1 00:00:01,920 --> 00:00:06,480 Speaker 1: Welcome to Brainstuff, a production of I Heart Radio, Hey 2 00:00:06,519 --> 00:00:11,959 Speaker 1: brain Stuff Lauren Vogelbaum. Here back in movie goers were 3 00:00:11,960 --> 00:00:16,040 Speaker 1: treated to an amazing site Superman reversing the spin of 4 00:00:16,079 --> 00:00:19,279 Speaker 1: the Earth, turning back time in the process and saving 5 00:00:19,400 --> 00:00:23,680 Speaker 1: his beloved Loess preposterous, of course, But what if something 6 00:00:23,880 --> 00:00:28,640 Speaker 1: did change the Earth's rotation? What if the rotation stopped completely? 7 00:00:30,200 --> 00:00:35,040 Speaker 1: Let's get our admittedly far fetched assumptions out on the table. First, 8 00:00:35,240 --> 00:00:38,720 Speaker 1: let's assume that the Earth stopped spinning gradually, as a 9 00:00:38,760 --> 00:00:42,960 Speaker 1: sudden deceleration would mean disaster, and second, will suppose that 10 00:00:43,080 --> 00:00:48,960 Speaker 1: Earth's ecosystems have survived the transition mostly intact. So what 11 00:00:49,120 --> 00:00:53,400 Speaker 1: does this new world look like? For starters? Earth would 12 00:00:53,400 --> 00:00:56,000 Speaker 1: now take a whole year to do what it pulls 13 00:00:56,040 --> 00:00:59,520 Speaker 1: off in a day cycle from night to day and back. 14 00:01:00,440 --> 00:01:03,080 Speaker 1: Cities would spend half the year in darkness and half 15 00:01:03,120 --> 00:01:05,760 Speaker 1: the year in full sunlight, just like the North and 16 00:01:05,800 --> 00:01:09,919 Speaker 1: South Poles do to day. And like the Poles, every 17 00:01:09,959 --> 00:01:13,880 Speaker 1: region would still experience different seasons, but the temperature swings 18 00:01:13,920 --> 00:01:17,080 Speaker 1: from seasoned season would be much greater for areas along 19 00:01:17,120 --> 00:01:21,840 Speaker 1: the equator. An equatorial region would spend infernally hot months 20 00:01:21,959 --> 00:01:25,479 Speaker 1: very close to the Sun, while that area's global counterpart 21 00:01:25,680 --> 00:01:28,800 Speaker 1: would spend dark, frigid months very far away from it. 22 00:01:29,440 --> 00:01:32,280 Speaker 1: That's trouble for the plants and animals that have adapted 23 00:01:32,319 --> 00:01:35,319 Speaker 1: to the climate of a region, and consequently for the 24 00:01:35,440 --> 00:01:39,560 Speaker 1: people living there as well. The polar regions would remain 25 00:01:39,680 --> 00:01:42,800 Speaker 1: relatively stable, except for the part where they would be 26 00:01:42,920 --> 00:01:46,560 Speaker 1: deep under water. In fact, the boundaries between ocean and 27 00:01:46,720 --> 00:01:49,440 Speaker 1: land on a spin free Earth would look nothing like 28 00:01:49,560 --> 00:01:54,000 Speaker 1: they do today. Because the Earth rotates, centrifugal force causes 29 00:01:54,040 --> 00:01:58,480 Speaker 1: the planet to bulge along the equator. No rotation, no bulge. 30 00:01:59,000 --> 00:02:01,600 Speaker 1: Without that bulge, all of the extra water held in 31 00:02:01,640 --> 00:02:05,080 Speaker 1: place along the equator would go rushing back toward the poles. 32 00:02:06,320 --> 00:02:11,119 Speaker 1: Ez We, a company that develops geography focused technology, modeled 33 00:02:11,200 --> 00:02:15,040 Speaker 1: the world's land and oceans after its equatorial bulge subsided 34 00:02:15,360 --> 00:02:18,160 Speaker 1: and found that the Earth would have a band of land, 35 00:02:18,440 --> 00:02:22,760 Speaker 1: one giant supercontinent that circles the equator and separates two 36 00:02:22,880 --> 00:02:27,040 Speaker 1: massive oceans to the north and the south, and Earth's 37 00:02:27,040 --> 00:02:31,240 Speaker 1: magnetic field might go away too. While we're not entirely 38 00:02:31,240 --> 00:02:34,959 Speaker 1: sure how that magnetic field is generated, the leading theory 39 00:02:35,040 --> 00:02:38,480 Speaker 1: states that it's the result of Earth's inter core rotating 40 00:02:38,600 --> 00:02:42,760 Speaker 1: slightly faster than its outer core. Yep, that's two different 41 00:02:42,840 --> 00:02:46,520 Speaker 1: rotations in one planet. Should both of them stop, the 42 00:02:46,639 --> 00:02:50,400 Speaker 1: mechanism behind Earth's magnetic field may as well, leaving us 43 00:02:50,400 --> 00:02:54,040 Speaker 1: exposed to harmful solar winds and other radiation from space. 44 00:02:55,880 --> 00:02:58,880 Speaker 1: So where would that leave us? We humans are an 45 00:02:58,880 --> 00:03:03,280 Speaker 1: adaptable species with powerful technology at our disposal, but survival 46 00:03:03,320 --> 00:03:06,440 Speaker 1: in this new environment would be a challenge. But sure, 47 00:03:06,520 --> 00:03:08,880 Speaker 1: we could try to light our homes in the darkness 48 00:03:08,880 --> 00:03:11,960 Speaker 1: and heat and cool them at great cost during wild 49 00:03:12,040 --> 00:03:15,880 Speaker 1: temperature swings, but not everything would be under our control. 50 00:03:16,480 --> 00:03:20,520 Speaker 1: Would crops survive the extremes of this new world? Could 51 00:03:20,720 --> 00:03:23,960 Speaker 1: any plants? If not, the entire food chain would be 52 00:03:23,960 --> 00:03:27,560 Speaker 1: in danger. Perhaps we could find new crops or modify 53 00:03:27,639 --> 00:03:30,959 Speaker 1: existing ones to tolerate this new environment, or maybe we 54 00:03:31,000 --> 00:03:34,640 Speaker 1: would become dependent on perennials that can survive harsh winters 55 00:03:34,639 --> 00:03:38,960 Speaker 1: and return with warm weather. You have to admit, it 56 00:03:39,000 --> 00:03:41,480 Speaker 1: doesn't feel like you're spinning around the center of the 57 00:03:41,520 --> 00:03:44,520 Speaker 1: Earth at hundreds of miles an hour, So we should 58 00:03:44,600 --> 00:03:48,600 Speaker 1: probably cut our scientific forebears some slack for assuming that 59 00:03:48,680 --> 00:03:51,520 Speaker 1: Earth was stationary and that the Sun rotated around it. 60 00:03:52,360 --> 00:03:55,640 Speaker 1: Thanks to a number of mathematicians and astronomers over the centuries, 61 00:03:55,880 --> 00:03:58,160 Speaker 1: we now know that the Earth spins on its axis 62 00:03:58,200 --> 00:04:01,320 Speaker 1: as it revolves around the Sun. But why does our 63 00:04:01,360 --> 00:04:06,040 Speaker 1: planet spin in the first place. Remember Newton's first law 64 00:04:06,080 --> 00:04:09,480 Speaker 1: of motion. It states that an object remains in whatever 65 00:04:09,560 --> 00:04:12,960 Speaker 1: state of motions in unless another force acts upon it. 66 00:04:13,720 --> 00:04:16,599 Speaker 1: You could say that the Earth is rotating because it's 67 00:04:16,600 --> 00:04:21,000 Speaker 1: been doing that for as long as it's existed. Before 68 00:04:21,040 --> 00:04:23,960 Speaker 1: there were planets in our Solar system, there was a spinning, 69 00:04:24,160 --> 00:04:27,200 Speaker 1: nebulous cloud of dust with our Sun at the center. 70 00:04:28,080 --> 00:04:31,520 Speaker 1: Over time, these dust particles collided into one another and 71 00:04:31,680 --> 00:04:35,960 Speaker 1: began to stick, forming larger and larger rocks and ultimately 72 00:04:36,080 --> 00:04:40,680 Speaker 1: planets through a process known as accretion. But remember the 73 00:04:40,760 --> 00:04:44,680 Speaker 1: cloud of dust or accretion disk, was rotating from the start. 74 00:04:45,360 --> 00:04:48,320 Speaker 1: As the particles that formed the Earth began to stick together, 75 00:04:48,600 --> 00:04:52,479 Speaker 1: that momentum was conserved, causing the growing planet to spin 76 00:04:52,560 --> 00:04:55,520 Speaker 1: faster and faster, much the way that a figure skater 77 00:04:55,640 --> 00:04:58,560 Speaker 1: does when they pull their arms in towards their body. 78 00:04:59,040 --> 00:05:01,440 Speaker 1: By the time the Earth had formed, it had all 79 00:05:01,480 --> 00:05:04,240 Speaker 1: of the angular momentum it would need to keep spinning 80 00:05:04,320 --> 00:05:07,640 Speaker 1: to this very day. And now that we know a 81 00:05:07,680 --> 00:05:10,680 Speaker 1: little bit about how planets and solar systems form, it's 82 00:05:10,720 --> 00:05:13,799 Speaker 1: probably not surprising that not only does our planet spin, 83 00:05:14,120 --> 00:05:16,560 Speaker 1: but all of them do, though not always in the 84 00:05:16,600 --> 00:05:21,680 Speaker 1: same direction. Since stars developed from rotating solar nebula, they 85 00:05:21,720 --> 00:05:27,800 Speaker 1: spin too, But how fast. Measuring the straight line speed of, 86 00:05:28,000 --> 00:05:31,640 Speaker 1: say a car, is a fairly simple and reliable process. 87 00:05:32,200 --> 00:05:35,000 Speaker 1: Measuring the speed of a rotating object like the Earth 88 00:05:35,440 --> 00:05:38,800 Speaker 1: is slightly more complicated. After all, if you stand at 89 00:05:38,800 --> 00:05:41,159 Speaker 1: one of the poles, you'll spin right along with the 90 00:05:41,200 --> 00:05:43,839 Speaker 1: rest of the Earth, but you'll be stationary with respect 91 00:05:43,880 --> 00:05:46,839 Speaker 1: to its center. A stand on the equator, though, and 92 00:05:46,880 --> 00:05:49,680 Speaker 1: you'll have a linear speed of one thousand and thirty 93 00:05:49,720 --> 00:05:52,400 Speaker 1: six miles an hour. That's one thousand, six hundred and 94 00:05:52,400 --> 00:05:55,760 Speaker 1: sixty seven kilometers per hour. That's faster than the speed 95 00:05:55,760 --> 00:05:58,159 Speaker 1: of sound and one of the reasons that we tend 96 00:05:58,200 --> 00:06:02,800 Speaker 1: to launch rockets towards the east. So is there anything 97 00:06:02,960 --> 00:06:07,599 Speaker 1: slowing the Earth's rotation down? Well, sure, but the forces 98 00:06:07,680 --> 00:06:10,560 Speaker 1: changing the speed of the Earth's rotation make an extremely 99 00:06:10,720 --> 00:06:15,120 Speaker 1: small impact. The tides, which are caused by the gravitational 100 00:06:15,160 --> 00:06:18,200 Speaker 1: forces between the Earth, the Sun, and the Moon produce 101 00:06:18,400 --> 00:06:22,160 Speaker 1: tidal friction as they interact with the Earth. That drag 102 00:06:22,360 --> 00:06:26,800 Speaker 1: adds about two point three milliseconds toward day every century. 103 00:06:27,360 --> 00:06:30,800 Speaker 1: Weather systems can change the Earth's rotation too, with winds 104 00:06:30,839 --> 00:06:35,800 Speaker 1: applying a breaking force to the planet's surface. Finally, earthquakes 105 00:06:35,839 --> 00:06:38,160 Speaker 1: can mess with the length of a day by actually 106 00:06:38,240 --> 00:06:42,360 Speaker 1: redistributing the Earth's mass. The two thousand eleven earthquake that 107 00:06:42,440 --> 00:06:46,560 Speaker 1: struck Japan actually accelerated the Earth's spin because it shifted 108 00:06:46,560 --> 00:06:49,560 Speaker 1: the mass towards the equator and shortened the day by 109 00:06:49,600 --> 00:06:54,320 Speaker 1: one point eight microseconds. So the next time you complain 110 00:06:54,400 --> 00:06:57,520 Speaker 1: about the day being too long or too short, don't despair. 111 00:06:57,920 --> 00:07:06,080 Speaker 1: It's changing all the time. Today's episode was written by 112 00:07:06,160 --> 00:07:09,200 Speaker 1: John and Attabury and produced by Tyler clang Or. More 113 00:07:09,200 --> 00:07:11,160 Speaker 1: on this and lots of other topics that you may 114 00:07:11,240 --> 00:07:13,880 Speaker 1: or may not find art stopping visit how stuff works 115 00:07:13,920 --> 00:07:17,000 Speaker 1: dot com. Brain Stuff is production of iHeart Radio or 116 00:07:17,040 --> 00:07:19,760 Speaker 1: more podcasts. My Heart Radio visit the iHeart Radio app, 117 00:07:19,840 --> 00:07:22,600 Speaker 1: Apple Podcasts, or wherever you listen to your favorite shows.