Moseley, after discussions with Bohr who was at the same lab ( and who had used Van den Broek's hypothesis in his Bohr model of the atom ), decided to test Van den Broek and Bohr's hypothesis directly, by seeing if spectral lines emitted from excited atoms fit the Bohr theory's demand that the frequency of the spectral lines be proportional to a measure of the square of Z.

However, the idea that electrons might revolve around a compact nucleus with definite angular momentum was convincingly argued at least 19 years earlier by Niels Bohr, and the Japanese physicist Hantaro Nagaoka published an orbit-based hypothesis for electronic behavior as early as 1904.

The Bohr model of the atom fixed the problem of energy loss from radiation from a ground state ( by declaring that there was no state below this ), and more importantly explained the origin of spectral lines.

The significance of the Bohr model was that it related the lines in emission and absorption spectra to the energy differences between the orbits that electrons could take around an atom.

This was, however, not achieved by Bohr through giving the electrons some kind of wave-like properties, since the idea that electrons could behave as matter waves was not suggested until twelve years later.

Still, the Bohr model's use of quantized angular momenta and therefore quantized energy levels was a significant step towards the understanding of electrons in atoms, and also a significant step towards the development of quantum mechanics in suggesting that quantized restraints must account for all discontinuous energy levels and spectra in atoms.

With de Broglie's suggestion of the existence of electron matter waves in 1924, and for a short time before the full 1926 Schrödinger equation treatment of hydrogen like atom, a Bohr electron " wavelength " could be seen to be a function of its momentum, and thus a Bohr orbiting electron was seen to orbit in a circle at a multiple of its half-wavelength ( this historically incorrect Bohr model is still occasionally taught to students ).

In our current understanding of physics, the Bohr model is called a semi-classical model because of its quantization of angular momentum, not primarily because of its relationship with electron wavelength, which appeared in hindsight a dozen years after the Bohr model was proposed.

The Bohr model was able to explain the emission and absorption spectra of hydrogen.

it was noted by Bohr that the existence of any sort of wave packet implies uncertainty in the wave frequency and wavelength, since a spread of frequencies is needed to create the packet itself.

In the quantum picture of Heisenberg, Schrödinger and others, the Bohr atom number n for each orbital became known as an n-sphere in a three dimensional atom and was pictured as the mean energy of the probability cloud of the electron's wave packet which surrounded the atom.

Aage Niels Bohr (; 19 June 1922 – 9 September 2009 ) was a Danish nuclear physicist and Nobel laureate, and the son of the famous physicist and Nobel laureate Niels Bohr.

In October 1943, shortly before he was to be arrested by the German police, Niels Bohr escaped to Sweden with his family, later travelling to London and on to work on the Manhattan Project.

By the late 1940s it was known that the properties of atomic nucleus could not be explained by the then-current models ( such as the liquid drop model developed by Niels Bohr amongst others ).

The Soviet scientists had suggested this name be given to element 105 ( which was finally called dubnium ) and the German team wished to recognise both Bohr and the fact that the Dubna team had been the first to propose the cold fusion reaction.

Bohr was heavily influenced by positivism.

* November 18-Niels Bohr ( born 1885 ), Danish physicist.

Bohr was born in 1887 to Christian Bohr, a professor of physiology, and Ellen Adler Bohr, a woman from a wealthy Jewish family of local renown.

Benny Lautrup ( born June 25, 1939 ) is a professor in theoretical physics at the Niels Bohr Institute at the University of Copenhagen.

* Niels Bohr was born in 1885, making him 38 when Heisenberg first came to work with him.

* Margrethe Bohr, known later in her life as Dronning or “ Queen ” Margrethe, was born in 1890 in Denmark.

Holger Bech Nielsen ( born 25 August 1941 ) is a Danish theoretical physicist, Professor emeritus at the Niels Bohr Institute, at the University of Copenhagen, where he started studying physics in 1961.

In 1940, shortly after the German occupation of Denmark, Bohr began his physics degree at the University of Copenhagen.

Bohr became a professor at the University of Copenhagen in 1956, and, following his father's death in 1962, succeeded him as director of the Niels Bohr Institute, a position he held until 1970.

On his return to Copenhagen in 1950, Bohr began working with Ben Roy Mottelson to compare the theoretical work with experimental data.

Werner Heisenberg had been an assistant to Niels Bohr at his institute in Copenhagen during part of the 1920s, when they helped originate quantum mechanical theory.

Born's idea was soon taken over by Niels Bohr in Copenhagen who then became the " father " of the Copenhagen interpretation of quantum mechanics.

Early quantum theory was significantly reformulated in the mid-1920s by Werner Heisenberg, Erwin Schrodinger, Max Born, Wolfgang Pauli and their collaborators, and the Copenhagen interpretation of Niels Bohr became widely accepted.

However, one of the main scientists associated with the Copenhagen interpretation, Niels Bohr, never had in mind the observer-induced collapse of the wave function, so that Schrödinger's Cat did not pose any riddle to him.

In fact, the modern explanation of the uncertainty principle, extending the Copenhagen interpretation first put forward by Bohr and Heisenberg, depends even more centrally on the wave nature of a particle: Just as it is nonsensical to discuss the precise location of a wave on a string, particles do not have perfectly precise positions ; likewise, just as it is nonsensical to discuss the wavelength of a " pulse " wave traveling down a string, particles do not have perfectly precise momenta ( which corresponds to the inverse of wavelength ).

The first isotope separator was developed at the Copenhagen Cyclotron by Bohr and co-workers using the principle of electromagnetic separation.

The group of Radek Wojtak of the Niels Bohr Institute at the University of Copenhagen collected data from 8000 galaxy clusters and found that the light coming from the cluster centers tended to be red-shifted compared to the cluster edges, confirming the energy loss due to gravity.

The Niels Bohr Institute is a research institute of the University of Copenhagen.

The Institute was founded in 1921, as the Institute for Theoretical Physics of the University of Copenhagen, by the Danish theoretical physicist Niels Bohr, who had been on the staff of the University of Copenhagen since 1914, and who had been lobbying for its creation since his appointment as professor in 1916.

The Copenhagen interpretation is the " standard " interpretation of quantum mechanics formulated by Niels Bohr and Werner Heisenberg while collaborating in Copenhagen around 1927.

He studied at the Institute for Theoretical Physics of the University of Copenhagen ( later to become the Niels Bohr Institute ), and Technical University of Denmark.

" Majorana also travelled to Copenhagen, where he worked with Niels Bohr, another Nobel Prize winner, and a friend and mentor of Heisenberg.

* Niels Bohr Institute, of the University of Copenhagen

* Cvitanović P., Artuso R., Mainieri R., Tanner G. and Vattay G. Chaos: Classical and Quantum Niels Bohr Institute, Copenhagen 2005 – textbook about chaos available under Free Documentation License

File: Niels Bohr. jpg | Niels Bohr ( 1885-1962 ): used quantum mechanical model ( known as the Bohr model ) of the atom which theorized that electrons travel in discrete orbits around the nucleus, showed how electron energy levels are related to spectral lines, received the Nobel Prize in Physics in 1922.

Groups of electrons were thought to occupy a set of electron shells about the nucleus .< ref > In 1922, Niels Bohr updated his model of the atom by assuming that certain numbers of electrons ( for example 2, 8 and 18 ) corresponded to stable " closed shells ".

* Niels Bohr ( 1885 – 1962 ), Danish atomic physicist, Nobel Prize in physics 1922

* Aage Bohr ( 1922 – 2009 ), Danish nuclear physicist, Nobel Prize in physics 1975, son of Niels Bohr

* Léon Brillouin La Théorie des Quanta et l ' Atome de Bohr ( Presse Universitaires de France, 1922, 1931 )

Niels Bohr, in his 1922 Nobel address, stated, " The hypothesis of light-quanta is not able to throw light on the nature of radiation.

* Niels Bohr ( Physics, 1922 )

Coster's thesis was on this subject, and he obtained his Ph. D. degree in 1922 in Leiden under Paul Ehrenfest ; his thesis was entitled " Röntgenspectra en de atoomtheorie van Bohr " ( X-ray spectra and Bohr's atomtheory ).