Astronomy & Cosmology - Alternative Universes
In 2008, Sasha Kashlinsky of the Goddard Space Flight Center analyzed observations of the motion of galactic clusters together with the three-year WMAP survey details. These motions should be random, but he has found evidence of non-random motion in a direction between the constellations of Centaurus and Vela, at speeds of up to 1,000 kilometers a second. He named this phenomenon Dark Flow. He suggests that the cause is a gravitational effect from beyond our horizon; that is, beyond what we can observe. Laura Mersini-Houghton (U of North Carolina) suggests it is caused by other universes exerting a gravitational pull on our Universe. Most scientists remain somewhat skeptical of these conclusions; some like Edward Wright at UCLA strongly so. A separate study by Watkins, Feldman & Hudson came to similar conclusions to Kashlinsky's group, albeit on a smaller scale. Using somewhat different methods, they found velocities exceeding 400 km/sec compared to an expected value of 110 km/sec.
In March 2010, Kashlinsky published further results based on the more comprehensive five-year WMAP study (released in 2008). This study permitted measuring the motion of 1,000 galaxy clusters out to 800 Mpc, compared to only 700 clusters out to 300 Mpc in the earlier study. Essentially, they came to similar conclusions. I have yet to see any comments on the new results. The seven year WMAP data was released on January 26th 2010, but it will take a while to analyze the data.
Recently, in April 2011, I heard that a team based at the University of Buffalo in the USA may have found evidence, based on type 1a supernovae, that contradicts Kashlinsky's findings, while supporting the predictions of the Lambda-Cold Dark Matter (CDM) model.
Evidence & Observations