An Etymological Dictionary of Astronomy and Astrophysics

The wavelength corresponding to the maximum emissive power of a black body is inversely proportional to the absolute temperature of the body: λ_max.T = 0.29 cm-deg. Wien’s law explains why objects of different temperature emit spectra that peak at different wavelengths. Hotter objects emit most of their radiation at shorter wavelengths; hence they will appear to be bluer. Wien’s law was an early attempt to describe the → blackbody radiation.
The law closely approximated the true shape of the blackbody spectrum at short wavelengths, but ultimately failed because it relied solely on classical physics. It was superseded by → Planck’s radiation law, which correctly describes the blackbody spectrum at all wavelengths.

See also: After the German physicist Wilhelm Wien (1864-1928), who found the law in 1896. He was awarded the 1911 Nobel Prize in physics; → displacement; → law.