Spacetime is material

TL;DR

This paper explores the ontological nature of spacetime, examining its materialistic aspects, debates between substantivalism and relationalism, and its role as a physical, dynamical system in modern physics.

Contribution

It provides a comprehensive analysis of spacetime's materialistic ontology, integrating philosophical debates with physical models and cosmological implications.

Findings

Spacetime can be interpreted as a physical, dynamical system.

The debate between substantivalism and relationalism is revisited in light of modern physics.

The mereology of spacetime has significant implications for cosmology.

Abstract

Space and time are central concepts for understanding our World. They are important ingredients at the core of every scientific theory and subject of intense debate in philosophy. Albert Einstein's Special and General theories of Relativity showed that space and time blend in a single entity called spacetime. Even after a century of its conception, many questions about the nature of spacetime remain controversial. In this chapter, we analyze the ontological status of spacetime from a realistic and materialistic point of view. We start by outlining the well-known controversy between substantivalism and relationalism and the evolution of the debate with the appearance of General Relativity. We analyze how to interpret spacetime as a physical system and how to model its properties in a background-free theory where spacetime itself is dynamical. We discuss the concept of change, energy, and the ontology of spacetime events. In the last section, we review the mereology of spacetime and its relevance in cosmology.