KMFJD
Lifer
- Aug 11, 2005
- 29,137
- 42,112
- 136
Well...it IS gonna run out sometime...maybe in a few billion years.
Overall, yes. Locally, galaxies merge rather often in the grand scheme of things. Our local group will remain 'local' for many (tens of? hundreds of? I forget) billion years, but (as far as we know) eventually those, too, will be too far away to see.How do galaxies collide? I thought they were all moving apart at the speed of red as the universe expands? One of them is a really crappy driver.
How do galaxies collide? I thought they were all moving apart at the speed of red as the universe expands? One of them is a really crappy driver.
Overall, yes. Locally, galaxies merge rather often in the grand scheme of things. Our local group will remain 'local' for many (tens of? hundreds of? I forget) billion years, but (as far as we know) eventually those, too, will be too far away to see.
Much like solid matter, the vast majority of galaxies are empty space.
Unlike solid matter, galaxies could easily pass thru each other with very little effect.
Speed is kinda relative too. They move at different speeds, in somewhat concert with each other due to gravity. Our local group is moving pretty synchronously compared to other galaxies. Andromeda 'catching up' is practically a snail's pace compared to our relative velocity vs other galaxies. Our merging with Andromeda will be some 4.5B years from now, if it was another galaxy it could be in a million years due to relative speeds.they all move at different speeds, right? It's like Andromeda is at the back of the grid running at Lewis Hamilton's pace, and the Milky Way is in P1 running at Max Verstappen's Pace. Eventually, Andromeda is going to catch up.
Based on my extensive knowledge (based upon watching a couple of youtube videos) they are now pretty sure that the Milky Way has already gone through two such collisions already. Some theorize (very controversial) that the sun actually originated in one such dwarf galaxy (named Sagittarius Dwarf) that was absorbed by the Milky Way. It's pretty amazing when you look into it the very expensive pure science NASA is pursuing and the extent to which our knowledge in those fields has been growing by leaps and bounds in the past two or three decades.
To me the most mind blowing factoid is that every single star we can see is part of the Milky Way and that there are probably billions if not trillions of other galaxies in the universe.