Space-Time as Substance

General relativity is often presented as having elevated space-time from a passive backdrop to a physical “fabric” in its own right — bending, rippling, carrying energy, and acting as a protagonist in the play of reality. This metaphor of a “substance-like” space-time has become so entrenched that it is repeated in textbooks, press releases, and even in serious theoretical discussions.

But treating space-time as a material fabric is itself a category error. It takes a symbolic architecture — a relational geometry encoding possible alignments of phenomena — and reifies it into a thing. In effect, the map is mistaken for the terrain.

Relationally, “space-time” is a theory of ordering, a system of constraints on how events can co-instantiate. To call it a substance collapses that systemic potential into an imagined material essence. It suggests that, absent “space-time,” nothing can exist, as though existence depended on a background stuff rather than on symbolic construals that bring phenomena into being.

The effect is to naturalise what is in fact a theoretical construction. By speaking of “ripples of space-time” as though they were waves on a pond, the discourse hides the cut that instals geometry as the language of gravitational relations. The metaphor smuggles ontology into physics, turning a relational ordering into a physical medium.

From a relational ontology standpoint, space-time is not “out there” as a fabric. It is a semiotic system — a construal of potential alignments. To ask whether space-time itself is “real” in the sense of substance is to fall into the very mirage this metaphor creates. What is real are phenomena as construed within a symbolic frame, not a hidden medium beneath them.