Microwaves – A Brief Introduction
A comedian once commented that we live in an age in which we stand in
front of the microwave oven and wish it would hurry up. We get so used
to our modern appliances that we forget what it was like before we had
them. In fact, a lot of people living now weren't even alive when the
household use of microwaves became common.
In fact, while the microwave oven was first invented in the 1940s (by
Percy Spencer while he was working for Raytheon, a radar company which
got a United States patent on the microwave) the first commercial and
home versions of the microwave were introduced to the market in the mid
1950s. However, they were very cost prohibitive and it wasn't until the
late 60s until more focus was put on home kitchen units - or electronic
ovens as they were called then. They were still pricey for that time;
around $500. In the 70s as production became more efficient, prices
started falling and more people began to buy them. In the mid 80s about
a quarter of the households had them, and today it is reported that 90
percent of homes have them.
INTERESTING FACT: While working on a different project, Percy Spencer
accidentally discovered that microwaves would cook food (a candy bar he
had in his pocket), and the first food he ever cooked in his invention
was popcorn.
The way a microwave oven works is by dielectric heating, a process that
heats moisture and polarised molecules (molecules repelling each other's
electrons) exciting and causing movement by the molecules in the food.
In most cases this will cause a very uniform heating of the food. You
cannot bake in a microwave, and they do not brown food like a regular
oven so are not the best form of cooking for all foods. However, these
days you can buy accessories that will help you to brown foods or keep
them crispy, such as a browning tray. Many prepackaged foods contain
their own trays, browning or crisping devices.
Just the terms microwave, radar, etc., set off some panic for many
people many years ago, and they refused to use these ovens. It was
thought by some that the cooked food would contain radiation, and it was
thought by some that a microwave oven could leak radiation. After years
of research most sources report and believe there is no danger to eating
food cooked in a microwave. However, some authorities recommend that you
check or replace an older microwave oven because the seals on the door
could wear out. It has not been declared a definitive danger, but a
recommendation.
But there are still people that refuse to use them, in spite of the fact
that studies on laboratory rats show no evidence of cancer risk due to
eating the food or from leakage from the microwave. On the other hand,
there are often signs at the entrance to convenience stores that warn
there are microwaves in use and they may affect a pacemaker. If you wear
a pacemaker, you should get your doctor’s advice on this.
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