1 00:00:01,920 --> 00:00:07,080 Speaker 1: Welcome to brain Stuff production of iHeart Radio. Hey brain Stuff, 2 00:00:07,120 --> 00:00:10,200 Speaker 1: I'm Lauren Vogelbaum, and this is another classic episode from 3 00:00:10,240 --> 00:00:13,800 Speaker 1: our previous host, Christian Sager. For me, one of the 4 00:00:13,880 --> 00:00:17,040 Speaker 1: weirdly comforting things about science is that it always leaves 5 00:00:17,079 --> 00:00:21,000 Speaker 1: itself open to further questioning and exploration. You can almost 6 00:00:21,040 --> 00:00:24,560 Speaker 1: always dig deeper. And that's the case with today's question, 7 00:00:25,239 --> 00:00:30,520 Speaker 1: why do balloons stick to our hair? Hey, brain Stuff? 8 00:00:30,600 --> 00:00:32,680 Speaker 1: Is Christian Sager here. When you were a kid, did 9 00:00:32,680 --> 00:00:35,720 Speaker 1: you ever rub a balloon really fast against your hair 10 00:00:35,840 --> 00:00:39,240 Speaker 1: to make it stick? What about as an adult? Well, 11 00:00:39,280 --> 00:00:44,200 Speaker 1: after many years of speculation, Case Western Reserve University scientists 12 00:00:44,240 --> 00:00:49,239 Speaker 1: have pinpointed exactly why this party trick happens. We've known 13 00:00:49,320 --> 00:00:52,640 Speaker 1: forever that when two objects are rubbed against each other 14 00:00:52,720 --> 00:00:55,880 Speaker 1: there's a build up of an electrical charge called static 15 00:00:55,880 --> 00:01:00,840 Speaker 1: electricity or tribo electric charging. If the two objects have 16 00:01:01,000 --> 00:01:05,679 Speaker 1: opposite charges positive and negative, they'll stick together. But some 17 00:01:05,880 --> 00:01:09,920 Speaker 1: objects appear to charge more or stick more closely together 18 00:01:10,240 --> 00:01:13,760 Speaker 1: than others, like the balloon on your hair. Now, why 19 00:01:13,840 --> 00:01:16,760 Speaker 1: is that? According to a new study published in the 20 00:01:16,880 --> 00:01:21,000 Speaker 1: journal Physical Review Materials, the crux of the phenomenon lies 21 00:01:21,360 --> 00:01:25,120 Speaker 1: and how strained the balloon material is. For the purpose 22 00:01:25,200 --> 00:01:30,760 Speaker 1: of this study, the scientists stretched a film of polytetrafluoroethylene. 23 00:01:31,000 --> 00:01:34,040 Speaker 1: Let's just call it PTFE for now. That's one of 24 00:01:34,120 --> 00:01:37,000 Speaker 1: the brand names for Teflon. They took that and they 25 00:01:37,120 --> 00:01:41,920 Speaker 1: rubbed it against a film of unstrained unstretched ptf E, 26 00:01:42,440 --> 00:01:45,680 Speaker 1: and they found that even though the materials were chemically identical, 27 00:01:46,040 --> 00:01:50,080 Speaker 1: they generated charge transfer in one direction as if they 28 00:01:50,200 --> 00:01:54,800 Speaker 1: had two different chemical compositions. The stretched or strange sheet 29 00:01:54,920 --> 00:01:58,400 Speaker 1: carried the positive charge, while the unstranged sheet carried a 30 00:01:58,600 --> 00:02:02,600 Speaker 1: negative charge. The more strained the material was, the more 31 00:02:02,720 --> 00:02:07,120 Speaker 1: likely it was to experience systematic charge transfer. This is 32 00:02:07,200 --> 00:02:11,040 Speaker 1: because the micro structure of the material was altered when strained, 33 00:02:11,240 --> 00:02:16,079 Speaker 1: leading to tiny holes and cracks. These imperfections allowed the 34 00:02:16,200 --> 00:02:22,320 Speaker 1: rubbing induced friction to facilitate charge transfer, leading to static electricity. 35 00:02:22,800 --> 00:02:26,239 Speaker 1: In a press release, co authored Dan Lax explained that 36 00:02:26,320 --> 00:02:29,360 Speaker 1: they think the void regions and the fibrils these are 37 00:02:29,480 --> 00:02:33,600 Speaker 1: tiny cell fibers. They think that those were strained when 38 00:02:33,600 --> 00:02:37,679 Speaker 1: the polymer had different bonding and thus a charge that 39 00:02:37,880 --> 00:02:41,800 Speaker 1: was different. The researchers also examined the phenomenon using packing 40 00:02:41,919 --> 00:02:45,040 Speaker 1: peanuts which just love to stick to people's arms. In fact, 41 00:02:45,320 --> 00:02:49,680 Speaker 1: polystyrene peanuts and plastic bags are currently being closely examined 42 00:02:49,960 --> 00:02:54,000 Speaker 1: to give us a better understanding of static electricity. Ideally, 43 00:02:54,360 --> 00:02:57,359 Speaker 1: scientists will nail it down so precisely that they will 44 00:02:57,400 --> 00:03:00,680 Speaker 1: be able to control it, helping to prevent tribe electric 45 00:03:00,800 --> 00:03:04,600 Speaker 1: explosions such as explosions of cold dust in minds, and 46 00:03:04,720 --> 00:03:09,119 Speaker 1: develop more effective products, for example, pesticides that will stick 47 00:03:09,200 --> 00:03:12,760 Speaker 1: better to plants or paints that will stick better to cars. 48 00:03:13,240 --> 00:03:16,640 Speaker 1: It may not seem that dangerous, but in fact static 49 00:03:16,720 --> 00:03:21,239 Speaker 1: electricity can ignite fuel vapors at the gas pump, causing fire. 50 00:03:21,560 --> 00:03:25,040 Speaker 1: To avoid such a catastrophe, try not to get back 51 00:03:25,240 --> 00:03:28,760 Speaker 1: in the car after you start the fueling process, because 52 00:03:28,840 --> 00:03:33,200 Speaker 1: sliding across the seat generates static electricity. If you must 53 00:03:33,280 --> 00:03:36,800 Speaker 1: re enter your vehicle, be sure to ground yourself first 54 00:03:36,960 --> 00:03:40,240 Speaker 1: when you get back out by touching the metal part 55 00:03:40,440 --> 00:03:48,760 Speaker 1: of your car door. Today's episode was written by Lee A. 56 00:03:48,800 --> 00:03:51,760 Speaker 1: Hooint and produced by Dylan Fagan and Tyler Clang. For 57 00:03:51,920 --> 00:03:53,760 Speaker 1: more on this and lots of other topics, visit how 58 00:03:53,800 --> 00:03:56,480 Speaker 1: stuff works dot com. Brain Stuff is production of iHeart 59 00:03:56,560 --> 00:03:59,080 Speaker 1: Radio or more podcasts in my heart Radio, visit the 60 00:03:59,120 --> 00:04:01,880 Speaker 1: iHeart Radio app, Apple podcasts, or wherever you listen to 61 00:04:01,920 --> 00:04:13,960 Speaker 1: your favorite shows. H