2026/05/24 by Eugene Y. S. Chua · 1 voice
Physics and Astronomy · #Coherence (philosophical gambling strategy) #Context (archaeology) #Metaphysics #Noncommutative and Quantum Gravity Theories #Philosophy of language #Philosophy of science #Quantum #Quantum Electrodynamics and Casimir Effect #Quantum Mechanics and Applications #Semiclassical physics #gr-qc #physics.hist-ph
paper · pdf · doi:10.1007/s11229-026-05662-2
published in Synthese 207(6) (Springer Science+Business Media)
arxiv published 2026/05/24 · arxiv updated 2026/05/24 · openalex publication_date 2026/06/11 · openalex created_date 2026/06/12 · openalex updated_date 2026/07/23
It is often said that time vanishes in quantum gravity. One general approach to quantum gravity accepts this fundamental timelessness but seeks to derive time's emergence at a non-fundamental level. To better assess such approaches, I develop the criterion of physical coherence and situate it in context by applying it to two programs for time's emergence, drawing from recent works by Chua and Callender (2021) and Chua (2025): semiclassical time and thermal time. Unlike some recent arguments for the metaphysical incoherence of time's emergence, which rule out all claims of time's emergence 'from on high' once we've fixed a definition of metaphysical emergence, my criterion of physical coherence leaves open the possibility that some programs in quantum gravity may succeed on their own terms in providing a physically coherent derivation of time from no-time. This sets a challenge for proponents of time's emergence to clarify the conceptual foundations of their program, while at the same time acting as a litmus test for a program's success.