Spacetime Conventionalism Revisited

TL;DR

This paper critically examines the thesis that the structure of spacetime is a matter of convention, analyzing five formulations and their implications for the foundations of general relativity.

Contribution

It offers a detailed analysis of five different formulations of spacetime conventionalism, identifying which are flawed and which open new research questions.

Findings

Three formulations of conventionalism are shown to fail.

Two formulations reveal new problems for the foundations of general relativity.

The analysis clarifies the role of geometric identities, symmetry, and conformal structure in spacetime theories.

Abstract

We provide five rearticulations of the thesis that the structure of spacetime is conventional, rather than empirically determined, based upon variation of the structures that are empirically underdetermined and modal contexts in which this underdetermination occurs. Three of the five formulations of conventionalism will be found to fail. Two are found to open up new interesting problems for researchers in the foundations of general relativity. In all five cases, our analysis explores the interplay between geometric identities, symmetry, conformal structure, and the dynamical content of physical theories with the conventionalism dialectic deployed as a tool of explication, clarification, and exploration.