The universe has a drain, and galaxies flow darkly to it

"Dark flows": a rich term, describing vast mysterious movements of cosmic matter.

Patches of matter in the universe seem to be moving at very high speeds and in a uniform direction that can't be explained by any of the known gravitational forces in the observable universe. 

Why the ominous name?

Kashlinsky calls this collective motion a "dark flow" in the vein of more familiar cosmological mysteries: dark energy and dark matter. "The distribution of matter in the observed universe cannot account for this motion," he says.

And where are these titanic streams of galactic clusters heading?  Right about here:

What to make of this?  We can enjoy reflections like this one:

The scientists deduced that whatever is driving the movements of the clusters must lie beyond the known universe.

Or we could cue up the wildest, most universe-smashing dreams of space opera (Steven Baxter alert!).  Or summon up nightmarish horrors from, well, beyond space, if not time. 

(via MetaFilter)