The same year that saw the invention of the atomic bomb also gave the world another hot device: the microwave oven. The principle behind microwave cooking was discovered by Percy Spencer, an engineer who worked for defense contractor Raytheon. After noticing a chocolate bar melted after accidentally being placed in front of a new “magnetron” vacuum tube, Spencer experimented with other foods, including popcorn (yes!) and an egg (not exactly). After these experiments, Spencer deduced that the food was being heated by low-density microwave energy that could penetrate solid objects. By October of 1946, Raytheon had filed a patent for a microwave based on Spencer’s idea.
The first oven intended for commercial sale in 1947 was almost six feet tall, tipped the scale at 750 pounds and cost $5,000 in 1947 dollars. The second version, produced in 1954, was better but still needed work: it gobbled electricity and cost $2,000– $3,000, at a time when the average cost of a new car was about $1,700. Figuring a home appliance manufacturer might have better luck than a defense contractor, Raytheon licensed the design to the Tappan Stove Company in 1952, but at $1,295, Tappan’s 1955 model still fell flatter than a microwave soufflé.
The food service industry was quicker on the uptake. Microwaves allowed the new generation of fast-food restaurants to thaw, cook, and sell large amounts of perishable food quickly, without violating health codes. Before long, manufacturers were employing microwaves to roast coffee beans, nuts, and potato chips. Factories even started using the ovens to treat non-food items like leather, tobacco, and cotton cloth. Regular households didn't care much about microwaves until 1967, when a relatively low-energy model costing just $500 came out.
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