Spinning galaxies offer Big Bang clues

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ANN ARBOR, Mich., July 8 (UPI) -- U.S. researchers say the shape of the Big Bang might have been more complicated than previously thought and that the early universe spun on an axis.

Physicists and astronomers have long believed the universe has mirror symmetry, like a ball, but scientists at the University of Michigan say their study of tens of thousands of spiral galaxies suggest otherwise, PhysOrg.com reported Friday.

Physics Professor Michael Longo and a team of undergraduates catalogued the rotation direction of the galaxies.

The mirror image of a counter-clockwise rotating galaxy would have clockwise rotation. Finding more of one type than the other would be evidence for a breakdown of symmetry, the researchers said.

Longo and his team uncovered an excess of left-handed, or counter-clockwise rotating, spirals in the part of the sky toward the north pole of the Milky Way and said the effect extended beyond 600 million light-years away.

"The excess is small, about 7 percent, but the chance that it could be a cosmic accident is something like one in a million," Longo said. "These results are extremely important because they appear to contradict the almost universally accepted notion that on sufficiently large scales the universe is isotropic, with no special direction."

A symmetric and isotropic universe would have begun with a spherically symmetric explosion in all directions, but if the universe was born rotating, like a spinning basketball, Longo said, it would have a preferred axis, and galaxies would have retained that initial motion.

So is the universe still spinning?

"It could be," Longo said. "I think this result suggests that it is."