The Infinite Monkey Cage - Does Size Matter?

Episode Date: July 2, 2012

Robin Ince and Brian Cox are joined on stage by comedian Andy Hamilton to discuss whether size matters? Material scientist Mark Miodownik and bioengineer Eleanor Stride also join the panel to discuss the advantages and disadvantages of being really huge, or extremely small, and why if you wanted to be a truly effective super hero, then being really really tiny is probably the greatest superpower you could have. Producer: Alexandra Feachem.

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Taxes extra at participating Wendy's until May 5th. Terms and conditions apply. This is a download from the BBC. To find out more, visit bbc.co.uk slash radio4. Ladies and gentlemen, you are stellar matter gone wrong.

And it's time you got used to that idea. This is the infinite monkey cage. And on my right, the 7 times 10 to the 27 atoms that were once in the shape of a gangly keyboard player and currently in the shape of a particle physicist who knows where all the stars in the galaxy are but normally needs help finding his own shoes.

That is entirely true, by the way. This man has no idea where anything is unless it's actually... If it's up in the sky, he's brilliant. If it's a fridge in a room... What's that white thing? Is that the fridge? Is that milk? I don't know. I've got a man to do that for me. It's... It's Professor Brian Cox.

Monkey cage is nothing if not educational, so I thought I'd tell you how Robin came to that number seven times ten to the 27. He took Avogadro's number, which, for back-of-the-envelope purposes here, on a monkey cage is the number of molecules present in one molecule of a substance of water, in this case approximately equal to 6 times 10 to the 23. So one mole of water has a mass of 18 grams. The average male weighs around 80 kilograms. We are then under the assumption that people are mainly watered. Robin is. That's 80 divided by 0.18 is 4,400 times 6 times 10 to the 23, which is about 2.6 times 10 to the 27 molecules.

Very important to show you're working. Anyway, all that water is currently grouchily taking the form of robinins. I got actually a nice thing before we get started and introduced the panel, which was someone sent me a picture of your book. It was the Wonders of the Solar System book in a charity shop in Streatham in which you'd been placed in the astrology section. I thought you'd like to know that. It's an easy mistake to make. Astrology, astronomy, they're very similar in many ways.

They're spelled in the same way. Astronomy is a study of the universe. Astrology is nonsense. Similar. You say that, but why are most astronomers Leo? So, um... Today we ask the question that is on everyone's lips. Does size matter?

Could a shrew be as big as an elephant? How big could the biggest giant be? We are joined by a man who writes of the interaction of big with small in the excellent sitcom Outnumbered. He's also dealt with any small man jokes that he has received over the last few years by every now and again pretending to be Satan. Not merely on Radio 4, it's Harry's game as well. He just sometimes does that.

At 2am he'll go round to an angry neighbour's house and just scratch on the windows wearing a little pair of horns. He is also the main reason we have him on, actually because he has knowledge of the largest land animal of the earth because he is, of course, Dr Elephant, the dentist in Peppa Pig, and he is the perfect man to ask does size matter andy hamilton and on the sides of the very big or at least bigger than andy i suppose sorry andy i shouldn't have said that ridiculous don't apologize because it'd be a hell of a long evening after every joke about my size you have to apologize it's it it's fine

it's fine i'll just sort it out afterwards. It'll be fine. And on the side of the very big, a man who has delivered the Royal Institution Christmas lectures in the BBC Four series Size Matters. He's Professor of Materials and Society at University College London, Mark Miodownik. Joining him, a scientist who does what some people think all scientists do, she sometimes makes mice glow. But she's also an expert on the science of micro-bubbles,

though, to be honest, I have to be honest, that we will probably spend more time saying, oh, go on, tell us, how do you make mice glow. But she's also an expert on the science of micro-bubbles, though to be honest, I have to be honest, we will probably spend more time saying, oh go on, tell us, how do you make mice glow? Please welcome Dr. Eleanor Stride, and this is our panel! Andy, we will start with you. So, does size matter? Well, as guest idiot, I would say... It depends what the context is. I mean, if it's out in the sort of tooth and claw environment and nature, size probably does matter.

For instance, if I'm up against a mammoth... I know that's unlikely. Not with Channel 5's new man versus mammoth. I know that's unlikely. Not with Channel 5's new man versus mammoth joke. Do you know what's really sad is if that gets broadcast, there'll be someone sitting in a room at Channel 5 going, do you know that might just work?

Can they bring back mammoths? Yeah, I think it depends entirely on the context. I mean, it's all relative. How big you are to start with dictates how big something looks to you. So when you're a child, everything looks big, doesn't it? And then you go back to places when you're an adult that you visited as a child and you think, well, it shrunk.

What's happened to it? Actually, though, Mark, it's an interesting point Andy makes. Size is relative. You hear it a lot. But is it relative? No, I wouldn't say it's relative. I don't want to start fighting it. If you were 5'3", you would think it was. Although all the laws of the universe all operate,

you know, at the same time, simultaneously, throughout the universe, anyone who's ever annoyingly flicked an ant off their plate only to see it fly through the air and fall and completely withstand this, A, the acceleration, B, the deceleration, and C, the impact on the floor, and then to see it run off, realizes that the world is not fair, that small things can get away with a lot, and us big things, relatively, essentially are very fragile. So what you're saying is that the point of flicking the ants on the floor,

that's when the next child goes, now I'm going to buy a magnifying glass. The sun, the sun will destroy him. And then the washing-up liquid. So we're not just going to deal with killing ants. But, I mean, this is, to me, interesting. It doesn't die, that's the thing. You see, actually, ants are, you know...

No, but it does if you get the magnifying... Oh, I shouldn't do this, should I? Because as an ant owner myself, I was disgusted when I listened to Radio 4 the other day. Seven of my ants are currently missing and I see an angry child with a large magnifying glass. It's because of stairs that people get so angry with ants. Because, basically, ants don't have to have stairs.

They can go up the sides of walls, go wherever they want. And we, it's only us big things that need stairs and lifts. And it's a real fag to have to constantly go up and down and press the button and all that kind of thing. So people get annoyed. They're like, oh, why are they getting off scot-free? I think I'll victimise them. That's my theory, anyway.

See, I'm interested. I'm going to throw this out to the audiences because I've never yet had anger with an ant. I know it's something that I've obviously been missing out on because I've tried anger on nearly everything else. But it's not anger, it's jealousy of an ant, which is even weirder, isn't it? It's actually being jealous of their ability

to be hurled ludicrous distances and survive intact. And geckos. I mean, let's not forget the gecko. Oh, those geckos, yeah. The question is, though, why? So what is it? What properties of the universe define the strength of an ant? So it turns out that these living creatures don't really have... You might think that they have much stronger muscles than us

or sort of armour, but actually they're made roughly of the same stuff as we are. And so the difference is only that they're much smaller than we are. So all the forces that gravity exerts on them are almost completely redundant. They almost don't feel gravity at all. It's a exerts on them are almost almost completely redundant they almost don't feel gravity at all it's it's a tiny force on them and they do feel smaller forces that we in a sense ignore things like surface tension and things called van der waals forces which are very small forces that affect their impact with a wall or any surface and they use those to climb up

things they're very sticky objects ants and they can control their stickiness and we essentially are dominated our lives are dominated by gravity and you may feel it's dominated by money or love but actually essentially your life is one big fight against gravity and there's a sort of intermediate size where gravity starts to make its effect and i think the intermediate size of most interest is the cat everyone knows that cats can essentially jump off very large heights. And they are big enough to really actually have quite big impacts on the floor.

Their mass is big enough. But it's a surprise. You'll notice this now that I've said this. There's a surprising number of stories in the media about every three months a cat will fall off a building, and I mean a big building, like 20 stories high, and survive. They're just at that intermediate size where the force of them hitting the floor, they're just at that intermediate size where the forces are hitting the floor.

They're just able to withstand it. Although, of course, if you throw an ant or cat or a human being off the Empire State Building, they'll all hit the ground at the same time. Well, they won't, will they? Well, there we are. This show has gone in a really different direction than I imagined.

Alright, in a vacuum. Okay, but... Hang on, right, so we've got an enormous building that. All right, in a vacuum. OK, but... Hang on, right, so we've got an enormous building that we've somehow placed in a vacuum. Now, does it matter about the cat dropping? Because surely it's going to die anyway because it's in a vacuum. At this point, they lose the cat arrogance. A cat...

Get the Empire State Building, put it in a big jar, pump all the air out, get a cat, an ant and a human being with breathing apparatus, scale to... Throw them off the top, they will hit the ground at the same time. Right, they'll all hit the ground at the same time. But actually, still the cat and the ant have a better chance of survival because it's not just air resistance that is doing the job for them. There's something which is about the kind of 3D nature of the world

that also acts in their favour, which is this thing about that they are 3d objects we are all 3d objects and that gives you a mass which is where your weight comes from and that essentially determines the you know the absolute force acting on you and they're different in those cases and so the force even though your acceleration is the same you're for the force acting, even though your acceleration is the same, the force acting is different because of your size. And so as you get smaller, basically, you get a smaller force acting on you and that means that anything smaller than essentially a hamster is always going to survive. And anything slightly bigger than a hamster, between a hamster and a dog,

has got a good chance of surviving. Not that I've thrown hamsters out, but you do hear these stories. And above a hamster, basically us, unless you're very're very very lucky and hit a tree you're going to die it's a famous haldane quote isn't it a man would break and a horse would splash more classic tea time listening for radio eleanor you're involved you're an engineer engineering i would say i imagine especially in the last 50 years in terms of the advances we've seen of the ability to make smaller and smaller things

at what point do we go into the world of the small with engineering? At what point do we approach that kind of what may well be called nanotechnology? I think it's a very good question because you're always worried about the molecular structure of whatever you're building. So actually in a way we've always been engineering with the very, very small. We just haven't

really known it and it's really the tools we've always been engineering with a very, very small. We just haven't really known it. And it's really the tools we've developed to characterize the materials that we're now working with that have allowed us to understand that and to actually engineer at the nano or the micro scale. And when does this... I suppose, as Robin said, nanoengineering, if you want to call it.

When do the properties of the micro world begin to affect the techniques you need to use to engineer machines? That's a very good question. I think, again, they always have. It's just that since we've developed the electron microscope, for example, we've started to understand what the microstructures of these materials are and how we can manipulate that. And that really is in the last 20, maybe 30 years.

Andy, if you could be three times the size and a giant yeah like to terrorize all of those i'm still worrying about the nano technology because when you're working with stuff that tiny you must lose a lot of it well it's i i don't want to go back to the ants but we actually had a crazy project last year that someone proposed trying to make ants glow so forget mice this was trying to make ants glow and we were doing that by introducing nano gold into the system and actually if you go beyond a certain size the nano gold does literally go everywhere and that causes you enormous problems so that was worth a fortune or is it not no no no because it's a billionth of meters worth of of gold yeah what's this smallish machine currently that anyone's built?

There are so-called nanobots that are supposed to be used in medical engineering. I'm not sure you can really describe them as machines because they're really taking natural processes and just manipulating them. So the so-called molecular rotors, for example, so the little molecules that when you shine a light on them, they rotate and you can measure that rotation

in order to make measurements on certain materials. Is that really a machine? I'm not sure. If it's something you actually want to, for example, go into the body and construct something, I think that we're still on micro scale. Yeah, so we are constructing things already on the scale of molecules. Yeah, absolutely. Sorry, Robin,

you wanted to ask me about what size giant I wanted to be. No matter how we try and deflect him away from trivia. The reason, I only wanted to know if you had the chance. This is a ridiculous question, I know, and then it's going to deflect somewhere else. But if you had the chance to take, ah, now, three times the size, would you take that opportunity?

Can I come back to being my ordinary size again? Mark, you're the specialist in this area. It's not like some fairy tale where I'm stuck being 16 feet tall, is it? Well, it could be. One of the ramifications would be, weirdly enough, your brain would get that much bigger. And although you might think that would make you far seeing, and perhaps would, it would reduce the amount of sleep that you had. There's this weird correlation with the bigger animals sleep less than the smaller animals, if you're a mammal, anyway.

So you become like Margaret Thatcher. You would only need two hours' sleep a night. You'd become a megalomaniac. And you'd take up politics. So now I'm a 16-foot-tall Margaret Thatcher. With a huge brain. Three times the volume of any known human. I didn't realise...

So do bigger people, do they sleep less then? Is that a proven thing? One of the really annoying things about this subject is that within the kind of species, the scaling laws don't seem to be very reliable. So, yeah, bigger people, smaller people within the human species don't obey many of these allotropic laws, that's what they're called. But there's a general scaling law people talk about which is basically that the larger you are

the longer you live with appropriate caveats so could you explain that a little bit i mean why do we think that is that bigger means longer lifespan yes the larger you are um essentially the way the biology has managed to make bigger bodies is making them more efficient. And so because of your metabolic rate is lower than smaller animals, your whole machinery doesn't get worn out quite so quickly. So you find there's this weird thing where, in mammals anyway, all mammals essentially, which have got the same machinery, you know, in terms of heart, lungs and all these kind of things, they all have the same number of heartbeats in their lifetime. And that's about one and a half billion. So whether you're a mouse or a bat or a cat or a dog

or you or me or an elephant, you've got one and a half billion heartbeats before basically something gives up mechanically. And if you've got a lower metabolism, that means your heart beats slower and then that means you use your heartbeats up slower, so you live longer. Eleanor, I suppose actually in that area, though, nanoscale, from what I can gather from your work,

is something that you are utilising for enhancing both medical knowledge and indeed also looking at ways of treating disease. So can you explain how how exactly this works the nanoscale for the kind of thing you're approaching again though the question of scale is really important so the body is amazing in terms of the range of holes for want of a better word that it has so you have something in your bloodstream only certain molecules will actually be able to escape into your tissues for example your brain to use and it varies throughout the body so in your brain you have very very tight very tight, tiny holes. So glucose can get across, but not much else. Elsewhere in

the body, in your stomach, for example, a lot of molecules can diffuse across. And that's really critical. Now, if we can modify those barriers temporarily, we can introduce drug molecules into different parts of the body. And that's what we're really manipulating. So we use light, sound, all sorts of physical stimuli to change the permeability of these membranes to actually get the drugs across to where they need to be. But the trick is to make sure that we reverse that permeability after we're finished, yes. Otherwise you've got a very leaky brain.

Indeed. Not good. So, again, also in terms of, I know, in the work of micro-bubbles that you're using, now that's the way of actually being able to examine the body as well. Is that right? It's both, yes. So, right, injecting bubbles into the bloodstream is not generally considered a terribly good idea.

In a scuba diver or an astronaut, it's a very bad thing. We engineer bubbles that have got a coating on them so they stay very small, so they don't block your blood vessels. But we then drive those bubbles with ultrasound. Because they're full of gas, they're very squishy, so they oscillate when you drive them with the sound that in turn produces a really big reflection so you can track where in the body these bubbles are flowing then we can also load the bubbles up with drugs and essentially we turn the sound power up enough to pop the bubble and release the drug and we can do so in a very very small area so we can localize the delivery of

these drugs so it's genuinely engineering in the sense you're constructing we are shaped objects that are tuned absolutely we are making tiny little cars everyone says to me when i explain well i think you're not an engineer that's not engineering it is we're using exactly the same principles just to create something on the very very small scale now what are the largest things we talk about other than the entire visible universe? So I mean once you get out of the kind of scale, our scale of things, the next scales up are all essentially dominated by gravity. It's funny that you know you sort of obviously you look up into the solar system and you see these round spheroid planets and the reason and it's

not just an accident they couldn't just be cubes they couldn't be oblongs the reason they're round is because gravity dominates them and pulls all the matter in even if they're solid they get pulled into spheres the gravity is such an enormous force it just forces everything into this kind of perfect sphere so so you know the world is just completely constrained by this enormous gravitational force and this constrains engineers in another way because if you want to build a really tall building, I mean, buildings we think might be impressive. The Shard has recently been built in London, and it's the tallest building in Europe,

although not as tall as the Eiffel Tower I found out the other day, which I thought was kind of funny, because no-one ever mentions that, which was built, you know, a long time ago, let's face it. But anyway... It's not got any rooms in it. It's not proper, is it? It's just scaffolding, isn't it? Well, but still it's still kind of weird because when you look at the shard it is just massive but it's tiny on a on the global context but b it's quite hard to build things bigger than that for lots of very

good engineering reasons mostly to do with gravity, so basically the strength in which we can build things. And in particular, and this is a bit of a surprise, it's to do with the wind. When the wind hits these buildings, it produces a downward force as the building is forced to bend over. And that is the thing that limits the height of buildings. So actually, it turns out to be, although gravity is one big thing, it's the weather, kind of surprisingly, the weather on Earth that is another limiting factor to the height of buildings. And I suppose, Eleanor, when we're talking about engineering and building big things, then we're talking really about the

strength of materials, the fundamental underlying strength of materials. So what are the strongest materials we know of? And do we know of any limits to how strong materials could be well ironically i think the strongest material is now considered to be the carbon nanotube which is absolutely tiny and it's because you have this tiny little cylindrical structure that can support a ridiculous weight compared to its size could you describe them a little bit um so you new form of carbon is discovered uh where you have these sheets. It's well known that you have graphite, which is made up of sheets of carbon. Carbon nanotubes are like those sheets rolled up into tiny little tubes,

which I'm looking at Mark desperately because this is actually his field of research. This show has never been better for everyone just passing back and forth. By everyone, I obviously don't mean you and me, Andy. No. But the experts going, I'm not sure. Each one of you, as you've been explaining things, has gone, this may well be wrong. I hope one of the other ones doesn't find me out.

I've never seen that. This is the essence of science. The essence of science is cultivating doubt, actually, and questioning things, isn't it? In fact, we've always been envious of the arts and your complete certainty about everything. And so what you see is a highly nuanced form of doubt which we expose at every opportunity. That's a brilliant...

It was a definition of science, a highly nuanced form of doubt. I like that. Doubtology, that would be the word. That should be the word, doubtology. Highly nuanced. Yeah, nuanced doubtology. Well, that could be the separate categories. You could do a PhD in nuanced, you know, and then applied.

Applied outology. Advanced outology. The more senior you get, the more paranoid you can make your students by just simply raising an eyebrow. Because you probably have no idea what the answer is, but simply going... LAUGHTER I don't know.

I like the idea, Andy, that there's... Depending on... Oh, well, that's not a science at all. There's very little doubt in that. This is... Sorry, back to the nanotubes. Well, Mark can explain in one minute without hesitation or repetition. Do the nanotube explanation, and then we can go back to Eleanor for the continuation of that.

OK, so what's so amazing about nanotubes is that they're made of carbon and when everyone ever explains something is strong, they always have to compare it to steel, which is really easy because steel's very heavy. And although it's extraordinarily strong, if you make something out of carbon, which is much, much lighter, then you're already in with a chance. So when they say it's stronger than steel,

they mean strong per weight and carbon is the best structural material we have that's as light as it can be. And then you have a tube. Well, you know, we all know what tubes are like, right? You have a piece of paper and it's quite strong and you pull it and eventually it rips. But you make it into a tube and now it becomes this stiff, much stronger

structure. Put the two together into strong bonds of carbon, very, very strong bonds, the strongest around really, molecularly, a tube structure and very light. And hey, presto, you've got a magic material called carbon nanotubes, which really could revolutionise building, and it can revolutionise almost everything

we make steel out of today. If I was a steel manufacturer now, I would be trembling in my... Well, I probably wouldn't be trembling, because I'd make a lot of money, but I'd be slightly worried. I'd be doubtful of what I just said, and then I'd be slightly worried about the carbon industry,

which is coming. But can you have skyscrapers made of carbon nanotubes? But that's where it becomes a problem, because you've got to put the carbon nanotubes into something, and that then becomes your weakest link. Right, right. Although people have now started to make cables out of nanotubes, and I think the whole problem with scale is that you can make tiny things that are very strong, out of nanotubes. And I think the whole problem with scale

is that you can make tiny things that are very strong, like these nanotubes, but then you have to make big things out of them. And biology, of course, has worked out how to do this. And we have all these amazing molecular structures that give us the strength we've got. And the best example, of course, is these trees, right? So these enormous 100-metre trees in California,

which are amazing structures, but it takes those trees 100 years to grow. And we are impatient humans, so we want to basically replicate biology's mastery of the molecular building structures using carbon, but we want to do it basically overnight. And that's going to be the hard bit, because growing it slowly is easy,

growing it fast is hard. But the idea that we might grow buildings, we might grow bridges, grow cars, I don't think is out of the question. Spiders have been growing structures for years and spider thread for a very long time was the strongest material until they met the carbon energy.

Spiders would be furious. They're one claim to fame which is that we make this fibre that is the strongest tensile material on the planet, and someone comes along with their fancy carbon. I've been evolving away

since the Cambrian explosion. 540 million years. We've also asked, though we have obviously a panel of experts, we always like to find out what our audience believe as well, and so we've asked them a very specific question with a certain caveat thrown in there as well to make so we've asked them a very specific question with a certain caveat thrown in there as well to make sure we knew which direction

they might otherwise go with the question. And the question is, not including anything on your own body, if you could change the size of one thing in the universe, what would it be? And we have, I would change the size of the universe itself as a whole so everything was closer.

Weekend away on Andromeda Galaxy, anyone? That's from Caroline. The value of Planck's constant, because if it's big, then I could see all the weird quantum nonsense. That's from Phil. And that's correct and factually accurate. There we are. That is how these are marked.

It is not an audience reaction. This one here, I don't know. My girlfriend's bottom. Is there any way he wants to make it bigger or smaller? We don't know. Are there any constants in science that govern the size of women's bottoms? But in space-time, it will get bigger or smaller depending on the curvature of space, won't it?

Yes. So it already is bigger and smaller. He can't fire his girlfriend into space, can he? It is in space. I think that would damage the relationship. So Gareth says that he'd change the value of pi. And I'm trying to work out what the implications of that would be. Well, we'll give you a moment and we'll come back to you.

Because pi is a property of Euclidean space. I suppose what you're actually saying is you'd curve space and it is curved by mass and energy, which is Einstein's general theory of relativity. So actually pi is variable in the universe already.

Do you know, on the 11 o'clock repeat of this, you are going to sound so stoned. The way you just drift off for a moment. Your brain leaves your body, rambles around pie for a moment, shake her hands with Euclid, and then returns. It's worth thinking about the implications of these suggestions.

Yeah, no, I agree, I agree, but perhaps in your own time. The Higgs boson, if it was a bit bigger, maybe Brian would have found it a bit quicker. What do you mean by bigger? Do you mean the coupling strength? Because that would increase the mass of the fundamental particles. You could change the structure of your atoms and you'd probably fall

to bits. Now that is a heckle put down. LAUGHTER APPLAUSE APPLAUSE of bits. Now that is a heckle put down. It's point-like anyway, probably. Now, serious point. Every so often we get a letter that we can actually read out on air. And Robin

is going to read the single letter out. This is from Laura. And Laura says she enjoys the show but has a major issue with the title. We know in the past I've had a lot of problems with different interpretations of the title. She writes, I was disappointed by your response to ongoing criticism that your programme's title promotes inhumane monkey husbandry practices.

Your assertion that an infinite monkey cage would be roomy is misleading at best. An infinite monkey cage might be roomy is misleading at best. An infinite monkey cage might be roomy or it might not. An infinitely tall cylindrical cage would feel pretty cramped if it were only as wide as the monkey inside it. The monkey's movements would be limited to climbing and spinning. While monkeys are avid climbers, I believe most would find such an environment claustrophobic. Now, you might think that an infinitely long, infinitely wide cage would have to be better. It wouldn't. It all depends on the cage height to monkey height ratio. Brian? The reason I like that, that's a real letter, and it's the first criticism we've ever had that is

legitimate in any way. It is absolutely true that infinite, we should have said, it would have said infinite volume, then that indeed would not imply that all the dimensions are infinite... We should have said, if we'd have said infinite volume, then that indeed would not imply that all the dimensions are infinite. You can have one dimension that's infinite and it would be infinitely large in the sense of infinite volume. So we should have been more specific. But it's true. So I agree with the correspondent,

and she suggests, actually, and I think we're going to do it now, that we should change the name of the programme to the Sustainable Monkey Habitat. Mark? Well, it's very appropriate for this programme, isn't it? Because it's all the size it really does matter. Mark Miodovny, thank you for our alibi.

Thank you very much for listening. Thanks to all our guests. Thanks to Eleanor, to Andy, to Mark, to Brian. Thank you. Thank you. If you've enjoyed this programme, you might like to try other Radio 4 podcasts, including Start the Week,

lively discussions chaired by Andrew Marr, and a weekly highlight from Radio 4's evening arts programme, Front Row. To find out more, visit bbc.co.uk slash Radio 4. In our new podcast, Nature Answers, rural stories from a changing planet, we are travelling with you to Uganda and Ghana to meet the people on the front lines of climate change. We will share stories of how they are thriving using lessons learned from nature. And good news, it is working. Learn more by listening to Nature Answers wherever you get your podcast. you