WEBVTT - Why doesn't the vacuum of space suck away Earth's atmosphere?

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<v Speaker 1>Welcome to brain Stuff from how Stuff Works dot com

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<v Speaker 1>where smart Happens. I am Marshall Brain with today's question.

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<v Speaker 1>If Nature of Horrors a vacuum, then why doesn't the

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<v Speaker 1>vacuum of space sec away all of Earth's atmosphere? From

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<v Speaker 1>our daily experience with nature, it does seem like Nature

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<v Speaker 1>of Horrors a vacuum. If you create a vacuum inside

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<v Speaker 1>a container here on Earth, Nature will fill the container

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<v Speaker 1>with air very quickly if you puncture that container. On

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<v Speaker 1>the other hand, we know that outer space is a

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<v Speaker 1>giant vacuum. Outer Space is infinitely larger than Earth, so

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<v Speaker 1>ninety nine point nine percent of our universe is a vacuum.

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<v Speaker 1>Based on this, it might be better to say that

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<v Speaker 1>nature loves a vacuum, so why doesn't the vacuum of

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<v Speaker 1>outer space suck away our atmosphere. Say you're standing on

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<v Speaker 1>Earth holding a glass bottle. If you attach the bottle

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<v Speaker 1>to a vacuum pump, pump out all the air, and

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<v Speaker 1>then seal the bottle, the bottle contains a vacuum. If

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<v Speaker 1>you put a hole in the bottle, air rushes in.

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<v Speaker 1>But the reason it rushes in is because of the

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<v Speaker 1>air pressure around the bottle. Standing on the ground, we

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<v Speaker 1>are standing in an ocean of air that rises many

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<v Speaker 1>miles above us. The air molecules stack up on each

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<v Speaker 1>other and they create the pressure of fourteen point seven

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<v Speaker 1>pounds per square inches sea level. The higher you rise

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<v Speaker 1>in the atmosphere, the shorter the stack of molecules, so

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<v Speaker 1>the lower the pressure at sea level. It's the weight

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<v Speaker 1>of all of the molecules stacked above the bottle, fourteen

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<v Speaker 1>point seven pounds of them in every square inch that

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<v Speaker 1>forces the molecule into the punctured vacuum. If you were

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<v Speaker 1>to travel in a rocket to the edge of the atmosphere,

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<v Speaker 1>you would find that there is no air pressure. Instead,

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<v Speaker 1>individual air molecules are zipping around in the vacuum of space.

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<v Speaker 1>The molecules can zip anywhere they like, but they tend

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<v Speaker 1>to zip towards the Earth because the Earth's gravity acts

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<v Speaker 1>on them, just could acts on anything else with mass.

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<v Speaker 1>The reason the vacuum of space doesn't attract the molecules

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<v Speaker 1>is because there is no suction to the vacuum space.

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<v Speaker 1>There's no air pressure forcing things into that vacuum. All

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<v Speaker 1>there is in space is molecules traveling through the vacuum.

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<v Speaker 1>You can see that there's no danger of the vacuum

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<v Speaker 1>sucking our atmosphere away, But it turns out that there

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<v Speaker 1>is another force that could strip away the atmosphere. That

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<v Speaker 1>force is called solar wind. Fortunately, the atmosphere is protected

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<v Speaker 1>from the solar wind by the Earth's magnetic field. Do

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<v Speaker 1>you have any ideas or suggestions for this podcast? If so,

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<v Speaker 1>please send me an email at podcast at how stuff

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<v Speaker 1>works dot com. For more on this and thousands of

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<v Speaker 1>other topics, go to how stuff works dot com.