Because Moffat, you see, doesn't think small when challenging established scientific dogma. This professor emeritus who has been at U of T since 1964 has decided to go after Albert Einstein himself, and Einstein's special theory of relativity; in particular, what that theory has to say about the absolute limit formed by the speed of light.

One of the conclusions contained within Einstein's 1905 theory is that the speed of light (300 million metres per second) is an absolute constant. It is the cosmic speed limit; nothing can, has or ever will travel faster. If there is an equivalent to holy writ in modern physics, this is it. Every physics advance of the last century assumes that on this score, Einstein had the final word.

That is until Moffat came along. In a paper published recently in the journal Physics Letters, he argues that while the speed of light may be the universal speed of light now, that doesn't mean that speed hasn't changed since the universe began.

Moffat's paper, co-authored with former graduate student Michael Clayton (now teaching at the Virginia Commonwealth University), tries to find an answer to a paradox that bedevils our understanding of the early history of the universe.

A growing body of measurements and theory indicate that if everything in the visible universe exploded outward from a single point (the so-called Big Bang) and that if nothing moves faster than light, then our universe is impossibly big.

As well, a universe that expands impossibly fast, or continues to accelerate now, implies some unknown gravitationally repulsive form of matter, unlike anything we currently know exists.

You can either assume this is true, say Moffat and Clayton, or you can assume the speed of light is much slower now than it was at the beginning of time. All you have to do is break Einstein's rule that the speed of light has never varied and all the big cosmological problems disappear.

"It is easier for me to question Einstein's theory than it is to assume there is some kind of strange, exotic matter around me in my kitchen," Moffat explains.

John Barrow, an author and professor of mathematical sciences at Cambridge University, believes Moffat may be on to something. "The simplicity of this new model and the striking nature of its predictions suggest that we should investigate it more seriously," he wrote in a recent article in New Scientist magazine. "[It] should provoke us to take a wide-ranging look at the constancy of nature's 'constants.'"

This is not the first time Moffat has taken on scientific orthodoxy, however. In the early 1980s he attracted wide attention for another challenge to Einstein, that time involving his later general theory of relativity.

But Moffat's non-symmetrical gravitational counter-theory never caught on. He had trouble getting a hearing for his latest notions as well: his paper on the speed of light was first written in 1991 but he couldn't find a publisher for years.

It is only in the last year, as new astronomical observations continued to add to the confusion, that the idea of a changing speed of light started receiving serious consideration by the mainstream.

Interestingly enough, Einstein himself was not angered by Moffat's ideas. In the early 1950s Moffat wrote the great physicist regarding his doubts about general relativity.

Einstein, then at Princeton, replied, not agreeing but not offended by the challenge either. "Every individual � has to retain his way of thinking if he does not want to get lost in the maze of possibilities. However, nobody is sure of having taken the right road -- myself least of all."

Forty years later, Moffat finds himself agreeing with that sentiment. "Shifting paradigms in science should never be easy. Scientists should stick with a theory that has been grounded in fact � until there's a real reason for changing. But if you think your ideas are right, then you have to persist," he says.

A scientific prodigy who taught himself physics before completing a PhD in three and a half years at Cambridge (having skipped an undergraduate degree), Moffat studied under 1979 Nobel laureate Abdus Salam.

A talented amateur painter, he now spends much of his time at his house in the Kawarthas with his wife, Pat, a science journalist and writer herself. He continues to work on heterodox theories of cosmology and particle physics and recently published a paper in the field of econometrics, suggesting that the mathematics of hydrodynamic flows could be used to predict the rise and fall of stock markets. It may be a completely different field but it's the same old impulse, it seems.

"I like to question things," he says, "to push things around and see how they work."