WEBVTT - From the Vault: The Invention of Soap 0:00:05.720 --> 0:00:08.280 Hey, welcome to Stuff to Blow Your Mind. My name 0:00:08.320 --> 0:00:11.360 is Robert Lamb and I'm Joe McCormick, and it's Saturday. 0:00:11.440 --> 0:00:13.520 Time to go into the vault for a classic episode 0:00:13.520 --> 0:00:16.040 of the show. Today we're fishing out an episode of Invention. 0:00:16.560 --> 0:00:19.079 I think so this one originally published in April of 0:00:19.120 --> 0:00:22.840 twenty It was an Invention episode on the invention of soap, 0:00:23.400 --> 0:00:26.200 and if I recall correctly, this one is like early 0:00:26.400 --> 0:00:30.800 COVID themed Yeah, I believe so. Um it was you 0:00:30.920 --> 0:00:32.479 lined up with a few different things. First of all, 0:00:32.520 --> 0:00:37.280 COVID and ore are sort of rediscovered relationship with soap 0:00:38.080 --> 0:00:41.680 at the time. But then also this was the final 0:00:41.760 --> 0:00:46.040 episode of Invention as a separate entity from Stuff to 0:00:46.040 --> 0:00:49.400 Blow Your Mind. But but the first also the first 0:00:49.440 --> 0:00:51.800 episode of Invention that was part of the Stuff to 0:00:51.840 --> 0:00:54.600 Blow Your Mind feet because now nowadays we'll still can 0:00:54.840 --> 0:00:58.440 we'll still do Invention episodes from time to time. Um, 0:00:58.480 --> 0:01:00.640 but they published in the Stuff to Blow Your Mind 0:01:00.680 --> 0:01:03.920 feed right. I'd also be curious to listen back to 0:01:03.960 --> 0:01:05.480 this one because it's going to be kind of a 0:01:05.520 --> 0:01:08.560 time capsule in the evolution of our understanding of like 0:01:08.600 --> 0:01:11.240 how COVID nineteen was spreading and stuff. So so I 0:01:11.280 --> 0:01:16.280 expect this one to be interestingly dated. All right, let's 0:01:16.480 --> 0:01:22.320 ladder up and get in there. Welcome to Stook to 0:01:22.319 --> 0:01:31.640 Blow Your Mind production of My Heart Radio. Hey you 0:01:31.680 --> 0:01:33.560 welcome to Stuff to Blow Your Mind. My name is 0:01:33.640 --> 0:01:36.560 Robert Lamb and I'm Joe McCormick and Robert I am 0:01:36.600 --> 0:01:40.160 ready to lather up. That's right. Uh. In this episode, 0:01:40.200 --> 0:01:43.640 we are going to be exploring uninvention. Uh we're getting 0:01:43.640 --> 0:01:45.640 into a little techno history here, but we're going to 0:01:45.680 --> 0:01:50.480 be considering soap. Soap has been on everyone's mind a 0:01:50.480 --> 0:01:53.360 bit more these days, I think. Uh, this is actually 0:01:53.360 --> 0:01:56.480 a topic that was suggested to us for our our 0:01:56.520 --> 0:02:01.120 previous side show, Invention, which is now back a part 0:02:01.200 --> 0:02:04.720 of Stuff to Blow Your Mind itself. Um, Soap is 0:02:04.920 --> 0:02:08.240 something that is I think easy to take for granted, uh, 0:02:08.960 --> 0:02:11.960 given normal situations. Right. Soap is just the thing that 0:02:12.040 --> 0:02:15.640 you uh, you know, speedily wash your hands with, you know, 0:02:15.680 --> 0:02:17.720 add a little bit of a nice smell, take some 0:02:17.760 --> 0:02:20.040 of the grease or grit off so you can move 0:02:20.080 --> 0:02:21.680 on to something else. Perhaps give you a little bit 0:02:21.720 --> 0:02:24.200 of peace of mind before you do things like prepare 0:02:24.240 --> 0:02:28.240 food or put your contacts in but lately it is, 0:02:28.440 --> 0:02:31.839 of course, has been stressed how essential it is via 0:02:31.960 --> 0:02:35.800 hand washing in the prevention of the spread of COVID nineteen. 0:02:36.200 --> 0:02:38.840 All right, so let's let's talk about soap. Soap is 0:02:38.880 --> 0:02:42.480 of course a human invention. But did we ever get 0:02:42.520 --> 0:02:44.280 by without it? I mean, it's hard for us to 0:02:44.320 --> 0:02:47.440 imagine life without soap, especially now, because it aids us 0:02:47.440 --> 0:02:49.960 in the cleaning of our bodies. It also helps us 0:02:50.000 --> 0:02:52.680 so via you know, detergents in the cleaning of our garments. 0:02:52.680 --> 0:02:56.760 We use uh, soaps to clean you know, objects and 0:02:56.800 --> 0:03:00.280 surfaces as well. It helps maintain basic hygiene, it evince 0:03:00.320 --> 0:03:02.800 the spread of disease, and it can also impart a 0:03:02.919 --> 0:03:05.760 pleasing odor. You know, what's not to love about soap? 0:03:05.840 --> 0:03:08.280 And how on earth can we get by without it? Now? 0:03:08.320 --> 0:03:11.320 Obviously we can look to the animal world for plenty 0:03:11.360 --> 0:03:14.840 of examples. Uh, But but a few common examples do 0:03:14.919 --> 0:03:18.080 tell us a lot. Birds, for instance, clean themselves with 0:03:18.120 --> 0:03:23.000 their beaks, and they use water or dust to bathe themselves. Cats, dogs, 0:03:23.040 --> 0:03:26.040 and cows are frequent examples of animals that look themselves 0:03:26.080 --> 0:03:30.200 to clean themselves. And uh, let's consider a few terms 0:03:30.240 --> 0:03:33.760 to put things in perspective as well. We're talking about grooming, 0:03:33.960 --> 0:03:36.480 which is a comfort behavior that is the practice of 0:03:36.520 --> 0:03:40.840 cleaning the body surface, including the cleaning and oiling of 0:03:40.920 --> 0:03:44.720 feathers with the bill or of the hair with the tongue. 0:03:44.920 --> 0:03:47.960 And there are a few broad categories here. There's first 0:03:48.000 --> 0:03:50.920 of all, auto grooming, that is an animal's grooming of 0:03:51.000 --> 0:03:54.560 itself and you know, ultimately that's what's going on when 0:03:54.640 --> 0:03:56.280 you take a shower in the morning or in the 0:03:56.320 --> 0:03:59.800 evening or whenever or both, you know, go go out. Uh. 0:03:59.840 --> 0:04:03.120 There's also all of grooming, which is an animal's grooming 0:04:03.160 --> 0:04:06.920 of another for parental or social reasons. Yeah, and uh, 0:04:07.080 --> 0:04:10.280 one thing that's very interesting is the the array of 0:04:10.480 --> 0:04:14.160 social dynamics that seem to take place through grooming behaviors, 0:04:14.200 --> 0:04:18.839 like say, primate grooming behaviors, where primates will sometimes pick 0:04:19.240 --> 0:04:22.120 pick little knits and bits and bugs out of each 0:04:22.120 --> 0:04:26.240 other's hair as a way to to manage and mediate 0:04:26.320 --> 0:04:30.159 social bonds within groups. Yeah, it becomes a part of 0:04:30.200 --> 0:04:34.080 the society for creatures like that and for creatures like us. 0:04:34.120 --> 0:04:37.200 So all of this amounts to a general physical removal 0:04:37.240 --> 0:04:41.560 of particles scraped away, picked away, washed away, and there 0:04:41.600 --> 0:04:45.919 may be bacteria sidal properties as well. Uh you know, 0:04:45.960 --> 0:04:49.360 particularly you'll see something there's some studies about saliva um 0:04:50.120 --> 0:04:53.159 and to what degree they may be able to kill bacteria. 0:04:53.720 --> 0:04:57.400 But this, this basic removal can deal with everything from 0:04:57.480 --> 0:05:01.120 sand and dirt to dead skin, cell alls, loose hairs, 0:05:01.200 --> 0:05:05.400 loose feathers, and like you mentioned, actual exo parasites, and 0:05:05.400 --> 0:05:08.839 of course in cleansing oneself, it's helpful to use nails 0:05:08.880 --> 0:05:13.400 and claws and beaks and all these these various uh um, 0:05:13.080 --> 0:05:16.040 you know, bio tools that we've already mentioned. But in 0:05:16.160 --> 0:05:19.719 dealing with with humans, in dealing with Homo sapiens and 0:05:19.760 --> 0:05:23.599 some of Homo sapiens closest kin, we of course have 0:05:23.680 --> 0:05:27.480 to get into tool use. We get into the techno 0:05:27.600 --> 0:05:30.279 history of the situation here. And one of the sources 0:05:30.320 --> 0:05:33.520 I was looking at for this episode was soaps from 0:05:33.560 --> 0:05:37.479 the Phoenicians to the twentieth century. A historical review by 0:05:37.839 --> 0:05:41.640 Role at All came out in n They point out 0:05:41.640 --> 0:05:44.760 a few key examples from quote the pre soap era, 0:05:45.400 --> 0:05:47.320 this is uh an area you might think of as 0:05:47.440 --> 0:05:50.600 the squeegee era, you know, where there we did have 0:05:50.640 --> 0:05:54.160 some tools we we probably were interested in cleaning ourselves, 0:05:54.200 --> 0:05:56.200 but we didn't have soap yet, So what can you do? 0:05:56.400 --> 0:05:58.800 Maybe you can kind of squeege your skin with a 0:05:59.279 --> 0:06:02.880 with a little bit of abrasive action. Yeah, And indeed, uh, 0:06:03.000 --> 0:06:07.599 Neolithic people apparently used flint scrapers to clean themselves, a 0:06:07.600 --> 0:06:11.440 basic way to remove dirt, grime, dead skin cells. You know, 0:06:11.640 --> 0:06:15.000 why depend on just those those So I'm guessing hard 0:06:15.120 --> 0:06:18.360 fingernails that you have, uh, during the Neolithic period, when 0:06:18.400 --> 0:06:21.360 you can also start using some some some tools. You're 0:06:21.400 --> 0:06:23.880 using tools to scrape other things. You need a good 0:06:23.920 --> 0:06:27.600 scraping as well, So grab some flint and get in there. Now. 0:06:27.640 --> 0:06:30.080 I really hope that they were not using the same 0:06:30.680 --> 0:06:34.920 hand axes, by faces or pieces of flint to process 0:06:35.000 --> 0:06:38.120 animal carcasses and then to scrape their own skin clean. 0:06:38.240 --> 0:06:42.560 But I have to guess there probably was a bit acrossover. Yeah, 0:06:42.560 --> 0:06:47.600 it seems inevitable, doesn't it. But so the use of 0:06:47.640 --> 0:06:50.960 a kind of a bit of mechanical leverage some some 0:06:51.160 --> 0:06:55.760 scraping with a tool did not stop with Neolithic Stone 0:06:55.800 --> 0:06:59.440 Age people. This actually did continue into classical civilizations like 0:06:59.480 --> 0:07:02.080 the Romans did something similar. Yeah, before the Age of 0:07:02.080 --> 0:07:04.719 plenty in the first centuries see the Greeks and Romans 0:07:04.920 --> 0:07:07.240 depended on what they had. Vapor baths. They had, you know, 0:07:07.480 --> 0:07:11.800 an extravagant bath system for sure, but also they would 0:07:11.880 --> 0:07:16.320 scrub and scrape the skin with a stridgle or skin 0:07:16.400 --> 0:07:19.920 scraper made of bone, ivory or metal. And this basically 0:07:20.000 --> 0:07:22.360 what it sounds like. You get the you get the 0:07:22.800 --> 0:07:26.680 skin itself, you know, nice and moist from a bath 0:07:26.800 --> 0:07:29.800 or perhaps via the application of an oil, and then 0:07:29.880 --> 0:07:32.880 you can start scraping away and remove that, you know, 0:07:32.920 --> 0:07:36.120 that outer layer of grime, dead skin, et cetera. I 0:07:36.120 --> 0:07:40.680 guess some people still use something like this to cleanse themselves. 0:07:40.720 --> 0:07:43.560 I mean in terms of just dealing with our skin. 0:07:43.880 --> 0:07:47.000 I mean, I know, for instance that just going to 0:07:47.040 --> 0:07:49.600 the y m c A. I'll hear some of the 0:07:49.600 --> 0:07:52.880 the older gentleman in the locker room. Uh, they would 0:07:52.920 --> 0:07:54.840 talk of ways that they would deal with the like 0:07:54.880 --> 0:07:58.160 the thickened callouses on their feet, and some of the 0:07:59.280 --> 0:08:01.720 sometimes bad add advice they would give each other would 0:08:01.720 --> 0:08:05.840 involve essentially scraping away the skin, generally with with tools 0:08:05.840 --> 0:08:11.200 and implements that were not designed for that purpose. Wait, 0:08:11.720 --> 0:08:13.679 it sounds like you've got a specific tool in mind, 0:08:13.760 --> 0:08:17.040 or they like using a food processor blade or what. Um, well, 0:08:17.080 --> 0:08:19.320 one was definitely. There was a guy that was telling 0:08:19.320 --> 0:08:20.760 me what you need to do is you need to 0:08:20.800 --> 0:08:24.640 get yourself safety raiser and then remove some of the 0:08:24.640 --> 0:08:27.320 safety features and then you can just you can, you know, 0:08:27.320 --> 0:08:30.360 scrape away some skin, uh, which sounds like a bad 0:08:30.440 --> 0:08:33.280 idea and I do not recommend anyone do that. Another 0:08:33.320 --> 0:08:34.640 person said, what you need to do is you need 0:08:34.679 --> 0:08:37.719 to get one of these and he held up um, oh, well, 0:08:37.760 --> 0:08:40.760 what's the what do you call these? It's the it's 0:08:40.800 --> 0:08:44.880 for the grating of say ginger for culinary purposes. A 0:08:44.960 --> 0:08:50.160 micro yes, a microplane. Uh. So he held microhide and 0:08:50.200 --> 0:08:51.640 he says, you can get one of these at bed 0:08:51.679 --> 0:08:54.920 bath and beyond. It works great. Again, I would not 0:08:54.960 --> 0:08:58.040 recommend using that in your body. I would recommend getting 0:08:58.640 --> 0:09:03.040 a sand ng or scrubbing implement that is designed for 0:09:03.240 --> 0:09:05.880 use on the skin and use on the feet. What 0:09:05.920 --> 0:09:10.200 you do is you get a stick blender and oh man, 0:09:10.840 --> 0:09:13.280 but that's not to say that that other folks weren't 0:09:13.320 --> 0:09:17.600 engaging in the use of essentially chemical approaches to the 0:09:17.640 --> 0:09:20.720 cleaning of the skin. The ancient Egyptians made use of 0:09:20.760 --> 0:09:23.400 soda to clean their skin as well as to treat 0:09:23.440 --> 0:09:27.160 diseases of the skin. Okay, so soda is interesting here 0:09:27.240 --> 0:09:30.240 because that suggests we're we're getting a little bit closer 0:09:30.280 --> 0:09:33.199 to soap like territories. This will make more sense when 0:09:33.240 --> 0:09:36.800 we explain soapen a bit. But but soda, of course 0:09:37.160 --> 0:09:40.760 is an alkali. It's a it's a base, and in 0:09:40.880 --> 0:09:44.080 certain combinations, in the presence of fats and water, this 0:09:44.200 --> 0:09:48.400 can actually have a lathering soap like effect. Yeah. So, 0:09:48.400 --> 0:09:51.240 so this is a nice ancient example. We'll get into 0:09:51.240 --> 0:09:53.760 some more in a bit. But oh, and then another 0:09:53.800 --> 0:09:57.600 example that wrowth at all point point out fifth century BC. 0:09:57.880 --> 0:10:01.520 During this time period, Herodotus wrote of the priest physicians 0:10:01.559 --> 0:10:04.920 of the temple of Ammon at Karnak in Egypt during 0:10:04.960 --> 0:10:09.800 the reign of Ramesses. This would have been leven thirteen 0:10:09.960 --> 0:10:14.360 through ten five BC, and Herodotas stated that they would 0:10:14.520 --> 0:10:17.400 quote bathe in cold water twice a day and twice 0:10:17.440 --> 0:10:22.000 a night, and cleansed their mouths with natron. Now natron 0:10:22.160 --> 0:10:26.160 was a mixture of sodium bicarbonate and sodium carbonate. That's 0:10:26.160 --> 0:10:29.960 what you call mummy mouth. Uh. One of my favorite 0:10:29.960 --> 0:10:33.439 books on the history of hygiene is a book titled 0:10:33.440 --> 0:10:36.400 Clean by Virginia Smith, and in that she points out 0:10:36.440 --> 0:10:40.600 that that natron was dissolved in water to clean the body, 0:10:40.640 --> 0:10:43.880 to clean clothes, furniture, and sometimes it could be ignited 0:10:43.880 --> 0:10:46.920 with incense as well. Priest would show it and drink 0:10:47.000 --> 0:10:49.840 it as a as a cleansing as well. So it 0:10:49.920 --> 0:10:52.920 wasn't just used in the creation of mummies. It was like, 0:10:53.080 --> 0:10:55.960 in a way, this kind of uh, this kind of posh, 0:10:56.080 --> 0:10:58.920 high status chemical for for all the you know that 0:10:59.080 --> 0:11:01.320 all your hygiene needs in a way and be like 0:11:01.600 --> 0:11:05.080 you've got to have that mummy mouth. Yeah. Now, I 0:11:05.080 --> 0:11:07.960 think one of the facts that we're getting into here 0:11:08.040 --> 0:11:11.160 with especially within with an atron example, is that we're 0:11:11.240 --> 0:11:15.440 dealing with medicine. We're dealing with medicinal uses. And that's 0:11:15.440 --> 0:11:17.560 one of the amazing things is when you start looking 0:11:17.600 --> 0:11:20.360 at some of the early history of what we think 0:11:20.360 --> 0:11:25.000 of as soap, you're often dealing more specifically with with 0:11:25.440 --> 0:11:29.200 medical practices and sort of the magic of early medicine 0:11:29.559 --> 0:11:31.680 as opposed to just sort of the like we don't 0:11:31.679 --> 0:11:35.000 think about soap as medicine, we don't think about hygiene 0:11:35.000 --> 0:11:38.800 as medicine. But it is, I mean, it is preventative medicine. 0:11:39.160 --> 0:11:43.240 Uh you know, you know, quite literally, yeah, totally. Now, 0:11:43.559 --> 0:11:47.880 other BC treatments included um using olive oil on the skin. 0:11:47.920 --> 0:11:50.160 I mentioned that already is something that you might apply 0:11:50.320 --> 0:11:54.320 before scraping. Clay and plant ashes as well. During the 0:11:54.360 --> 0:11:56.720 Biblical period, we see a form of soap made from 0:11:56.800 --> 0:12:01.120 plant derivatives, generally from salty regions where the plants gathered 0:12:01.160 --> 0:12:04.920 potash and soda, and the Bible actually mentions the washing 0:12:04.960 --> 0:12:10.760 materials bore, bore, it and she lig Acadian, Syrian, and 0:12:10.800 --> 0:12:15.320 Arabic languages all include words specific words for soap producing plants. 0:12:15.559 --> 0:12:18.000 Plants that would be you know, would definitely become important 0:12:18.240 --> 0:12:21.320 later on if not been in the creation of these 0:12:21.480 --> 0:12:24.600 soap like elements, and plant ash and clay were also 0:12:24.640 --> 0:12:30.080 widely used in the cultures of India, Peru, Chili, and Angola. Well, 0:12:30.160 --> 0:12:33.000 maybe this is a good place to stop and explain 0:12:33.160 --> 0:12:35.959 how soap actually works. But should we take a break first? 0:12:36.120 --> 0:12:42.400 We should, It will be right back, all right, we're back, 0:12:42.880 --> 0:12:46.760 So it's time to talk about how soap actually gets 0:12:46.840 --> 0:12:49.800 things clean. So in a lot of cases, of course, 0:12:49.800 --> 0:12:52.679 we all know that simply washing with water can be 0:12:52.800 --> 0:12:55.320 very effective. If you don't have soap, you might as 0:12:55.360 --> 0:12:57.880 well wash your hands with water because that gets a 0:12:57.920 --> 0:13:01.880 lot of stuff off. Maybe not everything, but lot right, Yeah, yeah, 0:13:01.960 --> 0:13:05.160 I mean it is again, it's it's often poorly understood 0:13:05.200 --> 0:13:07.840 by the people who use it, but it's highly effective. 0:13:08.040 --> 0:13:11.560 And actually, there was a very interesting passage about what 0:13:11.600 --> 0:13:13.840 I'm about to talk about in the book Until the 0:13:13.920 --> 0:13:16.439 End of Time by Brian Green, a recent guest on 0:13:16.480 --> 0:13:19.200 Stuff to Blow your Mind. The passage highlights the fact 0:13:19.240 --> 0:13:22.480 that water is good for washing things much for the 0:13:22.559 --> 0:13:25.800 same reason that it is the basis for life on Earth. 0:13:26.600 --> 0:13:28.760 And if if that doesn't make any sense, stick with 0:13:28.800 --> 0:13:31.200 me for a second. Here. So Green is talking about 0:13:31.200 --> 0:13:33.679 the chemical properties of water. He's talking about the fact 0:13:33.760 --> 0:13:37.840 that water is a polar molecule. So you've got a 0:13:37.920 --> 0:13:41.319 one atom of oxygen with two atoms of hydrogen. They're 0:13:41.360 --> 0:13:44.840 bonded together, and in this molecule there is a net 0:13:44.840 --> 0:13:48.160 negative charge at one end, the end where the oxygen 0:13:48.200 --> 0:13:51.000 atom is, and then there's a net positive charge at 0:13:51.000 --> 0:13:53.920 the other ends where where the two hydrogen atoms are. 0:13:54.559 --> 0:13:57.640 And this difference in electrical charge across the length of 0:13:57.640 --> 0:14:00.720 the water molecule is essential to its funk. And in 0:14:00.760 --> 0:14:04.960 the world of biochemistry, it's what makes water the molecule 0:14:05.080 --> 0:14:08.240 of life in a universe of death. And so that 0:14:08.400 --> 0:14:11.400 this distribution of electrical charge across the length of the 0:14:11.440 --> 0:14:15.680 molecule means that water can dissolve almost anything, not anything, 0:14:15.720 --> 0:14:19.760 but almost anything. The oxygen end will bind to almost 0:14:19.800 --> 0:14:22.880 anything that has even a slight positive charge, and the 0:14:22.960 --> 0:14:25.720 hydrogen tips at the other end will bind to almost 0:14:25.800 --> 0:14:29.520 anything that has even a slight negative charge. And Green 0:14:29.680 --> 0:14:32.400 rights that quote. In tandem, the two ends of a 0:14:32.440 --> 0:14:36.960 water molecule act like charged claws that pull apart almost 0:14:37.000 --> 0:14:40.760 anything that's submerged for a sufficient time. So if you 0:14:40.800 --> 0:14:43.360 are if you're like a hardcore soaker when it comes 0:14:43.360 --> 0:14:46.520 to cleaning the dishes, uh, this is this is a 0:14:46.720 --> 0:14:50.479 this is a ammunition for your defense against the scrubbers. 0:14:50.680 --> 0:14:53.840 Oh of course, yeah. I mean just sitting something in water, Yeah, 0:14:53.920 --> 0:14:56.560 it will tend to just pull things out. And it's 0:14:56.600 --> 0:15:00.240 funny because water is is the fluid of lie. If 0:15:00.280 --> 0:15:03.080 we we think of it as not something that's uh 0:15:03.160 --> 0:15:06.880 you know that rips everything apart at the molecular level, 0:15:07.160 --> 0:15:09.200 we think of it as this. You know, this this 0:15:09.320 --> 0:15:12.200 cleansing healing kind of liquid, which of course it is 0:15:12.280 --> 0:15:15.280 to us we need it to live, But chemically what 0:15:15.400 --> 0:15:17.720 it does, and the reason why it's so useful to 0:15:17.760 --> 0:15:21.200 our bodies is that it has this power to dissolve, 0:15:21.720 --> 0:15:24.520 and so in dissolving things. Green gives the example of 0:15:24.560 --> 0:15:27.600 table salt, a very very common example. Table salt is 0:15:27.640 --> 0:15:31.080 known chemically as sodium chloride. Sodium chloride is a molecule. 0:15:31.120 --> 0:15:33.560 It's made from one atom of sodium and one atom 0:15:33.560 --> 0:15:37.080 of chlorine, and when you drop crystals of table salt 0:15:37.120 --> 0:15:40.760 into water, the water molecules immediately start ripping them apart 0:15:40.840 --> 0:15:43.800 and dissolving them. So the oxygen in the H two 0:15:43.840 --> 0:15:48.000 O snags the positively charged sodium ions, and the hydrogen 0:15:48.080 --> 0:15:50.800 tips of the H two O molecule grab the negatively 0:15:50.920 --> 0:15:54.680 charged chlorine ions. But it's not just table salt. Water 0:15:54.720 --> 0:15:58.000 works this way for a huge number of chemicals and substances, 0:15:58.280 --> 0:16:01.200 and it's the reason water is good for washing things. 0:16:01.240 --> 0:16:05.240 Substances previously stuck to the outside of your skin or 0:16:05.280 --> 0:16:08.120 to the outside of a dish or a pan, are 0:16:08.360 --> 0:16:12.200 grabbed and dissolved by the water and carried away. When 0:16:12.200 --> 0:16:14.600 the water runs off of you or off of the 0:16:14.680 --> 0:16:17.680 dish onto the ground, downstream in a river, or down 0:16:17.720 --> 0:16:20.880 the drain. And here's where things get really interesting. Uh here, 0:16:20.880 --> 0:16:23.400 I just want to quote directly from Brian Green's book 0:16:23.480 --> 0:16:27.280 Until the End of Time. Quote, well, beyond its utility 0:16:27.280 --> 0:16:30.640 and personal hygiene, Water's capacity to grab hold of and 0:16:30.880 --> 0:16:36.520 ingest substances is indispensable to life. Sell interiors or miniature 0:16:36.600 --> 0:16:40.120 chemistry labs whose workings require the rapid movement of a 0:16:40.240 --> 0:16:45.640 vast collection of ingredients, nutrients in, waste out, commingling of 0:16:45.720 --> 0:16:50.320 chemicals to synthesize substances required for cellular function, and so on. 0:16:50.840 --> 0:16:55.400 Water makes this possible. Water, constituting some seventy of a 0:16:55.480 --> 0:17:00.760 cell's mass, is life's ferrying fluid. Nobel Laurea Albert's zen 0:17:00.880 --> 0:17:06.159 Georgy summarized it eloquently. Quote water is life's matter and matrix, 0:17:06.400 --> 0:17:10.560 mother and medium. There is no life without water. Life 0:17:10.600 --> 0:17:13.639 could leave the ocean when it learned to grow a skin, 0:17:14.200 --> 0:17:16.920 a bag in which to take the water with it. 0:17:17.400 --> 0:17:21.200 We are still living in water, having the water now inside. 0:17:21.600 --> 0:17:25.639 Oh wow, that's beautiful. Yeah, sloshy water bag creatures that 0:17:25.720 --> 0:17:30.159 we are. It's true, we're bladders of life. Waddling around 0:17:30.160 --> 0:17:33.920 in the desert above. But so this is amazing that 0:17:34.080 --> 0:17:37.679 it's basically the same reason that water is good for 0:17:37.760 --> 0:17:41.919 washing your hands, and the reason that astrobiologists are looking 0:17:41.960 --> 0:17:45.200 for signs of water on Mars. But while water is 0:17:45.240 --> 0:17:47.800 an amazing solvent and good for washing all kinds of 0:17:47.840 --> 0:17:50.360 stuff off your hands, there are some cases where it's 0:17:50.440 --> 0:17:53.560 hygiene powers fall short. You of course know about this 0:17:53.640 --> 0:17:57.000 if you ever tried to use water alone to wash 0:17:57.040 --> 0:18:00.639 an oily, greasy substance off your hands or off of 0:18:00.680 --> 0:18:02.639 a dish in the kitchen. So so you've got a 0:18:02.680 --> 0:18:06.439 frying pans covered in you know, residue of butter or something, 0:18:07.000 --> 0:18:09.359 and you try to run tap water over it to 0:18:09.400 --> 0:18:11.720 wash it off. Does it work? Of course not right, 0:18:11.800 --> 0:18:15.520 Like the water will maybe dislodge little bits of the 0:18:15.560 --> 0:18:19.040 butter residue, but mostly the oil on the surface of 0:18:19.040 --> 0:18:21.720 the pan will continue to stick and the water will 0:18:21.760 --> 0:18:24.240 kind of rush overtop it, or at best it will 0:18:24.280 --> 0:18:27.399 sort of push waves of the oil around through force. 0:18:28.000 --> 0:18:30.040 Now I do use that as an example because I 0:18:30.080 --> 0:18:32.719 know everybody has done it. But if you remember from 0:18:32.760 --> 0:18:35.600 our fat Bergs episode, please do not wash oil and 0:18:35.640 --> 0:18:38.000 grease down the drain lest you begin to make a 0:18:38.000 --> 0:18:42.280 soap dragon down the sewers below us. But here's another example. 0:18:42.320 --> 0:18:45.560 I'm sure everybody will be able to identify with Robert 0:18:45.560 --> 0:18:48.480 he ever put lotion on your hands, like a sort 0:18:48.480 --> 0:18:51.400 of oil based or kind of greasy lotion, and then 0:18:51.440 --> 0:18:53.480 you need to wash your hands. You go and wash 0:18:53.520 --> 0:18:58.000 your hands with just water without using soap. What happens there? Oh? 0:18:58.080 --> 0:19:01.880 You just you get with these least slipper hands. It's like, now, 0:19:01.920 --> 0:19:05.800 it's like lotion plus one, right exactly. The lotion does 0:19:05.840 --> 0:19:08.639 not get washed off. You have to use soap in 0:19:08.760 --> 0:19:11.760 order to get lotion grease off of your hands, and 0:19:11.800 --> 0:19:14.240 your hands will stay greasy no matter how much water 0:19:14.400 --> 0:19:16.760 you run over them, right Yeah, Like yeah, I mean 0:19:16.920 --> 0:19:19.119 obviously there's you know, so a certain amount of physical 0:19:19.119 --> 0:19:21.520 removal as possible. Generally, what I do is like I 0:19:22.200 --> 0:19:23.960 washing off my hands real quick, and then like, oh 0:19:24.000 --> 0:19:25.679 I had a lotion on and now I kind of 0:19:25.680 --> 0:19:28.560 have to use like a hand towel that to physically 0:19:28.560 --> 0:19:32.399 remove some of the lotion water mixture. Right. Uh, So, 0:19:32.560 --> 0:19:36.680 water by itself fails at washing away lipids, lipids or 0:19:36.680 --> 0:19:41.240 a class of substances including oils, fats, waxes, and steroids. 0:19:41.800 --> 0:19:44.199 And this is because simply oil and water do not 0:19:44.440 --> 0:19:47.400 mix easily, which is in turn due to the chemical 0:19:47.440 --> 0:19:50.080 properties of the two substances. So we were talking about 0:19:50.119 --> 0:19:53.520 how water is a polar molecule. It's got different electric 0:19:53.600 --> 0:19:57.160 charges at each end. And because of these different electric 0:19:57.200 --> 0:20:00.119 charges at each end of the water molecule, water are 0:20:00.280 --> 0:20:03.720 links up with itself very easily through a series of 0:20:03.760 --> 0:20:06.800 connections called hydrogen bonds. So you can kind of think 0:20:06.800 --> 0:20:09.000 of the analogy of legos. Right at the top of 0:20:09.040 --> 0:20:11.919 one block just very easily snaps onto the bottom and 0:20:11.920 --> 0:20:14.720 the next. Now, oils, on the other hand, are made 0:20:14.760 --> 0:20:18.359 up of non polar molecules, so they do not easily 0:20:18.480 --> 0:20:21.639 break through these bonds and link up with water molecules 0:20:21.680 --> 0:20:25.159 to form new compounds or dissolve into the water. So 0:20:25.400 --> 0:20:27.640 you say, say you take a jar and you put 0:20:27.680 --> 0:20:30.119 some oil and some water in the jar together, and 0:20:30.119 --> 0:20:33.439 then you shake it up really hard. If if you 0:20:33.520 --> 0:20:36.240 shake the jar like that, droplets of oil will be 0:20:36.280 --> 0:20:40.520 dispersed by force throughout the water. But these molecules of 0:20:40.560 --> 0:20:44.120 oil will after so first they will disrupt the hydrogen 0:20:44.160 --> 0:20:47.159 bonds between the water molecules they'll get kind of dispersed throughout, 0:20:47.520 --> 0:20:49.800 but they won't be able to form bonds with the 0:20:49.800 --> 0:20:54.760 water themselves. And instead, the disrupted water molecules I was 0:20:54.800 --> 0:20:58.040 reading about this, they they form a kind of molecular 0:20:58.080 --> 0:21:02.600 cage around the oil molecules. Uh. And this cage is 0:21:02.640 --> 0:21:05.560 this kind of almost crystalline type structure known as a 0:21:05.680 --> 0:21:10.680 class rate. And this cage actually represents a temporary decrease 0:21:10.920 --> 0:21:14.120 in the entropy of the water. So by forming these 0:21:14.240 --> 0:21:17.920 orderly structures around these droplets of oil suspended in the water, 0:21:18.320 --> 0:21:22.080 you are decreasing entropy. And we know that the universe 0:21:22.119 --> 0:21:25.560 does not tolerate decreases in entropy forever. The universe always 0:21:25.640 --> 0:21:29.960 wants to increase the entropy again. So gradually the mixed 0:21:30.040 --> 0:21:33.800 mass of water and oil manages to increase its entropy 0:21:33.880 --> 0:21:38.800 by spontaneously bumping around and rearranging until the oil molecules 0:21:39.240 --> 0:21:42.480 join up with one another into a solid mass and 0:21:42.640 --> 0:21:45.840 separate from the water to float on its surface. And 0:21:45.880 --> 0:21:47.879 of course, the reason that oil floats on top of 0:21:47.880 --> 0:21:50.520 water when it's separated is that oil is less dense 0:21:50.560 --> 0:21:53.520 than water. But for hygiene purposes, I guess all you 0:21:53.520 --> 0:21:56.160 have to remember is the short version that oil doesn't 0:21:56.200 --> 0:21:59.760 naturally dissolve in water like so many other substances do. 0:22:00.240 --> 0:22:02.400 And this is why water alone is not very good 0:22:02.440 --> 0:22:05.800 at dissolving and washing away oil or fat based substances. 0:22:06.040 --> 0:22:09.080 And this, of course is where soap comes in. Here's 0:22:09.160 --> 0:22:11.480 where we all know from experience you can't get the water, 0:22:11.480 --> 0:22:13.159 you can't get the lotion off your hands or the 0:22:13.200 --> 0:22:15.480 grease off your hands with water alone, but if you 0:22:15.600 --> 0:22:18.440 use some soap, it comes right off. Another example that 0:22:18.480 --> 0:22:20.560 comes to mind here is of course, with our hair. 0:22:21.080 --> 0:22:25.560 I think if you've ever experimented with just rigorously shampooing 0:22:25.760 --> 0:22:29.360 versus going no pooh as they say it, if they 0:22:29.359 --> 0:22:32.960 call it um, that you can definitely observe this in action. 0:22:33.440 --> 0:22:36.120 Uh so I feel the oils in your hair? Yeah, 0:22:36.160 --> 0:22:39.680 Like like I will generally go no shampoo for um 0:22:39.840 --> 0:22:42.320 for like a few weeks at a time, and I 0:22:42.359 --> 0:22:45.399 will my hair doesn't. It varies from person to person, 0:22:45.480 --> 0:22:47.959 you know, depending on you know, your particular hair and 0:22:48.480 --> 0:22:50.960