Who discovers how to cook food in a microwave?

It's not a single person who "discovered" how to cook food in a microwave, but rather a series of innovations and discoveries by several people. Here's a simplified timeline:

* 1890s: Percy Spencer, an engineer working for Raytheon, noticed a candy bar melted in his pocket while working near a magnetron (a vacuum tube that produces microwaves). This is considered the "Eureka!" moment in the history of microwave ovens.

* 1947: The first microwave oven was built by Raytheon. It was massive, weighing around 750 pounds and standing 5.5 feet tall. It was not intended for the home but for industrial purposes.

* 1950s: Smaller and more user-friendly versions were developed. The first microwave oven for home use was marketed in 1955.

* 1960s-1970s: Microwave ovens became more affordable and accessible to the public. The introduction of the "turntable" was a major development, ensuring even heating of food.

So, while Spencer's observation was key, the development of the microwave oven was a collaborative effort involving numerous engineers and scientists over many years.