Copenhagenish interpretations of quantum mechanics

TL;DR

This paper defines a class of Copenhagenish interpretations of quantum mechanics characterized by four postulates, explores their differences from orthodox views, and discusses their implications for the measurement problem and thought experiments.

Contribution

It introduces a formal framework for Copenhagenish interpretations, clarifies their distinctions from other interpretations, and analyzes their implications for quantum measurement and thought experiments.

Findings

Copenhagenish interpretations are characterized by four specific postulates.

They are not equivalent to orthodox or operationalist interpretations.

Multiple consistent descriptions of experiments are possible within these interpretations.

Abstract

We define a class of Copenhagenish interpretations encompassing modern interpretations that follow the Copenhagen spirit. These interpretations are characterized by four postulates: Observers Observe, Universality, Anti-$\psi$-ontology, and Completeness. We explain why such interpretations are not equivalent to the textbook (or orthodox) interpretation, nor to the view that one should shut up and calculate, nor to strict operationalism. We then discuss what lessons are implied for Copenhagenish interpretations by the measurement problem, the Wigner's friend thought experiment, and the simple variants of the Wigner's friend thought experiment that we term Wigner's enemy, stalkee, and penpal. In particular, we discuss how Copenhagenish interpretations give multiple distinct descriptions of each experiment, where these descriptions are each individually true, yet cannot be combined into any single description. To make such interpretations consistent, then, one requires epistemological constraints forbidding certain perspectives from being combined. We discuss these constraints, their motivations, and some of the challenges they introduce.