Microwave ovens were invented by accident by an engineer named Percy Spencer when a chocolate bar in his pocket melted while building magnetrons for radar sets in the 1940s. The microwave, which relies on radio waves to work, was theorized by James Maxwell Clark in 1864, and tested in 1886 by Henrich Hertz. Robert Watson-Watt patented radar after his 1935 high frequency radio wave experiment. Following World War II microwave frequencies began to be used for communications, and Dr. Percy Spencer’s accidental chocolate bar melting incident led to the patenting of microwave ovens by the company he worked for – Raytheon.
Microwave oven is a direct descendant of radar.
The first microwave oven that was made by Raytheon was 6 feet tall and weighed at least 750 pounds. Most people did not buy them because they cost about $5000.
The first food to be deliberately cooked with a microwave was popcorn.
By 1967 microwave ovens had come down in price and in size. They were approximately $495, but this was still expensive. At least they could fit on a counter top thanks to redesigning and improvements in technology.
The first public use of a microwave oven was in January 1947. Speedy Weeny vending machine was placed in Grand Central Terminal and it sold freshly prepared hot dogs.
The first commercial microwave oven was created in 1946, and by the mid-1990s 90% of the homes in the United States owned one.
The short, wide shape of a microwave oven, that is now common, was developed by Litton Industries in the ‘60s.
Although microwaves emit radiation (as Dr. Spencer discovered when his chocolate bar melted in his pocket), it is not dangerous or cancer-causing because the microwaves are non-ionizing. You won’t get cancer from your microwave, unlike the potential from x-rays.
The U.S. Bureau of Labor Statistics says that over 90% of American households owned a microwave oven in 1997.
Most people believe that microwaves cook from the inside out. This is not true. Similar to the way other types of heat cook food, microwaves cook from the outside inward.
Consumer ovens usually use microwaves of 2.45 gigahertz while large industrial/commercial ovens often use 915 megahertz microwaves.
When a microwave is running there are microwaves being absorbed by the food or liquid. If there is nothing in the microwave, the waves reflect between the cooking chamber and the tube, and will burn the magnetron out. Microwave cooking requires some water in the food in order to work.
A common idea that microwave ovens cook food “from the inside out” is a misconception.
Watching food cook in a microwave is not dangerous as some believe. The mesh in the glass window stops the microwaves from reaching you, and only light is able to pass through to your eyes.
The first consumer microwave was developed and manufactured in Iowa in 1967.
The microwave was designed to use a magnetron to create the microwaves that cook or heat food or liquid.
Microwave cooking was first discovered in the U.S.A in 1945.
NASA uses microwave technology for communication in deep space.
According to Energy Star, Microwave ovens use less energy (up to 80% less) than conventional ovens.
The first microwaves were cooled by water but they were later changed to be cooled by air.
Food with a high amount of water, salt, sugar or oils/fat cooks faster because of a higher rate of MW absorption.
The type of radiation that is used in microwave ovens is also used in speed cameras used by police, radar, and cell phones.
Different foods respond differently to microwaving.
Microwaves are also used for broadcasting television, treating muscle aches and pains, curing rubber, making bread rise, and curing plywood.
Steaming in the microwave is actually preferable to submerging foods in water, which can result in a loss of nutrients.
Some scientists and researchers believe that cooking food in a microwave changes it to the point that it becomes carcinogenic (cancer causing) in some cases.
According to a study by Harvard Medical School, “because microwave cooking times are shorter, cooking with a microwave does a better job of preserving vitamin C and other nutrients that break down when heated.”
Some believe that by cooking food with microwaves, nutrients such as vitamins and minerals are decreased or even destroyed.
Modern microwaves are regulated with stringent standards.
The microwave inventor Dr. Percy Spencer lived to 76 with no apparent health consequences from working around microwaves for much of his adult life.
The Slotted Choke Door Seal is the reason microwave ovens are safe and available for public and home use today.