The microwave was invented by accident, thanks to a melted candy bar.
The history of technology is filled with happy accidents. Penicillin, Popsicles, and Velcro? All accidents. But perhaps the scientific stroke of luck that most influences our day-to-day domestic life is the invention of the microwave oven. Today, 90% of American homes have a microwave, according to the U.S. Bureau of Labor Statistics, but before World War II, no such device — or even an inkling of one — existed.
During the war, Allied forces gained a significant tactical advantage by deploying the world’s first true radar system. The success of this system increased research into microwaves and the magnetrons (a type of electron tube) that generate them. One day circa 1946, Percy Spencer, an engineer and all-around magnetron expert, was working at the aerospace and defense company Raytheon when he stepped in front of an active radar set. To his surprise, microwaves produced from the radar melted a chocolate bar (or by some accounts, a peanut cluster bar) in his pocket. After getting over his shock — and presumably cleaning up — and then conducting a few more experiments using eggs and popcorn kernels, Spencer realized that microwaves could be used to cook a variety of foods. Raytheon patented the invention a short time later, and by 1947, the company had released its first microwave. It took decades for the technology to improve, and prices to drop, before microwaves were affordable for the average consumer, but soon enough they grew into one of the most ubiquitous appliances in today’s kitchens.
In 1964 at Bell Labs outside Holmdel, New Jersey, radio astronomers Arno Penzias and Robert Wilson were frustrated with their antenna. The sensitive equipment was picking up a persistent buzzing noise that the pair first thought might be coming from the machine itself, nearby New York City, or even pigeons nesting in the antenna. However, once every explanation appeared to be accounted for, the two astronomers still detected the hum no matter where they pointed the antenna in the sky. After speaking with astronomers at Princeton University, the duo realized that they had actually detected the cosmic microwave background, which is leftover radiation from the Big Bang and evidence for the very beginning of the universe some 13.8 billion years ago. Fourteen years later, Penzias and Wilson were awarded the Nobel Prize in physics for their groundbreaking — and serendipitous — discovery.
