His major was physics, which he studied under Professor Christian Christiansen, the university's only professor of physics at that time. In 1903, Bohr enrolled as an undergraduate at Copenhagen University. īohr was educated at Gammelholm Latin School, starting when he was seven. Niels was a passionate footballer as well, and the two brothers played several matches for the Copenhagen-based Akademisk Boldklub (Academic Football Club), with Niels as goalkeeper. Jenny became a teacher, while Harald became a mathematician and footballer who played for the Danish national team at the 1908 Summer Olympics in London. He had an elder sister, Jenny, and a younger brother Harald. Niels Henrik David Bohr was born in Copenhagen, Denmark, on 7 October 1885, the second of three children of Christian Bohr, a professor of physiology at the University of Copenhagen, and his wife Ellen née Adler, who came from a wealthy Jewish banking family. 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. After the war, Bohr called for international cooperation on nuclear energy. 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. In September 1943 word reached Bohr that he was about to be arrested by the Germans, so he fled to Sweden. After Denmark was occupied by the Germans, he met with Heisenberg, who had become the head of the German nuclear weapon project. Later, the synthetic element bohrium was named after him.ĭuring the 1930s, Bohr helped refugees from Nazism. He predicted the properties of a new zirconium-like element, which was named hafnium, after the Latin name for Copenhagen, where it was discovered. Bohr mentored and collaborated with physicists including Hans Kramers, Oskar Klein, George de Hevesy, and Werner Heisenberg. The notion of complementarity dominated Bohr's thinking in both science and philosophy.īohr founded the Institute of Theoretical Physics at the University of Copenhagen, now known as the Niels Bohr Institute, which opened in 1920. 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.

Although the Bohr model has been supplanted by other models, its underlying principles remain valid. Bohr was also a philosopher and a promoter of scientific research.īohr 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. Niels Henrik David Bohr ( Danish: 7 October 1885 – 18 November 1962) was a Danish physicist who made foundational contributions to understanding atomic structure and quantum theory, for which he received the Nobel Prize in Physics in 1922. As the photon energy of a single femtosecond pulse is raised from the threshold for two-photon double ionization at 39.5 eV to beyond the sequential ionization threshold at 54.4 eV, the electron ejection dynamics change from the highly correlated motion associated with nonsequential absorption to the much less correlated sequential ionization process.*Club domestic league appearances and goals Two-photon double ionization of the helium atom was the subject of early experiments at FLASH and will be the subject of future benchmark measurements of the associated electron angular and energy distributions.

Bohr model of helium atom