Who is Niels Bohr

childhood and education:
Niels Henrik David Bohr was born on October 7, 1885 in an intellectual and liberal family in Copenhagen. He and his brother, the later mathematician Harald Bohr, were instructed early on by their father, who worked as a professor of physiology, to deal with scientific questions. The mother, Ellen Adler, was of Jewish descent. In the Bohr house, intensive discussions were always held on different subject areas, including physics. In addition to their early intellectual orientation, both sons were also very active in sports and played football at a professional level.
Niels and Harald Bohr completed their school education at a secondary school in Copenhagen with a focus on Latin, which they completed with the Abitur. After school, Niels Bohr began studying physics and mathematics at the University of Copenhagen in 1903, but also attended lectures in philosophy, chemistry and astronomy. In 1911 he received his doctorate with a dissertation on the subject of "electron theory in metals".

Professional career and academic achievements:
Even during his studies, Niels Bohr stood out for his brilliant mind and received several awards. Therefore, in the year of his doctorate, he found a job in the renowned Cavendish Laboratory at Cambridge University, where he spent a year researching under the direction of the British physicist and Nobel Prize winner Joseph John Thomson. This had already succeeded in 1897 in detecting electrons with the help of a cathode ray tube. After a year with Thomson, Niels Bohr moved to Manchester to work in the laboratory of the famous physicist Ernest Rutherford as his assistant. During this time, Niels Bohr solved a problem that Rutherford's employees had been working on for a long time before the Danish physicist's arrival. It was about experiments in the course of which Rutherford's team had found that lead atoms were lighter than those of radium, although the two elements did not differ chemically from one another. During his work as Rutherford's assistant, Niels Bohr quickly realized that the properties of the two substances were not determined by their atomic nuclei, but by the electrons. He initiated some experiments in Rutherford's laboratory, with which the electrons in the shell of the hydrogen atom could be detected. In intensive theoretical discussions with Rutherford, Niels Bohr also pointed out the applicability of the still new quantum theory formulated by Max Planck and Albert Einstein. Based on this, Niels Bohr developed the famous atomic model that was named after him over the next few years. Bohr's model of the atom about the fixed orbits of electrons around the atomic nucleus explained the spectral lines within hydrogen and became one of the most important milestones in theoretical physics at that time. Today, however, it is considered obsolete as it was later superseded by quantum mechanics.
After his discovery, he was offered a position as a lecturer in Manchester in 1914. From 1916 Niels Bohr worked as a professor of theoretical physics at the University of Copenhagen, where in 1921 he initiated the establishment of his own department, namely the Institute for Theoretical Physics. In the following years it became one of the most important international centers for atomic research and attracted many leading European physicists from the interwar period. In the twenties, Niels Bohr was also a frequent guest in Göttingen, where he gave lectures that were referred to in the professional world as the "Bohr Festival". This made him known on an international level. During his visits to Göttingen, Niels Bohr met the young German physicist Werner Heisenberg, who later moved to Copenhagen and worked closely with Bohr. In 1922, Niels Bohr was awarded the Nobel Prize in Physics for his theoretical work on atomic structure.
The intensive theoretical discussions of the two leading scientists Niels Bohr and Werner Heisenberg were called the "Copenhagen Interpretation of Quantum Physics" and led Niels Bohr to develop the principle of complementarity about the behavior of light in the form of particles and waves. In the thirties, Niels Bohr mainly dealt with nuclear physics and from 1935 developed the so-called "droplet model" of atomic nuclei, with which he provided a conclusive explanation for many nuclear processes. Shortly before the outbreak of World War II, he had developed a theory of nuclear fission based on the work of Otto Hahn and his assistant Fritz Straßmann, which later made it possible to use it technically. After the occupation of Denmark by the Nazis, the highly respected physicist was initially involved in the resistance, but was forced to leave his homeland due to his half-Jewish descent and his marriage to a Jewish woman. After escaping in a fishing boat, which first took him and his family to Sweden and Great Britain, Niels Bohr finally emigrated to the United States.
It was there in 1943 that he learned of the progress that the Allies had already made in the field of atomic research. He traveled to Los Alamos with his son Aage to take part in the final phase of the construction of the atomic bomb.
After the end of the Second World War, he resumed his work at the institute he had founded in Copenhagen and over the next few years repeatedly campaigned for the peaceful use of nuclear power, including by organizing the First International Conference in Genoa. For this he was awarded the "Atom for Peace Award" in 1957. On November 18, 1962, Niels Bohr died in Copenhagen and was laid to rest in the assistance cemetery there. In 1997 the Element 107 was officially renamed "Bohrium" in honor of Niels and Aage Bohr.

Private:
During his time as Ernest Rutherford's assistant, Nils Bohr traveled back to Copenhagen to marry Margarete Noerlund. The happy marriage with her resulted in a total of six sons. The eldest son Christian died in 1934 on a sailing excursion. In 1922, when Niels Bohr was awarded the Nobel Prize in Physics, his son Aage Niels Bohr saw the light of day. He followed in his father's footsteps and also became a well-known physicist, who in turn was honored with the Nobel Prize in 1975 for his discoveries about particle motions in atomic nuclei.
Today Niels Bohr is also held responsible for rescuing countless people of Jewish descent. After his escape from Denmark he stayed in Sweden for some time, where he was able to convince the Swedish king in a personal conversation to grant asylum to over seven thousand Jews.

His collaboration and close friendship with the German physicist Werner Heisenberg led to the establishment of quantum mechanics in the 1920s. Political developments prior to World War II divided this extremely fruitful work. While Nils Bohr was involved in the construction of the atomic bomb on the American side, Werner Heisenberg worked for the Nazis' nuclear program. This led to a break between the two scholars, which the playwright Michael Frayn dealt with in his highly successful play "Copenhagen".