SciShow Tangents - Recycling

Episode Date: April 19, 2022

Get a jump start on Earth Day by joining us as we discuss garbage's sexy, complicated little brother: recycling! Grab the NordVPN deal ➼ https://nordvpn.com/TANGENTSTry it risk-free now with a 30-day money-back guarantee!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[Trivia Question]Minnesota paper waste ballhttps://www.pca.state.mn.us/featured/worlds-largest-wad-paper-0[Fact Off]Palimpsests (reusing parchment, but also documenting microbes)https://www.abaa.org/blog/post/the-history-of-vellum-and-parchmenthttps://www.theatlantic.com/technology/archive/2014/07/how-monks-remixed-technology-in-the-middle-ages/373956/http://www.archimedespalimpsest.org/about/imaging/https://royalsocietypublishing.org/doi/10.1098/rsos.170988https://link.springer.com/article/10.1007/s00248-014-0481-7Pressure-sensitive, reusable tape inspired by housefly feethttps://www.howitworksdaily.com/how-is-adhesive-tape-made/https://www.naturalhistorymag.com/biomechanics/172099/shoe-flyhttps://cen.acs.org/articles/85/i42/Adhesive-Tape.html[Ask the Science Couch]Sevier County (Dollywood and Gatlinburg) composting/waste managementhttps://www.seviersolidwaste.com/http://www.louisianaweekly.com/dollywoods-environmental-solution/https://www.zankerrecycling.com/sites/default/files/biocycle-nov-2010.pdfhttps://www.biocycle.net/mixed-waste-composting-facilities-review-2/https://greenblue.org/reloop-what-is-mixed-waste-processing-or-all-in-onedirty-mrf-recycling/http://compost.css.cornell.edu/MSWFactSheets/msw.fs6.html[Butt One More Thing]Iron nutrient recycling through whale poophttp://onlinelibrary.wiley.com/doi/10.1111/j.1467-2979.2010.00356.x/abstracthttps://www.ncbi.nlm.nih.gov/pubmed/16370118

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, with a new webcam and a new angle so that you don't look like you're in a closet, Sari Reilly. I'm out of the closet, as they say. And also our resident everyman, Sam Schultz. Hello. Hey, you guys. It's great to be together. I wanted to ask you a question, it's great to be together. I wanted to ask you a question and it's a simple question. If you could rock out

like so hard on any musical instrument, which instrument would it be? Because like, so I know a little bit of drums and it's really fun, but it does not look like as much fun

as like trombone. Oh, I see what you're saying. Or saxophone. I think maybe it's saxophone i think i want to wail on a sax you're like dancing with the saxophone while you're wailing on it yeah it's like i will i was gonna say it's like a lover but i didn't want to say that and that's like really just diving into the saxophone stereotypes too. Cradle it a little under. You're going to grow a mustache, start wearing a little dog. That's my second act.

Yeah. I'm just going to be a saxophone guy. Anchoring the science sax man. And I'll tell you science facts and play the saxophone. I would pay for that. That actually sounds really good. I think that sounds like a great next chapter for your career. You can really get the older audience who likes public radio with your sultry saxophone tones.

Well, this is what's happening. They get older, too. It's like every year my audience gets one year older. Sari, what do you want to wail on? I think a xylophone. I totally agree. It's like every year my audience gets one year older. So, Sari, what do you want to wail on? I think a xylophone. I feel like I would look very cool if I could play a xylophone extremely precisely and do like a xylophone solo.

Yeah, I think that you think you would look very cool. No, I also, no, I totally think you would look very cool i just think that like yeah in general xylophone isn't known to be like the the coolest of the instruments but i totally agree that when i see somebody who like really well on a xylophone i'm like dang i want to be their friend i would be nerd cool i think yeah nerd very nerd cool i feel like my answer is boring but i've always wanted to be able to just like walk up to a piano and like play a Billy Joel song and everybody's like, yeah.

Or play like a, uh, uh, who's that? Beetle, you know, Bruce Springsteen. Sam,

you're a resident. Every man. It's okay when you get science facts wrong, but when you think Bruce Springsteen is a Beatle, we might have to kick you off. Yeah, even I know that. I got my wires crossed. I got my wires crossed.

Paul McCartney, that's who I mean. Yeah. Well, what I like about that is you're not talking about people who can play the piano. You're talking about people who go, hit their hands up on the piano. Yeah, and sing the catchiest song of all time while they're doing it.

Yeah, it's like they're just banging on all time while they're doing it. Yeah. It's like they're just like banging on a percussion instrument that just happens to have notes. That's what I want for myself. Yeah.

Yeah. Being able to sit down and look cool at a public piano. That is worth a lot of work. The highest high you could ever have.

Okay. What a fun old time that we have here on this podcast. What is it about? Well, this is called SciShow Tangents. It's a trivia game show podcast thing where we get together to try to one-up a maze and delight each other with science facts, all while trying to stay on topic, which we traditionally spend the first part of the podcast definitely not doing. Our panelists are playing for Glory. These are our panelists, those two. They're also playing for Hank Bucks, which I will award as we play. And

at the end of the episode, one of them will be crowned the winner. But first, we must introduce the topic with the traditional science poem. This week, it's from me. Matter can neither be destroyed nor created, but our desire for certain molecules is never fully sated. And yet we take those compounds and we put them in the trash. Instead, why don't we take those things and trade them in for cash? If it could only be that simple, though sometimes it frankly is. Aluminum's so valuable, it's a big and booming biz. Only 25% of it ever mines been thrown away. The rest has been recycled and is still in use today. Of course, we're not the only ones who recycle and reuse. Old nests from years past are reused by Mama Goose. But those nests require maintenance, and recycling does too.

Many products lose their quality in their second or third use. And even when we do it, there still remains a cost. The energy and fuels used to do that work is lost. The best of all solutions is to not use so much stuff. But that's hard when adverts tell us that we never have enough. Sorry, I had to turn it into like a little bit of social commentary. Yeah, it's cool at the end there. It's kind of a shift.

So the topic for the episode is recycling, which that's going to have a fuzzy definition. Sari, what is recycling? So as far as I can tell, it's basically what you described in your poem, which is something that we would normally throw away that instead you turn into more materials. It's not just reusing it, though. Right. So if you take a glass bottle and then you use that glass bottle like you just refill it that's reuse that's reuse so like that used to be a thing and still is in some places you just take your glass bottle they clean it out they fill it back up in fact they do that at the one of the breweries here in town but that's reuse recycling is you melt the glass bottle you turn it into another glass bottle or into a marble or into whatever glass product you

want turning into something else that we can use for a purpose as opposed to just tucking it under some dirt and trying to pretend it doesn't exist. Like, I don't want to think about it anymore. I like the idea of tucking it in. Like, you were a good bottle. Go to bed now. Sleep forever. Sleep forever. Sari, I feel like you hear a lot lately about that recycling is so hard and it gets shipped off somewhere. And sometimes you put it in the recycle bin and it just doesn't actually end up anywhere. It gets dumped in the dump. What's going on there? Why is it so difficult?

So some things are easier, like metals or glass, not necessarily cost-wisewise but because they're a more homogenous thing where it's like if you melt like metals together then it'll just form a bigger pool of that metal and you can reuse it so aluminum and nickel and whatnot are are reused quite often and paper is also relatively easy as long as it's not contaminated with other things because you can mush it up like paper you just mush it up in some water any other like tape or plastics or stickers attached to that paper float away can be scraped off then you take that mush and you make it into more paper but we've gotten to a point where there are like 20 different types of plastics or more that's the that's the that's the big like a plastic bottle probably has like eight kinds of plastic in it.

So like, this is so annoying. There's like the soft plastic on the top of the cap. There's the cap plastic, which is different from the bottle plastic. There's the label plastic,

which is different from all of those other plastics. And sometimes the body of the bottle itself is built of layers of different plastic that have different purposes. So like it's,

there's an inner one to prevent like the leaching of certain chemicals into the product. There's an outer one that's like extra strong from, to prevent from like penetration. And like, it's all these different things that they want the bottle to do, but that makes it very hard to recycle that bottle.

Cause the moment you mix them all together, they become a weaker plastic. You're not just going to Intel big blob of melted plastic. You have to strip it. Whereas aluminum, you absolutely do end up with just a big blob of aluminum because it's an element. It's not a molecule. And some of them combust while some of them melt down.

Then it's like it's dangerous to be sorted to be composted. Is there an origin for the word recycling that isn't just, you know, what it is? It is what it is. You recycle? Yeah. You recycle? That's pretty much it. Yeah, and I thought about it for a little bit and I was like, maybe an interesting discussion is that re and cycle both seem redundant. Because cycle is like perpetuating.

Just cycle. Yeah, something cycling. Re is like a prefix to indicate any sort of like recurring thing or like back to an original or undoing or backwards. So like anything that you do again. And so I guess my interpretation is that you pull a material out of a cycle. Like when you have a Coke bottle in your hand, it is no longer being cycled. It is yours. And then you want to put it back into the cycle of materials like you turn it back into plastic pellets and it becomes material again that's how i parsed that it was like a branding exercise to me the word recycle feels like we thought of it in the 90s i'm sure that's not the case but yeah

recycle meaning to use material, was in 1922. Originally, it was like an industrial purpose. So only like the serious materials barons were using recycle. And then it was used for waste material reclaimed into a usable form by 1960. So it is a pretty recent thing. The idea of like, yeah, the hippies were like recycle dudes and that means it's time to move on to the quiz portion of our show this week we're gonna be playing a little game called recycling secret ingredient a lot of things these days are marketed as being made out of recycled goods and sometimes the way those recycled goods are

recycled involves some strange products. So for today, in honor of our theme, we're going to recycle a game that we haven't played in a while, Secret Ingredient. I will be describing some kind of product made out of recycled products, but I will be leaving out one key ingredient, and it's up to you to figure out what that secret ingredient is. So we're going to start out with our first secret ingredient. When you are eating something that's vanilla flavored, the compound that actually makes it taste that way is called vanillin, an extract derived from vanilla beans. But because a lot of people like the taste of vanilla, a big chunk of vanillin is made synthetically because it's hard to make all those vanilla beans. In 2021, researchers in Scotland genetically engineered bacteria to convert a recycled product into vanillin.

What was it? It could have been recycled soda cans, recycled plastic bottles, or recycled vanilla. I thought I knew it until you said those, and none of those are what I thought it was. What did you think it was? Sari, why don't you go first? I don't know. I feel like this is a trick question. I'm going to say recycled vanilla because that's food.

Where are they getting it? I don't know. From poop? Where is it coming from? Yeah, maybe from like mush. I don't know. Yeah. Mush?

You know, where they put the vanilla ice cream when they're done with it. They just poured in a giant pile and these researchers came, scooped it up, fed it to some bacteria and were like, eat this ice cream, poop out vanilla, please. So is that what you're going to say? Yes. I'm going to say recycled vanilla. I thought it was plastic shopping bags. So I'm going to go with plastic water bottles. Well, one way that scientists have been developing to recycle plastic bottles is to break down their building material called polyethylene terephthalate into the basic subunit called terephthalic acid. And one of the cool things about terephthalic acid is that it's chemically very similar to vanillin, so similar that it is possible to engineer E. coli bacteria to make that conversion happen. The researchers tested out bacteria by mixing them with terephthalic

acid and storing them at 37 degrees Celsius after a day. About 79% of the acid had been converted into vanillin. That's not the most appetizing process, I gotta say. No, yeah. Well, look, it used to come from beaver butts uh or something when you put it that way i suppose all right sari it's it's time to to try and return yourself here many of our electronics are built using rare earth metals which can be quite damaging to mine from the environment in 2015 researchers in japan developed a method to extract rare earth metals that could potentially be used to recycle those

metals from electronic circuits and phones. What was the secret ingredient to their technique? Was it just good old table salt? Was it owl pellets? Or was it salmon sperm? Those are three pretty different things. Yeah. I don't feel like an owl pellet would have a concentrated enough anything for it to be an owl pellet. That's just a hairball and my cat's hairball couldn't help me do nothing.

Salmon sperm. I'm just going to say it's that one because that's intriguing. Sam wants it to be salmon sperm. Okay. That was what I was

leaning towards too. I don't know why. I feel like it's got a weird chemical composition. It's probably basic. I don't know. I'm going to go with salmon sperm too.

Well, researchers have found that rare earth metals bind well to phosphate containing molecules. One molecule that happens to contain plenty of phosphate is DNA. But the downside of using DNA for this purpose is that it's soluble and it would need to be fixed to some kind of solid substrate. So instead, researchers turned to a cheap and easily accessible form of DNA, salmon sperm, also known as milt. Salmon sperm is regularly discarded by the tons, thanks to the fishing industry. Where is it coming from? Like, why do they just jizz in the water? Where do you think it's coming from, Sari?

But why? Is it like a panic response that they do something i don't know i don't know and then they're like i got all this sperm what do i do i don't know either i don't know i don't know like does it all does it all come out at once how do they capture it yeah if it goes straight into the water what does it do and then they're just swimming in it like they swim in their pee. I didn't do the research. Anyway, salmon sperm is regularly

discarded by the tons in the fishing industry. It's also made up of a ton of DNA, so it's a good source of phosphate. So the researchers created a milt powder, added it to a solution containing rare metals, and then dunked the mixture into an acid bath and centrifuged it out to extract the rare metals.

What the hell? This is the future that liberals want. Tons. Plural. Is there somebody there who's like, this salmon's about to pop. We got to get him out of water. Point him at something.

This boy. Oh no. Oh, no. All right. I have to move on because I'm worried about where we'll head. Sari, your final chance to tie it up is arriving now. If you have been to school or walked around a city, you've probably noticed the very gross problem of gum that someone has thrown away by sticking it to some surface that is definitely not a trash can. In cities, these dried up pieces of chewed gum can lead to high cleaning costs. In 2008, a company in the UK began working on a bright pink disposal bin called Gum Drops

for people to drop their chewed gum into. These bins are made of recycled material. What is the secret material that they are made of? Is it recycled candy wrappers, recycled gum, or recycled cleaning supplies? I mean, it's got to be gum, right? I'm going to guess cleaning supplies feels like the left field one. So I'm going to say that to make it like something not sticky so you could remove the gum. In 2008, Gumdrops, the company,

was founded with the goal of creating a closed-loop recycling system. Oh, no. It consists of their bright pink Gumdrop disposal bins, which look like bright pink bubbles. And when these bins are full of gum, they are then sent back to the company, which uses them to make more of these bright pink gum things. What a strange idea.

Eventually, like, this is a problem there's an exponential problem here where the more you get the more of them you can build it's like until the entire world is made out of yeah just gum gum drops yeah one street in london uh did a trial run of gum gum drop system and supposedly lowered the amount of gum litter by 40 percent which is frankly disappointing. Just, it's right there. It's right there. Just keep it in your mouth until you get to the gum drop.

There have been times when I've had to mostly spit gum out the window of a car on the highway because I just don't have the wrapper anymore. I feel so rude. That's like the meanest thing I feel like I've ever done is spit gum out on the ground. I cannot imagine littering. I once saw a man spit a cherry pit and I was like, I don't know.

I don't know if you can do that. That's how I know I'm a true square. It's made of wood. It's a piece of wood. That seems fine. I'm like, why am I having this reaction? Yeah. Anything food related that's not a wrapper, I feel like I'm like, why am I having this reaction? Yeah, anything food-related that's not a wrapper,

I feel like I'm loose about. I can't throw a banana peel on the ground. Well, somebody slips on it. Somebody could slip on it. All right, what are we doing now? Oh, of course, it means that it's time for a short break. And then, the fact off. All right, welcome back, everybody.

Sam is in the lead 2-2, wait, 3-1? Mm-hmm. 3-1? Oh, wow. Yeah. And now it's time for the Fact Off. Our panelists have brought science facts to present an attempt to blow my mind. After they have presented their facts, I will judge them and award Hank Bucks to the one that I think will make a better TikTok.

To decide who goes first, though, I have a trivia question. that I think will make a better TikTok. To decide who goes first, though, I have a trivia question. In 2014, the Minnesota Pollution Control Agency decided to create a visual of just how much paper Minnesotans throw into the garbage instead of recycling. So they took the amount of paper that's thrown into the garbage in less than 30 seconds and made that into the world's largest paper ball. How many pounds did that 30 seconds of paper weigh? I can only imagine it's

something that you can only roll and not pick up. So here's how I figure it. I bet each town throws away 200 pounds of paper every 30 seconds. How many towns are there in whatever state we're talking about? I don't know. 50? What's 200 times

50? 10,000. I bet it weighed 10,000 pounds. That seems like a lot, doesn't it? Uh-oh. I'm going to guess 1,500. Sari, you are correct or closer. You are not correct. It was 426 pounds, which is an amount that a human can lift. Like, not me, but a lot of humans could lift that amount. The ball was 9 feet 7 inches tall and 32 feet around. There was no tape or glue used in the making of the paper ball. I guess they just wetted them and stuck them together.

It was displayed at the Minnesota State Fair, and then it was brought to St. Paul for recycling. All right, that means that Sarah gets to decide who goes first. Okay. I'll go first to try and redeem myself. So a big push for recycling and reusing nowadays is to steer people away from the use then trash mentality about stuff, whether it's a plastic soda bottle or an old book that is kind of worn out and that nobody checks out from the library anymore.

That's not to say that humans were waste free hundreds or thousands of years ago. It's just that the idea of reusing hard to make stuff was more culturally normal. So take the old book example. Before and during the Middle Ages, which were from around 500 CE to somewhere in 1200 to 1500 CE, because I didn't know that, had to look it up, many books didn't have paper pages. Instead, they were made of parchment or vellum. And if you go to a craft store today, those are just words for different kinds of paper. But back then, they meant processed animal skins from goats or lambs or calves. Parchment was relatively time-consuming and expensive to make, so it behooved you. I didn't realize I made a pun there. but it behooved you to find a

way to recycle it rather than starting fresh. So sometimes books were chemically treated or physically scraped with a knife or pumice to remove the old ink and part of the top layer of treated skin and create a fresh writing surface. And this recycling process was common enough that this kind of document has a name in the study of old texts. It's a palimpsest, which is derived from Greek words for scrape and again. And I've only heard the word palimpsest in fictional media contexts like D&D, so it was very cool to find out it's a real historical thing. Because humans are always curious about what our ancestors were getting up to, basically ever since palimpsests existed, there were people trying to recover the erased texts.

In the 1800s, for example, an Italian priest named Angelo Mai used some pretty destructive chemical and physical methods to erase the top ink and suss out writing by ancient Romans or other past civilizations. And more recently, we've harnessed technology to digitally scan palimpsests, isolate different wavelengths of light,

and process those images with computer algorithms to reveal past writings, which is cool because one piece of parchment may actually hold hundreds of years of writing, but also because we can see what kinds of editing decisions people were making about which text to keep and which ones to recycle. And if that wasn't cool enough, now biologists are taking a crack at these palimpsests, too. They can compare DNA from the animal skin to modern animals to help learn about evolution. And because organic materials like parchment are naturally home to microbes like bacteria or fungi, either settling in from the air, sloughed off of skin or spit or sweat of whoever was writing, or growing in some other way from contamination.

So not only are palimpsests a treasure trove of recycled information, they're also an exciting newish area of research for tracking how life itself has biologically changed. That's cool. Dang, that is very cool. Are there any examples of people finding stuff that's like, ah, if we hadn't looked, we wouldn't have known the elixir of life. I couldn't find anything cool like that. I was trying to.

It seems like mostly people are just like, oh, we learned a new weird thing about how they didn't like this Bible and wanted to rewrite it and did another one. What did we decide we wanted to scrape over? The stuff that was inconvenient that we didn't want out there and also potentially like a recipe. Yeah. convenient that we didn't want out there and also potentially like a recipe yeah just like i had enough copies of that but i think they're hoping to learn more about the climate and like what situations these parchment books had gone through because you can tell if they've been exposed to different kinds of dust or floods or contamination and linking those to other geological records of

those incidents the big question now seems like how to sample material from these things without destroying them completely and there hasn't been a big like wow this is cool pop science to get other people interested in this yet can you see like more than one thing that was written? Like, so there's like the thing that's written and then like the thing underneath that. Could you go deeper? I think that's what the computer technology is trying to do because you can really just highlight

any sort of small indentation. I think once you get past three or so, then you start really damaging the parchment. Probably pretty messy. Yeah. Yeah. So it's pretty messy, pretty fragile, less likely to survive. So just like with modern recycling, if you do it three or four times,

suddenly your vellum is like, uh, yeah. All right. I love it. Sam, what you got for me? Tape. What would we do without it? How did people close up their moving boxes before the advent of packing tape, for instance, that they have to use like they wouldn't create a nail

them shut? Probably. That's what I think they're probably doing. Yeah, it seems right. As we all know, tape is real sticky. But the very wondrous thing about pressure sensitive adhesive tape is that it's real sticky on its own without having some water or some other chemical mixed in without having to dry. But how does it do this? It depends on the tape, but it's always polymers combined with some mix of rubber, acrylics, resins, et cetera, chemicals, basically. But taking this back to moving one thing that I would wager tape is most often stuck to is cardboard and paper and cardboard and paper are recyclable. And the plastic part of tape is also recyclable. Unfortunately, for the most part, due to the great chemicals that make tape sticky, tape ain't recyclable. A lot of recycling centers do take

cardboard with tape on them, but some don't. And either way, all that otherwise recyclable plastic is just going straight in the trash. And it's not like you can reuse tape. It's so like when you're done with it, it's just trash. That's the end of its life. Another marvelously sticky thing are the feet of the common housefly. These little fools are climbing all over the place. And unlike tape, their sticky little feet can be used again and again. It would be sad if they couldn't use their little feet again, but they can.

So how do they do that? feet yeah uh fly feet are pretty complicated and have a few different grasping mechanisms but one of them is sata satay cd ah cd those are tiny oily spatula shaped hairs that cover the tip of each fly foot. And since CD are flat on the end, they increase the surface area of the fly's foot exponentially. And the oily secretion on the hair helps adhere even more with capillary action. So every step the fly takes is sort of like taking with hundreds of little feet on each foot, sticky little feet. with hundreds of little feet on each foot, sticky little feet. So inspired by the all natural stickiness and reusability of the humble fly's foot, a team of scientists at the National Institute for Material Science in Japan studied the little spatula structures in 2020, and they figured out how they grow on the fly's foot in the first place.

Won't get into that part because I didn't really understand it. But basically what they figured out was that the way that they grow and what they're made of turned out to be pretty easy to replicate using nylon strands so the scientists did their science thing and they ended up with these long nylon strands the tips of which were covered in artificial i forgot how to say it already ceda cd cd the researchers applied a little water in place of the oil that the fly excretes and started sticking the strands to stuff. The strands started off being sort of sticky, but not really like in a super exciting way. But when they dried, their stickiness increased to the point where about 130 pounds or 60 kilograms, if you like metric, could be suspended with about three and a half square inches or nine square centimeters of adhesive material,

like that big of an equivalent piece of tape. And by twisting the strands in a certain way, they detach and be completely reusable again. So the researchers proposed that this technology, which is also cheaper than other biomimicry adhesives, could be used to make things like tape that could be made adhesive with something like water or like some kind of oil or something

instead of less wholesome unrecyclable chemicals and it would be way stronger than the sort of tape we use now and it would be completely reusable and recyclable so the artificial cd could also be used for all kinds of other stuff like making very sticky robots that can grab stuff giant fly like what i ever think about a robot I'm always like I like it but can you make it stickier

that's what the paper was just like what if robots were stickier what happens if a fly lands on it oh no

I don't know the universe collapses or something you gotta twist the fly and then it'll be unstuck. You got to twist space-time and then we're good. Yeah. I am excited for the future.

The future has rare earths being extracted by salmon sperm. It has deciphered palimpsests and it has tape that is unlike any tape you have ever experienced. You guys are very close to each other, but Sam was already two points ahead. So Sam, congratulations on being the winner of the episode. But I might make series into the TikTok because I think TikTok likes uncovering secret mysteries. That makes sense. I would love it if there was a spell on there that could, I don't know.

Aw, can we pivot into spells, please? Can we just start doing spells? I'd be so much better at spells. Welcome to SciShow Lies, where we just talk about spells and other mystical things. Mermaids, unicorns, that big shark that people think is still alive. Alien encounters. That means it's time to ask the science couch

where we ask listener questions to our virtual couch of finely honed scientific minds. This one is from at mental avocado who asks, is Dollywood and Gatlinburg's

system of recycling slash composting better than what is used in other places i do not know i don't know what that means no dollywood has special recycling in compost does dollywood have special recycling sari does and i didn't i had never heard of this either i'm gonna go ahead and say yes on on what grounds just because dolly kicks ass. Yeah, she seems like a really great lady, so whatever she thought of is probably great. I don't know how much she had to do with this.

So Dollywood and Gatlinburg are both in Sevier County in Tennessee. And Sevier County takes all the waste from nearby cities, mixed solid waste. So it's just anything. It's trash. It's recycling. It's glass. It's plastic. It's food.

Puts them in big rotating drums and like starts sifting it around, filters out the compost. And then from there, it's like sorts all the other stuff all the other plastics glasses other things and recycles it and it has been lauded i guess as one of the best versions of these mixed solid waste processing plants because instead of all this waste going straight to a landfill with these machines and the humans that are sorting them, it ends up reducing the amount of trash that goes to the landfill by about 60%. The other mixed waste processing plants that are across the U.S. are smaller than that. And I think they reduce the waste by about 40 to 50 percent from what I can tell. I guess part of what makes it good is that it is really low effort on the part of the consumer.

Like you don't need any sort of like manual sorting beforehand. So it's easy. It's easy for people. It seems like their facility is pretty efficient. And the sources that they get it from, I think, are generally more food heavy. They do collect it from townships, but Dollywood, I think, has mostly food waste. But a lot of the people that they take waste on from has a lot of organic waste so that they can compost well. They kind of know what proportions of waste they're

getting in to begin with. But the bad parts of it is that it, I don't know, this is where recycling gets very complicated, where there are a lot of things to consider on whether this is good or not. And is why like this whole, the whole point of recycling is that it's very complicated. So one of the thing is the quality of compost. If you're going to be using compost to grow other food, you need it to be of a certain level of not toxic. And the problem with these sort of mixed solid waste processing plants is that with everything jumbled in together, there's a chance that as it's being circled around in these machineries, there's heavy metals leaching in. There's other toxins

of brewing, kind of like we talked about where some compost plants, even industrial ones, don't take meats or bones or things like that because that promotes growth of potentially harmful bacteria. So you have to monitor the quality of compost. It can just be dangerous for the people who are working there if there's dangerous stuff being put in the garbage and you have people manually sorting the garbage. The last big thing, and this is like the most heady of them all, is like how much do you want to educate people?

Like how much do you want to educate people like how much do you want people to understand how their waste is being processed versus just dumping it all into a trash and then the systems are fixing it for them as opposed to like right actively contributing to a lower waste lifestyle and that's that's complicated because like there's a piece of you that wants the the dislike i i think that what's best is for people to have space in their minds to think about other things you know there's a lot going on in my life and i'd like to be able to think about that getting my kid to school and what am i gonna wear to work today uh and and like you know we've got a limited amount of life a limited amount of space

in our heads to to learn things and so there's part of it part of me that's like just let people live their lives and try and solve the problems for them and there's part of me that's like no this is a big part of who you are on this world it's the waste that you create and it's good to understand that that's not just like a big hole at the end of your driveway that like things disappear into. So Dolly Parton, no! You're doing it wrong! So it's just sort of by chance that Dollywood is in the county where they just have a really good mixed waste processing system. Yeah, I think so.

I think it was some combination of activism politics experimentation where they were like we're gonna have this thing and then dollywood is just there and that's what gets the news article clicks where it's like because dollywood doesn't have recycling bins and they're like we don't need them here at dollywood we have the best mixed waste recycling plant in all of the united states of america exactly that's all the articles i read about it i was trying to find deeper into the science and none of it. It was just like,

there's no recycling at Dollywood. Guess why? It's weirder than you think. Hey, look, people got to write headlines, Sarah. You know it.

All right. Well, if you want to ask the Science Couch for questions, you can follow us on Twitter at SciShow Tangents where we'll tweet out

topics for upcoming episodes every week. Or you can join us on the SciShow Tangents Patreon and ask us on Discord. Thank you to Quill and Saida on Discord and everybody else who asked us your questions for this episode. If you like this show and you want to help us out, it's super easy to do that. First, you can go to patreon.com slash SciShow Tangents to become a patron and get access to things like our newsletter and our bonus episodes and our Cars 2 commentary, where you can find out what is on the inside of a car's car. Second, you can leave us a review wherever you listen. That's very helpful, and it helps us know what you like about the show. And finally, if you want to show your

love for SciShow Tangents, just tell people about us. Thank you for joining us. I've been Hank Green. I've been Sari Reilly. And I've been Sam Schultz. SciShow Tangents is created by all of us and produced by Sam Schultz, who also edits a lot of these episodes, along with Seth Glicksman. Our story editor is Alex Villo. Our social media organizer is Paola Garcia Prieto. Our editorial assistants are Debuki Chirac-Rivardi and Emma Douster.

Our sound design is by Joseph Tuna-Medish. Our executive producers are Caitlin Hoffmeisterister and me hank green 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. Living things use iron for lots of molecular stuff, like how the phytoplankton floating around in the ocean need iron for photosynthesis. Krill eat the phytoplankton and then baleen whales eat the krill. But baleen whales don't need all that iron to survive, so they end up recycling those nutrients back into the water. And by that, I mean they poop a lot. According to research in a 2010 study, baleen whale poop has around 10 million times the iron content of Antarctic seawater. So their massive dumps are a key part

of the cycle of nutrients and help maintain a healthy, flourishing ocean ecosystem. If I could help the world just by pooping, I guess I would be a whale. But unfortunately, my poop does not... It causes more problems than it solves. Yeah, probably. For me as well, honestly.