Visible Light in the Electromagnetic Spectrum

Features

• The electromagnetic spectrum is made up of more than just visible light waves. Radio waves, microwaves and infrared waves make up the lower end of the electromagnetic spectrum, followed by visible light. Ultraviolet rays, x-rays and gamma rays make up the higher end of the spectrum.

Speed

• The speed of light is determined by its frequency multiplied by its wavelength. In a vacuum, visible light travels at a rate of about 86,282 miles per second.

Range

• The frequency of visible light ranges from 4.3 times 10 to the 14th power, to 7.5 times 10 to the 14th power. The wavelength of visible light is so small it is usually expressed in nanometers, ranging from 700nm to 400nm.

Types

• The spectral colors of visible light are red, orange, yellow, green, blue, indigo and violet. (̶0;Roy G. Biv̶1; is a popular mnemonic for remembering this sequence.) Red has the longest wavelength and lowest frequency, and violet has the shortest wavelength and highest frequency.

Characteristics

• Hue, saturation and brightness are the three attributes that define colors. Hue refers to the wavelength of the spectral color. Saturation relates to how many wavelengths (modes of spectral color) combine to make up a color. A color comprised of only one wavelength is considered fully saturated. Brightness refers to the luminosity of the color.

Fun Fact

• Hot objects emit more light with short wavelengths. Cold objects emit more light with longer wavelengths. Astronomers use this correlation between light and temperature to help them analyze stellar bodies.