Growth

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Speaker 24 Door listening to Radio Lab.

Speaker 25 Lab. Radio Lab.
From

Speaker 26 WN Weiss.

Speaker 1 Okay, so we're going to begin with producer Matt Kilty.

Speaker 28 Okay, Latzif.

Speaker 29 Let me take you to the land of the midnight sun.

Speaker 27 Whoa, is that Japan? No.

Speaker 1 No, rising sun is Japan. Oh, the midnight sun's probably got to be Antarctica or something.

Speaker 27 Alaska?

Speaker 31 Alaska.

Speaker 23 Oh, do you see the mountains all the way out there?

Speaker 32 Those are snowy.

Speaker 29 That's beautiful. Specifically.
Jagged mountains kind of everywhere. Palmer, Alaska, which is like an hour north of Anglo.

Speaker 24 I've never heard of it.

Speaker 35 Yeah, it's a little town where they host

Speaker 35 every summer the Alaska State Fair.

Speaker 28 Got a wallet? I have a phone. Okay.

Speaker 29 Which is where I went last August with.

Speaker 36 You know, I've never seen a corn dog that I don't like.

Speaker 29 My childhood best friend, Mike Gladney.

Speaker 31 So I'm pretty excited.

Speaker 29 And Mike and I were from Minnesota, which has a really big state fair. Alaska's.

Speaker 36 It's like a small county fair.

Speaker 29 It's a little bit smaller, but

Speaker 29 it does have a lot of good food.

Speaker 24 Oh, right there.

Speaker 29 A lot of classics, but also

Speaker 32 Alaska crab cakes.

Speaker 37 A lot of great seafood.

Speaker 29 Salmon quesip. Yeah.
And then, of course, games, rides.

Speaker 29 But

Speaker 36 Latif.

Speaker 25 Yeah.

Speaker 29 This little fair does have something very, very,

Speaker 33 very

Speaker 33 big.

Speaker 29 Which is the annual Great pumpkin way off.

Speaker 1 Ooh, so this is like competition, like a state fair competition.

Speaker 29 That's right. A competition to see who can grow the biggest, heaviest pumpkin in the state, but also maybe in the world.

Speaker 39 Okay. Because in Alaska.

Speaker 20 We grow the best pumpkins in Alaska. We grow the biggest pumpkins around.

Speaker 29 I know. Why is that?

Speaker 41 I think they put milk in them.

Speaker 40 And they just water them with milk the whole time.

Speaker 24 That's what I heard.

Speaker 29 Mike and I talked to one of the workers, Kathy Liska.

Speaker 43 This is my 31st year working in the crops department. And I've seen maybe, I think, about 25 Guinness World Records.

Speaker 31 Wait, pumpkin-specific.

Speaker 29 No, no, no, all sorts of stuff.

Speaker 25 Carrots, beets, cabbages.

Speaker 43 What's Alaska, you know, what's the fair known for? It's the giant vegetables.

Speaker 29 Because in Alaska, the land of the midnight sun, plants can get a ton of sunlight. And so essentially, you can grow these plants to like really, really big sizes.

Speaker 43 There's a lot of growers all around the world that'll be keeping their eye out around here to see what's going on.

Speaker 36 So. Okay, wait, we should describe what we got.

Speaker 29 We got it. Mike, Kathy, me.
You call it a barn, farm.

Speaker 43 It's an open-air arena, arena, yeah.

Speaker 24 This is our ag building.

Speaker 29 We're standing in the ag building. Smells like not good in here.
And we are standing inside this like cattle pen. This little fenced-in area.
We are surrounded by bleachers.

Speaker 24 So here we are, center ring.

Speaker 25 When out comes...

Speaker 47 Where's the...

Speaker 24 Oh, my God.

Speaker 40 Oh, my God.

Speaker 31 This huge...

Speaker 32 Wow. It's enormous.

Speaker 36 It's gigantic.

Speaker 48 It's gigantic.

Speaker 34 Orange pumpkin.

Speaker 36 It's intimidating. Look, Andrew.

Speaker 29 Kathy, is it okay if I touch the pumpkin? And this pumpkin...

Speaker 24 Do Do you feel the magic?

Speaker 29 You're touching it too. It's about the size of a Volkswagen beetle.

Speaker 35 Wow.

Speaker 24 It's got like a heartbeat.

Speaker 32 Well, it does actually wait. It's alive.

Speaker 1 It's just so big.

Speaker 29 Except it's like lumpy and like kind of blobby.

Speaker 1 Like job of the hut, kind of. Yeah.
Could you and Mike have fit in the pumpkin?

Speaker 29 We could have crawled inside the pumpkin and held each other.

Speaker 49 Weird.

Speaker 44 That's 98 days old right there, that pumpkin.

Speaker 29 So the pumpkin belongs to this guy, Dale Marshall of Anchorage.

Speaker 44 Yeah, I'm about sick of that thing, tell you the truth, you know.

Speaker 29 He's a seasoned grower. Are Are you pleased with your pumpkin this year?

Speaker 50 Oh, yeah, just getting one here. It's half the battle, you know.

Speaker 29 Like, when I see something this big, I'm like, this is frightening.

Speaker 36 I like it.

Speaker 50 I like the color. You know how long it took me to paint all those little spots on there?

Speaker 40 And while we're talking... Okay, oh, oh, they're putting a thing.

Speaker 29 Dale rushes over to his pumpkin.

Speaker 40 Something's happening.

Speaker 47 Here we go. Here we go.

Speaker 37 And basically, Michael, get over here, Mike.

Speaker 29 Mike and I get in position. And then we watch them as they push this pumpkin so it's underneath this crane.
And everybody looks like they're excited, they're anticipating.

Speaker 29 And dangling from the crane, bated breath are these straps.

Speaker 25 Everyone's circling.

Speaker 29 Okay, Dale's getting the straps ready. Dale takes the straps from the crane, wraps them down around the pumpkin.

Speaker 29 Pumpkin appears to be strapped in there, securing the rope, ties it all together with a rope.

Speaker 47 That's a curve rocket.

Speaker 24 And then

Speaker 47 you could hear a pin drop in here.

Speaker 29 The crane begins. The straps are tightening to lift the pumpkin.
Here we go. It's up.

Speaker 27 It's up off the pallet.

Speaker 29 If it's off the pallet. Up into the air, so it's dangling like two feet off the ground.

Speaker 29 And then. Jody, careful, Jody.

Speaker 29 Yep. A volunteer named Jodi gets on her back, climbs underneath this pumpkin.
So it's just dangling above her, and she inspects the pumpkin for like any holes, any tampering.

Speaker 28 All right.

Speaker 29 She gives a thumbs up.

Speaker 28 Jodi is a wild woman. And then...

Speaker 36 Okay, all right.

Speaker 29 They're transporting it over to the scale. The crane begins to lower the pumpkin onto this huge metal scale.
Okay, all right. They're taking the straps off and the rope.
All of it's coming off.

Speaker 36 Wow. Okay.
It's fully on the scale.

Speaker 29 Dale steps back from his pumpkin. It's on the scale.
It's being weighed. Okay.
And then

Speaker 30 the moment of truth.

Speaker 28 All right, here we are.

Speaker 29 Oh my God. 2,000 pounds.
Oh my God.

Speaker 40 Oh my God.

Speaker 29 First place,

Speaker 29 grand prize-winning 2,035-pound pumpkin.

Speaker 30 Oh my god.

Speaker 25 Oh my god. To put that into perspective,

Speaker 29 that is about eight to ten panda bears. Okay.
Just to give you a sense of the weight out of pandas. Anyway, high fives all around for Dale Dale's sake.
Dale's got his arms in the air.

Speaker 29 He's running around his pumpkin. Dale, how you feeling?

Speaker 51 Wow, I'm ecstatic.

Speaker 50 That's about 150 pounds more than I thought I was going to get.

Speaker 24 And then pretty quickly. Moving it, we're moving it.

Speaker 40 We're moving it.

Speaker 24 I'm out of here. I'm out of here.

Speaker 29 The local news crews surrounded Dale. He gets a ribbon, $1,000.

Speaker 29 And then

Speaker 21 that's pretty much it.

Speaker 28 Okay.

Speaker 36 Yeah, that's kind of everything.

Speaker 52 Huh.

Speaker 22 And was this a record-setting pumpkin then?

Speaker 28 No.

Speaker 29 Actually, it didn't even beat Dale's previous pumpkin record in the state.

Speaker 29 But

Speaker 40 it was a good pumpkin, first place pumpkin.

Speaker 1 But then, like, what happens to the pumpkin afterwards?

Speaker 29 Well, Dale typically takes his home. He says his grandkids like to play on it.

Speaker 29 And, or if you don't do that, you can donate it to the Alaska Zoo or the Wildlife Conservation Center where they will feed it to bears.

Speaker 22 Bears?

Speaker 53 Yeah, grizzly bears.

Speaker 1 That feels like an Alaska punchline joke that you would make up, right? No, it can't feed bears.

Speaker 35 It is bears.

Speaker 1 Because it's not fit for human consumption?

Speaker 27 Or is like, could you eat these?

Speaker 29 Yeah, yeah, you can eat them.

Speaker 27 I don't think they taste very good the bigger they get.

Speaker 25 They're not being grown for flavor.

Speaker 27 It's just so hard to imagine the point of this. What do you mean?

Speaker 18 Like, what are we, what,

Speaker 29 what are we doing?

Speaker 25 What are we doing here? Well, I mean,

Speaker 29 for the growers, I think it's just like, it's like pushing the limits. Like, just you're trying to grow something really stronger, faster, bigger, better.

Speaker 29 Yeah, exactly.

Speaker 24 But I think for us

Speaker 29 to be there like if you average it out dale's pumpkin grew 20 pounds a day and to just come

Speaker 29 and look upon that i think it's cray cray to see something that's just so incomprehensibly big i think it's crazy how big it is it just stirs up look how big that thing is this real sense it's gorgeous i think it's beautiful really of awe i do because it's so big i mean where else do you see something like that because seeing something like that just sort of makes you think about the fact that everything

Speaker 29 has this blueprint for growth, for how it's supposed to grow, for what it's supposed to grow into. And yet, here you are confronted by something that seemingly doesn't fit that blueprint

Speaker 23 at all.

Speaker 29 And that is what we're doing there, Latif.

Speaker 29 Coming together to feel a little bit of joy, a little bit of terror, brought on

Speaker 40 by an enormous pumpkin.

Speaker 52 Okay. All right.

Speaker 24 Sure.

Speaker 11 All right.

Speaker 17 This is Radio Lab.

Speaker 12 I'm Lulu Miller.

Speaker 27 I'm Lathafnaser.

Speaker 11 And today we are looking at growth,

Speaker 1 which is actually an episode we started working on when you were off growing a person.

Speaker 10 Yeah, actually my belly was just like that pumpkin.

Speaker 25 It was like

Speaker 25 two ties my toes or tie my shoes.

Speaker 11 And then the baby came out and she has already doubled in just a few months.

Speaker 20 She's already doubled in size.

Speaker 1 But we have more. This is not an hour about pumpkins.
As much as I know you would have wanted that, we have three different stories about growth. Growth that happens in places you'd never expect.

Speaker 1 Growth that follows a pattern that seems woven into the universe itself. And even a growth that has taken over the whole planet and, for better or worse, the surprising thing that might stop it.

Speaker 17 All right.

Speaker 11 Let's do this thing. Yeah.

Speaker 1 First up, we have a story from Becca Bressler.

Speaker 52 Hello.

Speaker 54 Hey.

Speaker 54 Okay, so I'm going to take you from pumpkins to carrots.

Speaker 25 Okay.

Speaker 27 Huge leap, huge leap.

Speaker 1 Orange vegetable to orange vegetable.

Speaker 54 Stick with me. This story starts in a kitchen.
Okay.

Speaker 56 So this was a few years ago, November 30th, 2021.

Speaker 54 With this woman named Ray Mondo.

Speaker 56 All of my housemates were away for the evening and I was making dinner.

Speaker 57 I have vegetables out.

Speaker 14 There's broccoli, there's carrots.

Speaker 54 Music is playing. Vibes are good.
Pretty normal evening.

Speaker 56 And as I'm chopping, chop, chop, chop, chop, chop, chop,

Speaker 14 all of a sudden,

Speaker 54 she looks down and was like, I just cut off my fingertip.

Speaker 54 The end of her left middle finger from halfway down the nail was just gone.

Speaker 46 The wound was just white for a moment, and then I saw just like the river of blood like rise.

Speaker 54 So she grabs paper towel, presses it up against her finger that's gushing blood.

Speaker 54 And she immediately calls her friend, Amy. My best friend, Amy, used to be a trauma nurse.

Speaker 1 Person to call, right person to call.

Speaker 14 So Amy picks up, they tell Ray to bandage it, keep pressure on it, go on the couch, elevate it, and just like dissociate for a while.

Speaker 27 Wait, but she didn't go to the ER or something?

Speaker 54 So actually, that was the question that consumed her.

Speaker 56 I'm like, how much is having a fingertip worth to me? Like, can I put a dollar amount on it?

Speaker 54 Her deductible was super high.

Speaker 56 If the emergency room bill were going to be $5,000, nah, I'm good. Like, I can live life without a fingertip.

Speaker 57 If it's $1,000,

Speaker 24 I'm like tempted, but like, geez.

Speaker 54 Yeah.

Speaker 58 I do really like having like all my fingertips.

Speaker 25 Like,

Speaker 54 but eventually she decides it's not worth it.

Speaker 42 No.

Speaker 46 And at that point, I was like, I'm done.

Speaker 56 I have a short middle finger now.

Speaker 54 This is just my life. Yeah.

Speaker 24 But

Speaker 54 over the next few days, as Ray gets into a routine of changing out the bloody bandage,

Speaker 54 she starts to notice a couple things happening.

Speaker 23 Uh-huh.

Speaker 59 One, what I noticed was my fingernail continued to grow outward

Speaker 57 in the same shape that it grew before.

Speaker 56 And two, the finger started to fill in underneath the fingernail that was growing outward.

Speaker 54 And after a few weeks, I was like, wait a minute, like,

Speaker 14 is my fingertip growing back?

Speaker 46 And

Speaker 46 slowly but surely, it was just sort of like,

Speaker 56 My finger was back.

Speaker 24 What?

Speaker 31 Like her whole fingertip grew back? Yeah. Like you couldn't even tell if anything happened to it?

Speaker 56 No. Now it's like, I would say 99.5%

Speaker 59 back to normal.

Speaker 1 Man, this feels so like, I mean, I've heard of human, like you can regrow skin.

Speaker 27 I get that.

Speaker 1 I feel like I've vaguely heard of someone regrowing part of a liver.

Speaker 25 Yeah.

Speaker 53 Maybe. Yeah.

Speaker 53 Yeah.

Speaker 1 But like,

Speaker 1 this is different. This is like, there's a whole, there's a bone in there.
There's like, there's so much going on.

Speaker 54 Yeah, it does feel more complicated.

Speaker 1 There's layers. It's a, it's a, it's a flesh lasagna that you're growing back.

Speaker 54 Actually, totally. I had never heard of this before.
And obviously this was very surprising to Ray.

Speaker 7 Oh, totally.

Speaker 54 And so actually she emailed us to tell us about this.

Speaker 1 To be like, what?

Speaker 1 I mean, how, like, am I a mutant with superpowers?

Speaker 54 Kind of, yeah. She wanted us to find out, how did this happen? Like, how did my fingertip grow back?

Speaker 59 Right.

Speaker 54 So Ray and I together called up.

Speaker 51 It's nice to meet you, Ray.

Speaker 19 Oh, it's so nice to meet you, too.

Speaker 54 This guy.

Speaker 51 Can I see your finger?

Speaker 24 Oh, yeah.

Speaker 54 So this is Ken Munioka. He actually studies fingertip regeneration.
Currently at

Speaker 51 Texas A ⁇ M University.

Speaker 54 And Ken wasn't that surprised to hear about Ray's fingertip.

Speaker 51 I felt bad for you, but I suspected it all came back.

Speaker 54 He says that people have been writing about this for nearly 100 years.

Speaker 51 Yeah. That story begins back in the 1930s.
A physician in Canada had a severely infected finger, and he basically removed the bone out of his finger.

Speaker 54 Just the tip of it.

Speaker 51 And he, he, but he x-rayed it, and he sort of followed it with time, and he found out that his whole finger regenerated.

Speaker 54 Whoa. Ken also told us that back in the 70s, doctors in the UK saw a bunch of kids with chopped-off fingertips.

Speaker 51 There was a reasonable number of them coming into the clinic.

Speaker 54 No idea what was going on over there, but.

Speaker 51 They documented hundreds of children regenerating their fingertips.

Speaker 54 So Ken studies this stuff at a microscopic level.

Speaker 51 In fact, I spend most of my time working with mice.

Speaker 54 Unfortunately, or fortunately, there aren't a lot of controlled studies around chopping off human fingertips and seeing how they grow back. But thanks to our good friends, the mice.

Speaker 51 We were able to follow the regeneration process using this machine called a micro-CT.

Speaker 54 What's that?

Speaker 51 So it's like a CT scanner, but it's like for tiny little things.

Speaker 54 And Ken says that when you cut off your fingertip, a few things happen.

Speaker 51 You know, the initial response to a trauma like that is an inflammatory response that cleans up the wound.

Speaker 54 Pretty standard stuff. But then,

Speaker 54 sometime after that, something very unusual happens.

Speaker 48 Stem cells that are in the nail bed that are normally required for having your nails grow continuously throughout your life, they sort of kick off this rebuilding process.

Speaker 48 Forming this sort of organizing response to make the other parts of the tissue in that lost fingertip.

Speaker 54 So this is Chris Arnold. He's a professor at West Virginia University.

Speaker 48 In the biology department.

Speaker 54 And he says that these stem cells under the nail call up a bunch of other stem cells in the body.

Speaker 51 You know, cells that can make bone.

Speaker 48 Skin tissue. Nerves.

Speaker 54 muscle tissue. And so these different types of cells basically start regrowing what was lost.
And eventually you have a whole brand new fingertip.

Speaker 52 Huh.

Speaker 1 Like we plumped back out to what it was.

Speaker 31 Yeah.

Speaker 54 How does it know when to stop, right? Like if your fingertip grows back, it doesn't become bigger than it was before.

Speaker 51 There's apparently there are signals to stop regeneration, but we don't know exactly where it's happening, when it's happening.

Speaker 54 Got it.

Speaker 22 Weird.

Speaker 31 Also, can I just say, what a weird use of stem cells.

Speaker 1 It's like you have these miracle cells in your body that can do whatever, regrow whatever. And then it's like, okay, you know what we need you for?

Speaker 1 Just keep regrowing nails that we're going to have to cut anyway.

Speaker 31 Seems like so futile, right?

Speaker 54 That's so, yeah. So that's exactly what I said to Chris.
Yeah.

Speaker 48 So it doesn't make a lot of sense for us, right? As like, why is it our nails like just keep growing and growing?

Speaker 48 But if you think a little earlier for earlier mammalian ancestors, maybe that's where you actually get more of the answer of why this is happening.

Speaker 48 Because, I mean, from our earlier sort of kind of rodent-like ancestors, known for the ability to dig, burrow into new environments where you're getting this constant damage.

Speaker 48 And so that may came along with it, this ability to constantly regrow from that damaged kind of part.

Speaker 52 Wow.

Speaker 54 It's kind of crazy to just like look down at them and be like, I have these because of rodents.

Speaker 22 Exactly. Yeah.

Speaker 53 Like, should I use them and burrow? I don't know. Yeah.

Speaker 53 Are you burrowing with them? Like, well, what are you, what are you using your nails for?

Speaker 25 I know. Really?

Speaker 11 I'm never going to look at my fingernails the same.

Speaker 31 It's like the former us hunched over trying to dig away.

Speaker 54 Yeah.

Speaker 48 But when Chris started telling me about other animals, there's animals that regenerate even better than that.

Speaker 54 I realized that we're not that impressive at all.

Speaker 48 Yeah, so if I could regenerate like a salamander, if I cut off my hand, a new hand would grow back in its place.

Speaker 54 And as you told me about more and more of these creatures, it just kept getting weirder.

Speaker 48 Like our friend the planaria.

Speaker 54 Mm-hmm. So there's this tiny little flatworm called a planaria.
And if you cut it into small pieces, even hundreds of them.

Speaker 48 Those pieces can regenerate the entire animal over again.

Speaker 23 Wow.

Speaker 48 So the whole body can grow from any part.

Speaker 54 Some starfish can also do this.

Speaker 54 You can cut cut off one of their arms and that can become a whole new starfish.

Speaker 48 There was a famous story where scuba divers were trying to get rid of a starfish population in their area by going down and cutting them into little pieces, only to find to their dismay that the next day they were, well, the next few weeks, they're even more starfish than they started with.

Speaker 54 Okay, now this is my favorite thing. So, you know, the classic one, lizards, right?

Speaker 40 Right.

Speaker 54 How they can break off their tails and grow them back.

Speaker 42 Yeah.

Speaker 54 What's amazing, though, is that they have this tearaway site on their tail.

Speaker 48 Kind of of like, I think of like the perforated part of like a ketchup packet or something.

Speaker 1 It's like a coupon.

Speaker 31 Exactly.

Speaker 54 But they're not the only animal that has one of these.

Speaker 48 The sea slug.

Speaker 27 Oh.

Speaker 48 But it's not the tail they're losing.

Speaker 22 They actually lose all of their body from the neck down.

Speaker 54 It turns out that when they're sick, they can just shed their entire body.

Speaker 48 And at the end, it's just a head that's swimming around that will then go on to regenerate all the rest.

Speaker 52 Oh my God.

Speaker 52 Wow.

Speaker 1 I've been sick over the last few weeks and that is just so relatable. Like I have thought about doing that so many times.

Speaker 32 No, I'm coughing.

Speaker 11 It is wild that you can just dispense of a body and be a head and then grow a new body. I mean, when it goes to that level, it feels like, it does feel like a superpower.

Speaker 54 No, totally. And I know these things feel like superpowers to us.

Speaker 47 Yeah.

Speaker 48 We generally think of animals more like a planaria, something that could regenerate regenerate its whole body as just something sort of weird and alien.

Speaker 54 But Chris told me that this thing that seems just like a strange little cork of nature is really not that strange at all.

Speaker 48 When we look at the tree of life, the ability of an organism to regenerate itself from a small piece, whole body regeneration, the most extreme form of regeneration, that is actually very widely distributed throughout the tree of life.

Speaker 4 Wow.

Speaker 48 And it's only been lost in a couple of branches. Ours is one of them.
And so it's not really weird that an animal can regenerate its whole body. It actually might be more weird that we can't.

Speaker 31 Why can't we do this, though?

Speaker 1 Like, why are we the ones left out?

Speaker 54 Yeah, I mean, scientists think that it's because we're complex, right? Like, they typically see these regenerative properties in simpler organisms.

Speaker 2 The more

Speaker 48 complex, the more many parts there are to a structure, the more interdependent those parts are. It makes sense that if you lose a part of that, it's really hard to recreate it.

Speaker 11 It's like a devil's bargain thing.

Speaker 17 Like, this is the price you pay for complexity.

Speaker 54 Yeah, it's the price we pay for like having our big old brains.

Speaker 42 And

Speaker 1 it costs a way more to fix a fancy car, you know what I mean? Than an off-the-shelf thing. Yeah.
Yeah.

Speaker 25 Totally.

Speaker 11 You know, I am curious,

Speaker 11 what does Ray think about all this?

Speaker 11 You know, how does this reporting change change her? Because she wrote to you feeling like she had a superpower. And now you've told her that not only doesn't she,

Speaker 11 we are, we pale in comparison to what most animals can do, that we are the outliers. We're the odd men out of being unempowered.
Does it, did it, did it change her sense of specialness?

Speaker 27 I mean,

Speaker 58 I don't think I feel less special. I think I feel

Speaker 58 way more connected to the tree of life.

Speaker 58 Like, oh, I got to experience this thing that like

Speaker 58 all the other, like, or like so many of the other, maybe the majority of the other like branches of the tree get to experience.

Speaker 56 And like,

Speaker 19 how cool that, you know, it was just a fingertip, but like

Speaker 12 I'm out there with all those other guys.

Speaker 54 Yeah. Yeah, you're in good company.

Speaker 56 Yeah, you know, before this story, I would not have associated my fingertips with sea slugs in the slightest.

Speaker 58 But I hope that going forward, that is what I continue to think of when I look at my, I don't even know what sea slugs look like.

Speaker 56 I'm going to have to go home, look at a picture of them, and then just like hold my fingertip up next to it and be like, that's me.

Speaker 55 Yeah.

Speaker 1 Producer Becca Bressler.

Speaker 1 We're going to take a quick break. And if you don't know what a sea slug looks like, or even you think you do,

Speaker 1 just look it up during the break because they're,

Speaker 1 I mean, it's like a Martian fashion show down there.

Speaker 1 So beautiful, so strange.

Speaker 12 We'll be right back with two more stories of growth.

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Speaker 11 Heyo, Lulu here. As you have likely heard, this summer the federal government defunded public media in America.

Speaker 11 Here at WNYC, that has resulted in a loss of $3 million each year that we cannot count on anymore. But while we may have been defunded, we have not been defeated.

Speaker 11 And that is where you, just maybe you, come in. If you have never supported Radiolab before, consider tossing a few bucks each month our way.

Speaker 11 The best way to do that is to join our membership program, The Lab. Go online, click a few buttons, and then for $7 a month, boom, you are supporting our team.

Speaker 11 And as a thank you this month, we will mail you a brand new, beautifully designed jumbo tote bag. One of those ones that can fit like all your beach stuff and your big grocery hauls.

Speaker 11 It will not fit, however, our gratitude. If the mission of public radio means something to you, if Radiolab means something to you, your support right now means more than ever.

Speaker 11 Please go on over to members.radiolab.org and check out what it takes to become a member.

Speaker 11 Check out the new design of the gorgeous tote bag, which has a sort of aquatic theme because of all the aquatic stories that we randomly did this year.

Speaker 31 One more time, members.radiolab.org.

Speaker 11 Check it out. Thank you so much for listening and standing with us when we need you the most.

Speaker 27 Hey, I'm Lothif Nasser.

Speaker 31 I'm Lula Miller. This is Radiolab.

Speaker 1 Today's episode is about growth.

Speaker 11 Pumpkins that can grow 20 pounds a day.

Speaker 27 Fingertips that miraculously grow back after they've been chopped off.

Speaker 11 Slugs that can chop off their own body and then grow the whole thing back.

Speaker 52 This growth I have at the bottom of my toenail.

Speaker 34 Yeah, so they're obviously all different kinds of growth, but it it seems like they must be like tied together by some underlying rules of nature.

Speaker 17 Oh, hello, Pat.

Speaker 34 Hi, I am here.

Speaker 34 I've invaded your host intro.

Speaker 53 Okay, great.

Speaker 36 This is Pat Walters.

Speaker 1 He's our managing editor.

Speaker 34 Yeah, and whenever we get curious about the rules governing nature and the universe,

Speaker 34 we tend to call this one particular guy.

Speaker 37 Hey, old man. Hey, how are you?

Speaker 41 This is actually very comfortable here.

Speaker 25 Let's talk all day.

Speaker 34 His name is Steve Strogatz.

Speaker 41 I'm a mathematician and math professor at Cornell University.

Speaker 38 Also has a great podcast called The Joy of Why.

Speaker 34 And I asked him, just like, what are the different ways things can grow?

Speaker 25 Okay, here we go.

Speaker 41 There's linear growth.

Speaker 33 A simple kind of growth, basically adding.

Speaker 41 Like one, two, three, four.

Speaker 34 This, if you're like me, is how that stack of the magazines grows on your desk each month.

Speaker 25 And then there's exponential.

Speaker 41 Growth that feeds on itself.

Speaker 34 The kind of growth that multiplies.

Speaker 41 Like one, two, four, eight.

Speaker 34 Picture each magazine on the stack giving birth to another issue of the magazine each month.

Speaker 33 No.

Speaker 24 The more of something there is, the faster it grows.

Speaker 18 This, of course, is how diseases spread and pandemics happen.

Speaker 41 Now, there are kinds of growth that are faster than exponential.

Speaker 25 What's that?

Speaker 37 There's something called blow-up.

Speaker 25 What's blow-up?

Speaker 41 Which sounds like what it is. Something goes from nothing, boom, to infinity in a finite amount of time.

Speaker 33 But Steve says this doesn't actually happen in in the real world.

Speaker 41 Because we don't believe there are infinite anythings in our existence.

Speaker 27 Oh, thank God.

Speaker 24 And then there are these other kinds of growth that are a little more, I don't know, peculiar.

Speaker 18 And Steve told me about this one that completely took me by surprise and showed me how these patterns, these invisible blueprints of growth, can sometimes stretch out and connect parts of the world that I didn't think had anything to do with each other.

Speaker 28 Hmm.

Speaker 41 So you've heard the name Fibonacci. There's the famous Fibonacci sequence, which is where I take a number like one and two, and then I add them to make three.

Speaker 41 And then I always take the two most recent numbers and add them to make the next number.

Speaker 64 So two plus three is five. Five plus three is eight.

Speaker 41 Where am I? Eight plus five is thirteen. These are all Fibonacci numbers, and you can keep going like that, and you can see they're getting big.

Speaker 34 So the sequence goes one, two, three, five, eight.

Speaker 34 And each number in the sequence is the sum of the two that came before it.

Speaker 11 So it keeps getting bigger in this strange and yet oddly

Speaker 35 predictable way.

Speaker 42 Yeah. Okay.

Speaker 34 And I think when I started talking to Steve about it, I had the vague sense that what was interesting about it is that it sort of shows up in nature,

Speaker 18 maybe in plants.

Speaker 25 Yeah.

Speaker 34 But according to Steve.

Speaker 41 The Fibonacci sequence was originally posed as a problem about rabbits growing, where there was some made-up population biology rule about how many rabbits give birth to how many other rabbits that led to the Fibonacci sequence.

Speaker 41 That's from 1200 A.D.

Speaker 41 And it's not even...

Speaker 33 They observed something in rabbits or something?

Speaker 41 No, it's a made-up, it's a textbook problem. It's fake.

Speaker 41 Rabbits don't really grow according to the Fibonacci sequence.

Speaker 62 Wait a minute.

Speaker 25 So they came up with the,

Speaker 65 where did the sequence come from?

Speaker 41 Well, it's got a good backstory.

Speaker 37 Yeah, what's that? So Fibonacci,

Speaker 41 Fibonacci, whose real name was Leonardo, but of Pisa, not of Vinci.

Speaker 34 Weirdly, Steve says a historian sort of randomly stuck him with the name Fibonacci in the 1800s, but all this happened about 600 years before that, when he was still just Leonardo of Pisa.

Speaker 41 So Leonardo of Pisa, a.k.a. Fibonacci, is an Italian mathematician whose dad was working in North Africa.
It's a really interesting, vibrant place.

Speaker 41 He's getting to meet people from Egypt and all over the Middle East as well as Sicily. And there's a lot of trading going on.
It's 1200, a very vibrant time in the Middle Ages.

Speaker 41 And this Leonardo learns about a fantastic new kind of math that has come from a different part of the world, from the traders coming from the Middle East.

Speaker 41 from Arabic world, including who have themselves learned math developed in India.

Speaker 41 And so when we talk about Hindu-Arabic numerals, the ones that we all use today to write with, 0, 1, 2, 3, up to 9, those digits are from India by way through Baghdad and finally into Europe through dun, dun, dun, Leonardo of Pisa.

Speaker 41 Fibonacci brought Hindu-Arabic numerals to Europe.

Speaker 41 So this, it's a really ironic thing that Fibonacci gave us the numbers that we all use today, and nobody really remembers that that's what he did.

Speaker 41 He wrote this book called Liba Rabachi, basically the book of counting, the book of reckoning, how to work with numbers in a really practical way.

Speaker 41 That merchants of the type that he was encountering in all these trading spots in the Middle East, everybody had to work with money, and Roman numerals were terrible.

Speaker 41 So everybody wanted a better way, and these Hindu-Arabic numerals were fantastic. You could do really good calculations in your head.

Speaker 41 So, anyway, he introduced this fantastic system of Indian numerals to Europe around 1200, and he just, as a little footnote in his book, not really a footnote, but the book is filled with practice problems about taxes, about interest, about all kinds of money problems.

Speaker 41 But he made up this problem about growth, that the rabbits take one month to mature, and then when they mature, they give birth to another set of rabbits, a pair of rabbits, and then that pair can mate, blah, blah, blah.

Speaker 41 Anyway, he made up this story about rabbits where the Fibonacci Fibonacci sequence comes out.

Speaker 34 Where did this, but the sequence, even though he applied it to a made-up story about rabbits.

Speaker 65 But don't we see the Fibonacci sequence

Speaker 65 represented in the future?

Speaker 45 Yeah, yeah, yeah, we totally do. Sure.

Speaker 41 Plants really do have it. I mean, there's a million places we could go.
We could, if you look at a pine cone,

Speaker 41 if you start following the straightest line that you can, you can make a certain number of windy spirals. So if you count them up, the number will end up being a Fibonacci number of these spirals.

Speaker 41 And no matter how you do it, you'll always get a Fibonacci number. Trevor Burrus, Jr.
So

Speaker 34 did he just wing it and throw it on some rabbits and then it turned out magically to be true?

Speaker 65 Or did it

Speaker 25 come from India?

Speaker 41 Well, okay, that's another good story. It's nice of you to keep asking me these kind of questions.

Speaker 37 Okay, so it turns out...

Speaker 41 that Fibonacci was not the first to think of the Fibonacci sequence.

Speaker 37 Oh.

Speaker 41 It's a misnomer, and we're only gradually starting to appreciate how much of European math is really Indian math or Arabic math. I mean, a lot of it is European.
I don't want to pretend it's not.

Speaker 41 But the Fibonacci sequence was known 400 years before Fibonacci, if not longer,

Speaker 25 in India.

Speaker 41 And in a really surprising place.

Speaker 41 It's in connection with poetry.

Speaker 37 With poetry.

Speaker 41 Yeah, let me, can I try to explain it to you?

Speaker 37 Yes.

Speaker 41 This will take a minute.

Speaker 25 Okay, yeah, do it.

Speaker 37 We can try. I guess there.

Speaker 25 Yeah, okay.

Speaker 41 So going way back a few hundred years before the birth of Christ, there are scholars in ancient India who are really interested in, let's call it meter, you know, like rhythm, patterns of rhythm in poetry.

Speaker 41 The poems

Speaker 41 have certain rules to them because the rules make it easier to remember.

Speaker 37 And in a time before people had books, because remember the printing press is in the future.

Speaker 41 Oh, right.

Speaker 37 Right.

Speaker 41 So like if you want to remember the Odyssey in ancient Greece or memorize the Koran,

Speaker 41 you're going to sing it.

Speaker 34 So it's not just because it sounds nice or is pretty, it's because it's a tool for remembering.

Speaker 37 It's the way human psychology works. Right.
So

Speaker 42 these ancient scholars in India were trying to just think what exactly are the possible patterns if we obey,

Speaker 42 if our poetry obeys a certain rule, which is that you can build it out of two types of syllables.

Speaker 41 You can have something that lasts one beat or something that lasts two beats.

Speaker 41 And so one question that people interested in the sort of the science of poetry were concerned with was,

Speaker 41 suppose I want to make a line that is, for example, four beats long. How many different ways can I make something that's four beats?

Speaker 41 Basically, I have two things I can play with. Something that's one beat long or two beats long, right? There's these two kinds of syllables.

Speaker 41 So I could do one plus one plus one plus one, that adds up to four.

Speaker 41 Or I could do a rhythm that was

Speaker 41 two, one, one.

Speaker 42 That would also add up to four.

Speaker 41 Or I could do one, two, one.

Speaker 42 That would be four.

Speaker 64 Or I could do two two.

Speaker 41 Or I could do one one two.

Speaker 45 I've said five possibilities.

Speaker 41 Now, what's interesting about that is that five is the fourth Fibonacci number.

Speaker 23 Oh.

Speaker 41 And in general, if I want to make something that's n beats long, there is the nth Fibonacci number ways of doing it.

Speaker 62 Whoa, wait. Okay.

Speaker 34 So to make a five-beat line, there would be... eight ways of doing that.

Speaker 27 And to make a six-beat line, there would be 13 ways of doing that.

Speaker 63 Yes.

Speaker 34 And a seven-beat line, there would be 21 ways of doing

Speaker 25 that.

Speaker 45 It's a growth problem, right? It's the growth of possibilities.

Speaker 41 It's the growth of creative possibilities in Sanskrit poetry. This was figured out in India by a person named Virahanka four centuries before Fibonacci was born.

Speaker 18 Wow.

Speaker 37 So

Speaker 34 they noticed this phenomenon present in poetry, studying the possibilities in Sanskrit poetry.

Speaker 34 And then like when I google the Fibonacci sequence and Wikipedia tells me it's like really all over nature, not just in pine cones, but pineapples and on sunflower seeds.

Speaker 33 Apparently, lots of flowers have a Fibonacci number of petals.

Speaker 25 Yes.

Speaker 34 I'm just now trying to like wrap my head around like, is that because there's something

Speaker 34 in the universe that like made its way into the Sanskrit poetry by way of humans that's that also made its way into the trees and the pineapples?

Speaker 62 And like, what's the, that's crazy.

Speaker 65 That's That's wild because I think about poetry as being so separate from

Speaker 25 a pineapple or

Speaker 34 the leaves on a tree.

Speaker 15 Yes.

Speaker 52 Well, okay.

Speaker 25 It's not a question. That's just a question.
No,

Speaker 41 it's an expression of wonder, which is appropriate. Why are Fibonacci numbers in botany? Why are they in so many plant structures?

Speaker 41 There are various theories out there. Some people will say that it has to do with like when a branch shoots out of a tree.

Speaker 41 it doesn't want to shoot out in a direction where it's covered over by another branch. It needs to get its own sunlight.

Speaker 41 So if the branches have to grow, I mean, natural selection, evolution will have disfavored the trees that don't follow this principle. That may have something to do with it.

Speaker 41 I'm not giving you a clear explanation because I don't honestly know.

Speaker 33 This is helpful.

Speaker 34 And then like

Speaker 34 maybe the same thing holds true for the poetry where people are trying to create new

Speaker 34 newness. You're trying to make,

Speaker 65 I don't know, create space in a sense.

Speaker 42 Yes.

Speaker 41 You're trying to create novelty subject to constraints.

Speaker 37 Right. Right?

Speaker 41 And you could say novelty subject to constraints is art.

Speaker 41 Like growth in creativity subject to constraints.

Speaker 15 That's what art is, right?

Speaker 24 Hmm.

Speaker 39 Yeah.

Speaker 25 Anyway.

Speaker 25 Huh.

Speaker 1 So what do you make of all that?

Speaker 24 I guess, I don't know.

Speaker 34 It sort of makes me see the plants as

Speaker 33 a little bit more artistic than it did before.

Speaker 34 And

Speaker 34 the poetry as

Speaker 34 like

Speaker 33 a little bit more

Speaker 34 from nature.

Speaker 11 That gives me goosebumps.

Speaker 28 That's really cool. Yeah.

Speaker 1 You're also missing the other takeaway here, which is that

Speaker 1 Fibonacci didn't discover the Fibonacci sequence, and that's not even his real name.

Speaker 25 He wasn't even named Fibonacci.

Speaker 35 That is the point.

Speaker 34 Let's bring it back down to Earth and focus on what really matters.

Speaker 40 What really matters is that he's not a family.

Speaker 42 Just that Fibonacci. He's a fraud.

Speaker 34 Let's just call him out. He's not who...

Speaker 38 We thought he was.

Speaker 11 Well, thank you, Pat. That was beautiful.
And we will be back in just a moment with one last growth story of planetary scale and import.

Speaker 19 And the little humans trying to control it.

Speaker 35 Stick with us.

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Speaker 11 Heyo, Lulu here. As you have likely heard, this summer the federal government defunded public media in America.

Speaker 11 Here at WNYC, that has resulted in a loss of $3 million each year that we cannot count on anymore. But while we may have been defunded, we have not been defeated.

Speaker 11 And that is where you, just maybe you, come in. If you have never supported Radiolab before, consider tossing a few bucks each month our way.

Speaker 11 The best way to do that is to join our membership program, The Lab. Go online, click a few buttons, and then for $7 a month, boom, you are supporting our team.

Speaker 11 And as a thank you this month, we will mail you a brand new, beautifully designed jumbo tote bag. One of those ones that can fit like all your beach stuff and your big grocery hauls.

Speaker 11 It will not fit, however, our gratitude. If the mission of public radio means something to you, if Radiolab means something to you, your support right now means more than ever.

Speaker 11 Please go on over to members.radiolab.org and check out what it takes to become a member.

Speaker 11 Check out the new design of the gorgeous tote bag, which has a sort of aquatic theme because of all the aquatic stories that we randomly did this year.

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Speaker 11 Check it out. Thank you so much for listening and standing with us when we need you the most.

Speaker 25 Lulu.

Speaker 28 Lattev.

Speaker 24 We are back.

Speaker 19 Okay, so

Speaker 1 with one more story of growth from producers Annie McEwen, I've just detangled my headphones.

Speaker 17 And Simon Adler.

Speaker 36 But go on, go on.

Speaker 19 All right. Let us begin.

Speaker 24 All right.

Speaker 19 So I think, like,

Speaker 19 I think, like most people, I thought for the longest time that the human population was growing really fast.

Speaker 67 We already have between three and seven times more people than we can permanently support.

Speaker 19 Maybe exponentially.

Speaker 67 The growth rate is just incredible.

Speaker 19 You know, people were popping kids out and blah, blah, blah.

Speaker 67 We are destroying our fossil fuels. We are dispersing our mineral resources.

Speaker 19 And that this was like a really big

Speaker 23 problem.

Speaker 18 We're freaked.

Speaker 30 Yeah, a ball of flesh expanding at the speed of light, I think.

Speaker 27 A ball of flesh expanding at the speed of light.

Speaker 53 Oh, God.

Speaker 19 This is Philip Cohen.

Speaker 30 I'm a professor of sociology at the University of Maryland.

Speaker 19 And I called him up to talk about this fear. It's one that I really took deep into my soul at some point in my life.
And he told me that, like, yes, this was a real concern starting around the 1950s.

Speaker 30 Population did start increasing exponentially. You know, 2 billion, 4 billion, 8 8 billion.

Speaker 25 Population bomb kind of thing.

Speaker 17 Yes, yeah, yeah, yeah.

Speaker 19 But that by the time I had even started worrying about it, by the 90s, really, it was no longer a problem.

Speaker 28 Right.

Speaker 30 You know, it's obviously a long, complicated story, and it's different around the world.

Speaker 30 But with better health care, better contraception, and access to education, a lot of women started having fewer children.

Speaker 19 Fewer kids meant slower growth. And as growth slowed, demographers predicted that population would just plateau.

Speaker 15 Yes.

Speaker 30 The idea was that the average woman was going to have two children and that world population would hit a peak around 10 billion, around 2060 or so. And after that, be stable.

Speaker 19 And we would all live happily ever after.

Speaker 25 Oh, thank God. Yeah, it's great.

Speaker 26 Big ol' exhale for Annie McEwen on the population front.

Speaker 17 That's right.

Speaker 19 But then.

Speaker 19 Like 10 seconds after I learned about this plateau and felt great about it, I learned that that is not what's happening.

Speaker 11 Hmm.

Speaker 28 Well,

Speaker 30 it would be in Europe the panic first started.

Speaker 19 Because instead of like watching things come to settle at a peaceful plateau, demographers noticed that, especially in Europe, but also in other parts of the world, you know, South Korea, China, Japan, that this drop in birth rates accelerates.

Speaker 19 The fall accelerates.

Speaker 37 Exactly.

Speaker 19 Birth rates in a bunch of places were now dipping too low.

Speaker 19 Okay, so I've got the latest fertility rate information here in front of me. So like, ask me, ask me a country and I'll tell you.

Speaker 11 Okay, France, France, France.

Speaker 19 Okay, so remember, for us to keep replacing ourselves, the number to hit is 2.1. France is 1.8.

Speaker 6 France is 1.8.

Speaker 25 Okay. Au revoir.

Speaker 59 Poland.

Speaker 19 Poland is 1.5.

Speaker 47 1.5. Wow.
Yeah.

Speaker 25 Mexico? Mexico.

Speaker 19 1.8.

Speaker 1 Cameroon.

Speaker 19 4.29.

Speaker 59 So they're above representative.

Speaker 47 Oh, they're high.

Speaker 24 Yeah, they're high.

Speaker 55 They're high. But they're falling.

Speaker 19 Like in the 80s, I think it was 6.7.

Speaker 47 Whoa.

Speaker 11 What about Ghana?

Speaker 19 3.5.

Speaker 19 But they also fell from over 6.

Speaker 40 Oh, wow.

Speaker 24 Italy?

Speaker 19 Italy is 1.3. Italy's low.

Speaker 25 Whoa.

Speaker 1 Italy's 1.3.

Speaker 45 Wow.

Speaker 7 Yeah. What are we?

Speaker 35 What's the U.S.?

Speaker 11 1.7. 1.7.
Yeah. Wow.
And where's it?

Speaker 17 The lowest?

Speaker 26 The lowest are like Korea and Japan, which I think Korea Korea is at like 0.6.

Speaker 23 No

Speaker 19 point six point seven.

Speaker 24 Yeah.

Speaker 53 Wow, that's so low.

Speaker 27 Wait, and Earth as a whole is what right now?

Speaker 19 It's 2.3.

Speaker 59 So we're just above total.

Speaker 54 Yeah.

Speaker 19 And Philip says that this downward trend is going to continue.

Speaker 30 The world population is going to hit a peak. around 10 billion, around 2060 or so.
And after that, it will almost certainly start to taper downward.

Speaker 19 So we are on the verge of beginning to shrink.

Speaker 22 Really?

Speaker 22 That makes me so happy.

Speaker 39 Yes.

Speaker 19 In a couple hundred years, it's projected that the Earth's population will actually be about 6 billion.

Speaker 23 Wow.

Speaker 31 That far down. So less than now.

Speaker 53 Oh, yeah.

Speaker 7 We were going a roller coaster and we're like, we're coming at that. We're like,

Speaker 1 it's like the tukka-tuka-tuka on the roller coaster before the the drop.

Speaker 55 Exactly. I am really pumped to hear that.
Whoa.

Speaker 59 I don't know.

Speaker 1 I think I kind of like the plateau. The plateau sounds so nice because the stability, it's like you can, you know what to plan for.
Like, you know what to do.

Speaker 11 But it's a stability of like un of a, of a herding earth and like strapped resources.

Speaker 7 How about a little less

Speaker 10 to drive cars and share weeds?

Speaker 1 That's fair, but I don't know.

Speaker 3 There's something that sounds sad about less people.

Speaker 1 It's like the parties ended.

Speaker 24 No. Like it's like the parties.

Speaker 55 It's really not sad. It's like, that's great.

Speaker 10 The parties, there's still so many people. The club is popping.

Speaker 19 Yes, the club is popping.

Speaker 7 Yeah.

Speaker 19 I think, I think when I heard this, I was like, okay, great. I feel relieved.
The skin ball is not going to happen. But I guess the thing that I was most struck by is just

Speaker 19 while I was freaking out about humans exploding off the planet, eating everything, there was a whole other group of people freaking out about the exact opposite.

Speaker 55 Really?

Speaker 13 Hey, would they be worried?

Speaker 19 Well, you know, some of them are the billionaires.

Speaker 68 You know, if we don't make enough people to at least sustain our numbers, perhaps increase a little bit, then civilization is going to crumble.

Speaker 19 Who are just like, let's grow, grow, grow so we can all make more money.

Speaker 68 I'd rather civilization went out with a bang than a whimper and adult diapers.

Speaker 19 But then there are like also regular economists, especially in like the Western capitalist economies, who say that the shrinking is a problem because our economy needs workers to just, you know, keep things chucking along.

Speaker 7 But I mean, what about immigration?

Speaker 11 Forget all the other reasons.

Speaker 11 Just looking at it from this economic viewpoint, I mean, people in the United States might not be having that many kids, but there are lots of people who would love to come and live here and therefore be workers in the economy.

Speaker 63 Yes.

Speaker 30 Anybody who says there's a population shortage or problem in any rich country has to at least answer the question of what about immigration?

Speaker 26 Like, were it not for immigration, the U.S.

Speaker 38 population would be falling right now.

Speaker 52 Really?

Speaker 19 Yes. Or it would be falling very soon.

Speaker 1 Which is so crazy that the

Speaker 1 administration in power right now, the whole thing is like, get people out, get people out. And it's like, yeah, we kind of need people right now.

Speaker 24 Yeah.

Speaker 19 And actually, when I spoke with another demographer on the phone, James Ramo, he told me that like all these countries that are, you know, really not immigrant friendly, in 50 years' time, they're going to be fighting to attract immigrants.

Speaker 22 Oh, I bet.

Speaker 24 I bet.

Speaker 19 But like, even with all these wealthy countries holding their doors wide open, that's that's only a temporary fix.

Speaker 30 That works for, you know, maybe a hundred years or 50 years.

Speaker 19 Because by the year 2100, 97% of the world's countries will be below replacement levels. So this sort of decline in fertility is happening everywhere.

Speaker 19 And it's happening more slowly in some countries than others, but it is happening.

Speaker 10 So basically in 70 years or so, most of the planet will be dipping.

Speaker 55 Yes.

Speaker 23 Hmm.

Speaker 19 And like, I think talking about the economy, especially the economy in the future, it can feel just very abstract.

Speaker 19 But for me, like the whole thing started to get kind of unsettling when I called up another demographer.

Speaker 25 Hello?

Speaker 55 Oh, I hear them. Hello.

Speaker 19 This one named Leslie Root.

Speaker 54 I am assistant professor of research at the University of Colorado Boulder.

Speaker 19 Who told me that fundamentally, this whole thing is a question of how will we care for each other.

Speaker 54 So this is, this is true of like any human society, right? That you have people who need to be supported and you have people who are capable of supporting.

Speaker 54 And people who need to be supported are the very young, right? Like human children are pretty hopeless.

Speaker 54 And like compared to other primates, right?

Speaker 17 They can't do anything.

Speaker 17 Yeah.

Speaker 55 Exactly.

Speaker 54 And the elderly. And then sort of the prime working years is when we are supposed to be able to produce more than we consume so that we can share it with other people.

Speaker 54 And so a big concern is that when you have lower fertility and imagine your population with like people flowing into and out of it, fewer people are flowing in and the people who are already in it are getting older and older.

Speaker 54 So you have what's called an aging population.

Speaker 19 So like in 200 years, when the population is down to 6 billion, that's going to be a very different 6 billion than the one we just experienced in the year 2000 because a lot of those people are going to be very old.

Speaker 19 And the worry is that like as society becomes more and more top heavy.

Speaker 54 What does that mean for our ability to support each other?

Speaker 19 Like, just super practically, you know, like, who are all the doctors going to be to take care of these old people, and who's going to staff the nursing homes, and like, who will grow the food to feed these old people?

Speaker 19 Like, you can sort of see that, like, as the proportion of young to old people shifts more and more out of whack, you have on the backs of these few young people kind of the burden of everything.

Speaker 19 Unless

Speaker 19 a whole bunch of us right now Pope told Italians to have more babies start to breed like rabbits Which is what a bunch of governments around the world are trying to get their citizens to do Putin has urged a Russian woman to have eight or more babies

Speaker 19 Here's a bunch of stuff that countries have tried

Speaker 19 Japan tried government-sponsored speed dating night

Speaker 19 Russia they're like hey if you have more than two kids we'll give you seven thousand dollars four times the average monthly wage Taiwan there was a presidential candidate in 2023 who was like hey the gift of yet another furry child.

Speaker 19 Everyone who has a baby should get a free pet as well.

Speaker 14 A free pet?

Speaker 24 That's like more, more worth it.

Speaker 19 There's also things like Sweden has these like amazing parental leave policies. 480 days.
Germany has got free daycare.

Speaker 31 That's money.

Speaker 19 And of course, there have also been some darker attempts to control, like in the U.S. and North Korea, where abortion has been banned.

Speaker 19 But the crazy thing is that, like, carrot or stick,

Speaker 19 none of this has worked.

Speaker 27 None of it has worked?

Speaker 24 Yeah.

Speaker 26 And the one thing I'll add to that is like with

Speaker 26 few exceptions and the exceptions are sort of explainable away, no country that has dipped below replacement rate has ever come back, gone back above.

Speaker 23 Wow.

Speaker 1 Interesting.

Speaker 30 Right. There really is no success story out there.

Speaker 30 Nobody has shown how you can turn this around.

Speaker 11 Huh, that's wild. I mean, do people have any idea why not?

Speaker 19 I don't know.

Speaker 19 I think it's because it's just really hard to answer the question, why does someone choose to have a kid or not?

Speaker 54 Yeah, there's a lot of like casting about for explanations of what exactly drives lower fertility.

Speaker 19 There are going to be a hundred reasons, big and small, why someone becomes a parent or not.

Speaker 54 You know, we meet a partner or we don't, and our partner has the same preferences that we do or they don't.

Speaker 19 We can find affordable housing or we can't. We have access to great health care or we don't.

Speaker 54 We get a good job with flexible hours, or we don't. We live near family who can babysit the kids, or we don't.

Speaker 19 You know, for every one person, the decision is going to be this like really complicated mess of reasons and circumstances.

Speaker 19 And if you zoom out from there to the national or like the global level, looking down and trying to understand this is just total chaos.

Speaker 19 Hmm.

Speaker 23 Right.

Speaker 49 You're not going to solve the mystery of why.

Speaker 49 And basically, there's nothing you can do about it.

Speaker 49 So what does this look like? You know, like, what does it look like when a society stops having children?

Speaker 19 This is Gideon Lewis Krause.

Speaker 49 I'm a staff writer at the New Yorker.

Speaker 19 He recently wrote an essay about declining population called The End of Children.

Speaker 19 And as he was starting to report the piece, he noticed that there were all these articles in Western media about South Korea.

Speaker 49 Obviously, South Korea with with the lowest fertility rate in the world comes up all the time in all of these columns.

Speaker 49 And I noticed that everybody invoked South Korea, but it didn't seem like anyone had gone there. And I thought, like, it would be interesting to hear from some South Koreans about this.

Speaker 19 South Korea is a country that has more deaths than births every year. And it's not an easy country to immigrate to.
So its population is getting older and smaller.

Speaker 19 And so it's sort of seen as almost like this bellwether for where the rest of us are headed. And so I got there, there and

Speaker 49 I got into the center of Seoul and I went to the subway at rush hour and you saw no children anywhere.

Speaker 49 But at first I thought like, oh, well, you know, in New York, like, would I take my kids on the rush hour subway? Like, probably not.

Speaker 49 But then pretty immediately, like, you really just don't, you know, you don't see playgrounds or like the handful of playgrounds that I saw were completely empty at any time of day.

Speaker 49 And you just don't see a lot of children. And there were these no kids zones everywhere.
There were signs on restaurants and other establishments that said no kids here.

Speaker 49 And I mean, so much of it is about a rapid shift in cultural norms about kids. So in fact, I met with this young economics reporter who writes about this for a living.

Speaker 49 And she was in her late 20s or early 30s. And she said, like, I understand all of this stuff on a deep economic level.
But when I write about it, I think, like, well, what would change my mind?

Speaker 49 And the answer is nothing. There's nothing that would make me want to have kids because it's the norm to not want to have kids.

Speaker 19 Gideon eventually made his way out to some of the more rural areas of the country where it's projected that about 2,000 schools are going to be closing in the next 10 years.

Speaker 49 And so I wanted to go visit one of these schools. So I went to one in the far south.
And this school, I think it had, as Max, it had about 1,300 students. Now it has five.

Speaker 26 It had...

Speaker 26 With five students.

Speaker 49 Five students, yeah.

Speaker 12 What grades?

Speaker 49 It had three first graders and two sixth graders.

Speaker 49 And when I was talking to the sixth grade teacher, I said to him, like, so you have two kids, like, do they get along? And he like looked at me like I was a complete idiot.

Speaker 49 And he was like, what do you mean, like, do they get along? Like, they don't know anyone else. They've been in school together since they started school.

Speaker 49 Like, the other child is like the only other child they know.

Speaker 59 What was it like walking through this school?

Speaker 38 Like, what did it look like?

Speaker 49 Well, there, you know, there's a feeling of great dignity and resignation about this stuff.

Speaker 49 So this, you know, the outside of the school had been freshly painted, and the inside was bright and totally broom swept and spotless. And everything was in perfect order, except it was empty.

Speaker 49 And like there was no heat on in the hallways. And almost all the classrooms were dark.
And some of the classrooms had photos of the last group of kids that occupied that classroom.

Speaker 49 And like the classroom was dark and just hadn't been opened in a couple of years. And

Speaker 49 the cafeteria had like a little proscenium stage with a curtain. And clearly they had had like school plays there and stuff.

Speaker 49 And like, you know, you probably could have seated 300 people in this cafeteria. Um, so it just felt like everyone had a like, there was no sense of decay.
It just felt like everyone had evaporated.

Speaker 10 Right.

Speaker 19 It does feel like children are disappearing.

Speaker 24 Yeah.

Speaker 23 And

Speaker 49 something like 200 nursery schools have been converted into retirement homes because there's like a radical dearth of retirement homes.

Speaker 49 And you can see that some of these nursery schools that have been turned into retirement homes, they've kept the same directors and they had kept the same like rubberized play floors.

Speaker 49 for the old people. And they even had, actually my fact checker, Emily, found this.

Speaker 49 When she talked to them, she was like, not only do we have the same rubberized play floors, we have the same crayons that like the kids used to use the crayons and now we just like the seniors use the crayons.

Speaker 25 There's something really dark about that. Yeah.
Yeah. Yeah.

Speaker 53 The bell curve of life.

Speaker 31 But this is our projection. Yeah.

Speaker 1 We've already in this very story been wrong twice about projections. We thought, oh my God, it was going to be a population bomb explosion.
Too many people.

Speaker 1 Then we were like, oh, it's going to level out so nicely, perfectly. That didn't happen.
How do we know that these projections are worth anything? Yeah.

Speaker 55 Yes.

Speaker 19 That's a great question. That is a great question.

Speaker 19 I think that

Speaker 19 we just don't know. We just don't know what's going to happen next.
But what we're heading towards is like really unprecedented. And there is no way to be like, oh, yeah, last time this happened.

Speaker 19 So we can project forward and imagine. That's right, right.
And I do think that.

Speaker 1 It's the last planet we were on.

Speaker 19 Yeah. And as fewer people have have fewer kids, those fewer kids are going to have fewer kids.
And this is just, mathematically, it seems tricky to get out of that spiral.

Speaker 19 However, we totally don't quite know. And I think that's very fair.

Speaker 19 What is very much agreed upon is that the population of the world is going to start declining. And that is a totally new thing for humanity.
And that is set to happen pretty soon.

Speaker 63 Yeah, yeah, it's pretty soon.

Speaker 27 I hope to live to see it.

Speaker 19 It's just interesting to imagine being on the planet and sort of looking around and being like, this is the most people there might ever be alive at one time.

Speaker 30 At that moment, yeah.

Speaker 63 It's big.

Speaker 30 It's like, yes, it's like going to the moon or,

Speaker 30 you know, our first nuclear bomb. I mean,

Speaker 30 it's a big moment in human history when

Speaker 30 we turn that around and for the first time, the global population is declining. You know, feeling like you might never come back from it.
Like

Speaker 30 you've changed direction.

Speaker 19 Yeah, it's a shift from growth to something else.

Speaker 19 Something new.

Speaker 52 Right, exactly.

Speaker 11 Producers Annie McEwen and Simon Adler.

Speaker 1 So that's the end of the growth show,

Speaker 36 a story about shrinking.

Speaker 25 Yeah.

Speaker 11 Yeah, from a pumpkin that was kind of growing uncontrollably to a population that seems to be shrinking uncontrollably.

Speaker 1 Well, at least we're making room for more giant pumpkins.

Speaker 17 There's always that, the silver lining, the orange lining.

Speaker 11 That, I guess, is our show.

Speaker 1 This episode was reported and produced by Matt Kilty, Becca Bressler, Pat Walter, Sindhun Yana Sambandan, Annie McEwen, and Simon Adler with additional reporting by Ray Mondo, and it was edited by Pat Walters.

Speaker 11 Mixing and sound design by Jeremy Bloom, fact-checking by Emily Krieger and Natalie Middleton, and special thanks to Ellie Tanaka, Keith Devlin, Devin Patel, Chris Golay, James Raymond, and Jessica Savage.

Speaker 14 I'm Lula Miller.

Speaker 36 And I'm Loftus Nasser.

Speaker 25 Thanks for listening.

Speaker 38 We'll see you soon.

Speaker 68 Hi. I'm Paolo Mara Biggs and I'm calling from Nuoli, American Sahamoa.
And here are the staff credits. Radiolab was created by Jad Abimrad and is edited by Soren Wheeler.

Speaker 68 Lulu Miller and Matapnasser are our co-hosts. Dylan Keefe is our director of sound design.
Our staff includes Simon Adler, Jeremy Bloom, Becca Bressler, W.

Speaker 68 Harry Fortuna, David Gable, Maria Paz Gutierrez, Sindhu Namasamadam, Matt Kealty, Enna McEwen, Alex Neeson, Sara Kari, Sara Sandback, Anissa Vitsa, Arianne Wack, Pat Walters, and Molly Webster.

Speaker 68 Our fact-checkers checkers are Diane Kelly, Emily Krieger, and Natalie Middleton.

Speaker 36 Bakatai, Tele Laba, Maro.

Speaker 69 Hey, I'm Steph. I'm from Melbourne, Australia.

Speaker 69 Leadership support for Radiolab science programming is provided by the Gordon and Betty Moore Foundation, Science Sandbox, a Simons Foundation Initiative, and the John Templeton Foundation.

Speaker 69 Foundational support for Radiolab was provided by the Alfred P. Sloan Foundation.

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