The ubiquity of chaos in classical mechanics (CM), as opposed to the situation in standard quantum mechanics (QM), might be taken as speaking against QM being the fundamental theory of physical phenomena. Bohmian mechanics (BM), as a formulation of quantum theory, may clarify both the existence of chaos in the quantum domain and the nature of the classical limit. Two interesting possibilities are (i) that CM and classical chaos are included in and underwritten by quantum mechanics (BM) or (ii) that (...) BM and CM simply possess a common region of (noninclusive) overlap. In the latter case, neither CM nor QM alone would be sufficient, even in principle, to account for all of the physical phenomena we encounter. In this talk I shall summarize and discuss the implications of some recent work on chaos and on the classical limit within the framework of BM. (shrink)

The central question addressed in this work is, 'What ontological commitments are entailed by accepting the standard quantum-mechanical formalism as a theoretical framework within which to construct a descriptively adequate physical world picture?' Arguments in recent literature concerning the ontology of quantum mechanics have made claims regarding the indistinguishability and individuality of quantum particles--viz., that quantum particles are indistinguishable in principle and lack any individual identity--as well as the non-separability of quantum systems--viz., that quantum systems cannot be spatially individuated and (...) exhibit inherent or non-supervenient relations. The first theme of this work is that these arguments make certain presuppositions--especially regarding the completeness of quantum mechanics, the criteria of attributing properties to systems, and the metaphysics of individuality--that are not demanded by either logical consistency or empirical adequacy; thus, some of those assumptions may be reasonably rejected, in which case one need not be committed to all of the above conclusions. The second theme is that such interpretive presuppositions, motivated by neither logic nor experiment alone, operate effectively as methodological criteria of theory selection; hence, by rejecting them one opens up possibilities for alternative interpretations of the standard theoretical formalism that have different ontological commitments. The orthodox, modal, and Bohmian interpretations are considered in particular, and their respective options for ontological commitment concerning the above issues are laid out in detail. This then raises the question of the comparative appraisal of these competing interpretations and their respective ontological commitments. The comparative appraisal of the two chief rival interpretations, the orthodox and Bohmian interpretations, is taken up at length. The case is made here that the Bohmian interpretation better exemplifies certain theoretical virtues, satisfies standard criteria of theoretical progress, and fulfills the traditional aim of physical theory than does the orthodox interpretation. Finally, it is argues that the "price" of the Bohmian interpretation--viz., non-locality--is not unreasonable given the results achieved. (shrink)

Statistical mechanics is one of the crucial fundamental theories of physics, and in his new book Lawrence Sklar, one of the pre-eminent philosophers of physics, offers a comprehensive, non-technical introduction to that theory and to attempts to understand its foundational elements. Among the topics treated in detail are: probability and statistical explanation, the basic issues in both equilibrium and non-equilibrium statistical mechanics, the role of cosmology, the reduction of thermodynamics to statistical mechanics, and the alleged foundation of the very notion (...) of time asymmetry in the entropic asymmetry of systems in time. The book emphasises the interaction of scientific and philosophical modes of reasoning, and in this way will interest all philosophers of science as well as those in physics and chemistry concerned with philosophical questions. The book could also be read by an informed general reader interested in the foundations of modern science. (shrink)