50th Anniversary: Niels Bohr’s Death

Niels Bohr was born in 1885 in Copenhagen, Denmark. He studied philosophy and mathematics at the University of Copenhagen before switching to study physics. He gained his Ph.D. in physics in 1911 from the same university. He spent several years as a postdoctoral researcher in the UK, first at Cambridge University with Joseph John “J. J.” Thomson, and later at the University of Manchester with Ernest Rutherford. In 1916, Bohr was appointed to the Chair of Theoretical Physics at the University of Copenhagen, a position created especially for him. In 1920 he became head of the newly formed Institute of Theoretical Physics at the same university, both of which positions he held until his death.

In 1922, Bohr was awarded the Nobel Prize in Physics for his work on the structure in the atom. His research continued, becoming more focused on the structure of the atomic nucleus. He also made contributions to the understanding of quantum mechanics, notably with the introduction of the Copenhagen interpretation and the concept of complementarity, both of which are used to explain how the act of measurement determines the outcome of the experiment for objects governed by quantum mechanics. For example, an experiment, such as the double-slit experiment, can demonstrate the wave or particle nature of an object, but not both as measurement of one property precludes the measurement of the second in the same experiment.

In 1943, Bohr was forced to flee German-occupied Demark for America. There, he became involved in the Manhattan Project to develop atomic weapons, where he acted as a consultant. After the war, Bohr returned to Copenhagen where he spent much of his life promoting peaceful applications of atomic physics, both politically and through helping to establish international research collaborations and facilities such as CERN, Geneva, Switzerland.

Bohr died on November 18, 1962. Three years later, the Institute of Theoretical Physics at the University of Copenhagen was renamed the Niels Bohr Institute. In 1997 element 107 was officially named bohrium in recognition of Bohr’s contributions to understanding atomic structure.