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The Electromagnetic Spectrum header graphic.

Electromagnetic Waves have different wavelengths
When you listen to the radio, watch TV, or cook dinner in a microwave oven, you are using electromagnetic waves.
A television with antennae.
Radio waves, television waves, and microwaves are all types of electromagnetic waves. They differ from each other in wavelength. Wavelength is the distance between one wave crest to the next.

Diagram showing the top of a wave is a crest, the 
bottom is a trough.

Waves in the electromagnetic spectrum vary in size from very long radio waves the size of buildings, to very short gamma-rays smaller than the size of the nucleus of an atom.

Diagram of the electromagnetic spectrum showing the relationship of wavelengths from radio to gamma waves.

Did you know that electromagnetic waves can not only be described by their wavelength, but also by their energy and frequency? All three of these things are related to each other mathematically. This means that it is correct to talk about the energy of an X-ray or the wavelength of a microwave or the frequency of a radio wave. The electromagnetic spectrum includes, from longest wavelength to shortest: radio waves, microwaves, infrared, optical, ultraviolet, X-rays, and gamma-rays.


To tour the electromagnetic spectrum, follow the links below!

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NASA Official: Ruth Netting
Last Updated: March 27, 2007
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