Interesting research has found that all the galaxies in our universe appears to be pulled toward something outside of the universe:

The force and direction of the flow holds steady across space and through time.

“It’s the same flow at a distance of a hundred million light-years as it is at 2.5 billion light-years and it points in the same direction and the same amplitude. It looks like the entire matter of the universe is moving from one direction to the next,” Kashlinsky said.

The observation fits theoretical models of how our universe might be impacted by sibling universes, predicted by string theory, that we cannot directly detect.

It’s like our universe is a box and everything that it contains is inside it like milk in a carton, physicist Laura Mersini-Houghton with University of North Carolina at Chapel Hill, told Discovery News.

“If our universe is all that’s there, then the liquid in the box shouldn’t be sliding. Whatever is pulling it has to be bigger than the size of the box,” she said. “There is a structure beyond the horizon of our universe and that structure is exerting a force on our universe and creating this flow.”

Pretty trippy.

The nature of reality is one of those questions we don’t ponder much. But, it’s certainly the most interesting question around.