A microwave oven functions by releasing micro-waves of energy, producing electromagnetic radiation as converted from electricity. These micro-waves agitate molecules of water, fats and sugars, causing them to move more quickly, and thereby transferring that energy into the whole of the food and raising its temperature. Water is a much lighter molecule than any fat or sugar, and it has much more motile electrons, meaning it responds more readily and rapidly to heating in a microwave oven. You may have noticed this if heating an equal volume of water versus coconut oil. (Butter actually contains some water, which is why it will heat up faster than pure oil.)
The term microwave can be misleading. It is called a microwave because its wavelength is smaller than radio waves. However, it is on the opposite end of the electromagnetic spectrum from the high frequency, short waves that are damaging such as x rays or gamma rays. Originally, the device which produces the microwaves, a magnetron, was invented by the British government for defense purposes. It was given to the United States after they entered World War II in exchange for their assistance. The technology was distributed to several American companies, and in 1945, Percy Spencer began experimenting with the device as a method to cook food. It was patented by October of that same year, and commercial sales of the device began in 1947. Its original price tag was $5,000 – that’s over $50,000 in today’s money, accounting for inflation. Prices fell over the next couple decades, owing largely to an innovation from the Litton company in the ‘60s that changed the configuration of the microwave oven, also leading to today’s recognizable silhouette.
Today, microwave ovens are safer and more effective than ever, with high power microwaves able to boil a cup of water in just one minute. Their convenience with respect to cooking time has made them a staple in household and modern living – even many restaurants use microwaves to warm your food before serving it. So, what should we know about how they treat our food?