High voltage! How electric power reaches your outlet

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HOPDAY MARTON: You're listening to Brains On where we're serious about being curious.

Brains On a supported in part by a grant from the National Science Foundation.

This month, Brains On is all about those [INAUDIBLE]

MOLLY BLOOM: Let's get started by tuning back into the electric games.

ANNOUNCER: Get ready for the race of a lifetime. Two inventors do brilliant scientific minds racing to be the first to bring electricity to every home in America. On the right, Thomas Alva Edison.

THOMAS EDISON: They call me the Wizard of Menlo Park because of my many amazing inventions. But in a few minutes, you can just call me the winner.

ANNOUNCER: On the left, you know him, you love him. Nikola Tesla.

NIKOLA TESLA: I was born in Eastern Europe where my genius was renowned. Now, I'm here in the States to shut you down. Booyah, Edison.

ANNOUNCER: Here we go. These two inventors from the late 1800s will rush as fast as they can to make an electrical grid that powers homes across the country. Who will win? Let's find out. On your marks, get set, go.

MOLLY BLOOM: This is Brains On from American Public Media. I'm Molly Bloom.

HOPDAY MARTON: I'm Hopday Marton. And this is part two of our series on electricity.

[MUSIC PLAYING]

You'll hear more about the competition between Tesla and Edison in a bit.

MOLLY BLOOM: First, let's dish some more about electrons.

HOPDAY MARTON: Last episode, we talked about how atoms exchange electrons to create static electricity.

MOLLY BLOOM: Today, we're going to talk about electricity in our plugs and lights. Something a lot of you are curious about.

BRENTON: Hi, I'm Brenton and I'm 8.

WILL: And I'm Will and I'm 11.

BOTH: And we have a question.

WILL: How do you get electricity into your home?

KID: How does electricity get to houses?

KID: How does electricity get to your house?

CARIS: My name is Caris from Austin, Texas.

JOSHUA: My name is Joshua. I live in Ellicott City, Maryland.

JOVIAN: Hi, my name is Jovian. I am from Kansas City. My question is, how does power go into your house into other electrical objects in it? Where does it come from?

KID: Where does electricity come from?

KID: Where does the electricity come from?

MAX: My name is Max and I'm from Boulder, Colorado.

LARA: My name is Lara. I live in Evanston, Illinois.

JONAH: My name is Jonah. I'm eight years old and I live in New York City. My question is, how is electricity made?

MOLLY BLOOM: The answer to all those questions is magic. Next topic. Just kidding. The real answer is very cool. Maybe even cooler than magic.

HOPDAY MARTON: When you talk about electrical power or talking about the flow of electrons through wires. When you plug something into a socket, you are tapping into that flow.

MOLLY BLOOM: When you plug-in a lamp, for example, the flow of electrons goes into one of the prongs of the plug. It goes through a cable connected to that prong. That cable brings the flow to the tiny wire in the light bulb. That's the part called the filament. And that wire gets so hot it gives off a glow. The electrons keep flowing through it and then they pass down another cable back out the other prong of the plug and back into the socket.

HOPDAY MARTON: It's always a closed loop so the electricity has to go through something and back to the socket to work.

MOLLY BLOOM: We call this a circuit.

HOPDAY MARTON: But electricity then start at your socket.

MOLLY BLOOM: In most cases, it starts dozens or even hundreds of miles away. It zips through cables to your home in less than a second. Let's break this down.

HOPDAY MARTON: The first step usually happens at a power plant. We call it generation.

MOLLY BLOOM: Yes, generation means making the electricity. Most electricity in the United States, for instance, is made by something called thermal generation.

HOPDAY MARTON: Thermal. Oh, it sounds like a thermometer.

MOLLY BLOOM: Right, it means relating to heat.

ROBOT: Thermal generation.

MOLLY BLOOM: Basically, with thermal generation, you start by using heat to make steam.

HOPDAY MARTON: You can get steam by burning wood, coal, or gas to heat up water.

MOLLY BLOOM: Nuclear reactors get steam by taking super hot nuclear materials and dunking the materials in water.

HOPDAY MARTON: Once you have steam, you send that gas through a series of blades called a turbine.

MOLLY BLOOM: A turbine is like the opposite of a fan. Instead of the fans spinning and blowing air at you, you push a gas through the fan and that turns the blades.

HOPDAY MARTON: Next, the spinning turbine power something called a generator.

ROBOT: Generator.

HOPDAY MARTON: This is where you actually generate electricity.

MOLLY BLOOM: Generators are where the mechanical energy from the moving turbines is converted into electrical energy.

HOPDAY MARTON: These magnets to manipulate magnetic fields, those fields push the electrons around sending them down the wires.

MOLLY BLOOM: Thus, we have the electrical power.

HOPDAY MARTON: These days, lots of places are also using wind, water, and even sunlight to make electricity. We'll talk more about that later.

MOLLY BLOOM: Step one, create steam with heat and water.

HOPDAY MARTON: That spins the blades of a turbine.

MOLLY BLOOM: The turbine powers a generator.

HOPDAY MARTON: The generator makes electricity.

ROBOT: And electricity charges the robot.

MOLLY BLOOM: Not quite yet.

HOPDAY MARTON: That's just step one. Electricity still needs to get from the generator to an outlet in your home.

MOLLY BLOOM: For that, it's step two - transmission.

ROBOT: Transmission.

HOPDAY MARTON: This is one that electricity made at the plant is sent or transmitted out to the world.

MOLLY BLOOM: First order of business is boosting that electricity to very high voltages.

HOPDAY MARTON: Voltage is a measure of the force of the electricity running through the cables.

MOLLY BLOOM: You can think of it like water pressure in a hose. If you have low pressure, the water barely trickles through. If you have high pressure, a lot of water rushes out. High voltage is like high water pressure, but for electricity.

HOPDAY MARTON: Our electricity needs to be high voltage so it could travel long distances fast and without losing too much power. Like how you need high water pressure to shoot water super far from a hose.

MOLLY BLOOM: To boost the current, the electricity is sent through a transformer.

ROBOT: Transformers. Robot.

HOPDAY MARTON: Wrong kind of transformer robot.

MOLLY BLOOM: Once the transformer steps up the voltage, the electricity is sent through high voltage transmission lines.

HOPDAY MARTON: You've probably seen these on road trips. They're carried by big metal towers.

MOLLY BLOOM: Picture something built by a mad scientist to power Frankenstein.

HOPDAY MARTON: Or the Eiffel towers less fancy cousin.

MOLLY BLOOM: Oh, that's a good one. These high voltage lines travel long distances. When they get to your neighborhood, the electricity needs to jump back down to a safer, lower voltage.

HOPDAY MARTON: To do that, the power is sent through another transformer.

MOLLY BLOOM: From there, the power travels to homes in smaller cables underground or connected to wood poles. Just before it reaches your house, it'll pass through another transformer to cut the voltage even more.

ROBOT: How many transformers?

HOPDAY MARTON: Are your house electricity is wired to all your lights and appliances and outlets.

MOLLY BLOOM: And then it's ready to charge your robots.

ROBOT: Finally. I was getting impatient.

HOPDAY MARTON: That's how electricity is made and distributed. Woo. What a journey.

MOLLY BLOOM: Well, let's reset our brains with something totally different.

HOPDAY MARTON: Can I do it this time?

MOLLY BLOOM: Sure, go ahead.

HOPDAY MARTON: It's time for the mystery sound.

MOLLY BLOOM: Here it is. OK, any guesses?

HOPDAY MARTON: My guess is that it's a motor.

MOLLY BLOOM: Excellent guess. What do you think that motor might be doing?

HOPDAY MARTON: It may be blowing wind.

MOLLY BLOOM: Excellent.

HOPDAY MARTON: I don't know. Just a motor.

MOLLY BLOOM: Just a motor. Well, mull it over a tiny bit more we'll have the answer in a bit. Right now, let's get back to that epic match-up from before.

ANNOUNCER: Edison versus Tesla.

MOLLY BLOOM: That whole electrical system we talked about earlier from the power plants to the transformers to the cables, that's called the electrical grid.

HOPDAY MARTON: Today, there are grids all over the world, but in the late 1800s not so much.

MOLLY BLOOM: Nikola Tesla and Thomas Edison both wanted to change that, but they had different ideas on how to do it. Back in the 1880s, there were two different schools of thought when it came to electricity.

HOPDAY MARTON: That's Allison Lantero. She hosts a podcast Direct Current and worked for the US Department of Energy.

MOLLY BLOOM: It's a government agency that studies stuff related to electricity and other power sources. Allison says Tesla and Edison clashed over whether this new grid should use alternating current or direct current.

HOPDAY MARTON: AC or DC? This debate became known as the War of Currents.

MOLLY BLOOM: Allison Lantero tells us the tale.

ALLISON LANTERO: There was Thomas Edison who was a big fan of direct current.

THOMAS EDISON: Technically speaking, DC is my jam.

ALLISON LANTERO: DC is direct current which is the kind of electricity that runs continuously in one direction. It's the kind of electricity that's in a battery. He number one had all the patents for direct current, which meant that he got money when people used it.

THOMAS EDISON: Hey, what can I say? Inventing things is my passion, but getting rich is my side hustle.

ALLISON LANTERO: But number two, it was something that he had established and he thought was the best way for America to become fully electrified.

THOMAS EDISON: It is my dream to see America running on direct current electric power. Lighting homes with Edison bulbs, playing music on their Edison phonographs, and paying for it all by signing checks with Edison Electric Pens. Patent pending.

ALLISON LANTERO: But the problem with DC is it's really, really hard to convert it to higher or lower voltages, which means it can't travel very far. On the other side was a guy named Nikola Tesla.

NIKOLA TESLA: Greetings, world. I'm here to solve your problems.

ALLISON LANTERO: He believed that alternating current was the way to go. Alternating current or AC is electric current that reverses direction a certain number of times per second. It's easier to convert it to higher and lower voltages, which means that we can send it much further.

NIKOLA TESLA: The AC power works really well with my nifty induction motor. Oh, did I mention I invented an induction motor? Well, I totally did invent an induction motor. It's amazing. Runs the AC electricity through it and it could power a factory. America will love it. I can hear them now. Tesla. Tesla. Tesla. Wow.

ALLISON LANTERO: Those were kind of the two schools of thought back then. Thomas Edison was fantastic at marketing and is credited with inventing numerous, numerous things.

THOMAS EDISON: Not the hashtag humble brag, but an electric vote recorder, the phonograph improved stock ticker, a motion picture camera. Those are just off the top of my head.

ALLISON LANTERO: He was not the person who invented the light bulb, but he did make it more efficient. And like I said, he was very good at marketing. Nikola Tesla, on the other hand, was also a big inventor but is much less known. He was a bit of a recluse and wasn't always that great at promoting his stuff.

NIKOLA TESLA: Genius sells itself. Edison is just hungry for attention. It's not like I'm going to play his game by say slapping my name on an electric car or something.

ALLISON LANTERO: He was also a little bit crazy.

NIKOLA TESLA: Crazy? Is it crazy to want to bring electric power to the world? Is it crazy to want to give that power away for free? Is it crazy to not ask for fame but simply for the satisfaction of a job well done?

ALLISON LANTERO: Later in life, he fell in love with a pigeon.

NIKOLA TESLA: I could see how that might look a little crazy.

[MUSIC PLAYING]

ALLISON LANTERO: When we talk about the War of the Currents, we actually don't even talk about Tesla that often. We usually talk about George Westinghouse because Westinghouse had bought the rights to use alternating current.

GEORGE WESTINGHOUSE: Oh, I'm George Westinghouse. Business is my business and business is good.

ALLISON LANTERO: He was really the one who was bidding on things and saying that this is the electricity of the future. Meanwhile, Edison still wanted to make money off of his patents for direct current. What he did, instead of saying direct current is the way to go, he decided to have a smear campaign against alternating current.

THOMAS EDISON: Extra. Extra. Did you hear alternating current is the worst? Because it is. Read all about it.

ALLISON LANTERO: He would take out ads in newspapers to say how dangerous alternating current was. He also would electrocute stray animals with alternating current to show how dangerous it was.

THOMAS EDISON: Seriously, dude?

NIKOLA TESLA: Not cool, Edison. Not cool.

ALLISON LANTERO: He went so far as to invent the very first electric chair using alternating current, just to prove that this was the more dangerous kind of electricity.

THOMAS EDISON: All I'm saying is AC is totes dangerous.

NIKOLA TESLA: Come on, Tom. Fire's dangerous if you stick your hand in it. Are we going to bend flames now?

THOMAS EDISON: That's absurd. It's not the same. It's not the same at all.

[INTERPOSING VOICES]

ALLISON LANTERO: So it really came down to the Chicago World's Fair which was in 1893.

[TRUMPETS BLOWING]

One of the things they wanted to do was have the entire fair be electrified. They set up a system for bids and they said, all right, how much is it going to cost to completely electrify this event?

General Electric had gotten the rights to Edison's patents, and they said OK, we can electrify your World's Fair for $554,000 using direct current. But George Westinghouse came and he said that he could do it for only $399,000. So he was going to save them over $150,000 using Tesla's alternating current. And so they went with alternating current.

NIKOLA TESLA: That is how you business my friends.

THOMAS EDISON: Yes, AC over DC, baby. Tesla and Westinghouse are making moves and taking names. Woo.

ALLISON LANTERO: About the same time, Westinghouse set up the first grid to electrify a city which was in, I believe, Buffalo, New York. That grid was run on alternating current. And so between those two things, alternating current won the day.

NIKOLA TESLA: Put that in your pipe and smoke it, Edison.

THOMAS EDISON: Oh, boo-hoo. How will I ever get over this defeat? Oh, I know. I'll just wipe my tears with all the money I've made from my millions of other inventions. But hey, congrats to you both Tesla and Westinghouse. I mean, whatever.

ALLISON LANTERO: After that, AC caught on in a big way. Grids grew and grew to eventually become the mega system we use today.

Ba ba ba ba ba ba ba ba ba Brains On.

HOPDAY MARTON: Thanks for being here. We really appreciate you.

MOLLY BLOOM: We make Brains On so curious kids like you have a place where your questions, ideas, and smarts are the star of the show.

HOPDAY MARTON: If you've got a question for the show, send it to us at hello@brainson.org.

MOLLY BLOOM: Or you can send us a drawing or mystery sound. When you do, we'll add you to the Brains Honor Roll. You'll hear the latest crew of Honor Rollies at the end of the show.

HOPDAY MARTON: If you're a fan, please, please, please, leave a review in Apple Podcasts. It'll help others find the show.

MOLLY BLOOM: Thanks.

HOPDAY MARTON: Back to our deep dive into the world of electricity. I'm Hopday Marton.

MOLLY BLOOM: I'm Molly Bloom. And now, it's time to answer some more of your questions. It's time to ask an electrical engineer.

JASON RONDEAU: My name is Jason Rondeau. I'm an electrical engineer with Los Angeles Department of Water and Power.

OLIN: Hi, I'm Olin from Cupertino, California. How much electricity is in power lines?

JASON RONDEAU: A power line that you drive past, say, if you're in your neighborhood will typically have thousands of volts. For reference, your home has about 120 volts where for electric outlets in the United States. Any given power line that you see driving around your neighborhood or your city, that's probably delivering electricity to hundreds of homes and businesses in your neighborhood.

ADRIAN: Hi, Brains On. I'm Adrian from Baltimore, Maryland, and I am 6 years old. My question is, why do different countries have different plug for electric outlets?

JASON RONDEAU: The US and Canada and Mexico all have the two or three prong outlet. But if you travel outside North America and parts of Central America, you notice that there are many, many different types of plugs. The voltage is actually are a little bit different based on the country you're in as well. Why? Well, as electricity use spread across the world, different countries develop their own plug standards. There were also some design innovations that made plugs a little bit safer.

There's something like 15 different plugs if you travel around the world. If every country decided to use one type of plug, that would require changing billions of electrical outlets and rewiring homes all over the world. We could do all of that or we could just keep doing what we're doing today, and we could buy an adapter and charge our mobile phones with an adapter when we leave for vacation.

HENRY: My name is Henry from Maple Grove, Minnesota. And my question is, how does electricity stay in the wires?

JASON RONDEAU: Yes. Electrical wires, electrical lines are made of electrical conductors, copper wires. That creates a path for electricity. That path travels through power lines and actually into your home and they're actually insulated with rubber and plastics. Rubber is not a conductor. Similar to the reason that the wires on your appliances are covered in plastics and rubbers is to ensure that electricity flows through that wire into the appliance. The same concept applies to the power lines that you see as you're driving through the streets.

ODIN: Hi, I'm Odin and I'm 8 years old.

MAGGIE: Hi, I'm Maggie and I'm 10 years old.

ODIN: We live in Denver, Colorado. And we would like to know why don't birds get electrocuted when sitting on power lines?

JASON RONDEAU: When a bird purchase on electrical wire, it doesn't create a new path for that electricity. But if a bird extended its wings and created a connection between two of the wires, there's a possibility of electricity flowing through that bird and that bird could get electrocuted because that bird now has created a path.

It needs a completed circuit for that electricity to travel. There is a possibility that a bird could get electrocuted. But again, if they're sitting in the middle of the wire and just perching right on top of that wire, the electricity is not flowing through them, it's flowing right through that wire and into your home.

HOPDAY MARTON: Thanks for tuning in to Ask An Electrical Engineer.

MOLLY BLOOM: Keep in mind electricity is dangerous and you should never touch a fallen power line. Hopday, I think it's time we get back to that mystery sound. Are you ready to give it another listen?

HOPDAY MARTON: Yes.

MOLLY BLOOM: All right. Here it is. Any new thoughts?

HOPDAY MARTON: A very strong air conditioner and a motor powering it. So the motor spinning to blow the wind.

MOLLY BLOOM: Excellent guess. Well, let's hear the answer.

ALEXIA: Hi, my name is Alexia JaDarius and LaDarius. And we live in the Virgin Islands. That was the sound of our generator that we used to power our house.

MOLLY BLOOM: Hopday, you were really close because a generator is basically a reverse motor. A motor takes electrical energy and makes it into mechanical energy, where a generator takes mechanical energy and converts it into electrical energy, so you can power things like the lights in your house. Alexia JaDarius in LaDarius are siblings from Ohio who recently moved to the US Virgin Islands. Their mom Elle says they've been without electricity since Hurricane Irma hit this past September.

ELLE: We're not expected to have electricity until sometime next year. So we currently have a generator. It took us a month and a half for it to be delivered to our island because nothing was coming in and no shipments were going out. Now, we get gas from the gas station and we supply that in our generator. And we run it a couple of hours a day, maybe two or three hours a day.

MOLLY BLOOM: She says the hurricane wrecked the grid. New poles and transformers are being brought in and workers from all over are helping to rebuild. But in the meantime, Elle and her kids are learning to make do with only a few hours of power a day from their generator.

ELLE: We have a lot of family time. We do a lot of reading and playing games. My children are home schooled. So we do a lot of dominoes and we do a lot of walks, we go to the beach quite often.

MOLLY BLOOM: 12-year-old JaDarius says he misses playing video games. But since you can't do that, he's been passing time exploring outdoors and doing all kinds of things with his friends.

JADARIUS: Wild horses, chase chickens, and draw stuff. We do all gummy.

MOLLY BLOOM: Those are wild chickens he's chasing by the way. Very hard to catch. His 13-year-old sister Alexia has been using the time off the grid to work on a book.

ALEXIA: My first book that I'm writing now is about a girl named Alex and she has two best friends, Tamara and Nina. They start to explore their houses more because they just moved there. Tamara's brother he was in the attic, and then he found a hidden door that was in his house.

MOLLY BLOOM: Alexia is still working on the book and she'll have plenty of time. It could be months before the grid is fixed. So for everyone living with power, 12-year-old LaDarius says, Don't take it for granted.

LADARIUS: They appreciate the light. You can took on electric stuff and you can have an air condition as fan.

MOLLY BLOOM: Hopday, have you spent any time without electricity?

HOPDAY MARTON: Over the summer, we were going on a trip to Ethiopia. We were visiting our Cousins and we've been using too much electricity. There is a bit of power outage.

MOLLY BLOOM: So you had to live without electricity for a bit in Ethiopia?

HOPDAY MARTON: Yeah, for a little bit. We were playing on there we and that used a lot of electricity. We heard a burning sound, the lights turned out, then after a minute it turned back on.

MOLLY BLOOM: Did you have to stop playing we then or could you go back to playing it?

HOPDAY MARTON: Other technology, we had wood work.

MOLLY BLOOM: Though it took too much power. Very interesting. Well, that was one family living off the grid because of a storm. Now, let's meet a family living off the grid for a different reason.

LIV: I'm Liv from Fairbanks, Alaska.

GWEN: I'm Gwen from Fairbanks, Alaska. And I'm also Liv's mother.

MOLLY BLOOM: Liv and Gwen actually lived 30 miles from Fairbanks and their home isn't connected to a grid at all.

GWEN: In Alaska, we don't have a continuous electric grid. Where we live on the outskirts of Fairbanks, there just is no power grid that goes out to where we live. For the last 25 years, we've just generated our own power at our place.

LIV: It gets our electricity from three big resources. Solar panels, generator, and a wind turbine.

GWEN: It works out pretty good. We cut our own wood and it's a pretty cool lifestyle. It's a neat way for the kids to grow up. Why do we live so far out of town, Liv?

LIV: Because we have sled dogs.

GWEN: How many dogs?

LIV: About 25.

MOLLY BLOOM: Twenty-five dogs. Liv is learning to mush those dogs. That's where the dogs pull him on a sled through snow. But don't think that means dogs do all the hustling. Life has to do work too.

LIV: A lot of work. I like steep up hills. There's no way that they'll carry and bring your entire sled for you on a big long uphill. You have to really run and maybe even push the sled.

MOLLY BLOOM: Liv and Gwen live in a house where electricity is made from wind and sun. But Gwen says how much they get of either can depend on the weather or the season.

GWEN: It varies a lot throughout the year for our house. During the summer, we have really good solar capacity in Alaska in the summer. The solar panels work really well. In the winter, they really don't do very much, we don't have much sun. But then during those seasons, we actually tend to have more wind.

The two resources balance each other out really nicely between the sun and the wind which we get at different times of the year. And then our diesel generator fills in and is our backup. And all of those different power sources feed into a battery system, which is really where we're drawing our power from. All those energy sources feed into a single battery, and then that's how we get our power for lights and other things that we want to run in the house.

MOLLY BLOOM: Gwen is actually the director for the Alaska Center for Energy and Power, so she thinks about these sorts of things a lot. She says our electrical grid is old and was designed in Tesla and Edison stayed to only send power one direction. From power plants to users. It was like a one way highway.

GWEN: But today, people want to have solar panels on their homes. They want to be generating their own power. Now, all of a sudden, this electrical highway is becoming a two way highway and it's much more complicated. But when you have a really large grid like that, you might have solar panels that are serving users that might be hundreds of miles away. And the power that's generated is being used less than 1 second later. But in Alaska, where you don't have a transmission grid, you can't send the power to a user far away. It's got to be used by the people locally. It's a tougher challenge.

MOLLY BLOOM: The good news is that solar and wind don't pollute like burning coal or what does. So more people are looking to switch to these sources. The bad news is that we can't always predict when the sun will shine or the wind will blow. Researchers are looking into ways to store energy created this way for when it's needed.

GWEN: People want to have power when they want to have power. They don't want to wait for the sun shine or the wind to blow, at least not in the United States. In other places in the world, you might be willing to accept that you only have electric power at certain times during the day when it's available.

MOLLY BLOOM: No matter how you get your electricity, Gwen says it's important to remember that it took a lot of work and a lot of resources to bring it to you. So don't waste it. Turn off lights and electronics when you aren't using them. Remember, there's plenty of fun stuff to do that doesn't require power at all. Go write a book, play with some dogs, or chase a wild chicken.

[MUSIC PLAYING]

HOPDAY MARTON: Most electricity come from power plants.

MOLLY BLOOM: It's stepped up to high voltages, sent through transmission lines to neighborhoods, and then stepped down to make it safe for use.

HOPDAY MARTON: Our grid uses alternating current, in part thanks to visionaries like George Westinghouse and Nikola Tesla.

MOLLY BLOOM: The electric grid of the future might be powered by wind turbines and solar panels.

HOPDAY MARTON: Still, electrical power is precious. So don't take it for granted. Turn off the lights when you leave a room.

MOLLY BLOOM: That's it for this episode of Brains On.

HOPDAY MARTON: Brains On is produced by Marc Sanchez, Sanden Totten, and Molly Bloom.

MOLLY BLOOM: We had production help this week from Emily Allen, Lauren Dee, and John Lambert, and engineering help from Veronica Rodriguez and Ryan Roberts. Many thanks to Leah Marton, Rachel Hill, Albert Rodriguez, Brenda Everson, John Moe, Stephen Smith, John Miller, Jeff Nilka, and Jess Horowitz.

HOPDAY MARTON: Before we go, let's welcome the latest group to join the Brains Honor Roll.

MOLLY BLOOM: These kids power our show with their drawings, questions, and mystery sounds. Here we go.

[LISTING HONOR ROLL]

We'll be back next week and powered up with an episode on batteries. Without them, say goodbye to that phone in your pocket.

HOPDAY MARTON: And your car.

MOLLY BLOOM: And modern life as you know it.

HOPDAY MARTON: We'll be back then. Thanks for listening.

[MUSIC PLAYING]