Something outside observable universe pulling galaxies
Cosmologists have discovered that 700 clusters of galaxies are being pulled by a massive gravity source that is outside the observable universe.
Since the universe is approximately 13.7 billion years old we can see no more than about 13.7 billion light years in any direction. However, the entirety of the universe is larger—potentially unimaginably larger—than that due to an early expansionary phase in the universe in which space itself expanded at an incredible rate. The mass that is pulling on those galaxy clusters, each of which is made up of many galaxies, lies beyond our event horizon, outside the observable universe.
Some of the researchers hypothesize that the mega mass in question is the result of an area of the universe that did not undergo as extensive a period of hyper inflation, leading to a more dense area of space.
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.
“The structures responsible for this motion have been pushed so far away by inflation, I would guesstimate they may be hundreds of billions of light years away, that we cannot see even with the deepest telescopes because the light emitted there could not have reached us in the age of the universe,” Kashlinsky said in a telephone interview. “Most likely to create such a coherent flow they would have to be some very strange structures, maybe some warped space time. But this is just pure speculation.”
Needless to say, scientists are very surprised at this unexpected finding.