SciShow Tangents - Armor

Starting point is 00:00:00 Hello and welcome to SciShow Tangents, the lightly competitive knowledge showcase. I'm your host, Hank Green, and joining me this week as always is science expert, Sari Reilly. Hello, here to be an expert. How's science doing? Oh, I think science is chugging along. I think it had a slow year because of the pandemic. Well, it had simultaneously a very slow year and a very fast year. Everybody's paying too much attention to it. Science hates to be the center of attention.

Starting point is 00:00:42 We like being in our little corners, you know, just like doing research. And then after years and years of working on one problem, showing up with a third of a solution being like, progress. What a very science expert answer. We're also joined by our resident everyman, Sam Schultz. Howdy, y'all. Is that what the regular people say? No, that's what I say now. It's my new thing

Starting point is 00:01:05 you say how do you i i say howdy and i never knew it until i went to australia and people were like do you actually say that in america sometimes for fun it's a fun thing no i definitely say howdy i just never realized it. So this is SciShow Tangents. Every week we try to one-up and amaze each other and delight each other and also delight you with science facts while also trying to stay on topic and failing at that. So Sari and Sam are playing for glory, and they're also playing for Hank Bucks, which we will award as we play.

Starting point is 00:01:40 And at the end of the episode, one of them will be crowned the winner. As always, now we shall introduce this week's topic with the traditional science poem, and it's from me this time. Don't poke me, I bleed. My epidermis has not the toughness it needs. Don't do it, my skin is just a flimsy membrane far too thin. Please wait, just wait, as I slowly strap on my breastplate and my visor and my helm, these things that help me guard my realm, my gauntlets and my tassets. How else can I insure these assets? My pauldron and boiled leather, they keep me safe in any weather. My placard, rebrace and greaves, and sabbatons upon my feet. And now I'm fully dressed, a knight,

Starting point is 00:02:22 ready to fight in any fight. So long as you're willing to wait, I can be safe from any fate. Our topic for the day is armor. Don't do it, my skin. I had to look up a diagram of a knight. Several of those words, I do not know what they mean. I know them from playing video games. Yeah. The sabatons are the shoes.

Starting point is 00:02:45 Sari, what is armor? Well, it's basically that. It's protection. Would my skin be armor? Because it does protect me from some stuff. Yeah. I think it's very subjective what we call armor or not. To a pile of mucus, our skin looks like pretty good armor.

Starting point is 00:03:03 But to like a lizard, skin weak bad yeah and then to a tortoise a lizard is like you gooey goosh yeah so if you're like slightly less gooey compared to someone else then you have armor but then you can also apply artificial armors. And then that's definitely armor because it is, you know, in comparison to the thing that it's covering. So armor is both a thing that we imagine other animals having because we don't have it and a thing that we make for ourselves. armor is something hard like skin is soft and so questionably armor but when we look at animals and we say that's armor right it's like a turtle shell or something that's really mineralized or bony or has keratin as its main structural component so that if you were to knock on it it'd be like oh that's hard or like a bug like a bug, it's like, ooh, that's crunchy. So you're saying, you're saying that my toes have special toe armor. Yeah. With a toe helmet on them.

Starting point is 00:04:11 And we all have helmets, yeah, because we have keratin. Yeah, I mean, I don't know that that's doing much good. Wait, our hair? Is that what you're talking about? Well, it's keratin, but I don't know. I don't think that it's doing the armor job. I mean, maybe it's like protecting us from certain rays and stuff, right? It's an armor against something.

Starting point is 00:04:27 Yeah, I don't think you can call like sunscreen armor. I think you could. Fingernails armor, I think. It's like, oh, there's the soft bit. And then you can tap on it and be like, that's not as soft. I get asked all the time why we have fingernails. And I do not have a good reason. Are there any clawless like mammals or things

Starting point is 00:04:45 like that that have gotten rid of these little keratin deposits on their toes? Sari, you are the resident science expert. You can't ask these questions. No, I don't know the answer. And it may be that I would, but I can't think of any. And in fact, I can't really think of any tetrapods that don't have fingernails. Yeah. I ask because that's my reasoning. It's like, well, we just haven't evolved to not have them. Everyone has them. And maybe check back in a couple hundred thousand years and humans will just have nubs.

Starting point is 00:05:17 They're definitely useful for like fine manipulation, scratching, picking the nose, getting out a splinter, stuff like that. But at this point, we have got we got tools for all that stuff. I don't we don't actually. Is there a special nose picking tool that I don't know about? That little thing you put in baby's noses that sucks the boogers out. Yeah, we had one of those, but we don't use it anymore. It's like some it's like Swedish. I don't know if it was actually Swedish, but it's some some european country was like there's too much snot in there i need a device for for literally using my own

Starting point is 00:05:50 lungs to suck boogers out of a child this is real this is real yeah there's like a there's like a device in the front where the booger gets stuck it doesn't get all that like it's it would be very difficult possibly impossible to get the booger to your. It doesn't get all the, like it would be very difficult, possibly impossible, to get the booger to your mouth. Too close for comfort still though. How did babies survive without booger suckers? Did they just like? You just got to suck them out,

Starting point is 00:06:16 mouth to nose. You know what I think? Boogers are armor in their own way. I guess kind of. They do like sort of trap foreign bodies can we move on though before we find out how everything is armor sorry what is where's the word armor it's not going to help our case that of limiting armor so armor the word is from around 1300 which means defensive covering worn in combat like a knight's armor or means of protection.

Starting point is 00:06:46 But it comes from arm and arma, which is weapons. Oh, arms. And tools. And then the root R means just to fit together, like all the pieces of armor fit together. So by those definitions, armor is both defensive and offensive. And if you just like put a puzzle together, maybe armor. Boogers all fit together in your nose. Is it related to the arms that, you know, I have on my body?

Starting point is 00:07:18 I think they come of our bodies is related to like weapons of a warrior with the root R to fit together. So like your body parts fit together. Your shoulder fits into your arm. And also these boys are weapons. Lethal. Yeah, it's the original watch out for these guns joke. Really scary. Yeah.

Starting point is 00:07:43 That means that it's time to move on to the quiz portion of our show i have a game that i would like you two to play against each other to see who um is going to win that's mostly all we will find out we will not find out much more than that but the game is called this or that and this is the armor edition of this or that so when it comes to armor you don't always need a giant heavy suit of metal to protect yourself. Sometimes you just need some good materials and a little clever engineering, both of which you can find in laboratories and in nature, in the wild. The following are descriptions of materials that have gone into making armor. Some of them belong to

Starting point is 00:08:21 animals, and some of them are the work of scientists developing new armor technology. Can you tell me which one is which? And I've got three for you, so get ready. Number one. Sometimes it's not just about the material that makes up the armor, but the structure of the empty space inside it. This material is very light, but it gets its strength from the complex fractal structures inside it that create many, many empty spaces less than 100 micrometers apart from each other. The shape and location of those empty spaces works to dissipate the shock waves on the material when faced with impact. Is that human-made armor or nature-made armor?

Starting point is 00:09:03 Oh, this is going to be a hard guess. This is just going to be me guessing completely. I feel like all armor is based on like shells and stuff like that. So it's only like it was impossible. No, no, no, no. No, it's not? I think, honestly, I don't think so. I think that nobody who got stabbed was like,

Starting point is 00:09:21 let's go and look to nature. And then they were like, let's cover up the part where people get stabbed on with stuff that can't get stabbed. Yeah, they didn't invent the word till the 1300s, though. Maybe they didn't have the idea until then either. I don't know. Maybe they just called it shells.

Starting point is 00:09:34 Man shells. I'm Clam Man. You can't kill me. Yeah, Clam Man was the best warrior of all time until the 1300s when everybody was Clam Man. Well, I'm going to say this is some kind of bug. Sam thinks bug. Sam thinks bug. I guess just to switch it up, I'll go man-made because we can blow a bunch of little chambers into things. That sounds like carbon nanotubes or something like that.

Starting point is 00:10:03 into things. That sounds like carbon nanotubes or something like that. Well, researchers at Los Alamos 3D printed tiny plastic cubes with even tinier fractal voids inside of them that they could very precisely place. In the past, similar shockwave dissipation technologies have been more randomly distributed, but this technology allowed them to pursue a more precise and reproducible design that could potentially be used as a protective armor for humans and for our vehicles. Sari gets a point. Not a bug. Not a bug.

Starting point is 00:10:35 Fact number two, or thing number two. This armor gets its strength from the fact that it is a hydrogel, a mixture that's 90% water that's mixed with a fibrous material. Those fibers cross-link together into layers, and as they stack, they begin to resemble the structure of plywood. A section of this hydrogel that is only about a quarter of a millimeter thick can have tens of thousands of those layers, creating a material that is as strong as the materials used to make car tires. I was going to say it was a plant until you said plywood.

Starting point is 00:11:10 I feel like that's too on the nose. I mean, a hydrogel. That sounds like something somebody in a lab's got to make to me. I'm going to go with man-made. I'm going to go with some sort of like sea creature. Is it a lobster? It is a lobster. Whoa.

Starting point is 00:11:28 What? So specifically, the soft hydrogel membrane covers lobster bellies. Scientists comparing this hydrogel to other natural hydrogels like collagen and natural rubber found that it is the toughest

Starting point is 00:11:42 natural hydrogel. For many of these other hydrogels, stretching the material causes it to become softer. But for the lobster hydrogel, stretching caused the material to become stiffer and tougher. The toughness of the material protects the lobster from predators, as well as from rocks on the ocean floor, while the flexibility makes it possible for lobsters to move the rest of their armored body around because, of course, they need to move those big tails for when they go when i go fast that's really cool they have little tire bellies basically yeah underneath their uh you know plates but lobster is like well protected

Starting point is 00:12:16 yeah they gotta figure it out do you guys want to know why the scientists decided to look into this yeah they were eating a lobster and they were like, this part is really chewy. Great. So always be on the lookout for great, great new sources of inspiration. And our final, our final armor of the game.

Starting point is 00:12:39 Creating armor for appendages and limbs requires some careful thinking of how best to balance strength with pragmatic needs like movement. Luckily, there's a shape for that. appendages and limbs requires some careful thinking of how best to balance strength with pragmatic needs like movement. Luckily, there's a shape for that. Squares! This armor is made up of 36 square plates stacked on top of each other, which provides protection from impact because these square plates move less compared to circular plates. But the armor also contains

Starting point is 00:13:02 strategically placed joints that allow the plates to slide against each other, providing flexibility for the wearer. Are there squares in nature? Probably a little like diatoms and something are square, right?

Starting point is 00:13:15 Oh yeah, diatoms are squares. There's squares in nature. Okay. There are squares in nature, Sari, because you're a square and you're part of nature. Oh! Wow!

Starting point is 00:13:24 Wow. The weed. Yeah, well, he had to fight back after last week. Pretty good. You're going to make me guess first. No, I'll guess first. I'm going to guess an animal because I don't think it's possible. It sounds so bizarre to me. It sounds so obvious that humans would be like, oh, yeah, squares. And there's going to be a weird animal,

Starting point is 00:13:46 square scales that I just don't know about. I think this one's a red herring. It sounds too weird to be an animal, but it is. That you have have the correct instinct. This is a seahorse's tail. Seahorse tails are made up of 36 bony square-like plates that get smaller as you go down the tail. Researchers created 3D

Starting point is 00:14:05 printed models of a seahorse tail along with analogous versions made with circular plates to study how the tail helps protect the seahorse. In addition to the flexibility and response to impact, the structure of the tail helps the seahorses grab things more efficiently. We should have square fingers then by that. Well, we kind of do. Yeah. Now that you've said it. It's kind of square.

Starting point is 00:14:24 There's definitely a little rectangle in the middle bit there. Yeah, we kind of do. Yeah. Now that you've said it. It's kind of square. There's definitely a little rectangle in the middle bit there. Yeah, it's not round. I've been to square all along. She's been to square all along. We all knew. We just didn't want to tell you. Sarah, you got all of them correct.

Starting point is 00:14:43 And Sam, you got one of them correct. So you got one of them correct so you have a bit of a hole to dig yourself out of as we head into the next round but first it's time for a short break Welcome back, everybody. It's time for the Fact Off. Our panelists have brought science facts to present in an attempt to blow my mind. After they have presented their facts, I will judge them and award Hank Bucks any way I see fit.

Starting point is 00:15:24 And to decide who goes first, I have a trivia question. Scale armor, thought to be a precursor to chain mail, is just what it sounds like. Small individual pieces of protective material attached and layered like scales onto a wearable garment. The result is that the wearer is moderately protected from weapons while being able to move and, you know, also look like a human-fish hybrid. And just like fish, scale armor is very old. The earliest known representation of scale armor dates back to what century B.C.?

Starting point is 00:15:56 Oh, no. That's when they never start going backwards. Yeah. It's when I really stop knowing when things happened. I'm going to say we're getting close to like the 6th century. I don't know what was happening in the world at that time. So it is truly just a number. Okay. The first thing that popped into my head was the 3rd centuryari Reilly because it's the 15th century BC. Oh, my God. And that's the 1400s. So that's how that works. How exactly? I don't know.

Starting point is 00:16:35 Well, it's the same way that we're in the 21st century. First century. Oh, yeah. We messed up somewhere along the way. That first one is just a bunch of zeros. Yeah. Screws everything up for the rest of time. Sam, you can go first.

Starting point is 00:16:48 I don't want to, but okay. When you think of armor, as we've talked about a lot already, you might think of a knight in a shining set of metal plate or a soldier wearing a flak jacket, you know, like in general combat-y stuff. But there are creatures out there that have picked such extreme places to live that they need armor just to survive and fairly recently scientists have found an extremophile with a pretty sweet suit of armor that'll be funny in retrospect in 2019 researchers at the university of virginia school of medicine were studying Sulfolobus islandicum, a single-celled organism.

Starting point is 00:17:27 That was probably nailed that pronunciation. That lives in acidic volcanic hot springs, like almost in anyone you could think of. They live there like they live in Yellowstone. They were trying to figure out what made them so indestructible, specifically because they have these little appendages called pili, which didn't look to them like they would be particularly sturdy, and they probably should have broken down in extreme environments, but they're covered in these things. So the team tried to dissolve the organisms and their pili

Starting point is 00:17:56 to investigate what they're made out of, and everything that they tried up to boiling them in lye did not work or break them down in any capacity. So they had to turn to cryo-electron microscopy, which uses electron beams to look at frozen samples of super delicate and small structures that would otherwise be burned up or damaged by regular electron microscopes. And another advantage to them that I didn't really understand, and maybe you can help me with this, is that you don't have to crystallize the thing that you're looking at like you do with an x-ray microscope. So from my understanding,

Starting point is 00:18:28 that has something to do with maintaining the structure of the thing that you're looking at and not just like what it's made out of. Is that pretty much right? Yes, I think you are correct. Yeah, so x-ray microscopy basically like relies on you turning something into a crystal and then you see how those individual molecules fit together, and that tells you about the bonds, whereas it's not like an actual picture. It's like data that tells you about the bonds. Okay.

Starting point is 00:18:56 What they found was that the pilli are covered in a shell of sugar, described as similar to how the outer shell of a candy apple is much harder than what it's surrounding. So researchers already knew that sugars could be added to things like protein structures to increase their strength, but nobody as far as they knew had ever seen sugar armor that was like used to this extent to basically cover the entirety of the outside of something and make it nigh indestructible. I mean, on its scale. And it's pilly. I just looked it up.

Starting point is 00:19:28 Pilly? Wow. I never would have guessed that one. Okay. On the pilly, the sugars are arranged in a way that make them completely stable so they resist breaking down in any kind of corrosive substance. So I think lye is a base and they live in acids. So you just can't mess with these guys

Starting point is 00:19:45 the researchers aren't sure how they make their sugar armor or if we would be able to recreate it but if we could hypothetically apply sugar armor to stuff we could make like almost anything indestructible on an atomic level and some of the stuff that they that they thought we could use this for was to make indestructible clothing or put them in medicines and pharmaceuticals to make things like vaccines that are super stable. Or you could add them to the atomic structure of things like building materials and maybe make bricks that would never weather. Candyland is the most powerful place on the whole planet. Yeah. You thought that it was just for all fun and games.

Starting point is 00:20:25 Turns out you can't out of sale candy land. Indestructible. What is it about this sugar that makes it so indestructible? Well, yeah, that's what I was going to say. I don't think it's the fact that it's sugar. I think it's more the fact that it's locked together in a way that there's nothing for it to lose or gain or whatever. All the atoms or whatever are spoken for. Indestructible microbe.

Starting point is 00:20:46 They took it from acid and put it in base and it was like, I don't care. I'm okay. I can live anywhere. Put me on an asteroid. Send me to Mars. I'll panspermia this whole business. Sari, what do you got?

Starting point is 00:20:57 Well, a little bigger than this little guy and not as sugary. I am going to talk about chitins, which are mollusks like snails. And if you haven't seen one before, I would imagine a snail getting flattened into a pancake shell and all. Or you can just Google it. And chitons live in the rocky area where the ocean tides move in and out called the intertidal zone. And they have one big foot to glom onto rocks and a really strong tongue-like radula that scrapes algae and other

Starting point is 00:21:26 stuff to eat and a flat shell made of around eight interlocking calcium carbonate plates for protection. And this armor has integrated tiny sensory organs called esthetetes that roughly detect light or chemicals or other stuff so that chitons can make choices about their environment without really exposing their tasty flesh. They're protected but can kind of gather information. But researchers have looked extra close at the West Indian fuzzy chiton since the late 1800s because this species is one of several that has evolved even more specialized aesthetics. Hundreds of eyes and these eyes have around 100 retinal cells each, which are structurally similar to those of snails and slugs. But what's extra cool is that the eyes are completely

Starting point is 00:22:10 integrated into their armor because the lenses are made of the same mineral, their transparent calcium carbonate crystal structures called aragonite. Over time, the eye lenses can get worn down naturally like the rest of their armor, so they all need to be continuously generated and replaced like all mollusk shells. And these crystal armor eyes serve two main purposes. One, providing continuous armor instead of a bunch of weak spots. And two, focusing light both in and out of water, which is great for being in an intertidal zone. They're not like fantastic eyes. Recent studies have found that all the sight data combined from all the eyes can help chitons detect shadowy shapes so they know to clamp down harder on their rock

Starting point is 00:22:53 to avoid being sucked up by a hungry predator like fish or crustaceans or octopuses. And I'll include a picture in the show notes. It's like the rough outline of a fish. The researchers who are measuring this, or like measuring the eyes and their vision capabilities, would pass different shadows over them and measure how much they like sucked onto their surface below. So they like, I don't know, I just imagine butt clenching, but it's really foot clenching where they like grab on harder so they are less likely to be able to be like scooped up and eaten.

Starting point is 00:23:27 Researchers think it makes evolutionary sense that they've developed hundreds of not so perfect eyes rather than one giant armor eye. That's great at seeing because we've all played video games and know the one giant eye is the weak spot. So that won't do. It's a good job, Kytans, for making the most of their weird ecological niche. That's super cool. There's something very strange to me about an animal that is covered in eyes. Also that those eyes are made of rock. All right. tiny, extraordinarily armored extremophiles, and their armor turns out to be made of sugar polymers

Starting point is 00:24:06 or a very bizarre alien-looking organism that has rock eyes. I've got to go with Sari. That's very weird. Well, that means it's time. First of all, that means that Sari has won our episode of SciShow Tangents, but it also means that it's time for Ask the Science Couch,

Starting point is 00:24:26 where we've got a listener question for our couch of finely honed scientific minds. And it's from at SimFing12. Why don't any living animals have the armor of Stegosaurus or Ankylosaurus? That's a fantastic question. Cause wild, just wild. When those things were first discovered,

Starting point is 00:24:47 the people must have been like, what, are you joking? But yeah, great big armored animals and those stegosaur plates look wrong. And then those like clubby tails with giant spikes on them. Well, stegosauruses had spikes on their tails, right? Yeah, they had spiky tails.

Starting point is 00:25:04 It's like antlers on your butt. Do you have anything for me on this? Because I don't know. Can I venture a guess? Oh, yeah. That it was because guys with lots bigger mouths were trying to chomp them than there are around now. But I guess to scale, you could have a squirrel with little spikes on its tail. Yes.

Starting point is 00:25:22 Never mind, I retract my guess. He's still got big herbivores with lots of armor. Yeah. Like rhinos and elephants. Anybody with antlers. Yeah, but from the scientific community, I guess this is a strike against the skin is armor. They argue that currently there aren't really

Starting point is 00:25:38 a lot of giant herbivores that are armored. They have tough skin, but they don't have the same plate-like structure as these reptiles did. It's just not a common thing nowadays to have giant organisms with heavy armor. I think Sam's guess is as good as any as far as why. There's one paper that really looked into it, particularly the tail weaponry,

Starting point is 00:26:02 because that's just such a bizarre thing, this like big club-like tail. Because other animals nowadays attack with their tails, but they don't have the club attached to it. And basically, they did what scientists do and looked at the animals with these factors compared to the animals without them and tried to draw out common traits. So their guesses are that there are four big things that evolutionarily came together to create these weaponized tails and big body armor, which was being an herbivore, so being a guy that gets eaten instead of one of the carnivores, being big and chunky, so like over I think 200 pounds was their threshold. And the last kind of tie in together and it's like the structure of their armor and what they call thoracic stiffness.

Starting point is 00:26:51 Because it's not easy to swing around a tail like that. So you need that bony structure on your outside to be able to like swing that without ripping off your butt in the process or like throwing out your back and so all these giant herbivores they were too big to hide and they needed to fight and they had a strong enough body structure that they could swing around their tail but that also led to other morphological and ecological constraints like how they were able to lay eggs and take care of their young and like other mobility things, which is why they don't think this trait

Starting point is 00:27:31 carried on to modern animals. Bony armor like this mainly shows up in medium insectivorous mammals. So like armadillos or pangolins or things like that. So those are now like the ecological niche where being armored can protect you from guys that are bigger than you, but also basically let you live your life, but also move around enough so that you can have your babies and protect them. There's oftentimes not clear answers in evolutionary biology. Like it sometimes it's just that things don't happen because you have to have a lot of things stacking up on each other for it to become possible and advantageous. And you actually

Starting point is 00:28:12 do have to have both of those things. Just because something would be advantageous doesn't mean it will evolve because it also has to be possible for the genes to do that thing. If you want to ask your question to the Science Couch, you can follow us on Twitter at SciShowTangents, where we'll tweet out the topics for upcoming episodes every week. Thank you to at 11thNight, at WatchWild185, and everybody else who tweeted us your questions for this episode. If you like our show and you want

Starting point is 00:28:35 to help us out, please go to patreon.com slash SciShowTangents to become a patron and get access to things like our newsletter and our bonus episodes, which we recorded the first one of today. It was a lot of fun. We're a bunch of goofballs. Second, you can leave us a review wherever you listen. That helps us know what you like about the show. And finally, if you want to show your love for SciShow Tangents, just tell people about us. Thank you for joining us. I've been Hank Green. I've been Sari Reilly. And I've been Sam Schultz.

Starting point is 00:29:03 SciShow Tangents is created by all of us and produced by Caitlin Hoffmeister and Sam Schultz, who edits a lot of these episodes along with Hiroko Matsushima. Our social media organizer is Paola Garcia-Pietro. Our editorial assistant is Deboki Trappervardi. Our sound design is by Joseph Poonamedish. And we couldn't make any of this without our patrons on Patreon.

Starting point is 00:29:19 So thank you to all of you. Thank you! And remember, the mind is not a vessel to be filled, but a fire to be lighted. But one more thing. But one more thing. Landsnails have a shell to protect them from predators, but sometimes they get eaten by birds anyway. Luckily, they're small enough that they show up again alive and well in bird poop. This also allows them to move from spot to spot more efficiently.

Starting point is 00:30:00 There's a number of animals that are able to be eaten and then get pooped out and survive which is a thing not me there was a scientist who saw a snake a very small snake get pooped out of a frog and then was like well that is something i gotta write a paper on uh so took the snake and it turned out that the snake had because of a lack of oxygen was alive, but brain damaged because it spent so long inside the frog. That's a brave frog eating a snake. They look like little worms.

Starting point is 00:30:33 They're called Bromidae blind snakes and they're not, and they're an invasive species. And like Florida frogs are like, that's a worm. And then their whole guts get wiggled through.

SciShow Tangents - Armor

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