Synthese

, Volume 188, Issue 1, pp 67–84

Everettian quantum mechanics without branching time

Article
First Online:
Received:
Accepted:

Abstract

In this paper I assess the prospects for combining contemporary Everettian quantum mechanics (EQM) with branching-time semantics in the tradition of Kripke, Prior, Thomason and Belnap. I begin by outlining the salient features of ‘decoherence-based’ EQM, and of the ‘consistent histories’ formalism that is particularly apt for conceptual discussions in EQM. This formalism permits of both ‘branching worlds’ and ‘parallel worlds’ interpretations; the metaphysics of EQM is in this sense underdetermined by the physics. A prominent argument due to Lewis (On the Plurality of Worlds, 1986) supports the non-branching interpretation. Belnap et al. (Facing the Future: Agents and Choices in Our Indeterministic World, 2001) refer to Lewis’ argument as the ‘Assertion problem’, and propose a pragmatic response to it. I argue that their response is unattractively ad hoc and complex, and that it prevents an Everettian who adopts branching-time semantics from making clear sense of objective probability. The upshot is that Everettians are better off without branching-time semantics. I conclude by discussing and rejecting an alternative possible motivation for branching time.

Keywords

Everett Quantum Branching Semantics Metaphysics Time Many worlds Lewis Belnap Divergence 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Bacciagaluppi G. (2002) Remarks on space–time and locality in Everett’s interpretation’. In Modality, probability, and Bell’s theorems. NATO Science Series.. Kluwer, DordrechtGoogle Scholar
  2. Belnap N., Müller T. (2010) Branching with uncertain semantics. British Journal for Philosophy of Science 61(3): 681–696CrossRefGoogle Scholar
  3. Belnap N., Perloff M., Xu M. (2001) Facing the future: Agents and choices in our indeterministic world. Oxford University Press, OxfordGoogle Scholar
  4. Bigelow J. (1988) The reality of numbers. Oxford University Press, OxfordGoogle Scholar
  5. Churchland P. (1981) Eliminative materialism and the propositional attitudes. Journal of Philosophy 78: 67–90CrossRefGoogle Scholar
  6. Deutsch D. (1985) Quantum theory as a universal physical theory. International Journal for Theoretical Physics 24: 1–41CrossRefGoogle Scholar
  7. Everett III, H. (1955). Wave mechanics without probability. Draft of Princeton Doctoral Dissertation.Google Scholar
  8. Gell-Mann M., Hartle J. (1990) Quantum mechanics in the light of quantum cosmology. In: Zurek W. (eds) Complexity, entropy and the physics of information. Addison-Wesley, Redwood City, CAGoogle Scholar
  9. Greaves H. (2004) Understanding Deutsch’s probability in a deterministic universe. Studies in History and Philosophy of Modern Physics 35(3): 423–456CrossRefGoogle Scholar
  10. Greaves H. (2007) Probability in the Everett interpretation. Philosophy Compass 2(1): 109–128CrossRefGoogle Scholar
  11. Hawthorne J. (2002) Causal structuralism. Philosophical Perspectives 15: 361–378Google Scholar
  12. Lewis D. (1973) Counterfactuals. Blackwell, OxfordGoogle Scholar
  13. Lewis D. (1986) On the plurality of worlds. Blackwell, OxfordGoogle Scholar
  14. Loewer B. (1996) Comment on Lockwood. British Journal for the Philosophy of Science 47(2): 229–232CrossRefGoogle Scholar
  15. Müller T. (2005) Probability theory and causation: A branching space–times analysis. British Journal for the Philosophy of Science 56: 487–520CrossRefGoogle Scholar
  16. Nolan D. (1997) Quantitative parsimony. British Journal for Philosophy of Science 48: 329–343CrossRefGoogle Scholar
  17. Price H. (2010) Decisions, decisions, decisions: Can Savage salvage Everettian probability?. In: Saunders S., Barrett J., Kent A., Wallace D. (eds) Many worlds? Everett, quantum theory, and reality.. Oxford University Press, OxfordGoogle Scholar
  18. Saunders S. (1993) Decoherence, relative states, and evolutionary adaptation. Foundations of Physics 23: 1553–1585CrossRefGoogle Scholar
  19. Saunders S. (1995) Time, quantum mechanics, and decoherence. Synthese 102(2): 235–266CrossRefGoogle Scholar
  20. Saunders S. (1998) Time, quantum mechanics, and probability. Synthese 114(3): 373–404CrossRefGoogle Scholar
  21. Saunders S. (2010) Chance in the Everett interpretation. In: Saunders S., Barrett J., Kent A., Wallace D. (eds) Many worlds? Everett, quantum theory, and reality.. Oxford University Press, OxfordGoogle Scholar
  22. Saunders S., Wallace D. (2008) Branching and uncertainty. British Journal for Philosophy of Science 59(3): 293–305CrossRefGoogle Scholar
  23. Wallace, D. (2005). Language use in a branching universe. Online, http://philsci-archive.pitt.edu/2554/.
  24. Wallace D. (2010) Decoherence and ontology. In: Saunders S., Barrett J., Kent A., Wallace D. (eds) Many worlds? Everett, quantum theory, and reality.. Oxford University Press, OxfordGoogle Scholar
  25. Wallace D. (2012) The emergent multiverse: Quantum theory according to the Everett interpretation. Oxford University Press, OxfordCrossRefGoogle Scholar
  26. Weiner M., Belnap N. (2006) How causal probabilities might fit into our objectively indeterministic world. Synthese 149: 1–36CrossRefGoogle Scholar
  27. Wilson A. (2010) Macroscopic ontology in Everettian quantum mechanics. Philosophical Quarterly 61(243): 363–382CrossRefGoogle Scholar
  28. Wilson, A. (forthcoming). Objective probability in Everettian quantum mechanics. British Journal for Philosophy of Science, To appear.Google Scholar
  29. Zurek, W. (2003). Decoherence and the transition from quantum to classical—REVISITED. Online, http://arxiv.org/abs/quant-ph/0306072.

Copyright information

© Springer Science+Business Media B.V. 2011

Authors and Affiliations

  1. 1.School of Philosophy & BioethicsMonash UniversityMelbourneAustralia

Personalised recommendations