Microwaves were discovered as a cooking technology by American engineer Percy Spencer in 1945, when he accidentally noticed a candy bar melting in his pocket while working with radar equipment that emitted microwave signals.

Discovery Process

• Percy Spencer was experimenting with a magnetron—a component producing microwaves for radar—at Raytheon Corporation during World War II.

• He noticed the melting candy bar and began additional experiments with other foods, such as popcorn and eggs, establishing that microwaves could rapidly heat food.

Invention of the Microwave Oven

• Spencer quickly developed and patented the first microwave oven in 1945 by directing magnetron microwaves into a metal box to contain and safely cook food.

• The first commercial model, the “Radarange,” was introduced in 1947 and was initially quite large and expensive.

Related Technological Context

• The magnetron, an essential component for generating microwaves, was first developed in 1940 in the UK by John Randall and Harry Boot for radar detection during World War II.

• Spencer’s innovation was realizing and developing the application of this technology for cooking, leading to the modern microwave oven.

In summary, Percy Spencer is credited with discovering and inventing the use of microwaves for cooking, completely transforming kitchen technology.