Dust buddies!
Mariakray/Getty Images/iStockphoto
Dust looks gray and boring to us, but it’s full of secrets! Like did you know that up close, dust is colorful? And there are creatures living in your dust? And some dust comes from outer space?
We’ll take you on a tour of the dust universe and show you how dust can help solve crimes. Plus, we learn about the tiny critters living all over your skin!
And of course there’s a Mystery Sound and a Moment of Um that answers the question: why do we jump when we’re scared?
Audio Transcript
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JAYDEN: You're listening to Brains On where we are serious about being curious. Brains On is supported in part by a grant from the National Science Foundation.
SANDEN TOTTEN: Wow. Just look at it. Do you know the best thing about this new skylight?
JAYDEN: Is it the sunlight that comes through it?
MOLLY BLOOM: Or the fact that the skylight is shaped like a brain?
SANDEN TOTTEN: Yeah, those things are cool, but have you looked closer to see the best thing?
MOLLY BLOOM: The light is filled with these amazing little specks.
JAYDEN: Ooh, I do see them. Wow.
MOLLY BLOOM: But what are they?
SANDEN TOTTEN: I like to imagine that each speck is a little animal. We're looking at micro poodles and nano hippos and mini zebras all just floating peacefully and tiny in this lazy river made of air.
MARC SANCHEZ: Or each speck could be a teeny tiny taco, a precisely petite pickle. Only one way to find out.
JAYDEN: Aren't those floaties dust?
MARC SANCHEZ: Oh, yeah, of course. Team dust all the way.
MENAKA WILHELM: I don't know you guys. This really reminds me of one of my favorite songs. Woah. What's dust got to do, got to do with it?
MOLLY BLOOM: Wow. Nice belting, Meneka.
MENAKA WILHELM: Oh, thanks, Molly.
JAYDEN: But are you sure those are the words to the song?
MENAKA WILHELM: Well, I do sometimes interpret song lyrics somewhat creatively. But no, I'm pretty sure you'll recognize the song. Let me sing you a little more. What's dust but a crusty debris notion? What's dust got to do, got to do with it?
MARC SANCHEZ: Who needs new friends when you've got all these dust piles? Oh-whoa. What's dust got to do?
SANDEN TOTTEN: I've never heard that song.
MARC SANCHEZ: What's dust got to do, got to do with it?
[THEME MUSIC PLAYING]
MOLLY BLOOM: You're listening to Brains On. I'm Molly Bloom, and my co-host today is Jayden from Delaware. Hi, Jayden.
JAYDEN: Hello.
MOLLY BLOOM: Jayden, today, we're talking all things dust. Dusty bunnies, dusty floors, dust mites. Just thinking about it makes me want to sneeze. Jayden, are you OK with having a little dust in your room or do you like things to be dust free, spic and span?
JAYDEN: Well, if I'm in a like grumpy mood and I don't want to be grossed out, I won't be happy with a little dust or halos on my nightstand. But if I'm in a really happy mood, then I'll just let it be.
MOLLY BLOOM: It depends on your mood. Do you like dusting and getting rid of the dust?
JAYDEN: Sometimes yes, and sometimes no. I'm a big fan of nature. Sometimes it just a twist to me that sometimes I just like to look at dust and wonder like how is it formed and how did it even get there.
MOLLY BLOOM: Yeah, and that's the question that you sent us. That's what you were curious about?
JAYDEN: Yeah.
MOLLY BLOOM: A lot of our listeners are curious about dust, too.
ALEXANDRA: Hi, Brains On. My name is Alexandra and I am from Jamaica Plain, Massachusetts. My question is, how is dust made and why?
AUGUST: My name is August from Wyoming, Ohio. My question is, how does dust float?
ELIZABETH: My name is Elizabeth.
WHITE: And my name is White.
ELIZABETH: We want to know what percentage of dust is human skin cells.
JAYDEN: It's like we need to get the dirt on dust. Where should we start?
MOLLY BLOOM: I know the perfect place. Elevator?
ELEVATOR: Yes, Molly.
MOLLY BLOOM: Take us to Marc's room.
ELEVATOR: You got it. We're here.
JAYDEN: Wow, that was so fast.
ELEVATOR: You have no idea. When I do a marathon, I finish before I even start. Now, I'm going to travel to the nearest black hole and back before you can blink. OK, buddy.
MARC SANCHEZ: Oh hey, Molly. Hey, Jayden. Nice to see you two. What's up?
JAYDEN: We're here on a mission.
MOLLY BLOOM: And your filthy room is exactly what we need.
MARC SANCHEZ: Filthy? What are you talking about?
MOLLY BLOOM: Oh, Harvey, the omnipresent voice activated virtual assistant, he likes when we use his full title. When was the last time Marc cleaned his room?
HARVEY: Scanning my database. Exactly, never.
MARC SANCHEZ: Yeah, that sounds about right. But listen, Molly, I don't clean because I don't want to disturb my dust buddies.
JAYDEN: Do you mean your dust bunnies?
MARC SANCHEZ: Bunnies? No. Don't be silly. Dust isn't a rabbit. It's my friend. My dust buddies. See? All right, here, they live under my bed.
MOLLY BLOOM: Spoiler alert. It's not just under your bed-ish.
MARC SANCHEZ: Come on. I'll introduce you to them. Let me just scooch the old zoom ray over here and set the dial.
MOLLY BLOOM: Whoa. Everything is so ginormous.
MARC SANCHEZ: You're just zoomed in so it looks like we've shrunk.
DUSTINY: Hey, look, everybody. It's Marc.
MARC SANCHEZ: Welcome back pal.
DUST: Long time.
MARC SANCHEZ: Hey, hey, dust buddies. This is Molly and Jayden. Molly, Jayden, this is Dustiny, Dustin, and Dusty.
JAYDEN: Well, dust is so much more tug of war close up.
DUSTY: Yeah, well, dust is made up of tons of different tiny materials. So it makes sense we'd all be different colors.
DUST: I'm a tiny fragment of Marc's red sweater.
DUSTINY: And I'm a pretty fungus.
DUSTY: I'm a micro piece of grass. And Barry over there is a microscopic living creature called a dust mite. He eats dead skin cells off the floor.
BARRY: What's up, everybody? Marc, you're delicious.
MARC SANCHEZ: Hey, thanks Barry. I try.
DUSTY: We just look great from far away when we're clumped together.
MOLLY BLOOM: So true. It's amazing. But there are so many different things down here. I thought all dust was the same.
DUSTINY: No, no, no, no, no. We are large. We contain multitudes.
BARRY: Yeah. We're sand, dead skin cells, hair and food, animal fur and pollen. Bits of plants and tires and rocks and tiny things that have fallen.
DUSTY: Bacteria and fungus and even mites all live in this dusty place. Believe it or not, there's even stuff that fell to Earth from outer space.
DUST: It's all in dust.
MARC SANCHEZ: Bravo. Nice work, dust buddies.
DUSTINY: Thanks. Singing is our second favorite thing.
MOLLY BLOOM: What's your first?
DUSTINY: Sneeze brides.
BARRY: That's when we fly up your nose and get our chewed back out. It's a total rush.
JAYDEN: What? Go back for a second. Did you say aerospace dust? Is that a theme?
DUSTY: You bet it is. Every year tens of thousands of tons of tiny cosmic particles enter our atmosphere. It's just so small you never notice, but as dust buddies notice. We welcome our intergalactic siblings.
MARC SANCHEZ: In fact, there's this theory that billions of years ago, some of the material for life might have come to Earth as cosmic dust. Space dust might have helped get life going. We can't prove it, but I like to pretend that's what happened.
JAYDEN: Well, this dust is blowing my mind right now.
MARC SANCHEZ: And get this. Every home has a unique blend of dust that reflects where it's located and who lives there. In my dust, there's dander from my Guinea pigs, dead skin cells from me, and Taco crumbs from my lunch. But also there are bits of dirt from my garden outside, some cement particles because my neighbors are redoing their driveway, and even trees from the park down the street.
DUSTINY: Everyone's dust tells a story.
JAYDEN: So we were down on the floor right now, but there was also dust on the shelves, the dresser, the dust, the mule.
MOLLY BLOOM: Everywhere.
JAYDEN: How did you all get there?
BARRY: Well, it's simple. We're so light, we can float.
DUSTINY: When Marc's rushing around getting ready for work in the morning, it whips us up and we go flying. Super fun stuff.
DUSTY: I'm hoping to one day float to the top of the ceiling fan. I hear the breeze up there is nice.
MOLLY BLOOM: Well, this has been fascinating. But we should leave before I sneeze up a storm. Nice to meet you dust buddies.
DUSTY: Likewise.
DUSTINY: Our pleasure.
BARRY: Please let me ride your sneeze.
MARC SANCHEZ: We're back to normal. See? Dust is awesome. Right?
JAYDEN: Yeah, it's way more interesting than I gave it credit for.
MOLLY BLOOM: Agreed. I almost feel bad vacuuming it.
MARC SANCHEZ: I knew you'd see it my way. I mean, there is no need to clean when you--
MOLLY BLOOM: I said almost.
MARC SANCHEZ: Molly.
MOLLY BLOOM: Sorry, Marc, but this room is disgusting.
[THEME MUSIC PLAYING]
The dust bunnies made a very good point about dust.
JAYDEN: About how fun it would be to light a sneeze?
MOLLY BLOOM: I was actually thinking about how every clump of dust tells a story.
JAYDEN: Oh yeah, that too.
MOLLY BLOOM: In fact, there are some people who can read the story told by dust. And they're using it to solve mysteries.
NOAH FIERER: My name is Noah Fierer. I'm a professor at the University of Colorado, and I'm a microbial ecologist. One thing we can use that dust to tell us is what bacteria are floating around in the air inside your home, because those bacteria float around in your air and then they land on surfaces.
We can also use that dust to tell you what insects might be living in your home. Because there's insects in there or parts of insects, there's insect poop. It also use dust to tell you what fungi or molds are in your home.
What do we do with this information on the microbes fountain dust? Well, one thing we can do, imagine is a crime scene or a package from somewhere. We can look at the dust inside that package and figure out where that package came from, just by looking at the bacteria and the fungi in the dust inside that package.
Where you live has a large influence on what microbes are in your dust. For example, if you live in Florida or Georgia, or Alabama, you're going to have different types of bacteria and fungi inside your home than if you're living in California or Nevada. We can also, for example, if somebody has a bunch of dust on their clothes, we have good evidence that we can figure out where that person has been.
We can actually look at the dust on an object or in a package or on clothing and figure out where that object or package or clothing had come from across the United States.
[THEME MUSIC PLAYING]
MOLLY BLOOM: Jayden, serious question. What do you think we'd call the world's first plant president?
JAYDEN: That would be the first plantsident. Well, maybe you would go by the title presiplant.
MOLLY BLOOM: Presiplant? I like both of those names. Well, we want to hear from you and the rest of our listeners about campaign slogans for plantsidents. Can you think of a catchphrase a plant might use to run for office?
JAYDEN: I never leave anybody out.
MOLLY BLOOM: Well, everyone else, you can record yourself reading your slogan for plants and you could hear it on our show. Send it to us at brains.on.org/contact. You can also send questions mystery sounds, drawings, and ideas to that same address.
JAYDEN: Brains.on.org/contact.
MOLLY BLOOM: That's how we got this question.
SHIFRA: My name is Shifra. I am 10 years old and I live in Sydney, Australia. My question is, why do people jump when they're scared?
JAYDEN: We'll be back with an answer during a moment of Uhm the end of the show.
MOLLY BLOOM: We'll read the most recent list of names to be added to the Brains Honor Roll.
JAYDEN: So keep listening.
MOLLY BLOOM: You're listening to Brains On from American Public Media. I'm Molly.
JAYDEN: And I'm Jayden.
MOLLY BLOOM: And this is the?
JAYDEN: Mystery sound.
MOLLY BLOOM: Are you ready, Jayden?
JAYDEN: Totally.
MOLLY BLOOM: All right, here it is.
[DIGGING SOUND]
What does that sound like to you? I'm going to give you a hint. It has to do with something that's not on this planet.
JAYDEN: Is it some asteroid or a meteor shower or something like that?
MOLLY BLOOM: It's a very, very good guess. Well, we're going to hear it again and give you another chance to guess in just a little bit.
[THEME MUSIC PLAYING]
A big part of the dust around is actually little creatures called dust mites. They're related to ticks and spiders but are so tiny that you can't see them with just your eye. You'd need a microscope to see these micro animals. They like to eat dead skin cells from you and your pets.
JAYDEN: But did you know there's another kind of eensy teensy mite that lives on your body?
MOLLY BLOOM: That's right. These are the demodex mites.
JAYDEN: And we want to learn all about these powers that go with us everywhere.
MOLLY BLOOM: Michelle Trautwein is an entomologist at the California Academy of Sciences.
JAYDEN: Welcome, Michelle.
MICHELLE TRAUTWEIN: Thank you.
JAYDEN: Where do these mites live on us?
MICHELLE TRAUTWEIN: The mites live actually inside of our skin. They live in our hair follicles. And we have two species, demodex folliculorum that lives right at the base of hairs and the hair follicle. And then there's another species, demodex brevis, which is smaller and chunkier. And it lives in our sebaceous glands, which are offshoots of our hair follicles.
When it comes to what they eat, we actually don't know but we assume several things. Maybe they eat sebum which is the gunk that your sebaceous glands generate. If you scrape your skin, you'll probably get a lot of white oily gunk off and that's sebum. They may also eat bacteria in our skin cells and some people have even suggested that they eat skin cells themselves.
MOLLY BLOOM: It's not just like the hair follicles on the top of our head; we have hair follicles all over.
MICHELLE TRAUTWEIN: That's right. They happen to not like hair follicles that have coarse, big hairs in them. They like hair follicles that have fine hairs. Your face is a place that they really love. If you think about the soft hairs on your face for both men and women, they really like those follicles that have the soft hairs in them.
JAYDEN: Interesting. What do these mice look like? How big are they?
MICHELLE TRAUTWEIN: They are very, very small. You can't see them with your eye. You need to have a microscope to be able to see them. What they look like? Actually, they're related to spiders but they look more like worms, tiny little worms with eight legs.
JAYDEN: Cool. How do you know they're there?
MICHELLE TRAUTWEIN: Well, I know they're there because multiple ways. One I've sampled a lot of people and so I've actually found mites on a lot of different people's faces. But another way that we know they're there is that I've worked with a team of scientists who samples people's faces, and we look for mite DNA. We found that almost every single person we've ever sampled has mite DNA on them, which means they live on everybody.
JAYDEN: How are these mite related to dust?
MICHELLE TRAUTWEIN: I don't know for sure, but I bet they contribute to dust. They probably are part of all that debris. And maybe you know that also in all that debris are these other animals called dust mites. And dust mites love to eat all those little bits of human skin and other kind of organic matter that dust makes up. Dust mites are also tiny, but they're actually a lot bigger than face mites.
They're also almost everywhere. You can find dust mites in almost every house that humans live in. I know because I've sampled many, many around the world and they all have dust mites. But interestingly enough, face mites and dust mites are not close relatives to each other.
There's like 30,000 species of mites that have been described, but there's probably over a million on the planet. It be like thinking of a grasshopper and a butterfly. They're both insects but they're really different and not close relatives. And that's the same thing with a face mite and a dust mite.
JAYDEN: If we study these mites, then what kind of stuff can we learn from them?
MICHELLE TRAUTWEIN: We can learn so many things. What's really exciting to me is that even though these mites live on all of our bodies, right on our faces, we know very, very little about them. That's really exciting to me as a scientist because it reminds me that there's so much that we have to learn and discover about the world. I want to learn more about how they've evolved with humans over time.
One of the things that we've discovered is that these mites are actually different on different people from different parts of the world. So that means that if your ancestors are from Africa, then you have different mites than if your ancestors are from, for example, East Asia or Europe or South America. I can use these mites and their DNA to make estimates about when ancient humans moved around the world. And that's a really exciting project for me.
JAYDEN: Thanks for answering our questions, Michelle.
MICHELLE TRAUTWEIN: Oh, sure. Any time. I love to talk about face mites.
MOLLY BLOOM: OK, Jayden. Let's try that mystery sound one more time. Now, remember, this sound does not come from Earth. Let's listen again.
[DIGGING SOUND]
What is your final guess?
JAYDEN: I still think it's a meteor shower or it also could be like a comet or an asteroid hitting something.
MOLLY BLOOM: Excellent guess. Here is the answer.
KEANNA JARDINE: The sound you just heard was of the space mission Stardust flying through comet dust in space. That sound came from NASA.
MOLLY BLOOM: It was comet dust. You were very close.
KEANNA JARDINE: Hi, my name is Keanna Jardine. I'm a planetary scientist at the University of Central Florida. I study the stickiness of asteroid dust.
MOLLY BLOOM: There is dust on Earth and in space. Dust in space is made out of tiny particles of material that float around in space between stars. Space dust is mostly chemical bits. It can form when stars explode or when asteroids collide. Sometimes that dust in space is a problem for space missions.
KEANNA JARDINE: It sure is. When the astronauts went to the moon, for example, the dust on the moon was a lot like powder. And it was much more fluffy than they thought it would be. So it made it difficult for them to move around. It got stuck under suits, on the instruments, it smelled weird, and it caused them to feel sick.
Some space dust and space debris can be dangerous to things like the space shuttle and the Space Station. Even if they run into a very small piece of dust, it can actually cause a lot of damage. It's almost like when it's a small rock hits your windshield of your car when you're on the highway. Even the smallest piece can cause a lot of damage because of how fast it's rotating around Earth.
MOLLY BLOOM: Scientists are also pretty sure that space dust has formed lots of planets and stars in our solar system. Billions of years ago, Earth started from a bunch of sticky grains of dust.
KEANNA JARDINE: Those small sticky grains ended up coming together to form bigger dust. As it grew bigger and bigger, we ended up with the Earth.
MOLLY BLOOM: We have dust to thank for our planet.
JAYDEN: I never knew that dust could actually make that sound.
MOLLY BLOOM: Yeah, this is a really tricky mystery sound. This is one of the harder ones for sure.
[THEME MUSIC PLAYING]
Dust comes from tiny bits of lots of different things.
JAYDEN: Like your dead skin, your clothes, your pets, and the environment.
MOLLY BLOOM: Bacteria and fungi and dust is different depending on where you live, and can even be used to fight crime.
JAYDEN: We all have my toenails steam and they can teach us about our ancestors.
MOLLY BLOOM: Dust even floats around in space, in between planets, and stars. That's it for this episode of Brains On.
JAYDEN: It was produced by Marc Sanchez, Meneka Wilhelm, Sanden Totten and Molly Bloom.
MOLLY BLOOM: We had production help from Christina Lopez, Ruby Guthrie, Rosie DuPont, and Mary Harvin. And engineering help from Cliff Bentley, Tom Byrne, and Veronica Rodriguez. Special thanks to Audrey Howell, Phyllis Fletcher, Cristina Lopez, Drew Jostad, and Melody Perkins.
JAYDEN: Now, before we go, it's time for a moment of--
KID: My question is, why do people jump when they're scared?
SARAH BENESCH: The simple answer is that it's a reflex reaction that our brain has learned. My name is Sarah Benesch. I'm a neurologist which is a doctor that takes care of brain conditions and spinal cord conditions. I work at the University of Minnesota. There's a response that we call the fight or flight response.
This goes back to the very origins of humans and we have to be able to survive all threats. When you're watching something scary or something scary is around, your brain reacts to that by getting this surge of energy that makes your muscles want to move and run away to safety or move and fight for your safety.
When you're scared, this surge of energy creates that jump and then your brain quickly shuts it down recognizing, Oh, there isn't actually a reason for me to run out of the movie theater because I was scared, or start fighting the person next to me with the popcorn because I was scared, because it was just a scary moment rather than a true threat.
MOLLY BLOOM: This list makes me jump with joy. It's time for the Brains Honor Roll. This is the latest group of friends who have sent in questions, drawings, and mystery sounds to help fuel the show.
[LISTING HONOR ROLL]
[THEME MUSIC PLAYING]
Brains On will be back soon with more answers to your questions.
JAYDEN: Thanks for listening.
SANDEN TOTTEN: Wow. Just look at it. Do you know the best thing about this new skylight?
JAYDEN: Is it the sunlight that comes through it?
MOLLY BLOOM: Or the fact that the skylight is shaped like a brain?
SANDEN TOTTEN: Yeah, those things are cool, but have you looked closer to see the best thing?
MOLLY BLOOM: The light is filled with these amazing little specks.
JAYDEN: Ooh, I do see them. Wow.
MOLLY BLOOM: But what are they?
SANDEN TOTTEN: I like to imagine that each speck is a little animal. We're looking at micro poodles and nano hippos and mini zebras all just floating peacefully and tiny in this lazy river made of air.
MARC SANCHEZ: Or each speck could be a teeny tiny taco, a precisely petite pickle. Only one way to find out.
JAYDEN: Aren't those floaties dust?
MARC SANCHEZ: Oh, yeah, of course. Team dust all the way.
MENAKA WILHELM: I don't know you guys. This really reminds me of one of my favorite songs. Woah. What's dust got to do, got to do with it?
MOLLY BLOOM: Wow. Nice belting, Meneka.
MENAKA WILHELM: Oh, thanks, Molly.
JAYDEN: But are you sure those are the words to the song?
MENAKA WILHELM: Well, I do sometimes interpret song lyrics somewhat creatively. But no, I'm pretty sure you'll recognize the song. Let me sing you a little more. What's dust but a crusty debris notion? What's dust got to do, got to do with it?
MARC SANCHEZ: Who needs new friends when you've got all these dust piles? Oh-whoa. What's dust got to do?
SANDEN TOTTEN: I've never heard that song.
MARC SANCHEZ: What's dust got to do, got to do with it?
[THEME MUSIC PLAYING]
MOLLY BLOOM: You're listening to Brains On. I'm Molly Bloom, and my co-host today is Jayden from Delaware. Hi, Jayden.
JAYDEN: Hello.
MOLLY BLOOM: Jayden, today, we're talking all things dust. Dusty bunnies, dusty floors, dust mites. Just thinking about it makes me want to sneeze. Jayden, are you OK with having a little dust in your room or do you like things to be dust free, spic and span?
JAYDEN: Well, if I'm in a like grumpy mood and I don't want to be grossed out, I won't be happy with a little dust or halos on my nightstand. But if I'm in a really happy mood, then I'll just let it be.
MOLLY BLOOM: It depends on your mood. Do you like dusting and getting rid of the dust?
JAYDEN: Sometimes yes, and sometimes no. I'm a big fan of nature. Sometimes it just a twist to me that sometimes I just like to look at dust and wonder like how is it formed and how did it even get there.
MOLLY BLOOM: Yeah, and that's the question that you sent us. That's what you were curious about?
JAYDEN: Yeah.
MOLLY BLOOM: A lot of our listeners are curious about dust, too.
ALEXANDRA: Hi, Brains On. My name is Alexandra and I am from Jamaica Plain, Massachusetts. My question is, how is dust made and why?
AUGUST: My name is August from Wyoming, Ohio. My question is, how does dust float?
ELIZABETH: My name is Elizabeth.
WHITE: And my name is White.
ELIZABETH: We want to know what percentage of dust is human skin cells.
JAYDEN: It's like we need to get the dirt on dust. Where should we start?
MOLLY BLOOM: I know the perfect place. Elevator?
ELEVATOR: Yes, Molly.
MOLLY BLOOM: Take us to Marc's room.
ELEVATOR: You got it. We're here.
JAYDEN: Wow, that was so fast.
ELEVATOR: You have no idea. When I do a marathon, I finish before I even start. Now, I'm going to travel to the nearest black hole and back before you can blink. OK, buddy.
MARC SANCHEZ: Oh hey, Molly. Hey, Jayden. Nice to see you two. What's up?
JAYDEN: We're here on a mission.
MOLLY BLOOM: And your filthy room is exactly what we need.
MARC SANCHEZ: Filthy? What are you talking about?
MOLLY BLOOM: Oh, Harvey, the omnipresent voice activated virtual assistant, he likes when we use his full title. When was the last time Marc cleaned his room?
HARVEY: Scanning my database. Exactly, never.
MARC SANCHEZ: Yeah, that sounds about right. But listen, Molly, I don't clean because I don't want to disturb my dust buddies.
JAYDEN: Do you mean your dust bunnies?
MARC SANCHEZ: Bunnies? No. Don't be silly. Dust isn't a rabbit. It's my friend. My dust buddies. See? All right, here, they live under my bed.
MOLLY BLOOM: Spoiler alert. It's not just under your bed-ish.
MARC SANCHEZ: Come on. I'll introduce you to them. Let me just scooch the old zoom ray over here and set the dial.
MOLLY BLOOM: Whoa. Everything is so ginormous.
MARC SANCHEZ: You're just zoomed in so it looks like we've shrunk.
DUSTINY: Hey, look, everybody. It's Marc.
MARC SANCHEZ: Welcome back pal.
DUST: Long time.
MARC SANCHEZ: Hey, hey, dust buddies. This is Molly and Jayden. Molly, Jayden, this is Dustiny, Dustin, and Dusty.
JAYDEN: Well, dust is so much more tug of war close up.
DUSTY: Yeah, well, dust is made up of tons of different tiny materials. So it makes sense we'd all be different colors.
DUST: I'm a tiny fragment of Marc's red sweater.
DUSTINY: And I'm a pretty fungus.
DUSTY: I'm a micro piece of grass. And Barry over there is a microscopic living creature called a dust mite. He eats dead skin cells off the floor.
BARRY: What's up, everybody? Marc, you're delicious.
MARC SANCHEZ: Hey, thanks Barry. I try.
DUSTY: We just look great from far away when we're clumped together.
MOLLY BLOOM: So true. It's amazing. But there are so many different things down here. I thought all dust was the same.
DUSTINY: No, no, no, no, no. We are large. We contain multitudes.
BARRY: Yeah. We're sand, dead skin cells, hair and food, animal fur and pollen. Bits of plants and tires and rocks and tiny things that have fallen.
DUSTY: Bacteria and fungus and even mites all live in this dusty place. Believe it or not, there's even stuff that fell to Earth from outer space.
DUST: It's all in dust.
MARC SANCHEZ: Bravo. Nice work, dust buddies.
DUSTINY: Thanks. Singing is our second favorite thing.
MOLLY BLOOM: What's your first?
DUSTINY: Sneeze brides.
BARRY: That's when we fly up your nose and get our chewed back out. It's a total rush.
JAYDEN: What? Go back for a second. Did you say aerospace dust? Is that a theme?
DUSTY: You bet it is. Every year tens of thousands of tons of tiny cosmic particles enter our atmosphere. It's just so small you never notice, but as dust buddies notice. We welcome our intergalactic siblings.
MARC SANCHEZ: In fact, there's this theory that billions of years ago, some of the material for life might have come to Earth as cosmic dust. Space dust might have helped get life going. We can't prove it, but I like to pretend that's what happened.
JAYDEN: Well, this dust is blowing my mind right now.
MARC SANCHEZ: And get this. Every home has a unique blend of dust that reflects where it's located and who lives there. In my dust, there's dander from my Guinea pigs, dead skin cells from me, and Taco crumbs from my lunch. But also there are bits of dirt from my garden outside, some cement particles because my neighbors are redoing their driveway, and even trees from the park down the street.
DUSTINY: Everyone's dust tells a story.
JAYDEN: So we were down on the floor right now, but there was also dust on the shelves, the dresser, the dust, the mule.
MOLLY BLOOM: Everywhere.
JAYDEN: How did you all get there?
BARRY: Well, it's simple. We're so light, we can float.
DUSTINY: When Marc's rushing around getting ready for work in the morning, it whips us up and we go flying. Super fun stuff.
DUSTY: I'm hoping to one day float to the top of the ceiling fan. I hear the breeze up there is nice.
MOLLY BLOOM: Well, this has been fascinating. But we should leave before I sneeze up a storm. Nice to meet you dust buddies.
DUSTY: Likewise.
DUSTINY: Our pleasure.
BARRY: Please let me ride your sneeze.
MARC SANCHEZ: We're back to normal. See? Dust is awesome. Right?
JAYDEN: Yeah, it's way more interesting than I gave it credit for.
MOLLY BLOOM: Agreed. I almost feel bad vacuuming it.
MARC SANCHEZ: I knew you'd see it my way. I mean, there is no need to clean when you--
MOLLY BLOOM: I said almost.
MARC SANCHEZ: Molly.
MOLLY BLOOM: Sorry, Marc, but this room is disgusting.
[THEME MUSIC PLAYING]
The dust bunnies made a very good point about dust.
JAYDEN: About how fun it would be to light a sneeze?
MOLLY BLOOM: I was actually thinking about how every clump of dust tells a story.
JAYDEN: Oh yeah, that too.
MOLLY BLOOM: In fact, there are some people who can read the story told by dust. And they're using it to solve mysteries.
NOAH FIERER: My name is Noah Fierer. I'm a professor at the University of Colorado, and I'm a microbial ecologist. One thing we can use that dust to tell us is what bacteria are floating around in the air inside your home, because those bacteria float around in your air and then they land on surfaces.
We can also use that dust to tell you what insects might be living in your home. Because there's insects in there or parts of insects, there's insect poop. It also use dust to tell you what fungi or molds are in your home.
What do we do with this information on the microbes fountain dust? Well, one thing we can do, imagine is a crime scene or a package from somewhere. We can look at the dust inside that package and figure out where that package came from, just by looking at the bacteria and the fungi in the dust inside that package.
Where you live has a large influence on what microbes are in your dust. For example, if you live in Florida or Georgia, or Alabama, you're going to have different types of bacteria and fungi inside your home than if you're living in California or Nevada. We can also, for example, if somebody has a bunch of dust on their clothes, we have good evidence that we can figure out where that person has been.
We can actually look at the dust on an object or in a package or on clothing and figure out where that object or package or clothing had come from across the United States.
[THEME MUSIC PLAYING]
MOLLY BLOOM: Jayden, serious question. What do you think we'd call the world's first plant president?
JAYDEN: That would be the first plantsident. Well, maybe you would go by the title presiplant.
MOLLY BLOOM: Presiplant? I like both of those names. Well, we want to hear from you and the rest of our listeners about campaign slogans for plantsidents. Can you think of a catchphrase a plant might use to run for office?
JAYDEN: I never leave anybody out.
MOLLY BLOOM: Well, everyone else, you can record yourself reading your slogan for plants and you could hear it on our show. Send it to us at brains.on.org/contact. You can also send questions mystery sounds, drawings, and ideas to that same address.
JAYDEN: Brains.on.org/contact.
MOLLY BLOOM: That's how we got this question.
SHIFRA: My name is Shifra. I am 10 years old and I live in Sydney, Australia. My question is, why do people jump when they're scared?
JAYDEN: We'll be back with an answer during a moment of Uhm the end of the show.
MOLLY BLOOM: We'll read the most recent list of names to be added to the Brains Honor Roll.
JAYDEN: So keep listening.
MOLLY BLOOM: You're listening to Brains On from American Public Media. I'm Molly.
JAYDEN: And I'm Jayden.
MOLLY BLOOM: And this is the?
JAYDEN: Mystery sound.
MOLLY BLOOM: Are you ready, Jayden?
JAYDEN: Totally.
MOLLY BLOOM: All right, here it is.
[DIGGING SOUND]
What does that sound like to you? I'm going to give you a hint. It has to do with something that's not on this planet.
JAYDEN: Is it some asteroid or a meteor shower or something like that?
MOLLY BLOOM: It's a very, very good guess. Well, we're going to hear it again and give you another chance to guess in just a little bit.
[THEME MUSIC PLAYING]
A big part of the dust around is actually little creatures called dust mites. They're related to ticks and spiders but are so tiny that you can't see them with just your eye. You'd need a microscope to see these micro animals. They like to eat dead skin cells from you and your pets.
JAYDEN: But did you know there's another kind of eensy teensy mite that lives on your body?
MOLLY BLOOM: That's right. These are the demodex mites.
JAYDEN: And we want to learn all about these powers that go with us everywhere.
MOLLY BLOOM: Michelle Trautwein is an entomologist at the California Academy of Sciences.
JAYDEN: Welcome, Michelle.
MICHELLE TRAUTWEIN: Thank you.
JAYDEN: Where do these mites live on us?
MICHELLE TRAUTWEIN: The mites live actually inside of our skin. They live in our hair follicles. And we have two species, demodex folliculorum that lives right at the base of hairs and the hair follicle. And then there's another species, demodex brevis, which is smaller and chunkier. And it lives in our sebaceous glands, which are offshoots of our hair follicles.
When it comes to what they eat, we actually don't know but we assume several things. Maybe they eat sebum which is the gunk that your sebaceous glands generate. If you scrape your skin, you'll probably get a lot of white oily gunk off and that's sebum. They may also eat bacteria in our skin cells and some people have even suggested that they eat skin cells themselves.
MOLLY BLOOM: It's not just like the hair follicles on the top of our head; we have hair follicles all over.
MICHELLE TRAUTWEIN: That's right. They happen to not like hair follicles that have coarse, big hairs in them. They like hair follicles that have fine hairs. Your face is a place that they really love. If you think about the soft hairs on your face for both men and women, they really like those follicles that have the soft hairs in them.
JAYDEN: Interesting. What do these mice look like? How big are they?
MICHELLE TRAUTWEIN: They are very, very small. You can't see them with your eye. You need to have a microscope to be able to see them. What they look like? Actually, they're related to spiders but they look more like worms, tiny little worms with eight legs.
JAYDEN: Cool. How do you know they're there?
MICHELLE TRAUTWEIN: Well, I know they're there because multiple ways. One I've sampled a lot of people and so I've actually found mites on a lot of different people's faces. But another way that we know they're there is that I've worked with a team of scientists who samples people's faces, and we look for mite DNA. We found that almost every single person we've ever sampled has mite DNA on them, which means they live on everybody.
JAYDEN: How are these mite related to dust?
MICHELLE TRAUTWEIN: I don't know for sure, but I bet they contribute to dust. They probably are part of all that debris. And maybe you know that also in all that debris are these other animals called dust mites. And dust mites love to eat all those little bits of human skin and other kind of organic matter that dust makes up. Dust mites are also tiny, but they're actually a lot bigger than face mites.
They're also almost everywhere. You can find dust mites in almost every house that humans live in. I know because I've sampled many, many around the world and they all have dust mites. But interestingly enough, face mites and dust mites are not close relatives to each other.
There's like 30,000 species of mites that have been described, but there's probably over a million on the planet. It be like thinking of a grasshopper and a butterfly. They're both insects but they're really different and not close relatives. And that's the same thing with a face mite and a dust mite.
JAYDEN: If we study these mites, then what kind of stuff can we learn from them?
MICHELLE TRAUTWEIN: We can learn so many things. What's really exciting to me is that even though these mites live on all of our bodies, right on our faces, we know very, very little about them. That's really exciting to me as a scientist because it reminds me that there's so much that we have to learn and discover about the world. I want to learn more about how they've evolved with humans over time.
One of the things that we've discovered is that these mites are actually different on different people from different parts of the world. So that means that if your ancestors are from Africa, then you have different mites than if your ancestors are from, for example, East Asia or Europe or South America. I can use these mites and their DNA to make estimates about when ancient humans moved around the world. And that's a really exciting project for me.
JAYDEN: Thanks for answering our questions, Michelle.
MICHELLE TRAUTWEIN: Oh, sure. Any time. I love to talk about face mites.
MOLLY BLOOM: OK, Jayden. Let's try that mystery sound one more time. Now, remember, this sound does not come from Earth. Let's listen again.
[DIGGING SOUND]
What is your final guess?
JAYDEN: I still think it's a meteor shower or it also could be like a comet or an asteroid hitting something.
MOLLY BLOOM: Excellent guess. Here is the answer.
KEANNA JARDINE: The sound you just heard was of the space mission Stardust flying through comet dust in space. That sound came from NASA.
MOLLY BLOOM: It was comet dust. You were very close.
KEANNA JARDINE: Hi, my name is Keanna Jardine. I'm a planetary scientist at the University of Central Florida. I study the stickiness of asteroid dust.
MOLLY BLOOM: There is dust on Earth and in space. Dust in space is made out of tiny particles of material that float around in space between stars. Space dust is mostly chemical bits. It can form when stars explode or when asteroids collide. Sometimes that dust in space is a problem for space missions.
KEANNA JARDINE: It sure is. When the astronauts went to the moon, for example, the dust on the moon was a lot like powder. And it was much more fluffy than they thought it would be. So it made it difficult for them to move around. It got stuck under suits, on the instruments, it smelled weird, and it caused them to feel sick.
Some space dust and space debris can be dangerous to things like the space shuttle and the Space Station. Even if they run into a very small piece of dust, it can actually cause a lot of damage. It's almost like when it's a small rock hits your windshield of your car when you're on the highway. Even the smallest piece can cause a lot of damage because of how fast it's rotating around Earth.
MOLLY BLOOM: Scientists are also pretty sure that space dust has formed lots of planets and stars in our solar system. Billions of years ago, Earth started from a bunch of sticky grains of dust.
KEANNA JARDINE: Those small sticky grains ended up coming together to form bigger dust. As it grew bigger and bigger, we ended up with the Earth.
MOLLY BLOOM: We have dust to thank for our planet.
JAYDEN: I never knew that dust could actually make that sound.
MOLLY BLOOM: Yeah, this is a really tricky mystery sound. This is one of the harder ones for sure.
[THEME MUSIC PLAYING]
Dust comes from tiny bits of lots of different things.
JAYDEN: Like your dead skin, your clothes, your pets, and the environment.
MOLLY BLOOM: Bacteria and fungi and dust is different depending on where you live, and can even be used to fight crime.
JAYDEN: We all have my toenails steam and they can teach us about our ancestors.
MOLLY BLOOM: Dust even floats around in space, in between planets, and stars. That's it for this episode of Brains On.
JAYDEN: It was produced by Marc Sanchez, Meneka Wilhelm, Sanden Totten and Molly Bloom.
MOLLY BLOOM: We had production help from Christina Lopez, Ruby Guthrie, Rosie DuPont, and Mary Harvin. And engineering help from Cliff Bentley, Tom Byrne, and Veronica Rodriguez. Special thanks to Audrey Howell, Phyllis Fletcher, Cristina Lopez, Drew Jostad, and Melody Perkins.
JAYDEN: Now, before we go, it's time for a moment of--
KID: My question is, why do people jump when they're scared?
SARAH BENESCH: The simple answer is that it's a reflex reaction that our brain has learned. My name is Sarah Benesch. I'm a neurologist which is a doctor that takes care of brain conditions and spinal cord conditions. I work at the University of Minnesota. There's a response that we call the fight or flight response.
This goes back to the very origins of humans and we have to be able to survive all threats. When you're watching something scary or something scary is around, your brain reacts to that by getting this surge of energy that makes your muscles want to move and run away to safety or move and fight for your safety.
When you're scared, this surge of energy creates that jump and then your brain quickly shuts it down recognizing, Oh, there isn't actually a reason for me to run out of the movie theater because I was scared, or start fighting the person next to me with the popcorn because I was scared, because it was just a scary moment rather than a true threat.
MOLLY BLOOM: This list makes me jump with joy. It's time for the Brains Honor Roll. This is the latest group of friends who have sent in questions, drawings, and mystery sounds to help fuel the show.
[LISTING HONOR ROLL]
[THEME MUSIC PLAYING]
Brains On will be back soon with more answers to your questions.
JAYDEN: Thanks for listening.
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