SciShow Tangents - Ceramics

Episode Date: December 10, 2019

From ancient clay pots to the heat-proof panels on the space shuttle, ceramics have been an integral part of human technology from the very beginning. I can’t even think of any jokes about ceramic! It’s just cool!More importantly! Over the last week or so, Hank has absolutely ruined everyones’ Twitter timelines with one simple question: “is butt legs?” In this episode, you get to bear ear-witness to the genesis of this wretched, society-shattering question! #buttislegsFollow us on Twitter @SciShowTangents, where we’ll tweet out topics for upcoming episodes and you can ask the science couch questions! If you want to learn more about any of our main topics, check out these links:[Truth or Fail]Non-deflatable footballhttps://en.wikipedia.org/wiki/Deflategatehttp://www.madehow.com/Volume-1/Air-Bag.htmlStrong waterhttps://pubchem.ncbi.nlm.nih.gov/compound/Aluminum-oxide#section=Mechanism-of-Actionhttp://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.470.4214&rep=rep1&type=pdfPajamashttps://www.underarmour.com/en-us/tb12https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3699878/https://www.espn.com/espnw/life-style/story/_/id/23315114/we-tried-do-tom-brady-recovery-pajamas-live-their-name[Fact Off]Moon artMagnetic fieldhttps://www.livescience.com/57868-earth-magnetic-field-spike-ancient-times.htmlhttps://www.space.com/43173-earth-magnetic-field-flips-when.htmlhttps://www.npr.org/sections/thetwo-way/2017/02/14/515032512/iron-age-potters-carefully-recorded-earths-magnetic-field-by-accidenthttps://www.newyorker.com/tech/annals-of-technology/earths-mysterious-magnetic-field-stored-in-a-jar?verso=true[Ask the Science Couch]Glazeshttps://edu.rsc.org/feature/the-chemistry-of-pottery/2020245.articlehttps://www.sciencedirect.com/topics/materials-science/glazeSpecific materials (tin, salt, etc.) https://www.thesprucecrafts.com/ceramic-and-glaze-fluxes-2745860https://pdxscholar.library.pdx.edu/cgi/viewcontent.cgi?article=1560&context=open_access_etdshttps://www.britannica.com/art/tin-glazed-earthenware[Butt One More Thing]Ceramic butt wipinghttps://www.scientificamerican.com/article/toilet-tissue-anthropologists-uncover-all-the-ways-weve-wiped/https://www.bmj.com/content/345/bmj.e8287.full

Hello and welcome to SciShow Tangents, the lightly competitive knowledge showcase starring some of the geniuses that make the YouTube series SciShow happen today. As always, I am joined by Stefan Chin. I'm not actually here today. Oh! Just kidding. Stefan, what's your tagline? Forged in the fires of cheese door.

That one worked for me. Nobody else. Sam Schultz is also here. Hello. What's your tagline? My back hurts. Ah, I hear that. Yeah.

Sari Riley is here fresh off the plane from New York City. Sari, what's your tagline? Massage your grapefruit. And I'm Hank Green, and my tagline is empty on the inside. They've been sad. They were sad last week, too. I'm not sad. I'm just hungry.

Every week here on Tangents, we get together to try to one-up a maze and delight each other with science facts. We're playing for glory, but we're also keeping score and awarding Sam books from week to week. We do everything we can to stay on topic, but we aren't great at that. So if the rest of the people on the podcast deem your tangent unworthy, you could be Dr. Sam book. Now, as always, we're going to introduce this week's science topic with the traditional science poem this week from Sari. Who looked at a lump of clay and thought, I ought to shape this as a pot?

Yeah! Or a bowl or painted urn? No, stop! That was so good! That was such a dope opening! Or a bowl or painted urn, then into the kiln and let it burn. Then from clay we switched to powder, like zirconia, which allowed her to craft a knife more sharp but brittle.

And I do not want to belittle the power of ceramic ittle. Resist crudges, make pieces for cars, insulate, help us reach the stars, protect our bods, make implantable rods against these odds. The materials aren't frauds. I did my best. What was the ittle part? I didn't know how to transition to the list of things. So that's not like a word.

I-T apostrophe L-L is what I was doing. So I do not want to belittle the power of ceramic. It will. Oh, gosh. That was a big wave. It's a ride. I'm, what is the word? Exhausted?

No, the opposite of that. Exhilarated? Yes, I am exhilarated by your poem. Thank you. That's very kind. Oh, boy. So, now we have to define ceramics. I actually couldn't find a good chemical definition of ceramics.

Material scientists seem to agree on what it is, but it seems like one of those things you look at and it's like, that's a ceramic because you took a material, a non-metallic solid that has a bunch of different bonds in it. ionic some covalent different materials inside and then you heat it up really hot and then it turns into materials that have similar properties that like aren't necessarily glass so it's not an amorphous so glass is not a ceramic no you can like glaze ceramics with glass when you glaze a pot that's a glass layer on top there are like characteristics that are common in lots of ceramics like they're usually brittle but they're really hard and they've got a high melting point and some of them have bad thermal and electrical conductivity so then they're good insulators but then also there are some of them that are semiconductors like zinc oxide is considered a ceramic and a conductor. So like that label doesn't even apply to everything.

So I don't know. It's like a bunch of materials that are shiny and you bake them maybe. I kind of consider myself, like if I was going to be a material, I feel like I'd be a ceramic. Because I can deal with a lot of pressure, a lot of heat. But if you punch me, I'm done. You'd be like a coffee mug with something fun on it. Yeah, absolutely. Fill me up.

Do you have a word breakdown? I can't remember the real word for that. Etymology. Yeah, I do. It is from the Greek karamikos, meaning potter's earth or pottery or wine jar or jar or earthen vessel. So pretty much it all goes back to pots. A revised definition, if you look at something and think, hmm, that could maybe be a pot, that's a ceramic probably.

But it seems like that heating process is a key part of the ceramic, and then it changes properties. I don't think it can be made by nature. Yeah, I think that's the inorganic part. All right. Thank you for the extremely loose definition of ceramics. I don't think it's your fault. And now it is time for Truth or Fail.

Where one of our panelists, it's me, has prepared three science facts for your education and enjoyment. But two of those facts are big old lies. The rest of you have to figure out which one of the lies and which one is the true, and if I fool you, I get a sandbuck. If you get it right, you get a sandbuck. You guys know who Tom Brady is? Yes.

A football man. He is a football man. Throws the ball. He throws the ball. He's one of the ones that throws the ball, which most of them don't usually do. Yeah, yeah. There's only one the ones that throws the ball, which most of them don't usually do. Yeah, yeah. There's only one person on each team whose job it is. Who's generally throwing the ball around.

There's like one on the field, but. Yeah, sure. You could have backups. Ceramic materials can do lots of very cool things and have contributed to society in many impressive ways. And notable football person Tom Brady of the New England Patriots recently got into the ceramics game. Which of the following is a real product that has been made with ceramics and has the stamp of approval from Gisele Bundchen's husband? Fact number one, because he ran into some trouble with this, a football that you cannot deflate.

Oh my goodness. The material used to create the football includes ceramic materials similar to those used in airbag inflators. Water infused with ceramic aluminum oxide, which is a bioceramic studied for use in bone grafts, and the water is marketed as strong water and it claims to make your bones stronger. is marketed as strong water and it claims to make your bones stronger or number three pajamas that help you sleep better and also help your muscles recover the fabric is lined with ceramic particles that emit far infrared radiation and so they warm your muscles with special radiation while you sleep okay sari's shaking her head but i I like this one. Yeah, I want that. That sounds nice. Give me the special radiation.

So our three options are a non-deflatable football, two, strong water, which has ceramic aluminum oxide in it, or three, sleepy pajamas

that radiate you. Lesson number one of PR, if you had a scandal around deflating footballs, you shouldn't make a product that's like calling attention to that. So that's totally fake. Lance Armstrong has that Livestrong brand and so Strongwater seems like, okay,

I'm trying to like get in and capitalize on that. It's plausible. The pajamas sound like something that is fake and wouldn't work, but I really want them to work. So I think that's the one I'm going with. They sound fake, but real. Yeah, like so many things in health.

Fake, but real. They're good for your bones? Is that what it was? It helps you recover. It's okay. It helps you sleep. The recovery and sleep and also strong bones feel like important things for a football man.

Getting knocked around, also getting old yeah so like i would need both those things fortify my bones get a good night's sleep radiate yourself young strong water such a captivating word though sounds like a goblin is selling it to you out of a cave would you like some strong water It will help you on your quest Water branded as not just water Is very in right now So I'm going to go with strong water Are people wearing pajamas? Is that a thing that people are still doing?

I don't know I personally do not I'm like basically wearing my pajamas now Yeah, I wear my pajamas in the day also I don't think that he would put his name on pajamas, personally. So I'm going to say Strongwater. Oh, Strongwater. That's a good point.

Should I switch my answer? You want him to get three points? Yeah. Oh, that's nice. I'll go with water. I'll go with water. We got three votes. Three on water.

We're all in. I gave you guys an opportunity. This is a bad idea. I gave you guys an opportunity. This is a bad idea. I gave you a clear one of them isn't true. You had a 50-50 chance, and 100% of you got it wrong. Wait, it was the pajamas? It was the pajamas. It was the pajamas.

Sam, you swayed me. I'm sorry. So aluminum oxide is used in bioceramics, which has been studied for bone grafts, but it has not been put in water. It doesn't look like it would be soluble in water, so it would be very dusty. And it would also do nothing, as is the case with, let's be honest, all this shit that they're putting in water now. But if you call it strong water, I would expect a slightly chalky flavor, which I would expect from bone dust.

Yeah, absolutely. It's like, look, you're not drinking this water because it tastes good. You're drinking it for your bones, boy. Strong water is just milk. Non-deflatable football, of course, was made up.

They do use ceramics in airbags based on their piezoelectric properties. Like mechanical stress can turn into an electric charge. So that's what piezoelectric is when you like push on something it produces electricity so why is that good for airbags they need an electric charge to be generated when they undergo a lot of g-force i think it's like a signal that the g-force has been exceeded and the airbag should go off oh it's the triggering mechanism

i think so okay the pajamas are totally real. They're made by Under Armour. And then on the inside, they have this, like, mesh of printed-on bioceramics. So, Tom Brady is super into, like, a ton of stuff that's marginally proven. So, there have been rat studies and very small human studies. And one of them is far infrared saunas where you go in and there's, like, infrared radiation, but it's, like, further out. And that, he thinks, makes him more comfy and like heal faster. And then he also, there's these bioceramics that absorb the infrared radiation that your body produces and re-emits it as far infrared radiation. And like he had these wraps that he would wrap himself with.

And then Under Armour was like, hey, we could put that in clothes and you could get paid a lot every time we sell one. And he was like, dope, we could put that in clothes and you could get paid a lot every time we sell one. And he was like, dope, I will do that. And so you wear them all night and they radiate on you all night long and then you wake up feeling the same, but like maybe placebo effect or maybe they actually do something. It's not clear. I'm looking on this website

and there are like these very short shorts. The short shorts are hilarious. Yeah. Just for if your hips are stiff yeah yeah just the butt you need to rejuvenate the old butt yeah yeah your butt's tired from running the football back and forth on the field all day it's like i if i'm gonna invest in my right infrared muscle rejuvenation i'm gonna cover up my whole body. Yes. Get all those muscles. Absolutely. Not the tiny pants. And the tiny pants are cheaper, but not much

cheaper. Yeah, they're like $60 instead of $100. Yeah, but they're tiny. But I guess some people just want tiny pants. Like, they like to sleep in tiny pants. Like me, for example. And maybe someone just has, like, a really sore butt from doing, like, squats only. i don't know

stephan what is a butt exercise squats squats is yeah squats okay it's a butt one you can do like a rear leg lift kind of a thing you know get some glute action yeah so you're only exercising your glutes so you only need the butt fabric you're a butt model maybe some people don't want smaller legs but they do want a bigger butt it's true yeah it's true society asks too much of us little little legs big butt no that's not how it works butt is part of legs but his legs we can what i don't think it's too controversial to say but his legs it's a whole different muscle it's a whole different muscle. It's a whole different muscle. Okay, that's like saying torso is butt. Stomach is butt. Is that true?

Sometimes. No, it's not like that at all. Butt is legs because butt moves legs. It helps the legs go. Butt's what moves the legs. Yeah, you need one without the other. Yeah, but shoulder is not arms. Yes, it is.

Shoulder is arms. yes it is shoulder is arms no no way shoulder is part of the torso oh it affects i know i know how this debate can be settled it's the first person who stands up and shouts shoulder is arms this is what i've learned being a boss is if you stand up everyone shuts up I was just like well I guess I guess Hank really believes this strongly

I disagree with you now alright so I got three freaking points out of that somehow when I really expected to get zero you guys were super on the pajama train early

I got very lucky seems more plausible than pajamas. It seems easier just to put your name on some water. Yeah. It's true. And that's more of a health thing normally for an extreme, like a pro athlete. So now I guess it's time for a short break, and then we will be back for the fact off. Hello, welcome back.

Sam Buck totals. Sarah's got one for her poem. I've got three. Sam and Stefan both got zero. Boy, this feels good. It's been a long time since I felt like I was on top. I am deeply in last place. Yes, correct. But now you have a chance to get some poin

because it's time for the Fact Off. Two panelists have brought science facts to present to the others in an attempt to blow our minds. Sari and I have a Sam Buck to award the fact that we like the most, and it's Sam versus Stefan. And who will go first is going to be determined by who answers this trivia question fastest

and correctest. Oh my god. So stressful. Okay. According to Pliny the Younger, lemnian clay could be used for all manner of medicinal needs. Which did he not specify as something lemnian clay could be used for all manner of medicinal needs. Which did he not specify as something lemnian clay could cure? One, watering eyes.

Two, diarrhea. Three, serpent wounds. Or four, copious menstruation. Watering eyes. Did you say serpent wounds? Yeah. Okay. Wait.

We didn't think this all the way through. Because neither of us are right. The ones you have left are diarrhea and copious menstruation. You should go first. Diarrhea. Copious menstruation. Stefan, it was diarrhea. Lemony and Clay doesn't do anything for that, but the rest of them lots.

Wait, so does it actually? I don't think so. No, it probably actually helps diarrhea and none of the others if we're going by Punny the Younger's usual track record. But you do get to go. Or you get to choose who goes. Okay, same go. Okay, thanks. In late 1969, Apollo 11's landing on the moon had given everyone space fever.

I still got it. Yeah, you still have it. You weren't even around back then. One of the people with space fever was a New York sculptor named Frosty Myers. He decided that he wanted to put the first work of art on the moon. So he collected six sketches from some of the most famous artists at the time, like Andy Warhol, who drew a penis, and Robert Rauschenberg, and got to work on trying to figure out how to get them onto Apollo 12,

which was launching within the next couple months. So he got in contact with an arts organization called Experiments in Art and Technology, or EAT, that had recently been founded by a group of engineers and artists. And EAT's goal was to hook artists up with scientists to give the artists access to cutting-edge technology, but also to inject some humanity and creativity into the technological world that they thought was kind of growing out of control at the time. They set Myers up with

a scientist at Bell Labs named Fred Waldhauer, who also was one of the co-founders of EAT. And he used what was at the time state-of-the-art machinery that was normally used to make circuits for telephones to create 16 ceramic tablets, three quarters of an inch by half an inch, etched with the tiny reproductions of these six drawings, and they called the tablet the Moon Museum. So before he talked to EAT, I think Myers had already approached NASA about getting his art on Apollo 12 officially, and they seemed like they liked the idea,

but then they never really returned his calls after that. Well, did they liked the idea but then they never really like returned into his calls after that well did they see the penis they probably saw the penis so i think at first they were like cool and then they saw the penis because there's lots of pictures of it at the time yeah for the newspaper where somebody's thumb is purposefully on top of the penis picture so they probably just didn't think it was like the best optics so they wouldn't return any of his calls or anything like that but waldhauer the guy who made the ceramic tiles had a plan b he knew somebody who was working on the project on apollo 12 so he shipped them a moon museum and told them to slip it into the lander somewhere which seems like incredibly dangerous potentially yeah no that's one of the main things you don't want is is objects that you like foreign objects but this

is what i read that during apollo 12 engineers and stuff would sneak little pieces of paper and trinkets and photos into the foil covering on the outside of the lander. Okay. That's what they say, at least. That was a rumor, at least, that this guy had heard, so he thought there was a chance to get it slipped in. So two days before launch, November 12th, 1969, the artist got a mysterious telegram at his house from Cape Canaveral that said, You're A-okay, all systems are go, signed John F.

Who John F. is is a secret that Waldhauer took with him to his grave. So nobody knows who he sent it to. John F. How many John Fs were there? It could be John F. Kennedy. I think, yeah, he was not alive at that time, I think, yes. Oh my goodness. No, definitely not.

Oh, okay, well probably not. So there's pretty much no way to know if it actually is up on the moon. But potentially the first piece of art on the moon is this little ceramic tablet with a penis on it. Wikipedia says it could be viewed as a rocket ship or a penis. And I'm like, could it? Just turn my computer around upside down. Two boosters. I love it, though.

I love it. And I like that it might be there and it might not be there i just think once they saw these they could have gone back for three more artists why why three more well three of them look okay and three of them could use a little your mouse isn't good enough taken off the project stefan what fact do you have for us? About 2,700 years ago, in a kingdom that is located around present-day Jerusalem, it was a time of political instability, but also a very stable bureaucratic tax system,

which worked out well for these researchers. And ceramics, I guess the thing that happens is when you are heating up the material, and ceramics i guess the thing that happens is when you are heating up the material within the materials there's like little magnetic particles that contain iron and when you get past a certain temperature those particles orient themselves based on the direction and strength of the earth's magnetic field and then when you cool it down so once it becomes the pot or whatever those particles are locked in that orientation so in this region where this kingdom used to exist they found a bunch of clay pots and they somehow knew that these were used to send goods to the ruler as like part of the tax system so they you know fill it with wine and send off your wine and then you paid your taxes since these

were like government goods they stamped them with like the royal seal of whoever was ruling at the time so every time there was a new ruler there was a new seal because of that they can tell when each jar was made based on what seal was right on the thing to within about 30 years right and so they've been able to create this timeline of what the earth's magnetic field was like during the 600 year span based on all these jar handles but wouldn't you have to know like which way the jar was facing when it cooled down the particles orient based on the direction and the strength of the magnet magnetic field they don't know where exactly the jars were made so they can't necessarily tell anything based on the

direction but they can tell stuff about the strength of the magnetic field that's the part that involves ceramics from that they learned that during that first part of it was like a sixth century timeline that was about the eighth century to the second century BCE. And during the first part of that, the strength of the magnetic field spikes to about two and a half times what it is today, which one of the articles mentioned that might be the strongest it's ever been. Then after that, it declined by almost 30% over the next 30 years, and then it remained kind of stable for the rest of that period, declining slowly. And that is a much faster and sharper change in magnetic field strength than we knew was possible for Earth's magnetic field.

And I guess just for comparison, we've been measuring the field directly for the last like almost 200 years since we invented magnetometers. And in that time, over 200 years, we've seen it decrease by about 10% in strength so 30 percent in 30 years is pretty significant and then they're also hoping that they can go sort of backwards with it where if they have this like timeline of what the magnetic field is doing they can like find artifacts that don't have a stamp yeah and then you can match it to that timeline and like date them that way another weird thing that i found in this was that the amount of carbon 14 that is produced depends on the strength of the earth's magnetic field

and so and that's the isotope that we use for carbon dating and so when the earth's magnetic field is weaker there is more carbon 14 produced which skews how old we think the thing is and so by knowing, like having a good sense of how the field strength was changing, you can match, you can like get rid of that skewing and get more accurate dating. So to explain how those two

seemingly completely unrelated things are related, carbon-14 is produced when solar winds, like solar radiation, hits carbon in our atmosphere. And so that's like a fairly steady process but when the magnetic field is less strong more solar winds interact with our atmosphere if the magnetic field is really strong would that have negative effects that anybody would ever notice no i don't think so does the magnetic field make magnets work like on fridges no okay a magnetic field make magnets work? Like on fridges? No.

Okay. A magnetic field, but a different one. A littler one, I'd imagine. Yeah, a little one inside the magnet that you're putting on your fridge. So in the way that there are different electric currents, there are different electric fields, and there are different magnetic fields that can be at different scales, depending on what system you're looking at. So the way that your magnet is interacting with your fridge is a much smaller magnetic field than the one that is affecting the whole Earth.

But if you calculated the very small magnetic field, the Earth is probably influencing it a fractional amount because it's within this larger field. This is the part of physics where my brain goes, but I don't understand magnets, don't understand electricity. Yeah. I don't know why they let me graduate college.

It's fine. It's okay. Dad just put you in the same boat as Insane Clown Posse. Someone made this joke because I also said I didn't understand magnets

when I was with my friends like a couple days ago. And then this same thing, this like three word phrase came up and I still don't understand insane cloud posse and what i mean it's a band they have a song called miracles yeah and they talk about all the things that happen in the world that are miraculous yeah and one of the lines in

the song is magnets how do they work i mean they could look at look it up but then it wouldn't be a miracle anymore yeah also like ultimately like forces, you know, we understand them, but also, where did any of it come from? Yes. So, at the root, ICP is right. Yeah, they were speaking to the scale and limit of human understanding. That doesn't make it a miracle. Okay, debatable. But I do love that the insane clowns were like i want to make a song about miracles

yeah rainbows are in it i understand rainbows yeah i don't know i think they might understand them too they just like their song was really a list of things that they liked you can like things without knowing how they work okay who's getting docked the point for the clowns and you are what that's all about magnets that was was fine. Yeah, that was our lead. Magnets are science. They're not ceramics. Now we have to decide which person is going to get our sandbox, Sari.

Are you ready? Wait, there are magnets called ceramic magnets, though. Oh, well, I guess maybe they are. Iron oxide and strontium carbonate. Get with it. It looks like the not-science couch knows something about magnets.

Maybe you guys are a little bit more like the insane clown posse than you thought. Alright, Sari, it's time for you to pick your person. Do you want to give it to Stefan for the pots that were affected by magnetic fields and we could tell science things about that

or to Sam for the ceramic art experiment that is probably but maybe not on the moon that has a penis on it. Three, two, one. Sam. Whoa, I'm surprised. I'm surprised, too.

It's just goofy. It's just goofy. I like the penis on the moon. They're in a wacky mood today, Stefan. Yeah. It's not your fault. Yours was extremely good. That was a better science fact.

But I just like... Penises on the moon. Now it's time for Ask the Science Couch, where we ask listener questions to our couch of finely honed scientific minds. This question comes from at Chronic Tanvi. How do different glazes work? And we talked a little bit about glazes earlier. Yeah, maple.

And I didn't know, but now I do. You get silica and you paint it on a thing and you heat it up and it turns to glass. So the ceramic piece, whatever it is, whether it's a piece of equipment or a pot, is generally based on an oxide, nitride, boride, or carbide compound that gets fired at a high temperature. And then glazes are a layer that you can add on top of that compound to make it less porous and make it like smooth or decorate it it seems like that that's like the main purpose of glaze is like aesthetic or if you want to make it waterproof or make like a i don't know thin glassy layer imagine what that can do the possibilities are endless i can picture it now the main ingredients in it are silicon dioxide which is like the main substance usually a substance like aluminum oxide which makes the glaze more

viscous just like helps with the bonding inside and then something called a flux which is usually an alkali or alkaline earth metal oxide so like for example calcium oxide is a flux that lowers the melting point of the glaze to the firing temperature of the pot because usually the the glaze and the pot melt at different temperatures or like bake at different temperatures so you need to match those up right because it's a lot of like heat chemistry all the like the texture and the color of the glaze are related to how you melt it as you have the main compounds of silica in your glaze, then you can add in different things. And like historically, people used different things as fluxes or as reinforcement in the middle of their glaze. So ash glazes were really important in East Asia. Usually they used wood or straw and burnt them up and then mixed in the ash somehow, or they set up

the kiln so that you could put wood or straw inside the kiln so then when it heats up really, really hot, then the ash just kind of scatters naturally. Tin glazing or lead glaze, which was less good for our health, but you could add in metals to make it shinier. There was salt glaze where people would throw in salt into the kiln and just make it all bumpy i like it because you know how they figured that out was they were like what if we put salt in

it's not like they're like a complicated understanding of how the chemistry of glazes work i just like once upon a time that's how everything was figured out we were like well just try this try that that's you know i feel like i've been around a lot of potters in my life and i feel like they still kind of do it. Still do it. Yeah, they're like, ooh, that turned out neat. Yeah. Don't tell anyone. Yeah.

Anyone who was working with ceramics before we had a really solid grasp of thermodynamics was just experimenting and doing trial and error and figuring out these, like, very complicated relationships between, like, okay, I add a little bit more of this mineral and then it looks nicer. You just gotta do that a bunch. You gotta do it so much. That's how I make my soda syrups. Honestly. And someday people will talk about you in the same lofty tones that we talk about ancient potters.

If you want to ask the Science Couch your questions, you can follow us on Twitter at SciShowTangents where we will tweet out topics for upcoming episodes every week. Thank you to at FutterDuds, at Dana001, and everybody else who tweeted us your questions this episode. Final Sam Buck scores. Sari with one, Sam with two, me with three. I didn't even mention to Stefan because he didn't care. Moon dick.

If you like this show and you want to help us out, it's really easy to do that. First, you can leave us a review wherever you listen. That's very helpful and lets us know what you like about the show. Also, we're looking at iTunes reviews for topic ideas, so leave those there. Second, you can tweet out your favorite moment from the episode. 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. I've been Stefan Chin. And I've been Sam Schultz. SciShow Tangents is a co-production of Complexly and the wonderful team at WNYC Studios. It's created by all of us and produced by Caitlin Hoffmeister and Sam Schultz, who also edits a lot of these episodes along with Hiroko Matsushima. Our editorial assistant is Deboki Chakravarti. Our sound

design is by Joseph Tuna-Medish. Our social media organizer is Victoria Bongiorno. And we couldn't make any of this without our patrons on Patreon. Thank you. And remember, the mind is not a vessel to be filled, but a fire to be lighted. But one more thing. In ancient Greece, people used little ceramic discs called pesoi to wipe their butts.

So it seems like much like today, you'd have a bunch of little pieces of paper, like junk mail or whatever, laying around the house. You could wipe your butt with those. But back in the day, you just had a bunch of pieces of broken pottery lying around or something and so you could just wipe your butt smooth them down and that stuff apparently some of these discs might have originated as something called ostraca oh yeah which were pieces of pottery that you would use to cast a vote to exile someone from the city for 10 years i love it so it was like part of it was a mechanism for the people to like fight back against corrupt politicians. So if those discs then became like toilet paper,

you'd basically be wiping your butt with the names of your political enemies. Yeah. Very poor. They still make toilet paper like that to this very day. Oh really? Yeah. You could just put like,

like toilet paper with like Trump on it. Trump, Obama, anybody. Depending on your political leanings. You could just put like toilet paper with like Trump on it. Trump, Obama, anybody. Depending on your political leanings. Anybody you want to wipe your butt with.

You could just leave a Sharpie in your bathroom. You could customize it every time. Every time. You could be mad at different people

on different days. Yeah. It's like a grand human tradition.