WEBVTT - What If the Earth Stopped Spinning? 0:00:01.920 --> 0:00:06.480 Welcome to Brainstuff, a production of I Heart Radio, Hey 0:00:06.519 --> 0:00:11.959 brain Stuff Lauren Vogelbaum. Here back in movie goers were 0:00:11.960 --> 0:00:16.040 treated to an amazing site Superman reversing the spin of 0:00:16.079 --> 0:00:19.279 the Earth, turning back time in the process and saving 0:00:19.400 --> 0:00:23.680 his beloved Loess preposterous, of course, But what if something 0:00:23.880 --> 0:00:28.640 did change the Earth's rotation? What if the rotation stopped completely? 0:00:30.200 --> 0:00:35.040 Let's get our admittedly far fetched assumptions out on the table. First, 0:00:35.240 --> 0:00:38.720 let's assume that the Earth stopped spinning gradually, as a 0:00:38.760 --> 0:00:42.960 sudden deceleration would mean disaster, and second, will suppose that 0:00:43.080 --> 0:00:48.960 Earth's ecosystems have survived the transition mostly intact. So what 0:00:49.120 --> 0:00:53.400 does this new world look like? For starters? Earth would 0:00:53.400 --> 0:00:56.000 now take a whole year to do what it pulls 0:00:56.040 --> 0:00:59.520 off in a day cycle from night to day and back. 0:01:00.440 --> 0:01:03.080 Cities would spend half the year in darkness and half 0:01:03.120 --> 0:01:05.760 the year in full sunlight, just like the North and 0:01:05.800 --> 0:01:09.919 South Poles do to day. And like the Poles, every 0:01:09.959 --> 0:01:13.880 region would still experience different seasons, but the temperature swings 0:01:13.920 --> 0:01:17.080 from seasoned season would be much greater for areas along 0:01:17.120 --> 0:01:21.840 the equator. An equatorial region would spend infernally hot months 0:01:21.959 --> 0:01:25.479 very close to the Sun, while that area's global counterpart 0:01:25.680 --> 0:01:28.800 would spend dark, frigid months very far away from it. 0:01:29.440 --> 0:01:32.280 That's trouble for the plants and animals that have adapted 0:01:32.319 --> 0:01:35.319 to the climate of a region, and consequently for the 0:01:35.440 --> 0:01:39.560 people living there as well. The polar regions would remain 0:01:39.680 --> 0:01:42.800 relatively stable, except for the part where they would be 0:01:42.920 --> 0:01:46.560 deep under water. In fact, the boundaries between ocean and 0:01:46.720 --> 0:01:49.440 land on a spin free Earth would look nothing like 0:01:49.560 --> 0:01:54.000 they do today. Because the Earth rotates, centrifugal force causes 0:01:54.040 --> 0:01:58.480 the planet to bulge along the equator. No rotation, no bulge. 0:01:59.000 --> 0:02:01.600 Without that bulge, all of the extra water held in 0:02:01.640 --> 0:02:05.080 place along the equator would go rushing back toward the poles. 0:02:06.320 --> 0:02:11.119 Ez We, a company that develops geography focused technology, modeled 0:02:11.200 --> 0:02:15.040 the world's land and oceans after its equatorial bulge subsided 0:02:15.360 --> 0:02:18.160 and found that the Earth would have a band of land, 0:02:18.440 --> 0:02:22.760 one giant supercontinent that circles the equator and separates two 0:02:22.880 --> 0:02:27.040 massive oceans to the north and the south, and Earth's 0:02:27.040 --> 0:02:31.240 magnetic field might go away too. While we're not entirely 0:02:31.240 --> 0:02:34.959 sure how that magnetic field is generated, the leading theory 0:02:35.040 --> 0:02:38.480 states that it's the result of Earth's inter core rotating 0:02:38.600 --> 0:02:42.760 slightly faster than its outer core. Yep, that's two different 0:02:42.840 --> 0:02:46.520 rotations in one planet. Should both of them stop, the 0:02:46.639 --> 0:02:50.400 mechanism behind Earth's magnetic field may as well, leaving us 0:02:50.400 --> 0:02:54.040 exposed to harmful solar winds and other radiation from space. 0:02:55.880 --> 0:02:58.880 So where would that leave us? We humans are an 0:02:58.880 --> 0:03:03.280 adaptable species with powerful technology at our disposal, but survival 0:03:03.320 --> 0:03:06.440 in this new environment would be a challenge. But sure, 0:03:06.520 --> 0:03:08.880 we could try to light our homes in the darkness 0:03:08.880 --> 0:03:11.960 and heat and cool them at great cost during wild 0:03:12.040 --> 0:03:15.880 temperature swings, but not everything would be under our control. 0:03:16.480 --> 0:03:20.520 Would crops survive the extremes of this new world? Could 0:03:20.720 --> 0:03:23.960 any plants? If not, the entire food chain would be 0:03:23.960 --> 0:03:27.560 in danger. Perhaps we could find new crops or modify 0:03:27.639 --> 0:03:30.959 existing ones to tolerate this new environment, or maybe we 0:03:31.000 --> 0:03:34.640 would become dependent on perennials that can survive harsh winters 0:03:34.639 --> 0:03:38.960 and return with warm weather. You have to admit, it 0:03:39.000 --> 0:03:41.480 doesn't feel like you're spinning around the center of the 0:03:41.520 --> 0:03:44.520 Earth at hundreds of miles an hour, So we should 0:03:44.600 --> 0:03:48.600 probably cut our scientific forebears some slack for assuming that 0:03:48.680 --> 0:03:51.520 Earth was stationary and that the Sun rotated around it. 0:03:52.360 --> 0:03:55.640 Thanks to a number of mathematicians and astronomers over the centuries, 0:03:55.880 --> 0:03:58.160 we now know that the Earth spins on its axis 0:03:58.200 --> 0:04:01.320 as it revolves around the Sun. But why does our 0:04:01.360 --> 0:04:06.040 planet spin in the first place. Remember Newton's first law 0:04:06.080 --> 0:04:09.480 of motion. It states that an object remains in whatever 0:04:09.560 --> 0:04:12.960 state of motions in unless another force acts upon it. 0:04:13.720 --> 0:04:16.599 You could say that the Earth is rotating because it's 0:04:16.600 --> 0:04:21.000 been doing that for as long as it's existed. Before 0:04:21.040 --> 0:04:23.960 there were planets in our Solar system, there was a spinning, 0:04:24.160 --> 0:04:27.200 nebulous cloud of dust with our Sun at the center. 0:04:28.080 --> 0:04:31.520 Over time, these dust particles collided into one another and 0:04:31.680 --> 0:04:35.960 began to stick, forming larger and larger rocks and ultimately 0:04:36.080 --> 0:04:40.680 planets through a process known as accretion. But remember the 0:04:40.760 --> 0:04:44.680 cloud of dust or accretion disk, was rotating from the start. 0:04:45.360 --> 0:04:48.320 As the particles that formed the Earth began to stick together, 0:04:48.600 --> 0:04:52.479 that momentum was conserved, causing the growing planet to spin 0:04:52.560 --> 0:04:55.520 faster and faster, much the way that a figure skater 0:04:55.640 --> 0:04:58.560 does when they pull their arms in towards their body. 0:04:59.040 --> 0:05:01.440 By the time the Earth had formed, it had all 0:05:01.480 --> 0:05:04.240 of the angular momentum it would need to keep spinning 0:05:04.320 --> 0:05:07.640 to this very day. And now that we know a 0:05:07.680 --> 0:05:10.680 little bit about how planets and solar systems form, it's 0:05:10.720 --> 0:05:13.799 probably not surprising that not only does our planet spin, 0:05:14.120 --> 0:05:16.560 but all of them do, though not always in the 0:05:16.600 --> 0:05:21.680 same direction. Since stars developed from rotating solar nebula, they 0:05:21.720 --> 0:05:27.800 spin too, But how fast. Measuring the straight line speed of, 0:05:28.000 --> 0:05:31.640 say a car, is a fairly simple and reliable process. 0:05:32.200 --> 0:05:35.000 Measuring the speed of a rotating object like the Earth 0:05:35.440 --> 0:05:38.800 is slightly more complicated. After all, if you stand at 0:05:38.800 --> 0:05:41.159 one of the poles, you'll spin right along with the 0:05:41.200 --> 0:05:43.839 rest of the Earth, but you'll be stationary with respect 0:05:43.880 --> 0:05:46.839 to its center. A stand on the equator, though, and 0:05:46.880 --> 0:05:49.680 you'll have a linear speed of one thousand and thirty 0:05:49.720 --> 0:05:52.400 six miles an hour. That's one thousand, six hundred and 0:05:52.400 --> 0:05:55.760 sixty seven kilometers per hour. That's faster than the speed 0:05:55.760 --> 0:05:58.159 of sound and one of the reasons that we tend 0:05:58.200 --> 0:06:02.800 to launch rockets towards the east. So is there anything 0:06:02.960 --> 0:06:07.599 slowing the Earth's rotation down? Well, sure, but the forces 0:06:07.680 --> 0:06:10.560 changing the speed of the Earth's rotation make an extremely 0:06:10.720 --> 0:06:15.120 small impact. The tides, which are caused by the gravitational 0:06:15.160 --> 0:06:18.200 forces between the Earth, the Sun, and the Moon produce 0:06:18.400 --> 0:06:22.160 tidal friction as they interact with the Earth. That drag 0:06:22.360 --> 0:06:26.800 adds about two point three milliseconds toward day every century. 0:06:27.360 --> 0:06:30.800 Weather systems can change the Earth's rotation too, with winds 0:06:30.839 --> 0:06:35.800 applying a breaking force to the planet's surface. Finally, earthquakes 0:06:35.839 --> 0:06:38.160 can mess with the length of a day by actually 0:06:38.240 --> 0:06:42.360 redistributing the Earth's mass. The two thousand eleven earthquake that 0:06:42.440 --> 0:06:46.560 struck Japan actually accelerated the Earth's spin because it shifted 0:06:46.560 --> 0:06:49.560 the mass towards the equator and shortened the day by 0:06:49.600 --> 0:06:54.320 one point eight microseconds. So the next time you complain 0:06:54.400 --> 0:06:57.520 about the day being too long or too short, don't despair. 0:06:57.920 --> 0:07:06.080 It's changing all the time. Today's episode was written by 0:07:06.160 --> 0:07:09.200 John and Attabury and produced by Tyler clang Or. More 0:07:09.200 --> 0:07:11.160 on this and lots of other topics that you may 0:07:11.240 --> 0:07:13.880 or may not find art stopping visit how stuff works 0:07:13.920 --> 0:07:17.000 dot com. Brain Stuff is production of iHeart Radio or 0:07:17.040 --> 0:07:19.760 more podcasts. My Heart Radio visit the iHeart Radio app, 0:07:19.840 --> 0:07:22.600 Apple Podcasts, or wherever you listen to your favorite shows.