IT’S citizen science in action. More than 85,000 members of the public have knocked a dent in the cosmic “axis of evil” that threatens to bring down standard cosmology.
In 2005, Kate Land and João Magueijo at Imperial College London noticed an unexpected alignment of hot and cold spots in the cosmic background radiation – the relic radiation of the big bang. The alignment seemed to defy standard cosmology, which predicts that the universe is isotropic and so should look the same in every direction.
The case for this so-called axis of evil grew stronger in 2007, when Michael Longo at the University of Michigan in Ann Arbor studied 1660 spiral galaxies and found the majority appear to line up with the axis, and a higher-than-expected number rotate in a certain direction. To check Longo’s claim, Land, now at the University of Oxford, and her colleagues recruited the public to classify the orientation of almost 900,000 other galaxies as part of an online project called Galaxy Zoo.
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At first, things looked good for the axis. The volunteers found a lot more anticlockwise than clockwise galaxies in the Northern hemisphere of the sky – matching Longo’s findings. But to double-check the findings, Land’s team flipped the images of the some of the galaxies and ran them past a subset of the volunteers again.
It turned out people have a preference when picking orientation: despite the mirroring, 52 per cent of the galaxies were still described as anticlockwise. “Rather than the universe being odd, it might be that people are odd,” says Land. The team has submitted the findings to Monthly Notices of the Royal Astronomical Society ().
Longo, however, is unconvinced. The mirroring analysis was only carried out for 5 per cent of the galaxies studied and he believes this sample is too small to justify rejecting the original excess that users spotted, which corroborated the existence of the axis. “[Land and colleagues] have done an impressive job of organising the Galaxy Zoo project, but I believe their analysis is flawed,” he says.
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