WEBVTT

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Have you ever been floating in a swimming pool,

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all comfy and warm, thinking,

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"Man, it'd be cool to be an astronaut!

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You could float out in outer space,

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look down at the Earth and everything.

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It'd be so neat!"

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Only, that's not how it is at all.

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If you are in outer space,

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you are orbiting the Earth,

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it's called free fall.

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You're actually falling towards the Earth.

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Alright, think about this for a moment.

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That's the feeling you get

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if you're going over the top of a roller coaster,

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going, like, "Whoooooaaaahhhh!"

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Only, you're doing this the whole time

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you're orbiting the Earth

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for two,

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three,

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four

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hours,

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days,

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whatever it takes, right?

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So, how does orbiting work?

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Let's take a page from Isaac Newton.

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He had this idea,

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a little mental experiment.

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You take a cannon,

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you put it on top of a hill.

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If you shoot the cannon ball,

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it goes a little bit away.

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But, if you shoot it harder,

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it goes far enough so that it lands

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a little bit past the curvature of Earth.

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Well, you can imagine

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if you shot it really, really, really hard,

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it would go all the way around the Earth

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and come back, boom!

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and, like, hit you in the backside or something.

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Let's zoom way back

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and put you in a little satellite

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over the North Pole of the Earth

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and consider north to be up.

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You're going to fall down and hit the Earth.

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But, you are actually moving sideways really fast.

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So, when you fall down,

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you're going to miss.

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You're going to end up on the side of the Earth,

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falling down,

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and now the Earth is pulling you back in sideways.

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Alright, and so it's pulling you back in

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and you fall down,

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and so you miss the Earth again,

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and now you're under the Earth.

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And, the Earth is going to pull you up,

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but you're moving sideways still.

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So, you're going to miss the Earth again.

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Now, you're on the other side of the Earth,

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moving upward and the Earth's pulling you sideways.

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Alright, so you're going to fall sideways,

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but you're going to be moving up and to a miss.

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And, now you're back on top of the Earth again,

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over the North Pole,

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going sideways and falling down,

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and yep, you guessed it.

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You'll keep missing because you're moving so fast.

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In this way, astronauts orbit the Earth.

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They're always falling towards the Earth,

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but they're always missing,

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and therefore, they're falling all the time.

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They feel like they're falling,

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so you just have to kind of get over it.

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So, technically, if you ran fast enough and tripped,

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you could miss the Earth.

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But, there's a big problem.

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First, you have to be going 8 kilometers a second.

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That's 18,000 miles an hour,

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just over Mach 23!

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The second problem:

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if you're going that fast,

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yes, you would orbit the Earth

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and come back where you came from,

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but there's a lot of air in the way,

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alright, much less people and things.

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So, you would burn up due to atmospheric friction.

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So, I do not recommend this.