Question: would the earth ever go back into a bubble?

Maria McNamara answered on 15 Nov 2019:

I’m not really sure what you mean here. If you mean will there be a Big Crunch, we’re not sure. The mass of the universe (as best we can measure) seems close to the threshold between a ‘Big Crunch’ scenario and the alternative scenario where the universe continues to expand forever. If you ask me the Big Crunch seems a lot more positive / exciting – at least then there is the chance for everything to start over, rather than a future universe that is impossibly sparse and cold.