Light Spectrum | ASU - Ask A Biologist

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Infrared: invisible light rays (for humans) that are beyond the red end of the visible spectrum.... more

Ultraviolet: (1) light waves at wavelengths less than those visible to humans. Also called UV light. (2) invisible light rays just below the violet end of the spectrum... more

light chart

As you can see from the illustration above, visible light is only a very small portion of all light waves. You may ask yourself why is it that we only see the "visible" portion of light? If you study the illustration above, you will see at the earth's surface almost all the wavelengths with any significant energy are visible (see the green peak). There are some very small amounts of ultraviolet and infrared wavelengths that are present. In some cases, insects and other animals have adapted to see with those wavelengths.

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