Microwaves Were Discovered by Accident

In the midst of World War II's technological race, the American company Raytheon was a major producer of magnetron tubes, the core component of radar systems. In 1945, a self-taught engineer named Percy Spencer was conducting tests on a new magnetron when he noticed something odd. The Peanut Cluster bar he kept in his pocket for a snack had turned into a gooey, melted mess. Unlike someone who might just be annoyed at the laundry bill, Spencer’s scientific curiosity was sparked. He immediately suspected the radar waves were responsible.

Driven by his hunch, Spencer set up a controlled experiment. He aimed the magnetron tube at a bag of popcorn kernels, which quickly began to pop all over the lab. His next test subject was an egg. A curious colleague leaned in to look at the egg as it began to tremble, only for it to explode from the rapid internal pressure, splattering hot yolk everywhere. This messy but conclusive test proved that concentrated, low-frequency microwaves could cook food far faster than a conventional oven.

Realizing the commercial potential, Raytheon patented the technology. The first microwave oven, called the "Radarange," was released in 1947. However, it was a far cry from today's countertop models. Standing nearly six feet tall, weighing over 750 pounds, and costing the equivalent of over $50,000 today, it was initially used only in restaurants, ships, and military bases. It would take another two decades of refinement before a smaller, more affordable version brought this accidental wartime discovery into kitchens around the world.