Response to Stuart Kauffman: The Cosmic Mind and NIODA

Non-locality, indeterminacy, the meaning of the Schrödinger equation, and quantum measurements are interpretation issues in quantum mechanics that go beyond our typical view of the world through the classical physics lenses of the mechanistic determinism. In “Cosmic Mind?,” Stuart Kauffman offers an interpretation of the Schrödinger equation and quantum measurements that might support a cosmic mind. Robert John Russell in NIODA uses the indeterminacy to offer a mechanism for God to interact with nature. This response reviews these two interpretations of quantum mechanics with respect to the two-slit and EPR experiments and how these two interpretations of quantum mechanics could solve issues of interpretations.     

Mandelstam's interpretation of quantum mechanics in comparative perspective

In his 1939 Lectures, the prominent Soviet physicist L. I. Mandelstam proposed an interpretation of quantum mechanics that was understood in different ways. To assess Mandelstam's interpretation, we classify contemporary interpretations of quantum mechanics and compare his interpretation with others developed in the 1930s (the Copenhagen interpretation and the statistical interpretations proposed by K. R. Popper, H. Margenau, and E. C. Kemble). We conclude that Mandelstam's interpretation belongs to the family of minimal statistical interpretations and has much in common with interpretations developed by American physicists. Mandelstam's characteristic message was his theory of indirect measurement, which influenced his discussion of the “reduction of the wave packet” and the Einstein, Podolsky, and Rosen argument. This article also reconstructs what lay behind Mandelstam's interpretation of quantum mechanics. This was his operationalism, by virtue of which his interpretation resembled Kemble's, in which the statistical and Copenhagen views had been combined. Like Popper and Margenau, Mandelstam followed R. von Mises's empirical conception of probability. Mandelstam, like the other proponents of the statistical approach to quantum mechanics, was affected by the culture of macroscopic experimentation with its emphasis on statistical (collective) measurement.     

Realism and Objectivism in Quantum Mechanics

The present study attempts to provide a consistent and coherent account of what the world could be like, given the conceptual framework and results of contemporary quantum theory. It is suggested that standard quantum mechanics can, and indeed should, be understood as a realist theory within its domain of application. It is pointed out, however, that a viable realist interpretation of quantum theory requires the abandonment or radical revision of the classical conception of physical reality and its traditional philosophical presuppositions. It is argued, in this direction, that the conceptualization of the nature of reality, as arising out of our most basic physical theory, calls for a kind of contextual realism. Within the domain of quantum mechanics, knowledge of ??reality in itself??, ??the real such as it truly is?? independent of the way it is contextualized, is impossible in principle. In this connection, the meaning of objectivity in quantum mechanics is analyzed, whilst the important question concerning the nature of quantum objects is explored.     

The Status of our Ordinary Three Dimensions in a Quantum Universe 1

There are now several, realist versions of quantum mechanics on offer. On their most straightforward, ontological interpretation, these theories require the existence of an object, the wavefunction, which inhabits an extremely high‐dimensional space known as configuration space. This raises the question of how the ordinary three‐dimensional space of our acquaintance fits into the ontology of quantum mechanics. Recently, two strategies to address this question have emerged. First, Tim Maudlin, Valia Allori, and her collaborators argue that what I have just called the ‘most straightforward’ interpretation of quantum mechanics is not the correct one. Rather, the correct interpretation of realist quantum mechanics has it describing the world as containing objects that inhabit the ordinary three‐dimensional space of our manifest image. By contrast, David Albert and Barry Loewer maintain the straightforward, wavefunction ontology of quantum mechanics, but attempt to show how ordinary, three‐dimensional space may in a sense be contained within the high‐dimensional configuration space the wavefunction inhabits. This paper critically examines these attempts to locate the ordinary, three‐dimensional space of our manifest image “within” the ontology of quantum mechanics. I argue that we can recover most of our manifest image, even if we cannot recover our familiar three‐dimensional space.     

God, Chaos, and the Quantum Dice

A recent noninterventionist account of divine agency has been proposed that marries the probabilistic nature of quantum mechanics to the instability of chaos theory. On this account, God is able to bring about observable effects in the macroscopic world by determining the outcome of quantum events. When this determination occurs in the presence of chaos, the ability to influence large systems is multiplied. This paper argues that, although the proposal is highly intuitive, current research in dynamics shows that it is far less plausible than previously thought. Chaos coupled to quantum mechanics proves to be a shaky foundation for models of divine agency.     

Scientific Representation: Paradoxes of Perspective

David Lewis is a natural target for those who believe that findings in quantum physics threaten the tenability of traditional metaphysical reductionism. Such philosophers point to allegedly holistic entities they take both to be the subjects of some claims of quantum mechanics and to be incompatible with Lewisian metaphysics. According to one popular argument, the non-separability argument from quantum entanglement, any realist interpretation of quantum theory is straightforwardly inconsistent with the reductive conviction that the complete physical state of the world supervenes on the intrinsic properties of and spatio-temporal relations between its point-sized constituents. Here I defend Lewis's metaphysical doctrine, and traditional reductionism more generally, against this alleged threat from quantum holism. After presenting the non-separability argument from entanglement, I show that Bohmian mechanics, an interpretation of quantum mechanics explicitly recognized as a realist one by proponents of the non-separability argument, plausibly rejects a key premise of that argument. Another holistic worry for Humeanism persists, however, the trouble being the apparently holistic character of the Bohmian pilot wave. I present a Humean strategy for addressing the holistic threat from the pilot wave by drawing on resources from the Humean best system account of laws.     

Bohm's Ontological Interpretation and its Relations to Three Formulations of Quantum Mechanics

The standard mathematical formulation of quantum mechanics is specified. Bohm's ontological interpretation of quantum mechanics is then shown to be incapable of providing a suitable interpretation of that formulation. It is also shown that Bohm's interpretation may well be viable for two alternative mathematical formulations of quantum mechanics, meaning that the negative result is a significant though not a devastating criticism of Bohm's interpretation. A preliminary case is made for preferring one alternative formulation over the other. This revised version was published online in June 2006 with corrections to the Cover Date.     

Subjectivist – observing and objective – participant perspectives on the world: Kant,aquinas and quantum mechanics

Theological thinking is influenced by perspectives on the relation of scientific knowledge to reality. Two paradigms for understanding the nature of human knowledge are considered in relation to quantum mechanics: the subjective-observing perspective of Kant, and the objective-participant perspective of Thomas Aquinas. I discuss whether quantum mechanics necessarily implies a subject centered perspective on reality, and argue, with reference to d'Espagnat's notion of veiled reality, that quantum non-separability challenges this view. I then explore whether the objective-participant perspective of Thomas Aquinas provides a more fruitful context for understanding quantum mechanics. I discuss quantum measurement in terms of the transition from potentiality to actuality, and knowledge as the latent intelligibility of the world realized. However, the negative nature of our knowledge of quantum non-separability also challenges this perspective. Our theological thinking in response to quantum knowledge must therefore proceed tentatively, balancing a via positiva, with a via negativa.     

Consciousness and biological order: Toward a quantum theory of life and its evolution

Biological order is discussed within the context of the idealist interpretation of quantum mechanics. A quantum mechanism is proposed for quantum speciation and for quantum evolution, in general. It is shown that an extension of neo-Darwinism to include quantum evolution via a quantum mechanism can resolve some of the recent controversies that have rattled evolution theory. It is pointed out that the quantum approach has the further benefit of giving a straightforward insight into the nature of life itself. Experimental support for some aspects of the theory is discussed.     

Response to Stuart Kauffman: The Measurement Problem in Quantum Mechanics

Richard Feynman, a 1965 Nobel Prize winner in physics, quoting an unknown philosopher, said: “It is necessary for the very existence of science that the same conditions always produce the same results.” And Feynman's reply: “Well, they don't.” Double-slit experiments with both slits open and the wave interference pattern created by electrons falling on a screen behind the slits speak volumes to those two statements and the interpretive problem created by the non-deterministic behavior of microscopic matter. Quantum mechanics (QM) with its successes over the last 85 years has created the information age, and with insights into nature has given humans an economy concentrated with products based on quantum technology. All this even with questions about the fundamental aspects of measurement in the quantum world still being debated! Discussing the measurement aspect of QM does not require a physics background where physics scholars join other scholarly disciplines engaged in gaining knowledge about the reality of the one world of human experience. The necessary tools for discussion are imagination, speculation, and curiosity. But for a new credible interpretation of the measurement problem, quantum training or a quantum theoretician is required.     

Teilen,Trennen und Vereinen: EPR ohne Holismus

Dividing, Separating and Unifying. EPR Without Holism. In the standard interpretation of quantum mechanics parts of composed systems are correlated in a non-causal way, they are ontologically dependent on each other. In this paper I try to defend traditional realism giving a non-holistic interpretation of the EPR-paradox. An analysis of events in the macroscopic world shows that dividing and unifying objects is quite dif-ferent from changing (modifying) objects. In application to quantum mechanics I argue that a measurement at a given single-system changes (modifies) this object, but the EPR-measurement divides the given object. Therefore this given object is an undivided and dividable One and not a composed system. If parts are produced (by EPR-measurement) correlations do not occur.

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Teilen, Trennen und Vereinen: EPR ohne Holismus

     

Speakable in quantum mechanics

At the 1927 Como conference Bohr spoke the famous words “It is wrong to think that the task of physics is to find out how nature is. Physics concerns what we can say about nature.” However, if the Copenhagen interpretation really adheres to this motto, why then is there this nagging feeling of conflict when comparing it with realist interpretations? Surely what one can say about nature should in a certain sense be interpretation independent. In this paper I take Bohr’s motto seriously and develop a quantum logic that avoids assuming any form of realism as much as possible. To illustrate the non-triviality of this motto, a similar result is first derived for classical mechanics. It turns out that the logic for classical mechanics is a special case of the quantum logic thus derived. Some hints are provided as to how these logics are to be used in practical situations and finally, I discuss how some realist interpretations relate to these logics.     

Macroscopic Oil Droplets Mimicking Quantum Behaviour: How Far Can We Push an Analogy?

We describe a series of experimental analogies between fluid mechanics and quantum mechanics recently discovered by a team of physicists. These analogies arise in droplet systems guided by a surface (or pilot) wave. We argue that these experimental facts put ancient theoretical work by Madelung on the analogy between fluid and quantum mechanics into new light. After re-deriving Madelung’s result starting from two basic fluid mechanical equations (the Navier–Stokes equation and the continuity equation), we discuss the relation with the de Broglie–Bohm theory. This allows to make a direct link with the droplet experiments. It is argued that the fluid mechanical interpretation of quantum mechanics, if it can be extended to the general N-particle case, would have a considerable advantage over the Bohm interpretation: it could rid Bohm’s theory of its non-local character.     

Determinism and locality in quantum mechanics

In current philosophical debate Bell's theorem is often refered to as a proof of the impossibility of determinism in nature. It is argued here that this conclusion is wrong. The main consequence of the theorem is the non-local character of quantum theory itself and it is shown how this quality leads to a contradiction with the theory of relativity. If hidden variable theories are impossible, it is so because no empirically founded interpretation at all can be compatible with both quantum mechanics and relativity.     

Divine Action and Quantum Theory

Recent articles by Nicholas Saunders, Carl Helrich, and Jeffrey Koperski raise important questions about attempts to make use of quantum mechanics in giving an account of particular divine action in the world. In response, I make two principal points. First, some of the most pointed theological criticisms lose their force if we attend with sufficient care to the limited aims of proposals about divine action at points of quantum indetermination. Second, given the current state of knowledge, it remains an open option to make theological use of an indeterministic interpretation of quantum mechanics. Any such proposal, however, will be an exploratory hypothesis offered in the face of deep uncertainties regarding the measurement problem and the presence in natural systems of amplifiers for quantum effects.     

On Quantum Propensities: Two Arguments Revisited

Peter Milne and Neal Grossman have argued against Popper's propensity interpretation of quantum mechanics, by appeal to the two-slit experiment and to the distinction between mixtures and superpositions, respectively. In this paper I show that a different propensity interpretation successfully meets their objections. According to this interpretation, the possession of a quantum propensity by a quantum system is independent of the experimental set-ups designed to test it, even though its manifestations are not.     

In Defence Of The Phase Space Picture

While the Phase Space formulation of quantum mechanics has received considerable attention it has seldom been defended as a viable interpretation. In this paper I expound the Phase Space Picture, use it to provide a quasi-classical ‘hidden variables’ interpretation of quantum mechanics and offer a defence of it against various objections. This revised version was published online in June 2006 with corrections to the Cover Date.     

The classical limit of quantum theory

Both physicists and philosophers claim that quantum mechanics reduces to classical mechanics as 0, that classical mechanics is a limiting case of quantum mechanics. If so, several formal and non-formal conditions must be satisfied. These conditions are satisfied in a reduction using the Wigner transformation to map quantum mechanics onto the classical phase plane. This reduction does not, however, assist in providing an adequate metaphysical interpretation of quantum theory.Earlier versions of this essay received helpful criticism from Bruce Knight, Clark Glymour, and Donald Martin.     

ON THE APPLICABILITY OF THE QUANTUM MEASUREMENT FORMALISM

Customary discussions of quantum measurements are unrealistic, in the sense that they do not reflect what happens in most actual measurements even under ideal circumstances. Even theories of measurement which discard the projection postulate tend to retain two unrealistic assumptions of the von Neumann theory: that a measurement consists of a single physical interaction, and that the topic of every measurement is information wholly contained in the quantum state of the object of measurement. I suggest that these unrealistic assumptions originate from an overly literal interpretation of the operator formalism of quantum mechanics. I also suggest, following Park, that some issues can be clarified by distinguishing the sense of the term 'measurement' occurring in the quantum-mechanical operator formalism, and the sense of 'measurement' that refers to actual processes of gaining information about the physical world.