SciShow Tangents - Green

Episode Date: March 15, 2022

Grass... money... Ninja Turtles... some of the best things in the world are all the same color: green! This week, we're taking a deeper look at this most verdant of colors. Head to https://www.patreon.com/SciShowTangents to find out how you can help support SciShow Tangents, and see all the cool perks you’ll get in return, like bonus episodes and a monthly newsletter!And go to https://store.dftba.com/collections/scishow-tangents to buy your very own, genuine SciShow Tangents sticker!A big thank you to Patreon subscribers Garth Riley and Tom Mosner for helping to make the show possible!Follow us on Twitter @SciShowTangents, where we’ll tweet out topics for upcoming episodes and you can ask the science couch questions! While you're at it, check out the Tangents crew on Twitter: Ceri: @ceriley Sam: @im_sam_schultz Hank: @hankgreen[Definition]https://www.wired.com/2012/06/the-crayola-fication-of-the-world-how-we-gave-colors-names-and-it-messed-with-our-brains-part-ii/  [Truth or Fail][Trivia Question]Green spaces reduce systolic blood pressurehttps://www.sciencedirect.com/science/article/abs/pii/S0048969721075914?via%3Dihubhttps://www.cdc.gov/bloodpressure/about.htm#:~:text=The%20second%20number%2C%20called%20diastolic,%E2%80%9C120%2F80%20mmHg.%E2%80%9D[Fact Off]Green glacier mysteryhttps://www.nationalgeographic.com/science/article/icebergs-can-be-emerald-green-now-we-know-why?loggedin=truehttps://www.eurekalert.org/news-releases/859296Emerald ash borer pest control by biomimicry and electrocutionhttps://ag.umass.edu/landscape/fact-sheets/emerald-ash-borerhttps://www.aphis.usda.gov/aphis/resources/pests-diseases/hungry-pests/the-threat/emerald-ash-borer/emerald-ash-borer-beetlehttps://www.nature.com/articles/s41598-017-01496-8https://www.psu.edu/news/research/story/femme-fatale-emerald-ash-borer-decoy-lures-kills-males/https://www.pnas.org/doi/full/10.1073/pnas.1412810111[Ask the Science Couch]U.S. green paper moneyhttps://www.bankofcanadamuseum.ca/2019/02/the-canadian-roots-of-the-greenback/https://www.visitthecapitol.gov/exhibitions/artifact/hr-240-legal-tender-act-february-25-1862https://www.moneyfactory.gov/resources/faqs.htmlhttps://www.scientificamerican.com/article/important-improvement-in-bank-note/https://cite.case.law/barb/56/84/https://cite.case.law/barb/56/96/[Butt One More Thing]Orb weaver buttshttps://commons.wikimedia.org/wiki/File:Spider_-_Eriophora_nephiloides,_Caves_Branch_Jungle_Lodge,_Belmopan,_Belize.jpghttps://digitalcommons.library.umaine.edu/cgi/viewcontent.cgi?article=4263&context=etd

Hello and welcome to SciShow Tangents, the lightly competitive science knowledge showcase. I'm your host, Hank Green. And joining me this week, as always, is science expert, Sari Reilly. Hi. And our resident everyman, Sam Schultz. Well, hi there. We're headed into St. Patrick's Day, which may have something to do with today's topic. So there's a thing at McDonald's and maybe elsewhere called the shamrock shake. Have you guys ever had a shamrock shake? I have not. I have also not

oh no i also have not okay and so what i want us to do is stop the podcast right now okay and all go to mcdonald's what i actually want to know by far for me the best flavor combination of any sweet food is mint and chocolate. Oh, yeah. That's a good one. Like, sometimes people will come into my house and they'll bring a chocolate bar. And I'm like, yes, excellent. A chocolate bar.

And sometimes it will be chocolate. And I'm like, great, fantastic. Sometimes it will be something mixed with chocolate. And if it is not mint, I'm like, why? If you're going to put something into the chocolate, why wouldn't it be mint? This is my best flavor combination. It's what I had in my wedding cake.

It's all I ever want. Whoa, you had a mint chocolate wedding cake? I did, yeah. Was it an ice cream cake or was it just a mint chocolate cake? It was a chocolate cake with a minty, like a thick peppermint patty mint icing in between the layers. Oh my God, that's so good.

You guys got to get married, Sam. Or you, Sari. Whoever, I don't care. I want to go to a wedding. What a, yeah. Andy's Mints, that's one of the top tier candies, I would say. I love that shit. Junior Mints. Also good. Peppermint patties. Oh yeah, so good.

So you guys seem to be on board with mint and chocolate. I love, well, I don't know if this really counts, but I love malt, like a chocolate malt. So chocolate plus malt is a good one. I like chocolate plus orange, too. No! This is one of my least favorites. So sorry. I don't know.

What about chocolate and strawberry? No, chocolate, fruit, I'm always out. You don't even like a chocolate strawberry? Well, I haven't eaten a strawberry since 2004 because of my sickness. Tiny seeds. Somebody's got to invent a seedless strawberry for you. You can pick them off. It just takes a really long time.

That sounds really miserable, yeah. I think we've scientifically proven that chocolate mint is like the unbeatable, basically. Everybody seems to agree. Yeah. Every week here on Tangents, we get together to try to one-up, amaze, and delight each other with science facts while also trying to stay on topic.

Our panelists are playing for Glory and for Hank Bucks, which I will be awarding as we play. And at the end of the episode, one of them will be crowned the winner. Now, as always, we introduce this week's topic with a traditional science poem.

This week, it's from me. But I have to say, you have to pay attention, because it is interactive. Oh, okay. Okay. 550 nanometers wavelength, 2.25

electron volts. I've got two people I could ask. I'm going to ask Sam Schultz. What does it mean? What does what mean? What does it mean? Green. Hey, Nick's the color of the biggest whale and the color of the face that's kind of smiley. We've got two people I could ask. I'm going to ask Sari Reilly. What does it mean? Green. green the color you get when you're getting ill most of the nation of brazil famously chlorophyll an army man's twill and a one dollar bill the last name of the man who's talking now sam and sari together wow what does it mean green the topic of today's episode is green. That was really, really good. So the topic for today's episode is green, which is a color.

It's the first time we've ever done a color. It's the color of my last name. I share it with a lot of wonderful people. And Sari, what is green? Well, yeah, it's a color. And I'm glad you mentioned wavelength because that's how I was going to define it. It's like in the middle of the visible spectrum. According to one lighting company that I found that will remain nameless because we're not sponsored. It's from 490 to 570 nanometers.

But that in itself gets at the subjectivity of green because I'm sure that other people will have their own sense of like what wavelengths encompass the color green and that extends across linguistics and cultures so like because we are english-speaking and we were all born and raised in the united states like we were pretty much taught the roy g biv rainbow of colors minus the indigo probably i don't know i only learned it was in there but not for any clear reason just to make a bit of make the yeah because we needed a vowel yeah but green's right in the middle of that uh and so it's like a crayola crayon it's green and it's become a pretty standard like one of the classic colors that things can be is green yeah but sure in other cultures like particularly before modern times

when english has become like such a dominant language and culture then there's a lot of like linguistic relativity and and so people talk about this a lot, how some cultures combine the words for blue and green or didn't have separate words for them until more recently. So before modern times, Korean and Japanese and classical Chinese, so in a lot of Asian countries and I think Middle Eastern and South American, basically across the world, as far as we can tell, there was less of a distinction between blue and green. And they were both kind of just considered the same part of the spectrum. And a lot of the words for green derive from words for like plants or vegetation rather than as like blue was the color. And then when we decided to add green in, then it's like, okay,

let's just borrow the word for plant and stick it in there. And that'll be an extra color now. Yeah. I mean, it seems to me like green would be one that it's one you see a lot, mostly in one situation, which is vegetation. That non-distinction between blue and green. It's not something that I've ever been able to wrap my head around, I guess, because those seem like the two colors in the world.

The most common ones? Yeah, before people were walking around, it's like blue, green. Those are the two earth colors, you know? Yeah, they're the earthiest colors. I like them both. They also make a great color together. Yeah. I've always been a huge fan of teals.

Oh, combined, of course. Is there any significance to it being in the middle of the rainbow? Does that mean anything special for green? I've heard it's like the hardest color for us to see or something like that. Is that true? And that red is the easiest color for us to see. something like that. Is that true? And that red is the easiest color for us to see. Does that mean anything at all? I don't know specifically what you're talking about.

I know that night vision is in green because we can tell the difference between shades really well. And so that's why I think the developers of night vision chose green so that we can like distinguish we can see it real good yeah so i think opposite of what you're saying okay and what where's the word comes from plants yeah it comes from plants specifically grow so like the same root as grow and grass and why is your last name green? I think that, well, I don't know, but oftentimes it's due to the place where the person lived. Hank of the Green Hill or something, perhaps. Hank of the Green. Yes.

It's from my Irish side. That's the only foreign country I've been to besides Canada. And it is extremely green. Beautiful. Super green. Yeah. Because it's always moist. It's quite rainy and moist. Yes.. Beautiful. Super green. Yeah. Because it's always moist. It's quite rainy and moist.

Yes. Not as much blue there, but there is quite a bit of green. Well, now that we have a pretty good handle on what exactly green is and also that it, of course, is made up. But the green I see, is it the same as the green you see?

Because people are always bothering me about this. I don't know. I know. Neither do I. I don't know. I know. Neither do I. Let's move on. It must mean that it is time for the quiz portion of our show. This week,

we're going to be playing a little game of truth or fail. But green edition, because most of our planet is green, thanks to chlorophyll, the amazing pigment that allows many microbes

and plants to make their own food. But chlorophyll is good for so much more than just photosynthesis, and people have been working on using the chemistry of chlorophyll for other applications. It's a really great molecule. Why not try to do other stuff with it? The following are three stories of green, in quotation marks, technologies, big air quotes, that use chlorophyll, but only one of them is real. Which one is it? Is it, number one, a gut imaging smoothie? So to help doctors study the inside of a patient's stomach, scientists created a green juice

made out of chlorophyll-based nanoparticles that can be imaged with different scanning techniques. But it could also be fact number two, a plant-ish based laundry detergent. Chemists concocted a laundry detergent made of chlorophyll and an iron powder called wash blue that when mixed together react to make whites brighter in the wash. Or that one might be fake too, and it could be fact number three, a less frustrating cooking experience. Scientists invented a new process for making nonstick coating for cookware that uses a molecule in chlorophyll as a surfactant during the manufacturing process, resulting in a vibrant green but easy to clean cooking surface. So which is the true

chlorophyll-based innovation? Is it a gut imaging smoothie, a plant-ish based laundry detergent, or a less frustrating cooking experience on your nice green pans? I think I would have seen a green pan and I can't think that I ever have. There's a lot of pans, man. It is, according to me, the hardest color to see though. So maybe I didn't notice. You just didn't see it. Yeah.

I think you'd see a vibrant green pan it's a weird thing it'd be kind of gross to cook on a green pan too i don't think it would sell i don't think you want to cook on a green pan that one's right out of my opinion i love a great non-stick pan i think that's true sign of middle age is loving a good knife for a good cookware yeah that moment where you have like a real favorite pan. Aw. Yeah. I just got a new knife and I cut my finger

really bad with it. Oh, no. But the thing I thought was, this is a hell of a knife. Oh, what an old man thing to do. But, yep. I think for the same,

I feel like the green smoothie seems straight out of sci-fi, which could either mean it's real and someone's experimenting with it or it's absolute garbage. Because can you even image that? I don't know. I don't know enough about your gut and digestion that like, could you drink a smoothie? And it probably tastes horrible. People definitely eat like chlorophyll supplements.

I see it all on TikTok. People being like, you got to buy this chlorophyll powder. Change your life. That one just seems like too, that one seems overly complicated to me. Like what's that knife that cuts the knife that cuts the thing? Occam's razor. Slap chop. Oh.

The slap chop oh yeah yeah occam's slap chop to this it just seems like you make a pill or something smoothie is so messy yeah yeah i don't but we can't we can't go on. We have to decide what Occam's Slap Chop does. Because Occam's Razor cuts away things around, if there's excess information, you don't have to have this thing cause this thing. It's just this thing on its own. So you're cutting away things. But Occam's Slap Chop, it turns big ideas into small digestible bits

that we can much more easily understand. It's just the modern, easy to clean alternative to the razor. I think it's what we do during the definition section of these episodes. We take something simple, like a word that should be straightforward, and then we're like, but actually. We've ruined it for you. It's no good anymore. It's just tiny bits that don't make sense. Well, you know what?

We've made up a great new term today. And also, I think that the plant-ish based laundry detergent has to be the correct one. When you eliminate the impossible, only the possible remains. Sherlock Holmes' slap chop. Yeah. They all got one now. Yeah. I was thinking the laundry detergent too.

I don't quite understand it, but. I don't either. I don't know what the hell it means at all, but you know, that doesn't matter. I don't understand a lot of things. So I'm going to go with that too. Wow. There are so many points

that are going to no one at all the secret ingredient that turns some beers green is called wash blue it's an iron powder used to brighten whites in the wash so you can use this to brighten whites or to turn beer green don't try that at home though because you have to put the right amount in that seems wrong but yeah right i'm also confused because i guess it's it's blue and it makes like white can be like whiter if it's a little bluer. Yeah. But also beer is already yellow. So you put some blue in it and it gets green.

Weird. But anyway, that's all I know. But do you want to know what the real fact is? I'd love to. Is it the smoothie? In 2016, researchers at the University of Buffalo reported that they had come up with a way to turn chlorophyll into an imaging tool to help doctors look into a patient's gastrointestinal tract. We have

some ways to do this. We have x-rays, ultrasounds, endoscopies, but they have their limits and limits in their safety and in the contrast that they provide with the final image. So, the team decided to see if they could use chlorophyll to create a safe, edible contrast agent

that would also be able to withstand the harsh chemicals of our guts. So to do that, they did some chemical stuff to the chlorophyll, turned it into a related marticle. Marticle? You got artemis and marticles. Molecule. Molecule. That is a type of nanoparticle structure.

It's called a surfactant stripped induced frozen micelle, I guess. So they suspended these nanoparticles in liquid and then fed them to mice or drank them to mice. And they found that they were able to use the dye to image with multiple techniques and it helped improve the contrast of their images. Okay. And as for our last thing there, the cooking surface, this was very loosely inspired by a project developing Phytol, a molecule in chlorophyll, into a non-toxic tool to clean up oil spills. So not related and you're right. There are no green pans. I wouldn't think that chlorophyll would be bad to use in laundry detergents because my experience with grass is that stuff sticks around.

Don't come out. Yeah. I thought it was something with the blue wash. I don't know. Chemicals are weird. Yeah, chemicals are weird. You take one thing, you do one thing to it, it turns from a poison into a delicious treat.

Or vice versa. You never know. Be very careful out there, everybody. Don't be pouring stuff in your beer unless it's supposed to be in there. That's right. Well, now it's time to take a short break, and then we will be back with the Fact Off. 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.

And after they have presented their facts, I will judge them and award Hank Bucks to the one that I think is going to make the best TikTok. To decide who goes first, I have a trivia question for you. And I got a tiebreaker too, which is how many calories are in a shamrock shake? Many studies have found that green spaces like parks can reduce blood pressure and the odds of hypertension or high blood pressure by 1 to 9%. the odds of hypertension or high blood pressure by one to nine percent this reduction goes for both systolic pressure when you pump blood throughout the body and diastolic blood pressure between heartbeats on average by how many millimeters of mercury do green spaces reduce systolic blood pressure i'm gonna guess something that would make you die probably on accident um uh two that's that's that's good you would not die i'm gonna say 10 sam schultz is our winner today because it was 0.77 which is a lot

but it's not nothing so get get out there, touch grass. What they really should do is people who've been on Twitter all day, how much does it reduce your blood pressure when you go out and see a park? Because I know it is effective for me. How many calories do you think is in a large shamrock shake? I bet it's a little bit lower than you think. I think there are 980. Okay. Oh, I was going to guess

600. Oh. Oh. Sam was closer but only barely. It was 800. They use the low-fat stuff at McDonald's.

This is a really effective advertisement for McDonald's at least for me. I think it will, yeah. It's working on me. Anyway, Sam, that means that you get

to decide who goes first in both cases. So thanks for not messing it up. Double winner. How about that? Uh-huh. I think I'll, I guess I'll go first. So icebergs, they're usually white or blue, right?

Yeah, that's my experience. They couldn't possibly be any other colors, could they? Eh, wrong. As you can possibly intuit from the title of this episode, there are some very special icebergs in a very special color, green. There's documentation of these striking emerald-looking icebergs dating back to the 1900s, but I'd have to assume they go way back to the dawn of whenever icebergs started to exist. But scientists have never been able to determine why they're green until recently. So some icebergs are white and those are ones made of compacted snow and they're

white because they're full of air. Something about being full of air makes them reflect white and some are blue and those form in an entirely different way. They're made from frozen ocean water that clings to the sides or like overhangs of glaciers until they eventually just plop off into the ocean. And those ones are not full of air bubbles because they're just made differently. And not being full of air bubbles makes them reflect blue. Now, green ice is definitely made of marine ice like the blue ones, since core samples of them are not full of air. But the reason they were green was not something that scientists knew for a long, long time. So the initial theory proposed by a team of researchers studying the icebergs off of Antarctica's Armory Coast in 1988

was that the ice was somehow filled with an unusually high amount of dead marine life, which tends to decompose into a yellow goo. And so I know from art school that blue plus yellow equals green. However, the team didn't have the equipment to test that theory in 1988. They were just like, that's got yellow equals green. However, the team didn't have like the equipment to test that theory in 1988. They were just like, that's gotta be right. But then they went back in 1996, same team. And this time they brought,

I assume a mass spectrometer or something. And they found that the green icebergs did not have an unusually high amount of carbon. Shoot, then they didn't know what to think. So flash forward to 2016 on an unrelated study looking at core samples of green icebergs discovered an overlooked clue to the mystery the icebergs had 500 times more iron in them than other colored icebergs and iron plus ocean water equals oxidation aka rust which can be kind of orange yellow and as i said before yellow plus

blue equals green so that's the current theory for why the icebergs are green but how did all that iron get in there in the first place it's likely coming from the ground up dusty remains of rocks that glaciers scrape over as they flow around which apparently is known as glacial flower which i just learned, which is a very charming name, I think. So anyway, this dust pours into the ocean at points where glaciers and the ocean meet, and it fills the water with iron rich dust. And it's ready to end up in sea ice and rust up into green. And if this turns out to be what's happening, scientists also think that the green icebergs could be an important part of some sea life's nutrient cycles, because it's bringing iron out into the ocean.

And that's just something that we have never even thought about. And that could also be a very bad thing if there aren't any icebergs someday soon-ish left to do that. Green ice. I'm looking at some pictures of green ice. It's pretty cool. They're pretty. Yeah, they're pretty. I like that nobody cared that much.

That's kind of what it seems like. They kind of found it by accident. They're like, it's not a big deal it's green yeah it took them until 1988 to look into it then they were wrong we don't have the right machine see you in a decade and then they were like well we're wrong uh see you in another decade and i think that was fun too eventually we'll learn, but we're not in any rush. Not the most pressing of life's mysteries, I suppose. It's cold up there and we have to bring heavy equipment and who's going to give us money? Yeah, nobody, no billionaire is like,

oh, you're going to figure out what color ice is? Hold on, I need to give you cash. Sarah, what do you got for us? So the emerald ash borer is an objectively beautiful iridescent beetle but even though it's green in color it's an absolute menace to greenery specifically to the ash trees that give them their namesake the larvae grow by eating up the inner bark tissue called the phloem which is where sugars get transported and gradually kill the tree and in

fact emerald ash borers have been responsible for tens of millions of tree deaths in at least 35 states in the U.S. since they were first found in 2002. And I say found because they're an invasive species and likely came from a shipping crate full of wooden packing materials or something else made of ash from Asia where they're a native species. So all the forestry, conservation, etc. researchers in the U.S. are understandably concerned because dead trees could have ripple effects through ecosystems. So unlike green ice, they get funding for this. And there are classic strategies to track and get rid of insect pests like sticky traps hung from trees or chemical insecticides,

but some scientists are exploring more creative solutions for example a paper in 2014 involved creating decoy beetles that electrocuted living emerald ash borers that tried to mate with them which is absolutely bonkers okay it was it was it was good and i i was excited before you told me the situation in which they expect to electrocute the beetles. Yeah, it's nuts. So, like, all that astonishment being said, when I actually read cool layered nanostructures on their wing covers, a.k.a. their cuticles, that reflect light as opposed to pigments like the melanin in our skin. So these scientists were like, how might we copy that? There's so much research into like pheromones, but what if we try and make something iridescent like that?

And they came up with a pretty straightforward solution. They made a mold of a dead emerald ash borer with a vaporized form of nickel, like the metal, and then they used the mold to create what they called bioreplicated decoys out of plastic sheets, which had basically the same surface texture at the nanometer level, minus some little hairs that they didn't replicate and then they took these decoys some 3d printed ones that were kind of sparkly green but didn't have the nanostructures and some dead emerald ash borers and pinned them to ash leaves in the sunlight which is apparently a come hither visual signal for mating and in all these tests the male beetles landed on the dead beetles and the bioreplicated decoys almost all of the time,

though they often flew away from the decoys after a second because they realized they were duped. But they were very suspicious of the 3D printed ones and rarely got close. So the researchers' mold worked, which is cool in and of itself, that they were able to replicate this nanostructure. But like I mentioned earlier, that wasn't all. They wanted to propose a pest control solution and tested 4,000-volt bug-zapping traps baited with their various decoys. And even that short landing on the bioreplicated decoys was enough time to zap the heck out of males and stun and or kill them. So turns out all you need is bait for a pesky beetle trap is the exact right shade of iridescent green.

That's so rude. Well, yeah. You know, it's rude to eat a bunch of trees, too. They don't know. They don't know what they're doing wrong. That's right. And they never will. They'll never know anything now.

No. So it's worrying if you just stun them and they're like, well, that was awful. I'm going to go eat more trees now. So you got to put like a sticky pad down underneath so that they fall onto something and they're like, no, I'm stunned, but I'm stuck. You can't do that because then a bear is going to walk up to that and try to eat some beetles and then be like, I got a thing on my nose. So I'm just exploring all the different possibilities here. The beetles go off and stress eat even more trees because they're like, oh, my nose. So I'm just exploring all the different possibilities here. The beetles go off and stress eat even

more trees because they're like oh my penis. No. How many volts is it? 4,000 which I think is like yeah a lot but I think it's like

comparable to fly like electric fly zappers. Yes. I imagine that it's probably based on the same technology. Give me a bit of a hurt if I touched it though. Yeah. Yeahappers. Yeah. I imagine that it's probably based on the same technology. Yeah.

It'd give me a bit of a hurt if I touched it though. Yeah. Yeah, you'd notice. Okay. I like this one a lot, Sari. This is pretty good. It's got a lot of angles

that I like. It's got some great razzle dazzle to it. It's got a lot. It's shiny. It's literally shiny. Yeah. It's got sex.

It's got death. It's got all the things that people care the most about. Shiny things, sex, and death. Well, since you guys came into this tie, it feels very clear to me that the Razzle Dazzle's going to win it. Sarah's taking the episode. Congratulations.

Now that means it's time to ask the science couch where we've got a listener question for our couch of finely honed scientific minds. Chris B. on Discord and at pizza death god on twitter both asked why is money in the united states green and i don't even have a guess like that was long enough ago that they were just like it should be green and they didn't have to have a reason that's i mean it's weird to me to think that i've never thought about yeah the fact that somebody had to make that decision and everybody was like,

cool, cool, cool. Is it because it's hard? Is it like a hard die to fake? I have no idea. You're on the right track of the historical reason. I initially, I think I have to- Was it Benjamin Franklin?

Oh, it seems like something he would do, doesn't it? Yeah. No, you can't add that onto his list of smart people things. In the 1800s, so before the U.S. Civil War, any printed money was made by like an engraver and usually tan paper made of cloth or isinglass, which is like a gelatin sheet made from fish air bladders, which is just like the weirdest material choice. They were like, let's get something hard to make so that people won't counterfeit it. And they use black ink on that paper. So successfully counterfeiting a banknote in those days, you needed to be like good at engraving and then finding that weird paper that they make, being able to make it. Then in the mid-1800s, like the 1840s

to 60s, photographic printing got more widespread. So it was easier to counterfeit even with multiple colored inks. So photographs were in black and white, but you could still take a picture back when the bills were in black and white and then print more money. Or if there was some colored ink, it was really easily removed. So you'd like wash off the colored ink, print the black and white, and then re-add the colored ink. And so counterfeiting, huge problem.

People were like, this is easy. If I can afford a camera, I can make more money and then buy more cameras. And then, I don't know, crime. And then, because that was a problem, then came the search for uncounterfeitable ink. And it seemed like a lot of this was happening in like the late 1850s. And it was both in America, but notably in Canada.

So there was an American chemist and scientist who was teaching in Canada named Dr. Thomas Stary Hunt, who developed a particular kind of green ink to help fight counterfeiting. And for some reason, he wasn't able to patent it. So some guy named George Matthews, who was a chemist employed by the Montreal City Bank, patented it and then passed on the money. Money was complicated about the thing. But it was basically an oxide of chromium, which produced a green tint. And a lot of chemists at the time weighed in and was like this is so hard to erase

we can't do it i tried i tried i can't take this ink off a bill what what do you want this the science says it's legit and this is where it gets fuzzy because it was thought to be resistant and there's a scientific american article from july 1858 that says quote every possible chemical test has been applied to the erasing of the impression but not one has been successful the black impression so the black ink and the paper itself being destroyed where the green tint is signed some names but in august 1857 the Executive Committee of the Association of Banks for the Suppression of Counterfeiting voted unanimously that it can't recommend patent green ink. So there's some miscommunication in the olden days where some group of people were like, this is not going to cut it because they found out that it could be sulfuric acid could like get the ink off the paper, the green ink off the paper. But then it got reported more widely that it was like, no, this is great.

The scientists say it's great. And regardless, the U.S. banknote printers were sufficiently impressed. They were like, I guess let's go. Let's just use this green patent green ink and used it on on Civil War bank notes, most notably on the back, which is where the name Greenbacks came from. And then in America, a different person held the patent. This is where I tried to dig into old case law and then got overwhelmed slash bored, which is a very weird combination of feelings. So if you like case law, the link is in the show notes. But he was arguing about

getting money because the government's using green ink, but I think they ruled against him and was like, no, we're just using the green ink. And then since then, it's been a holdover. So regardless of its counterfeiting prevention ability, green ink just became more readily available in the early 1900s, and it was relatively resistant to changes, like good enough. And it was found by the government to be like psychologically good to have green money because people associate green with like growth and I don't know, like positive emotions. Like you always see a green checkmark. Even that was in the early 1900s.

So they were like, green money gives us a good feeling and, like, makes people feel good about it. And so it just became a holdover. And that's how we ended up today being about green money, where we just, we thought it was good, anti-counterfeiting. And then we were like, eh, it's already green. Let's keep going. People will get mad if we try to change it now. Oh, yeah. But they are. The $10 bill is already green. Let's keep going. People will get mad if we try to change it now. Oh, yeah. But they are.

The $10 bill is not green. The $10 bill is kind of pink now. Yeah. Yeah, pinky yellow. But when do you ever see a $10 bill? When do you ever see an any dollar bill? That's what I was just thinking. I was like, what the hell does a dollar bill look like?

I can't even remember. Oh, they're all weird different colors now. Now I'm mad. Change them back. If you want to ask the Science Couch your question, you can follow us on Twitter at SciShowTangents, where we will tweet out topics for upcoming episodes every week, or join the SciShowTangents Patreon and ask us on Discord.

Thank you to at RadagastWiz, at AirbyDragons, and everybody else who asked us your questions for this episode. Those are both very... Very thematically appropriate, appropriate. Yes, exactly. If you like this show and you want to help us out, it's really easy to do that. First, you can go to patreon.com slash scishowtangents and you can become a

patron of the show and get access to things like our newsletter and our bonus episodes, which are very fun. Second, you can leave us a review wherever you listen. That helps us know what you like about the show and helps other people to find 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 have been Hank Green. I've been Sari Reilly. And I've been Sam Schultz. SciShow Tangents is created by all of us and produced by Sam Schultz, who edits a lot of these episodes, along with Seth Glicksman.

Our story editor is Alex Billow. Our social media organizer is Paola Garcia Prieto. Our editorial assistants are Deboki Chakravarti and Emma Douster. Our sound design is by Joseph Tuna Mettish. Our executive producers are Caitlin Hoffmeister and myself, Hank Green. We couldn't make any of this, of course, 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. Orb weavers are spiders that make spiral-shaped webs,

and they're pretty great to look at, too. We look at some orb weavers to let us know when our food is getting too toxic because they eat aquatic insects. So the amount of mercury in them can be used as detectors for the mercury levels in fish that we eat. That's not about green, but some orb weavers like male Eryphora nephiloides are just fun to look at

because they have bright green butts, which helps them blend into trees. So we just found a green butt. Yeah, we just found a green butt. And then we were like, and here's a science fact that's unrelated to the green butt. Yeah. At least we found somebody that had a green butt and a different color rest of their body. I feel like that counts.

Yeah, you can't have an animal that's just green all over. No. Like those bugs that Sari likes to kill. Yes. And... Yeah, that I specific... I set up the electrocution in my backyard. Sari wrote this paper.

Sari is a bug murderer and she loves it. Yeah. She's confessing to her crimes right now.