Niels Bohr

Niels Bohr ForMemRS
Bohr in 1922
Born	Niels Henrik David Bohr (1885-10-07)7 October 1885 Copenhagen, Denmark
Died	18 November 1962(1962-11-18) (aged 77) Copenhagen, Denmark
Resting place	Assistens Cemetery, Copenhagen
Alma mater	University of Copenhagen
Known for	Bohr magneton Bohr model Bohr radius Bohr–Einstein debates Bohr–Sommerfeld model Bohr–Van Leeuwen theorem Bohr–Kramers–Slater theory Complementarity Copenhagen interpretation Correspondence principle
Spouse	Margrethe Nørlund ​ (m. 1912)​
Children	6, including Aage and Ernest
Parents	Christian Bohr Ellen Adler
Awards	Nobel Prize in Physics (1922) Hughes Medal (1921) Matteucci Medal (1923) Franklin Medal(1926) ForMemRS (1926) Max Planck Medal (1930) Faraday Lectureship Prize (1930) Copley Medal (1938) Order of the Elephant (1947) Atoms for Peace Award (1957) Sonning Prize (1957)
Scientific career
Fields	Theoretical physics
Institutions	University of Cambridge Victoria University of Manchester University of Copenhagen
Thesis	Studies on the Electron Theory of Metals (1911)
Doctoral advisor	Christian Christiansen
Other academic advisors	Thorvald Thiele Harald Høffding
Doctoral students	Hendrik Kramers I. H. Usmani
Other notable students	Lev Landau
Signature

Niels Henrik David Bohr (7 October 1885 – 18 November 1962) was a Danish theoretical physicist who made foundational contributions to understanding atomic structure and quantum theory, for which he received the Nobel Prize in Physics in 1922. Bohr was also a philosopher and a promoter of scientific research.

Bohr developed the Bohr model of the atom, in which he proposed that energy levels of electrons are discrete and that the electrons revolve in stable orbits around the atomic nucleus but can jump from one energy level (or orbit) to another. Although the Bohr model has been supplanted by other models, its underlying principles remain valid. He conceived the principle of complementarity: that items could be separately analysed in terms of contradictory properties, like behaving as a wave or a stream of particles. The notion of complementarity dominated Bohr's thinking in both science and philosophy.

Bohr founded the Institute of Theoretical Physics at the University of Copenhagen, now known as the Niels Bohr Institute, which opened in 1920. Bohr mentored and collaborated with physicists including Hans Kramers, Oskar Klein, George de Hevesy, and Werner Heisenberg. He predicted the properties of a new zirconium-like element, which was named hafnium, after the Latin name for Copenhagen, where it was discovered. Later, the synthetic element bohrium was named after him.

During the 1930s, Bohr helped refugees from Nazism. After Denmark was occupied by the Germans, he met with Heisenberg, who had become the head of the German nuclear weapon project. In September 1943 word reached Bohr that he was about to be arrested by the Germans, so he fled to Sweden. From there, he was flown to Britain, where he joined the British Tube Alloys nuclear weapons project, and was part of the British mission to the Manhattan Project. After the war, Bohr called for international cooperation on nuclear energy. He was involved with the establishment of CERN and the Research Establishment Risø of the Danish Atomic Energy Commission and became the first chairman of the Nordic Institute for Theoretical Physics in 1957.