John Moffat does not look particularly threatening. With his white hair and vaguely European accent, the mild-mannered physicist can walk unnoticed along the streets of Waterloo, Ont., where he has worked for the past three years.
However, when it comes to explaining the structure of the universe, Dr. Moffat -- or at least his ideas -- are closer to the edge. For every seemingly established idea in physics, from Albert Einstein's theory of gravity, to string theory, to cosmic inflation, he has an alternative approach. His non-conformity has won him both friends and enemies over the years in a career that has spanned more than half a century (he recently celebrated his 70th birthday).
"John is a bit of an iconoclast," says Clifford Will, a leading gravity expert at Washington University in St. Louis. "His approach has always been a bit perpendicular to what everyone else is doing."
Physics was not Dr. Moffat's first career choice. Born in Denmark, he turned to painting at an early age. He dropped out of school to pursue the artist's life in Paris, where his abstract paintings were displayed alongside those of Russian master Serge Polyakoff. (Dr. Moffat still paints; he had a display at the Lindsay Gallery in Lindsay, Ont., northwest of Toronto, last spring.)
However, when he ran short of funds, Dr. Moffat returned to Copenhagen, where he soon discovered a second skill. Poring over physics books in the public library, he found that he had a knack for relativity and quantum theory, right down to their thorny mathematical innards. He started writing scientific papers, and sent a couple of them to Albert Einstein, who, to his surprise, seemed genuinely interested in his work. The two men corresponded for several years, until Einstein's death in 1955.
Over the next few years, Dr. Moffat rubbed shoulders with Europe's top physicists, including Niels Bohr and Erwin Schrodinger, of quantum-theory fame, and Abdus Salam, who would later win a Nobel Prize for his work in particle physics. With the help of Dennis Sciama, a physicist who also mentored Stephen Hawking, Dr. Moffat entered Trinity College at Cambridge. He became the first student in the college's history to be admitted to a PhD program without an undergraduate degree.
By this time, Dr. Moffat was already establishing himself as a maverick. In his first two years at Cambridge, he wrote papers on differential geometry and on modifications to Einstein's theory of gravity, known as general relativity.
He also worked on "unified field theories." Considered unpopular at the time, this was the attempt to merge general relativity with electromagnetism; it was this quest that had obsessed (and ultimately frustrated) Einstein in the final decades of his life.
Dr. Moffat later turned to particle physics and quantum field theory, an outgrowth of quantum mechanics that attempts to describe the universe in terms of particles and fields.
After a few years in the United States, Dr. Moffat was offered a job at the University of Toronto in 1963, and became a tenured professor one year later. It would be his home for the next three decades.
At U of T, his unorthodox approach to physics continued. In the 1970s and 1980s, he further explored modifications to general relativity, including a "non-symmetric gravitational theory," in which extra terms are added to Einstein's equations (think of it as giving space a "twist" in addition to being curved).
But it was in the early 1990s that he came up with the idea that would eventually make him -- sort of -- famous.
According to special relativity, the first part of Einstein's revolutionary theory, nothing can travel faster than light. But suppose that the speed of light has varied over time, Dr. Moffat suggested.
If light had travelled faster billions of years ago, he argued, it might help to explain some of the strange properties the universe has today. For example, astronomers wonder why distant parts of the universe seem so much alike: No matter where they aim their telescopes, they see the same kinds of galaxies distributed with roughly the same density across the sky.