Max Planck

Max Planck , 1858-1947, German physicist. Seeking to explain the experimental spectrum (distribution of electromagnetic energy according to wavelength) of black body radiation, he introduced the hypothesis (1900) that oscillating atoms absorb and emit energy only in discrete bundles (called quanta) instead of continuously, as assumed in classical physics. The success of his work and subsequent developments by Albert Einstein, Niels Bohr, Werner Heisenberg, Erwin Schrödinger, and others established the revolutionary quantum theory of modern physics, of which Planck is justly regarded as the father. In 1918, Planck received the Nobel Prize in physics for his work on black body radiation. He was professor at the Univ. of Berlin (1889-1928) and president (1930-35) of the Kaiser Wilhelm Society for the Advancement of Science, Berlin, which after World War II was reconstituted as part of the Max Planck Institutes. He was an editor of the Annalen der Physik and member of the Royal Society (London) and the American Physical Society. His name is honored in Planck's constant . English translations of his works include A Survey of Physics (1925, new ed. 1960), Introduction to Theoretical Physics (5 vol., 1932-33), Treatise on Thermodynamics (3d rev. ed. 1945), and Scientific Autobiography and Other Papers (1949).

Planck, Max Karl Ernst Ludwig (1858–1947) German theoretical physicist whose revolutionary quantum theory helped to establish modern physics. In 1900, he came to the conclusion that the frequency distribution of black body radiation could only be accounted for if the radiation was emitted in separate ‘packets’ called quanta, rather than continuously. His equation, relating the energy of a quantum to its frequency, is the basis of quantum theory. Planck's constant is a universal constant (symbol h) of value 6.626 × 10⁻³⁴ joule seconds, equal to the energy of a quantum of electromagnetic radiation divided by the radiation frequency. Planck received the 1918 Nobel Prize in physics.