Quantum Galaxies

Earlier studies of WMAP data have determined that the universe is 13.7 billion years old, give or take a few hundred thousand years. They have also measured variations in the cosmic microwave background so huge that they stretch across the entire sky. Those earlier observations are strong indicators of inflation, but no smoking gun, said Turner, who was not involved in the research. They represent tiny inhomogeneities -- dense spots in the superhot primordial soup that was the universe in the first stages of inflation -- blown up to hundreds of light-years in size by the subsequent expansion of the universe.

The new analysis was able to characterize variations in the microwave background over smaller patches of sky -- only billions of light-years across compared to hundreds of billions. Due to some weird aspects of quantum physics, those smaller lumps popped into existence during the middle and end of the inflationary process as tiny subatomic particles.

Then they would have expanded with the space they occupied to become of today's stars and galaxies. Slightly denser than their surroundings, they would have pulled additional material in by gravity, building up into the massive galaxies and superclusters observable today.

"Galaxies are nothing but quantum mechanics writ large across the sky," said Brian Greene, a Columbia University physicist.