Microwave ovens are a staple in American kitchens and a lifeline for college students, but that was not always the case. Percy Spencer developed and patented the first microwave oven after noticing that a magnetron was emitting heat-generating microwaves during an experiment with radar in 1945.
The first models were huge—about 6 feet in height and weighing more than 750 pounds. After World War II, when wartime technologies were adapted for domestic purposes, the ovens became smaller and more suitable for homes.
