Today in History: The Inventor of the Microwave Is Born

M.C. Millman

Today marks the birthday of Percy Spencer, the inventor of the popular kitchen appliance that sped up food preparation for us all - the iconic microwave. 

Born in Maine on July 19, 1894, Spencer was an American physicist. During his stint with the U.S. Navy, he studied radio technology. He taught himself calculus and physics from textbooks.

While working at the Raytheon Manufacturing Company, Spencer and his colleagues produced radar equipment. According to the Lemelson-MIT, they produced a high-powered vacuum tube that generated microwaves. This was used during World War II to detect enemy submarines and places. Spencer developed a system to mass-produce this machine, improving the U.S. Military's technological capabilities. As a result, he was awarded the Distinguished Public Service Award from the U.S. Navy. 

Spencer's discovery of the microwave oven can be added to the long list of life-changing inventions created by accident. According to a blog by the Library of Congress, the inventor was observing radar sets in operation when he noticed the chocolate bar in his pocket melted. When he saw this, Spencer began experimenting with various foods by pointing microwaves at them and watching them cook. He then went on to construct the first-ever microwave oven. 

Spencer submitted the first design to the U.S. Patent Office on October 8, 1945, but was only granted the patent on January 24, 1950. He named his invention Radarange. 

According to the Lemelson Center, the first microwave ovens were marketed in 1947, weighing 750 pounds and standing almost 6 feet tall. They were used exclusively in larger food establishments, like restaurants and railroad cars, to heat up or cook large amounts of food quickly. 

The first domestic microwave oven was put on the market in 1955, but it was bulky and had a hefty price tag of $1,300. The first compact microwave oven came out in 1967 and cost $495. Today, microwave ovens are found in almost every home, offering a cheap and convenient way to cook and reheat foods daily.