Friday, August 8, 2014

Statistical interpretation is not minimalist

A reader suggests the Statistical Interpretation of quantum mechanics, aka the Ensemble interpretation, is superior to others.

My main complaint is that this claims to be a "minimalist interpretation". It is not. Sometimes the many-worlds also claims to be minimalist. It is not either. The most minimal of the of the mainstream interpretations is the Instrumentalist interpretation.

The statistical interpretation essentially says that only probabilities are observable, and only in large systems. But quantum mechanics is commonly used to make predictions about small systems, such as a the energy levels of a 2-particle hydrogen atom. Turning this into a statistical observation about an ensemble of hydrogen atom is to add a lot of extraneous junk. A minimalist interpretation has to say something about one atom.

I prefer the positivist interpretation, as being truly minimalist.

Probability is a mathematical layer with multiple interpretations, and any quantum mechanics interpretation that requires probability is not minimalist.

Part of the confusion is that people think that probability is essential to quantum mechanics, via the Born rule. Probability is important to quantum mechanics in the same way that it is important to other scientific theories, but not essential.

11 comments:

  1. "Quantum Reprogramming: Ensembles and Single Systems: A two tier approach to Quantum Mechanics" c. 1995 by Evert Jan Post

    "In quantum mechanics, physics somehow is involved in situations halfway
    between science and religion. The many useful applications of the
    Schroedinger equation indicate that the belief works. In fact, it works so
    often and so weIl that the sheer statistical evidence of applicability is taken
    as proof and substantiation of the stated beliefs. Whenever we run into an
    exception we are inclined to suspect first an error in the implementation of
    our beliefs and not the belief itself. We have not yet reached the courage
    of our convictions to test our quantum mechanical beliefs beyond the point
    where we keep overwhelming ourselves with the brute force of statistics.
    In the following, two examples will be examined which give direct and
    near-incontrovertible evidence of the inapplicability of the Schroedinger
    equation to highly ordered systems. The experimental evidence for one of
    these examples has, quite surprisingly, been around for almost three
    decades. The argument goes back to the discovery of flux quantization and
    it is based on the experimentally confirmed absence of a residual zero-point
    flux in superconducting rings.
    The second example is of more recent vintage and relates to the
    quantum Hall effect."

    ...

    "This state of affairs, in turn, places in question the
    applicability of the Schroedinger process to physical situations that are
    distinguished by a high degree of cooperative behavior."

    "Electromagnetic Noise and Quantum Optical Measurements" by Haus

    "We have taken the point of view that quantum theory is a statistical theory that predicts only the outcome of an ensemble of measurements. The outcome of a single measurement is described only probabilistically."

    ...

    "Finally, it is the authors view, shared by many physicsts, that quantum theory is *fundamentally* a probabilistic theory that is complete in the sense defined by John Bell"

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  2. From the Evert Jan Post book:

    "If no thing else, the reprogramming shows that properly chosen ensemble
    specifications bring the Popper proposition into a revealing quantitative
    relationship with the Schroedinger equation. While this fact still does not
    establish beyond a shadow of a doubt that the Schroedinger equation is an
    ensemble tool, it does make the ensemble option a good deal more probable
    than the single-system option. As a remaining restraint preventing an allout
    support of the ensemble option, one should consider that even these
    explicit quantitative relations between ensemble statistics and Schroedinger
    results still fall short of aiding in a complete derivation of the Schroedinger
    equation from first principles.
    In fact, considering the lacunar nature of the derivational origin of the
    Schroedinger equation, there should be real doubt whether this equation
    will ever be derivable from first principles. After all those years of investigation
    and contemplation, it is more likely that Herman Weyl's words are
    to be taken more literally than ever intended: the Schroedinger equation's
    relation to Hilbert space was (and still is) "afavor offortune."
    With all reservations in place, it is thus concluded that the Schroedinger
    equation comes conceivably closest to describing dilute ensembles of
    identical single systems in quantum states that are randomized in phase and
    orientation. The word "conceivably" here conveys that there is no proof by
    derivation to completely substantiate this statement. All of this indicates
    that there is no known context for which the Schroedinger equation can be
    given a status of absolute physical exactness. The many statements to the
    contrary in the quantum mechanical textbook literature, therefore, are to
    be regarded as the products of wishful thinking.
    Overwhelmed by the equation's unparalleled success, earlier theorizing
    had always tacitly assumed an absolute and exact status for quantum mechanics'
    major tool of inquiry. Physical imagery kept drifting around on
    this magic cloud, which had brought so much "fortune" beyond what
    physics had deserved on the basis of "merit." Hence, when the Copenhagen
    interpretation became available as an intellectual vehicle for consolidating
    this equation's position of "fortune," the Copenhagen view automatically,
    yet unjustifiably, assumed the same aura of near-perfect truth that had already
    been identified with the Schroedinger equation and spectral theory.
    Now, in retrospect, physics should have had some real doubts that such a
    lofty assignation, even for the Schroedinger equation, might not be on
    altogether solid grounds.
    In the course of this reprogramming, evidence has been compiled which
    amply supports the Popper-ensemble proposition in conjunction with a required
    phase-and-orientation randomness of its constituent elements. It is
    the best that can be done for the Schroedinger equation, which, incidentally,
    is a lot better than what the textbook literature has done for the mutual
    relation of the Schroedinger equation and the single system. The textbook
    method simply postulates an interrelation between single-system and
    Schroedinger equation, and then, depending on Copenhagen-related convictions,
    this premise is made "plausible" with mystifying statistical considerations,
    which, until this day have not found their "universe of discourse. "

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  3. From Evert Jan Post:

    "That, in a nutshell, is how Hilbert space and its spectral properties became
    the realm of reality for the Twentieth Century physicist, almost to the
    exclusion of spacetime itself. Fortunately, the representation theory of
    groups retained a last powerfullink between spacetime and Hilbert's configuration
    space of quantum states. The group theoretical method was a
    last concession to a phenomenology of microphysical symmetry.
    Somehow, and again ironically, symmetry had been permitted to penetrate
    the fog of uncertainty shrouding microphysical structure. Weyl and
    Wigner had shown the way.
    The emergence of macroscopic quantum effects, however, brought us
    back from the abstract multi-dimensional Hilbert spaces into a reality of
    more intuitive spacetime model-making. Over and above symmetry, the
    mathematical machinery instrumental for implementing greater balance
    between formal and intuitive procedures in physics must be expected to
    call, more than be fo re , on the topology-oriented studies initiated in
    mathematics by Poincare, Brouwer, Hopf, de Rham, and Hodge.
    A recognition of this new impending reality has been very difficult for
    physics. For more than half a century, it has preached the gospel of a
    quantum mechanics, in which Hilbert space became almost a sole storage
    place of fundamental physical truth. Those involved in the study of quantum
    mechanical fundamentals have been brushing up Hilbert space formalisms,
    using group theoretical methods for finding out more about the
    spacetime structure of the objects gene rating the Hilbert space superstructures.
    There is, at this time, no real acceptance of a need to complement
    this procedure with intuitive conjecture by following in both directions the
    threads of logic interconnecting suspected cause and perceived effect.

    attitude is understandable in an interpretational atmosphere, which, as a result
    of its own premises, had been forced to restriet the rules of causality in
    the microdomain.
    While the use and function of Hilbert space, as it now stands, is not to
    be underestimated, its primary role is instrumental for ensembles, not for
    single systems! The Hilbert integral equation as definer of eigenvalue situations
    has an ensemble connotation, because it defines the wave function
    W in any point in terms of W everywhere else through the process of
    integration in the physical domain (chapter XVII;8).
    The Hilbert integral equation as Schroedinger equivalent has an
    inherent "smeared-out plurality" wh ich seems out-of-context for a single
    system. The period integral assessment, by contrast, does not have this
    reflexive interconnectedness of its spatial parts, which is so characteristic
    of the Schroedinger plurality. The period integral's domain of integration
    can be shrunk unto the single (microphysical) object of observation. It is
    capable of exploring topological structure, where Schroedinger's process is
    confined to essential physical features of the ensemble constituents only.
    This inability of making an adequate ensemble versus single-system
    distinction led quantum mechanics into the dead-end street of formal abstraction.
    This escape in abstraction became misleadingly acceptable.
    Getting out of this dead-end situation, the man-made fog of "uncertainty"
    needs to be lifted so that horizons become visible again. After that, a view
    of the single-system domain comes into focus, thus opening up a potential
    for the more intuitively oriented methods of topological modelling in
    actual spacetime, not Hilbert space! There is presently, at best, a general
    but vague awareness of the nature of these deficiencies in contemporary
    quantum mechanics. The existing situation of a long standing status quo
    reveals physics' reluctance in coming to grips with the cited predicament.

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  4. The confusion continues:

    http://physics.stackexchange.com/questions/41373/is-the-statistical-interpretation-of-quantum-mechanics-dead

    and then there is this guy:

    http://arxiv.org/abs/1112.2446

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    Replies
    1. There are some sensible answers there, including one by Motl.

      Delete
  5. I hate the name "statistical interpretation". It just causes confusion.

    The best book on quantum mechanics, Anthony Sudbery's "Quantum mechanics and the particles of nature: An outline for mathematicians" c. 1985 has nine different interpretations listed:

    1. The Minimal interpretation
    2. The Literal interpretation
    3. The Objective interpretation
    4. The Epistemic ('subjective') interpretation
    5. The Ensemble interpretation
    6. The Relative-state and Many-worlds interpretation
    7. The Quantum-logical interpretation
    8. The Hidden-variable interpretation
    9. The Stochastic interpretation

    According to Sudbery, Bohr's interpretation is strongly expressed by the Minimal interpretation. He sure gives Bohr a good tongue lashing too:

    "Moreover, it cannot be true that the sole purpose of a scientific theory is to predict the results of experiments. Why on earth would anyone want to predict the results of experiments? Most of them have no practical use; and even if they had, practical usefulness has nothing to do with scientific inquiry. Predicting the results of experiments is not the purpose of a theory, it is a test to see if the theory is true. The purpose of a theory is to understand the physical world"

    Sudbery is of the opinion that "No one interpretation is generally accepted" including the Copenhagen which he believes has been applied to at least four different interpretations listed above.

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  6. I am not familiar with that book. I agree that no one interpretation is generally accepted, that most probably accept Copenhagen but many people mean different things by that, and that Bohr's interpretation is minimalist.

    The longer quote describes the quest for scientific "realism". It sounds great until you start drawing untestable conclusions.

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  7. "...is to add a lot of extraneous junk."

    Thats the whole purpose of String Theory, that is for its insiders (masquerading as award winning (bogus Milner prize) "scientists") to add complexity so that the only court recognized experts are the string practitioners (tiny few) themselves.

    What the thieves are doing with String Theory is fencing in science so that String Theory is considered both more fundamental than Level 1 Quantum Mechanics (see here String theory proponent Ron Maimon hierarchy in this link: http://physics.stackexchange.com/questions/22618/are-quantum-mechanics-calculations-useful-for-engineering/22620#22620) and yet provides all the tools for the bottom layer where all the engineering applications take place).

    So take for example a definition of the applicability of Quantum Mechanics from "The Odd Quantum" by Sam Treiman:

    "The quantum mechanical
    rules, the concrete equations, are de finite and well
    established. In principle one can compute the structure of oil
    molecules and work out the way these molecules interact
    among themselves in bulk oil and thence go on to the viscosity
    of oil. But a completely detailed calculation that traverses
    the whole route from the individual molecule and its ingredients
    all the way up to the astronomical number (about 10E24) of
    molecules present in even a small drop of oil is utterly unthinkable.
    The single molecule is already complicated enough. Thus,
    approximations and aggregate treatments have to be adopted
    along the way, relying on various rich and active fields of scienti
    c inquiry; for example, the fi eld of statistical mechanics. A
    pumper who wants highly accurate predictions of flow rate is
    well advised to adopt the empirical value of viscosity. But that
    same pumper may also share with others a curiosity about why
    things are the way they are. Moreover, there is the possibility
    of learning enough at the microscopic level to design molecular
    additives that can alter the viscosity in wanted directions."

    Imagine, trillions of dollars of "molecular additives", coatings, etc that do not work as advertised and are deliberate fabrications (fraud). Thats the purpose of string theory.. passing off bogus science and engineering in the small as legitimate to reap obscene profits. And non observable because I bet they imbed their all subsuming "Grand Theory of Everything" into a hocus pocus "quantum" (remember String theory is more fundamental than quantum mechanics) processor run by Google. If you say "string theory is garbage" but its so big that you cannot understand it all then you lose.

    Of course this is tin foil hat stuff. Roger takes an optimistic outlook in his book that science will continue to progress. I say it definitely won't in the era of internetworked communications. The singularity is an increasing wealth concentration due to ignorance of science, not an uplifting of standard of living.

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  8. Ensemble interpretation conjured up by Popper and supported by Einstein. Gee, I hope this isn't another case of physicists supporting it because of Einstein idolizing? But, as they said with "Nobody ever got fired buying IBM"...I guess the same applies here...after all, guess who is the most popular scientist of all time at the Nobel prize website?

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  9. Uh oh, I found some more plagiarizers in: "E.C.G. Stueckelberg, An Unconventional Figure of Twentieth Century Physics" c.2009 by by Editors Lacki, Ruegg, Wanders

    "While developing his grand “field theory of matter” of the late 1930s, Stueckelberg
    forged some of the basic tools that permitted contemporary and later successes
    of quantum field theory."

    .....

    "Whether or not this isolation is judged unfair, it prevented Stueckelberg
    from inflecting the course of theoretical physics as much as his genuine creativity
    could have done. His unitary field theory of 1936–39 nonetheless
    anticipated several features of modern grand-unified theories, and contained
    Yukawa’s theory as a particular case. The tools he developed in this earlier
    period permitted his and his collaborators’ post-war progress on renormalized
    quantum electrodynamics, including important results on regularization,
    causal Green functions, and S-matrix theory. Had these results been
    expressed in a form as seductive as Feynman’s, Schwinger, and Tomonaga’s,
    and Freeman Dyson’s contemporary writings, Stueckelberg would be more
    often recognized as a central figure of this extraordinary episode of the history
    of physics."
    ...

    "Now,
    we do not think that the value of Feynman’s fabulous contribution to physics
    is in any way diminished by the historical fact that Stueckelberg had already
    come up with the classical and quantum interpretation of an antiparticle as a
    particle going backwards in time. With hindsight, one can only lament that
    Stueckelberg’s papers, published during the war in French in a journal of neutral
    Switzerland, did not receive the attention they should have merited."
    ....

    "In
    general, Stueckelberg’s style, language and choice of journals did not favour
    the propagation of his ideas. He was quite isolated and his work progressed
    in parallel with those of celebrities like R. P. Feynman, J. Schwinger and S.
    Tomonaga. These circumstances explain why Stueckelberg’s contributions
    are so little known and may seem marginal. It is, in fact, unquestionable that
    some of his findings have a deep and lasting importance, such as his showing
    that collision processes cannot be understood if their causal time evolution is
    ignored."

    PHYSICS: Its not what you know but its who you know and how its presented

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  10. Physicist Tony Rothman said terrible things about all of Physics in the 2011 May-June issue of American Scientist in the article "The Man Behind the Curtain: Physics is not always the seamless subject it pretends to be"

    "Nevertheless, as a physicist travels along his (in this case) career, the hairline cracks in the edifice become more apparent, as does the dirt swept under the rug, the fudges and the wholesale swindles, with the disconcerting result that the totality occasionally appears more like Bruegels Tower of Babel as dreamt by a modern slumlord, a ramshackle structure of compartmentalized models soldered together into a skewed heap of explanations as the whole jury-rigged monstrosity tumbles skyward"

    ...

    "One doesn't have to go so far in quantum theory to be confused. The concept of electron "spin" is basic to any quantum mechanics course, but what exactly is spinning is never made clear. Wolfgang Pauli, one of the concept's originators, initially rejected the idea because if the electron was to have a finite radius, as indicated by certain experiments, then the surface would be spinning faster than the speed of light. On the other hand, if one regards the electron as a point particle, as we often do, then it is truly challenging to conceive of a spinning top whose radius is zero, not to mention the aggravation of infinite forces"

    Then he attacks the 2-slit experiment:

    "....Rather than describing how the light interacts with the slits, thus explaining why it behaves as it does, we merely demand that the light wave meet certain conditions at the slit edge and forget about the actual forces involved. The results agree well with observation, but the most widely used of such methods not only avoids the guts of the problem but is mathematically inconsistent"

    He goes on and on...attacking Lagrangian mechanics, ....etc

    "The great swindle of of introductory physics is that every problem has an exact solution. Not only that, students are expected to find it.

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