yego.me
💡 Stop wasting time. Read Youtube instead of watch. Download Chrome Extension

Levitating Barbecue! Electromagnetic Induction


3m read
·Nov 10, 2024

Let's switch it on. Let's see what it does. Through this coil of thick wire, we're about to pass a huge alternating electric current. On top is a 1 kg aluminum plate. So we hear that noise. What's that noise? It's the vibration of the plate because it's vibrating at two times the frequency of this one.

Woah! Woooaaaahhhhhhh!! Hahaha, how does it do that? It's magical. To find out, I've come to the place where it all started - The Royal Institution in London. This is the key to Faraday's magnetic lab. It's amazing that the lock still works. From the 1870's on, this became a storeroom, which is why it survived, and it survived intact; all the joinery giant electromagnet are exactly the same as Faraday left it. So this is exactly as Faraday would have had it.

That's right, yup. In Faraday's time, it was known that electric current creates a magnetic field, but it remained an open question whether the reverse is possible -- if a magnetic field could generate electric current. Faraday answered this question with his most famous apparatus: Faraday's electromagnetic induction ring. Which is this.

In August 1831, Faraday wrapped two coils of insulated wire around this iron ring. But in 1831, you could not go down to your local electrical hardware shop and ask for x hundred meters of insulated wire; you had to insulate the wire as you went. So as you pushed and pulled the wire in and out of the ring, you had to insulate it. It takes 10 working days, which was a huge investment of time. But the investment paid off.

When Faraday connected a battery to one of the coils, he saw a brief pulse of current in the other coil. And when he disconnected the battery, he saw a pulse of current in the other direction. He realized that current was induced in the second coil only when the magnetic field through it was changing. And if they hadn't been wrapped on the same ring, Faraday may have noticed that the two coils repel each other when the current is induced, and that's due to the interaction of their magnetic fields.

Which brings us back to this. Through the bottom coil, we are passing a huge electric current: 800A which alternates in direction 900 times per second. This ensures there will always be a changing magnetic field above the coil. Instead of a second coil, we're using the aluminum plate, but the principle is the same; the changing magnetic field induces currents in the plate that create an opposing magnetic field -- so it levitates.

How awesome is that?! This current is not only good for levitating the plate. It can also make lightbulbs glow. A gift. Uh, thank you. Oh. That is cool. Not too close because it will burn the lamps. Can I put it there? Yeah. And just as current in a toaster element heats it up, the induced current in the plate dissipates its energy as heat.

And some water too! Thank you. Yeah, to see the temperature. Check out how hot this plate is. Oh, that is nuts! Is this your favorite demo? It's a flying BBQ or something. Tell me this is not the best dinner table centerpiece. It levitates, gives you light, and you can cook on it. And all the while, you're demonstrating Faraday's Law of electromagnetic induction.

More Articles

View All
How To Introduce Yourself To Someone You Find Interesting
Here’s the question everybody asks themselves at some point in their lives: how much do first impressions actually matter? Well, we don’t mean to sound superficial, but the honest answer is a lot more than you could imagine, actually. That’s because for …
Quotient rule | Derivative rules | AP Calculus AB | Khan Academy
What we’re going to do in this video is introduce ourselves to the Quotient Rule, and we’re not going to prove it in this video. In a future video, we can prove it using the Product Rule, and we’ll see it has some similarities to the Product Rule. But her…
We are in the "First Inning" of the Real Estate Crash - Billionaire Real Estate Investor
So, we’ve seen discounts already of, let’s say, 10-15%. Are we going to see discounts of 50%? Are we going to see buildings just turned over to the banks? I mean, what does it look like in terms of the bottom for this market? Billionaire real estate inves…
Photo Ark | Series Trailer
[Music] All right, this’ll work. Okay, we’re ready for the cobra. [Music] He’s running away from me. There we go, that’s just the first one. I’m all worn out. Okay, for the past 15 years, I’ve made a thousand trips to photograph over 10,000 species and s…
15 Ways to Get Ahead of 98% of People
98% of people aren’t living up to their full potential. They form their opinions based on superficial things that they hear. They can’t manage themselves, but they also don’t think enough about themselves, what they want, and what makes them happy. All of…
How Banks Work
After we posted the video about the SVB situation, a lot of you guys asked us to make a follow-up on how banks actually work. So here it is! Now, before we get into the video, Alux as a company is safe and healthy. We’re bootstrapped, which means we star…