The Microwave Oven
Percy Spencer invented the microwave oven, which uses a type of radiation to warm food quickly and efficiently. People now use the device on a daily basis to heat foods ranging from popcorn to frozen dinners. One this day in 1945, the patent application for the microwave cooking process was filed.
The first half of the twentieth century become synonymous with large-scale war and scientific innovation, the combination of which led to the development of many technologies including the introduction of radar. In a deal between British and American researchers, the cavity magnetron was developed into a viable radar system, and by 1941 magnetrons for radar systems were being manufactured at a rate of 17 per day at Raytheon. It was during this time that a researcher at Raytheon, Percy Lebaron Spencer, made two important discoveries.
Firstly, he was awarded the Distinguished Public Service Award by the US Navy for significantly improving the manufacturing process of magnetrons and increasing production more than 100-fold. Secondly, perhaps more famously, in 1945 while standing in front of an open magnetron he noticed that a chocolate bar had melted in his pocket. After several other ‘‘tests’’ including popping popcorn and exploding eggs he concluded that microwave radiation could be tailored for use in cooking devices and hence the invention of the microwave oven.
By 1947 the first commercial microwave oven had been manufactured by Raytheon, although during the first few years of commercialization these ovens stood at nearly 6 feet tall and weighed over 700 pounds. By the 1970s microwave ovens had become much more accommodating for household use, and by 1975 the sales of microwave ovens started to exceed those of gas oven ranges in the USA.
Excerpted with permission, Royal Society of Chemistry.