on that field? Okay? And I guess, you know, the gridiron football, they mark out the 100 yards. So let's go back to yards here. Okay.

100 yards. Let's map 14 billion years into 100 yards okay big bang is right at the beginning at one end zone okay right and let's keep walking down you have to go 10 20 30 40 50 60 70 now it's going it's counting down to like 40 to 30 you got to go to the opponent's 30-yard line before the solar system is born. Wow. The universe has spent nearly two-thirds of its life without the solar system. To this day, there are religious people or people motivated by religious philosophies

who say that the conditions in the universe are just right for life. Just right for human life. Because had any of these parameters been different, then we wouldn't be here. So it's perfectly tuned. And I'm saying, if two-thirds of the history of the universe, there was no solar system, what does it mean to say that it was perfect for life? That sounds really inefficient. See, if it was perfect for life, you'd have life going right away.

But no, you have to slowly make the heavy elements from the light elements. All that happened in the first three minutes. Okay, well, you made hydrogen, and then you start making stars after the dark ages. The James Webb Space Telescope is exquisitely tuned to look just at the end of the dark ages in the early universe where we had matter and energy, but no stars yet. They had to be made and then assemble into galaxies and have enough of these to make enough heavy elements to make planets because planets have a lot of heavy elements in them, and they're made in the centers of stars.

That takes time. We are a second, third generation star system that made the sun. And we see stars being born today, looking deep inside gas clouds. And those stars have planets in orbit around them, all of them made of the heavy elements that occurred later. So you got to get to your opponent's 30-yard line before you even see the solar system. Now you keep trudging along. You'd say, well, when did life kick in?

Life kicked in pretty quickly after Earth cooled down. Take a few steps. You have evidence, earliest evidence of life on Earth. Microbial life. How about life that looked interesting? How about anything such as that? Okay.

Well, you got to get down to the four-yard line. The four-yard line, single-celled organisms become multi-celled organisms. And the multi-celled organisms become multi-celled organisms and the multi-celled organisms can do things like they have legs and antennae and and eyeballs or early early versions of eyeballs sensory sensors of what is happening in their environment that's at the four yard line the four yard line keep walking you walking. You keep going. You keep

going. Now, what? Okay. Well, when do we get to human civilization? How about just civilization? Now, how about, no, forget civilization. How about just cavemen? Okay? Troglodytes, which is the gender-neutral version of cavemen. Cave dwellers. How about, where are they?

Cave dwellers appeared at the near side of the thickness of a blade of grass at the zero yard line. So right before the next end zone, you are one thickness of the blade of grass towards the end zone to find cave dwellers. Cave dwellers, correct. We're in the goal line. Yeah. You are one thickness of the blade of grass towards the end zone to find cave dwellers. Cave dwellers. Correct. We're in the goal line. Correct. And now you move your way through the thickness of that

blade of grass and find, okay, the development of agriculture. That's like, that's two-thirds of the way, two-thirds of the way through the thickness of the blade. Agriculture. Then you keep going, okay? And then you get, like, Moses.

Go half again through what remained of that. You get Moses and then Jesus and then Muhammad. All of this in the last one-third to one-tenth in that range of the blade of grass that is at the end zone after you travel the hundred yards to get there. It's fourth and a tenth of a blade in grass. We're not sure. Is he going to go for it? Apparently, the coach doesn't have a lot of confidence in his offense. They're going to kick.

It looks like they're going to kick the field goal. They only made it to trial and error. They can't make it. So what's the theory, Neil, when things move like that, that all of a sudden just completely accelerate at a ridiculous speed, comparative to what we've experienced

through that time? Well, so what happens is, what civilization did and the discovery of science as a tool to shape civilization, we can have rapid progress. Or if you don't want to value judge the inventions of science, we can say we have rapid change. Yeah.

You know, 110 years ago, horses was the way to go. And 100 years ago, you couldn't give away a horse. That was a very fast change, especially in cities. Agriculture take a while before they had good tractors. But point is,

yeah, you can have change because it happens quickly. It's sort of hidden in this timeline. You have to like zoom in and expand it, zoom in, expand it, zoom in and expand it. And only then do you get to see what's going on in our timeline. You have to like zoom in and expand it, zoom in, expand it, zoom in and expand it, and only then do you get to see what's going on in our lives.

In all fairness to the change with horses, it was motivated by poop. So, I mean, that will speed things up. Horse manure. Horse manure will speed some things up.

Right, because there were no pooper scooper laws. That's right. That's a lot of mess. Horse manure. Horse manure will speed some things up. Right, because there were no pooper scooper laws. That's a lot of mess. If your horse dropped some dump. That was it. You didn't get off and clean that stuff up. That's it. They didn't have central park diapers.

They didn't have those. They didn't do that. You just stepped in some steaming horse. There you go. If you came behind. So, Gary, you'd have to zoom in. Yep. Steaming horses. There you go.

If you came behind. So, Gary, you'd have to zoom in on this timeline to see where we are in our modern civilization, which has been so significantly touched by the progress of science. So, I get that. The point of this exercise, however, is to see what we are relative to the universe. E.

And for those who say, oh, the universe was created just for us. And all these stars are just for me. And the people or Mercury is in retrograde and Mercury is affecting my life. Really? Really? Look at this universe. Look at how big it is. Look at how old it is. Look at how many stars are in it. Really? And so this transformation of a timeline into a distance line, I think,

is one way to gain perspective on this. And of course, we did something similar to that in Cosmos, And of course, we did something similar to that in Cosmos. First done in the original Cosmos with Andrewian co-writer with Steve Soder and of course, Carl Sagan. They have what's called the Cosmic Calendar. What they did was there was they took time and they put it into time, right? They took the history of the universe and laid it from January 1st to December 31st. Okay. And so that's a little different. We did time into a distance.

They did time into a time. Why did they do that? Because we have words for those time units. We have things called months. We have a year. We have months. We have weeks. We have days.

We have hours. We have minutes. We have seconds. So because we have ready-made vocabulary to describe much smaller units of time than a year, it became very helpful to represent it in that fashion. So it's a matter of when was civilization just like a minute ago or two, I have to recalculate that to get the numbers right. But we have words for this. And when was the automobile invented? Like a fraction of a second into the past. Yeah.

And you say, damn, we haven't been here any amount of time at all. So, the things like the James Webb Telescope, will that make us think about the calibration of time and the universe in a different way? Or just it literally enlighten us as to what happened? That's an excellent, excellent question. So, okay, so the James Webb Space Telescope, I just did a fast calculation in real time,

will go back to the seven-yard line. Oh, wow. Now, the real question is, who's returning this kickoff? Because that will make a big difference in how long that timeline really is. Yeah. But think about it. I mean, it's a lot of universe between one end zone and the other. Right.

But what that means is we will have access to almost the entire playing field, almost the entire timeline of the universe. From seven yards up to 100 yards, this is an extraordinary triumph of modern astrophysics enabled, empowered by brilliant engineers that enabled us to work with this telescope to begin with. All so that science can tell you,

you ain't so special. Science is really good at that. That's to tell you right now. What we really want to know is to be able to look in the other direction and predict the future, which we do with some, I can tell you about solar eclipses in 10, 100, 1,000 years from now, and what exact minute the sun will disappear as viewed from any point

on Earth's surface, I can do that, all right? Some other predictions are a little fuzzier, but still have real foundations to them, like humans are warming the Earth, all right? And that can melt the polar ice caps and flood our coastal cities. All right. Oh, you want to know what minute that will happen? The calculations are harder than it is for an eclipse to give you the exact minute that's going to happen. But I can speak statistically of the likelihood that storms are going to wash over your beachfront property. At a point not always mentioned,

the storms that take out resort beachfronts destroy people's rich people's second homes and in some other low-lying countries it destroys people's only homes so there's an important difference there and what's going on getting all green on you right here. Nothing wrong with that. It's good stuff. So there you have it. Gary. Well, thank you. Gridiron timeline. And it's some fast cut. You just take ratios.

It's an exercise in ratio taking. It's so simple, Gary. So simple. So all I did, just so I can tell you. So James Webb, space soldier, is observing galaxies maybe back to a billion years after the Big Bang. So, you take the ratio of 1 billion to 14 billion. All right.

And what is that fraction? Then you multiply that fraction by 100 yards. And that'll tell you how many yards you'll back at sea. I get about 7 yards. And you know why we don't have to do that? Because you did it for us. Yes. You don't like calculating?

It's fun with calculations. We probably don't have as much joy doing it as you do. Yeah. So, all right. That's our segment here. All right.

So, when we come back, we'll do one more of these. Yes. And then we'll call it a day. Yay. This is Star Talk. Things you thought you knew. We'll be right back.

Guys, we're back. Third segment of Things You Thought You Knew. And Chuck, you really do have COVID right now. I do. This is heroic. We need a medal. There was a thing I thought I knew, which was I thought I didn't have it. And then I found out. The thing I know now is that I do.

And all because of science. Because of science. I got to tell you. Yes. I'm glad to know you're not in the hospital. Yes. Because you're a vaccinated fellow. So what I want to talk about is the stability of rotating objects. Ah.

Yeah. The stability of them. There's a lot of applications to a lot of things. But let's look at Earth for a moment. And if you have some sport reference you want me to kick in later, I can probably figure out a way to... We utilize stabilizing spin

with just about everything. I mean, if you think of a golf shot when you're chipping out of the sand trap, if you think about a two-point shot where you're rotating and backspin... In basketball. Yeah, I mean, the spiral pass, literally, from a quarterback on a Hail Mary,

we use in soccer to hit one side of the ball so it will spin and rotate and give itself a true trajectory. So, yeah, this is something that manifests itself regularly in sport. Correct. So, what I think we talked about in a separate one of these is what effect spinning the ball has on its otherwise ballistic trajectory moving according to the forces of gravity.

Because then you have air forces pushing on it. Right. So that's one thing. I'm now just referring to a spinning object with or without air forces. Just what does it do for it? And a spinning object has its path stabilized because it's spinning oh i thought it was due to really good therapy

chuck every time i use the word stable you think it emotionally i gotta tell you yeah there's you can be physically stable. There's a reason. You could be physically stable. Brain fog again. Brain fog, yeah. So when you look at a perfect spiral thrown by a quarterback, the ball, its arc is true. You have this wind on it that'll have an effect. But if you don't have wind you know

exactly where that ball is going to land and from the arc that it has been given so knowing where it's going to land is the reliability of its arc brought to you by the fact that it's spin stabilized. Okay? So, in baseball, Chuck, what is the pitch where the ball does not spin? I think they call that the flubber pitch. No, that's the knuckleball. Knuckleball. The knuckleball does not spin. Have you ever seen a knuckleball?

No, I haven't. Okay. Yeah. I mean, now that we have the high-speed cameras in baseball, you can just see the stitching without not spinning, and there it goes. When you have a knuckleball, it is completely susceptible to the slightest breeze, the slightest gust of air, the slightest. We'll move it from its appointed path.

And that's why a knuckleball is notorious for pass balls. So, Chuck, tell Gary, because he's a Brit, what a pass ball is. I don't know. I guess it's where you confuse the pitcher. I mean, you confuse the catcher. Yeah, well, not on purpose. So, the pitcher throws the ball in a catchable way, but it's moving to the left, to the right.

So the catcher puts up the catcher's mitt where the ball should land, and then it lands six inches to the side, and then they miss the ball. A completely catchable ball that they could not track using their normal senses because the ball was not spinning and it was not spin stabilized. Ah. That is not to be confused with a wild pitch.

Right. Where no matter what the catcher did, they're not going to catch it. It's like three feet outside. It's in the stands. It bounces off the ground and it throws it in the stands. Those are wild pitches.

It went over to first base and hit somebody's mom in the head. That's a wild pitch. That is wild. And a little subtle point, a baseball subtle point, Gary, is the pitcher and the batter are in every play of every game. If the pitcher throws a wild pitch or the catcher has a pass ball, it is not counted as an error.

Okay. They handle the ball so much that you got to cut them some slack. Okay. So Earth. Yes. Okay. Is spinning in its orbit. Oh, by the way,

the moon is tugging on Earth. If you tug on a spinning object that is tipped, because you know Earth is tipped on its axis. Yes. Then it will precess. So Earth, you know, there's another word for precess. It's called wobble. Yes.

Wobble. You ever play with tops? Nobody does this anymore. You play with the top. I love tops. I love gyroscopes, things like that. You spin the top and as it slows down, it tips over and it begins to wobble.

Okay, that's because Earth is tugging on its center of mass, and in response, it precesses. This is a battle of forces going on with the rotating object, because the rotating object doesn't want to do what you want it to do, but as a consequence, it precesses. So Earth's precessional period is 26,000 years. So in other words, our North Pole is pointing to the North Star right now. 13,000 years from now, we are pointing in the whole other direction.

And you got to find other North Stars for us as that happens over the period of history that we've been even tracking this stuff. So now, not only are we precessing, we're also bobbing up and down. Okay? So we're tipped at 23.5 degrees now. But over time, our spinning axes will bob from like 21 degrees to 24 degrees. So we're back and forth up so the earth is twerking. forth up so the earth is twerking the earth is spinning processing bobbing and twerking and orbiting all at once all at once that's earth for you what are you saying is that that angle

likely to change i know what you've said there's a there's a 21 to 24 in fact that affects climate yes that affects climate that Yes. That affects climate. Because it tells how we are tipped towards or away from the sun at what time of year that happens. So, yes.

And when you combine all these factors, there's something called the Malkovich cycles, which is the long-term climate cycle that our best understanding tells us

is what gives us the periodic ice ages. I think you said Malkovich, not Milankovich. Milankovich. Do it a second. I'm thinking of the actor. It would be kind of cool, though. Thank you.

With the Malkovich. Okay. Get out of my head, Earth. I saw that movie. That was a great movie. Okay. So, yeah, so the Milankovich cycles. Thank you for correcting me there.

So, it turns out on Mars, it doesn't have, it's got two moons, but they're lame excuses for moons. Okay. So, I won't even count them as one. It has essentially no important moons, but Phibos and Deimos are smaller than the island of Manhattan. Okay. So, give me a break here. Okay. Phobos and Deimos are smaller than the island of Manhattan, okay?

So give me a break here. So it turns out the moon prevents it from bobbing too far, okay? And it's a restoring force to it. Mars has no such restoring force. So it would bob much more significantly in its variations, creating much more extreme climate on Mars than we want to go and live there. Some people want to go and live there. My favorite person who wanted to go live there,

I think Chuck was my co-host at the time. Chuck, remember this guy? He was signed up for the Mars One, one-way trip to Mars. And one of us asked him, so how does your family feel about this? And he said, my wife encouraged it. She's so loving.

She encouraged me to go on this one-way trip tomorrow. Fire the pool boy, buddy. So anyhow, I'm just, so have you ever done the experiment where you take a bicycle wheel and hold it on each side and then you spin it yes yeah have you ever done that

okay if you take a bicycle wheel hold it the ones in the physics labs have handles on them but your regular one won't but that won't matter

just grab it by I was going to say grab it by the nuts excuse me grab it by do exactly that grab it by the axle okay there you go aka nuts grab it by the axle Don't do exactly that. Grab it by the axle. There you go.

A.K.A. nuts. Grab it by the axle and then have someone spin it. Okay? While they're spinning it, I will ask you to just tip it. You will find that the spinning wheel is fighting you

to prevent you from doing it. And it's weird to feel this. Now, if you are on a spinning chair, like one of these boardroom nicely lubed chairs where you spin yourself once and you go three or four times around in one pump,

okay? If you have this spinning bicycle wheel and then you try to spin it, your body responds by taking some of the angular momentum of the wheel and giving it to the chair. So you try this. Just remove your front wheel or your bicycle.

That's the easy one. Hold it in front of you on a spinny chair. Lift your legs off the ground, of course. So lift your legs up and down like you're on a swing. And then have somebody spin the wheel just as fast as they can with their hand. And just try to tip it. Tip the wheel.

You will start spinning in the chair because you are a coherent system. Okay? Where all the forces have to balance out. And so anyhow, spinning objects are fascinating. Yeah. Not only for the Magnus effect that we spoke about in another show, but for the fact that you can be spin stabilized as you move through the vacuum of space.

And I love it. Oh, by the way, rifle bullets. Yes. They're spun up. In fact, that's what rifling means. Okay? If you rifle the inside of a gun, you are putting curves in it

that force this fast-moving bullet as it comes out to spin. And that stabilizes the bullet as it goes forward. Nice. There it is. There you go. Everything you wanted to know

about spin, stabilized, anything. Thank you. So, that's all we have time for, guys. That was fascinating. Yes. Yeah, and Chuck, you going to have COVID next time? Are you on the mend? There's no more COVID left for me to get.

I'm at a ball. And you put your mark on those strains, right? That's right. It's like Chuck has been here on the COVID. They're going to name a strain after me. The next strain will be the Chuck-resistant strain. That's what I'm waiting for. Oh, there you go.

There you go. And Gary, always good to see you, man. My pleasure, Neil. Thank you for explaining. This has been StarTalk. Things you thought you knew edition. Kissed by sports. I'm Neil deGrasse Tyson.

Your personal astrophysicist. Keep looking up.