(1858-1947) German physicist who framed the quantum theory 1900. His research into the manner in which heated bodies radiate energy led him to report that energy is emitted only in indivisible amounts, called “quanta”, the magnitudes of which are proportional to the frequency of the radiation. His discovery ran counter to classical physics and is held to have marked the commencement of the modern science. Nobel Prize for Physics 1918.
Planck was born in Kiel and studied at Munich. He became professor at Kiel 1885, but moved 1888 to Berlin as director of the newly founded Institute for Theoretical Physics. He was also professor of physics at Berlin 1892–1926. Appointed president of the Kaiser Wilhelm Institute 1930, he resigned 1937 in protest at the Nazis' treatment of Jewish scientists. In 1945, after World War II, the institute was renamed the Max Planck Institute and moved to Göttingen. Planck was reappointed its president.
Planck's idea that energy must consist of indivisible particles, not waves, was revolutionary. But an explanation for photoelectricity was provided by Albert Einstein in 1905 using Planck's quantum theory, and in 1913 Danish physicist Niels Bohr successfully applied the quantum theory to the atom.