We have a process of continuous energy exchange that is formed be the spontaneous absorption and emission of light. This is represented in quantum mechanics by the quantum wave particle function expanding out as an inverse sphere. In this theory this forms part of one universal process with the inverse square law of Newton's gravity. The wave particle duality of light is acting like the bits or zeros and ones of a computer forming a blank canvas that we can interact with turning the possible into the actual within our own reference frame! Time is an emergent property formed by a process of spherical symmetry forming and breaking that we see and feel as the future continuously coming into existence light photon by light photon relative to the position and energy and momentum of the atoms!
The extra dimensions of String Theory and parallel universes of Hugh Everett Many worlds interpretation are just future possibilities and opportunities in our one three dimensional Universe of continuous energy exchange or what I like to call continuous creation.
The conventional model of cosmology is that most galaxies recede from one another as space itself inflates like the surface of a balloon — which would explain why other galaxies appear redshifted from our own galaxy's point of view.