Main Question or Discussion Point
gravity pulls two galaxies. Andromeda and Milky Way are going to collide in few billion years. this seems to show that everything in the universe is moving close to each other i.e. contracting. but, since the universe was formed, it has been expanding due to dark energy. how do you explain this? secondly, are they (force by dark energy and gravity) in equlibrium? if not which one is dominating?