Who Invented The Microwave?

Like many anecdotes related to technological breakthroughs, the story commonly told about the invention of the microwave is a simplified exaggeration. Legend has it that an engineer at the Raytheon Corporation named Dr. Percy Spencer was experimenting with microwave tubes when he discovered that a chocolate bar in his pocket had melted. But the real story of how the microwave oven was invented is much more interesting than that.

The rest of the story

It's true that Spencer was a Raytheon engineer involved in creating the microwave oven. But like any engineer, he didn't need a melted chocolate bar to know about the connection between heat and microwave radiation. After all, sunlight is radiation.

Spencer proposed the creation of a microwave technology-based oven in 1945 as a commercial operation for Raytheon to pursue after the lapse of their military contracts. The idea was enthusiastically received, and a team of engineers began working on a prototype microwave oven. The designer and builder of this new microwave oven was a Raytheon engineer named Marvin Bock.

"Refreshing corn popped takes 20 seconds is good."

Bock's careful experimentation with microwave heating technology is the reason why some people credit him as being the inventor of the microwave oven. The challenges were numerous: a microwave oven had to be small enough for commercial use; federal regulations prohibited Bock from using microwaves that were not either 915 or 2450 megahertz; and he had to figure out how to deal with uneven heating.

Bock's initial solution was to use a small motor to move one wall of the microwave back and forth during cooking. But this device was too expensive and caused radiation leakage. Bock's eventual answer to uneven heating was the use of hanging, rotating rods.

The notes Bock took once he moved on to cooking experiments provide a humorous insight into the engineer at work. "Refreshing corn popped takes 20 seconds is good," he wrote. And on another occasion: "Noted that chicken Fricassee took a minute and tasted good."

Eventually Bock's experimentation led to the production of the first microwave oven. It was over 5 feet tall, weighed 670 pounds, and required a 220-volt power line and separate water pipe for cooling the radar tube. Raytheon began selling their Radarange microwave oven in 1948, but microwaves would be a money-losing business until the end of the 1960s.