German physicist Max Planck (1858-1947). Planck pioneered quantum mechanics, revolutionizing classical physics. His 1900 paper describing black body radiation proposed that radiation must be emitted or received in energy packets (quanta), rather than continuously. Quantum theory was fully accepted after its successful prediction of the photoelectric effect (Einstein, 1905) and of the electronic structure of atoms (Bohr, 1913). Planck received the 1918 Nobel Prize for Physics for his work.
