The microwave was invented after a researcher walked by a radar tube and a chocolate bar melted in his pocket.

Like many of today's great inventions, the microwave oven was a by-product of another technology.

It was during a radar-related research project around 1946 that Dr. Percy Spencer, a self-taught engineer with the Raytheon Corporation, noticed something very unusual.

He was testing a new vacuum tube called a magnetron, when he discovered that the candy bar in his pocket had melted.

This intrigued Dr. Spencer, so he tried another experiment. This time he placed some popcorn kernels near the tube and, perhaps standing a little farther away, he watched with an inventive sparkle in his eye as the popcorn sputtered, cracked and popped all over his lab.