WEBVTT - Invention Playlist II: Walls 0:00:08.840 --> 0:00:12.080 Hey, welcome to Invention. My name is Robert lamp and 0:00:12.200 --> 0:00:15.200 I'm Joe McCormick. Today we're talking about an invention that 0:00:15.240 --> 0:00:18.320 it's certainly been in the news a bit recently. Um, 0:00:18.400 --> 0:00:22.120 we're talking about walls. Okay, Now, we're not a political show, 0:00:22.160 --> 0:00:24.439 but some of the statements on the nature of walls, 0:00:24.560 --> 0:00:28.400 the purpose of walls, the historical and modern effectiveness of 0:00:28.560 --> 0:00:33.240 walls are unavoidable here and and hopefully, uh, this is 0:00:33.240 --> 0:00:36.520 all gonna be useful by the time we finished this episode. 0:00:36.600 --> 0:00:40.320 You're gonna have, you know, a deeper context regarding the 0:00:40.400 --> 0:00:43.680 nature of walls and what a wall is, uh, the 0:00:43.720 --> 0:00:47.000 next time you were subjected to the news. Now, I 0:00:47.040 --> 0:00:51.000 noticed we've been on a tear recently of extremely ancient inventions. 0:00:51.159 --> 0:00:53.479 I think we did roads and then the wheel, and 0:00:53.560 --> 0:00:55.760 now we're on walls. It's almost like we're just going 0:00:56.120 --> 0:00:58.960 further and further back in time. And so I'm sure 0:00:58.960 --> 0:01:01.400 we'll get back to some some more recent or high 0:01:01.440 --> 0:01:05.600 tech gadgets soon, but definite biographies involved to the thing 0:01:05.600 --> 0:01:08.160 about the more modern inventions. But I do really like 0:01:08.360 --> 0:01:10.840 doing this kind of thing we're doing by like looking 0:01:10.880 --> 0:01:15.080 at the most basic technologies that exist like the wheel 0:01:15.280 --> 0:01:18.360 and the wall, because there's so many interesting ways to 0:01:18.440 --> 0:01:21.600 look at their you know, they're they're multi millennial legacy 0:01:21.640 --> 0:01:24.520 and impact on human culture and history. Now, i'd say, 0:01:24.520 --> 0:01:26.399 in addressing the wall, we are going to be talking 0:01:26.400 --> 0:01:29.760 a little bit about a few interesting tidbits of of 0:01:29.800 --> 0:01:32.039 physical construction. But this isn't gonna be so much an 0:01:32.080 --> 0:01:36.480 episode about like wall materials and all that. You obviously 0:01:36.520 --> 0:01:39.039 that is a very rich subject on its own, but 0:01:39.120 --> 0:01:41.039 I think we're gonna be thinking more about the role 0:01:41.120 --> 0:01:45.520 that walls play in geopolitical history. Yeah, yeah, because certainly 0:01:45.560 --> 0:01:47.400 the history of walls is kind of the history of 0:01:47.560 --> 0:01:51.720 construction and engineering in a broader sense. And we have 0:01:51.760 --> 0:01:54.440 to be clear here too about how we're we're looking 0:01:54.480 --> 0:01:56.880 at walls, because there's there's a very good chance that 0:01:56.920 --> 0:01:58.880 if you're listening to the show right now, you are 0:01:59.240 --> 0:02:02.880 either con hanged within walls or perhaps adjacent to a wall. 0:02:04.600 --> 0:02:08.040 Even if you're just driving down the road. Um, you know, 0:02:08.440 --> 0:02:11.600 you you can probably see some walls right now. Maybe 0:02:11.639 --> 0:02:14.400 you're forming part of a human wall, maybe you're walking 0:02:14.440 --> 0:02:17.120 on top of a mile high wall. Yeah, all these 0:02:17.120 --> 0:02:20.720 are possible, and any of us can build a crude 0:02:20.720 --> 0:02:23.640 wall out of sticks or rocks, etcetera, with only the 0:02:23.680 --> 0:02:26.760 most basic engineering skills. And in a basic sense, I mean, 0:02:27.400 --> 0:02:29.600 this is something that exists in nature. I mean, why 0:02:29.600 --> 0:02:32.400 do we have the idea that certain types of animals 0:02:32.440 --> 0:02:35.320 and maybe some of our ancestors sought out caves for shelter. 0:02:35.440 --> 0:02:38.000 It's because they've got walls and a roof, right, These 0:02:38.040 --> 0:02:41.040 like they limit the the they limit your exposure to 0:02:41.040 --> 0:02:43.400 the weather through a roof especially, but they also limit 0:02:43.480 --> 0:02:47.120 the number of access points through which other animals, say, 0:02:47.120 --> 0:02:50.919 could reach you exactly. So we're largely going to talk 0:02:50.960 --> 0:02:54.280 about walls as barriers around cities and then more to 0:02:54.320 --> 0:02:57.919 the point, as freestanding divisions. And in this we really 0:02:57.960 --> 0:02:59.840 need to think of them. I think I I believe 0:03:00.080 --> 0:03:03.960 a sort of of geoengineering project. Uh. You know, it's 0:03:03.960 --> 0:03:06.480 easier to see this in walls that are created using 0:03:06.520 --> 0:03:09.440 elements from the natural surroundings. Say a wooden fence or 0:03:09.440 --> 0:03:12.720 a beautiful moss covered stone wall in Ireland. You know, 0:03:12.800 --> 0:03:14.800 something that would you really looks good on a calendar, 0:03:15.720 --> 0:03:18.520 But it's less obvious when you behold something like say 0:03:18.560 --> 0:03:21.800 the Great Wall of China or the Peace Lines or 0:03:21.800 --> 0:03:25.040 Peace Walls of Ireland or the Berlin Wall something of 0:03:25.080 --> 0:03:28.400 this nature. But a wall essentially seeks to do what 0:03:28.480 --> 0:03:33.000 the environment does naturally. It's a sheer, vertical rise in 0:03:33.080 --> 0:03:39.280 elevation manufactured to impose a particular cultural, political, or personal domain. 0:03:39.680 --> 0:03:42.320 You know. Well, you can just imagine somebody perhaps you know, 0:03:42.440 --> 0:03:46.240 a far side cartoon caveman, thinking, you know, I wish 0:03:46.280 --> 0:03:48.440 my property were on top of a mountain to keep 0:03:48.480 --> 0:03:51.680 my enemies away. Well, boom, here's how a wall works. 0:03:51.840 --> 0:03:55.480 Now you have a mountain or something that functions like 0:03:55.600 --> 0:04:00.800 a mountain, creating a vertical obstacle between your and somebody 0:04:00.840 --> 0:04:03.680 else's stuff. But there are multiple different ways to think 0:04:03.720 --> 0:04:06.000 about the idea of a wall as protection, and this 0:04:06.040 --> 0:04:09.160 will come out when we talk about the more macroscopic 0:04:09.200 --> 0:04:13.119 wall projects throughout history as we go on. Because there's 0:04:13.160 --> 0:04:16.200 one type of being protected in walls that's literally like 0:04:16.240 --> 0:04:18.680 I need a barrier to like keep people from coming 0:04:18.720 --> 0:04:21.560 in and stealing all my things, or to keep you, 0:04:21.560 --> 0:04:23.680 I don't know, a lion from coming and grabbing me 0:04:23.680 --> 0:04:26.320 while I'm asleep. But on the other hand, you've also 0:04:26.440 --> 0:04:30.239 got the type of protection that is the psychological sense 0:04:30.320 --> 0:04:33.320 of privacy, right that a wall is a barrier that 0:04:33.400 --> 0:04:36.640 people can't see through that allows you to feel like 0:04:36.720 --> 0:04:40.760 you are not constantly being say, observed by your neighbors. Yeah, 0:04:40.800 --> 0:04:43.640 like like a privacy fence in one's backyard. We tend 0:04:43.680 --> 0:04:46.480 not to think of them as walls of wood. I 0:04:46.520 --> 0:04:49.240 will erect walls of wood between me and my so 0:04:49.360 --> 0:04:52.240 called neighbors. No, it's privacy fence, you know, just in 0:04:52.320 --> 0:04:54.880 case you don't want to, you know, walk around shirtless 0:04:54.880 --> 0:04:57.360 in your backyard, which you should. It's your backyard. Do 0:04:57.360 --> 0:05:00.120 what you want or you don't want people steal in 0:05:00.200 --> 0:05:04.800 your genius invention that you're building back there exactly so, 0:05:04.960 --> 0:05:09.960 its stated earlier prehistoric times, before walls, they required humans 0:05:09.960 --> 0:05:14.039 to depend on naturally occurring barriers. You know. Uh, where 0:05:14.080 --> 0:05:17.159 can one position themselves so that they're best protected from 0:05:17.200 --> 0:05:21.120 the elements, predators, enemies, etcetera. And these could these could 0:05:21.160 --> 0:05:23.919 be any number of things, right in addition to vertical 0:05:24.040 --> 0:05:28.360 changes in elevation, Uh that could be uh, rivers, pond streams, 0:05:28.680 --> 0:05:33.400 swampy areas, etcetera. And of course early humans and Neanderthals 0:05:33.520 --> 0:05:36.919 were nomadic. Uh. There was nothing to be gained in 0:05:36.920 --> 0:05:39.719 the creation of heavy duty barriers because you were always 0:05:39.800 --> 0:05:42.560 or at least cyclically on the move. You had no cities, 0:05:42.920 --> 0:05:45.839 You had no domesticated herds or crop fields that needed 0:05:45.880 --> 0:05:49.000 to be cut off from other aspects of the natural world. Um, 0:05:49.120 --> 0:05:52.160 there were also precious few of you to begin with. 0:05:52.880 --> 0:05:56.400 But of course all that changed. Cities gave rise to walls, 0:05:56.440 --> 0:05:59.680 and city states and empires gave rise to even more. 0:05:59.720 --> 0:06:03.080 Wall is a division between the ever expanding, ever advancing 0:06:03.160 --> 0:06:05.919 tribes of humanity. Right, you're correct to point out that 0:06:05.960 --> 0:06:08.400 the wall revolution. I mean, we we don't know when 0:06:08.520 --> 0:06:11.279 the first wall was created, but it would have to 0:06:11.279 --> 0:06:13.279 be linked to the idea I would think of of 0:06:13.320 --> 0:06:17.800 a sedentary lifestyle, like as people stop moving around and 0:06:17.880 --> 0:06:21.360 settle in places, to live in one place and stay there. 0:06:21.880 --> 0:06:23.760 And we do, in fact see some of the earliest 0:06:23.880 --> 0:06:27.440 archaeological evidence of walls in the most ancient of the 0:06:27.480 --> 0:06:31.160 sort of city states of the ancient Near East, for example, 0:06:31.240 --> 0:06:33.919 like there are ten thousand year old walls that have 0:06:33.960 --> 0:06:36.520 been discovered in the city of Jericho. Now, when it 0:06:36.560 --> 0:06:38.320 comes to what we were talking about, the more sort 0:06:38.360 --> 0:06:41.920 of freestanding barrier walls that might mark the border of 0:06:41.960 --> 0:06:45.080 a territory or uh, you know, or something more like 0:06:45.120 --> 0:06:47.040 the Great Wall of China, which will discuss it more 0:06:47.080 --> 0:06:50.239 length as we go on. Among the world's earliest known 0:06:51.240 --> 0:06:54.960 defensive barrier walls, or the walls of ancient Mesopotamia specifically, 0:06:55.680 --> 0:06:58.960 uh some walls constructed in the twenty one century BC 0:06:59.360 --> 0:07:03.200 by the sumer Arian rulers Shulgi and shu Sin. And 0:07:03.240 --> 0:07:05.880 these were constructed in the region that is modern day 0:07:05.880 --> 0:07:10.040 Iraq in order to defend the ancient civilization of Summer 0:07:10.240 --> 0:07:14.440 against attacks of nomadic people's known as the Amorites. And 0:07:14.520 --> 0:07:16.600 so this wall was also known as the Wall of 0:07:16.680 --> 0:07:20.280 the Land or the Amorite Wall. We think that it 0:07:20.360 --> 0:07:23.400 probably reached more than a hundred miles in length, stretching 0:07:23.440 --> 0:07:26.720 between the twin rivers bound that bound Mesopotamia as the 0:07:27.240 --> 0:07:30.520 Tigress and the Euphrates. And while this wall was probably 0:07:30.560 --> 0:07:33.440 meant to protect Sumerian cities, it was not, as we said, 0:07:33.480 --> 0:07:36.800 a city wall. It's kind of a border wall. I 0:07:36.840 --> 0:07:40.160 found one piece of ancient Sumerian poetry in fact, that 0:07:40.240 --> 0:07:42.200 seems to be referring to the wall, or at least 0:07:42.200 --> 0:07:45.480 to a fictional analog of it, and it's translated and 0:07:45.600 --> 0:07:48.800 explained in a book called Reading Sumerian Poetry by the 0:07:48.800 --> 0:07:53.480 scholar Jeremy Black. And in this ancient Sumerian poem, you've 0:07:53.480 --> 0:07:57.680 got the legendary Sumerian king in Merkar, and he's out 0:07:57.720 --> 0:08:00.720 with his army at war, laying siege to a foreign city, 0:08:00.800 --> 0:08:04.120 and he gets all demoralized, feeling he's not having a 0:08:04.160 --> 0:08:07.440 good time, and he arranges to send a message back 0:08:07.480 --> 0:08:09.960 to the mighty goddess in Ana, one of our favorites 0:08:10.000 --> 0:08:12.240 from stuff to blow your mind. She you know, she 0:08:12.480 --> 0:08:15.760 shrieks power through the rebel lands, and he's out at 0:08:15.800 --> 0:08:18.960 war while Innana is residing back in her temple in 0:08:19.000 --> 0:08:22.400 the city of Unugs, a Sumerian city also known as Uruk, 0:08:23.080 --> 0:08:26.160 and so in Makar's message implies that you know, once 0:08:26.240 --> 0:08:29.320 within on his help, his reign had been really great. 0:08:29.720 --> 0:08:34.000 It was great and glorious, and he built powerful, impressive structures. 0:08:34.040 --> 0:08:37.439 But now things have gone bad, and he feels abandoned 0:08:37.440 --> 0:08:40.040 by the goddess and Anna while she sits at home 0:08:40.360 --> 0:08:43.000 refusing to come to his aid to help him accomplish 0:08:43.040 --> 0:08:47.440 glorious things again. And this is Black's translation of this 0:08:47.520 --> 0:08:51.280 passage from the poem The Wall of Unug extended out 0:08:51.400 --> 0:08:54.800 over the desert like a bird net. But here and now, 0:08:54.840 --> 0:08:58.560 my attractiveness to her has ended. My army hangs on 0:08:58.640 --> 0:09:01.600 me as a cow hangs on its calf, like a 0:09:01.640 --> 0:09:05.320 son who hating his mother, leaves his city. My princely 0:09:05.400 --> 0:09:08.600 sister Holy Anna has run away from me to brick 0:09:08.640 --> 0:09:12.440 built Coolaba. So that first line there, that line the 0:09:12.520 --> 0:09:15.520 wall of Unug extended out over the desert like a 0:09:15.559 --> 0:09:18.880 bird net. I love that image, and Black writes that 0:09:18.960 --> 0:09:22.520 this metaphor actually does refer to a real technology, quote, 0:09:22.760 --> 0:09:25.520 a long net of a type used for snaring low 0:09:25.600 --> 0:09:29.840 flying birds, extending out across the open country. Though I 0:09:29.840 --> 0:09:32.560 do find it interesting that here the metaphor for the 0:09:32.600 --> 0:09:36.640 wall is an animal trap, not a defensive structure. Yeah, 0:09:36.720 --> 0:09:39.840 something to snare, and uh, I guess it makes it 0:09:39.880 --> 0:09:43.880 feels maybe metaphorically more imposing, like this is a thing 0:09:43.960 --> 0:09:47.160 in which upon which you die, as opposed to this 0:09:47.240 --> 0:09:50.000 is a thing that stands between the two of us. Yeah. 0:09:50.000 --> 0:09:52.520 Though it's funny because the wall, as invoked in the 0:09:52.559 --> 0:09:56.920 poem is not so much invoked as a literal defensive 0:09:57.000 --> 0:10:00.720 measure that is effective at its purpose. Instead, it's invoked 0:10:00.760 --> 0:10:04.160 as an emblem of the city of Unug's former power 0:10:04.240 --> 0:10:07.320 and prosperity. This is a fictional account being told in 0:10:07.360 --> 0:10:10.600 this poem. Uh the historical context when the poem was 0:10:10.679 --> 0:10:14.320 being read probably meant to call to mind more like 0:10:14.400 --> 0:10:18.400 the more recent and real construction of that defensive wall 0:10:18.440 --> 0:10:21.200 I mentioned earlier, the walls built by the king's Shulgi 0:10:21.280 --> 0:10:23.920 and shu Sin, known as we mentioned earlier, as the 0:10:23.920 --> 0:10:26.199 Wall of the land, and also as the keeper at 0:10:26.240 --> 0:10:29.400 bay of the nomads. That's a good title, nice and formal, 0:10:30.040 --> 0:10:32.240 and that that's that's kind of a recurring theme in 0:10:32.280 --> 0:10:35.960 these older walls. It's a way of keeping out the 0:10:36.000 --> 0:10:39.160 nomadic people's. But no matter how much the author of 0:10:39.200 --> 0:10:43.600 this poem thought of this wall as this great building accomplishment, 0:10:43.720 --> 0:10:46.559 you know that symbolizes the glory and splendor of Invercar's 0:10:46.600 --> 0:10:50.640 former rule, Ultimately the real wall failed to protect Summer 0:10:50.840 --> 0:10:55.440 and the Sumerian civilization. It fell to attacks from multiple enemies, 0:10:55.480 --> 0:10:58.760 the Amorrits and the Elamites. The wall didn't work all right. 0:10:58.840 --> 0:11:00.800 On that note, let's take a quick break, and when 0:11:00.800 --> 0:11:03.320 we come back, we're gonna talk about the Great Wall 0:11:03.360 --> 0:11:12.120 of China. Okay, we're back now on the subject of 0:11:12.200 --> 0:11:16.120 city walls, kind of the the initial precursor to these 0:11:16.160 --> 0:11:20.200 dominion walls. Um To really drive home the importance of 0:11:20.280 --> 0:11:25.840 walls here, the interconnectedness between walls and cities. Uh consider 0:11:25.960 --> 0:11:30.920 that the Mandarin Chinese word for wall, ching is also 0:11:31.040 --> 0:11:36.920 the word for city, so chang shih more specifically means town, 0:11:37.400 --> 0:11:39.719 and the Great Wall of China, which we're about to 0:11:39.760 --> 0:11:43.920 get into here is uh chiang Ching. And they the 0:11:44.040 --> 0:11:48.280 Chinese also had a god of walls and moats. Let's 0:11:48.280 --> 0:11:50.200 not forget that moats are very much in the same 0:11:50.480 --> 0:11:54.480 geoengineering vein here right along with things like trenches and ditches. 0:11:54.760 --> 0:11:56.880 If a wall is a fake mountain, the moat is 0:11:56.880 --> 0:12:02.120 a fake river. Exactly to make a kind of observation. Sorry, 0:12:02.200 --> 0:12:04.920 So the name of this god was shing Wong, and 0:12:05.200 --> 0:12:07.600 it's it's a bit complex, but the god, this city god, 0:12:07.640 --> 0:12:10.800 is sort of a representative spirit and protective deity that 0:12:10.880 --> 0:12:14.560 looks after the city. But it also encompasses deified to 0:12:14.640 --> 0:12:18.200 see city leaders that protect the city via the spirit realm, 0:12:18.600 --> 0:12:20.960 and they also represent the residents of the city and 0:12:21.000 --> 0:12:22.760 dealings with the King of the dead, so of the 0:12:22.840 --> 0:12:25.400 King of the dead comes for residents of the city. 0:12:25.520 --> 0:12:28.320 He's like the immediate contact that sort of thing. Is 0:12:28.320 --> 0:12:30.640 there a reason for that? You know why him? Well, 0:12:30.720 --> 0:12:33.480 it gets kind of it's kind of a complicated history there, 0:12:33.480 --> 0:12:37.240 because with several phases to it. On one hand, there's 0:12:37.280 --> 0:12:40.679 this idea of like veneration of an individual that was 0:12:40.720 --> 0:12:45.760 important to the people UH during their life, and then 0:12:45.960 --> 0:12:48.360 it makes sense that their their spirit would sort of 0:12:48.400 --> 0:12:51.319 hang around and be important after death, part of the 0:12:51.320 --> 0:12:55.960 whole veneration of ancestors. But then also this ends up 0:12:56.000 --> 0:13:01.080 being emphasized at different points by by by China, by 0:13:01.160 --> 0:13:05.559 Chinese rule as well. Now along these lines, in Chinese traditions, 0:13:05.600 --> 0:13:09.079 there's more to a wall than mere physical construction. A 0:13:09.160 --> 0:13:11.719 wall is also kind of a spell that keeps out 0:13:11.760 --> 0:13:17.160 evil forces in addition to say, you know, invaders, physical invaders, nomads, 0:13:17.520 --> 0:13:21.480 northern barbarians. So yeah, let's talk a little bit about 0:13:21.520 --> 0:13:26.320 the Great Wall. So the original wall was built more 0:13:26.360 --> 0:13:30.080 than two thousand years ago, UH during the the Chin 0:13:30.240 --> 0:13:35.720 dynasty UH led by Emperor Chin Xi Wong, who stuffed 0:13:35.760 --> 0:13:38.040 all your mind. Listeners may remember, we've we devoted an 0:13:38.160 --> 0:13:41.680 entire episode UH to to his life and his tomb, 0:13:41.800 --> 0:13:45.840 his undisturbed tomb, which has been legendarily appointed with many 0:13:45.880 --> 0:13:48.960 fine booby traps which we we very much hope are real, 0:13:49.080 --> 0:13:52.560 but we don't know. Yeah, possibly rivers of lead, I believe, 0:13:53.080 --> 0:13:57.080 or of mercury. It was mercury, yes, So anyway, he was, 0:13:57.240 --> 0:14:01.360 he was an imposing figure. He united the seven warring kingdoms, 0:14:01.440 --> 0:14:04.480 and uh, there were these separate walls built by independent 0:14:04.559 --> 0:14:08.400 kingdoms that he then had linked together to protect against 0:14:08.400 --> 0:14:12.080 those marauders, those northern barbarians. And the oldest parts of 0:14:12.120 --> 0:14:14.920 this wall system seemed to date back to the seventh 0:14:14.920 --> 0:14:19.520 century b C. Now, hundreds of thousands of workers uh 0:14:19.800 --> 0:14:23.680 spent ten years uh working on this. We're talking prisoners, 0:14:23.680 --> 0:14:28.000 political enemies, peasants, uh, and then various dynasties would go 0:14:28.040 --> 0:14:29.560 on to work on it some more. But it wasn't 0:14:29.640 --> 0:14:32.520 until the rise of the Ming dynasty in thirteen sixty 0:14:32.600 --> 0:14:34.880 eight that the Great Wall of China as we know 0:14:34.920 --> 0:14:38.200 it today really was brought to full fruition. So how 0:14:38.200 --> 0:14:41.640 great is this wall? Well, it's reported length is widely 0:14:41.760 --> 0:14:46.480 disputed and ranges anywhere from fifteen hundred miles or two thousand, 0:14:46.480 --> 0:14:50.120 four hundred fourteen kilometers to four thousand, one hundred sixty 0:14:50.120 --> 0:14:53.400 three miles or sixty seven hundred kilometers. Uh. You know 0:14:53.480 --> 0:14:56.360 essentially the idea here as it can go from the 0:14:56.360 --> 0:14:59.400 construction from the Gobi Desert to the Yellow Sea. But 0:14:59.480 --> 0:15:03.200 it came about in installments, right, Yeah, So it wasn't 0:15:03.280 --> 0:15:06.920 just one day a great import decided to build the wall. 0:15:06.960 --> 0:15:09.240 They were like, look, we have all these these existing walls, 0:15:09.360 --> 0:15:13.200 let's stitch these together. And also let's reinforce areas. So 0:15:13.520 --> 0:15:15.880 there were areas that they didn't know you only add 0:15:15.960 --> 0:15:17.960 length to it. They added double and triple walls in 0:15:18.000 --> 0:15:22.720 some places to reinforce what was already there. Um and 0:15:22.520 --> 0:15:24.360 and that's why in some areas you have a wall 0:15:24.400 --> 0:15:26.680 that is thick enough to drive a car on top 0:15:26.800 --> 0:15:29.480 if if if you wanted to and had permission to 0:15:29.480 --> 0:15:33.240 do so. Obviously, how do you get permission for that, Well, 0:15:33.240 --> 0:15:35.440 there's a there's a whole system you have to go through. Joe, 0:15:35.600 --> 0:15:38.760 I bet they're stingy with those permissions. I imagine they are. Now. 0:15:38.800 --> 0:15:42.080 I think most people know this anti factoid at this point. 0:15:42.880 --> 0:15:45.440 But as we've discussed on stuff to blow your mind 0:15:45.520 --> 0:15:47.680 before that that old trope that you can see the 0:15:47.680 --> 0:15:50.560 Great Wall of China from space. Not true. I'm not true. 0:15:50.720 --> 0:15:53.800 I mean it's still very impressive, don't be wrong, But 0:15:53.800 --> 0:15:56.680 but no, idea, it is not visible from space. There 0:15:56.720 --> 0:15:58.720 are plenty of things that humans have made that are 0:15:58.840 --> 0:16:01.600 visible from space, but the Great Wall of China is 0:16:01.640 --> 0:16:03.240 not really one of them. Now, I was looking at 0:16:03.240 --> 0:16:08.000 one interesting study about ancient Chinese construction methods, specifically with 0:16:08.000 --> 0:16:11.080 with walls in ancient China, and this is that many 0:16:11.120 --> 0:16:15.080 of them were built with a powerful mortaring material that 0:16:15.240 --> 0:16:19.800 was made with the secret ingredient of sticky rice. Have 0:16:19.880 --> 0:16:22.160 you read about this? No, I'm not familiar with this one. 0:16:22.200 --> 0:16:23.960 So I first came across this because our friend and 0:16:24.000 --> 0:16:26.480 colleagues got Benjamin linked us to a piece on it. 0:16:27.080 --> 0:16:29.960 But I was I was reading about this a little deeper, 0:16:30.000 --> 0:16:32.960 and so basically, here's the deal. So you've got mortar, right. 0:16:33.040 --> 0:16:35.400 Mortar it's the building material that you used to help 0:16:35.440 --> 0:16:38.720 bond stones or bricks or other hard elements together into 0:16:38.720 --> 0:16:41.680 a structure. And mortar goes way back. You use a 0:16:41.720 --> 0:16:45.080 paste like this, even it was used in the Pyramids. Uh. 0:16:45.120 --> 0:16:48.520 Now a common mortar used throughout history is lime or 0:16:48.720 --> 0:16:52.440 slake clime. Uh. Then slake clime is limestone that has 0:16:52.480 --> 0:16:55.360 been heated to a high temperature and hydrated with water. 0:16:55.960 --> 0:16:59.160 But about fifteen hundred years ago, it seems that construction 0:16:59.200 --> 0:17:02.320 engineers in a China discovered a way to make this 0:17:02.520 --> 0:17:08.680 powerful and resilient composite inorganic organic mortar by mixing slaked 0:17:08.760 --> 0:17:13.159 lime with soup or porridge based on sticky rice, and 0:17:13.240 --> 0:17:16.480 together the slaked lime and the sticky rice soup make 0:17:16.560 --> 0:17:20.080 a mortar that is much stronger than other known technologies. 0:17:20.359 --> 0:17:22.399 So there was a study about this in two thousand 0:17:22.359 --> 0:17:26.800 and ten by fu Weei, Yang, Bingjian Jong, and Chinglen 0:17:26.800 --> 0:17:29.960 Ma and it was called study of sticky rice lime 0:17:30.160 --> 0:17:34.320 mortar technology for the Restoration of Historical masonry construction in 0:17:34.359 --> 0:17:37.640 Accounts of Chemical Research in two thous and the research 0:17:37.680 --> 0:17:41.960 identified the most important ingredient as a polysaccharide known as 0:17:42.000 --> 0:17:45.200 a melo pecton, which is an element of starch, which 0:17:45.280 --> 0:17:47.040 is of course found in rice, but is also in 0:17:47.040 --> 0:17:50.359 all kinds of starchy foods like potatoes and corn and stuff. 0:17:50.880 --> 0:17:53.720 And the author's right that when they tested the sticky 0:17:53.800 --> 0:17:58.119 rice based mortar against more traditional lime only mortars, the 0:17:58.160 --> 0:18:01.879 sticky rice based one quote has more stable physical properties, 0:18:01.920 --> 0:18:05.240 has greater mechanical strength, and is more compatible, which makes 0:18:05.280 --> 0:18:09.159 it a suitable restoration order for ancient masonry. Um so 0:18:09.240 --> 0:18:11.280 they suggest we could even use this today if we're 0:18:11.280 --> 0:18:15.640 like restoring ancient buildings that need their bricks stuck together better. Interesting. 0:18:15.920 --> 0:18:19.000 I mean, I hate to waste good, good sticky rice, yeah, 0:18:19.400 --> 0:18:22.879 in in building a structure. But but it sounds convincing. Well, 0:18:22.880 --> 0:18:25.359 this wouldn't be the only case actually where food crop 0:18:25.440 --> 0:18:30.200 based starches have proven useful as a non food adhesive. Apparently, 0:18:30.240 --> 0:18:33.399 potato starch makes a popular kind of wallpaper paste. Have 0:18:33.440 --> 0:18:35.880 you ever read about this? I looked it up there, 0:18:35.920 --> 0:18:41.080 like recipes online for for making your own wallpaper paste outtatos. Interesting. 0:18:41.480 --> 0:18:44.280 I mean, I guess now it makes sense here as well, 0:18:44.320 --> 0:18:47.239 because I have learned from the Fallout games that if 0:18:47.280 --> 0:18:49.960 you have vegetable starch, you can turn that into adhesive 0:18:50.000 --> 0:18:55.040 at a workstation. Really so so so it lines out 0:18:55.320 --> 0:18:58.400 up with the Fallout technology trees. I never knew those 0:18:58.400 --> 0:19:01.000 games are so educational they but that is a great 0:19:01.080 --> 0:19:03.320 kind of ingenuity. Like you take the things you say, well, 0:19:03.320 --> 0:19:05.399 we eat this for breakfast, but what if we also 0:19:05.600 --> 0:19:08.560 used it to hold bricks together. Yeah, yeah, like it's 0:19:08.600 --> 0:19:11.760 sticky in my mouth. I bet we could. We could 0:19:11.880 --> 0:19:14.840 use this if we had to in constructing a wall. Now, 0:19:14.880 --> 0:19:18.320 following the Manchu invasion of the seventeen hundreds, the Great 0:19:18.320 --> 0:19:21.400 Wall of China was largely abandoned as a military priority. 0:19:21.960 --> 0:19:26.440 What's more, maus a tongue um, he ended up encouraging 0:19:26.440 --> 0:19:28.280 the Chinese people to use bricks in other parts of 0:19:28.280 --> 0:19:32.560 the wall or building projects. Uh So a large portion 0:19:32.640 --> 0:19:36.760 of the wall was essentially vanished during all that as well. 0:19:36.880 --> 0:19:39.800 But ultimately the big question here that that one might 0:19:39.840 --> 0:19:43.160 ask is did the Great Wall of China work right? 0:19:43.200 --> 0:19:46.320 Did it like repel invaders from the north right? And 0:19:46.320 --> 0:19:48.359 there's a there's a you know, there's a lot of 0:19:48.400 --> 0:19:52.760 fascinating history and discussion on this topic. I will point 0:19:52.800 --> 0:19:56.680 out that there's an excellent article in National Geographic called 0:19:56.680 --> 0:20:01.200 The Great Wall of China's Long Legacy by Bore Pellaguero 0:20:01.920 --> 0:20:05.560 Alcade and uh it's I'll try to link to it 0:20:05.600 --> 0:20:07.239 on the landing page for this episode, but it's well 0:20:07.280 --> 0:20:11.920 worth checking out. It really goes goes in deep but 0:20:11.920 --> 0:20:16.880 but in a very readable, digestible manner. So the most 0:20:16.880 --> 0:20:19.720 specific threat that the wall was dealing with were again 0:20:19.760 --> 0:20:23.760 the northern barbarians, the neumatic people's uh you know from 0:20:23.960 --> 0:20:27.960 from Mongolia and and so forth, And it was never 0:20:28.080 --> 0:20:31.359 the only protection in place. It's always important to note 0:20:31.359 --> 0:20:33.920 with walls, like it's easy to just have that stark 0:20:33.960 --> 0:20:37.240 image of the wall in your mind. Is this this 0:20:37.359 --> 0:20:41.960 tremendous human geoengineering project. I have made a mountain and 0:20:42.080 --> 0:20:45.320 nunshell cross. But generally there's other stuff going on with 0:20:45.359 --> 0:20:49.520 a wall, be it just a military or certainly there was. 0:20:49.680 --> 0:20:53.560 The Chinese did have military forces, but there were also 0:20:53.600 --> 0:20:58.800 economic policies under various rulers to keep the northern people 0:20:58.840 --> 0:21:02.480 in check. Economic policies what could that amount to ransom? 0:21:02.560 --> 0:21:08.560 Basic essentially yes, like economic stimulus et cetera, making payments 0:21:08.560 --> 0:21:11.520 and saying hey, here's here, you don't want to come 0:21:11.520 --> 0:21:14.040 and invade us, just here take some some of this. 0:21:15.080 --> 0:21:17.200 But this only worked for so long, and then the 0:21:17.400 --> 0:21:20.919 Genghis Khan led the Mongol invasion in twelve eleven captured 0:21:20.920 --> 0:21:23.440 the capital, and in twelve fifteen his son Kubla Khan 0:21:23.800 --> 0:21:27.480 conquered all of China and founded UH, the Yon dynasty 0:21:27.800 --> 0:21:31.280 and UH ultimately the con rule lasted less than a century, 0:21:31.400 --> 0:21:35.440 and following a peasant uprising, the Ming dynasty again uh 0:21:35.600 --> 0:21:37.840 took power in thirteen sixty eight. And again this is 0:21:37.880 --> 0:21:40.320 where the wall as we know it really came together. 0:21:41.040 --> 0:21:45.119 Um according to that National Geographic article. You know, they 0:21:45.160 --> 0:21:49.199 were employing economic means as well um foreign aid to 0:21:49.280 --> 0:21:53.840 keep the barbarians at bay. But this didn't work perfectly. 0:21:54.160 --> 0:21:59.520 Border attacks continued until one when trading posts were built 0:21:59.560 --> 0:22:02.359 on the board, which apparently helped ease tensions. But again 0:22:02.400 --> 0:22:07.040 this is kind of a uh An economic solution, UH 0:22:07.080 --> 0:22:10.400 that is working alongside all of this wall building that's 0:22:10.440 --> 0:22:13.720 going on at the time. Now, this ongoing Mongol conflict 0:22:13.960 --> 0:22:17.520 weakened the Ming dynasty and it fell to another peasant uprising. 0:22:17.760 --> 0:22:22.159 And then under the Ching dynasty, China's northern border expanded 0:22:22.160 --> 0:22:25.520 well beyond the wall, making it even more unnecessary. But 0:22:25.600 --> 0:22:28.679 though it remained a symbol of cultural pride, but a 0:22:28.760 --> 0:22:31.600 relic of the past at the same time. So I 0:22:31.600 --> 0:22:34.120 feel like the Great Wall of China side. Besides being 0:22:34.119 --> 0:22:36.919 one of the most iconic examples of a you know, 0:22:36.960 --> 0:22:42.760 a free standing dominion wall in human history, it also 0:22:42.920 --> 0:22:46.320 has some some potential lessons about the limitations of walls, 0:22:46.720 --> 0:22:50.840 the life cycle of walls, um, you know, and just 0:22:51.000 --> 0:22:56.040 again the nature of walls not working in isolation because 0:22:56.080 --> 0:22:59.280 obviously any wall, they're in their numerous ways to get 0:22:59.359 --> 0:23:03.440 under it, to go over it, to go through it, etcetera. Uh, 0:23:03.640 --> 0:23:06.760