Skip to main content

Nonlocality Versus Modified Realism

Abstract

A large number of physicists now admit that quantum mechanics is a non-local theory. The EPR argument and the many experiments (including recent “loop-hole free” tests) showing the violation of Bell’s inequalities seem to have confirmed convincingly that quantum mechanics cannot be local. Nevertheless, this conclusion can only be drawn inside a standard realist framework assuming an ontic interpretation of the wave function and viewing the collapse of the wave function as a real change of the physical state of the system. We show that this standpoint is not mandatory and that if the collapse is not considered an actual physical change it is possible to recover locality.

This is a preview of subscription content, access via your institution.

Notes

  1. See for example [27] for a typical exposition of this quest.

  2. A detailed presentation of Convivial Solipsism and its consequences is given in [23,24,25].

  3. See https://www.youtube.com/watch?v=9CEr2GfGilw.

  4. Actually, things are more complex than that. There is a subtlety due to the decoherence mechanism and the choice of the preferred basis that we forget here. See [24] for a detailed account of this point.

  5. See for example Wallace [39] who claims having proved the Born rule in this context and Kent [40] who denies that it is the case.

  6. Actually the hanging-on mechanism is a little bit more complex if both decoherence and the relativity of states (see below) are taken into account, but this has no impact on what we want to say here. See [24] for a more detailed presentation.

  7. See [24] for a more detailed comparison between Convivial Solipsism and the relational interpretation and QBism and for a description of the issues that, from my point of view, these two latter interpretations face.

  8. Of course, we do not pretend being able to explain how awareness happens. This is probably one of the most difficult problems of the contemporary science. Neuroscientists are hardly beginning to understand some mechanisms showing how consciousness works and how different it is from what our own consciousness itself thinks it is working.

  9. See [25] for a more detailed discussion of this point.

  10. Actually, experiments showing the violation of Bell’s inequalities in such a situation have been carried on.

References

  1. Bell, J.S.: On the Einstein–Podolski–Rosen Paradox. Physics 1, 195 (1964)

    Article  Google Scholar 

  2. Spekkens, R.W. Phys. Rev. A. 2007, 75, 032110. arXiv:quant-ph/0401052 (2005)

  3. Harrigan, N.; Spekkens, R.W. Found. Phys. 2010, 40, 125. arXiv:0706.2661(2007)

  4. Pusey, M.F., Barrett, J., Rudolph, T.: On the reality of the quantum state. Nat. Phys. 8(6), 476–479 (2012)

    Article  Google Scholar 

  5. Colbeck, R., Renner, R.: Is a system’s wave function in one-to-one correspondence with its elements of reality? Phys. Rev. Lett. 108, 150402 (2012)

    ADS  Article  Google Scholar 

  6. Lewis, P.G., Jennings, D., Barrett, J., Rudolph, T.: Distinct quantum states can be compatible with a single state of reality. Phys. Rev. Lett. 109, 50404 (2012)

    Article  Google Scholar 

  7. Aspect, A., Grangier, P., Roger, G.: Experimental realization of Einstein–Podolsky–Rosen–Bohm Gedankenexperiment: a new violation of Bell’s Inequalities. Phys. Rev. Lett. 49, 91–94 (1982)

    ADS  Article  Google Scholar 

  8. Aspect, A., Dalibard, J., Roger, G.: Experimental test of Bell’s Inequalities using time-varying analyzers. Phys. Rev. Lett. 49, 1804–1807 (1982)

    ADS  MathSciNet  Article  Google Scholar 

  9. Christensen, B.G., McCusker, K.T., Altepeter, J.B., Calkins, B., Gerrits, T., Lita, A.E., Miller, A., Shalm, L.K., Zhang, Y., Nam, S.W., Brunner, N.: Detection-loophole-free test of quantum nonlocality, and applications. Phys. Rev. Lett. 111, 130406 (2013)

    ADS  Article  Google Scholar 

  10. Hensen, B., Bernien, H., Dréau, A.E., Reiserer, A., Kalb, N., Blok, M.S., Ruitenberg, J., Vermeulen, R.F.L., Schouten, R.N., Abellán, C., Amaya, W., Pruneri, V., Mitchell, M.W., Markham, M., Twitchen, D.J., Elkouss, D., Wehner, S., Taminiau, T.H., Hanson, R.: Loophole-free Bell inequality violation using electron spins separated by 1.3 kilometres. Nature 526, 682 (2015)

    ADS  Article  Google Scholar 

  11. Giustina, M., et al.: Significant-loophole-free test of bell’s theorem with entangled photons. Phys. Rev. Lett. 115, 250401 (2015)

    ADS  Article  Google Scholar 

  12. Shalm, L.K., et al.: Strong loophole-free test of local realism. Phys. Rev. Lett. 115, 250402 (2015)

    ADS  Article  Google Scholar 

  13. Handsteiner, J., et al.: Phys. Rev. Lett. 118, 060401 (2017)

    ADS  Article  Google Scholar 

  14. Page, D.N.: The Einstein–Podolsky–Rosen Physical Reality is completely described by quantum mechanics. Phys. Lett. 91A, 57 (1982)

    ADS  MathSciNet  Article  Google Scholar 

  15. Bitbol, M.: An analysis of the Einstein–Podolsky–Rosen correlations in terms of events. Phys. Lett. 96A, 57 (1983)

    ADS  Google Scholar 

  16. Caves, C.M., Fuchs, C.A., Schack, R.: Quantum probabilities as Bayesian probabilities. Phys. Rev. A 65, 022305 (2002)

    ADS  MathSciNet  Article  Google Scholar 

  17. Fuchs, C.A.: QBism, the perimeter of Quantum Bayesianism. arXiv: 1003:5209 (2010)

  18. Fuchs, C.A., Schack, R.: Quantum-Bayesian coherence. Rev. Mod. Phys. 85, 1693 (2013)

    ADS  Article  Google Scholar 

  19. Fuchs, C.A., Mermin, D.N., Schack, R.: An Introduction to QBism with an Application to the Locality of Quantum Mechanics. arXiv: 1311:5253 (2013)

  20. Everett, H.: On the Foundations of Quantum Mechanics, Ph.D. thesis. Princeton University, Department of Physics (1957)

  21. Everett, H.: Relative state formulation of quantum mechanics. Rev. Mod. Phys. 29, 454–462 (1957)

    ADS  MathSciNet  Article  Google Scholar 

  22. DeWitt, B.S., Graham, N. (eds.): The Many-Worlds Interpretation of Quantum Mechanics. Princeton University Press, Princeton (1973)

    Google Scholar 

  23. Zwirn, H.: Decoherence and the Measurement Problem. In: proceedings of “Frontiers of Fundamental Physics 14”, PoS(FFP14) 223 (2015)

  24. Zwirn, H.: The measurement problem: decoherence and convivial solipsism. Found. Phys. 46, 635–667 (2016)

    ADS  MathSciNet  Article  Google Scholar 

  25. Zwirn, H.: Delayed choice, complementarity, entanglement and measurement. Phys. Essays 30, 3 (2016)

    Google Scholar 

  26. d’Espagnat, B.: Le Réel voilé, analyse des concepts quantiques. 1994, Fayard. English Transl: Veiled Reality: An Analysis of Quantum Mechanical Concepts. Westview Press, Boulder, Colorado (2003)

  27. Goldstein, S.: Quantum theory without observers. Physics Today 51, 42–47 (1998)

    Article  Google Scholar 

  28. Wigner E. P. Interpretation of quantum mechanics. 1976, In: Wheeler, J.A., Zurek, W. (eds.) Quantum Theory and Measurement. Princeton University Press (1983)

  29. Wigner, E.P.: Symetries and Reflections. Indiana University Press, Bloomington (1967)

    Google Scholar 

  30. London, F., Bauer, E.: La théorie de l’observation en mécanique quantique. Hermann (1939)

  31. Einstein, A. to Heitler, W. 1948 translated in Fine, A. Einstein’s Interpretation of Quantum Theory. In: Beller, M., Cohen, R.S., Renn, J. (eds). Einstein in Context. Cambridge University Press (1993)

  32. Vaidman, L. Many Worlds Interpretation of Quantum Mechanics. In: Zalta, E.N. (ed) The Stanford Encyclopedia of Philosophy. http://plato.stanford.edu/entries/qm-manyworlds/ (2014)

  33. Albert, D.: Quantum Mechanics and Experience. Harvard University Press, Cambridge-London (1992)

    Google Scholar 

  34. Albert D.; Loewer B. Interpreting the Many Worlds: Interpretations. Synthese 82, 195–213 (1988)

    Google Scholar 

  35. Barrett, J.: Everett’s relative-state formulation of quantum mechanics. In: Zalta, E.N. (ed) The Stanford Encyclopedia of Philosophy. https://plato.stanford.edu/entries/qm-everett/ (2014)

  36. Barrett, J.: Everett’s pure wave mechanics and the notion of worlds. Eur. J. Philos. Sci. 1, 277–302 (2011)

    MathSciNet  Article  Google Scholar 

  37. Everett, H.: The theory of the universal wave function. 1956. First printed in DeWitt, B.S.; Graham, N. (eds) The Many-Worlds Interpretation of Quantum Mechanics. Princeton University Press, Princeton, pp. 3–140 (1973)

    Google Scholar 

  38. Vaidman, L.: On schizophrenic experiences of the neutron or why we should believe in the many-worlds interpretation of quantum theory. Int. Stud. Philos. Sci. 12, 245–261 (1998)

    MathSciNet  Article  Google Scholar 

  39. Wallace, D.: A formal proof of the born rule from decision theoretic assumptions. In: Saunders, S., Barrett, J., Kent, A., Wallace, D. (eds.) Many Worlds? Everett, Quantum Theory and Reality. Oxford University Press, Oxford (2010)

    MATH  Google Scholar 

  40. Kent, A.: One World versus Many: The Inadequacy of Everettian Accounts of Evolution, Probability, and Scientific Confirmation. In: Saunders, S., Barrett, J., Kent, A., Wallace, D. (eds.) Many worlds? Everett, quantum theory and reality. Oxford University Press, Oxford (2010)

    MATH  Google Scholar 

  41. Barrett, J.: The Quantum Mechanics of Minds and Worlds. Oxford University Press, Oxford (1999)

    Google Scholar 

  42. Vaidman, L.: Quantum Stud. (2014). https://doi.org/10.1007/s40509-014-0008-4

    Article  Google Scholar 

  43. d’Espagnat, B.: Conceptual Foundations of Quantum Mechanics. Benjamin, New York (1971)

    Google Scholar 

  44. Rovelli, C.: Relational quantum mechanics. Int. J. Theor. Phys. 35, 1637–1657 (1996)

    MathSciNet  Article  Google Scholar 

  45. Rovelli, C., Smerlak, M.: Relational EPR. Found. Phys. 37, 427–445 (2007)

    ADS  MathSciNet  Article  Google Scholar 

  46. Laudisa, F., Rovelli, C.: Relational quantum mechanics. In: Zalta, E.N. (ed) The Stanford Encyclopedia of Philosophy. http://plato.stanford.edu/entries/qm-relational/ (2008)

  47. Einstein, A., Podolsky, B., Rosen, N.: Can quantum-mechanical description of physical reality be considered complete? Phys. Rev. 47, 777–780 (1935)

    ADS  Article  Google Scholar 

  48. Fine, A.: The Einstein–Podolsky–rosen argument in quantum theory. In: Zalta, E.N. (ed) The Stanford Encyclopedia of Philosophy. https://plato.stanford.edu/entries/qt-epr/ (2013)

  49. Bohm, D.: Quantum Theory. Prentice Hall, New York (1951)

    Google Scholar 

  50. Clauser, J.F., Horne, M.A., Shimony, A., Holt, R.A.: Proposed experiment to test local hidden-variable theories. Phys. Rev. Lett. 23, 880–884 (1969)

    ADS  Article  Google Scholar 

Download references

Acknowledgements

I want to thank Chris Fuchs for many enlightening discussions about QBism and Lev Vaidman for exchanges allowing me to better understand his own presentation of Everett’s interpretation.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Hervé Zwirn.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Zwirn, H. Nonlocality Versus Modified Realism. Found Phys 50, 1–26 (2020). https://doi.org/10.1007/s10701-019-00314-7

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s10701-019-00314-7

Keywords

  • Non-locality
  • Collapse
  • Measurement problem
  • Consciousness
  • Everett’s interpretation
  • Convivial solipsism