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{{Infobox scientist
| name        = Werner Heisenberg
| birth_name  = Werner Karl Heisenberg
| birth_date  = 5 December 1901
| birth_place = Würzburg, German Empire
| death_date  = 1 February 1976
| death_place = Munich, West Germany
| nationality = German
| fields      = Theoretical physics, quantum mechanics, nuclear physics
| workplaces  = University of Leipzig; Kaiser Wilhelm Institute for Physics; Max Planck Institute for Physics, Munich
| alma_mater  = University of Munich
| known_for   = Matrix mechanics; uncertainty principle; Copenhagen interpretation; isospin; S-matrix
| awards      = Nobel Prize in Physics (1932)
}}

'''Werner Karl Heisenberg''' (1901–1976) formulated the first complete version of [[Quantum Mechanics|quantum mechanics]] and, with Niels Bohr, the interpretation of it that became orthodox. On this wiki he is a central figure chiefly as the author of that interpretation — the point at which, in the view of many researchers catalogued here, physics abandoned the requirement that its theories describe something real.

==Contributions==

In 1925, working on Heligoland, Heisenberg produced a formulation of quantum theory built solely from observable quantities — the frequencies and intensities of spectral lines — deliberately refusing to model the unobservable orbit of the electron. Max Born and Pascual Jordan recognised his arrays as matrices, and the three developed '''matrix mechanics''', the first consistent quantum theory. Schrödinger's wave mechanics of 1926 was shown to be mathematically equivalent.

In 1927 Heisenberg published the '''uncertainty principle''', that the position and momentum of a particle cannot both be sharply defined, with the product of the uncertainties bounded below by a quantity of the order of Planck's constant. Interpreted with Bohr's complementarity, this became the '''Copenhagen interpretation''': the wave function is a complete description, and questions about what a particle is doing between measurements are not merely unanswerable but improper. He received the 1932 Nobel Prize in Physics for the creation of quantum mechanics.

His other work includes the neutron–proton exchange model of nuclear forces and the isospin formalism (1932), the S-matrix programme, and an unsuccessful late attempt at a unified field theory. During the Second World War he led German nuclear research; what he intended by that work has been argued about ever since, and no consensus exists. After the war he directed the Max Planck Institute for Physics.

==On this wiki==

The dispute here is not with Heisenberg's mathematics but with the philosophy attached to it — the doctrine that a theory need not describe a mechanism. See [[:Category:Quantum Theory]].

'''[[Evert Jan Post]]''' is the most sustained critic. In ''[[Heisenberg's Epistemological Omission]]'' he argues that Heisenberg conflated statements about ensembles with statements about single systems, and that the omission has been carried forward uncorrected for a century; he develops the correction in ''[[Quantum Reprogramming: Ensembles and Single Systems: A Two-Tier Approach to Quantum Mechanics|Quantum Reprogramming: Ensembles and Single Systems]]'' and ''[[Quantum Reprogramming - A Long Overdue and Least Intrusive Reality Adaptation of the Copenhagen Interpretation]]''. His verdict is delivered in the title of ''[[On the Wages of Copenhagen's Non-Classical Sins]]'', and his remedy in ''[[Ending Quantum Physics' Dependence on Copenhagen Doctrine]]''. Post's position is notably moderate in method and radical in conclusion: he holds that the required repair is small, and that its consequences are large.

'''[[Wladimir Guglinski]]''' argues in ''[[The Missed U-Turn: The Duel Heisenberg vs Schrodinger]]'' that the discipline took the wrong branch in 1926, and that Schrödinger's wave picture, had it been read realistically, would have kept physics describing something. '''[[Alan McCone]]''' brings a philosophical objection in ''Stanley Jaki's Critique of Heisenberg's Interpretation of the Uncertainty Principle'' (2002): that indeterminacy of ''measurement'' was silently converted into indeterminacy of ''being''. '''[[David L Bergman]]''' presses the same point as a matter of principle in ''[[The Law of Cause and Effect: Dominant Principle of Classical Physics]]'', and '''[[Richard Oldani]]''' examines what a particle's position can mean in ''[[A Dialogue on Position]]''.

The constructive alternative most often advanced here is the '''stochastic interpretation''', in which quantum indeterminacy reflects an underlying real random medium rather than an absence of underlying reality. '''[[Jean Pierre Vigier]]''' is its chief representative in this collection — see ''[[Jean-Pierre Vigier and the Stochastic Interpretation of Quantum Mechanics]]'' — and the position connects the quantum debate directly to the [[Aether|aether]] literature. '''[[Greg Volk]]''' places the whole episode in context in ''[[Assessing Conceptual Trends in 20th Century Physics]]''.

It should be said clearly that the uncertainty relations themselves are not in dispute in this literature; what is disputed is the inference from them to the claim that no underlying description exists. That is an interpretive question, and mainstream physics has never settled it either — Bohmian mechanics, spontaneous-collapse models and many-worlds all remain live in the professional literature.

==See also==

* [[Paul Dirac]]
* [[Quantum Mechanics]]
* [[Wave-Particle Duality]]
* [[Evert Jan Post]]
* [[Jean Pierre Vigier]]
* [[Aether]]

[[Category:Scientist|Heisenberg Werner]]
[[Category:Quantum Theory]]
[[Category:Philosophy]]