Cambridge Science Festival: Battle of the Brains

It's time to take a little break in the competition because this show is just one ofhundreds of events at Cambridge Science Festival. Festival coordinator Lucinda Spokes explains just how big the festival really is...

Lucinda - We ran for 14 days; we have, this year, 350 events and we hope to reach at least 45,000 people.

So the theme is data and knowledge; we're collecting and generating so much more data than we've ever done in the past so, an interesting thing about whether all the data we collect makes us perhaps, cleverer.

It allows us to show some of the amazing science that we do here in Cambridge. It allows us to work with partners from both within the University but also external to the University, and we hope that the University of Cambridge and all of our partners show the amazing scientific community that is here in Cambridge and allows us to share it with thousands of people.

What actually the festival gives is space, and a safe space for people to discuss scientific issues. We firmly believe, this is not us telling people about science, it's about engaging in a two-way conversation. So the things that are concerning people, the things that are interesting people, and subjects that concern and interest people, and giving people a face and a time to actually voice their opinions, their views, their excitement, their worries about some of the big advances in science that are happening today that will, potentially, change our future.

Silicon is great but what if it could be cheaper, bendier and printable? Maybe thenwe could get our food talking to our fridge. Naked Scientists regular and circuit bender extraordinaire Stuart Higgins is trying to make smart food a reality...

Stuart - In my left hand I have a silicon wafer; it's like a shiny blood colour; it looks very metallic and it's hard and, if I were to drop this, it would smash like glass.

Smith - It's a disk. It's what 4 or 5cms across and thin, shiny - it's like a CD really.

Stuart - Yes, it looks very similar to a CD. It's got the same kind of rainbow colours if you look at the surface of it. This is silicon, so if you think in terms of your phone and the chips inside your phone or your computer, this is what they're made on - this is this hard material. Now that's great but, as I said, if I drop this it's going to smash - it's not going to be so good. What if there was a way we could make electronics using plastic, with the benefits of plastic but also with the electrical benefits of silicon.

Smith - Why would you want to do that?

Stuart - Has anyone ever dropped their smartphone? So if you drop something like a glass screen or if you drop something that's a hard crystal substance like silicon, it's going to smash - it's going to shatter to shatter into lots of pieces. So I'm looking in my research at ways of taking new materials that are based on plastics that can also be semiconductors; can also be electrical in their nature. So we often think of plastics as insulators; that's why we make our plug sockets out of them; that's why we make our cables out of them because we don't want electricity to get through. But, actually, it turns out that there are special kinds of plastics that can act as conductors; they can conduct electricity and they can also act as semiconductors and a semiconductor is something that, in the right circumstances, turns into a conductor.

Smith - And that's what you've got here is it?

Stuart - Yes. So in my right hand I have this flexible piece of... well it's a piece of plastic.

Smith - Okay. So this is about the same size as the wafer of silicon. I can see through it; it's completely transparent, thin piece of... looks like cling film but a bit thicker and it's got some coppery coloured stuff on it.

斯图尔特——是的,我们看着,行动ually it's gold. So if you look closely at this substrate you see this kind of pattern of gold wiring, essentially, and all of these wires are connected together with little devices called transistors and a transistor is a switch. It's like an electrical switch where you press it and turn it on and you turn if off and it's the fundamental building block inside every microprocessor. So when your computer does calculations, it's transistors that are switching on and off.

Smith - How might we make that?

Stuart - The benefits of plastics are that you can actually turn them into inks so, if you're doing something like silicon, you have to use very industrial processes - it's a very hard material to work with. But, if you've got a semiconductor that's also a plastic, you can dissolve it, you can turn it into an ink that could go into a printer, for example. An inkjet printer like we have at home. So one of the things we look at is ways of printing circuits on plastics. We send the design from the computer to the printer and it prints out the circuit on the piece of plastic and in that way we're looking at ways of building up layers and creating these kind of flexible circuits.

Smith - What sorts of things could you make that do with that same technology because I know what my phone can do but, am I close to having a roll up phone?

Stuart - You're a little away from it yet because the silicon technology is so far developed; it's had many, many years of development. The phone inside your pocket has a billion transistors in it - incredibly complicated. This piece of plastic I have here has 120 transistors. We're still years and years behind but one of the things we are looking at doing is incorporating it into other kinds of products. So, in my particular research I look at radio tags and I'm interested in seeing whether we could make a flexible radio tag. A bit like your smart card or you security card when you swipe it on a door and looking at ways we can make that onto a flexible substrate. And the reason for doing that is if you can make things flexible, and you can print circuits, and you can do that cheaply and easily, then you could think about putting circuits where you wouldn't normally find them, for example, maybe on packaging. So, as you referred to earlier, imagine having a milk carton in your fridge that's talking to the fridge itself and can actually tell you when the milk is about to go off. Or that you know by looking at your smartphone, what's in your fridge when you're out shopping so you know what to buy next.

Smith - It would be food for thought, wouldn't it?

Stuart - Exactly. That's where the idea is that if we can develop new materials and we can develop processes and ways of making these circuits that do that, then it opens up a huge new range of technologies.

Smith - It's an obvious question. Why aren't we doing it now?

Stuart - Well, the problem is that these plastics, while they're good, is there not that good. They're still quite a lot worse than silicon and, in particular, the charges, the electricity going on inside this circuit is moving a lot slower than it would in silicon.

Smith - Now I asked you for a bit of a demo to show us the speed of these things. What demo have you got lined up for us?

Stuart - So, I'm trying to illustrate here what happens if you've got a slow transistor; if you've got a slow switch that turns on and off. Now, in some ways, if you've got your smartcard talking to the reader and it's kind of speaking very slowly and you've got the reader speaking very fast in return and trying to get things really quickly, those two can't talk to each other, they can't understand each other, and particularly if you've got transistors that can also be used as an amplifier. If that amplifier can't see all the frequencies then you start to miss information.

In this first clip I'm going to play a spoken recording and it's going to have all of the high frequencies cut out as if the transistor wasn't switching fast enough. So, we're going to listen to that and try and understand what's being said and see how difficult it is to hear what's happening. After that I'm going to play the second clip with all the frequencies present so we can hear what it says.

Smith - Let's do it...

Audio - [Muffled]

Audio - I am sometime able to eject a very fine spray of saliva out of my mouth. Why are we evolved to do this?

Smith - Right. So why do they sound differently intelligible between the two?

Stuart - So, in that first clip we were hearing only the low frequencies and actually, in order to gain all the information and for our brains to be able to interpret it all, we need to have at least some of the frequencies there. We need to have as high a range of frequencies as possible so in the second clip when we can hear everything, it's much clearer.

Food security is a pressing issue, our population is rising whilst climate change isbattering our agriculture. On top of that wheat, one of our staple crops has hit a brick wall in yield increase - is it time to get turbo charging? Howard Griffiths thinks so, as he displayed something that looked suspiciously like the contents of a cornfield to Chris Smith...

Howard - Well, it is the contents of a corn field and what I'd like to do is hand out some of these to some of these youngsters here...

Smith - What are you dishing out?

Howard - Well I'm giving out some ears of wheat that I collected from a field and it illustrates... How many of you like toast for breakfast?

Audience - Yes!

Howard - Excellent. Well wheat is a staple product of the world; it feeds and it gives us a huge amount of protein. The ears that I'm holding up in front of you contain little grains and those little grains - you can pull them apart and have a look - those are the seeds of the wheat and having sown one of those seeds in the autumn, the farmer was then able to grow all these ears of wheat. Well these are the ones that are left behind that he didn't quite manage to harvest.

史密斯——的比例the world relies on this simple stuff - this cereal crop?

Howard - A huge proportion of the world relies on this as a staple diet. It's one of the major protein inputs because it's go so much nitrogen in it but there is a problem with it because, over the last 10 or 15 years or so, the yields from wheat have begun to plateau. They've reached a stable level; they're not increasing as much as they used to do over the previous 30 years since the green revolution.

Smith - Why is that a problem?

Howard - Well, that's a bit of a problem because the world's population is increasing and also we're likely to get a change in climate in the future which will mean, increasingly, crops won't be as productive as they have been in the past.

Smith - You're saying then we could be facing a hungry future?

Howard - Yes indeed. I mean there are other issues that we need to tackle; not just about increasing the productivity of the wheat, we've got to minimise waste. For instance, these ears I've picked up, the farmer hadn't managed to harvest them and all around the world there's a huge amount of food waste that we need to try and minimise...

Smith - So you stole that?

Howard - Well - I helped myself. I liberated it, that's the word we tend to use. Also, of course, we've got to improve our distribution of these sorts of foodstuffs so that it helps people who don't have food but also doesn't destroy their economy by distributing it in a way that would upset the national product of a particular country.

史密斯-我们有这的收益率情况s very important food crop are not going up. The human population is going up; we also anticipate that the environment's going to change because of things like climate change so that may also dent the yield. So what's your solution?

霍华德-有另外一些er sorts of plants. How many of you like cornflakes?

Smith - I'd say Kellog's are not doing very well in this room. There's only about two or three hands up..

霍华德-还有其他版本的玉米片available from your local supermarket - you do realise? So, cornflakes are made from maize corncob - do you all know what a corncob looks like? Each one of those little granules on a corn cob, that's where your cornflakes come from. Now they come from of a plant that actually have a higher rate of productivity and they're what we call turbocharged, so naturally this is a plant that has managed to increase its productivity by force feeding the enzyme that fixes carbon from the atmosphere.

Smith - This energy that comes to us from wheat, we get effectively from the sun don't we? Because this plant captures the energy from the sun through the process of photosynthesis and it stores it chemically in a form that we can then eat?

Howard - Absolutely. Plants are magnificent; when you think they take that amazing energy we get from sunlight for free and they turn it into the products that feed us, they clothe us... How many of you are wearing cotton at the moment? And they also fuel us. If you came in a car, that's fuel that was laid down by plants millions ,and millions, and millions of years ago.

Smith - How can we therefore, make that plant better at being a natural solar panel then?

Howard - Well, one way would be to take that pathway that we get in sweetcorn and maize and encourage staple crops like wheat or rice to see if we could adopt that pathway into them as well.

Smith - Right. So basically, take what the maize is really good at and confer that same science on the wheat? Why doesn't the wheat do that already?

Howard - It hasn't had to because it evolved in a wet and cool environment, whereas maize comes from a tropical environment where it's hot and often water limited, so that's the advantage of that crop as well as having this turbocharger.

Smith - How can you put this turbocharger, as you put it, into the wheat? Is that feasible?

霍华德——这是一个真正的problem because it means that we would have to find wheat that had a slightly different structure within their leaves which would allow us to put that pathway in. We have an alternative solution and that alternative solution... You can see here I'm holding up a vial of green cells...

Smith - I thought it was a urine specimen. It's in one of those pots the doctor give you Howard.

Howard - Chris - if your urine has got that colour I think you do need to see a doctor.

Smith - I did have a patient with that once and he was on a certain drug that made his wee go green. But why does it look green then - what's in that pot?

Howard - This has got a microscopic algae in it; it actually grows in soil and solutions. Many of you have buckets in your gardens that have been gathering water all over the winter , I bet they've gone a bit green haven't they - yes? So that algae is all very close relatives of it. Other sorts of things grow in ponds and in buckets and in soil.

Smith - And they're plants are they?

Howard - They are plants indeed. Well, they're related to plants and they also have a mechanism which turbocharges their photosynthesis and they do it in every single cell. So what we are wondering is, they have a much simpler mechanisms for concentrating that carbon dioxide and improving the efficiency of the enzyme, could we try to persuade all the cells in a plant like wheat. If they could adopt that mechanism,maybe that would improve their photosynthesis and that would help us increase that yield of wheat, and rice, and so on by 10 or 20%, which is what we will need to do over the next 50 to 100 years

Smith - You're saying, take the machinery from the stuff that makes the pots in your garden go green and put that into wheat, and it would like putting a Porsche engine into a Lada?

Howard - Indeed, that is the sort of idea - yes. I hadn't quite thought of it like that.

Smith - But is it feasible?

Howard - It is feasible. We have actually managed to get parts - little microscopic components that help to pump the carbon inside the cell walls of the algae to work inside plants.

Smith - And if you do this, what sort of increase in productivity of normal wheat might we be able to see?

Howard - Well, we would hope to see a 15% increase in wheat yield, I would imagine would be the sort of thing that would maintain that stability for the future. In the short term, of course, we're going to rely on traditional genetics, traditional breeding that will help to bring in new traits and help to maintain pathogen resistance but, in the future, perhaps we could get away with this mechanism.

Professor Hugh Hunt wants to stop the arctic melting, and as strange as it mightseem - the giant floating helium balloons he brought wih him have got something to do with it, but what?

Hugh - Well they are balloons - helium filled balloons and it's all about buoyancy. You might remember Archimedes and he got into a bath and he famously announced "eureka." He understood buoyancy...

Smith - He was the first naked scientist - Hugh.

Hugh - Yes - one of the first naked scientists. So I have this apple here and when I put it into the water it floats and that's because the density of the apple is less than the density of the water. Now with a helium balloon, the density of the helium is less than the density of air which is why the balloon floats. What I'd like to do is to measure how much this helium balloon lifts, so I've got some scales here - turn the scales on - and this apple... Who'd like to come and measure the apple - would you like to come up?

Berrow - What's your name?

Emily - Emily Warren.

Hugh - Emily. So Emily, how much is that apple weighing there? I've put the apple on there, that's how many grams?

Emily - 135.

Hugh - Right - 135 grams. Then when I put the apple into the bag here which is being lifted up by the helium balloon it's...

Emily - 132 grams.

Hugh - So how much has it got lighter?

Emily - 3 grams.

Hugh - 3 grams. So this little balloon here is lifting only 3 grams. Thank you very much. Now here I've got a bigger balloon, and you can see that this big balloon, well it has already got one apple in there, I can put a second apple in there...

Smith - When you say big - it's 3ft wide.

Hugh - Well yes, it is quite big - about 80cm wide, and what's interesting is, this balloon is about four times bigger than the small balloon. But because the volume goes up as the cube of the size, it's four times bigger, but 4 cubed is 64 - 64 times bigger in volume. And 64 x 3 - it's about 200 grams. Now 3 grams - 200 grams. One apple was only 120 grams. 2 apples - can't quite hold two apples but you can see how that works. Now it's interesting with volume. We can demonstrate how things go up with the cube. I'd like to have a volunteer - who'd like to volunteer? What's your name.

Johnny - Johnny

Hugh - Come here Johnny. I'd like to do a little experiment because I want to prove that volume - your weight goes up with your size cubed. Now your height is about 150cm and my height is about 182 cms and if we do 150 divided by 182 and cube that, then that should be the ratio of our weights. 150 divided by 182 and we cube that and that tells us the ratio of our weights is about .55, and I'm 80kg so you should weight about 45kg - let's see if this works. Right Johnny are you going to stand on there. I reckon you should be about 45kg.

Berrow - So on the scales now of course.

Hugh - Okay 34kg but you should try this. If you work out your weight it goes as a cube of your height. So someone who's half your height will be ⅛ of your weight. Now this is really important...

Thank you Johnny, you can sit down now.

这是非常重要的,因为我的东西interested in doing is trying to refreeze the arctic. Because we know about global warming but the arctic especially is getting very, warm and one of doing this is to spray tiny particles up into the stratosphere. That's what volcanic eruptions do when they put tiny particles in the stratosphere and that helps to cool the planet. Well, we could do this artificially and we might need a very big balloon to hold up a very big hose to spray these particles up.

史密斯和粒子他们是你想要的东西to put up?

Hugh - Well, we know that volcanoes would put up sulphur dioxide but maybe there's other particles like titanium dioxide or silicon dioxide. Tiny particles about half a micron in diameter - that's under a 1000th of a millimeter which is about the wavelength of light, which is why these particles are good at scattering light.

Smith - What - so you want to put them up there and they will reflect light...?

Hugh - ...And they will reflect light back into space. We only need to reflect a tiny bit of light and that will help to cool the planet. Getting the particles up to a height of maybe 14, 16, 18 kilometers - we could do it with aircraft but that in itself is quite damaging to the environment. So instead, if we have a big balloon, then we can use the big balloon to lift up a hose and one of the things about the hose is that trying to do that safely... If I have a hose - well there's a cable here...

Berrow - So it looks like you're attaching the chain from a bath plug to a 3ft wide pink balloon at the moment. That's fairly accurate I would say?

Hugh - Yes, so I've now got this balloon on the end of a chain and then what happens is, when you start to have the balloon going high up into the sky, the wobbling of the chain may well cause the chain to break. This chain will be a pipe to pump stuff into the atmosphere and we've really got to get the engineering right to make sure that all doesn't go terribly wrong.

Berrow - So something like wind would have a huge effect on this because, obviously, it's going straight up into the sky?

Hugh - Yes, wind is a real problem. The high winds in the jetstream and big storms. And actually, thinking about how we might cool the north pole is a very pressing problem for us to deal with right now.

Berrow - Does it matter that we're thinking of putting particles at that level when people talk about the ozone layer and the fact that it's going away? Does it matter that we're starting to try and tamper with things like that?

Hugh - Well it really matters, and there's huge questions about whether we should be meddling with the atmosphere, meddling with the climate in this way, but we are already pumping 35 billion of CO2 into the atmosphere. Unless we stop doing that in a hurry and it doesn't look like we will, we may not have any choice.

Berrow - So this is possibly the answer?

Hugh - Well very reluctantly it may well be the answer but hopefully in the next five or ten years we will have figured out how to reduce our CO2 emissions.