Hey there! Have you ever wondered how batteries work? It’s a really cool story that starts with frog legs! Let’s dive into it.
A long time ago, a scientist named Galvani was studying a frog in his lab. He wasn’t planning to eat it; he wanted to learn how muscles work. Back then, nobody really knew how animals moved their muscles. To find out, scientists would do something called a dissection, which means they carefully looked inside the animal’s body.
Galvani had soaked the frog’s legs in salt water to keep them fresh. When he started to cut the leg, something amazing happened—it twitched and jumped! This was super surprising because the frog was no longer alive. Galvani thought he had found a special power in the frog’s muscles.
News of Galvani’s discovery spread quickly. Another scientist named Volta was curious and decided to investigate. He found out that the twitching had more to do with the metals Galvani used than the frog itself.
Volta noticed that the frog’s leg only twitched when touched by two different metals. Galvani used a copper tool and an iron knife. Volta thought maybe the special power was in the metals, not the frog.
Volta experimented by using two pieces of metal, one copper and one iron, connected by wires. At first, nothing happened. Then he remembered the salt water. He added a piece of cardboard soaked in salt water between the metals. When he connected them, he felt a slight shock!
Volta stacked more of these metal and salt water sandwiches, creating a stronger shock. He even made a spark, like a tiny lightning bolt! Volta had invented the first battery. In some languages, batteries are still called “Volta’s pile” because of this discovery.
Back then, people didn’t know what batteries could be used for. But now, we use them for so many things! Batteries power our smartphones, electric cars, and even flashlights. They’re super important because they let us use electricity without needing to be plugged into a wall.
Today’s batteries might look different from Volta’s first battery, but they work the same way. They use two different metals and a liquid solution, like salt water or acid, to create electricity.
Isn’t it amazing how a curious experiment with frog legs led to something we use every day? Thanks for exploring this with me! Stay curious, and keep asking questions. Who knows what other mysteries we can solve together!
Make Your Own Simple Battery: Gather some coins (like pennies), aluminum foil, and paper towels. Cut the paper towels into small squares and soak them in salt water. Stack the coins and aluminum foil with the wet paper towel squares in between each layer. Try to light a small LED bulb by connecting it to the top and bottom of your stack. Observe what happens and think about how this relates to Volta’s first battery.
Battery Hunt: Look around your home and make a list of all the items that use batteries. For each item, think about why a battery is used instead of plugging it into the wall. Discuss with a family member or friend how life would be different if we didn’t have batteries.
Question Time: Imagine you are a scientist like Galvani or Volta. What everyday object would you like to investigate to discover something new? Write down your ideas and share them with your class. What do you think you might find out?
Sure! Here’s a sanitized version of the transcript:
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(phone ringing) – Hi, Doug! – Hi, Waylon! – I have a question for you. How do batteries work? – That’s a great question. Before I say anything more, I’m curious: how do you think batteries work? Now would be a good time to pause the video and discuss. Okay, you ready? Well, believe it or not, the answer to this question involves a story about frog legs.
Now, some people prepare and eat the legs of frogs, just like some people eat chicken legs. But one scientist by the last name of Galvani had a dead frog in his laboratory one day. Not because he was going to eat it, but because he was getting ready to study it. Galvani was really interested in figuring out how people’s bodies work, things like muscles and organs. At that time, this was a few hundred years ago, nobody knew yet how exactly people or animals move their muscles. It’s hard to see how muscles work from the outside of an animal’s body, so it can help to look inside. If an animal dies, scientists can do an operation, like a doctor. This is what’s called a dissection.
So Galvani had prepared the frog’s legs so that he could dissect them and study the muscles. Because he didn’t want the frog’s legs to rot, he had soaked them in some salt water overnight. He got one out, put it in his dissection pan, and then, as he started to cut it with his scalpel, something amazing happened. The leg suddenly began to twitch and jump. Now, obviously, this was extremely surprising. The frog, after all, was dead. Its legs shouldn’t have been able to move. Galvani got so excited. He felt that he had discovered some kind of special power within frogs’ muscles. He thought he must be so close to unlocking the secret of how animals move their muscles.
Well, news of Galvani’s discovery spread fast among all the scientists living at that time. Lots of them were excited to see if they could unlock the secret of how animals move. One of those scientists, a scientist by the last name of Volta, found something even more surprising than Galvani. As Volta tried to repeat Galvani’s experiments, he became convinced that the twitching of the frog’s leg actually had almost nothing to do with the frog and everything to do with the metal tools that Galvani was using.
For example, Volta found out that in one of Galvani’s experiments, the frog’s leg would only twitch when it was being touched by two different metals. You see, Galvani had used a tool containing the metal copper to hold the frog’s leg in place. And Galvani’s knife was made of a different kind of metal, a metal containing iron. Volta wondered, what if this special power that Galvani discovered was actually something contained not in frogs’ muscles but in the two different metals? Using no frog legs at all, Volta took two pieces of metal, one of copper and one of iron, just like the metals used in Galvani’s experiment.
Then, he connected a piece of wire to each metal disk. When he touched the two wires together, well, at first, nothing happened. But that’s when Volta remembered there was one other substance involved in Galvani’s frog leg experiments: salt water. Volta added a little disk of cardboard soaked in salt water between the pieces of metal. Suddenly, now when he connected these together, he could feel a slight shock. By stacking up little sandwiches of each metal, separated by disks of salt water-soaked cardboard, Volta discovered that he could increase the strength of the shock. With enough of these little disks all piled up, he could even create a spark. It looked just like he was making a little lightning bolt.
What Volta had just invented was the very first battery. In fact, to this day, in some languages like in French, a battery still goes by the name of Volta’s pile. At the time that the battery was invented, Volta and others didn’t actually know what kinds of things they’d be useful for. No one had invented anything powered by electricity yet. But over time, as you can guess, that all changed. Today, batteries are one of the most useful inventions ever. Since batteries are a portable form of electricity, they allow us to power things without having to be anywhere near an electrical outlet. Without batteries, we’d have no ability to use smartphones, electric cars, not even flashlights.
Today’s batteries may look different from the first battery ever invented, although some look incredibly similar on the inside. Either way, all batteries still work the same basic way. They all use Volta’s amazing discovery that when you sandwich together two different metals between some kind of liquid solution, like salt water or acid, electricity is produced.
That’s all for this week’s question. Thanks, Waylon, for asking it! Now, for the next episode, I reached into my question jar and picked out three questions submitted to me that I’m thinking about answering. When this video’s done playing, you’ll get to vote on one. You can choose from: Why are school buses yellow? Who invented the piano? Or, do fish sleep? So submit your vote when the video’s over. I want to hear from all of you watching. There are mysteries all around us. Stay curious and see you next week.
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