Microwave oven is invented in Cambridge.

Originally called the Radarange, it is invented by Percy Spencer at the Raytheon Corporation. The first microwave, it is 5 feet 6 inches tall and weighs 750 pounds. It was developed after Spencer noticed that a candy bar in his back pocket melted while he stood in front of a magnetron and that popcorn popped when placed near the radar device. A home model is not marketed until 1966.