Big bang sound waves explain galaxy clustering

Big bang sound waves explain galaxy clustering

12 January 2005

Sound waves that roared through space after the big bang left behind a subtle imprint in the way galaxies are clustered today, reveal two major studies. The results bolster the standard theory that the universe is flat, and measuring the distance between the sound ripples may provide a new cosmic yardstick to probe the past.

Two independent teams mapping the universe have found that galaxies are currently huddled together slightly more often at distances of 500 million light years as a result of conditions in the early universe. They announced the finding on Tuesday at a meeting of the American Astronomical Society in San Diego, California, US.

The results back the standard models of a flat universe, dominated by dark matter and dark energy, that has been expanding - or undergoing a process of inflation - since the big bang. Generally speaking, the distance between galaxies matches the pattern of sound wave ripples from the early universe.

"The triumph is that the signal is seen at the expected location," says Richard Ellis, an astronomer at the California Institute of Technology, US, and a member of the 2-degree Field Galaxy Redshift Survey (2dF) team.

The discovery is especially powerful because the groups used different observations and statistical techniques to arrive at the same conclusion, says Martin Rees, an astronomer at Cambridge University, UK....cont'd

http://www.newscientist.com/article.ns?id=dn6871