Although this microwave background is mostly smooth, the Cobe satellite in 1992 discovered small fluctuations that were believed to be the seeds from which the galaxy clusters we see in today's Universe grew.Apparently, on one side of the sky, the cosmic microwave background fluctuations are 10% stronger than on the other.
Dr Adrienne Erickcek, and colleagues from the California Institute for Technology (Caltech), now believes these fluctuations contain hints that our Universe "bubbled off" from a previous one.
Their data comes from Nasa's Wilkinson Microwave Anisotropy Probe (WMAP), which has been studying the CMB since its launch in 2001.
Sean Carroll conceded that this might just be a coincidence, but pointed out that a natural explanation for this discrepancy would be if it represented a structure inherited from our universe's parent.The problem to solve, according to the BBC News article, "Hints of 'time before Big Bang" by Chris Lintott (Co-presenter, BBC Sky At Night, St Louis, US) is the fact that time runs in only one direction - forward - but other forces in nature can be reversed. Conventionally, the second law of thermodynamics is held responsible. But, says Prof. Sean Carroll (California Institute of Technology), cosmologists should broaden their horizons.
An American physicist friend insists that this is all "horse puckey", and I suspect he is right. Any time something can be reasonably explained as just "a coincidence", one might perhaps best explain it that way.