Microwaves

Microwaves are part of the electromagnetic spectrum


The microwaves region of the electromagnetic spectrum stretches from wavelengths of about 1 mm to around 50 cm. All materials absorb microwaves by different amounts and this absorption is important in some of the uses of microwaves.

Microwaves have a number of uses:

(a) microwaves ovens for cooking food
(b) in communication - the signals transmitted and received by your mobile phone are carried by microwaves
(c) for detecting water - satellites are used to study rain and clouds by measuring the amount of microwaves emitted by transmitters on Earth that is absorbed by water vapour in the atmosphere.
(d) in radar such as the radar speed cameras or by aircraft and ships
(e) by astronomers using radio telescopes – the wavelength emitted by the huge clouds of hydrogen in the galaxy is about 21 cm – right in the middle of the microwave region of the spectrum

See also:
Electromagnetic spectrum
Microwave ovens
Mobile phones