When Are Thought Experiments Poor Ones?

A characteristic of contemporary analytic philosophy is its ample use of thought experiments. We formulate two features that can lead one to suspect that a given thought experiment is a poor one. Although these features are especially in evidence within the philosophy of mind, they can, surprisingly enough, also be discerned in some celebrated scientific thought experiments. Yet in the latter case the consequences appear to be less disastrous. We conclude that the use of thought experiments is more successful in science than in philosophy. This revised version was published online in August 2006 with corrections to the Cover Date.     

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.     

The Life and Works of a Bottom-Up Thinker

A brief account is given of the author's life as a physicist and then a priest. The twin foundations of the author's theological endeavors have been a respect for traditional Christian thinking, though not exempting it from revision where this is needed, and a style of argument termed bottom-up thinking, which seeks to proceed from experience to understanding. The diversity of the world faith traditions is perceived as a major source of perplexity. A revised and modest natural theology and the issue of divine action have been at the top of a science and theology agenda. A defense is sketched in realist terms of the metaphysical strategy of using an ontological interpretation of the unpredictabilities of chaos theory to support a notion of top-down causality through active information. The success of Christian theology as a resource of total explanation depends on a credible account of eschatological hope. Reference is made to practical experience of ethics in the public square.     

A study of the spin-Hamiltonian parameters for Cr5+ at the rhombically-distorted tetrahedral P5+ site of Ca2PO4Cl crystal using a two-mechanism model

The complete high-order perturbation formulae of spin-Hamiltonian (SH) parameters (g factors g_i and hyperfine structure constants A_i , where i = x, y, z) containing contributions from both the crystal-field (CF) and charge-transfer (CT) mechanisms (the latter mechanism is neglected in the widely-used CF theory) are established for d¹ ions in rhombic tetrahedra. From these formulae, the SH parameters of Cr⁵⁺ ion at the rhombically-distorted tetrahedral P⁵⁺ site of Ca₂PO₄Cl crystal are calculated. The CF and CT energy levels used in the calculation are obtained from the optical spectra of the studied Ca₂PO₄Cl : Cr⁵⁺ crystal. The calculated results showed reasonable agreement with the experimental values. The signs of the hyperfine structure constants A_i and the relative importance of the CT mechanism to SH parameters are acquired from the calculations.     

Light as a Solution to Puzzles AboutLight

Light is puzzling in modern physics–witness wave-particle duality, the two-slit experiment, and the invariant speed of light. These puzzles are not intrinsic to light but arise from overly narrow views of light. Disregarding the expansive, unitary nature of light that informs everyday experience, modern physics treats light as if it were self-bounded and separable. Further, physics assumes that light is not complicit with observations of light, that the two are separable. By likening light to light-illuminated entities, these attitudes set the stage for puzzles. When,however, conceptions of light are aligned with visual experience, those puzzles become occasions of understanding.This is because visual experience already embodies that aspect of light which physics finds so anomalous: nonseparability. Light's interactive vastness shows up wherever light shows up, and because no observer can back away from light or step outside its integrative embrace, different parts of light (photons) cannot be lifted out ofthe observation as distinct – i.e., distinctly-observed – entities. This revised version was published online in August 2006 with corrections to the Cover Date.     

The presumption of movement

The conceptualisation of movement has always been problematical for Western thought, ever since Parmenides declared our incapacity to conceptualise the plurality of change because our self-identical thought can only know an identical being. Exploiting this peculiar feature and constraint on our thought, Zeno of Elea devised his famous paradoxes of movement in which he shows that the passage from a position to movement cannot be conceptualised. In this paper, I argue that this same constraint is at the root of our incapacity to conceptualise the unseen movement at the micro-level and that the aporetic idea of super-position far from opening the gate on a deeper reality is a symptomatic word for this lack of understanding.

On infinite EPR-like correlations

The paper investigates, in the framework of branching space–times, whether an infinite EPR-like correlation which does not involve finite EPR-like correlations is possible. The authors read earlier versions of this paper at the seminar ‘Chaos and Quantum Information’ at the Jagiellonian University in Kraków on April 16, 2007 and at the seminar ‘On Determinism’ at the University of Bonn on April 20, 2007.     

Science and Theology in the Twenty-First Century

The current interaction of science and theology is surveyed. Modern physics describes a world of intrinsic unpredictability and deep relationality. Theology provides answers to the metaquestions of why that world is rationally transparent and rationally beautiful and why it is so finely tuned for carbon-based life. Biology's fundamental insight of evolutionary process is to be understood theologically as creation "making itself." In the twenty-first century, biology may be expected to move beyond the merely mechanical. Neuroscience will not have much useful interaction with theology until it attains theories of wide explanatory scope. Computer models of the brain do not meet this requirement. A theological style of bottom-up thinking comes closest to scientific habits of thought. Complexity theory suggests that information will prove to be an increasingly important scientific concept, encouraging theology to revive the Thomistic notion of the soul as the form of the body. Another gift of science to theology will lie in providing a meeting point for the encounter of the world faith traditions.     

Discussions

Summary  In their paper, ‘When are thought experiments poor ones?’ (Peijnenburg and David Atkinson, 2003, Journal of General Philosophy of Science 34, 305-322.), Jeanne Peijnenburg and David Atkinson argue that most, if not all, philosophical thought experiments are “poor” ones with “disastrous consequences” and that they share the property of being poor with some (but not all) scientific thought experiments. Noting that unlike philosophy, the sciences have the resources to avoid the disastrous consequences, Peijnenburg and Atkinson come to the conclusion that the use of thought experiments in science is in general more successful than in philosophy and that instead of concocting more “recherché” thought experiments, philosophy should try to be more empirical. In this comment I will argue that Peijnenburg’s and Atkinson’s view on thought experiments is based on a misleading characterization of both, the dialectical situation in philosophy as well as the history of physics. By giving an adequate account of what the discussion in contemporary philosophy is about, we will arrive at a considerably different evaluation of philosophical thought experiments.

For I am convinced that we now find ourselves at an altogether decisive turning point in philosophy, and that we are objectively justified in considering that an end has come to the fruitless conflict of systems. We are already at the present time, in my opinion, in possession of methods which make any such conflict in principle unnecessary. What is now required is their resolute application. (Schlick, ‘The Turning Point in Philosophy’, 1930/1959, p. 54).

     

Separate- versus <Emphasis Type="Italic">common</Emphasis>-common-cause-type derivations of the Bell inequalities

Standard derivations of the Bell inequalities assume a common-common-cause-system that is a common screener-off for all correlations and some additional assumptions concerning locality and no-conspiracy. In a recent paper (Graßhoff et al., The British Journal for the Philosophy of Science, 56, 663–680 (2005)) Bell inequalities have been derived via separate common causes assuming perfect correlations between the events. In the paper it will be shown that the assumptions of this separate-common-cause-type derivation of the Bell inequalities in the case of perfect correlations can be reduced to the assumptions of a common-common-cause-system-type derivation. However, in the case of non-perfect correlations a non-reducible separate-common-cause-type derivation of some Bell-like inequalities can be given. The violation of these Bell-like inequalities proves Szabó’s (International Journal of Theoretical Physics, 39, 911 (2004)) conjecture concerning the non-existence of a local, non-conspiratorial, separate-common-cause-model for a δ-neighborhood of perfect EPR correlations.