In their quest to unify the strong and electroweak interactions, Physicists have proposed theories of supersymmetry which treats fermions (matter particles) and bosons (force particles) on equal footing. The supersymmetry of reality is both intuitive and inimitable in its unification of these two fundamental types of particles. It makes sense. This is because there appears to be a two sided nature to reality on the surface. However, all of the apparent separations within it which allow local interactions to not be instantiated into a single thing, but rather, into numerous things, give an appearance of multiplicity. In physical terms, supersymmetry unifies reality into two types of fundamental particles, which interact and therefore become one. This oneness or unification between these two and only two types of particles leads us to assume that reality must be treated as a whole. This implies that the required distances between two or more points in space needed for the interactions between two or more bodies that have a deterministic influence on their paths or trajectories is nothing more than an apparent manifestation of one and only one thing. So we may conclude that all things are one because they exist in relation to each other. Further reading: No Big Bang? Quantum equation predicts universe has no beginning. And: Introduction to Supersymmetry.
Correct me if I'm wrong; Does SRT say that light signals beyond the observable universe will never reach earth regardless of how long it is allowed to travel?
In short yes. In more detail, the further we look, the faster the Universe is expanding and is known as "Hubble's Law"
Reality manifests itself as a variety of objects carrying and containing physical energy in a variety of ways. It is one thing, a unified field.