Niels Bohr
Danish physicist who received the 1922 Nobel Prize in Physics and founded the Niels Bohr Institute.
Niels Henrik David Bohr was a Danish theoretical physicist whose work fundamentally reshaped the understanding of atomic structure and quantum theory. Born in Copenhagen in 1885, he was the son of a physiology professor and a banker’s daughter, and he grew up alongside a sister who became a teacher and a younger brother, Harald, who became a mathematician and Olympic footballer. Bohr himself was a passionate goalkeeper for the Akademisk Boldklub. He studied physics at the University of Copenhagen under Christian Christiansen, also taking courses in astronomy, mathematics, and philosophy. In 1905, he won a gold medal from the Royal Danish Academy for an experimental investigation of liquid surface tension, improving upon Lord Rayleigh’s method by accounting for viscosity and finite amplitudes. His doctoral thesis, completed in 1911, extended the electron theory of metals developed by Paul Drude and Hendrik Lorentz, though it was written in Danish and initially attracted little attention outside Scandinavia; it later contained what became known as the Bohr–Van Leeuwen theorem. After his doctorate, Bohr traveled to England on a Carlsberg Foundation fellowship, meeting J. J. Thomson at Cambridge. His most famous contribution, the Bohr model of the atom, proposed that electrons occupy discrete energy levels and revolve in stable orbits, jumping between levels. Though superseded, its core principles remain valid. He also conceived the principle of complementarity, arguing that phenomena could be analyzed in terms of contradictory properties, such as wave and particle behavior. This idea dominated his scientific and philosophical thinking. In 1920, he founded the Institute of Theoretical Physics in Copenhagen (later renamed the Niels Bohr Institute), where he mentored figures like Hans Kramers, Oskar Klein, George de Hevesy, and Werner Heisenberg. He predicted the existence of a new element, later named hafnium after Copenhagen, and the synthetic element bohrium was named in his honor. During the 1930s, he aided refugees from Nazism. After Germany occupied Denmark, he met with Heisenberg, now leading the German nuclear project. In 1943, learning of his imminent arrest, Bohr fled to Sweden, then to Britain, where he joined the Tube Alloys project and later the British mission to the Manhattan Project. After the war, he advocated for international nuclear cooperation
- died
- 18 November 1962
- field
- Theoretical physics
- nationality
- Danish
- known_for
- Bohr model of the atom, principle of complementarity, founding the Niels Bohr In
Verified Timeline
Lore & Background
He married Margrethe Nørlund in a civil ceremony at the Slagelse town hall on 1 August 1912. Margrethe was essential to his work from the beginning: in 1912, Niels wrote, 'I went to the country with my wife and we wrote a very long paper,' sharing credit with her. She transcribed and typed his dictated thoughts, a job his mother had filled before the marriage. Drafts circulated between the two many times, and she insisted he explain his ideas in language understandable to readers. According to son Hans Bohr, 'My mother was the natural and indispensable center…Her opinions were his [father's] guidelines in daily affairs.' The Bohrs had six sons; Harald died at about 10 from meningitis, and Christian drowned at 18 when a storm overtook his boat. Aage Bohr became a celebrated physicist and won the Nobel Prize. During World War II, when German physicist Werner Heisenberg came to Copenhagen in 1941 to urge Bohr to join his research for Germany, Bohr was not convinced. In 1943, the family escaped to Sweden, then to England, returning to Denmark after the war. Niels died in 1962.
Reader's Guide
Niels Bohr's significance is rooted in his foundational contributions to atomic structure and quantum theory. He won the Nobel Prize for Physics in 1922. In 1921, he founded the Institute for Theoretical Physics (now the Niels Bohr Institute) at the University of Copenhagen, where the family lived on campus. Margrethe Bohr was a welcome fixture in his work, spending time with his assistants and teammates at the Institute, and later recalling the warmth of the home when young scientists joined them. She collaborated as a sounding board, helping Niels explain concepts in 'plain language.' According to Crease, 'She was not only Bohr's constant companion, she was also his intellectual collaborator, a sounding board who helped him with his letters and essays, and to explain his ideas to himself.... she was very smart.' The play 'Copenhagen' by Michael Frayn dramatizes her role, showing how she pushed both Bohr and Heisenberg to speak about intention and motivation in plain language. After World War II, Bohr returned to Copenhagen to restore and expand his damaged Institute. He died in 1962.
Did You Know?
- Niels Bohr received the 1922 Nobel Prize in Physics, and his son Aage Bohr won the 1975 Nobel Prize in Physics.
- Bohr founded the Institute for Theoretical Physics (now the Niels Bohr Institute) at the University of Copenhagen in 1921.
- Margrethe Bohr transcribed and typed Niels's dictated thoughts, a job his mother had filled before the marriage.
- Two of the Bohrs' six sons died young: Harald at about 10 from meningitis, and Christian at 18 from drowning in a storm.
- In 1943, the Bohr family escaped to Sweden and then to England, returning to Denmark after World War II.
More in Scientists And Mathematicians 1-24
Spotted an error? Know more?
This is a living reference — every entry is fact-audited, and reader corrections feed straight into our audit queue. Suggest an edit · See this site's audit record