it ain't necessarily so

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A discussion of interpretations and misinterpretations of quantum mechanis



It Aint Necessarily SoInterpretations and Misinterpretations of Quantum Theory

John StachelFrontiers of Fundamental Physics 14Faculty of Sciences (AMU)Marseille, 15-18 July 2014


2It Ain't Necessarily Soby George GershwinIt ain't necessarily soIt ain't necessarily soThe t'ings dat yo' li'bleTo read in de Bible,It ain't necessarily so.I'm preachin' dis sermon to show,It ain't nece-ain't neceAin't nece-ain't neceAin't necessarily ... so !

My Apologies in AdvanceTime limits require brevity and brevity is the mother of dogmatism.None of my statements should be interpreted dogmatically they are all meant to stimulate critical thinking and further discussion.For a copy of my PowerPoint just email 4Examples of Misinterpretations from Two Widely Praised 2013 BooksWhat is the Copenhagen interpretation?Are Duality and Complementarity the same?Princeton University Press, 2013

Einstein and the QuantumStone attacks the Copenhagen interpretation, focusing on Borns probabilistic interpretation of the wave-function, Heisenbergs uncertainty principle and Bohrs mysterious complementarity principle. (p. 281) Einstein and the QuantumEinsteins later critiques of quantum theory focused less on its indeterminacy and more on its strange epistemological status. In quantum mechanics the actual act of measurement is part of the theory; these magic coins just mentioned exist in a state of (heads, tails)-(tails, heads) uncertainty until they are measured, and then they are forced to decide which state they are in.

Heisenbergs Copenhagen InterpretationStone does not seem to be aware that he is giving Heisenbergs interpretation of quantum mechanics, which is quite different from Bohrs interpretation.You dont have to take my word for this:

Nine formulations of quantum mechanics, Daniel F. Styer et al, Am. J. Phys. 70 (2002): pp. 288-297

[O]f the two primary architects of the Copenhagen interpretation, Werner Heisenberg maintained that observation of the position will alter the momentum by an unknown and undeterminable amount, whereas Niels Bohr warned specifically against phrases, often found in the physical literature, such as disturbing of phenomena by observation.

Nine formulations of quantum mechanics, Daniel F. Styer et al, Am. J. Phys. 70 (2002): pp. 288-297

The wave function should be regarded as a mathematical tool for calculating the outcomes of observations, not as a physically present entity existing in space such a football, or a nitrogen molecule, or even an electric field.Examples of Misinterpretations from Two Widely Praised 2013 BooksWhat is the Copenhagen interpretation?Are Duality and Complementarity the same?Pegasus Books, 2013

Farewell to RealityDanish physicist Niels Bohr and German Werner Heisenberg argued that particles and waves are merely the shadowy projections of an unfathomable reality into our empirical world of measurement and perception. . This approach to quantum theory became known as the Copenhagen interpretation.At the heart of this interpretation lies Bohrs notion of complementarity, a fundamental duality of wave and particle behavior. But According to Bohr They Are NotSince Bohr introduced and developed the concept of complementarity in quantum mechanics, on this one Ill let Bohr speak for himself:Niels Bohr 1885-1962

The Causality Problem in Atomic Physics (1938)It is true that the duality between the undulatory and corpuscular conceptions exists for matter as well as for light, but this is only one aspect of a symbolical formalism and its interpretation must be found in the classical conceptions. Just as the mass and charge of the electron can only be defined classically, the description of the pheno-mena of radiation cannot dispense with the idea of the electromagnetic wave field.The Causality Problem in Atomic Physics (1938)The concepts of the photon and the material wave are on the contrary purely abstract methods of considering the general nature of complementarity that exists, by reason of the individuality of the quantum of action, between the spatio-temporal representation and the principle of conservation of momentum and energy. DUALITY CLASSICAL (h=0) Radiation Matter Waves Particles MATHEMATICAL REPRESENTATION Characteristics Trajectories (wave fronts) (world lines, characteristic strips) DUALS Bicharacteristics Ensemble of trajectories (rays) (characteristic function) QUANTUM MECHANICAL (h>0) photon wave function

COMPLEMENTARITYSPACE-TIME DESCRIPTION CONSERVATION OF (x,t) ENERGY- MOMENTUM (E, p) CLASSICAL (h=0)Both can be defined and measured for an individual systemEither can be chosen to define a complete ensemble QUANTUM MECHANICAL (h>0)Only open systems can be treated One must choose betweenthem to define and measure an individual system

Outline of the Talk:

Some backgroundinformation on my approach21Traditional ViewA theory is a conceptual framework providing predictions . The results of experiments or observations decide whether the theory is right or wrong

22Gaston Bachelard (1884-1962)

23The Formation of the Scientific Spirit (1938)In order to include new experimental tests, it is necessary to deform the original concepts, study their conditions of applicability, and above all incorporate the conditions of applicability of a concept into the very meaning of the concept.


The New Scientific Spirit (translation 1934).

[P]henomena must ... be carefully selected, filtered and purified; they must be cast in the mold of scientific instruments and produced at the level of these instruments. Now instruments are just materialized theories. The phenomena that come out of them bear on all sides the mark of theory 25The Lesson From BachelardDont separate meaning and measurement: Incorporate the conditions of applicability of a concept into the very meaning of the concept!26Outline of the Talk:

2) Measurability Analysis

27Measurability Analysis

Measurability analysis identifies those concepts that a theory defines as meaningful within some context and investigates to what extent the values associated with these concepts are ideally measurable in the defining context (e.g. concepts of hardness and viscosity in the context of fluid and solid states of matter in classical thermodynamics).28Peter G. BergmannCollaborator of Einstein

Pioneer in study of quantization of generally covariant theories, including GR

29Bergmann and Smith 1982 Measurability Analysis for the Linearized Gravitational Field Measurability analysis identifies those dynamic field variables that are susceptible to observation and measurement (observables), and investigates to what extent limitations inherent in their experimental determination are consistent with the uncertainties predicted by the formal theory.30Prolegomena to any future QuantumGravity (Stachel 2007) [M]easurability analysis is based on the relation between formalism and observation; its aim is to shed light on the physical implications of any formalism: the possibility of formally defining any physically significant quantity should coincide with the possibility of measuring it in principle; i.e., by means of some idealized measurement procedure that is consistent with that formalism. 31Warning!This is not operationalism Its not real because its measurable, it must be measurable because its real!32Simple Classical ExampleHardness and Viscosity can be applied to any substance, but not simultaneously. If it is in solid state, hardness applies; if it is in a fluid state viscosity applies. 33

Outline of the Talk:

3)What quantization is and is not

34What is NOT Being Claimed Quantization only makes sense when applied to fundamental structures or entities.

35The Mystique Surrounding Quantum Mechanics Anything touched by this formalism thereby seems to be elevated or should it be lowered? to a fundamental ontological status. The very words quantum mechanics conjure up visions of electrons, photons, baryons, mesons, neutrinos, quarks and other exotic building blocks of the universe.36The Mystique Surrounding Quantum Mechanics (contd) But the scope of the quantum mechanical formalism is by no means limited to such (presumed) fundamental particles. There is no restriction of principle on its application to any physical system. One could apply the formalism to sewing machines if there were any reason to do so! (Stachel 1986)

37What IS Quantization? Quantization is just a way accounting for the effects of h, the quantum of action, on any process involving some system, or rather on theoretical models of such a system-- fundamental or composite, in which the collective behavior of a set of more fundamental entities is quantized38Some Non-fundamental Quanta1) quasi-particles: particle-like entities arising in certain systems of interacting particles, such as phonons and rotons in hydrodynamics (Landau 1941)2) phenomenological photons: quantized electromagnetic waves in a homogeneous, isotropic dielectric (Ginzburg 1940)

39Two Kinds of Relations

There are relations, in which the things are primary and their relation is secondary: relations between thingsThere are relations, in which the relation is primary while the things are secondary: things between relations40Par