Based on the WMAP and Planck experiments the universe geometry is flat, to some small measurement error bar, and infinite in extent. That means it had a beginning and will expand forever.
That's not quite true. These observations also established that the relationship between curvature and expansion doesn't hold because of the presence of a cosmological constant. Even universes with positive curvature can expand forever.
Thanks for bringing that up. I'd like to read about that. The following result is what I was referring to. The 4th paragraph. http://map.gsfc.nasa.gov/news/index.html The measurement error bar is within .004 of flat. Most of that range is on the positive side. Not that it would make any difference. LOL. The result you brought to my attention is something I haven't read about. Such as how much positive curvature before we would call the universe closed?
Any positive curvature would close the universe, in terms of possible paths through space, but that doesn't mean it would stop expanding. The cosmological constant would continue to accelerate expansion indefinitely. For example, see http://map.gsfc.nasa.gov/universe/bb_concepts_exp.html
Ok. I did know what you're talking about. So we have Omega 5 a closed universe with no cc. Then Omega 1 a flat universe with no cc. Then Omega .3 a open universe with no cc. And finally our Omega 1 universe which has both a matter component .3 with a cc component of .7 resulting in the measured acceleration of expansion.
