>>12381425When you think about it, it is really sad. At some point due to expansion all galaxies will be so far away from each other with an expansion so fast that light from other galaxies will never reach each other. Every galaxy will be its own observable universe and any life forming in those galaxies will never know there were other galaxies out there. They will assume their galaxy is the entire universe since that will be all that is left to observe. Hints of the big bang such as the cosmic background radiation will be long gone as well.
To add to this, if the expansion of the universe doesn't stop (nothing indicates presently that it will ever stop) then eventually galaxies get ripped apart by the expansion, then solar systems, then individual objects in the solar systems, then eventually individual atoms get ripped apart, and all of these things will be so far apart from one another they'll effectively all be in their own observable universe. Yes, even atoms, will be so far apart they'll have their own observable universe.