Mysterious New 'Dark Flow' Discovered in Space
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.
The scientists deduced that whatever is driving the movements of the clusters must lie beyond the known universe.
A theory called inflation posits that the universe we see is just a small bubble of space-time that got rapidly expanded after the Big Bang. There could be other parts of the cosmos beyond this bubble that we cannot see.
In these regions, space-time might be very different, and likely doesn't contain stars and galaxies (which only formed because of the particular density pattern of mass in our bubble). It could include giant, massive structures much larger than anything in our own observable universe. These structures are what researchers suspect are tugging on the galaxy clusters, causing the dark flow.
http://www.space.com/scienceastronomy/0 ... flows.html