Quantum Decoherence and Interlevel Relations

Doctoral Dissertation


Quantum decoherence is a dynamical process whereby a system’s phase relations become delocalized due to interaction and subsequent entanglement with its environment. This delocalization, or decoherence, forces the quantum system into a state that is apparently classical (or apparently an eigenstate) by prodigiously suppressing features that typically give rise to so-called quantum behavior. Thus it has been frequently proposed by physicists and philosophers alike that decoherence explains the dynamical transition from quantum behavior to classical behavior.

Statements like this assume the existence of distinct realms, however, and the present thesis is an exploration of the metaphysical consequences of quantum decoherence motivated by the question of the quantum-to-classical transition and interlevel relations: if there are in-principle classical' andquantum’ levels, what are the relations between them? And if there are no such levels, what follows? Importantly, the following philosophical investigations are carried out by intentionally leaving aside the measurement problem and concerns about particular interpretations of quantum mechanics. Good philosophical work, it is argued, can be done without adopting a specific interpretational framework and without recourse to the measurement problem.

After introducing the physics of decoherence and exploring the four canonical models applied to system-environment interactions, it is argued that, ontologically speaking, there exist no levels. This claim–called the “nontological thesis’–exposes as ill-posed questions regarding the transition from the quantum regime to the classical regime and reveals the inappropriateness of interlevel relations (like reduction, supervenience and emergence) operating within metaphysical frameworks. The nontological thesis has further important consequences regarding intralevel relations: not only are there no meaningful ways to carve the world into levels, but there are no meaningful ways to carve the world into parts and wholes either.

These conclusions, supported by quantum decoherence and the empirical success of its models, drastically alter the philosophical terrain–not just in physics or in the philosophy of physics, but in traditional metaphysics as well.


Attribute NameValues
  • etd-04152011-145851

Author Elise M. Crull
Advisor Don Howard
Contributor John LoSecco, Committee Member
Contributor Don Howard, Committee Chair
Contributor Katherine Brading, Committee Member
Contributor Michael Rea, Committee Member
Degree Level Doctoral Dissertation
Degree Discipline History and Philosophy of Science
Degree Name Doctor of Philosophy
Defense Date
  • 2011-03-28

Submission Date 2011-04-15
  • United States of America

  • quantum-to-classical transition

  • classical mechanics

  • quantum mechanics

  • interlevel relations

  • decoherence models

  • mereology

  • ontology

  • supervenience

  • philosophy of science

  • reduction

  • system-environment interaction

  • levels

  • parts and wholes

  • entanglement

  • emergence

  • decoherence

  • philosophy of physics

  • metaphysics

  • University of Notre Dame

  • English

Record Visibility Public
Content License
  • All rights reserved

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