Nature Podcast

This is a transcript of the 20th August edition of the weekly Nature Podcast. Audio files for the current show and archive episodes can be accessed from the Nature Podcast index page (, which also contains details on how to subscribe to the Nature Podcast for FREE, and has troubleshooting top-tips. Send us your feedback to

Kerri Smith: This week, new leads in the hunt for elusive gravitational waves and the secrets they might hold.

Vuk Mandic: That really is the only way we know to probe the universe when it was younger than one minute.

Adam Rutherford: Could antioxidants be encouraging cancer rather than helping prevent it.

Joan Brugge: It might be that they have support protective effects in certain individuals and tumour promoting effects in other individuals.

Adam Rutherford: And it's the 100th anniversary of the amazing adventures of fossil hunter Charles Doolittle Walcott.

Nicola Jones: He was in the Canadian Rockies and he was looking for trilobites and he found some of those but at the same time he also stumbled upon something much, much stranger.

Kerri Smith: This is the Nature Podcast. I'm Kerri Smith.

Adam Rutherford: And I'm Adam Rutherford. First this week early results are in from two massive projects aiming to detect waves propagating through space-time. Colin Stuart goes boldly.

Colin Stuart: For 400 years now telescopes have been snuffling up light from space. More recently astronauts began to collect not only visible wavelengths but signals from across the electromagnetic spectrum. All the way from gamma rays to radio waves, yet it is fluctuations of a completely different kind that currently making waves in the world of astronomy. In a paper in this week's Nature, a huge team of astrophysicists report their latest findings in the hunt for elusive gravitational waves. Unlike light which oscillates through space gravitational waves are oscillations of space itself. To discover more of what they found I called co-author Vuk Mandic of the University of Minnesota. He started by telling me what exactly these cosmic ripples are and where it is they come from. Nature 460, 990–994 (20 August 2009)

Vuk Mandic: A gravitational wave is essentially a perturbation or ripple effect in the fabric of space-time. For example, if we have two neutron stars or two black holes which are inspiraling towards each other, as they do that they produce a perturbation or ripple effect in the matrix, in the fabric of space-time. So these are waves which are very much propagating through space-time, very much like the electromagnetic waves but they cannot be observed with a standard electromagnetic type instruments, so we have developed very special interferometer detectors which have very long arms 4 km and so on, with standard mirrors and they are designed to look for these small perturbations in the space-time.

Colin Stuart: So to have a 4 km long detector that gives me the impression that these waves you are looking for are incredibly, incredibly small.

Vuk Mandic: Yes, that's correct. They are expected to be at the level of 10-19 meters which is essentially something like ten thousand times smaller than the size of a proton. The way the gravitational-wave detectors, interferometric detectors work is if a gravitational-wave passes through the effect that it imposes on the space around us is they would stretch one arm or one dimension and shrink the other. And what we do is we have an interferometric measurement, so we take a laser beam and send it into the interferometer which has an L-shape, so we split the beam into two halves and each beam then propagates in an arm which is 4-km long and then comes back reflects back from the mirror and when they get superposed the two arms have exactly the same length, the light that comes back will exactly perfectly superpose and we will have a nice beam coming out. But if one arm is slightly longer than the other which would be the case if a gravitational-wave passes through then the net result would be that the two light beams coming back from the end mirrors will be slightly shifted with respect to each other by measuring this fluctuation in the intensity of the light coming out of the interferometers we can deduce whether gravitational waves has passed through or not.

Colin Stuart: So you have got two 4-km tracks in your detector. How do you insulate it, so that if a truck is driving by or a plane is taking off near by it does not interfere with the measurements.

Vuk Mandic: Excellent question, really a lot of the effort that goes into commissioning and developing these detectors goes into understanding effects of this sort. First of all these detectors have state of the art suspensions and seismic isolation systems which allow a significant suppression by many, many orders of magnitude of seismic fluctuations or of any other vibrational type of noise such as the kinds of things that you have mentioned.

Colin Stuart: There is expected to be this random background of waves coming from all areas of the sky from all different sources but you did not find any gravitational waves in your experiment.

Vuk Mandic: That is correct. We have not observed the stochastic gravitational-wave background, so we establish an upper limit on the amplitude of how loud this background could possibly be given how sensitive our instruments are. What this means is that some of the models of the stochastic background which predict the background to be very loud have bee ruled out.

Colin Stuart: So what can that tell us about the early stages of our universe then if you haven't found this level of gravitational waves.

Vuk Mandic: Well, one of the models which is very interesting to physicists and astrophysicists is the Big Bang itself. In other words, the Big Bang itself is supposed to produce this background of gravitational waves that were produced essentially immediately after the Big Bang. These waves essentially be travelling since then until today without really being perturbed much by the matter they encounter on the way and this is really unique for gravitational waves. They are really the only wave we know to probe the universe when it was younger than one minute and this is really where the gravitational waves are holding much of their promise.

Colin Stuart: What does that tell us then about the first minute of our universe?

Vuk Mandic: The universe during that first minute was very hot and the energy scales of particles that existed is very high and to a large extent not really accessible to us in laboratories. So this is really a unique way for us to probe such physics to learn a little bit more about the laws that govern the particles and the energies of such high scales.

Colin Stuart: And so what's the future hold for gravitational-wave astrophysics?

Vuk Mandic: As we speak, LIGO and Virgo are upgrading or preparing the upgrades for the future, so sometime in 2014 we are expected to have detectors called advanced LIGO and advanced Virgo. These instruments are expected to give us another factor of a thousand or so better sensitivity than what we have at this point in terms of searching for this stochastic background and also for other types of gravitational wave sources. So we expect that what we have observed today up to date essentially we are looking at it as a hint of what is to come because these new detectors are expected to go a long way in probing various models of the stochastic background.

Adam Rutherford: That was Vuk Mandic talking to Colin. Coming up later in the show, a dark site to antioxidants and the aptly-named Snorkel genes that help rice survive floods. But before that a celebration of the world's most famous fossil site.

Kerri Smith: One-hundred years ago this month a geologist strolling through the Canadian Rockies stripped over a piece of rock that may not seem at first glance like something worth shouting about but the rock turned out to be rather special. As you are about to hear even the geologist in question didn't realise quite how special it was at that time. One of Nature's editors Nicola Jones has joined me in the studio to tell us more. Hello Nicola. Nature 460, 952–953 (20 August 2009)

Nicola Jones: Hello.

Kerri Smith: Now a 100-years ago this month the naturalist Charles Walcott came across something pretty special in the Canadian Rockies.

Nicola Jones: He did and his full name is Charles Doolittle Walcott which is a fantastic name. Yes, he was in the Canadian Rockies and he was looking for trilobites which are like woodlice type fossils from about 500 million years ago, the Cambrian period and he was looking for those and he found some of those but at the same time he also stumbled upon something much, much stranger.

Kerri Smith: Tell us about that, you can't leave us hanging in that way?

Nicola Jones: Also he was up there looking for fossils, he actually had his wife there with him and his children and they are all on a donkey trail going up to the mountains and he had found some trilobites in a specific area and he was out looking for more fossils and his wife's horse was apparently going to trip or stumble on a bit of rock. So he helped it break up this rock to avoid the horses stumbling on it and found some really weird-looking fossils within that rock which he drew that day and these fossils have subsequently been described as all sorts of things like jelly fish or worms or but basically they are the preserved soft parts of creatures from the Cambrian 500-million years ago which no one had seen before Charles Doolittle Walcott had broken apart this bit of rock.

Kerri Smith: Now before we go back to the relevance of that into the importance of finding these squeegee creatures buried in this rock, how did he know where to look, why were they walking in this particular bit of the Rocky Mountains that day.

Nicola Jones: So he had been to the Rocky Mountains before in search of these trilobites the woodlice-type things but those fossils had been found a lot in various places around North America. There was nothing quite so special about them, but he was interested in the area because there was a known site of trilobites there and he had actually been in to London co-incidentally because it was the centenary of Charles Darwin and he was in London for those celebrations and he was being given an honorary degree and while he was there he popped into the Natural History Museum and found a little document which said there was some trilobites found on one mountain in the Rocky Mountains and there probably should be some on the mountain just across the way. So the next summer when he went back he decided to go and try find that.

Kerri Smith: When he came across these creatures then these fossilized soft-bodied creatures, as you said no one had really seen anything like that before, what did he do with them, how did he interpret them?

Nicola Jones: Well, it was interesting because he probably didn't really recognize quite how strange it was or important it was when he first found it. He just spent a couple of days looking at these fossils and then went off to go look at some more trilobites again but eventually it did dawn on him the interest of the find that he had. So no one had seen soft-bodied creatures from before the Cambrian or even after the Cambrian, so it's a really isolated bit of history and no one really knew what to make of these things

Kerri Smith: And so he returned to the spot every summer for what the next kind of couple of decades.

Nicola Jones: He spent 18 seasons in this part of the Rockies, but of those 18 seasons he only actually spent three full seasons looking specifically at these weird fossils.

Kerri Smith: And what did he do in order to catalogue them, did he just kind of collect bits of rock, draw the things and stored them away.

Nicola Jones: He collected the rocks, drew them and then made his best guess at what it was. So he kind of worked on the assumption as lots of people did back then that all life was related to modern life, so he just looked at the bits and decided what they looked most like and then put them in that category which is why he had things like jelly fish and worms. But it turned out in subsequent years, in fact these fossils kind of languished on the top shelf of a museum for many, many years in part because his third wife, his surviving wife at that time that he died didn't want anyone poking through his fossils but by the time someone did come and kind of collect them again in the 1970s and take a second look at them they realized it's not really the jelly fish and the worms that Walcott had thought they were but may be something different and may be something stranger.

Kerri Smith: So have they put these fossils that he originally amassed and grouped according to his own principles into new groups, did he inadvertently find new species.

Nicola Jones: He did, he inadvertently found all sorts of strange things, so there was one thing that he found that he thought was a shrimp or that some people have thought was a shrimp at that time and it turned out not even to be a whole creature, it turned out to be a bit of a creature like the leg on something much larger. And when they finally pieced all these bits together when they found more fossils that had all the bits and their relative proportions, you know, in the right way for each creature then they could start assigning new names to these things.

Kerri Smith: And what's the legacy then of the Burgess Shale of the place he found all of these things. Are people still traipsing up there and finding all kinds of squeegee creatures.

Nicola Jones: So the person who has written the essay in Nature this week, his name is Desmond Collins and he was the curator at these fossils at the Royal Ontario Museum for really long time. He is retired now and he spent 18 seasons just like Walcott in the Rocky Mountains also looking for new fossils and yeah, so some of these mysteries like the creature that turned out to be a whole thing rather than just the leg of a thing have only been discovered in, you know, recent years.

Kerri Smith: And so how does this site compare to, you know, are there other sites with these kinds of Cambrian fossils in them.

Nicola Jones: Well, definitely the best such site for a very long time for about 60 years if you said Cambrian fossils, they just sort of meant the same thing as Burgess Shale fossils. People use the words almost interchangeably. These days there are a couple of other sites including one in China where you can also see Cambrian fossils, but so much of the work has been done in the Burgess Shale that's really the site for the Cambrian.


Adam Rutherford: Nature's Nicola Jones there. Coming up science news in a handy takeaway form but before that a water-loving variety of rice gives up its genetic secrets. Charlotte Stoddart wades in and finds them out.

Charlotte Stoddart: Rice is a very thirsty crop, but sudden flooding can ruin it. There are some varieties of rice that can survive submergence by shooting up in height but these deepwater plants produce around five times less rice than their flood-prone relatives. Now a team headed up Motoyuki Ashikari of Nagoya University in Japan have identified two genes which they enduringly named SNORKEL1 and SNORKEL2 that contribute to this deepwater response. If these can be introduced into high yielding varieties it could really enhance rice production for farmers in flood prone areas. I spoke to Julia Bailey-Serres who has written an analysis piece on the research for this week's magazine. Before diving into the genetics she described the extent of the flooding problem. Nature 460, 959–960 (20 August 2009)

Julia Bailey-Serres: Well, over 30% of the rice-growing areas are susceptible to submergence due to either flash floods or to prolonged floods. So it's actually a very large amount of land one estimate is that in Asia the amount that is susceptible to flooding is twice the size of the rice growing area in Thailand.

Charlotte Stoddart: But there are some varieties of rice aren't there, that can actually survive or deal with flooding.

Julia Bailey-Serres: Yes there are. Farmers have had for a very long time land rices or really traditional rice lands that can actually deal quite well in areas that are flooded.

Charlotte Stoddart: Right, okay. So I guess what the Japanese team set out to do was to find out what makes these deepwater rice varieties, what makes them able to survive flooding. What did they find?

Julia Bailey-Serres: The Japanese team was looking for regions within the rice genome that actually allowed a deepwater rice variety to elongate its inner nodes rapidly when it was submerged. The characteristic of the deepwater rice is that if the plants are about 70 to 80% submerged their internodes, really their stems will rapidly elongate and it's this trait that allows the plant to maintain some leaf area above the water and photosynthesize effectively and so it was presumed that this trait would be determined by some regions on the rice chromosome. And they used a method called molecular mapping and automatically narrowed down three different regions in the rice genome of a deepwater rice that were contributing to this rapid elongation response under water and then they focussed on the region that was on chromosome 12 that conferred the greatest amount of this elongation response.

Charlotte Stoddart: Right and was it within this region that they found two genes, the two genes that they named SNORKEL1 and SNORKEL2.

Julia Bailey-Serres: That's right, so after really a lot of work, genetic work, they were able to pinpoint two genes in this very small area that were genes that actually encode what we called transcription factors and so these are proteins that bind to DNA and are really turning genes on and off within the plant cell. And they were able to show that these genes were actually the relevant genes by taking them from the deepwater rice and using genetic engineering producing transgenic rice plants and that were not deepwater rice and showing by acquiring these the rice would become more likely deepwater rice and have the capability to elongate their internodes when they were under the deepwater condition.

Charlotte Stoddart: So what does now need to be done before we can engineer high-yielding varieties of rice, engineer them so they have these Snorkel genes and may be these other gene regions and then gives these varieties to farmers so that they can grow them in flood prone areas.

Julia Bailey-Serres: Well, I think that this Japanese group has positioned us so that we can do that. It's not mandatory that we really understand what's going on in these three distinct regions, what's important is that they are delineated molecularly and that they can use molecular markers and essentially an advanced breeding strategy to introduce these regions into high-yielding rice and in fact this is what they did do in their paper and so we're there with what they have done. They should now be able to use advanced breeding strategies and introduce these three regions of the rice chromosomes into other rice varieties and potentially be able to deliver a rice line that will have a deepwater rice response and also have both grain quality and yield characteristics of more advanced lines that are being used.

Charlotte Stoddart: Wow, so if I were a rice farmer in a flood prone area, I would be really excited by this. I mean, when could I get my hands on this variety.

Julia Bailey-Serres: I am afraid you are going to have to ask the authors that question. I don't actually have that information. This is bred rice as opposed to genetically modified rice and so there shouldn't be any restrictions that whether or not a farmer can grow it in its field but presumably there will be a process of certification and over time in the development of these new deepwater varieties but there should not be any sort of regulatory issues associated with it because it is rice that's just has introduced into regions that were naturally occurring within the rice that is already grown.

Adam Rutherford: Julia Bailey-Serres talking to Charlotte. In some parts of the world of course the problem is too little water rather than too much as a paper on this very topic this week and over our Nature video we have made a short film about it. It's about GRACE, a satellite mission that uses Gravity measurement to monitor the world's water resources.(Video clip)GRACE is the Gravity Recovery and Climate Experiment and it's a two-satellite mission. These two satellites are following each other around in orbit around the earth and is sort of looking downward like most earth-orbiting satellites do, these satellites are actually looking each other and measuring the distance between the two satellites.The data reveals a serious problem in Northern India.India is a hot hot spot on the trend map; it's well looking strange signal that's extremely strong and in this case negative, so it's one that really caught our attention.And subtracting relevant signals the water table here averaged a 6-metre drop.Over the course of the 6-year time series you can see that we go from a lot of blues to yellows to eventually a situation where it's mostly red and that shows it's approximately where these ground water source declines have occurred.

Adam Rutherford: That film along with all our expanding library of cinematic experiences is available through the home page.

Kerri Smith: News chat coming up with the leader of the news hound pack Mark Peplow. First though is there a dark side to friendly antioxidants. Here's Natasha Gilbert.

Natasha Gilbert: If you are a green tea drinking blue-berry gussing advocate of the positive health effects of antioxidants you may wish to take note. It seems this so called alexia of modern life has a dark side too. Test on cells derived from breast tissue have shown that antioxidants actually help cancer to spread, they do it by helping tumours overcome the body's defences against rogue-wandering cells. The results are published in Nature this week. I called Joan Brugge at Harvard Medical School in Boston Massachusetts to find out more. Nature advance online publication (19 August 2009)

Joan S. Brugge: Zach Schafer and others in our lab investigated the mechanisms that allow tumour cells to survive outside of their normal environment within tissues and we found quite unexpectedly that antioxidants can rescue cells from energy deficit that are caused by displacement of cells from their natural niches.

Natasha Gilbert: So antioxidants help cancer cells to survive, is that right?

Joan S. Brugge: That is inferred from our studies as tumour cells grow they are displaced from their natural interactions with other cells and normal cells are unable to function when they are outside their natural homes. We found that antioxidants allow the cells to maintain normal energy levels under these conditions.

Natasha Gilbert: So antioxidants, is it that they are good for other kinds of cells and that's why they help cancer cells to survive?

Joan S. Brugge: So, in general, there is lot of evidence indicating that antioxidants are protective in most context, so antioxidants protect the cells from being damaged under conditions from which high levels of oxidants build up with themselves. So generally they are very protective but our study suggests that under certain conditions excess exposure to antioxidants may allow cells to escape from natural mechanisms where oxidants are used to prevent outgrows of abnormal cells.

Natasha Gilbert: Why did you look at antioxidants?

Joan S. Brugge: We looked at antioxidants because we saw an increased level of oxidants in cells that were outside of their normal niches so we wanted to see what would happen if we would just neutralize those oxidants and we didn't expect that we will see such dramatic effect on the energy levels.

Natasha Gilbert: So can you describe the experiments that you did?

Joan S. Brugge: These studies were performed in cell culture, we had taken cells that were derived from human breast and grew them under conditions that attempted to mimic the environment of tumour cells that moved from their natural tissue context. We then treated the cells with antioxidants to determine whether this treatment would allow the cells to survive and maintain normal energy levels.

Natasha Gilbert: What sort of antioxidants did you use?

Joan S. Brugge: We used two that are commonly used in cell culture, one is a vitamin E analogue called Trolox and the other is N-acetylcysteine. It neutralizes hydrogen peroxide which is one of the most common oxidants that is produced in the cells.

Natasha Gilbert: What clues does this gives us to fighting cancer?

Joan S. Brugge: I think that the studies raise the possibility that suppressing natural antioxidant pathways may be beneficial in complimenting certain therapeutic approaches for cancer treatment. Many tumours show very high levels of natural antioxidants. These are enzymes that maintain high levels of antioxidants within the tumour cells and perhaps by separating or inactivating those programs through therapies that may compliment or may improve the efficacy of the other cancer therapies.

Natasha Gilbert: So what can we take away from this study?

Joan S. Brugge: These studies identify yet another mechanism where by the cell protects itself. The most rapid mechanism for the cell to protect itself is to activate a cell death program called apoptosis; but once cells escape that process there's actually backup mechanisms to try to ensure that cells that aren't in their normal environment are unable to survive so increase in levels of oxidants itself could be a protective mechanism by eliminating abnormal cells.

Natasha Gilbert: So does this mean we should not be drinking too much green tea and eating too many blue berries?

Joan S. Brugge: I think it's a bit too early to extrapolate from our initial studies, our study suggests that this is important to investigate the relevance of antioxidants in animal models and in humans more clearly. Dietary oxidants are metabolized in ways that are quite distinct from natural antioxidant processes. So this is one complication in interpreting results. Our studies may help explain why very large clinical trials of antioxidants have been difficult to interpret because it might be that they have supposed protective effects in certain individuals and tumour promoting effects in other individuals and so without doing very detailed analysis of different sub-populations of individuals it may be difficult to interpret.

Natasha Gilbert: Are you going to be doing studies in animals?

Joan S. Brugge: Yes, we are going to be looking at that, especially looking at protective effects of natural antioxidants, we would like to see whether inactivation of antioxidant programs within tumour cells could prevent a survival of human tumour cells.

Kerri Smith: That was Joan Brugge talking to Natasha.


Adam Rutherford: Finally this week Mark Peplow is here with the highlights from the News section. Hi Mark.

Mark Peplow: Hello Adam.

Adam Rutherford: First up some troubling news regarding nanoparticles in China.

Mark Peplow: Yeah, this is a very worrying report that has come out in the European Respiratory Journal. We have seen experiments done in the past where nanoparticles have been tested in animals and they seem to be having some toxic effects and there have been growing concerns about what nanoparticles actually do in terms of adverse health reactions. Sadly we have the first documented cases of ill health caused by nanoparticles in humans. Now clearly this is a deliberate trial. This is the consequence of how just absolutely terrible health and safety in a workplace.

Adam Rutherford: So, what's the story, what actually happened?

Mark Peplow: So, basically there are several women in an unidentified printing factory in China aged between 18 and 47 and what they are doing day in and day out, they are sort of scraping this paste of polyacrylate plastic over polystyrene boards and heating it up. It's all part of basically creating, sort of, decorative screens for printing on and they are doing in conditions where there is no ventilation, no proper breathing protection anything like that, so it's terrible and they worked there between like six months and a couple of years and all of them went down with these awful lung conditions, where they have excessive discoloured fluid in the lung lining, they have what's called pleural granulomas which are ball like collections of immune cells and basically two of them subsequently died and the others have recovered but are still with severe lung problems. And when they investigated cells from the lungs they found nanoparticles there, nanoparticles just about 30-billions of a meter wide which matched exactly nanoparticles found in their work place and that the study's author say is the cause of their lung conditions.

Adam Rutherford: And do we know whether it's simply the size of these particles that are being inhaled or something chemical in the particles that is causing the pathology?

Mark Peplow: Well, this is the tricky bit and this is what's dividing experts that we have talked to about this. The people who did the study say that you know assuming that nanoparticles in the lungs are the same as those found in the work place, they are very relatively benign chemicals, so it's the nanoness, it's the size of them in the lungs that's actually causing the problems and they are going a lot deeper than you would expect microparticles a thousand times larger to go, so they go deeper and they cause more problems that's the argument. But it has to be said there's a lot of other things going on and there is clearly unregulated factory environment, chemical fumes, all sorts of things in the air, it's a filthy place to work and that's something that really they haven't ruled out but there could be other chemical fumes in the air which are massively contributing to these lung effects. The point that Andrew Maynard who is a nanotechnology expert at the Woodrow Wilson International Center for Scholars makes is that the study really raises the bar for doing proper research as fast as possible to find out exactly what the dangers are in working with nanomaterials. People have been saying for years, there's simply none of the research out there to be able to tell what the true risks are.

Adam Rutherford: Alright, but in other news we've got some positive news about climate change and the run up to Copenhagen.

Mark Peplow: Yeah, we have a story in this week's issue about something called the Amazon Funds; setup about a year ago in Brazil, it's basically a major initiative to try and attract international aid to help conserve the rain forest. It's the largest forest conservation initiative in the world. Now within the next few weeks they are going to be enhancing the first project they are actually getting funding under this initiative.

Adam Rutherford: And what are those projects and what are they going to do?

Mark Peplow: Well, one example is a really good example actually is a 17 million US dollar project in a region called Para which is in its simplest form paying farmers not to cut down rain forests, instead of clearing it so that they can grow cows or crops they are paid to keep the rain forests as it is.

Adam Rutherford: Well, right that's all very well, but how can you stop global warning one farmer at a time; that 17 million dollars isn't a great deal of money.

Mark Peplow: Yeah you're absolutely right Adam. The estimate is that if you roll this out over like 10,000 farming families in that region you would reduce carbon dioxide emissions by about the same amounts as if you took about half a million vehicles of the road for one year. Now that's not loads, it's really not, but the reason what people are so excited about this project is sets the standard for something called REDD. Now that stands for Reducing Emissions from Deforestation and Degradation and it covers a whole range of plans which are going to be discussed at the Copenhagen climate summit in December. REDD is being held up as one of the things that we can really get right at Copenhagen and where you can basically get industrialized rich nations paying to preserve the forests that we have at the moment. Deforestation accounts for about 20% of global greenhouse gas emissions. So stopping that deforestation is one of the main ways we can make an impact. Now the project that I've just talked about is tiny but if you multiply that by thousands across the world and they really are talking about agreeing to those sorts of things at Copenhagen then that could make a big impact.

Adam Rutherford: So, this is the first example of how addressing deforestation can work and this is specific to the Amazon, or we going to see this rolled out across the rest of the world?

Mark Peplow: This plan is already well underway in places like Indonesia and various countries in Africa; in fact we will be having a feature in the magazine within a few weeks about projects in Africa on this front. So there's a lot of opportunities there for discussing these sorts of things. I guess one of the key things is that it not only helps to sort of balance the carbon budget globally but if you look at a lot of these countries they are rapidly developing nations and yet deforestation in Brazil for example accounts for 70% of it's emissions. If it can tackle those it makes a big dent in the possible future mission that that country is going to see.

Adam Rutherford: Right good stuff. Now to finish with we have had lasers, we have had maizes, and now we have got SPASERS. What is a SPASER, please Mark?

Mark Peplow: It is the world's smallest LASER at the moment at least. It's effectively a miniature laser that's contained in a sphere of silica just 44 billionth's of a meter across. This SP of SPASER refers to Surface Plasmons. This is a ripples in the electrons that set around tiny nanoparticles and what scientists have managed to do is to use light, basically to sort of stimulate those ripples of electrons so that they in turn emit light but crucially light that's coherent; they are all the waves of the light are all lined up together just like they are in a laser and that makes them potentially far more useful than these sort of glowing nanoparticles that were seen in the past which can emit light but it's incoherent.

Adam Rutherford: And for our biology listeners the ASER bit stands for Amplification by Stimulated Emission of Radiation, how did I do?

Mark Peplow: You're very, very good Adam.

Adam Rutherford: Thank you. Now what is the SPASER for? Is it just a proof of principle or we going to see new technologies based on this?

Mark Peplow: At this stage it's proof of principle and you expected me to say that; it's great that they stimulate this coherent light but at the moment it's coming out in all directions usually you want a beam of laser light but the people working in this field have been seeing rapid progress here and they are confident that's, you know, a sort of solved out in a year type problem. Of course you can use this sort of SPASER light, LASER light coming from these nanoparticles you can potentially use it for laboratory experiments, explorations like where you need very, very small LASER sources but one of the things that people are most excited about is the possibility of using it in light based computing rather than using electrons carry information, you case use photonics to use light to carry information around the computer and that field has been growing for quite a long time and one of the key things that you would need to be able to do in that is the very precisely control the generation of light and this is a very promising way of doing that within future light-based computers.

Adam Rutherford: Okay Thanks Marks, set SPASERS to stun. More info at well, have a guess, it has to do with Nature and news and slashes.

Kerri Smith: Is it by any chance? That's all from us this week next time a very hot Jupiter and some news on monkeys and mitochondria. I'm Kerri Smith.

Adam Rutherford: And I am Adam Rutherford. We dig fossils.