Microwaves are basically extremely high frequency radio waves, and are made by various types of transmitter.
Microwaves have wavelengths that can be measured in centimeters! The longer microwaves, those closer to a foot in length, are the waves which heat our food in a microwave oven.
Their wavelength is usually a couple of centimetres. Stars also give off microwaves.
Microwaves cause water and fat molecules to vibrate, which makes the substances hot.
That is why we should not put certain food substances such as eggs into microwaves as the egg shells of eggs do not contain water and fat molecules while the yolk and white contains these molecules and therefore if we put an egg into microwaves the white and yolk would expand and therefore cause the egg to explode from the inside.
Microwaves are good for transmitting information from one place to another because microwave energy can penetrate haze, light rain and snow, clouds, and smoke.
These qualities make them able to be used in speed cameras and radars
Prolonged exposure to microwaves is known to cause "cataracts" in your eyes, which is a clouding of the lens, preventing you from seeing clearly. We should also never put aluminum foil inside microwaves as . When the strong microwaves produced by a microwave oven interact with a sheet of aluminum foil, their electric fields cause the mobile electrons in the foil to accumulate at the sheet’s sharp, pointed tips. This build-up of electrons creates a strong electric field in the surrounding air.
When the electric field becomes strong enough, it causes free electrons in the air to accelerate and jar loose more electrons from gas molecules in the air, which then go on to jar even more electrons loose. This chain reaction creates an electrical charge in the air, which shows itself as sparks. Although rounded metal objects such as spoons are less likely to create sparks, the safest bet is to avoid putting any kind of metal in the microwave.
sources:http://www.darvill.clara.net/emag/emagmicro.htm
http://cfbt-us.com/wordpress/wp-content/uploads/2010/04/wavelength_lr.jpg
http://indianapublicmedia.org/amomentofscience/metal-in-the-microwave/
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