This is a new volume of original essays on the metaphysics of quantum mechanics. The essays address questions such as: What fundamental metaphysics is best motivated by quantum mechanics? What is the ontological status of the wave function? What is the nature of the fundamental space (or space-time manifold) of quantum mechanics?
This is a new volume of original essays on the metaphysics of quantum mechanics. The essays address questions such as: What fundamental metaphysics is best motivated by quantum mechanics? What is the ontological status of the wave function? Does quantum mechanics support the existence of any other fundamental entities, e.g. particles? What is the nature of the fundamental space of quantum mechanics? What is the relationship between the fundamental ontology of quantum mechanics and ordinary, macroscopic objects like tables, chairs, and (...) persons? This collection includes a comprehensive introduction with a history of quantum mechanics and the debate over its metaphysical interpretation focusing especially on the main realist alternatives. (shrink)
Once upon a time, the twentieth-century investigations of the behaviors of sub-atomic particles were thought to have established that there can be no such thing as an objective, observer-independent, scientifically realist, empirically adequate picture of the physical world.
It is argued that certain recent advances in the construction of a theory of the collapses of Quantum Mechanical wave functions suggest the possibility of new and improved foundations for statistical mechanics, foundations in which epistemic considerations play no role.
We discuss two recent attempts two solve Schrodinger's cat paradox. One is the modal interpretation developed by Kochen, Healey, Dieks, and van Fraassen. It allows for an observable which pertains to a system to possess a value even when the system is not in an eigenstate of that observable. The other is a recent theory of the collapse of the wave function due to Ghirardi, Rimini, and Weber. It posits a dynamics which has the effect of collapsing the state of (...) macroscopic systems. We argue that the modal interpretation cannot account for non-accurate measurements and that both accounts have the consequence that in ordinary measurement situations the observables that ends up well defined are not quite the ones that we want to be well defined. (shrink)
A many-worlds interpretation is of quantum mechanics tells us that the linear equations of motion are the true and complete laws for the time-evolution of every physical system and that the usual quantum-mechanical states provide complete descriptions of all possible physical situations. Such an interpretation, however, denies the standard way of understanding quantum-mechanical states. When the pointer on a measuring device is in a superposition of pointing many different directions, for example, we are to understand this as many pointers, each (...) in a differentworld, each pointing in a different determinate direction. We ask here whether such talk makes any genuinely intelligible sense of the term world. We conclude that it does not. (shrink)
I distinguish between two conceptually different kinds of physical space: a space of ordinary material bodies, which is the space of points at which I could imaginably place the tip of my finger, or the center of a billiard-ball, and a space of elementary physical determinables, which is the smallest space of points such that stipulating what is happening at each one of those points, at every time, amounts to an exhaustive physical history of the universe. In all classical physical (...) theories, these two spaces happen to coincide – and what we mean by calling a theory “classical”, and all we mean by calling a theory “classical”, is precisely that these two spaces coincide. But once the distinction between these two spaces in on the table, it becomes clear that there is no logical or conceptual reason why they must coincide – and it turns out that a very simple way of pulling them apart from one another gives us quantum mechanics. (shrink)
A Quantum-Mechanical automation, equipped with mechanisms for the measurement and the recording and the prediction of certain physical properties of the world, is described. It is inquired what sort of empirical description such an automation would produce of itself. It turns out that this description would be a very novel one, one such as was never imagined in the conventional discussions of measurement.
On April 1, 2016, at the Annual Meeting of the Pacific Division of the American Philosophical Association, a book symposium, organized by Alyssa Ney, was held in honor of David Albert’s After Physics. All participants agreed that it was a valuable and enlightening session. We have decided that it would be useful, for those who weren’t present, to make our remarks publicly available. Please bear in mind that what follows are remarks prepared for the session, and that on some points (...) participants may have changed their minds in light of the ensuing discussion. (shrink)
It is inquired how much an observer can ascertain of the quantum state of a system of which he and his measuring apparatus form a part; how much, for example, observers like ourselves can ascertain of the quantum state of the Universe. It turns out that no practicable experiment (and: perhaps, no experiment whatever) can establish that that state is not the vacuum. Some of the implications of this curious result are discussed.