New evidence supports the idea that we live in an area of the universe that is "just right" for our existence. The controversial finding comes from an observation that one of the constants of nature appears to be different in different parts of the cosmos.
If correct, this result stands against Einstein's equivalence principle, which states that the laws of physics are the same everywhere. "This finding was a real surprise to everyone," says John Webb of the University of New South Wales in Sydney, Australia. Webb is lead author on the new paper, which has been submitted to Physical Review Letters.
Even more surprising is the fact that the change in the constant appears to have an orientation, creating a "preferred direction", or axis, across the cosmos. That idea was dismissed more than 100 years ago with the creation of Einstein's special theory of relativity.
At the centre of the new study is the fine structure constant, also known as alpha. This number determines the strength of interactions between light and matter.
A decade ago, Webb used observations from the Keck telescope in Hawaii to analyse the light from distant galaxies called quasars. The data suggested that the value of alpha was very slightly smaller when the quasar light was emitted 12 billion years ago than it appears in laboratories on Earth today.
Now Webb's colleague Julian King, also of the University of New South Wales, has analysed data from the Very Large Telescope (VLT) in Chile, which looks at a different region of the sky. The VLT data suggests that the value of alpha elsewhere in the universe is very slightly bigger than on Earth.
The difference in both cases is around a millionth of the value alpha has in our region of space, and suggests that alpha varies in space rather than time. "I'd quietly hoped we'd simply find the same thing that Keck found," King says. "This was a real shock."
Moreover, the team's analysis of around 300 measurements of alpha in light coming from various points in the sky suggests the variation is not random but structured, like a bar magnet. The universe seems to have a large alpha on one side and a smaller alpha on the other.
This "dipole" alignment nearly matches that of a stream of galaxies mysteriously moving towards the edge of the universe. It does not, however, line up with another unexplained dipole, dubbed the axis of evil, in the afterglow of the big bang.
Earth sits somewhere in the middle of the extremes for alpha. If correct, the result would explain why alpha seems to have the finely tuned value that allows chemistry – and thus life – to occur. Grow alpha by 4 per cent, for instance, and the stars would be unable to produce carbon, making our biochemistry impossible. ...
via Laws of physics may change across the universe - space - 08 September 2010 - New Scientist.