Interviewer: Kerri Smith
Coming up: Winston Churchill’s surprising passion for science.
Interviewee: Mario Livio
I find this not only refreshing but at some level astounding.
Interviewer: Adam Levy
And, how our bodies maintain the walls around our organs.
Interviewee: Interviewee: Jody Rosenblatt
When cells die we thought they would just create holes in that barrier but they don’t.
Interviewer: Kerri Smith
Plus the material that behaves bizarrely when you poke it. This is the Nature Podcastfor February the 16th2017. I’m Kerri Smith.
Interviewer: Adam Levy
And I’m Adam Levy.
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Interviewer: Adam Levy
First up this week, Noah Baker finds out about the scientific side of one of Britain’s most iconic political leaders.
Audio Clip: Winston Churchill
We shall fight on the beaches, we shall fight on the landing grounds, we shall fight in the fields and in the streets, we shall fight in the hills; we shall never surrender…
Interviewer: Noah Baker
Rousing words, which echo in the annals of history. Winston Churchill is known as an iconic war time leader, orator, author and even painter. But he’s less known as a strident supporter of science. During the Second World War, Churchill invested in research leading to the development of Radar. Churchill sought advice from statisticians on how best to defeat German U-boats. Military officials complained about Churchill’s science-first approach, arguing, ‘are we fighting this enemy using weapons or slide-rules?’ To which Churchill is said to have simply puffed his cigar and responded, ‘good idea – let’s try the slide-rule’. But Churchill’s passion for science ran deeper than just government policy as is demonstrated in a previously unpublished essay originally penned by Churchill in 1939. It tackles the topic of extra-terrestrial life and it came as a real surprise to astrophysicist and author Mario Livio when he unexpectedly came across the essay.
Interviewee: Mario Livio
I was giving a talk at Westminster College in the US.
Interviewer: Noah Baker
Westminster College is also home of the National Churchill Museum and curator James [Timothy] Riley brought the previously unseen essay to show to Livio to get a scientist’s perspective.
Interviewee: Mario Livio
He gave me a copy of the essay and we agreed that I would read it and let him know what I think of it.
Interviewer: Noah Baker
The essay had a striking impact on Livio.
Interviewee: Mario Livio
I honestly had no idea that Churchill had such a profound interest in science as to think about this in a deep way and even write essays about this. I find this not only refreshing but at some level astounding that Churchill would delve into such topics.
Interviewer: Noah Baker
What really impressed him was the way Churchill approached his writing.
Interviewee: Mario Livio
He really approaches the problem the way a scientist would. Firstly he realisesthat this is a fascinating question: are we alone in the universe? He first tries to define what life means.
Audio Clip: words of Winston Churchill read by Richard Hodson
It may seem that this is rather like the well-known story of the elephant. We may not be able to define an elephant but we know one when we see it. About life, that is not quite true.
Interviewee: Mario Livio
Then, he tries to think, okay, so what are the conditions that are necessary for life?
Audio Clip: words of Winston Churchill read by Richard Hodson
If life in the form we know it is to exist anywhere it can only be in the regions of comparatively moderate temperature, say, between a few degrees of frost and the boiling point of water.
Interviewee: Mario Livio
The he goes methodically about the bodies in the solar system and looks at each one of those. Then he looks at the possibility of are there other planets? None were known at the time outside the solar system. He really advances in this problem, just the way we would today – scientists would today. So, I find this just incredible.
Interviewer: Noah Baker
It wasn’t just Churchill’s methodical approach which struck Livio, but his scepticism.
Interviewee: Mario Livio
He used a particular model, for example, for planet formation which was a model from 1917 by astrophysicist James Jeans. That model turned out to be wrong but at the time he wasn’t sure if it was wrong or not and that was the only model he knew. So at first he describes that model and what the consequences of that model are. And the consequences actually were, if that model were true, that life may be extraordinarily rare. But then he says:
Audio Clip: words of Winston Churchill read by Richard Hodson
This speculation depends upon the hypothesis that planets were formed in this way. Perhaps they were not.
Interviewee: Mario Livio
Maybe this model is wrong, he says. This is exactly the attitude that a scientist would adopt.
Interviewer: Noah Baker
Churchill wasn’t a trained scientist but he clearly highly valued the way scientists think and sought counsel from experts of the day. He was the first Prime Minister to hire a scientific advisor: physicist and Churchill’s friend, Frederick Lindemann.
Interviewee: Mario Livio
When the war broke out he realised, I think, that science was going to be key for success in the war and as a result of that I think he felt that he really needed to have somebody with whom he can consult on scientific matters.
Interviewer: Noah Baker
Livio believes that Churchill’s approach to science should act as a lesson for modern day politicians.
Audio Clip: words of Winston Churchill read by Richard Hodson
You know, if anything, we are more dependent on science today to solve the biggest problems that humanity is facing than even at the time of Churchill. If Churchill found it important to appoint a science advisor and to meet with scientists and to listen to them in order to inform his decisions, then I think that it is certainly true today. And I would have hoped that any high ranking politician today that has to make decisions, that at least partly if not wholly, depended some level on science, should have a science advisor.
Audio Clip: words of Winston Churchill read by Richard Hodson
I for one am not so immensely impressed by the success we are making of our civilizations here that I am prepared to think we are the only spot in this immense universe which contains living, thinking creatures, or that we are the highest type of physical and mental development which has ever appeared in the vast compass of space and time.
Interviewer: Adam Levy
That was Mario Livio speaking with Noah Baker. Quotes from Churchill’s essay were kindly provided by John [Timothy] Riley at the National Churchill Museum in Missouri, US, and were read by Richard Hodson. You can read more about the work in a Comment piece written by Livio at nature.com/news.
Interviewer: Kerri Smith
Still to come in the News Chat: how Turkey’s tumultuous political situation is affecting scientists. We get an update from our correspondent, Alison Abbot, who is just back from visiting several labs in the country. And in the Research Highlights: deep ocean pollution and cool buildings.
Interviewer: Adam Levy
Now though, researcher Corentin Coulaiscreates materials unlike any other. Last August he published a paper detailing a shape-shifting cube. When the cube is squished, a smiley face emerges from one of the previously flat sides. Here’s Corentin…
Interviewee: Corentin Coulais
It’s not really a property that you would relate to a material but more a property you would associate with a machine.
Interviewer: Adam Levy
But Corentin isn’t out of ideas for these bizarre meta-materials just yet.
Interviewee: Corentin Coulais
One of my endeavours is to push the limits of what we can do with meta-materials.
Interviewer: Adam Levy
And so Corentin has developed a meta-material that responds strangely when you give it a push. You see, normal materials don’t care which side you push them from. It’s easiest to imagine if you think about a plate jelly. That’s jellow to you Americans. Take this jelly conveniently placed between me and Kerri.
Interviewer: Kerri Smith
Mmmmm, right, I’m ready for the jelly.
Interviewer: Adam Levy
I don’t think you are ready for this jelly, because I haven’t finished explaining.
Interviewer: Kerri Smith
Eurgh, okay. I’ll wait patiently for the jelly.
Interviewer: Adam Levy
Thanks, okay, so if I push my side of the jelly, Kerri’s side will ‘wibble’ over by as certain amount.
Interviewer: Kerri Smith
Yeah, what, by about 10 centimetres or so?
Interviewer: Adam Levy
Yeah, looks about 10 centimetres. Now, if I stop and Keri pushes her side with the same force I pushed with…
Interviewer: Kerri Smith
Pushing the jelly now…
Interviewer: Adam Levy
Then I will measure, yeah, the same 10 centimetres of ‘wibble’ on my side. And this should happen with all materials. It doesn’t matter if Kerri or I push it, the opposite side should move by the same amount, regardless. But, surprise, surprise, Corentin’s new meta-material doesn’t behave like this. His material ‘wibbles’ more if you push it on one side, versus if you push the other: handy for building things that don’t get disturbed by vibrations, for example. I called him up to see how he did it.
Interviewee: Corentin Coulais
The idea was to break the symmetry of motion and to do this we needed to first have a non-symmetric structure and second was to break one of the assumptions of the theorem that grounds this property which is linearity. And so linearity is very simple and intuitive, and you encounter it when you take a spring and if you want to deform the spring by a certain amount you have to exert a certain force. And if you want to pull on the spring twice as much, you have to exert twice as much force, and that’s linearity. Now by using a specific architecture which can reconfigure when you pull on it, you can break this proportionality, this linearity, and that’s the second ingredient that we used.
Interviewer: Adam Levy
Looking at the figure here, it looks kind of like a fishbone, about 10 centimetres long, with a spine down the middle and then ribs along the length. But what would I see if I pulled one end of this spine, versus if I were to pull the other end?
Interviewee: Corentin Coulais
What you see in the paper is that you see that the structure the snaps. So if you pull it from one side you are going to trigger motion but only in the near vicinity of where you were pulling. But the structure is designed such that now if you pull and push on the other side the motion that you trigger is going to propagate across the whole structure. Therefore that makes a very strong difference between pulling from one side or pulling from the other.
Interviewer: Adam Levy
When you finally managed to come up with this design, how did you feel when you actually tested it out and it did what you were hoping it would do?
Interviewee: Corentin Coulais
[Laughs]Well when you say it sounds so simple: isn’t that trivial? It’s always nice to have a desktop scale experiment as I do because then you can really see what you observe.
Interviewer: Adam Levy
Well meta-materials have been in the news quite a bit lately. You actually worked on a cube where if you squish it a smiley face appears. Can these approaches be combined in a useful way or are they just all useful in different settings?
Interviewee: Corentin Coulais
I think what I do, including this smiley cube, is to create and augment the toolbox of functionalities that you can obtain using meta-materials. And I’m very happy to primarily focus on that job but then I guess these are concepts or ideas that have to be taken on board by people who are interested in applications or more applied – in mastering how objects deform for application. So for instance people making, fabricating, shoes or prostheses are very interested in having tools to be able to control how things deform and transmit motion. As a researcher I am mostly interested in developing new concepts and then transmitting it and giving it to people who might be interested in using it for a specific application.
Interviewer: Adam Levy
What’s next in you plans for interesting meta-materials?
Interviewee: Corentin Coulais
As you saw we have materials that are used to channel mechanical energy in a smart way. So, transmit motion in one way or have a programmable, morph-able texture. But then what I would be very interested in in the future is finding ways to convert, not only mechanical energy, but for instance to convert chemical or electro-magnetic energy into this mechanical energy. There’s a lot to be done.
Interviewer: Adam Levy
That was Corentin Coulais who is now based at the University of Amsterdam’s Institute of Physics. Check out the paper at nature.com/nature and to see a video of Corentin’s smiley face meta-material, head to our YouTube channel: youtube.com/NatureVideoChannel.
Interviewer: Kerri Smith
Coming up, ‘we’re gonna build a wall’, a cell wall that is. But first, some more of the best research in bite-size form: it’s the Research Highlights read by Noah Baker.
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Interviewer: Noah Baker
Pollution has managed to infiltrate even the deepest chasms of the Pacific Ocean. A UK based team sent a deep sea lander to depths of up to 10,000 metres and used a funnel to catch some of the little critters living there. In some crustaceans from the Mariana Trench, levels of one type of pollutant called polychlorinated biphenyls were 50 times higher than in crabs from one of China’s most polluted rivers. These chemicals were banned in the 1970s but they probably ended up in the bottom of the ocean when plastic debris or contaminated dead animals sank. The paper is in Nature Ecology and Evolution.
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A thin film could help cool buildings by radiating their heat through the atmosphere into space. Scientists in Colorado manufactured the film by embedding tiny glass micro-beads in a polymer and then coating the back, the building side, with silver. The film reflects most sunlight and it’s particularly good at reflecting an infra-red wavelength that passes straight out of the atmosphere. They’re not the first to make this kind of material but theirs is cheaper to make and works around the clock. The paper is in Science.
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Interviewer: Kerri Smith
Adam, what do you think is the toughest, most bad-ass organ?
Interviewer: Adam Levy
Maybe the liver because it has to deal with all that alcohol you throw at it? Oh no, wait, maybe the brain because it has to bury all the difficult thoughts? Or the heart, because it can heal after it’s broken? I don’t know.
Interviewer: Kerri Smith
Well, I was actually angling for skin.
Interviewer: Adam Levy
Skin?
Interviewer: Kerri Smith
Interviewee: Jody Rosenblatt
They’re very tightly linked cells. They look like bricks in a wall so you’d think that doesn’t look that challenging – yeah, it can act as a barrier but the thing that surprised us is that these cell types are turning over by cell death and cell division, some of them at the highest rates in the body, and we think how is it maintaining this barrier when there are cells that are dividing and dying. When cells die we thought they would just create holes in that barrier but they don’t. And then the other thing is, how do you make that tight link between the number of cells dividing and the number of cells dying?
Interviewer: Shamini Bundell
Because if more cells die than are formed from division then there aren’t enough cells, and then what would happen?
Interviewee: Jody Rosenblatt
We think that could really be a central cause of a lot of inflammatory diseases: things like asthma, colitis. And then on the flip side, we’ve seen epithelia turn over the fastest rates; we think that’s probably why these are the types of cells that get cancers the most often. 90% of all cancers arise in these types of simple epithelia.
Interviewer: Shamini Bundell
So the balance between cell death and cell division is really important. And you’ve been interested for a while now in how the epithelia maintain that balance. And before we get onto your latest paper, your previous research was on cell death: so, how the barrier can work if the cells that make it regularly die and leave a hole.
Interviewee: Jody Rosenblatt
They don’t just form holes. What they do instead it is they get shoved out by their neighbouringcells and what we found then drives that is just simple crowding. So there’s too many cells; some get shoved out to die.
Interviewer: Shamini Bundell
And that’s what you call the cells getting extruded, pushed out of the layer. And you were also able to work out how the cells work out when they’re overcrowded and should start extruding.
Interviewee: Jody Rosenblatt
Yeah, so that’s a sensor that we found called Piezo1 and it senses the crowding and then it will spark a spark of calcium and then one cell will go onto extrude. We don’t know yet what drives one cell to extrude versus another cell but we just know that it happens in regions of the epithelium that are 1.6 fold more crowded. So once they get around that level, then they say somebody’s got to go.
Interviewer: Shamini Bundell
So you’ve found the trigger for how the message is communicated?
Interviewee: Jody Rosenblatt
Yeah.
Interviewer: Shamini Bundell
So that’s how the cells in the epithelia know they’re over crowded, know they need to get rid of some people. And then you’ve got a new paper out this week which is about the opposite: how do cells know when they need to strengthen that barrier.
Interviewee: Jody Rosenblatt
We just started thinking about what happens in the case where there’s not enough cells. Could stretch on the other hand activate cells to divide? And part of the reason that we started thinking this is that what we saw. So when we were just looking at lots of different epithelia, we always noticed that the regions where they were dividing were more stretched and actually when we went into measure it there was, again, 1.6 fold more stretch then the places where there weren’t.
Interviewer: Shamini Bundell
And that makes sense that not enough cells leads to cell division. It’s the opposite of the first study where overcrowding led to cell death. And you looked into what the actual channel was gain that was triggering it and it was Piezo, again, the same channel?
Interviewee: Jody Rosenblatt
We were really kind of shocked because we were thinking how does one single stretch activated channel control two opposing things with opposing read-outs and all the time knowing that the main thing that it did was cause a calcium spark. And so calcium sparks are just this very simple signal that is like an off/on switch. So that suggested to us that it depends on what the cells are primed to do and then the calcium just says, ‘yep, you’re on, you’re going to do it’. In the case of the cells extruding, maybe they can’t divide. In the case where the cells are stretched, we know that they’re acting on cells that are in a certain stage of the cell cycle to push them into the last stage of the cell cycle.
Interviewer: Shamini Bundell
So you think that in an epithelium that’s already stretched, the cells are primed to divide, whereas in an epithelium that’s overcrowded, they’re primed to extrude?
Interviewee: Jody Rosenblatt
That’s true and then there’s another aspect. So, that Piezo is localized to a different region so we think that could also control its output.
Interviewer: Shamini Bundell
So the Piezo1 channel’s ended up in a different region in the cell, perhaps in a different membrane. But we don’t know how it gets there. Is there another signal controlling that? And we don’t know how the cells are primed to divide or extrude in the first place, so actually this finding about Piezo detecting, stretching or crowding is just one tiny part of a much bigger puzzle.
Interviewee: Jody Rosenblatt
Yeah I think we’re at this really exciting stage where there’s a lot of guesses about what’s going on. But we think that understanding what controls the cell division and cell death in epithelia is of critical importance. And now, as we’ve discovered this whole signaling that’s involved in extrusion, and we’re hoping in the cell division pathway, we’re finding that it’s mis-regulated in cancers we have no cure for yet and so by understanding that fundamental piece we’ll be much better able to actually treat these types of diseases rather than just try and patch and repair the symptoms of these diseases which is what we’ve been doing.
Interviewer: Kerri Smith
That was Jody Rosenblatt from the University of Utah talking to Shamini Bundell about her epithelia, more details of which can be found in a paper and a News & Views in this week’s issue: nature.com/nature.
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Interviewer: Kerri Smith
Time for the News now, and this week we have a special report on Turkish science. The Turkish government wants to plough funding into science but its bold vision might be compromised by the volatile political situation there: the conflict between the government and Kurdish separatists has been escalating which some scientists have spoken out against. And in July 2016 the military attempted a coup. That ended up involving scientists as well because the group thought to be behind the coup had infiltrated universities and other institutions. So the Turkish president, Erdoğan, wanted to get rid of them but he rather threw the baby out with the bathwater and lots of academics lost their jobs. The latest wave of dismissals came just last week when 330 academics were sacked. Nature’s senior European correspondent Alison Abbott visited Turkey to see how scientists are coping. Alison, welcome to the podcast. How have academics been affected by the political situation in Turkey?
Interviewee: Alison Abbott
After the coup attempt Erdoğan was keen to remove the Gülenists and I think most scientists agree this is something that needed to be done. But during these purges which have come in waves of decrees directly from Erdoğan, in the universities 7300 and more have already lost their jobs.
Interviewer: Kerri Smith
So to find out more about what it’s like trying to do science in this environment, Alison, you travelled to Turkey in January this year.
Interviewee: Alison Abbott
So, I went there in January because I’d been following Turkey for many years and I just really wanted to get into the labs and ask people directly there, what they’re thinking in this very sensitive time. I was very surprised when I went there to learn of a serious government plan to build up a strong research base. This I found completely at odds with what I heard from the scientists who are all very nervous about what’s going to happen. Some actually are in the process of leaving, some in the process of planning to leave. People who are very good there, who have big international grants to help them work independently – ERC grants, EMBO grants – they have the freedom to move those grants outside to other countries and I think a lot of them are just going to do this and the big plan will have to be fulfilled with people who are not in the first ranks of research and that is not what the government wants.
Interviewer: Kerri Smith
As you say, the plan that Turkey seems to have to boost its science enterprise into the future seems completely at odds, doesn’t it, with the current situation? What did you learn about the science plan that is meant to be going ahead?
Interviewee: Alison Abbott
Well, they’re building, they’re creating – this all happened since 2014 – they’ve created a system of national research centres which didn’t exist before. All the research was more or less carried out in universities. Universities are highly bureaucratized and highly centralized; they can’t make any of their own decisions. They’ve created a National Institute of Health, like the US NIH, which has 6 different institutes with research centres and they’re recruiting this year alone, 300 new posts. They have introduced competition between universities to make some of them elite and give them elite status, like the German excellence initiative, and these universities will be rewarded by having more positions, more money and a little bit of autonomy to make their own decisions. What else? They’ve opened up 2,000 new PhD positions so that the new plans will have a new generation to feed into them. It’s very systematic.
Interviewer: Kerri Smith
There must be some mixed feeling then amongst the scientists you visited about this brave new world versus what they’ve all been through just lately?
Interviewee: Alison Abbott
Yes of course there’s mixed feelings and a lot of Turkish scientists who trained abroad came home expressly because they wanted to work at home. They wanted to be home with their families. They wanted to help build up the research base in Turkey again, and now they’re seeing what’s happening they don’t particularly feel safe. They don’t know what’s going to happen politically from one day to the next. The coup has upset them. The government’s response to the coup with all these purges has upset them so they do understand that the government plans to build up a research base and they find that encouraging. It’s just, personally, you know, it’s difficult.
Interviewer: Kerri Smith
With everyone feeling so nervous about it, are the government going to be able to go ahead with their plan? Will scientists eventually start going back?
Interviewee: Alison Abbott
I think the government will go ahead with its plan anyway. I mean, the plan is now underway. It’s really the question, how successful can it be? It’s better than not having a plan at all but if you can’t attract the best scientists to work in your system then obviously you can fill it with scientists who are not the best. That’s not so good.
Interviewer: Kerri Smith
Alison Abbot on the line from Munich. You can read more about her visit to Turkey in her feature at nature.com/news.
Interviewer: Adam Levy
That’s all we’ve got time for this week, but if you didn’t get enough of last week’s story on how we might get a spacecraft to our nearest exoplanet, head over to our YouTube Channel, youtube.com/NatureVideoChannel. There’s some pretty cool animations on how it all might happen. See you next week. I’m Adam Levy.
Interviewer: Kerri Smith
And I’m Kerri Smith.
