Scientists Say: Wavelength

Wavelength (noun, “WAYV-lehngth”)

This is the distance between one peak and the next in a series of waves. It can also be the distance between two troughs, or the low point of each wave. A wavelength is the distance over which a wave goes through one cycle, and before it starts to repeat. Wavelength can be used to measure any phenomenon that moves in waves, from waves on the sea to waves of light or sound.

In a sentence

By analyzing wavelengths of light reflected off of the ocean, scientists have been able to identify what type of plankton are causing a red tide.

Follow Eureka! Lab on Twitter

Power Words

(for more about Power Words, click here)

plankton     Small organisms that drift or float in the sea. Depending on the species, plankton range from microscopic sizes to organisms about the size of a flea. Some are tiny animals. Others are plantlike organisms. Although individual plankton are very small, they form massive colonies, numbering in the billions. The largest animal in the world, the blue whale, lives on plankton.

wavelength     The distance between one peak and the next in a series of waves, or the distance between one trough and the next. Visible light — which, like all electromagnetic radiation, travels in waves — includes wavelengths between about 380 nanometers (violet) and about 740 nanometers (red). Radiation with wavelengths shorter than visible light includes gamma rays, X-rays and ultraviolet light. Longer-wavelength radiation includes infrared light, microwaves and radio waves.