What was the first battery?

0:46 Welcome to Science Is Not Boring by kidopoly.com. I'm Mira. And I'm Finn! A big hello to Josephine, who is five, and Lincoln, who is twelve, in Flower Mound, Texas.

1:00 They listened together on the drive to school and asked how batteries first started. Great question, guys.

1:07 And a huge high five to Titus, who is five, in North Carolina, who asked how batteries store electricity.

1:15 If you haven't already, tap follow wherever you're listening, so you never miss an episode.

1:21 Finn, imagine turning on your flashlight. But instead of putting in a normal battery, you had to power it using a dead frog.

1:30 Wait, a frog? Like an actual slimy, croaking swamp frog? Are you serious right now?

1:39 I am totally serious. The wild, unbelievable discovery of the world's very first battery actually started with a dead, twitchy frog.

1:50 That is the weirdest thing I've ever heard. How do you go from a frog to the batteries inside my video game controller?

1:57 Today we are travelling back in time to the 1700s to uncover the shocking true story of the battery. We're going to talk about twitching muscles, a scientist who tasted his own experiments and the invention that changed the entire world. To understand just how mind-blowing this invention was, we have to travel back to the year 1780.

2:21 Over 240 years ago. What was the world like back then?

2:26 Dark and quiet. There were absolutely no light bulbs, no phones, no electric ovens. People read by the wobbly light of wax candles or oil lamps. So electricity didn't even exist yet. Well, electricity is a force of nature, so it always existed. People knew about lightning strikes, and scientists played around with static electricity, like when you rub a balloon on your hair.

2:54 Oh yeah, I love doing that. Your hair stands straight up like a crazy porcupine.

2:59 Exactly. But scientists in the 1700s could only make quick random sparks. They had absolutely no way to store electricity or make it flow constantly in a steady stream.

3:12 So they couldn't turn it on and off like a switch. It was just unpredictable sparks.

3:18 Right, but that all started to change in a cold stone laboratory at the University of Bologna in Italy. Let me introduce you to a 43-year-old scientist named Luigi Galvani. Luigi Galvani? Was he an electrician? Nope, he was an anatomy professor. Anatomy is the study of the structure of bodies and all their parts.

3:43 Oh, is this where the frog comes in? You guessed it. It was late in the year 1780. Galvani was dissecting a frog to study its muscles and nerves. A very normal thing for a doctor to do. Picture the scene. It's a wooden table. Galvani has the frog laid out. Across the room, one of his assistants is cranking a special machine that creates static electricity sparks.

4:10 Okay, static sparks flying, a frog on a table. Sounds like a mad scientist movie.

4:16 It gets weirder! As the static machine sent sparks through the air, another assistant accidentally touched the frog's sciatic nerve with a steel scalpel.

4:27 Wait, what happened? What did it do?

4:29unknown Zap!

4:30 The frog's leg kicked violently! Even though the frog was dead, its muscles twitched and jumped like it was trying to hop off the table. Whoa! A zombie frog! How is that even possible? Galvani was completely amazed. He spent years testing it over and over. He found that if you touched the frog with two completely different metals, like brass and iron, the leg would kick every single time.

4:57 Did he know why? Galvani published his findings in 1791. He proudly declared that he had discovered something called animal electricity.

5:07 Animal electricity? So he thought the electrical power was coming from inside the frog itself.

5:14 Exactly! He thought living creatures had a special electric fluid inside them, like some kind of magical life force that made muscles move.

5:22 Well, he wasn't totally wrong, right? Our brains do send electrical signals to our muscles so we can move.

5:29 That is a brilliant point, Finn! Our nervous systems do use tiny electrical signals, but Galvani was wrong about where the big zap was coming from in his experiment.

5:40 If the zap wasn't coming from the frog's special life force, where was it coming from?

5:44 To answer that, we have to travel to another Italian city, Pavia, to meet a physics professor named Alessandro Volta.

5:52 Alessandro Volta? I know that name. Wait, the word volt, like the volt in a battery, is that named after him?

6:00 Ding ding ding! Yes it is! In the 1790s, Volta read Galvani's paper on the zombie frogs. Volta was suspicious. He realised the frog was just acting like an electrical detector.

6:14 So the frog was just reacting to the power, not making it.

6:18 Right! Volta proved that the electricity actually came from the two different metals touching the wet fluids of the frog. To prove it, Volta did something totally gross.

6:30 Oh no, grosser than a dead frog? What did he do?

6:35 He tested the metals on his own tongue. He put a silver coin on top of his tongue and a strip of zinc under his tongue and connected them with a wire. Ew! Why would anyone do that? Because human saliva is salty, just like the fluids in a frog. When the metals touched, Volta felt a sour, tingly shock on his tongue.

6:58 No frog required.

7:00 Wow, so it's just the two metals reacting with the spit.

7:04 Exactly. So in the year 1800, Volta built the very first battery. He called it the voltaic pile. He took a small disc of copper, then a disc of zinc, and separated them with a piece of cardboard soaked in salt water.

7:20 Why salt water?

7:21 The salt water acts as an electrolyte. That's a chemical paste or liquid that lets electricity flow. When you stack these copper and zinc discs high into a literal pile, it creates a chemical reaction that constantly pushes electrons through a wire.

7:37 So instead of one quick spark, it was a steady, flowing river of electricity. He actually trapped lightning in a stack of coins.

7:47 That is the perfect way to describe it. The voltaic pile changed the entire world. In 1801, Volta even travelled to Paris to show his invention to the famous leader, Napoleon Bonaparte, who gave him a gold medal. How big was this first battery?

8:05 Was it pocket-sized?

8:08 Not at all. The stacks were sometimes a foot tall or more. A stack of 50 pairs of discs could produce around 50 volts, which is enough to give you a very nasty shock.

8:21 50 volts? So you definitely wouldn't want to lick that one.

8:25 Definitely not. But think about what this led to. Because of Volta's battery, other scientists could finally study continuous electricity. It led to the telegraph, light bulbs, radios, and everything we use today.

8:41 To answer Titus's question from earlier, that's how batteries store electricity, right? They don't actually store raw electricity. They store chemicals that make electricity when they react.

8:53 Exactly right, Finn! And today, the scale is mind-blowing. Humans use over 15 billion throwaway batteries every single year.

9:04 15 billion? That's almost two batteries for every single person on Earth.

9:10 And we have batteries as small as a single P for hearing aids, all the way up to electric car batteries that weigh over a thousand pounds. A single electric car battery actually contains over 4,000 tiny individual battery cells packed inside it.

9:28 A thousand pounds? That's as heavy as a grand piano. And to think, it all started with a salty frog leg on a wooden table.

9:36 Alright, Finn, it's quiz time! Are you ready to test your battery brain?

9:41 Oh I am completely fully charged and ready. Let's go!

9:45 First question. What kind of animal accidentally helped discover the first battery? Next one. What is the full name of the scientist who invented the voltaic pile? Question three. What two different metals did he use for his battery discs? Here's number four. What gross way did the scientist test his two metals before building the battery?

10:27 Last question. What electrical word was named in honour of this inventor? Great job! Let's see how you did. The first answer is a frog, specifically its twitching leg. For question two, the inventor's name was Alessandro Volta. Number three, he stacked discs made of copper and zinc. For the fourth question, he tested the metals by putting them directly on his tongue.

11:00 And the final answer is the volt! It is the standard unit of electrical potential.

11:06 I will seriously never look at my toy batteries the same way again. I'm just glad they don't have frog parts inside them.

11:14 Me too, Finn. Hey, if you listeners thought the voltaic pile was cool, please leave us a five-star review. Just scroll down and tap the stars on your app.

11:24 And be sure to tap follow so you never miss an adventure. Oh, and we have sister shows too. History and philosophy is not boring, and maths is not boring. Go give those a listen and a follow as well.

11:35 Want to shout out on the show? Or just want to say hi? Send us an email at hello at kidopoly.com. See you next time on Science Is Not Boring. Bye!