Which is cooler? Fire or Lasers?
Images courtesy US Forest Service and SLAC
Time for our next debate: fire vs lasers! Listeners sent us over 100 topics to choose from, they voted and this was the winning showdown.
Fire and lasers are both super cool — but which is COOLER? Producer Marc Sanchez has tricks up his sleeve for team fire and Sanden Totten gives his all for team laser. Plus: Two mystery sounds that play a pivotal role in the debate.
Audio Transcript
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SOPHIA: You're listening to Brains On, where we're serious about being curious.
[MUSIC PLAYING]
ANNOUNCER: It's time for the ultimate showdown, the moment we've all been waiting for. Our listeners sent in over 100 debate topics to choose from. We narrowed it down to 10. You voted and chose fire versus lasers. Which is cooler, fire or lasers?
Do you think you've made up your mind already? You ain't heard nothing yet. Keep listening.
MOLLY BLOOM: You're listening to Brains On from MPR News and Southern California Public Radio. I'm Molly Bloom. Being a fair, impartial debate moderator and judge is tricky. So to help co-host this episode, we have asked back Sophia Choo. Hello, Sophia.
SOPHIA CHOO: Hello.
MOLLY BLOOM: Sophia helped moderate our debate about cats.
SOPHIA CHOO: Are they evil, or just misunderstood?
MOLLY BLOOM: And she proved herself a real diplomat, so we are very glad she's here to help us with our next debate.
SOPHIA CHOO: Fire versus lasers.
MOLLY BLOOM: Let's get right to it. Representing Team Laser is producer Sanden Totten.
SANDEN TOTTEN: Pew, pew. Hey, everybody.
SOPHIA CHOO: And representing Team Fire is Marc Sanchez.
MARC SANCHEZ: Crackle, crackle, crackle. Hello.
MOLLY BLOOM: We're going to hear Marc and Sanden's arguments in just a minute. But we also asked our listeners to write in to tell us which they thought was cooler and why.
SOPHIA CHOO: We're going to hear some of their reasons throughout the show.
MOLLY BLOOM: And for some reason coming into this, Marc, you thought fire was going to be the underdog. But I have to say, the votes that we've gotten have been remarkably split so far. This is a close one.
BINI: Hi, Brains On. This is Bini from Bangalore, India. I like fire better because it is useful for cooking, camping, eating, water, et cetera. Bye.
ISAAC: My name is Isaac from Duluth, Minnesota. I like lasers better because they can be focused on one thing, but fire might spread.
CREW: Laser!
SOPHIA CHOO: We've asked Marc and Sanden to prepare opening statements. We flipped a coin to see who's first. Marc, you're up.
MARC SANCHEZ: First off, I want to thank the moderators for having me here. Thank you very much, Sophia. Thank you, Molly. And thank you, Brains On listeners.
Fire, at least in its natural state, has been around forever. Lasers are like the new kid on the block. And I know it's easy to be dazzled by all the cool things lasers promise. But I'm here to tell you that fire will be here long after we stop chasing lasers around like kittens in the living room.
Before I lay out my case, let's just be crystal clear. Fire can be very dangerous. You should always, always, always-- how often, people?
CREW: Always.
MARC SANCHEZ: Use caution when fire is part of the equation. You have to ask an adult to either help you or at least be around when you're learning about fire. With such an ominous warning, I get it. It's easy to see why fire gets such a bad rap.
But I don't think fire is all that bad. What fire needs is a shift in thought, a pivot, an image makeover. We only think of it in terms of evil and destruction, but it has been and continues to be enormously helpful in stuff we take for granted.
For starters, hot food. Anyone here eat a hot meal in the last day, or hour? Fire most certainly had something to do with cooking it. How about staying warm? Yeah, heat, heat, people.
Unlike lasers, heat is kind of important to, I don't know, survival. And let's not forget light. Have you ever wanted to see at night? I mean, before the light bulb, torches lit the way for centuries. You have fire to thank for that.
Over the course of this episode, I intend to lay out a clear path that shows fire is superior to lasers. Thank you, and thank fire.
MOLLY BLOOM: Thank you, Marc. Sanden, let's hear your opening statement.
[CLEARS THROAT]
SANDEN TOTTEN: I shall begin. Thank you. First of all, the word laser is just really cool to say. Come on, la-ser. Say it. See for yourself.
CREW: Laser.
MOLLY BLOOM: It's pretty fun.
MARC SANCHEZ: Whatever.
SANDEN TOTTEN: Right? Sure, lasers, yeah, they're not as old as fire. I get it. They've only been around since the 1960s. But we've been dreaming about powerful beams and ray guns for a lot longer than that. And you know what? Now that we have them, lasers totally live up to the hype.
OK, so at its core, a laser is an intense, very narrow beam of light. Which sounds simple, but the number of things we can do with lasers is mind-boggling. They can be used in medicine to help with tricky surgeries. They can be used in manufacturing to cut certain things and weld other things together.
They are in your CD players and in your DVD players. They can be used for laser light shows, for laser tag. There's even a laser on NASA's Curiosity rover on Mars. All this, and we're only starting to scratch the surface of what a laser can do. People are coming up with new ways to use them all the time. These are like real, literal bright ideas.
And while fire is neat, it's also super hard to control. Lasers are the opposite. They are a perfect example of something precise and very controllable. Now, a note of caution. Lasers are also very powerful. And they can injure the eye or even cause blindness, so be very careful around them.
Still, when used safely, lasers are pretty amazing. We can use them to tickle an atom or blast a hole in something. So people, join me on Team Laser, and we'll beam into a brighter, better future.
SOPHIA CHOO: Well done, Sanden. Let's hear what our listeners had to say.
LAUREN: Hello, I am Lauren from Grand Rapids, Michigan. I think lasers are better because they are light that can cut through things.
KATHERINE: I'm Katherine from Grand Rapids, Michigan. And I think fire is better because its colors are more fascinating.
SOPHIA CHOO: Onto the first round. We're calling it, What the Wood?
MOLLY BLOOM: Sanden, you're up.
SANDEN TOTTEN: So to explain the way lasers work, I thought it would be best if we went to the source itself. So I'm going to take us on a tour of a magical place called Laser World, where lasers are made. Let's listen in.
TOUR GUIDE: Welcome to Laser World, everyone. Please keep your hands and legs inside the tram at all times. We are about to get moving. Any questions?
TOURIST 1: Can we feed the lasers?
TOUR GUIDE: What? No, that's, that's impossible. Where did you even hear?
TOURIST 2: I want to touch the lasers.
TOUR GUIDE: No, definitely not that. No touching.
TOURIST 3: Can I take a selfie with a laser?
TOUR GUIDE: You know what? Enough questions. Let's just get going. Fun fact, laser is an acronym. It stands for light amplification by stimulated emission of radiation.
TOURIST 2: That's not fun.
TOUR GUIDE: Yes, it is. OK, look to your left. There's a special guest, Theodore Maiman. He invented the first laser in 1960.
THEODORE MAIMAN: Hello. My laser used a ruby rod to make a deep red beam of light. Pew, pew.
ALL: Whoa!
TOUR GUIDE: Next, we are entering the Laser Hall of Fame. Here you get to see all the important inventions we rely on that use laser technology.
TOURIST 4: Like ray guns. Zap! You're toast.
TOUR GUIDE: Well, actually, some researchers are working on laser weapons, but they are still in the early stages of development. And we'd rather focus on some of the less destructive uses of lasers.
TOURIST 5: Oh, man. Then what do lasers do?
TOUR GUIDE: Well, if you'd let me continue the tour, here's the scanner from your grocery store. It uses lasers to read barcodes.
ALL: Ooh!
TOUR GUIDE: CD and DVD players use lasers to scan for tiny bumps coded in a disk and translate those into sounds or images.
ALL: Ooh!
TOUR GUIDE: And over here, we have a laser light show.
[MUSIC PLAYING]
ALL: Wow!
TOURIST 6: Those colors would make an amazing Instagram filter.
TOUR GUIDE: And perhaps the most important use of a laser, making your cat chase that little red glowing dot.
[CAT GROWLING]
[GLASS BREAKING]
[CAT SQUALLING]
Oops, looks like someone has a mess to clean up.
TOURIST 7: Quick question. Can I feed the cat?
TOUR GUIDE: Seriously? Like what, do you just have too much food? Leave the cat. Let's move on. Next, we are going to see how a laser is made. To do that, we need to shrink down to the size of an atom. Are you ready?
TOURIST 8: Do we have a choice?
TOUR GUIDE: Nope. Here we go.
ALL: Whoa! Status update?
TOURIST 9: Feeling tiny.
TOUR GUIDE: Here we are entering a laser chamber. Check it out.
TOURIST 6: Location update, some kind of glass tube? How do I tag myself on this?
TOUR GUIDE: That's right. This one is filled with gas, but some lasers use solids, like the ruby mentioned earlier, and others use liquids. The gas is getting charged with energy from a flash bulb. As the gas gets charged, electrons in the gas atoms get excited and enter a higher state of energy. Let's listen in.
[SCATTING]
[ELECTRONIC BUZZ]
That's the light powering up the electrons.
ELECTRON: Whoa! So much energy.
TOUR GUIDE: This happens to electrons all throughout the gas. The key for a laser is to have the majority of the atoms reach this heightened state.
ELECTRON: Whoa! So much energy.
TOUR GUIDE: Now, as the electrons lose that energy and return to their normal state, they release a packet of light called a photon.
[ELECTRONIC WHIR]
ELECTRON: Calming down now.
[SPARK]
There goes a photon.
TOUR GUIDE: This happens all over in the gas.
[ELECTRONIC WHIR]
ELECTRON: Calming down now. Calming down now. There goes a photon. There goes a photon.
TOUR GUIDE: And interestingly enough, as that photon passes by another highly energized electron, it can trigger that electron to calm down and release another photon as well.
TOURIST 10: Wow, that's a lot of photons flying around.
TOUR GUIDE: Exactly. That's kind of how a light bulb works, scattering light willy-nilly in all different directions and what have you.
TOURIST 11: Well, what makes a laser so special, then?
TOUR GUIDE: What makes a laser special is that first, all those photons are coherent, meaning they are in sync with each other. And they are monochromatic, meaning they are all the same color. Light bulbs cast light with a broad spectrum of colors that together look white.
TOURIST 6: Huh. Hashtag, the more you know.
TOUR GUIDE: Second, those photons are trapped by two mirrors on either side of this tube. See?
TOURIST 6: A mirror? Really? Let me check my lipstick.
TOUR GUIDE: Leave this tram, and I will end you. Where was I? Oh, yeah. The photons are trapped in the chamber by mirrors. Some photons escape through the sides of the tube, but those trapped between the two mirrors go back and forth. That amplifies the light beam.
But here's the secret to a laser. One mirror is slightly see-through, so a small number of photons can escape through it, exiting the laser chamber as a sweet, pure beam of laser light.
TOURIST 9: Whoa!
TOURIST 5: Whoo!
[APPLAUSE]
TOUR GUIDE: See how it's beaming out that end of this tube? So a laser is made by energizing electrons so they shoot out photons. Then, a reflective surface traps and amplifies those photons, while letting some escape out as a steady beam.
TOURIST 1: Amazing. Quick question, though. Can I feed--
TOUR GUIDE: No. Whatever it is, you can't feed it. Just, let's end this tour. Thank you for visiting Laser World. Come back any time, just not when I'm working, please.
ANNOUNCER: (SINGING) Brains On!
SOPHIA CHOO: Now, Marc.
MARC SANCHEZ: To know fire is to love fire. But first, what is fire? Quite simply, fire is a chemical reaction that gives off heat. Every fire has three ingredients, heat, fuel, and oxygen.
We've said it before, and the same applies in this episode. Everything around us is made up of atoms. Fried chicken? Atoms. Leaves on a tree? Atoms. Even the oxygen we breathe is made up of atoms.
Now, oxygen is a gas, and under normal conditions, its atoms are just kind of bouncing off each other. But when heat is introduced, look out. Heat excites atoms, which means a lot more bouncing off each other. The higher the heat, the faster the atoms move.
Put that heat source next to the fuel of, say, the hydrogen and carbon atoms of the wax on a candlewick, and those atoms start bouncing around, too. In fact, they start moving so much that they change from a solid to a gas. They vaporize. And that is called pyrolysis, when the fuel turns into a gas.
Now we have oxygen, hydrogen, and carbon gas atoms all coming together and still very excited. When these atoms mingle and rearrange, they give off blue light. I'm guessing you've all seen a burning candle. If you look at the bottom part of the wick, you'll see the flame is blue.
WOMAN: But what makes the other colors, the red and orange and yellow?
MARC SANCHEZ: Soot.
MAN: Gesundheit.
MARC SANCHEZ: Thank you, but that wasn't a sneeze. Soot is the answer. Soot is what makes the rest of the flame glow those red, orange, and yellow colors. Instead of bonding with the oxygen atoms, some of the carbon atoms come together with each other and form soot.
Think of it like a piece of charcoal, except really, really microscopically tiny. Charcoal bricks glow when they're heated. So does lava from a volcano. And so does soot. These glowing pieces of soot rise up-- because heat rises-- into a nice kind of conical flame we see when we look at a candle. And that, my friends, is fire.
[MUSIC PLAYING]
MOLLY BLOOM: OK, now on to the second round of the fire versus lasers debate. It's time for Mystery Sounds.
[RANDOM SOUNDS]
I have a mystery sound for each of you, related to fire for you, Marc, and lasers for you, Sanden. Marc, here is your mystery sound.
[SOUND OF ENGINE RUNNING]
Any guesses?
MARC SANCHEZ: It's pretty hypnotic, so I might have zoned out a bit there.
MOLLY BLOOM: I mean, Sophia, you can help him, too. He might need you.
MARC SANCHEZ: Yeah, what do you think it is? What does it sound like to you, Sophia?
SOPHIA CHOO: It sounded slightly like a generator of some sort.
MARC SANCHEZ: Ooh, I like that word. I couldn't think of a good description. But yeah, generator, definitely something mechanical. I'm going to go with a giant stove.
MOLLY BLOOM: OK. We'll let you stew on that for a bit. Sanden, here is your mystery sound.
SANDEN TOTTEN: Bring it on.
[POP]
[CLICK]
[POP]
[CLICK]
[POP]
[CLICK]
[POP]
[CLICK]
MOLLY BLOOM: Any guesses?
SANDEN TOTTEN: I picture somebody at one of those firing rifle ranges, and they're shooting a clay disk, and they shoot the disk.
MOLLY BLOOM: Sophia, do you have any guesses?
SOPHIA CHOO: It did sound like a firing range.
SANDEN TOTTEN: Did you hear people mumbling in the background, too, Sophia?
SOPHIA CHOO: Yeah.
SANDEN TOTTEN: What was that about?
SOPHIA CHOO: I have no clue what it could be.
SANDEN TOTTEN: Didn't they know we're recording a mystery sound?
MOLLY BLOOM: Well, I think we need to build a little suspense here, so we're going to be back with the answers in just a bit.
[MUSIC PLAYING]
SOPHIA CHOO: Do you have a mystery sound to share with us? Or a question you'd like to hear answered on the show? Or maybe you just want to send a high five or a drawing?
MOLLY BLOOM: Email them to us at brainson@m-- as in Minnesota-- pr.org.
SOPHIA CHOO: You can also send us actual mail.
MOLLY BLOOM: You can find the address at our website, brainson.org.
SOPHIA CHOO: And while you're there, you can also listen to all of our past episodes and sign up for our newsletter.
MOLLY BLOOM: And in order to say thank you to all the kids who write to us with their ideas, suggestions, and curiosity, we created the Brains Honor Roll. If you've written to us, we will get to you, we promise. But we're hearing from so many of you that there's a bit of a wait. So thank you for your patience.
[MUSIC PLAYING]
[LISTING HONOR ROLL]
MOLLY BLOOM: You're listening to Brains On from MPR News and Southern California Public Radio. I'm Sophia Choo.
MOLLY BLOOM: And I'm Molly Bloom.
SANDEN TOTTEN: And I'm Sanden Totten for lasers.
MARC SANCHEZ: And I'm Marc Sanchez, Team Fire.
MOLLY BLOOM: Sophia, in your opinion, who is winning the debate so far?
SOPHIA CHOO: Um.
MARC SANCHEZ: There's candy in it for Team Fire.
MOLLY BLOOM: No pressure.
SOPHIA CHOO: I think it's tied for right now because you both have really good points.
MOLLY BLOOM: That is very diplomatic.
MARC SANCHEZ: That's good to hear.
SANDEN TOTTEN: Yeah, I mean, we're shaking hands on the outside. But wait for--
MARC SANCHEZ: Boxing gloves.
SANDEN TOTTEN: --the next round, Marc. Boxing gloves are coming on, I think.
MOLLY BLOOM: Well, let's see if this next round changes your mind. It's the lightning round.
ANNOUNCER: Lightning.
MOLLY BLOOM: Your coolest facts about fire and lasers.
SOPHIA CHOO: Ready, set, go.
MARC SANCHEZ: Fire is good for the brain. It's thought that around 2 million years ago, Homo erectus, our early ancestors, learned how to harness and reproduce fire.
Archaeologists like John Gowlett of the University of Liverpool think that this set Homo erectus on a path to productivity. For the first time, we could see after the sun went down. That is a textbook example of a game changer. Instead of going to sleep when the sun went down, Homo erectus had the chance to think and develop its brain.
And while we're still on the subject of fires and brains, you have to admit that there's pretty much nothing better than sitting around a campfire and staring at it. It's super relaxing and meditative. Our early ancestors thought so, too.
Matt Rossano, a psychologist at the University of Louisiana, thinks that getting into a meditative state helped enable the brain to think more and be less reactionary. Instead of being freaked out by a predator jumping from behind a bush, we now have the headspace to make plans for that kind of thing in advance.
[PING]
ANNOUNCER: Lightning.
SANDEN TOTTEN: Lasers may just be light, but that doesn't mean they're lightweights. See what I did there? See, see? When it comes to slicing and dicing, lasers are used to cut all kinds of things, including sheets of metal.
So how does a light slice something as hard as metal? Great question. It has to do with the intensity of the laser. You see, the laser doesn't cut the metal so much as it melts away or evaporates a very small sliver of it. You take a high-powered beam and tightly focus it on metal to make this happen.
It's sort of like how you can take a magnifying glass and tightly focus sunlight to burn a leaf or a piece of paper. That's kind of how laser cutting works. And this helps companies and inventors that need to make very precise cuts in tough materials do that so that they can create cool new things, and invent awesome stuff, and basically change the world. So thanks, lasers.
[PING]
ANNOUNCER: Lightning.
MARC SANCHEZ: Fires help keep forests healthy. To illustrate this point, I'm going to bring in a couple of familiar voices. Follow me back, won't you, to the not so distant past. It's from the episode we did about trees.
SANDEN TOTTEN: Where I am in California, we have lots of forest fires. But here's the thing. In some ways, forest fires are actually good for the forest. Some trees actually need a forest fire to help them reproduce.
MARC SANCHEZ: There you have it, Sanden Totten, arguing in favor--
SANDEN TOTTEN: What?
MARC SANCHEZ: --of fire. Can we hear a little bit of that again? Can we hear a little bit of that again?
SANDEN TOTTEN: In some ways, forest fires are actually good for the forest.
I never thought I'd be saying this in a debate, but my opponent is absolutely right.
MARC SANCHEZ: I can't argue with that guy. He's so well-spoken and smart. There are trees that depend on fire to open up their seeds. Sara McAllister studies how forest fires work at the Missoula State Fire Sciences Lab. And she told me about the longleaf pine that starts out looking like a piece of grass.
SARA MCALLISTER: That will sit there for a few years until a fire comes and actually clears the forest of all of its competition. But it also kills a particular fungus that will actually damage the tree if it tries to kind of keep growing before a fire.
So once a fire comes and kind of clears the path, these trees will shoot up, like, five feet in a year and turn from little clumps of grass into big, tall trees.
MARC SANCHEZ: These trees are vital parts of the forest's ecosystem, not to mention, they give off oxygen so we can, you know, breathe.
[PING]
ANNOUNCER: Lightning.
SANDEN TOTTEN: So that was a pretty clever trick, Marc, using me against myself. But you know another cool trick? Using lasers as tweezers. The idea of laser tweezers is actually kind of simple and still very cool.
So imagine you have something like a protein you want to research. These are really important parts of humans and lots of things, but they tend to be all folded up. So how do you unfold this protein? Well, your fingers are way too clumsy and way too big to try that yourself. So, laser tweezers.
Researchers can attach a tiny sphere to either end of the protein. Then, using a laser, they can zap that sphere and hold it in place with a laser beam. Then, they attach the other end of the protein to a slide and simply start pulling back away from the trapped sphere.
It's like if you nailed one end of a Slinky to a wall and then started walking in the other direction with the other end. Pretty soon, you've unslinked the Slinky, you've uncurled it. And in the case of the protein with the laser tweezers, you've unfolded this tiny protein. And now, you can study how it folds and what's inside it and all this great stuff, thanks to lasers.
[PING]
ANNOUNCER: Lightning.
MARC SANCHEZ: Fire was the original internet. Well, sort of. Some American Indian tribes used fire to communicate. These fiery messages could be read as far as 100 miles away. Chinese soldiers on the Great Wall of China also used smoke signals. They lit a mixture of saltpeter, sulfur, and wolf poop to signal to each other. And while it may not have smelled too good, they could send a message about 300 miles in just a few hours. And this was back in 900 BC.
And hopefully you'd never find yourself lost in the woods. But if you do and there's no GPS and your cell phone is out of batteries, smoke signals and fire could save your life.
[PING]
ANNOUNCER: Lightning.
SANDEN TOTTEN: Here's a cool fact. Did you know there are mirrors on the moon? Seriously. In 1969, astronauts Buzz Aldrin and Neil Armstrong first set foot on the moon. Pretty cool. A little while later, they left a bunch of mirrors.
Why? So scientists on Earth could bounce lasers off the moon. That's right, bouncing lasers off the moon. That's just so cool. So basically they would beam a laser at these lunar mirrors from the Earth. And the laser would hit the mirrors and bounce right back to where they came from. And by measuring how long it took for a pulse of this laser to go to the moon and back, scientists could calculate how far away the moon is with amazing accuracy.
They've done it lots of times, and this has taught us all sorts of interesting things about the moon. For example, did you know the moon is slowly spiraling away from Earth at a rate of about 3.8 centimeters a year? Come back, moon. We love you.
Once again, lasers are helping us learn all sorts of cool things about the universe. They rule.
[FIVE PINGS]
ANNOUNCER: Lightning.
NOAH: Hello, I'm Noah from San Diego. I like lasers better they are cool because they are made out of light and can start fires.
IAN: My name is Ian, and I'm 6 years old. The reason why I like fire better than lasers is because lasers wold just make a hole in the fire. The end.
MOLLY BLOOM: I am exhausted after that. I would say we should let you guys take a breather, but there's no time for that. Let's go back to the mystery sound. Who wants to go first?
SANDEN TOTTEN: Maybe I should go first because Marc went first last time.
SOPHIA CHOO: Fair.
MOLLY BLOOM: Excellent. Let's hear your sound one more time.
[POP]
[CLICK]
[POP]
[CLICK]
[POP]
[CLICK]
[POP]
[CLICK]
Any new guesses, Sanden? And I just want to say that there's a little click in there, too. you Might not have heard it.
SANDEN TOTTEN: Yeah, there's a click. There's a lot going on there. I don't know. Sophia, what are you thinking?
SOPHIA CHOO: I don't know.
SANDEN TOTTEN: I'm sticking with my rifle range idea. Maybe they're using a laser to target things with rifles?
MOLLY BLOOM: Well, here's Rob Fornasiere. He'll let us know what it is.
ROB FORNASIERE: Ryan is one of our relief pitchers out there. And when he's right and fully in good shape in game competition, he'll throw [POP] anywhere from 90 to 93 miles an hour. But you can see, [POP] he's just playing catch right here. And he's throwing about 50 [POP] to 55. That was 52 right there from Cody. [POP] 52 miles an hour.
MOLLY BLOOM: So that was University of Minnesota Assistant Baseball Coach Rob Fornasiere, and that was the sound of two of his pitchers playing catch indoors. And how does he--
SANDEN TOTTEN: Whoa!
MOLLY BLOOM: Yeah. And how does he know exactly how fast they're throwing the ball? That's where lasers come in. Did you hear that? That was that faint click between throws.
SANDEN TOTTEN: Yeah.
MOLLY BLOOM: Yeah, that is Rob using a device called a speed gun to measure how fast the baseballs are moving. His device uses a microwave laser, which is also known as a maser. I did not know that word before researching this, but that's how he does it.
SANDEN TOTTEN: I've done masering.
MOLLY BLOOM: You did some masering.
[SHEEP BAAING]
Well, the sound of the sheep means we made a little mistake. I said this speed gun used masers, and that's not true. Mesas are like lasers, but they use microwaves instead of visible light. There are speed guns that use microwaves, and there are speed guns that use lasers. But there aren't speed guns that use masers. This speed gun uses microwaves.
[SHEEP BAAING]
Now back to the show.
They also use it to measure throws from outfielders. That measures arm strength. And they also use it to measure what's called exit velocity. That's how fast the ball is moving when it leaves the bat after being hit.
These speed guns first started to be used in baseball in the 1960s. Before that, they had a less exact way of knowing how fast pitchers could throw.
ROB FORNASIERE: They literally had a car that was driving at an x amount of speed down a long road. And they had a baseball player standing next to where the car would go. And the car maybe was going, let's say, at 70 miles an hour.
And at the precise moment the car would pass the pitcher, he'd release the ball, and we'd see whether the car or the ball could pass the mark quicker. And so that's where they started to determine how fast balls were actually thrown.
SANDEN TOTTEN: Wow. That's so cool. I always love learning more about America's favorite pastime, lasering.
[LAUGHTER]
MARC SANCHEZ: Cool it, cool it, Sanden.
MOLLY BLOOM: Well, let's see how Marc does.
[SOUND OF ENGINE RUNNING]
MARC SANCHEZ: Are there any little clicks that I need to be paying attention to?
MOLLY BLOOM: No little clicks in there. Sorry.
MARC SANCHEZ: All right, so we've got generator. If I just say fire, do I get, like, half credit? Do I get half a point?
MOLLY BLOOM: I'm sorry, no.
MARC SANCHEZ: All right. Well, I'm going to say an industrial stove. I'm going to stick with that.
MOLLY BLOOM: OK, here is the answer.
CHARLIE JOHNSON: Hi, I'm Charlie Johnson. And I'm the chef/owner of Q Fanatic BBQ. That was the sound of our smoker, the rotisserie on our smoker. We smoke all our meats in the smoker.
And it kind of looks like a big Ferris wheel. And it goes around, and that's the motor that makes the Ferris wheel go around. And we use logs, logs or split wood, to smoke all our meat-- hickory, actually. Smoking adds flavor.
Historically, it preserves meat, but we use it as a flavoring, kind of like some people use salt and pepper. But classically, it was used to preserve food. There's a fire. We have a gas assist that helps light the wood. And so then it has fans that blow on the wood when it needs to get, when the smoker needs to get hotter, to stoke the fire.
MARC SANCHEZ: Can I defer to the judges here? Because, I mean.
SOPHIA CHOO: It's a smoker, not a stove.
MOLLY BLOOM: You were very close. I mean, we should probably give you half credit.
MARC SANCHEZ: At least.
MOLLY BLOOM: I think. Because it is kind of--
MARC SANCHEZ: It's used for--
MOLLY BLOOM: A cooking device.
MARC SANCHEZ: --cooking.
MOLLY BLOOM: I mean, you weren't exact, but you were--
MARC SANCHEZ: Yeah, but fire is-- I mean, so much of it's cooking.
MOLLY BLOOM: It's true. It's a tough one. It's a tough call.
SOPHIA CHOO: All right, Marc. I'm down for half a point.
MOLLY BLOOM: OK, Sophia gave him half a point, our judge.
SANDEN TOTTEN: All right, good listening, good listening, Marc.
MOLLY BLOOM: You know, so just like Marc talked about earlier, how fire is good for the brain, that also goes for harnessing fire to cook, too. Our ancestors were able to get more calories and more nutrition from cooked food than they were from raw food. And this helped their brains to get bigger and to spend less time searching for food and then chewing it.
ANNOUNCER: (SINGING) Ba, ba, ba, ba, ba, ba, ba, ba, ba, ba, ba, Brains On.
SOPHIA CHOO: Time for a final round. We're calling it Coming Soon.
MOLLY BLOOM: Sanden, you first.
SANDEN TOTTEN: Well, we all know fire is a great source of energy. Sure, I'll give it that. But what if I told you lasers might help us create an even better source of energy, an unlimited, clean form of sustainable energy?
SOPHIA CHOO: I'm listening.
SANDEN TOTTEN: I spoke with Dr. Kate Lancaster. She's with the University of York at their Plasma Institute, and she's working on a project to do this very thing.
KATE LANCASTER: So my specialty is-- well, it's called laser plasma physics. So it's taking some of the world's most powerful lasers and firing them at a piece of material until basically all the atoms fall apart. And one of the purposes of doing that is to try and make miniature stars.
MOLLY BLOOM: Wait, did she just say miniature stars?
SANDEN TOTTEN: Yeah. A star, like our sun, but tiny and here on Earth. This idea is called nuclear fusion power. And if we could pull it off, it would solve so many of our energy problems without adding a ton of pollution.
You see, the sun is like a very hot energy-producing machine. If we could harness even a piece of that here on Earth, we'd be able to power, well, pretty much everything.
SOPHIA CHOO: Sure, but how would we do that?
SANDEN TOTTEN: Kate says we'd need to recreate the reactions happening in the sun here on Earth in a highly controlled environment. So to do that, her team takes two kinds of hydrogen and forms them into small pellets of fuel.
To make that pellet turn into a tiny star, they need to make it very dense and very hot, just like our sun. That will create a reaction where the helium is converted to hydrogen. It gives off lots of energy in the process. So the team, they make this hydrogen pellet, and then they take it to a specialized laser firing room to make that happen.
KATE LANCASTER: So there's a tiny little ball bearing-sized pellet in the middle of this huge chamber that looks like the Death Star from Star Wars. And 192 beams come in from all angles. And essentially what happens when you do that is the lasers, when they shine on the fuel, they can heat up an outer layer of the fuel, which flies away very rapidly.
SANDEN TOTTEN: And this helps compress it. See, when that outer layer flies away, it actually pushes back on the rest of the pellet in the opposite direction. This is a basic law of physics. For every action, there's an equal and opposite reaction.
KATE LANCASTER: It's kind of like the air coming out of the back of a balloon. The balloon has to go in the opposite direction. So if you do that all around a sphere, an outer layer of the sphere flies away, caused by the lasers. And then the rest of the fuel has to move into the center and be very, very dense and small. And then it needs to get hot.
SANDEN TOTTEN: And she means, like, really hot, like 150 million degrees centigrade hot. Luckily, lasers can help here, too. Because when they smack this pellet of fuel, it creates a shockwave, and that shockwave is full of energy. And since that energy has nowhere to go but into the pellet, it converts into heat. And that raises the temperature of this tiny little pellet.
So there you have it. To make nuclear fusion, you basically need to get a fuel pellet very dense and very hot. That will kick off a reaction like the one in our sun that produces lots of energy. Lasers can help you do both things, by compressing the fuel and by heating it up. Pretty cool.
MOLLY BLOOM: So how far along is this technology, Sanden? Can we use it to power our cities soon?
SANDEN TOTTEN: Well, it's still in the early stages of development. This idea of nuclear fusion, of harnessing the power of a star right here on Earth, it's been around for decades. But it's really complicated, and it needs to be very precise to work. No one has mastered it yet.
So Kate Lancaster says part of the problem is that we need high-energy lasers that can fire many times a second. And we don't have those yet, but we're working on them. And fusion power is so promising. It could solve so many of our energy problems. It doesn't pollute, like gas or coal. Once it's working, it's practically limitless. So because of all this, researchers keep trying to get it right.
KATE LANCASTER: We're a number of decades away from putting any kind of electricity on the grid, which is precisely why we need any budding scientists or engineers listening right now to help us. Because I'm going to get old, and people like me are going to get old. We're going to need new people to help us work on this stuff.
SANDEN TOTTEN: So it might be far off, but one day, lasers could help power the world, and that's pretty awesome.
SOPHIA CHOO: Marc, your last chance. The mic is yours.
MOLLY BLOOM: It's hard to compete with powering the world.
SOPHIA CHOO: Mm-hmm.
MARC SANCHEZ: Powering the world is one thing, but let's have a little fun, shall we? Our planet has had a relationship with fire since the beginning of time. So there's no doubt it will be here for years to come.
But what's next? If you've ever been to an amusement park, watched the big game, or celebrated your patriotic heart out, then you've probably seen a fireworks show. People first started using these colorful, loud bursts of fire around 2,000 years ago in China. And over the years, we've grown accustomed to bigger and better shows.
John Conkling is a chemist and has helped fireworks manufacturers push the field into a new era.
JOHN CONKLING: It's not your grandfather's fireworks anymore where everybody goes out and sits on a little hill, and they shoot some up in the air-- bang, bang, bang, bang, ooh, aah-- and that's the end of it.
SANDEN TOTTEN: As a chemist, John helps fireworks manufacturers mix a secret sauce of chemicals to come up with cool new colors.
JOHN CONKLING: Well, sodium makes a yellow-orange color. Copper compounds can make a blue color. Strontium, which is not one of your everyday elements, but it will produce a beautiful red color.
SANDEN TOTTEN: The fireworks that we see in the sky look a lot different than what you're used to seeing at a roadside stand. Each colorful burst starts out as a spherical casing that's a little bigger than a softball. Inside the casing are a few stages of gunpowder. The first is on the bottom, with a fuse sticking out. The casing is stuffed into a tube, then the fuse is lit.
The gunpowder ignites and explodes the first stage, launching everything up into the air. The explosion also lights another fuse inside the casing that's attached to even more gunpowder. A few seconds later, when the casing is high in the sky, stage two explodes and ignites little pellets full of chemicals that have been meticulously laid out in a pattern.
JOHN CONKLING: The Chinese developed a lot of what are called pattern shells that will burst as a five-pointed star or a smiling, happy face. You can produce letters up in the sky by this good engineering. It's how you package the pellets of color composition into the fireworks casing.
And if you do it very, very carefully, lots of trial and error, you can actually get that firework to explode up in the air. And those pellets will go out and hold the pattern you're trying to create. And that's really the newest thing in fireworks.
SANDEN TOTTEN: John says that if you really want to wow a crowd these days, you have to play on their emotions. You have your basic bang bang fireworks, and then you have these pattern shells that he was talking about. But throw in a sound system, and people go bananas.
JOHN CONKLING: Any of the more major shows today, I mean, they're really multimedia presentations. The lasers sometimes-- I mean, you can add all sorts of stuff into them.
SANDEN TOTTEN: Wait, wait, wait, wait. Did he just say lasers?
MARC SANCHEZ: Well, sure, yeah. I mean, yeah, I guess so. Lasers may play a part in fire's future, but it's a small part, teensy. There's really nothing quite like the sensory experience of fireworks.
JOHN CONKLING: When that firework launches into the air, you get that whomp. And everybody's pulse starts beating a little faster. And then up in the sky, boom, you can feel that shockwave. And that's what makes fireworks. I think that trumps lasers.
MARC SANCHEZ: And there you have it. Mic drop, hashtag end of story, fire forever. I'm out.
MOLLY BLOOM: Wow. That is a lot to ponder. Sophia, do you think you can declare a winner after all of this?
SOPHIA CHOO: Well, I've and tallying points, and Marc won by half a point.
MOLLY BLOOM: With that mystery sound?
SANDEN TOTTEN: He won by the mystery sound?
MOLLY BLOOM: Oh, man. Mystery sound's a tiebreaker.
MARC SANCHEZ: I got a good set of ears.
SANDEN TOTTEN: Wow, wow. I got to hand it to you, though, Marc. That was well played. You Used myself against myself, and you correctly identified half a mystery sound. That was good.
MARC SANCHEZ: Sir, Sanden, you were a truly worthy opponent. And I am deeply impressed by lasers, and especially the future of lasers.
MOLLY BLOOM: I have to say, I might be Team Lasers on this one. So this was a squeaker. I really want to hear what people say about this.
SANDEN TOTTEN: Yeah, come on over to the light side.
MOLLY BLOOM: Do you, our dear listeners, agree with the verdict? There's a poll at our website, brainson.org, where you can vote for the team that you think won, fire or lasers.
[MUSIC PLAYING]
Well, that's it for this episode of Brains On.
SOPHIA CHOO: Brains On is produced by Marc Sanchez, Sanden Totten, and Molly Bloom.
MOLLY BLOOM: Many thanks to Veronica Rodriguez, Sam Choo, A Martinez, Megan McCarty, Julian Burrell, Taylor Orci, Sara McAllister, and Eric Brigham.
SANDEN TOTTEN: If you want to give us a shout-out, share your opinion, or get in touch with us, there's lots of ways you can do that. You can find us on Twitter and Instagram. We're @brains_on.
MARC SANCHEZ: Or if you're on Facebook, you can just search for us there. Search for Brains On.
SANDEN TOTTEN: And this will not be our last debate. After all, I have to win one, now that Marc just took the lead. So start thinking of more topics for us. We'll need them.
SOPHIA CHOO: If you're a fan of Brains On, consider leaving a review in iTunes. It really helps other kids and parents to find out about the show.
MOLLY BLOOM: We'll be back soon with more answers to your questions.
SOPHIA CHOO: Thanks for listening.
[MUSIC PLAYING]
ANNOUNCER: It's time for the ultimate showdown, the moment we've all been waiting for. Our listeners sent in over 100 debate topics to choose from. We narrowed it down to 10. You voted and chose fire versus lasers. Which is cooler, fire or lasers?
Do you think you've made up your mind already? You ain't heard nothing yet. Keep listening.
MOLLY BLOOM: You're listening to Brains On from MPR News and Southern California Public Radio. I'm Molly Bloom. Being a fair, impartial debate moderator and judge is tricky. So to help co-host this episode, we have asked back Sophia Choo. Hello, Sophia.
SOPHIA CHOO: Hello.
MOLLY BLOOM: Sophia helped moderate our debate about cats.
SOPHIA CHOO: Are they evil, or just misunderstood?
MOLLY BLOOM: And she proved herself a real diplomat, so we are very glad she's here to help us with our next debate.
SOPHIA CHOO: Fire versus lasers.
MOLLY BLOOM: Let's get right to it. Representing Team Laser is producer Sanden Totten.
SANDEN TOTTEN: Pew, pew. Hey, everybody.
SOPHIA CHOO: And representing Team Fire is Marc Sanchez.
MARC SANCHEZ: Crackle, crackle, crackle. Hello.
MOLLY BLOOM: We're going to hear Marc and Sanden's arguments in just a minute. But we also asked our listeners to write in to tell us which they thought was cooler and why.
SOPHIA CHOO: We're going to hear some of their reasons throughout the show.
MOLLY BLOOM: And for some reason coming into this, Marc, you thought fire was going to be the underdog. But I have to say, the votes that we've gotten have been remarkably split so far. This is a close one.
BINI: Hi, Brains On. This is Bini from Bangalore, India. I like fire better because it is useful for cooking, camping, eating, water, et cetera. Bye.
ISAAC: My name is Isaac from Duluth, Minnesota. I like lasers better because they can be focused on one thing, but fire might spread.
CREW: Laser!
SOPHIA CHOO: We've asked Marc and Sanden to prepare opening statements. We flipped a coin to see who's first. Marc, you're up.
MARC SANCHEZ: First off, I want to thank the moderators for having me here. Thank you very much, Sophia. Thank you, Molly. And thank you, Brains On listeners.
Fire, at least in its natural state, has been around forever. Lasers are like the new kid on the block. And I know it's easy to be dazzled by all the cool things lasers promise. But I'm here to tell you that fire will be here long after we stop chasing lasers around like kittens in the living room.
Before I lay out my case, let's just be crystal clear. Fire can be very dangerous. You should always, always, always-- how often, people?
CREW: Always.
MARC SANCHEZ: Use caution when fire is part of the equation. You have to ask an adult to either help you or at least be around when you're learning about fire. With such an ominous warning, I get it. It's easy to see why fire gets such a bad rap.
But I don't think fire is all that bad. What fire needs is a shift in thought, a pivot, an image makeover. We only think of it in terms of evil and destruction, but it has been and continues to be enormously helpful in stuff we take for granted.
For starters, hot food. Anyone here eat a hot meal in the last day, or hour? Fire most certainly had something to do with cooking it. How about staying warm? Yeah, heat, heat, people.
Unlike lasers, heat is kind of important to, I don't know, survival. And let's not forget light. Have you ever wanted to see at night? I mean, before the light bulb, torches lit the way for centuries. You have fire to thank for that.
Over the course of this episode, I intend to lay out a clear path that shows fire is superior to lasers. Thank you, and thank fire.
MOLLY BLOOM: Thank you, Marc. Sanden, let's hear your opening statement.
[CLEARS THROAT]
SANDEN TOTTEN: I shall begin. Thank you. First of all, the word laser is just really cool to say. Come on, la-ser. Say it. See for yourself.
CREW: Laser.
MOLLY BLOOM: It's pretty fun.
MARC SANCHEZ: Whatever.
SANDEN TOTTEN: Right? Sure, lasers, yeah, they're not as old as fire. I get it. They've only been around since the 1960s. But we've been dreaming about powerful beams and ray guns for a lot longer than that. And you know what? Now that we have them, lasers totally live up to the hype.
OK, so at its core, a laser is an intense, very narrow beam of light. Which sounds simple, but the number of things we can do with lasers is mind-boggling. They can be used in medicine to help with tricky surgeries. They can be used in manufacturing to cut certain things and weld other things together.
They are in your CD players and in your DVD players. They can be used for laser light shows, for laser tag. There's even a laser on NASA's Curiosity rover on Mars. All this, and we're only starting to scratch the surface of what a laser can do. People are coming up with new ways to use them all the time. These are like real, literal bright ideas.
And while fire is neat, it's also super hard to control. Lasers are the opposite. They are a perfect example of something precise and very controllable. Now, a note of caution. Lasers are also very powerful. And they can injure the eye or even cause blindness, so be very careful around them.
Still, when used safely, lasers are pretty amazing. We can use them to tickle an atom or blast a hole in something. So people, join me on Team Laser, and we'll beam into a brighter, better future.
SOPHIA CHOO: Well done, Sanden. Let's hear what our listeners had to say.
LAUREN: Hello, I am Lauren from Grand Rapids, Michigan. I think lasers are better because they are light that can cut through things.
KATHERINE: I'm Katherine from Grand Rapids, Michigan. And I think fire is better because its colors are more fascinating.
SOPHIA CHOO: Onto the first round. We're calling it, What the Wood?
MOLLY BLOOM: Sanden, you're up.
SANDEN TOTTEN: So to explain the way lasers work, I thought it would be best if we went to the source itself. So I'm going to take us on a tour of a magical place called Laser World, where lasers are made. Let's listen in.
TOUR GUIDE: Welcome to Laser World, everyone. Please keep your hands and legs inside the tram at all times. We are about to get moving. Any questions?
TOURIST 1: Can we feed the lasers?
TOUR GUIDE: What? No, that's, that's impossible. Where did you even hear?
TOURIST 2: I want to touch the lasers.
TOUR GUIDE: No, definitely not that. No touching.
TOURIST 3: Can I take a selfie with a laser?
TOUR GUIDE: You know what? Enough questions. Let's just get going. Fun fact, laser is an acronym. It stands for light amplification by stimulated emission of radiation.
TOURIST 2: That's not fun.
TOUR GUIDE: Yes, it is. OK, look to your left. There's a special guest, Theodore Maiman. He invented the first laser in 1960.
THEODORE MAIMAN: Hello. My laser used a ruby rod to make a deep red beam of light. Pew, pew.
ALL: Whoa!
TOUR GUIDE: Next, we are entering the Laser Hall of Fame. Here you get to see all the important inventions we rely on that use laser technology.
TOURIST 4: Like ray guns. Zap! You're toast.
TOUR GUIDE: Well, actually, some researchers are working on laser weapons, but they are still in the early stages of development. And we'd rather focus on some of the less destructive uses of lasers.
TOURIST 5: Oh, man. Then what do lasers do?
TOUR GUIDE: Well, if you'd let me continue the tour, here's the scanner from your grocery store. It uses lasers to read barcodes.
ALL: Ooh!
TOUR GUIDE: CD and DVD players use lasers to scan for tiny bumps coded in a disk and translate those into sounds or images.
ALL: Ooh!
TOUR GUIDE: And over here, we have a laser light show.
[MUSIC PLAYING]
ALL: Wow!
TOURIST 6: Those colors would make an amazing Instagram filter.
TOUR GUIDE: And perhaps the most important use of a laser, making your cat chase that little red glowing dot.
[CAT GROWLING]
[GLASS BREAKING]
[CAT SQUALLING]
Oops, looks like someone has a mess to clean up.
TOURIST 7: Quick question. Can I feed the cat?
TOUR GUIDE: Seriously? Like what, do you just have too much food? Leave the cat. Let's move on. Next, we are going to see how a laser is made. To do that, we need to shrink down to the size of an atom. Are you ready?
TOURIST 8: Do we have a choice?
TOUR GUIDE: Nope. Here we go.
ALL: Whoa! Status update?
TOURIST 9: Feeling tiny.
TOUR GUIDE: Here we are entering a laser chamber. Check it out.
TOURIST 6: Location update, some kind of glass tube? How do I tag myself on this?
TOUR GUIDE: That's right. This one is filled with gas, but some lasers use solids, like the ruby mentioned earlier, and others use liquids. The gas is getting charged with energy from a flash bulb. As the gas gets charged, electrons in the gas atoms get excited and enter a higher state of energy. Let's listen in.
[SCATTING]
[ELECTRONIC BUZZ]
That's the light powering up the electrons.
ELECTRON: Whoa! So much energy.
TOUR GUIDE: This happens to electrons all throughout the gas. The key for a laser is to have the majority of the atoms reach this heightened state.
ELECTRON: Whoa! So much energy.
TOUR GUIDE: Now, as the electrons lose that energy and return to their normal state, they release a packet of light called a photon.
[ELECTRONIC WHIR]
ELECTRON: Calming down now.
[SPARK]
There goes a photon.
TOUR GUIDE: This happens all over in the gas.
[ELECTRONIC WHIR]
ELECTRON: Calming down now. Calming down now. There goes a photon. There goes a photon.
TOUR GUIDE: And interestingly enough, as that photon passes by another highly energized electron, it can trigger that electron to calm down and release another photon as well.
TOURIST 10: Wow, that's a lot of photons flying around.
TOUR GUIDE: Exactly. That's kind of how a light bulb works, scattering light willy-nilly in all different directions and what have you.
TOURIST 11: Well, what makes a laser so special, then?
TOUR GUIDE: What makes a laser special is that first, all those photons are coherent, meaning they are in sync with each other. And they are monochromatic, meaning they are all the same color. Light bulbs cast light with a broad spectrum of colors that together look white.
TOURIST 6: Huh. Hashtag, the more you know.
TOUR GUIDE: Second, those photons are trapped by two mirrors on either side of this tube. See?
TOURIST 6: A mirror? Really? Let me check my lipstick.
TOUR GUIDE: Leave this tram, and I will end you. Where was I? Oh, yeah. The photons are trapped in the chamber by mirrors. Some photons escape through the sides of the tube, but those trapped between the two mirrors go back and forth. That amplifies the light beam.
But here's the secret to a laser. One mirror is slightly see-through, so a small number of photons can escape through it, exiting the laser chamber as a sweet, pure beam of laser light.
TOURIST 9: Whoa!
TOURIST 5: Whoo!
[APPLAUSE]
TOUR GUIDE: See how it's beaming out that end of this tube? So a laser is made by energizing electrons so they shoot out photons. Then, a reflective surface traps and amplifies those photons, while letting some escape out as a steady beam.
TOURIST 1: Amazing. Quick question, though. Can I feed--
TOUR GUIDE: No. Whatever it is, you can't feed it. Just, let's end this tour. Thank you for visiting Laser World. Come back any time, just not when I'm working, please.
ANNOUNCER: (SINGING) Brains On!
SOPHIA CHOO: Now, Marc.
MARC SANCHEZ: To know fire is to love fire. But first, what is fire? Quite simply, fire is a chemical reaction that gives off heat. Every fire has three ingredients, heat, fuel, and oxygen.
We've said it before, and the same applies in this episode. Everything around us is made up of atoms. Fried chicken? Atoms. Leaves on a tree? Atoms. Even the oxygen we breathe is made up of atoms.
Now, oxygen is a gas, and under normal conditions, its atoms are just kind of bouncing off each other. But when heat is introduced, look out. Heat excites atoms, which means a lot more bouncing off each other. The higher the heat, the faster the atoms move.
Put that heat source next to the fuel of, say, the hydrogen and carbon atoms of the wax on a candlewick, and those atoms start bouncing around, too. In fact, they start moving so much that they change from a solid to a gas. They vaporize. And that is called pyrolysis, when the fuel turns into a gas.
Now we have oxygen, hydrogen, and carbon gas atoms all coming together and still very excited. When these atoms mingle and rearrange, they give off blue light. I'm guessing you've all seen a burning candle. If you look at the bottom part of the wick, you'll see the flame is blue.
WOMAN: But what makes the other colors, the red and orange and yellow?
MARC SANCHEZ: Soot.
MAN: Gesundheit.
MARC SANCHEZ: Thank you, but that wasn't a sneeze. Soot is the answer. Soot is what makes the rest of the flame glow those red, orange, and yellow colors. Instead of bonding with the oxygen atoms, some of the carbon atoms come together with each other and form soot.
Think of it like a piece of charcoal, except really, really microscopically tiny. Charcoal bricks glow when they're heated. So does lava from a volcano. And so does soot. These glowing pieces of soot rise up-- because heat rises-- into a nice kind of conical flame we see when we look at a candle. And that, my friends, is fire.
[MUSIC PLAYING]
MOLLY BLOOM: OK, now on to the second round of the fire versus lasers debate. It's time for Mystery Sounds.
[RANDOM SOUNDS]
I have a mystery sound for each of you, related to fire for you, Marc, and lasers for you, Sanden. Marc, here is your mystery sound.
[SOUND OF ENGINE RUNNING]
Any guesses?
MARC SANCHEZ: It's pretty hypnotic, so I might have zoned out a bit there.
MOLLY BLOOM: I mean, Sophia, you can help him, too. He might need you.
MARC SANCHEZ: Yeah, what do you think it is? What does it sound like to you, Sophia?
SOPHIA CHOO: It sounded slightly like a generator of some sort.
MARC SANCHEZ: Ooh, I like that word. I couldn't think of a good description. But yeah, generator, definitely something mechanical. I'm going to go with a giant stove.
MOLLY BLOOM: OK. We'll let you stew on that for a bit. Sanden, here is your mystery sound.
SANDEN TOTTEN: Bring it on.
[POP]
[CLICK]
[POP]
[CLICK]
[POP]
[CLICK]
[POP]
[CLICK]
MOLLY BLOOM: Any guesses?
SANDEN TOTTEN: I picture somebody at one of those firing rifle ranges, and they're shooting a clay disk, and they shoot the disk.
MOLLY BLOOM: Sophia, do you have any guesses?
SOPHIA CHOO: It did sound like a firing range.
SANDEN TOTTEN: Did you hear people mumbling in the background, too, Sophia?
SOPHIA CHOO: Yeah.
SANDEN TOTTEN: What was that about?
SOPHIA CHOO: I have no clue what it could be.
SANDEN TOTTEN: Didn't they know we're recording a mystery sound?
MOLLY BLOOM: Well, I think we need to build a little suspense here, so we're going to be back with the answers in just a bit.
[MUSIC PLAYING]
SOPHIA CHOO: Do you have a mystery sound to share with us? Or a question you'd like to hear answered on the show? Or maybe you just want to send a high five or a drawing?
MOLLY BLOOM: Email them to us at brainson@m-- as in Minnesota-- pr.org.
SOPHIA CHOO: You can also send us actual mail.
MOLLY BLOOM: You can find the address at our website, brainson.org.
SOPHIA CHOO: And while you're there, you can also listen to all of our past episodes and sign up for our newsletter.
MOLLY BLOOM: And in order to say thank you to all the kids who write to us with their ideas, suggestions, and curiosity, we created the Brains Honor Roll. If you've written to us, we will get to you, we promise. But we're hearing from so many of you that there's a bit of a wait. So thank you for your patience.
[MUSIC PLAYING]
[LISTING HONOR ROLL]
MOLLY BLOOM: You're listening to Brains On from MPR News and Southern California Public Radio. I'm Sophia Choo.
MOLLY BLOOM: And I'm Molly Bloom.
SANDEN TOTTEN: And I'm Sanden Totten for lasers.
MARC SANCHEZ: And I'm Marc Sanchez, Team Fire.
MOLLY BLOOM: Sophia, in your opinion, who is winning the debate so far?
SOPHIA CHOO: Um.
MARC SANCHEZ: There's candy in it for Team Fire.
MOLLY BLOOM: No pressure.
SOPHIA CHOO: I think it's tied for right now because you both have really good points.
MOLLY BLOOM: That is very diplomatic.
MARC SANCHEZ: That's good to hear.
SANDEN TOTTEN: Yeah, I mean, we're shaking hands on the outside. But wait for--
MARC SANCHEZ: Boxing gloves.
SANDEN TOTTEN: --the next round, Marc. Boxing gloves are coming on, I think.
MOLLY BLOOM: Well, let's see if this next round changes your mind. It's the lightning round.
ANNOUNCER: Lightning.
MOLLY BLOOM: Your coolest facts about fire and lasers.
SOPHIA CHOO: Ready, set, go.
MARC SANCHEZ: Fire is good for the brain. It's thought that around 2 million years ago, Homo erectus, our early ancestors, learned how to harness and reproduce fire.
Archaeologists like John Gowlett of the University of Liverpool think that this set Homo erectus on a path to productivity. For the first time, we could see after the sun went down. That is a textbook example of a game changer. Instead of going to sleep when the sun went down, Homo erectus had the chance to think and develop its brain.
And while we're still on the subject of fires and brains, you have to admit that there's pretty much nothing better than sitting around a campfire and staring at it. It's super relaxing and meditative. Our early ancestors thought so, too.
Matt Rossano, a psychologist at the University of Louisiana, thinks that getting into a meditative state helped enable the brain to think more and be less reactionary. Instead of being freaked out by a predator jumping from behind a bush, we now have the headspace to make plans for that kind of thing in advance.
[PING]
ANNOUNCER: Lightning.
SANDEN TOTTEN: Lasers may just be light, but that doesn't mean they're lightweights. See what I did there? See, see? When it comes to slicing and dicing, lasers are used to cut all kinds of things, including sheets of metal.
So how does a light slice something as hard as metal? Great question. It has to do with the intensity of the laser. You see, the laser doesn't cut the metal so much as it melts away or evaporates a very small sliver of it. You take a high-powered beam and tightly focus it on metal to make this happen.
It's sort of like how you can take a magnifying glass and tightly focus sunlight to burn a leaf or a piece of paper. That's kind of how laser cutting works. And this helps companies and inventors that need to make very precise cuts in tough materials do that so that they can create cool new things, and invent awesome stuff, and basically change the world. So thanks, lasers.
[PING]
ANNOUNCER: Lightning.
MARC SANCHEZ: Fires help keep forests healthy. To illustrate this point, I'm going to bring in a couple of familiar voices. Follow me back, won't you, to the not so distant past. It's from the episode we did about trees.
SANDEN TOTTEN: Where I am in California, we have lots of forest fires. But here's the thing. In some ways, forest fires are actually good for the forest. Some trees actually need a forest fire to help them reproduce.
MARC SANCHEZ: There you have it, Sanden Totten, arguing in favor--
SANDEN TOTTEN: What?
MARC SANCHEZ: --of fire. Can we hear a little bit of that again? Can we hear a little bit of that again?
SANDEN TOTTEN: In some ways, forest fires are actually good for the forest.
I never thought I'd be saying this in a debate, but my opponent is absolutely right.
MARC SANCHEZ: I can't argue with that guy. He's so well-spoken and smart. There are trees that depend on fire to open up their seeds. Sara McAllister studies how forest fires work at the Missoula State Fire Sciences Lab. And she told me about the longleaf pine that starts out looking like a piece of grass.
SARA MCALLISTER: That will sit there for a few years until a fire comes and actually clears the forest of all of its competition. But it also kills a particular fungus that will actually damage the tree if it tries to kind of keep growing before a fire.
So once a fire comes and kind of clears the path, these trees will shoot up, like, five feet in a year and turn from little clumps of grass into big, tall trees.
MARC SANCHEZ: These trees are vital parts of the forest's ecosystem, not to mention, they give off oxygen so we can, you know, breathe.
[PING]
ANNOUNCER: Lightning.
SANDEN TOTTEN: So that was a pretty clever trick, Marc, using me against myself. But you know another cool trick? Using lasers as tweezers. The idea of laser tweezers is actually kind of simple and still very cool.
So imagine you have something like a protein you want to research. These are really important parts of humans and lots of things, but they tend to be all folded up. So how do you unfold this protein? Well, your fingers are way too clumsy and way too big to try that yourself. So, laser tweezers.
Researchers can attach a tiny sphere to either end of the protein. Then, using a laser, they can zap that sphere and hold it in place with a laser beam. Then, they attach the other end of the protein to a slide and simply start pulling back away from the trapped sphere.
It's like if you nailed one end of a Slinky to a wall and then started walking in the other direction with the other end. Pretty soon, you've unslinked the Slinky, you've uncurled it. And in the case of the protein with the laser tweezers, you've unfolded this tiny protein. And now, you can study how it folds and what's inside it and all this great stuff, thanks to lasers.
[PING]
ANNOUNCER: Lightning.
MARC SANCHEZ: Fire was the original internet. Well, sort of. Some American Indian tribes used fire to communicate. These fiery messages could be read as far as 100 miles away. Chinese soldiers on the Great Wall of China also used smoke signals. They lit a mixture of saltpeter, sulfur, and wolf poop to signal to each other. And while it may not have smelled too good, they could send a message about 300 miles in just a few hours. And this was back in 900 BC.
And hopefully you'd never find yourself lost in the woods. But if you do and there's no GPS and your cell phone is out of batteries, smoke signals and fire could save your life.
[PING]
ANNOUNCER: Lightning.
SANDEN TOTTEN: Here's a cool fact. Did you know there are mirrors on the moon? Seriously. In 1969, astronauts Buzz Aldrin and Neil Armstrong first set foot on the moon. Pretty cool. A little while later, they left a bunch of mirrors.
Why? So scientists on Earth could bounce lasers off the moon. That's right, bouncing lasers off the moon. That's just so cool. So basically they would beam a laser at these lunar mirrors from the Earth. And the laser would hit the mirrors and bounce right back to where they came from. And by measuring how long it took for a pulse of this laser to go to the moon and back, scientists could calculate how far away the moon is with amazing accuracy.
They've done it lots of times, and this has taught us all sorts of interesting things about the moon. For example, did you know the moon is slowly spiraling away from Earth at a rate of about 3.8 centimeters a year? Come back, moon. We love you.
Once again, lasers are helping us learn all sorts of cool things about the universe. They rule.
[FIVE PINGS]
ANNOUNCER: Lightning.
NOAH: Hello, I'm Noah from San Diego. I like lasers better they are cool because they are made out of light and can start fires.
IAN: My name is Ian, and I'm 6 years old. The reason why I like fire better than lasers is because lasers wold just make a hole in the fire. The end.
MOLLY BLOOM: I am exhausted after that. I would say we should let you guys take a breather, but there's no time for that. Let's go back to the mystery sound. Who wants to go first?
SANDEN TOTTEN: Maybe I should go first because Marc went first last time.
SOPHIA CHOO: Fair.
MOLLY BLOOM: Excellent. Let's hear your sound one more time.
[POP]
[CLICK]
[POP]
[CLICK]
[POP]
[CLICK]
[POP]
[CLICK]
Any new guesses, Sanden? And I just want to say that there's a little click in there, too. you Might not have heard it.
SANDEN TOTTEN: Yeah, there's a click. There's a lot going on there. I don't know. Sophia, what are you thinking?
SOPHIA CHOO: I don't know.
SANDEN TOTTEN: I'm sticking with my rifle range idea. Maybe they're using a laser to target things with rifles?
MOLLY BLOOM: Well, here's Rob Fornasiere. He'll let us know what it is.
ROB FORNASIERE: Ryan is one of our relief pitchers out there. And when he's right and fully in good shape in game competition, he'll throw [POP] anywhere from 90 to 93 miles an hour. But you can see, [POP] he's just playing catch right here. And he's throwing about 50 [POP] to 55. That was 52 right there from Cody. [POP] 52 miles an hour.
MOLLY BLOOM: So that was University of Minnesota Assistant Baseball Coach Rob Fornasiere, and that was the sound of two of his pitchers playing catch indoors. And how does he--
SANDEN TOTTEN: Whoa!
MOLLY BLOOM: Yeah. And how does he know exactly how fast they're throwing the ball? That's where lasers come in. Did you hear that? That was that faint click between throws.
SANDEN TOTTEN: Yeah.
MOLLY BLOOM: Yeah, that is Rob using a device called a speed gun to measure how fast the baseballs are moving. His device uses a microwave laser, which is also known as a maser. I did not know that word before researching this, but that's how he does it.
SANDEN TOTTEN: I've done masering.
MOLLY BLOOM: You did some masering.
[SHEEP BAAING]
Well, the sound of the sheep means we made a little mistake. I said this speed gun used masers, and that's not true. Mesas are like lasers, but they use microwaves instead of visible light. There are speed guns that use microwaves, and there are speed guns that use lasers. But there aren't speed guns that use masers. This speed gun uses microwaves.
[SHEEP BAAING]
Now back to the show.
They also use it to measure throws from outfielders. That measures arm strength. And they also use it to measure what's called exit velocity. That's how fast the ball is moving when it leaves the bat after being hit.
These speed guns first started to be used in baseball in the 1960s. Before that, they had a less exact way of knowing how fast pitchers could throw.
ROB FORNASIERE: They literally had a car that was driving at an x amount of speed down a long road. And they had a baseball player standing next to where the car would go. And the car maybe was going, let's say, at 70 miles an hour.
And at the precise moment the car would pass the pitcher, he'd release the ball, and we'd see whether the car or the ball could pass the mark quicker. And so that's where they started to determine how fast balls were actually thrown.
SANDEN TOTTEN: Wow. That's so cool. I always love learning more about America's favorite pastime, lasering.
[LAUGHTER]
MARC SANCHEZ: Cool it, cool it, Sanden.
MOLLY BLOOM: Well, let's see how Marc does.
[SOUND OF ENGINE RUNNING]
MARC SANCHEZ: Are there any little clicks that I need to be paying attention to?
MOLLY BLOOM: No little clicks in there. Sorry.
MARC SANCHEZ: All right, so we've got generator. If I just say fire, do I get, like, half credit? Do I get half a point?
MOLLY BLOOM: I'm sorry, no.
MARC SANCHEZ: All right. Well, I'm going to say an industrial stove. I'm going to stick with that.
MOLLY BLOOM: OK, here is the answer.
CHARLIE JOHNSON: Hi, I'm Charlie Johnson. And I'm the chef/owner of Q Fanatic BBQ. That was the sound of our smoker, the rotisserie on our smoker. We smoke all our meats in the smoker.
And it kind of looks like a big Ferris wheel. And it goes around, and that's the motor that makes the Ferris wheel go around. And we use logs, logs or split wood, to smoke all our meat-- hickory, actually. Smoking adds flavor.
Historically, it preserves meat, but we use it as a flavoring, kind of like some people use salt and pepper. But classically, it was used to preserve food. There's a fire. We have a gas assist that helps light the wood. And so then it has fans that blow on the wood when it needs to get, when the smoker needs to get hotter, to stoke the fire.
MARC SANCHEZ: Can I defer to the judges here? Because, I mean.
SOPHIA CHOO: It's a smoker, not a stove.
MOLLY BLOOM: You were very close. I mean, we should probably give you half credit.
MARC SANCHEZ: At least.
MOLLY BLOOM: I think. Because it is kind of--
MARC SANCHEZ: It's used for--
MOLLY BLOOM: A cooking device.
MARC SANCHEZ: --cooking.
MOLLY BLOOM: I mean, you weren't exact, but you were--
MARC SANCHEZ: Yeah, but fire is-- I mean, so much of it's cooking.
MOLLY BLOOM: It's true. It's a tough one. It's a tough call.
SOPHIA CHOO: All right, Marc. I'm down for half a point.
MOLLY BLOOM: OK, Sophia gave him half a point, our judge.
SANDEN TOTTEN: All right, good listening, good listening, Marc.
MOLLY BLOOM: You know, so just like Marc talked about earlier, how fire is good for the brain, that also goes for harnessing fire to cook, too. Our ancestors were able to get more calories and more nutrition from cooked food than they were from raw food. And this helped their brains to get bigger and to spend less time searching for food and then chewing it.
ANNOUNCER: (SINGING) Ba, ba, ba, ba, ba, ba, ba, ba, ba, ba, ba, Brains On.
SOPHIA CHOO: Time for a final round. We're calling it Coming Soon.
MOLLY BLOOM: Sanden, you first.
SANDEN TOTTEN: Well, we all know fire is a great source of energy. Sure, I'll give it that. But what if I told you lasers might help us create an even better source of energy, an unlimited, clean form of sustainable energy?
SOPHIA CHOO: I'm listening.
SANDEN TOTTEN: I spoke with Dr. Kate Lancaster. She's with the University of York at their Plasma Institute, and she's working on a project to do this very thing.
KATE LANCASTER: So my specialty is-- well, it's called laser plasma physics. So it's taking some of the world's most powerful lasers and firing them at a piece of material until basically all the atoms fall apart. And one of the purposes of doing that is to try and make miniature stars.
MOLLY BLOOM: Wait, did she just say miniature stars?
SANDEN TOTTEN: Yeah. A star, like our sun, but tiny and here on Earth. This idea is called nuclear fusion power. And if we could pull it off, it would solve so many of our energy problems without adding a ton of pollution.
You see, the sun is like a very hot energy-producing machine. If we could harness even a piece of that here on Earth, we'd be able to power, well, pretty much everything.
SOPHIA CHOO: Sure, but how would we do that?
SANDEN TOTTEN: Kate says we'd need to recreate the reactions happening in the sun here on Earth in a highly controlled environment. So to do that, her team takes two kinds of hydrogen and forms them into small pellets of fuel.
To make that pellet turn into a tiny star, they need to make it very dense and very hot, just like our sun. That will create a reaction where the helium is converted to hydrogen. It gives off lots of energy in the process. So the team, they make this hydrogen pellet, and then they take it to a specialized laser firing room to make that happen.
KATE LANCASTER: So there's a tiny little ball bearing-sized pellet in the middle of this huge chamber that looks like the Death Star from Star Wars. And 192 beams come in from all angles. And essentially what happens when you do that is the lasers, when they shine on the fuel, they can heat up an outer layer of the fuel, which flies away very rapidly.
SANDEN TOTTEN: And this helps compress it. See, when that outer layer flies away, it actually pushes back on the rest of the pellet in the opposite direction. This is a basic law of physics. For every action, there's an equal and opposite reaction.
KATE LANCASTER: It's kind of like the air coming out of the back of a balloon. The balloon has to go in the opposite direction. So if you do that all around a sphere, an outer layer of the sphere flies away, caused by the lasers. And then the rest of the fuel has to move into the center and be very, very dense and small. And then it needs to get hot.
SANDEN TOTTEN: And she means, like, really hot, like 150 million degrees centigrade hot. Luckily, lasers can help here, too. Because when they smack this pellet of fuel, it creates a shockwave, and that shockwave is full of energy. And since that energy has nowhere to go but into the pellet, it converts into heat. And that raises the temperature of this tiny little pellet.
So there you have it. To make nuclear fusion, you basically need to get a fuel pellet very dense and very hot. That will kick off a reaction like the one in our sun that produces lots of energy. Lasers can help you do both things, by compressing the fuel and by heating it up. Pretty cool.
MOLLY BLOOM: So how far along is this technology, Sanden? Can we use it to power our cities soon?
SANDEN TOTTEN: Well, it's still in the early stages of development. This idea of nuclear fusion, of harnessing the power of a star right here on Earth, it's been around for decades. But it's really complicated, and it needs to be very precise to work. No one has mastered it yet.
So Kate Lancaster says part of the problem is that we need high-energy lasers that can fire many times a second. And we don't have those yet, but we're working on them. And fusion power is so promising. It could solve so many of our energy problems. It doesn't pollute, like gas or coal. Once it's working, it's practically limitless. So because of all this, researchers keep trying to get it right.
KATE LANCASTER: We're a number of decades away from putting any kind of electricity on the grid, which is precisely why we need any budding scientists or engineers listening right now to help us. Because I'm going to get old, and people like me are going to get old. We're going to need new people to help us work on this stuff.
SANDEN TOTTEN: So it might be far off, but one day, lasers could help power the world, and that's pretty awesome.
SOPHIA CHOO: Marc, your last chance. The mic is yours.
MOLLY BLOOM: It's hard to compete with powering the world.
SOPHIA CHOO: Mm-hmm.
MARC SANCHEZ: Powering the world is one thing, but let's have a little fun, shall we? Our planet has had a relationship with fire since the beginning of time. So there's no doubt it will be here for years to come.
But what's next? If you've ever been to an amusement park, watched the big game, or celebrated your patriotic heart out, then you've probably seen a fireworks show. People first started using these colorful, loud bursts of fire around 2,000 years ago in China. And over the years, we've grown accustomed to bigger and better shows.
John Conkling is a chemist and has helped fireworks manufacturers push the field into a new era.
JOHN CONKLING: It's not your grandfather's fireworks anymore where everybody goes out and sits on a little hill, and they shoot some up in the air-- bang, bang, bang, bang, ooh, aah-- and that's the end of it.
SANDEN TOTTEN: As a chemist, John helps fireworks manufacturers mix a secret sauce of chemicals to come up with cool new colors.
JOHN CONKLING: Well, sodium makes a yellow-orange color. Copper compounds can make a blue color. Strontium, which is not one of your everyday elements, but it will produce a beautiful red color.
SANDEN TOTTEN: The fireworks that we see in the sky look a lot different than what you're used to seeing at a roadside stand. Each colorful burst starts out as a spherical casing that's a little bigger than a softball. Inside the casing are a few stages of gunpowder. The first is on the bottom, with a fuse sticking out. The casing is stuffed into a tube, then the fuse is lit.
The gunpowder ignites and explodes the first stage, launching everything up into the air. The explosion also lights another fuse inside the casing that's attached to even more gunpowder. A few seconds later, when the casing is high in the sky, stage two explodes and ignites little pellets full of chemicals that have been meticulously laid out in a pattern.
JOHN CONKLING: The Chinese developed a lot of what are called pattern shells that will burst as a five-pointed star or a smiling, happy face. You can produce letters up in the sky by this good engineering. It's how you package the pellets of color composition into the fireworks casing.
And if you do it very, very carefully, lots of trial and error, you can actually get that firework to explode up in the air. And those pellets will go out and hold the pattern you're trying to create. And that's really the newest thing in fireworks.
SANDEN TOTTEN: John says that if you really want to wow a crowd these days, you have to play on their emotions. You have your basic bang bang fireworks, and then you have these pattern shells that he was talking about. But throw in a sound system, and people go bananas.
JOHN CONKLING: Any of the more major shows today, I mean, they're really multimedia presentations. The lasers sometimes-- I mean, you can add all sorts of stuff into them.
SANDEN TOTTEN: Wait, wait, wait, wait. Did he just say lasers?
MARC SANCHEZ: Well, sure, yeah. I mean, yeah, I guess so. Lasers may play a part in fire's future, but it's a small part, teensy. There's really nothing quite like the sensory experience of fireworks.
JOHN CONKLING: When that firework launches into the air, you get that whomp. And everybody's pulse starts beating a little faster. And then up in the sky, boom, you can feel that shockwave. And that's what makes fireworks. I think that trumps lasers.
MARC SANCHEZ: And there you have it. Mic drop, hashtag end of story, fire forever. I'm out.
MOLLY BLOOM: Wow. That is a lot to ponder. Sophia, do you think you can declare a winner after all of this?
SOPHIA CHOO: Well, I've and tallying points, and Marc won by half a point.
MOLLY BLOOM: With that mystery sound?
SANDEN TOTTEN: He won by the mystery sound?
MOLLY BLOOM: Oh, man. Mystery sound's a tiebreaker.
MARC SANCHEZ: I got a good set of ears.
SANDEN TOTTEN: Wow, wow. I got to hand it to you, though, Marc. That was well played. You Used myself against myself, and you correctly identified half a mystery sound. That was good.
MARC SANCHEZ: Sir, Sanden, you were a truly worthy opponent. And I am deeply impressed by lasers, and especially the future of lasers.
MOLLY BLOOM: I have to say, I might be Team Lasers on this one. So this was a squeaker. I really want to hear what people say about this.
SANDEN TOTTEN: Yeah, come on over to the light side.
MOLLY BLOOM: Do you, our dear listeners, agree with the verdict? There's a poll at our website, brainson.org, where you can vote for the team that you think won, fire or lasers.
[MUSIC PLAYING]
Well, that's it for this episode of Brains On.
SOPHIA CHOO: Brains On is produced by Marc Sanchez, Sanden Totten, and Molly Bloom.
MOLLY BLOOM: Many thanks to Veronica Rodriguez, Sam Choo, A Martinez, Megan McCarty, Julian Burrell, Taylor Orci, Sara McAllister, and Eric Brigham.
SANDEN TOTTEN: If you want to give us a shout-out, share your opinion, or get in touch with us, there's lots of ways you can do that. You can find us on Twitter and Instagram. We're @brains_on.
MARC SANCHEZ: Or if you're on Facebook, you can just search for us there. Search for Brains On.
SANDEN TOTTEN: And this will not be our last debate. After all, I have to win one, now that Marc just took the lead. So start thinking of more topics for us. We'll need them.
SOPHIA CHOO: If you're a fan of Brains On, consider leaving a review in iTunes. It really helps other kids and parents to find out about the show.
MOLLY BLOOM: We'll be back soon with more answers to your questions.
SOPHIA CHOO: Thanks for listening.
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