A Local Interpretation of Quantum Mechanics

pEduardo NahmadAcharp

Alyssa Ney

The aim of this volume is to develop and evaluate the suggestion that if one adopts the interpretation of quantum mechanics initially proposed by Hugh Everett, today frequently referred to as the “many-worlds interpretation,” then one can avoid the kind of nonlocality that is often thought to be a consequence of quantum entanglement according to other approaches, and thus permit the compatibility of these two pillars of modern physics: quantum mechanics and special relativity. Although this is an idea that seems to have been recognized by Everett and is sometimes touted as a reason to prefer his approach to interpreting quantum mechanics over others, the precise way in which Everett’s interpretation achieves this locality, indeed whether it even does achieve locality, has been debated, including among the interpretation’s proponents. The aim of this introductory chapter is to provide readers with a background of this debate concerning the locality of Everettian quantum mechanics. We begin with a brief historical introduction to Everett’s proposed interpretation of quantum mechanics and its later development into the many-worlds interpretation. The following section discusses how the by now well-established phenomenon of quantum entanglement seems to imply what Albert Einstein, in a 1947 letter to Max Born, called “spooky action at a distance,” and a tension with special relativity. We then discuss why one might think that the many-worlds interpretation allows one to avoid nonlocality in this sense. The next sections bring the reader up to date with how the locality of Everettian quantum mechanics has been debated both by critics and proponents of the interpretation. As we will see, the desire to understand Everettian quantum mechanics as an interpretation that avoids nonlocality has opened up some interesting debates concerning both what it means to say an interpretation of quantum mechanics is local and over the metaphysical and mathematical interpretation of Everettian quantum mechanics itself. This introductory chapter concludes with a summary of the contributions to the present volume in the context of this ongoing debate.

Stig Stenholm, Luigi Accardi, Guillaume Adenier +5 more

‎Louis Marchildon

Abstract Initially proposed by Hugh Everett III as the “theory of the universal wave function,” the many worlds interpretation has since been developed and refined into one of the most influential ways of giving meaning to quantum mechanics. This volume explores the idea that if one adopts the many worlds interpretation, then one can avoid what Einstein called “spooky action at a distance,” the non-locality that is supposed to be a consequence of quantum entanglement according to other approaches. The essays in this volume articulate a clear and defensible formulation of the argument from locality for preferring the many worlds interpretation of quantum mechanics over its rivals and evaluate it. They question in what sense those in quantum foundations should care about locality, in particular, whether and how an interpretation of quantum mechanics must avoid action at a distance in order to maintain consistency with special relativity. Finally, these essays assess whether the many worlds theory needs a particular metaphysical or mathematical interpretation in order to achieve the aim of providing a local interpretation of quantum mechanics.

Walter E Thirring