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 ?
Among the experiments themselves are to determine the wavelength of monochromatic light (sodium light) by Newton's ring, to determine the specific rotation of cane sugar solutions using half-shade polarimeter, to verify Stefan's Law by electric method using a vacuum diode, to determine the energy band gap of a given extrinsic semi-conductor material by thermal variation using a four probe method, and to determine the coefficient of viscosity of a water by Meyer's disc method.
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].
We have the famous Newton's laws of motion, Heisenberg's uncertainty principle, Stefan's law, Bragg's law, Hund's rule, Mossbauer effect to name but a few.
He studied hot bodies over a considerable range of temperature and, in 1879, was able to show that the total radiation of a body was proportional to the fourth power of its absolute temperature (Stefan's law).
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].
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].