In my hypothesis, mass acts like a vacuum cleaner that sucks in the tiny quantum foam particles that make up space. Those particles reappear at random locations anywhere in the universe. At any distance we are used to, it seems to act like gravity in every way that I know about.
Inside galaxies where there is lots of mass, gravity dominates. At very long distances, large volumes of empty space would seem to expand, thus looking like a force that pushes galaxies away from each other.
Outside galaxies, there is vast space with virtually no mass, so the expansion force dominates.
In our neighborhood (the closest 83 galaxies) there is roughly 10 billion times more space outside of galaxies than inside galaxies. That expansion force pushes against the outside of the galaxies, gently squeezing each galaxy tighter at the same time it pushes them all apart from each other.
Outside galaxies, there is vast space with virtually no mass, so the expansion force dominates.
In our neighborhood (the closest 83 galaxies) there is roughly 10 billion times more space outside of galaxies than inside galaxies. That expansion force pushes against the outside of the galaxies, gently squeezing each galaxy tighter at the same time it pushes them all apart from each other.
