The elements of the week are tungsten and thorium, which are alloyed to make the filament in the special type of vacuum tube—called a magnetron—that produces radiation in your microwave oven. Bill and the Engineer Guy team first explain the anatomy of a basic microwave oven, then come through with a great, memorable visualization that intuitively links the wave’s oscillating electric and magnetic fields to the rotational vibrations of water molecules, in the food, that actually heat it up. Other highlights include mapping the standing wave in the cooking cavity by heating a platter of grated cheese, and a cross-section of a real magnetron with overlays and a handy analogy explaining how it works. [Thanks, Bill!]