Definition of: quantum mechanics
quantum mechanics

The branch of physics developed in the first part of the 20th century that was highly successful in explaining the behavior of atoms, molecules and nuclei. Developed between 1900 and 1930 and combined with the general and special theory of relativity, it revolutionized the field of physics. The new concepts, which were the particle properties of radiation, the wave properties of matter, quantization of physical properties and the idea that one can no longer know exactly where a single particle such as an electron is at any one instance were necessary to explain all of the new experimental evidence that was available at the time. For example, quantum mechanics explains the behavior of semiconductors which are used to make the myriad devices we use every day. See wave-particle duality and quantum state.

Following are the important contributors to the foundation of quantum mechanics and the principles they uncovered.

 Year  Researcher    Contribution

 1901  Planck        Blackbody radiation

 1905  Einstein      Photoelectric effect

 1913  Bohr          Spectra theory

 1922  Compton       Photon scattering

 1924  Pauli         Exclusion principle

 1925  de Broglie    Matter waves

 1926  Schroedinger  Wave equation

 1927  Heisenberg    Uncertainty principle

 1927  Davison &     Wave properties of
        Germer        electrons

 1927  Born          Interpretation of the

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