Objectivity of the Quantum Theory

Quantum objects and their theory *
The idealistic interpretation of Quantum Theory *
The problem of measuring *
The wave-particle-dualism *
Complementarity *
The EPR-Argument *
Nature of our world *
A new interpretation: Decoherence*
  A picture
about the problem.

Quantum objects and their theory

Of course there is some difference between the things in the "outer world" and our theories about them. Although Schelling and Hegel were convinced about the deep identity of thought and world, they approve some differences on the way to this identity.

If there should be intelligence, the intelligence must step out of the synthesis to produce it by consciousness [...]. (Schelling 1800, p. 141).

In the sciences of nature we use several prerequisites. We have to distinguish the different aspects of the actuality (Wirklichkeit), which are dialectically contradictory, in order to have the possibility to compare and measure them and to work with mathematics, which is without dialectical contradictions (Wahsner 1993/1996, p. 187).

Than we have on the one hand the "outer world" and on the other hand our "picture" of it. With respect to Classical Mechanics people often think that it deals with ordinary bodies of the outer world. But this is a misunderstanding.

In Quantum theory this misunderstanding leads to great problems of interpretation. We donít speak about "little quantum-bodies". Quantum theory is about "states", which are defined as vectors in a special space, the mathematical Hilbertspace and mathematical defined operators in this space, the "observables", give the connection to the observable world. Operators in this Hilbertspace have astonishing characteristics: They are not exchangeable ("nichtkommutativ") and therefore some observables (like place and impulse and time and energy) are not simultaneously measurable very exactly. And some phenomena depend on our devices (dualism of wave and particle). It was shown that these astonishing characteristics correspond to results of practical experiments in the quantum world. It seems, our theory is not false.

The idealistic interpretation of Quantum Theory

The influence of our experiment practice gives the rise to some idealistic interpretations. Fritjof Capra thinks, "the human consciousness plays an important role in the course of observation" (Capra 1982/1988, S. 90):

My conscious decision how I want to observe the electrons determines the characteristics of the electron to a certain degree. If I ask a particle-question Ė I will get a particle-answer. If I ask a wave-question Ė I will get a wave-answer. (Capra 1982/1988, S. 91)

Not bad. But the following sentence is to be the conclusion:

The electron has no characteristics, which are independent from our consciousness. [Ö] The structures, which are observed by scientists in nature, are closely connected with the structures of the consciousness, with their conceptions, thoughts and values. (Capra 1982/1988, S. 91)

Capra refers to a remark of Heisenberg, that "the >>path<< of the electron comes into being through our observation" (Heisenberg 1963, p. 22).

I think Capra ignores another important remark of Heisenberg:

Of course we are not allowed to misunderstand the insertion of an observer in such a sense, that subjectivist features are brought in the description of nature. The observer has merely the function to record; but it doesnít matter, if the observer will be a device or a living being. The record, i.e. the transition from possibility to the facts, is used and canít leave out. (Heisenberg 1990, p. 128).

And more clear:

Surely the quantum mechanics doesnít contain subjectivist features; it doesnít insert spirit or consciousness of the physicist as a part of the atomic event. (Heisenberg 1990, p. 39).

The problem of measuring

The possibility for the "behaviour" of a quantum-system is given by the motion-equation (Schrödinger-equation) for the state-vector Y and the possibilities, which are realizing by chance (More about laws in microphysics see: Schlemm 2002b).

Before measuring we have only information about the discrete spectrum of eigenvalues of observables, i.e. a statistical proposition as information about the state. (The statistics belongs to repeated measurements, not an ensemble of particles!)

If we measure, then we act in a materialistic way with our technical devices. The quantum-objects and the device become one system; they are not longer independent from each other. The wave function is not a product of the wave function of the object and the wave function of the device (Meier, Zimdahl 1986). Now a projection happens to one eigenstate, which is determined only statistically, and we canít know it before measuring. This is often called "reduction of wavefunction" Ė but we can get more precisely information now. In our measurement we have interrupted the whole quantum process, we had neglected certain aspects of motion (Hörz 1964, p. 135).

We can analyse the measuring process in three phases (Böhm 1988, p. 189):

1. Preparation: The macroscopic devices are prepared.

2. Interaction: The "elementar quantum-phenomenon" (Bohr) takes place. There the statefunction is developed to eigenvectors. There comes into being a state of superposition.

3. Registration: A macroscopic effect is produced. On special eigenstate is selected, which corresponds to one projected part of the whole Hilbertspace. This eigenstate corresponds to the "measuring quantity" ("magnitude"?), which is only "a part" of the formerly state. Only after the 3. phase Bohr speaks about a "quantum phenomenon". It covers both micro- and macroworld.

The wave-particle-dualism

Experiments with quantum-objects show astonishing characteristics. We can see characteristics of waves with light, if we observe light-interference at grids and we can see characteristics of particles, if we observe the light-electric effect. We canít say, if light "is" a wave or a particle current. The cause of that feature is, that light is neither a wave nor a particle current at all. It seems that the light "decides" to be a wave or a particle-current in dependence of our devices (of course even the cause of the "decision" would be the materialistic device, not our subjective consciousness!). But there mustnít be a decision at all, if "light" is quite another phenomenon. We produce misunderstandings if we identify quantum objects with classical imaginable objects like waves and particles.

Complementarity

Above I remarked, that operators in a Hilbertspace lead to uncertainty or nonsharpeness of measuring quantities. Some observables (like place and impulse and time and energy) are not simultaneously measurable very exactly. Niels Bohr generalized, that in quantum theory a time-space-description of the world and causality are complementary (Bohr 1931, p. 36). The question now is: what does this mean? Is there any disturbance of the place of the quantum-object by the influence of the impulse of the waves of our device? Is there any undisturbed path of a "little body" at all? The answer, that Bohr gave, is: No, we are not allowed to use our classical imagines of "bodies" and "paths" with exact space-impulse-coordinates. The spaces (or impulses) are not disturbed. If we observe one of the complementary quantities, the other quantity is not defined! (see Röseberg 1978, p. 107).

Only if we donít consider this rule, we are seduced to think that our devices disturbed the given path or even our consciousness would do this.

The EPR-Argument

Einstein, Podolski and Rosen couldnít accept the described Copenhagen interpretation. They couldnít accept, that two physical quantities canít simultaneously exactly be measured. They suggested to perfect the theory by "hidden parameters". To show, that the given description of quantum mechanics is incomplete, they did a thought-experiment. In this though-experiment we see, that we canít reformulate the quantum- theory and that the measuring at one of two correlated "quantums" disturbs the other "quantum". That means, that the two correlated "quantums" are not-factorisable, not localisable. It is shown, that quantum theory is complete, although there is non-localizability. It is interesting, that Bohr and Einstein and the others never did interpret this as a distance-effect, as many people now. The non-localizability doesnít speak about "two particles, which are interconnected", but about one superposited state. We spoke about the difference of "states" in quantum theory and "things" above. Even if we usually speak about "photons" in experiments to test the theorem of Bell (which was derived to decide the questions whether there is a perfection of quantum theory or not), we have to learn that there doesnít exist isolated things. But it isnít necessary to conclude that there is a spiritual identity, that appears in the interconnectedness of quantum objects, as Capra and other people do.

Nature of our world

Quantum Theory shows us, that our world in a more fundamental level is not imaginable as "mechanistically" sum or interaction of "really" isolated things. The mechanistical word-view assumes, that bodies are isolable, space and impulse would be infinitely exactly measurable, other characteristics would be unessential and the law of dynamic motion would be identical with causality. (The mechanistical worldview is not necessarily identical with the science of Newtonian Mechanics). Quantum objects show that these assumptions can failure. Its objects have an inner structure, work permanently in interactions, are determined by more characteristics than space and impulse and have statistical laws (see about statistical laws Schlemm 2002a).

In a poetic speech Capra is right to emphasize the universal interconnectedness (dialecticians did know that long befor Quantum Theory about the "normal world" too.). The world itself is a dialectically universal connection, all particulars are merely relative. To "comprehend" (begreifen) that world, we need dialectical thinking. All analytical methods are subordinated.

A new interpretation: Decoherence

In 1975 Ulrich Röseberg supposed that the cause of the mysterious features of quantum objects is based in interactions with objects from the physical vacuum. He wrote:

The interaction with this [vacuum, A.S.] could be responsible for the nondifferentiability of the trajectories. If this hypothesis would be valid, then the characteristics of motion of microobjects would be an expression of the space-time-characteristics of the microworld. The probabilistic statements of the theory would be arise from the effect of lower levels of structure (vacuum) into the higher level (microobjects). (Röseberg 1975, p. 95). Al the time the materialistic interpretation of the interpretation of Copenhagen assumed that the statistic behaviour in the quantum world would show real interactions. The original Copenhagen interpretation used interactions between micro- and macroworld to explain the "collapse of wavefunction". The Decoherence interpretation moves the border and considers other microworld-interaction as cause of the "decoherence (Zureck 1991). Röseberg didn't know that already in 1970 the physicist Zeh suggested to rename the total superposition of states in "coherent". Then the former "collapse of wavefunction" is the "decoherence" of this coherent superposition. Decoherence describes the fleeting interactions between an object and its environment, which allow the object to select on concrete state from a lot of simultaneous possibilities. (Hergett, p. 6). Such a selection from a field of possibilities is no brand-new for non-mechanizistians (see Schlemm 2002b). The conception of decoherence makes clear that we have the effect of decoherence without human observer (see Tegmark, Wheeler 2001, Zureck 1991). Tegmark and Wheeler discuss three several forms of interactions. Firstly the interactions between subject and object and secondly the interactions between the subject and (quantum) environment and thirdly the interactions between object and its environment. (Zurak uses instead of "subject" an detector, see Zureck 1991, p. 39) It is shown that the primary interaction is that between the object and its environment. The authors (Tegmark, Wheeler) then discuss the situation of an observer. If he could isolate the object from its environment, his own neuronal activity would cause decoherence and therefore we are never able to perceive the superposition itself. I think that is an invitation for esotericians, who can think that our (maybe controlled) activity of our mind (through our neurons) can influence the foundation of the world. But I don't think so because the objects are never isolable and the other interactions will be much more powerful. When we perceive a system, we intercept a tiny fraction of the environment that has interacted with that system. (Zurek, quot. in Siegfried 2002). If only for that reason the characteristics of quantum objects disappear in the macroscopic world. About the transition from quantum to classical Zurek writes: Decoherence destroys superpositions. The environment induces, in effect, a superselection rule that prevents certai superpositions from being observed. Only states that survive this process can become classical. (Zurek 1991, p. 44).The coherence will be a "measurement by the environment" (Hergett, p.10). That encourages realistic/materialistic interpretations of quantum theory. Classical objective reality can emerge from the quantum substrate, the decoherence doesn't need an observer.
The decisive innovation of the decoherence-conception is the consideration of the influence of the environment and the consideration of the object and the measuring instrument as open systems (see Müller 2003). We see: a realistic view on objects of science leads us to accept more complex, no isolated states as the "real", the "objective" states! Reality is not the sum of isolated objects, it is a complex totality!

Is the Quantum Theory a non-classical theory?

V. Stepin assumes, following i.e. L.I.Mandelshtam, that there is an important difference between classical and nonclassical strategies of theoretical investigation.

The classical strategy is characterised by a clear meaning of the used "mathematical magnitudes" and we have at first the link between mathematical magnitudes and real objects and than follows the establishment of the equations, the laws.

The nonclassical, more modern way is another: "Now first of all we try to guess the mathematical apparatus operating magnitudes meaning of which (at least partly) is entirely unclear" (quot. Mandelshtam). More detailed Stepin assumes, that "in order to find laws of a new area of phenomena, we take mathematical expressions for laws of a neighboring correlations between physical magnitudes. the obtained correlations are regarded as hypothetical equations describing new physical processes." (Stepin I, p. 2).

As we know the quantum theory began with the quantum hypothesis of Planck about the prohibition of non whole number energies in a harmonic oscillator. The difference of classical sciences and the "non-classical" quantum theory here is, that in classical physics the nature doesnít jump and in the non-classical quantum world it does. We can follow the historic way of finding the new theory and I think weíll find no such new strategy, as Stepin assumes. Always there is a great difference of the way of finding the theory and the deductive representation of their results. If you compare the usually imagined way of classical physics and the deductive representation of modern scientists, you can think, that there is such a great difference. But if you compare the historic way of both and the deductive representation you will find more correspondences.

Literature:

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Bohr, Niels (1931): Atomtheorie und Atombeschreibung. Berlin: Julius Springer.
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Capra, Fritjof (1987/1990): Das Neue Denken. Bern, München, Wien: Scherz Verlag.
Hergett, Waldemar: Dekohärenz. In: http://www.mpi-hd.mpg.de/ato/lasercool/teaching/Materiewellen/dekohaerenz.pdf.
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Meier, Wolfgang; Zimdahl, Winfried (1986): Einige Aspekte der Interpretation des quantenmechanischen Messprozesses. In: Wiss. Zeitschr. Friedrich-Schiller-Univ. Jena, Naturwiss. R., 35. Jg. (1986), H.6, S. 781-788.
Müller, Rainer (2003, Orig.-jahr unbekannt): Dekohärenz - vom Erscheinen der klassischen Welt. In: Internet http://www.cip.physik.uni-muenchen.de/~milq/kap6/images/decoher.pdf
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Siegfried, Tom (2002): Reality check: Scientists share ideas on the mysteries of existence. In: The Dallas Morning News 03/31/2002, see Internet http://www.kmsb.com/technology/sci/reality.506562.html (29.01.2003)
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Tegmark, Max; Wheeler, John A. (2001): 100 Jahre Quantentheorie. In: Spektrum der Wissenschaft Heft 4/2001.
Wahsner, Renate (1993/1996): Gott arbeitet nicht. Zur Notwendigkeit, Karl Marx einer optimalen Messung zu unterziehen In: Wahsner 1996, S. 175-202.
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Zurek, Wojciech H. (1991): Decoherence and the transition from quantum to classical. In: Physics Today October 1991, p. 36-44.




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