Would not an expanding arm or spiral be sucked up and/or distorted by all the billion other galaxies?
I’ve been watching the Science Channel. hehe
There is too much distance to the next galaxy for that to be a factor
There is likely some influence within our galactic neighborhood...Interesting fact Andromeda M31 Galaxy, is it’s approaching our galaxy and is expected to collide with it several billion years from now.
If we don’t annihilate each other first, our night sky prior to collision should be filled from horizon to horizon with the spectacular great Andromeda Galaxy.
BTW, in about 5 billion years, the sun will eventually expand into a red giant anyway, cooking all the inner planets in out solar system, leaving the earth a piece of charcoal, with the tiny piece of charcoal eventually being vaporized...
So either way, in a few billion years, earth is done...Or before that if some cataclysmic cosmic event occurs.