Fascinated with physics
Monthly lectures on theoretical science pack Queen St. bar Many people are enthralled with the cosmos, finds Dan Falk
Nov. 20, 2006. 01:00 AM
DAN FALK

Writing in the introduction to Stephen Hawking's A Brief History of Time, the late astronomer Carl Sagan marvelled at the wide-eyed curiosity of children; the rest of us, he observed, rarely pause to consider the deepest riddles of the universe. Few of us, he said, spend much time wondering "where the cosmos came from, or whether it was always here; if time will one day flow backward and effects precede causes; or whether there are ultimate limits to what humans can know."In one sense, Sagan was right; it is only a small minority who ponder such questions on a regular basis. That includes scientists, of course ? or at least those physicists and cosmologists who work on the frontiers of their field. But there is also an ever-increasing group of ordinary citizens who yearn for an understanding of their cosmic habitat.

Some read books like Brian Greene's The Fabric of the Cosmos, or watch TV specials like the three-part series based on Greene's first book, The Elegant Universe; others subscribe to Scientific American or Discover, or attend public lectures at the University of Toronto or the Perimeter Institute for Theoretical Physics in Waterloo.

But the setting doesn't need to be scholarly or academic. Here in Toronto, science buffs drop by the Rivoli bar on Queen St. W. for a "conversation caf?" known as Caf? Scientifique www.cafescientifique.ca).

Held on the third Saturday of each month, the sessions are organized by the Ontario Science Centre and feature expert researchers. The sessions also encourage the audience to get involved, with participants learning from each other and the experts."They just love science," says Julie Jones of the Science Centre, who has moderated the past few sessions of Caf? Scientifique. "They're not necessarily scientists," she says of the audience. "They're the people who read the science page in the newspaper, or they subscribe to New Scientist.

They just have an appetite for all of these things."The topic this Saturday had the weighty title "Strings vs. Loops: Why can't physicists decide how to quantize gravity?"

The title refers to two competing strategies for uniting Albert Einstein's theory of gravity, known as general relativity, with quantum theory. One approach ? the one that has been getting the most press ? is string theory, which suggests that the universe is made up of tiny vibrating strings.

The other, not quite as well known, is called loop quantum gravity, which proposes that space and time may be "quantized" in discrete chunks, rather than being continuous, as both Sir Isaac Newton and Einstein had assumed.

One of the two invited experts was physicist Lee Smolin of the Perimeter Institute, one of the creators of loop quantum gravity. He's also the author of The Trouble With Physics, a provocative new book that argues that too many physicists are joining the string-theory bandwagon at the expense of other possible approaches. Holding up the string side of the discussion was particle theorist Cliff Burgess, also from Perimeter.

The conversation swirled around advanced topics such as supersymmetry, higher dimensions, and the nature of "dark energy." But the discourse also drifted into subjects rarely mentioned in physics journals. The relationship between physics and philosophy triggered a number of perceptive questions from the audience. At one point, Smolin recommended a trilogy of science fiction novels by U.S. author Neal Stephenson.

Some in the audience, like retired computer programmer William Kisin, have come to simply sit and listen. Kisin took some physics classes "many years ago," but hasn't kept up with new ideas such as string theory. "I'm an observer, looking at it from the outside, trying to get some flavour of what people are doing," he says.Others, like college teacher Fred Knittell, are looking for ideas they can pass on to their students.

Our fascination with finding nature's ultimate laws, he says, goes back to Einstein, who "reinvented the universe" using no tools other than his mind. "It has that kind of `big-picture' sense to it, of finding an underlying symmetry that can explain diverse phenomena in a new, common language," Knittell says. "And it is stranger than fiction in a lot of cases."Still others have specific interests that intersect with the ideas presented.

For Teresa Barrett, a Caf? Scientifique "regular," that interest is centred on philosophy, which she studied as an undergraduate. "I know that there's a debate about whether string theory is a valid theory, because it's not been proven, and there's some debate as to whether it's just metaphysical, or if it's actually physics."Smolin isn't surprised to see such passion from non-scientists ? ordinary people who follow what he and his colleagues do, sometimes in remarkable detail.

"We live in a highly literate society, where people are very interested in knowing what we know about nature," he says. Adds Burgess: "I remember when I first heard the Perimeter Institute was planning to hold regular public lectures."I remember thinking, `That's a great idea, but it will probably only last a year, and then they'll run out of audience.' But they pack the room with 500 people every month, and they've been doing it for years."Dan Falk is a science journalist based in Toronto.