Secrets of sustainable cities

Tech giant Amazon is about to start offering its till free technology to other high street stores. But how can a store be till free, and what implications does this have for how we shop? Tech correspondent and angel investor Peter Cowley spoke to Georgia Mills about how a till-free shop would work...

Peter - Yes, the technology is actually called "Just Walk Out". It's an experiment that Amazon started about two or three years ago and it went into "production" in 2018. So there are now 25 stores around the US, though none outside that. The way it works is you have an app on your phone - you assume you have the app - you scan on entry, you are then tracked around the store. Not your face; not with your phone position, because you might not have a phone on it; it's to do with your clothing, your size and your gait. So you're tracked round, and then you pick items up off the shelf which has a weighing sensor on it, and put it in your bag or hold it your hand, and then walk on, collect everything, and then you just simply walk out of the store.

Georgia - So are there just cameras around the whole store, just monitoring every movement?

Peter - Correct. So there are a number of cameras, which are quite complex I suspect, and they sort of have technology in the cameras itself, rather than just going straight to the cloud, which then hands over the people to the next camera. It probably reads occasionally if you're in the same clothes, the same size, et cetera, and walking the same way. It might get confused.

Georgia - So if a basketball team all go in at the same time...

Peter - Exactly, exactly! Or you could joke about sort of having a, you know, coming out in a wheelchair and going in without the wheelchair or something. So that's the idea, so you can effectively pick up anything you want.

Georgia - Right. And then something tells you what's been taken off the shelves.

Peter - Correct. So what it's doing is building picture of the item, which it will recognise, and once it's done that it then knows that human being it's following has that much with them. But if you take something out of your bag and put it back on the shelf, it'll reweigh that and decide you've put it back.

Georgia - Right. And so I'm guessing if there are stores that work on this, it works and you can't confuse it. Taking things around, putting them back in different places...

Peter - Clearly, although it's not all over the internet, an awful lot of that's been tried. Both internally for the two years when they had the employees all trying that sort of thing, I suspect changing their clothes, taking their jumpers off, and everything else, in order to confuse it. Because what they're trying to do, of course: you don't want too much theft, so this is where you take it off the shelf and it doesn't see that you've hidden it somewhere. And conversely, which is almost more important, you don't want people falsely accused of shoplifting. And it's quite important that the app apparently will tell you what you've bought; so before you've left the store door you can check that if you wish, if you don't trust it. And then you can argue much more easily when you're inside the store than when you've got home.

Georgia - Right. And how does the actual paying bit happen? Does the money, just when you leave the store, does the money just fly out of your account?

Peter - Exactly in the same... yes, exactly as if it comes out... you've got a credit card attached your Amazon account and if you're using the cash version, you will have a cashier there, which will... they've determined that that person with that shape, et cetera, has bought that amount and then you'll pay for that.

Georgia - So does this make shoplifting harder?

Peter - One suspects so. In fact the amount of shoplifting the States, or worldwide, is quite a lot. It's about $50 billion lost worldwide, which is about 1.3%. If you can reduce that, that's good. So I suspect it will reduce shoplifting by the consumer. Of course, an awful lot of shops' 'shrinkage', as it's called, actually happens by staff.

Georgia - Right. So is that the main impetus for doing this? Because I'm guessing it's not cheap or easy to turn your shop into a till free.

Peter - Yeah. They're talking about about a million dollars, because you've got the cameras and you've got all the shelves, and you need weighing, and so on. And there's two drivers. One is for us as consumers because we can just go in and pick up a sandwich, a bottle of milk or whatever, and walk straight out, so we don't have to queue up or scan stuff, et cetera. And the secondary of course is for the stores because that way they can reduce the staffing, the checkout staffing. You've still got other staff because you'll have people hanging around helping people. And it's less space of course as well. You know, the checkouts all take space up, don't they?

Georgia - I mean I'm just thinking, the number of times I'm going to buy like a giant pack of chocolate and I get to the tail and I'm like, "no, this is foolish purchase." It sounds like it's going to make impulse purchasing a lot easier.

Peter - Yes! In fact there is some figure that says actually the shops sell more because of this. And I don't think it's because of maybe people, I don't know, not being told by the shop assistant "are you sure you want that?" I would hope they don't. It's because it's more convenient. Nip in and walk out again.

Georgia - Are there any other downsides or benefits we haven't discussed?

Peter - I don't think so. I mean it's to do with cost saving, it's to do with convenience. The downside of course is the loss of jobs potentially. The other thing, the big thing of course, is data. As always with these tech giants we're giving away more and more data, and that suspect. What Amazon has done in the last week while we are talking about it is they've released it to other shop chains. Obviously they'll charge for that, it won't be free, but Amazon will be collecting that data so Amazon will know even more about what our preferences are.

Georgia - Right. So even if you're choosing not to shop with Amazon, if you go into a shop with this technology, they'll be still getting your data.

Peter - I assume so depending on the contract between the shop and Amazon, but I suspect that will be the case.

Georgia - How common do you think this will be? Just briefly.

Peter - I think in time for smaller stores it will be extremely common, but I don't think you'll be doing your weekly shop there. But then with the coronavirus around at the moment a lot of the weekend shopping is going online anyway, isn't it?

Adam Murphy’s been looking back home with this tribute to Irish science…

It’s March which means St Patrick’s Day is now upon us.

And although the parades have been cancelled, there’s no reason not to celebrate, and here on the Naked Scientists, that means looking at the best of Irish science.

Robert Boyle was a 17th Century chemist, born in Waterford, and was a pioneering chemist. Boyle’s law, which relates how the pressure of a gas changes with its volume, is still taught to schoolkids today.

In a world where climate change is becoming more and more of an issue, its worth remembering John Tyndall, who did incredible work on the greenhouse effect and showed how much heat the different gases in our atmosphere can trap.

Kathleen Lonsdale, from Kildare, did groundbreaking work in using X-Rays to learn about the shape and structure of different molecules, like benzene.

Given that you need electricity to listen to what I’m saying, You should give a nod to George Stoney, who did work on electricity, and even gave us the word for the fundamental single unit of electricity, the electron.

Heading into space, Jocelyn Bell Burnell was the first person to spot evidence for pulsars, a special kind of spinning star made only of particles called neutrons. That discovery won the Nobel Prize...although not for Burnell.

And the next time you’re walking headfirst into a strong wind, remember to thank Francis Beaufort from Meath, who came up with a scale that measures wind speed, from light air, to a hurricane.

Ireland has plenty of Nobel prizes in subjects like literature, and peace. But there are also two prizes in the sciences. Ernest Walton won the Nobel Prize in 1951 along with John Cockroft, for being the first people to split the atom.

And in 2015, Irish born scientist William Campbell won the Prize in Physiology and Medicine for his role in discovering drugs for fighting infections caused by roundworms.

So if celebrating Irish culture is a part of your March plans, raise a glass to the scientists of Ireland.

While we could reuse waste heat underground to grow crops or power our houses, we could use less heating in the first place by using something called natural ventilation.  Shaun Fitzgerald, visiting professor of sustainable buildings at the University Cambridge spoke to Georgia Mills about how we could learn from past building design to reduce our dependence on heating and cooling systems...

Shaun - Well I do have a demo and it's a demo that we can do at home in the kitchen and I've got two glasses of orange juice here and some Grenadine. So I'm going to suggest that we think about actually different ventilation strategies using my orange juice, and one is going to be for summer and one is going to be for winter. And the summer one is going to be our tequila sunrise mocktail where we have the Grenadine and we're going to pour it into the glass with the orange juice. But if you pour it in nice and slowly, just down the side of the glass, what you will find is that at the bottom of the glass we have our lovely syrup and this is showing what we call a stratified environment where the Grenadine represents your cool fresh air at the bottom, which is the occupied zone. And the orange juice is the warm air. So this is a great summer drink for a summer ventilation strategy.

Georgia - Right, so the air is sitting on top of each other. They're not mixing.

Shaun - Exactly. So we've got the warm air at the top that we don't like, but we've got the nice cool air that we brought in and that's surrounding us. Whereas in the winter, we don't want actually that classic tequila sunrise. What we want to do is to put it in really quickly and it's all mixed up.

Georgia - Oh yeah, that's terrible. If you served me that in a bar, I'd be furious.

Shaun - So it's a terrible tequila sunrise, but it is a fantastic drink for winter. And that's really the purpose of how we use different ventilation strategies, different natural ventilation strategies. And it's critical that you do different strategies between the seasons in order to derive the benefits of not using fan power, which is the fundamental reason why we like natural ventilation to reduce the energy load.

Georgia - Right, so at the moment in summer when it's warm, we're blasting the air con and that's using loads of energy. In winter, we're super cold, we've got the heating on. You're arguing that there's a better way of doing this. And that's by thinking carefully about how we mix the air, basically. How we shake our cocktails?

Shaun - We are. And indeed, the previous way of doing natural ventilation was to always just bring the cold air in at low level and have a stratified environment. So that in the winter, actually people don't have to use heaters to preheat the incoming cold air. Whereas if you have my bad tequila mocktail here, then I can use all the heat gains that Ruchi alluded to from within the building itself, to actually provide the heating for the cold air. So this is a much lower ventilation energy strategy by using mixing in the winter.

Georgia - Right. And so in the sort of metaphor of these drinks, are we at the bottom of the drink? So where the cold air sits in the summer, that's where we'd be?

Shaun - Exactly. We sit on the bottom. Gravity means that we're going to sit on the floor.

Georgia - Good. Excellent. As it should be. So how do we do this in real life, outside of the drink?

Shaun - So how do we do this in real life? We ensure that in the winter we bring the cold air in at high level, so that when it comes in, it mixes with enough of the warm room air naturally rather like an inverted volcano really. When you have a volcano erupting, what happens is the hot gases pull in, all of the cold air and you then have mixed air in the middle of the volcanic plume five kilometers up. And that's exactly what we want to do in reverse, in the winter. We want to bring cold air in at a high level, make sure it mixes with enough warm room air and you no longer have a cold draft, but you've used the heat from people, IT, lights, to provide the heating source for that cold air. And in the summer you want to do something different. You want to bring the warm air - so it's not as cold in the summer of course, but it's cooler. It's sufficiently cool to be nice - we want to bring that in at low level directly onto the occupants. So you open the windows at low level, to provide inlet ventilation in the summer and close them in the winter and bring the air in from high level. That's it. And that's what they were doing a long time ago with sash windows in Victorian houses in the UK. But they clearly didn't understand actually getting the apertures correctly and all the strategies being automatically controlled.

Georgia - How much energy savings could there be?

Shaun - Well, naturally ventilated buildings can consume a factor of two less than mechanically ventilated buildings overall. Not all of it's to do with just the reduction in fans and pumps, but the way that they're built, they need to be shallower planned so that they have lower lighting loads as well. So factor two reduction. But by applying the right natural ventilation strategy, you can reduce the energy even further. So with this new strategy of changing how you bring the air in between summer and winter, we can save heating bills by a factor of three from one strategy to the other. So it's enormous.

Georgia - So has this been brought in then? This sounds like a great idea.

Shaun - So we discovered this in about 2005 and it has now not only been adopted by buildings with products now in them, but it was adopted by school regulations in 2018. So any new or refurbished school that's going to be ventilated, needs to be thought of as wherever you can, you'd naturally ventilate. And if you're going to naturally ventilate, you need to use my mocktail example here, making sure you change the strategy between winter and summer, so that you mix the incoming cold air with warm room air in the winter to save your heating bills.

Georgia - Excellent. And so this has been actually brought in and implemented for all new schools. That's brilliant. Is it going to be used elsewhere or in other countries? How much could this be applied basically?

Shaun - So other countries with similar climates to the UK are definitely looking at this. We're in touch with those. But it does not apply to all countries. And the reason being is that if you are in a hot, humid summer environment, so if I was in Florida, I can't dehumidify the air naturally and therefore you have to mechanically ventilate in those climates. But a lot of people live in temperate zones. We've gravitated to quite nice places in the world. The North Western seaboard of the US, all of the coastal areas of Europe, they could all use this natural ventilation strategy. And that's what many people are now thinking about doing. So.

From the old to the new, what if instead of building new parts to a city, you could go into a computer and tweak bits of the city, and see what happens before laying a brick, a little like SimCity, it's called a digital twin and Mark Girolami, professor of civil engineering at Cambridge, joined Adam Murphy to chat about this new technology...

Mark - First of all, you need to take two perspectives here. The first is, what is digital and what is the twin? Now, engineering and science, for centuries, have always thought of the idea of a twin, an abstracted notion of some reality that you would want to understand and ultimately control. If you think of things such as the tide predicting machines from William Thompson going way back to the 1840s, that was a twin of the tidal systems that allowed individuals to predict when tides would be in or out, and they could then decide on when to set sail. So that's the whole notion of the twin, the digital component of course is that moving from some sort of physical and mechanical twin of a system that we want to study, to a digital, a computer based representation. And having those two things together, coupling the digital representation with the physical via data, provides us with this whole notion of a digital twin, which is much more different than a classical mathematical model where we would run simulations a bit like SimCity, but we'll never actually be going out and building our city from scratch and seeing if reality actually mirrors what the simulation suggested it would be.

Adam - And then whereabouts do we see this being used? What kind of applications does it have?

Mark - Digital twins are being used right across all of the sciences, right across all of the engineering disciplines. And of course what we're talking about today is urban infrastructure, city planning, regional planning. And we are seeing digital twins from rooms in our building. So what are the environmental conditions like? We heard about the underground farms, there are digital twins of those. How do you remove the heat, how do you control the heat, and how can you use those digital twins to predict the type of yield that the farm would produce? Right up to whole buildings where we have digital replicates of the geometry of the construction of the building, and then of course of the physics as well. And that then extends to whole urban central areas, it extends to cities, to transportation systems, to distribution of energy to the measurement and hopefully the improvement of air conditions.

Adam - How do you go about getting the data that you actually then put into these digital twins?

Mark - So data comes from a number of sources, and the obvious one is sensors. And what we are seeing certainly within city environments and urban environments is an almost "Renaissance" of being able to obtain data at unprecedented scales, that we've never had before. So whole pieces of infrastructure are getting sensors, networks of sensors, placed upon them and generating that data. And furthermore, citizens are also being able to contribute data. If you think of the iPhone I've got, if you look at that little sticker at the back, that measures nitrous oxide levels, and it communicates to the iPhone. And this measures the amount of nitrous oxide that I am experiencing in the location that I am in, at that particular time. And that then gets shared to help people that are, for example, in this case here, trying to improve upon the way in which air quality is measured and ultimately the actual improvement of the quality of air itself.

Adam - So taking that example where you have people with these sensors on the backs of their phone, what can you actually do in the digital twin to improve the city?

Mark - So as soon as you start getting measurements, you can take those measurements, you can take that data, and you can incorporate it into your digital representation. That can then be used to refine the predictions that come from the model. It can be used to validate the predictions that come from the model, and then ultimately guide policy makers and decision makers as to whether the predictions that are being made, and the levels of uncertainty associated with those, are something that should be acted upon. Because let's remember the aphorism that all models are wrong, but some are useful. And the key is that, you know, we need to understand that our digital twins are based on models that are wrong, but hopefully they are useful.

Adam - How far away for recently, like putting on a virtual reality headset and being able to walk around the digital twin of the city?

Mark - Well, we're actually there. You can put virtual reality headsets on and walk around whole buildings, you can take pieces apart and so on. It's the exact same. I just saw some work coming out of Berlin, where you're sitting as the driver in a train and actually going right through the city and experiencing the whole environment, the whole urban environment, and traveling through it. So that sort of technology is there. It emerged from the sixties, seventies, and eighties, in the technology that was used in developing flight simulators. And now, that's being used in being able to plan, design and develop and test cities.

Adam - And then if that's what we're doing now, what is the future of a digital twin?

Mark - Well, the fantastic thing that you would want from a digital twin is to have something that is going to be predictive. Something that is going to allow us to take into account those events that are going to have really high consequences. For example, the period of time that we're living through at the moment. Having digital twins that would enable us to forecast, and to look at multiple types of different scenarios, and act upon them. Now, that's at the global level, at the public level, but even at the individual level. If I go back to my little sticker on the back of my iPhone, a federated digital twin could then send a message to my phone to say, you should probably stop walking down Euston road because the pollution levels are too high. It's going to aggravate your asthma. I suggest you turn right here and go in to Costa coffee or whatever for five minutes.