The expansion of the universe and how stars and galaxies still collide How can it be that all galaxies and stars are moving away from each other yet they still collide?  From what I have researched it as an open universe (or many open universes) yet the idea of stars and galaxies colliding boggles me.
The expansion is overridden on a small scale by gravity. Our galaxy is not expanding, and the stars are bound together.  In fact, a whole group of galaxies don't notice the overall expansion.