 So welcome, everyone. Thank you for joining us here at the Mechanics Institute online for our tech in the city series. For law cities, a secret history of the urban age with author, Annalie Newitz, who we welcome back. I'm Laura Shepherd, director of events at Mechanics Institute, and we are also proud to co present this program with the Gerta Institute and gray area, our long time collaborators on our tech in the series series series programs. If you're new to Mechanics Institute, we were founded in 1854 and we're one of San Francisco's most vital literary and cultural centers in the heart of the city. We feature our general interest library and international chess club and ongoing author events and our Friday night cinema lip film series. We have such good news for you that the library is now open five days a week so come on down, get your books, do your research hang out in our beautiful Bozart's library. This program will also have a Q&A so hold your questions and put them in the chat and Annalie will engage with you with your questions. Okay, so I'd like to introduce our program. I think that Newitz debunks the myth that lost cities were miraculously discovered by modern modern archaeologists. According to Newitz, she has spent the last seven years talking to archaeologists that no city is ever lost. She'll be sharing us sharing with us some of her research on four ancient cities and abandoned metropolises through their grandeur their glory and their demise. Annalie Newitz is a contributing opinion writer for the New York Times. She is a founder of I09 and a former editor in chief at Gizmodo. Her other books include Scatter, Adapt and Remember and the Novels Autonomous and the Future of Another Timeline. And Annalie was recently featured on Ira Fledo's Science Friday recommending the best sci-fi books for your summer reads and you can see that online as well. So please welcome Annalie Newitz. I'm giving some kind of screen share. Yes, somebody is sharing their screen. I did send them a private chat. It must have accidentally clicked. I think it's John. John, could you look at the top of your screen and possibly stop sharing. You'll see an option that says stop share screen sharing. There we go. Excellent. Thank you. All right. Welcome, Annalie. Hi, thanks so much for having me. And thank you, Laura, for inviting me to come. Mechanics Institute is one of my favorite libraries in the world and certainly in the city. It's really, it's always a pleasure to come and chat with everybody and tell you the latest odd thing that I've been up to, which in this case is working on a book that took me about seven years to do. Four Lost Cities was really the culmination of a ton of travel that I did going to different archaeological sites and visiting the cities, talking to archaeologists, seeing for myself what cities look like when they've been abandoned for 500 years or 8,000 years. So what I'm going to do today is just give you a little taste of what I talk about in Four Lost Cities. I'm going to talk to you about a couple of cities from the past and then kind of jump ahead into looking at the future of San Francisco and just leave you with a few ideas about how ancient history can help us prepare for the future of our own cities today. One of the things about cities that I find particularly interesting and moving to is that they are social history. Cities are built by collectives of people. Oftentimes when you read accounts of city building you hear things like the King built a road. But we all know the King was busy in his castle being fed by servants and it was actually workers and city dwellers who built that road. And so that was with that thought in mind, I kind of tackled this book with an aim to look at those people who were building the roads and what it meant for them and what their lives were like. And kind of what it means to have a collective enterprise like a city that lasts for multiple generations. So what I'm going to do is I'm going to share my screen and show you some images from the oldest city I talk about in my book and you should be seeing a map of Chattel who you and this is a beautiful map that Jason Thompson made for the book. He normally designs game maps for Dungeons and Dragons so it has a little bit of a fantasy feel but it's all real. Chattel was a city that was here. Hello. Sorry somebody did somebody ask a question or. Whatever. Technology. So Chattel was a city that was at its height about 9,000 years ago. It was in central Turkey, and you can still see the remains there today. And it's a it's a city that was occupied continuously for 2000 years so it's a much much sort of more successful city than San Francisco and by some measure because of course there's really only been San Francisco as such for a little over 150 years. The way that people lived here. This picture makes it look like, you know, the entire city was was built around this river but actually what happened was, people lived on that east mound for a really long time maybe about 1000 years, and then they started to build up the west mound as well so as the west mound was being built the east mound was kind of falling into dust so you have to imagine that this was a city that changed a lot over time. One of the things that happened at that city was people were at the height of something that is called the Neolithic period, which you probably heard about oftentimes people will talk about it as caveman times, which it wasn't Neolithic which means new Stone Age. And the reason why it was the new Stone Age was because we'd had the Paleolithic for a really long time, which was kind of the Stone Age, the more modern Stone Age. And then the Neolithic was a period of really rapid transformation where people were using stone tools to do all kinds of crazy things. I'm just going to show you a few pictures from the dig at Chitalhoyev when I visited back in 2013. So, here you're just seeing people excavating. This was a huge city and so the excavation looks gigantic. These are just the old walls of the city and they built a beautiful shade structure on top of it so it's not quite as hot to work there, which believe me the people who are digging this up are very grateful for. These are a couple of graves that have been excavated and one of the many interesting things about life at Chitalhoyev is that people buried their dead under their beds. That was just part of their spiritual tradition. So here you can see that this part of the floor was a little bit elevated. They call it a bed platform archaeologists who work there. And so underneath you would have had the bones of your beloved elders and ancestors kind of keeping you company, I guess. The other thing about Chitalhoyev was that it didn't really look like a modern city as we think of it. There were no public squares, there was no marketplace, there were no palaces. It was very much like a honeycomb structure with all the houses being roughly the same size and all squished up together like apartments, people sharing walls, you know, being very, very closely packed in. And the way that people got into their houses was through their roofs. You would have to send a ladder to get into the city and walk across people's roofs and people did a lot of work on the roof, you know, they did cooking up there and preparation of various items, making clothes, making weapons, making tools. And then you would just send a ladder to get down into your house. So here's just more houses this is Ian hotter who led the excavations at Chitalhoyev for several decades. And he's showing us all of the layers in the city, because houses were built on top of houses. And you can actually see this kind of swirling pattern in the rock wall that he's showing us and those those that pattern those layers are all floors. And so each time a house was abandoned they would burn the house actually burn a bunch of stuff in it, tear it down and then rebuild it and so leave this kind of blackened ashy floor. And we'll talk about that more later when I get to the next city. Here's more layers. This just shows you how deep the city goes. So to get back to this point that I was making about the Neolithic, being the stone age, and being this kind of moment of transition for humans who had been working with stone tools. One of the things that you can see in this picture is if you, this is a very, very deep excavation into part of the east mound so you can see kind of how big this excavation is of a very tiny part of the city, but also how deep it is because of course the deeper you get, the closer you get to the earliest parts of the city because the newest parts are on top and the oldest parts are on the bottom. So, down toward the bottom. I'm not sure if actually it's too clear here but there's a little stripey stick. And the stripey stick is at what's called the dairy line. And archaeologists like to talk about that at Chautalhoyuk because we have such a nice layered structure here that we can actually see a moment in time that they can mark physically with this little stripey stick where people start cooking with dairy products, and that means a couple of things. It means that they had domesticated some animals, namely goats in this case. And also that we can see residue of milk in a lot of their cookware. And through chemical analysis we can see that they were cooking with milk and actually there's a lot of evidence that they used dried milk and to make instant soup, which I think is delightful I love the idea that 9,000 years ago people had already figured out how to make instant soup. And this is a really interesting transition for the Neolithic period, because suddenly you can see all this evidence of how people are engaging in agriculture and animal husbandry and it's changing their life ways. It's changing how they live. People had been living nomadically for tens of thousands of years before they settled down into cities like Chautalhoyuk. The Neolithic is famously that period when people go through the agricultural revolution and start living in a subtle place their whole lives, which is you have to imagine would have been just a mind blowing culture shift for people whose whole belief system and traditions were based on being nomads. And so that little dairy line is a big flag. It tells us how people were changing at all in all parts of their lives because of this sedentary life. The other thing that that dairy line tells us is that people started making fired pottery because it was a lot easier to cook with milk if you had a pot that you could put over the fire and leave there for a period of time to kind of bubble and you add other ingredients and you add your dried milk and you get a nice stew out of it. If you can believe this, before people had fired pottery, they had to do things like cook with heated stones so you'd have an unfired clay pot. You couldn't put it over the fire because it would break. You'd fill it with all your stuff, you know, your various items that you're going to have in your stew and then you would heat up rocks and put them in the water or in the stew to heat it up. Or you could do things like barbecuing and you could cook over the fire, which they did a lot. They all had hearts. But this was a big shift. Again, having fired pottery really, really was game changing for people. It was kind of like the Internet Revolution. It changed the way people did work because they could do things like leave food cooking on the stove while they went off and did other stuff. It was a huge time saver for people. And so it allowed them to spend more time inventing other tools and becoming more proficient at farming and animal husbandry. So, before we leave Chitalhuyuk, here I'm going to just show you a few more pictures. This is a very awesome picture of wall painting at Chitalhuyuk. You can see there there's a white plastered wall with this red abstract design. And this is everywhere. The whole city is just packed with beautiful designs. Everybody painted there and plastered their walls all the time. And I just got my house painted this past week and I kept thinking, you know, this is something they did at Chitalhuyuk all the time. They were always painting their homes and kind of making them more beautiful and more livable. And this is just one of the many figurines that was found at Chitalhuyuk of a revered elder who looks pretty badass there. She's got two jaguars next to her. So she's a pretty commanding figure. And this is what it might have looked like inside of one of those little houses at Chitalhuyuk. There's the bed platform. There was that bull's head there. That would have been a skull, a bull's skull that they plastered and used to maybe it was decorative, maybe it was spiritual, maybe it was both. We don't know. There's a lot of mysteries about Chitalhuyuk. And one of the final mysteries about the city that I want to mention is that we don't completely understand why this city was abandoned, but we do have a couple of ideas. And those are related to how the city went through this really rapid neolithic change in how people were living. Remember, they're living in a settled way and the kind of tools they were using. And also the population size, because most people at this time in history were living in pretty small groups, you know, like around maybe 50 people would be a nice sizable community, or 100 people would be quite amazing. This city probably had 5000 or give or take of 1000 people, 5000 people living there at once, which would have been just astonishing to anyone at that time who was living in a typical way. One of the archaeologists I talked to Ian Kite, he thinks that one reason that people may have abandoned the city was that living at that size over time was very difficult for people because they had kind of grown up with values that came from small communities, very small communities that were nomadic. And once people were living in a settled way at a large population size, it was almost like- Why can't you just leave them alone? Do you need this? I think, folks, please mute your mics. Because we're hearing a little commentary. Anyway, so the interesting thing that happens is it's possible, Ian Kite thinks, that maybe the social organization of the city couldn't keep up with the infrastructure of the city. And what I mean by that is that people at that time had made enough breakthroughs technologically to build this incredible place, to live their year round, to do agriculture, but maybe they just hadn't quite figured out how to have a society politically that existed at that size. Maybe it was a kind of a social or a cultural problem that drove people away from the city after they'd lived there for about 2000 years. So for generations and generations, it was kind of working out, and then eventually it just came to a stop. And people don't really start building big cities in this area again for about 2000 years after Chitalhoyuk is abandoned. And then we start to see the cities emerge that we've all studied in school, the great Mesopotamian cities of Oruk, and have, you know, these huge ziggurats and big, wide streets and marketplaces and plazas that we recognize in cities today. So there seems to have been a kind of retreat from urban life, at least briefly. And then people return and when they return, their cities just look completely different. And so I think as I take you forward a little bit closer to the present and the future, I think it's interesting for us to hold in mind the idea that sometimes our problem with the city is a social or cultural problem. And that maybe sometimes our infrastructure and our technology outpaces what we know how to do culturally and as a community. Okay, I want to take you to another city before we come into the present. Are you sure you don't need to get out and start over. So we don't keep missing all of this. I don't know why you have to keep touching things why you can't just leave. You're probably being heard by these other people here. Fine, I don't care. Folks, please mute your microphones. Thanks so much. All right, so I'm going to talk a little bit about another city in the book, which is many thousands of years later, all across the world all the way across the world. This is the city of Cahokia, which is located today in southern Illinois. It's an incredible indigenous city that was built starting in kind of the late 900s. So about 1000 years ago, and it really becomes quite large in around 1050. And at the time that Cahokia is growing as a city, its population is, you know, around 30,000 people which rivals the population of Paris at that time so it's a very impressive city on a global scale. And it's huge and the reason why I love this map is that you can see how far the city stretched. It stretched all the way from southern Illinois through what is today East St. Louis and all the way across the Mississippi into what is today St. Louis. But the part of Cahokia that we think of as the central area the downtown area is in southern Illinois, and it's marked by this incredible earthen pyramid called today monks mound we don't know what the people building the city called it. But they were part of a tradition called the mound builders. They were part of the Mississippian culture, which was a big culture of linked indigenous groups that lived all the way up and down the Mississippi. There would have been tremendous cultural diversity among Mississippians different languages and traditions, but they also shared enough traditions that they often traveled to each other's homes. It appears that almost annually, people came to Cahokia, people from all up and down the Mississippi came to Cahokia for partying and for spiritual pageantry and just kind of an annual get together of all the friends and families that were separated during the year. And they, the city was built, as I said, around these massive earthen mounds, monks mound is incredibly huge. I think I have a picture here. This is what it looks like today and you can climb to the top and when you get to the top you can see East, you can see St. Louis all the way across the river. It's just incredible. And it's something that appears to have been built very rapidly. The city, when people first arrived there when the framers of the city first arrived, there were groups called the Woodland Indians who were living in small villages along the Mississippi and then suddenly this new group comes in and they just start building these crazy mounds that are just huge. Monks Mound has like the footprint of the great pyramid at Giza just to give you a sense of how large it is. And in fact, when Europeans first stumbled across the remains of the city, they had a theory that the ancient Egyptians had built it, which turned out to be wrong. I also thought ancient aliens had built it, so that was also wrong. The thing that's really interesting about Cahokia, and the reason why I wanted to bring it up. And here I'll introduce you to some of the archaeologists that I worked with there. This is a dig that I went to there. I attended the dig actually two years in a row so I got to kind of see how they progressed. And they were excavating near Monks Mound in a small residential neighborhood. And what they talked to me about the two lead archaeologists. Let me find a picture of them. And that is Melissa Baltus on the left and Sarah Barris on the right. And they are two world experts on this area, and they're particularly interested in how the city started, and how the city ended. And even like Chatalhoyuk, Cahokia's ending is kind of mysterious. We're not entirely sure why people left. But I'm going to give you one of the ideas that Melissa had about maybe why they left and I think it sheds a lot of light on how cities work in the present. One of the things at Cahokia is they, they haven't left behind anything that we recognize as writing so we don't have any stories from the people who lived there 1000 years ago kind of telling us what was going on. What we do have is a very detailed city grid. And we know that the city underwent and this is just from people mapping and digging and doing magnetometry overviews of the area, and looking at the arrangement of mounds and understanding how it changed over time. The city starts out when it's first being built, kind of looking a little bit like just a bunch of villages squished together you know it's a lot of small neighborhoods that just kind of get next to each other. And when the city reaches its height when it's at its most populated. Suddenly, we've got that monks mound right in the center of the city. It's got this huge, huge public Plaza right next to it which clearly is intended for people to come and listen to whoever's on top of the mound, talking to them and telling them stuff. Also the Cahokians and the Mississippians generally are very sports loving society and so they also play a lot of ball games in that in that Plaza so it's a dual use Plaza sports and political events. So when the grid is changed, it becomes a very strict north south grid with monks mound kind of at the center and archaeologists think that that suggests that there was some kind of centralized control in the city not only do we see these monumental pieces of architecture that suggests that some people were elevated higher than others. So we also see that someone is telling everyone where to put streets and and how to arrange them you really can't have a super rigid grid without having some centralized authority that's kind of planning the city. So I think the city went through a phase of some kind of centralized government or governance, or maybe a set of leaders that kind of all agreed to work together. We don't know but it's clear that that the city's organization really changed and toward the end of that period and this is my favorite part of the story. What happens is I'll take you back to that map so you can see a cool picture of it. So you can see here how there's a fence all the way around monks mound, and that fence is only built toward the end of this period of the rigid grid system when the city seems to have centralized control so somebody decided they needed to put a big fence around and protect whoever or whatever was in there maybe it was a ruling group. Maybe it was other fancy stuff. We're not sure. There's no evidence of a big war so it doesn't seem like they were defending against outsiders. It's pretty easy to tell when there's been a big war there's usually, you know, lots of burning and projectile points and you can kind of see the damage. We don't see any of that here. So you can see what seems like an effort to keep out the riff graph. And then, shortly after we see this fence go up seems like the riffraff did get in, because that grand Plaza and monks mound become a trash heap, and the layout of the city changes once again, it's very, very different. It goes back to being much more of a neighborhood pattern, instead of having that rigid grid you start to see houses arranged in a courtyard pattern around little courtyards that feel again much more neighborhoody. And so it seems like there was some kind of social movement that swept through the city and really changed the way people wanted to live together, changed the way they wanted to build, changed their relationship to this massive mound in the middle of their city. So it's a, it's a very striking transformation. And it's very interesting from my perspective if you're thinking about cities as a collective endeavor to think about what does it mean if the city grid has that much of a change. And what what does that imply about where the city is going. So, before I get to figuring out what might have happened to the city I want to tell you about one of the really interesting traditions that we see practiced throughout Cahokia. So here we see Sarah and Melissa, they're deep into a pit here that they've dug with the help of their students. And that's for a big public building that would have been in a small neighborhood area. And it seems like this is an area that came from later in the city's life so after that rigid grid. This is back. This is toward the end of the city's life when people are living back in kind of courtyard patterns in neighborhoods. This is a public house that would have been surrounded by private homes so people kind of used this public house for you know barbecues and parties and other events. And I'm not kidding about the barbecues by the way we found when we were excavating a lot of remains of barbecue, like they really liked to barbecue deer. So I dug up a lot of deer bones and actually tasted one but that's a question if you have any questions about tasting a thousand year old deer bone just ask me later. So what they're doing in this picture is called scrying. And they're highlighting areas where they found walls and the circles that they're making on the ground there are where they found post holes so places where people sank a piece of wood into the ground. So that would be part of a wall or part of a support structure for one of the houses at Coke yet. And the thing that they that we find, no matter where you're digging whether it's a public house or a private house, whether it's early in the city's life or late in the city's life is that when people were done with a house, they would burn it. I wouldn't burn the whole thing they were very interested in preserving any kind of wood that was still structurally sound to use for another house. So they would pull up the wood walls, and they would lay out various items that were spiritually or personally on the floor of the house, and they would light it on fire. And it's just like what I showed you earlier at Chattahoyup where I showed you those layers of the house that had the kind of layers of burning and ash. Over time, you see the same thing at Cahokia, where you know you've hit a floor when you find a layer of ash, and you dig through that and then you find the next house underneath, or the next floor underneath and so these are houses that are built on the floor of overtime. But there's always this ritual of what archaeologists refer to as closing up house. And at Cahokia, we have strong evidence that this ritual extended beyond houses. There was this incredible discovery a few years ago, when a new freeway was being put into East St. Louis. And a precinct of Cahokia was discovered during the dig for this freeway. And so they brought in what are literally called emergency archaeologists to rescue everything they could find. And one of the things they found was an entire miniature city that had been burned down in one of these closing up rituals. And it's not a miniature city like a wee itsy bitsy city. People actually built, you know, small houses that were that had wooden walls that had like little tiny baskets and offerings inside of them and each of those little houses. You know, was was fairly, you know, it was like the size of an outhouse let's say. So they weren't huge but they weren't tiny. And there were dozens of them that were burned as if there was some kind of spiritual push to change the city itself or some kind of ritual around closing up not just a house, but a whole neighborhood. And this was again, it was it was not a place where people had lived I mean it was purpose built for this sacrifice or for this burning. No one had lived in these houses they were fake houses. I think that this is why so many archaeologists are really fascinated with this idea of burning and closing up at Cahokia because we so we see so many different examples of it, and it seems so integral to how people understood their relationship with the city and their relationship with the land. And it also suggests that people who built houses at Cahokia, thought of them as having a finite lifespan that built into a house was the idea that it would end, and we would burn it away for the next thing. It's very different from like a Western or European idea when we build houses. We think of them as like lasting forever, you know, a house is successful if it lasts for hundreds of years and a city is successful if it lasts for thousands of years. This kind of closing up ritual suggests that maybe the Cahokians didn't see it that way maybe they didn't see houses and cities as things that needed to last, they lasted for as long as they, is people wanted them when people were sick of them they changed the way they were laid out they changed their cities layout and eventually over time, as the city was abandoned. It really seems as if people didn't have any particular, they didn't have a fight, they didn't seem to have any kind of environmental problems. They just searched and searched for evidence of flooding or fires or something that might have driven people away. There's no evidence of that it seems like slowly their neighborhoods got further and further apart. And eventually they were just like, Okay, we're done. The city was great. We liked it. Now we're going to leave. People who left Cahokia, probably eventually became part of the Suin tribes, which we switch are, you know, all across Central US and Canada. And this is, and so Cahokia is kind of a an ancient civilization that is the deep tradition for many, many tribes in North America. Like ancient Rome is for Westerners were like lots and lots of different groups kind of trace their roots back there. And, you know, the city kind of lived on in in the memories of the people who left, but they didn't feel like it was a big deal to leave. I love that idea and to finish up to, I really want us to think about the notion that a city doesn't have to be permanent, and that a city should change to suit our needs over time. And I think that the Cokians may have had the right idea about that in some ways. I want to conclude by thinking just a little bit about San Francisco and what the future of San Francisco might be like. I have this image that was used recently in an exhibit about the future of San Francisco. This is actually a pretty old architectural idea invented by a Belgian architect named Vincent Calabo, and it's a floating city. And it's called, he calls them lily pads, and therefore climate refugees, and the idea is that these cities float around. This is his idea for what they might look like in a coastal city this is Monaco but could be San Francisco. And I think that this is such a great image to think with because it reminds us that the shape of a city doesn't always have to be exactly what we think it might be. And in San Francisco, as we look into the next 100 years, or the next 500 years, all we're going to be having to cope with is change there's going to be massive transformations in the climate. We're going to be dealing with fires we're going to be dealing with potentially flooding from sea level rise. You know that an earthquake is coming eventually I mean it's statistically very likely to come quite soon that we're going to have a pretty big earthquake along with San Andreas fault. So our city is going to be dealing with tremendous physical changes environmental changes, and we're going to have to do something like what people at Cahokia did we're going to have to change the city grid, we're going to have to change the way we build. And so, on top of that, we're going to be having to do a lot of innovation politically and socially. And this is why I want to kind of bring it back as I conclude to to Talho Yoke. And that idea that in kite had about he calls it the Neolithic dead end, where people just couldn't come up with a way to live together politically at a size that was so big 5000 people I know it sounds silly now, but at that time obviously quite enormous. And I think in San Francisco, because this is one of the cities that is responsible for many of the innovations and the internet, and the web and various apps that are replacing the web. I think it's worth wondering, whether we are at a stage kind of like the people in the Neolithic, where we're going to have to invent some kind of new way to live together at the scale of the internet, billions of people talking to each other all the time, or billions of people in one nation arguing together at the same time. We're having to deal with that kind of social transformation at the same time that we're dealing with all of this transformation in our environment. And in order to do that, we might have to do things like invent floating cities that sale around to help people who have been displaced by climate change, or something even weirder. I think that it's really important that as we move into the future that we remember to think about weird stuff, and about how incredibly changeable our cities are, and how much that depends on the agreements that we make with each other. So thanks for listening to me talk about cities. It was lovely doing this and I'm happy to answer questions. And I see that people are asking a zillion questions while I was in projection mode and couldn't see them. Pam Troy, our events assistant will read off the questions that you have in chat so keep putting them in the chat and Pam will come back and read off a few of them to start. Sounds great. I am here. Hang on just one second. I had kind of a question. The first, the first city you talked about. And your theory is that it was, it was, it was basically a social decision for them to abandon the cities that correct rather than a crisis that came up. Yeah, I mean, maybe, maybe it was a social crisis but yeah I think it may have been social. We don't know for sure. I was just it's just that if you are you are heavier, the bones of your ancestors in your bed that that sounds like it's kind of an attachment to a place or attachment it just seems that it would, you know, it that just think that raises a whole lot of kind of puzzling I mean I think that you're probably right it's just there there are crises that will arise that will not be reflected, you know, materially, but it's it just. Yeah, I mean, I think, I mean I'm glad that you brought up the thing about having your ancestors buried in your house because I think it shows how attached people were to their homes, because it's very hard. I mean, it's always hard to leave your home behind, no matter what, but it's especially hard if your home is also a place that you think of as being where you can commune with your ancestors. And if that is how they thought of it, archaeologists, when I was there, there were a bunch of archaeologists visiting at the same time and they had this kind of very mannered brawl over. Whether to tall who you whether the people there experienced an idea of history, or an idea of like cosmology or spirituality and whether the city reflected a historical sensibility or like a spiritual sensibility. You know, there were people arguing on both sides and I think really it's both, you know that the city kind of embodied a sense of spiritual history. And that it would have taken some kind of cultural crisis to drive people away and also it would have been slow, you know this was a city that people lived in continuously for 2000 years so abandonment took place over on the scale of hundreds of years so it was slowly shrinking for a very long time. And I will say another thing about people leaving they didn't really leave the area, like what what Ian hotter says he was the guy that was running the excavation there for so long. He said that as the city gets smaller, we start to see all around the city on the Konya plane, which is the area around it. And all these little villages springing up all of a sudden. And it's like he said it's like a dandelion scattering at seeds and like all of these people go live separately. But they're still kind of in the same area and people keep using to tell who you as a graveyard. So it continues to occupy a very prized place among the people who live there so yeah I think it was hard to let go but I think they had. to try living at a smaller size again. Well there's a question from Andrew, oh, August. Is it possible to know how much time elapsed time lapsed between the burning down of houses is it possible that they were burned. When someone died, and a new generation built the new house. So, so, of course, we see this burning pattern in both to tell you 9,000 years ago and Cahokia, which is about 1000 years ago. And yeah, it's, it seems as if people did it generationally. There's one house at Chattahuyuk, which a Berkeley archaeologist named Ruth Tringham. She did a very intensive analysis for many years of one house to try to understand that life cycle of the house. And it does seem in that case that the house was not burned until the very last person in the family had died. And she was that last remaining person was kind of the matriarch of the family. She was laid on top of the other people in the burial area under the beds, and then the house was burned, and then a new house was built on top. And it seems very similar at Cahokia. People did not bury their dead under their houses at Cahokia so we don't have a sense of who lived where. In fact, we don't really know where they buried their dad or what they did with them. But we do know that we see that same pattern of a house being used for about 40 years. And then there's a layer of burning, and then there's a pause sometimes and sometimes not sometimes it's just like hey build another house right away, burn it, lay a new floor, build it up. So it's maybe it was passed down. Maybe it was a new family would come to town. But yeah, it's it seems like there may have been sometimes a pause and sometimes not between burnings. Well, we have two questions that are kind of similar on one from Sinbag and one from John. And I'm just going to kind of give them throw them at you at the same time. So resource exhaustion was ruled out as a factor and famine attack environmental disturbance all of those were categorically ruled out as factors this is these things did not happen. Okay. And both were both were asking about that. And then Daniel ransom asks, while Catholic is too ancient to connect to any modern culture ethnicity or ethnicity, the people people of Cahokia, have living descendants today have the archaeologists working in Cahokia had dialogue or involved indigenous people indigenous people in their work. Yeah, so. Yes, I mean the thing about Cahokia is that, like I said, it kind of it's so ancient that it doesn't actually have a connection to any like living tribe per se. A lot of anthropologists both indigenous anthropologists and Western anthropologists your Europeans and various other Westerners have surmised that there are a lot of connections between Suen tribes histories and oral traditions and some of the iconography that we see at Cahokia. And there is some hint in the oral tradition that people in Suen tribes trace their lineage back to a city at the fork of two rivers, which would be the Mississippi in the Missouri. But there are no Suen tribes that claim Cahokia as an ancestral home. There is there are a couple of tribes that are shepherding some of the mountains so that they they have stepped into to take care of them but they again they don't claim a direct lineage. So, there are a number of indigenous groups that have like the Osage and the Cherokee that use the Cahokia State Park for events and that consider it to be part of their cultural tradition. And there's a lot of indigenous archaeologists and anthropologists who've worked on it. There's also a number of indigenous artists who've incorporated imagery of Cahokia into their work and I talk about that in my book. And I actually interviewed an author, Rebecca Roanhorse, who recreates a version of Cahokia in one of her novels. And in order to kind of show what the indigenous world was like before contact with Europeans. So I think it's like I said I do think that it's kind of like Rome for the Europeans and that of course yes there's Italians and they can say they're, you know, whatever, descended from Rome but Rome was a really different place. So, and a lot of people who lived in Rome did kind of scatter throughout or lived in Roman colonies kind of scattered throughout Europe so. So it's really complicated it's complicated to follow a direct line between Cahokia and a single modern group. It's kind of cool about it. I think it makes it a more haunting and profound kind of city because it's the sort of, it's the, it's the sort of spiritual and historical beginning for a whole bunch of different cultures. And the question that someone asked before about cities move on due to like famine attack and environmental disturbance. You know, with Cahokia like I said I there's none of that with Chattel Huyuk. There were periods in the city's history when they had massive droughts and the climate did change radically over time. There was evidence that people kept living there and they just changed the kind of things that they ate based on changes in weather patterns so they seem to have survived a lot of that stuff and then left for other reasons, which is kind of cool. Armando says thank you, Emily that was a really great presentation. As we think about the future about what cities might be like what other novel or weird ideas, should we be thinking about in terms of city design or layout. Great question and I hope that you guys will come up with some answers. I love the idea of mobile cities which is why I showed you guys those lily pad cities the floating cities. I don't know how realistic those are especially given how unappealing cruise ships are right now. I feel like these cities are maybe just giant cruise ships so. So that might be more of a model to think with but not necessarily something we would actually do. I think it's worth exploring the idea of temporary cities, cities that are not intended to last cities that are intended to host people for a generation or two, and then bio degrade as as conditions change so that people can move further inland or whatever we need to do to suit the environment and suit ourselves. I am particularly fond of some of the incredibly weird visions coming out of this New York based group called the living, like living room but just living. And they are a group of architects who have been experimenting with using building materials that are alive. So whether they are alive because they're built with biological materials or semi biological materials or they're kind of alive because they're smart in the sense that they are programmable. There could be things like a city where you had a building that could whose walls could repair themselves. Or whose walls were semi permeable so they could allow in rainwater and store that rainwater for use later. They could be, you know, allowing in cool air and letting out warmer air. So the possibility that you could have these kinds of living cities that have huge parts of the downtown devoted to animal migration. So, animals don't get stopped at the border of the city they're welcomed in and it's like here's a road. Did the antelope need to come through, go for it. Oh are there moose here. That's great we've got a moose road that's awesome. I mean, we probably wouldn't be able to tell the moose that we could sort of gently guide them down the road. And so I think imagining ways that we could make cities more like living organisms more like things that function within the ecosystem. There are already ecosystems we know that they're full of living things are full of humans and non human animals and trees and all kinds of stuff. But what if we more purposefully designed them to be that way. And again design them to be a little bit biodegradable like don't, don't worry about your house lasting 100 years if your house lasts long enough for you to live there your whole life. It doesn't have to last longer than that. Let the next people build a house that's more sustainable. I really like that idea. Sin bed asks, do we know where the earth and material to build the mounds was sourced. That is a super good question and I have a very big answer for you that I will try to squish down to a little answer. Yes, the city is actually built out of mounds and also depressions in the earth, which archaeologists call borrow pits, and they call them borrow pits because it's literally where people took the earth, borrowed it to build the mounds. And archaeologists believe that the spiritual system that people adhered to at coquia involved thinking about the world above the world on land and the world below. And so there would have been significance to areas that were below the earth as well as areas that were were above. We know the borrow pits filled with water every year. And in fact, some of them still do. And actually right outside the interpretive center at coquia, and if you go I highly recommend you visit the interpretive center it's very nice. There's a big borrow pit right out front and it's always full of stagnant water and people are always grumbling about it but that's the architecture of the city. And the thing that's so cool is there was a small excavation in the side of months mound where archaeologists were actually able to see the basket mounds of dirt that people have brought dirt and clay, because you could just see these little round areas of different colored dirt and different kinds of clay. So we know that they brought it in with baskets so they'd scoop it out here with a basket dump it and pat it down really hard. So yeah, it's it seems like moving earth around was actually a big part of spiritual practice. It sounds really tiring to me, but okay she asked, is there DNA remaining in the city that could be linked to today. So, not at coquia, the area around coquia if you haven't been to southern Illinois or in that area. It's called the American bottom. And it's very, very humid and damp and muddy, and it's very bad for preservation of genetic materials so we do have a few human remains that were excavated. Before regulations preventing us from excavating the ancestors of indigenous people, which much needed law very in favor of that. So we have very few human remains at all for good reason and the few that we have are not in any shape to do that which is kind of disappointing but we can't find it. At Chetal Ho Yoke, there has been some loose talk of doing some DNA sequencing, I don't think they're there yet. But I think it might be possible, the preservation there might be better, but it hasn't happened yet so it's definitely stay tuned I think that would be super cool to find out, especially at Chetal, who these people were. And then Bad also asks, have any connections been established between the coquian mound builders and the serpent mound tribes Georgia. Yeah, this is another really good question. So, North America has a really long tradition of mound building it goes back about 5000 years. There have been different phases, like different cultures have arisen that seem to really love mound building. It's almost certain that the people at Cahokia would have seen the remains of these previous mound building civilizations, and we're probably trying to imitate them. There's no evidence that they're connected, I mean they're, they're, you know, they're separated by like 1000 years. And in some cases by by 3000 or 4000 years. So it would have been kind of like, you know, the way that the US capital is designed to look like an ancient Roman building. You know there's parts of the US capital that are classical Roman architecture. And that's probably the kind of thing that was going on at Cahokia where they, the Cahokians were like, Oh, there's this ancient tradition of mound building these are our venerable ancestors. If we're going to build a super badass city. Let's do it like that. Let's like, let's, you know, revive these ancient super cool traditions of these other successful civilizations. We're definitely in homage for sure. Um, Dustin asks, do you think we'll see more cities becoming like this with streets turning into canals. It's a good question I think we will see that whether we want to or not. I mean, you know, whenever we have hurricane season, you know a lot of cities in Texas become like Venice, even though they don't want them to. You know, of course, cities in Louisiana and Florida as well. So, I think the question is, whether we're going to keep pretending like that stuff isn't happening and just letting our cities flood uncontrollably every year or if we are actually going to say hey, guess what floods, they're going to happen every year. Why don't we build canals. Why don't we build houses on stilts. Why don't we rebuild cities in a different place. And that's the big decision point that we're at right now. That's why I think we're kind of in a new neolithic, a neo-neolithic, where suddenly we're having to change really fast as a civilization to kind of meet the needs of our people. I mean, we can't just sit here and say, all right, well, California is going to burn down every year, whatevs, you know, we have to start really intervening, right, and, you know, doing what we can to prevent that kind of stuff from happening. I'm sorry to switch from floods to fires, but fires are very much on my mind right now as a San Francisco. And Don Fox asks, were there any excavations of the mound? If so, was anything discovered? There was the excavation that I mentioned at Monks Mound where they discovered the basketfuls of dirt and clay, so they discovered like how the mounds were built, essentially. There was, back in the 1960s, there was an archaeologist named Melvin Fowler who excavated a mound at Cahokia. Again, this was before the regulations around excavating indigenous remains. So he was allowed to just do what he wanted. And he excavated the brilliantly named Mound 72. And Mound 72 was special because it had a peaked top. So it's a top that looked like a rooftop. It would have looked a lot like the rooftops of the houses that people built at Cahokia. And he had a sense that that meant that it was probably pretty special. It was also located directly south of Monks Mound, I believe, so it's on that north-south grid. And yeah, they discovered some pretty incredible stuff, some human remains. It looks like there were kind of human sacrifices that went along with some of their festivals that they had. So some of the remains they found appear to have been sacrifices, other remains they found appeared to be the bones of ancestors that had been disinterred and brought especially to be reburied during this whatever the ceremony was where they created this mound. They found tons of offerings in that mound, piles and piles of just beautiful projectile points. The people at Cahokia were kind of famous up and down the Mississippi for making these just gorgeous projectile points with really beautiful detailing, very thin, probably very deadly. And actually archaeologists who are excavating at cities, at mound cities, very, very distant from Cahokia find these projectile points so they know that people went to Cahokia, you know, picked up a souvenir and brought it back home because they were so cool or so significant. And so, yeah, so Mound 72 yielded a lot of stuff. The other mound that was excavated was in St. Louis. It was called the Big Mound. It was about as big as Monks Mound. And in the late 19th century, St. Louis wanted to build a railway, and they wanted some landfill for under the railway so they were like, Well, we don't need that mound because that's just Indian stuff. So they dismantled the entire mound. They destroyed tons and tons of beautiful artifacts. There are accounts from the time of people finding incredible jewelry and human remains and all kinds of figurines and they just tossed it in the garbage and that mound is now landfill under the railway station. So, so that was not cool. And now it's very rare that people excavate mounds because they are very concerned about not disturbing human remains. It's pretty clear that not all the mounds do contain human remains but we don't know which is which and so people like I said are very, very careful about doing it. Laura, I think you had a question. Laura? Emily, yes. I've had a question because I've been thinking a lot about the COVID year and the change in our workforce, moving out of the city, changing and dropping out of the workforce and all of these shifting patterns that are happening, lack of certain workforces in different areas in the city. So I'm wondering if you could talk more about Angkor because there was a mention in your press materials about how Angkor had a unsustainable workforce. Was that too little too much? And just a reflection of what we're going through right now with employment and the workforce in San Francisco. Yeah, that's a really good question and so it's a big answer. So again, I'll try to, I'll try to be brief, but one of the things I found in looking at all four of the cities that I talk about in my book is that a big question that keeps coming up is who were the laborers? Who were what we call now essential workers? Like who were the people doing the building? Who were the people doing the cooking? Who were the people doing the farming? The people who were essential to the city's functioning? And then how were those people treated? And at Angkor, which was a massive city that was going concern right around the exact same time as Cohokea, it's located today in Cambodia, and a thousand years ago was a part of the Khmer Empire, which stretched across big parts of Southeast Asia. And we do have writing from Angkor, so we have a lot more information about how the civilization saw itself. And a lot of that writing deals with labor and how people were put to work, when they were put to work, how they were put to work. But Angkor had a system very similar to our debt system in the States, which is called debt slavery. So instead of owing the bank money for your whole life, instead you would owe the king or the temple labor for your whole life. So you would spend a certain amount of every year providing free labor as tax to the city. And some of that labor was actually, you know, I don't think there's not a lot of evidence that it was horrific labor like some of it involved bookkeeping and art, making statues. Some of it was backbreaking ditch digging stuff and, you know, farming and things like that. So it wasn't all super fun. And it seems at a place like Cohokea, we were just talking about how did people build those mounds. Well, they were building them by lifting baskets of dirt. So that's pretty hard labor. There's a big question around how people were inspired to do that. How do you get a bunch of people to build giant mounds? Backbreaking labor takes like 30 years to build a mound, a mound of the size of the monks mound. So one of the things we see, the pattern we see emerging, if we can talk about a pattern over 9,000 years is that cities tend to get abandoned when the essential workers are mistreated. And mistreatment can be anything from, you know, exactly what you'd expect, things like enslavement and, you know, inability to control where you live and what kind of work you do to other problems, problems with, you know, where people worked, problems with, you know, availability of resources for workers, problems with rights for workers in Pompeii, which I talk about. We have lots and lots of information about the laws that governed enslaved people and freed slaves that, you know, make it clear that they were not treated very well. At various points they were mistreated and at various points they had a little bit more rights. So when we look at San Francisco, when we look at the future of cities, I think it's very important to be thinking about who are the essential workers, who are the people that are maintaining the city, and what kinds of, how are they being treated, what kinds of rights do they have, what kinds of resources do they have, because if they are mistreated over periods of time, they will abandon the city. And abandonment can take a lot of forms, like one form of abandonment can simply be gentrification. If you're priced out of the city, from the point of view of history, it still looks like you're abandoning the city even if you're doing it in reality quite reluctantly. Like if you're booted out because your landlord forces you out, you're still abandoning the city. So gentrification is a big danger sign actually. It's a sign that a city could potentially start forcing abandonment. And so that's why of course gentrification is such an incredibly hot political issue. There's a question from Carol Verberg. Talking about the future, you refer to a we that seems to not really exist right now to the smaller past civilizations show more consciousness of interdependence, which enabled group policy decisions. I don't see a way into EG disposable cities as long as private property trumps any sense of the comments. Yeah Carol you are right to call me on saying we as if there's some magical we that, you know, agrees on everything I mean that's, it's definitely right to say that that's not, that's not a real thing. It's never been a real thing. All of the cities that I looked at were very diverse, they were full of people from all over speaking different languages. And one of the pieces of continuity throughout history is that cities are built by immigrants and there's a lot of different ways that we know this. And a lot of it has to do with new science around chemistry that allows us to see where people were born versus where they died so it can tell you if they traveled a long way to be where they are. I think a lot of them did. So, the question is, yeah, how do we get to a provisional we how do we get to some kind of sense of a community or a public that shares a political will to improve a city or to make a city more livable for everyone in the city not just for the fancy rich people. That's why I kind of emphasized in what I was talking about the problems around politics, and the questions around politics and how politics shape a city, and also how politics can lead to abandonment of a city. And I think it's especially here in San Francisco because it's a city of engineers and technologists and artists. We think of progressing to a better world, meaning like, let's build something will build it will be better will build it better. And sorry, I'm doing the presentation. Sorry. And we think of. You know that it's just a matter of like physically rebuilding things but it's not right it's a matter of reimagining our political relationships to each other and so I'm hoping that as we move into the future of San Francisco and the food, the future of, you know the west. So let's say that we have an opportunity as we're rebuilding our infrastructure to think about how we want to rebuild that we, and what is that we look like, and maybe coming up with better forms of democracy new kinds of democracy, democracy is a structure. We can rebuild it. It sounds scary but might be a good idea might be time. Okay, one more question from Sinbad. Do I recall correctly that at least some of the mounds were thought to be middens like the local shell mounds. Um, they might be in some of the mound cities. In Cahokia, they usually use trash pits. So they didn't tend to pile stuff. There might be some though. I don't know for sure but I do know that they did have some pretty intense trash pits. That's one of the things that people have excavated at Cahokia. And the pocket hat has a great paper he's the one of the main popularizers of archaeology at Cahokia and he's now the Illinois State archaeologist. And he excavated a trash pit that was so rank it still smell like when he finally got to the bottom of it he said that there was a horrible aroma and they actually found they found the remains of barbecue of course because everybody's always having barbecue parties, but they also found a layer of ants, like in the trash pit. So that's, that's like the archaeologists dream job you know let's excavate trash oh here's the ant layer. Here's the poop layer. They definitely did that and they also they put their poop in the in like the rivers and in the water so. So actually, one of the ways that we know the population of Cahokia is by measuring the amounts of poop in the lakes and the rivers. So the more people the more poop. So that's some fun facts for you. So I have one more question. And it's from Elizabeth ground weekend. Fascinating presentation in your own imaginative pathway only which came first archaeology or urban planning. I, I guess urban planning. I mean urban planning has been going on since cities and villages started so I think of archaeology as being pretty modern like I think of it as being a very western idea and it really gets going and like the late 18th and early 19th century, you know, in Europe. It's really not. It's really a pretty peculiar thing that that we do here and not always appreciate it for good reason. Great. Well, I want to thank Anna Lee knew it's for her inspiring views, stretching our minds to the past present and into the future with her new book for law cities and which you can, you can get those book the book at in at any independent or such as Alexander book calm. And also just to remind you that you should be in touch with your local state and national representatives for infrastructure bills, because we need it. We need it for our, and we needed for our redesigning and strengthening our cities and our urban landscapes. So, Emily, thank you for being so inspiring, as always, and look forward to having you back for whatever is Yeah, returning in person hopefully soon. Yes. All right. Thanks everybody. Thanks for coming. Thank you everyone. And good night. Thank you. Thank you everybody and I guess we can all just say bye. And I will close the doors very shortly. It's good to see everyone.