WEBVTT - What can gravity do for you?

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<v Speaker 1>Welcome to Stuff from the Science Lab from how stuff

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<v Speaker 1>works dot com. You guys, welcome to the podcast. This

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<v Speaker 1>is Alison. I don't know if the science editor at

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<v Speaker 1>how stuff works dot com. And there is Robert Lamb,

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<v Speaker 1>science writer and how stuff works dot com. So, Alison,

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<v Speaker 1>have you seen the movie Phantasm? I've not seen it.

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<v Speaker 1>It's a nineteen seventies flick, right, yeah, harror flick. You

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<v Speaker 1>haven't seen it. I have not, but you've mentioned it before, right, Well, okay,

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<v Speaker 1>it's awesome. It's um. I mean it's it's horrible, but

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<v Speaker 1>it's awesome. It's um. The basic plot line here is

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<v Speaker 1>you have a mortuary where some funny things are happening.

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<v Speaker 1>There silver balls flying around, stabbing people in the head. Uh.

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<v Speaker 1>And there are these dwarves running around in these little

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<v Speaker 1>like I think they're yellow, little yellow robes, okay, like

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<v Speaker 1>evil dwarves. Right, And you come to find out that

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<v Speaker 1>all of this basically has to do with gravity. There's

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<v Speaker 1>a really tall man, like a scary old man. It's

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<v Speaker 1>really tall, Okay. And it turns out he's from another

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<v Speaker 1>planet where the gravity is more intense, like a larger world. Okay,

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<v Speaker 1>so that's why he's taller when he comes to this world, okay,

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<v Speaker 1>and the deal with the dwarves, he's taking corpses and

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<v Speaker 1>smushing them down, making a more compact and bringing him

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<v Speaker 1>back to life a zombies and then sending them to

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<v Speaker 1>this other world to be like slaves. All right, So

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<v Speaker 1>dwarves are being used as as as zombies. Dwarves are

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<v Speaker 1>being used as slave labor on another world where there's

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<v Speaker 1>more gravity. And so this all occurs thanks to gravity. Yes,

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<v Speaker 1>like it Like for me anyway, as as a kid.

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<v Speaker 1>You know, it's like, you know, gravity is, They're great,

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<v Speaker 1>but I never think about it. But then somebody comes

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<v Speaker 1>along and shows me how gravity is affect you know,

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<v Speaker 1>zombie dwarves and uh and it it really you know,

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<v Speaker 1>unders it really resonated with me and underlining how amazing

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<v Speaker 1>gravity is. I mean, um, like I said, we take

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<v Speaker 1>it for granted because it's everywhere, because every pretty much

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<v Speaker 1>every physical act on the planet um involves gravity in

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<v Speaker 1>somewhere and within another. So that's what we're going to

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<v Speaker 1>talk about the day. We're gonna We're gonna basically talk

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<v Speaker 1>about four examples um of technologies that utilize gravity in

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<v Speaker 1>a way that highlight just how amazing it is. But

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<v Speaker 1>of course to do that, we need to talk briefly

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<v Speaker 1>about about gravity itself. Now, we have an excellent article

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<v Speaker 1>on how Stuff Works dot Com about this um and

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<v Speaker 1>I recommend checking that out if you want more details.

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<v Speaker 1>But basically, two schools of thought. There's there's Newton Newton's

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<v Speaker 1>uh a theory of universal gravitation from back in the

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<v Speaker 1>sixt eighties, and this is the idea. The gravity is

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<v Speaker 1>a predictable force that acts on all matter in the universe,

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<v Speaker 1>and it's a function of both mass and distance. Right. Basically,

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<v Speaker 1>each particle of matter attracts every other particle of matter,

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<v Speaker 1>all right. Whether we're talking about a great or a

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<v Speaker 1>massive sign. Okay, whether we're talking about a spaceship or

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<v Speaker 1>I don't know, a dog, everything has gravity, all right.

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<v Speaker 1>And if ever, and if the only two things you

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<v Speaker 1>had in the universe were a dog and a spaceship,

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<v Speaker 1>they would each have a great gravitational pull and it

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<v Speaker 1>would be drawn to each other. Okay, um, go ahead.

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<v Speaker 1>And then along comes Einstein. Yes, along comes Einstein, and

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<v Speaker 1>he says, fooie to this whole dog and spaceship business.

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<v Speaker 1>And he says that, he says that gravity isn't even

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<v Speaker 1>a force, all right, he's a he's seeing it more

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<v Speaker 1>as a distortion in the shape of space time, all right,

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<v Speaker 1>as the you know, a distortion in the fourth dimension.

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<v Speaker 1>And in Einstein's footsteps. You have some more modern theories

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<v Speaker 1>as well, okay, that are less even even less proven.

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<v Speaker 1>There's the idea that UM that gravity is due to

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<v Speaker 1>little particles called gravitons that that cause objects to be

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<v Speaker 1>attracted to one another. And there's another theory that there's

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<v Speaker 1>gravitational radiation UM, which which is supposedly the ideas that

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<v Speaker 1>gravitational radiation is generated when an object is accelerated by

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<v Speaker 1>the external force. Basically, the idea here is that gravity

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<v Speaker 1>is is awesome and every day it's mysterious. Um. Basically,

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<v Speaker 1>the idea here that it is that as every day

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<v Speaker 1>as gravity is, there's a lot we don't know. There's

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<v Speaker 1>a lot we don't know about it. It's still kind

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<v Speaker 1>of a mystery in many ways. All right. So with that,

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<v Speaker 1>let's kick off with four cool things that gravity can

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<v Speaker 1>do for you. Yeah, what do you got? What can

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<v Speaker 1>gravity do for you? Well, if you listen to our

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<v Speaker 1>Fighting Asteroids podcast, we touched on this briefly but gravity

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<v Speaker 1>can actually I could save the Earth from being destroyed

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<v Speaker 1>by some crazy space rock and always good. Yeah, I

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<v Speaker 1>like this. Um, So this thing called a gravity tractor,

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<v Speaker 1>and I'm not talking about the the grateful dead cover

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<v Speaker 1>band that seems to be located in upstate New York

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<v Speaker 1>of the same name. This gravity tractor, actually, um might

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<v Speaker 1>have a might have a chance of being built. According

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<v Speaker 1>to the BBC, there's this British company by the name

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<v Speaker 1>of E. A. D. S Astrium that they finally started

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<v Speaker 1>taking concrete steps to make the graph tractor reality. So

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<v Speaker 1>it's the graph tractor gonna do it well. It's a

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<v Speaker 1>robotic spacecraft weighing roughly ten tons or so, and it

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<v Speaker 1>has a has a particularly daunting task. Once it's launched

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<v Speaker 1>into space, it has to get within forty eight m

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<v Speaker 1>so roughly a hundred fifty feet of the space rocking question.

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<v Speaker 1>And once it gets within that range, it has to

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<v Speaker 1>pull the rock toward it, and the two of them

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<v Speaker 1>march happily off on a path that's not kind of

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<v Speaker 1>coincide with the Earth and now in theory though it

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<v Speaker 1>could also if you had a New York area jam

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<v Speaker 1>band floating in space. It could also use its immense

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<v Speaker 1>gravity to to pull them aside as well. Right right,

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<v Speaker 1>and I think if you pull the string cheese incident

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<v Speaker 1>on there, I mean it could just do crazy winners

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<v Speaker 1>with a space rocks headed our way. Um. And the

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<v Speaker 1>other chicky thing about the tractors, it's gonna we have

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<v Speaker 1>to launched. The other chicky thing about the tractors that

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<v Speaker 1>has to be launched fifteen years ahead of time. So

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<v Speaker 1>we're kind of we're kind of stuck. This is what

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<v Speaker 1>we're relying on right now. So gravity, it can it

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<v Speaker 1>can save you from a space rock someday. Perhaps what

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<v Speaker 1>else can it do out in space? Well, gravity can

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<v Speaker 1>also help you fire a spaceship to some distant corner

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<v Speaker 1>of the Solar System. I like the way that sounds. Yeah,

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<v Speaker 1>this is something we call gravity assist. Sometimes you see

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<v Speaker 1>it referred to as a gravity slingshot, but that's a

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<v Speaker 1>little misleading. Um, so just think of it. It's gravity assist,

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<v Speaker 1>all right. And to understand that, you need to think

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<v Speaker 1>of the Solar System in terms of the Sun's gravity. Well, okay,

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<v Speaker 1>imagine a bathtub, all right, It's filled with water and

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<v Speaker 1>it has a little boat in it. Okay, you pull

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<v Speaker 1>the drain, the water begins to to to go to

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<v Speaker 1>to leave the bathtub in the form of a whirlpool.

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<v Speaker 1>The little boat is going to be pulled towards the whirlpool,

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<v Speaker 1>all right. In the scenario, the Sun is the whirlpool.

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<v Speaker 1>It's the object of the most mass and if it

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<v Speaker 1>has the most gravitational pool and spacecraft, right, and it's

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<v Speaker 1>gonna if it's if the little toy boat is moving

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<v Speaker 1>towards the world pool, it's gonna go faster to move

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<v Speaker 1>away from the world pool. It has to work harder

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<v Speaker 1>and it's going slower. Okay, that's basically the gravity well.

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<v Speaker 1>So if we want to send something farther out into

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<v Speaker 1>the gravity well, out to one of the outer planets, um,

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<v Speaker 1>we need to we need a little help, all right,

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<v Speaker 1>and and it and it uh, it's more effective if

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<v Speaker 1>we don't have to depend on say, you know, thrusters

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<v Speaker 1>and rockets to do all of the work and take

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<v Speaker 1>a take advantage of inherent force. Right. So that's where

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<v Speaker 1>the gravity assist comes in. And this is a fly

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<v Speaker 1>by technique where we can add or subtract momentum to

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<v Speaker 1>increase or discrete decrease the energy of a spacecraft. Orbit,

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<v Speaker 1>so we've used it. Yes, UM. Take, for for example,

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<v Speaker 1>Voyager two launched in um, we flew it by Jupiter.

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<v Speaker 1>Will first, just you know, to see Jupiter, that was

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<v Speaker 1>one of its mission objectives. But also um, by flying

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<v Speaker 1>flying by Jupiter, this provided traject trajectory boost to shoot

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<v Speaker 1>it towards Saturn. Now again go back and going back

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<v Speaker 1>to the spaceship and the dog. You know, both both

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<v Speaker 1>the spaceship and the dog have mass and therefore have

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<v Speaker 1>their own gravitational pool. Right, So Voyager two has its

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<v Speaker 1>own gravitational pool, as does Jupiter. All right. So when

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<v Speaker 1>the spacecraft actually tugs on Jupiter as it goes past,

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<v Speaker 1>all right, and actually decreases the planet's orbital momentum by

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<v Speaker 1>a tiny amount, very tiny amount. In return, the spacecraft

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<v Speaker 1>acquires momentum from Jupiter. Except as we're talking, a significant

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<v Speaker 1>amount of momentum, and uh, and it it shoots it

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<v Speaker 1>off in this new trajectory. Okay. Uh. One of the

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<v Speaker 1>more useful analogies, uh that that you find for this

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<v Speaker 1>is imagine a kid standing next to um a train track, okay,

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<v Speaker 1>and he has a softball in his hand. The softball

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<v Speaker 1>is a spacecraft, all right, And then hurtling down the

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<v Speaker 1>train track is a locomotive, al right. The locomotive is Jupiter.

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<v Speaker 1>If you were to throw the softball and hit the

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<v Speaker 1>front of the coming train, then the softball would would

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<v Speaker 1>veer off into another direction with the momentum of the train.

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<v Speaker 1>So it's it's very useful for for shooting off any

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<v Speaker 1>number of probes UH into into the surrounding Solar system

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<v Speaker 1>and uh A lot of people have even looked at

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<v Speaker 1>considered possibilities of using it for the future use of

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<v Speaker 1>man space spacecraft being able to like use the the

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<v Speaker 1>Sun's gravity to shoot an aircraft off to a not

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<v Speaker 1>an aircraft, of using the Sun's gravitational poole to um

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<v Speaker 1>to shoot a spaceship off towards another system. Have you've

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<v Speaker 1>seen Star Trek or any number of science fiction properties,

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<v Speaker 1>then you've you've you've heard examples of this, So I'd

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<v Speaker 1>say that's a cool thing. Gravity shooting you to a

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<v Speaker 1>distant corner of the galaxy. On a more earthly level,

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<v Speaker 1>gravity can perhaps let your home someday. And this is

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<v Speaker 1>an idea that's been around for quite a while. Back

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<v Speaker 1>in the nineteen seventies, there are a bunch of fellows

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<v Speaker 1>at the Lawrence Livermore lab who thought we should try

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<v Speaker 1>to harness the energy potential of gravity courtesy of black hole.

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<v Speaker 1>So this is what they had in mind. You guys,

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<v Speaker 1>remember that a black hole forms when this big old

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<v Speaker 1>star is dying and it's collapsing inward, and the end

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<v Speaker 1>result is this tiny object that's just unspeakably dense. So

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<v Speaker 1>the gravitational force of a black hole is large, so

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<v Speaker 1>large that not even light can escape it. I know

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<v Speaker 1>you guys know this, but let's just reiterate it. So

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<v Speaker 1>the idea was, according to these scientists, was well, let's

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<v Speaker 1>locate a black hole, well, get it to orbit the Earth.

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<v Speaker 1>That's now that that's the point I think where you

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<v Speaker 1>just you cancel this plan like that just sounds like

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<v Speaker 1>the worst idea ever. Hey, let me just okay, it

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<v Speaker 1>gets better, Okay, Okay. So you're gonna get the said

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<v Speaker 1>black hole to orbit the Earth with the help of

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<v Speaker 1>a spaceship, and once it's in permanent orbit, just you know,

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<v Speaker 1>kind of hanging out like black hole does, you're gonna

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<v Speaker 1>tap the power of said black hole by firing matter

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<v Speaker 1>into it. Okay. So the whole plan is we're going

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<v Speaker 1>to go and find the most destructive force in the universe.

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<v Speaker 1>We're going to bring it home and then we're going

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<v Speaker 1>to feed it. Yes, yes, and then wait, it gets better.

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<v Speaker 1>So you know that things get really tiny, as are

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<v Speaker 1>you know, hurtling towards their on their death spiral towards

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<v Speaker 1>a black hole. Well, all that getting tiny business generates

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<v Speaker 1>an amounse amount of energy, and they thought that this

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<v Speaker 1>amount of energy could in fact be enough to start

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<v Speaker 1>a fusion reaction. So this one, this idea of a

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<v Speaker 1>black hole gravity thing, actually never came to fruition. I

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<v Speaker 1>think probably the the first point of business was moving

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<v Speaker 1>the black hole, or actually maybe even locating black hole

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<v Speaker 1>and then moving black hole. So a couple of a

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<v Speaker 1>couple of a couple of holes in this plan. Yes,

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<v Speaker 1>the latest incarnation of gravity power is a lamp. It's

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<v Speaker 1>a little bit simpler and a black hole. No no, no, no, um.

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<v Speaker 1>Let me explain. It's conceived of by this grad student

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<v Speaker 1>at Virginia Tech, and I think he entered his invention

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<v Speaker 1>in some sort of TEO thousand in a green Tech award.

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<v Speaker 1>And it's a guy by the name of claymont. Well.

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<v Speaker 1>Clay calls his lamp the gravity So conceptually, here's how

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<v Speaker 1>Clay's gravity powered lamp works. If you picture kind of

0:12:38.480 --> 0:12:43.040
<v Speaker 1>a cylinder shaped floor lamp, maybe about five feet tall. Um,

0:12:43.240 --> 0:12:45.440
<v Speaker 1>Now imagine that there are these like five ten pound

0:12:45.440 --> 0:12:48.920
<v Speaker 1>brass swats sitting there at the top. And for those

0:12:48.960 --> 0:12:50.640
<v Speaker 1>of you guys who don't know what one is, there's

0:12:50.640 --> 0:12:54.280
<v Speaker 1>a ball screw in in the in the floor lamp.

0:12:54.320 --> 0:12:56.160
<v Speaker 1>And what is the what is ball screw? I had

0:12:56.200 --> 0:12:58.719
<v Speaker 1>no idea before I started doing this podcast. Well, it's

0:12:58.720 --> 0:13:02.240
<v Speaker 1>a it's a linear screw and um, something rotates downward

0:13:02.320 --> 0:13:05.200
<v Speaker 1>on it. So it's kind of like falling on the

0:13:05.200 --> 0:13:08.160
<v Speaker 1>ball screw. It's moving downward on the ball screw. And

0:13:08.200 --> 0:13:10.520
<v Speaker 1>as these brass weades moved downward on the ball screw,

0:13:10.920 --> 0:13:16.439
<v Speaker 1>the screw rotates, and that rotational motion is able to

0:13:16.480 --> 0:13:20.120
<v Speaker 1>spin a generator and convert the motion into electricity. So

0:13:20.200 --> 0:13:21.880
<v Speaker 1>if you can't quite picture, you can always check out

0:13:21.880 --> 0:13:24.400
<v Speaker 1>the illustration. We have a good one on our how

0:13:24.400 --> 0:13:28.520
<v Speaker 1>gravity powered lamps were an article. So anyway, this electricity

0:13:28.520 --> 0:13:32.280
<v Speaker 1>powers ten led bulbs which light up and whaila you

0:13:32.320 --> 0:13:34.439
<v Speaker 1>have light. And do you think, well, how long is

0:13:34.480 --> 0:13:37.000
<v Speaker 1>that going to take? Because gravity can happen relatively fast right,

0:13:37.760 --> 0:13:40.280
<v Speaker 1>falling objects might be down to the bottom and lamp,

0:13:40.280 --> 0:13:43.280
<v Speaker 1>but actually it takes four hours, so that would be

0:13:43.400 --> 0:13:45.400
<v Speaker 1>a good amount of light. Would it would work faster

0:13:45.520 --> 0:13:50.679
<v Speaker 1>on the the phantasm planet with the dwarves? Sure would, Surewood.

0:13:51.320 --> 0:13:54.439
<v Speaker 1>It's also worth noting here that the hour glass is

0:13:54.480 --> 0:13:58.720
<v Speaker 1>actually a gravity powered timetelling device. Yeah, and it seems

0:13:58.720 --> 0:14:02.160
<v Speaker 1>like a little bit of a simple concept than the

0:14:02.160 --> 0:14:06.319
<v Speaker 1>The gravity powered lamp also cuckoo clocks, but are also

0:14:06.400 --> 0:14:11.520
<v Speaker 1>worth considering that they're actually powered by black holes. So anyway,

0:14:11.559 --> 0:14:13.719
<v Speaker 1>the thing with Poort Clay's lamp is that the d

0:14:13.880 --> 0:14:16.400
<v Speaker 1>technology isn't quite where it needs to be, and the

0:14:16.480 --> 0:14:18.559
<v Speaker 1>LEDs aren't as efficient as they need to be, and

0:14:18.640 --> 0:14:21.800
<v Speaker 1>so that means the weights would have to be much heavier.

0:14:21.840 --> 0:14:24.560
<v Speaker 1>And that's about where we are with the gravity powered lamp.

0:14:24.640 --> 0:14:28.000
<v Speaker 1>So you cannot buy one at your local lamp star.

0:14:28.280 --> 0:14:31.280
<v Speaker 1>It sounds promising, though, I like the idea of gravity

0:14:31.280 --> 0:14:35.400
<v Speaker 1>powered electronics. Well, I'll tell you another thing that gravity

0:14:35.440 --> 0:14:40.080
<v Speaker 1>can do for us. What gravity can help us understand

0:14:40.080 --> 0:14:43.400
<v Speaker 1>what's going on underneath the Earth surface. And how many

0:14:43.480 --> 0:14:45.960
<v Speaker 1>do that? Well, think of it this way. Imagine an

0:14:46.000 --> 0:14:50.080
<v Speaker 1>appetizer sampler platter. All right, you know it's it's covered

0:14:50.120 --> 0:14:54.640
<v Speaker 1>with fried cheese sticks, hush puppies. What are the what's

0:14:54.680 --> 0:14:57.520
<v Speaker 1>the meat on the stick called? Oh, chicken settee? Chicken

0:14:57.560 --> 0:15:01.560
<v Speaker 1>sette all right, all of idea of different foods. Now,

0:15:02.080 --> 0:15:05.760
<v Speaker 1>something late and fluffy too, right? Yeah? Like, well, hush

0:15:05.800 --> 0:15:09.360
<v Speaker 1>puppies are lighting fluffy? Right? Well, what's something light and

0:15:09.360 --> 0:15:13.240
<v Speaker 1>fluffy do you get as an appetizer? Um, we'll see.

0:15:13.240 --> 0:15:15.680
<v Speaker 1>I think that's the thing. Most appetizers, they're so hideously

0:15:15.800 --> 0:15:19.240
<v Speaker 1>unhealthy that you get them in small portions first, right, okay,

0:15:19.240 --> 0:15:23.240
<v Speaker 1>So imagine something light and fluffy appetizer, but hush puppy.

0:15:23.640 --> 0:15:26.440
<v Speaker 1>So so you have all these different items on the plate, right,

0:15:26.880 --> 0:15:31.880
<v Speaker 1>and all of them have different densities, okay, which means

0:15:32.720 --> 0:15:36.400
<v Speaker 1>and all of them have gravitational pools, all right, And

0:15:37.000 --> 0:15:40.880
<v Speaker 1>the more dense the appetizer item, the more gravitational pool

0:15:40.920 --> 0:15:45.520
<v Speaker 1>it has. Okay, Okay, all right, Well, our planet is

0:15:45.560 --> 0:15:49.480
<v Speaker 1>basically an appetizer platter when it comes to gravity. All right,

0:15:51.120 --> 0:15:55.720
<v Speaker 1>there are our planet has is covered with varying densities

0:15:55.760 --> 0:15:59.600
<v Speaker 1>of rock. Um, you have you have water that's cold,

0:15:59.640 --> 0:16:01.720
<v Speaker 1>you have water that's hot, and of course there's different

0:16:01.720 --> 0:16:04.000
<v Speaker 1>tensity there. Um. You know, you look under the Earth,

0:16:04.000 --> 0:16:06.800
<v Speaker 1>they're gonna be they're gonna be empty caverns, they're going

0:16:06.880 --> 0:16:10.080
<v Speaker 1>to be uh, you know, blocks of solid bedrock. There's

0:16:10.120 --> 0:16:13.200
<v Speaker 1>going to be you know, liquid magma. So gravity is

0:16:13.200 --> 0:16:15.120
<v Speaker 1>gonna vary according to where are you on there. That's

0:16:15.120 --> 0:16:17.640
<v Speaker 1>interesting because I guess I just think of it as

0:16:17.680 --> 0:16:20.400
<v Speaker 1>such a constant uniform Yeah. Yeah, we think of it

0:16:20.480 --> 0:16:24.720
<v Speaker 1>more as uh, you know, a pizza with a pizza's

0:16:24.720 --> 0:16:28.240
<v Speaker 1>worth of you know, of a uniform gravitational pool. But

0:16:28.720 --> 0:16:31.960
<v Speaker 1>like if you go up to Hudson Bay in Canada, Um,

0:16:32.200 --> 0:16:34.960
<v Speaker 1>the gravity is actually less there. And I need to

0:16:35.000 --> 0:16:38.359
<v Speaker 1>stress that it's not not less in the sense that

0:16:38.360 --> 0:16:41.480
<v Speaker 1>that you can go to, uh to Hudson Bay and

0:16:41.600 --> 0:16:43.800
<v Speaker 1>uh and feel like you lost weight. It's right, You're

0:16:43.800 --> 0:16:45.240
<v Speaker 1>not gonna be able to fit in your skinny jeans,

0:16:45.240 --> 0:16:49.320
<v Speaker 1>are right. The Earth's gravity is still pretty uniform, um,

0:16:49.400 --> 0:16:54.240
<v Speaker 1>all all across the globe, but it varies um to

0:16:54.360 --> 0:16:57.560
<v Speaker 1>it to a slight degree um wherever you go. All right,

0:16:58.680 --> 0:17:00.720
<v Speaker 1>So um, you know, most people say, well, what does

0:17:00.840 --> 0:17:04.119
<v Speaker 1>what does that matter? Right? It matters when you start

0:17:04.440 --> 0:17:09.400
<v Speaker 1>looking into fluid dynamics, alright. The ocean, for instance, Um,

0:17:09.480 --> 0:17:12.800
<v Speaker 1>you have it dictates the flow of hot and cold water,

0:17:13.160 --> 0:17:16.000
<v Speaker 1>all right. I think of it as a topography, okay,

0:17:16.160 --> 0:17:18.639
<v Speaker 1>Like if you have a hill next to a plane,

0:17:19.200 --> 0:17:21.360
<v Speaker 1>you know water is gonna flow down that hill. All right.

0:17:21.760 --> 0:17:23.800
<v Speaker 1>Well you have the same kind of topography going on

0:17:24.000 --> 0:17:27.880
<v Speaker 1>across the planet, except in terms of gravity, with fluids

0:17:27.960 --> 0:17:33.240
<v Speaker 1>drawn towards the areas of higher gravity. Okay. So we're

0:17:33.320 --> 0:17:36.920
<v Speaker 1>very interested in finding out exactly what this uh, this

0:17:37.200 --> 0:17:40.280
<v Speaker 1>secret topography looks like. We in fact, we've launched to

0:17:40.760 --> 0:17:45.520
<v Speaker 1>um Um orbiting a spacecraft. There's a European Space Agencies

0:17:45.920 --> 0:17:49.919
<v Speaker 1>Gravity Field and Steady State Ocean Circulation Explore and this

0:17:50.000 --> 0:17:53.440
<v Speaker 1>is up there right now, um, yes, called GHOS. See

0:17:54.000 --> 0:17:56.320
<v Speaker 1>that one went up in two thousand nine. And then

0:17:56.359 --> 0:18:00.320
<v Speaker 1>there's NASA's Gravity Recovery and Climate experiment that's called Race

0:18:00.720 --> 0:18:03.480
<v Speaker 1>and Grace went up in two thousand two. All right, ghost.

0:18:03.520 --> 0:18:07.080
<v Speaker 1>These mission has been to take a picture of what

0:18:07.920 --> 0:18:10.719
<v Speaker 1>this uh, the secret topography of gravity, which we call

0:18:10.800 --> 0:18:13.240
<v Speaker 1>the geode, to take a picture of what that looks

0:18:13.280 --> 0:18:16.199
<v Speaker 1>like right at nay moment of time, Like what are

0:18:16.200 --> 0:18:19.200
<v Speaker 1>the highs, what are the lows? Uh? Grace has been

0:18:19.359 --> 0:18:24.000
<v Speaker 1>looking at how the geo changes, because it's always changing too.

0:18:24.119 --> 0:18:26.040
<v Speaker 1>It's not like like you can you know, you'll be

0:18:26.040 --> 0:18:27.520
<v Speaker 1>able to go here, and oh, the gravity is always

0:18:27.520 --> 0:18:30.080
<v Speaker 1>going to be this, especially when it comes to the ocean.

0:18:30.160 --> 0:18:32.520
<v Speaker 1>And why do we care if the geo changes? Because

0:18:32.560 --> 0:18:35.720
<v Speaker 1>the more we understand how the ocean transports heat and water,

0:18:35.880 --> 0:18:38.359
<v Speaker 1>the more we understand how the ocean moves, And the

0:18:38.359 --> 0:18:40.119
<v Speaker 1>more we understand how the ocean moves, the more we

0:18:40.200 --> 0:18:43.520
<v Speaker 1>understand how the atmosphere moves. See, it's all a part

0:18:43.560 --> 0:18:47.280
<v Speaker 1>of Earth's outer layer of fluid, all right, and that

0:18:47.359 --> 0:18:50.800
<v Speaker 1>is where our weather takes place. UM and uh and

0:18:50.920 --> 0:18:54.399
<v Speaker 1>you know everything from from fierce hurricanes, two patterns of

0:18:54.480 --> 0:18:58.800
<v Speaker 1>drought and uh floods and what have you? All right, UM,

0:18:58.840 --> 0:19:01.560
<v Speaker 1>so it helps us a better understanding of global climate.

0:19:02.320 --> 0:19:05.800
<v Speaker 1>On a more specific note, UM scientists think it will

0:19:05.800 --> 0:19:09.040
<v Speaker 1>be able to look, uh, look at changes in in gravity,

0:19:09.200 --> 0:19:13.880
<v Speaker 1>changes in density too, to determined shifts and water mass

0:19:13.960 --> 0:19:17.399
<v Speaker 1>caused by droughts or floods. And it will also also

0:19:17.760 --> 0:19:21.960
<v Speaker 1>allow us to better understand plate tectonics, UH, seismic activity.

0:19:22.119 --> 0:19:26.080
<v Speaker 1>You know, what's what's happening underneath underneath the soil um

0:19:26.080 --> 0:19:28.440
<v Speaker 1>in the crust to you know, the leads to two

0:19:28.520 --> 0:19:32.040
<v Speaker 1>two earthquakes and uh another phenomena and uh and just

0:19:32.119 --> 0:19:37.639
<v Speaker 1>the geological geophysical processes that underlie the the Earth. Sorry,

0:19:37.640 --> 0:19:39.520
<v Speaker 1>but it's pretty it's pretty I'm getting a little long

0:19:39.520 --> 0:19:41.919
<v Speaker 1>winded here, but it's pretty pretty, pretty awesome, and that's

0:19:41.920 --> 0:19:44.919
<v Speaker 1>why we're looking into it. So I hope you've inspired

0:19:44.920 --> 0:19:47.800
<v Speaker 1>some reverence for gravity and you besides the kind of

0:19:47.840 --> 0:19:49.639
<v Speaker 1>gravity that trips you up and makes you fall flat

0:19:49.680 --> 0:19:53.120
<v Speaker 1>on your face and gravity is pretty cool. Um. So

0:19:53.160 --> 0:19:55.160
<v Speaker 1>now we would like to take a moment to imagine

0:19:55.200 --> 0:19:59.919
<v Speaker 1>a world without gravity. Oh, we were going to talk

0:20:00.080 --> 0:20:02.080
<v Speaker 1>about it or just imagine it, because I was just

0:20:02.119 --> 0:20:05.520
<v Speaker 1>going to picture it. Yeah. One thing that's really gonna

0:20:05.520 --> 0:20:08.440
<v Speaker 1>suck is that all the atmosphere is going to drift

0:20:08.480 --> 0:20:12.720
<v Speaker 1>off into space and we're not gonna be able to breathe. Yeah. Also,

0:20:12.880 --> 0:20:14.359
<v Speaker 1>I don't think I don't think our hair is gonna

0:20:14.359 --> 0:20:17.320
<v Speaker 1>look right. I mean, how do you style your hair

0:20:17.359 --> 0:20:20.520
<v Speaker 1>for that? That's true? I mean what kind of products

0:20:20.600 --> 0:20:25.639
<v Speaker 1>could could combat that effect? Um? I think that it

0:20:25.640 --> 0:20:28.840
<v Speaker 1>would suck if the the oceans boiled away and just

0:20:28.920 --> 0:20:32.879
<v Speaker 1>kind of float it off into the void um. On

0:20:32.960 --> 0:20:35.240
<v Speaker 1>a more mundane level, I think eating would kind of

0:20:35.359 --> 0:20:39.679
<v Speaker 1>pose a number of challenges. Only the astronauts. They'd be

0:20:39.720 --> 0:20:42.640
<v Speaker 1>sitting there, happy as you please, eating their dinner out

0:20:42.640 --> 0:20:45.000
<v Speaker 1>of their bags. Everybody else would just be in full

0:20:45.000 --> 0:20:48.160
<v Speaker 1>freak out mode. Yeah, like trying to run after their

0:20:48.200 --> 0:20:53.200
<v Speaker 1>hamburger which had floated off into bun Yeah, and the

0:20:53.280 --> 0:20:55.960
<v Speaker 1>chop bits of onion and I'm sorry, catch ups. Just

0:20:56.000 --> 0:20:59.680
<v Speaker 1>a globular thing floating out there. Yeah, yeah, that would

0:20:59.680 --> 0:21:02.240
<v Speaker 1>be bad. So that would be a world without gravity,

0:21:02.280 --> 0:21:05.040
<v Speaker 1>and we hope that we may never encounter it. So

0:21:05.080 --> 0:21:06.880
<v Speaker 1>if you want to tell us why you think gravity

0:21:06.920 --> 0:21:09.360
<v Speaker 1>is cool or maybe not so cool, send us an

0:21:09.359 --> 0:21:12.240
<v Speaker 1>email at science stuff at how stuff works dot com,

0:21:12.400 --> 0:21:15.400
<v Speaker 1>or go read about gravity where we're at site. Yeah,

0:21:15.400 --> 0:21:17.119
<v Speaker 1>and when you got to check out the blogs where

0:21:17.680 --> 0:21:21.840
<v Speaker 1>we handle any number of scientific specs, including zombies from

0:21:21.840 --> 0:21:32.600
<v Speaker 1>time to time. Thanks for listening, guys. For more on

0:21:32.640 --> 0:21:35.119
<v Speaker 1>this and thousands of other topics, is that how stuff

0:21:35.119 --> 0:21:38.679
<v Speaker 1>works dot com. Want more how stuff works, check out

0:21:38.720 --> 0:21:40.920
<v Speaker 1>our blogs on the house stuff works dot com home

0:21:40.960 --> 0:21:47.720
<v Speaker 1>page