Microwaves
What Are They?
Microwaves are a portion or "band" found at the higher frequency end of the radio spectrum, but they are commonly distinguished from radio waves because of the technologies used to access them. Different wavelengths of microwaves provide different information to scientists. Medium-length microwaves penetrate through clouds, dust, smoke, snow, and rain to reveal the Earth's surface. L-band microwaves, like those used by a Global Positioning System (GPS) receiver in your car, can also penetrate the canopy cover of forests to measure the soil moisture of rain forests. Most communication satellites use C-, X-, and Ku-bands to send signals to a ground station.
How They're Made
Microwaves are basically extremely high frequency radio waves, and are made by various types of transmitter. In a mobile phone, they're made by a transmitter chip and an antenna, in a microwave oven they're made by a "magnetron". Their wavelength is usually a couple of centimetres. Stars also give off microwaves.
Uses
Microwaves cause water and fat molecules to vibrate, which makes the substances hot, which means we can use microwaves to cook many types of food. Mobile phones use microwaves because they can be generated by a small antenna, which means that the phone doesn't need to be very big.
Microwaves are also used by fixed traffic speed cameras, and for radar, which is used by aircraft, ships and weather forcasters. The most common type of radar works by sending out bursts of microwaves, detecting the "echoes" coming back from the objects they hit, and using the time it takes for the echoes to come back to work out how far away the object is. Microwaves that penetrate haze, light rain and snow, clouds, and smoke are beneficial for satellite communication and studying the Earth from space.
Dangers
Prolonged exposure to microwaves is known to cause cataracts in your eyes, which is a clouding of the lens, preventing you from seeing clearly. Recent research indicates that microwaves from mobile phones can affect parts of your brain. Other research is inconclusive, although there is a feeling that you're more vulnerable if you're young and your brain is still growing.
Future Possibilities
In the future, microwaves will be able to be used in landing systems for airplanes, and for the use of global navigation satellites.
Microwaves are a portion or "band" found at the higher frequency end of the radio spectrum, but they are commonly distinguished from radio waves because of the technologies used to access them. Different wavelengths of microwaves provide different information to scientists. Medium-length microwaves penetrate through clouds, dust, smoke, snow, and rain to reveal the Earth's surface. L-band microwaves, like those used by a Global Positioning System (GPS) receiver in your car, can also penetrate the canopy cover of forests to measure the soil moisture of rain forests. Most communication satellites use C-, X-, and Ku-bands to send signals to a ground station.
How They're Made
Microwaves are basically extremely high frequency radio waves, and are made by various types of transmitter. In a mobile phone, they're made by a transmitter chip and an antenna, in a microwave oven they're made by a "magnetron". Their wavelength is usually a couple of centimetres. Stars also give off microwaves.
Uses
Microwaves cause water and fat molecules to vibrate, which makes the substances hot, which means we can use microwaves to cook many types of food. Mobile phones use microwaves because they can be generated by a small antenna, which means that the phone doesn't need to be very big.
Microwaves are also used by fixed traffic speed cameras, and for radar, which is used by aircraft, ships and weather forcasters. The most common type of radar works by sending out bursts of microwaves, detecting the "echoes" coming back from the objects they hit, and using the time it takes for the echoes to come back to work out how far away the object is. Microwaves that penetrate haze, light rain and snow, clouds, and smoke are beneficial for satellite communication and studying the Earth from space.
Dangers
Prolonged exposure to microwaves is known to cause cataracts in your eyes, which is a clouding of the lens, preventing you from seeing clearly. Recent research indicates that microwaves from mobile phones can affect parts of your brain. Other research is inconclusive, although there is a feeling that you're more vulnerable if you're young and your brain is still growing.
Future Possibilities
In the future, microwaves will be able to be used in landing systems for airplanes, and for the use of global navigation satellites.