Interpreting Bananaworld: A response to Bub's Quantum Mechanics for Primates

TL;DR

This paper critiques Bub's interpretative principle in quantum mechanics, proposing an alternative that emphasizes the contextual nature of quantum observables and the incomplete spatiotemporal differentiation of the physical world.

Contribution

It introduces a new interpretative principle that clarifies the role of measurement conditions and the non-intrinsic nature of spatial distinctions in quantum theory.

Findings

Quantum observables depend on measurement context

Spatial distinctions are not intrinsic but realized by macroscopic objects

The spatiotemporal differentiation of the universe is incomplete

Abstract

The interpretative principle proposed by Bub in 1211.3062v1 [quant-ph] is justified only for all practical purposes (Bell's "FAPP trap"). An alternative interpretative principle is proposed. It brings to light those features of the quantum world because of which the fundamental theoretical framework of physics is a "mere" probability calculus, and it amply justifies Bohr's insistence that quantum-mechanical observables cannot be defined without reference to the experimental conditions in which they are measured. It implies that the spatial distinctions we make cannot be intrinsic to space, that regions "of space" must be realized by macroscopic objects, that the spatiotemporal differentiation of the physical world is incomplete, that the positions of macroscopic objects (suitably defined) are definite in a nonclassical sense, and that unconditional factuality can be consistently attributed to them.