SciShow Tangents - Bake A Cake! | Compilation

Episode Date: August 15, 2024

For those who want a megadose of Tangents shenanigans, this compilation is for you! In the many seasons of Tangents we've covered lots of interconnected topics, and now you can listen to them back-to-back like the best podcast many-feature ever. This compilation has been handcrafted from premium ingredients, sifted and whisked together with care, and baked to podcast easy listening perfection. Bon Appetite! Original episodes: S1 E5 - Eggs, original airdate: December 11, 2018 S2 E18 - Sugar, original airdate: March 10, 2020 S2 E26 - Salt, original airdate: May 5, 2020 S2 E38 - Milk, original airdate: August 18, 2020 S3 E44 - Yeast, original airdate: January 18, 2022 Sources for each episode can be found in the descriptions of the original episodes. Want more SciShow Tangents? Check out hundreds more episodes of our podcast here: https://scishow-tangents.simplecast.com, or wherever you get your podcasts! 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 find great SciShow Tangents merch! A big thank you to Patreon subscriber Garth Riley 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

INTRO MUSIC Hello and welcome to SciShow Tangents, the lightly competitive knowledge showcase starring some of the geniuses that make that good old YouTube channel, SciShow, happen. Today we are joined by musician and artist and producer, Stefan Chen. Hello. What's up? What's your tagline? Uh, Pickle Bob.

And we also got over there, Sam Schultz. Also artist, also grand folk. What's your tagline? What's a grand folk? You're just a good person. Oh. I thought you weren't going to say any nice things about me. You were just going to say, Sam.

So maybe that's just my tagline, Sam. Sam Schultz, it's Sam. And over here on the science couch with me is Sarah Rea Riley, science communicator and MIT graduate. Yeah, we got that degree on the science couch. What's your tagline? Shipping and handling, not included. And I'm Hank Green, creator of SciShow

and general YouTube person, I guess. My tagline today is pant balls. Every week on Tangents, these four friends get together. We try to one-up each other and amaze and delight each other with science facts. We're playing for glory, but we're also keeping score, awarding Hank bucks from week to week. We do everything we can to stay on topic, but judging by our previous conversations,

this group will not be good at that. So if someone on the podcast wants to go on a tangent, they've got to give up one of their Hank bucks. No Hank bucks, no tangents. We all start with none, so let's stay on target. Oh, okay. And as always, we introduce this week's topic with a science poem Overduck overduck Release your prize. Oh gosh How many spheroids can overduck supply? No nest in sight we must improvise a Frying pan will do salmonella. Goodbye. I wasn't comfortable with the accent

Salmonella, goodbye. I wasn't comfortable with the accent. I was trying to read it as if I was casting a spell, sort of. Oh, that's good. Which is not related to the topic this week, which is eggs. Which is, our topic is eggs, but I do like, eggs are kind of magic. And I especially think that like a fried egg is magic. Because can you, wow, what a thing. This beautiful encapsulation of some of the best food.

And you know, I used to think that eggs were like a lot of like fat and calories and stuff. It's 80 calories an egg. You know, when we were younger, I feel like TV was really trying to tell us that eggs were bad for us. Remember that? They used to be like jokes on the Simpsons

about how bad eggs were for you and stuff. Yeah, they're gonna give you all the cholesterol. And it's true that if you have cholesterol problems you might want to avoid eggs. Also it's true that the US government categorizes eggs as meat because they have enough protein I guess. But they are not by vegetarians considered to be meat. Sure. What else would they be? They're what? They're not by vegetarians considered to be meat. Sure. What else would they be? They're what? They're, I don't know, they're food. Okay. Don't yell at me.

Animal products. Milk is not considered. They're like milk. Milk is not meat. They're like milk. Where they come out of an animal, a whole of an animal, and then it goes into our mouth. Right. So for the world, what, what,

can we get a good definition of what an egg is? It's a, it's like the, it's the piece before the sperm comes along that's gonna make the baby. Yeah, it's like a really cool, weird cell. All eggs are just one cell. They're squishy. They got a nucleus inside and that's where the sperm fuses. They combine their genetic information

and then they can start dividing to become a new organism, but they can come in all shapes and sizes, like fluid-filled sacks, or some of them get laid with mineral coating to protect them from the weather. And now it is time for... TITLE FLAW. One of our panelists this week, me, has prepared three science facts for our education and enjoyment, but only one of those facts is a true fact. The others I made up. And the other three panelists are going to have to figure out either by deduction or wild guesses,

which is the true fact. If they do, they get a Hank Buck. If they are tricked, I get a Hank Buck. Would you like to hear my facts, you guys? Oh, yeah. I feel like this is going to be hard because it seems like none of us know very much about eggs. So far. Number one, there's a species of trout.

It's actually here in Montana called the brown trout. And it carries, get ready, two different kinds of eggs. It has real viable eggs and it has fake eggs that are just like fluid filled sacks. Why would that happen? Well, trout have courtship and they make babies by like having sort of like a little interaction. And if the female thinks that looks like a good male,

she will leave her eggs in the water and he will inseminate them, just like release his sperm. And that's how the eggs get fertilized. But if she doesn't like the look of the male and he keeps bugging her, she will release some of her fake eggs and he will try, like just do his thing and then swim away and stop bothering her.

That's like, I promise this is my real phone number. Fact number two, it can be good to give you little ones a chance to grow in their egg. So give them some time to do that thing. But a species of deep sea octopus takes this to a crazy extreme with eggs that go from like laying to hatching, takes more than four years.

The mother also spends that entire time like hanging out over her clutch, making sure that nobody comes to bother them and she does not eat during that time. And so, and also this is especially weird because most octopuses only live for two years. So this also makes this the longest living octopus because she spends more time guarding her eggs

and not eating or moving than most octopuses spend being alive. And finally, number three, eggs are super packed with nutrition because you want to give your baby that chance at life, and so you want to give good food in there. But that also makes them a delicious snack. So there are different strategies that animals use to protect their eggs.

This is a weird one that I hadn't heard of before. Trilobites did this by laying eggs that are like spiky sea urchin looking things. And they're like spiny, chitin covered balls that they had to push out of their cute little trilobite cells, which probably wasn't super fun, but I don't know because I am not a trilobite and I can't ask them because they've been extinct for 250 million

years. So we have number one, fake trout eggs, number two, long-lived octopus eggs, or number three, spiny trilobite eggs. I think it's number one. That seems, I feel like I've heard of similar strategies before, though I can't remember like what the specific example was. And the octopus thing, I also feel like I've heard about an octopus that made the ultimate

sacrifice to take care of its eggs. But I don't know. Four years seems like a long time, especially if it's like twice as long as other octopus. And then, I don't know, spiky eggs don't make any sense to me. That one sounds so boring, I feel like. It's surreal. Boring. But also, trilobites are like, I don't want to call them basic, but they're just doing

their best. That's a long time ago. Yeah, a long time ago. They got spiky eggs to it. I'm also leaning towards... You think spiky eggs is too advanced for a trilobite? No, I think it fits with a trilobite. If I was a trilobite and I had a random mutation to make my eggs special, spiky eggs seem to

make sense. Okay. Let's bump them around. Seems like a big leap. Yeah. I think it's... The fish one sounds really familiar to me too, because I know fish make fake eggs in their bodies sometimes, and sometimes the babies eat them too.

So if they... Before they lay the eggs, they're like fake eggs, and the fish hatch inside them and then eat the fake eggs, and then are birthed. What the heck? Wait, what? So the fish aren't in eggs anymore? Yes.

They break out of their eggs and then they like, there's these extra eggs that are just nutritional support for them, for the fish that are swimming around inside their moms. Yeah. I see. Yeah, their bodies make lunch boxes. But that costs them? It's like a gusher. Yes.

Oh. One egg per baby. It's caviar for them. They're fancy. Literal caviar. Yeah. But because it sounds real, that makes me want to say it's fake. Because I don't trust Hank. Yeah. That's how I feel about that one, too. What was the middle one again? Octopus. Octopus. I think that one was bullshit.

I don't think that was one at all. Straight BS. Yeah. If you had said that the baby octopus eat the mom, I would have been like, yeah, that makes sense. But just like sitting there for four years, I'm like, no way. They can't do that. I say the fake eggs. Fish eggs.

Fake fish eggs. Sam. I say the fake fish eggs. Octopus mom. Octopus mom. Ceri is correct. eggs. Octopus mom. Octopus mom. Ceri is correct. No!

Octopus mom. That sounds so boring for them. Okay, let's start with octopus mom. So this is at the Monterey Bay Aquarium Research Institute, MBARI I think is what it is. And they went down, they saw this octopus mom sitting on her eggs. And then like a few months later, they went down. She was still there. A few months after that, they went down, they saw this octopus mom sitting on her eggs. And then like a few months later, they went down,

she was still there. A few months after that, they went down, and then years later, they've been watching, going on the exact same spot. This octopus mom is not moving, dying slowly, her eyes are filming over, her body is shrinking. She's getting, like her skin's getting all saggy. And then they go down one day, four and a half years later,

53 months after they first spotted her, and she's gone, they assume dead, and all 165 octopus eggs have hatched, and some of the octopi, or octopodes, or whatever, are around and are like the most developed baby octopuses they've ever seen. How recently was that? This was 2011.

Okay. So she could have been there for longer than four and a half years. Yeah, probably not much longer, cause I think that they had been to the spot where she was. They even tried to give her a crab, which is the food that they eat. To see if she would eat like,

cause you know, they're not down there all the time, so they don't know, she may have eaten something, she may have eaten like an egg that died. She might've like nombed on some of those. And it was like deep sea. So metabolisms are very low down there. It's like three degrees Celsius. So you can live a long time.

And like the creatures in the deep sea in general have weirdly long lifespans. But like, this is the longest from fertilization to hatching or being birthed of any animal we've ever seen. Any animal ever? Yeah. Whoa. Yeah, cause elephants are like two years or something,

and that's one of the longer ones. Have they observed this in any other octopuses or was it just maybe this one octopus? Well, they think it's this species, but this is the only example that they've ever seen of it. It was just sort of a luck thing. Do they know where she went, or is it just like, disappear, probably went off to go die somewhere?

I think she just died. They floated away. And that's common in octopuses, like that mothers will sort of guard the brood and then die. Was the first one based on any true things or did you just make up the fish? Oh, totally.

The brown trout actually fakes orgasm. Oh, no. Weird. That's even weirder. Right. It'll like go through the motions of laying eggs, but it won't actually do it. It'll like do all the same body movements. And then the male will be like,

that looked right and release its sperm and walk away. And then trilobite eggs just look like normal eggs that we do know what they look like, which is pretty cool. We have fossilized trilobite eggs, but also there are some really weird shaped eggs, particularly sharks. So some species of sharks will lay like screw shaped conical eggs that like the goal is

to get them like sort of wedged somewhere where it's harder for something that wants to eat them to get them out. But like they think that they're screw shaped so they're easier to lay. Like they want them to have edges and stuff, but they don't want them to like be impossible to get out of a body. So they sort of like screw themselves out of the shark. Did you find shark egg sacks a lot when you lived down south? Uh, we found like...

Mermaid's purses? Yeah, mermaid's purses. Those are skate egg pouches. But those are a shark, aren't they? And sharks. They're in a class called chondrichthys with sharks and skates and all the other cartilaginous fishes. So I think they're like ghost fishes are in that category too.

And they all have these pouch shaped eggs. Anyway, that's my facts you guys. I got two Hank Box. You nailed us. You got two. Which means I got one now because I already spent one in the beginning. Pre-spent. After our break, we're going to go our fact-off with Sam and Ceri. But first, let's talk to our sponsors.

[♪ INTRO & MUSIC PLAYING [♪ INTRO & MUSIC PLAYING [♪ INTRO & MUSIC PLAYING [♪ INTRO & MUSIC PLAYING So I have two Hank bucks, but I spent one earlier in the episode, so I have one. Sari has one. I have one. Our panelists over here, Sam and Stefan, have zero.

It's time for our Fact-Op 2 panelists to bring science facts to present to the others in an attempt to blow our minds. The presentees each have a Hank Buck to award to the fact that they like the most. However, if both facts are giant snoozes, the present is can choose not to award their Hank Buck and instead throw it in the trash, which we're not gonna do. Don't be ridiculous.

We're gonna choose who goes first by asking who touched a chicken most recently. Ooh, I bet I know. Probably me. Yeah. I touched a chicken like two days ago. What? You guys touched chickens so frequently. Yeah. I touched a chicken like two days ago. What? You guys touched chickens so frequently.

I was like Hank touched one last Friday. Well me too. I touched a chicken also. It was a good chicken. It was a really good chicken. You may even have to rethink a bunch of stuff. Yeah, really smart chicken. Also I did not realize how big a chicken poop is. Oh my God.

Did it poop? Yes. It pooped into Jesse's hands. Did it poop? It pooped like an egg. It was like an egg. It was like an egg shape and size. Was it solid?

It was solid enough that Jesse just caught it and it was like. And it smells so bad. I didn't get a whiff of it. If you're confused, this was while we were filming SciShow Talk Show with Jesse, who brings in some animals for us to see. The chicken being probably one of the more quotidian ones that we hung out with. But also one of the more like amazing to look at.

And its eyes were so like thinking about the stuff going on around it. It was like talking and it was very calm. It was a moving experience. It was a beautiful chicken. Yeah. There's beauty all around us. If you know where to look for it. That's my science fact. Stick insects are insects that look like sticks. They spend most of their time trying to look like sticks, so that might not seem like they have very interesting lives,

but their eggs are super interesting. First of all, they're parthenogenetic, so they can basically like clone themselves. Is that what that means pretty much? Yeah, okay. If they aren't viable, males around the females can just lay fertilized eggs, which they do by going to the tops of trees, laying the eggs, and then kicking them with their feet so that they sprain all around the forest.

They all lay eggs that look like seeds, and a lot of them lay eggs that look like seeds that have a little nub on them called the Capitulum which is a fatty structure that mimics the part of seeds that Ants are attracted to and so the ants find their seeds Chomp on them bring them back to their nest put them in their garbage bin after they eat the fatty part off Which is not important to the to the stick insect Then they hatch in the trash part of the ants' nest. They're just safe in there.

And they look like ants when they come out. So then they sneak out of the nest because they look like ants. They look like ants! But finally, their eggs look like seeds and they're hard like seeds too. They're made out of the stuff that kidney stones are made out of. This is the thing though. This is the big thing. That...

You should have stuck with one fact, Sam. They're hard like that. So parasite wasps can't put their parasite babies inside of the stick bug's eggs. But, they found out that if a stick bug's eaten while pregnant by a bird, it is possible for that bird to not digest the eggs and then fly away and poop their eggs out somewhere far away and they can still hatch. Seed dispersal. Even like they're eating a whole stink insect eggs are still inside the stick insect

Yes, and they can't be digested because of what they're made out. That's cool. That's really weird So you said something about like the material from kidney stones? Yes, so this is like a hard mineral substance of some kind protecting Calcium oxalate count. That's a good. That's a good hard mineral Yeah, do you does the bird poop poop help the babies grow at all? Kind of like seeds and actual fertilization? They said that they already had pretty bad survival rate for their eggs. So they fed a bird 70 eggs and 14 of them emerged capable of hatching and two of those did hatch into babies.

And from what I could tell, that wasn't too much worse than in nature. So it doesn't help them. And I guess like, when you got that many babies, and I don't know how often stick insects make the next generation, when you got that many babies and that kind of mortality rate,

that is like a recipe for like good evolution happening. You know, like the ones that are gonna do good. They're on every continent except for Antarctica. Is that the one? Yeah, usually. What's the one on the bottom? Is that, is that Antarctica? I'd say yes, you got it right.

I honestly like that it has this mineralization going on cause that's very weird and that's like, that's hardcore insect stuff right there. But I like better that they have this like fatty thing that the ants are like, I'm gonna take that and eat it. And it feeds the ants and then they wake up and they're like, ah, it's hatching. I'm like, I'm a good old stick insect.

I look like an ant, so don't eat me. They live in their old ant dump. Yeah, get born in an ant dump. I was raised in this here ant dump. All right, Sari, go. When doctors are analyzing semen, they look at qualities like motility, which is like how many moving sperm there are, the volume of it, so how many sperm per milliliter

usually, concentration, and the morphology. Are the sperm normal looking? Can they fertilize an egg properly? And normal sperm densities can vary, and it's really, really hard to predict fertility even with all these different variables, because there are a lot of biochemical factors that go into a sperm fertilizing an egg. You have to have the right enzymes and antigens and it has to be able to actually like penetrate inside. So you can run lots of different tests to figure out whether something is fertile besides just straight up in vitro fertilization, which is like taking a human sperm and inhuman egg

and seeing whether it works. There's a lot of like ethical mumbo jumbo around that. So instead, scientists have come up with a different method for testing for infertility, seeing whether human sperm can penetrate and fertilize hamster eggs. And it's called the hamster test. No, don't do it. Don't put them in the hamster.

Don't put them in. Because it's not going gonna fertilize the egg. It goes inside the egg. It goes inside but it's not gonna make a baby. One of these days it will. Don't make a mamster. It can make cells. Yeah, it's called a...

Wait. Humpster? H-U-M-S-T-E-R? No, don't make a humster. So they make like little zygote, hamster-human hybrids. And that's more ethical? I thought it was non-viable? It's not viable, but it can like become a zygote, from my understanding.

But it's non-viable. Of course. And like they've never tried implanting it into a human or a hamster. Like they don't want to go there. But wait. But what if they did? What happens? I don't think it would work. They think that the hamster genome and the human genome are too incompatible.

Like that's why it's a hamster test, not a chimpanzee test. Because that's like way scarier. Well also there's a lot more hamster eggs around than chimpanzee eggs. We could have been doing this the whole time. We could have animal people. No, we can't have animal people. Sorry. We just shouldn't. Sorry. Did I miss this?

So hamster eggs are similar to human eggs? Yes. They're not more similar than like mouse eggs? So the test involves, it's called the hamster zona free ovum test. So they modify the hamster eggs to make the test possible. So they modify the hamster eggs to make the test possible. it's called the hamster zona free ovum test. So they modify the hamster eggs to make the test possible.

The zona pellucida is the outer membrane on eggs. And usually that's necessary to initiate the sperm fusing with the egg reaction. Like that's where the antigens bind, some sort of chemical reaction goes, and then it like gives the sperm permission. I don't know, I hate using language like that when describing biology, but essentially that to merge and bind to the cell membrane and fuse. And so these hamster eggs have the zona pellucida removed. So it doesn't have this

outer protective layer on the egg. So it is easier for the sperm to penetrate the egg. A lot of the chemical barriers are gone, but it's still a test of whether the sperm can actually get into an egg cell, which is oftentimes a very hard part of fertilization. I got to give a Hank Buck for Humpsters. Who knew? But like, Sarah's already got two Hank Bucks. I know. Give me the Hank Bucks!

That's how it goes, the rich get richer. Yeah. The poor get the picture. That's me. It would be like that car commercial with the dancing hamsters. Remember that one? The big hamstermen. And they're like, remember that?

No. For the box-shaped cars. Pre-Sions. Sions? Oh yeah, no, yeah that? For the box shaped cars, pre-Sions. Oh yeah, that was the thing. And they pulls up and the hamsters and their track jackets jump out and they do a dance. Well now I have to give Sam a Hank Buck just so we'll have one to spend on that. Terrible tangent. Terrible.

These are the things I learned instead of science. Instead of... Somebody's got to watch the hamster commercials. And now it's time to ask the science couch, where we ask listener questions to our science couch, Finely Honed Scientific Minds. Me and Sari over here, hopefully Sari can back me up because my Finely Honed Scientific Mind has been dulled on corndogs. At Valerie2776 asks,

are there any eggs not shaped like eggs? So we talked about shark eggs being like the little mermits pouches, but also the weird screw shaped ones. So those are definitely not egg shaped at all. So wait, I have a quick question. Yeah. Do sharks have their babies live inside of them?

Some of them. And then put them in a thing or just some of them give life? Some of them give life. Yeah, they put the embryos straight into the pouches. And sometimes the pouches just stay inside. The pouch is always involved. So like whale sharks, they have the egg cases.

They have the mermaid's purses inside them, but they just hatch inside them. And so they still have big old egg cases made of this collagen tough fiber. But is it more like an evolutionary holdover? I think so, yeah. Interesting. And so like whale sharks have the biggest eggs

of any organism, but we don't always consider them eggs because they're on the only thing inside. Yeah, they don't lay them. Yeah, which is like a very weird thing. Our definition of egg is where it is, not only what. Mollusks have weird egg shapes too. Oh yeah?

Yeah, so gastropods fall under mollusks, but even I think clams and oysters and things like that lay eggs. Yes, they do. Yeah, so if you look up WELC, W-H-E-L-K egg case, it's also called a mermaid's necklace, which I thought was really like beautiful to go along with the mermaid pouch.

All the accessories for the mermaid. So they are like a snail, a sea snail. Welks are? Welks are. And aren't they like conch shell looking things? Yeah, they're like what lives inside conch shells. And their egg pouches are like these long stringy like accordion shaped things which are very weird.

Yeah, super weird. Yeah, so there are all these different like packages for eggs or packages for embryos that organisms can have. But the eggs themselves are just little spheres. I think so. I think so. Yeah. And this is like almost all marine organisms

and things that make a bunch of eggs do have those little individual spheres because it's the easiest shape to make. Yeah. You know, if you're going to fill a package with liquid, the natural shape it will take is a sphere. I think that's probably why they're that shape. Probably, yeah.

Just physics. So why are eggs egg-shaped? Like a chicken egg, bird eggs, because bird eggs tend to mostly be egg-shaped. Bird eggs mostly tend to be egg-shaped, and we thought that there were, they had a lot of theories for it. Like, you won't want your egg to be completely round, otherwise it might roll off a cliff, or they need to fit together in the nest

in a nice way to cluster and stay warm, and like all fit under a chicken butt. But according to a 2017 study, it's more complicated than that. Ooh, this is new information. Yeah. New information. Fresh info.

That fresh research. They looked at nearly 50,000 eggs of 1,400 bird species. So it's a pretty comprehensive study and correlated bird egg size and shape with what they eat, where they make their nests, how big they are and how good they are at flying. And that last one seems like a weird wild card thing, but it ended up being the most important factor

because the way the egg fits in the oviduct determines the egg shaped. And that is just based on how streamlined their body is. So if they're more aerodynamically shaped, then their eggs end up being like pointier. Yeah. Okay, we have our Hank Buck winner for the day. It's not Stefan with zero.

It's not Sam with zero. It's not me with one. It's Sari with two. Unless there's some tangent you went on that I didn't notice. I don't think so. I don't think so. I think you were very good.

I was so focused on real egg facts. I didn't have any. There's too many good real egg facts. Yeah, that's the problem. If you like this show and you want to help us out, there's a bunch of easy ways to do that. First, you can leave us a review on iTunes. We're just trying to make this thing,

just getting started. The more support we can get. It's a little egg. It's a little egg. You gotta sit on it, everybody. Warm it up. Second, we would love it if you Tweet out your favorite moment from this episode.

Thank you to Emily Cody, a cyber organizer, Quail Edwards, and everyone else who tweeted your questions to us. And finally, if you want to show your love for Tangents, you could just tell people about our show. All the people who you think might think, wow, that was fun and I learned things. Those guys seem pretty nice and cool. Thank you for joining us. I have been Hank Green. I've been Stefan Chin. I've been Sam Schultz.

I've been Sari Reilly. SciShow Tangents is a co-production with WNYC Studios. Our art and music are by Hiroko Matsushima and Joseph Tuna-Medish. Our social media organizer is Victoria Bon giorno. And we couldn't make any of this stuff without our patrons on Patreon. And remember, the mind is not a vessel to be filled, but a fire to be ignited. But one more thing. Female snakes can store sperm in their butts until they're ready to have their eggs fertilized

by it and it can be there for months. BLEUGH! Hello and welcome to SciShow Tansience, the lightly competitive knowledge showcase starring some of the geniuses that make the YouTube series SciShow happen. When the Hank's away, the Sam will play edition. Whoa. Part two. I'm Sam, the host this week, because Hank is gone. And this week, as always, we're joined by Stefan Chen.

How's it going? Stefan, what's your favorite dessert? Right now, I'm really crushing on alternative ice creams. Oh, like coconut. So like, yeah, coconut or the almond milk. Coconut is good. Yeah. We're also joined by Sari Riley.

Yep. I'm here. How are you? Tired. You have a sleeping cap on. Yeah, I'm here. How are you? Tired. You have a sleeping cap on. Yeah, I'm always tired. I got a blanket. I do have my office snuggie. It has like a pouch.

Oh, it has a pocket in it. Wait, do you have arms? I do have arms and my snuggie has arms also. Are you typing with that thing? Is that what's going on there? Yeah, when I'm really cold. Yeah, during the winter time is when the garage that I work in, and these working conditions, too cold. Yeah, during the wintertime is when the garage that I work in and these working conditions too cold.

It's a finished garage. Yeah, it is. It looks like a fleece lined wizard's robe. Thank you. Yeah, that's grand. I have never described myself as grand while wearing this, but thank you. You should.

I don't think you look that grand. What's your favorite dessert? I really like like fudgy cakes. I don't know what they're called. Like lava cakes? Lava cakes. The ones that are volcanoes but with chocolate inside. With the stuff inside of them?

Yeah. Those are pretty good. Also, this week again, we're joined by Deboki Chakravarti, SciShow Tangents editorial assistant and the host of the upcoming Crash Course Organic Chemistry. Hello, Deboki. Hello. How are you? I'm good I'm really stressed out about picking a favorite dessert though. You had a lot of time I know but they're all so good and I don't want to offend any of them It's like I love all desserts except like chocolate raspberry things. Oh my god. Well, you don't what I for some reason

That is like the one thing I don't like that's the best chocolate berry combination. Oh, yeah I can't do like other chocolate berries chocolate strawberries. I can do that. Like that is really good actually I just like I can do it I will consume it but I guess I've been on a real donut kick lately. So I'm gonna go with that I feel like donuts don't even count as dessert don't They're like a breakfast. It's true every week on SciShow tangents We get together and try to one-up a maze and delight each other with science facts.

We're playing for glory, but we're also playing for sandbox. And we're keeping score. I'm in last place. I might even be in last place compared to Deboki. That's how few points I have. We do everything we can to stay on topic, but judging by previous conversations, we will not be good at that because we might talk about donuts. So if the rest of the team deems a tangent unworthy, you'll be forced to give up a sand

buck. Now, as always, we introduce this week's topic, which I already hinted at a little bit, with the traditional science poem this week by Stephen Chin. I put sugar in my coffee, and I put honey in my tea. If you add a little heat, you could probably caramelize my teeth. Candy doughs for breakfast? Sure, that seems fair. What do we have for dinner?

Well, a frosted treat I have prepared. But I know, I know, too much is not good for me. Lactose, fructose, or glucose? Pick your enemy. You've made it very clear I shouldn't eat sugar every moment when I'm waking. So I'll try my best to reduce it even when I'm baking. But a gram or two here, a sprinkling there, try not to get too irate, about the ways that people consume their carbohydrates.

Either way, the discussion around sugar can sometimes get pretty thorny, but I say an unsweetened life like high fructose syrup is pretty corny. Oh wow, Stefan, I want to watch you write a poem someday. Just like see inside your brain. See the whole process. Yeah. When you make a really bad rhyme, how happy you are about it.

I'm just giggling to myself. Or how you imagine things like candy teeth. That's disgusting and horrifying. I don't think you realize how horrifying it is and some of the things you say are. You're like the Shakespeare cause you invent new concepts that blow our minds. But instead of like inspiring us, you disgust us.

Yeah. You're like extreme Shakespeare. I'll take it. Edgy Shakespeare. Some kind of Mountain Dew Shakespeare. So this week's topic is sugar. Sarah and Deboki, what is sugar? Well, Stefan said a very key word in his poem, carbohydrates,

which are sugars. And so they're one of the main groups of biomolecules. So carbohydrates are things with carbon, hydrogen, and oxygen, usually in a one to two to one ratio. So like C6H12O6 is a glucose molecule. Glucose is one of the simplest ones. Fructose is a different form of a simple sugar, but then you can get more complicated.

So like sucrose is table sugar, and that's a glucose and a fructose molecule bonded together. We have glycogen, which is a polysaccharide that's in our bodies for energy storage, and then in plants there's cellulose and starch. And one of those is fiber, I think cellulose, that's indigestible for us. So it just like clears out our intestines and starch is like, when you say a food is starchy, that's because it has starch polysaccharides in it.

And are all of those sweet or some of them are not sweet? Sweetness is about kind of like how our taste receptors and our tongue respond to it. So I'm guessing it would vary a lot, like depending on the kind of sugar it is, the extent to which we're going to think of it as sweet is going to depend on how it binds to those receptors. So I think there are animals that will process some sugars as sweet, but they won't taste other sugars the same way. But usually the simpler sugars are the ones that we think of as activating our taste buds

to cause sweetness. So like if you add high fructose corn syrup to something that is a sweetener. You know, I did not know that sugars and carbohydrates are the same thing. So thanks. That's what's cool about chemistry. All of these things boil down to very simple structures that somehow repeat into very weird things that are different from each other. So like there's complex carbohydrates and not ones of those.

And I feel like one of them is worse for you than the other one is what science says. Science says a lot of things about this stuff. People have a lot of opinions about sugar because it's something that is necessary for our body. So like we need glucose and to metabolize glucose in order to make energy to do anything. But because sugar tastes good, we've started adding it to food because it tastes good.

And now people have all kinds of opinions about what that is doing to our bodies, but there's not a lot of scientifically backed conclusions. And even some of the conclusions that we have are funded by like big sugar industry or big fats industry. So for example, at some point in the rel- like the last few decades there were a bunch of studies funded by sugar companies that found that fat was nutritionally worse for us than sugar. But like they were being funded by sugar companies. So the scientists were more inclined to draw conclusions that were in that person, like in the sugar company's favor.

And I think a lot of nutrition science is fairly fraught like that. So to boil it back. So sugar and fat are feuding with each other basically. Yeah, for like which one's less healthy. Because everyone wants their own product to sell. And as far as like complex sugars versus simple sugars, there's something to be said about if your body needs to expend more energy to digest something. So like if you are eating pasta, or if you're eating an apple where there's a lot of other

things besides sugar in there, and the sugar molecules are bound up or like they're longer chains as opposed to just like individual monomers which are like one molecule chunks like glucose then it's like slightly healthier for you because your body has to put in the effort to break it down as opposed to like eating a spoonful of table sugar that's gonna get into your bloodstream faster and cause a sugar spike and then like a decrease which is what people are like oh that's bad get into your bloodstream faster and cause a sugar spike and then like a decrease, which is what people are like, ah, that's bad if you have a sugar rush and then a crash.

Okay. But it's more complicated than like sugar bad because if we cut out all sugar from everything or all carbohydrates from everything, we would die. What is the etymology of sugar? Sucre. Is that part of it? Sucre. Yeah. That's from old, that's the old French. Sucre, which comes from medieval Latin sucarum

and from Arabic sucre, which Hall seems to like trace back to sugar, but also like grit or gravel. And then glucose is from Greek, basically pronounced the same, but spelt a little differently. That means sweet wine. Where the wine part come from? This etymology page says, it first was obtained from grape sugar. So maybe they had a lot of grapes and then were like, this is the only sweet thing I've ever tasted in my whole life. All right. Well, I think we have a pretty in-depth view of sugar.

More than usual. There's so much more than I could have imagined. We don't usually know anything about anything, but this time we did. So now it's time for TIGER FAIR. Where one of our panelists has prepared three science facts for your education and enjoyment, but only one of those facts is real. The other two are big fat lies, and you guys have to figure out which one it is. If you do, you get a Sand Buck.

If you don't, I get a Sand Buck because this time I am lying to you. So here are my facts. One thing that humans and bees have in common is that we both love a sweet treat. Bees spend their lives in search of nectar, just like we spend our lives in search of Oreo cookies and gummy worms. And just like competing candy in the candy bar aisle, flowers have different ways of advertising themselves to make sure bees pick them. Which of these flower nectar facts is true? Number one, some flowers have light-sensing organs that can detect the shadows of a nearby

hovering bee trying to pick out a snack. The flower then increases the amount of sugar in its nectar to try to woo the bee. Number two, some flowers' nectar contains nicotine, and when bees drink this nectar, they become basically brand loyal, remembering and seeking out that flower at a higher rate than bees usually do that kind of thing. Or number three, in big cities, flowers face stiff competition, as city-dwelling bees have been found to go for soda and other processed sugars over flower nectar. So, licensing organs, extra sugar, nicotine brand loyalty addiction basically, or big city bees love

Sotypop. I love the idea of like big tobacco flowers, big super nefarious. So the nicotine one seems just reasonable because I feel like I have a vague recollection of bees also being addicted to things, like experiencing addiction in similar behavioral ways. Behavioral. The shadow one, I don't know, plants have a lot of receptors that I don't know about. There's so many things that causes shadows, like if it was a cloudy day. Oh.

How do they know it's a bee? No, this is a good point. Can you have a bee shaped receptor? Well, like what you maybe do if you're a flower and you're really dedicated to this approach is like you have like a spot selection receptor, like it has to like discern between shadows just like in a small area versus like the whole flower.

Flowers don't have a lot else to think about either. That's true. and shadows just like in a small area versus like the whole flower. But... Flowers don't have a lot else to think about either. That's true. They just think about it to find bees all day. And then the soda one, I feel like wasps I've seen drink soda. I don't know. They just start... Oh no. What?

Well, I had an image of like at a picnic, I see soda cans left out and like bees coming to them. But I think it might just be wasps that I've seen. I want to say nicotine because that seems like a plant thing anyway. Oh, to Bokeh, you go. Oh, no. They all seem like they could be so true. Well, no, I think I think the shadow one seems like BS. B.S. I feel like I could see the big cities thing being a real thing.

You know what? I'm going with nicotine. I have a feeling. The answer was the nicotine one. I was so scared. So the nicotine one. Lots of plants make nicotine as a way to stop leaf eating creatures from eating them because it's toxic, I guess, in a high enough dosage.

And plants that make nicotine, like tomato plants, like tons of plants that aren't just tobacco plants, have small amounts of nicotine in their nectar and pollen. So in 2017, some scientists were like, hey, wouldn't that be bad for the bee? Or like, make the bee not want to go to that plant. So they did what scientists do, and they made a bunch of fake flowers that had four varying

levels of nicotine from no nicotine to a bunch of nicotine and they let bumblebees go at the flowers. The flowers all had different designs too corresponding to how much nicotine they had. They let the bumblebees go to the flowers and then the next time they let the bumblebees go to the flowers, they went to the flowers that had a little tiny bit of nicotine over any other type of flower, and they were repelled by the flowers that had a ton of nicotine. So then they switched the flower designs around and they put the bumblebees back out, and the bumblebees still went to the design that had previously had the palatable amount of nicotine,

even if it had too much nicotine in it now. So basically it just showed that they have like brand loyalty. Like they will go to that flower that has a little bit of nicotine over any type of flower, even if the other flowers in the area have a better like nutritional value than the nicotine flower. I guess they get addicted. It didn't say that one way or the other. I don't know what it is. They just get like a little buzz from it maybe, because they're bees. They like the what it is. They just get like a little buzz from it. Maybe because they're bees Yeah, it feels yeah, we mostly smoke tobacco as far as like cigarettes Mm-hmm. Is it just that like other plants don't have enough nicotine to make them super smokable?

You want to smoke a tomato? Yeah so my uninformed guess is that the only thing we Cultivate tobacco for is nicotine, whereas other nightshade plants are either poisonous to us. So I think that, like, belladonna, which is the stuff that was used to dilate your eyes, and it still is used to dilate your eyes. For fashion.

Yeah, for fashion or as eye doctors. So they're either deadly or we grow them for food, like potatoes or tomatoes or, or eggplants. And so tobacco seems like one that's just like, it's just a leaf and probably has a certain concentration of nicotine that we realized you could smoke. And maybe through human intervention have made it even more so.

Possibly, yeah, like selective breeding or, yeah. So it's not impossible, Stefan. Keep the dream alive. So the flowers with light-sensing organs. A 2018 study of evening primrose flowers found that they can use their bowl-shaped petals to pick up the specific vibrations of pollinating insects' wing beats. Oh, cool. That does make sense as like a more specific detector. Yeah.

When they detect that sound, they increase the amount of sugar in their nectar by up to 20%. Scientists think that this happens because nectar is costly to make for a flower. So if they're only making it when they know that an insect is around or like they're only making that certain quality of nectar, when they know that they can attract a pollinating insect, then that's just better for them. They can survive longer. They have more resources to go around for other processes they need to do.

How do the plants detect the sound? I think it's, so they're pretty sure it's from the petals because they pulled petals off of other, of the same flower and they weren't making more nectar when they, so they would shoot the bee sound at the flower and they think it vibrates the petals in the right way to make them be like, aha, bees are around. And city bees, in 2016, a study in Raleigh, North Carolina found that, kind of to researchers' surprise, local bees did not have more processed sugar in their diet

than the Humble Country bees. They tested for carbon-13, which I guess is present in sugar cane, and in specific bees and they didn't find any more of it than they find in any other kind of bee, which was surprising because there's lots of like soda pop and candy all over cities. They don't know if this would hold up for even bigger cities in Raleigh, North Carolina, because Raleigh has 50% green space compared to like New York City, which only has 10% green space. But it seems like they don't like our human sugars.

Good job, bees. Yeah, good job. It's a very healthy choice that you're making. All right, next up, we are going to take a short break and then we'll be back for the fact off. We're back from our short break now. Let's go over the scores, shall we? Stefan, you have two points putting you in the lead. Ceri and me each have one point, and Davoki unfortunately.

Not so great. You don't have any points in your last place. But you have a chance to get some points now, because it's time for the fact-off, where two panelists bring science facts to present to the others in an attempt to blow their minds. The presentees, which is me and Stefan, each have a Hankbuck. Oh my god. Why would I say that of all people? Each have a Sand Buck to award

to the fact that they like the most, but if both facts are terrible, we won't give anybody any points. So they better be good. The two people who are presenting? Sarie and Deboki, the battle of the big brains. And to decide who goes first, Stefan has a trivia question for you. The United States claims the glory of the highest average for sugar consumption per capita. How many grams of sugar does highest average for sugar consumption per capita. How many grams of sugar does the average US resident eat per day? Okay, so this is a bad question for me because I just eat food without looking at nutrition labels.

And I eat like a bag of candy sometimes. And I have no concept of what a gram is. So 150? is that smaller? I don't know. We can't tell you yet. I know you can't tell me. 150 is my guess. I'll go double, Sari. I'll go 300 grams.

Wow. The answer is 126.4. Sari somehow got extremely close. Wild. I was like thinking of a bag of Sour Patch Kids. Like that's probably like my daily intake of sugar. So apparently in a small pack of Sour Patch Kids, like a fun size pack, like very fun. Oh very small. Yeah. There is 19 grams of sugar. Oh that's not bad at all. You can eat like 10 of those. We did so many.

I want to go first, I think, because it's related to the truth or fail. So I think it'll be a nice transition. So honey bees aren't the only insects that store sweet, sugary goo for later. There are stingless bees that make honey, honey wasps, and even these insects called honey pot ants. And in a few different species across the

Americas one of them is myrmecocytus mexicanus but also there are species in Africa and Australia they have a food storage system to help them through times when there isn't as much water or flowers blooming or other things like that and they still need sugar to give them energy. The way they do it is certain worker ants so like is a class of ants, not soldiers or drones or the queen, become what are called repletes who hang from a ceiling and act as sugary food storage orbs.

And this is because of an anatomical adaptation of their butts. Their abdomen is made of stiff plates called sclerites that are connected by a squishy membrane called the arthrodial membrane. So like a balloon, as more nectar and stuff goes inside them, their butt can inflate. So the plates go really small and far apart and it's mostly membrane, but it can also deflate and look like a normal ant butt. So they're hanging from the ceiling and when another worker brushes their antenna, they're like a vending machine and they just like barf up one serving of food.

I was like, are they butt suckers? No. So they brush their antennas and they're like, food please. And then they barf up one serving size of food that either that ant eats or carries away to someone else that needs it. So this is their sugar storage system. And here's a picture of them. They can get as big as small grapes. Why do they have to hang off the ceiling? To get out of the way for other people.

I love that they're called repletes. It makes it sound so sci-fi. If we had the sci-fi version of this world, and there was an organism that did that for us, we would call them repletes. Yeah. So it's mostly just an adaptation for them to store, they don't have honeycombs to store honey or anything.

This is just like, they use their fellow ants as nectar storage. I want to study the brains of this class of ants to see if they're happy. That's a good point. Ant worker satisfaction is really important. Yeah, can we send out a survey? It seems like it could either be like a living the dream

or a living nightmare. Yeah. No in between though. Can they eat from their own butt sacks? I assume so. So like that's how they don't die because they're not dead. They have to stay alive so that they can be a vending machine. They can just sit there.

They don't even have TVs to watch while they're hanging off the ceiling. You got to just think thoughts. Oh weird. And then be ready for someone to brush your antenna and be like, I have time to barf again. Maybe we're all just ants hanging on the ceiling. You ever think about that? No. All right.

Beautiful fact. Thank you. Equal parts horrifying and beautiful. Like all the best facts are. Deboki? Okay. Well, this fact will take a turn. The Port Wentworth Sugar Plant was built in Georgia in 1917 and was eventually bought

by the Imperial Sugar Company. The plant operated for around 80 years without any problems until February 7th, 2008, when the refinery was suddenly torn apart by an explosion. Refineries have lots of heavy machinery, so you might think, okay, some of this machinery, something went super wrong, and that's what caused the explosion. But it was actually the sugar. More specifically, the sugar dust that was released by the machinery during a lot of this refinery process.

So sugar is flammable, so if you've held a marshmallow over a fire too long, I've done that and suddenly you're like, oh, my marshmallow is on fire. It's organic, it burns, but when we're cooking, we're not really too afraid of things exploding when we're dealing with sugar. But in the Imperial Sugar Refinery, the equipment they were using was basically dispersing like a lot of sugar dust everywhere. So according to a report carried out by NASA after the explosion, there were several inches to several feet of sugar dust on light fixtures and beams. But the real problem was the sugar dust that

was floating around in the air. Once one of those ignites, because it's floating around, it has access to all of this oxygen around it. So that oxygen will fuel the flame, plus there are other sugar dust particles that are floating around in the air. So there's this whole chain reaction where one sugar dust ignites, it then sets off another particle and another particle, and it just keeps building and building. And so especially if you're not in a well-ventilated area, like as those things are igniting, the air in the room expands and like if it happens fast enough, you get an explosion. So this is actually called a dust explosion and

it's not restricted to sugar. It can happen like with wood and other sources of particles. It's really just like things that can ignite and that are like accumulating too much in an unventilated room. But that's just the primary explosion, which is like called the primary explosion because when it explodes it will basically disperse other particles in other areas, which can then keep that chain going. So you'll actually get secondary explosions that can be even more powerful than that primary explosion. In the case of the sugar refinery,

they're not actually quite sure what, like, set off that initial ignition, but they think it was most likely the hot surface of an overheated ball bearing that just, like, interacted with a piece of sugar and that just, like just got them going. And this was considered one of the worst dust explosions in decades. And the worst part is that investigations showed that it was preventable.

The sugar industry had known about the risks of this since the 1920s, and it was really just that they weren't cleaning things and they weren't taking the safety issues seriously. Again, the rest of us, we don't really need to be worried about sugar dust explosions in our homes. The particles have to be pretty large, apparently like four times larger than a grain of table salt. And like from what I've read, the dust layer has to be like about one thirty second of an inch, which is actually like when you're dealing with sugar is

pretty thick and the room has to be unventilated. So this was like mostly a lesson to people in the industry and to NASA, which is also worried about in close paces. When did this happen? In 2008. Oh. Yeah. Yeah, the whole time I was like, this is an old timey factory story.

They just didn't know any better. No, this was recent. Is it common that NASA looks into like explosions like that? Or do they investigate weird explosions? Is that kind of their... I was surprised to find this report and like my sense from reading their conclusions that they mostly want to like apply what they learn to like their own kind of enclosed system sort of things.

To life and space capsules and stuff. Yeah and it seems like this explosion was like a really big event. Like it was like really big in like the industrial world of like just what what are we doing in terms of safety? Did people die? Yes. Yeah, unfortunately, there were like 14 14 people died and a lot of injuries So there was a lot of anger obviously over the explosion Was there a certain level of cleanliness like the factory was supposed to be that it wasn't? Yes Yeah

So like they basically were when they when they did the investigation after they were just like yep They did not like do any of the safety protocols. They weren't cleaning things. Like again, like several feet of sugar dust, like that's a lot. And like they had just been doing like some modifications, I think, on one of the areas which it like enclosed it even further. And so like that's even worse because you're making the volume smaller. You're packing all of that in.

Like it can just burn and expand so quickly. It's interesting too because I think sugar is especially one of those things, like we were talking about with the definition section, like we don't really understand what a carbohydrate is and we don't really understand what a sugar is and we can say that it turns into energy in our body, but this is a very clear example of how like no it is fuel it is energy Just packaged in a different way and then when it's released. Okay, Stefan. Are you ready? I think so I'll count then up to three one two three go either way up Well, no one two three Nice split well very good facts

Excellent facts, in fact, I would say. And now it's time for Ask the Science Couch, where we will ask a question from one of our listeners to our couch of finely honed scientific minds. At Kimabo Peep wants to know, does sugar cause changes in behavior? I feel like that is what you, when you're a kid, you're watching all kinds of cartoons where people are eating sugar and bouncing off the walls. I've never even thought that it wouldn't be the case that that is what happens. So is it? It seems like it is mostly a myth. Okay. So I want to preface this whole section with the fact that like we are not doctors here.

The nutrition field is very fraught with a lot of different opinions and hyperactivity is something that apparently a lot of people have debated about for a long time. But it seems like the idea came from something called the Fine Gold Hypothesis. There was a doctor in like the 1970s, I think, who suggested that a diet with artificial food coloring, preservatives, and sugars would make kids hyperactive. And this is before we really understood ADHD really well. And so they were specifically talking hyperactive and ADHD symptoms. And so cutting out those things would reduce hyperactivity. But according to a meta-analysis from 1983 and further research up until the present day,

foods high in refined sugar don't increase hyperactivity by any measurable amount. Kids' bodies regulate those sugars properly, and if anything, you get a short energy boost from it, but it shouldn't affect behavior to the intensity that these claims are making. And some doctors think that it has to do with the social aspect of it. So like times when kids are generally more hyperactive or like a birthday party or Halloween when it's otherwise like an exciting thing. And so your kid is probably just excited because they're excited, not because they're eating a bunch of cake.

Yeah. Yeah. Wow, you're blowing the lid off everything. Yeah. But there are still some people that are like, it does seem like for my child especially, it is associated with hyperactivity and I don't wanna like invalidate those things. I would like people to think more critically

about why they're drawing those conclusions, but I'm not telling anyone how to raise their kids on SciShow Tandis. Good, I was just gonna feed my future children lots of sugar. I know. Also, anecdotally, I ate so much sugar all the time and I was fine. I was like a fine kid. Yeah, you have a fairly sleepy demeanor.

Yeah, I do. You talk about being sleepy all the time. People mention addiction to sugar, which is like an inherently behavioral trait. So addiction in psychology is both like neurochemistry and behavioral changes. So if you're addicted to like hard drugs or something or alcohol, then that usually involves a physical dependence on that and changes in behavior. So you like recede from your social life in order to like use this substance. And so by those definitions, sugar isn't really addictive.

And so people say sugar is addictive because it lights up the reward pathways in your brain, but a lot of things do that. And not all of those things are addictive. Largely, it doesn't seem like people are willing to put themselves in pain or in physical harm or recede from their social groups to get more sugar. So it doesn't match the addictive quality of other addictive substances.

But it's like a catchy headline to say like Oreos are addictive. Yeah. This has been the most informative episode of SciShow. In like a long time. And then this is the thing that blew my mind, so I saved it for the end. But there is potentially a positive effect of sugar on behavior for old people. Where there's originals. That's why they're housing those things down all the time.

Where there have been a couple studies from the Food and Agriculture Organization of the United Nations and the World Health Organization that have shown that a glucose or fructose supplement seems to improve memory for older people because like their glucose levels is depleted. And so if like they got a little boost before a memory exercise or something, then they like performed cognitively better. And so a little sugar for an old person as a treat

might be okay. Yeah. Just can we like define the old person as like 30? Yeah. And then like I'm just like. Well, here we are. What is the old person as like 30? And then like I'm just like... Yeah. Well, here we are. What is the age range of that actually?

It just says elderly human subjects. And I didn't trace back the study to find, I think it was behind enough paywalls, so I didn't find how elderly is elderly. But I think like qualitatively your memory starts to deteriorate from old age because that like naturally happens as a part of us growing older. Right. It's already happening. Yeah, definitely.

Yeah, so they need a little sugar. We're not eating enough candy, Stefan. We gotta step it up. Eat like two Sour Patch Kids packs. Yeah. And you're good. They don't remember everything that ever happened to you in your entire life. Oh no!

Oh, I better avoid it. Shoot. If you want to ask the Science Couch your question, follow us on Twitter at SciShowTangents where we'll tweet upcoming topics out for you to ask us about. Thank you to at PetunaF, at Dana001, and everybody else who tweeted us your questions for this and every episode. Final, Sandbuck scores. Duboki and me tied for last place with one point.

Sari and Stefan tied for first place with one point. Sari and Stefan tied for first place with two points. So my two episode score is three then, right? I believe so, that's great. You can buy some stuff in the Sandbook store. Little eraser, little bendy dinosaur. Tits rolls. All the props on the shelf behind us. Deboki, it's the end of our time with you for now.

Thank you so much for being here and for being smart in Hank's stead. Thank you for having me. It was a lot of fun. Where can people find more of you? So you can find me on Twitter at okidoki underscore Boki, but I will be hosting Crash Course Organic Chemistry, which will be starting mid April approximately.

And you can also see more of my work at Journey to the Microcosmos, which I do writing for. And it is awesome. Highly recommended. For all of these things. And you're one of the forces behind this show. Yes. So you touch every episode.

Your ghost is always with us. If you like this show and you wanna help us out, it's really easy to do that. First, leave us a review wherever you listen. It's very helpful and it helps us know what you think about the show, what we can improve, what we should keep doing. And we'll be looking at iTunes reviews

for topic ideas for future episodes. Second, tweet out your favorite moment of the episode. And finally, if you want to show your love for SciShow Tangents to book, are you ready for this? Just tell people about us. Great job. Oops. Close enough.

And if you want to listen to SciShow Tangents ad free, you can do that on Luminary. Thank you for joining us for SciShow Tangents ad free, you can do that on Luminary. Thank you for joining us. For SciShow Tangents, I have been Sam Schultz. I've been Stefan Schin. I've been Sari Reilly. I'm Deboki Chakrabarti. SciShow Tangents is a co-production of Complexly and the wonderful team at WNYC Studios.

It's created by all of us and produced by Caitlin Hofmeister and me, 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 Bon giorno. 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. Rectal prolapse is where your rectum sort of slides out of your body due to muscle strain or weakness.

And one non-surgical way to reduce rectal prolapse is apparently sprinkling granulated sugar, aka sucrose, on the prolapse for like 15 minutes to absorb extra water and make it shrink. Where do you learn these things? Who discovered this? I know. Also that.

I think they figured out first that sugar was a desiccant and then someone was like, try sprinkling it on your prolapsed rectum. They're all just standing around looking at a prolapsed rectum, throwing out ideas. What kind of desiccants do we have? They're pouring all kinds of spices and sugars and stuff on it. See what works. Seasoning it like a little turkey. Yeah.

Oh, god. Hello and welcome to SciShow Tangents, the lightly competitive knowledge showcase starring some of the geniuses that make the YouTube series SciShow happen. This week, as always, I'm joined by Stefan Chin. What's up? I don't know. I gotta be totally honest with you. I started off really strong there, but that's as much as I got. I started out at a 10 and I have nowhere else to go to.

Stefan, what sport did you play in high school? Oh, well, I played the bench for a football team. Oh, yeah. All right. Stefan, what's your tagline? Uh, hop, hoppin' away. I love it. Sam Schultz is also here as well. What's your favorite Cheech and Chong movie?

I've never seen any of them, so I don't know. I was just thinking about Chong last night. I don't know why. They both seem like pretty nice guys to me. What's your tagline? It's too nice outside to be podcasting. Sorry about that. We should all be doing it outside. Sari Riley, how are you doing? I'm okay. Also wishing I was outside and not in a blanket fort full of bugs. I want outside

bugs. Sari, do you have a favorite pair of pants? Yes, I have these pair of black sweatpants that have, I don't know, elastic around the ankles and have really, really deep pockets and they have a hole in the side or they're starting to get a hole in the side and I need to mend it

because I can never let these big comfy sweatpants go. I think elastic around the ankles is the number one key thing for a good pair of sweatpants. I don't like a floppy bottom on my sweatpants. Yeah, I wanna like hike them up because I need to do something with my feet. I don't know, like walk into the ocean. What?

Than I can. Sari, what's your tagline? Fortified. Nice, and I'm Hank Green and my tagline is Princess Leia's magical mystery mansion. Ooh, I'd go there. That sounds like a good idea. It sounds spooky to me. We could play board games or something. Oh God, I'd go there. Sounds like it. It sounds spooky to me.

You could play board games or something. Oh, God, that'd be fun. With Princess Leia. Every week here on SciShow Tangents, we get together to try to one up a maze and delight each other with science facts. We're playing for glory, but we're also keeping score and awarding

sandbox from week to week. Now we do everything we can to stay on topic, but judging by previous conversations, we won't be great at that. So if the team deems a tangent unworthy, we will force you to give up one of your sandbox. So tangent with care! Now, as always, we introduce this week's topic with a traditional science poem. This week from Stefan.

Combinations of things with pluses and minuses. Ionic assemblies for rinsing your sinuses. Used to make your food tasty or for food preservation. Used to energize some batteries and on the rims of tequila based libations. Salt helps keep things right in my cells. Not enough sodium and they'll start to swell. But a dash of strontium chloride will redden the flames. A pinch of sodium bisulfate is what this pool contains.

They're in the soils of Mars, but Mark still grew a potato. And you can use salt to make homemade Play-Doh. Clearing icy roads and maybe raising my blood pressure, anions and cations do so many things once they're together. Oh, yes. Wow. That was really good. That was a very Stefan Rhein scheme. I love it. You have no regard for syllables, and I love it. No, I don't follow those rules. So our topic for the day is salt

and you didn't just stick with table salt, which is what we generally call salt, but you were also talking about salts generally, which are just ionic compounds of which there are many, many, many. And some of them are, well, really just one of them is delicious. No, the lead one is super tasty.

That's why those- There's two that are delicious. Right. Oh yeah. Yeah. Sweet but deadly. Yeah, there are many, many salts. Sari, I guess I should let you tell me what salt is. I mean, you already kind of told me what salt is.

I kind of did it. I'm sorry. No, that's okay. You're a chemistry man, so you can do it. Sodium chloride is the one that we eat, so that's in table salt. It's also the one that we sprinkle on the roads, so it's rock salt as well. I think the most common one, so if you're like, I have salt, people are usually referring to sodium chloride.

It's what's in the ocean and makes the ocean the most salty, even though there are other ionic compounds in the ocean. Salt is important for the human body like Stefan mentioned. You need sodium ions for action potentials in nerve cells, so they help with the electrical impulses that let you move or feel things or send signals to your brain. And they help with osmotic regulation, which is the swelling of cells. Stefan basically covered it too in his poem. So the basics of salts are, ionic compounds are like ions are an atom, but they are charged.

And an ionic compound is when two charged atoms, so these ions have opposite charge and they stick together because of that. So they're basically in a normal molecule, you're sharing electrons. And an ionic compound, it's just like these two atoms, and you shouldn't even call them atoms because if they are charged, they aren't anymore, and they are ions. So these two ions have opposite charge and they stick together because of that.

They aren't even sharing electrons, they're just sort of like stuck together. And that's why when you put them in solution, they often can dissolve really easily because the two ions actually dissociate and they're sort of floating around in there separately. And then when you evaporate the water away, they jam back up together again. But you can't like suddenly take all the sodiums out and just leave the chlorines behind because they are sort of dependent on each other for their existence. You can do that, but it becomes a big problem. And just one little asterisk, ions can be polyatomic, so they can have more than one

atom in them, so like a sulfate ion, for example. All right, it's time now for TIDIOTFAKE! One of our panelists, it's Sam this week, has prepared three science facts for our education and enjoyment, but two of those facts are fake and only one of them is real. We have to figure out which is the true fact and if we do we get a Sand Buck. If not, Sam gets the Sand Buck. Sam, what are your facts? Alright, these are three accidents related to salt that highlight the folly of man's hubris. Ooh. Great.

Number one. An oil drilling operation in a lake in Louisiana Number 1 An oil drilling operation in a lake in Louisiana accidentally breached a salt mine beneath the lake, causing a massive whirlpool that swallowed the drilling equipment along with several boats, huge chunks of the shoreline, and basically the entire lake. 2 A research boat studying a newly discovered species of starfish living off the coast of Greenland hit a patch of sea ice, which released a bunch of super-cooled, super-salty brine water that was too cold

to freeze, but froze all the water around it as it sank, eventually settling on and freezing most of the starfish colony they were studying to death. Or number three, inspired by the concept of ice hotels, an entrepreneur in Bolivia built a hotel made of blocks of salt at Salar de Uyuni, the world's largest salt flat. Unfortunately, climate change has increased rainfall in the region dramatically, and by the end of 2017, the hotel had almost melted down to its foundation. Oh, okay.

We've got three facts here. One, an oil drilling operation in a lake in Louisiana accidentally breached an old salt mine beneath the lake, causing a massive whirlpool that swallowed the drilling equipment, along with several boats and a lot of the shoreline. Two, a research boat studying a new starfish hit a patch of... Wait, what did it do? It hit a patch of sea ice, which shook out a bunch of briny water.

Okay, that water was cold, but didn't freeze because it was so briny and it sank and all the water around it froze and that killed all the starfish. Yeah. That's very good. Or number three, just like ice hotels, an entrepreneur in Bolivia built a salt hotel.

Unfortunately, it got rained on a bunch and it had almost melted down by 2017. Boy, all those seem really, really real to me. Yeah. I feel like the Salt Hotel is a little bit too much hubris for me. Like, I don't know. Even, like, it rains everywhere, even in the desert.

Not in a salt flat. There's lots of like desert-y salt flats, yeah. And ice hotels exist as well. And so I could totally see someone building a salt hotel There's lots of like desert-y salt flats, yeah. And ice hotels exist as well. And so I can totally see someone building a salt hotel with the idea in mind that they'd have to patch it up every once in a while. Just not that they have it completely dissolved

because it's raining too much instead of just once in a blue moon. I know that this thing happens where they're, the way that they get salt out of the ground sometimes, I find this fascinating, is instead of digging it out, they will pump hot water down into the salty area and it will dissolve the salt that's underwater and they pump out the salty water

and then they evaporate it because it's like so super saline. And then, but what's left behind is this giant empty cavern. And I know that this happens in the Southern US and I know that if you puncture that salty cavern, like shit's going down, literally. And like, I know that that's a thing. I don't know if this specific thing is a thing.

And then we got this boat that killed all the starfish. And I don't know if this is possible, but like, it seems so cool that I want it to be, not that I want the starfish to die because they are apparently newly discovered rare species of starfish, but I want it to be real because it's so weird, and also the hubris of man.

Yeah, I've definitely heard of brine pools before, and I know that they are these super salty pools, essentially, at the bottom of the ocean, that if fish go into them they experience toxic shock because it's so radically different. So they definitely can kill organisms and especially if salty water just went on starfish, it's not like they can swim out of the way very quickly. All that to say it seems plausible. They all seem plausible. They all seem plausible. Alright, I'm gonna go for the starfish.

And I can't exactly explain why. It's real good. I wanna learn more about it. That one smells the fishiest to me. Oh, wow. So I'm gonna go with the salt hotel. Okay. I guess I'll split it out because I truly have no idea.

I will go with the lake hole. Okay, lake hole. Okay, lake hole. Okay, you ready for the answer? Sam's got a guaranteed two points. The right answer is the lake hole. No! I knew it was a thing! It was a different lake hole.

I thought for sure a southern boy like you would have known about this one. So in 1980 an oil rig was doing exploratory drilling in Lake Peinure in Louisiana, and it accidentally pierced the underground Crystal Diamond salt mine with a 14-inch drill. So water started pouring into the hole and dissolving the interior of the salt mine, which some of it was held up by pillars of salt basically that they had just carved out to keep the thing supported. So the mine collapsed and the hole got way bigger than 14 inches and a whirlpool formed at the surface of the lake that sucked in the entire drilling platform, 11 barges, a tugboat and tons of dirt from the shore of the lake.

And within like three hours, the whole lake had drained into the mine. And then a 400 foot geyser shot out of the hole because of the compressed air. And then the hole caught on fire because there was a natural gas leak, because there were natural gas lines under the lake too. Then the flow of a nearby canal reversed and water from the Gulf of Mexico started filling the lake bed and it made a 150 foot waterfall.

It was the tallest waterfall in Louisiana that's ever existed like in recorded history. So then it went from an 11 foot deep freshwater lake to a 1300 foot deep saltwater lake. And this whole thing, nobody died. It happened so slow that they evacuated everybody, but they just couldn't get all the boats out. So they had to get sucked down. And the oil company paid the salt mine $45 million. I don't think they paid anybody else any other stuff.

And that was that. Was the salt mine operating at million. I don't think they paid anybody else any other stuff. And that was that. Was the salt mine operating at that point? Yeah. Yeah. Wow. I think that was an abandoned part of the mine. Like that was an old part, but it was operational. Yeah.

So a whole lake. And no starfish died. So, well, okay. That's not entirely true. I'm going to send you a video in a second. Starfish are dying out there. Just not both. Constantly. Both start making a second. Starfish are dying out there. Just not both. Both start making it happen.

Every day a starfish dies. So brinicles are underwater icicles that are formed by brine water leaking out from sea ice. It just kind of naturally comes out of the ice. So the water sinks and it freezes the less salty water around it. And it forms a tube of ice that reaches from the sea ice down to the floor of the ocean. It can't go too far and it can't be too choppy of water, so they don't happen very often. But this video in particular shows it falling onto a colony of starfish and

freezing them. It really does. It just was not happening. And they do not survive. No. So the brinicle is made of salt? It's made of the super cold water falls down and freezes a tube of just the less salty ocean water around it. Ah, that's so cool. I'm sorry to all the starfish, but wow, that is awesome. I'm sure they don't always fall on starfish. And this video is ridiculously good. That's a fantastic video.

We'll put it up at sizeshowtangents.org. And then the Salar de Uyuni in Bolivia is the largest salt flat in the world. And it's home to, in fact, several salt hotels, but none of them have melted away due to rainfall. The first one was built in the exact middle of the salt flat, and it had to be abandoned after 10 years because they didn't have a way to get all the poop away from the hotel.

They forgot about that. So eventually there was 10 years worth of poop and they had to get out of there. Just dig a deeper hole, you're fine. All right, Sam, congratulations. Sari, congratulations to you as well. Well, next up, we're gonna take a short break and then the fact off. ["The Facts of the World"]

Welcome back, everybody. Sam Buck totals. Stefan and Ceri have one. Sam has two. And I'm coming in a zlast with zero. Absolutely nothing so far. But we'll see if I can get clawback some amount of credibility here in the Fact Off. Two panelists have brought science facts to present to the others in an attempt to blow their minds. You guys each have a sandbox to award to the fact that you like the most.

Or you could just throw it away, because that's not very nice. And to decide who goes first, I hear there is a trivia question. The open ocean has a salinity of 3.5%, or 35 grams per liter of water. What is the salinity of the Dead Sea? Ooh. I will say 7.9%. I'm gonna say 10.2%. Okay.

The answer is 33.7. Oh, wow. It's very salty. Holy moly. Oh, I had no idea. That is salty. Don't put that in your mouth. So, Sarie wins.

Oh, I guess I win. Sarie wins. What do you want to do with that information? You were slightly closer. I will go first. Okay. So, coconut water is that clear liquid inside of coconuts that's getting boxed up

for commercially using purposes now. And it seems like another health fad because people are making all sorts of health claims about it. And it does have sugars and vitamins and ions like sodium and potassium in it, which make it almost like a sports drink. But supposedly during World War II, when medical supplies were scarce, both British and Japanese soldiers used coconut water for an emergency treatment as a saline substitute that they would inject into their veins for rehydration.

So like an IV drip but of coconut water. And then just like hang a coconut from instead of a bag and have the water go straight into you. And there's one published study of one man who had it successfully used in an emergency on the Solomon Islands. And this is because when people get severely dehydrated or lose blood, doctors can use intravenous therapy to get fluid back in the body. It doesn't replace all the functions of plasma and the lost blood, but just having hydration is really important. And so IV therapy- And keep all those blood vessels filled up with stuff.

Yeah, filled up with stuff that's at a similar salinity to blood. So you still have the saltiness in there and you still have all the things in salts that help your cells function in addition to the fluid volume. And like we mentioned in the definition section, our cells need ions like sodium for basic chemical functions, like nerve firing. So in a pinch, these reports, mostly just anecdotal, say that coconut water can be used to replenish those compounds, rehydrate and survive. It's similar enough to blood that it won't cause a negative reaction.

And scientists who reflect on this nowadays, mostly just in interviews, say this is probably pretty dangerous because coconut water doesn't have the right balance of chemicals, unlike carefully made saline solutions. It doesn't have enough sodium and has too much calcium and potassium, which could throw off our cellular systems. So it's definitely not a replacement for plasma or blood if better things are available, but it may do in a pinch if you're in an emergency situation and need some IV drip. But there was a person recently who actually did this in the Solomon Islands, and why? I think it was someone who was on pretty normal medical treatment, like trying to be rehydrated,

maybe had gone through some surgeries, but the hospital that they were at ran out of saline solution. And so the doctors were like, well, we've been treating this patient for a while and we are waiting two days to get any saline solution delivered. What should we do? And then they were like, uh, coconut? And so there's a picture of a coconut as an IV in this paper.

All right, I guess that means that it's my turn, everybody. So if you wanted to figure out how high up in the air a satellite was, because that's really important sometimes, like for example, if you're trying to measure polar ice caps and how much they are shrinking or lowering, you really want to know exactly how up your satellite is. And what if you wanted to do that, but you wanted to use salt to do it?

Well, my friends, it's possible. So when you're trying to calibrate the height of your satellite, you want to shine basically a laser onto something shiny and flat, So you know exactly what the level is and you know how shiny it is. And usually we use the oceans for this because the oceans are fairly flat and they're fairly shiny and they're everywhere. So that's nice.

The oceans do have that going for them. They're almost the majority of the planet. But two things, one, the ocean actually isn't that flat. So one, there are waves, sometimes there are big waves. Two, there are tides. We sort of know where the tides are, but like we don't know exactly what they're going to be. And so yeah, the sea level,

which we think of as a constant thing, is not actually constant, it changes, and that's what tides are. In the 2000s, NASA wanted to find an alternative to calibrate the Ice Cloud and Land Evaluation Satellite, or ICESAT, which measures changes in ice sheet elevation in Antarctica and Greenland. And for this purpose, it's really important to have extremely accurate measurements. So they needed something very static that didn't have a lot of clouds above it. This is also a problem. You can usually find some ocean that doesn't have a lot of clouds above it. This is also a problem.

You can usually find some ocean that doesn't have clouds, but someplace specific, you wanna make sure it is not clouds. And also that's bright and shiny enough to reflect the laser. And where was it? It's the Salar de Uyuni in Bolivia, everybody. It's back. Oh!

It's back. They used the salt hotels. So many, many, many millennia ago, this area was covered by a lake called Lagomintian. Around 15,000 years ago, that lake started shrinking and the water evaporated, leaving behind thick crusts of halite or salt. It can get more than 10 meters thick,

so that's why you can carve a hotel block out of it. The salt flat is not only super cool to look at, it also turns out it's great for calibrating your satellites. And it's even more helpful because this salt flat is extremely flat. So the area gets rain between December and March, so this is a thing it actually gets rained on, and when that water comes in and mixes with the salt and then evaporates away again, the salty surface gets left behind a super physically homogenous structure.

It's one of the flattest surfaces on earth. Over an area of 9,000 square kilometers, there's less than one meter of elevation change. So using trucks equipped with GPS antennas, scientists were able to measure out the topography of the Silar de Uyuni, make their calibrations about five times better than using the ocean as a calibration tool. Wow. But it has to be able to see Bolivia. Yeah, it has to be able to fly over Bolivia sometimes.

Okay. Yeah. So it's got to go over there every once in a while. Be like, I'm gonna head over to Bolivia, be right back. And then come back. No, I imagine the orbit is set up so that it hits that every once in a while. They should include that in the salt hotel marketing. Please don't lick the hotel, you might throw off the satellites. Yeah, well one of the problems that both the hotels and the entire area has is that the salt flat contains around 50 to 70% potentially of the world's entire supply of lithium.

Lithium has become more important recently because of batteries. And so everybody's got their eye on this salt because it could be super, super useful and the sort of electrification of the entire transportation infrastructure that may be coming in the next few decades.

So you guys have to vote for either Ceri, with during World War II people using coconut water from coconuts as a saline drip into their veins, but it's probably not as good as modern medicine, or you have mine where they are calibrating the altitude of a satellite using a really, really big, flat, white thing that is basically 9,000 square kilometers of salt. I think I'm ready. All right. Three, two, one.

Sari? Ah, I got a point. Ah. I just think Sari's fact might save my life one day. Oh, that is an excellent point. I'm going to keep coconuts on hand now just in case. What's going to save your life more? Add that to your survivalist bunker?

Yeah. This is my whole thing with survivalism. What's going to save your life more? The potential that someday you will be in need of rehydration where there are coconuts, or two, being able to maybe invest in a salt flat futures that's gonna make you billions. Billions!

Billions! You can get as much human blood as you want with billions of dollars. That's true. All right, now it's time for Ask the Science Couch, where we've got listener questions for our couch of finely honed scientific minds. This one comes from at Maddie Hable.

Where did the phrase salt in a wound come from, and why does salt make a wound hurt more? Well, I imagine that the phrase salt in the wound came from the fact that it hurts more. But why, why? That is an undeniable scientific fact I can confirm from having had salt in a wound. But why does it make it hurt more? I have a guess. But Sari, I would like you to confirm my guess. My guess is that the salt in the wound actually destroys cells by sucking water out of them and breaking them.

And that breaking of the cells is sensed by the nervous system and the nervous system says, stop, I hate that with pain. Did I get it right? That is a good guess and also part of my guess. I couldn't find a scientist who was just like, this is why this happens. So I kind of cobbled together an answer.

And that was one part of it that I was going to say, where it was like, I imagine it's just going to bust open your cells because it messes up the concentration of salt in your body and your cells don't like it. And so then they explode. So yes, I think that's part of it. I think part of it has to do with concentrations being messed up or just like the salt physically rubbing into your cells and causing more abrasiveness in an already damaged area.

They're kind of sharp. Yeah, they're pointy crystals. Yeah. I think another part of it has to do with your nociceptors, which are the sensory receptors that are associated with pain. Those are the things that get activated if you touch something too hot or you pinch your skin. They can be activated through lots of different things like too high,

too low temperatures, mechanical stimulation, but also chemical stimulation. So like an acid burn or something like that. And from what I can tell in literature, this is where my biochemistry knowledge is very rusty. It seems like nociceptors, so the nerve cells that sense these kind of extreme stimuli and signal to your brain so that your brain says, can interpret that signal as pain and tell you to stop doing the thing, have chloride channels in them and have like sodium, potassium chloride channels.

So not just sodium potassium channels in them. And so it's possible that because salt, table salt is sodium chloride, then the additional chloride is also activating them in some way or like changing the concentration in the way that these particular receptors sense things. So basically what we're saying is that one of these ions, probably the chloride ion itself

is activating the pain receptor. So even if no damage is being done, pain is being felt. And maybe that's why it like that pain is so immediate, the moment that salt hits the wound. That is a much better way to phrase what I was rambling about. It does seem to happen really immediately. Like the moment the salt hits the wound, it's like zing!

It's like taste almost. Yeah, that's what I was gonna say. It is almost like you're tasting the pain instead of... Yeah. Did you guys know that the inside of a person's penis has taste buds in it? The inside of a person's penis? Yeah. Why? No!

Wait, yeah, yeah, I did actually know that. Taste buds? I had seen that. Does the rectum have taste buds as well? Oh, I bet. No, as far as we can tell, the only place outside of the mouth in the human body that has taste buds is the urethra of a person with a penis.

But why? Weird. Do you really want to know why? I think you're already losing a point, so you might as well tell them. Oh no! Just struggling to understand why you said that. Because we're talking about taste buds in your arm and being able to taste salt with pain. It's the opposite. It's that the inside of your penis can, being able to taste salt with pain. It's the opposite.

It's that the inside of your penis can, it's not taste exactly, but it can sense the sugars in semen and it senses that with pleasure. And so when you ejaculate, it's a signal of enjoyment. So basically the inside of your dick can taste your jizz is what I'm saying. Your balls can't taste soy sauce, is that? No, no, this is a fact I learned from Christy Wilcox

because she did a bunch of research on whether your balls can taste soy sauce. And they can't, but your dick can taste your jizz. Do I have negative one point, you guys? Yeah, I think you have negative one. God damn it. Sari, do you know if there's any more depth of where this phrase came from?

It's basically what you were saying in both positive and negative ways. So, saltwater was often used as an antiseptic in the mid-1800s. People sailing on ships were like, I guess if I rub salt in my wounds, then it'll be a little bit better than if I don't.

Does that actually work? Because there's a lot of stuff in the ocean water, right? That's the problem is there's a lot of stuff in the ocean water. So like if you have feet wounds, I don't know why feet in the ocean is my thing today. But don't go wading in the ocean. Like there are other ways we have better medicine now to treat it. But like to some degree, there was a plastic surgeon that found that fighter pilots

that had burns on their body and fell into the ocean healed better than ones that fell on land. So there's something to sailing solutions helping with healing. Wow. If you wanna ask the Science Couch, you can follow us on Twitter at SciShow Tangents, where we will tweet out topics

for upcoming episodes every week. Thank you to at littlegreyfish at Kirstebeth, and everybody else who tweeted us your questions for this episode. Sam Buck final scores! Sari and Sam tie for the lead. I get nothing and Stefan gets one. Which means that Sari and Stefan are tied

for the season lead. Sam is one point behind and I'm just dragging up the rear. Only like a couple points behind Sam though. Four points out of the lead, it's true. One good episode and you're all right. All right, we'll see if it happens. If you like this show and you wanna help us out, it's easy to do that. You can leave us a review wherever you listen. That's super helpful and helps us know what you like about the show.

Second, you can tweet out your favorite moment from the episode and finally if you want to show your love for SciShow Tangents just tell people about us. If you want to listen to SciShow Tangents ad free you can do that on Luminary. Thank you for joining us. I've been Hank Green. I've been Sari Reilly. I've been Stefan Chein. And I've been Sam Schultz. SciShow Challenge is a co-production of Complexly and the wonderful team at WNYC Studios. It's created by all of us and produced by Caitlin Hofmeister and Sam Schultz, who is also our editor. Our editorial assistant is Deboki Chakravarti.

Our sound design is by Joseph Tuna-Medish. Our beautiful logo is by Hiroko Matsushima. 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. To survive in salt water, some marine vertebrates have salt glands that let them excrete excess salts so that they can drink salty water without being more dehydrated.

In some birds and reptiles, these glands are located around their eyes or nostrils, so it looks like they're snotting or crying goopy salt. But in sharks and rays and skates, the salt glands are in their rectum, so their salt goop comes out their butts. Can they taste it? I don't know, it's not the inside of a penis, so no. It's beautiful. INTRO MUSIC Hello and welcome to SciShow Tangents!

It's a lightly competitive knowledge showcase starring some of the geniuses that make the YouTube series SciShow happen. This week, as always, I always I Hank Green am joined by Stefan Chinn. Hey Stefan. What's your tagline? The chicken is in the coop I repeat the chicken is in the coop Sam Schultz is also here with us today. Hello. What's your tagline? big pile of rocks Man the the world is heavy right now. Sari, Riley is here with us as well. Sari, have you been getting enough to drink? Yes, I have my water bottle here.

I think today I have definitely sweated out more than I have consumed, so I'm probably dehydrated. Yeah, it's hot here. It's so hot. It's like a hundred freaking degrees. Oh man. We should all go down to the lake independently by ourselves. Sari, what's your tagline?

Surf's up. Nice. And my name is Hank Green and my tagline is, can you dig it? Every week here on SciShow Tangents, we get together to try to one up a maze and delight each other with science facts, things that are just true about the universe. We're playing for glory, but we're also keeping score and awarding Sam bucks from week to week.

We do everything we can to stay on topic here on SciShow Tangents, but judging by the last 30 seconds, we won't be great at it. So if the rest of the team deems your tangent unworthy, we'll force you to give up one of your sandbox. So tangent with care. And now as always, we introduce this week's topic with the traditional science poem this week from Sari.

From mammary gland and secreted from teat, to paraphrase Marge Simpson, I just think it's neat. Milk gives nutrition to babies, but that is just the beginning. It's much more than fat. From biochemical signals to bacteria for the gut, it's social and psychological. And honestly, what makes us want to drink cow milk or digest lactose? The questions seem endless if you look close.

And it's not crop milk or milky almond goo. It's an adaptation that unites every mammal to you. So I guess in a sense, milk evolutionarily rules. Plus we can call it moo juice, which I don't know. I guess it's cool. I mean, we can call a particular milk moo juice. You can call all milk moo juice if you want. Yeah, that's true. I'm down. You're right. That's true. Absolutely. Almond moo juice. Almond you want. Yeah, that's true. I'm down. You're right.

That's true. Absolutely. Almond moose juice. Yeah, language is fluid. Yeah. As the regulators who would like to make it so that we can't call almond milk milk should know, because this is a current debate happening in government because the milk industry is not happy about all the plant milks.

If they proposed a better name, but I thought that they wanted to call it nut juice, which is like not appetizing. Can't do that. Can't call it nut juice. I mean, milk is also pretty gross. That's just the idea. And what I like about almond milk and the other plant milks

is that they have, and I get to tangent as much as I want because I can't win this season. Is that you have separated the idea of like a biological secretion from the stuff that I put in my cereal. And that's wonderful. I want that to happen. Even for the biological secretion that I do occasionally

still sometimes put on my cereal. I want to separate the idea of what milk is from the fact that it came out of a teat. Well, milky also, like there's the word milky to describe other things. And I don't know which came first. Oh, I think milk, the secretion came first, would be my guess. Yeah, probably.

And then milky things that looked like milk. But anyway, I feel like all the nut juices all have that same milky consistency, which is why we call it milk. Should we call them almond milky? Soy milky, cashew milky. That's really cute. That's fun. Yeah. Was milk the second beverage ever?

Water first, then milk? So like fish were drinking down there in the ocean. Yeah, just water. But the mammals were like, I came up with a new beverage. I bet something sucked blood before the first mammal. Oh shoot. It's gotta be blood, you're right. Third beverage, milk.

So Sari, do you know what milk is? We've been talking about it a little bit. It is something that unites all mammals. Milk is the nutrient-rich liquid produced in the mammary glands that is a source of nutrition for infant mammals. A milk scientist reached out to me on Twitter to be like, don't fall into the trap of just saying milk is nutrition. So this is me saying milk is way more than nutrition. There's like biochemical aspects to milk in that it helps build infants' immune systems

and convey chemical signals, like even hormonal signals from mothers to children. There's like a social aspect of it because like the fact that humans drink milks of other species is weird, relatively speaking, as far as mammals go. Okay, and do you know the etymology of milk? Not milk, but I do know milk.

Okay, a lot of people do say milk, and that troubles me. Well, I hate to break it to you, Stefan, but the Proto-Indo-European root is melg, which means to wipe, to rub off, to stroke, to milk, in reference to the hand motion involved in milking an animal. So, before humans harvested it, this substance had no name.

Well, that's true of all things. I don't think so. If they saw other animals drinking it, and they didn't think, I should name that stuff. It was just a nameless white thing. Well, it may have had a name, but we didn't have the word milk until we were stroking it out of cows.

Yeah. It probably had a name in various languages when it was like, when you were breastfeeding a baby or something like that. Like, there's probably a word for that specific, but it has no connection to the word milk that we use now to describe this. Humans have milk too. I forgot about that. Yeah. Even the origins around the word milk are kind of mysterious because there's another

Proto-Indo-European root, galog or galag, which is where we get like galactose or like galaxy, lactation, things like that. Oh, because the galaxy's milky! It's milk. Wow. But it says, the absence of a common word for it is considered a mystery. So really my guess is, Sam,

that everyone had a different word for milk and then for some reason, milk won. Now it is time for True to the Faith. One of our panelists has prepared three science facts for our education and enjoyment, but only one of those is a true fact. The other panelists have to figure out which one is the true fact. One of our panelists has prepared three science facts for our education and enjoyment, but only one of those is a true fact. The other panelists have to figure out which one is the true fact.

And if we do, we get a Sam Buck. If not, then Sam will get the Sam Buck because Sam is presenting the facts for us today. Sam, tell me your three facts. If you aren't lactose intolerant, cow's milk is generally seen as a nice, safe, boring drink. But sometimes cows can eat something which can turn plain old milk deadly. Which one of these is one of those things? Number one.

Cows chew cud. They can't get enough of the stuff. But there are some grass species that, during this fermentation-y process of ruminant digestion, releases poisonous compounds, including cyanide. While it isn't a large enough dose to harm something as big as a cow, it can end up in the cow's milk where it can cause severe illness and even sudden death.

Two, sweet potatoes are a fairly common part of many cows diets, but if a cow eats too many of them, it can cause big trouble for people. Indigestible sugars from the potatoes can accumulate in the milk and when this sugary milk is drank by humans, it can overfeed the gut microbiome, leading to severe malnutrition and even death. Or number three, throughout the American Midwest, you can find an unassuming white-flowered

herb known as white snake root, which happens to be incredibly poisonous. If ingested by cows, their milk is contaminated by the toxin, making the milk harmful and potentially deadly. So we've got three different ways that maybe milk is deadly and two of them are made up. We've got some grass species that release poisonous compounds and make cyanide that end up in the cow's milk while it's, the cyanide is created while it's digested. We've got indigestible sugars from sweet potatoes, which are apparently a fairly common part of cow diets and can lead to like an overabundance of your gut microbiome, is that right?

Yes, exactly. And lead to malnutrition and even death. Yes. And then white snake root, which has a toxin that makes it potentially deadly. Why do cows eat sweet potatoes, Sam? It's more expensive to feed them good stuff. So sweet potatoes are kind of just like,

here cow, you need some calories. It's just like what's around, like the extra sweet potatoes, the bad ones that they don't want to take to the store. Yeah, yeah, yeah. Okay. Would it be just as bad if they ate regular potatoes? Do we specifically,

I guess I don't know enough about United States agriculture. Are we making too many sweet potatoes? Do people not like sweet potatoes here? I would guess people don't know enough about United States agriculture. Are we making too many sweet potatoes? Do people not like sweet potatoes here? I would guess people don't like sweet potatoes as much as they like a regular potato. But I don't know. This has always been weird to me, because I enjoy a sweet potato more than I enjoy a potato,

but I want to eat potatoes more than I want to eat sweet potatoes. You don't always want sweet, and a potato pairs better with more things. It's true, yeah. That's true. to eat sweet potatoes. You don't always want sweets, and a potato pairs better with more things. That's true, yeah, that's true. Also, you mostly get fries from regular potatoes, and I feel like those are just chemically engineered to make you addicted.

I love me a lot, ketchup-y fry. And also, the sweet potatoes, I think they have a problem where they grow weirdly, so there's a lot of bad sweet so that there's a lot of like bad sweet potatoes. There's a lot of sweet potatoes that don't like sort of fit the grocery store desired potato shape. Give them to cows.

But that has nothing to do with whether Sam's fact is true. No. I can't, I accept that it's possible for a potato to need to eat a cow, but I don't accept that that means that. Excuse me. Cow. I guess if there was a dead cow underground, we could eat the cow.

Yeah. That's how it all is. The circle of life. The circle of life. That's beautiful. We've got some beef fed potatoes over here. Yeah. We've got two plants here, just grasses generally, and certain species can convert to being toxic

inside of the cow is the first factor. Whereas the third fact is snake root itself seems to be toxic and can contaminate the milk that way. I like that it's called snake root because that sounds like it's dangerous. It's also white snakeot, because that sounds like it's dangerous. It's also White Snake Root, like White Snake, the most dangerous band in rock and roll history. I'm going to go with White Snake Root. I don't really have anything to base it on. It's too

wibbly for me. It doesn't matter though, because I'm not going to win. I'm going to go with Sweet Potatoes, because the grass stuff is just, they're too close together. But that means probably that one of them is true. I'm going to stop overthinking it. I'm probably wrong, but sweet potatoes. The sweet potato one is the only one that I think is fake. Oh, I'd be cheating the game then. Because I don't...

Two of them are definitely fake. Two of them are definitely fake. But the sweet potato one is the only one that I feel like I have any sense of. Because sweet potatoes, I feel like we're really good at digesting sugars. I'll go with the snake root also. Go to Twitter.com slash SciShow Tangents and vote on the thing that you think is the true fact. Right. Did you vote yet? Here it goes. The right answer is snake root.

Hey, Points occurred. Snake root milk contamination is real, and it's called milk sickness when people drink the tainted milk. And it apparently killed thousands of people on pioneer days, including, according to some accounts, Abraham Lincoln's mother. Symptoms include weakness, nausea, vomiting, constipation, and death within two days. So it's like pretty nasty stuff. And it happens mostly in places where people are drinking the milk from a single cow. So it was almost unheard of in bigger cities and

it mostly occurred on homesteads and small frontier towns. And because of that, no, there were like no doctors out there to study what was going on. And it was just like, wow, people sure do die sometimes, I guess. And basically that's what it was. People just chalked it up to like insects or tainted water or other frontier hazards because people were just dropping dead for like no reason. So in 1809, that was the first published account of it. But it took until 1906 for the plant to be identified because nobody was on the case.

And then that information spread so ranchers can watch out for it now. The toxin isn't destroyed in pasteurization, so I guess watch what your cows are eating, because if you're only drinking milk out of one cow and you live in the Midwest or Eastern seaboard, they could be poison death cows. When you buy a gallon of milk, does that contain the milk of many cows?

I believe that it does. I think it does, yeah. Okay, yeah. This is also true of, like, hamburger meat. Well, that's what they say about ground beef, but I feel like if you get your ground beef from a, you know... It depends on how you get it, that's right. A local shop. But yeah, milk comes into a big vat,

and then the vat is then done, like all the chemistry is done on it to make the different kinds of milks. So number one, the cyanide cow cud thing. Cud chewing doesn't really have anything to do with it, but there are certain grasses that produce cyanogenic glycosides, which I think basically is like cyanide locked up in sugar, something like that. And usually these grasses are totally safe for cows to eat. But if the grass is planted somewhere

that experiences severe drought and heat often enough, the compounds can break down in the grass and it releases the cyanide. And whether or not this can end up in the milk doesn't really matter because cows grazing on grass like this can die within a few hours of grazing. You don't milk a dead cow. That's one of the rules.

Yeah, probably one of the first rules that they thought up was out. So, yeah, and it killed like 16 cows in Texas a few years ago, so it just happens every now and then, I think. Do you just like dig up all the grass and you're like, let's just torch the land, dig it up. I should have looked into that more.

I don't know. I think you just be more careful about what grasses you're planting. And I think that was the problem with the Texas thing, was it was mixed incorrectly and there was the kind of grass that wasn't drought tolerant. I'm pretty sure. So probably he got to just start all over again. Then the undigestible sweet potato sugars is based on human milk oligosaccharides. Is that how you say it milk oligosaccharides.

Is that how you say it? Sure. Oligosaccharides. Yeah, yeah. Which is a sugar in human breast milk that humans can't digest, but it's thought to feed and bolster the gut microbiome of infants. And it's in human milk. I guess that's called breast milk.

Human milk is a little weird to say. It is. It's kind of strange, because it sounds like you're buying it at the store. Like a cow's buying it at the store. And it's like, if you have the humans eat the wrong kind of grass, they just die. Yeah. Yeah. Which is probably very much more true for humans than it is for cows.

Probably a lot more stuff we can eat that will kill us. Next up, we're going to take a short break. Then it'll be time for the fact off Welcome back everybody Sandbook totals very easy to convey to you because it's a tie game with everyone at one, which means it's a race between me and Stefan for who's gonna win this episode of SciShow Tangents because we're about ready to do the fact off. Stefan and I have each brought science facts

to present to the others and an attempt to blow their minds. And whichever fact blows your mind more, the presentee gets to give a sam-buck too. So we're gonna do this thing and we're gonna decide who goes first with a trivia question that will be read to me by someone. In what year did milk start being sold in plastic coated paper cartons?

I'm gonna say 1943. coated paper cartons. I'm gonna say 1943. 1962. Ooh, big gap there. Hankwins, the answer is 1932. Whoa. Wow. Gosh, we had plastic back then? When did plastic start?

Geez. We had some crummy plastics before we had like cool plastics. That right. Right. Bakelite was 1907. Yeah. Wow. Everybody thinks that those things are just cardboard and that they're not. They're like, look, there's no plastic. And I'm like, it's still plastic. Do you think that just paper can hold milk in what universe? Would you think, oh, I'll milk? In what universe would you think,

oh, I'll just pour milk into this cardboard box and that will work? This is also true by the way of aluminum cans. They are also lined with plastic. So you're still drinking out of plastic when you're drinking out of aluminum cans as well. I didn't know that. Everything is plastic.

Anyway, I guess that means I'm gonna go first. So I wanna tell you about a wallaby and you wanna hear about a wallaby, but first I'm gonna tell you a little bit about milk. So there's usually two kinds of milk. You get colostrum right when the baby is born and this is the case in most mammals. And then after that, the milk composition is static.

So a cow's milk might vary between species, but like the individual produces like, you know, three to 4% fat, three and a half percent protein, five percent lactose. Humans make three to 5% fat, 1% protein, 7% carbohydrate. And it's that way the whole time that that animal is making milk doesn't shift. But there is a group of mammals that does this differently, marsupials, and it's best exemplified by the tamar wallaby, which has a very short pregnancy. So it's only pregnant for 28 days,

and then the baby is born, and it's very, very underdeveloped and dependent on the mom. And it's basically attached directly to the mother's teeth and does not let go. So to compensate for that short gestation, the wallaby babies go through a very long lactation period, it can last for up to 350 days.

And during that long lactation period, the baby wallaby's nutritional needs change. So the mother changes its milk accordingly. And this is weird already, but it's going to get weirder. So while nursing in the pouch, the wallaby mother produces milk that's higher in carbohydrates and lower in protein and fat, but 200 days postpartum, the milk composition shifts to being higher in fat and protein and lower in carbs. The wallaby will then leave the pouch at around 250 days, but can continue suckling for up to a hundred more days off of that high fat and protein milk.

But sometimes the mother ends up having another baby while that first baby is still drinking milk, whatever that's called, before that baby has been weaned. And that new baby needs the old kind of milk. And so internally you have two different teats producing two different kinds of milk. It's called asynchronous concurrent lactation. And just imagine that you've walked into a McDonald's

and you get to pick whether you want root beer or Dr. Pepper. That's the situation except it's the situation, except it's the inside, except it's teats and it's a wallaby. So the older baby can drink from the teat that has the older baby milk and the younger baby can drink from the younger baby milk. Yeah, but does the older baby ever have

a little nip of the good shit? Yeah. I don't think so good. Like, I think that mostly during this period of time, ever have a little nip of the good shit? Yeah. I don't think so. Like, I think that mostly during this period of time, the younger baby never leaves the teat. Oh, right. And so it's like basically connected.

Older baby can kick that little baby off of the teat. Yeah. Give me. It also probably isn't very much because the little baby is so little. They're so little, they're just like little jelly beans. Yeah, yeah. And we have no idea how they do this.

Scientists had some thoughts about how it might work, but they were wrong. And so we do not know how on earth this mammal have basically lactates. It's like it's being a soda fountain and like making different milks at the same time. What the heck? Did the scientists think it had to do with the babies?

Like are the babies biting the teat or releasing a chemical in some way? They thought that it had to do with the suckling patterns. So like a little baby would suckle differently and more continuously than a big sort of, you know, basically juvenile. But they tested that to try and like, like stimulate the teats as if they were one or

the other and try and get it to switch. But that didn't work. There's some things just beyond our realm. We will never know. No, Sam, just because we don't know something doesn't mean it's beyond our realm. Ten years from now, we'll come back and do another episode on tomorrow wallabies and I'll tell you all about how they regulate their milk because we'll know by then.

Then we'll know that. Stefan, what do you have for us? I've got platypuses. Platypuses are weird. They are mammals, but they are in a unique group of mammals known as monotremes, which is just platypuses and echidnas. And they are egg laying. And they're just weird because they look like a collection

of different animals' body parts. They have duck bills and webbed feet and beaver tails and no nipples, which is important for this episode. So because they have no nipples, some people say they sweat out their milk, but that's not really true. They don't really sweat at all. They just lay on their backs and like ooze milk

through their skin onto their bellies so their young can like lick it up. With a nipple, like the milk goes straight into the baby's mouth. But here the milk is getting exposed to the environment and so you've got dirt and bacteria, all kinds of things that could make the babies more susceptible to infection. But luckily platypus milk is extra anti antimicrobial. So I think all milks

have some antimicrobial properties in them, but monotremes have a couple extras that are unique to that group of animals. And one of these proteins is MLP, monotreme lactation protein, and it occurs in an unusually high concentration for an antimicrobial protein in their milk. And in 2018, teams at CSIRO, which is the Australian National Science Agency, and Deakin University, which is also in Australia, they were able to replicate MLP, this protein in a lab and then figure out the structure of the protein. And it turned out to be sort of a novel, never seen before structure. So it seems like the protein is made up mostly of alpha helices, which is this like spiral structure that's very common

across all kinds of proteins. But this protein, specifically, because it's mostly these helices, it's just like this mass of like spirals, and it reminded them of Shirley Temple's hair. So they called the structure Shirley Temple. Scientists are so weird. I say that like knowing that I'm vaguely a scientist, but Shirley Temple protein.

So like the structure of proteins in general influences how each protein behaves. And they don't know exactly how that structure interacts with bacteria, but they know it is more antimicrobial. And they're interested in seeing how that structure could be used to fight antibiotic resistance basically, because that's becoming a bigger and bigger problem over time. And as antibiotics are becoming less effective, we have to keep exploring all these different options. So they're like, okay, this is unique protein. It's got a weird structure that

we don't know of. Can we recreate this and like create different medications that could fight antibiotic resistant bacteria? They did note though that since proteins break down when you ingest them, they don't think you could make an oral treatment with this, but probably like an ointment or a wound dressing or something that could be more effective. They were in 2018 looking for collaborators to take this research to the next level. So if that's you, it's time to save the world, buddy. I have a question about what happens to the extra milk.

Do the babies just just lick the milk belly until there's no more? Or at some point, does the platypus mom have to be like, I got things to do, and then flips over and gets rid of some milk? That's a good question. I don't know. Well, they swim a lot, so I imagine whatever is left over washes off. They don't get a stinky milk belly. Look, there's probably a lot that's stinky about a platypus life.

Yeah. Yeah, I guess so. You are choosing between two facts. We've got Tamar Wallabies who can change their milk continuously as a baby wallaby develops and produce different kinds simultaneously for two differently aged babies. Or from Stefan, platypus milk contains a unique antimicrobial protein that could unlock new ways

to fight antibiotic resistant bacteria. You guys ready? Three, two, one. Hank. Hank. Hey, I'm cleaning up today. I'm back, I'm back. Now it is time to ask the science couch where we've got a listener question

for our virtual couch of finely honed scientific minds. This week from Krebshouting who asks, why is milk mostly uniform in color no matter the animal it comes from? And I assume that this is because milk is an emulsion of little fat droplets and that's what it looks like when you do that, right? Yeah, yeah, you're enough of a chemist to guess at an answer.

Do you wanna explain what an emulsion is in chemistry? Yeah, so like milk has fat dissolved in it, but we all know what happens when you put fat in water. Like they don't mix together. Oil and water don't mix. That's like a metaphor, it's so true. But if you can create chemical ways to get tiny droplets of fat But if you can create chemical ways

to get tiny droplets of fat to have little things around them that basically keep that droplet dissolved in water so that it doesn't separate out or doesn't separate out easily. And that is an emulsion. It's when two substances that normally would not dissolve in each other,

dissolve in each other, dissolve in each other somehow. I think, basically. I'm 40. I haven't been a chemist in a long time now. Yeah, that's basically it. So there are, in milk, which is like water is the main liquid in it. There are fat globules and protein globules. And when milk is homogenized, then it's gone through like extra processing to make it like a smooth milky color instead of like, I think if you get milk more freshly or less processed from farms,

it can separate into like cream on top. And that's because it's like less of an emulsion. And the fat particles are what are key here because they're so much bigger than the protein particles. So just like the way color works is light is made up of a spectrum. And so light hits an object and then what gets reflected back into our eyes is the color we see. And so like off of most plant leaves, only the color green is reflected back into our eyes because of chloroplasts.

And the fat molecules reflect back all wavelengths of light into our eyes. So that's why it appears white to us. So thank the fat. If you want to ask the Science Couch your question, follow us on Twitter at SciShow Tangents, where we'll tweet out topics for upcoming episodes every week.

Thank you to at Tangential Otter, at Hayletts, and everybody else who tweeted us your questions this week. Sand Buck final scores for once. I win. Three points to everybody else's one, which makes it so that I am only five points behind. You're in striking distance. So I just need to do that a bunch of times.

If you like this show and you wanna help us out, it's very easy to do that. You can leave us a review wherever you listen. That's very helpful. Let us know what you like about the show. You can also tweet out your favorite moment from the episode. And finally, if you wanna show your love

for SciShow Tangents, just tell people about us. Thank you for joining us. I've been Hank Green. I've been Sari Reilly. I've been Stefan Schinn. And I've been Sam Schultz. SciShow Tanchits is a co-production of Complexly and the wonderful team at WNYC Studios. It's created by all of us and produced by Caitlin Hoffmeister and Sam Schultz,

who also edits a lot of these episodes along with Hiroku Matsushima. Our social media organizer is Paola Garcia Prieto. Our editorial assistant is Deboki Trapparvarti. Our sound design is by Joseph Tuna-Medish. 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. The selenodon is a shrew-like venomous mammal that's only on the islands of Cuba and Hispaniola. They are mammals, so they produce milk, but babies have to drink it from teats near their mom's butt.

Ooh, butt teats. So they got butt teats. And the ecologist Joe Nunez Minow described it as, quote, the teats are sort of in the armpit of the rear legs, and sometimes the females will kind of run around dragging the babies. Oh. And... These animals gotta get their shit together.

They don't look right. Yeah, they do look a little upsetting. Oh yeah, they are weird. They diverged like 76 million years ago from other mammals and trees. So it's like they're a weird evolutionary offshoot. They're one of the only venomous mammals. And so the butt teats are actually pretty low

on the number of weird things about them. ["Side Show Tangents Theme"] Hello and welcome to SciShow Tangents. It's the lightly competitive science knowledge showcase. I'm your host Hank Green and joining me this week as always is science expert, Sari Reilly. Hello. Not as always. You've got to take that out of the description.

I feel like I'm truant. That's true. As sometimes. And also our resident everyman, Sam Schultz. I'm always here. We can't get rid of you. Nope. You're always there.

You're always right down the street from me. Uh huh. And that house I've never been inside of because it's COVID. Yeah. Stay out. You should come over sometime when there is not a pandemic. I would love to. I'd love to meet your cat especially.

He's so cute. He looks extremely freaking cute all the time. He's very cute, but he is a wild man. I think, I think that he got neutered today. Oh no. Oh yeah. I'm pretty sure it said on the schedule, gummy bear vet. And I think that that was about, it's definitely time. He has this great habit of being really relaxed

and adorable, and then you stand up to do something, and then he runs head first into your legs. Uh oh. Why? I don't know! Like a mountain goat. He gives you a butt? Yeah.

It's very... And he'll do it to like the wall sometimes. Cool. He's either not coordinated or he just really likes to run into stuff. His head is very hard. He doesn't seem to mind at all. And he also will attack but no without claws. So that's okay He just like goes and he just like bear hugs your ankles That's cute, but he got his little gummy bears cut off today. So now he'll be a different guy. Oh

Wow, I Was just inside and I didn't ask but I I didn't see Gummy Bear. Oh no. Or his gummy bears. Anyway, every week here on SciShow Tangents we don't usually talk about the testicles of our pets, but we do try to one-up a maze and delight each other with science facts while trying to stay on a topic. Our panelists are playing for glory, but they're also playing 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 with one of those Burger King crowns that you get when you are a child. Now as always, we introduce this week's topic with the traditional science poem this week from Sari. When you're baking a loaf or doing the most for a feast. That's yeast. That's it. You don't need any more. I'm happy. I'm satisfied. That was a full meal.

I feel like I just had a number four McDonald's. That was great. Well, just like a McDonald's where I order a size larger fries than I ever want, but I'll eat it anyway. I got five more stanzas for you. Or you're in the lab at work for eukaryotic quirks, knowledge increased, that's yeast. Or you're brewing an ale before you set sail, west or east, that's yeast. Or you're shopping in a store, buy a pouch of some spores, they're not deceased. That's yeast.

Or your biome is thrown off and your skin starts to slough and wrinkles creased. That's yeast. Whoa! Or you're just breathing air, yes it's there too I swear, a tiny beast. That's yeast. That's yeast! We're like 100% of the way through a children's book. Yeah, that's pretty good.

Oh man, that's yeast. So the topic for today's episode is yeast, which is a single-celled fungus. And that's basically all I got. Sari, what's yeast? That's basically all you need to know. They've been around for a while, but interestingly, I didn't dig into this, but I should have probably, but they evolved from multicellular ancestors.

I guess that makes sense. So they are single cells, but at some point, their ancestors were multicellular. And they were like, actually, no. No. We'll go back to being a little bit simpler. Why does that make sense? So like, because yeast is a fungus,

this is a thing that people say all the time. There's like these two kinds of organisms. There's autotrophs who make their own food and heterotrophs who like get food by eating autotrophs or other heterotrophs. So sometimes you hear like things talked about as like a single celled plant, but that usually just means that they are autotrophs.

So they make their own food, but they're not really single celled plants. They're just, they get food the same way. But a single celled fungus indicates that it is an ancestor of a fungus. So like, did we draw the line at fungus before or after the sort of multicellular portion of evolution on earth.

And I always sort of assumed that it was after. Yeah, okay. Which I guess is the case, is why that makes sense to me. It's more of a vibe. What else do you know about yeast though? Some more fun facts. Most of the yeasts reproduce asexually. So they bud off of each other.

So like create a little bud and bloop. But one of my favorite words in biology, some yeast cells reproduce sexually by mating and they produce a nodule. So almost like budding, but instead of splitting in half, it's just a nodule with like sex chromosomes and stuff called a shmoo. And the cells join together in a process called shmooing. Oh, the shmoo is from Lil Abner. It was a comic strip. The shmoo was an animal that you could

milk or eat or could like do labor for you. It was like the perfect animal. And it was like a pet. And you could do anything you wanted to with the shmoo. And they loved to be eaten as well. So they wouldn't be sad when you ate them. Wow. Shmoo. Well, that's, again, unsatisfied. What a satisfying episode we've had, now that I know about shmoos.

Who did that? Who made that decision? I don't know. Someone did, and it's stuck. And I guess, like,ast do look like that. They just kind of blob. They do look a little like the Shmoo. I'm glad my thing I went to college for is paying off.

I did take comic book history. Maybe it's named after him. I think it probably is. They do kind of look like him. Yeast is kind of similar where it like does what we want it to and then we eat it when we're done. This was my question about yeast. So we make bread and beer and stuff out of it.

What is our relationship with it? Is it mutualistic or parasitic? What is it? This is a great question because a lot of the yeast that we experiment on in labs or like bread and beer, it's all one species and maybe subspecies of that called Saccharomyces cerevisiae. But there are a bunch of other, I think like hundreds to thousands of other known species of

yeast. And some of them are like, like thrush the disease on your tongue or like athlete's foot that can be caused by yeast that is not Saccharomyces cerevisiae. And there are yeasts that like live at the bottom of the ocean. And there are yeasts in the air and there are yeasts in all kinds of environments. So I think a lot of our relationship with yeast is non-existent or like just we coexist in the world, like we coexist with a lot of other microorganisms. But as far as like us cultivating it for beer and bread, we like farm it. I don't know, what is our relationship with animals?

We like grow it to eat. Yeah, there's tiny livestock, really, really tiny livestock. Do we have a parasitic relationship with livestock? Oh gosh, I think that that's its own, it's its own thing. It is a agricultural relationship. Okay. But I don't know. Do we parasitize farm animals? Eww.

I feel like we kind of do. We kind of. Yeah. It certainly feels that way sometimes. But I don't know. Yeast is, it just feels like a tool to me, even though of course it is alive. So maybe that's mean to think, but it is a single-celled organism. Where does the word yeast come from? So the only interesting thing about the etymology of yeast that I could found

is that it comes from the same root word as eczema, which is like bizarre to me. That seems bad. And it comes from what we know of the Proto-Indo-European root Y-E-S, I don't know if it Proto Indo European root, YES. I don't know if it's pronounced yes or not, to boil, foam or froth. So we defined yeast by the thing that it does because we didn't know what it was back in the day of early fermentation. We were just like, ah, this thing, this goop bubbles.

And so we're going to call it the bubbly thing. What's eczema have to do with this? Eczema is like a bubbly skin condition. I guess your skin doesn't actually bubble, but it's itchy and it flakes off and it like Froths as much as skin can froth. Okay, and I think eczema used to be a term For like any sort of skin condition. So like when Greek physicians were using eczema It was any sort of like pus-filled thing. So if you're a real pussy, they'd be like, you're a bit yeasty. Yeah. Well, I guess that means it's time to move on to the quiz portion of our show. This week, we're going to be playing a good old game of this or that. So yeast has been a faithful companion

of humans since before we knew that yeast existed. And as we have learned more about yeast and genetics, we've also learned how to add genes and engineer a yeast's own pathways to get the organism to brew up medicines and biofuels and lots of other useful stuff for people. So this is why I think of yeast as a tool, not just because it's good at bread, because you can do lots of different stuff with it. Another popular option isn't yeast, it's E. coli, a bacteria, which like yeast is easy to grow, easy to engineer, but which one is better? It depends. Sometimes the bacteria is better, sometimes the yeast, and for today's game of This or That, I'm going to tell you something that scientists have made using yeast or bacteria, and you're going to have to guess which of those two

things was better at it. Are you ready to play? Sure. Yes. Round number one, psilocybin is a psychedelic that is currently mostly illegal, though that's starting to change because scientists are exploring its potential applications for treating a bunch of different mental illnesses,

but it is expensive to extract from its original mushroom sources, and it is expensive to extract from its original mushroom sources, and it's expensive to synthesize it chemically. Now you might just say, let them chew on the mushrooms. That makes sense, but maybe it's good to have it direct so that you know exactly what you're getting, so scientists have engineered biological pathways in both E. coli and in yeast to get them to successfully produce psilocybin. However, one of them is notably cheaper than the other one.

Which one is it? Oh, cheaper. Oh, I feel like yeast being a fungus is a trick, kinda, right? Do you feel that way? That's what I was wondering. That was my only thread of logic, because otherwise these are all complete guesses. But like, yeast is a fungus.

A mushroom's a fungus. I'm gonna guess yeast. I think I am too. Yeast is, you know, yeast is a fungus, a mushroom's a fungus. I'm gonna guess yeast. I think I am too. Yeast is, you know, it's everywhere. That's a cheap thing. They're both cheap, but you are correct. So a team of scientists was able to engineer E. coli

to get it to produce psilocybin, but there was a notable cost involved because prokaryotes, like E. coli, aren't able to express a key enzyme that is needed in the pathway. So they had to add that ingredient extra and it costs $288 a gram. So that's not great. That's no good. The yeast, however, doesn't have that problem because it's a eukaryote that is fully capable

of expressing that enzyme. So you are exactly right that you were looking for something that was more akin to the thing that originally created psilocybin. So yeah, yeast is better at making psilocybin without that expensive reagent, so it can just churn it out. Round number two, this one's about human milk, which has a lot of valuable nutrition in it, including a sugar called 2-FL. It might help combat the growth of pathogens in our gut. Unfortunately, there's not a whole lot of this sugar in human milk, so scientists have been trying to see if we can get bacteria and yeast to make it for us.

So if you wanna milk some milk sugar from yeast or E. coli, which one would you be more likely to do that from? Cause it's better at it. Which teat do you want to grab? I think that's what you were going to ask. Who is your single-celled cow in this situation? I feel like because it's a sugar, that's relatively simple, and that's something a bacteria could do.

But also... Doesn't yeast eat sugar though? Yeah, that's what I was thinking, because yeast ferments sugar. So yeast would probably use up the sugar. Opposite of what you want. So I think it's the bacteria. I think you're right. Well, I'm gonna guess whatever Sarah's guessing. Same.

I'm gonna guess bacteria. Yeah. Once again, not only are you correct, you're correct about why you're correct. So just go with whatever Sari says, Sam. In 2018, scientists engineered Saccharomyces cerevisiae to produce 2-FL, resulting in a final concentration of 92 milligrams per liter. Meanwhile, previous work with engineered E. coli reported the bacteria was able to produce two grams per liter. Meanwhile, previous work with engineered E. coli

reported the bacteria was able to produce two grams per liter, so about 23 times the concentration that the yeast was able to make. The yeast engineers gave a few possible reasons why this might be, including the lack of a particular metabolic pathway to make the sugar,

and also the fact that the yeast might be making a lot of other products while fermenting, and finally, that the yeast might just not be very good at transporting the sugar out of itself, because it's hogging that sugar for itself instead. And so now it is time for your final this or that for the episode. Snake venom is very complex, and scientists have been studying venoms because they have enzymes and other chemicals in them that can be really important for developing new medicines, so they're just very biologically active, they can do a lot of different cool things.

There are some obvious advantages, though, to being able to make snake venom without having a whole snake involved in the process. So scientists have engineered yeast and E. coli to produce the proteins found in snake venom. Which organism has the dubious honor of being better at making the proteins found in snake venom, which organism has the dubious honor of being better at making the proteins found in snake venom E. coli or yeast. Oh, wouldn't it be so cool if yeast could do it? I feel like I wanna guess yeast

just based on how cool it would be. Just little funguses. I'm just gonna go with yeast out of coolness. Yeast out of coolness. Oh, I'm gonna go with yeast out of coolness. Yeast out of coolness. Oh, I'm gonna go with yeast out of complexity because... Oh, yeah. Because eukaryotic, but I don't have any idea. This one could...

This one's a crap shoot. Well, the answer is yeast. One of the snake venom proteins that scientists have studied are called dysintegrins, and they are promising, despite their origins, because they can help study cell adhesion, intracellular signaling, apoptosis, and other important cellular processes. When expressed in E. coli, the bacteria were able to make one milligram per liter. Meanwhile, a species of yeast called Pitchia pastoris was able to make up to 10 to 15 milligrams

per liter of a disintegrant protein. The reason E. coli is not as good at making snake venom is because snake venom proteins get a lot of their unique structure from a type of linkage called disulfide bonds, but E. coli is just really bad at making those bonds compared to yeast. Probably because it's just not as complicated a organism. So again, Sarie right not just because she's right for all the right reasons But it didn't matter because it was tie all the way through I'm getting smarter Well the score is three to three next up we're gonna take a break, then it will be time for 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 any way I see fit. Which mostly is by which one's going to make a better TikTok video. To decide who goes first, though, I have a trivia question. Here it is. Yeast are generally cells with spherical nuclei in the middle, and our bodies have cells like that too.

But in our bodies, nuclei with funky shapes are more common in aging and cancer populations. So to study how nuclei turn into different shapes, researchers at the National Institutes of Health paused the yeast reproductive process in what's called a mitotic arrest. The yeast genetic material stopped separating into two nuclei, but the nuclear envelope around them didn't stop expanding. It formed a flare of excess material. What percent of genetically typical wild type yeast cells will develop a flare in mitotic arrest? What the fuck are you talking about? You're going to give me a number between zero and a hundred. So mitosis is cell division.

So it's like one cell turning into two cells. If you break that and it just like overproduces stuff, how much will get wiggly and how much will like just do nothing, I assume, and be completely broken. 34%. It's great. 5%. You said 5%, Sari?

Yeah. 90%. Uh-oh. You seem so surprised, Sari, like you knew a lot about this. No, I have no idea about it. I just can picture it very clearly. Okay.

But that means that Sam gets to choose who goes first. I think I'll go first. I have no concept of what's interesting or boring in yeast, so I'm just gonna get it out of the way. Okay, humans, we love yeast. It's such a weirdly useful, weird little guy, and we've developed quite a mutualistic, I don't know, we talked about this earlier,

some kind of relationship with yeast where we eat it. We make it into bread, we make it into beer, all kinds of yeast stuff. And even the animal kingdom has gotten in on the action. Like there's ants that use a type of yeast in their fungus farming practices. And fairly recently we discovered another yeast slash organism relationship

and a surprising one we hadn't seen before. So the charmingly named stinking hellbore is a flowering plant in the buttercup family that grows in Southwestern Europe. So instead of flowering in the spring or summer, when there's bugs everywhere and all the other flowers are doing their flowering, the Stinking Hellbore flowers in late winter, when the temperatures are generally around seven degrees

Celsius, I think 44 degrees Fahrenheit. Even though it's chilly, these flowers do get pollinated mostly by bumblebees, but around this time pollinators are pretty rare. And there are also other cold weather problems like smell doesn't travel very far in cold, dry air. So these flowers need to pull out all the stops to get a bee visit. So their big trick to do this is the symbiotic relationship that they have with yeast.

So as pollinators visit the flowers, they leave behind the local species of yeast, which the flowers keep alive and thriving by providing them with sugar in their nectar. So the yeast do what they do, and they eat the sugar and create heat in the process. And researchers found that the insides of these flowers could be two to seven degrees Celsius warmer than they are outside of the flowers depending on how much yeast they collected. And they also looked at flowers that had been prevented from being pollinated and found that they had no yeast and no extra heat. So they were collecting heat, yeast and making heat. So the heat does a couple of things the

researchers think. It makes the nectar warmer, which makes it smellier, which attracts more bees, and it possibly also just gives the bees like a nice little warm place to come hang out. It's like, hey, it's cold out there, bee. Come hang out inside of me. And they studied the bees in the area and found that when given the choice, the bees preferred a warmer flower.

So that seems pretty likely too. And these flowers were the first ever plant found that relies on another organism to make heat. And I think it still holds that distinction. This was in 2010, and I think that's still the case. There are other flowers that make themselves warm to get smellier, like some corpse flower family plants, but they warm up with a chemical reaction that they do themselves. And other flowers just rely on the good old sun to get warm. What's this plant called again? Stinking Hellbore. Okay, I'm looking at it. It looks, it doesn't look stinky. No, it doesn't look too bad. I believe it is.

I don't even know if it is stinky. I didn't actually see any description of what it smells like. Nobody calls a plant a stinking halbor if it doesn't. It's also called a dungwort. Oh, yeah. Halborous Fetidus, which doesn't sound good either. No. Fetidus sounds stunky. Oh, Lord. So the flower feeds yeast to create warmth for bees.

Yeah. Yep. It's like a three way mutualistic relationship. The bee thing is a little bit more sketchy than that definitely makes heat to make itself smellier But but that's for the meat to get the bees to come that's for the bees for sure Yeah, but like that doesn't necessarily actually I guess it helps the bees because the bees get something once they get there, right? The bees get a little snack. They get a little snack. They get a little food, but it's not necessarily a little toasty bee sleeping bag, but it probably is. I'm gonna say it is.

I'm gonna say it. Look, scientists are so conservative. Yeah, if you could go somewhere that was seven degrees warmer than it was where you were, you would go there. All right, Ceri, you got a steep hill to overcome because it's a three-way mutualism with hot stinky flowers and cozy bee sleeping bags. What yeast fact do you have?

So to Sam's a buttercup of a fact, I have the rowdy mutualism, I think, because it's very similar, but also a little bit different. So fruit flies, specifically Drosophila melanogaster and yeast, specifically Saccharomyces cerevisiae are both popular lab organisms because they're relatively harmless. We have a good understanding of their genetics and we can mess around with them to learn about other eukaryotic organisms like we've talked about. But outside of those day jobs in the natural world, they're kind of friends too. When many different yeasts eat sugars for energy, they produce volatile organic compounds

that have stinky or fruity aromas like isoamyl acetate and ethyl acetate. For example, think of the smell of a rotting apple or some of the notes in beer and wine that I can never detect because it all tastes gross. Unlike me, fruit flies love those stinks. The adults follow the stink to eat the yeast and preferentially lay eggs on fermenting stuff like fermenting fruits because yeast is easy food for freshly hatched larvae. And while some yeast cells get eaten, others get stuck to the fruit fly leg hairs

and get carried away to more sugar rich environments where they can grow happily. This is a well-known mutualism and fruit flies and yeast have sorted out some of their differences along the way. For example, fermenting yeast make ethanol, which is toxic and can disrupt cell membranes in other organisms like fruit flies and apes and whatnot. So fruit flies have enzymes called alcohol dehydrogenase, the same as us, to metabolize ethanol. And for a while, we thought that was the end of the story. The alcohol is an unfortunate hurdle that fruit flies tolerate to crunch on yeast. But in a 2012 paper, researchers found that the flies may actually be seeking out and

using the ethanol as a sort of medicine. The researchers raised some Gesophila melanogaster larvae in a lab on control food with no ethanol or food that contained anywhere from 4 to 10% ethanol. For reference, 6% is about the amount in yeast cells that grow on rotting fruits. And then they offered up the fly larvae up to two kinds of parasitic wasps, both of whom just straight up lay their eggs in or on the fly larvae so that the kinds of parasitic wasps, both of whom just straight up lay their eggs in or on the fly larvae so that the wasp babies can eat when they hatch. One of the wasps was El Heterotoma, a generalist that feeds on all kinds of Drosophila species,

and it avoided laying eggs on the boozier fruit flies. When it did, though, more of the wasp babies died or were really sickly when the researchers cut open the flies and checked on the babies. The other was El Bullardi, a specialist parasite that specifically preys on Drosophila melanogaster, and it was a little more ethanol resistant. Not as much as the fruit flies, but it held up better than the generalist wasp. And in a separate test, infected fruit fly larvae sought out more ethanol-rich food over the control food.

So they basically self-medicated with alcohol when they sensed there was something wrong. Even though ethanol is dangerous, eating poison to kill off your parasite is better than getting eaten by a hungry baby wasp, I guess. This is wild. This, so, but what, what ill effect does a fruit fly experience from consuming poisonous alcohol? Do they get fucked up? Well, drunk babies? Yeah, I don't know. I don't think they have, like, the cognition to be drunk, necessarily. Like, you could Like you could definitely experience

like the motor control problems. They're just falling over. Probably like drunk bees. Like drunk bees. Fairly similar. Like just not as controlled, but also probably just like damage to their cells and they don't have as many.

So it's like, it feels bad because they don't have a giant liver helping filter stuff. Right, right, right. Yeah, they don't have all that machinery. So they're like, their hangovers are way worse. Probably lifetime long. Yeah. Yeah.

That's it. They don't got long to shake it really. Yeah. Mm-hmm. But how do they know where the, that the wasps are near? Oh, they know that the wasps, once they've been infected already.

Oh, okay. So like they've got a baby wasp inside them and they feel sick. And then they're like, gotta drink up. Oh, okay. That's how you know there's a baby wasp in you. Yes. Yeah. It doesn't know the wasps are near. It knows that it's already got got. I got confused. A challenge has been laid at my feet and now I, the great King Hancuff, have to decide which one of you I will execute. We're not having a good enough fact. I think that the bee is cuter and stinkier and a little weirder.

That's what people love on TikTok. Cute, stinky, and weird. That's why they like me! Um, alright, wow. Now it's time to Ask the Science Couch, where we've got some listener questions for our virtual couch of finely honed scientific minds. What is it? It's from Emily17 on Discord who asks, when and how did we first classify yeast as a fungus and what

did we think about it before then? What a great question. You look at a single thing and you're like, ah, it's just like a single cell thing. And then do you have to like do the genome first? Can you look at it and be like, oh, its organelles look like fungus organelles? Who figured this out? Who indeed? I realized now I have three pages of notes.

I got way too excited about this freaking question. I'm going to distill it down because I found Google books where people just talked about the history of microorganisms. And I'm like, I actually love this. This is, I'm a nerd. Back when we didn't know really what yeast was, we knew it was important because brewers would like scrape the dregs from the bottom of jars or

the scum at the top and reuse it. Oh my God, that's great. Nobody's going to die of that. Yeah. No, we're like, that's what makes it foamy. Yeah. That's the good stuff. They were like, wow, a precipitate. But at least in written material that we can find, didn't think too hard

about the chemical reaction. They were just like, we need this fizz, better put it in the next fizz to keep it going. And so I don't know if the general consensus was this, but my understanding was that it was just a chemical that hung around and helped with reactions, kind of like, I don't know, baking powder. You had it, didn't wanna get rid of it,

and you could just keep generating more. And then in literature in the 1600s to 1700s, scientists were trying to figure out, like, quantify the fizz. They described what they called, quote, a ferment and defined it as, quote, a body existing in a state of internal motion that then transferred that motion to other particles.

So they thought the fizz was an inherent trait. And they were describing yeast kind of like, we describe temperature where it's like the motion of molecules like the wiggles. They were like, yeast is the wiggles. And so like it's transferring the wiggles to our bread and our beer. And that's what makes it fizz.

So it's just like a fundamental force of nature to them or something? We didn't know anything. Everything was very confusing and people were doing their best with the information they had. It's so funny that it took us that long to look at it and be like, maybe we should figure out what that is. Well, we didn't know about microbes. We didn't know that there were small things that were alive that you couldn't see. Hey, we were just like, beer exists?

That's enough for me? Is that all they're doing? I worry about it, and then I drink some, and I stop worrying about it. The first time someone observed yeast was in 1680. It was a man named Antony van Lee Luenhoek, who lived in Holland. And he was like you, Sam, was like, I got a look in beer. He took a rudimentary microscope and was like, what the heck is in here?

Well, he was like the first guy who had microscopes. Yeah. And so he found these globules, what he called globules, in beer that were made of like six separate little lumpy things that were about the same size and shape of a red blood cell. So about like seven micrometers. And what he saw, what that was, is yeast that had divided but which is still clustered up into different cells. But he was like, yeast?

This is yeast, I think. But he wasn't sure what it was. He was like, it's inanimate, maybe, and derived from flour, but like, I can see it now. I can see these like little animals, which are bacteria, but then there's like yeast. And then more chemists came into play. Lavoisier in 1789 came up with an equation for fermentation

and we started to understand like, okay, this is how sugar is converted into ethanol and carbon dioxide by yeast. And other chemists chimed in and were like, okay, we've got the idea of alcoholic fermentation. Didn't really think about yeast during this time. They were just like, it's there also. We're chemists where we wanna know what's happening

with the CO2 and the C6H1206. Then in 1838, Charles Cagnard Latour, I pronounced a French man's name in a very English way, used a better microscope to observe yeast cells. And he sat in a brewery and like sampled them over time. So it was like, oh, you're brewing beer. I'm going to take one every hour. And saw the same globules, but then saw the process of budding.

And so he saw them protruding. He found some schmooze. Oh. He saw some schmooze. And he was like, holy shit, this is not an inanimate thing. Yeah. It's an animate thing. And he described it as vegetable activity.

So he was like, they're not animal-like, they're vegetables, they're the other thing. So we got another step on the path, not necessarily closer, but maybe closer. And then around the same time, Theodore Schwann, who did a lot as far as microbiology and developing the idea that living structures came from cells and differentiation of cells, and those are what make organisms and they don't generate spontaneously.

He was like, ah, yes, yeast is a moving, living thing. And it is a sugar fungus. I don't know how he came to the term fungus, but I don't think it came through intense taxonomy. He was just like a little plant, a fungus, and then it feeds on sugar. So that's where the word saccharomyces comes from. So it's like sugar, saccharin, and then myasys, which is like mycology.

I think that's study of mushrooms or fungus. Yeah, so he was just like, sugar fungus. And then we just kind of kept it as a fungus from there. I guess a fungus would be, like probably maybe the kind of vibe around a fungus was a plant that eats, rather than a plant that makes its own stuff. It's kind of the situation with a fungus, if you look at it with fuzzy eyes

that isn't aware of the last 200 years of science, you're like, it's weird, there's some plants that eat stuff, and some plants that make their own food, and those ones are fungus, and those ones are plants. Yep. And so he kind of classified it as a fungus. And then 1800s were a mess. There was a denunciation of yeast it as a fungus. Then 1800s were a mess. There was like a denunciation of yeast as a living organism. A bunch of people were like, no, it can't be alive. Like fermentation is like a reaction between air

and plant juice and whatnot. And yeast is just a byproduct. And then eventually Louis Pasteur of pasteurization was like, no, microbes really exist, guys. And established more about fermentation, like aerobic and anaerobic, which is oxygen using or not oxygen using. In 1883, Emil Christian Hansen isolated pure strains of yeast. And I think at that point, we started diving into genetics and understanding them. The 1900s are just learning about the genetic sequencing of yeast and also learning about what enzymes yeast have to help with fermentation.

But that early stuff was a wild roller coaster. Thank you for sitting with me through it. Yeah, it feels a little bit like we kind of lucked into the right answer, where it was like, okay, so this thing is consuming sugars, and it's more plant-like and less animal-like, and so we're gonna be like, that seems like a fungus to me. And so we named it correctly for once, saccharomyces,

for sugar mushroom. Nice-hmm. Nice. Well thank you, Emily, for your question. If you want to ask the Science Cow to your question, you can follow us on Twitter at SciShow Tangents, where we will tweet out topics for upcoming episodes every week. Or you can join the SciShow Tangents Patreon and ask us on Discord. Thank you to at wancho bros, at scribe of stories, 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 so 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, which we are recording this week. Yeah, I have to prepare a lot for it, but we'll get there. 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 edits a lot of these episodes, along with Haruka Matsushima. Our story editor is Alex Billo, our social media organizer is Paolo Garcia Prieto, our editorial assistants are Deboki Chakravarti and Emma Dowster, our sound designer is by Joseph Tuna-Medish, and our executive producers are Caitlin Hoffmeister and me, Hank Green. And of course, we could not 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. [♪ INTRO & MUSIC PLAYING The Mind is not a vessel to be filled, but a fire to be lighted. The Mind is not a vessel to be filled, but a fire to be lighted.

The Mind is not a vessel to be filled, but a fire to be lighted. But one more thing! Yeast is a fungus that populates our gastrointestinal tracts and our poop, so a study published in the journal Microbiome analyzed the fungal makeup of poop samples from about 300 pairs of moms and their babies, and they found that babies were more likely to have detectable fungal DNA in their poop if their mothers did too. And baby poop had more de-hansiniae, which is a yeast also found in cheese, and might have something to do with breastfeeding.

Then, when they are three months old, they join everyone else in having more s-ceravissii, or baker's yeast, in their poop. So turns out, you are what you eat! Poop. Eat shit. Eat shit, SciShow Tangents listeners!