[Luke Skyfreeper]

just before the Big Bang occurred, another universe very similar to ours may have been contracting

I thought we already decided our universe is destined to expand forever; in which case such a universe is not that similar to ours.

The current researcher seems to have a different opinion about our universe's fate...

[Stone Mountain]

I thought we already decided our universe is destined to expand forever; in which case such a universe is not that similar to ours.

I'm not sure that there's a consensus on that. I think it depends on the amount of "black matter" in the universe - if there is enough, then eventually, the universe will cease to expand and eventually retract into intself because of gravity. If there isn't enough matter for gravitation to do this, then the universe will keep expanding. At least this was the way I remembered it...