SciShow Tangents - Precious Metals

Episode Date: August 27, 2019

Almost all of human culture and economics is structured around a handful of pretty metals that we have arbitrarily assigned value to!  Follow 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]Silver nanoparticleshttps://jnanobiotechnology.biomedcentral.com/articles/10.1186/s12951-017-0254-9https://www.eurekalert.org/pub_releases/2018-05/osu-elc051418.phphttps://www.sciencemag.org/news/2019/07/embryo-inspired-bandage-17-times-stickier-band-aidhttps://www.eurekalert.org/pub_releases/2019-02/ez-pnf021419.phpCopperhttps://www.ncbi.nlm.nih.gov/books/NBK225400/https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/copper-toxicityPlatinumhttps://www.ncbi.nlm.nih.gov/pubmed/29632935https://www.forbes.com/sites/carmendrahl/2017/04/14/why-is-platinum-in-some-chemotherapy-drugs-and-can-we-improve-them/#1a89a88417d4[Fact Off]Alchemy and phosphorus:https://phys.org/news/2019-01-phosphorus-years-discovery-vital-element.htmlhttps://www.npr.org/sections/health-shots/2016/02/02/465188104/phosphorus-starts-with-pee-in-this-tale-of-scientific-serendipityGold vein earthquakes: https://www.nature.com/news/earthquakes-make-gold-veins-in-an-instant-1.12615https://www.smithsonianmag.com/smart-news/earthquakes-are-basically-gold-factories-4659100/[Ask the Science Couch]Nickel allergy/reactivity:https://www.nickelinstitute.org/about-nickel/https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4783936/https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3047925/https://books.google.com/books?id=CpAM1U1efqcC&pg=PA120Gold allergy/reactivity:https://www.ncbi.nlm.nih.gov/pubmed/11244133https://books.google.com/books?id=1mk3lFVtBSQC&pg=PA104Implant metals:https://www.ncbi.nlm.nih.gov/pubmed/9440845[Butt One More Thing]Metals in poop:https://pubs.acs.org/doi/abs/10.1021/es505329qhttps://www.pnas.org/content/112/29/8803.full

Hello and welcome to SciShow, Tangent's Delightly Competitive Knowledge Showcase starring some of the geniuses that make the YouTube series SciShow happen. This week, as always, I'm joined by Stefan Tjid. Hello. How's your week going, master of producing? Well, I took the last four days off, so I've been playing a lot of video games. What's your tagline? Swedish melodic death metal.

Ooh. To go with the topic. Topic, which we haven't discussed yet. Sam Schultz is also here. Hello. Artist and magician, Sam Schultz. Yes, and what else? Can you do a magic trick for us?

Whoa! So magic. That was neat. Gosh, wow. I wouldn't have expected you would have been able to pull that one off so fast. What's your tagline? These pretzels are making me thirsty.

That's the whole thing about them. Sarah E. Reilly is also here. I am. How you doing? I'm okay. I was in an airport, well, three airports all day yesterday. What's your tagline? Shoot me through that salmon cannon.

Whoa. Please, please. That's the noise it makes. And I'm Hank Green. I just ate a really big cookie made for me by two men named Lenny and Larry. And my tagline is vasculated hair. Ooh. What does vasculated mean?

Vasculated is like an area of tissue that has blood vessels. Oh, gross. So imagine every hair just has a little blood vessel in it. Yeah. Oh, your hair would be really heavy, right? Yeah, it'd be like nice and lustrous though, I think. Take better care of itself, that's for sure, than these dead protein strands that I have to like spend money buying products to condition. I need to be conditioned.

Oh, wow. Every week here on SciShow Tangents, we try to get together to one-up amaze and delight each other with science facts. We're playing for glory, but we're also keeping score. And we award Hank bucks from week to week. We keep track of who's leading. We do everything we can to stay on topic, but judging by previous conversations and all the blood hair talk we just had, we won't be great at that. So if the rest of the team deems your tangent unworthy from this point forward, we can force you to give up a Hank buck. So tangent with care.

Who's winning, Sam? All right. So in last place is Stefan with 47 points. Still last. Second to last place, Sari with 49 points. Tied for first, Sam and Hank. Oh, wow. I thought Sari was coming up.

Well, maybe you didn't update it. No, I did. Okay. All right. Now, as always, it's time to introduce the topic with the traditional science poem this week from Sari Reilly. There are certain objects we treasure and covet that help us express the feeling of it when magic things happen or we see a nugget of kindness or truth or we simply love it. But if I say that something is worth its weight in tin, it sounds off, like a cobalt mine of information. Do you want to strike pewter or go for the lead

if i had a heart of calcium i'd likely be dead silence is lithium or iron or zinc doesn't capture the same feeling i think or all that glitters is not brass sounds like i'm talking out of my ass though precious metals are precious because that's what we're told. Shiny, rare, and expensive. It's hard to replace gold. Oh, wow. Wow, Siri. That was really good. There were so many elements. And brass.

And brass. And brass. And pewter. Pewter's an alloy, too. Wonderful. So our topic for the day is precious metals, which sounds subjective. Yeah, it is. Okay, just making sure.

Is it totally subjective? It seems like to me there was something about how reactive or not reactive they were was important to it, too. But maybe that's just not really true either? I think when you're trying to draw a hard box, you're going to find some wiggles outside of the hard box. But, like, precious in that they are valuable, is that really all it is? I think so. It's, like, rare, naturally occurring metal that is valuable according to humans.

And so like our idea of precious metals have probably changed over time. Well, I'm saying probably, have definitely changed over time. Because right now we value things like gold and silver and platinum, palladium. Oh, palladium. I don't really think about palladium much

except for like catalysts. Yeah, but industrial uses. And so those are like the four that keep coming up for modern day precious metals. What other ones did we used to have? Was copper precious once upon a time? Was aluminum? Aluminum was. Copper probably.

Bronze in the bronze age. Yeah. Iron probably at some point when we only in the iron age yeah all the ages copper in the copper age stone was a precious metal in the stone age but yeah i don't know it seems like the precious label is just like yeah humans like it okay it looks nice pretty yes and that has something to do with its chemical properties but something to do with this arbitrary societal construct of we decided to say yeah of value and also like i think that it's to some extent it's you like these are elements that are used as

storage of economic value yeah so like for a very long time we turned it into jewelry and coins and we're like here are our coins and then now for the rest of human history, we're going to have this association between these metals and value. Right. Sari, thank you for helping us figure out this subjective thing, and also for your really, really great,

really great science poem that I feel like should be published in a book. Uh-huh. Oh. Are we making a book? Maybe we should make a book. I think we should make a book. I'm going to be on our kickstarter

it's a poetry book yeah for when you're pooing I thought it was just poetry about poo oh and we're going to start with Sam Schultz has brought in three science facts for our education and enjoyment but only one of those facts

is true and we have to only one of those facts is true, and we have to guess or know which one is the true fact to get ourselves a Hank Buck, and if we get fooled, Sam gets the Hank Buck. Sam! Yeah? Hit us with those facts! Okay. In the field of consumer products, silver nanoparticles

seem to be having a bit of a moment. Silver's antibacterial properties make it an excellent additive to things like wound dressings, kitchen utensils, toothpaste, clothing, washing machines, like anything that you don't want to have bacteria on.

They just put it in washing machines? Yeah, so this is a crazy thing I read. There's washing machines that are advertised as not needing to have hot water to clean the clothes because they have these plates in them that electrode off nanoparticles that are supposedly supposed to clean the clothes because they have these plates in them that electrode off like nanoparticles that are supposedly supposed to clean all your laundry without using hot water yeah love it so

they're like really useful in a lot of situations but there is concern from scientists that introducing tons of silver nanoparticles is maybe having unforeseen consequences which of these is a side effect of nanoparticles being introduced into consumer products and then into the world at large? Okay. Number one, the nanoparticles in the human body can cause intestinal problems, low blood pressure, psoriasis, and can even end up deposited in the cornea, leading to a silver ring around the eye.

A silver ring around the visible part of the eye? Like I can see it? Yeah. That'd be great. Like you can see it. You'd look so badass. It does sound really cool, but probably not good for you. Number two, the nanoparticles can enter cells and oxidize, becoming a cytotoxin that destroys the cell.

Or number three, the nanoparticles wipe out beneficial bacteria in rivers, leading to an overabundance in nutrients and causing algae blooms that crowd out local wildlife. I feel really good about the first one, even though I feel like I would have seen pictures of people. There's that guy who ate a bunch of carrots. He only ever ate carrots, and he turned orange. Is that true? Yeah. And then there was another guy who ate silver nitrate all the time because he thought it was good for him, and he turned blue. And so I heard about the orange guy and the blue guy i heard about both those guys but silver i feel like i would have heard about silver eye yeah so we're guessing on silver nanoparticles causing psoriasis and other diseases and a silver ring

around the eye we've got they can oxidize and destroy cells or they can cause algae blooms by killing off bacteria in rivers that crowd out wildlife. The destroying cells sounds plausible because our cells

self-destruct all the time. If something bad happens to them, it's like, ah, something's wrong. And that's why silver nanoparticles are antibiotic

because they cause cells to kill themselves. Yeah. Oh's wrong. And that's why silver nanoparticles are antibiotic. Because they cause cells to kill themselves. Yeah. So. Oh, no. Now that sounds plausible, too. How am I supposed to decide? If I just blow a bunch of silver nanoparticles on Stephano, he'd just die. He'd explode.

He'd explode. Burst like a... Maybe I'll get a silver eye. Do it! Yeah. That's the only way we'll know. There's only one way to end up. And if neither of those happens, it's the last one. will know there's only one way to end up if neither of those happens it's the last one yeah yeah for sam's next magic trick give us all silver eyes

are algae gonna be more resistant to the silver like if the bacteria i feel like yes okay i think yeah like i think that it could be different. It could definitely be different. They're very different organisms. Yeah, and a lot of things cause algae blooms. So fertilizer runoff is enough to cause algae overgrowth. This is hard. It's hard, but I know the right answer. Oh, shoot. I'm guessing.

Just for clarity, I don't actually know the right answer. I'm going to go with the silver eye because I think it's great. Okay. It is very cool. I'm going to go with algae blooms because it sounds weird and I know

a medium amount about algae blooms but not this and so I can add it to my algae blob in my brain. I'm going to go with the second one.

Spread it out. Okay. Whichever one that is. He doesn't know. They all sound equally plausible to me. They do sound equally plausible so the correct answer is number three go into water and uh so that's basically the long and short of it they end up in the thing and they kill and they decrease the amount of competition basically and there's too many nutrients in the water and the algae can bloom and crowd out everything um i think that that is kind of a little bit hypothetical right

now there have been studies on it that have shown that it does kill the beneficial bacteria and rivers but then there was a little bit more concrete stuff that they're worried that it could interfere with wastewater treatment because it would end up in the tanks with the bacteria and it would like depress their ability to break stuff down. And it also ends up in fish. And this one has a lot more research about it, it looks like. And it can cause like permanent gill inflammation and it takes them like six months to get those silver particles out of their bodies. Oh, no.

So they're just a bunch of little sick fish. Permanent gill inflammation is a very bad band name. So it's a jam band and they're kind of low energy. So number one is not silver poisoning, it's copper poisoning. So you get a ring? You get a copper ring around your eye. There's a picture of it on Wikipedia. And then number two, the cell death thing,

that maybe probably happens with silver nanoparticles. I couldn't find anything about it in particular. But platinum nanoparticles will very quickly oxidize and kill cells. And they're studying it as a cancer treatment right now. And it could potentially be just as effective at destroying cancer. Like they found it so far to be as effective at destroying cancer as chemotherapy with less side effects. Wow, that's awesome.

So it was different metal nanoparticles, all of them. Yes, different precious nanometal whatevers. But as discussed, copper is not a precious metal. Okay, well, it was hard to find a bad gold one.

Gold seems like it's okay for the most part. Gold's great. Yeah, hit me with those gold nanoparticles. You can eat gold all day long and nothing bad will happen to you. Look, copper's precious to me. And you can't eat gold all day long. That's very expensive. Next up, we're going to take a quick break, and then it'll be time for the Fact Off.

And we're back. Hank Buck totals, everybody. A series coming out with two. Sam's also got a score of two. Yes, because I fooled two people. All right. You all guessed a different one. Yeah, we did. Only you got it right.

Okay, now I understand. It all makes sense. And now it's time for the fact-off, where Stefan and I have brought a science fact each to present to the others. And the others have to decide which fact is the most mind-blowing. And hopefully it's mine, because I'll get a Hank Buck. Or two, even. So, I guess we're going to start off, since we're talking about metals today, we're going to go back and forth.

Stefan and I are going to name metal bands. Oh, cool. Interesting. Rings of Saturn. Pantera. Nile. Tool. In Fl cool. Interesting. Rings of Saturn. Pantera. Nile. Tool. In flames.

Aerosmith? Oh, no. Slipknot. Oh, yes. Coffin burglars. Probably. Probably a metal band. He's like, Sam's going to have to judge this because these all sound fake.

I was going to look up coffin burglars real quick and see if it's a thing. Everything is a band. Coffin burglars band. It's not. I could have just said coffins. Coffins. Coffins is a metal band. I should have just said coffins.

Right. I guess that means I go first or you get to choose who goes first. Oh, you can go first, sure. Okay, I'm going to do it. So, alchemists are very much into gold. That was kind of the whole thing. They really wanted people to make gold out of stuff that wasn't gold. And the key, they believed, was the mystical philosopher's stone, which, true to its role in Harry Potter, was supposed to provide the elixir of life that could help a person live forever.

And also, it would be capable of transmutation, turning more basic metals like lead into much more valuable metals like gold. The only challenge was figuring out how to make the Philosopher's Stone. And to this ultimately fruitless end, alchemists had all kinds of ideas. This ultimately fruitless end. Alchemists had all kinds of ideas. Even Isaac Newton took a stab at it with a recipe that called for one part fiery dragon and some doves of Diana and at least seven eagles of Mercury. So in the 17th century, an alchemist named Henning Brand turned to a slightly less esoteric ingredient list than Newton was working off of. Water. And by water, I mean pee.

Lots of pee. Well, it's golden color. Using this, like, alchemy cookbook. Exactly. Using this alchemy cookbook, he needed, and supposedly, 1,500 gallons of human urine. What? Brand thought that if he boiled, cooled, mixed, and distilled the pee enough and in the right

ways, the final product would be the Philosopher's Stone. It turns out that he was wrong, but his efforts were not a total waste. As Brand finished up his distillation, the glass chamber filled with fumes that turned into a

shiny white liquid that he named phosphorus, after the Greek word for morning star or the planet Venus, the bringer of light. It took six years for Brand to be convinced that he hadn't actually created the Philosopher's Stone because it

was a really weird, cool thing that he had made. But in that time he had learned that this new thing could do a lot of cool stuff, like glow in the dark, for example, and explode a lot. And that's the story of how the unsuccessful search for a way to turn lead into gold led to the discovery of phosphorus, which is the first time an element was discovered basically ever. That wasn't like a naturally occurring one

that you would just find. Oh, cool. When did this happen? In the 1700s. No, in the 17th century. So in the 1600s. In his initial attempts to create the Philosopher's Stone, he bankrupted himself.

But then his wife died and he was able to marry a rich widow. Oh, great. So it turned out fine. And also his wife, the new widow, had a grown-up son who was able to help him in the lab a bunch. And also maybe pee a bunch too. Oh, yeah. I imagine so.

So maybe it was just he and his wife and his son peed a lot. Just keep drinking water. But he actually said in his notes that he preferred the pee of beer drinkers because it had a more yellowish tint, which he thought was probably more concentrated already. So the main thing that he did, first he let the pee sit out in the heat for a long time to become really gross and stinky, and then he

distilled it. So he got all of the water off the pee, so it was like a syrupy pee sludge. How? Why? How long was he doing this for, do you know? Took a lot of time, I think, to do it. He probably smelled really bad. I wouldn't want to give him a kiss. Oh my god, yes. The deodorization

technology was not there back in the day. Oh, yeah, no. Can you imagine being like, my wife died and I need to continue my alchemy. What woman can I find to marry me? To marry the piss doctor. Like distilled piss man.

But you don't advertise yourself as distilled piss man. In your Tinder bio, you write alchemist. Going to make you very rich. Going to find the secret to gold. And then a woman might come along and say, oh, I like gold. I like gold so much, I will put up with the pee sludge that you keep in the basement.

I'll let you use my son as your assistant with this pee sludge. And I will happily pee into the bucket for you. Yes, for you, my love. And for the gold that you'll produce. All right. Stefan, time for go time. So earthquakes happen along fault lines. Tectonic plates be moving around, getting real rowdy,

and then you get an earthquake. And so along the fault, the rock is just kind of rubbing against each other. But there are cracks, and they were calling them fault jogs here, that run out from the faults. And so those don't experience rubbing of like rock against rock when there's an earthquake. They just open up a little bit. And so this study from 2013 was trying to figure out what happens in these cracks that are near the faults when there's an earthquake and they expand. And so we know that like a lot of gold deposits form from like hot

And so we know that a lot of gold deposits form from hot, mineral-laden fluids that are flowing through rock. They just kind of take gold from throughout the rock and concentrate it and deposit it in cracks. And so the same thing in these fault line cracks, they're filled with these hot, pressurized, super-saturated fluids. So when there's an earthquake and they expand a little bit, that extra room causes an extreme drop in pressure. And so the example they used was if there was a magnitude four earthquake, 11 kilometers below the surface could cause a 1000 fold reduction in pressure. And so when that happens, the liquid expands to fill the space and basically instantly vaporizes. And so all the minerals and gold and stuff in the fluid is instantly deposited in these fault jogs in just a few tenths of a second. Whoa, what does that look like?

It looks like a tiny gold vein. That's what it looks like. And like extremely tiny earthquakes that you could never feel, but we could only detect with like seismometers, can reduce the pressure enough to have this effect. But you could have hundreds of thousands of earthquakes per year and over hundreds of thousands of years, like that can eventually build up into significant gold deposits. Right, okay.

Because these cracks get ruptured again and again. I love it. And so potentially this could help us find new gold to mine, but also they think that understanding how the cracks repressurize after an earthquake can help us understand how that affects how much the ground moves later. And so predicting aftershocks, that could be helpful if they incorporate fluid pressure into those equations. This is something that I know so little about that I wish I knew more about, like how crystals form, how like veins of metals occur in rocks. Yeah, that's how I feel. Like because we've we've known about like how the fluids like deposit gold over time.

Just not that earthquakes can cause this like instant deposition. And then that happens over and over again. Yeah. Yeah. So like it just keeps re-rupturing and then like there's these just like it just keeps building up over time the same fault and then you end up with a commercially viable vein i like this one though because the thing about like you know water vaporizes but all the stuff in the water has to go somewhere and so it like just rushes to the nearest surface to be like,

I need to crystallize somewhere, somewhere. This water vapor is instantaneous. It's like disappeared. All of my good, my solution is ended. Panic. Yeah. Panic gold. I love panic chemicals.

I love it when the chemicals panic. So it's time for you guys to assign your points. I'm never not going to be on Dr. Piss's side. I'm going to give mine to Dr. Piss. Dr. Piss has one point. I did like Dr. Piss. It was very good. But I know nothing about geology.

Me neither. And so the earthquakes depositing gold minerals and other things is very cool mine wasn't even really about precious metals yeah there was no gold the pursuit of precious metals the pursuit of precious metals so I give my handbook to Stefan

alright it's time for ask the science couch where we're going to ask some listener questions to our couch of finely honed scientific minds. Sam, hit me. All right. At Nits and Laughs asks, is there any reason people are more allergic to nickel over something like silver or gold? I didn't know people were allergic to nickel, so I should just exit the science.

Is that what turns you green? Is that an allergic reaction? That's a totally different. That's copper. Okay. So people are allergic to nickel. That's more commonly seen in women for the sake of these studies because of the jewelry wearing portion of the population. Because a lot of cheap or costume jewelry or like the stuff you buy at Target will be made of nickel.

It's like fairly abundant. of nickel it's like fairly abundant so rings earrings apparently about 10 to 15 percent of the human population suffers from contact hypersensitivity to metals and it's more in again the they've only studied in women versus men but it's more common in women than men with about 10 percent in women versus two percent in men. And it seems like it is partially because of repeat exposure. So this is an allergy that is developed over time as opposed to something that someone is necessarily born with. And so the more you're in contact with nickel or other metal alloys that you can be allergic to, the more likely you are to develop a dermatitis allergic reaction to it. If you're in that 15%, does that mean that you are allergic to all of a certain type of metal? Or is that 50% like some in the 50% are allergic to nickel, some are

allergic to something else? Yeah, I think so. So one study had found that the three most prevalent metal allergies were to nickel-2- to sulfate, which affects like the larger section of the population, followed by cobalt chloride, which is about 5% of the population, and potassium dichromate, which is about 3% of the population. So there are different hypersensitivities to different metals. And then collectively, it's like 10 to 15%. But nickel is the most prevalent, and we're not entirely sure why. Besides maybe it's just in a lot of the things that we wear. So maybe a lot like a lot of contact is happening combined with maybe some kind of your immune system is more likely to identify it as something that might be biological or some kind of invader. Yeah.

Like it's just your immune system is more aware of it. Yes. Yeah. That is the thing that I didn immune system is more aware of it. Yes. Yeah. That is the thing that I didn't explain is what an allergy is. An allergy is when your immune system reacts to something as though it is an invader, as though it is bad and so like mounts an immune response to it when really it doesn't particularly matter to your body. Right.

Another part of this is that metallic nickel and nickel alloys are soluble under like water humid conditions. So kind of like what we were talking about in the definition section. They're more reactive. Yeah, they're more reactive. And well, it also soluble, which means like easier to get into you. Yep. So they like the sweat, the salts and amino acids and compounds in human sweat can react with nickel to make it, like ions break off and then it can absorb through your skin. And then that causes like the release of certain immune chemicals or interacts with certain immune chemicals.

Whereas something like gold is more resistant to chemical attack, like if it's more pure and it doesn't ionize readily in contact with sweat. So it doesn't end up inside of you as easily. Yeah. Okay. But if people are wearing gold or silver jewelry and having an allergic reaction to it, that's oftentimes because that kind of jewelry is plated with nickel and then plated with a thin layer of gold. And so those nickel ions can seep through the gold and into your skin. And so like more pure silver gold jewelry is usually recommended to people who have this kind of allergy because, I don't know, it's slightly more stable.

Right. Slightly less likely to trigger this allergic reaction. In my very quick search of the internet, I was only able to find one study that sort of confirmed this, but they tested just with a patch test, which is a pretty common allergy test where they just put a bunch of like very small samples of stuff on your skin in this case, because it's dermatitis that they're looking for. And of 4,101 patients that were tested, 33.5% of them had nickel allergies. Wow, that's a lot of people.

I'm guessing that they searched specifically for people who were sensitive. Right, who said that they had an allergy. Yeah, or like who were already in for allergy testing or something like that. Right, right. And so preface it with that. And we don't know why this happens. We don't really know why any allergies happen. Oh, my God.

Yeah. It's really annoying because it's a pretty big problem and it seems to be getting worse. And we have no idea why. Our immune systems appear to be getting worse. Like they're not getting worse at being immune systems, but they're getting worse at like not not getting worse at being immune systems but they're getting worse at like not being too good at being immune systems like they're getting a lot of false flags yeah interesting huh yeah and so we're not sure what about like we can take guesses like nickel can dissolve through your skin and it interacts with these kinds of cells because we can do studies about that.

But why in the first place our bodies are overreacting to nickel in this way and in a way that's disproportionate to any other metal that we wear on our bodies? Why is that? I don't know. Is it because we've been wearing nickel stuff or using nickel in a lot of things across history? And so now something has changed in our DNA. No one knows. Allergies are weird. Allergies are weird. If you want to ask your question to the Science

Couch, follow us on Twitter at SciShowTangents where we will tweet out the topics for upcoming episodes every week. Thank you to Little Chris, Elliot Sloan, and everybody else who tweeted us your questions this week. Final scores. I came in with one.

Stefan came in with one. We got a tie for first between Sari and Sam. Hooray. I don't think I've won in a long time. Yeah. Congratulations on your barely a win. Yeah. Shared win.

Shared victory. If you like this show and you want to help us out, you can do that in a bunch of ways. You can leave us a review wherever you listen. You can also tell us what topic you think we should cover while you're leaving that review because we'll be looking at iTunes reviews for topic ideas for future episodes. Second, you can tweet out your favorite moment from this episode because I love reading about those. And finally, if you want to show your love for SciShow Tangents, just tell people about us. If you want to read more about any of today's topics, check out SciShowTangents.org to find links to all our sources and maybe a picture of a weird person's eyeball

or a normal person's weird eyeball. Thank you for joining us. I've been Anne Green. I've been Sari Reilly. I've been Stefan Juh. I've been Sam Schultz. SciShow Tangents is a co-production of Complexly and the awesome 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 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. Oh. So there's a researcher who's studying waste sludge, tracking how metals and nanomaterials and various things that we use, like soaps and detergents and whatever, how they were flowing into the environment. So he took a bunch of these sludge samples from across the U.S. There's apparently a place called the National Sewage Sludge Repository. Oh, all right.

Where do they keep that? I don't know. Indianapolis, Indiana. Almost definitely. But so he was looking at the samples with an electron microscope and he noticed

a small amount of gold and sort of thought it might be a fluke, a contamination. So he was double checked, investigated further and came to find that in these samples

there's gold, platinum, silver and other precious metals in the waste. And the gold was at one part per million. Some of the other ones were at different concentrations. That's pretty concentrated. They don't know where it's coming from. They hypothesize maybe gold faucets or dental fillings or the gold leaf that you use on foods or if you're chugging Goldschlager or something like that.

It's 100% the Goldschlager. Goldschlager. like chugging Goldschlager or something like that. It's 100% the Goldschlager. Goldschlager. But in the U.S., it seems like everyone is pooping out about $13 worth of precious metals per year. Oh, wow. We got to mine the turds.

Oh, my God. Wow. That's astounding. It's not that much as I was hoping, you know. Your government check for $13. This is how we're going to get to universal basic income, isn't it? We're going to all sell our shit. Your poop-fudge dividend.