4.4: The Electromagnetic Spectrum
The Electromagnetic Spectrum , or EMS , is the range of frequencies of electromagnetic radiation. Electromagnetic Radiation is a fundamental phenomenon of electromagnetism, acting as waves and as particles – photons, which move through space carrying radiant energy.
We see the Visible light portion of the EMS, wavelengths of 400 nm to 700 nm. The wavelengths longer than visible light include Radio, Microwave, and Infrared (IR) waves. Visible Light ; sometimes called ROYGBIV , includes Red, Orange, Yellow, Green, Blue, Indigo, and Violet. Visible light is a very small part of the EMS. Shorter Wavelengths than visible light include Ultraviolet (UV), X-rays, and Gamma Rays. Only radio, some IR, and visible light gets through Earth’s atmosphere.
A mnemonic to remember the EMS in correct order from the longer to shorter wavelengths is R eal M en I n V irginia U se X tra G lue.