Information-Theoretic Interpretations of Quantum Mechanics, the 20th annual UWO philosophy of physics conference, was held on June 11-12, 2016 at Western University. The workshop was inspired by Jeffrey Bub’s recently published book Bananaworld: Quantum Mechanics for Primates (Oxford University Press). The workshop brought together diverse views on issues raised by and related to Professor Bub’s work on developing an information-theoretic interpretation of quantum theory. The program and further details on the workshop can be accessed on the Information-Theoretic Interpretations of Quantum Mechanics website.

A video playlist of the first day of the workshop has been created on the Rotman Institute YouTube Channel. This includes videos of the first five speakers, along with a special session with commentaries and a general discussion. Remaining videos from the workshop will be available soon.


Richard Healey (University of Arizona, Philosophy): Correlations, probabilities and quantum states

In Bananaworld Jeffrey Bub advocates what he calls an information-theoretic interpretation of quantum theory. This may usefully be compared to the pragmatist approach I have been developing in recent years. We agree on many key issues, standing shoulder to shoulder against realist as well as instrumentalist enthusiasts. But I cannot accept some things he says in his book and remain puzzled by others. After locating our common ground I’ll focus on some points on which I think we disagree. Most of these have to do with the nature and function of quantum states and probabilities and what these have to do with information.

Robert Spekkens (Perimeter Institute for Theoretical Physics): Leibniz’s principle of the identity of indiscernibles as a foundational principle for quantum theory

Debates concerning the interpretation of quantum theory have always been deeply concerned with the relation between that which we posit to be real and that which we observe. Leibniz’s principle of the identity of indiscernables also concerns this relation. It asserts that if two scenarios are observationally indiscernible in principle, then any ontological account of the world should represent these two scenarios as physically identical. Einstein seems to have been deeply committed to the principle, given that the strong equivalence principle and the hole argument are both instances of it. This suggests that Leibniz’s principle should be considered as a central pillar in the conceptual foundations of general relativity. In this talk, I will explore the extent to which Leibniz’s principle may also serve as a conceptual foundation for quantum theory, specifically, within an information-theoretic approach to the reconstruction of quantum theory.

Rüdiger Schack (Royal Holloway University of London, Mathematics): Participatory realism

Adan Cabello’s recent classification of quantum interpretations introduces the term “participatory realism” for interpretations in which measurement outcome probabilities are not determined by real properties. Examples include QBism and the Copenhagen interpretation. In this talk I compare different forms of participatory realism. I discuss what the challenges are for participatory realism, and how these challenges are met by QBism.

Matthew Pusey (Perimeter Institute for Theoretical Physics): Is QBism 80% complete, or 20%?

I will outline two views on the status of QBism, one that seems to be presumed in most discussions of the subject, and the other that I read in (or read into!) the writings of QBism’s originators. The former view is that QBism has already provided the main elements of an information-theoretic interpretation of quantum theory, perhaps with a few technical questions on SIC-POVMs and the like remaining. The latter view is eloquently summarised by Fuchs’ statement that “quantum theory is just the start of our adventure. The quantum world is still ahead of us.” I will argue that the QBism under the former view is irreparably linked to dubious ideas from the philosophy of mind (though perhaps not the ideas you expect), whilst QBism under the latter view is a promising research programme.

Jeffrey Bub (University of Maryland, Philosophy, IPST, QuICS): ‘Yes! We have no bananas’

Why write a book about quantum mechanics that’s all about bananas with stronger than quantum correlations? I’ll talk about nonlocality via superquantum PR-box correlations as the focus of Bananaworld, how the probabilistic constraints of quantum correlations characterize the structure of information in a universe with intrinsically random events, and how the measurement problem appears from this perspective.

Subscribe to the Rotman Institute YouTube Channel.