How do vacuums work?
APM Studios
Vacuums are full of surprises! Did you know that they blow air out to suck things up? Or that old-fashioned vacuums were so huge, they had to be hauled from house to house by horses?!
Join Molly and co-host Baker as they learn all about these awesome appliances. They’ll dig into vacuum history, shrink to the size of air molecules and explore the inside of this curious contraption, and even check out a vacuum museum in Missouri. All that, plus a tricky new mystery sound that will blow you away!
Featured Expert: Tom Gasko, vacuum repairman and collector. You’ll find his collection in Rolla, MO at Mid Missouri Vacuum.
Audio Transcript
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BAKER: You're listening to Brains On, where we're serious about being curious.
CHILD: Brains On is supported in part by a grant from the National Science Foundation.
BAKER: Tom Gasko has loved vacuums ever since he was a little kid.
TOM GASKO: When my mother would go visit her friends from high school, we would go. And after about 20 minutes, the lady whose home we were in would notice that I wasn't in the room anymore. And she would ask my mother, where is Tom? Well, my mother would say, where do you keep your vacuum cleaner, because that's where Tom is?
Trust me, when he's done with it, he's going to take the hair off of the brush roll. He's going to clean the filter. He'll put a clean bag in, and maybe even wipe it off. And then they might let me run it. That was a treat. I was very little. So this was a thrill.
MOLLY BLOOM: Tom loves vacuums so much that to him, the sounds they make are music.
TOM GASKO: Vacuum cleaners all hit different notes. The pitch of a motor is a musical note. So some of them are very loud, and some of them are very muffled and quiet. And so it was always interesting to plug it in and push that button for the first time to see what that monster sounded like.
BAKER: For Tom, the shape of every vacuum is a beautiful sculpture.
MOLLY BLOOM: And the way the dirt moves as it gets sucked in is like dancing.
TOM GASKO: As a vacuum cleaners rotating brush rotates, it taps a carpet and makes the sand and grit and the debris kind of move a little bit. So right before you come up to it, you'll see that the stuff is moving. My thrill was to watch that stuff move, but never quite get the vacuum far enough to where it inhaled it.
BAKER: Today, Tom runs a vacuum repair shop in Missouri, but also a museum dedicated to his personal collection of vacuums. He has 600 of them.
MOLLY BLOOM: The oldest is from 1879. And he even has one he designed himself.
BAKER: Today, we're going to get a peek inside Tom's collection.
MOLLY BLOOM: And inside the vacuums themselves.
BAKER: This episode is guaranteed to suck you in. Sing it, vacuums.
MOLLY BLOOM: You're listening to Brains On from APM Studios. I'm Molly Bloom, and my co-host today is Baker from Snoqualmie, Washington. Hi, Baker.
BAKER: Hi, Molly.
MOLLY BLOOM: You sent us this question last year, and it was very hard to resist.
BAKER: Hello, Brains On. I was wondering about the history of vacuum cleaners, how they work, what is a vacuum anyways. And it just vacuums? So I would really like it if you could help me out. Thank you.
MOLLY BLOOM: So, Baker, how did you first get interested in vacuums?
BAKER: I saw this TV advertisement, and I thought it was cool.
MOLLY BLOOM: Do you remember what it was about that advertisement that really made you interested?
BAKER: I think something about having multiple tools that you could switch out. And it made it super cool to my young brain.
MOLLY BLOOM: So within different tools, you mean sort of like there's different attachments you can use?
BAKER: Yeah. There's this stick one that helps clean up in all the corners. And there's the carpet one, the hardwood one, just a lot of them.
MOLLY BLOOM: And you're like, that can do so many things. That's so cool.
BAKER: Yeah.
MOLLY BLOOM: So do you have a favorite vacuum?
BAKER: My favorite vacuum is a stick wireless vacuum.
MOLLY BLOOM: OK, please describe that more to me. So it's wireless, meaning you don't have to plug it in?
BAKER: Yeah. And it has a battery.
MOLLY BLOOM: And what makes it a stick?
BAKER: There's one part that has the motor in it, and the rest is just a long stick with the two at the bottom.
MOLLY BLOOM: Gotcha. So it's almost like a broom.
BAKER: Yeah.
MOLLY BLOOM: So what is your favorite thing about vacuums?
BAKER: When I'm sweeping, I get usually very annoyed with how hard it is to get all the places and then sweep it all up and then put it in the dustpan. Vacuums, it basically does that all in half the time and effort.
MOLLY BLOOM: I understand that you love vacuum so much that you even asked for one for a Christmas present. Can you tell us about that?
BAKER: It's this Dyson cordless stick vacuum with the different attachments that I saw on that ad.
MOLLY BLOOM: And did you get it?
BAKER: Yes, I did. It's now our main vacuum. We also have a Bissell at home, but we usually use the Dyson.
MOLLY BLOOM: How old were you when you asked for the Christmas vacuum?
BAKER: Six.
MOLLY BLOOM: So do you still like vacuums as much as you did when you were six?
BAKER: No, I enjoy vacuuming because it's a bit of one of those things that is calming. But I prefer reading and doing video games.
MOLLY BLOOM: OK, so you're like, I'll still-- I still appreciate the vacuum, but it's not like your favorite thing like it used to be.
BAKER: Yeah.
ROBOT: Brains, brains, brains on.
MOLLY BLOOM: Before we get into the history of vacuums, let's look at how these magnificent machines work. And to do that, we're going to hop into one of our special vehicles, the ATOM.
BAKER: Ooh, that stands for the Amazing Truck Of Minimization. I've always wanted to go inside a truck that can shrink me down and take me inside of things.
MOLLY BLOOM: Way to dream, big Baker-- or small. Hop in.
Can you please push the big blue shrink button?
BAKER: On it.
MOLLY BLOOM: Oops, you've made us squirrel size. And now Penelope The Poodle is headed this way.
BAKER: What should I do?
MOLLY BLOOM: Don't panic. This is easy. See that dial over there? Just move it from squirrel size, past tennis ball size, past dog treat.
BAKER: Did a dog build this thing?
MOLLY BLOOM: No, but it did go through a thorough, multi-step review process from our Brains On Dog Advisory Council.
BAKER: Penelope is getting closer.
MOLLY BLOOM: Turn the dial to flea size and then press the Shrink button again. Perfect. Now we're too small for her to see. And we're the perfect size to get sucked up by a vacuum.
BAKER: I hear it coming now.
MOLLY BLOOM: Yes. Hear that musical roar? That's the sound of the vacuum's motor and air moving through the machine.
BAKER: That's why modern vacuums need to be plugged in or have a battery to make the motor go.
MOLLY BLOOM: And the motor is making a fan move that blows air back out of the vacuum.
BAKER: Blows out? Excuse me. I think you mean sucks in.
MOLLY BLOOM: It's actually both. I know, it's kind of mind-blowing. Here's how it works.
Even though air is invisible, it's made up of stuff called air molecules. Molecules are teeny tiny, so we can't see them with our eyes or even microscopes. We're going to have to get even smaller to see how this vacuum works. Baker, switch the dial to molecule size and push Shrink. OK, now we're the same size as the molecules that make up the air.
BAKER: Whoa. Those dust bunnies are huge. And I can see the air molecules.
MOLLY BLOOM: Wild, right? Here's the thing about air molecules, they want to be spread out evenly. So if something causes the molecules to be blown away, new ones will want to move in to take their place.
BAKER: The vacuum is getting closer.
MOLLY BLOOM: See how the air molecules closer to the vacuum are going inside? That's because the vacuums fan has blown out the air molecules that were inside of it. So now there's a spot inside the vacuum where those air molecules used to be. It's empty. And remember, these little molecules want to be spread out evenly.
BAKER: So the air molecules nearby swoop in to balance it out.
MOLLY BLOOM: And as they swoop in, they take with them the nearby dirt and sand and--
BAKER: Us.
MOLLY BLOOM: And now we're getting blown out the other side of the vacuum with the air.
BAKER: Wow, what a ride. But what happened to all the dirt and dust?
MOLLY BLOOM: If we were still as big as a flea, we would have gotten pulled up into the part of the vacuum that collects the dirt and other little particles. It can trap those things, because they're bigger than air. But since we're air-sized, we're too small to get trapped by the vacuum. So the vacuums fan blew us right back out.
OK, you can unshrinkinate us. Turn the dial to human size, and then press the blue button again.
BAKER: What an adventure.
MOLLY BLOOM: And an educational one at that.
BAKER: I didn't know that to suck stuff up, vacuums have to blow air out.
MOLLY BLOOM: Here's another cool thing. Before the vacuum was invented, some people were trying to make machines that would blow dirt into a container rather than suck it in. Turns out, that didn't work.
BAKER: Sounds messy. So who finally figured out vacuums?
MOLLY BLOOM: It was the early 1900s in England.
BAKER: Oh, yeah. Back then, people mostly got around using horses and carriages. They were just starting to put telephones in their homes, but they didn't have any TV or radio.
MOLLY BLOOM: You really know your history.
BAKER: Well, I listened to "Forever Ago," the excellent history podcast hosted by Joy Dolo.
MOLLY BLOOM: That is a great podcast. But back to vacuums. Remember, how I mentioned that the first vacuums blew dirt into containers? Well, in 1901, an inventor named Hubert Cecil Booth saw this blowing cleaning machine on display in London and thought he could do better.
Hubert thought it would make more sense to have a machine that sucked dirt in.
BAKER: That does make more sense.
MOLLY BLOOM: Yes. Other engineers told Hubert that it was impossible to make a machine that could suck in dirt, but Hubert had designed bridges and Ferris wheels, so he was pretty sure he could tackle this, too. And he did.
BAKER: Way to go, Hubert.
MOLLY BLOOM: The first vacuum he created was not like the ones we have in our homes today. In fact, this vacuum was so big it couldn't even fit in a house. It was as big as a minivan and was pulled from house to house by horses. It was nicknamed Puffing Billy.
BAKER: I love that.
MOLLY BLOOM: Me, too. So, Baker, have you given any of your vacuums nicknames?
BAKER: No, but as soon as I get home, I'm planning to.
MOLLY BLOOM: Nice. Do you have any ideas?
BAKER: Maybe Dust Striker, because it strikes the dust bunnies in the face.
MOLLY BLOOM: Nice. I love that name. It's action-packed. So Puffing Billy would go house to house. And because it was too big to fit inside, a worker would put a hose in through the window and suck up dirt through a big tube. Even though it was noisy and clunky, the machine did the job incredibly well and was very popular, at least for the people who could afford it.
One visit from the vacuum could cost the same as someone might pay a maid to clean their house for a whole year. It was really only something the very rich could afford. What do you think about that, Baker?
BAKER: I think that we're lucky that in our day, vacuums cost a lot less.
MOLLY BLOOM: But back then, these very rich and fancy people loved this new technology. They would even host vacuuming parties where they would have their friends over to eat fancy sandwiches, cut into little triangles, and watch the vacuum, suck out all their dead skin cells, caviar crumbs, and the fur from their purebred exotic cats.
BAKER: OK. I love vacuums and I love parties. How have I not thought of this?
MOLLY BLOOM: Baker, can you imagine a huge horse-drawn vacuum going door to door?
BAKER: I can imagine that if it's in olden times. Right now, I think it would most likely be driven by a car.
MOLLY BLOOM: Good point. Do you think people would like this kind of service today, like if it just came door to door and put a giant hose in your window?
BAKER: No, I think people would just, like, go out, say, get out my yard and just use their own vacuum.
MOLLY BLOOM: Fair, fair. So you do love vacuums and you do love parties. Would you want to go to a vacuum party?
BAKER: If it was a party for vacuums like birthday. But I don't want to, I mean, eat food and just enjoy myself while there's a huge vacuum going on, and I can't talk to anyone because it's so loud.
MOLLY BLOOM: That's a great point that I did not think of. Yeah, it must be so loud at the vacuum party. That would be very hard to socialize. But I love your idea of it being a party for vacuums to attend. That's brilliant. OK, so Dut Striker have to have a birthday party coming up, I think?
BAKER: I think its fifth birthday is around Christmas, maybe like January 1st. I think that would just be an appropriate time, because that's when we started really using the vacuum every day.
MOLLY BLOOM: Absolutely. I can't wait for you to throw this birthday party. Please take pictures and send it to us.
BAKER: Understood.
MOLLY BLOOM: Well, we're going to hear how vacuums finally got small enough to come inside. But first, I have something that's small enough to fit in your ear, Baker. It's the--
[WHOOSHING]
[HIGH-PITCHED SOUND]
CHILD: [WHISPERING] Mystery sound.
MOLLY BLOOM: Are you ready?
BAKER: Yeah.
MOLLY BLOOM: OK. Here it is.
[TAP]
[TAP]
[TAP]
MOLLY BLOOM: Hmm. Let's hear it again.
[TAP]
[TAP]
[TAP]
MOLLY BLOOM: What do you think, Baker?
BAKER: It sounds mysteriously like a ping pong ball hitting a wooden table. I may or may not have tried to play table tennis but just did not work out.
MOLLY BLOOM: [LAUGHING] That's a really good guess. And to be honest with you, I don't know what this is either. And I also heard that ping pong ball sound. That's what I was thinking. OK, so we're on the same page. We're going to hear it again, get another chance to guess and hear the answer after the credits, so stick around.
[MUSIC PLAYING]
We love hearing from you. We love getting your questions, mystery sounds, and high fives. You're all so curious and smart. And something that we find extra super duper delightful is when you send us your artwork inspired by the show. Maybe you want to draw a picture of me and Baker in the atom shrinking down to the size of a molecule, or maybe Penelope poodle or maybe a collection of vacuums? Whatever you want to draw, we would love to see it. You can send us your drawings at brainson.org/contact. And while you're there, you can send us mystery sounds, drawings, and questions.
BAKER: Like this one.
CHILD: When did people first start having pets?
MOLLY BLOOM: You can find answers to questions like these on the Moment of Um podcast. It's a daily dose of facts and fun every weekday. You can find it wherever you listen to Brains On. Just search for Moment of Um.
BAKER: So keep listening.
ANNOUNCER: Brains On! Universe is a family of podcasts for kids and their adults. And since you're a fan of Brains On, we know you'll love the other shows in our universe. Come on, let's explore.
ROBOT: Entering Brains On! Universe. Whoa. So many podcasts! Brains On, Smash Boom Best, Forever Ago. Picking up signal. Forever Ago, a history podcast starring Joy Dolo.
JOY DOLO: Flare's gum was so sticky when the bubble popped. It was so hard to get off your skin. You'd have to scrub it off with harsh chemicals.
ROBOT: Me love sticky facts! Zorp! Signal down. Quick, need Forever Ago now!
ANNOUNCER: Search for Forever Ago wherever you get your podcasts.
ROBOT: (SINGING) Brains On. On. On.
BAKER: You're listening to Brains On. I'm Baker.
MOLLY BLOOM: And I'm Molly. And today, we're talking about vacuums.
BAKER: Before the break, we learned that vacuums work by blowing air out using a fan and a motor.
MOLLY BLOOM: That makes new air molecules rush to fill the space, bringing with them the dirt and dust from our floors. The first vacuums were as big as minivans, and people would pull them from house to house using horse drawn carriages.
BAKER: But over time, vacuum technology has changed a lot.
MOLLY BLOOM: About 100 years ago, lots of tools and household appliances started to be made much more cheaply.
BAKER: And they shrunk down to personal size, so you could actually fit them in your house.
SHAHLA FARZAN: OK, Molly. Hey, Baker.
MOLLY BLOOM: Brains On editor, Shahla Farzan.
SHAHLA FARZAN: I heard you were talking about one of my favorite appliances-- vacuums. And I just had to stop by. I actually just got back from a trip to a vacuum cleaner museum.
BAKER: Seriously? That's so cool.
SHAHLA FARZAN: It was cooler than cool. The museum is inside this vacuum repair shop in Missouri, and it's run by a guy named Tom Gasko.
BAKER: We know Tom. He's the guy we heard at the very beginning of the show. He loves vacuums.
SHAHLA FARZAN: He does. And I got to see Tom's vacuum collection in person. Some of them are super old, like more than 100 years old. And the earliest ones didn't even use electricity or motors. Tom showed me one with a really rad name.
TOM GASKO: Here is the dust killer.
SHAHLA FARZAN: Is that what it's actually called?
TOM GASKO: Yeah, that's what it's called.
SHAHLA FARZAN: Wow.
TOM GASKO: So the dust killer has got bellows. The kids would stand right there and move that lever back and forth.
BAKER: The dust killer? That is a great name.
SHAHLA FARZAN: It had something called bellows, which is sort of like an air pump that you move by hand and that would help suck up the dirt.
BAKER: What about the first electric vacuums? Did Tom have any of those in his collection?
SHAHLA FARZAN: Yeah, he had this really old one from 1910. It had a long handle with a bag hanging off of it. And here's how it worked. The dust and dirt got vacuumed up inside using the electric motor. And then it was trapped in a bag.
BAKER: Oh, yeah. There are still vacuums like that today. Once the dirt's inside the bag, you empty it or you place it with a new one.
SHAHLA FARZAN: Right. Tom said vacuums started changing pretty fast after this point. By the 1920s, the first canister vacuum made its debut.
MOLLY BLOOM: Those are the kind that have a long hose attached to a body or a canister that moves around the floor.
SHAHLA FARZAN: One of my favorite things about looking through Tom's collection was seeing just how much vacuum style has changed over the years based on what people thought looked good. He showed me one vacuum that looked just like R2-D2 from Star Wars and another one called the Hoover floating vacuum.
BAKER: It floated?
SHAHLA FARZAN: Kind of. It used air to hover just over the floor. Here, listen to this.
TOM GASKO: The Hoover has no wheels or runners. When you turn it on, the air comes out the saucer on the bottom, and it floats, it lifts the vacuum up off of the floor and it floats behind you on a cushion of air. It's the coolest thing.
SHAHLA FARZAN: Is this from the 60s or--
TOM GASKO: You can tell it's the 60s because not only the color, but it's designed to look like the planet Saturn. In the 60s, we were trying to get to the moon. And The Jetsons, Star Trek. These were new TV shows. Science fiction TV shows were all the rage. And so vacuum cleaners, which followed what was happening in the world, just became very much like planets or spacecrafts.
SHAHLA FARZAN: Tom even had a vacuum in his collection that he designed himself. It was purple and silver with all kinds of special features like big wheels. So it could go up and down stairs. But I think one of the best things about Tom's collection is that every single vacuum still works.
MOLLY BLOOM: Wow. That's pretty amazing. You know, vacuums used to be very expensive. Buying one was a big deal.
BAKER: Yeah. If you're spending a lot of money, you want to make a good choice.
SHAHLA FARZAN: Right. You'd pick out the perfect vacuum for your house, depending on its size, layout, what kind of floor you had. And if your vacuum stopped working, you wouldn't just throw it out, you'd take it to get fixed. Tom still has the vacuum his mom bought just before he was born, back in 1962. It cost $250 back then, which today would be more than $2,000. But that vacuum still works.
TOM GASKO: You know, if you buy a good vacuum, you can have it your whole life. Literally. My mother bought one vacuum cleaner her entire life. And there it is. I have it. And I still use it and it still works. It's quiet. It's efficient.
BAKER: Whoa, that's so cool. I can't wait to buy my forever vacuum.
MOLLY BLOOM: Ditto. Thanks for telling us about your vacuum adventure, Shahla.
SHAHLA FARZAN: Oh, you bet. Bye, Molly. See you, Baker.
BAKER: See you!
CHILDREN: Brains On!
MOLLY BLOOM: Vacuums have changed a lot over the past 100 years, and they don't just look different. There have been lots of developments in vacuum technology.
BAKER: Yeah, robot vacuums that can clean your house on their own have been around for almost 30 years and they've gotten so advanced.
MOLLY BLOOM: Today, scientists are working on robot vacuums that can memorize the layout of a room, avoid a sleeping dog, and take voice directions from their owners.
BAKER: And today, vacuums do more than just clean homes and schools and offices.
MOLLY BLOOM: There are these huge vacuum trucks that look remarkably similar to the early vacuums we talked about. They've got long attachments mounted onto big semi trucks, but instead of going door to door to suck the dirt out of expensive carpets and rich neighborhoods, these are used to help clean up after natural disasters.
BAKER: These giant vacuum trucks can suck up debris, floodwater, and even hazardous chemicals that are dangerous for humans to touch.
MOLLY BLOOM: Natural disasters like hurricanes and wildfires are happening more often because of climate change. And so these trucks are being used more and more often.
BAKER: Luckily, vacuum technology might also be able to help us slow down climate change.
MOLLY BLOOM: Climate change is happening because humans are putting more greenhouse gases into the atmosphere like carbon dioxide. It's released by burning fossil fuels like the gasoline in our cars.
BAKER: Yeah, but some companies are developing giant vacuums that can suck carbon dioxide out of the air and trap it in special containers.
MOLLY BLOOM: And then that carbon dioxide can be used to make bubbles in drinks like soda and seltzer. Some of these vacuum companies are even starting to sell the carbon dioxide to beverage companies.
BAKER: Refreshing.
MOLLY BLOOM: Vacuums keep our homes clean and may also one day help keep our planet clean.
BAKER: Cheers to that.
[MUSIC PLAYING]
MOLLY BLOOM: Air molecules want to be spread out evenly.
BAKER: So vacuums work by creating a space inside the vacuum where there aren't air molecules.
MOLLY BLOOM: Air molecules want to go inside the vacuum to even things out, and that air takes dirt and dust with it. The dirty stuff is trapped by the vacuum and the air blows back out.
BAKER: The first vacuums were invented more than 100 years ago. They're as big as a minivan and were super expensive to use.
MOLLY BLOOM: But over time, they got smaller. Inventors started coming up with vacuums in all different shapes, colors and designs.
BAKER: And their designs and technology are still changing today.
MOLLY BLOOM: That's it for this episode of Brains On.
BAKER: This episode was written by--
MOLLY BLOOM: Molly Bloom.
BAKER: And--
NICO GONZALEZ-WISLER: Nico Gonzalez-Wisler.
BAKER: It was produced by--
ROSIE DUPONT: Rosie Dupont.
BAKER: Our editors are--
SHAHLA FARZAN: Shahla Farzan.
BAKER: And--
SANDEN TOTTEN: Sanden Totten.
BAKER: Fact checking by
RUBY GUTHRIE: Ruby Guthrie.
MOLLY BLOOM: We had engineering help from Tim Meinig, Robert Jacob Springer and Derek Ramirez with sound design by--
RACHEL BREES: Rachel Brees.
MOLLY BLOOM: Original theme music by--
MARC SANCHEZ: Marc Sanchez.
BAKER: We had production help from the rest of the Brains On! Universe team--
ANNA GOLDFIELD: Anna Goldfield.
LAUREN HUMBERT: Lauren Humbert.
JOSHUA RAY: Joshua Ray.
MARC SANCHEZ: Marc Sanchez.
CHARLOTTE TRAVER: Charlotte Traver.
ANNA WEGEL: Anna Weggel.
BAKER: And--
ARON WELDESELASSIE: Aron Weldeselassie.
MOLLY BLOOM: Beth Perlman is our executive producer. And the executives in charge of APM Studios are Chandra Kavati and Joanne Griffith. Special thanks to Janine Saltman, Lucas saltman and Delta.
BAKER: Brains On is a non-profit public radio program.
MOLLY BLOOM: There are lots of ways to support the show. Subscribe to Brains On Universe on YouTube, where you can watch animated versions of some of your favorite episodes or head to brainson.org.
BAKER: While you're there, you can send us mystery sounds, drawings, and questions.
MOLLY BLOOM: OK. Baker, are you ready to hear the mystery sound again?
BAKER: Yeah. All right, here it is.
MOLLY BLOOM: What do you think now?
BAKER: Well, maybe, it-- I'm still going with my first answer, but also that it reminded me of like, that toy where there's a ping pong ball on a string attached to a paddle. So ping pong ball hitting something.
MOLLY BLOOM: I'm going to guess-- a person playing ping pong, but, like, very slowly. So, like, maybe in lesser gravity. So maybe they're playing ping pong on the moon.
BAKER: Yeah. I don't understand how the person was able to get us that sound if they're on Earth.
MOLLY BLOOM: Fair point. All right. Well, should we hear the answer?
BAKER: Yes.
MOLLY BLOOM: All right, here it is.
NOAH: Hi, I'm Noah from New South Wales, Australia. And that is the sound of me throwing darts on a dart board.
MOLLY BLOOM: Oh. Darts on a dart board.
BAKER: I can't say I've heard that before.
MOLLY BLOOM: Well, I think you were close because we were thinking, like, playing a game of some sort, right?
BAKER: Yeah, like with stuff hitting stuff.
MOLLY BLOOM: Exactly. You're not that far off. So yeah, so darts, there's like, that's where the game, where there's a board hanging on the wall that's like a circle.
BAKER: And then you throw these things at it. And the closer you get to the center, the more points you get.
MOLLY BLOOM: Exactly. Yeah. And those are called darts. I guess we have to play darts now.
BAKER: Yeah.
MOLLY BLOOM: Now, it's time for the Brains Honor Roll. These are the kids who keep the show going with their questions, ideas, mystery sounds.
[LISTING HONOR ROLL]
We'll be back next week with an episode all about body temperature.
BAKER: Thanks for listening.
CHILD: Brains On is supported in part by a grant from the National Science Foundation.
BAKER: Tom Gasko has loved vacuums ever since he was a little kid.
TOM GASKO: When my mother would go visit her friends from high school, we would go. And after about 20 minutes, the lady whose home we were in would notice that I wasn't in the room anymore. And she would ask my mother, where is Tom? Well, my mother would say, where do you keep your vacuum cleaner, because that's where Tom is?
Trust me, when he's done with it, he's going to take the hair off of the brush roll. He's going to clean the filter. He'll put a clean bag in, and maybe even wipe it off. And then they might let me run it. That was a treat. I was very little. So this was a thrill.
MOLLY BLOOM: Tom loves vacuums so much that to him, the sounds they make are music.
TOM GASKO: Vacuum cleaners all hit different notes. The pitch of a motor is a musical note. So some of them are very loud, and some of them are very muffled and quiet. And so it was always interesting to plug it in and push that button for the first time to see what that monster sounded like.
BAKER: For Tom, the shape of every vacuum is a beautiful sculpture.
MOLLY BLOOM: And the way the dirt moves as it gets sucked in is like dancing.
TOM GASKO: As a vacuum cleaners rotating brush rotates, it taps a carpet and makes the sand and grit and the debris kind of move a little bit. So right before you come up to it, you'll see that the stuff is moving. My thrill was to watch that stuff move, but never quite get the vacuum far enough to where it inhaled it.
BAKER: Today, Tom runs a vacuum repair shop in Missouri, but also a museum dedicated to his personal collection of vacuums. He has 600 of them.
MOLLY BLOOM: The oldest is from 1879. And he even has one he designed himself.
BAKER: Today, we're going to get a peek inside Tom's collection.
MOLLY BLOOM: And inside the vacuums themselves.
BAKER: This episode is guaranteed to suck you in. Sing it, vacuums.
MOLLY BLOOM: You're listening to Brains On from APM Studios. I'm Molly Bloom, and my co-host today is Baker from Snoqualmie, Washington. Hi, Baker.
BAKER: Hi, Molly.
MOLLY BLOOM: You sent us this question last year, and it was very hard to resist.
BAKER: Hello, Brains On. I was wondering about the history of vacuum cleaners, how they work, what is a vacuum anyways. And it just vacuums? So I would really like it if you could help me out. Thank you.
MOLLY BLOOM: So, Baker, how did you first get interested in vacuums?
BAKER: I saw this TV advertisement, and I thought it was cool.
MOLLY BLOOM: Do you remember what it was about that advertisement that really made you interested?
BAKER: I think something about having multiple tools that you could switch out. And it made it super cool to my young brain.
MOLLY BLOOM: So within different tools, you mean sort of like there's different attachments you can use?
BAKER: Yeah. There's this stick one that helps clean up in all the corners. And there's the carpet one, the hardwood one, just a lot of them.
MOLLY BLOOM: And you're like, that can do so many things. That's so cool.
BAKER: Yeah.
MOLLY BLOOM: So do you have a favorite vacuum?
BAKER: My favorite vacuum is a stick wireless vacuum.
MOLLY BLOOM: OK, please describe that more to me. So it's wireless, meaning you don't have to plug it in?
BAKER: Yeah. And it has a battery.
MOLLY BLOOM: And what makes it a stick?
BAKER: There's one part that has the motor in it, and the rest is just a long stick with the two at the bottom.
MOLLY BLOOM: Gotcha. So it's almost like a broom.
BAKER: Yeah.
MOLLY BLOOM: So what is your favorite thing about vacuums?
BAKER: When I'm sweeping, I get usually very annoyed with how hard it is to get all the places and then sweep it all up and then put it in the dustpan. Vacuums, it basically does that all in half the time and effort.
MOLLY BLOOM: I understand that you love vacuum so much that you even asked for one for a Christmas present. Can you tell us about that?
BAKER: It's this Dyson cordless stick vacuum with the different attachments that I saw on that ad.
MOLLY BLOOM: And did you get it?
BAKER: Yes, I did. It's now our main vacuum. We also have a Bissell at home, but we usually use the Dyson.
MOLLY BLOOM: How old were you when you asked for the Christmas vacuum?
BAKER: Six.
MOLLY BLOOM: So do you still like vacuums as much as you did when you were six?
BAKER: No, I enjoy vacuuming because it's a bit of one of those things that is calming. But I prefer reading and doing video games.
MOLLY BLOOM: OK, so you're like, I'll still-- I still appreciate the vacuum, but it's not like your favorite thing like it used to be.
BAKER: Yeah.
ROBOT: Brains, brains, brains on.
MOLLY BLOOM: Before we get into the history of vacuums, let's look at how these magnificent machines work. And to do that, we're going to hop into one of our special vehicles, the ATOM.
BAKER: Ooh, that stands for the Amazing Truck Of Minimization. I've always wanted to go inside a truck that can shrink me down and take me inside of things.
MOLLY BLOOM: Way to dream, big Baker-- or small. Hop in.
Can you please push the big blue shrink button?
BAKER: On it.
MOLLY BLOOM: Oops, you've made us squirrel size. And now Penelope The Poodle is headed this way.
BAKER: What should I do?
MOLLY BLOOM: Don't panic. This is easy. See that dial over there? Just move it from squirrel size, past tennis ball size, past dog treat.
BAKER: Did a dog build this thing?
MOLLY BLOOM: No, but it did go through a thorough, multi-step review process from our Brains On Dog Advisory Council.
BAKER: Penelope is getting closer.
MOLLY BLOOM: Turn the dial to flea size and then press the Shrink button again. Perfect. Now we're too small for her to see. And we're the perfect size to get sucked up by a vacuum.
BAKER: I hear it coming now.
MOLLY BLOOM: Yes. Hear that musical roar? That's the sound of the vacuum's motor and air moving through the machine.
BAKER: That's why modern vacuums need to be plugged in or have a battery to make the motor go.
MOLLY BLOOM: And the motor is making a fan move that blows air back out of the vacuum.
BAKER: Blows out? Excuse me. I think you mean sucks in.
MOLLY BLOOM: It's actually both. I know, it's kind of mind-blowing. Here's how it works.
Even though air is invisible, it's made up of stuff called air molecules. Molecules are teeny tiny, so we can't see them with our eyes or even microscopes. We're going to have to get even smaller to see how this vacuum works. Baker, switch the dial to molecule size and push Shrink. OK, now we're the same size as the molecules that make up the air.
BAKER: Whoa. Those dust bunnies are huge. And I can see the air molecules.
MOLLY BLOOM: Wild, right? Here's the thing about air molecules, they want to be spread out evenly. So if something causes the molecules to be blown away, new ones will want to move in to take their place.
BAKER: The vacuum is getting closer.
MOLLY BLOOM: See how the air molecules closer to the vacuum are going inside? That's because the vacuums fan has blown out the air molecules that were inside of it. So now there's a spot inside the vacuum where those air molecules used to be. It's empty. And remember, these little molecules want to be spread out evenly.
BAKER: So the air molecules nearby swoop in to balance it out.
MOLLY BLOOM: And as they swoop in, they take with them the nearby dirt and sand and--
BAKER: Us.
MOLLY BLOOM: And now we're getting blown out the other side of the vacuum with the air.
BAKER: Wow, what a ride. But what happened to all the dirt and dust?
MOLLY BLOOM: If we were still as big as a flea, we would have gotten pulled up into the part of the vacuum that collects the dirt and other little particles. It can trap those things, because they're bigger than air. But since we're air-sized, we're too small to get trapped by the vacuum. So the vacuums fan blew us right back out.
OK, you can unshrinkinate us. Turn the dial to human size, and then press the blue button again.
BAKER: What an adventure.
MOLLY BLOOM: And an educational one at that.
BAKER: I didn't know that to suck stuff up, vacuums have to blow air out.
MOLLY BLOOM: Here's another cool thing. Before the vacuum was invented, some people were trying to make machines that would blow dirt into a container rather than suck it in. Turns out, that didn't work.
BAKER: Sounds messy. So who finally figured out vacuums?
MOLLY BLOOM: It was the early 1900s in England.
BAKER: Oh, yeah. Back then, people mostly got around using horses and carriages. They were just starting to put telephones in their homes, but they didn't have any TV or radio.
MOLLY BLOOM: You really know your history.
BAKER: Well, I listened to "Forever Ago," the excellent history podcast hosted by Joy Dolo.
MOLLY BLOOM: That is a great podcast. But back to vacuums. Remember, how I mentioned that the first vacuums blew dirt into containers? Well, in 1901, an inventor named Hubert Cecil Booth saw this blowing cleaning machine on display in London and thought he could do better.
Hubert thought it would make more sense to have a machine that sucked dirt in.
BAKER: That does make more sense.
MOLLY BLOOM: Yes. Other engineers told Hubert that it was impossible to make a machine that could suck in dirt, but Hubert had designed bridges and Ferris wheels, so he was pretty sure he could tackle this, too. And he did.
BAKER: Way to go, Hubert.
MOLLY BLOOM: The first vacuum he created was not like the ones we have in our homes today. In fact, this vacuum was so big it couldn't even fit in a house. It was as big as a minivan and was pulled from house to house by horses. It was nicknamed Puffing Billy.
BAKER: I love that.
MOLLY BLOOM: Me, too. So, Baker, have you given any of your vacuums nicknames?
BAKER: No, but as soon as I get home, I'm planning to.
MOLLY BLOOM: Nice. Do you have any ideas?
BAKER: Maybe Dust Striker, because it strikes the dust bunnies in the face.
MOLLY BLOOM: Nice. I love that name. It's action-packed. So Puffing Billy would go house to house. And because it was too big to fit inside, a worker would put a hose in through the window and suck up dirt through a big tube. Even though it was noisy and clunky, the machine did the job incredibly well and was very popular, at least for the people who could afford it.
One visit from the vacuum could cost the same as someone might pay a maid to clean their house for a whole year. It was really only something the very rich could afford. What do you think about that, Baker?
BAKER: I think that we're lucky that in our day, vacuums cost a lot less.
MOLLY BLOOM: But back then, these very rich and fancy people loved this new technology. They would even host vacuuming parties where they would have their friends over to eat fancy sandwiches, cut into little triangles, and watch the vacuum, suck out all their dead skin cells, caviar crumbs, and the fur from their purebred exotic cats.
BAKER: OK. I love vacuums and I love parties. How have I not thought of this?
MOLLY BLOOM: Baker, can you imagine a huge horse-drawn vacuum going door to door?
BAKER: I can imagine that if it's in olden times. Right now, I think it would most likely be driven by a car.
MOLLY BLOOM: Good point. Do you think people would like this kind of service today, like if it just came door to door and put a giant hose in your window?
BAKER: No, I think people would just, like, go out, say, get out my yard and just use their own vacuum.
MOLLY BLOOM: Fair, fair. So you do love vacuums and you do love parties. Would you want to go to a vacuum party?
BAKER: If it was a party for vacuums like birthday. But I don't want to, I mean, eat food and just enjoy myself while there's a huge vacuum going on, and I can't talk to anyone because it's so loud.
MOLLY BLOOM: That's a great point that I did not think of. Yeah, it must be so loud at the vacuum party. That would be very hard to socialize. But I love your idea of it being a party for vacuums to attend. That's brilliant. OK, so Dut Striker have to have a birthday party coming up, I think?
BAKER: I think its fifth birthday is around Christmas, maybe like January 1st. I think that would just be an appropriate time, because that's when we started really using the vacuum every day.
MOLLY BLOOM: Absolutely. I can't wait for you to throw this birthday party. Please take pictures and send it to us.
BAKER: Understood.
MOLLY BLOOM: Well, we're going to hear how vacuums finally got small enough to come inside. But first, I have something that's small enough to fit in your ear, Baker. It's the--
[WHOOSHING]
[HIGH-PITCHED SOUND]
CHILD: [WHISPERING] Mystery sound.
MOLLY BLOOM: Are you ready?
BAKER: Yeah.
MOLLY BLOOM: OK. Here it is.
[TAP]
[TAP]
[TAP]
MOLLY BLOOM: Hmm. Let's hear it again.
[TAP]
[TAP]
[TAP]
MOLLY BLOOM: What do you think, Baker?
BAKER: It sounds mysteriously like a ping pong ball hitting a wooden table. I may or may not have tried to play table tennis but just did not work out.
MOLLY BLOOM: [LAUGHING] That's a really good guess. And to be honest with you, I don't know what this is either. And I also heard that ping pong ball sound. That's what I was thinking. OK, so we're on the same page. We're going to hear it again, get another chance to guess and hear the answer after the credits, so stick around.
[MUSIC PLAYING]
We love hearing from you. We love getting your questions, mystery sounds, and high fives. You're all so curious and smart. And something that we find extra super duper delightful is when you send us your artwork inspired by the show. Maybe you want to draw a picture of me and Baker in the atom shrinking down to the size of a molecule, or maybe Penelope poodle or maybe a collection of vacuums? Whatever you want to draw, we would love to see it. You can send us your drawings at brainson.org/contact. And while you're there, you can send us mystery sounds, drawings, and questions.
BAKER: Like this one.
CHILD: When did people first start having pets?
MOLLY BLOOM: You can find answers to questions like these on the Moment of Um podcast. It's a daily dose of facts and fun every weekday. You can find it wherever you listen to Brains On. Just search for Moment of Um.
BAKER: So keep listening.
ANNOUNCER: Brains On! Universe is a family of podcasts for kids and their adults. And since you're a fan of Brains On, we know you'll love the other shows in our universe. Come on, let's explore.
ROBOT: Entering Brains On! Universe. Whoa. So many podcasts! Brains On, Smash Boom Best, Forever Ago. Picking up signal. Forever Ago, a history podcast starring Joy Dolo.
JOY DOLO: Flare's gum was so sticky when the bubble popped. It was so hard to get off your skin. You'd have to scrub it off with harsh chemicals.
ROBOT: Me love sticky facts! Zorp! Signal down. Quick, need Forever Ago now!
ANNOUNCER: Search for Forever Ago wherever you get your podcasts.
ROBOT: (SINGING) Brains On. On. On.
BAKER: You're listening to Brains On. I'm Baker.
MOLLY BLOOM: And I'm Molly. And today, we're talking about vacuums.
BAKER: Before the break, we learned that vacuums work by blowing air out using a fan and a motor.
MOLLY BLOOM: That makes new air molecules rush to fill the space, bringing with them the dirt and dust from our floors. The first vacuums were as big as minivans, and people would pull them from house to house using horse drawn carriages.
BAKER: But over time, vacuum technology has changed a lot.
MOLLY BLOOM: About 100 years ago, lots of tools and household appliances started to be made much more cheaply.
BAKER: And they shrunk down to personal size, so you could actually fit them in your house.
SHAHLA FARZAN: OK, Molly. Hey, Baker.
MOLLY BLOOM: Brains On editor, Shahla Farzan.
SHAHLA FARZAN: I heard you were talking about one of my favorite appliances-- vacuums. And I just had to stop by. I actually just got back from a trip to a vacuum cleaner museum.
BAKER: Seriously? That's so cool.
SHAHLA FARZAN: It was cooler than cool. The museum is inside this vacuum repair shop in Missouri, and it's run by a guy named Tom Gasko.
BAKER: We know Tom. He's the guy we heard at the very beginning of the show. He loves vacuums.
SHAHLA FARZAN: He does. And I got to see Tom's vacuum collection in person. Some of them are super old, like more than 100 years old. And the earliest ones didn't even use electricity or motors. Tom showed me one with a really rad name.
TOM GASKO: Here is the dust killer.
SHAHLA FARZAN: Is that what it's actually called?
TOM GASKO: Yeah, that's what it's called.
SHAHLA FARZAN: Wow.
TOM GASKO: So the dust killer has got bellows. The kids would stand right there and move that lever back and forth.
BAKER: The dust killer? That is a great name.
SHAHLA FARZAN: It had something called bellows, which is sort of like an air pump that you move by hand and that would help suck up the dirt.
BAKER: What about the first electric vacuums? Did Tom have any of those in his collection?
SHAHLA FARZAN: Yeah, he had this really old one from 1910. It had a long handle with a bag hanging off of it. And here's how it worked. The dust and dirt got vacuumed up inside using the electric motor. And then it was trapped in a bag.
BAKER: Oh, yeah. There are still vacuums like that today. Once the dirt's inside the bag, you empty it or you place it with a new one.
SHAHLA FARZAN: Right. Tom said vacuums started changing pretty fast after this point. By the 1920s, the first canister vacuum made its debut.
MOLLY BLOOM: Those are the kind that have a long hose attached to a body or a canister that moves around the floor.
SHAHLA FARZAN: One of my favorite things about looking through Tom's collection was seeing just how much vacuum style has changed over the years based on what people thought looked good. He showed me one vacuum that looked just like R2-D2 from Star Wars and another one called the Hoover floating vacuum.
BAKER: It floated?
SHAHLA FARZAN: Kind of. It used air to hover just over the floor. Here, listen to this.
TOM GASKO: The Hoover has no wheels or runners. When you turn it on, the air comes out the saucer on the bottom, and it floats, it lifts the vacuum up off of the floor and it floats behind you on a cushion of air. It's the coolest thing.
SHAHLA FARZAN: Is this from the 60s or--
TOM GASKO: You can tell it's the 60s because not only the color, but it's designed to look like the planet Saturn. In the 60s, we were trying to get to the moon. And The Jetsons, Star Trek. These were new TV shows. Science fiction TV shows were all the rage. And so vacuum cleaners, which followed what was happening in the world, just became very much like planets or spacecrafts.
SHAHLA FARZAN: Tom even had a vacuum in his collection that he designed himself. It was purple and silver with all kinds of special features like big wheels. So it could go up and down stairs. But I think one of the best things about Tom's collection is that every single vacuum still works.
MOLLY BLOOM: Wow. That's pretty amazing. You know, vacuums used to be very expensive. Buying one was a big deal.
BAKER: Yeah. If you're spending a lot of money, you want to make a good choice.
SHAHLA FARZAN: Right. You'd pick out the perfect vacuum for your house, depending on its size, layout, what kind of floor you had. And if your vacuum stopped working, you wouldn't just throw it out, you'd take it to get fixed. Tom still has the vacuum his mom bought just before he was born, back in 1962. It cost $250 back then, which today would be more than $2,000. But that vacuum still works.
TOM GASKO: You know, if you buy a good vacuum, you can have it your whole life. Literally. My mother bought one vacuum cleaner her entire life. And there it is. I have it. And I still use it and it still works. It's quiet. It's efficient.
BAKER: Whoa, that's so cool. I can't wait to buy my forever vacuum.
MOLLY BLOOM: Ditto. Thanks for telling us about your vacuum adventure, Shahla.
SHAHLA FARZAN: Oh, you bet. Bye, Molly. See you, Baker.
BAKER: See you!
CHILDREN: Brains On!
MOLLY BLOOM: Vacuums have changed a lot over the past 100 years, and they don't just look different. There have been lots of developments in vacuum technology.
BAKER: Yeah, robot vacuums that can clean your house on their own have been around for almost 30 years and they've gotten so advanced.
MOLLY BLOOM: Today, scientists are working on robot vacuums that can memorize the layout of a room, avoid a sleeping dog, and take voice directions from their owners.
BAKER: And today, vacuums do more than just clean homes and schools and offices.
MOLLY BLOOM: There are these huge vacuum trucks that look remarkably similar to the early vacuums we talked about. They've got long attachments mounted onto big semi trucks, but instead of going door to door to suck the dirt out of expensive carpets and rich neighborhoods, these are used to help clean up after natural disasters.
BAKER: These giant vacuum trucks can suck up debris, floodwater, and even hazardous chemicals that are dangerous for humans to touch.
MOLLY BLOOM: Natural disasters like hurricanes and wildfires are happening more often because of climate change. And so these trucks are being used more and more often.
BAKER: Luckily, vacuum technology might also be able to help us slow down climate change.
MOLLY BLOOM: Climate change is happening because humans are putting more greenhouse gases into the atmosphere like carbon dioxide. It's released by burning fossil fuels like the gasoline in our cars.
BAKER: Yeah, but some companies are developing giant vacuums that can suck carbon dioxide out of the air and trap it in special containers.
MOLLY BLOOM: And then that carbon dioxide can be used to make bubbles in drinks like soda and seltzer. Some of these vacuum companies are even starting to sell the carbon dioxide to beverage companies.
BAKER: Refreshing.
MOLLY BLOOM: Vacuums keep our homes clean and may also one day help keep our planet clean.
BAKER: Cheers to that.
[MUSIC PLAYING]
MOLLY BLOOM: Air molecules want to be spread out evenly.
BAKER: So vacuums work by creating a space inside the vacuum where there aren't air molecules.
MOLLY BLOOM: Air molecules want to go inside the vacuum to even things out, and that air takes dirt and dust with it. The dirty stuff is trapped by the vacuum and the air blows back out.
BAKER: The first vacuums were invented more than 100 years ago. They're as big as a minivan and were super expensive to use.
MOLLY BLOOM: But over time, they got smaller. Inventors started coming up with vacuums in all different shapes, colors and designs.
BAKER: And their designs and technology are still changing today.
MOLLY BLOOM: That's it for this episode of Brains On.
BAKER: This episode was written by--
MOLLY BLOOM: Molly Bloom.
BAKER: And--
NICO GONZALEZ-WISLER: Nico Gonzalez-Wisler.
BAKER: It was produced by--
ROSIE DUPONT: Rosie Dupont.
BAKER: Our editors are--
SHAHLA FARZAN: Shahla Farzan.
BAKER: And--
SANDEN TOTTEN: Sanden Totten.
BAKER: Fact checking by
RUBY GUTHRIE: Ruby Guthrie.
MOLLY BLOOM: We had engineering help from Tim Meinig, Robert Jacob Springer and Derek Ramirez with sound design by--
RACHEL BREES: Rachel Brees.
MOLLY BLOOM: Original theme music by--
MARC SANCHEZ: Marc Sanchez.
BAKER: We had production help from the rest of the Brains On! Universe team--
ANNA GOLDFIELD: Anna Goldfield.
LAUREN HUMBERT: Lauren Humbert.
JOSHUA RAY: Joshua Ray.
MARC SANCHEZ: Marc Sanchez.
CHARLOTTE TRAVER: Charlotte Traver.
ANNA WEGEL: Anna Weggel.
BAKER: And--
ARON WELDESELASSIE: Aron Weldeselassie.
MOLLY BLOOM: Beth Perlman is our executive producer. And the executives in charge of APM Studios are Chandra Kavati and Joanne Griffith. Special thanks to Janine Saltman, Lucas saltman and Delta.
BAKER: Brains On is a non-profit public radio program.
MOLLY BLOOM: There are lots of ways to support the show. Subscribe to Brains On Universe on YouTube, where you can watch animated versions of some of your favorite episodes or head to brainson.org.
BAKER: While you're there, you can send us mystery sounds, drawings, and questions.
MOLLY BLOOM: OK. Baker, are you ready to hear the mystery sound again?
BAKER: Yeah. All right, here it is.
MOLLY BLOOM: What do you think now?
BAKER: Well, maybe, it-- I'm still going with my first answer, but also that it reminded me of like, that toy where there's a ping pong ball on a string attached to a paddle. So ping pong ball hitting something.
MOLLY BLOOM: I'm going to guess-- a person playing ping pong, but, like, very slowly. So, like, maybe in lesser gravity. So maybe they're playing ping pong on the moon.
BAKER: Yeah. I don't understand how the person was able to get us that sound if they're on Earth.
MOLLY BLOOM: Fair point. All right. Well, should we hear the answer?
BAKER: Yes.
MOLLY BLOOM: All right, here it is.
NOAH: Hi, I'm Noah from New South Wales, Australia. And that is the sound of me throwing darts on a dart board.
MOLLY BLOOM: Oh. Darts on a dart board.
BAKER: I can't say I've heard that before.
MOLLY BLOOM: Well, I think you were close because we were thinking, like, playing a game of some sort, right?
BAKER: Yeah, like with stuff hitting stuff.
MOLLY BLOOM: Exactly. You're not that far off. So yeah, so darts, there's like, that's where the game, where there's a board hanging on the wall that's like a circle.
BAKER: And then you throw these things at it. And the closer you get to the center, the more points you get.
MOLLY BLOOM: Exactly. Yeah. And those are called darts. I guess we have to play darts now.
BAKER: Yeah.
MOLLY BLOOM: Now, it's time for the Brains Honor Roll. These are the kids who keep the show going with their questions, ideas, mystery sounds.
[LISTING HONOR ROLL]
We'll be back next week with an episode all about body temperature.
BAKER: Thanks for listening.
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