Is our universe merely one of billions? Evidence of the existence of 'multiverse' revealed for the first time by a cosmic map of background radiation data gathered by Planck telescope. This past week, the first 'hard evidence' that other universes exist has been claimed to have been found by cosmologists studying the Planck data. They have concluded that it shows anomalies that can only have been caused by the gravitational pull of other universes.
"Such ideas may sound wacky now, just like the Big Bang theory did three generations ago," says George Efstathiou, professor of astrophysics at Cambridge University."But then we got evidence and now it has changed the whole way we think about the universe."
Scientists had predicted that it should be evenly distributed, but the map shows a stronger concentration in the south half of the sky and a 'cold spot' that cannot be explained by current understanding of physics. Laura Mersini-Houghton, theoretical physicist at the University of North Carolina at Chapel Hill, and Richard Holman, professor at Carnegie Mellon University, predicted that anomalies in radiation existed and were caused by the pull from other universes in 2005. Mersini-Houghton will be in Britain soon promoting this theory and, we expect, the hard evidence at the Hay Festival on May 31 and at Oxford on June 11.
Dr Mersini-Houghton believes her hypothesis has been proven from the Planck data that data has been used to create a map of light from when the universe was just 380,000 years old. "These anomalies were caused by other universes pulling on our universe as it formed during the Big Bang," she says. "They are the first hard evidence for the existence of other universes that we have seen."
Columbia University mathematician Peter Woit writes in his blog, "Not Even Wrong," that in recent years there have been many claims made for evidence of a multiverse, supposedly found in the CMB data. "Such claims often came with the remark that the Planck CMB data would convincingly decide the matter. When the Planck data was released two months ago, I looked through the press coverage and through the Planck papers for any sign of news about what the new data said about these multiverse evidence claims. There was very little there; possibly the Planck scientists found these claims to be so outlandish that it wasnt worth the time to look into what the new data had to say about them.
"One exception," Woit adds, "was this paper, where Planck looked for evidence of 'dark flow'. They found nothing, and a New Scientist article summarized the situation: 'The Planck teams paper appears to rule out the claims of Kashlinsky and collaborators,' says David Spergel of Princeton University, who was not involved in the work. If there is no dark flow, there is no need for exotic explanations for it, such as other universes, says Planck team member Elena Pierpaoli at the University of Southern California, Los Angeles. You dont have to think of alternatives.'"
"Dark Flow" sounds like a new SciFi Channel series. It's not! The dark flow is controversial because the distribution of matter in the observed universe cannot account for it. Its existence suggests that some structure beyond the visible universe -- outside our "horizon" -- is pulling on matter in our vicinity.
Back in the Middle Ages, maps showed terrifying images of sea dragons at the boundaries of the known world. Today, scientists have observed strange new motion at the very limits of the known universe - kind of where you'd expect to find new things, but they still didn't expect this. A huge swath of galactic clusters seem to be heading to a cosmic hotspot and nobody knows why.
Cosmologists regard the microwave background -- a flash of light emitted 380,000 years after the universe formed -- as the ultimate cosmic reference frame. Relative to it, all large-scale motion should show no preferred direction. A 2010 study tracked the mysterious cosmic 'dark flow' to twice the distance originally reported. The study was led by Alexander Kashlinsky at NASA's Goddard Space Flight Center in Greenbelt, Maryland.
"This is not something we set out to find, but we cannot make it go away," Kashlinsky said. "Now we see that it persists to much greater distances - as far as 2.5 billion light-years away," he added.
