Mr Snowman Said
Beyond the edge of the Universe there lies nothing.. zilch. You may as well as what's north of the North Pole. It is truly -nothing-.
I must agree with Mr Snowman on this one.
I believe The unviverse is almost certainly closed. I try to think of it this way:
We live on an inflating sphere of an onion like structure with a new layer of the onion set down every qantuum of time. When we look at alpha centauri, we are looking into the sphere to see what the light was like when it left alpha centrauti 4 years ago, so you can think of what you are seeing as being 4 years deep and 4 light years away on the surface.
Now, when you look at the light from distant pulsars say 8 billion light years, you are looking 8 billion years deep but now much more than 8 billion light years distant as the sphere that this galaxy was on has
expanded up. Hence the universe may be 13 billion years old, but the most distant object to us is much more than 13 billion light years away. Hence we can never go there.
The alternative is that the universe is truly infinite and that we can only see for 13 billion light years and that this is our sphere of influence. Anything outside of that can never reach us nor be reached by us. This then indicated that we have a near steady state universe that never expands, only our sphere expands at the speed of light. This is the idea of many bubble like universes all occupying the same infinite space.
Then there is the concept of one universe per brane or one universe per quantuum event over all time since the begining of time. Or the idea of one univers per quantuum event for infinite time and that time itself is an illution casued by the sequnece of going from one univers to the next sequentially.
All the above are real scientific suggestions for the nature of the multi-verse. You raise a very valid question Mr R.I.N.G. but I'm afraid that science can't give you a handwaving answer never mind a straight answer, just a hunch.