How did they invent the lightbulb?

Have you ever looked up at a booming thunderstorm and wondered what lightning actually is? Did you know a single bolt of lightning is five times hotter than the surface of the sun?! In this electrifying episode, Mira and Finn uncover the shocking true story of how humans tamed the wildest force in nature: electricity! Join us as we travel back in time to 1752 to watch Benjamin Franklin fly his famous kite into a dark, brewing storm. Then, zoom all the way down to a microscopic level to meet the tiny, hyperactive, invisible bits of energy called electrons! We will also follow the famous inventor Thomas Edison on his wild race to create the very first working lightbulb. You won't believe the bizarre things his team tested to make a bulb glow—they tried 6,000 different materials, including a hair pulled right out of a man's beard! From dangerous lightning bolts zapping at 270,000 miles per hour to the quiet hum of your bedroom lamp, discover how human curiosity lit up the entire world. It's basically magic, but it's real science!

Transcript

SPEAKER_00 0:00

Welcome to Science is Not Boring by Kidopoly.com. I'm Mira! And I'm Finn. Hey Finn, did you know that a single bolt of lightning tearing through the sky can reach 50,000 degrees Fahrenheit? That's about 30,000 degrees Celsius.

SPEAKER_01 0:17

Wait, 50,000 degrees? But that's. Hold on. Isn't that hotter than the surface of the Sun? You got it! It is actually five times hotter than the surface of the Sun. Five times hotter? Right over our heads? That is completely wild.

SPEAKER_00 0:34

It is. Imagine looking up at a pitch black sky, hearing the deep, rumbling boom of thunder, and watching a blinding flash of jagged light rip across the clouds. For most of human history, a lightning bolt was the most powerful, terrifying thing in the world.

SPEAKER_01 0:51

Because nobody knew what it actually was, right? They thought it was magic, or sky monsters throwing spears at the ground.

SPEAKER_00 0:58

Exactly. But human curiosity changed everything. We didn't just figure out what lightning was, we literally tamed it. We learned how to capture that exact same wild energy and put it inside a tiny glass bulb just to light up our bedrooms.

SPEAKER_01 1:14

So today we're talking about how we went from dodging massive lightning bolts in the sky to flicking a switch to turn on a lamp. I love this already.

SPEAKER_00 1:22

We sure are. We're exploring the epic story of electricity. From a famous kite flying in a dark thunderstorm to a race between inventors to build the very first light bulb.

SPEAKER_01 1:33

Okay, before we trap it in a glass bowl, what actually is lightning? I mean, if you zoom way, way in with a microscope, what is happening up there?

SPEAKER_00 1:44

At the very tiniest level, lightning is a massive flow of electricity. And electricity is entirely made of microscopic invisible bits called electrons.

SPEAKER_01 1:55

Electrons? How tiny are we talking? Are they the size of a grain of sand?

SPEAKER_00 2:01

Not even close. They are so unbelievably small that billions of them could fit on the very tip of a single needle. They are the tiny, hyperactive puzzle pieces that make up everything in the universe.

SPEAKER_01 2:15

Billions on a needle point! That's impossible to even picture.

SPEAKER_00 2:19

I know! Now, imagine you're high up inside a dark, freezing storm cloud. Billions of ice crystals and water droplets are violently crashing into each other, transferring those tiny electrons as they rub together.

SPEAKER_01 2:34

Oh, like when I shuffle my socks on the living room rug to shock my sister.

SPEAKER_00 2:39

Exactly like that, but on a massive scale. They build up a huge electrical charge, sometimes packing up to one billion volts of electricity. And then suddenly, zap! They blast down toward the ground at 270,000 miles per hour.

SPEAKER_01 2:57

270,000 miles per hour? No wonder it sounds like a literal explosion when the thunder hits.

SPEAKER_00 3:03

Oh yeah, that intense super hot energy expands the air so violently and so fast that it creates a massive shockwave. That explosive shockwave is the thunder you hear echoing in your chest.

SPEAKER_01 3:17

Okay, so if lightning is just a giant electric zap, zooming from the clouds, who actually figured that out?

SPEAKER_00 3:24

Enter a super curious scientist and inventor named Benjamin Franklin. The year was 1752, and the place was the city of Philadelphia. Benjamin Franklin had a wild theory. He thought the terrifying lightning tearing up the sky was the exact same stuff as that tiny studic spark you get from the doorknob.

SPEAKER_01 3:46

Wait, he wanted to test that. How? You cannot just reach up and catch a lightning bolt.

SPEAKER_00 3:53

He came up with a legendary experiment. Now, we have to pause and say right now, this is incredibly dangerous. You should always stay safe indoors during a storm, and absolutely never, ever try to touch electricity or fly a kite in a storm.

SPEAKER_01 4:09

Yeah, no kidding. I like my hair unsinged, thank you very much.

SPEAKER_00 4:14

But in June 1752, Franklin built a kite out of a silk handkerchief and two cedar sticks. He tied a heavy metal key near the bottom of the string and flew it right up into a dark, brewing thunderstorm. Did the kite get hit directly? Did it explode? Amazingly, no direct strike. Instead, the kite string got soaked by the rain and it acted like a bridge. The electrical charge floating in the storm clouds travelled silently all the way down the wet string.

SPEAKER_01 4:46

And then what happened to the key?

SPEAKER_00 4:48

When Franklin brought his knuckle close to that metal key, a visible spark jumped right onto his hand. He proved it once and for all. The mighty storm clouds were full of electricity.

SPEAKER_01 4:59

He proved it! The sky monsters were just giant sparks. But okay, knowing what it is doesn't mean we can use it.

SPEAKER_00 5:07

That's right. To use electricity, scientists had to build pathways for it. They discovered that certain metals, like copper, act like superhighways for those tiny electrons to travel on.

SPEAKER_01 5:20

So if the electrons are on a superhighway, do they zoom down the copper wire like tiny race cars? Here is the weirdest part.

SPEAKER_00 5:28

The individual electrons in a wire actually move incredibly slowly. Literally about one metre per hour. That's slower than a snail.

SPEAKER_01 5:37

Wait, what? Slower than a snail? But when I flip a light switch, the lamp turns on instantly.

SPEAKER_00 5:43

That's because the wire is already packed full of electrons. When you push one in at the switch, it instantly bumps its neighbour, which bumps the next one, like a million falling dominoes. That invisible energy wave travels through the wire at almost the speed of light.

SPEAKER_01 5:59

Okay, so we have this invisible, super fast energy highway filled with bumpy electrons. How do we turn that electrical wave into actual light?

SPEAKER_00 6:09

We have to fast forward to 1879. A famous inventor named Thomas Edison was determined to build a safe, reliable light bulb. The basic science is simple. If you squeeze electricity through a really, really thin wire, the electrical resistance makes the wire heat up so much that it naturally glows. Oh, I know this!

SPEAKER_01 6:35

It's exactly like those glowing orange wires you see inside a toaster when it's heating up the bread.

SPEAKER_00 6:40

Exactly like a toaster. But Edison faced a massive problem. If a thin wire gets that incredibly hot out in the open air, the oxygen makes it instantly catch fire and melt.

unknown 6:55

Poof!

SPEAKER_00 6:56

It burns right up.

SPEAKER_01 6:58

Well, a lamp that instantly explodes into flames is a pretty terrible lamp. So what did Edison do to fix it?

SPEAKER_00 7:05

He used a vacuum pump to suck almost all the air out of a glass bulb, creating a completely empty space inside. Because without oxygen, a fire literally cannot burn.

SPEAKER_01 7:19

That is so clever. But he still had to put something inside the glass to glow, right? Right.

SPEAKER_00 7:26

He needed the perfect glowing string called a filament. And let me tell you, his team tested everything. They tested over 6,000 different materials in that lab. 6,000? What kind of stuff were they burning? They tried everything, from regular cotton and cedar wood, to fishing line and even tortoise shell. Legend says he even tested a hair pulled right out of a man's bushy beard.

SPEAKER_01 7:57

Ew, a glowing beard hair lamp? That is so gross, no thank you.

SPEAKER_00 8:03

Don't worry, the beard hair failed. Finally, in October 1879, he took a simple piece of cotton sewing thread, baked it in an oven until it turned completely black and carbonised, and sealed it inside the glass bulb. And did it catch fire this time? No. He flipped the switch and it glowed a beautiful steady orange light for 14 and a half hours straight. They had finally tamed the lightning.

SPEAKER_01 8:35

14 and a half hours? That's long enough to stay up all night reading comics in bed. But wait, how did those glowing bulbs actually get into people's houses?

SPEAKER_00 8:47

That was the next big hurdle. A light bulb is totally useless if you don't have electricity flowing to it. So, in 1882, Edison built the first commercial central power plant in the United States.

SPEAKER_01 9:02

Where exactly did he put a giant power plant?

SPEAKER_00 9:06

It was called the Pearl Street Station, right in the middle of busy New York City. His team dug up the roads and laid massive copper wires under the cobblestone streets.

SPEAKER_01 9:18

I bet the whole city was lining up to sign up for electricity immediately, right?

SPEAKER_00 9:24

Actually, no. People were pretty nervous about invisible energy coming through wires into their living rooms. When the station first turned on, it only had 82 customers, powering about 400 lamps total.

SPEAKER_01 9:39

Wow, just 82 people. And now there are billions of miles of electrical wires covering the entire planet, from giant cities to tiny towns.

SPEAKER_00 9:50

It truly changed human history forever. Before the light bulb, when the sun went down, everything went pitch dark. Humans had to live by the dim, flickering light of candles, or incredibly smelly gas lamps.

SPEAKER_01 10:06

It is so weird to think about. That massive, terrifying billion volt lightning bolt exploding out of a storm cloud is the exact same force humming quietly in the tiny battery of my toy remote control car.

SPEAKER_00 10:20

It really is magical. We took the wildest, most untamable power in all of nature, figured out its secrets, and learned how to invite it right inside our homes, just to read a bedtime story. Alright, Finn, I think it's time for the quiz. Let's see how many of these shocking facts you actually remember.

SPEAKER_01 10:41

Oh, I am so ready. Bring on the lightning round. Hit me.

SPEAKER_00 10:45

First question. Compared to the surface of the sun, exactly how hot is a lightning bolt? Next one. In what year did Benjamin Franklin do his famous and very dangerous kite experiment? Question three. Thomas Edison tested 6,000 materials for his bulb. What gross human material did he actually test? Here is number four. How many hours did Edison's very first successful cotton thread light bulb burn? Last question. When Edison's first commercial power plant opened in New York City, exactly how many customers did it have? Great job! Let's go through the answers and see how you did. The answer to question one is a lightning bolt is five times hotter than the surface of the sun. For question two, Franklin flew his silk kite in the year 1752. three, the answer is he actually tested a hair pulled from a man's beard. Question four, that first successful cotton bulb burned for fourteen and a half hours. And the final answer is, that first commercial power plant had just 82 customers.

SPEAKER_01 12:19

I honestly will never look at my bedroom lamp the same way again. Just knowing there are billions of tiny electrons bumping into each other inside the wall right now. It is basically magic, but it is real science.

SPEAKER_00 12:33

That is exactly why science is never boring. Hey, speaking of experimenting, if you thought Thomas Edison trying 6,000 different materials was wild, we would love it if you left us a five-star review. Just scroll down on your app and tap those five stars.

SPEAKER_01 12:50

Oh, and please do not forget to check out our site, kidopoly.com. We have tons of really fun learning games and cool activities waiting for you to try.

SPEAKER_00 13:00

And if you want a special shout out on the show, or just want to tell us what wild topic we should cover next, send us an email at hello at kidopoly.com. Thanks for exploring the science of Sparks with us today. See you next time on Science is Not Boring.