This paper examines the ontological implications of the standard cosmological resolution to the Hubble–relativity conflict. The apparent superluminal recession of distant galaxies, inferred from Hubble's law, is traditionally reconciled with special relativity by interpreting the recession as a consequence of the expansion of space itself, rather than motion through space. While mathematically consistent within general relativity, this interpretation implicitly commits to a substantivalist view of spacetime that stands in tension with the treatment of the vacuum in classical electromagnetism. We do not claim a logical inconsistency, but rather highlight an interpretative divergence: the constants μ₀ and ε₀, which determine the speed of light, can be understood either as properties of spacetime or as properties of the electromagnetic interaction. The cosmological model's dynamical conception of space contrasts with the more minimalist conception found in electromagnetism, inviting reflection on the ontological commitments embedded in our most successful theories. The paper also surveys several alternative interpretations of cosmological redshift—including modified gravity theories, tired light hypotheses, and geometric frame models—noting both their motivations and their challenges. The aim is not to advocate for any specific alternative, but to demonstrate that the current paradigm is one among several logical possibilities and to encourage critical reflection on the interpretative choices that shape our understanding of the universe. This work contributes to the foundational literature on spacetime ontology and the philosophy of cosmology. It is intended for researchers interested in the conceptual foundations of modern physics, as well as philosophers of science working on issues of realism, underdetermination, and theory interpretation.
Emamifar et al. (2026) studied this question.