Niels Bohr (1885-1962)

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    Early Years

    Niels Bohr (Niels Henrik David Bohr) was born on October 7th, 1885 in Copenhagen, Denmark. Bohr enrolled in the University of Copenhagen in 1903 to study Physics. He received his doctorate degree, eight years later, in 1911. His dissertation was on the electron theory of metals (Aaserud).
  • Bohr's Atomic Model

    In 1913, Bohr developed his own atomic model. Bohr's Atomic Model depicts the atom as a small, positive nucleus surrounded by negative electrons that travel in orbits around the nucleus, with electromagnetic forces providing attraction. He proposed that an electron could drop from a higher energy orbit to a lower one, emitting a photon of discrete energy ("Niels Bohr").
  • Copenhagen Interpretation

    During 1926-1927, Niels Bohr (now a professor at The University of Copenhagen) and his assistant Werner Heisenberg, developed what is known as the Copenhagen Interpretation of Quantum Theory. They stated that reality could only be ascribed a measurement & that quantum effects themselves were essentially characterized by indeterminacy. This interpretation was composed of Bohr's Complementarity Principle and Heisenberg's Uncertainty Principle (Aaserud).
  • Complementarity Principle

    Along with Heisenberg's Uncertainty Principle, Bohr's Complementarity Principle is a fundamental part of the Copenhagen Interpretation. This principle was first presented in a lecture in 1927 at a conference in Como, Italy. It states, "that a complete knowledge of phenomena on atomic dimensions requires a description of both wave and particle properties" (Britannica 1998). Watch Video
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    Later Years

    In 1939, Bohr developed his "liquid-drop" model of the atomic nucleus and became President of the Royal Danish Academy (and served as president until his death). During this time, he was awarded the Order of the Elephant by the Danish government in 1947, and wrote his "Open Letter" to the UN in 1950 regarding the peaceful-only use of nuclear energy. Bohr died on November 18, 1962 (age 77) in Copenhagen. ("Niels Bohr").