Great Idea 9

Idea 9: The quantum theory

         Quantum theory is the theoretical basis of modern physics that explains the nature and behavior of matter and energy on the atomic and subatomic level. In a pioneering act, Max Planck in 1900 presented his quantum theory to the German Physical Society. Planck explained the black body radiation by assuming that the atomic oscillators emit energy in the form of small packets called quanta of energy. Further Albert Einstein explained photoelectric effect by assuming that light consists of quanta or packets of energy called photons. The three themes of quantum theory are; the quantization of energy, the probabilistic behavior of energy quanta, and the wave–particle nature of  matter.
    The foundations of quantum mechanics were established during the first half of the 20th century by Max Planck, Niels Bohr, Werner Heisenberg, Louis de Broglie, Arthur Compton, Albert Einstein, Erwin Schrödinger, Max Born, John von Neumann, Paul Dirac, Enrico Fermi, Wolfgang Pauli, Satyendra Nath Bose, Arnold Sommerfeld, and others. The Copenhagen interpretation of Niels Bohr became widely accepted.