By Nicolle Wahl
Professor emeritus John Moffat of physics has his own ideas
about relativity. Since the beginning of the 20th century,
Albert Einstein’s famous theory has formed the backbone
upon which cosmology experts have sought to explain how
the universe began and eventually how it will end.
But in spite of Einstein’s genius, his theories have
presented several problems for physicists such as how to
explain the expansion of the universe and the existence
of mysterious “negative-mass” matter. In 1981 the
inflationary universe model was proposed to solve some
of these problems. It suggested that for a fraction of a
second at the beginning of the universe, it expanded at
an exponentially fast rate. But even this theory left
some questions unanswered.
In the early 1990s Moffat proposed a radical alternative
theory: that the speed of light was faster closer to the
time of the big bang. His early calculations suggested
that light travelled as much as 1,030 times faster than
its present value (186,000 miles per second) just
following the explosive beginning of the universe.
Moffat’s unconventional theory sent waves through the
physics community. “When you start to change physics on
a fundamental level, when you start to change Einstein’s
theory, you’re changing our whole understanding of
space-time,” Moffat says.
Last month theoretical astrophysicist Joao Maguelijo of
Imperial College London published Faster than the Speed
of Light, a new book describing his theories on a
variable speed of light and acknowledging Moffat’s
groundbreaking work. In August 2002 the journal Nature
published a paper by Paul Davies from the Australian
Centre for Astrobiology, a followup on other papers
based on Moffat’s theory.
“Had I not been aware of John’s work, I would not have
myself made a small contribution to this field,” Davies
says. “John has shown how it is possible to think outside
the square when confronting some of the puzzles of
cosmology. In particular, his cosmological solutions
seem to be in good agreement with the remarkable new
astronomical results showing that the fine structure
constant seems to have varied over cosmological history.”
This work may herald a major reinterpretation of
cosmological data, Davies adds, and require important
changes to the conceptual scheme used as a framework for
cosmology over the last half century. But Moffat has his
detractors within the physics community. Michael Duff,
director of the Michigan Center for Theoretical Physics
at the University of Michigan and a long-time friend of
Moffat, has published rebuttals of Moffat’s theory.
“Moffat has lots of provocative ideas,” says Duff. “He’s
contributing to the debate, so although I have to
disagree with him, he’s every bit entitled to express
his opinion, and he does so quite effectively. I happen
to disagree with him.”
Duff suggests that proponents of the changing speed of
light theory are confusing a change in physics with a
change in the units used to measure it. Asking whether
the speed of light has changed over cosmological time
scales is like asking whether the number of litres to a
gallon has changed,” he says, adding that those who take
Moffat’s view are at risk of drawing false conclusions.
But the publication of Davies’ paper, along with the
increased profile of the changing speed of light theory,
gives Moffat a certain sense of vindication. Although
retired, he regularly publishes papers on the topic and
recently spoke at international conferences in France
and Portugal. And while he acknowledges that his
controversial theory has detractors, he is pleased that
his model is undergoing rigorous scientific testing.
“The physics community is a very conservative community,
and so it should be,” says Moffat. “This is not a
trivial matter. You don’t just go around changing
paradigms in science willy-nilly.”
[Nicolle Wahl is a news services officer with the
department of public affairs.]
RELATED STORIES:
* Speed of light may not be constant, physicist suggests
(Sept. 30, 1999)
http://www.newsandevents.utoronto.ca/bin/19990930b.asp
* Challenging Einstein (Oct. 25, 1999)
http://www.newsandevents.utoronto.ca/bin/19991025g.asp
[NOTE: A photo of John Moffat is available at
http://www.newsandevents.utoronto.ca/bin4/030224d.asp ]
