Does quantum mechanics have a restricted range?

Ascertain whether the validity of quantum mechanics is restricted in scope, rather than universally applicable across all physical regimes and scales.

Background

By invoking Paul Davies’s list of open questions, the paper highlights uncertainty about the domain of applicability of quantum mechanics. This question targets the possibility that quantum mechanics may cease to be accurate or complete under certain conditions, an issue intertwined with debates on measurement, nonlocality, and integration with relativity that the paper surveys.

The author’s proposed non-collapse, decoherence-inspired framework aims to preserve a universally quantum description while accounting for classicality, but the question of range remains explicitly open in the cited framing.