The fastest thing you own is probably your microwave's light

Microwaves cook by making water molecules flip billions of times a second in an oscillating field. The radiation itself is light, traveling at 300,000 km per second. A microwave oven works by flooding its cavity with electromagnetic radiation at about 2.45 gigahertz. That radiation is light, just at a wavelength your eyes cannot see, and like all light it travels at roughly 300,000 kilometres per second. The heating comes from frequency, not speed. Water molecules are electrically lopsided, and the oscillating field twists them billions of times a second; the resulting friction warms food from within rather than conducting heat in from a hot surface. That explains the oven's quirks. Ice heats poorly because its molecules are locked in a lattice and cannot rotate, which is why defrost cycles pulse. Standing waves create hot spots, which is what the turntable is for. The door's mesh has holes far smaller than the 12-centimetre wavelength, so microwaves reflect while light passes.

The fastest thing you own is probably your microwave's light

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