Hey all,
Here's a testament to the provisional nature of even our most well accepted
scientific truths.....
Scientists: Speed of Light May Change
Change in Speed Would Debunk Einstein Theories
By Michael Christie
Reuters
SYDNEY (Aug. 7) - A team of Australian scientists has proposed that the
speed of light may not be a constant, a revolutionary idea that could unseat
one of the most cherished laws of modern physics -- Einstein's theory of
relativity.
The team, led by theoretical physicist Paul Davies of Sydney's Macquarie
University, say it is possible that the speed of light has slowed over
billions of years.
If so, physicists will have to rethink many of their basic ideas about the
laws of the universe.
''That means giving up the theory of relativity and E-mc squared and all
that sort of stuff,'' Davies told Reuters.
''But of course it doesn't mean we just throw the books in the bin, because
it's in the nature of scientific revolution that the old theories become
incorporated in the new ones.''
Davies, and astrophysicists Tamara Davis and Charles Lineweaver from the
University of New South Wales published the proposal in the August 8 edition
of scientific journal Nature.
The suggestion that the speed of light can change is based on data collected
by UNSW astronomer John Webb, who posed a conundrum when he found that light
from a distant quasar, a star-like object, had absorbed the wrong type of
photons from interstellar clouds on its 12 billion year journey to earth.
Davies said fundamentally Webb's observations meant that the structure of
atoms emitting quasar light was slightly but ever so significantly different
to the structure of atoms in humans.
The discrepancy could only be explained if either the electron charge, or
the speed of light, had changed.
IN TROUBLE EITHER WAY
''But two of the cherished laws of the universe are the law that electron
charge shall not change and that the speed of light shall not change, so
whichever way you look at it we're in trouble,'' Davies said.
To establish which of the two constants might not be that constant after
all, Davies' team resorted to the study of black holes, mysterious
astronomical bodies that suck in stars and other galactic features.
They also applied another dogma of physics, the second law of
thermodynamics, which Davies summarizes as ''you can't get something for
nothing.''
After considering that a change in the electron charge over time would
violate the sacrosanct second law of thermodynamics, they concluded that the
only option was to challenge the constancy of the speed of light.
More study of quasar light is needed in order to validate Webb's
observations, and to back up the proposal that light speed may vary, a
theory Davies stresses represents only the first chink in the armor of the
theory of relativity.
In the meantime, the implications are as unclear as the unexplored depths of
the universe themselves.
''When one of the cornerstones of physics collapses, it's not obvious what
you hang onto and what you discard,'' Davies said.
''If what we're seeing is the beginnings of a paradigm shift in physics like
what happened 100 years ago with the theory of relativity and quantum
theory, it is very hard to know what sort of reasoning to bring to bear.''
It could be that the possible change in light speed will only matter in the
study of the large scale structure of the universe, its origins and
evolution.
For example, varying light speed could explain why two distant and causally
unconnected parts of the universe can be so similar even if, according to
conventional thought, there has not been enough time for light or other
forces to pass between them.
It may only matter when scientists are studying effects over billions of
years or billions of light years.
Or there may be startling implications that could change not only the way
cosmologists view the universe but also its potential for human
exploitation.
''For example there's a cherished law that says nothing can go faster than
light and that follows from the theory of relativity,'' Davies said. The
accepted speed of light is 300,000 km or 186,300 miles per second.
''Maybe it's possible to get around that restriction, in which case it would
enthrall Star Trek fans because at the moment even at the speed of light it
would take 100,000 years to cross the galaxy. It's a bit of a bore really
and if the speed of light limit could go, then who knows? All bets are
off,'' Davies said.
Reuters 14:05 08-07-02
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