1 00:00:00,560 --> 00:00:03,600 Speaker 1: Welcome to brain Stuff from how Stuff Works dot com 2 00:00:03,640 --> 00:00:07,960 Speaker 1: where smart Happens. I am Marshall Brain with today's question. 3 00:00:08,480 --> 00:00:12,000 Speaker 1: If Nature of Horrors a vacuum, then why doesn't the 4 00:00:12,080 --> 00:00:16,360 Speaker 1: vacuum of space sec away all of Earth's atmosphere? From 5 00:00:16,360 --> 00:00:19,760 Speaker 1: our daily experience with nature, it does seem like Nature 6 00:00:19,760 --> 00:00:22,600 Speaker 1: of Horrors a vacuum. If you create a vacuum inside 7 00:00:22,600 --> 00:00:26,160 Speaker 1: a container here on Earth, Nature will fill the container 8 00:00:26,200 --> 00:00:29,840 Speaker 1: with air very quickly if you puncture that container. On 9 00:00:29,880 --> 00:00:32,559 Speaker 1: the other hand, we know that outer space is a 10 00:00:32,800 --> 00:00:37,240 Speaker 1: giant vacuum. Outer Space is infinitely larger than Earth, so 11 00:00:37,360 --> 00:00:42,000 Speaker 1: ninety nine point nine percent of our universe is a vacuum. 12 00:00:42,040 --> 00:00:44,320 Speaker 1: Based on this, it might be better to say that 13 00:00:44,440 --> 00:00:47,720 Speaker 1: nature loves a vacuum, so why doesn't the vacuum of 14 00:00:47,720 --> 00:00:51,400 Speaker 1: outer space suck away our atmosphere. Say you're standing on 15 00:00:51,440 --> 00:00:55,000 Speaker 1: Earth holding a glass bottle. If you attach the bottle 16 00:00:55,040 --> 00:00:57,040 Speaker 1: to a vacuum pump, pump out all the air, and 17 00:00:57,040 --> 00:01:00,360 Speaker 1: then seal the bottle, the bottle contains a vacuum. If 18 00:01:00,400 --> 00:01:02,880 Speaker 1: you put a hole in the bottle, air rushes in. 19 00:01:03,400 --> 00:01:06,040 Speaker 1: But the reason it rushes in is because of the 20 00:01:06,120 --> 00:01:09,640 Speaker 1: air pressure around the bottle. Standing on the ground, we 21 00:01:09,720 --> 00:01:12,880 Speaker 1: are standing in an ocean of air that rises many 22 00:01:12,959 --> 00:01:16,319 Speaker 1: miles above us. The air molecules stack up on each 23 00:01:16,360 --> 00:01:19,679 Speaker 1: other and they create the pressure of fourteen point seven 24 00:01:19,680 --> 00:01:23,160 Speaker 1: pounds per square inches sea level. The higher you rise 25 00:01:23,200 --> 00:01:26,880 Speaker 1: in the atmosphere, the shorter the stack of molecules, so 26 00:01:27,000 --> 00:01:30,559 Speaker 1: the lower the pressure at sea level. It's the weight 27 00:01:30,720 --> 00:01:34,240 Speaker 1: of all of the molecules stacked above the bottle, fourteen 28 00:01:34,280 --> 00:01:37,200 Speaker 1: point seven pounds of them in every square inch that 29 00:01:37,319 --> 00:01:41,119 Speaker 1: forces the molecule into the punctured vacuum. If you were 30 00:01:41,120 --> 00:01:44,120 Speaker 1: to travel in a rocket to the edge of the atmosphere, 31 00:01:44,240 --> 00:01:47,919 Speaker 1: you would find that there is no air pressure. Instead, 32 00:01:48,200 --> 00:01:52,120 Speaker 1: individual air molecules are zipping around in the vacuum of space. 33 00:01:52,640 --> 00:01:56,000 Speaker 1: The molecules can zip anywhere they like, but they tend 34 00:01:56,080 --> 00:01:59,320 Speaker 1: to zip towards the Earth because the Earth's gravity acts 35 00:01:59,320 --> 00:02:02,040 Speaker 1: on them, just could acts on anything else with mass. 36 00:02:02,360 --> 00:02:06,080 Speaker 1: The reason the vacuum of space doesn't attract the molecules 37 00:02:06,280 --> 00:02:09,480 Speaker 1: is because there is no suction to the vacuum space. 38 00:02:09,919 --> 00:02:13,760 Speaker 1: There's no air pressure forcing things into that vacuum. All 39 00:02:13,800 --> 00:02:18,960 Speaker 1: there is in space is molecules traveling through the vacuum. 40 00:02:19,000 --> 00:02:21,359 Speaker 1: You can see that there's no danger of the vacuum 41 00:02:21,440 --> 00:02:24,440 Speaker 1: sucking our atmosphere away, But it turns out that there 42 00:02:24,639 --> 00:02:28,239 Speaker 1: is another force that could strip away the atmosphere. That 43 00:02:28,280 --> 00:02:32,679 Speaker 1: force is called solar wind. Fortunately, the atmosphere is protected 44 00:02:32,720 --> 00:02:36,320 Speaker 1: from the solar wind by the Earth's magnetic field. Do 45 00:02:36,360 --> 00:02:39,880 Speaker 1: you have any ideas or suggestions for this podcast? If so, 46 00:02:40,000 --> 00:02:42,680 Speaker 1: please send me an email at podcast at how stuff 47 00:02:42,720 --> 00:02:45,480 Speaker 1: works dot com. For more on this and thousands of 48 00:02:45,480 --> 00:02:50,080 Speaker 1: other topics, go to how stuff works dot com.