Definition
Emissivity is a quantity in physics that depends on wavelength and that characterizes the efficiency with which a surface radiates, compared to a black body at the same temperature. A black surface has an emissivity close to 1 and a polished reflecting surface, an emissivity close to 0. Because of Kirchhoff’s law, the same quantity characterizes also the ability of a surface to absorb or to reflect impinging radiation. Emissivity is a positive, dimensionless quantity, lower than or equal to 1.
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© 2011 Springer-Verlag Berlin Heidelberg
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Rouan, D. (2011). Emissivity. In: Gargaud, M., et al. Encyclopedia of Astrobiology. Springer, Berlin, Heidelberg. https://doi.org/10.1007/978-3-642-11274-4_506
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DOI: https://doi.org/10.1007/978-3-642-11274-4_506
Publisher Name: Springer, Berlin, Heidelberg
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