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Have you ever been floating[br]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,[br]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,[br]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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Think about this for a moment:[br]that's the feeling you get

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if you're going over the top[br]of a roller coaster, going, like, "Whoa!"

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Only you're doing this

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the whole time you're orbiting the Earth,

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for two, three, four hours, 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,[br]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 cannonball,

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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 if you shot[br]it really, really, hard,

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it would go all the way around the Earth

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and come back -- boom! -- and hit you[br]in the backside or something.

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Let's zoom way back[br]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[br]and hit the Earth.

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But you are actually moving[br]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[br]of the Earth, falling down,

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and now the Earth is pulling[br]you back in sideways.

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So it's pulling you back in[br]and you fall down,

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and so you miss the Earth again,[br]and now you're under the Earth.

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The Earth is going to pull you up,[br]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[br]of the Earth, moving upward,

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and the Earth's pulling you sideways.

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So you're going to fall sideways,

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but you're going to be moving up[br]and so you'll miss.

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Now you're back on top of the Earth[br]again, 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[br]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, and therefore,[br]they're falling all the time.

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They feel like they're falling,[br]so you just have to get over it.

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So technically, if you ran[br]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[br]eight 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[br]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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much less people and things.

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So you would burn up[br]due to atmospheric friction.

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So, I do not recommend this.