Who Invented the Microwave

With all the technological advancements we are accustomed to in this day and age, it is sometimes easy to forget where certain inventions come from. It’s easy to get caught up in modern life and not appreciate the origins of human civilizations technological achievements. One such appliance that we often take for granted is the microwave oven. It’s hard to imagine a time without the microwave, but in the not-so-distant past, the microwave oven was still in its infancy; in fact, microwave energy was only discovered to have the ability to cook food within the last 65 years.

So who invented the microwave oven? Microwave energy was first found to possess the ability to cook foodstuff in 1946. This discovery was actually stumbled upon by accident. Self-taught engineer Percy Spencer was doing some radar related research for the Raytheon Corporation when he made an unusual discovery. Spencer was performing tests on a new vacuum tube known as the magnetron when, to his great surprise he discovered that the candy bar tucked away in his pocket had melted. Intrigued by this discovery, Spencer scattered some popcorn kernels close to the magnetron tube; to his delight the kernels popped all over his laboratory. The next day Spencer continued his experiments by testing the effects the magnetron had on an egg. The egg’s internal temperature rapidly climbed until a spurt of hot yolk exploded from it’s quaking shell. From there forward, more experiments began. This was known as the “Speedie Weenie” project.


Dr. Spencer eventually designed a metal box with an opening in which to feed microwave power; inside the box, the energy was unable to escape, which created a higher density electromagnetic field. When food was placed inside this box and exposed to the microwave energy, the food cooked rapidly . This ultimately revolutionized cooking, as well as the microwave oven.

The very first microwave oven made its debut in 1947. The ovens stood at a total of five and a half feet tall and weighing 750 lbs. The first generation of microwave ovens cost nearly $5000 to own, and the magnetron tube required water-cooling, which involved the installation of plumbing. The microwave didn’t do well at all originally, until some improvements were made to the magnetron’s cooling system. Once an air-cooling system was developed and plumbing was no longer necessary, the microwave started to pick up in popularity.

Over the next three decades, microwave ovens, much like the garage doors, became more widely accepted. By 1975 sales of the microwave had surpassed those of gas range ovens. The following year the microwave became a more common household appliance than the dishwasher. As the pace of every day life increased, so did the need for a quick and energy efficient way to cook our meals.

By the 21st century, it’s safe to say that just about every home in America includes a microwave oven. The contemporary microwave is definitely a far cry from the “Speedie Weenie,” although it couldn’t have existed without Percy Spencer’s initial discovery that microwave energy heats food quickly!

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