Interviewer: Benjamin Thompson
Hello and welcome to the Nature Podcast. This week, we’ll be finding out how giant engineering projects could help slow down sea level rise.
Interviewer: Shamini Bundell
And we’ll be hearing how diamonds are helping to increase the resolving power of NMR. This is the Nature Podcast for the 15th March 2018. I’m Shamini Bundell.
Interviewer: Benjamin Thompson
And I’m Benjamin Thompson.
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Interviewer: Shamini Bundell
Here on the Nature Podcast, we talk quite a lot about climate change.
Interviewer: Benjamin Thompson
Agreed, but it is quite important.
Interviewer: Shamini Bundell
True, well, we’ve got another climate change-related story today, but this one is rather unusual. Rather than focusing on preventing the planet from warming up, today we’re talking about how to slow down sea level rise. There’s a proposal from a group of scientists writing in a Comment piece in this Nature this week, that one solution could be massive engineering projects in Antarctica. I got in touch with one of the scientists proposing this. John Moore is a glaciologist who knows Antarctica pretty well.
Interviewee: John MooreWorking in Antarctica, the first thing I would say that you notice is the silence, it is so quiet. There’s no cars, there’s no wind rustling through trees, and if you look around, of course you see no evidence of humanity existence at all except the tent that you’re living in.
Interviewer: Shamini Bundell
So, it feels like this pristine environment is one of the last places you’d want to be doing big construction projects in, but these glaciers and ice shelves are already under threat, or disappearing, right?
Interviewee: John Moore
The northern parts of the Antarctic Peninsular are where the ice shelves have started to collapse in the last 20 years or so, so yeah, what used to be a solid ice shelf perhaps 200 metres thick, is essentially open water, or covered by just a metre or two of sea ice.
Interviewer: Shamini Bundell
And that brings us to the problem, which is that all this melting ice is what’s actually making the sea levels rise.
Interviewee: John Moore
At the moment, it’s not making a very big contribution to sea level rise, but it’s expected that Antarctica will become more and more significant, and even dominant through the rest of this century, to global sea level rise.
Interviewer: Shamini Bundell
And we’re talking about really big predictions for the amount of sea level rise, so maybe on average a metre over the next hundred years, and then obviously, floods become more common too, so that’s going to become somewhat problematic.
Interviewee: John Moore
Without any adaptation measures to avoid flooding, the damage would run into trillions of dollars per year. More realistically, with adaptation done along coastlines, building walls, dikes etc., hardening cities and vulnerable infrastructure such as nuclear power stations, that’s expected to be of the order or perhaps 10 to 50 billion dollars per year by the end of the century.
Interviewer: Shamini Bundell
So, I guess that’s the current assumption, what I would assume that we’re going to do about sea level rise is, okay fine, let’s try and protect coastal cities, let’s kind of do what we can, as it happens. But your Comment piece is sort of suggesting an alternative route, to try and pre-emptively stop some of that sea level rise.
Interviewee: John Moore
So, one idea is simply to build a wall, so that you actually, physically stop the warm water from being able to approach the ice. The other part, is to try to stabilise the ice shelves by giving them some land to make contact with, and what that does is that the ice shelf grinds up against this little island that we built and very much stabilises the flow, it means that the ice shelf itself is much less vulnerable to disintegrating. The third idea is a little bit different, we’re taking these large ice streams that are flowing very, very quickly, on a thin layer of melt water. So, if you can dry the bottom of the bed of the glacier, it will increase the friction, and it will slow the glacier down, which in turn, will mean that there’s less melt water produced because it’s sliding a lot slower. And, as you slow the glacier down it is carving less ice into the ocean.
Interviewer: Shamini Bundell
All three of those ideas sound just kind of, huge.
Interviewee: John Moore
By definition geoengineering is not small-scale. But in terms of the comparison to existing civil engineering projects, it is not total science fiction. The kinds of numbers that you get are either of the order of very large engineering projects like the Suez Canal, or an order of magnitude or so larger than that.
Interviewer: Shamini Bundell
Now, despite that sounding very expensive, you argue that it’s still actually going to be much cheaper than the total future cost of protecting all the coastlines and power stations and things. But are people actually going to be willing to do it? What’s been the general reaction to these ideas?
Interviewee: John Moore
Whenever I talk about it with my colleagues, the initial reaction is absolute horror at the idea of going to Antarctica and doing this large construction project, which would be certainly much bigger than anything going on in Antarctica at the present. But when people actually consider what the alternatives are, then you have to make a balance and try to figure out, well you know, perhaps you have to risk damaging some comparatively small region, but to try to preserve the bigger ice sheet and the bigger global sea level.
Interviewer: Shamini Bundell
And say we manage it, how much time does that actually give us?
Interviewee: John Moore
It depends of course on how much warming of the atmosphere is taking place at the same time. So, this is not an alternative, I can’t emphasise that too strongly. This is not an alternative to finding alternatives to burning fossil fuels, that has to be done as well. But our simulations at the moment, suggest that we could delay sea level rise for perhaps 2, 300 years by making these kinds of constructions in the West Antarctica.
Interviewer: Shamini Bundell
That was John Moore of the Beijing Normal University and the University of Lapland. You can read the Comment piece to find out more about how to geoengineer a glacier at nature.com/news.
Interviewer: Benjamin Thompson
Later in the show, we’ll be learning about the state of Russian science, that’s coming up in the News Chat. Next though, were joined by Emily Banham for a quick update on the latest science. It’s time for the Research Highlights.
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Interviewer: Emily Banham
Robots have already gained some remarkable abilities. They can swim like octopuses and wriggle like worms. And now, feelings are within their grasp, the feeling of touch, that is. Researchers from Harvard University made rubber robotic fingers infused with sensors made from a conductive gel that collects data from whatever surface they come into contact with. The team used three of these flexible fingers to make a soft hand, that could hold a ball and report its temperature and texture. Soft and supple sensors could help give future robots a real feel for their surroundings. Get hold of the full paper in Advanced Materials.
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Interviewer: Emily Banham
Wild petunia pips have performed the fastest pirouette ever observed in nature. While the flower is already famous for launching its seeds as great speeds, it’s only now that they’ve been caught on high-speed cameras. When flung from the flowers fruit, the seeds rotate up to 100,000 times a minute. That’s about as fast as a dentist’s drill. Shaped like wagon wheels, the seeds spin in an upright position, but rotate backwards as they fly forwards. This creates an aerodynamic effect that propels the pips up, up and away, sending some seeds soaring a whopping seven metres away from the plant. Catch this research in the Journal of the Royal Society Interface.
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Interviewer: Shamini Bundell
Ben, I have something to ask you. It’s been something I’ve been thinking about for a long time…
Interviewer: Benjamin Thompson
Oh yeah?
Interviewer: Shamini Bundell
Well, look, we’ve been working together for six months now, and well, we just have a really great time.
Interviewer: Benjamin Thompson
Yeah, I mean, we have a great time, definitely.
Interviewer: Shamini Bundell
So…
Interviewer: Benjamin Thompson
Wait, is that a diamond?
Interviewer: Shamini Bundell
Benjamin Thompson…
Interviewer: Benjamin ThompsonNo, not happy about this at all, my wife is going to be so angry…
Interviewer: Shamini Bundell
Will you… image some nanoscale chemical structures with me?
Interviewer: Benjamin Thompson
What?
Interviewer: Shamini Bundell
This little diamond is full of quantum defects called NV centres, and Ron Walsworth and his team from Harvard have been using it for nuclear magnetic resonance imaging. It’s really cool, I thought you might want to have a look?
Interviewer: Benjamin Thompson
Phew… I mean yeah, that does sound interesting, and exactly what I thought you were going to ask. So, how does this diamond magnetic resonance thing work then?
Interviewer: Shamini Bundell
Ah, well. Noah Baker has been talking to Ron Walsworth to find that out.
Interviewer: Noah Baker
If scientists want to study something, they need to measure it, and there’s a whole host of different things to measure: mass, density, charge, so on. When measuring really tiny things, one of the properties that scientists use is magnetic fields. You see, all matter is made up of molecules, which are made up of atoms, and inside each of those is a nucleus. Now, these nuclei can have a quantum property called spin, and associated with that is a magnetic field. Essentially, nuclei can act like tiny magnets, and by measuring their magnetic field, scientists can get a picture of what’s there and what it’s doing. The process is called nuclear magnetic resonance, or NMR. I called up Ron Walsworth who told me some more.
Interviewee: Ron Walsworth
Okay, so NMR is a commonly used technique. The information you can get out measuring the magnetic fields that are emitted by these little spinning nuclei is remarkable. You can learn a lot about the structure of molecules, and their behaviour, their chemical properties, etc. And so, it’s a very, it’s become over the last many decades, a very widely used tool. It’s also the basis of MRI.
Interviewer: Noah Baker
And, so, in this paper you’re investigating a new type of sensor, one that can be used to detect these magnetic fields, sort of a new way to do NMR. I guess first, what’s wrong with the current system or why does it need improving?
Interviewee: Ron Walsworth
Yeah, so I mean, the wonder of NMR and MRI comes from the fact that, partially comes from the fact these magnetic fields that are emitted by these little nuclei, interact with matter weakly, it can pass out, let’s say of a sample or a body, into a coil that is traditionally used a coil wire to detect the signal. But that weak interaction has meant that when you get the very small quantities of matter at the, let’s say, at the scale of an individual biological cell, there’s too little signal being emitted for conventional technology to be able to detect the signal. So, you kind of, things got too small to be observed. So, what we do, is we’re using a new way to detect the signal that actually provides better sensitivity at the smaller scale.
Interviewer: Noah Baker
Okay, so what is this new detector that you’re using to replace coils of wire?
Interviewee: Ron Walsworth
We use a particular type of quantum defects in diamond.
Interviewer: Noah Baker
Tell me about these defects then, and how can they be used to measure magnetic fields?
Interviewee: Ron Walsworth
So, two neighbouring carbon atoms are replaced in the diamond by a nitrogen atom and a missing carbon atom known as a vacancy. And this little so called nitrogen-vacancy quantum defect or colour centre, which can give a red colour to diamond, also has remarkable properties. When illuminated with light, with visible light, it will radiate in the red, and the intensity of the red light it gives off, is a strong function of the local magnetic field. Okay, so, each little NV defect inside of diamond is itself a little, magnificent atomic-scale sensor of magnetic fields.
Interviewer: Noah Baker
Okay, so, you put your sample on a bit of diamond containing these NV centres. You shine a light on the NV centres so that they fluoresce, but the light that they emit will be modified in a specific way by the tiny magnetic fields of the nuclei in the sample. So, it’s kind of like the sample is leaving an imprint in the light, and you can look at that light and work out what left the imprint?
Interviewee: Ron Walsworth
Exactly right. If you look at the signal of the red fluorescence as a function of time, it carries the imprint of the NMR signal from the sample on it. And so, we’ve essentially in some ways, converted the NMR signal into an optical signal, and the time variations of that optical signal carry the molecular information that’s in the NMR signal there. And we can do this with this high spectral resolution, this high special resolution, and non-invasively.
Interviewer: Noah Baker
So, give me some numbers here. What is the increase in resolution you’ve managed to get with this new system that you’re working with?
Interviewee: Ron Walsworth
So, if we’re looking at molecules outside the diamond like we’re doing here, it’s about a two order or magnitude increase, a hundred fold increase in spectral resolution.
Interviewer: Noah Baker
What do you want to unleash your discovery on, do you have anything in particular you want to look at now, I suppose?
Interviewee: Ron Walsworth
So, we’re not ready to being solving biological problems and chemical problems yet, but the problems that we want to address are things like being able to non-invasively, because the diamond sits outside itself, non-invasively monitor chemical reactions that are going on within living cells. We’d also like to be able to watch, not just in biological cells but let’s say, small chemical reactions that are relevant for developing pharmaceuticals etc. that can occur on these small-length scales and really be able to watch that non-invasively. So that’s the goal.
Interviewer: Noah Baker
And what have you got left to do to get to that place?
Interviewee: Ron Walsworth
Yeah, so, we now have the spectral resolution, great. The thing we’re missing is enough sensitivity to be able to monitor these processes in real time. The data that’s in our paper, you know, one of these individual high spectral resolution results maybe took ten hours of signal averaging – that’s too long. If we want to be able to watch real time phenomena we need to be able to do it in real time.
Interviewer: Noah Baker
It strikes me that, you know, on the very base of it, that the ingredients that you’re using in this technology, it’s quite simple. You’re using laser light, you’re using a diamond containing these NV centres. How much is there that you can tweak and modify to improve these things that you’re talking about?
Interviewee: Ron Walsworth
You’re right, you might think hmm, okay, it’s so simple there isn’t much left to improve, is there? Well, yes and no. The sensitivity of the NVs two signals are strongly dependent upon what’s going on within the diamond, and the diamond has lots of unwanted impurities inside of it that we and others are working on ways to reduce and to control. We can also come from collecting more and more of the light that the NVs are emitting, we’re not doing an optimal job yet, and since that carries the information, we want to get all those photons the NVs are emitting, we’re working on that. Lastly, we can boost the signal from the signal source. The little nuclear spins that are generating the magnetic fields in the sample, right now, we operate at a kind of medium strength magnetic fields, and there’s no reason we can’t operate at a much higher field, and the higher the field the stronger the signal they give off.
Interviewer: Shamini Bundell
That was Ron Walsworth from Harvard University in the USA, speaking with Noah Baker. You can read more about the study over at nature.com/nature.
Interviewer: Benjamin Thompson
Finally, this week it’s the News Chat, and I’m joined in the studio by Ewen Callaway, one of the reporters here at Nature. Thanks for joining us Ewen.
Interviewee: Ewen Callaway
Yeah, sure.
Interviewer: Benjamin Thompson
Well, our first story today, we are going to head to Russia. This Sunday sees the country’s next presidential election, and I think it seems more likely than not that Vladimir Putin is going to win. But now some researchers are hoping that this will represent maybe the ideal time for the country to get behind science in a way that maybe hasn’t happened for a while?
Interviewee: Ewen Callaway
Yeah, so this story comes from my colleague Quirin Schiermeier, who covers Russia from Germany. And his sense in reporting this story is yes, Putin is all but, you know, a dead cert he’s going to be re-elected, and he’s starting to talk about science and innovation like he actually cares, like you know, this is something that he might actually improve, and win work on in his term. Since the fall of the Soviet Union, there’s been a long-term decline in Russian science, which used to be really quite prominent, especially in physical sciences. And, yeah, the question remains, is this talk, you know?
Interviewer: Benjamin Thompson
So, looking into this a bit though, it doesn’t seem that maybe things are as bleak as some people are painting? Certainly, investment has increased over recent years.
Interviewee: Ewen Callaway
Yeah, there’s been slight increases in investment, though, you know, it’s not clear whether it’s really making a difference. I think one of the problems that Quirin writes about and which he’s written about extensively in the past, is that in Russia, in Russian science institutes, there’s a kind of an embedded old guard that’s very resistant to change, resistant to having kind of western style science institutes that, you know, that are quite nimble and flexible and reward excellence. And so, reformers in Russian science, I think are finding it really hard to put this money to good use, I guess you’d say, that you could be ploughing money into a rotten system, so I think that’s a real lingering concern here.
Interviewer: Benjamin Thompson
Which begs the question then I guess, what reforms are needed as we move forward?
Interviewee: Ewen Callaway
They really centre on I think, these institutes affiliated with the Russian Academy of Sciences, there are more than 700 of them, and an evaluation that was completed in January found that like a full one quarter of them are really underperforming, they’re not putting out papers, these papers aren’t getting cited, and kind of other metrics.
Interviewer: Benjamin Thompson
And science as we know is very much a collaborational thing, and it doesn’t exist within a bubble. What does Russian science need to do maybe to continue collaborating and to reach out in the world, and it is already doing so?
Interviewee: Ewen Callaway
Well I think Quirin’s sense in reporting this story was that a lot of the problems with Russian science and a lot of, you know, areas for improvement are internal, but simmering beneath all this of course is Russia’s role as an increasingly isolated state, at least vis a vis the West, the country’s annexation of Crimea, its role in the Syrian civil war, you know its allegations of tilting elections have not won it favours with the West to put it lightly. And, I think there is concern that this could isolate Russian science further. It’s not having an effect so far, Quirin reports. Russia is still part of ITER, which is the experimental fusion reactor in the south of France, and they’re still part of other big infrastructure, and smaller collaborations are happening. But I think there’s a real concern that, like Russia itself, Russian science could grow isolated from the rest of the world.
Interviewer: Benjamin Thompson
Alright, well next we’re going to take a bit of a side-step and we’re going to talk about AI in healthcare, and in particular sort of the ethics around patient data usage. Before we start though Ewen, maybe, you know, you can tell our listeners what are some of the advantages of AI being used in healthcare?
Interviewee: Ewen Callaway
Yeah, this is based on a story from my colleague Amy Maxmen who’s based in San Francisco, which as you know is AI central. And you know, we’ve been hearing a lot of news about, you know, Google DeepMind developing AI that can, you know, beat the world’s best Go players, and things like that. But I think a lot of people hope that, you know, a similar approach, deep learning, can be used for other applications, and one that we’re hearing a lot about is in biomedical research, especially in looking at images, whether it’s of, you know, cancer biopsies or brain scans or something like that, and picking out patterns that are not necessarily obvious either to the naked eye, or with other types of computer algorithms used to find patterns in them.
Interviewer: Benjamin Thompson
Yeah, and I think we had an example last year we covered on the podcast, about skin cancer being identified by a computer, by an AI brain. But there is a worry that the people, sort of patients in particular, can be disempowered by these big kind of faceless corporations having access to their data.
Interviewee: Ewen Callaway
I think the real challenge with deploying AI and deep learning with medical data, like medical imaging data, is the data itself, because these algorithms, I think they really thrive and the only way they get good is by being trained on lots and lots of data. And I guess this creates a challenge with healthcare systems, with healthcare data where it’s often siloed at different hospitals or you know GP clinics and things like that. And so, there’s this issue of how do we safely share this data to improve these algorithms, doctors don’t want to go sharing, you know, their patients’ data with a corporation if they can’t be confident that it’s absolutely secure.
Interviewer: Benjamin Thompson
Yeah, and so Amy’s story is looking at something slightly different, and about a different technology being used to secure this data?
Interviewee: Ewen Callaway
You know, talk about buzzwords, you know, we’ve got AI, we’ve got deep learning, the next one is blockchain which is a term I have personally struggled to understand. But what I do know is this, it’s a cryptography technology that is the basis for cryptocurrencies such as bitcoin.
Interviewer: Benjamin Thompson
Yes, but rather than being used for sort of currency movement, this one’s involved in patient data.
Interviewee: Ewen Callaway
The hope is, is that to solve this problem people are using blockchain technology to be able to share large quantities of private medical data without worrying that it’s going to fall into the wrong hands. So, you can get improvements, I think, in AI algorithms, without compromising patient confidentiality.
Interviewer: Benjamin Thompson
Thanks, Ewen. For more on these stories don’t forget to head over to nature.com/news. We’ve also got some breaking news listeners which is that Stephen Hawking, one of the most influential science figures of his generation, has passed away at the age of 76. Head over to nature.com/collections/hawking, where you’ll find our obituary, and a collection of news articles about his life and work. We’ve also got a video about three of his most influential publications which you can find at youtube.com/naturevideochannel. Thanks for listening everyone, I’m Benjamin Thompson.
Interviewer: Shamini Bundell
And I’m Shamini Bundell.
Geoengineer polar glaciers to slow sea-level rise
Russian science chases escape from mediocrity
