Microwave Oven Was Accidental Invention

The technology that would eventually heat leftovers in kitchens worldwide was first perfected for spotting enemy aircraft during World War II. The key component was the magnetron, a high-powered vacuum tube that generates microwaves for radar systems. In 1945, a self-taught Raytheon engineer named Percy Spencer was testing a new magnetron when he felt a strange sensation and noticed a chocolate bar in his pocket had turned into a gooey mess. Intrigued, he aimed the tube at popcorn kernels, which quickly popped all over the lab. A second experiment with an egg confirmed his hypothesis, though it ended with the egg exploding in a colleague's face.

Realizing the potential of this phenomenon, Spencer and Raytheon developed a new application for the military technology. The process works by using microwaves to agitate the water molecules within food. This rapid vibration creates heat, cooking the food from the inside out (Review). The first commercial unit, aptly named the Radarange, was released in 1947. It was a far cry from today's countertop models, standing nearly six feet tall, weighing 750 pounds, and carrying a price tag of $5,000—the equivalent of over $60,000 today. Due to its enormous size and cost, its initial market was limited to restaurants and institutional kitchens.