Fighting Floods: Who Gets Hit?
Extreme weather events are becoming more common, and sea levels are set to rise. So could we be about to find ourselves in very deep water? This week we're exploring how to spot where and when floods will occur, and how to avert disaster. Plus, in the news, a GM mosquito to fight malaria, what really killed the dinosaurs, and general relativity 100 years on...
In this episode
00:49 - GM mosquitoes fight malaria
GM mosquitoes fight malaria
with Professor Anthony James, University of California, Irvine
Malaria infects more than 300 million people each year, leading to hundreds of thousands of deaths, three quarters of them children. A mosquito, genetically engineered to prevent the spread of the disease, has been unveiled by scientists in the US this week. The new mosquito carries genes that enable it to block the growth of the malaria parasite, so that it cannot pass on the disease. This new approach, which is referred to as a gene drive, means that when the mosquitoes mate, they automatically always pass on the anti-malarial genes. Anthony James, at the University of California Irvine spoke to Chris Smith about how this works...
Anthony - What we're doing here is putting genes into mosquitoes that make it so the parasite will not survive in the mosquito. And if we do that then the parasite can't complete those aspects of its life cycle that it needs the mosquito for, and can't be transmitted to humans.
Chris - How do you encourage the gene to find its way into the wild population? Does it give them an advantage so that they're more likely to pick up the gene because, otherwise, wouldn't it just fizzle out?
Anthony - This is the beauty of the gene drive system is that it favours its own inheritance. So the way to think about it is, if you have an insect that has your gene it and it mates with a wild mosquito, all the progeny of that wild mosquito will have our gene drive in it, so it doesn't really need a major fitness advantage to propagate itself.
Chris - And biochemically, what does this modified mosquito do differently that means that malaria just can't grow in it?
Anthony - It has a number of genes in it that have components that interact with the malaria parasite and prevent the malaria parasite from completing its development in the mosquito. The technology was based on the observations that there are many different malaria parasites, so there are malarias that infect mice, there are malarias that infect humans. So humans don't get mouse malaria and mice don't get human malaria. So many years ago a number of our colleagues took the human parasites, put them into mice and then identified components of the mouse immune system that would essentially fight off the human parasites. We took those components and built little miniature genes out of them and then put them into the mosquitos, so basically what we have is a mosquito that has a small part of the mouse immune system that allows it fight off the human parasite.
Chris - Malaria has, notably, become resistant to a large number of drugs and there are only a few left that really work reliably now. So, is there not a danger that quite quickly the parasite would become resistant to this intervention in your mosquito and it would find a way around this blockade and carry on business as usual?
Anthony - Yes. So this is a good question and so we see this actually in many drug treatments, not just to parasites, but bacteria and fungal infections for example. And so the strategy is to, when treating these infectious agents is to not give one, but two different drugs, and the idea is that while the parasite may successfully work its way around one of those, trying to do both at the same time is very difficult, and the probability of that happening is very low. And that's exactly what we've done in our mosquitos, we've actually put in two genes, that target different stages of the parasite, and so the parasites may figure out how to get around one of them but, in that same parasite, to figure out how to get around one and the chances of it, at the same time, figuring how to get around the second one make it so that it's extremely unlikely that we'll see resistance.
Chris - What about safety. Could this in any way endow the mosquito with any other abilities to cause disease, or spread these sorts of genes into other things that shouldn't have them?
Anthony - That's a good question as well, and so we look at the large number of blood-born pathogens that are out there and we look at the fact that there are mosquitoes feeding on people that have these blood-born pathogens, and we see a high degree of whole specificity; meaning things like HIV, things like hepatitis do not actually grow on mosquitos. - if they could, they already would. The changes that we're making are very targeted and very directed and don't influence at all portions of the cellular machinery that would make the mosquitos good hosts for that.
Chris - Is the going to work? What evidence have you got that this is a real prospect?
Anthony - The evidence is the fact that we have genes that will make the mosquitoes resistant to malaria parasites, and we have a technology now that allows us, at least in the cages, to spread them through large numbers of mosquitos. And so, just in a laboratory, we can design it so that it has the properties that we hope it will manifest, but we've got to test it at every level. So, I can't guarantee exactly what we made in the laboratory today would be something that would be used in the field, in fact, I doubt very much that it would, but we have the blueprint for making something that could work that way.
Chris - And the possible timescale?
Anthony - For the science, it will go fairly quickly. The confounding factor is a positive one in a sense. We need a regulatory environment , a community engagement environment, and a social environment that will accept the use of these technologies, and it's very difficult to tell how quickly these things will mature to the point where there will be acceptance for using this. So, while we may make a lot of progress in the science and the laboratory, whether this ever goes to the field will be dependent on the social side of it, and the regulatory side of it, and at this point it's very difficult to tell you how quickly that will move along.
06:41 - Computers that know your mood
Computers that know your mood
with Peter Cowley, Tech Investor
Machines are getting increasingly able to tell our faces apart, which has big implications in security. But can this technology be a double edged sword? What's more, modern computers are getting much better at recognising emotions. Peter Cowley explained to Kat Arney how this technology works, and where we might see it being used in the future...
Peter - Well it's quite technical, but if I run through very briefly. There are really four methods that do that. One is geometric i.e. the position, size of the eyes, nose, check bones, etc. The next version is to add 3D to that, so that's the depth of the eye sockets, the nose and the chin. There's a photometric way of doing it which is effectively taking a statistical comparison between your face and one stored on the database and finally, we add to that skin texture analysis - lines, patterns, spots, colour, etc.
Kat - How could this work in things like passports... those kind of security systems. Because my face doesn't look a lot like my passport photo a lot of the time?
Peter - The big issues are really in detecting whether you are looking directly on or not, or turning your head. The lighting, hair, whether you've got your glasses on or not which is why, of course, you have to take your glasses off at the passport thing at the airports. And also if you're still alive or not, of course. You could have just had somebody print out a photograph of you. But yes, the ones that are being used, to answer your question are, as you say passports. In fact, Australia and New Zealand are already using that. Things like criminals in crowds. I'm sure the security forces use that a tremendous amount. Silly little things like greeting hotel guests, so as you walk in it says "hello Mr Smith" etc. ATMs - to replace pins. That might be better than a pin might it etc. etc. And we already use them, in fact because of these smile detectors in our cameras on our phones that you say "smile" and then it detects the smile has occurred and will then take the photograph.
Kat - I find that kind of stuff really fascinating - that can see faces and all these sort of things. And you said the smile detector. So we're starting to see stories now coming out about facial recognition software that can detect emotions. Tell me a bit about this. What is this kind of technology?
Peter - Again a bit of tech to start with. First of all we have apparently 33 muscles in our face of which 9 are around the eyes, 4 is on the nose and 12 around the mouth. They've produced something that is standard throughout the world, a facial action coding system which splits into action units, some of which are really unusual like nostril dilator, and lip corner depressor. So based on those 30 action units, and the movement between that, then systems are in place to detect one of 7 base emotions which are joy, sadness, surprise, anger, fear disgust and contempt. So, if you are looking at somebody and in the conversation you will have, you know, a pretty constant emotion. But there are also what's called 'micro-expressions' which just last about 50 milliseconds. And I actually tested this on somebody the other day - I mentioned somebody's name - you see this sort of look of slight unease and then a smile appeared after that.
Kat - How well does this kind of stuff work. Because maybe some people hide their emotions. Is this technology actually good?
Peter - Well. Apparently there are something like 1 in 400 of us who are actually pretty good lie detectors. Who can actually recognise the lie because of this micro-expression occurring. This is being used primarily for research at the moment and it's moving into other applications like training autistic children - about emotions, because they struggle with recognising what the emotion is of the person they're facing. Robert carers - these are starting to happen in Japan.
Kat - On a more trivial thing. Could it perhaps say, if you're chatting with someone on social media or something you could go "hey, they look like they fancy you a bit" or a smart mirror that says "oh you look at bit sad today" and tells you "you're looking fabulous.
Peter - Some listeners might have heard of 'Tinder' which is an app that's used by younger people than me for finding mates you could be doing by just looking at the photograph and swiping either way.
Kat - It's quite a terrifying thought. Could this have security implications? What's going on here?
Peter - The two big issues around at the moment are the usual, the sort of false positive and false negative. If you start making decisions based on something that's statistically correct or not, and you get it wrong, then you are potentially going to make the wrong decision. Lie detector, for instance, accusing somebody of lying and their not.
Kat - And potentially things like banking and security. Stuff like that..
Peter - Exactly, yes. And the big one that's floating around which is in all technology spheres is privacy. And, in fact, I have noticed that people put post-it notes over the camera when they're not using Skype so it can't be looked at, you can't be hacked into.
11:29 - Volcanoes didn't do-in the dinosaurs
Volcanoes didn't do-in the dinosaurs
with Dr Anja Schmidt, Leeds University
Over the past 40 years, the exact cause of the death of the dinosaurs has been hotly debated. Some favour the theory that a massive meteor hit the Earth and changed the climate, while others argue that a sequence of huge volcanic eruptions also contributed to the mass extinction. Research this week from Leeds University has poured cold water on the latter theory, suggesting that the impacts of these volcanoes would have been relatively small. Georgia Mills spoke to lead researcher Anja Schmidt to find out how they investigated a mystery 60 million years old...
Anja - I'm running climate models and, what I did is, I gathered all the information we have about this volcanism that happened 65-66 million years ago. So we needed to know, how long were these eruptions, how much volcanic gases were emitted and then once we had all this information, we put that in a very sophisticated computer model, and then we could simulate what these omissions would do to the environment, but also to climate.
Georgia - And what did you find out when you ran these simulations?
Anja - Some researchers, previously, actually suggested that, because of these volcanic eruptions, temperatures on earth would drop really drastically and they call this a so called "volcanic winter". Just imagine, really, really cold surface temperatures. But what we find actually when running this climate model with all the information we gathered, we find that temperatures didn't drop that drastically. So the situation wasn't as grim as previously suggested by some scientists. So with our work, we actually find that because there is a drop in temperature, but it would probably be okay for most animals and plants, so they would have been able to cope with these temperature changes.
Georgia - Why would a volcano erupting cause a drop in temperature in the first place?
Anja - So, volcanos emit a lot of gases, and one of the most prominent gases is sulphur dioxide and, once sulphur dioxide is in the atmosphere, it actually gets chemically converted to form very, very small particles - you can't see them with your bare eye. But these particles, they basically reduce the amount of energy that comes down to the surface from the Sun. So less energy reaches the surface and, therefore, you end up with the cooling of the Earth's surface. We're really sure that depending on how long this eruption lasted. So if they lasted, for example, a decade we find that the surface temperatures returned back to normal very quickly, within a couple of decades. So, as quickly as 50 years, for example, and that's just a normal process. Basically there's a big kick to the Earth's system because of these volcanic emissions and these particles in the atmosphere, so they reduce the energy but, all of these particles eventually fall out of the atmosphere, and the Earth's temperatures can basically return back to normal.
Georgia - Is it just the cooling temperatures that volcanos could have impacted?
Anja - No. Actually some scientists actually thought about the fact that, following a volcanic eruption, the atmosphere gets very, very acidic and you get what we call "acid rain." Acidic rain can actually damage vegetation, so we also assess this in our model, and what we actually find is rather surprising. We find that in some parts of the world, vegetation would indeed have died off because of the acid rain but, this effect, we don't see it on a global scale. So we can't explain a global scale mass extinction with acid rain due to volcanism.
Georgia - In your paper you mentioned that this simulation would be accurate provided that climate feedback systems, so the way the climate worked in the past, was the same as it is today. Do we have any reason to suspect that it was the same?
Anja - We don't know for sure because we are really talking about many million years ago. So we had to make this assumption, that was the best assumption we could make at the time, but it could well be that the climate feedbacks would actually be very different in ancient times, but we still don't know. So that's another area of research, to understand climate feedbacks. So how does the climate react to a volcanic forcing, as we call it, so if the system is kicked by a big volcanic eruption - how does it react?
Georgia - Why should we care what killed the dinosaurs that happened 60 million years ago? It's probably not going to happen again. Why research this?
Anja - So, I think one thing is dinosaurs are really, really fascinating. Young and old are fascinated by creatures that are not around anymore. They were really, really powerful; they also looked a bit weird didn't they with their head gear, some had really nice colours and even feathers, and I think it's fascinating and they were so powerful and we still don't understand what actually killed them. So that's one reason to study that, and in terms of volcanic eruptions, I think it's very important to understand what volcanic eruptions can do to climate and the environment because, for sure, there may be another eruption in our lifetime. Completely different than the eruption I was talking about in my study, but you may also know that now people are talking about ways to mitigate global warming, and one of these is called geoengineering. So people propose to put in tiny particles into the atmosphere; very similar to what we have after a volcanic eruption. So my work can also help to understand the consequences of doing this kind of geoengineering.
16:48 - Do fish really have a 3 second memory?
Do fish really have a 3 second memory?
with Kat Arney
You may have been told you have the memory of a goldfish during forgetful spells, but is this really such an insult? Kat Arney takes on another Mythconception...
Kat - It's not clear where this myth originated, but it's often been used for comic effect, particularly by people whose memories aren't the best... What was I saying? There's even been a movie named after the supposed phenomenon - a romantic comedy rather than a fishy feature film.
In fact, most fish - including goldfish - are more than capable of performing pretty good feats of learning and memory, and anyone who has kept pet fish will know that they're not usually swimming about in a permanent state of freaked-out amnesia. And it's not hard to disprove either - the claim has been debunked by many people; from university researchers and TV mythbusters to curious schoolkids.
For example, there's evidence that fish can distinguish colours, shapes, tastes and sounds. They may even recognise their owners, and certainly learn to become habituated to them, as well as other fish in their tank. And these memories last for months, not minutes.
According to a study by animal psychologists at Plymouth University, goldfish can even tell the time. The researchers trained the fish to nudge a lever to get food, but they fixed it so it only dispensed the goodies for one hour per day. The clever fish adapted quickly, learning to cluster around the lever as lunchtime approached.
Scientists are now trying to unpick the molecular nuts and bolts that underpin a goldfish's mind, by training them to respond to different coloured light cues associated with food. And it's likely that the fundamental processes at the heart of a goldfish's mind are similar to those in ours, despite a few million years of evolutionary separation.
Furthermore, scientists have studied other fishy minds. At the Society for Experimental Biology annual meeting in 2014, a Canadian researcher presented data showing that African cichlids - small fish that are popular in domestic aquariums - can be trained to go to different parts of their tank to receive food. After three days of training, the fish were put into a different aquarium for 12 days. After that, they were popped back into the training arena, and showed a strong preference for seeking out the areas where they'd previously found yummy food.
Of course, it makes little sense for animals like these fish to have virtually no capacity for making memories at all. In the wild they need to be able to remember the locations of safe places to eat free from the threat of predators, so while they're unlikely to win Mastermind any time soon, it's not surprising that they have a reasonable amount of brainpower. And, of course, any fish that can't remember the location of dinner aren't likely to do very well in evolutionary terms.
There's more. Scientists in Israel managed to train sea-dwelling fish to respond to particular sounds played over an underwater loudspeaker, coming towards the source of the sound and return for food. Importantly, they could remember their audio cue months later, flocking back for a feed when the sound was played again months later after living in the wild. There's more to this than a biological curiosity though. Many species of marine fish are farmed in large underwater pens, and this can have knock-on effects on their health and wellbeing. Perhaps a sonic signal, sent out to free-living fish that have previously been trained in captivity could be a good way of enticing them back to be caught,
Finally, perhaps my favourite fishy fact that I've discovered is this: goldfish can tell the difference between different types of music, according to a study from Japanese scientists. In their tests, fish were able to discriminate between the famous Toccata and Fugue in D minor by Johann Sebastian Bach - a piece of neatly precise organ music - and Igor Stravinsky's effusive and orchestral Rite of Spring. Although the main finding was that they're not really fans of loud music at all, which isn't that surprising.
So next time someone makes a joke about goldfish having a tiny memory-span, you can remember that this is one myth that needs to be forgotten.
20:58 - General relativity, 100 years on...
General relativity, 100 years on...
with Professor Gerry Gilmore, University of Cambridge & Sam Genders, Diagrams
One hundred years ago, on the 25th of November, Albert Einstein presented his theory of general relativity to the world. This theory fundamentally changed aspects of physics that hadn't altered since Isaac Newton first came up with them, hundreds of years earlier. Over night, Einstein became a celebrity - in fact the first scientific celebrity. Connie Orbach has been hearing how, beginning with a whistlestop tour, thanks to the UK's Science and Technology Facilities Council and David Tenant, of what general relativity is all about...
David - At 26, he figured out nothing less than a new theory of space and time. It led to a nifty way of simplifying physics by treating space and time as one thing - spacetime. But Albert was just warming up. He wasn't happy with Isaac Newton's mysterious force of gravity. Naturally he started work on his own theory and sure enough, he cracked it.
Mass causes space time to curve. The natural motion of thing is to follow the simplest path through space time but, since objects with mass curve space time, stuff moves towards the most massive object - that's what you feel as gravity. It's warped space and time that's keeping your feet on the ground.
Connie - So that general relativity - a theory to end all theories. But how did Einstein himself become so famous. I caught up with Professor Gerry Gilmore at Cambridge University's Institute of Astronomy to find out...
Gerry - We're going down to this end of the building which is where the Director used to live and going into the room that used to be the Director's sitting room where the great people would have worked, and there's a whole string of famous people lived in this half of the building. The one that's particularly relevant for this current centenary is Sir Arthur Eddington, who in 1919, showed that light is bent by the sun in just exactly the way that Einstein's general relativity, which is 100 years old today, predicted. That was the event - the public announcement of that - which was in November, 1919 was what made Einstein famous. That's when Einstein appeared on the front page of the New York Times and London Times and became a celebrity. That was the beginning of scientific celebrity and it changed our view of scientists completely.
Connie - Early A-lister...
Gerry - Absolutely.
Connie - An A-lister indeed. And if you ask many people today, Einstein will still be on their dream dinner party list. Let's go back 100 years to find out how it all came about...
Gerry - Okay, so this was, of course, right in the middle of the darkest days of the First World War but, in spite of that, mathematical physics in Germany was advancing at a spectacularly fast rate, so there were several people racing towards what became general relativity - Einstein got there first - but none of this was known in the West. The only connection between German science and the outside world was via The Netherlands - a neutral country at the time - they were communicating both with Einstein and with Eddington and so the people in Leiden realised the importance of what Einstein was doing and sent the work to England to be published by Eddington. Eddington also independently realised the enormous value of this and further developed the work himself, and took it upon himself to market and explain relativity to Western scientists. And so he wrote books and articles which were hugely popular, hugely influential. Whereas Einstein's own work marketing the theory didn't actually appear in English until the 1920s, so Eddington had already done it.
Connie - Since then, we're now a 100 years on from that this theory still stands.
Gerry - That's right, yes. It turns out that general relativity has been tested to astonishing precision and every single test we've done of it over the last 100 years, it turns out to be dead right. It's truly remarkable. So the whole subject of black holes and space, all these wonderful things we take for granted, X-ray astronomy, massive exotic events, quasars; these are all extreme version of general realistic phenomena, none of which happened under Newton. And every single day we astronomers are studying things that just exactly follow general relativity. So we know it's accurate because the description of the solar system around us to much better than one part in a million.
Connie - Einstein's theory has inspired scores of scientists with his work but, beyond that, he has also become a figure of popular culture in literature, art and, on this centenary, also in music and Sam Genders has written a song to commemorate the anniversary with his band, Diagrams. I got in touch with Sam to see what inspired him...
Sam - He was obviously a really interesting person and came up with these incredible ideas and, for me, there's something so inspiring about the fact that so much, so much of the work he did just came from pure maths and thought experiments. And so much science is done through technology these days that I find that really exciting.
Connie - The bending of space and time is something which can quite easily be kind of turned into music in a way. It's got quite a romantic element to it...
Sam - Yes, it's sort of metaphorically ripe for kind of slightly ambiguous lyrics that could be about science, or could be about relationships. Einstein himself was a, as far as relationships went, especially romantic ones, was a fairly complicated human being and so, within the song, there are sort of these threads of relationship and playing on the words a little bit of general relativity about how we do all see things from certain different perspectives. So yes, it inspired me anyway.
Connie - Sam joins the pile of people inspired by Einstein - science's first A-lister, but he couldn't have got there alone. Work on relativity made him a great scientist, but Sir Arthur Eddington made him famous..,
Gerry - Yes, Eddington deliberately made Einstein a superstar. It was part of a conscious programme, for a small number of people lead by Eddington, to try and rebuild scientific connections between Germany and the rest of the world after the war. But Einstein was all over the front page of the New York Times and the front page of the London times - a world shaken by a new theory; Newton wrong; the stars are not where they ought to be - all this sort of stuff, and so this started the cult of celebrity science.
28:36 - How do we predict the weather?
How do we predict the weather?
with Dr Rob Thompson, University of Reading
One impact of climate change is that scientists predict more severe extreme weather events such as flooding. Floods are most commonly caused by rainfall, but how do we know when it is going to rain, and by how much? Rob Thompson is a meteorologist at the University of Reading, and he explained to Chris Smith how we predict the weather...
Rob - So these days, computer models have really been run to work out the physics of what's going on in the atmosphere. In essence, fluid dynamics of what's happening with the water moving around in the air systems and that how weather forecasting is done for any kind of weather really; rain, flooding, or droughts, etc.
Chris - What are the giveaways when you look at the pictures and the models that you're gathering that tells you there's a lot of energy in the atmosphere in one place that might lead to a storm, and there's also a lot of water which would potentially turn into a flood?
Rob - You kind of get two different types of flood really. So when we're thinking flooding, you get flooding caused by very intense rain, sort of thunderstorm type events where very heavy rain falls for usually a fairly short period. But we also get, of course a lot of river flooding where it rains necessarily desperately hard, but for hours and hours, or even days on end and that, obviously, can cause rivers to burst their banks and so on. And they're quite different mechanisms; the weather that generates them is really quite different and different forecasting challenges.
Chris - How far ahead can you see into the future?
Rob - These days, I would say sort of out to about five days our weather forecasts are pretty good, certainly in terms of predicting the general weather systems, what kind of weather we are going to have. Much beyond that, out to probably ten days there's certainly significantly better than just guess work. Beyond that really, tends to be much more difficult.
Chris - What would you say your level of accuracy is? What percentage error do you give on your forecasts these days?
Rob - Predicting for instance the temperatures, the Met Office will quote values of around 95% of the time being correct to within a couple of degrees for daytime maximum for instance for tomorrow. So that's sort of really the good kind of numbers.
Chris - And when might you be able to tell that there's bad news on the way? How far in advance can you say - well that really looks like it's building towards something that could dump an enormous amount of water or be a torrential deluge over a period of time that would lead to a flood?
Rob - So again, it would depend to some extent on what kind. So if you're talking the sort of intense rainfall, we're probably a few days out now; we'd probably be in a situation where there's definitely the possibility of really heavy strong convection. Convection is basically the sort of shower clouds and thunderstorm. It's basically just caused by the hot air rises. We all know that hot air rises and it's what leads to thermals and also, if it gets going strongly, it leads to full on clouds, thunderstorms and eventually a lot of rain can fall, and we'll really know the conditions are setting up to make that very likely a few days out. What we don't know is where it would trigger. I think the best way to analogy for that is to think of putting a saucepan of water on a hob, you can predict fairly accurately what time it's going to start boiling. So we all know if you put hot water on the hob, it will boil in a few minutes time. But what we can't really predict at the moment is exactly where each of the bubbles are going to form in the bottom of your saucepan and start bubbling up, and that's kind of what happens with these heavy rain storms at the moment. The models can predict that it's going to start happening over a fairly wide area, but they're not very good at the moment at saying precisely when and exactly how hard any rain would be, so exactly how intense the storms that would generate would be.
32:58 - The "augmented reality sandpit"
The "augmented reality sandpit"
with Liz Lewis, Newcastle University
To avoid catastrophic flooding, planners also need to know where it is likely to occur. To get this glimpse into the future, researchers like New Castle University hydrologist Liz Lewis use physical and computer model simulations. Sam Mahaffey went to see their newest piece of kit, an augmented reality sandpit, but first took a look around the facility.
Sam - I'm meeting Liz in the Novak Hydraulics Lab at Newcastle University. It's a long, high-ceilinged room full of pipes, pumps, and huge tanks of water running from one end to the other. The noise you can hear is the sound of water gushing into a big open top channel right in the middle of the room. I asked Liz why it's so difficult to predict where floods are going to hit?
Liz - In some ways it's very easy because we know how water flows - water flows downhill and it pools when it can't get out, but there are lots of other compounding factors such as, the drains might be blocked and the ground's already wet. Somewhere might have flood defences in place already but they might not have been opened or shut at the right time and there's a big human element of it. So it might happen in the night when roads getting flooded isn't so bad, but it might happen at rush hour which means you get lots of traffic jams so knowing where the water's going to go is one thing, but its knowing how that's going to affect our transport networks and our distribution networks.
Sam - How do scientists and engineers do this?
Liz - There are lots of things to think about and we do it with models. We have physical models like you can hear in the background, and we also have computer models which lets us run thousands of simulations of something happening and have a look at a whole range of outputs.
Sam - When I think of a model, I think of what I'm looking at right now. Which is this sort of scaled down river with water flowing through it; there is sand and gravel that's like the river bed. How useful are these kinds of physical models?
Liz - These models are very useful, but we probably don't use them like you would think, so we don't build a physical model city. Instead what we've got here is kind of a segment of a river bed and we use it for understanding how water flows. We look at how the water will move the sand and the gravel around, so looking at sediment transport. So we use it more to understand the processes which we can then build into our computational models.
Sam - These computational models sound really complicated but Liz promised to show me something that would explain it all and it gave us chance to get away from the noisy lab... I'm in a dimly lit room but in front of me is a big box of sand and projected onto the sand is a map with contours and some little Lego pieces in the corner - don't know what we're going to do with those. Liz, what am I looking at here?
Liz - So this is the department's augmented reality sandbox. What we've got set up here is a kind of a metre square sandbox, full of sand and above it we've got a projector and we also have an X-Box Connect, which is a 3D camera, so that can sense the surface of the sand. And so what that does is the camera senses the surface of the sand, that feeds down into the computer that's at the bottom and that projects back on to it these contours, which is the topography, which the model uses to figure where to route the water.
Sam - What does this sand correspond to?
Liz - So, what we're doing with the sand is basically building hills and a valley, so we can make a nice flat catchment like you'd find in Cambridge on the Fens, or we can build a really steep sided catchment like you'd find in Scotland and we can use that to demonstrate how water's going to flow in these different environments. Shall we have a go?
Sam - Yes, lets.
Liz - What we're going to do now is build some mountains.
Sam - Okay. So Liz is gouging out a big valley into the sand.
Liz - The map that's projected onto the surface of the sand has changed completely now the contours are in a completely different place.
Sam - You can kind of see that it's looking like some hills now.
Liz - At the bottom of this valley and where the river widens out, we've got this kind of flood plain now - so a of flat bit, and this is historically where towns and villages were built along next to a river. So what we are going to do is put our lego houses and build a mini city at the bottom of this valley to see what happens when different amounts of rain occur and to see where it's going to get flooded.
Sam - So this is what the lego's for. We're going to build a model village. Okay, so now we've got our topography and we've got a little village at the bottom. Please can we make it rain..
Liz - Yes, so we make it rain by holding our hands above the surface and, again, the 3D camera is sensing that my hand's there and so what it does is it simulates water directly underneath where my hand is. So I've put it over the top of the catchment - so this is kind of at the very top of the valley where it's steepest, and we can see that this digital simulated water is flowing really quickly down the sides, and really quickly down the river, and the water's swooshing up the sides and completely devastating the little lego town that we built.
Sam - It looks like an aerial view of what you might see during a flood. As you hover your hand over, rainfall is collecting on the ground, just flowing downhill straight towards our lego houses. Behind this sandbox presumably there's lots of computery things going on that's working out what's downhill and what will affect where the water goes?
Liz - That's right. So, there is a computational model behind this which is using proper hydraulic equations to route the water. So that basically means it knows the shape and size of the channel and it knows how much water has been simulated.
Sam - What kind of uses do you have for these computer models?
Liz - There are lots of reasons that we build models. Firstly to understand where might flood; to understand how big the flood is going to be; to understand what it's likely to impact. So is it going to flood near our hospital or is it going to flood near our supermarket. And then lastly, the really important thing is what can we do to prevent flooding. So what we can do now in this sample box; we can put a little lego wall in here, and we can empty all the water out and then we can create another storm and this time, when the water flows down the sides and it gets towards the city, it doesn't enter the city because we've built this big flood defence.
40:01 - The human cost of flooding
The human cost of flooding
with Claire Grisaffi, The British Red Cross
Wherever you live, a flood is devastating, damaging possessions and displacing you from your home. But some countries are hit harder than others, which can lead to poor sanitation and threats from disease. The Red Cross are often being deployed to countries affected, but why are some places more at risk from floods than others? Claire Grisaffi, a water, sanitation and hygiene technical advisor for the British Red Cross, explained to Chris Smith...
Claire - The first thing is lack of infrastructure. The immediately obvious one being in terms of flood defences, but you're also lacking in transport and communication infrastructure, which means then it's so much more difficult to have good early warning systems in place, evacuation routes much more difficult and much more challenging.
Chris - What about the general geography of where these countries are. Does that make a difference?
Claire - Oh absolutely. So one of the reasons why so many lower and middle income countries haven't developed is because they are in disaster prone areas. So south-east Asia particularly is one of the most affected regions in the world in terms of flooding and typhoons, so you get into this negative cycle.
So infrastructure is destroyed, your GDP is massively impacted and then you can't afford to build back better and build systems for protection and everything else, so it's kind of like a cyclic problem. It's a really massive barrier to economic growth.
You also have issues because it tends to be that in lower and middle income countries your population growth is much higher, so you have more people and then the most vulnerable people tend to be in the most high risk areas, so flood plains, coastal areas, and all that sort of comes together to mean that in low income countries just many more people die from the same kind of extreme event than richer countries.
Chris - I suppose if you have got those sorts of population and space pressures, and also a financial pressure, people don't also tend to build very well. They'll knock up shanty towns and things like that which are much more vulnerable to exigent weather conditions compared with more robustly build settlement.
Claire - Yes, absolutely. So your infrastructure, when it is there, tends to be lower quality and the population is also more vulnerable in other ways. So they don't maybe have the kind of coping strategies, they're lower income, higher rates of malnutrition. All of that comes together to mean that a flooding event has a much bigger impact.
Chris - And when a flood does happen, apart from obviously people can lose their homes. How are people impacted?
Claire - Well the big issues, obviously people lose their homes and they're displaced; they also lose all their belongings; they lose access to all the basic services; they don't have access to clean water; no sanitation, which means then have huge public health risks. The water might be contaminated. For example, if you are in an area with pit latrines and the pit latrines are flooded, if you have maybe septic tanks; there's massive contamination risks, which means there's an increased risk of things like cholera. And then you also have stagnant water, which means you've got breeding grounds for mosquitos, you've got risks from malaria and dengue.
So those are the kind of immediate impacts, so you lose everything, you're in a very high risk environment and you're all kind of clustered into maybe an evacuation centre if you're lucky in a very small area of land.
Chris - What about longer term? What then?
Claire - You're livelihood is decimated basically. So at the local level, households lose their crops and you're talking about countries where most people are going to be reliant on subsistence agriculture, so they lose that which then leads to increased security risks.
And then at the national level the economic impacts are huge; infrastructure is destroyed; transport infrastructure, communication, water supply.... In Myanmar recently, millions of dollars of infrastructure was destroyed and I think they've had to massively reduce their rice exports because of the damage to the crops, so the national level economic impact can be really, really huge.
Chris - What can an organisation like the Red Cross do about this?
Claire - So the Red Cross and Red Crescent Movement has an enormous capacity because it has national societies in 189 countries and 70 million volunteers worldwide, so the reach is really, really huge. And it also works as an auxiliary to governments, so it's quite different to most of the organisations in the humanitarian sector, so it has a mandate to support the government in terms of early warning systems, supporting evacuations and everything else. So basically the volunteers - I mean they just get out there immediately, out into the communities; they help people evacuate; they do rescue operations. They would then start distributing relief items. Most national societies have pre-positioned stocks of things like tarpaulins, and soap, and buckets, so really basic equipment to get that out immediately to households that have been displaced and affected. They also do things like providing drinking water and, in some areas, they also do some kind of basic health services. So that's the really kind of acute response; getting out, supporting people, doing evacuations, doing rescue, and getting out distributions of essential equipment.
Chris - How do you make sure that those essentials go to the people who most need it, because we have seen situations - there was the Boxing Day tsunami in 2004, for example - there were people complaining that, while there was no shortage of aid, and equipment, infrastructure turning up, in some countries bureaucracy, and in other cases corruption, were stopping that much needed aid actually getting where it needed to go.
Claire - Absolutely. That's a critical issue. I think accountability to beneficiaries is a massive issue for everyone working in the humanitarian sector, and there's more and more focus on this.
In the Red Cross, Red Crescent they have a very clear kind of structure already in place before an emergency, down to a local branch and out to volunteers, which helps to have that kind of accountability, because you have an existing local knowledge and existing local networks.
But yes, I mean it's an issue. There were 2,000 volunteers out providing emergency relief in Myanmar, and then how do you keep track of everything and make sure it is going to the most vulnerable people is really, really hard.
Chris - How do you decide when your job is done or when you say, look we've done as much as we can here. Now it's time for someone else to take over and take things forward? Because, obviously the problems don't go away as soon as the flood waters recede. Where do you draw the line and then move your efforts elsewhere?
Claire - I think this is another great thing about the Red Cross and the Red Crescent movement is that you don't move elsewhere. I mean maybe, for example, the British Red Cross would provide some of the funding for an emergency response and some of their recovery but the national society stays they and carry on working. In Myanmar, they're continuing to work on recovery programmes after the floods - things like livelihoods, agriculture and so they're not going anywhere, they're staying there.
47:19 - Can we learn to live with floods?
Can we learn to live with floods?
with Ilan Kelman, University College London
It's predicted that climate-driven extreme weather events, such as flooding, are going to become more common and more severe around the globe. The big question is what can we do about it? How are we going to protect ourselves into the future? Dr Ilan Kelman, a researcher for Risk and Disaster Reduction at the Institute for Global Health at UCL, spoke to Kat Arney about how we can reduce the risk...
IIan - The first thing that we can do is actually learn from our past. So, flooding has always happened and humans have been dealing with it for 10,000 years, sometimes better, sometimes worse. So, let's look at what went wrong, what went right, and try and implement that. We can do that at the very small level, at the household level, so people can make decisions in their open properties to use flood resistant finishes, flood resistant materials. But there's much wider issues in terms of planning, urban governance, dealing with people's streets, houses, infrastructures, and that means planning, living with rivers, living with coasts. A flood plain is called that for a reason...
Kat - That's the bit that floods?
IIlan - That's the bit that floods. It has a job to do, so maybe we should think about the way we live, how we live, where we live, and let the flood plain do its job.
Kat - So where are some parts of the world that are doing this well, that are coping with flooding and flood plains?
IIan - Well, I grew up in Toronto, Canada and I always enjoyed the ravine system which was wonderful recreational pathways, wildlife, cycling, walking. Then when I got into this as a profession I realised, in fact, it came from flooding. So 1954, a devastating hurricane went through Toronto - Hurricane Hazel. It killed about 83 people and, in response, the government said "well, we're going to let the ravines, the rivers be flood plains, which is what they are meant to be being beside a river." So they designated it to be green areas, greenways, recreational pathways and building is now forbidden there.
Kat - Now, as the global population does increase though, building is encroaching on flood plains. I've lived in East London which is basically a swamp and they are building all kinds of things right next to the river. And is this risky, not just in London but in other parts of the world? Should we just not be building there at all? Can it be possible to build safely in these areas?
IIan - Wherever we build there is going to be some risks. Therefore, we have to ensure that we have the knowledge and work with the people in the areas to determine what risks they do want; what risks they don't want. If we avoided all flood plains in all of the risky areas we wouldn't be able to build anywhere. That's where we decide - well maybe at the local level, maybe at the household level. What we have to do is accept that some houses, some buildings are going to be flooded at times but, construct them in such a way that it's easy to wash them out, clean them afterwards and then go back and live there.
Kat - And presumably tell people to store stuff in waterproof boxes?
IIan - Well, part of it is ensuring there are not valuables on the ground floor; part of it ensuring we do have an adequate warning system; part of it is people knowing they are in the flood plain and therefore being able to respond and react when warnings are issued.
Kat - Tell me a bit more about some of the kinds of strategies that we can use to enable us to build on flood plains because, for example, just building urbanisation increases the risk of flooding. Are there ways, for example, planning or housing could help to mitigate some of those risks.
IIan - This is a lot of the challenge that people do need a place to live, we do need the infrastructure. As soon as you pave something over that increases run off but there are ways to reduce that so we can use, for example porous material on the roads. That means it will rain on the road and go straight through, rather than necessarily giving driveways, rather than necessarily paving over front gardens. It would be possible to keep them as plants. And also, a lot of it is simply the layout and the planning to ensure that when it does rain the water does go into the river, and that the river has a capacity to take that water rather than bursting it's banks.
Kat - Is there a risk of kind of over-engineering this? How often would these kind of events happen? Would it make it worth it in financial terms to build all this kind of stuff in?
IIan - Well, certainly at the moment in places in the UK, we are over-engineering anyway and a lot of the over-engineering is an attempt to separate people from the water. That makes a lot of sense, no-one wants to be flooded. It does keep us dry. On the other hand then, when it does rain and as the rainfall patterns change, when flooding happens it seems unusual - people are not ready for it. So, what we have to do is actually work with people, and ourselves to try and determine what balance are we seeking. How often will we accept being flooded or do we want to completely separate ourselves from the water, recognising that maybe every 50 years, maybe every 100 years, there's going to be a massive flood. There's no quick fix, there's not silver bullet. We simply need to recognise there's a whole variety of solutions we can take and it really depends on how much we are going to accept being flooded, to what degree, and how frequently.
Kat - And we've just heard from Claire earlier about the vulnerability of developing countries that are poorer. How can they cope with these kinds of risks?
IIan - Everyone, whether they are in Myanmar as Claire mentioned, whether they are in East London where you live, everyone has some form of knowledge but, they also have gaps in their knowledge. That's where it's not about going in and bestowing our wonderful aid and wonderful ideas on these poor people, it's actually about ensuring we work with the people, we use their knowledge, recognise what they don't know and work together to avoid the risk of flooding.
Can I play a guitar in space?
Felicity Bedford spoke to Jim Woodhouse from Cambridge University's Engineering Department to find out...
Jim - You normally hear a guitar because the vibrating woodwork alters the air pressure - alternately compressing and rarifying it. Those pressure changes travel through the air as sound waves. Once they get inside your ear they cause vibration in your inner ear, which gets turned into electrical nerve impulses, which travel to your brain.
Felicity - Simple enough, Now say we were to blast off into space with our acoustic guitars, would we have any luck?
Jim - There can be no sound in space because there's no air to transmit the sound waves. So if your pluck an acoustic guitar in space, the strings in the guitar body will vibrate roughly the same as the would on Earth, but no sound will be made.
Felicity - But , if no energy is being lost as sound waves, does this guitar string vibrate forever?
Jim - The string will vibrate for a little bit longer than usual because energy is not being carried away in sound waves, but it won't be very different. Most of the energy goes into internal friction in the wood of the guitar body and that will still be the same. That energy simply turns into heat in the wood.
Felicity - So, if you find yourself floating in space, happily playing a guitar, will you ever know if your music is any good?
Jim - If our spaceman could manage to make a mechanical connection to the vibrating woodwork, they might get some sound transmitted via bone conduction, which is when sound vibrations travel through your bones to your skull and reach your inner ear that way. When Beethoven was deaf he managed to hear his piano by fixing a piece of wood to it and gripping it in his teeth. That wouldn't be easy to do while wearing a space suit.
Felicity - Thanks Jim. Although that doesn't bode well for our space jam, what about on the international space station, which, fortunately, contains air? The space boffins have been hearing from a real astronaut, Tim Peake who is set to launch this month.
Tim - So no, there is a guitar on board and of course I'll be playing, I love to play but I'm not sure I'm ready to release my skills to the world yet.
Richard - So you won't be sharing that?
Tim - Never say never but I've got no intention to at the moment.
Felicity - That's a shame Tim because, as Andrea said on facebook, - Your music would be out of this world.