PLANCK, MAX (KARL ERNST LUDWIG)

born , April 23, 1858, Kiel, Schleswig died Oct. 4, 1947, Gttingen, W.Ger. theoretical physicist who originated quantum theory. For that achievement he was awarded the Nobel Prize for Physics in 1918. A brief account of the life and works of Max Planck follows; for a full biography, see Planck. Planckwhose forebears were scholars, lawyers, and public servantswas sent to the Maximilian Gymnasium in Munich, where he chose science as a career over his other great love, music. He went to Berlin to study with H.L.F. von Helmholtz and G.R. Kirchhoff but returned to Munich to take his doctorate in 1879 on the second law of thermodynamics. He became Privat-Dozent at the University of Munich in 1880 and extraordinary professor of theoretical physics at Kiel in 1885. Two years later he was made professor of theoretical physics at Berlin, where he lived for the rest of his life. In 1930 he had become president of the Kaiser Wilhelm Society in Berlin (after World War II, the Max Planck Society). In 1900 Planck formulated the correct mathematical description of thermal radiation from a perfect absorber (blackbody) and showed that the formulation required a discontinuous process of emission or absorption involving discrete quantities of energy. Those discoveries initiated the field of quantum physics and earned for Planck the Nobel Prize.