Make a Wave Light with Aluminum Foil Balls!

“Golden Age “Radio” is said to have ended in the 50s, with the advent of radio.

Radio waves are a form of electrical radiation, like visible light. But they are at the end of the spectrum, which makes them harmless to people, because low frequency means low power. (High-pitched, high-energy radiation such as x-rays or gamma rays is another matter.) This is one of the reasons radio waves are suitable for wireless communication. They can also walk long distances and pass through obstacles like walls.

So radio is as important as ever. But did you know that you can make your own radio and receiver at home with simple materials? I’ll show you how. It’s a fun project and a great excuse to explore some cool physics.

What Are Electromagnetic Waves?

What are waves? Imagine you have a long rope tied to one side of the door. You stand across the room, holding the other side. Now, if you move your hand up and down, you will create a disturbance in the string, and the disturbance will travel along the length of the string. That’s it wave. Basically, waves transfer energy without transferring matter.

What if you remove the cable? In that case, you may look like a sad person shaking hands with an imaginary friend. Without cable, there are no waves. Waves need something to “vibrate” within them—they need a medium. You can’t have ocean waves without water. You cannot have sound waves in space, because there is no air for them to travel through.

But what if, instead of a string, you shake an electric current (like an electron) up and down? Electric coins create electric fields, so this to move charge will create an oscillating electric field, and that creates a wave of electricity. And here’s where it gets weird: It’s clear that a change in electricity also makes a difference. magnet garden. And vice versa: A change in magnetism causes a change in electricity. We know this Maxwell’s effect.

This means that we have electric and magnetic oscillations that go hand in hand, and each is a coupling to the other. The combination is called electromagnetic radiation, also known as “light.” Yes, radio waves are lighter and lighter he can propagating itself through the void—at the speed of light, as it were.

Piezoelectric Radio Station

Well, let’s play the radio! For the transmitter, all you need is a grill reflector – you know, the kind with a long tube. When you hold the trigger, gas is released from the end of the tube and ignited by a small spark. Here’s one I cut in half:

Photo: Rhett Allain