Stefan's law


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Stefan's law

(ˈstɛfənz)
n
(General Physics) the principle that the energy radiated per second by unit area of a black body at thermodynamic temperature T is directly proportional to T4. The constant of proportionality is the Stefan constant, equal to 5.670400 × 10–8 Wm–2 K–4. Also called: Stefan-Boltzmann law
[C19: named after Josef Stefan (1835–93), Austrian physicist]
References in periodicals archive ?
The outer cavity has a perfect emissivity ([member of] = 1) and is able to pump out additional photons, as required by Stefan's law [4].
In 1898, Scheiner brought apparent unification to the problem when he applied Stefan's law [6] to data acquired by Pouillet, Secchi, Violle, Soret, Langley, Wilson, Gray, Paschen, and Rosetti [13].
Extrapolations from Stefan's law of the proportionality of total radiation from a black body to the fourth power of the absolute temperature, are therefore not certainly applicable to the problem, even though the law has been verified through a range of some hundreds of degrees" [20].
Through this letter, I wish to highlight that the modeling of the Earth's energy balance [5,6] requires re-evaluation first of Kirchhoff's law of thermal emission [7-11] and its associated consequences for the application of Stefan's law [12], and second of the assignment of the microwave background [13,14] to the oceans of the Earth [15,16].
This is known as Stefan's law of emission ([epsilon] = [sigma][T.