Max Planck initiated the study of quantum mechanics when he announced in 1900 his theoretical research into radiation and absorbsion of a black body. Planck studied at the University of Munich and then at Berlin where his teachers included Helmholtz and Kirchhoff. He returned to Munich and received his doctorate at the age of 21. In 1885 Planck was appointed to a chair in Kiel and, after the death of Kirchhoff, Planck succeeded him in Berlin. While in Berlin Planck did his most brilliant work and delivered outstanding lectures. He studied thermodynamics in particular examining the distribution of energy according to wavelength. By combining the formulas of Wien and Rayleigh, Planck announced in 1900 a formula now known as Planck's radiation formula. Within two months he made a complete theoretical deduction of his formula renouncing classical physics and introducing the quanta of energy. At first the theory met resistance but due to the successful work of Niels Bohr in 1913 calculating positions of spectral lines using the theory, it became generally accepted. Planck took little part in the development of quantum theory, this being left to Paul Dirac and others. Planck took on administrative duties such as Secretary of the Mathematics and Natural Science Section of the Prussian Academy of Sciences. He received the Nobel Prize for Physics in 1918. Planck remained in Germany during World War II and his son Erwin was executed for plotting to assassinate Hitler.