How the now-ubiquitous machines work is still a mystery to many people who own them. In order to shed a little light on the appliance, ChefSteps made a YouTube video.
Microwaves still have magnetrons, or vacuum tube, in them, and when you press the power button, they send out electromagnetic waves, better known as microwaves. Everything happens inside an insulated chamber, so the microwave radiation doesn’t escape. A waveguide then directs the microwaves to the food, and a fan scatters the beam into several, so a greater amount of the food gets cooked.
The video ends there, making it a short and sweet explanation. If you want to know a little more, you can check out this 2012 video from Bill Hammack, a professor in the Department of Chemical Engineering at the University of Illinois at Urbana-Champaign. He further explains how a microwave differs from other cooking methods: “In a traditional oven or stove, we heat food by placing a pan on a burner or in the oven where the walls radiate heat, which cooks the outside of the food. The insides cook when heat transfers from the surface of the food to its interior.”
With a microwave, “energy from the magnetron penetrates into the food, which means the whole mass of the food can be cooked simultaneously.” The professor even goes on to explain why your microwave will make some parts of your flatbread piping hot while leaving other spots ice cold.
Frankly, we’ll never look at our bag of popcorn/unpopped kernels the same way again.