spacetoday.net: Astronomers see Big Bang ripples

Posted: Wed, Jan 12, 2005, 8:07 AM ET (1307 GMT)
Large-scale patterns of galaxies can be linked to sound waves created by the Big Bang, astronomers said Tuesday. Those sound waves propagated through the dense hot gas that permeated the universe shortly after the Big Bang; those waves created density fluctuations in the gas. More galaxies should have formed in the denser regions after the waves stopped, about a million years after the Big Bang. Observations of large-scale galaxy structure made by the Sloan Digital Sky Survey show that galaxies structures tend to be about 500 million light-years apart, the amount predicted by theory given the amount of expansion of the universe.