Left-handed spiral galaxies dominate northern skies
And right-handed ones are more common in the south, according to a new survey. What’s going on?

The universe seems to be asymmetric in a number of strange ways. The molecules of life tend to be left handed rather than right handed, the certain weak decays such as the beta decay of cobalt-60 are asymmetric and cosmologists have seen a number of unexplained asymmetries in the cosmic microwave background.
Michael Longo at the University of Michigan has long been searching for another asymmetry–a preference for right or left handedness in spiral galaxies. And he says he’s found it, previously in an analysis of over 2600 nearby spiral galaxies and now in an analysis of 15,000 more.
The evidence seems to indicate that left handed spirals are more common in the northern hemisphere, above the northern galactic pole. And although the signal is less strong, right-handed spirals appear more frequently in the south.
What’s more, Longo says the axis of this alignment points directly towards the mysterious cold spot in the cosmic microwave background, which was discovered in the southern hemisphere in 2004
Nobody knows what caused the cold spot although there are no shortage of ideas. The cold spot could be evidence that our galaxy sits in the middle of a supervoid, a giant empty bubble, say some researchers. Others say it could be the imprint of a parallel universe beyond our own.
If Longo’s bias is real and linked to the spot, get ready for another round of speculation that attempts to link these observations together.
Ref: arxiv.org/abs/0904.2529: Evidence for a Preferred Handedness of Spiral Galaxies
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