FUN FACTS ABOUT THE MICROWAVE/MICROWAVE OVEN
Who Invented Microwave Ovens?
In 1946, an engineer named Percy Spencer, who worked at the Raytheon Corporation, was experimenting with a magnetron tube (a tube which forms microwaves). His snack, a candy bar in his lab coat pocket, had melted during his experiment. This puzzled him so much, that he set up an experiment. This time he put some popcorn kernels near the magnetron tube and ran to the other side of the room. Soon, all of the kernels had exploded and the entire lab was popping with corn! Spencer was placing an egg near the microwaves, when a curious colleague came in to see what he was up to. They both watched as the egg shook and trembled. When the colleague went in for a closer look, hot egg yolk splattered all over his face. It then came to Spencer: If microwaves melt chocolate, pop popcorn, and explode an egg, maybe they can be used to cook other foods as well! Spencer placed a magnetron tube into a metal box, in which he placed other food items. This metal box contained and reflected the microwaves and cooked the food that was placed inside. And thus, the first microwave oven was created.
HOW DO MICROWAVES HEAT UP FOOD?
．Microwaves are a type of radio waves.
．The most commonly used radio wave frequency is about 2,500 megahertz (2.5 gigahertz).
．Radio waves in this frequency range are absorbed by water, fats and sugars. When they are absorbed they are converted directly heat
．Microwaves in this frequency range are not absorbed by plastics, glass or ceramics.
．Metal reflects microwaves, which is why metal pans should never go into the microwave oven.
．Microwave heating works by heating the water molecules in foods.
．The frequency used in microwave ovens optimally heats water molecules.
．The microwave energy is converted into heat energy of the water molecules, which in turn heat the other molecules in the food.
．That’s why dry foods such as rice and pasta will not cook in a microwave unless they sit in some water.
USES OF MICROWAVES
Microwave lengths can be used in many ways. Here are some of them:
- Detecting the speed of cars and motorcycles
- Drying and Curing plywood
- Sending telephone messages
- Treating muscle aches
- Broadcasting TV
- Curing resins and rubber
- Raising bread and donuts
- Cooking potato chips