How does soap work?

Lemonade Lemonade Brain on Universe Brain on Universe Brain on Universe You're listening to Brain's On. When we're serious about being curious. When you wash your hands, there's a battle going on. One between the soap and the dirt and germs on your skin. It's a nasty fight with brutal attacks. And no mercy. The soap wins and the dirt and germs lose. Big time. But how? Yeah, what exactly does soap do to cause those filthy foes? Turns out soap has a special design that makes it the perfect thing to kill germs and clean dirt. But to see how it works, you have to zoom in super close. Which is exactly what we're going to do. Keep listening! Hi, I'm Mark Sanchez, here to talk about an important issue. Do you have questionitis? It's a common condition that afflicts curious kids and sometimes adults too. Symptoms include wondering what octopus is dream of, contemplating how Jell-O wiggles, asking why penguins can't fly, and questioning the existence of time itself. If you or somebody you love is dealing with questionitis, there is help. By joining SmartyPass, you can get access to hundreds of episodes of Brains On that answer your questions, all without ad-rics. You also get Forever Ago, Smash Boom Best, and Moment of Um. Ad-free. And if that's not cool enough, you get invited to online hangs with me, Molly and Sandin, and you support the work we do helping other people with questionitis. Because you have a gazillion questions and we have a gazillion answers. Join SmartyPass at BrainsOn.org slash SmartyPass. Thanks. Buh-buh-buh-buh-buh-buh-buh-buh-buh-buh-buh Brains On. You're listening to Brains On, part of the Brains On universe. I'm Molly Bloom and my co-host today are sisters Hope and Heaven from Aralee, North Carolina. Hi guys! Hi! Today we're scrubbing and bubbling and tackling this listener question. How does soap work? So Hope and Heaven. Are you both pretty good at remembering to wash your hands? Yeah. Yes. Do you prefer, let's start with you Hope, do you prefer bar soap or liquid soap? I prefer liquid soap because it's less slippery than bar soap because usually when you're in the shower or bath and you're holding the bar soap, the water's on your hands and sometimes it just slips in the water. Mm-hmm. How about you, Heaven? Liquid soap is, I just find more helpful because if it does fall off your hands, it just falls on the ground and it's in a bottle so it won't get dirty. So, and also if the bar soap falls out, it will get dirty. Are you guys shower people or bath people? Shower people. And how about fruity smelling soap or flowery smelling soap? How about start with Heaven? I prefer fruit smells. I prefer flower smells because it makes you feel like I'm in like a garden of flowers while I'm taking a shower. Or a bath. Oh yes, very nice. I mean, you can't go wrong either way. You know, I kind of like a cucumber smelling soap, which is a little bit odd, but I really find it refreshing. Okay, so I have a question. I'm going to start with Heaven. Who takes longer in the morning to get ready in the bathroom? Would you say you or Hope? Hope. Yeah, it's definitely me. I take like the longest in the bathroom in the morning. Of course she does. So, Heaven, do you have any tips for how to go quicker in the morning? Yeah, of course. In the morning, she gets ready slower because she's usually sleeping when I'm awake. And also with her shower, she takes like long and sometimes I hear her singing in the shower, but she takes like forever. Yeah. Brains on. Well, let's go. Brains on. Well, let's get to it, the science of soap. We know it's important when we wash our hands. But what exactly does it do besides, you know, smelling good? And making those fun, foamy bubbles. One way to find out, zoom in real close and see what's going on. Luckily, we have a zoom ray for that. Oh, the zoom ray. I've always wanted to see it in action. Well, here we go. This device lets us look super close at something so we can see stuff on a microscopic level. Ready to zoom, Hope and Heaven? Super ready. Zoom us in, Molly. Okay, I'm going to wash my hands. Heaven, you aim the ray at the sink and hope. Please push that red button right there. Got it. Whoa! We're so close up. We can see stuff that's normally too small to see. Super cool. I know. Now, as you can see, there's some dirt on my hands. The water is washing over it and some of it's coming off, but not all of it. Yeah, some of it looks stuck on there. And what are those spiky looking balls? Oh, those are viruses. Maybe some cold germs, must have picked them up somewhere. You can also see some bacteria, an even tiny fungi on my hands. Gross. No offense, Molly. No, I get it. Same. We are covered in tiny micro things. Most are harmless, but it's good to wash up and get rid of the bad ones. Those are the ones that can make us sick. So, let's vanquish those viruses. Watch as I add some soap into the mix. Whoa! Look at those tiny lollipops. Those are soap molecules. Molecules are tiny pieces of something. Up super close, tiny pieces of soap do look like lollipops. You can see each molecule of soap has a round ball on one end and a long tail on the other. Now, the thing about soap is that those two ends are very different. One side, the side that looks like a ball, it loves being in water. Like, look at that soap molecule there. Oh, a bath. Yay! Let's go for a swim. But the other side, the long, thin tail, it hates water. It wants to get as far away from wet things as possible. Water? Yuck! No! Get it away from me! Get it away! Yikes. It's too tough for those two sides to be paired together. Yeah, they're opposites like a dog and a cat sharing the same body. Exactly. And this is what makes soap such a great cleaner. Because that long stem that hates water, it's going to look for any way it can to get away from the water. Splish, splash. So fun in the bath. Am I right, tail? Ah, are you out of your mind? Water is the worst. Get me out of here. Wait, is that some dirt? Oh, yay! That's not water. Let me bury myself in that. Ah, safe at last. Huh? The tail end of the soap just buried itself in that grime in your hands, like sticking a pin in a pin cushion. Look, lots of soap molecules are doing the same thing. The dirt on your hands is now covered in soap molecules, and they're lifting the dirt off your skin. Yeah, and look, those water-hating soap tails are also burying themselves in the viruses on my hands. Oh, this germ looks like a safe place to hide. Let me just wiggle in here. Ah, that's better. Whoa, lots of soap molecules are burying themselves in that virus. They're frying the virus open. The soap broke the germ apart. All the viruses on your hands, they're being utterly destroyed. Viruses are bursting all over the place. Cool. Yeah, now that I'm done lathering my hands with all this soap, watch me rinse it off. The side of the soap that loves water is going to follow the water as it washes off of me. And it's going to take its tail that's buried in viruses and dirt with it. More water? Yay! Let's surf this wave. Come on, tail. Woo-hoo! What a ride. Whee! I'm holding on to this germ and I won't let go. I hate water! Wow, the soap took all that grime in all those dead viruses with it. Your hands aren't gross anymore. Thank you. Now hit that button there and we'll zoom back out. That was action packed. Yeah, the soap molecules went to town sticking into that dirt and busting up those germs. Like I said, soap is powerful stuff. So next time you wash your hands, picture that wild battle between soap and grime. And remember, don't rush it. Yeah, give soap around 20 seconds to do its thing. That's like singing the birthday song twice. Or singing this soap song we wrote twice. Happy washing! Coming up, we're going to learn when humans started making soap. But first, let's take a break for the... Mr. Sam. Okay, are you guys ready to guess the mystery sound? Yes. Awesome, here it is. I know what it is. Yeah, I have a guess too. Yeah. Okay, let's hear. Who wants to guess first? Yeah, you can go heaven. Okay, so I have heard this sound before in my own home. So I believe it's a wash, it's in a washroom. It's a washer. Like when you put clothes in and then pour the thing and then start. Yeah, it sounds like a washing machine. Like, yeah, a washing machine, like you pressing the buttons and then letting it turn the clothes in the inside. It feels like you too, like heard that and you're like, I know this sound. Yeah. Awesome. Okay, well, we're going to hear it again at the end of the show. Get another chance to guess and hear the answer. So stay tuned. Right now, we're working on an episode all about light bulbs. Light bulbs are often used to symbolize getting an idea. When you get a good idea, you might imagine a light bulb turning on over your head. Ding! Or maybe when you get a good idea, you shout, Eureka! Well, we want to hear from you. We would love for you to invent a new word to say for when you get a good idea. So hope and heaven, what's your new word or phrase to announce a good idea? Mine is, I think, like a happy or like happy face. Yeah. Maybe like, inside of a light bulb symbol, we'll use a happy face symbol. Yeah. I think I'd say Brin Zong probably. Oh, I'm honored. I'm so honored. That's amazing. Well, listeners, we want to hear from you to send your answers to us at BrainsOn.org slash Contact. We'll play some of them on an upcoming episode. Today's episode is sponsored by Great Wolf Lodge. At Great Wolf Lodge, there's adventure for the whole family. You and your pack can splash away in the indoor water park where it's always 84 degrees. There's a massive wave pool, a lazy river, and tons of water slides for your pack to enjoy together. And the fun doesn't stop there. Get ready to explore and play at Adventure Packed Attractions from MagiQuest, a live action game that takes place throughout the lodge to the Northern Lights Arcade. There's also a bunch of great dining options and complimentary daily events like nightly dance parties all under one roof. And the best part? With 22 lodges across the country, you're always only a short drive away from adventure. So bring your pack together at a lodge near you. Book your stay today at GreatWolf.com and strengthen the pack. Hey friends, it's your two favorite viruses, Me, Gilly, and Me, Kara. And this is... Going viral with Kara and Gilly. Oh yeah. Oh yeah. Oh yeah. Yeah. Hey Viralinos, long time no see. We missed you. We hope you've been staying in Feckty, making people sick, living your best life, riding on a sneeze. For sure, for sure. So, we just wanted to interrupt this episode of Brains On real quick to talk about something. Soap. I hate it. Oh, the worst. Unfun fact, soap is highly effective at killing viruses. Yeah. For those who don't know, viruses like us are just microscopic little things that want to get in your body and make you super sick. Fun, right? I think so. And we love hanging out on like doorknobs. Railings. Phones. Pencils, your friend let you during math. Anywhere we can get to your hands, because we don't actually move by ourselves. You have to touch something to pick us up. Or maybe if we're lucky, we'll be sneezed onto you. The achoo choo choo, like traveling on a sneeze. Get it? Maybe keep workshopping that one. But however it happens, once we're on your hands, there's a good chance you'll put us in your mouth or your nose. Maybe when you're eating, maybe when you're picking your nose. We're the Bostrels of your nostrils. Yeah, sure. And once we get in, the virus party starts. Ain't no party like a virus party because the virus says don't stop. Like literally, we start multiplying, taking over the place. We have a blast and you'll get sicky sick real quicky quick. But so many of you humans really know how to ruin a party. Party poopers. We get on your hands, we're ready to get the party started. But then you go and wash your hands with soap. It stops the whole party before it even starts. We get washed away down the drain and you stay healthy. Bummer town. Bummer city. Bummer nation. So remember, if you love being sick with viruses. And honestly, who doesn't? Then say nope to soap. Thanks. We are back. I'm Molly. I'm Hope. And I'm Heaven. And we're exploring the sudsy world of soap. We learned soap long kills have one side that loves water. And one side that really doesn't. And that side sticks to the dirt and germs to get away from water. That helps get that grime off your skin. So water can rinse it all away. Humans have been making soap for a long time. At least 5,000 years. Historians found recipes for it from cultures in ancient Mesopotamia. Egypt, Greece, and Rome. No one knows how it was invented. But one pretty good guess is that it was a happy accident. Maybe something like this. Long ago, a group of people had a cookout. They had some good food. They had a good time. A group of people had a cookout. They ate some meat roasted over a fire. Fat from the meat dripped into the flames and mixed with the burnt wood. The fat mixing with ashes created a chemical reaction, creating a slippery sludge. Maybe it rained the next day. And that sludge was washed down in the nearby river. When the people went to wash clothes in that river or clean up their bodies, they noticed that sludge from the fire made the water super good at taking off dirt and grime. And a very early version of soap was born. That's one theory of how soap was discovered. But probably lots of cultures figured this out in lots of ways over many years. Because thankfully, soap is fairly easy to make. The ingredients are pretty common. It's made by mixing fatty acids with a certain kind of substance called a base. In the example above, the fatty acid came from the fat in the cooked meat. But you can use fatty acids from plants too, like avocados or coconuts. And the base in our example came from the burnt ashes of the wood. More modern soap makers often use something called lye, which is made from ash. Once you combine the fatty acids and the base, they make a reaction called saponification. Which makes, you guessed it, soap. Like magic. But actually, it's chemistry. Over many, many years, humans got better at making soaps. But get this, for hundreds of years, washing your hands with soap was not very common. Soap was mostly used for washing fabrics. Or in religious ceremonies. Coming up, we'll tell you about two people who helped change that. Stick around. But first, let's check the mail bag. Music Hey friends, it's me, Mark. Checking the mail, checking the mail. Ooh, it looks like we got a note from two people who recently listened to the Smash Boom Best debate. Soy sauce versus maple syrup. In that one, Team Soy Sauce talks about a food hack where you can mix soy sauce with vanilla ice cream. Check it out. And if you put some in softened vanilla ice cream, then re-freeze it, it'll make a butterscotch flavor. It's one of those viral food hacks. Well, these two listeners tried it, and here's what they thought. I'm Barrett, I'm Ted. I'm Craig, I'm 8. And we live here in Anchorage, Alaska. The vanilla ice cream with soy sauce in it. The vanilla ice cream with soy sauce in it is actually a pretty good butterscotch. It's delicious. Ooh, very interesting. Who knew a debate show like Smash Boom Best would have such a great dessert tip? More like Smash Boom Digest. Am I right? Huh? Thanks for sending us your food review, Barrett and Craig. And if you tried something inspired by an episode, let us know. Send it to us at BrainsOn.org slash contact. Thanks, see you later. What's up, viralinos? It's us again, Kara. And Gilly. Two viruses with a microphone and a dream. A dream of infecting you so your nose fills with boogies. Ah, boogies. Little green gobs of joy. But, sadly, soap ruins our plans, like all the time. All the time. Lucky for us, today, we have a guest who says he can beat soap. He's a germ influencer popular in the grimasphere. Let's welcome Sal Monnello. Hey, Sal. What up, Kara and Gilly? So, tell us, Sal. You're a germ, right? Yep, I'm a bacteria, not a virus like you two. I'm a single-celled organism. And my thing is, I like to make people poop a lot. Like, if I get inside a human, I'm gonna make them sick and I'm gonna make them poop a ton. Right. And so, you say you aren't afraid of soap? No way. I'm not afraid of anything. I mean, look how jacked I am. Are you jacked? Can germs even be jacked? You just look like a regular bacteria. Look, bacteria like me aren't like you viruses. We don't get pried apart and exploded by soap because our cell walls are different from how you viruses are made up. Soap can't hurt me, bro. Watch this. Yeah. Yeah. Yeah. What are you? Yeah. Wait. Whoa, what's going on? I'm covering myself in soap. Ew, why? To prove how tough I am. Okay, but I don't think you should... See? The soap molecules didn't break me apart. I win. I am the best. Yeah, but you're still covered in soap, dude. That's not a good idea. Now, watch me rinse it off. Woo-hoo! Uh, you might not want to do that. Oh, no. The soap has me surrounded and it's making me float in the water. No, dang. I'm being carried off by the water now. I severely overestimated my ability to beat soap. Wow, who could have seen this coming? Only us a little bit? Okay. I may have let my many insecurities manifest as an outsized need to look super tough. And now I'm being washed down the drain because of it. I should have talked about my feelings instead. Well, we tried to help him. Viruses and bacteria. No match for soap. That reminds me of the time I got stuck talking to E. coli, hanging out in that kitchen faucet. He truly wouldn't stop talking about poop. But we can. And we will. Until next time, stay infecty and don't get sanitized. We are back on our soap box talking about soap. Soap that seems like a dream. But get this, for centuries, people didn't use soap to get germs off hands. Which sounds weird, but there's a good reason. For centuries, people didn't know germs existed. They knew people got sick, but they weren't really sure why. We didn't have microscopes powerful enough to see things as small as germs. But eventually that changed. Cut to the country of hungry in the mid-1800s. Still before we knew about germs. There was a doctor named Igna Semmelweis. My patients keep getting sick. What could be the reason? He noticed something at his hospital. Doctors would spend a lot of time inspecting dead cadavers. It was part of their work. Then they'd go straight from that to treating patients. Those patients got sick pretty often. So Igna has wondered, Could the doctors be picking up something by touching the dead? And then they'd transfer to otherwise healthy patients? Could that be making people sick? It was a theory. So to test it, he tried something weird and new. He asked the doctors to clean their hands before seeing healthy patients. And guess what? It totally worked. Way fewer patients got sick. Bravo! The hands are the key. Clean them and you will save more patients. Even though he had really strong evidence that washing hands helped save lives, he couldn't really explain why this worked so well. He just knew that it did. So most doctors ignored him. They kept not washing their hands. Jump a few years forward and over to a city then called Constantinople. Today it's called Istanbul in the country of Turkey. Back then England had a hospital there to treat soldiers who got sick during an ongoing war. And working at the hospital was a woman named Florence Nightingale. She was a statistician, which means she was really good at using numbers and patterns to understand how the world works. But at this hospital, she was also helping treat patients. And Florence noticed that a lot of soldiers died from illness, not wounds from the war. And she had a hunch that the filthy and crowded hospitals might be to blame. She didn't know about germs either, but she thought keeping things clean could make a difference. So she made a bunch of changes like making sure the patients got fresh air. And she had nurses regularly wash their faces and hands. And once again, this saved a lot of lives. Florence Nightingale became a hero in England and her methods soon spread to many other hospitals. Not too long after this, the idea that tiny things called germs were making people sick caught on. And suddenly washing hands made a lot more sense. But it goes to show that sometimes smart people can come up with great solutions even when they don't fully understand the problem. So next time you scrub your hands, think of pioneers like Ignaz and Florence. Soap molecules have one end that loves being in water and one end that doesn't. The side that avoids water will attach to dirt and germs and help lift them off your hands. That makes it easier for the water to rinse all that gravel away. Humans have been making soap for thousands of years. But it wasn't until the mid-1800s that we started washing our hands to stay healthy. That's it for this episode of Brains On. This episode was produced by me, Molly Bloom, Mark Sanchez, and Sandeck Totten. It was sound designed by Mark Sanchez who also wrote our theme music. We had engineering help from Matt Sanders, special thanks to Joy and Terry Cesar, Hezekiah, Harmony, Haven and Hart, Avery, Aubrey and Anthony, and Ken Taborsky at Kota the North for all of his website help. Okay, Hope in Heaven, are you ready to hear the mystery sound again? Yes. Yes. Okay, here it is. Okay, my guess was I had two guesses, the washing machine or a microwave, but I'm kind of leaning towards the microwave now after I heard the sound. So, I like her, I have both the washing machine and the microwave, but I'm kind of leaning to the washing machine because it really sounds like that. Okay, I love it. You guys ready to hear the answer? Yes. Okay, here's the answer. Hi. My name is Rosa. I'm from Somerset, and that was the sound of my dad turning on the washing machine. Washing machine is correct. I'm straight. I'm straight. Nice. Incredible work. You were both right the first time. Yes. And then we got distracted by a microwave, which is totally fine because microwaves do kind of sound like that too. So, I totally get it. Yeah, like the beeping and then the closing the door. Mm-hmm. Well, great ears you guys. I'm very impressed. Thank you. Now it's time for the brain's honor roll. The incredible kids who keep the show going with their questions, ideas, mystery sounds, drawings, and high fives. Elizabeth from Calgary, Thomas from Sao Paulo, Leo from Lafayette, Colorado. You reached the top of your list of best-selling books. And you're now on the list of best-selling books. And you're now on the list of best-selling books. And you're now on the list of best-selling books. And you're now on the list of best-selling books. Thomas from Sao Paulo, Leo from Lafayette, Colorado. Yuretsa from La Grande, California. Zoe from Los Altos, California. Noah from Wellwind Garden City, United Kingdom. Jackson from Palisade, California. Hannah from Danvers, Massachusetts. Audrey from Seattle. Smya from Singapore. Holden from Culver City, California. And Tanella from Waukegan, Illinois. Moran from Calgary. Mia Rose from Perth, Australia. TJ from Boston. Ekum from San Francisco. Ren from Victoria, British Columbia. Noah from Seoul. Maya from San Diego. Francis from Lincoln, Nebraska. Kira and Luke from Marietta, Georgia. Clara from Edmonton, Alberta. Miles from Westport, Connecticut. Isabel and Gia from Encino, California. Eleanor from Pleasant Hill, California. Barrett from Winter Park, Florida. Wade from Denver. Judah from Munich, Germany. Victor from Santander, Spain. James from Nashville. Addison from Plainfield, Illinois. Joan from Seattle. Arlo from Wellington, New Zealand. Katherine from Madison, Wisconsin. Aubrey and Noah from Grand Rapids, Michigan. Flynn from Lehigh, Utah. Oliver from Santiago de Compostela, Spain. Ben from San Francisco. Rhett, Cleo and Dax from Los Angeles. Amelia from Denver. Lucy from Saskatoon. Chris from Wellington, New Zealand. Ivy from Kiesel Town, Virginia. Roan from Eagle River, Alaska. Caleb from Randolph, New Jersey. Ivy and Marcus from St. Louis. Larry and Annie from Los Angeles. Ishaan from Sunnyvale, California. Ben from Chesapeake, Virginia. Aowyn from Orangevale, California. Evie from Austin, Texas. Judah from McDonough, Georgia. Kaimani from London, England. Odette from El Paso, Texas. Coralyn from Simsbury, Connecticut. Ezra from Portland, Maine. Marley from Toronto. Felix from Calgary. Leonardo from Escondido, California. Edward from Ridgefield, Connecticut. Everly from Aldergrove, British Columbia. Milo from Golden, Colorado. Abby from Elm Grove, Wisconsin. Asha from Torrance, California. Sebastian from Toronto. And Isaac from Gallup, New Mexico. We'll be back next week with an episode about the Earth spinning. Thanks for listening.