Stefan's law

British  

/ ˈstɛfənz /

noun

1. Also called: Stefan-Boltzmann law.  the principle that the energy radiated per second by unit area of a black body at thermodynamic temperature T is directly proportional to T ⁴ . The constant of proportionality is the Stefan constant, equal to 5.670400 × 10 ^–8 Wm ^–2 K ^–4

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Etymology

Origin of Stefan's law

C19: named after Josef Stefan (1835–93), Austrian physicist

Example Sentences

So far as the experimental results available at that time were concerned, Stefan’s law could be regarded only as an empirical expression of doubtful significance.

From Project Gutenberg

This result is usually known as Stefan's Law.

From Project Gutenberg

According to Stefan’s Law, the radiation varies for a perfect radiator with the 4th power of the absolute temperature; so that if Mars were at 124° abs., while the Earth were at 289° abs., the Earth would be radiating its heat nearly 30 times faster than Mars.

From Project Gutenberg

Then by applying Stefan's law, that the radiation is as the 4th power of the surface temperature, he reaches the final result that the actual heating power at the surface of Mars is considerably more than on the Earth, and would produce a mean temperature of 72° F., if it were not for the greater conservative or blanketing power of our denser and more water-laden atmosphere.

From Project Gutenberg

This however is the amount of radiation measured by the Bolometer, and to get the temperature of the radiating surface we must apply Stefan's law of the 4th power.

From Project Gutenberg