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A team of
astrophysicists based in
Australia
and
England
has uncovered evidence that the laws of physics are different in
different parts of the universe. The
team, from the
University
of
New South Wales
, Swinburne University of Technology and the
University
of
Cambridge
, has submitted a report of the discovery for publication in the journal
Physical Review Letters. A
preliminary version of the paper is currently under peer review.
The
report describes how one of the supposed fundamental constants of Nature
appears not to be constant after all. Instead,
this 'magic number' known as the fine-structure constant - 'alpha' for
short - appears to vary throughout the universe. After
measuring alpha in around 300 distant galaxies, a consistency emerged,
and it appears that this magic number, which tells us the strength of
electromagnetism, is not the same everywhere as it is here on Earth.
It also seems to vary continuously along a preferred axis through
the universe.
The
implications for our current understanding of science are profound. If
the laws of physics turn out to be merely 'local by-laws', it might be
that whilst our observable part of the universe favours the existence of
life and human beings, other far more distant regions may exist where
different laws preclude the formation of life, at least as we know it.
If the results are correct, clearly new physical theories will
need to be developed to satisfactorily describe them.
The
researchers' conclusions are based on new measurements taken with the
Very Large Telescope (VLT) in
Chile
, along with their previous measurements from the world's largest
optical telescopes at the Keck Observatory in
Hawaii
. Mr Julian King from the
University
of
New South Wales
explained how, after combining the two sets of measurements, the new
result 'struck' them. The
Keck telescopes and the VLT are in different hemispheres - they look in
different directions through the universe. Looking to the north with
Keck we see, on average, a smaller alpha in distant galaxies, but when
looking south with the VLT we see a larger alpha.
It varies by only a tiny amount - about one part in 100,000 -
over most of the observable universe, but it's possible that much larger
variations could occur beyond our observable horizon.
The
discovery will force scientists to rethink their understanding of
Nature's laws. The fine
structure constant, and other fundamental constants, are absolutely
central to our current theory of physics. If
they really do vary, we'll need a better, deeper theory. While
a 'varying constant' would shake our understanding of the world around
us extraordinary claims require extraordinary evidence. What
we're finding is extraordinary, no doubt about that.
It's one of the biggest questions of modern science - are the
laws of physics the same everywhere in the universe and throughout its
entire history? The group
are determined to answer this burning question one way or the other.
Researchers
involved in the project are Professor John Webb, Mr Julian King,
Professor Victor Flambaum and PhD student Matthew Bainbridge from the
University of New South Wales, Dr Michael Murphy from Swinburne
University and Professor Bob Carswell at the University of Cambridge
(UK).
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