Niels Bohr
Niels Bohr | |
|---|---|
| Born | October 7, 1885 Copenhagen, Denmark |
| Died | November 18, 1962 (aged 77) Copenhagen, Denmark |
| Nationality | Danish |
| Known for | The Bohr model of the atom, the correspondence principle, complementarity, the Copenhagen interpretation, the liquid-drop model of the nucleus |
| Awards | Nobel Prize in Physics (1922) |
| Scientific career | |
| Fields | Atomic physics, nuclear physics, foundations of quantum theory |
| Institutions | University of Copenhagen, Institute for Theoretical Physics (Copenhagen) |
Niels Henrik David Bohr (7 October 1885 – 18 November 1962) was a Danish physicist whose 1913 model of the atom opened quantum physics to calculation, and whose later interpretive doctrine — complementarity, the core of the Copenhagen interpretation — is the principal target of the quantum-foundations criticism collected on this wiki.
In a three-part paper of 1913, Bohr proposed that the electron in a hydrogen atom occupies only certain stationary orbits in which, contrary to classical electrodynamics, it does not radiate, and that radiation is emitted or absorbed only in transitions between them, with frequency fixed by the energy difference divided by Planck's constant. The model reproduced the Balmer series and derived the Rydberg constant from more basic quantities. He received the Nobel Prize in Physics in 1922 for this work. In 1921 he founded the Institute for Theoretical Physics in Copenhagen, which became the centre of the field; Heisenberg, Pauli, Gamow and many others worked there.
Bohr's correspondence principle required that quantum results reproduce classical ones in the appropriate limit. His complementarity principle, presented at Como in 1927, held that wave and particle descriptions are mutually exclusive but jointly necessary, and that which one applies is fixed by the experimental arrangement — from which he concluded that it is meaningless to ask what a system is doing between measurements. This position, elaborated with Heisenberg, became the standard teaching interpretation and the subject of his long public argument with Albert Einstein, including the exchanges over the 1935 Einstein–Podolsky–Rosen paper. On the nuclear side Bohr developed the compound-nucleus concept and, with John Wheeler in 1939, the liquid-drop account of fission. Element 107, bohrium, is named after him.
On this wiki
The Quantum mechanics article here draws the distinction that most of the criticism depends on: the formalism's predictive success is not in dispute, but the Copenhagen reading of it is treated as an interpretive choice presented as an experimental result. Complementarity, on this view, converts an unsolved problem — what happens between measurements — into a prohibition on asking.
Specific engagements catalogued here include:
- Evert Jan Post, On the Wages of Copenhagen's Non-Classical Sins (2004) and Quantum Reprogramming - A Long Overdue and Least Intrusive Reality Adaptation of the Copenhagen Interpretation (2005), which argue that period-integral and pre-metric structures already present in classical theory account for phenomena Copenhagen declared non-classical.
- Franco Selleri, Complementarity vs. Causality in Space and Time (1993), and his edited volume Wave-Particle Duality (1992), from a local-realist standpoint.
- Thomas E Phipps, Problems of Quantum Mechanics (Apeiron, 1996).
- John-Erik Persson, Confusing Copenhagen Complementarity (2013) and The Great Confusion: Wave or Particle? (2011).
- Louis Groarke, Has an Experimental Violation of Bohr's Complementarity Principle Been Observed? (Apeiron, 1999).
- Paul Marmet, Absurdities in Modern Physics: A Solution (1993).
The Bohr atom itself is a separate and equally active thread. Several researchers here regard the quantised-orbit postulate as a placeholder that a physical model of electron structure ought to replace:
- Jaroslav G Klyushin builds hydrogen from toroidal electron and proton structures in an aether with position-dependent local light speed, in "Non-Bohr" Model of Hydrogen Atom and Expansion of Bohr's Quantum Postulates.
- James Keele, Unified 'No Field' Theory and the Bohr Atom (2003), derives the orbit condition from a direct-action force law.
- Randell L Mills, The Fallacy of Feynman's and Related Arguments on the Stability of the Hydrogen Atom According to Quantum Mechanics (2005), disputes the standard argument that only quantum mechanics can keep the atom from radiative collapse.
- Carl R Littmann and Geoffrey Hunter examine mass relations and structural models against the Bohr picture.
- The toroidal-ring tradition of Alfred L Parson — see Toroidal Ring and Category:Toroidal Ring — is a contemporaneous structural rival to Bohr's orbits that is well represented here.
The realist alternatives that Copenhagen was long held to have excluded are documented under David Bohm, Louis de Broglie, Jean Pierre Vigier and John Stewart Bell. The historical point the Quantum mechanics article stresses is that von Neumann's 1932 "impossibility proof" against hidden variables — widely taken as closing the question — rested on an assumption stronger than physics requires, a flaw identified by Grete Hermann in 1935 and generally ignored until Bell restated it in the 1960s.
None of this is a claim that Bohr's atomic physics was wrong. His model was the first to make atomic spectra calculable, and the criticism here is aimed at the interpretive framework he built afterwards rather than at the 1913 papers.