From Many Branches to Many Worlds

Abstract

In this thesis I make a comparison between Hugh Everett’s III interpretation of quantum mechanics and David Wallace’s interpretation of quantum mechanics. I will do this in the first place by developing a basic paradigm of similarity between them, and, secondly, by discussing the differences between their respective philosophical frameworks in which their interpretations are embedded. The development of the basic paradigm of similarity will lead me to the conclusion that it is both Everett’s and Wallace’s aim to identify structures within the wavefunction that are stable over large periods of time, i.e., structures that can be described with Newtonian mechanics. Moreover, it will lead me to the conclusion that the probability measures that Everett and Wallace develop are specifically aimed at those structures. The discussion of their respective philosophical framework will lead me to the conclusion that those frameworks determine the meaning of the structures in the wavefunction. For the difference between Everett and Wallace does this mean that there is a shift from Everett’s branches to Wallace’s worlds.