As if the mysteries of dark matter and dark energy weren't vexing enough, another baffling cosmic puzzle has been discovered.
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. Astronomers are calling the phenomenon "dark flow."
The stuff that's pulling this matter must be outside the observable universe, researchers conclude.
Read the whole article, Mysterious 'dark flow' discovered in space:
Stuff pulling on matter believed to be outside the observable universe