Subject: Re: OT: what does an expanding universe mean?
If (and that's a big "if") our current models are correct, there is no "edge" or "margin" in the 3D universe. It appears to be expanding into at least a 4D space (which we can't visualize with our limited 3D perceptions). Is there an "edge" or "margin" in 4D? Not a clue. Maybe someone whom has done the math could say, since mathematics is the only way we can describe that dimension.

I posted a recent paper on the science board about the "speed up". It was/is a new notion about dark energy (not matter). Obviously, still conjecture, but some conjecture supported by observations. When talking about anything beyond 3D, it's more a question of whether the math works. We can't measure or access any higher dimensions than the 3 we can perceive. At least not yet.