D3 S1 Jerome Romagosa - Unlucky Branches: (Dis)confirmation in Many Worlds

The Many-Worlds Interpretation of Quantum Mechanics: Current Status and Relation to Other Interpretations.
Research workshop of the Israeli Science Foundation, Tel-Aviv University, October 2022

Jerome Romagosa

Unlucky Branches: (Dis)confirmation in Many Worlds

MWI entails the existence of unlucky branches: parts of the universe (or multiverse) in which experimentally observed outcome distributions differ substantially from the outcome distributions that quantum mechanics would have us predict. My interest lies in using unlucky branch thought experiments to explore David Albert’s (2015) claims that Everettian quantum mechanics (i) is insusceptible to ordinary confirmation and disconfirmation, and (ii) cannot make sense of our sense of surprise when observing a set of low-probability experimental results. I offer a perdurantist approach to Lev Vaidman's self-locating uncertainty in order to explain the sense of surprise. I then demonstrate that some inhabitants of unlucky branches may find themselves facing a rational antinomy with respect to whether they ought to take their observations to confirm or disconfirm the MWI.