If when you look through a telescope at distant galaxies, what you see happened millions of years ago because the speed of light is quite slow.
The universe is also expanding so the galaxies are getting further away. Eventually they will be so far away that it will be too far for even light to reach us. If you think of the speed of light as the maximum speed of information transmission, no information could be exchanged with those galaxies.
In effect those galaxies are now in separate universes. It's beyond the range that information can be exchanged with our one so they cant effect each other.
The universe is also expanding so the galaxies are getting further away. Eventually they will be so far away that it will be too far for even light to reach us. If you think of the speed of light as the maximum speed of information transmission, no information could be exchanged with those galaxies.
In effect those galaxies are now in separate universes. It's beyond the range that information can be exchanged with our one so they cant effect each other.