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WAS the early Universe a tangle of gargantuan swirls? That’s one explanation
for the observation by astronomers that light from quasars in the same part of
the sky is polarised in roughly the same direction.

Quasars are thought to be the cores of extremely distant young galaxies that
pump out huge amounts of energy. Astronomer Damien Hutsemékers of the
University of Liège in Belgium noticed the polarisation effect two years
ago in data gathered at the European Southern Observatory in Chile. Thinking
that it must be an illusion produced by his telescope, Hutsemékers combed
quasar data from other telescopes. He found that they showed the alignment as
well.

Now Hutsemékers and his colleague Hervé Lamy report even
stronger evidence in a paper to be published in Astronomy and Astrophysics.
After studying the effect in existing data, the researchers predicted which way
light from quasars in a particular region of the sky should be polarised. When
they examined 13 new quasars in this region they found that 10 of them were
polarised in just the way they had predicted.

A similar claim about the polarisation of radio waves was made three years
ago, but was later shown to be the result of flawed statistical analysis.
According to Beverley Wills of the University of Texas at Austin,
Hutsemékers and Lamy seem to have done the maths correctly: “I think
they’ve been pretty careful with the statistics,” she says.

One explanation for the phenomenon is that intergalactic magnetic fields are
filtering out photons of certain polarisations by turning them into axions,
particles invented to account for the missing dark matter needed to make up the
Universe’s mass.

Another possibility is that the galaxies containing the quasars have the same
orientation. suggesting that the primordial Universe contained swirls billions
of light years across. Astronomer Michael Beitenholz of York University in
Toronto is sceptical, but he admits we know so little about how galaxies and
galaxy clusters formed that “there is room to play there”.