•  333
    The Bare Theory Has No Clothes
    with Rob Clifton and Bradley Monton
    In Richard Healey & Geoffrey Hellman (eds.), Quantum Measurement: Beyond Paradox, University of Minnesota Press. pp. 32-51. 1998.
    We criticize the bare theory of quantum mechanics -- a theory on which the Schrödinger equation is universally valid, and standard way of thinking about superpositions is correct.
  •  256
    Characterizing quantum theory in terms of information-theoretic constraints
    with Rob Clifton and Hans Halvorson
    Foundations of Physics 33 (11): 1561-1591. 2002.
    We show that three fundamental information-theoretic constraints -- the impossibility of superluminal information transfer between two physical systems by performing measurements on one of them, the impossibility of broadcasting the information contained in an unknown physical state, and the impossibility of unconditionally secure bit commitment -- suffice to entail that the observables and state space of a physical theory are quantum-mechanical. We demonstrate the converse derivation in part, a…Read more
  •  235
    Testing models of cognition through the analysis of brain-damaged patients
    British Journal for the Philosophy of Science 45 (3): 837-55. 1994.
    The aim of cognitive neuropsychology is to articulate the functional architecture underlying normal cognition, on the basis of congnitive performance data involving brain-damaged subjects. Throughout the history of the subject, questions have been raised as to whether the methods of neuropsychology are adequate to its goals. The question has been reopened by Glymour [1994], who formulates a discovery problem for cognitive neuropsychology, in the sense of formal learning theory, concerning the ex…Read more
  •  223
    Two dogmas about quantum mechanics
    with Itamar Pitowsky
    In Simon Saunders, Jonathan Barrett, Adrian Kent & David Wallace (eds.), Many Worlds?: Everett, Quantum Theory & Reality, Oxford University Press. 2007.
    We argue that the intractable part of the measurement problem -- the 'big' measurement problem -- is a pseudo-problem that depends for its legitimacy on the acceptance of two dogmas. The first dogma is John Bell's assertion that measurement should never be introduced as a primitive process in a fundamental mechanical theory like classical or quantum mechanics, but should always be open to a complete analysis, in principle, of how the individual outcomes come about dynamically. The second dogma i…Read more
  •  187
    Quantum Mechanics is About Quantum Information
    Foundations of Physics 35 (4): 541-560. 2005.
    I argue that quantum mechanics is fundamentally a theory about the representation and manipulation of information, not a theory about the mechanics of nonclassical waves or particles. The notion of quantum information is to be understood as a new physical primitive—just as, following Einstein’s special theory of relativity, a field is no longer regarded as the physical manifestation of vibrations in a mechanical medium, but recognized as a new physical primitive in its own right.
  •  180
    Indeterminacy and entanglement: the challenge of quantum mechanics
    British Journal for the Philosophy of Science 51 (4): 597-615. 2000.
    I explore the nature of the problem generated by the transition from classical to quantum mechanics, and I survey some of the different responses to this problem. I show briefly how recent work on quantum information over the past ten years has led to a shift of focus, in which the puzzling features of quantum mechanics are seen as a resource to be developed rather than a problem to be solved
  •  171
    Why the quantum?
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 35 (2): 241-266. 2004.
  •  162
    Von Neumann’s ‘No Hidden Variables’ Proof: A Re-Appraisal (review)
    Foundations of Physics 40 (9-10): 1333-1340. 2010.
    Since the analysis by John Bell in 1965, the consensus in the literature is that von Neumann’s ‘no hidden variables’ proof fails to exclude any significant class of hidden variables. Bell raised the question whether it could be shown that any hidden variable theory would have to be nonlocal, and in this sense ‘like Bohm’s theory.’ His seminal result provides a positive answer to the question. I argue that Bell’s analysis misconstrues von Neumann’s argument. What von Neumann proved was the imposs…Read more
  •  162
    The problem of properties in quantum mechanics
    Topoi 10 (1): 27-34. 1991.
    The properties of classical and quantum systems are characterized by different algebraic structures. We know that the properties of a quantum mechanical system form a partial Boolean algebra not embeddable into a Boolean algebra, and so cannot all be co-determinate. We also know that maximal Boolean subalgebras of properties can be (separately) co-determinate. Are there larger subsets of properties that can be co-determinate without contradiction? Following an analysis of Bohrs response to the E…Read more
  •  125
    Maxwell's Demon and the Thermodynamics of Computation
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 32 (4): 569-579. 2001.
    It is generally accepted, following Landauer and Bennett, that the process of measurement involves no minimum entropy cost, but the erasure of information in resetting the memory register of a computer to zero requires dissipating heat into the environment. This thesis has been challenged recently in a two-part article by Earman and Norton. I review some relevant observations in the thermodynamics of computation and argue that Earman and Norton are mistaken: there is in principle no entropy cost…Read more
  •  123
    Revised Proof of the Uniqueness Theorem for ‘No Collapse’ Interpretations of Quantum Mechanics
    with Rob Clifton and Sheldon Goldstein
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 31 (1): 95-98. 2000.
    We show that the Bub-Clifton uniqueness theorem (1996) for 'no collapse' interpretations of quantum mechanics can be proved without the 'weak separability' assumption.
  •  111
    The Quantum Bit Commitment Theorem
    Foundations of Physics 31 (5): 735-756. 2001.
    Unconditionally secure two-party bit commitment based solely on the principles of quantum mechanics (without exploiting special relativistic signalling constraints, or principles of general relativity or thermodynamics) has been shown to be impossible, but the claim is repeatedly challenged. The quantum bit commitment theorem is reviewed here and the central conceptual point, that an “Einstein–Podolsky–Rosen” attack or cheating strategy can always be applied, is clarified. The question of whethe…Read more
  •  111
    Local Realism and Conditional Probability
    Foundations of Physics 36 (4): 585-601. 2006.
    Emilio Santos has argued (Santos, Studies in History and Philosophy of Physics http: //arxiv-org/abs/quant-ph/0410193) that to date, no experiment has provided a loophole-free refutation of Bell’s inequalities. He believes that this provides strong evidence for the principle of local realism, and argues that we should reject this principle only if we have extremely strong evidence. However, recent work by Malley and Fine (Non-commuting observables and local realism, http: //arxiv-org/abs/quant-p…Read more
  •  107
    Contextuality and Nonlocality in 'No Signaling' Theories
    Foundations of Physics 39 (7): 690-711. 2009.
    We define a family of ‘no signaling’ bipartite boxes with arbitrary inputs and binary outputs, and with a range of marginal probabilities. The defining correlations are motivated by the Klyachko version of the Kochen-Specker theorem, so we call these boxes Kochen-Specker-Klyachko boxes or, briefly, KS-boxes. The marginals cover a variety of cases, from those that can be simulated classically to the superquantum correlations that saturate the Clauser-Horne-Shimony-Holt inequality, when the KS-box…Read more
  •  107
    A uniqueness theorem for ‘no collapse’ interpretations of quantum mechanics
    with Rob Clifton
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 27 (2): 181-219. 1996.
    We prove a uniqueness theorem showing that, subject to certain natural constraints, all 'no collapse' interpretations of quantum mechanics can be uniquely characterized and reduced to the choice of a particular preferred observable as determine (definite, sharp). We show how certain versions of the modal interpretation, Bohm's 'causal' interpretation, Bohr's complementarity interpretation, and the orthodox (Dirac-von Neumann) interpretation without the projection postulate can be recovered from …Read more
  •  106
    Epr
    Foundations of Physics 22 (3): 313-332. 1992.
    We present an exegesis of the Einstein-Podolsky-Rosen argument for the incompleteness of quantum mechanics, and defend it against the critique in Fine. (1) We contend,contra Fine, that it compares favorably with an argument reconstructed by him from a letter by Einstein to Schrödinger; and also with one given by Einstein in a letter to Popper. All three arguments turn on a dubious assumption of “separability,” which accords separate elements of reality to space-like separated systems. We discuss…Read more
  •  106
    Correlations, Contextuality and Quantum Logic
    Journal of Philosophical Logic 42 (3): 483-499. 2013.
    Quantum theory is a probabilistic theory that embodies notoriously striking correlations, stronger than any that classical theories allow but not as strong as those of hypothetical ‘super-quantum’ theories. This raises the question ‘Why the quantum?’—whether there is a handful of principles that account for the character of quantum probability. We ask what quantum-logical notions correspond to this investigation. This project isn’t meant to compete with the many beautiful results that informatio…Read more
  •  103
    Quantum probabilities as degrees of belief
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 38 (2): 232-254. 2007.
  •  101
    J. S. Bell's argument that only “nonlocal” hidden variable theories can reproduce the quantum statistical correlations of the singlet spin state in the case of two separated spin-1/2 particles is examined in terms of Wigner's formulation. It is shown that a similar argument applies to a single spin-1/2 particle, and that the exclusion of hidden variables depends on an obviously untenable assumption concerning conditional probabilities. The problem of completeness is discussed briefly, and the gr…Read more
  •  101
    Quantum computation and pseudotelepathic games
    Philosophy of Science 75 (4): 458-472. 2008.
    A quantum algorithm succeeds not because the superposition principle allows ‘the computation of all values of a function at once’ via ‘quantum parallelism’, but rather because the structure of a quantum state space allows new sorts of correlations associated with entanglement, with new possibilities for information‐processing transformations between correlations, that are not possible in a classical state space. I illustrate this with an elementary example of a problem for which a quantum algori…Read more
  •  100
    Schütte's tautology and the Kochen-Specker theorem
    Foundations of Physics 26 (6): 787-806. 1996.
    I present a new 33-ray proof of the Kochen and Specker “no-go” hidden variable theorem in ℋ3, based on a classical tautology that corresponds to a contingent quantum proposition in ℋ3 proposed by Kurt Schütte in an unpublished letter to Specker in 1965. 1 discuss the relation of this proof to a 31-ray proof by Conway and Kochen, and to a 33-ray proof by Peres
  •  100
    Hidden Variables and the Copenhagen Interpretation—A Reconciliation1
    British Journal for the Philosophy of Science 19 (3): 185-210. 1968.
  •  94
    I consider to what extent the phenomenon of interference precludes the possibility of attributing simultaneously determinate values to noncommuting observables, and I show that, while all observables can in principle be taken as simultaneously determinate, it suffices to take a suitable privileged observable as determinate to solve the measurement problem.
  •  92
    Quantum Mechanics as a Principle Theory
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics 31 (1): 75-94. 2000.
    I show how quantum mechanics, like the theory of relativity, can be understood as a 'principle theory' in Einstein's sense, and I use this notion to explore the approach to the problem of interpretation developed in my book Interpreting the Quantum World.
  •  90
    Hidden variables and locality
    Foundations of Physics 6 (5): 511-525. 1976.
    Bell's problem of the possibility of a local hidden variable theory of quantum phenomena is considered in the context of the general problem of representing the statistical states of a quantum mechanical system by measures on a classical probability space, and Bell's result is presented as a generalization of Maczynski's theorem for maximal magnitudes. The proof of this generalization is shown to depend on the impossibility of recovering the quantum statistics for sequential probabilities in a c…Read more
  •  87
    Some reflections on quantum logic and schrödinger's cat
    British Journal for the Philosophy of Science 30 (1): 27-39. 1979.
  •  86
    Miller's paradox of information
    with Michael Radner
    British Journal for the Philosophy of Science 19 (1): 63-67. 1968.
  •  76
    On Bohr's response to EPR: A quantum logical analysis (review)
    Foundations of Physics 19 (7): 793-805. 1989.
    Bohr's complementarity interpretation is represented as the relativization of the quantum mechanical description of a system to the maximal Boolean subalgebra (in the non-Boolean logical structure of the system) selected by a classically described experimental arrangement. Only propositions in this subalgebra have determinate truth values. The concept of a minimal revision of a Boolean subalgebra by a measurement is defined, and it is shown that the nonmaximal measurement of spin on one subsyste…Read more