How a melted candy bar led to the microwave oven

In 1945, Percy Spencer, an engineer at Raytheon, discovered an unusual phenomenon while working with radar equipment. He noticed a candy bar in his pocket had melted, leading him to suspect the cause might be the magnetron, a key component in radar technology that produced microwave energy. Intrigued by this unexpected result, Spencer conducted further tests.

He placed popcorn kernels near the equipment, which caused them to heat up and pop, confirming his theory that microwave energy could indeed heat food rapidly. To test his hypothesis further, Spencer exposed an egg to the microwave energy, causing pressure to build up until the egg exploded. These experiments demonstrated that microwave energy had the potential to heat food quickly and efficiently.

The discovery was connected to the broader development of radar technology during World War II, as magnetrons were essential for generating high-frequency radio waves used in radar systems to detect objects. Recognizing the significance of his accidental find, Spencer designed experiments to understand the effect better. Raytheon then set about developing a practical application for this discovery.

The first commercial microwave oven, called the Radarange, was unveiled in 1947 and was an enormous, cumbersome appliance weighing hundreds of pounds. Due to its size and high cost, early microwaves were primarily used in commercial settings rather than households. Over time, engineers worked to make microwave ovens smaller, more affordable, and easier to use.

The introduction of countertop models in the 1960s, such as the Amana Radarange priced at $495, brought microwave technology closer to home kitchens. Despite its initial high price, the microwave oven gradually became a staple appliance in homes worldwide for reheating leftovers, cooking frozen meals, and making quick snacks.