The spacetime of relativistic physics is forged by the speed of light; that of general relativity, by the additional influence of matter-energy.Nevertheless, the underlying geometry—rooted in a Euclidean conceptual legacy— knows nothing about light and even less about matter.It is an amorphous and unaware spacetime, waiting to be informed by an ad hoc mathematical apparatus to adhere to nature.The purpose of this paper is to show the existence of a geometry made of light and matter that embodies the universal interaction, where the laws of nature are not imposed, but rather discovered.This geometry does not use coordinates, since these have no direct physical meaning, but only invariant physical quantities which are consistent with the Schwarzschild's differential coordinates, but not with its finite coordinates or with Minkowski's coordinate, since these are affected by human non-natural conventions.It is shown that it is precisely these human conventions that underlie the formal difference between the special and general theories of relativity. Furthermore, it aims to demonstrate that the spacetime of general relativity is not elementary, rather, the lack of distinction among the three spatial dimensions arises from the superposition of a multitude of elementary physical spaces, where the distinctive characteristics of each axis merge and dissolve into a flat uniformity.Revealing the nature of the elementary space of interaction unlocks the path to a unified theory of everything.