WEBVTT - Mud, Part 1 0:00:03.040 --> 0:00:07.000 Welcome to Stuff to Blow Your Mind, a production of iHeartRadio. 0:00:12.520 --> 0:00:14.680 Hey, welcome to Stuff to Blow your Mind. My name 0:00:14.720 --> 0:00:15.320 is Robert. 0:00:15.160 --> 0:00:18.480 Lamb and I am Joe McCormack. And today we are 0:00:18.520 --> 0:00:22.440 going to be starting a series of episodes on mud, 0:00:22.840 --> 0:00:25.360 a topic that I promise is more interesting than you 0:00:25.440 --> 0:00:28.200 might think. And to get us started today, I wanted 0:00:28.240 --> 0:00:32.440 to talk about a section from an English epic poem 0:00:33.000 --> 0:00:37.600 that endorses the belief that mud just happens to give 0:00:37.680 --> 0:00:42.760 rise to monsters or monstrous creatures of various shapes. So 0:00:42.800 --> 0:00:46.360 the poem in question is a late sixteenth century epic 0:00:46.400 --> 0:00:50.960 poem by the English poet Edmund Spencer called The Fairy Queen. 0:00:51.600 --> 0:00:53.400 I took a class in college where we read this, 0:00:53.520 --> 0:00:55.720 or we read part of it. To be honest, there's 0:00:55.720 --> 0:00:57.920 a lot that I forget about it, but it's very 0:00:58.000 --> 0:01:01.920 much your classic poem with you know, heroic knights, the 0:01:01.960 --> 0:01:05.360 Red Cross Knight, and damsels in distress and witches and 0:01:05.400 --> 0:01:09.360 ogres and all that. And there's an interesting passage toward 0:01:09.440 --> 0:01:11.039 the beginning of The Fairy Queen. I think it's in 0:01:11.080 --> 0:01:15.240 book one, canto one, where Spencer implies a belief about 0:01:15.319 --> 0:01:19.560 the way nature works a belief that the mud, specifically 0:01:19.600 --> 0:01:24.040 the mud of the Nile River, spawns monsters, and Spencer 0:01:24.080 --> 0:01:28.200 writes quote as when old Father Nihilis gins to swell 0:01:28.319 --> 0:01:32.840 with timely pride above the Egyptian veil, his fatty waves 0:01:32.880 --> 0:01:37.120 do fertile slime out well and overflow each plane and 0:01:37.200 --> 0:01:40.560 lowly dale. But when his later spring gins to a 0:01:40.680 --> 0:01:45.039 veil huge heaps of mud, he leaves wherein their breed 0:01:45.319 --> 0:01:50.000 ten thousand kinds of creatures, partly male and partly female, 0:01:50.080 --> 0:01:54.520 of his fruitful seed, such ugly monstrous shapes elsewhere may 0:01:54.600 --> 0:01:58.200 no man read. And then Spencer later cites the same 0:01:58.240 --> 0:02:01.360 belief again as a kind of illustration of a general principle. 0:02:01.640 --> 0:02:05.360 He writes, but reason teacheth that the fruitful seeds of 0:02:05.400 --> 0:02:10.639 all things living through impression of the sunbeams in moist complexion, 0:02:11.120 --> 0:02:15.280 do life conceive and quickened are by kind. So after 0:02:15.440 --> 0:02:20.799 Nihilus inundation, infinite shapes of creatures men do find informed 0:02:20.880 --> 0:02:24.480 in the mud on which the sun hath shined. So 0:02:24.520 --> 0:02:28.160 I think he seems to be saying, like mud plus 0:02:28.200 --> 0:02:33.160 sunshine equals monsters, or at least creatures of infinite shapes, 0:02:33.200 --> 0:02:37.400 which in some passages he seems to think might be monsters. 0:02:37.480 --> 0:02:42.720 Maybe among infinite variation, there will necessarily be some monsters. 0:02:43.560 --> 0:02:46.040 And I'm interested in this belief because, on one hand, 0:02:46.120 --> 0:02:48.960 it just sort of reflects some ancient beliefs that are 0:02:49.000 --> 0:02:52.600 carried over into the medieval and Renaissance period about where 0:02:52.639 --> 0:02:57.519 life comes from, ideas now obsolete theories like spontaneous generation 0:02:57.720 --> 0:02:59.480 that you know that life forms, which is sort of 0:02:59.520 --> 0:03:02.160 like arise in the mud or in like a wet 0:03:02.200 --> 0:03:05.000 bag of flour or something. But I also like it 0:03:05.080 --> 0:03:10.680 because it imagines the mud in the floodplain of a 0:03:10.720 --> 0:03:14.640 great river like the Nile as a as a source 0:03:14.800 --> 0:03:18.720 of both like sort of mystery and danger, but also 0:03:19.639 --> 0:03:22.600 great possibility. And this does correspond to the kind of 0:03:22.639 --> 0:03:25.359 the double nature of mud and of a river like 0:03:25.400 --> 0:03:27.320 the Nile. So you think of the Nile River delta, 0:03:27.400 --> 0:03:31.240 it is a place of incredibly fertile soil that you 0:03:31.280 --> 0:03:34.400 know that supplies food and crops for all of the 0:03:34.480 --> 0:03:37.720 areas around. But also if you know you get stuck 0:03:37.720 --> 0:03:39.560 in the mud, that's a place you don't want to be, 0:03:39.640 --> 0:03:42.000 and it is a place where you will find lots 0:03:42.040 --> 0:03:45.640 of life that is maybe life that's kind of strange 0:03:45.720 --> 0:03:48.360 to you. You don't usually go wading into the mud, 0:03:48.360 --> 0:03:49.880 and if you do, I don't know all kinds of 0:03:50.040 --> 0:03:53.520 weird little mollusks and creepy crawleys and critters are in there, 0:03:53.600 --> 0:03:55.280 and you don't know what you might find. 0:03:55.840 --> 0:03:58.920 Yeah, yeah, this is really interesting. We should also note, 0:03:59.480 --> 0:04:03.760 you know, it does accurately, though monstrously, refer to the 0:04:03.760 --> 0:04:07.800 the the inundation of the Nile, which is a topic 0:04:07.800 --> 0:04:10.040 we did an entire episode at least one episode on 0:04:10.120 --> 0:04:13.320 in the past. I mean, the Nile overflows its banks 0:04:13.360 --> 0:04:17.440 and it brings life and has this this very prominent 0:04:17.560 --> 0:04:24.440 role in especially an ancient Egyptian belief and mythology. But yeah, this, 0:04:24.440 --> 0:04:27.080 this dual nature of mud is quite interesting and something 0:04:27.080 --> 0:04:29.359 that that we're going to be talking about quite a 0:04:29.360 --> 0:04:32.120 bit in these episodes, because it at once it is 0:04:32.160 --> 0:04:34.440 like you want to build something, well, you're gonna need 0:04:34.480 --> 0:04:37.720 something like mud or mud itself. But of course it's 0:04:37.760 --> 0:04:41.160 also the place where you know, many a famous military 0:04:41.200 --> 0:04:44.240 campaign has perished in the mud, So you know, it's 0:04:44.279 --> 0:04:48.080 the thing from which monsters emerge, but it's all you know, 0:04:48.120 --> 0:04:50.200 it's the thing where you might find a pig, but 0:04:50.279 --> 0:04:55.320 you also will find gleaming butterflies, you know, cascading and 0:04:55.720 --> 0:05:00.280 swirling around something, some stinking pile of mud. Yeah, it 0:05:00.279 --> 0:05:02.840 does seem to have this dual nature, at least from 0:05:02.839 --> 0:05:04.000 the human vantage point. 0:05:04.279 --> 0:05:06.520 So our goal is after we're done with this series, 0:05:06.560 --> 0:05:08.680 you will never think about mud the same way. And 0:05:08.720 --> 0:05:11.440 when it gets stuck to your shoes, you might still 0:05:11.480 --> 0:05:13.360 be mad, but there will also be a part of 0:05:13.400 --> 0:05:16.440 you that that's kind of reflective and stops to be 0:05:16.480 --> 0:05:18.960 amazed at what it is. Your dog has just gotten 0:05:19.000 --> 0:05:19.839 all over your couch. 0:05:20.279 --> 0:05:24.000 Yeah, and if you're like me too, just even thinking 0:05:24.000 --> 0:05:26.880 about this topic, it means that you've had the Primus 0:05:26.920 --> 0:05:30.800 song my Name is Mud just flipped on in your brain. 0:05:30.839 --> 0:05:33.359 I haven't even listened to it to encourage or extinguish it, 0:05:33.400 --> 0:05:36.040 but it's just there as I read these various papers 0:05:36.040 --> 0:05:40.920 about mud or mmama mud, Right, I guess that's the 0:05:40.920 --> 0:05:45.359 way it's said, and so I'll take your word for it. 0:05:45.360 --> 0:05:47.760 It's a solid jam. It's got some colossal bass and 0:05:47.839 --> 0:05:48.520 drums on there. 0:05:48.800 --> 0:05:52.160 Oh yeah, that's Primus. They rattle the furniture. But anyway, 0:05:52.279 --> 0:05:55.320 we should go straight to the question what is mud? 0:05:55.360 --> 0:05:58.520 What is it made? Of In general, mud seems to 0:05:58.520 --> 0:06:01.520 have a kind of loose definition. We all know it 0:06:01.560 --> 0:06:04.120 when we see it, but there may not be strict 0:06:04.160 --> 0:06:08.880 scientific criteria about what counts, except maybe in certain contexts, 0:06:08.920 --> 0:06:11.400 like when you're talking when you get to some things 0:06:11.440 --> 0:06:13.560 we'll get to in a minute about like particle size 0:06:13.600 --> 0:06:18.680 and what solidifies into certain kinds of rock. But just generally, 0:06:18.839 --> 0:06:22.320 I mean, mud is some sort of wet soil, but 0:06:22.720 --> 0:06:26.200 exactly how wet, Exactly what are the properties of the 0:06:26.200 --> 0:06:28.720 soil for it to count as mud versus just being 0:06:28.800 --> 0:06:32.839 kind of like, I don't know, damp, gross stuff that 0:06:32.920 --> 0:06:34.599 might be in the eye of the beholder of the 0:06:34.600 --> 0:06:36.080 beat or of the bee treader. 0:06:36.720 --> 0:06:39.480 Yeah, I would, I would. I think that sometimes we 0:06:39.560 --> 0:06:41.680 know it when we see it, but we definitely know 0:06:41.760 --> 0:06:44.000 it when we step on it or step in it. 0:06:44.560 --> 0:06:46.560 I guess that's the thing, right, If I'm able to 0:06:46.560 --> 0:06:49.719 step on it, well maybe it's not fully mud. But 0:06:49.800 --> 0:06:52.240 if I'm in it, well I am in mud now. 0:06:52.720 --> 0:06:54.680 But I think the other Yeah. The other interesting thing 0:06:54.680 --> 0:06:56.919 about mud is a lot of it does depend on 0:06:56.960 --> 0:06:59.120 where you're coming from, you know, like if you were 0:06:59.200 --> 0:07:03.119 a domestic hog, well, mud is just simply good there's 0:07:03.720 --> 0:07:05.400 not much else to say about that, though we will 0:07:05.400 --> 0:07:09.440 get into how various animals use mud later on in 0:07:09.480 --> 0:07:12.920 a subsequent episode, but just from the human perspective, it's 0:07:13.000 --> 0:07:16.000 kind of interesting. One of the books I was looking at, 0:07:16.040 --> 0:07:18.280 and we'll come back to later when we get more 0:07:18.360 --> 0:07:21.720 in depth on this is a book titled Mud, a 0:07:21.800 --> 0:07:26.200 Military History by ce Wood, which, if you haven't thought 0:07:26.200 --> 0:07:28.800 about it much before, or you haven't you're not like 0:07:28.800 --> 0:07:34.240 a military history enthusiast, you might not realize that, Oh yeah, mud. 0:07:34.400 --> 0:07:36.080 Mud is the sort of thing that you could write 0:07:36.120 --> 0:07:40.760 an entire book about just from the perspective of war 0:07:40.880 --> 0:07:43.480 and military operations. But that's what this book is. 0:07:43.800 --> 0:07:46.560 When I think of mud and armed conflict. Obviously, you know, 0:07:46.680 --> 0:07:49.240 terrain and especially mud have played a big role in 0:07:49.760 --> 0:07:52.960 worse throughout history, but I think especially of Eastern Europe 0:07:53.000 --> 0:07:53.720 for some reason. 0:07:54.200 --> 0:07:58.320 Yeah, big big war machines, big tanks stuck in the mud, 0:07:58.760 --> 0:08:02.840 or has a Wood mentions a time or two the 0:08:02.880 --> 0:08:05.440 idea of one of these colossal tanks just going down 0:08:05.480 --> 0:08:08.680 a muddy hill as if it were like a sled 0:08:09.160 --> 0:08:12.760 on a snowfield or something, you know, just out of control. 0:08:13.120 --> 0:08:17.560 Things like that occurring mud changes what you can and 0:08:17.600 --> 0:08:22.120 can't do in many instances any with things ranging from 0:08:22.120 --> 0:08:28.520 infantry to horses to modern industrial war machines. But like 0:08:28.560 --> 0:08:31.040 I said, we'll get back to that more in the future. 0:08:31.080 --> 0:08:34.000 But I thought it was interesting that Wood opens just 0:08:34.080 --> 0:08:37.760 dealing with this basic ambiguity concerning mud and writes that, Okay, 0:08:37.760 --> 0:08:41.040 if we're going to be just very broad about it, 0:08:41.040 --> 0:08:44.439 it comes down to soil consisting of mineral and organic 0:08:44.480 --> 0:08:49.280 matter combined with moisture at such a level relative to 0:08:49.320 --> 0:08:52.679 the exact compositions of the soil to make it unstable 0:08:52.880 --> 0:08:57.200 and likely to move and flow underfoot or underhoof or 0:08:57.240 --> 0:09:02.000 under wheeler track, etc. Wood points out that while many 0:09:02.040 --> 0:09:06.520 military minds have considered mud and other soil issues beneath 0:09:06.520 --> 0:09:10.160 their strategic consideration, but they have always done so at 0:09:10.240 --> 0:09:13.920 their peril, because mud, as we'll get into later, does 0:09:13.960 --> 0:09:17.640 make a difference in war has come to very famously 0:09:17.679 --> 0:09:22.720 define certain war zones. He points out that not everyone 0:09:22.920 --> 0:09:26.880 has certainly ignored this fact, and in nineteen forty four, 0:09:27.200 --> 0:09:30.280 the US Army conducted a series of tests regarding mud. 0:09:30.600 --> 0:09:32.160 They're like, all right, let's get down to it. Let's 0:09:32.160 --> 0:09:36.560 classify some mud because we have only so many resources 0:09:36.600 --> 0:09:40.520 for our rubber tires, so we needed to decide where 0:09:40.520 --> 0:09:42.479 we need to send them, where we need to prioritize 0:09:42.520 --> 0:09:45.679 our best tires. And so this is a situation where 0:09:45.720 --> 0:09:49.120 we're dealing with sort of a narrowed perspective concerning mud. 0:09:49.480 --> 0:09:52.480 This is just mud concerning like, let me roll some 0:09:52.600 --> 0:09:56.680 vehicles across it. But they classified mud into two types 0:09:56.880 --> 0:10:02.079 and two subtypes. Okay, Type one bottomless mud. Now, this 0:10:03.040 --> 0:10:06.679 just means that the MUD's consistency cannot support a vehicle 0:10:06.720 --> 0:10:09.760 with tires that have twenty pounds of pressure, or that 0:10:09.840 --> 0:10:14.080 the underlying hard layer of earth beneath the mud beneath 0:10:14.080 --> 0:10:16.520 the layer of mud is too far beneath the vehicle's 0:10:16.520 --> 0:10:17.360 ground clearance. 0:10:17.679 --> 0:10:19.880 Okay, so this sounds like dangerous mud. 0:10:20.360 --> 0:10:23.079 Yeah, this is the mud that your vehicle is going 0:10:23.120 --> 0:10:25.960 to get stuck in and or sink into. And then 0:10:26.040 --> 0:10:30.160 Type two is just all other types of mud. But 0:10:30.320 --> 0:10:33.839 this does feature two subtypes, Type A and type B. 0:10:34.559 --> 0:10:38.320 Type A has a quote unquote cleaning quality, meaning that 0:10:38.360 --> 0:10:41.920 it contains enough moisture to work as a liquid. So 0:10:42.000 --> 0:10:45.000 like this, like type A mud gets on your vehicle 0:10:45.520 --> 0:10:47.839 and you know it kind of flows off. I mean 0:10:48.040 --> 0:10:51.319 it's I don't think cleaning quality means that your tank 0:10:51.440 --> 0:10:53.520 or your truck is going to be clean after the 0:10:53.600 --> 0:10:56.280 mud has a rent sofa a little bit. Yeah, it 0:10:56.280 --> 0:10:59.400 flows away, but it's it's this a cleaning quality Type 0:10:59.440 --> 0:11:04.600 B is adhesive or sticky. So this is the mud 0:11:04.600 --> 0:11:07.720 in type of mud. This is the type of mud 0:11:07.760 --> 0:11:12.480 that the big pickup pickup truck driver seeks out when 0:11:12.480 --> 0:11:14.599 they go out into the wilderness to make sure that 0:11:14.640 --> 0:11:18.240 they return to city life with a vehicle completely encased 0:11:18.520 --> 0:11:22.640 in mud. Okay, So more on the military angle later on. 0:11:23.160 --> 0:11:25.600 So this is not necessarily a helpful way to understand 0:11:25.720 --> 0:11:28.200 mud as a whole, but rather to a way to 0:11:28.280 --> 0:11:30.560 underline that the meaning of mud kind of depends on 0:11:30.600 --> 0:11:32.880 what you're trying to do in it or through it, 0:11:33.200 --> 0:11:35.679 and mud therefore could be your threat or your treasure, 0:11:35.720 --> 0:11:38.120 depending on what you're looking to get out of the situation. 0:11:38.720 --> 0:11:41.080 Very true. Now, I found an article that I thought 0:11:41.120 --> 0:11:44.280 was helpful. It was from two thousand and three in 0:11:44.440 --> 0:11:47.599 the Washington Post, and being in the Washington Post, I 0:11:47.600 --> 0:11:50.680 would say a little overly concerned with these specific types 0:11:50.679 --> 0:11:53.640 of mud found around the Washington d C. Metro area, 0:11:53.720 --> 0:11:57.560 but I'm mostly ignoring those parts because it does helpfully 0:11:57.600 --> 0:12:01.760 consult a bunch of soil scientists on the definitions and 0:12:03.080 --> 0:12:06.280 categories of mud. So it was called a World Gone 0:12:06.400 --> 0:12:09.720 Mud by Joel Aikenbach from June fifteenth, two thousand and three. 0:12:10.440 --> 0:12:14.679 First of all, it consults a researcher named Trish Steinhilber 0:12:15.240 --> 0:12:20.800 from the University of Maryland Agricultural Nutrient Management Program, who says, 0:12:20.920 --> 0:12:23.959 you know, we would just call it wet soil, So 0:12:23.960 --> 0:12:26.839 that's one perspective, it's just wet soil. But then the 0:12:26.920 --> 0:12:31.560 article cites another soil physicist, or sorry, another soil researcher, 0:12:31.640 --> 0:12:34.160 this time a soil physicist also from the University of 0:12:34.160 --> 0:12:38.720 Maryland named Robert Hill, who says mud should be differentiated 0:12:38.760 --> 0:12:42.760 from merely wet soil because it has different physical properties 0:12:42.800 --> 0:12:47.000 as commonly understood, Like we've been saying, mud is sticky 0:12:47.320 --> 0:12:50.439 in a way that not all wet soils are, and 0:12:50.720 --> 0:12:54.319 this stickiness is due to the presence of a higher 0:12:54.360 --> 0:13:01.560 proportion of smaller particles, especially clay particles. So, as you 0:13:01.640 --> 0:13:05.560 probably know, soil is made from a mixture of different materials. 0:13:05.679 --> 0:13:08.440 Some of those materials are organic, so they can be 0:13:09.080 --> 0:13:12.920 decaying organic matter or decaying bits of plants and animals 0:13:12.920 --> 0:13:16.080 and all that, but also inorganic matter, and we're going 0:13:16.160 --> 0:13:19.320 to focus on the inorganic matter for the moment. The 0:13:19.559 --> 0:13:24.480 inorganic solid particles that make up soil are generally produced 0:13:24.520 --> 0:13:28.559 by the erosion and breakdown of larger rocks over time, 0:13:29.080 --> 0:13:32.360 which can happen due to physical forces like wind, rain, 0:13:32.480 --> 0:13:35.040 and ice, or it can be due to break down 0:13:35.040 --> 0:13:38.880 by organisms like fungi and bacteria. And we all know 0:13:38.960 --> 0:13:42.080 soil can have different consistencies. You stick your hands into 0:13:42.080 --> 0:13:45.199 the soil in one place, it just feels different than 0:13:45.200 --> 0:13:48.280 the soil in another place. One of the major factors 0:13:48.320 --> 0:13:51.360 that you can use to sort soil into different categories 0:13:51.480 --> 0:13:56.320 is the average particle size in the soil. So if 0:13:56.520 --> 0:14:00.920 particles are bigger than two millimeters, that's gravel. You know 0:14:02.000 --> 0:14:05.240 that's going to pop under your car tire. Particles of 0:14:05.960 --> 0:14:09.920 less than two millimeters in diameter but more than zero 0:14:10.040 --> 0:14:15.480 point zero five millimeters are sand. Then smaller than sand, 0:14:15.760 --> 0:14:19.040 you've got silt, which is made of particles less than 0:14:19.200 --> 0:14:22.760 zero point zero five millimeters in diameter. And then at 0:14:22.760 --> 0:14:26.680 the very bottom, the finest grain soil is clay, which 0:14:26.720 --> 0:14:32.280 means particles smaller than zero point zero zero two millimeters 0:14:32.320 --> 0:14:36.200 in diameter. Now, apart from particle size, there are also 0:14:36.280 --> 0:14:40.240 some at least common chemical properties you'll find at these 0:14:40.240 --> 0:14:43.920 different areas, like they tend to derive from different types 0:14:43.960 --> 0:14:47.800 of minerals, like clay typically features a standard mineral constituent, 0:14:47.880 --> 0:14:52.480 which is hydrous aluminum philosilicates. But for the moment, we 0:14:52.480 --> 0:14:55.320 can just think about these as particles of different sizes. 0:14:55.760 --> 0:14:59.720 So by one definition, any sufficiently wet soil made of 0:15:00.040 --> 0:15:03.760 any mixture of these particles could be mud. But if 0:15:03.760 --> 0:15:07.240 you're going with the definition of mud as sticky slop 0:15:07.360 --> 0:15:09.400 that kind of sucks to the bottom of your shoes 0:15:09.440 --> 0:15:12.480 and you might get stuck in it usually means it's 0:15:12.520 --> 0:15:16.960 made up of mostly silt and clay sized particles, silt 0:15:17.000 --> 0:15:21.040 sized and clay sized particles, and things get especially sticky 0:15:21.120 --> 0:15:22.760 if it has a lot of clay. 0:15:23.400 --> 0:15:26.240 And again there's this fine line, like I know, I 0:15:26.280 --> 0:15:29.760 instantly think back to some cave environments that I've been in, 0:15:30.320 --> 0:15:35.440 and mud at just the right consistency, it's like it's sticky, 0:15:35.640 --> 0:15:38.240 but you're not slipping in it. It's almost something you 0:15:38.280 --> 0:15:41.840 want to walk on, but that line is very thin 0:15:42.160 --> 0:15:46.040 between between that and like the treacherous mud that you 0:15:46.120 --> 0:15:50.320 will slip in. So it's fascinating when you start getting 0:15:50.320 --> 0:15:51.480 into the way this breaks down. 0:15:52.040 --> 0:15:55.600 Yeah, is the mud grippy like maybe rubber? Or will 0:15:55.600 --> 0:15:57.720 it fly out from under you like a banana peel? 0:15:58.440 --> 0:16:02.200 And that does I think come down to something having 0:16:02.240 --> 0:16:04.760 to do with the water content as well as the 0:16:04.800 --> 0:16:09.000 particle size. So if mud is wet soil or sticky 0:16:09.000 --> 0:16:12.280 wet soil, we've explained the soil part it tends to 0:16:12.320 --> 0:16:15.880 be the smaller particle sizes clay sized and silt sized 0:16:15.880 --> 0:16:18.800 particles that make mud, But there's also the wetness angle. 0:16:18.920 --> 0:16:21.480 How wet does soil have to be for it to 0:16:21.520 --> 0:16:24.960 be mud. Here we get to the concept of cohesive 0:16:25.080 --> 0:16:30.360 soil and what are called adderberg limits. So Cohesive soils 0:16:30.440 --> 0:16:34.520 are soils that tend to stick or clump together as 0:16:34.560 --> 0:16:38.760 opposed to crumbling. Cohesive soils tend to have again, more 0:16:38.920 --> 0:16:44.119 clay sized particles. Smaller particles stick together better, and cohesive 0:16:44.160 --> 0:16:47.880 soils can be in three states, depending on how wet 0:16:47.920 --> 0:16:52.920 they are. These states are non plastic, plastic, and viscous. 0:16:53.520 --> 0:16:58.640 Non Plastic means hard difficult to mold or deform. This 0:16:58.720 --> 0:17:02.200 is usually when they're dry. Cohesive soils dry up kind 0:17:02.240 --> 0:17:05.159 of hard like bricks, and they form tough earth, so 0:17:05.200 --> 0:17:08.280 you can think about like hard clay ground, you know 0:17:08.320 --> 0:17:12.040 what that's like. When cohesive soils get wet, though, they 0:17:12.040 --> 0:17:15.639 can cross one of these Adderberg limits, that the plastic limit, 0:17:15.720 --> 0:17:20.280 and become plastic. So this means they become soft or moldable, 0:17:20.440 --> 0:17:24.560 So think about wet clay and then beyond that limit, 0:17:24.600 --> 0:17:27.720 there's another limit, another limit, which is the liquid limit, 0:17:27.880 --> 0:17:30.879 and this is the viscous stage where there's sort of 0:17:30.920 --> 0:17:34.119 like a liquid goop. So you can add water to 0:17:34.320 --> 0:17:37.679 non plastic soil until it crosses the plastic limit, becomes 0:17:37.680 --> 0:17:40.639 soft and mouldable. You can add more water until it 0:17:40.680 --> 0:17:44.920 crosses the liquid limit. Where the liquid limit is explained 0:17:44.920 --> 0:17:48.040 in this Washington Post article as if you cut a 0:17:48.200 --> 0:17:51.280 groove in the mud, the mud will flow back in 0:17:51.440 --> 0:17:55.080 to fill it. That's the liquid limit, which actually has 0:17:55.119 --> 0:17:59.280 some analogies in the culinary world, like if you ever 0:17:59.720 --> 0:18:02.399 did back of the spoon test for the thickness of 0:18:02.440 --> 0:18:04.720 a sauce in the kitchen. The French term for that 0:18:04.840 --> 0:18:07.480 is nape, where if you like wipe your the tip 0:18:07.520 --> 0:18:10.399 of your finger along the back of a spoon coated 0:18:10.400 --> 0:18:13.520 in the sauce. It should leave a trail rather than 0:18:13.560 --> 0:18:15.840 having the sauce flow back in to fill the gap. 0:18:15.960 --> 0:18:17.320 That that's nape. 0:18:17.440 --> 0:18:19.640 One of the many culinary techniques in Abo. You just 0:18:19.680 --> 0:18:21.800 like jab your fingers into things like. 0:18:21.840 --> 0:18:24.119 Yeah, stick, yeah, stick your finger in the food. 0:18:24.480 --> 0:18:27.320 Yeah, let the meat touch your face, and that will 0:18:27.320 --> 0:18:29.160 determine if it is the right temperature. 0:18:29.520 --> 0:18:31.679 But so, the definition of the liquid limit is that 0:18:31.760 --> 0:18:33.720 it does not pass the back of the spoon. Test 0:18:33.800 --> 0:18:35.400 if you cut a groove in it, it will flow 0:18:35.440 --> 0:18:38.199 back in to fill the gap. So it sounds to 0:18:38.240 --> 0:18:42.760 me like the definitional sweet spot for mud is a 0:18:42.800 --> 0:18:47.080 wet cohesive soil. It's made primarily of silt or clay 0:18:47.080 --> 0:18:49.840 sized particles, especially if there's a lot of clay sized 0:18:49.880 --> 0:18:54.959 particles that is above the plastic limit and below the 0:18:55.000 --> 0:18:59.560 liquid limit. Somewhere in there, though, I was thinking that 0:19:00.560 --> 0:19:03.960 even sort of fully liquid glop we do sometimes call mud, 0:19:04.000 --> 0:19:06.320 don't we, But that's not usually the first kind of 0:19:06.359 --> 0:19:07.440 substance I think. 0:19:07.280 --> 0:19:11.040 Of, right, right, Like I come back to the example 0:19:11.200 --> 0:19:15.040 of mud pies, you know, I think a lot of 0:19:15.119 --> 0:19:17.159 us did this as a kid. If you're allowed to 0:19:17.160 --> 0:19:19.720 play in the mud, you get some little like pie 0:19:19.760 --> 0:19:22.840 crusts or just little whatever, you know, cups and pans, 0:19:23.600 --> 0:19:26.479 pour the mud up, slap the mud together, and then 0:19:26.520 --> 0:19:29.200 you set it in the sun too dry, into mud cakes. 0:19:30.080 --> 0:19:32.159 But yeah, it's like if you're pouring it, if you're 0:19:32.200 --> 0:19:34.760 just complete all you know it is completely pouring it 0:19:34.840 --> 0:19:37.639 into the pan that doesn't really feel like mud. That's 0:19:37.680 --> 0:19:41.840 just like mud water or something that's like on the 0:19:41.880 --> 0:19:43.959 way to mud, but not mud quite yet. The moisture 0:19:43.960 --> 0:19:46.159 still levels too high. And I guess in baking you 0:19:46.200 --> 0:19:49.360 have variations of that as well. Right like you said 0:19:49.400 --> 0:19:51.600 the sauce is too runny, the batter is too runny, 0:19:51.600 --> 0:19:52.040 et cetera. 0:20:01.640 --> 0:20:03.439 I think the mudpie test is a good one. And 0:20:03.480 --> 0:20:05.880 you know what, that actually brings me to the next 0:20:05.920 --> 0:20:09.200 thing I want to talk about, which is this might 0:20:09.240 --> 0:20:13.560 be something you'd never considered before. Was there a time 0:20:13.680 --> 0:20:17.000 on Earth when it would have been really difficult to 0:20:17.080 --> 0:20:21.240 make a mudpie? I would argue, based on some research 0:20:21.280 --> 0:20:23.840 I've been reading about that, Yes, if you go back 0:20:23.920 --> 0:20:26.919 before or five hundred million years ago, go to the 0:20:26.960 --> 0:20:30.879 pre Cambrian period, and you walk around on Earth's continents 0:20:31.440 --> 0:20:34.520 trying to find a place to make a mudpie, You're 0:20:34.520 --> 0:20:36.880 gonna probably strike out. You're going to be out of luck, 0:20:36.960 --> 0:20:42.560 because there was a time basically before there was mud 0:20:42.800 --> 0:20:46.400 on land on Earth, or before there was very much 0:20:46.480 --> 0:20:49.160 mud to be found on land. So here I want 0:20:49.200 --> 0:20:50.960 to go to an article I was reading in the 0:20:51.280 --> 0:20:55.440 journal Science in the year twenty eighteen by Woodward Fisher, 0:20:55.520 --> 0:21:00.639 who is a Caltech geobiologist. The article is called Early 0:21:00.720 --> 0:21:04.760 Plants and the Rise of Mud, and this article is 0:21:04.840 --> 0:21:10.600 primarily summarizing and contextualizing a study that was published by 0:21:10.600 --> 0:21:12.760 a couple of different authors in the same issue of 0:21:12.840 --> 0:21:16.680 the journal Science in twenty eighteen. This article is very 0:21:16.680 --> 0:21:22.480 good in putting these findings in context. So Fisher mentions 0:21:22.520 --> 0:21:26.439 that you know, life on Earth has several times that 0:21:26.480 --> 0:21:32.960 we know about reshaped fundamental geophysical features and processes at 0:21:33.000 --> 0:21:36.000 the Earth's surface. There are ways in which you could 0:21:36.040 --> 0:21:40.600 say that life has fundamentally changed the planet itself, at 0:21:40.680 --> 0:21:43.000 least what's happening on the surface and in the atmosphere. 0:21:43.400 --> 0:21:46.840 So perhaps the first example that will likely come to 0:21:46.880 --> 0:21:51.480 your mind is the oxygenation of the oceans in the atmosphere. 0:21:51.680 --> 0:21:56.080 It was the evolution of photosynthesis in cyanobacteria and other 0:21:56.160 --> 0:21:59.400 life forms that triggered this shift. You know, we didn't 0:21:59.400 --> 0:22:04.160 always have an oxygen atmosphere. Another major geophysical change triggered 0:22:04.160 --> 0:22:08.399 by life that Fisher mentions is the evolution of mineral 0:22:08.640 --> 0:22:14.560 skeletons by life forms, again particularly algae, and the presence 0:22:14.560 --> 0:22:18.080 of those skeletons change the way that ocean floors are 0:22:18.160 --> 0:22:21.080 formed and then subsequently the kinds of rock layers that 0:22:21.800 --> 0:22:25.360 would form when they solidified over the eons. But this 0:22:25.480 --> 0:22:30.160 article is focused on another discovery of this sort, how 0:22:30.200 --> 0:22:35.360 the evolution of land based plants changed the Earth by 0:22:35.400 --> 0:22:39.840 affecting mud. So the citation for the study here is 0:22:40.280 --> 0:22:43.679 William J. McMahon and Neil S. Davies. The article is 0:22:43.680 --> 0:22:48.320 called evolution of alluvial mud rock forced by early land 0:22:48.400 --> 0:22:53.920 plants again Journal Science, twenty eighteen. So when soil made 0:22:53.960 --> 0:22:57.800 mostly out of clay or silt sized particles gets compacted 0:22:57.880 --> 0:23:02.560 in the ground and lithifies into the resulting rock layer 0:23:02.840 --> 0:23:05.320 is called mud rock, and there are many kinds of 0:23:05.400 --> 0:23:09.920 mud rock. When geologists look for layers of mud rock 0:23:10.280 --> 0:23:15.119 from the past, they notice something interesting. There is extremely 0:23:15.480 --> 0:23:20.480 little mud rock from river bottoms and floodplains before a 0:23:20.480 --> 0:23:22.960 certain geologic period in the history of the Earth. So 0:23:23.000 --> 0:23:25.679 if you look in the pre Cambrian era or the 0:23:25.720 --> 0:23:31.080 early Paleozoic era, there's very little mud rock on the continents. 0:23:31.480 --> 0:23:34.160 And I'll do a little refresher on the basic geologic 0:23:34.240 --> 0:23:37.439 timeline of the early to mid Palaeozoic. So you've got 0:23:37.480 --> 0:23:41.560 the Cambrian period, this is roughly five hundred million years ago. 0:23:42.280 --> 0:23:47.240 Before the Cambrian period, most life on Earth is small, soft, 0:23:47.359 --> 0:23:52.200 and unicellular. And then the Cambrian period represents a sort 0:23:52.200 --> 0:23:56.400