Niels Bohr

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Niels Bohr : biography

07 October 1885 – 18 November 1962

On the 1st of August in Copenhagen Bohr married Margaret Norlund, the sister of Harald’s close friend Niels Eric Norlund whom he met in 1909. During their honeymoon trip in England in Scotland Bohr with his wife visited Reserford in Manchester. Borh gave him his article “The theory of braking of charged particles during their passing through material” which was ready for publishing (it was published in 1913). It was a start of close friendship between Bohrs and Reserfords. Communication with Reserford made an indelible imprint (in scientific and personal meaning) on the Bohr’s future destiny. He wrote after several years: “Reserford always had a kind interest to all young scientists who he had to deal with… For me Reserford became a second father.”

When Bohr returned to Copenhagen he started to teach in university and at the same time he intensively worked on the quantum theory of the atom’s structure. The first results were in his rough copy which he sent to Reserford in July of 1912 – it was named “Reserford’s memorandum”. But decisive success was reached at the end of 1912 and at the beginning of 1913. The key moment was the acquaintance with patterns of disposition of spectral lines and general combination principle for frequency of atoms’ radiation in February of 1913. Afterwards Borh said: “When I saw Balmer series I immediately understood the question.”

In March of 1913 Borh sent to Reserford the preliminary version of the article and in April he went to Manchester for several days in order to discuss his theory. The result of his work was three parts of revolutionary article “About the structure of atoms and molecules” which was published in the magazine “Philosophical magazine” in July, October and December of 1913 and contained the quantum theory of hydrogen atom. There are two main components in the Bohr’s theory: general statements (postulates) about behaviour of atomic systems which save their value and were comprehensively checked and specific model of atom’s structure which has a historic interest nowadays. Bohr’s postulates contained suppositions about existence of stationary conditions and radiating passages between them according to Planch’s conceptions about quantization of material’s energy. The model atom theory of Bohr originated from supposition about possibility to describe movements of electrons in the stationary atom according to the classical physics with had additional quantum conditions (for example, quantization of electron’s angle moment). Bohr’s theory made it possible to base emission and absorbtion of radiation in serial spectrums of hydrogen and also explain (with correction for given mass of electron) hydrogen-like spestrums with half-integral quantum numbers which had been earlier observed by Charles Pikering and Alfred Fauler as a theoretical receipt of Ridber’s coefficient’s value.

Bohr’s work immediately attracted attention of physicists and stimulated rapid development of quantum ideas. His contemporaries estimated at his true worth the important step which Danish scientist made. In 1936 Reserford wrote: “I consider the primary quantum theory of spectrums which was suggested by Bohr to be one of the most revolutionary of all ever made in science and I dint know any other theory that has such success.”

In 1949 Albert Einstein recollected about his impressions of acquaintance with Bohr’s theory: “All my attempts to adapt the theoretical basis of physics to this results failed. I always considered it to be a miracle that this hesitant and full of contradictions base was enough for Bohr, a person with genius intuition and delicate sixth sense, to find main laws of spectral lines and electronic covers of atoms including their meaning for chemistry. I find it a miracle now. This is the highest musicality in the field of thoughts”.

In spring of 1914 Bohr was invited by Reserford to replace Charles Darvin, the grandson of the famous naturalist, as a lector on mathematician physics in the Manchester University. He stayed in Manchester since autumn of 1914 till summer of 1916. At that time he tried to spread his theory on many-electron atoms but quickly reached a deadlock. In September of 1914 he wrote: “There is no simple correlation between energy and number of circulations for systems with two or more particles and that’s why ideas like I used before can’t be used for definition of “stationary conditions” of the system. I suppose that this problem may contain very considerable difficulties which can be surmounted only by refusal of the usual conceptions more than it needed before and the only reason of reached success is the simplicity of examined systems”.