Niels Bohr

Danish physicist and Nobel prize laureate, 1885-1962

Bohr 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. Although the Bohr model has been supplanted by other models, its underlying principles remain valid. 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. The notion of complementarity dominated Bohr's thinking in both science and philosophy.

Source: Wikipedia

Bohr, Niels

physicist and Nobel Laureate (1885-1962). The Penetration of Atomic Particles through Matter. Signed and Inscribed, "Professor H[elmut L.] Bradt / with kind regards," on the title-page at upper edge. 144 pages, printed wrappers, "H.L. Bradt / 1949" penciled in Bradt's hand at upper right of front Copenhagen. 8vo.
$ 3,413 / 3.000 € (62820)

With seven pages of notes written by Bradt including equations and diagrams analyzing and criticizing Bohr's work, laid in. - Helmut L. Bradt (1917-1950) was a visiting professor of physics at the University of Rochester who, with Morton F. Kaplan, recorded photographic evidence of a new atomic particle: the neutral meson. His father, Gustav Bradt, was a friend of Albert Einstein.

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Bohr, Niels

Physiker (1885-1962). Typed letter signed. Kopenhagen. 1 S. 4to. Beiliegend ein Kuvert mit roten Lacksiegeln des Instituts.
$ 2,844 / 2.500 € (49379/BN33757)

To the Austrian physicist Heinrich Mache from the Vienna University of Technology, thanking for a collection of rare earth elements which the Austrian scientist Carl Auer von Welsbach had donated, and sending therefore 500 Danish Crowns for supporting the University's scientific projects. - On stationery with printed letterhead of the Universitetets Institut For Teoretisk Fysik; traces of folding.

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Bohr, Niels

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Autograph ist nicht mehr verfügbar

Letter to "Architect Jensen", thanking him for flowers and congratulations on his 50th birthday. In part (translated from the Danish original): "My wife and I were so looking forward to setting up our summer home in Klintebjerg, based on your beautiful plans, and we are sorry that the circumstances meant that the execution of these plans had to be abandoned". - In fine condition.