Daniel and Kelly’s Extraordinary Universe - What Is A Space Elevator?

Episode Date: April 11, 2019

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This is an I-Heart podcast. December 29th, 1975, LaGuardia Airport. The holiday rush, parents hauling luggage, kids gripping their new Christmas toys. Then, everything changed. There's been a bombing at the TWA terminal. Just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, terrorism. Listen to the new season of Law and Order Criminal Justice System

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I know how overwhelming it can feel if flying makes you anxious. In session 418 of the Therapy for Black Girls podcast, Dr. Angela Nielbornet and I discuss flight anxiety. What is not a norm is to a lot. allow it to prevent you from doing the things that you want to do, the things that you were meant to do. Listen to therapy for black girls on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. Hey, Daniel, did you ever think about being an astronaut?

I always wanted to be an astronaut from some points of view. Like, I wanted to be out in space. I wanted to see the stars. I wanted to see the Earth. under me, but I was also sort of terrified of getting up there. It's really extremely difficult. I talked to an astronaut last year, and he said it was like riding the tip of an explosion to be on a rocket.

And that scares me, I mean, especially after the Challenger disaster. You know, that was very vivid in my mind when I was a kid. It seems terrifying, and it seems dangerous, and it is. You know, it's just basically you strapped to a rocket, you know? Yeah. You're literally riding an explosion. That's right. You're like surfing a fireball, yeah.

But would you want to go to space if it was easier? Yeah, I think so. You know, if you could just like, you know, get in your car and say, take me to space or something like that. Siri, take me to space. That's right. Google, directions to space, please. Well, what if it was just as easy as getting into an elevator

and then pressing the space button? I think I would sign it for that. Yeah. Cue the elevator music. Hey guys, this is Jorge, and I'm Daniel. And welcome to our podcast, Daniel and Jorge, Explain the Universe, a production of IHeart Radio. In which we take crazy stuff in the universe, including stuff people want to make and explain it to you, break it down, make sure you can understand the next time you're at. a party and wanting to impress your friends with your cool science knowledge.

That's right, all the crazy ideas out there in the universe and the cosmos and all the crazy ideas in people's heads that may or may not be possible. That's right. I'm a particle physicist. And I'm a cartoonist. And together we wrote a book called We Have No Idea, which explores all the mysteries of the unknown and the things we don't know about the universe. And together twice a week, we try to take you up into space and out into the cosmos.

And today we're going to talk about a very interesting idea. that's been out there floating in science and engineering circles, and definitely on the Internet, which is a pretty interesting and different way to get to space. Yeah, which is really fascinating because it seems like we're sort of trapped on Earth. You know, gravity keeps us here. We've talked a lot about how gravity deforms space and makes it difficult to get off of Earth.

And it's nice that gravity holds you down to Earth, but sometimes you want to get up to space. You know, if humanity wants to explore the stars and build space technology and space industry and space habitats, then eventually we've got to get off of this planet. And so we've got to somehow counteract that gravity and climb up into space. Yeah, and the main way we've been doing that so far is by strapping ourselves into a giant tube full of flammable gasoline or hydrazine or a rocket fuel

and then lighting that up and hoping that the explosion kind of takes us up into space. It's basically the high-tech equivalent of taping a bunch of fireworks to your legs and setting them off, right? Which we advise our listeners not to do. That's right. Or, you know, riding the shockwave from a bomb on your surfboard or something, right? Sounds like a bad idea. Yeah, it's carefully channeled explosions. But there might be a different way to get to space, and this is a pretty interesting idea,

because I feel like it's the kind of idea a six-year-old would come up with. Like, if you ask a six-year-old, hey, how do you get to space? space this is what they might come up with oh my god i totally should have done that i should have gone to a kindergarten classroom and said what's the best way to get to space i would have gotten some awesome ideas like lasso the moon and climb up the rope or something like that yeah probably you get a lot of a just use of a spaceship duh jump really hard now today's topic on the podcast is Are they possible? How do they work?

How would they work? Should you ride in one? What should you pack? What's the protocol for when you're standing in a space elevator? Do you make eye contact? Do you go to the furthest opposite corner of an elevator? Do you say, oh, wait, I'll take the next one. Do you nod and do the what's up?

Or when they leave, do you say, have a good day? What's the protocol? I don't know. But, you know, if we do develop space up, elevators would be a whole impact on culture. You know, people will meet and fall in love on space elevators, right? It become an element in fiction. You'll see them in movies

and comic books. Yeah, it's a pretty fascinating idea. And just the concept of elevators. You have a favorite elevator, right, Daniel? I do have a favorite elevator. I love that in Europe, when you get into an elevator, the ground floor is listed as zero. For some reason, that just like tickles the

nerd in me. And at the large Hedron Collider, the experiments are deep, deep underground. They're like 100 meters underground so that the radiation produced in the collisions doesn't affect anybody above ground. And so they have this elevator you can take down into the tunnel where the accelerator is and the collisions happen

and it just has two buttons. One of them says zero for the ground level and the other one says minus one. And so you press it and you go whoosh, down 100 meters which is really far deep, deep into the ground. So that one's really fun. There are two options, zero and minus one. Yeah, exactly.

There's a much more dramatic elevator in some other physics experiments, like in Snow Lab in Canada, they go, I think, miles underground because they have their experiments underground in a mine, like an old abandoned mine. Did I ever tell you I have written the CERN elevator down to the bottom? You have, really? Did you sneak in? Did you pass the retinal scanner? Yes, I am a physics ninja, remember.

You're not the physics ninja. That was our listener. Don't try to take credit. No, how did you get in? Did you... No, I was giving a tour, and I went down there, and it was super exciting, super fun. I didn't get to walk the tunnels, but I was kind of disappointed to see that the one comic strip that was up on the walls there was an XKCD comic strip. Did you take it down and replace it with one of yours?

No, no, it was a well-earned. It was a really funny comic. It was well-earned. So, yeah, so getting to space is really expensive. Right? And so the idea that you might be able to take an elevator sounds pretty appealing. Yeah, it's really interesting why getting to space is so expensive. You might think, like, what's the big deal? You just build a rocket and you shoot it up there, right? How expensive could rocket fuel be? Yeah. Right. But the problem is that you need a huge amount of fuel to get to space, and you can't refuel a rocket along the way, right? You have to lift all the fuel you're going to need from the beginning.

Yeah. I saw this presentation by an astronaut once who said that basically 95% of your rocket, like by weight, like 95% of the weight of your rocket is basically fuel. Yeah, exactly. Imagine if you were going to drive across the country, but there were no gas stations between here and there. And so you need to like pack all the fuel, right? So you like had a huge tanker and you fill it with fuel. So now you need extra fuel to bring that fuel, right? And so pretty soon you're carrying like a train of tankers with you. and so you're right most of the fuel is there just to lift the other fuel yeah so a lot of your fuel

just goes to lifting the fuel that you need to lift the other fuel to maybe a little bit use some of that to lift you up yeah exactly it's diminishing returns every pound of fuel you add

a very very small amount of it actually lifts you up and so that's why rockets are pretty inefficient and super expensive yeah so when you see a rocket just imagine 95% of that long tube is basically like an explosive, right?

Yeah, it's not basically an explosive. It is an explosive. I mean, you explode your way to space, right? Like, this is the plan, right? It's ride an explosion to space. And so that's pretty expensive, right? I was looking it up. It turns out that if you want to send one kilogram,

that's like two something pounds, of stuff into space, it costs like $20,000. It doesn't matter what it is. Gold, mashed potatoes, hamsters, one kilogram of whatever cost about $20,000. dollars to send to space. Wow. So it's like $10,000 a pound. Yeah, exactly. That's some pre-mo caviar, you know. And say you want to build something, right? You want to build a factory in space that can make spaceships or that can make habitats or domes or spacesuits or whatever,

right? You have to send every piece of that stuff from Earth because we don't have any manufacturing in space yet, right? And so you have to lift it all. It would cost so much money to make stuff on Earth and then lift it up into space. Yeah, yeah. Like all those space stations you see in science fiction movies, you've got to wonder,

how did they get all that metal and stuff up there? Yeah, which is exactly why I think with the future is to build a space-based industry, right? Build that stuff in space, right?

Building a factory in space that can manufacture stuff so you don't have to lift it from the Earth. But then first you have to build that first factory, right? You have to get it started somehow. Well, you have to get up

the raw materials too, right? Well, there's plenty of raw materials in asteroids, right? There's lots of good metals and stuff in asteroids. So if you can build an asteroid mining factory in space, then you're set to go. But the first one you have to build on Earth and lift it. Right. Well, so rockets seem pretty a little bit inefficient and kind of dangerous. And so there's this other idea to get things up into space called the space elevator.

Yeah, exactly. And so we're going to dig into how a space elevator works and what should you take one? and is it possible and is it feasible? But before we do, we thought we would ask folks around the UC Irvine campus if they had heard of a space elevator, if they thought it was reasonable, or if they thought it was just some crazy idea a fuzzy-haired physicist was asking them about. So before you listen to these answers, think about it for a second. How much do you know about space elevators?

Here's what people had to say. No. What would be your best guess is what a space elevator would be? The one in the Charlie and the chocolate factory. perfect no what is that what would be your best guess a space elevator

can I get a good can I get a hint elevator to space elevator to space no I would not I don't think it's that all right thanks very much

any best guess what that might be I have no idea yes do you think it's possible feasible it seems possible I don't know about feasible

when do you think we might see one in action I think that as I understand it, the limitations have to do with materials constraints right now and the strength of the materials. So the last I heard they were working on like carbon fiber that could support its own weight up to the low Earth orbit. But I don't know how that's going. Is it like a thing used for like the spaceships to like launch it up, I guess? Something similar to that? All right.

Elevator in space. Elevator in space or elevator two space? To space? Sure. Do space. You'd like to have a space elevator? No, I think I might die in it. On a space station or something like that, it like takes you to the... Like from the bridge to engineering or something?

Yeah. Something like that. All right. Maybe something that launches you into space. Cool. All right. So it sounds like not a lot of people ever heard what a space elevator is. Someone said that it was like the one Charlie and the Chocolate Factory. That was a great answer. Yeah, I love that. I love seeing people think on their feet.

They're like, haven't heard that. What could it be? They're like, I've heard these words before. Space and elevator. Is it an elevator that uses space, takes you to space? Yeah, or an elevator in space, right? That was one of my favorite idea. Oh, yeah.

Oh, it's sort of like in Star Trek when you go from like the bridge to engineering that uses an elevator, right? So very few people thought from first principles that it might be an elevator to space. one of the guys we interviewed happens to be a professor of Earth System Science and so he was very knowledgeable about the topic as you can hear

Oh I see He was a ringer He was definitely a ringer, yeah He really elevated the topic here That's right That's right Before we dive in Let's take a short break

December 29th 1975, LaGuardia Airport. The holiday rush, parents hauling luggage, kids gripping their new Christmas toys. Then, at 6.33 p.m., everything changed. There's been a bombing at the TWA terminal. Apparently, the explosion actually impelled metal glass. The injured were being loaded into ambulances, just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, and it was here to stay.

Terrorism. Law and Order Criminal Justice System is back. In Season 2, we're turning our focus to a threat that hides in plain sight. That's harder to predict and even harder to stop. Listen to the new season of Law and Order Criminal Justice System on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Imagine that you're on an airplane and all of a sudden you hear this. Attention passengers, the pilot is having an emergency and we need someone, anyone to land this plane.

Think you could do it? It turns out that nearly 50% of men think that they could land the plane with the help of air traffic control. And they're saying like, okay, pull this, do this, pull that, turn this. It's just, I can do my ice close. I'm Manny. I'm Noah. This is Devon. And on our new show, No Such Thing, we get to the bottom of questions like these.

Join us as we talk to the leading expert on overconfidence. Those who lack expertise lack the expertise they need to recognize that they lack expertise. And then, as we try the whole thing out for real. Wait, what? Oh, that's the runway. I'm looking at this thing. Listen to No Such Thing on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Hey, sis, what if I could promise you you never had to listen to a condescending finance, bro, tell you how to manage your money again. Welcome to Brown Ambition. This is the hard part when you pay down those credit cards. If you haven't gotten to the bottom of why you were racking up credit or turning to credit cards, you may just recreate the same problem a year from now. When you do feel like you are bleeding from these high interest rates, I would start shopping for a debt consolidation loan, starting with your local credit union, shopping around online, looking for some online,

line lenders because they tend to have fewer fees and be more affordable. Listen, I am not here to judge. It is so expensive in these streets. I 100% can see how in just a few months you can have this much credit card debt when it weighs on you. It's really easy to just like stick your head in the sand. It's nice and dark in the sand. Even if it's scary, it's not going to go away just because you're avoiding it. And in fact, it may get even worse.

For more judgment-free money advice, listen to Brown Ambition on the IHeart Radio app, Apple Podcast, or wherever you get your podcast. All right, let's jump into it, Daniel. So what is a space elevator? The idea of a space elevator is to avoid having to do the rocket lift, right? And instead of having to push yourself up out of Earth's gravity, right? And every time you're pushing yourself out of Earth's gravity, you're doing two things. First, you're keeping yourself up.

And second, you're lifting yourself up. So, for example, say you're like, you know, 500 feet above the earth and you just want to hover. You don't want to go anywhere any higher. Even that, just that takes energy, right? You have to continually push yourself up. Yeah. So imagine if instead you could just climb a ladder, right? There's like a ladder to space.

Then when you wanted to take a break, you could stop, right? And you could rest. And the ladder would support you. The ladder would provide that essentially the counterbalancing force against gravity to keep you up while you rested and then do the rest of your climb, right? You could literally just hang out. Yeah, exactly. Hang out in space.

Yeah, so if you could build a ladder to space, then that would save you a lot of that energy, right? The other idea is avoid carrying all your energy with you, right? The rocket, as we were saying earlier, the big problem with the rocket is you have to carry the fuel, and then the fuel to carry the fuel, and the fuel to carry the fuel and all that stuff. So if you could somehow get the energy from the ground

as you were climbing, you know like people like throwing you you know candy bars as you're climbing of the ladder then you wouldn't have to carry all those candy bars with you oh i see so the idea of a space elevator is build something you can climb and send the energy up to the the car that climbs the the climbs the elevator while it's on the way so doesn't have to carry it all like the like the real elevator in a building like you get the power from it um you don't carry all the gasoline to power the elevator it just comes to you through the cables attached to the elevator, right?

That's right. This would be a slightly different structure because an elevator in a building is usually attached to the cable, and then there's an engine at the top that's pulling on the cable or something. So the basic idea here is you have a huge cable, you attach it to the ground on Earth, and then you lift the other end all the way up into space and attach it to something in space. So the idea I said earlier a six-year-old, like lassoing the moon, that's basically the idea, is like tie a string between the earth and something in space.

Wow. Okay, so I think the basic idea is to build something permanent. You know, not a rocket you use once and then throw it away, but like build a structure, something, like a link between Earth and space, and then just climb that every time you want to go into space. Exactly, yeah. And so then it's reusable, and you don't have to carry all the fuel with you. We'll talk in detail about how you can accomplish that.

And you can take breaks, right? you don't have to provide the hovering lift as well as the climbing lift. So there's a lot of possible advantages if you can build that kind of structure. You can just hang on. Yeah, exactly. You can just hang on. You can like clamp onto the rope or whatever to prevent yourself from falling. A rocket can't do that, right?

It has nothing to hang on to. It's just as the air around it to push against. And when I first heard about the concept of a space elevator, I thought, like, how is the rope going to stay up, right? I mean, if you just take a long rope and just like throw the end. end into the sky, it falls down, right? There's no way it, like, stays up in the sky. How does that even work, right?

Well, you're assuming that it looks like a rope, right? Like a, this elevator could take different forms. Like, it could be just a one rope that goes off into infinity, like jacking the beanstalk. Or it could be, what if you just built a really, really tall tower? Like, if you just, you know, the Burke Khalifa in Dubai, what if you just keep building that up, up, up into space? What would happen then?

Well, the bottom of the tower, we get crushed, right? The problem with building something up from the ground and not having it be pulled from outer space. So that's the key about the space elevator is that you build it so long and so high, and the rope goes so far that it's basically getting pulled from space. We'll talk about that in a moment. But the problem with building a tower is basically like a compression structure. Every layer sits on top of the previous layer, and the next layer sits on top of that. And by the time you get to, you know, really, really tall, the bottom layer is. supporting the entire structure, right?

And that has to be super strong or super wide or made out of crazy materials to go anywhere close to the distance of space. So you have to have this thing be really light so we can get height without having a lot of weight. But technically it's possible, is it? Is it possible to just build a giant pyramid that's really, really tall?

Is it possible? I mean, Mount Everest is a giant pyramid that's pretty, pretty tall, but I don't know if we could build it. You know, like, it's... These things have to go get pretty wide in order to support all that weight. Eventually, yeah, maybe you could build the tower of Babel into space. But I think it's as difficult as space elevators are, a space tower would be even more difficult.

I see. All right. Yeah, the space elevator has the advantage that the top of it, the rope is so far out into space that it pulls on the rope. Okay, yeah, I just think maybe we're jumping ahead, right? because maybe some people think it's an elevator, so it means that there's an elevator shaft that takes you all the way up. But you're saying that the primary way that this might work

is using a cable. Yes, yeah, exactly. It has to be a cable. You can't just build a building that goes all the way up into space. It has to have something at the top of it that's so far into space that it's basically escaped the earth's gravity

and is pulling whatever it is up. And so is that the prevailing idea that this way it could work maybe? Like, the idea is that it's not an elevator shaft or a tower, it's like a string, basically. You attach a string to Earth, and you swing around something really heavy out into space that keeps that rope, that string, and tension. Yeah, exactly. And then maybe you can use that, maybe you can climb that rope in tension, that rope up into space.

Yeah, exactly. You attach a string from the ground to something up in space, and that thing up in space is pulling on the string, right? It's keeping it up. And then, yeah, then you just climb up that rope. And so it's more like a space ladder than a space elevator if you want to think about it that way. Yeah, more like a space cable. It's like a space fire pole, right?

Yeah, yeah. But then you would ride an elevator. Like you wouldn't climb it by hand. You would be inside of an elevator like structure that then climbs up the rope or the pole. Yeah, you'd have to be crazy strong to climb it by hand. yeah the basic components are you have station on the ground the cable that goes up some counterweight up in space to keep it up and then you have something that climbs it some like car or some device that basically crawls up the rope the thing that like climbs the ladder for you and that like slurps its way up the rope so those are the basic components yeah

it's hard to imagine how that rope stays up like what keeps that rope vertical yeah exactly that's the thing that puzzled me for a long time when I was thinking about the space elevator, because it's just counter to your intuition, right? You think the things that go up in the sky come down, right? But the truth is, if you throw things high enough up into the sky, they don't come down, right? They go into orbit. And so at some point, the force of gravity weakens enough, and the centrifugal force is strong enough that they stay up there. You know, imagine, for example, you are, you have a bucket with a rope and you're swinging it around yourself, right? Then, you know, water, for example, can stay in the bucket, even if the bucket goes upside down, right? Why is that? It's because of this apparent force, the

centrifugal force. And so that's pushing things away if you're spinning, right? It's the fact that the earth is spinning provides this sort of outwards apparent centrifugal force. And so it'd be like the earth is rotating around and you tie string to it and the swinging around of some big weight at the end of the rope is what keeps the rope. vertical and intention. And then you can climb that rope to get to space. Exactly. The center of mass of the whole structure is above the orbit level, right? At some point above the earth, the force of gravity gets weaker, and the centrifugal force actually gets stronger with distance.

And so at some point above the earth, they're equal. That's what we call like where a geosynchronous orbit can happen, where it's in balance, it can just stay in orbit. And so the idea is to put something really heavy above that so that the average weight, like where's the average bit of mass of the space elevator, is above that orbit level. And so it's just like something in orbit. I mean, you can think of it like something in orbit with that dangles down really, really low.

Oh, I see. It doesn't have to be attached to Earth, is what you're saying. It doesn't have to be attached to Earth, but it's better if it is, right? You don't want to climb something which is actually dangling. But just in point of view of the physics, like, why does it stay up? It's, you know, the fact that it's attached to Earth is not what keeps it up, right? The thing that keeps it up is that it's attached to the part in space. That's interesting.

Like people in the International Space Station could potentially, I mean physically, just kind of let out a little bit of string down into Earth, and at some point it might touch the Earth. And it would just hang there between the station and Earth. Right. And your intuition tells you that should work, right? And that's basically the same thing. And then you just clip that rope to your garage.

And you're done. Yeah. But the key is that the thing is in geosynchronous orbit, right? So it's always above the same part of the Earth. Because you don't want this rope like dragging across the surface of the Earth, right? That wouldn't be a lot of fun. Like a Bruce Willis movie. Exactly.

Exactly. So you want to have some like big station on the ground where this thing clips in. And so you have this like a spaceport on the ground and then a place you can arrive above the Earth. And so that's the basic physics of it. Well, this is pretty cool. You said you told me that basically, the point at which you would reach this geostationary orbit is about 36,000 kilometers out into space. Yeah, exactly.

So you need to have enough mass above that height so that on average, the mass of the whole thing is just above 36,000 kilometers above the Earth. And just for reference, like the moon is about 380,000 kilometers away. So it's like a tenth of the way to the moon. You could have this elevator. Yeah, exactly. So that makes it sound totally plausible, right? You don't even need to lasso the moon. You just have to lasso the space station, right?

Exactly. But that's a really long rope, right? Well, let's see how long would it take you to get there, like 36,000 kilometers away, and let's say that your elevator is going up at 200 kilometers per hour. It would take you how much is that? Well, that's, you know, five hours to go 1,000 kilometers, right? So 180 hours or so.

So that's a few days, you know. When you get in at the bottom, you're going to look around because you're going to be with those folks for a while. Oh. And then hope nobody passes some wind or bring some chili. It's much longer. Something's smelly-te-pe. Pay attention to what everybody's eating just before they get on the space elevator. No, it's a lot like a super long airline flight, but days long, right?

Wow, that would be amazing. But then at the end of the two days, at the end of the, what is it, 10 days, you'd be in space. Yeah, exactly. It would be in space. And even that number, like 200 kilometers per hour, that's pretty fast. That's pretty fast for an elevator, right? So I don't know how plausible or how comfortable that would be. It seems to be pretty zippy for an elevator.

But if you get those speeds up, then you could get the time down. And, you know, 10 days is a long time for a passenger. But I think in the beginning, the more important thing is lifting up cargo. If you're going to build industry and space so you can build spaceships and habitats and all that kind of stuff, then you've got to lift stuff up into space. Okay, so that's the concept. You put a cable between the Earth. You tie it down here and you tied the other end to something heavy

and swinging around the Earth in orbit, geosynchronous orbit, and then you just pull yourself up to cable to get to space. Yeah, sounds simple. Just pull yourself on up. Yeah, let's do it. Hold on. I'm going to take care of this. I can imagine you selling tickets at the bottom you like. It's $1,000 and just pull yourself on up.

Yeah. Well, let's get into why it's. possible or maybe impossible. But first, let's take a quick break. December 29th, 1975, LaGuardia Airport. The holiday rush, parents hauling luggage, kids gripping their new Christmas toys. Then, at 6.33 p.m., everything changed. There's been a bombing at the T.W. the UA terminal.

Apparently, the explosion actually impelled metal glass. The injured were being loaded into ambulances, just a chaotic, chaotic scene. In its wake, a new kind of enemy emerged, and it was here to stay. Terrorism. Law and order, criminal justice system is back. In season two, we're turning our focus to a threat that hides in plain sight. That's harder to predict and even harm. harder to stop.

Listen to the new season of Law and Order Criminal Justice System on the IHeart Radio app, Apple Podcasts, or wherever you get your podcasts. Imagine that you're on an airplane and all of a sudden you hear this.

Attention passengers. The pilot is having an emergency and we need someone, anyone, to land this plane. Think you could do it? It turns out that nearly 50% of men think that they could land the plane with the help of air traffic control. And they're saying like, okay, pull this, until this. Do this. Pull that. Turn this. It's just,

I can do my eyes close. I'm Manny. I'm Noah. This is Devon. And on our new show, no such thing, we get to the bottom of questions like these. Join us as we talk to the leading expert on overconfidence. Those who lack expertise lack the expertise they need to recognize that they lack expertise. And then, as we try the whole thing out for real. Wait, what? Oh, that's the run right. I'm looking at this thing. See? Listen to no such thing on the IHeart radio app, Apple Podcasts, or wherever you get your podcasts. Hey, sis, what if I could promise you you never had to listen to a condescending finance, bro, tell you how to manage your money again. Welcome to Brown Ambition. This is the hard part when you pay down

those credit cards. If you haven't gotten to the bottom of why you were racking up credit or turning to credit cards, you may just recreate the same problem. a year from now when you do feel like you are bleeding from these high interest rates i would start shopping for a debt consolidation loan starting with your local credit union shopping around online looking for some online lenders because they tend to have fewer fees and be more affordable listen i am not here to judge it is so expensive in these streets i 100% can see how in just a few months you can have this much credit card debt when it weighs on you it's really easy to just like stick your head in the sand it's nice and dark in the sand even if it's so

scary, it's not going to go away just because you're avoiding it. And in fact, it may get even worse. For more judgment-free money advice, listen to Brown Ambition on the IHeart Radio app, Apple Podcasts, or wherever you get your podcast. All right, so that's a space elevator. It's a giant rope tied to earth and tied on the other end to something floating out into space. and the idea is that we just get on an elevator that climbs that rope. So where's the, what's the difficult part here? Why can we just build one?

Oh, I'm building one right now. It should be done next week. You want to come down and try it out? It's made out of paper clips. Oh, I can see it from here. Oh, my gosh. There's a lot of hard parts in this. First of all, you're talking about attaching a rope

to something heavy out in space. What, right? Like, do you corral an asteroid? Do you collect a bunch of space junk and build a garbage mountain in space. Like, you need something big and heavy that you can understand and snap a cable to. Wait, why does it mean to be, like,

how heavy does it need to be? Like, does it need to be, you know, like the size of the moon or the size of a bus or what? It needs to be definitely thousands and thousands of kilos. Exact size depends on the distance. So the longer your rope, the further away this rock can be and the lighter it can be, right?

Because this centrifugal force grows with radius. And so it doesn't need to be as heavy if it's longer. But then you have to build a longer rope. If you want a shorter rope, then you need a larger mass. And so it's a bit of a balancing act. We just collect all those junk satellites and make a giant satellite ball, and that's it. Yeah. Or maybe we could just, like, gather all the plastic from the ocean and use that, right? A huge, you know, plastic straw ball in space would be pretty cool.

So that's problem number one. Yeah, is the thing that's out there holding the elevator up? Yeah. But the bigger problem is connecting it, right? Like, say you have a big asteroid in space. You're all set to big, built your space elevator. How do you make such a rope? You know, this thing has to be like thousands of kilometers long.

It has to be super strong. It has to never, ever, ever break, right? And most importantly, it has to be strong enough to hold itself up. What do you mean, strong enough to hold itself up? Didn't we say that the rope is pretty much kind of floating out into space? Yeah, well, you can imagine this sort of two, halves of it, right? There's some average point where half the mass

of the space elevators above it and half the mass is below it. Everything above that point is getting pulled out into space. Cool. Everything below that point is getting pulled down towards the earth. It still has weight, right? So even if the whole thing is being held up, then those elements of the rope that are

right there at that halfway point, they have to be strong enough to hold all that weight below them. Even if there's a force on the other end pulling on the rope to provide it to keep it up, the rope has to be strong enough, right? But why does it need to be in tension, I guess is my question? Because couldn't you just have something in geosynchronous orbit? Like

if something's in orbit, there's nothing holding it, right? So couldn't you just have a slack line? Well, I think a slack line would make for a pretty wild ride, you know, as your elevator's like whipping to the atmosphere. Not a completely taunt or like a barely taunt. It's not about the tension, right? It's just

about having a really, really long cable that's suspended by itself, right? Even if you You lower, say you lowered that cable from the space station, right? You didn't even tie it to Earth. The part where it attaches to the space station is going to be pulled down by the entire weight of the cable, right? Oh, I see.

So the cable itself just has to be strong enough to hold that weight. It's not about the strength of the pulling force. Like, let's say Superman wants to pull on the moon, okay? So yeah, maybe he's strong enough. He ties a rope around the moon, and he's strong enough to pull hard enough on the rope to move the moon, to move the moon, but is the rope strong enough? Probably not. Probably the rope would snap, right?

So this is about making a rope that's strong enough to hold all that weight, hold all that force that's keeping it in space. Oh, I see. So there doesn't need to be tension between the space object and the earth, but the rope itself weighs a certain amount. Exactly. So it's being pulled down by itself, basically. Yeah, exactly.

It's got to be strong enough to hold itself up. so you need something which is really strong you also want it to be very light so that it doesn't have to be that strong so it's this constant balance and people in materials are doing this kind of research all the time trying to make really strong

really light materials not just for space elevators you know for like bulletproof vests and for buildings and for airplanes and being both strong and light is like one of the hardest things in materials right you know that

you're an engineer yeah I thought I was going to say I thought you were going to say that I am strong in light which is totally true Thank you, Daniel. You're brilliant, like light, and you're also very strong-willed, so there you go. I have a strong personality is what you're saying.

Exactly, and so it's difficult to find materials that are strong enough to fit the bill. I mean, this thing is crazy long, right? It's like, I mean, 36,000 kilometers is just a huge number, right? And so we've never met anything that long. We don't have materials that can hold themselves up when they're. that long. That would be like a rope that goes around the earth basically, right? Like you start a rope here and you

keep going until you come back on the other end from the other side. That would be how long the rope would need to be, right? Exactly. It's crazy. It's hard to even really imagine building something that big, literally planet-sized. Yeah. Wow. Okay, so what are the alternatives?

Like titanium, what if you use titanium or adamantium? Adamantium, yeah. If you use Marvel Comicsium, You know, then you can do anything. No, the strongest metals we have, if you made a thin rope of them, they can hold themselves up if you make it like, you know, 20 or even 30 kilometers long. But eventually, eventually they just fall apart, right?

The weight at the bottom will be stronger than the internal strength of the material. It will tear itself apart. And you can try lighter stuff like Kevlar or carbon fiber. These are fancy materials people develop that are pretty light. And those can maybe make like, you know, 100 kilometers, a few hundred kilometers. But remember, we're looking for something that's like tens of thousands of kilometers. And so recently people have done research and they've come up with even crazier materials. Like, have you ever heard of carbon nanotubes?

I have, yeah. Is that like YouTube? Is that like YouTube Red? Is that the, no? Yeah, it's the super premium version of YouTube. Exactly. Carbon nanotubes are this really cool development. It's a totally different way to arrange carbon.

Carbon is an amazing element. You know, it's the backbone of organic chemistry, right? Every molecule in your body has carbon as its backbone. It's incredibly flexible. Also, it doesn't have a lot of protons in it because it's early in the periodic table. So you can make structures in it that don't have a lot of dead weight. Like a lot of the materials we use, the protons and the neutrons, which provide most of the weight of the stuff, don't really control.

tribute much to the strength of the object. But a carbon nanotubes like pure chemical bonds, right? Yeah, exactly. Most of the strength comes from the chemical bonds, which really just come from the electrons, which are pretty light. So you want to find a material which has a small number of protons and neutrons like carbon

and can arrange itself in clever ways. And so people have figured out ways to make like these spherical shells of carbon. Those are called bucky balls or these tubes of carbon. It's really pretty incredible. And of course, folks out there might know that carbon can make graphite. It can make diamonds. right it's really it's like a you know an engineer's dream when it comes to a basic building material so

this is almost kind of like a a cable made out of diamonds right almost like it's it's a very specific carbon arrangement yeah exactly it's a very specific arrangement of carbon and people have and they're incredibly strong right they're stronger than anything anybody has ever made right and the current calculations tell us that like you could probably make a carbon nanotube that goes five, maybe 10,000 kilometers, and it could hold itself up, which is pretty good, right? That's getting in the range of what you need.

It's still a little low. But the problem is that we're not really that good at making carbon nanotubes yet. Like the longest one we've ever made is like centimeters in length. Oh, so we're almost there. Well, I've heard this idea of using carbon nanotubes, I know that are like single atom, single molecule strands.

And I always thought, well, you're going to pull a whole elevator on a single strand of molecules. But I think the idea is not that there's a single strand up to space, but like a bundle of these fibers, right? Yeah, I think you could weave them together to get additional strength and also redundancy, right? Another problem with carbon nanotubes is that they're not very robust to, for example, lightning strikes. You strike it with lightning and basically evaporates. So that means you need to always predict the weather exactly correctly or you're susceptible to these lightning strikes to evaporate your cable. That would be a long ride down if your space elevator gets fried by a lightning strike.

I think it's faster on the way down and the way up if the cable snaps. Yes, there's a lot of challenges there. We don't even have, we don't have the technology, right? Carbon nanotubes aren't yet good enough. and we don't even know how to make carbon nanotubes that are long enough. But, I mean, physically, carbon tubes could be, could work, or they just, even those are not physically able to get to 36,000 kilometers? I think there's a lot of uncertainty still,

because there's a lot of ways you can make them. And so people think about weaving them together and to get them extra strong. So I think it's possible, right? Nobody knows exactly how to do it, but I certainly wouldn't say it's ruled out. It's definitely in the category of things that people imagine. You just have to find the right solution, like the right engineering material solution. And one of the problems is that often you're surfing on the backs of other industries. Like if there are other reasons why people are trying to push to make long carbon nanotubes,

then cool, space elevator can wait until some other industry figures out the problem and then they can just order a big tube, right? The problem is nobody else really needs carbon nanotubes thousands of miles long. We need them for electrical conductivity and all sorts of other applications that are, you know, millimeters or centimeters. Or Spider-Man. Spider-Man needs them. He makes them himself, though, and he's not shared the patent, so we're screwed from that point of view. So you need a dedicated effort to develop these things to be long enough for space elevators.

And that's expensive, right? That's a huge investment. So you were saying it's like a nascent industry? There's a lot of applications of them in solid-state. You know, physics, you know, and in biophysics and using them for all sorts of stuff. But most of those applications, they can be pretty short, right? They use them for conductivity, for circuits, for, like, filtering stuff, for picking stuff out of other kinds of goo. But nobody else other than space elevators needs them to be this long.

So you need somebody to develop it. But, you know, there are people out there who are working on it. People who think this would be awesome or people who correctly think it would be huge economic windfall. The first person to build a space elevator, you know, and he, you know, and he's, you know, instead of charging $20,000 per kilo could charge like their very reasonable price of $500 per kilo or get a lot of business. Wow.

But you're saying this might be achievable with a few if we just invest enough money into it. Yeah, it might be, right? Somebody needs to develop the technology to build these long cables and to make them robust. And, you know, people estimate how much this might cost. It's really just speculation because nobody really knows. It's research, right?

You could have a moment of inspiration and figure something out tomorrow. or you could sink billions of dollars in and get nowhere. But it's definitely in the billions or tens of billions of dollars category in terms of research projects. Just people saying, hey, give me $20 billion, I'll get you to space. Yeah, I wouldn't believe a firm price tag. But that's probably the right order of magnitude is 10 or 20 billion to develop and to build this thing. And, you know, some people are talking about like trying it first on the moon.

Because on the moon to be much easier because the gravity is much lighter on the moon. So the space elevator wouldn't need to be as high. It would need to be as long. It's not as risky. You mean like a space elevator from the moon out into space, to take off from the moon? Yes, exactly. Out into orbit around the moon, basically.

Just as sort of a warm-up project. Because also, imagine you build a space elevator and it's working fine and then it breaks, right? That could be a big disaster. Like, what if it breaks where the cable snaps at the top end, right then this huge cable falls from the sky right and it's right as you said it's as long as the circumference of the earth so like where's this thing going to fall it's going to slice people in half like it seems crazy wow it would keep falling for a long time yeah or if it snaps at the bottom right

and then you're dragging this like very sharp hot fast moving cable across the surface of the earth right wow none of these pictures sound very rosy no exactly and so if you're considering considering investing in a space elevator company, think about the legal liabilities, right? Wow. Well, which is why I think we should just make it out of spider webbing, which is... Does Spider-Man answer your phone calls these days?

How do you get in touch with that guy? I don't know how much is a Marvel movie. It's about $100 million. Done. That's right. Done. You know, one of my favorite science fiction stories is about a physicist who has an idea

for some awesome technology, and he can't get any funding agencies to fund it for him. So instead he pitches it to Hollywood as a movie. And they make a movie, and he uses Hollywood's huge budget to build a quote-unquote prop of his device, and it actually works. And so he uses Hollywood as a way to fund his research.

You should pitch it as a movie. A movie about a guy who talks on his podcast, about a story, about a physicist. This sounds like an awesome pitch so far. I can just imagine you go into like a movie studio head and being, hey, sir, can I give you my quick elevator pitch? That's right. We're taking the space elevator, so I have 10 days to give you my pitch for this movie.

Okay, great. So that's the idea of the space elevator. It would sort of liberate us from this need for rocket fuels and rockets, and which are explosive and expensive. That's right, and we didn't even get to touch on it, but very briefly, like, you could avoid having to carry all the energy for the space elevator by, like, using laser beams. You could, like, shoot laser beams from the ground

to send energy up there. Or if you use carbon nanotubes, they could be electrified, so they could, like, send the electricity along the wire, like an electric bus or something. Oh, my God. So you should just stop right there and just call it a laser space elevator. I mean, that just sells... A laser vater.

A laser space evader. How are you going to get to space? I'm going to laservate my way to space. Yeah. Cool. Good luck with that. Wear a helmet. Yeah, but I think this stuff is important. I think it's interesting.

I think if we're going to build a space industry, if we're going to develop humanity into space and, you know, populate space and all that kind of stuff, we've got to get started. We've got to get over this hump where it costs so much money to get something into space. And it's so risky, and it takes months of planning, right? It has to be more routine, it has to be cheaper.

Yeah, yeah. Avengers, get on it. So Jorge, after listening to all of that, if somebody builds the space elevator, would you pay to take a ride up into space? Let's do the calculation. Say it costs $200 per kilo, right? Then how much would your ride on the space elevator cost? How much would it, for me, really like that sounds like $10,000 or something?

All right, so would you spend $10,000 to get into space? Totally. Yeah. Wouldn't you? I mean, if I knew it was safe. Yeah, well, I'll take your deposit right now. What was your credit card number? No, I probably would. I think getting to be up in space would be exhilarating. Of course, if the price drops that low, then a lot of people will do it and maybe it won't feel as exciting anymore. I think it would also depend on who's going on in the elevator with me. When you're on a transatlantic flight, do you like stare out the window, agog, the technology anymore? No, you're probably just like watching movies.

You lowered the window. You ignore what's going on outside, right? So people adapt pretty quickly to this kind of stuff. Like a real elevator, right? Like if you showed a real elevator to someone 10,000 years ago, they'd be like, what? You can go up 1,000 feet up into the air just by getting onto this box. Yeah.

And these days, people are just like impatiently mashing the buttons, cursing the thing for being so slow, right? Humans never satisfied. Somebody told me that New York is the only place. where the closed door button actually works. What? Are you saying the closed door button doesn't usually work?

I think that's just there for psychological comfort. Oh my God, that blows my mind. Are you serious? Yeah. Have you ever been in one where it actually works? I don't know. I guess I had the impression

that frantically matching that button did something. Yeah. No. No. I'm going to apply that technique to other places. You know,

like I have a knob a button outside my office door that says complain to professor and people come over and just mash the button and feel satisfied. Ring doorbell for physics answers. And it doesn't do anything.

It doesn't do anything. It just pulls up a copy of our book. We have no idea. Yeah, exactly. We have no idea. So there you go. There you go. Well, I hope the next time you get into an elevator,

you maybe imagine yourself getting onto the space elevator. And imagine when you get off that you'd be in a whole different world. Or I imagine that maybe one of our listeners has heard about space elevators for the first time and is so inspired that he or she will sink

their fortune into investing in space elevators and make it real and actually go to space. Make it so. It's John Lusby Carpentice. Engage. All right, thanks for listening, everybody. And if you have questions about what we said, send us some feedback at questions at

Danielanhorpe.com. Or send us a suggestion for what topic you'd like to hear us talk about. Thanks for listening. If you still have a question after listening to all these explanations, please drop us a line we'd love to hear from you. You can find us at Facebook, Twitter, and Instagram at Daniel and Jorge, that's one word, or email us at Feedback at Danielandhorpe.com.

Thanks for listening, and remember that Daniel and Jorge Explain the Universe is a production of iHeartRadio. For more podcasts from IHeartRadio, visit the IHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows. December 29th, 1975, LaGuardia Airport. The holiday rush, parents hauling luggage,

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