XI Международная студенческая научная конференция Студенческий научный форум - 2019

Niels Henrik David Bohr (d. Niels Henrik David Bohr, pronunciation ; October 7, 1885, Copenhagen - November 18, 1962, ibid.) - Danish theoretical physicist and social activist, one of the founders of modern physics. Winner of the Nobel Prize in Physics (1922). Member of the Danish Royal Society (1917) and its president since 1939. He was a member of more than 20 world academies of sciences, including a foreign honorary member of the USSR Academy of Sciences (1929; corresponding member since 1924)

Niels Bohr was born in the family of Christian Bohr, professor of physiology at the University of Copenhagen (1858–1911), who twice became a candidate for the Nobel Prize in Physiology and Medicine, and Ellen Adler (1860–1930), daughter of an influential and very wealthy Jewish banker and parliamentarian. David Baruch Adler (d. David Baruch Adler; 1826–1878) and Jenny Raphael (1830–1902) from the British Jewish banking dynasty Raphael Raphael & sons. Bora's parents were married in 1881.

Youth. Bohr theorem - van Leuven (1885–1911)

To rule

At school, showed a clear tendency to physics and mathematics, as well as philosophy. This was facilitated by the regular visits of colleagues and friends of the father - the philosopher Harald Goeffding, the physicist Christian Christiansen, the linguist Wilhelm Thomsen. A close friend and classmate of Bohr in this period was his second cousin (on the maternal line), the future Gestalt psychologist Edgar Rubin (1886-1951), known in the future, among the optical illusions he proposed was the so-called Rubin vase (Eng. Rubin vase; 1915) Rubin attracted Bohr to the study of philosophy.

Bohr's other hobby was football. Niels and his brother Harald (who later became a famous mathematician) supported the amateur club AB (the first was for the goalkeeper’s position and the second for the midfielder). Later, Harald successfully played in the national team of Denmark and won silver in its composition at the 1908 Olympics, where the Danish team lost to the English in the final.

In 1903, Niels Bohr entered the University of Copenhagen, where he studied physics, chemistry, astronomy, and mathematics. Together with his brother, he organized a student philosophical circle, in which its participants in turn gave reports. At the university, Niels Bohr carried out his first work on the study of oscillations of a jet of fluid to more accurately determine the magnitude of the surface tension of water. A theoretical study in 1906 was awarded a gold medal

Danish Royal Society. In subsequent years (1907-1909), it was supplemented by experimental results obtained by Bohr in the father’s physiological laboratory and published according to the ideas of the leading physicists Ramzai and Rayleigh.

In 1910, Bor received a master's degree, and in May 1911 he defended his doctoral dissertation on the classical electron theory of metals. In his dissertation work, Bohr, developing the ideas of Lorentz, proved an important theorem of classical statistical mechanics, according to which the magnetic moment of any set of elementary electric charges moving according to the laws of classical mechanics in a constant magnetic field, in a steady state is zero. In 1919, this theorem was independently rediscovered by Hendrik van Leuven and is called the Bohr theorem — van Leuven. It directly implies the impossibility of explaining the magnetic properties of a substance (in particular, diamagnetism), while remaining within the framework of classical physics. This, apparently, was the first collision of Bohr with the limitations of the classical description, which led him to questions of quantum theory.

Bohr in England.

Theory of Bohr (1911-1916)

To rule In 1911, Bor received a 2,500 kronor scholarship from the Carlsberg Foundation for an internship abroad. In September 1911, he arrived in Cambridge to work at the Cavendish Laboratory under the guidance of the famous JJ Thomson. However, the cooperation did not work out: Thomson was not interested in the young Dane, who immediately pointed out an error in one of his works and, moreover, spoke poorly in English. Subsequently, Bohr recalled this:

I was disappointed; Thomson was not interested that his calculations were wrong. This was my fault. I did not know English well enough and therefore could not explain myself ... Thomson was a genius who, in fact, pointed the way to everyone ... In general, working at Cambridge was very interesting, but it was absolutely useless. As a result, in March 1912, Bor moved to Manchester to Ernest Rutherford, whom he had met shortly before.

In 1911, according to the results of his experiments, Rutherford published a planetary model of the atom. Bohr was actively involved in the work on this topic, which was facilitated by numerous discussions with the famous chemist Georg Heveshi, then working in Manchester, and with Rutherford himself. The initial idea was that the properties of the elements are determined by an integer number - the atomic number, which is the role of the nuclear charge, which can change in the processes of radioactive decay. The first application of the Rutherford model of the atom for Bohr was the consideration in the last months of his stay in England the processes of interaction of alpha and beta rays with matter. In the summer of 1912, Bor returned to Denmark.

On August 1, 1912, the wedding of Bora and Margaret Nörlund took place in Copenhagen, the sisters of Harald’s close friend Niels Eric Nörlund, whom he met in 1909. During the honeymoon trip to England and Scotland, Bor and his wife visited Rutherford in Manchester. Bohr handed him his prepared for publication article "Theory of deceleration of charged particles during their passage through matter" (it was published in early 1913). However, it was the beginning of a close friendship between the families of the Hogs and Rutherford. Communication with Rutherford left an indelible imprint (both scientifically and personally) on the further fate of Bohr, who after many years wrote:

Very characteristic of Rutherford was the benevolent interest, which he showed to all the young physicists with whom he had a long or short deal. for me, Rutherford became the second father.