From: Spudboy100@aol.com
Date: Fri May 17 2002 - 14:38:21 MDT
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1991000/1991223.stm
The Universe may be a stranger place than we imagined because of new evidence
that appears to show the very laws of physics have changed since the cosmos
was young. Analysis of the light coming from distant quasars suggests that a
fundamental physical constant may have been increasing slightly over the past
six billion years. This has major implications for our understanding of
physics.
John Webb, New South Wales University.
The so-called fine structure constant - which measures the strength with
which subatomic particles interact with one another and with light - may have
been smaller at earlier times in the history of the Universe. "This has major
implications for our understanding of physics," Dr John Webb of New South
Wales University, Australia, told BBC News Online. "If this is correct, it
will radically change our view of the Universe. We have to be cautious but it
could be revolutionary. We have seen something in our data - but is it what
we think?" Fabric of the Universe The team looked at so-called absorption
lines in the spectra of quasars, the highly active, bright cores of galaxies
at the farthest reaches of the Universe. Gas clouds between Earth and the
quasars absorb some of this light at specific wavelengths and produce the
spectral lines.
The spacing between the wavelengths absorbed by the intervening atoms depends
on alpha. If alpha changes, then so will the absorption pattern in the
spectra. The researchers looked for this effect using the world's largest
telescope: the 10-metre Keck facility in Hawaii. Dr Webb and his co-workers
found evidence that alpha was slightly smaller in the past than it is now.
The team say there is a one in 10,000 chance that the result is a statistical
fluke. They also say they have eliminated 13 potential sources of systematic
error. Strange, wrong but interesting Since the 1930s, physicists have
discussed whether the so-called constants of the Universe that appear in the
equations for the fundamental laws of physics - such as the speed of light in
vacuum and the electron charge - are indeed constant. Dr Webb said: "It was
Dirac and Milne who talked about this first. Their ideas were strange, wrong,
but very interesting. When I came across them, they made me think." The
current value of alpha could not have been very different in the past.
A small variation in alpha would imply that carbon atoms could not be stable,
and carbon-based life such as us could not have arisen. In fact, modern
attempts to unify gravity with the other fundamental forces do allow for
Nature's constants to vary. Proposed theories can accommodate changes in
alpha over time. Known as string theories, they allow either a 10- or
26-dimensional universe, rather than our 4D one. Something in the data Other
scientists have reacted with interest and caution after reviewing the quasar
data. Faced with the possibility of toppling cherished views on the Universe,
Dr Webb condones this approach. "There is something in the data. There is a
signal there. Others have looked at our data and agree there is something
there, but is it real or some unknown instrumental effect?" The next step is
to look for the same effect using a different telescope, the Very Large
Telescope (VLT) in South America. "If after looking for the same effect in
the VLT data we were to see the same thing, it would be strong evidence that
the effect is real. It would be remarkable to have identical errors from Keck
and the VLT," said Dr Webb. "If we see the same thing, I will not be 100%
certain but let me say I would be largely convinced," he added. "We will know
in about a year."
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