You ever look at a microwave and wonder what’s going on in there? I mean, I know what the thing does: It unevenly heats my food. I know how to use it: Increase the amount of heating time the more food you’re heating, lower the power level if you’re worried about the food toughening up. I even have a vague idea that the machine is hitting the food with something—particles, waves, particles and waves—but I don’t know exactly what, and I don’t know how it’s doing it, and I don’t know what purpose that weird mesh you see on some of them serves.
So, Wikipedia:
A microwave oven (commonly referred to as a microwave) is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range. This induces polar molecules in the food to rotate and produce thermal energy in a process known as dielectric heating.
Shit. This is gonna be more complicated than I thought.
Basically, what we have going on here is that microwaves are shooting electromagnetic waves at your food, which is responding by heating itself. What does that mean? Let’s start with the waves.
Per NASA, electromagnetic waves are the same as light, or as radio waves, but not the same as water waves or sound waves because those need a physical medium to move through, specifically a liquid or a gas, respectively. If you fill your sink with water, you can make waves in that liquid, and when you shout, you’re making sound waves in the air. If I have it right, you’re basically shaking the water, or shaking the air. Electromagnetic waves do the same thing, except instead of shaking a physical substance, they shake the magnetic field and the electric field that exist all around the universe—even in outer space (which is why light can travel through space, but sound cannot). My understanding—and again, I’m getting this from Wikipedia and NASA and not some college or even high school-level physics course, so take this with the appropriate salt—is that the electromagnetic field is a big array of electricity moving all around everything. An electromagnetic wave shakes that electricity up, moving it in ways it wasn’t previously going, just as a wave in the ocean moves the water from its previous position.
So, a microwave works by shaking up the electromagnetic field in and around your food. Your food, in turn, responds to that. Why? Because your food is made up of atoms, and atoms include electrons. When the electromagnetic field gets wavy, the electrons in some of the atoms in your food move their molecules around, which transfers energy in the form of heat as the molecules rub against one another.
In the shortest explanation possible, then, microwaves work by shaking up your food’s electrons. And if you’ll excuse me, I’ve got some lentil soup electrons that need shaking.
