This may sound a little strange, but it seems that popcorn was the first food to be microwaved deliberately. In 1946, dr. Percy Spencer, an engineer working for Raytheon, noticed that chocolate bars would easily melt when held close to a working magnetron (a by then novelty vacuum tube). So he tried putting some corn kernels near a magnetron, turn it on and.... pop! Historians tell us it took them a while to add salt and butter - you know, they were just engineers woking on the leading edge of technology...