WEBVTT - The Invention of Soap 0:00:03.040 --> 0:00:05.360 Welcome to stot to Blow Your Mind production of My 0:00:05.480 --> 0:00:14.600 Heart Radio. Hey you welcome to Stuff to Blow Your Mind. 0:00:14.680 --> 0:00:17.480 My name is Robert Lamb and I'm Joe McCormick and 0:00:17.600 --> 0:00:20.639 Robert I am ready to leather up. That's right. Uh. 0:00:20.960 --> 0:00:23.760 In this episode, we are going to be exploring un invention. 0:00:24.320 --> 0:00:26.759 Uh we're getting into a little techno history here, but 0:00:26.800 --> 0:00:30.680 we're going to be considering soap. Uh. Soap has been 0:00:30.720 --> 0:00:34.360 on everyone's mind a bit more these days, I think. Uh, 0:00:34.400 --> 0:00:36.680 this is actually a topic that was suggested to us 0:00:37.080 --> 0:00:41.200 for our our previous side show, Invention, which is now 0:00:41.560 --> 0:00:45.560 back a part of Stuff to Blow Your Mind itself. Um, 0:00:45.800 --> 0:00:48.400 soap is something that is I think easy to take 0:00:48.479 --> 0:00:52.960 for granted, uh, given normal situations. Right, soap is just 0:00:53.040 --> 0:00:55.720 the thing that you uh, you know, speedily wash your 0:00:55.760 --> 0:00:58.320 hands with, you know, add a little bit of a 0:00:58.400 --> 0:01:00.680 nice smell, take some of the grease or grit off 0:01:01.080 --> 0:01:02.720 so you can move on to something else, perhaps give 0:01:02.760 --> 0:01:04.360 you a little bit of peace of mind before you 0:01:04.400 --> 0:01:07.640 do things like prepare food or put your contacts in. 0:01:08.160 --> 0:01:11.640 But lately it is of course has been stressed how 0:01:11.800 --> 0:01:15.880 essential it is via handwashing in the prevention of the 0:01:15.920 --> 0:01:19.160 spread of COVID nineteen. All right, so let's let's talk 0:01:19.160 --> 0:01:22.400 about soap. Soap is, of course a human invention. But 0:01:22.720 --> 0:01:25.200 did we ever get by without it? I mean, it's 0:01:25.240 --> 0:01:27.960 hard for us to imagine life without soap, especially now, 0:01:28.120 --> 0:01:30.240 because it aids us in the cleaning of our bodies. 0:01:30.640 --> 0:01:33.080 It also helps us via you know, detergents, in the 0:01:33.080 --> 0:01:36.319 cleaning of our garments. We use uh, soaps to to 0:01:36.440 --> 0:01:39.559 clean you know, objects and surfaces as well. It helps 0:01:39.600 --> 0:01:42.880 maintain basic hygiene, it prevents the spread of disease, and 0:01:42.920 --> 0:01:46.240 it can also impart a pleasing odor. You know, what's 0:01:46.240 --> 0:01:48.440 not to love about soap? And how on earth can 0:01:48.440 --> 0:01:51.080 we get by without it? Now? Obviously we can look 0:01:51.240 --> 0:01:54.840 to the animal world for plenty of examples, but but 0:01:54.880 --> 0:01:58.120 a few common examples do tell us a lot. Birds, 0:01:58.160 --> 0:02:01.120 for instance, clean themselves with their eeks, and they use 0:02:01.240 --> 0:02:04.680 water or dust to bathe themselves. Uh. Cats, dogs and 0:02:04.760 --> 0:02:07.720 cows are frequent examples of animals that lick themselves to 0:02:07.800 --> 0:02:11.880 clean themselves. And uh, let's consider a few terms to 0:02:11.919 --> 0:02:15.360 put things in perspective as well. We're talking about grooming, 0:02:15.520 --> 0:02:18.040 which is a comfort behavior that is the practice of 0:02:18.080 --> 0:02:22.400 cleaning the body surface including the cleaning and oiling of 0:02:22.480 --> 0:02:26.280 feathers with the bill or of the hair with the tongue. 0:02:26.480 --> 0:02:29.560 And there are a few broad categories here. There's first 0:02:29.560 --> 0:02:33.239 of all, auto grooming, that is an animal's grooming of itself. 0:02:33.639 --> 0:02:36.360 And you know, ultimately that's what's going on when you 0:02:36.440 --> 0:02:38.239 take a shower in the morning or in the evening 0:02:38.320 --> 0:02:41.400 or whenever or both, you know, go go out. Uh. 0:02:41.440 --> 0:02:44.720 There's also al of grooming, which is an animals grooming 0:02:44.760 --> 0:02:48.480 of another for parental or social reasons. Yeah, and uh, 0:02:48.680 --> 0:02:51.840 one thing that's very interesting is the the array of 0:02:52.040 --> 0:02:55.760 social dynamics that seem to take place through grooming behaviors, 0:02:55.760 --> 0:03:00.400 like say, primate grooming behaviors where primates will sometimes pick 0:03:00.800 --> 0:03:03.679 pick little knits and bits and bugs out of each 0:03:03.720 --> 0:03:07.799 other's hair as a way to to manage and mediate 0:03:07.919 --> 0:03:11.760 social bonds within groups. Yeah, it becomes a part of 0:03:11.760 --> 0:03:14.680 the society for for creatures like that and for creatures 0:03:14.720 --> 0:03:17.520 like us. So all of this amounts to a general 0:03:17.680 --> 0:03:22.520 physical removal of particles scraped away, picked away, washed away. 0:03:22.720 --> 0:03:27.320 And there may be bacteria sidal properties as well. Uh, 0:03:27.320 --> 0:03:29.960 you know, particularly you'll see something there's some studies about 0:03:29.960 --> 0:03:33.959 saliva m into what degree they may be able to 0:03:34.040 --> 0:03:38.160 kill bacteria. But this, this basic removal can deal with 0:03:38.200 --> 0:03:42.680 everything from sand and dirt to dead skin cells, loose hairs, 0:03:42.760 --> 0:03:47.000 loose feathers, and like you mentioned, actual exo parasites, and 0:03:47.000 --> 0:03:50.400 of course in cleansing oneself, it's helpful to use nails 0:03:50.440 --> 0:03:53.680 and claws and beaks and all these uh these various 0:03:53.800 --> 0:03:56.840 uh uh you know, bio tools that we've already mentioned. 0:03:56.880 --> 0:03:59.960 But in dealing with with humans, in dealing with home 0:04:00.120 --> 0:04:04.560 sapiens and some of Homo sapiens closest kin, we of 0:04:04.760 --> 0:04:07.960 course have to get into tool use. We get into 0:04:08.040 --> 0:04:11.320 the techno history of the situation here. And one of 0:04:11.360 --> 0:04:13.680 the sources I was looking at for this episode was 0:04:14.040 --> 0:04:18.400 soaps from the Phoenicians to the twentieth century. A historical 0:04:18.480 --> 0:04:23.039 review by roth at All came out in they point 0:04:23.040 --> 0:04:26.320 out a few key examples from quote the pre soap era, 0:04:26.960 --> 0:04:28.920 This is uh an area you might think of as 0:04:29.040 --> 0:04:32.160 the squeegee era, you know, where there we did have 0:04:32.200 --> 0:04:35.760 some tools. We we probably were interested in cleaning ourselves, 0:04:35.760 --> 0:04:37.760 but we didn't have soap yet. So what can you do? 0:04:38.000 --> 0:04:40.360 Maybe you can kind of squeege your skin with a 0:04:40.839 --> 0:04:44.440 with a little bit of abrasive action. Yeah, and indeed, uh, 0:04:44.600 --> 0:04:49.159 Neolithic people apparently used flint scrapers to clean themselves, a 0:04:49.200 --> 0:04:53.040 basic way to remove dirt, grime, dead skin cells. You know, 0:04:53.200 --> 0:04:56.640 why depend on just those those So I'm guessing horrid 0:04:56.680 --> 0:04:59.880 fingernails that you have, uh during the Neolithic period, when 0:05:00.000 --> 0:05:02.960 you can also start using some some some tools. You're 0:05:03.000 --> 0:05:05.479 using tools to scrape other things. You need a good 0:05:05.480 --> 0:05:09.200 scraping as well, So grab some flint and get in there. Now. 0:05:09.240 --> 0:05:11.640 I really hope that they were not using the same 0:05:12.279 --> 0:05:16.480 hand axes, by faces or pieces of flint to process 0:05:16.600 --> 0:05:19.679 animal carcasses and then to scrape their own skin clean. 0:05:19.800 --> 0:05:24.120 But I have to guess there probably was a bit acrossover. Yeah, 0:05:24.160 --> 0:05:28.840 it seems inevitable, it doesn't it. But so the use 0:05:28.960 --> 0:05:32.320 of a kind of a bit of mechanical leverage some 0:05:32.320 --> 0:05:36.520 some scraping with a tool did not stop with Neolithic 0:05:36.680 --> 0:05:40.120 or Stone Age people. This actually did continue into classical 0:05:40.160 --> 0:05:43.359 civilizations like the Romans did something similar. Yeah, before the 0:05:43.360 --> 0:05:45.719 Age of plenty in the first centuries. See, the Greeks 0:05:45.720 --> 0:05:48.400 and Romans depended on well, they had vapor baths, they 0:05:48.400 --> 0:05:52.080 had you know, an extravagant bath system for sure, but 0:05:52.240 --> 0:05:56.320 also they would scrub and scrape the skin with a 0:05:56.480 --> 0:05:59.840 st strigle or skin scraper made of bone, ivory or 0:06:00.000 --> 0:06:02.320 at all. And this basically what it sounds like. You 0:06:02.360 --> 0:06:06.560 get the you get the skin itself, you know, nice 0:06:06.560 --> 0:06:09.799 and moist from a bath or perhaps via the application 0:06:09.839 --> 0:06:12.880 of an oil, and then you can start scraping away 0:06:12.960 --> 0:06:15.760 and remove that, you know, that outer layer of grime, 0:06:15.880 --> 0:06:19.840 dead skin, etcetera. I guess some people still use something 0:06:19.960 --> 0:06:23.600 like this to cleanse themselves. I mean in terms of 0:06:23.640 --> 0:06:26.760 just dealing with our skin. I mean, I know, for 0:06:27.240 --> 0:06:29.479 instance that just going to the y m c A, 0:06:29.960 --> 0:06:32.760 I'll hear some of the the older gentleman in the 0:06:32.800 --> 0:06:35.320 locker room. Uh, they would talk of ways that they 0:06:35.320 --> 0:06:38.200 would deal with the like the thickened callouses on their feet, 0:06:38.680 --> 0:06:42.600 and some of the sometimes bad advice they would give 0:06:42.640 --> 0:06:46.480 each other would involve essentially scraping away the skin, generally 0:06:46.480 --> 0:06:49.159 with with tools and implements that were not designed for 0:06:49.240 --> 0:06:54.560 that purpose. Wait, it sounds like you've got a specific 0:06:54.600 --> 0:06:57.280 tool in mind, or they like using a food processor 0:06:57.279 --> 0:06:59.880 blade or what. Um, Well, one was definitely there was 0:07:00.000 --> 0:07:01.560 a guy that was telling me what you need to 0:07:01.560 --> 0:07:04.960 do is you need to get yourself safety raiser and 0:07:05.000 --> 0:07:07.400 then remove some of the safety features and then you 0:07:07.400 --> 0:07:10.880 can just you can, you know, scrape away some skin. Uh, 0:07:10.960 --> 0:07:13.120 which sounds like a bad idea, and I do not 0:07:13.200 --> 0:07:15.720 recommend anyone do that. Another person said, what you need 0:07:15.760 --> 0:07:16.960 to do is you need to get one of these 0:07:17.000 --> 0:07:20.200 and he held up, um, oh, well, what's the what 0:07:20.240 --> 0:07:22.800 do you call these? It's the it's for the the 0:07:22.960 --> 0:07:27.760 grating of say ginger, for culinary purposes. A microplane. Yes, 0:07:27.800 --> 0:07:32.120 a microplane. Uh. So he held a microplane and he says, 0:07:32.200 --> 0:07:33.960 you can get one of these at bed, bath and beyond. 0:07:34.120 --> 0:07:37.360 It works great. Again, I would not recommend using that 0:07:37.520 --> 0:07:42.120 on your body. I would recommend getting a standing or 0:07:42.360 --> 0:07:45.920 scrubbing implement that is designed for use on the skin 0:07:46.080 --> 0:07:48.080 and use on the feet. What you do is you 0:07:48.080 --> 0:07:52.960 get a stick blender and oh man, but that's not 0:07:53.000 --> 0:07:55.800 to say that that other folks weren't engaging in the 0:07:55.960 --> 0:07:59.920 use of essentially chemical approaches to the cleaning of the skin. 0:08:00.000 --> 0:08:03.160 In the ancient Egyptians made use of soda to clean 0:08:03.200 --> 0:08:06.880 their skin as well as to treat diseases of the skin. Okay, 0:08:06.920 --> 0:08:10.440 so soda is interesting here because that suggests we're we're 0:08:10.480 --> 0:08:13.760 getting a little bit closer to soap like territories. This 0:08:13.800 --> 0:08:16.600 will make more sense when we explain soapen a bit. 0:08:16.760 --> 0:08:20.080 But but soda, of course is an alkali. It's a 0:08:20.280 --> 0:08:24.280 it's a base, and in certain combinations, in the presence 0:08:24.280 --> 0:08:27.400 of fats and water, this can actually have a lathering 0:08:27.520 --> 0:08:30.880 soap like effect. Yeah. So, so this is a nice 0:08:30.960 --> 0:08:33.440 ancient example. We'll get into some more in a bit. 0:08:33.960 --> 0:08:36.640 But oh, and then another example that growth at all 0:08:36.760 --> 0:08:40.400 point point out fifth century BC. During this time period, 0:08:40.520 --> 0:08:43.920 Herodotus wrote of the priest physicians of the temple of 0:08:43.920 --> 0:08:48.760 Ammon at Karnak in Egypt during the reign of Ramesses. 0:08:48.800 --> 0:08:53.240 This would have been uh eleven thirteen through ten five BC, 0:08:54.160 --> 0:08:57.280 and Herodotus stated that they would quote bathe in cold 0:08:57.280 --> 0:09:00.480 water twice a day and twice a night, and lensed 0:09:00.640 --> 0:09:04.560 their mouths with natron. Now, natron was a mixture of 0:09:04.600 --> 0:09:10.760 sodium bicarbonate and sodium carbonate. That's what you call mummy mouth. Yeah. Uh. 0:09:10.800 --> 0:09:13.280 One of my favorite books on the history of hygiene 0:09:13.960 --> 0:09:16.960 is a book titled Clean by Virginia Smith, and that 0:09:17.360 --> 0:09:20.439 she points out that that natron was dissolved in water 0:09:20.840 --> 0:09:24.600 to clean the body, to clean clothes, furniture, and sometimes 0:09:24.640 --> 0:09:27.520 it could be ignited with incense as well. Priest would 0:09:27.600 --> 0:09:30.040 chew it and drink it as a as a cleansing 0:09:30.120 --> 0:09:33.320 as well. So it wasn't just used in the creation 0:09:33.360 --> 0:09:35.720 of mummies. It was like, in a way, this kind 0:09:35.760 --> 0:09:39.719 of uh, this kind of posh, high status chemical for 0:09:39.720 --> 0:09:41.840 for all the you know that all your hygiene needs. 0:09:41.840 --> 0:09:43.680 In a way, it can be like you've got to 0:09:43.720 --> 0:09:47.080 have that mummy mouth. Yeah. Now, I think one of 0:09:47.120 --> 0:09:50.400 the facts that we're getting into here with especially within 0:09:50.640 --> 0:09:54.319 with the Natron example, is that we're dealing with medicine. 0:09:54.320 --> 0:09:57.320 We're dealing with medicinal uses. And that's one of the 0:09:57.360 --> 0:09:59.560 amazing things is when you start looking at some of 0:09:59.559 --> 0:10:02.600 the earth the history of what we think of a soap, 0:10:03.000 --> 0:10:08.480 you're often dealing more specifically with with medical practices and 0:10:08.720 --> 0:10:12.000 sort of the magic of early medicine as opposed to 0:10:12.080 --> 0:10:14.000 just sort of the like we don't think about soap 0:10:14.080 --> 0:10:17.679 as medicine, we don't think about hygiene as medicine. But 0:10:17.880 --> 0:10:21.920 it is, I mean, it is preventative medicine. Uh, you know, 0:10:22.320 --> 0:10:26.920 you know, quite literally, yeah, totally Now, Other BC treatments 0:10:26.920 --> 0:10:29.920 included um using olive oil on the skin. I mentioned 0:10:29.920 --> 0:10:31.760 that already is something that you know it might apply 0:10:31.880 --> 0:10:35.920 before scraping. Clay and plant ashes as well. During the 0:10:35.920 --> 0:10:38.360 Biblical period we see a form of soap made from 0:10:38.360 --> 0:10:42.679 plant derivatives, generally from salty regions where the plants gathered 0:10:42.720 --> 0:10:46.520 potash and soda, and the Bible actually mentions the washing 0:10:46.559 --> 0:10:52.760 materials bore, bore, it and slig Acadian, Syrian, and Arabic 0:10:52.880 --> 0:10:56.920 languages all include words specific words for soap producing plants. 0:10:57.160 --> 0:10:59.559 Plants that would be you know, would definitely become important 0:10:59.760 --> 0:11:02.600 later are on, if not then in the creation of 0:11:02.640 --> 0:11:05.920 these soap like elements, and plant ash and clay were 0:11:05.920 --> 0:11:10.400 also widely used in the cultures of India, Peru, Chili, 0:11:10.480 --> 0:11:13.120 and Angola. Well, maybe this is a good place to 0:11:13.559 --> 0:11:16.719 stop and explain how soap actually works. But should we 0:11:16.760 --> 0:11:19.160 take a break first? We should, it will be right 0:11:19.160 --> 0:11:25.520 back than alright, we're back, So it's time to talk 0:11:25.559 --> 0:11:30.320 about how soap actually gets things clean. So in a 0:11:30.320 --> 0:11:32.440 lot of cases, of course, we all know that simply 0:11:32.520 --> 0:11:35.640 washing with water can be very effective. If you don't 0:11:35.760 --> 0:11:38.080 have soap, you might as well wash your hands with 0:11:38.160 --> 0:11:40.680 water because that gets a lot of stuff off. Maybe 0:11:40.720 --> 0:11:43.760 not everything, but a lot, right, Yeah, yeah, I mean 0:11:43.800 --> 0:11:47.120 it is again, it's it's often poorly understood by the 0:11:47.160 --> 0:11:50.120 people who use it, but it's highly effective. And actually, 0:11:50.320 --> 0:11:53.640 there was a very interesting passage about what I'm about 0:11:53.640 --> 0:11:55.720 to talk about in the book Until the End of 0:11:55.800 --> 0:11:58.400 Time by Brian Green, a recent guest on Stuff to 0:11:58.400 --> 0:12:01.240 Blow your Mind. The passage highlights the fact that water 0:12:01.400 --> 0:12:05.000 is good for washing things much for the same reason 0:12:05.120 --> 0:12:08.520 that it is the basis for life on Earth. And 0:12:08.600 --> 0:12:10.440 if if that doesn't make any sense, stick with me 0:12:10.520 --> 0:12:12.840 for a second here. So Green is talking about the 0:12:12.880 --> 0:12:15.400 chemical properties of water. He's talking about the fact that 0:12:15.480 --> 0:12:19.720 water is a polar molecule. So you've got a one 0:12:20.200 --> 0:12:23.680 atom of oxygen with two atoms of hydrogen. They're bonded together, 0:12:24.280 --> 0:12:27.480 and in this molecule there is a net negative charge 0:12:27.840 --> 0:12:30.320 at one end, the end where the oxygen atom is, 0:12:30.600 --> 0:12:32.920 and then there's a net positive charge at the other 0:12:33.080 --> 0:12:37.160 ends where the two hydrogen atoms are. And this difference 0:12:37.160 --> 0:12:40.160 in electrical charge across the length of the water molecule 0:12:40.280 --> 0:12:43.920 is essential to its function in the world of biochemistry. 0:12:44.120 --> 0:12:47.520 It's what makes water the molecule of life in a 0:12:47.640 --> 0:12:51.360 universe of death, and so that this distribution of electrical 0:12:51.440 --> 0:12:54.400 charge across the length of the molecule means that water 0:12:54.520 --> 0:12:58.920 can dissolve almost anything, not anything, but almost anything. The 0:12:58.960 --> 0:13:02.400 oxygen end will bind to almost anything that has even 0:13:02.440 --> 0:13:05.680 a slight positive charge, and the hydrogen tips at the 0:13:05.720 --> 0:13:08.600 other end will bind to almost anything that has even 0:13:08.640 --> 0:13:12.960 a slight negative charge. And Green rights that quote in tandem, 0:13:13.040 --> 0:13:16.160 the two ends of a water molecule act like charged 0:13:16.400 --> 0:13:20.160 claws that pull apart almost anything that's submerged for a 0:13:20.160 --> 0:13:23.320 sufficient time. So if you are if you're like a 0:13:23.320 --> 0:13:27.200 hardcore soaker when it comes to cleaning the dishes, uh, 0:13:27.240 --> 0:13:30.080 this is this is a this is a ammunition for 0:13:30.160 --> 0:13:33.199 your defense against the scrubbers. Oh of course, yeah. I 0:13:33.200 --> 0:13:36.080 mean just sitting something in water, Yeah, it will tend 0:13:36.160 --> 0:13:39.079 to just pull things out. And it's funny, because water 0:13:39.320 --> 0:13:42.640 is the fluid of life. We we think of it 0:13:42.679 --> 0:13:46.240 as not something that's uh, you know that rips everything 0:13:46.280 --> 0:13:49.560 apart at the molecular level. We think of it as 0:13:49.640 --> 0:13:53.080 this you know, this this cleansing, healing kind of liquid, which, 0:13:53.080 --> 0:13:54.880 of course it is to us. We need it to 0:13:54.960 --> 0:13:58.360 live but chemically, what it does and the reason why 0:13:58.400 --> 0:14:00.920 it's so useful to our bodies is that it has 0:14:01.000 --> 0:14:05.199 this power to dissolve, and so in dissolving things. Green 0:14:05.280 --> 0:14:08.160 gives the example of table salt, a very very common example. 0:14:08.480 --> 0:14:12.040 Table salt is known chemically as sodium chloride. Sodium chloride 0:14:12.080 --> 0:14:14.440 is a molecule. It's made from one atom of sodium 0:14:14.440 --> 0:14:17.880 and one atom of chlorine, and when you drop crystals 0:14:17.920 --> 0:14:21.280 of table salt into water, the water molecules immediately start 0:14:21.400 --> 0:14:24.800 ripping them apart and dissolving them. So the oxygen in 0:14:24.840 --> 0:14:28.280 the H two O snags the positively charged sodium ions, 0:14:28.680 --> 0:14:31.280 and the hydrogen tips of the H two O molecule 0:14:31.360 --> 0:14:35.320 grabbed the negatively charged chlorine ions. But it's not just 0:14:35.400 --> 0:14:37.960 table salt. Water works this way for a huge number 0:14:38.000 --> 0:14:41.520 of chemicals and substances, and it's the reason water is 0:14:41.560 --> 0:14:45.480 good for washing things. Substances previously stuck to the outside 0:14:45.480 --> 0:14:48.520 of your skin or to the outside of a dish 0:14:48.600 --> 0:14:52.120 or a pan, are grabbed and dissolved by the water 0:14:52.520 --> 0:14:55.320 and carried away when the water runs off of you 0:14:55.640 --> 0:14:58.400 or off of the dish, onto the ground downstream in 0:14:58.440 --> 0:15:01.000 a river, or down the drain and here's where things 0:15:01.000 --> 0:15:03.440 get really interesting. Uh here, I just want to quote 0:15:03.480 --> 0:15:07.720 directly from Brian Green's book Until the End of Time. Quote, well, 0:15:07.760 --> 0:15:11.440 beyond its utility and personal hygiene, water's capacity to grab 0:15:11.560 --> 0:15:16.600 hold of and ingest substances is indispensable to life. Cell 0:15:16.720 --> 0:15:21.080 interiors or miniature chemistry labs whose workings require the rapid 0:15:21.120 --> 0:15:26.040 movement of a vast collection of ingredients nutrients in, waste out, 0:15:26.440 --> 0:15:30.920 commingling of chemicals to synthesize substances required for cellular function, 0:15:31.200 --> 0:15:35.760 and so on. Water makes this possible. Water, constituting some 0:15:35.920 --> 0:15:41.080 seventy of a cell's mass, is life's ferrying fluid. Nobel 0:15:41.200 --> 0:15:46.000 Laureate Albert's zent Georgy summarized it eloquently. Quote water is 0:15:46.080 --> 0:15:50.000 life's matter and matrix, mother and medium. There is no 0:15:50.200 --> 0:15:53.840 life without water. Life could leave the ocean when it 0:15:54.000 --> 0:15:57.160 learned to grow a skin, a bag in which to 0:15:57.240 --> 0:16:00.520 take the water with it. We are still living in water, 0:16:00.760 --> 0:16:05.120 having the water now inside. Oh wow, that's beautiful. Yeah, 0:16:05.320 --> 0:16:09.520 sloshy water bag creatures that we are. It's true, we're 0:16:09.600 --> 0:16:14.040 bladders of life waddling around in the desert above. But 0:16:14.200 --> 0:16:18.240 so this is amazing. It's basically the same reason that 0:16:18.400 --> 0:16:21.560 water is good for washing your hands and the reason 0:16:21.640 --> 0:16:25.360 that astrobiologists are looking for signs of water on Mars. 0:16:25.760 --> 0:16:28.400 But while water is an amazing solvent and good for 0:16:28.440 --> 0:16:30.720 washing all kinds of stuff off your hands, there are 0:16:30.800 --> 0:16:34.360 some cases where it's hygiene powers fall short. You of 0:16:34.360 --> 0:16:36.680 course know about this if you've ever tried to use 0:16:36.800 --> 0:16:40.960 water alone to wash an oily, greasy substance off your 0:16:41.000 --> 0:16:43.440 hands or off of a dish in the kitchen. So 0:16:43.680 --> 0:16:45.960 so you've got a frying pans covered in you know, 0:16:46.400 --> 0:16:49.640 residue of butter or something, and you try to run 0:16:49.720 --> 0:16:52.360 tap water over it to wash it off. Does it work? 0:16:52.400 --> 0:16:55.800 Of course not right, Like the water will maybe dislodge 0:16:55.960 --> 0:16:59.760 little bits of the butter residue, but mostly the oil 0:16:59.840 --> 0:17:02.160 on the surface of the pan will continue to stick 0:17:02.600 --> 0:17:05.119 and the water will kind of rush overtop it, or 0:17:05.160 --> 0:17:07.320 at best it will sort of push waves of the 0:17:07.359 --> 0:17:10.680 oil around through force. Now I do use that as 0:17:10.680 --> 0:17:13.040 an example because I know everybody has done it. But 0:17:13.400 --> 0:17:16.119 if you remember from our fat Bergs episode, please do 0:17:16.160 --> 0:17:18.960 not wash oil and grease down the drain lest you 0:17:19.000 --> 0:17:21.520 begin to make a soap dragon down the sewers below us. 0:17:22.280 --> 0:17:25.400 But here's another example. I'm sure everybody will be able 0:17:25.400 --> 0:17:29.480 to identify with Robert he ever put lotion on your hands, 0:17:29.480 --> 0:17:32.040 like a sort of oil based or kind of greasy lotion, 0:17:32.680 --> 0:17:34.639 and then you need to wash your hands. You go 0:17:34.720 --> 0:17:37.679 and wash your hands with just water without using soap. 0:17:37.920 --> 0:17:40.760 What happens there? Oh? You just you get with these 0:17:41.040 --> 0:17:44.920 least slippery hands. It's like, now it's like lotion plus one, 0:17:45.720 --> 0:17:48.720 right exactly, The lotion does not get washed off. You 0:17:48.840 --> 0:17:52.000 have to use soap in order to get lotion grease 0:17:52.080 --> 0:17:54.640 off of your hands, and your hands will stay greasy 0:17:54.680 --> 0:17:57.880 no matter how much water you run over them, right, Yeah, Like, yeah, 0:17:58.119 --> 0:18:00.320 I mean obviously there's you know, a sort amount of 0:18:00.320 --> 0:18:03.000 physical removal was possible. Generally, what I do is like 0:18:03.040 --> 0:18:05.159 I I washing off my hands rel quick, and then 0:18:05.200 --> 0:18:06.920 are like, oh, I had a lotion on and now 0:18:06.920 --> 0:18:08.439 I kind of have to use like a hand towel 0:18:08.520 --> 0:18:13.080 that to physically remove some of the lotion water mixture. Right. 0:18:13.680 --> 0:18:17.520 Uh So, water by itself fails at washing away lipids, 0:18:17.720 --> 0:18:21.880 lipids or a class of substances including oils, fats, waxes, 0:18:21.920 --> 0:18:25.320 and steroids. And this is because simply oil and water 0:18:25.480 --> 0:18:28.320 do not mix easily, which is in turn due to 0:18:28.359 --> 0:18:31.159 the chemical properties of the two substances. So we were 0:18:31.160 --> 0:18:34.280 talking about how water is a polar molecule. It's got 0:18:34.320 --> 0:18:37.960 different electric charges at each end. And because of these 0:18:37.960 --> 0:18:40.920 different electric charges at each end of the water molecule, 0:18:41.280 --> 0:18:45.200 water links up with itself very easily through a series 0:18:45.240 --> 0:18:48.199 of connections called hydrogen bonds. So you can kind of 0:18:48.200 --> 0:18:50.600 think of the analogy of legos. Right the top of 0:18:50.600 --> 0:18:53.480 one block just very easily snaps onto the bottom and 0:18:53.520 --> 0:18:56.320 the next. Now, oils, on the other hand, are made 0:18:56.359 --> 0:18:59.880 up of non polar molecules, so they do not easily 0:19:00.080 --> 0:19:03.240 break through these bonds and link up with water molecules 0:19:03.280 --> 0:19:06.760 to form new compounds or dissolve into the water. So 0:19:07.000 --> 0:19:09.200 you say, say you take a jar and you put 0:19:09.240 --> 0:19:11.680 some oil and some water in the jar together, and 0:19:11.720 --> 0:19:15.000 then you shake it up really hard. If if you 0:19:15.080 --> 0:19:17.800 shake the jar like that, droplets of oil will be 0:19:17.880 --> 0:19:22.080 dispersed by force throughout the water. But these molecules of 0:19:22.119 --> 0:19:25.680 oil will after So first they will disrupt the hydrogen 0:19:25.720 --> 0:19:28.719 bonds between the water molecules. They'll get kind of dispersed throughout, 0:19:29.119 --> 0:19:31.359 but they won't be able to form bonds with the 0:19:31.359 --> 0:19:36.359 water themselves, and instead the disrupted water molecules I was 0:19:36.400 --> 0:19:39.600 reading about this, they they form a kind of molecular 0:19:39.640 --> 0:19:44.159 cage around the oil molecules. Uh. And this cage is 0:19:44.200 --> 0:19:47.119 this kind of almost crystalline type structure known as a 0:19:47.240 --> 0:19:52.240 class rate. And this cage actually represents a temporary decrease 0:19:52.480 --> 0:19:55.680 in the entropy of the water. So by forming these 0:19:55.800 --> 0:19:59.520 orderly structures around these droplets of oil suspended in the water, 0:19:59.840 --> 0:20:03.640 you are decreasing entropy. And we know that the universe 0:20:03.720 --> 0:20:07.199 does not tolerate decreases an entropy forever. The universe always 0:20:07.200 --> 0:20:11.520 wants to increase the entropy again. So gradually the mixed 0:20:11.640 --> 0:20:15.359 mass of water and oil manages to increase its entropy 0:20:15.440 --> 0:20:20.400 by spontaneously bumping around and rearranging until the oil molecules 0:20:20.800 --> 0:20:24.080 join up with one another into a solid mass and 0:20:24.240 --> 0:20:27.399 separate from the water to float on its surface. And 0:20:27.440 --> 0:20:29.439 of course, the reason that oil floats on top of 0:20:29.480 --> 0:20:32.119 water when it's separated is that oil is less dense 0:20:32.160 --> 0:20:35.080 than water. But for hygiene purposes, I guess all you 0:20:35.119 --> 0:20:37.720 have to remember is the short version that oil doesn't 0:20:37.800 --> 0:20:41.399 naturally dissolve in water like so many other substances do. 0:20:41.840 --> 0:20:44.000 And this is why water alone is not very good 0:20:44.000 --> 0:20:47.400 at dissolving and washing away oil or fat based substances. 0:20:47.640 --> 0:20:50.679 And this, of course is where soap comes in. Here's 0:20:50.760 --> 0:20:53.040 where we all know from experience you can't get the water, 0:20:53.080 --> 0:20:54.760 you can't get the lotion off your hands or the 0:20:54.760 --> 0:20:57.080 grease off your hands with water alone, but if you 0:20:57.160 --> 0:21:00.240 use some soap, it comes right off. Another example comes 0:21:00.240 --> 0:21:02.760 to mind here is of course, with our hair. I 0:21:02.800 --> 0:21:07.720 think if you've ever experimented with just rigorously shampooing versus 0:21:07.840 --> 0:21:11.240 going no pooh as they say it, if they can't 0:21:11.520 --> 0:21:15.200 um that you can definitely observe this in action. Uh 0:21:15.520 --> 0:21:17.920 so I feel the oils in your hair? Yeah, Like 0:21:17.920 --> 0:21:21.640 like I will generally go no shampoo for um for 0:21:21.720 --> 0:21:24.160 like a few weeks at a time, and I will 0:21:24.400 --> 0:21:27.240 my hair, doesn't It varies from person to person, you know, 0:21:27.280 --> 0:21:29.960 depending on you know your particular hair, and you know 0:21:30.080 --> 0:21:32.520 in a particular oil and how it builds up. But 0:21:32.720 --> 0:21:34.680 with my own hair, like a little bit of oil 0:21:34.880 --> 0:21:37.760 will build up in my hair, will will look tolerable 0:21:37.840 --> 0:21:39.400 and um, you know, I won't have to do much 0:21:39.440 --> 0:21:41.240 with it. But then eventually I'll come a point where 0:21:41.320 --> 0:21:44.359 I start feeling a little oily, and therefore I bust 0:21:44.359 --> 0:21:47.320 out the shampoo, and when I do, all the oil 0:21:47.400 --> 0:21:49.879 is gone. And now and then I just look like 0:21:49.880 --> 0:21:52.160 like a troll doll. You know, I said, Now there's 0:21:52.200 --> 0:21:54.159 no oil in my hair at all, and it's just 0:21:54.200 --> 0:21:57.359 this poofy uh blonde mess. But I bring this up. 0:21:57.400 --> 0:21:59.600 There's just an example of you know, this is a 0:21:59.640 --> 0:22:02.920 way to observe that water. Even a lengthy shower, a 0:22:03.000 --> 0:22:06.880 lengthy blast of of hot, steamy water is not going 0:22:06.960 --> 0:22:09.800 to get that oil out of your hair um, even 0:22:09.840 --> 0:22:12.200 if it's just day after day, twice a day even, 0:22:12.640 --> 0:22:16.880 uh not until you add that magical soap, right, Yeah, 0:22:16.960 --> 0:22:19.800 the oil just does not come away in the water. 0:22:20.200 --> 0:22:23.600 So soap is made by Classically, it's made by combining 0:22:23.640 --> 0:22:26.720 a fatty acid such as an oil or an animal fat. 0:22:26.960 --> 0:22:29.720 You know, you can use like a animal tallow or 0:22:29.800 --> 0:22:33.320