# Simple Realism and Canonically Conjugate Observables in Non-Relativistic Quantum Mechanics

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## Abstract

In this paper we list some minimal requirements for a physically natural, straightforwardly realist interpretation of non-relativistic quantum mechanics. The goal is to characterize what one might call a ‘simple realism’ of quantum systems, and of the observables associated with them.

Simple realism as developed here is a generalized interpretation-scheme, one that abstracts important shared features of ‘Einsteinian naive realism,’ the so-called ‘modal’ interpretations, and the orthodox interpretation itself. Some such schemes run afoul of the classic ‘no-go’ theorems, while others do not. The role of non-commuting observables plays a major role in this success or failure. In particular, we show that if a simple-realist interpretation attributes simultaneously definite values to *canonically conjugate* observables, then it necessarily falls prey to Kochen-Specker contradictions.

This exercise provides some insight into ‘why modal interpretations work,’ while more generally placing limits on the scope of simple realism itself. In particular, we find that within the framework of simple realism, the only consistent interpretation of the uncertainty relations is the orthodox one. What's more, we point out that similar conclusions are bound to hold for many other non-commuting observables as well.

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