What Do We Know?

Electromagnetic radiation consists of alternating electric and magnetic fields originating from a source. Electromagnetic radiation is classified by its wavelength, frequency and energy. Wavelength and frequency are inversely proportional; radiation with a long wavelength will have a low frequency. However, energy is directly proportional to frequency. This means that high frequency radiation is high energy radiation.

Electromagnetic radiation is usually organized by frequency or wavelength ranges into an electromagnetic spectrum. To see the wavelengths and frequencies corresponding to the various ranges, open the Electromagnetic Spectrum Learning Tool. Move the slider bar to explore the wavelength, frequency and energy of the different colors of visible light.