I am firmly of the opinion that space is infinite.
If there are multiple universes in space that are expanding like ours, they should eventually collide with ours. Perhaps they already have and we just don't know it because the visual confirmation of such phenomena could be billions of years away.
Perhaps there is just one infinitely large universe, and we can't see it all because we are sitting in what appears to be a 14-billion-light-year-radius spherical arena. Maybe more will appear over time. Maybe light just won't travel more than 14 billion light years before it totally dissipates or gets absorbed in dark matter or is negated by other forces that we have not yet discovered.
I think our collective knowledge of space, matter and time is still in its infancy.
I also think the "Big Bang" Theory is just that, for we have no way of proving it. Some think the universe has always been here, another theory with zero weight of confirmation.
The primary issues are "From whence cameth all that stuff?" and "When?". The larger issue is "How?". The largest issues are "Who dunn-it?" and "Why?".

