Rayleigh scattering

views updated

Rayleigh scattering The scattering of electromagnetic radiation by spherical particles with radii that are less than 10% that of the wavelength of the incident radiation. Such scattering by air molecules produces the blue effect of the sky. Particles such as dust and smoke, that are significantly smaller than 0.4 μm (the wavelength of the blue/violet or lower limit of the visible spectrum) can also scatter visible radiation. Reddish colours at sunset and sunrise result from Rayleigh scattering; these longer wavelengths pass directly through the atmosphere to the observer, while particles in the air scatter out radiation of shorter wavelengths. See also MIE SCATTERING.

More From encyclopedia.com