One side sees three spatial dimensions evolving over time. That is the view you have described, kosta50.
The other sees four dimensions - three of space and one of time (space/time continuum.) And admits that there may be additional spatial and temporal dimensions. I hold to this view.
The space/time continuum is a postulate to special relativity, general relavity, geometric physics and physical cosmology.
The bottom line is that space and time do not pre-exist, rather space/time is created as the universe expands. IOW, the universe is not expanding "into" anything.
That the universe is expanding (and thus had a real beginning of space and time) was confirmed by measurements of the cosmic microwave background radiation in the 1960's. It is also known as the most theological statements ever to be made by modern science. (Jastrow)
The universe appears to be expanding but then it all goes back to 100 point of view. From the earthly vista, Potlemaic navigational system, based on heliocentric assumptions, still works (because science doesn't discover the truth, but creates working models). And from a position on earth, his observations and assumptions appear valid. Just as Newtonian physics work on earth but breakd down in space.
We are traveling at about 1,000 miles/hr through "space" and would never know it. But we are really not going anywhere because we are spinning in circles, literally speaking!
In fact, the entire universe seems to be going around in circles, leaving evidence of cooling at the completion of each round!