Is empty spacetime a physical thing?

TL;DR

This paper explores whether empty spacetime, devoid of matter and fields, can be considered physically real by examining its observability through quantum mechanics, challenging traditional views of spacetime as purely geometric.

Contribution

It introduces new foundational ideas suggesting that empty spacetime might be observable, countering the standard view that it is purely a geometric, non-physical entity.

Findings

Quantum considerations challenge the negative conclusion about empty spacetime's observability.

Proposes a conceptual framework for observing geometric spacetime points.

Questions the traditional view of spacetime as a purely geometric, non-physical entity.

Abstract

This article deals with empty spacetime and the question of its physical reality. By "empty spacetime" we mean a collection of bare spacetime points, the remains of ridding spacetime of all matter and fields. We ask whether these geometric objects--themselves intrinsic to the concept of field--might be observable through some physical test. By taking quantum-mechanical notions into account, we challenge the negative conclusion drawn from the diffeomorphism invariance postulate of general relativity, and we propose new foundational ideas regarding the possible observation--as well as conceptual overthrow--of this geometric ether.