Microwaves!

You might think the science behind microwaves is relatively simple — the machine produces microwaves (as its name suggests), which in turn warm up your food. However, that’s only partially correct.

While it’s true that microwaves warm up food, it’s not the food itself that’s being warmed, but the water inside the food.  Microwaves, along with X-rays, radio waves, gamma rays, and visible light, are part of the electromagnetic spectrum. But microwaves contain an interesting property — they’re readily absorbed by water, fats, and sugars.

These materials absorb microwaves as atomic motion, essentially vibrating the water molecules in food, which in turn produces heat. Of course, this is only part of the microwave’s convenient food-warming equation, as this slice of the electromagnetic spectrum isn’t absorbed by plastic, glass, and most ceramics, making it a convenient way to heat up food without heating up its container. 

But have you ever accidentally put a piece of metal in a microwave?

Yikes.

What’s happening to create this explosive situation is that the microwaves are moving the free electrons found in the conductive metal’s surface, which causes the object to reflect microwaves. If the metal is smooth all over, such as a spoon, this won’t likely be a problem, but sharp edges like the tines on a fork  will produce sparks and potentially catch some flammable material in the microwave on fire. A microwaved metal will also create an imbalance with dielectric breakdown in air,  which can cause an electrical arc that can punch a hole in the interior wall, rendering the microwave too unsafe to use.

Long story short, just don’t put metal in the microwave — ever.

Much love,