Is Empty Spacetime Observable or Merely Theoretical?

[wolram]

http://arxiv.org/abs/gr-qc/0506068

Title: Is empty spacetime a physical thing?
Authors: Diego Meschini, Markku Lehto
Comments: Latex, 21 pages

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.

 

[Dale]

I am not sure that it makes much difference. Any spacetime in this universe has matter or fields, so any spacetime we would encounter would not meet this assumption. I think it is very clear that spacetime with fields is physical, and that is the sort we will encounter here.