WEBVTT - From the Vault: Mud, Part 1 0:00:06.200 --> 0:00:08.559 Hey, welcome to Stuff to Blow Your Mind. My name 0:00:08.640 --> 0:00:12.479 is Robert Lamb. It's Saturday. We're venturing back into the vault. 0:00:12.800 --> 0:00:15.480 This is going to be part one of our let's see, 0:00:15.480 --> 0:00:18.280 this was a four part series that we did on mud. 0:00:18.800 --> 0:00:20.680 You know, if you listened recently, you may have heard 0:00:20.680 --> 0:00:24.320 our series on dust. Well, similar we're talking about mud 0:00:24.360 --> 0:00:25.960 and there so we get into all sorts of different 0:00:25.960 --> 0:00:28.400 angles here in these four episodes. So it might seem 0:00:28.440 --> 0:00:31.200 mundane on the surface, but once you sync into it, 0:00:31.640 --> 0:00:33.760 I think you'll find it as fascinating as we did. 0:00:34.040 --> 0:00:37.840 This episode originally published on seven six, twenty twenty three. 0:00:38.240 --> 0:00:38.840 Here we go. 0:00:42.400 --> 0:00:46.400 Welcome to Stuff to Blow Your Mind, a production of iHeartRadio. 0:00:51.880 --> 0:00:54.040 Hey, welcome to Stuff to Blow your Mind. My name 0:00:54.080 --> 0:00:54.680 is Robert. 0:00:54.520 --> 0:00:57.840 Lamb, and I am Joe McCormack. And today we are 0:00:57.880 --> 0:01:01.760 going to be starting a series of episodes on mud, 0:01:02.200 --> 0:01:04.720 a topic that I promise is more interesting than you 0:01:04.800 --> 0:01:07.559 might think. And to get us started today, I wanted 0:01:07.600 --> 0:01:11.800 to talk about a section from an English epic poem 0:01:12.360 --> 0:01:16.960 that endorses the belief that mud just happens to give 0:01:17.040 --> 0:01:22.080 rise to monsters or monstrous creatures of various shapes. So 0:01:22.160 --> 0:01:25.720 the poem in question is a late sixteenth century epic 0:01:25.760 --> 0:01:30.319 poem by the English poet Edmund Spencer called The Fairy Queen. 0:01:30.959 --> 0:01:32.720 I took a class in college where we read this, 0:01:32.880 --> 0:01:35.080 or we read part of it. To be honest, there's 0:01:35.080 --> 0:01:37.280 a lot that I forget about it. But it's very 0:01:37.360 --> 0:01:41.520 much your classic epic poem, with heroic knights, the Red 0:01:41.560 --> 0:01:45.240 Cross Knight, and damsels in distress and witches and ogres 0:01:45.280 --> 0:01:48.840 and all that. And there's an interesting passage toward the 0:01:48.840 --> 0:01:50.880 beginning of The Fairy Queen. I think it's in book one, 0:01:51.000 --> 0:01:55.120 Canto one, where Spencer implies a belief about the way 0:01:55.280 --> 0:01:59.360 nature works, a belief that the mud, specifically the mud 0:01:59.400 --> 0:02:04.200 of the Nie River, spawns monsters, and Spencer writes quote 0:02:04.520 --> 0:02:08.440 as when old father Nilus gins to swell with timely 0:02:08.560 --> 0:02:12.880 pride above the Egyptian veil, his fatty waves do fertile 0:02:13.000 --> 0:02:17.320 slime out well and overflow each plane and lowly dale. 0:02:17.760 --> 0:02:20.840 But when his later spring gins to a veil, huge 0:02:20.960 --> 0:02:25.520 heaps of mud he leaves wherein their breed ten thousand 0:02:25.680 --> 0:02:29.720 kinds of creatures, partly male and partly female, of his 0:02:29.840 --> 0:02:34.840 fruitful seed, such ugly, monstrous shapes elsewhere may no man read. 0:02:35.600 --> 0:02:38.360 And then Spencer later cites the same belief again as 0:02:38.360 --> 0:02:41.480 a kind of illustration of a general principle. He writes, 0:02:41.760 --> 0:02:45.400 but reason teacheth that the fruitful seeds of all things 0:02:45.480 --> 0:02:50.600 living through impression of the sunbeams in moist complexion, do 0:02:50.760 --> 0:02:56.000 life conceive and quickened are by kind. So after Nilus inundation, 0:02:56.280 --> 0:03:00.560 infinite shapes of creatures men do find inform in the 0:03:00.639 --> 0:03:04.160 mud on which the sun hath shined. So I think 0:03:04.200 --> 0:03:10.000 he seems to be saying like mud plus sunshine equals monsters, 0:03:10.080 --> 0:03:13.760 or at least creatures of infinite shapes, which in some 0:03:13.800 --> 0:03:18.000 passages he seems to think might be monsters. Maybe among 0:03:18.120 --> 0:03:23.480 infinite variation there will necessarily be some monsters. And I'm 0:03:23.480 --> 0:03:25.720 interested in this belief because, on one hand, it just 0:03:25.760 --> 0:03:28.919 sort of reflects some ancient beliefs that are carried over 0:03:29.000 --> 0:03:32.760 into the Medieval and Renaissance period about where life comes from, 0:03:32.800 --> 0:03:37.480 ideas now obsolete theories like spontaneous generation that you know 0:03:37.560 --> 0:03:40.080 that life forms, which is sort of like arise in 0:03:40.160 --> 0:03:42.360 the mud or in like a wet bag of flower 0:03:42.520 --> 0:03:47.160 or something. But I also like it because it imagines 0:03:47.680 --> 0:03:51.000 the mud in the floodplain of a great river like 0:03:51.040 --> 0:03:56.040 the Nile as a source of both like sort of 0:03:56.120 --> 0:04:00.960 mystery and danger but also great possibility. And this does 0:04:01.000 --> 0:04:03.440 correspond to the kind of the double nature of mud 0:04:03.520 --> 0:04:05.520 and of a river like the Nile. So you think 0:04:05.520 --> 0:04:08.320 of the Nile River delta, it is a place of 0:04:08.360 --> 0:04:12.280 incredibly fertile soil that you know, that supplies food and 0:04:12.360 --> 0:04:15.920 crops for all of the areas around. But also if 0:04:16.000 --> 0:04:17.960 you know, you get stuck in the mud, that's a 0:04:18.000 --> 0:04:19.599 place you don't want to be. And it is a 0:04:19.600 --> 0:04:23.200 place where you will find lots of life that is 0:04:23.200 --> 0:04:25.920 maybe life that's kind of strange to you. You don't 0:04:26.000 --> 0:04:28.200 usually go wading into the mud, and if you do, 0:04:28.320 --> 0:04:30.760 I don't know, all kinds of weird little mollusks and 0:04:30.800 --> 0:04:33.640 creepy crawleys and critters are in there, and you don't 0:04:33.680 --> 0:04:34.640 know what you might find. 0:04:35.200 --> 0:04:38.279 Yeah, yeah, this is really interesting. We should also note, 0:04:38.839 --> 0:04:43.120 you know, it does accurately, though monstrously refer to the 0:04:43.120 --> 0:04:47.159 the the inundation of the Nile, which is a topic 0:04:47.160 --> 0:04:49.400 we did an entire episode at least one episode on 0:04:49.480 --> 0:04:52.679 in the past. I mean, the Nile overflows its banks 0:04:52.720 --> 0:04:56.800 and it brings life and has this this very prominent 0:04:56.920 --> 0:05:03.320 role in especially in ancient Egyptian belief and mythology. But yeah, 0:05:03.360 --> 0:05:06.440 this dual nature of mud is quite interesting and something 0:05:06.440 --> 0:05:08.719 that that we're going to be talking about quite a 0:05:08.720 --> 0:05:11.480 bit in these episodes because it at once it is 0:05:11.520 --> 0:05:13.800 like you want to build something, well, you're gonna need 0:05:13.839 --> 0:05:17.080 something like mud or mud itself. But of course it's 0:05:17.120 --> 0:05:20.520 also the place where you know, many a famous military 0:05:20.560 --> 0:05:23.640 campaign has perished in the mud, so you know, it's 0:05:23.640 --> 0:05:27.440 the thing from which monsters emerge, but it's all you know, 0:05:27.480 --> 0:05:29.560 it's the thing where you might find a pig, but 0:05:29.640 --> 0:05:34.680 you also will find gleaming butterflies, you know, cascading and 0:05:35.080 --> 0:05:39.520 swirling around something some stinking pile of mud. So yeah, 0:05:39.520 --> 0:05:41.920 it does seem to have this dual nature, at least 0:05:42.040 --> 0:05:43.479 from the human vantage point. 0:05:43.640 --> 0:05:45.880 So our goal is after we're done with this series, 0:05:45.920 --> 0:05:48.040 you will never think about mud the same way. And 0:05:48.080 --> 0:05:50.800 when it gets stuck to your shoes, you might still 0:05:50.839 --> 0:05:52.720 be mad, but there will also be a part of 0:05:52.760 --> 0:05:55.800 you that that's kind of reflective and stops to be 0:05:55.839 --> 0:05:58.320 amazed at what it is. Your dog has just gotten 0:05:58.360 --> 0:05:59.200 all over your couch. 0:05:59.600 --> 0:06:03.360 Yeah, and if you're like me too. Just even thinking 0:06:03.360 --> 0:06:06.240 about this topic, it means that you've had the Primus 0:06:06.279 --> 0:06:10.160 song my Name is Mud just flipped on in your brain. 0:06:10.200 --> 0:06:12.719 I haven't even listened to it to encourage or extinguish it, 0:06:12.760 --> 0:06:15.400 but it's just there as I read these various papers 0:06:15.400 --> 0:06:20.599 about mud or mummama mud, Right, I guess that's the way. 0:06:20.480 --> 0:06:24.719 It's said, and so I'll take your word for it. 0:06:24.720 --> 0:06:27.120 It's a solid jam. It's got some colossal bass and 0:06:27.200 --> 0:06:27.880 drums on there. 0:06:28.160 --> 0:06:31.520 Oh yeah, that's primus. They rattle the furniture. But anyway, 0:06:31.640 --> 0:06:34.680 we should go straight to the question what is mud? 0:06:34.720 --> 0:06:37.880 What is it made of? In general, mud seems to 0:06:37.880 --> 0:06:40.880 have a kind of loose definition. We all know it 0:06:40.920 --> 0:06:43.479 when we see it, but there may not be strict 0:06:43.520 --> 0:06:48.240 scientific criteria about what counts, except maybe in certain contexts, 0:06:48.279 --> 0:06:50.760 like when you're talking when you get to some things 0:06:50.800 --> 0:06:52.920 we'll get to in a minute about like particle size 0:06:52.960 --> 0:06:58.040 and what solidifies into certain kinds of rock. But just generally, 0:06:58.200 --> 0:07:01.719 I mean, mud is some sort of wet soil, but 0:07:02.080 --> 0:07:05.560 exactly how wet, Exactly what are the properties of the 0:07:05.560 --> 0:07:08.080 soil for it to count as mud versus just being 0:07:08.160 --> 0:07:12.200 kind of like I don't know, damp, gross stuff that 0:07:12.280 --> 0:07:13.960 might be in the eye of the beholder, of the 0:07:13.960 --> 0:07:15.480 beat or of the bee treader. 0:07:16.080 --> 0:07:18.840 Yeah, I would. I would. I think that sometimes we 0:07:18.920 --> 0:07:21.040 know it when we see it, but we definitely know 0:07:21.120 --> 0:07:23.360 it when we step on it or step in it. 0:07:23.920 --> 0:07:25.920 I guess that's the thing, right. If I'm able to 0:07:25.960 --> 0:07:29.080 step on it, well maybe it's not fully mud. But 0:07:29.160 --> 0:07:31.600 if I'm in it, well I am in mud now. 0:07:32.080 --> 0:07:34.040 But I think the other Yeah. The other interesting thing 0:07:34.080 --> 0:07:36.280 about mud is a lot of it does depend on 0:07:36.320 --> 0:07:38.480 where you're coming from, you know, like if you were 0:07:38.560 --> 0:07:42.480 a domesticated hog, well, mud is just simply good. There's 0:07:43.080 --> 0:07:44.760 not much else to say about that, though. We will 0:07:44.760 --> 0:07:48.800 get into how various animals use mud later on in 0:07:48.840 --> 0:07:52.280 a subsequent episode, but just from the human perspective, it's 0:07:52.360 --> 0:07:55.360 kind of interesting. One of the books I was looking at, 0:07:55.400 --> 0:07:57.640 and we'll come back to later when we get more 0:07:57.720 --> 0:08:01.080 in depth on this is a book titled Mud, a 0:08:01.160 --> 0:08:05.560 Military History by ce Wood, which, if you haven't thought 0:08:05.560 --> 0:08:08.160 about it much before, or you haven't you're not like 0:08:08.160 --> 0:08:13.679 a military history enthusiast, you might not realize that, oh yeah, mud. 0:08:13.760 --> 0:08:15.440 Mud is the sort of thing that you could write 0:08:15.480 --> 0:08:20.119 an entire book about just from the perspective of war 0:08:20.240 --> 0:08:22.840 and military operations. But that's what this book is. 0:08:23.160 --> 0:08:25.920 When I think of mud and armed conflict. Obviously, you know, 0:08:26.040 --> 0:08:28.600 terrain and especially mud have played a big role in 0:08:29.120 --> 0:08:32.319 worse throughout history, but I think especially of Eastern Europe 0:08:32.360 --> 0:08:33.080 for some reason. 0:08:33.559 --> 0:08:37.680 Yeah, big big war machines, big tanks stuck in the mud, 0:08:38.120 --> 0:08:42.200 or as as Wood mentions a time or two, the 0:08:42.240 --> 0:08:44.800 idea of one of these colossal tanks just going down 0:08:44.840 --> 0:08:48.040 a muddy hill, as if it were like a sled 0:08:48.520 --> 0:08:52.080 on a snowfield or something, you know, just out of control. 0:08:52.480 --> 0:08:56.920 Things like that. Occurring mud changes what you can and 0:08:56.960 --> 0:09:01.280 can't do in many instances with any with things ranging 0:09:01.280 --> 0:09:07.720 from infantry to horses to modern industrial war machines. But 0:09:07.840 --> 0:09:09.840 like I said, we'll get back to that more in 0:09:09.640 --> 0:09:12.640 the future. But I thought it was interesting that Wood 0:09:12.640 --> 0:09:16.360 opens just dealing with his basic ambiguity concerning mud and 0:09:16.400 --> 0:09:19.080 writes that, Okay, if we're going to be just very 0:09:19.120 --> 0:09:22.760 broad about it, it comes down to soil consisting of 0:09:22.800 --> 0:09:27.120 mineral and organic matter combined with moisture at such a 0:09:27.240 --> 0:09:30.680 level relative to the exact compositions of the soil to 0:09:30.800 --> 0:09:35.480 make it unstable and likely to move and flow underfoot 0:09:35.600 --> 0:09:40.520 or underhoof or under wheeler track, etc. Wood points out 0:09:40.520 --> 0:09:44.000 that while many military minds have considered mud and other 0:09:44.120 --> 0:09:48.600 soil issues beneath their strategic consideration, but they have always 0:09:48.679 --> 0:09:52.480 done so at their peril, because mud, as we'll get 0:09:52.520 --> 0:09:54.840 into later, does make a difference in war has come 0:09:55.280 --> 0:09:59.920 to very famously define certain war zones. He points out 0:10:00.400 --> 0:10:05.160 that not everyone has certainly ignored this fact, and in 0:10:05.240 --> 0:10:08.320 nineteen forty four, the US Army conducted a series of 0:10:08.360 --> 0:10:11.120 tests regarding mud. They're like, all right, let's get down 0:10:11.120 --> 0:10:13.760 to it. Let's classify some mud. Because we have only 0:10:13.880 --> 0:10:19.040 so many resources for our rubber tires, so we needed 0:10:19.080 --> 0:10:20.840 to decide where we need to send them, where we 0:10:20.840 --> 0:10:24.280 need to prioritize our best tires. And so this is 0:10:24.320 --> 0:10:27.000 a situation where we're dealing with sort of a narrowed 0:10:27.040 --> 0:10:31.240 perspective concerning mud. This is just mud concerning like, let 0:10:31.280 --> 0:10:35.000 me roll some vehicles across it. But they classified mud 0:10:35.120 --> 0:10:41.200 into two types and two subtypes. Okay, Type one bottomless mud. Now, 0:10:41.400 --> 0:10:45.520 this just means that the MUD's consistency cannot support a 0:10:45.640 --> 0:10:48.560 vehicle with tires that have twenty pounds of pressure, or 0:10:49.000 --> 0:10:53.120 that the underlying hard layer of earth beneath the mud 0:10:53.120 --> 0:10:55.319 beneath the layer of mud is too far beneath the 0:10:55.400 --> 0:10:56.720 vehicle's ground clearance. 0:10:57.040 --> 0:10:59.240 Okay, so this sounds like dangerous mud. 0:10:59.679 --> 0:11:02.439 Yeah, this is the mud that your vehicle is going 0:11:02.480 --> 0:11:05.320 to get stuck in and or sink into. And then 0:11:05.400 --> 0:11:09.520 type two is just all other types of mud. But 0:11:09.679 --> 0:11:13.199 this does feature two subtypes, Type A and type B. 0:11:13.920 --> 0:11:17.680 Type A has a quote unquote cleaning quality, meaning that 0:11:17.720 --> 0:11:21.280 it contains enough moisture to work as a liquid. So 0:11:21.360 --> 0:11:24.360 like this, like type A mud gets on your vehicle 0:11:24.880 --> 0:11:27.199 and you know, it kind of flows off. I mean 0:11:27.400 --> 0:11:30.679 it's I don't think cleaning quality means that your tank 0:11:30.800 --> 0:11:32.880 or your truck is going to be clean after the 0:11:32.960 --> 0:11:35.640 mud has a rent stock a little bit. Yeah, it 0:11:35.640 --> 0:11:38.760 flows away, but it's it's this a cleaning quality. Type 0:11:38.800 --> 0:11:43.560 B is adhesive or sticky. So this is the the 0:11:43.679 --> 0:11:46.680 mudd in type of mud. This is the type of 0:11:46.760 --> 0:11:51.320 mud that the the big pickup pickup truck driver seeks 0:11:51.360 --> 0:11:53.679 out when they go out into the wilderness to make 0:11:53.720 --> 0:11:56.400 sure that they return to city life with a vehicle 0:11:56.480 --> 0:12:01.240 completely encased in mud. Okay, So more on the military 0:12:01.280 --> 0:12:04.199 angle later on. So this is not necessarily a helpful 0:12:04.240 --> 0:12:06.840 way to understand mud as a whole, but rather to 0:12:07.200 --> 0:12:09.360 a way to underline that the meaning of mud kind 0:12:09.360 --> 0:12:11.160 of depends on what you're trying to do in it 0:12:11.600 --> 0:12:14.360 or through it, and mud therefore could be your threat 0:12:14.440 --> 0:12:16.640 or your treasure, depending on what you're looking to get 0:12:16.679 --> 0:12:17.480 out of the situation. 0:12:18.080 --> 0:12:20.440 Very true. Now, I found an article that I thought 0:12:20.480 --> 0:12:23.640 was helpful. It was from two thousand and three in 0:12:23.800 --> 0:12:26.959 the Washington Post, and being in the Washington Post, I 0:12:26.960 --> 0:12:30.040 would say a little overly concerned with these specific types 0:12:30.040 --> 0:12:33.000 of mud found around the Washington d C. Metro area. 0:12:33.080 --> 0:12:36.920 But I'm mostly ignoring those parts because it does helpfully 0:12:36.960 --> 0:12:42.080 consult a bunch of soil scientists on the definitions and 0:12:42.480 --> 0:12:45.640 categories of mud. So it was called a World Gone 0:12:45.760 --> 0:12:49.040 Mud by Joel Aikenbach from June fifteenth, two thousand and three. 0:12:49.800 --> 0:12:54.120 First of all, it consults a researcher named Trish Steinhilbert 0:12:54.600 --> 0:13:00.199 from the University of Maryland Agricultural Nutrient Management Program, who says, 0:13:00.280 --> 0:13:03.319 you know, we would just call it wet soil. So 0:13:03.320 --> 0:13:06.199 that's one perspective. It's just wet soil, But then the 0:13:06.320 --> 0:13:10.920 article cites another soil physicist, or sorry, another soil researcher, 0:13:11.000 --> 0:13:13.520 this time a soil physicist also from the University of 0:13:13.520 --> 0:13:18.080 Maryland named Robert Hill, who says mud should be differentiated 0:13:18.120 --> 0:13:22.160 from merely wet soil because it has different physical properties. 0:13:22.160 --> 0:13:26.360 As commonly understood, like we've been saying, mud is sticky 0:13:26.679 --> 0:13:29.800 in a way that not all wet soils are, and 0:13:30.080 --> 0:13:33.679 this stickiness is due to the presence of a higher 0:13:33.720 --> 0:13:40.920 proportion of smaller particles, especially clay particles. So, as you 0:13:41.000 --> 0:13:44.960 probably know, soil is made from a mixture of different materials. 0:13:45.040 --> 0:13:47.800 Some of those materials are organic, so they can be 0:13:47.880 --> 0:13:51.720 you know, decaying organic matter or decaying bits of plants 0:13:51.760 --> 0:13:55.160 and animals and all that, but also inorganic matter, and 0:13:55.200 --> 0:13:58.160 we're going to focus on the inorganic matter for the moment. 0:13:58.600 --> 0:14:03.319 The inorganic solid particles that make up soil are generally 0:14:03.360 --> 0:14:07.920 produced by the erosion and breakdown of larger rocks over time, 0:14:08.440 --> 0:14:11.720 which can happen due to physical forces like wind, rain, 0:14:11.840 --> 0:14:14.400 and ice, or it can be due to break down 0:14:14.400 --> 0:14:18.240 by organisms like fungi and bacteria. And we all know 0:14:18.320 --> 0:14:21.440 soil can have different consistencies you stick your hands into 0:14:21.440 --> 0:14:24.560 the soil in one place, it just feels different than 0:14:24.560 --> 0:14:27.640 the soil in another place. One of the major factors 0:14:27.680 --> 0:14:30.720 that you can use to sort soil into different categories 0:14:30.840 --> 0:14:35.680 is the average particle size in the soil. So if 0:14:35.880 --> 0:14:40.280 particles are bigger than two millimeters, that's gravel. You know 0:14:41.360 --> 0:14:44.600 that's going to pop under your car tire. Particles of 0:14:45.320 --> 0:14:49.280 less than two millimeters in diameter but more than zero 0:14:49.400 --> 0:14:54.800 point zero five millimeters are sand. Then smaller than sand, 0:14:55.120 --> 0:14:58.400 you've got silt, which is made of particles less than 0:14:58.560 --> 0:15:01.960 zero point zero five million meters in diameter. And then 0:15:02.000 --> 0:15:05.680 at the very bottom, the finest grain soil is clay, 0:15:05.800 --> 0:15:10.600 which means particles smaller than zero point zero zero two 0:15:11.040 --> 0:15:15.240 millimeters in diameter. Now, apart from particle size, there are 0:15:15.280 --> 0:15:19.400 also some at least common chemical properties you'll find at 0:15:19.440 --> 0:15:23.000 these different areas, like they tend to derive from different 0:15:23.000 --> 0:15:27.160 types of minerals, like clay typically features a standard mineral constituent, 0:15:27.240 --> 0:15:31.840 which is hydrous aluminum philosilicates. But for the moment, we 0:15:31.840 --> 0:15:34.680 can just think about these as particles of different sizes. 0:15:35.120 --> 0:15:39.160 So by one definition, any sufficiently wet soil made of 0:15:39.360 --> 0:15:43.120 any mixture of these particles could be mud. But if 0:15:43.120 --> 0:15:46.600 you're going with the definition of mud as sticky slop 0:15:46.720 --> 0:15:48.760 that kind of sucks to the bottom of your shoes 0:15:48.800 --> 0:15:51.840 and you might get stuck in it usually means it's 0:15:51.880 --> 0:15:56.320 made up of mostly silt and clay sized particles. Silt 0:15:56.360 --> 0:16:00.400 sized and clay sized particles, and things get especially sticky 0:16:00.480 --> 0:16:02.120 if it has a lot of clay. 0:16:02.760 --> 0:16:05.560 And again there's this fine line, Like I know, I 0:16:05.640 --> 0:16:09.120 instantly think back to some cave environments that I've been in, 0:16:09.680 --> 0:16:14.800 and mud at just the right consistency, it's like it's sticky, 0:16:15.000 --> 0:16:17.600 but you're not slipping in it. It's almost something you 0:16:17.640 --> 0:16:21.200 want to walk on. But that line is very thin 0:16:21.520 --> 0:16:25.400 between between that and like the treacherous mud that you 0:16:25.480 --> 0:16:29.680 will slip in. So it's fascinating when you start getting 0:16:29.680 --> 0:16:30.840 into the way this breaks down. 0:16:31.400 --> 0:16:34.960 Yeah, is the mud grippy like maybe rubber? Or will 0:16:34.960 --> 0:16:37.080 it fly out from under you like a banana peel? 0:16:37.800 --> 0:16:41.560 And that does, I think come down to something having 0:16:41.600 --> 0:16:44.120 to do with the water content as well as the 0:16:44.160 --> 0:16:48.360 particle size. So if mud is wet soil or sticky 0:16:48.360 --> 0:16:51.640 wet soil, we've explained the soil part. It tends to 0:16:51.680 --> 0:16:55.240 be the smaller particle sizes clay sized and silt sized 0:16:55.240 --> 0:16:58.160 particles that make mud. But there's also the wetness angle. 0:16:58.280 --> 0:17:00.840 How wet does soil have to be for it to 0:17:00.880 --> 0:17:04.320 be mud. Here we get to the concept of cohesive 0:17:04.440 --> 0:17:09.720 soil and what are called Aderberg limits. So cohesive soils 0:17:09.800 --> 0:17:13.880 are soils that tend to stick or clump together as 0:17:13.920 --> 0:17:18.119 opposed to crumbling. Cohesive soils tend to have again more 0:17:18.280 --> 0:17:23.480 clay sized particles. Smaller particles stick together better, and cohesive 0:17:23.520 --> 0:17:27.240 soils can be in three states, depending on how wet 0:17:27.280 --> 0:17:32.240 they are. These states are non plastic, plastic, and viscous. 0:17:32.880 --> 0:17:37.560 Non Plastic means hard, you know, difficult to mold or deform. 0:17:37.840 --> 0:17:41.320 This is usually when they're dry. Cohesive soils dry up 0:17:41.440 --> 0:17:44.359 kind of hard like bricks, and they form tough earth, 0:17:44.440 --> 0:17:47.560 so you can think about like hard clay ground, you 0:17:47.600 --> 0:17:51.200 know what that's like. When cohesive soils get wet, though, 0:17:51.240 --> 0:17:54.119 they can cross one of these Aderberg limits, that the 0:17:54.119 --> 0:17:57.840 plastic limit and become plastic, so this means they become 0:17:58.040 --> 0:18:03.240 soft or moldable, think about wet clay, and then beyond 0:18:03.400 --> 0:18:06.160 that limit there's another limit, another limit which is the 0:18:06.200 --> 0:18:09.960 liquid limit, and this is the viscous stage where there's 0:18:10.000 --> 0:18:12.919 sort of like a liquid goop. So you can add 0:18:12.960 --> 0:18:16.639 water to non plastic soil until it crosses the plastic limit, 0:18:16.720 --> 0:18:19.879 becomes soft and mouldable, you can add more water until 0:18:19.920 --> 0:18:23.800 it crosses the liquid limit. Where the liquid limit is 0:18:23.800 --> 0:18:27.280 explained in this Washington Post article as if you cut 0:18:27.320 --> 0:18:30.520 a groove in the mud, the mud will flow back 0:18:30.560 --> 0:18:34.120 in to fill it. That's the liquid limit, which actually 0:18:34.240 --> 0:18:38.399 has some analogies in the culinary world, like if you 0:18:38.440 --> 0:18:41.080 ever did the back of the spoon test for the 0:18:41.200 --> 0:18:43.840 thickness of a sauce in the kitchen. The French term 0:18:43.880 --> 0:18:46.280 for that is nape, where if you like wipe your 0:18:46.560 --> 0:18:48.960 the tip of your finger along the back of a 0:18:49.000 --> 0:18:52.199 spoon coated in the sauce, it should leave a trail 0:18:52.400 --> 0:18:54.680 rather than having the sauce flow back in to fill 0:18:54.760 --> 0:18:56.280 the gap. That's nape. 0:18:56.800 --> 0:18:59.080 One of the many culinary techniques in you just like 0:18:59.200 --> 0:19:01.160 jab your finger into things like. 0:19:01.200 --> 0:19:03.520 Yeah, stick, yeah, stick your finger in the food. 0:19:03.840 --> 0:19:06.680 Yeah, let the meat touch your face, and that will 0:19:06.680 --> 0:19:08.520 determine if it is the right temperature. 0:19:08.880 --> 0:19:11.040 But so the definition of the liquid limit is that 0:19:11.119 --> 0:19:13.120 it does not pass the back of the spoon test 0:19:13.160 --> 0:19:14.760 if you cut a groove in it, it will flow 0:19:14.800 --> 0:19:17.560 back in to fill the gap. So it sounds to 0:19:17.600 --> 0:19:22.119 me like the definitional sweet spot for mud is a 0:19:22.160 --> 0:19:26.440 wet cohesive soil. It's made primarily of silt or clay 0:19:26.440 --> 0:19:29.200 sized particles, especially if there's a lot of clay sized 0:19:29.240 --> 0:19:34.320 particles that is above the plastic limit and below the 0:19:34.359 --> 0:19:39.040 liquid limit. Somewhere in there, though, I was thinking that 0:19:39.920 --> 0:19:43.320 even sort of fully liquid glop we do sometimes call mud, 0:19:43.359 --> 0:19:45.679 don't we, But that's not usually the first kind of 0:19:45.720 --> 0:19:46.880 substance I think of. 0:19:47.400 --> 0:19:50.639 Right, right, Like, I come back to the example of 0:19:51.440 --> 0:19:54.600 mud pies. You know, I think a lot of us 0:19:54.600 --> 0:19:56.720 did this as a kid. If you're allowed to play 0:19:56.720 --> 0:19:59.040 in the mud, do you get some little like pie 0:19:59.119 --> 0:20:03.160 crust or little whatever, you know, cups and pans pour 0:20:03.240 --> 0:20:05.960 the mud up, slap the mud together, and then you 0:20:06.000 --> 0:20:08.560 set it in the sun too dry into mud cakes. 0:20:09.440 --> 0:20:11.520 But yeah, it's like if you're pouring it, if you're 0:20:11.560 --> 0:20:14.119 just complete all you know it is completely pouring it 0:20:14.200 --> 0:20:16.920 into the pan, that doesn't really feel like mud. That's 0:20:17.040 --> 0:20:21.199 just like mud water or something that's like on the 0:20:21.240 --> 0:20:23.320 way to mud. But not mud quite yet. The moisture 0:20:23.320 --> 0:20:25.359 still level is too high. And I guess in baking 0:20:25.440 --> 0:20:28.760 you have variations of that as well. Right like you said, 0:20:28.760 --> 0:20:30.960 the sauce is too runny, the batter is too runny, 0:20:30.960 --> 0:20:31.399 et cetera. 0:20:40.840 --> 0:20:42.720 Oh, I think the mudpie test is a good one. 0:20:42.720 --> 0:20:44.960 And you know what, that actually brings me to the 0:20:45.000 --> 0:20:48.280 next thing I want to talk about, which is this 0:20:48.400 --> 0:20:52.520 might be something you've never considered before. Was there a 0:20:52.640 --> 0:20:55.880 time on Earth when it would have been really difficult 0:20:56.280 --> 0:20:59.640 to make a mud pie? I would argue, based on 0:20:59.680 --> 0:21:02.560 some research I've been reading about that, Yes, if you 0:21:02.640 --> 0:21:06.199 go back before five hundred million years ago, go to 0:21:06.200 --> 0:21:09.600 the pre Cambrian period, and you walk around on Earth's 0:21:09.640 --> 0:21:12.880 continents trying to find a place to make a mud pie, 0:21:13.720 --> 0:21:16.240 you're gonna probably strike out. You're gonna be out of luck, 0:21:16.320 --> 0:21:21.960 because there was a time basically before there was mud 0:21:22.160 --> 0:21:25.760 on land on Earth, or before there was very much 0:21:25.840 --> 0:21:28.520 mud to be found on land. So here I want 0:21:28.560 --> 0:21:30.520 to go to an article I was reading in the 0:21:30.640 --> 0:21:34.800 journal Science in the year twenty eighteen by Woodward Fisher, 0:21:34.880 --> 0:21:40.000 who is a Caltech geobiologist. The article is called Early 0:21:40.080 --> 0:21:44.119 Plants and the Rise of mud, and this article is 0:21:44.200 --> 0:21:49.960 primarily summarizing and contextualizing a study that was published by 0:21:49.960 --> 0:21:52.119 a couple of different authors in the same issue of 0:21:52.200 --> 0:21:56.040 the journal Science in twenty eighteen. This article is very 0:21:56.040 --> 0:22:01.840 good in putting these findings in context. So Fisher mentions 0:22:01.880 --> 0:22:05.800 that you know, life on Earth has several times that 0:22:05.840 --> 0:22:12.320 we know about reshaped fundamental geophysical features and processes at 0:22:12.359 --> 0:22:15.360 the Earth's surface. There are ways in which you could 0:22:15.400 --> 0:22:19.960 say that life has fundamentally changed the planet itself, at 0:22:20.040 --> 0:22:22.360 least what's happening on the surface and in the atmosphere. 0:22:22.760 --> 0:22:26.199 So perhaps the first example that will likely come to 0:22:26.240 --> 0:22:30.840 your mind is the oxygenation of the oceans in the atmosphere. 0:22:31.040 --> 0:22:35.440 It was the evolution of photosynthesis in cyanobacteria and other 0:22:35.520 --> 0:22:38.760 life forms that triggered this shift. You know, we didn't 0:22:38.760 --> 0:22:43.479 always have an oxygen atmosphere. Another major geophysical change triggered 0:22:43.520 --> 0:22:47.760 by life that Fisher mentions is the evolution of mineral 0:22:48.000 --> 0:22:53.920 skeletons by life forms, again, particularly algae, and the presence 0:22:53.920 --> 0:22:57.920 of those skeletons change the way that ocean floors are formed, 0:22:57.960 --> 0:23:01.440 and then subsequently the kinds of rock lay that would 0:23:01.480 --> 0:23:05.159 form when they solidified. Over the eons. But this article 0:23:05.240 --> 0:23:09.679 is focused on another discovery of this sort, how the 0:23:09.720 --> 0:23:16.160 evolution of land based plants changed the Earth by affecting mud. 0:23:16.760 --> 0:23:20.159 So the citation for the study here is William J. 0:23:20.320 --> 0:23:24.160 McMahon and Neil S. Davies. The article is called evolution 0:23:24.359 --> 0:23:28.720 of alluvial mud rock forced by early land plants again 0:23:28.880 --> 0:23:34.040 Journal Science, twenty eighteen. So when soil made mostly out 0:23:34.040 --> 0:23:37.480 of clay or silt sized particles gets compacted in the 0:23:37.520 --> 0:23:42.320