The Big Rip and Dark Energy

The big rip is an idea that comes back to this question of dark energy. We don't know what it is that's making the universe expand faster. But there are other hypothetical possibilities for dark energy. It would start by building up on really large scales and pull all galaxy clusters apart. And then kind of get more powerful as it goes farther down and you'd eventually tear apart molecules, tear apart atoms, and ultimately tear apart the universe itself.