 Right, so in this talk I want to do something which I guess is a little bit bold, but I'd like to explore this issue whether there are circumstances where archaeological and historical data not only give us the opportunity to develop theories and control settings, but potentially where they might be just as good as, or maybe even better than modern data. I think really where the inspiration for talking about this came from was an ask on the Guardian by Chris Gosden. He made the point essentially that although archaeology has been spectacularly successful I think was his phrase in the last 50 years, actually in many ways the sort of public perception of its value as a social science right now is really historically low. And I think part of this is this problem that although we've become very good at capturing the public imagination, precisely through the kind of stories that I think you were talking about, and reconstructing ancient lives, I think we also need to remind ourselves of what most social scientists would regard as some of the unique gifts of the historical and archaeological record. So yeah, I mean this is just five minutes brainstorming and this is by no means comprehensive, but I think the most basic is obviously the enormous variety of settlement forms and ways of life that it gives us access to. But it's also often our only source of long-term serial data for the development of societies as well as our only way of tracking both their rise and fall. So in many ways I think we could think of past societies as complete experiments in how to live or how to go about living. This data is also one of our only ways of understanding and explaining resilience. So my argument here would be that it's simply not enough to look at situations where social groups have overcome obstacles. You also have to look at situations where they haven't. It's kind of quite important. Yes, these data often come from quite a quite simpler context. Now I don't at all mean here that ancient life was any less complicated or sophisticated. More that some of the constraints that social scientists talk about might have been sort of more reduced. So things like the access to energy sources, technology, or even just a number of people who are around to resolve a problem. I think this means that the choices that were sometimes made by social groups were more stark. Think about the eruption of Asubius. You leave or you don't. But also I think we potentially face fewer issues with how we capture, disseminate and use data. Some ethical issues, some restricted access, anonymization, privacy concerns. That's not always, by no means always the case, but Scott and I have certainly talked to economists and complex systems people who have said, well, in terms of GDP data, you don't want to know how the sausage is made. So at the same time, we also think it's worth pointing out that at least my experience has been that most social scientists, economists, anthropologists, complex systems theorists have become increasingly aware of the importance of growth and decline. And they really do have a genuine interest and respect for our data. So this suggests, I think, an enticing idea that we can use text from archaeological data as a sort of repository of experiments in different forms of social and economic organization. And to do this, I think it's vital to make sure that we not only take advantage of any opportunities we have to contribute our expertise and understanding, but also I think we do need to engage with more seriously with general models of human behavior, perhaps especially if we don't agree with them, as well as using comparative evidence-based formal approaches, which is part of why I asked about code, with an emphasis on synthesizing material and making sure that it's openly available. And not to be too clear, but I would say that using historical and archaeological data to investigate issues of contemporary concern is no more weird than testing spacesuits in the desert. So for the rest of the time, I'd like just to give one, I guess, ongoing working example where I think we can reveal something about how assessments operate using ancient data. So this comes out with some of the work that I've been doing with Scott, some of the work of the social reactors project, but I'd like to, in particular, to focus on transport infrastructure and the magnitude of traffic flows, which I think might be used to add to a growing body of theory about how the size of assessments relates to their known attributes. Yeah, so this is only possible because recent research, which is based on a conception of assessments of social networks embedded in the built environment, which allows design models for the relationship between the estimated population of sites and the infrastructure and social economic conditions. So you can just see the kind of relationships we're talking about. Essentially as the size of these increases, social economic measures or infrastructure expand at different rates. But the most important component of these models is that individuals in larger cities not only live at higher densities, but also have more social contacts. So what this allows us to do is to suggest a model for how we would expect mixing spaces to change as they increase in size by thinking about the needs of how much space is required for a community to interact in pursuit of their daily goals and how that space expands as assessment increases. This allows us to make formal expectations about how the infrastructural areas of cities would expand with population, which in the past we've found can help explain quantitative patterns in public spaces for an agarai and street networks in ancient cities, in Roman cities, in the imperial period. So without wanting to go into too much detail, one of the interesting aspects of these results is they suggest that dimensions of street networks generally increase a little slower than the estimated populations of sites. So the total areas of street networks increased with a slope of about two-thirds. So as population increases, the total street area increases with a slope of two-thirds. But more intriguingly, the average lengths expand with a slope of about half, and the average width for the slope of six was very slow. So what about transport infrastructure? What about connections? What about flows in and out of cities? Well, actually, I think this is one of the areas of Roman data, at least, where we know the least. So although there's been a sort of flurry of interest in recent years about ancient cities, we're still largely in the dark about how much traffic flowed in and out of them. This is in part because of the issues with using commodities as proxies of trade. So the most obvious approach has been to use small fines as a reflection of the overall skirt of trade. But it's virtually impossible to collect quantities at the site level. Very few sites have been extensively located and excavated. There are inevitable concerns about the representatives of the material we have. There are challenges in extrapolating from observed assemblages to the total amount that was originally exchanged. There are the issues of what has entered the material record in the first place. So uncertainties about the extent to which vessels were reused or recycled. And then there's the question of the move to perishable containers. So barrels, skins, that sort of thing. And then inconsistencies of recording of different types of materials. So Roman archaeologists love finewears, but they've really given coursewares very short shrift. Obviously, the reason for that is dating. It's important it's dating with us. So it's difficult to compare the ratios to different classes of material. And in particular, it's very difficult to look at the ratios imported to local wares. So today I want to explore another option, which is very simply just to estimate flows into cities directly from the built environment. And I think this is where anciencies use are an ideal candidate and potentially a better candidate than looking at modern cities for the simple fact that they were surrounded by physical walls. So this means that all traffic has to go through gates. And then you can, you know, if you have good data, you can then just measure the width of those gates directly from maps and plans. So I mean, I won't talk too much about the caveats here. I mean, I know that these walls have a defensive purpose. I know that I know that they help to control and regulate traffic. But I think, you know, the argument would be that their architects would strike a balance between defensive and logistical needs. So we'd expect these gates to reflect balance that would allow traffic to flow without sacrificing defensive concerns. But it's also worth pointing out that particularly as Eric Polo has shown recently, there's increasing evidence for a sort of systematic approach to traffic in the ancient world. There's the management of congestion through traffic segregation. There's the preference for right sided driving. And all of this reflects a concern to make cities inhabitable and functional. And then there's also the clear fact that the cities that as time goes on, city gates get larger, which reflects our evidence for the broad demography of the of the Roman world. And the funny we know that gates added or removed their rebuilt says clearly they're in flux. The other advantage, of course, is these gates are extremely common. So the cities that we know existed, 64% of them had walls at some point. You know, it's really useful. So along with cities street networks, they're the most durable features. And they also survive despite recent occupation, actually. In many ways, ancient gates are still part of the fabric of modern cities. So this allows us to at least count the number of gates. So essentially what I've done is to measure the width of the gates when we know that they existed, and then to use either direct evidence or evidence from modern city to count the numbers of gates. And then you can simply multiply the average by the total. That gives you a very good approximation of the holes in the city wall, as it were. So what does this show? Well, I think the results actually do show that there's this pretty surprising and systematic relationship between the estimated population seats and the total gate width. So this is entirely consistent with the kind of theoretical work I showed before. Just to sort of point out a couple of things about this. I mean, in the first place, this is extremely sublinear. So this means that the total numbers and widths of gates increases very, very slowly. So what's going on here is gates are used more intensively as they get bigger. So basically gates receive augmented traffic. But it's also interesting to think about this as an average rate of flow. So this allows us to potentially estimate the total volume by simply multiplying whatever figure we have here by the total population. Essentially we're saying that this is a per capita figure that we're then converting into an aggregate figure. And if that's the case, this would show that the amount of traffic flowing into ancient cities was pretty much identical to the indirect proxies that we have for the modern world. The most important one being cell phone data. So the number of people that came in and out of ancient cities is about the same as the volume of telephone calls that go into cities in Portugal. Just a couple of other things to point out. It's potentially quite interesting to think that both the total numbers and the average width of these gates increase at the same rate. So yeah, sorry for the hideous table here. But the point here is just to recognize that the numbers and the widths, the average widths, increase with a very similar exponent. So it's quite interesting, you know. It's not just that you have more gates in bigger cities, you also have wider gates in bigger cities. So this is something quite interesting about the jump from potentially just having a situation where a person or a cart is going in and out to actually segregated traffic. So yeah, as big as cities get, you know, as cities get bigger, you've actually have to develop a concern for essentially people not getting crushed to death as they go through the gate. But perhaps the most, yeah, I'll come to that in a minute, perhaps the most interesting thing about this is actually that the way in which the the average widths of these gates expands is virtually the same as the way that the average width of the streets within cities expands. So actually, this is saying something which I don't think we've seen before, which is that the the way in which transport infrastructure within a city expands is actually a correlate of the way the embeddedness of that city within its wider transport network expands. So just from doing something very simple like measuring the width of the street and the width of the gate, you can begin to sort of, at least you can start to clutch it, the something which has been eluded us, at least in the edge of the world, which is houses these are embedded in the wider economy, without having to quantify things like small fines or various other things. And then just to give two kind of interesting examples, it's also kind of nice that if you look at the distribution of the widths of these gates, so this is Rome, you can see it follows this sort of power law-like structure, which is very much as we would expect modern cities to function. So again, you've got this similarity between ancient cities and modern cities. It's also true of Pompeii as well. So I don't want to make too much of this evidence, I don't want to overreg the pudding too much, but I'd like to say that it does give us a couple of ways where we can see one or two things which so far we haven't been able to see in modern data, which is very short, sharp, dirty, doesn't require collecting millions of observations, doesn't require doing anything other than taking traditional manuals about Roman archaeology out of the Sackler Library or whatever your local library is and just measuring it from a plan. This data already exists, there are no privacy concerns, the only issue is potentially questions about estimated population, which I'm happy to talk about at some point. And hopefully this gives us a new way of grappling with how cities are connected and integrated. But I'd also like to say this is just one example. I think it's obvious that there are so many other ways that we can use our data to contribute to issues of contemporary concern. We've already heard about climate change, we've already heard about the way in which just the sheer number of us affects our relationship with resources. I was also glad to hear Stephanie being mentioned, the way in which numbers affect food webs. Or even just the way in which group size has effects on changing levels of wealth and inequality and inequality. I think this is something that Scott's going to talk about next or at least touch on. So I'll leave it there. Thank you.