Does there really exist an “axis of evil”?

If you read the title above as having something to do with international security, then I’m sorry to disappoint you. This keyboard worrier wants to discuss something completely different today.

For those remaining my subject is new evidence that a cosmological feature observed a few years ago by two researchers at Imperial College London could be an artefact of their analysis. Or, more accurately, the minds of astronomical analysts. But if the original interpretation does turn out to be wrong, the universal axis of evil was a romping good story while it lasted.

Three year microwave sky - NASA WMAP

Back in 2005, while studying maps of the cosmic microwave background radiation, Kate Land and João Magueijo spotted an unexpected large-scale alignment of hot and cold spots in this afterglow of the big bang, and dubbed it the “axis of evil”. The cosmic microwave background is a low-level radio signal coming from all parts of the sky, with an equivalent temperature of just four degrees above absolute zero.

Standard cosmological models predict that the universe is roughly isotropic, or looks pretty much the same in all directions. Tiny variations in background temperature give texture to the void, and without this there would be no stars and galaxies. But large patterns are out of the question.

So when an intergalactic alignment was observed in data from NASA’s funkily-named Wilkinson Microwave Anisotropy Probe, we were presented with news stories such as “‘Axis of evil a cause for cosmic concern'”. You must admit that his alliterative gem beats terrestrial terrorist threats for journalistic gravity.

But a re-analysis of spiral galaxies that appeared to line up in the sky has cast doubt on the original interpretation of Land and Magueijo, and following them that of Michael Longo at the University of Michigan.

Land, who is now at the University of Oxford, has found that people have a subconscious bias when it comes to picking clockwise and anticlockwise orientations in images presented to them. She discovered this when some of the galaxy images were flipped, and then run past a subset of the original volunteer analysts with the same result. “Rather than the universe being odd, it might be that people are odd,” she says. Rarely has a truer work been spoken.