Quantum Theory without Observers—Part Two

APR 01, 1998

The paradoxes of quantum theory can be resolved in a surprisingly simple way: by insisting that particles always have positions and that they move in a manner naturally suggested by Schrödinger’s equation.

DOI: 10.1063/1.882241

Sheldon Goldstein

Albert Einstein believed in the possibility of a quantum theory without observers—a version of quan tum theory for which the notions of measurement, observation and observer are not invoked in its very formulation, but rather emerge from an analysis of more fundamental concepts. Niels Bohr believed that such a theory was “in principle” impossible. In part one of this article, I described one approach to such a theory, that of decoherent histories (DH). Although much progress has been made, it could be argued that this approach has not yet yielded a theory that is sufficiently well defined to provide decisive support for Einstein’s view. The theories I discuss in this final part of the article are completely well defined and hence provide a conclusive refutation of Bohr’s impossibility claims.

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References

1. G. C. Ghirardi, A. Rimini, T. Weber, Phys. Rev. D 34, 470 (1986).https://doi.org/PRVDAQ
2. J. S. Bell, Speakable and Unspeakable in Quantum Mechanics, Cambridge U.P. Cambridge, England (1987).
3. G. C. Ghirardi, in Structures and Norms in Science, M. L. Dalla Chiara et al., eds., Kluwer Academic, Dordrecht, The Netherlands (1997).
4. D. Dürr, S. Goldstein, N. Zanghi, J. Stat. Phys. 67, 843 (1992).https://doi.org/JSTPBS
5. K. Berndl, D. Dürr, S. Goldstein, G. Peruzzi, N. Zanghi, Commun. Math. Phys. 173, 647 (1995).
6. D. Bohm, Phys. Rev. 85, 166, 180 (1952).https://doi.org/PHRVAO
7. J. S. Bell, Rev. Mod. Phys. 38, 447 (1966);
reprinted in ref. 2.
8. E. P. Wigner, in Quantum Theory and Measurement, J. A. Wheeler, W. H. Zurek, eds., Princeton U.P., Princeton, N.J. (1983) p. 262.
9. M. Born, Z. Phys. 38, 803 (1926); https://doi.org/ZEPYAA
English translation in Wave Mechanics, G. Ludwig, ed., Pergamon, Oxford, England 11968) p. 206.
10. L. de Broglie, in Electrons et photons: Rapports et discussions du cinquieme conséil de physique tenu á Bruxelles du 24 au 29 Octobre 1927 sous les auspices de l’Institut International de Physique Solvay, Gauthier‐Villars, Paris (1928).
11. D. Dürr, S. Goldstein, N. Zanghi, in Bohmian Mechanics and Quantum Theory: An Appraisal, J. Cushing, A. Fine, S. Goldstein, eds., Kluwer Academic, Dordrecht, The Netherlands (1996).
12. J. S. Bell, Physics 1, 195 (1964);
reprinted in ref. 2.
13. J. von Neumann, Mathematische Grundlagen der Quantenmechanik, Springer Verlag, Berlin (1932);
English trans. by R. T. Beyer, Mathematical Foundations of Quantum Mechanics, Princeton U.P., Princeton, N.J. (1955).
14. N. D. Mermin, Rev. Mod. Phys. 65, 803 (1993).https://doi.org/RMPHAT
15. R. P. Feynman, R. B. Leighton, M. Sands, The Feynman Lectures on Physics, vol. 1, Addison‐Wesley, New York (1963), p. 37‐2.
16. R. Feynman, The Character of Physical Law, MIT Press, Cambridge, Mass. (1967).

More about the authors

Sheldon Goldstein, Rutgers University, New Brunswick, New Jersey.