'Space is big. Really big. You just won't
believe how vastly, hugely, mind-bogglingly big it is. I mean,
you may think it's a long way down the road to the
chemist,
but that's just peanuts to space'.
I liked the idea posited by someone at some stage that the universe is actually a space created in a finite dimensional space, which is finite for the dimensions we see and feel, but is expanding through the collision of two (or more) 'membranes' of potential energy which exist in multiple dimensions not available to us.
The concept I remember was that membranes of potential energy exist in multiple dimensions and that from time to time these membranes collide and cross each other - like a wave-form in two dimensions colliding with another in different dimensions (but having at least one the same or they wouldn't collide) and that collision changing the potential energy to actual energy.
The expansion theory at the early start can then be explained by the increase in actual energy as the membranes cross over their respective boundaries - like a pencil moving along the edge of a rule except the rule is moving in the opposite direction to the pencil (i.e. the pencil is going right along the edge of the rule, while the rule is going left). So, the point at which the energy first transformed (when the pencil first touched the edge of the rule) is moving away from the 'current' point of energy transformation (where the pencil is at any given time excepting the initial point of touch) at faster than the speed of light, hence being able to expand and move faster than light in our four dimensions.
This gives the appearance of an infinite universe, but with a boundary where potential energy is constantly being created into actual energy.
So, what is beyond the finite border is potential energy in the form of membranes in many dimensions - but depth is a function created by the crossing of two or more membranes and by our perception of those dimensions, that depth would not exist beyond the boundary because it's created only as the membranes collide.
What's beyond the membranes? This theory can't answer that because there is no concept of beyond under this theory, it's potential energy rather than a physical manifestation of that energy.
I'm just a philosopher on this, not trained in any way
