Against the disappearance of spacetime in quantum gravity

Abstract

This paper argues against the proposal to draw from current research into a physical theory of quantum gravity the ontological conclusion that spacetime or spatiotemporal relations are not fundamental. As things stand, the status of this proposal is like the one of all the other claims about radical changes in ontology that were made during the development of quantum mechanics and quantum field theory. However, none of these claims held up to scrutiny as a consequence of the physics once the theory was established and a serious discussion about its ontology had begun. Furthermore, the paper argues that if spacetime is to be recovered through a functionalist procedure in a theory that admits no fundamental spacetime, standard functionalism cannot serve as a model: all the known functional definitions are definitions in terms of a causal role for the motion of physical objects and hence presuppose spatiotemporal relations.

arXiv commentforthcoming in Synthese, special issue on Spacetime Functionalism

References in corpus (7)

• Bell-Type Quantum Field Theories
• Raiders of the lost spacetime
• Benefits of Objective Collapse Models for Cosmology and Quantum Gravity
• Time Remains
• Frequently asked questions about Shape Dynamics
• Observables and unobservables in quantum mechanics: How the no-hidden-variables theorems support the Bohmian particle ontology
• Binding quantum matter and space-time, without romanticism