, Volume 190, Issue 16, pp 3625–3649

Decoherence and the Copenhagen cut



While it is widely agreed that decoherence will not solve the measurement problem, decoherence has been used to explain the “emergence of classicality” and to eliminate the need for a Copenhagen edict that some systems simply have to be treated as classical via a quantum-classical “cut”. I argue that decoherence still relies on such a cut. Decoherence accounts derive classicality only in virtue of their incompleteness, by omission of part of the entangled system of which the classical-appearing subsystem is a part. I argue that this omission is only justified by implicit classical assumptions that objectify a subsystem and are employed via either a traditional Copenhagen cut or a functionally equivalent imposition of separability on a system in a non-separable state. I argue that decoherence cannot derive classicality without assuming it in some other form, and I provide an analysis of when it is appropriate to make these otherwise implicit classical assumptions by adopting a minimalistic Copenhagen-style approach to measurement. Finally, I argue that, ironically, the conditions for making these assumptions may be better satisfied in standard measurement situations than in cases of environmental monitoring.


Decoherence Heisenberg cut Copenhagen interpretation Bohr Measurement Classical assumptions 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Bacciagaluppi, G. (2007). The role of decoherence in quantum mechanics. In E. N. Zalta (Ed.), The Stanford encyclopedia of philosophy (Fall 2008 Edition)
  2. Blanchard P., Giulini D. et al (1999) Decoherence: Theoretical, experimental, and conceptual problems. Springer, New YorkGoogle Scholar
  3. Bohm D. (1951) Quantum theory. Prentice-Hall, New YorkGoogle Scholar
  4. Bohr N. (1928) The quantum postulate and the recent development of atomic theory. Nature 121(supplement): 580–590CrossRefGoogle Scholar
  5. Bohr, N. (1963). The genesis of quantum mechanics. In Essays 1958–1962 (pp. 74–78). New York: Wiley.Google Scholar
  6. Bokulich A. (2004) Open or closed? Dirac, Heisenberg, and the relation between classical and quantum mechanics. Studies in History and Philosophy of Modern Physics 35: 377–396CrossRefGoogle Scholar
  7. Bub J. (1997) Interpreting the quantum world. Cambridge University Press, CambridgeGoogle Scholar
  8. Camilleri K. (2009) A history of entanglement: Decoherence and the interpretation problem. Studies in History and Philosophy of Modern Physics 40: 290–302CrossRefGoogle Scholar
  9. Damski, B., Quan, H. T., et al. (2009). Critical dynamics of decoherence. arXiv:0911.5729v1.Google Scholar
  10. d’Espagnat B. (1971) Conceptual foundations of quantum mechanics. Addison Wesley, New YorkGoogle Scholar
  11. Dickson M. (2007) Non-relativistic quantum mechanics. In: Butterfield J., Earman J., Gabbay D., Thagard P. R., Woods J. (Eds.), Philosophy of physics (Handbook for the philosophy of science). North Holland, Amsterdam, pp 275–416CrossRefGoogle Scholar
  12. Dickson, M., & Dieks, D. (2007). Modal interpretations of quantum mechanics. In E. N. Zalta (Ed.), The Stanford encyclopedia of philosophy. (Spring 2009 Edition)
  13. Dopfer, B. (1998). Zwei Experimente zur Interferenz von Zwei-Photonen Zustanden Ein Heisenbergmikroskop und Pendellosung. Dissertation, Institut fur Experimentalphysik, Innsbruck.Google Scholar
  14. Englert B.-G., Schwinder J. et al (1988) Is spin coherence like humpty-dumpty?. I. Simplified treatment. Foundations of Physics 18: 1045–1056CrossRefGoogle Scholar
  15. Guilini D. et al (1996) Decoherence and the appearance of a classical world in quantum theory. Springer, BerlinCrossRefGoogle Scholar
  16. Horodecki M., Horodecki R. (1998) Are there basic laws of quantum information processing?. Physics Letters A 244: 473–481CrossRefGoogle Scholar
  17. Howard D. (1994) What makes a classical concept classical?. In: Faye J., Folse H. J. (Eds.), Niels Bohr and contemporary philosophy. Kluwer Academic, Dordrecht, pp 210–230Google Scholar
  18. Jacques V., Wu E. et al (2005) Single-photon wavefront-splitting interference: An illustration of the light quantum in action. European Physical Journal D 35: 561–565CrossRefGoogle Scholar
  19. Jacques V., Wu E. et al (2007) Experimental realization of Wheeler’s delayed-choice gedanken Experiment. Science 315: 966–968CrossRefGoogle Scholar
  20. Joos E. (1999) Elements of environmental decoherence. In: Blanchard P., Giulini D., Joos E., Kiefer C., Stamatescu I.-O. (Eds.), Decoherence: Theoretical, experimental, and conceptual problems. Springer, New York, pp 1–17Google Scholar
  21. Joos E. (2003) Decoherence through interaction with the environment. In: Joos E., Zeh H. D., Kiefer C. (Eds.), Decoherence and the appearance of a classical world in quantum theory. Springer, Berlin, pp 35–136CrossRefGoogle Scholar
  22. Joos, E. (2007). Decoherence: An introduction. Physics and Philosophy. Retrieved Jan 2, 2010 from
  23. Kim Y.-H., Yu R. et al (2000) Delayed choice quantum eraser. Physical Review Letters 84: 1–5CrossRefGoogle Scholar
  24. Kwiat P., Englert B.-G. (2004) Quantum-erasing the nature of reality, or perhaps, the reality of nature?. In: Barrow J. D., Davies P. C. W., Harper C. L. (Eds.), Science and ultimate reality: Quantum theory, cosmology, and complexity. Cambridge University Press, Cambridge, pp 306–328CrossRefGoogle Scholar
  25. Landsman N. P. (2007) Between classical and quantum. In: Butterfield J., Earman J., Gabbay D., Thagard P. R., Woods J. (Eds.), Philosophy of physics (Handbook for the philosophy of science). North Holland, Amsterdam, pp 417–554CrossRefGoogle Scholar
  26. Liu C. (1998) Decoherence and idealization in quantum measurement idealization IX: Idealization. In: Shanks N. E. (Ed.), Contemporary physics. Rodopi, Amsterdam, pp 75–98Google Scholar
  27. MacKinnon E. M. (2008) The new reductionism. The Philosophical Forum 39: 439–461CrossRefGoogle Scholar
  28. Pessoa O. Jr. (1997) Can the decoherence approach help to solve the measurement problem?. Synthese 113: 323–346CrossRefGoogle Scholar
  29. Scarcelli G., Zhou Y. et al (2007) Random delayed-choice quantum eraser via two-photon imaging. European Physical Journal D 44: 167–173CrossRefGoogle Scholar
  30. Schlosshauer M. (2004) Decoherence, the measurement problem, and interpretations of quantum mechanics. Reviews of Modern Physics 76: 1267–1305CrossRefGoogle Scholar
  31. Schlosshauer M. (2007) Decoherence and the quantum-to-classical transition. Springer, BerlinGoogle Scholar
  32. Schwinger J., Scully M. O. et al (1998) Is spin coherence like Humpty-Dumpty? II. General theory. Zeitschrift für Physik D 10: 135–144Google Scholar
  33. Scully M. O., Drühl K. (1982) Quantum eraser: A proposed photon correlation experiment concerning observation and delayed choice in quantum mechanics. Physical Review A 25: 2208–2213CrossRefGoogle Scholar
  34. Scully M. O., Englert B.-G. et al (1991) Quantum optical tests of complementarity. Nature 351: 111–116CrossRefGoogle Scholar
  35. Scully M. O., Walther H. (1998) An operational analysis of quantum eraser and delayed choice. Foundations of Physics 28: 399–413CrossRefGoogle Scholar
  36. Stamp P. C. E. (2006) The decoherence puzzle. Studies in History and Philosophy of Modern Physics 37: 467–497CrossRefGoogle Scholar
  37. Tanona S. (2004a) Idealization and formalism in Bohr’s approach to quantum theory. Philosophy of Science 71: 683–695CrossRefGoogle Scholar
  38. Tanona S. (2004b) Uncertainty in Bohr’s response to the Heisenberg microscope. Studies in History and Philosophy of Modern Physics 35: 483–507CrossRefGoogle Scholar
  39. Tanona, S. (2010). Theory, coordination, and empirical meaning in modern physics. In M. Domski & M. Dickson (Eds.), Discourse on a New Method. Open Court.Google Scholar
  40. Ulfbeck O., Bohr A. (2001) Genuine fortuitousness. Where did that click come from?. Foundations of Physics 31: 757–774CrossRefGoogle Scholar
  41. Wickes, W. C., Alley, C. O., et al. (1983). A ‘delayed-choice’ quantum mechanics experiment. In J. A. Wheeler and W. H. Zurek (Eds.), Quantum theory and measurement (pp. 457–461). Princeton: Princeton University Press.Google Scholar
  42. Zanardi P., Lidar D. A. et al (2004) Quantum tensor product structures are observable induced. Physical Review Letters 92: 060402CrossRefGoogle Scholar
  43. Zeh H. D. (2006) Roots and fruits of decoherence. Séminaire Poincaré 1: 115–125Google Scholar
  44. Zeh, H. D. (2009). How decoherence can solve the measurement problem. Retrieved Jan 2, 2010 from
  45. Zeilinger A. (1999) Experiment and the foundations of quantum physics. Reviews of Modern Physics 71: S288–S297CrossRefGoogle Scholar
  46. Zurek W. H. (1981) Pointer basis of quantum apparatus: Into what mixture does the wave packet collapse?. Physical Review D 24: 1516–1525CrossRefGoogle Scholar
  47. Zurek W. H. (1993) Preferred states, predictability, classicality, and the environment-induced decoherence. Progress in Theoretical Physics 89: 281–312CrossRefGoogle Scholar
  48. Zurek W. H. (1998) Decoherence, einselection, and the existential interpretation (the rough guide). Philosophical Transactions A A356: 1793–1820Google Scholar
  49. Zurek W. H. (2002) Decoherence and the transition from quantum to classical—revisited. Los Alamos Science 27: 2–25Google Scholar
  50. Zurek W. H. (2005) Probabilities from entanglement, Born’s rule from envariance. Physical Review A 71: 052105CrossRefGoogle Scholar
  51. Zurek W. H. (2009) Quantum Darwinism. Nature Physics 5: 181–188CrossRefGoogle Scholar
  52. Zwolak M., Quan H.T. et al (2009) Quantum Darwinism in a mixed environment. Physical Review Letters 103: 110402CrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2012

Authors and Affiliations

  1. 1.Department of PhilosophyKansas State UniversityManhattanUSA

Personalised recommendations