= Max Planck
{c}
{tag=Physicist}
{title2=1858-1947}
{wiki}
<Max Planck> introduced energy elements proportional to <frequency>, $\epsilon=h\nu$, in his statistical treatment of thermal resonators. This led to a mean resonator <energy> $\overline E=h\nu/(e^{h\nu/(k_B T)}-1)$ and the corresponding <black-body radiation> spectrum, connecting <entropy> counting with measured radiation. For $h\nu\ll k_B T$, expanding the exponential gives $\overline E\approx k_B T$; at high <frequency> the denominator suppresses the energy exponentially. The energy-element argument was a step toward <quantum theory>, without yet being the later light-quantum account of a free <photon>.<On the Law of Distribution of Energy in the Normal Spectrum by Max Planck>[1901 paper, section 10, equations (11)–(12); modern temperature notation]{ref}
A <physicist> whose work on <black-body radiation> led to <Planck's law> and the use of the <Planck constant>. He received the 1918 <Nobel Prize in Physics>.<Max Planck by Lorenz Friedrich Beck>[Biographical account: theoretical-physics appointments, radiation work, 1858 birth and 1947 death]{ref}
\Image[https://commons.wikimedia.org/wiki/Special:Redirect/file/Max%20Planck%201933.jpg?width=250]
{title=Portrait of <Max Planck>}
{description=Unknown photographer; Nationaal Archief / gahetna.nl source recorded on Commons. Public domain (anonymous historical photograph, as declared on Commons). Source and usage information on the linked Wikimedia file page.}
{source=https://commons.wikimedia.org/wiki/File:Max_Planck_1933.jpg}
{width=250}
Back to article page
