Microphysical reality and quantum formalism : proceedings of the Conference 'Microphysical Reality and Quantum Formalism', Urbino, Italy, September 25th - October 3rd, 1985
Microphysical Reality, Quantum Formalism, Alwyn van der Merwe, F. Selleri, Gino Tarozzi
Quantum Measurements.- Quantum mechanics of macroscopic systems and measurement processes.- The haunted measurement in quantum theory.- A quantum-statistical model of quantum measurement.- Potential and real states in quantum mechanics.- Wave function collapse in the ensemble interpretation.- Nonlinear models for quantum-mechanical measurements.- Meaning and measurability of nonlocal quantum states.- New Developments of Quantum Theory.- The mathematical expression of the uncertainty principle.- Quantization of Hamiltonian theories based on a probability operator.- Classical to quantum: A generalized phase transition.- Quantum description of microscopic and microscopic systems: Old problems and recent investigations.- Towards a process formalism in quantum physics.- A generalized Schroedinger formalism from a Hamiltonian flow in a higher dimensional space.- How the nonlinear phenomena impose the reinterpretation of quantum mechanics.- On the equivalence between the superposition principle and a global gauge invariance.- Meanings of Quantum Theory.- The 2-photon elementary quantum phenomenon and spacetime structure.- Causality as indentified with conditional probability and the quantal nonseparability.- Realism versus positivism: An attempt at reconcilement in the Einstein-Bohr debate.- Four-dimensional realism and waves carrying physical data codedly as keys to understandable models.- Testing interpretations of quantum mechanics.- On the relation between the recent new statistical prediction of quantum mechanics by Albert, Aharonov, and D'Amato, the EPR reasoning, and Bell's Inequality.- Beyond quantum theory: A realist psycho-biological interpretation of physical reality.- Locality, causality, quantum events, and all that.- The Einstein-Bohr debate: I. The background.- Contingency and lawfulness: Conditions for encounter.- Epr Paradox: Critical Examinations.- Towards a realist theory of measurement.- The tacit postulate on single events and the comparison of classical and quantum spin correlation experiments.- Weak realism for pairs of correlated systems.- Comments on EPR, locality and reality.- The EPR and the proposal of action at a distance.- The discription of separated systems and quantum mechanics and a possible explanation for the probabilities of quantum mehanics.- Against dualism: An observation concerning non-locality.- Bell's theorem: A note on locality.- EPR paradox considered as a criticism of the statevector reduction in the quantum mechanical description of correlated separated systems.- EPR and the strange nature of the quantum state or why I can live with EPR.- Why the EPR paradox has been resolved in favor of Einstein.- Probability and the way out of the great quantum muddle.- Where lies the mistake in the clauser and Home proof of Bell's theorem?.
Quantum Measurements.- Quantum mechanics of macroscopic systems and measurement processes.- The haunted measurement in quantum theory.- A quantum-statistical model of quantum measurement.- Potential and real states in quantum mechanics.- Wave function collapse in the ensemble interpretation.- Nonlinear models for quantum-mechanical measurements.- Meaning and measurability of nonlocal quantum states.- New Developments of Quantum Theory.- The mathematical expression of the uncertainty principle.- Quantization of Hamiltonian theories based on a probability operator.- Classical to quantum: A generalized phase transition.- Quantum description of microscopic and microscopic systems: Old problems and recent investigations.- Towards a process formalism in quantum physics.- A generalized Schroedinger formalism from a Hamiltonian flow in a higher dimensional space.- How the nonlinear phenomena impose the reinterpretation of quantum mechanics.- On the equivalence between the superposition principle and a global gauge invariance.- Meanings of Quantum Theory.- The 2-photon elementary quantum phenomenon and spacetime structure.- Causality as indentified with conditional probability and the quantal nonseparability.- Realism versus positivism: An attempt at reconcilement in the Einstein-Bohr debate.- Four-dimensional realism and waves carrying physical data codedly as keys to understandable models.- Testing interpretations of quantum mechanics.- On the relation between the recent new statistical prediction of quantum mechanics by Albert, Aharonov, and D'Amato, the EPR reasoning, and Bell's Inequality.- Beyond quantum theory: A realist psycho-biological interpretation of physical reality.- Locality, causality, quantum events, and all that.- The Einstein-Bohr debate: I. The background.- Contingency and lawfulness: Conditions for encounter.- Epr Paradox: Critical Examinations.- Towards a realist theory of measurement.- The tacit postulate on single events and the comparison of classical and quantum spin correlation experiments.- Weak realism for pairs of correlated systems.- Comments on EPR, locality and reality.- The EPR and the proposal of action at a distance.- The discription of separated systems and quantum mechanics and a possible explanation for the probabilities of quantum mehanics.- Against dualism: An observation concerning non-locality.- Bell's theorem: A note on locality.- EPR paradox considered as a criticism of the statevector reduction in the quantum mechanical description of correlated separated systems.- EPR and the strange nature of the quantum state or why I can live with EPR.- Why the EPR paradox has been resolved in favor of Einstein.- Probability and the way out of the great quantum muddle.- Where lies the mistake in the clauser and Home proof of Bell's theorem?.
1. Quantum Mechanics, Reality and Separability: Physical Developments of the Einstein-Podolsky-Rosen Argument.- Realism in Quantum Mechanics and a New Version of the EPR Experiment.- Discussion: M. Cini, F. De Martini, K. Kraus, T.W. Marshall, K.R. Popper, H. Rauch, M.C. Robinson, F. Selleri, J. Six, G. Tarozzi, J.-P. Vigier..- The Physical Origin of the Einstein-Podolsky-Rosen Paradox.- Does the Bell Inequality Hold for All Local Theories?.- Is it Possible to Save Causality and Locality in Quantum Mechanics?.- Einstein-Podolsky-Rosen Experiments and Macroscopic Locality.- On the Compatibility of Local Realism with Atomic Cascade Experiments.- Is the Einstein-Podolsky-Rosen Paradox Demanded by Quantum Mechanics?.- Infinite Wave Resolution of the EPR Paradox.- On Non Local Influences.- Einstein Locality for Individual Systems and for Statistical Ensembles.- Can Nondetected Photons Simulate Nonlocal Effects in Two-Photon Polarization Correlation Experiments?.- 2. The Stochastic Interpretation of Quantum Processes.- Quantum Theory of Measurement without Wave Packet Collapse.- A Causal Fluidodynamical Model for the Relativistic Quantum Mechanics.- On the Nonlinear Schrodinger Equation.- Recent Developments in de Broglie Nonlinear Wave Mechanics.- The Role of the Quantum Potential in Determining Particle Trajectories and the Resolution of the Measurement Problem.- When is Statistical Theory Causal?.- Radiation Damping and Nonlinearity in the Pilot Wave Interpretation of Quantum Mechanics.- Stochastic Electrodynamics and the Bell Inequalities.- Nonlocal Quantum-Potential Interpretation of Relativistic Actions at a Distance in Many-Body Problems.- 3. The Realistic Interpretation of the Wave Function: Experimental Tests on the Wave-Particle Dualism.- Third Kind Measurements and Wave-Particle Dualism.- Quantum Effects in the Interference of Light.- Tests of Quantum Mechanics by Neutron Interferometry.- A Unified Experiment for Testing both the Interpretation and the Reduction Postulate of the Quantum Mechanical Wave Function.- Epilogue.- Evolutionary Epistemology.
This article surveys a selection of key conceptual and interpretational developments in quantum mechanics, tracing the theory from its foundational postulates to contemporary discussions of measurement, nonlocality, and the emergence of classicality. Beginning with the structure of Hilbert space and the postulates governing state evolution and measurement, the epistemic stance of the Copenhagen interpretation and its modern reformulations are examined. The Einstein-Podolsky-Rosen argument, Bell's theorem, and Hardy's paradox are then discussed as probes of locality and realism, alongside the deterministic but explicitly nonlocal de Broglie-Bohm theory. The measurement problem and the implications of contextuality are analyzed in relation to objective collapse models, which introduce new physical dynamics to account for definite outcomes. Finally, the role of decoherence in the suppression of interference and the emergence of classical behavior is explored, together with the interpretational frameworks of many-worlds and consistent histories. This material aims to provide a coherent introductory overview of how several of the most prominent interpretations address the central concern of what quantum mechanics tells us about the nature of physical reality.
The Italian Debate on Quantum Paradoxes.- 1. The Epistemological Roots of Quantum Paradoxes.- Waves, Particles and Complementarity.- Chance: Chaos or Logic?.- Some Critical Considerations on the Present Epistemological and Scientific Debate on Quantum Mechanics.- 2. Einstein Locauty, Separable Reality, and Quantum Correlations.- Physical Consequences of Reality Criteria for Quantum Phenomena.- Possible Link Between EPR Paradox and Waves.- A Criticism of Some Recently Proposed Models that Violate the Bell Inequality.- A Phenomenological Analysis of the EPR Argument.- 3. Causal and Deterministic Interpretations of Quantum Formausm.- Causal versus Orthodox Interpretation of Quantum Mechanics.- Perspectives of Physical Determinism.- Determinism, Separability, and Quantum Mechanics.- 4. Quantum Theory and Gravitation.- Can Singularities and Multidimensional Spaces Influence the Evolution of Quantum Mechanical Systems?.- Subquantum Mechanics and Graviton Blas.- 5. Logic and Probability in Quantum Mechanics.- Foundations of Quantum Mechanics. A Quantum Probabilistic Approach.- On the Adequacy of a Nonclassical Logic for Quantum Theory.- Remarks on the Hypothesis of Hidden Variables.- 6. Historical Developments of the Einstein-Bohr Controversy.- Historical Considerations on the Conceptual Experiment by Einstein, Podolsky and Rosen.- Continuity and Discontinuity: The Einstein-Bohr Conflict of Ideas and the Bohr-Fock Discussion.- How Italian Philosophy Reacted to the Advent of Quantum Mechanics in the Thirties.- Italian Studies in the Foundations of Quantum Physics. A Bibliography (1965-1985).
This article surveys a selection of key conceptual and interpretational developments in quantum mechanics, tracing the theory from its foundational postulates to contemporary discussions of measurement, nonlocality, and the emergence of classicality. Beginning with the structure of Hilbert space and the postulates governing state evolution and measurement, the epistemic stance of the Copenhagen interpretation and its modern reformulations are examined. The Einstein–Podolsky–Rosen argument, Bell’s theorem, and Hardy’s paradox are then discussed as probes of locality and realism, alongside the deterministic but explicitly nonlocal de Broglie–Bohm theory. The measurement problem and the implications of contextuality are analyzed in relation to objective collapse models, which introduce new physical dynamics to account for definite outcomes. Finally, the role of decoherence in the suppression of interference and the emergence of classical behavior is explored, together with the interpretational frameworks of many-worlds and consistent histories. This material aims to provide a coherent introductory overview of how several of the most prominent interpretations address the central concern of what quantum mechanics tells us about the nature of physical reality.
This paper starts with the observation that the combination of the so-calld EPR argument and Bell's theorem reveals one of the most paradoxical features of quantum reality, i.e. the no-separability of two contingent events. If we accept the conclusion of the revised EPR argument together with Bell's theorem, we are necessarily led to the denial of local causality which was presupposed by the original version of Einstein's criticism against quantum physics.. As the concept of local causality is a cornerstone of Einstein's theory of relativity, we next consider the problem of compatibility between the theory of relativity and quantum physics. Popper's proposal of going back to Lorentz's theory is examined and rejected because the quantum correlation of EPR is not to be interpreted as “an action at a distance” which we can control and use as the operational definition of absolute simultaneity. An inquiry into something like aether as hidden reality behind the theory of relativity is considered as retrogressive as the so-called hidden variable theory of quantum physics. Accepting the non-separability of local elements of reality as the undeniable fact, we discuss the possibility of a realistic interpretation of quantum physics which transcends scientific materialism and classical determinism. As an example of such projects, Stapp's theory is examined with respect to a Whiteheadean process philosophy which provides the meta-physical background for his realistic interpretation of quantum physics. Finally, we present another version of quantum meta-physics based on “the philosophy of organism” which is broad enough to include observer and observed, local causality and non-local correlation, space and time, and potentiality and actuality in the inseparable unity of physical reality.
List of participants Preface Part I. Introduction: 1. The function of the colloquium - editorial 2. The conceptual problem of quantum theory from the experimentalist's point of view O. R. Frisch Part II. Niels Bohr and Complementarity: The Place of the Classical Language: 3. The Copenhagen interpretation C. F. von Weizsacker 4. On Bohr's views concerning the quantum theory D. Bohm Part III. The Measurement Problem: 5. Quantal observation in statistical interpretation H. J. Groenewold 6. Macroscopic physics, quantum mechanics and quantum theory of measurement G. M. Prosperi 7. Comment on the Daneri-Loinger-Prosperi quantum theory of measurement Jeffrey Bub 8. The phenomenology of observation and explanation in quantum theory J. H. M. Whiteman 9. Measurement theory and complex systems M. A. Garstens Part IV. New Directions within Quantum Theory: What does the Quantum Theoretical Formalism Really Tell Us?: 10. On the role of hidden variables in the fundamental structure of physics D. Bohm 11. Beyond what? Discussion: space-time order within existing quantum theory C. W. Kilmister 12. Definability and measurability in quantum theory Yakir Aharonov and Aage Petersen 13. The bootstrap idea and the foundations of quantum theory Geoffrey F. Chew Part V. A Fresh Start?: 14. Angular momentum: an approach to combinatorial space-time Roger Penrose 15. A note on discreteness, phase space and cohomology theory B. J. Hiley 16. Cohomology of observations R. H. Atkin 17. The origin of half-integral spin in a discrete physical space Ted Bastin Part VI. Philosophical Papers: 18. The unity of physics C. F. von Weizsacker 19. A philosophical obstacle to the rise of new theories in microphysics Mario Bunge 20. The incompleteness of quantum mechanics or the emperor's missing clothes H. R. Post 21. How does a particle get from A to B? Ted Bastin 22. Informational generalization of entropy in physics Jerome Rothstein 23. Can life explain quantum mechanics? H. H. Pattee 24. Discussion: phenomena and sense data in quantum theory D. S. Linney and C. F. von Weizsacker Index of persons Index of subjects.