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Wien's displacement law
Wien's displacement law The relation between the wavelength of peak emission from a black body and its temperature. At low temperatures black-body radiation is confined mainly to the infrared region of the spectrum, but at progressively higher temperatures the peak of the emission is displaced to progressively shorter wavelengths. According to the law, the wavelength of peak emission, λmax, multiplied by T, the thermodynamic temperature of the body, is a constant. Although celestial bodies are not perfect black bodies, the displacement law is still useful for predicting the wavelengths near which most of their radiation is emitted. For example, the cosmic background radiation has T = 2.7 K and λmax = 1 mm; a cool, red star has T = 3000 K and λmax = 1 μm (in the infrared); the Sun, T = 6000 K and λmax = 500 nm (visible); the hottest normal stars, T = 30 000 K and λmax = 100 nm (ultraviolet); planetary nebula nuclei T = 100 000 K and λmax = 30 nm (extreme ultraviolet). The law is named after the German physicist Wilhelm Wien (1864–1928).
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"Wien's displacement law." A Dictionary of Astronomy. 1997. Encyclopedia.com. 1 Jun. 2012 <http://www.encyclopedia.com>. "Wien's displacement law." A Dictionary of Astronomy. 1997. Encyclopedia.com. (June 1, 2012). http://www.encyclopedia.com/doc/1O80-Wiensdisplacementlaw.html "Wien's displacement law." A Dictionary of Astronomy. 1997. Retrieved June 01, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O80-Wiensdisplacementlaw.html |
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Wilhelm Wien
Wilhelm Wien , 1864–1928, German physicist. He was professor at the universities of Giessen (1899), Würzburg (1900–1920), and Munich (from 1920). He received the 1911 Nobel Prize in Physics for his studies on the radiation of heat from black objects. He is noted also for his work on hydrodynamics, X rays, and the radiation of light. |
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"Wilhelm Wien." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. 1 Jun. 2012 <http://www.encyclopedia.com>. "Wilhelm Wien." The Columbia Encyclopedia, 6th ed.. 2011. Encyclopedia.com. (June 1, 2012). http://www.encyclopedia.com/doc/1E1-Wien-Wil.html "Wilhelm Wien." The Columbia Encyclopedia, 6th ed.. 2011. Retrieved June 01, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1E1-Wien-Wil.html |
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Wien's displacement law
Wien's displacement law The law which states that the wavelength of electromagnetic radiation emitted by a material is inversely proportional to the absolute temperature of that material. As the absolute temperature increases, the wavelength of emitted radiation becomes shorter.
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AILSA ALLABY and MICHAEL ALLABY. "Wien's displacement law." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. 1 Jun. 2012 <http://www.encyclopedia.com>. AILSA ALLABY and MICHAEL ALLABY. "Wien's displacement law." A Dictionary of Earth Sciences. 1999. Encyclopedia.com. (June 1, 2012). http://www.encyclopedia.com/doc/1O13-Wiensdisplacementlaw.html AILSA ALLABY and MICHAEL ALLABY. "Wien's displacement law." A Dictionary of Earth Sciences. 1999. Retrieved June 01, 2012 from Encyclopedia.com: http://www.encyclopedia.com/doc/1O13-Wiensdisplacementlaw.html |
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