Percy Spencer was working near a magnetron in 1945 when he noticed the chocolate bar in his pocket had melted. The Raytheon engineer had been helping develop radar equipment, one of the technologies that allowed Allied forces to detect enemy aircraft and ships during World War II. The unexpected puddle of chocolate suggested that the magnetron’s microwaves could do something besides locate approaching bombers. They could also cook lunch. Spencer’s discovery eventually produced the microwave oven, one of many familiar products with roots in military operations, defense research or wartime manufacturing. Some inventions on this list were commissioned directly by armed forces. Others grew from civilian research funded by defense agencies or attempts to solve problems faced by troops. Together, these inventions changed how people travel, communicate, eat, work and repair whatever just broke in the garage.
The November 1933 cover of “Short Wave Craft” depicts a radio-wave cooking demonstration presented at the Chicago World’s Fair. Radar magnetron research during World War II later led to the practical microwave oven. (“Short Wave Craft,” November 1933/Wikimedia Commons)
1. Microwave Ovens
