On October 8, 1945, Raytheon Manufacturing Company filed a patent for what’s now a staple kitchen appliance in homes around the world: the microwave oven. The appliance, invented by Raytheon employee Percy Spencer, now sits in more than 90 percent of American homes.
Spencer, who dropped out of grammar school at the age of 12 to work at a weaving mill, joined the U.S. Navy at the age of 18 as a radio operator. While in his post, he self-studied various subjects: trigonometry, calculus, physics and more.
After World War I, he was honorably discharged and landed a job at the Raytheon Company, a U.S. defense manufacturer, with the knowledge he learned while on duty. There, he worked with his colleagues to produce equipment for radios and radars—specifically the magnetron, which emits microwaves. Spencer also led the way in developing methods to mass produce smaller magnetrons, which historically were larger and difficult to manufacture in large quantities.
