From Quartz, the story of the microwave oven, which sales figures show is in decline:
The microwave, like many ingenious inventions before it, was birthed by mistake.
Before microwave radiation melted cheese, it served as the magic behind radars, which sent microwave signals out to objects to gauge their distance. But in 1945, Percy Spencer, an engineer at Raytheon, the maker of the first microwave, noticed something peculiar while experimenting with the technology. The high-powered radar turned a chocolate bar in Spencer’s pocket into goo. He then deliberately experimented with—you guessed it—popcorn. And it worked. Next, he tried an egg, which promptly exploded (onto a nearby coworker, as the story goes.)
“The microwave energy is like rubbing your hands together, only it rubs the molecules of food together as they are vibrating three thousand million times a second,” Norman Krim, a former vice president at Raytheon explained in a documentary about the device.
Shortly after Spencer’s discovery, Raytheon invested heavily in developing the first commercial microwave. It was called the Radarange, and it was ridiculously powerful. It could, according to its manual, fry an egg in only 12 seconds. But it was also the size of a refrigerator, stood almost six feet tall, weighed over 700 pounds (320 kilograms), and cost $3,000.