Speaker 1: Audible dot com is the leading provider of digital audio
Speaker 1: books and spoken word, with over one tho titles to
Speaker 1: choose from. Audible lets you listen to your favorite books anywhere, anytime.
Speaker 1: Go to audible podcast dot com slash stuff brain to
Speaker 1: get a free audio book download of your choice when
Speaker 1: you sign up today. Welcome to brain Stuff from how
Speaker 1: stuff works dot com where smart happens. Hi. I am
Speaker 1: Marshall Brain with today's question. If Nature of Horrors a vacuum,
Speaker 1: then why doesn't the vacuum of space sec away all
Speaker 1: of Earth's atmosphere? From our daily experience with nature, it
Speaker 1: does seem like Nature of Horrors a vacuum. If you
Speaker 1: create a vacuum inside a container here on Earth, nature
Speaker 1: will fill the container with air very quickly if you
Speaker 1: puncture that container. On the other hand, we know that
Speaker 1: outer space is a giant vacuum. Outer space is infinitely
Speaker 1: larger than Earth. Ninety nine point nine percent of our
Speaker 1: universe is a vacuum. Based on this, it might be
Speaker 1: better to say that nature loves a vacuum, So why
Speaker 1: doesn't the vacuum of outer space suck away our atmosphere?
Speaker 1: Say you're standing on Earth holding a glass bottle. If
Speaker 1: you attach the bottle to a vacuum pump, pump out
Speaker 1: all the air, and then seal the bottle. The bottle
Speaker 1: contains a vacuum. If you put a hole in the bottle,
Speaker 1: air rushes in. But the reason it rushes in is
Speaker 1: because of the air pressure around the bottle. Standing on
Speaker 1: the ground, we are standing in an ocean of air
Speaker 1: that rises many miles above us. The air molecules stack
Speaker 1: up on each other and they create the pressure of
Speaker 1: fourteen point seven pounds per square inch at sea level.
Speaker 1: The higher you rise in the atmosphere, the shorter the
Speaker 1: stack of molecules, so the lower the pressure at sea level.
Speaker 1: It's the weight of all of the molecules stacked above
Speaker 1: the bottle, fourteen point seven pounds of them in every
Speaker 1: square inch that forces the molecule into the punctured vacuum.
Speaker 1: If you were to travel in a rocket to the
Speaker 1: edge of the atmosphere, you would find that there is
Speaker 1: no air pressure. Instead, individual air molecules are zipping around
Speaker 1: in the vacuum of space. The molecules can zip anywhere
Speaker 1: they like, but they tend to zip towards the Earth
Speaker 1: because the Earth's gravity acts on them, just like it
Speaker 1: acts on anything else with mass. The reason the vacuum
Speaker 1: of space doesn't attract the molecules is because there is
Speaker 1: no suction to the vacuum space. There's no air pressure
Speaker 1: forcing things into that vacuum. All there is in space
Speaker 1: is molecules traveling through the vacuum. You can see that
Speaker 1: there's no danger of the vacuum sucking our atmosphere away,
Speaker 1: but it turns out that there is another force that
Speaker 1: could strip away the atmosphere. That force is called solar wind. Fortunately,
Speaker 1: the atmosphere is protected from the solar wind by the
Speaker 1: Earth's magnetic field. From on this and thousands of other
Speaker 1: topics because it how stuff works dot com. Audible dot
Speaker 1: com is the leading provider of digital audio books and
Speaker 1: spoken word, with over one thousand titles to choose from.
Speaker 1: Audible lets you listen to your favorite books anywhere, anytime.
Speaker 1: Go to audible podcast dot com slash stuff brain to
Speaker 1: get a free audio book download of your choice when
Speaker 1: you sign up today.