Extrait
It was in the summer of 1989, during a trip to upstate New York, that I began to think seriously about the possibility that science, pure science, might be over. I had flown to the University of Syracuse to interview Roger Penrose, a British physicist who was a visiting scholar there. Before meeting Penrose, I had struggled through galleys of his dense, difficult book,
The Emperor's New Mind, which to my astonishment became a best-seller several months later, after being praised in the
New York Times Book Review. In the book, Penrose cast his eye across the vast panorama of modern science and found it wanting. This knowledge, Penrose asserted, for all its power and richness, could not possibly account for the ultimate mystery of existence, human consciousness.
The key to consciousness, Penrose speculated, might be hidden in the fissure between the two major theories of modern physics: quantum mechanics, which describes electromagnetism and the nuclear forces, and general relativity, Einstein's theory of gravity. Many physicists, beginning with Einstein, had tried and failed to fuse quantum mechanics and general relativity into a single, seamless "unified" theory. In his book, Penrose sketched out what a unified theory might look like and how it might give rise to thought. His scheme, which involved exotic quantum and gravitational effects percolating through the brain, was vague, convoluted, utterly unsupported by evidence from physics or neuroscience. But if it turned out to be in any sense right, it would represent a monumental achievement, a theory that in one stroke would unify physics and solve one of philosophy's most vexing problems, the link between mind and matter. Penrose's ambition alone, I thought, would make him an excellent subject for a profile in
Scientific American, which employed me as a staff writer.
When I arrived at the airport in Syracuse, Penrose was waiting for me. He was an elfin man, capped with a shock of black hair, who seemed simultaneously distracted and acutely alert. As he drove us back to the Syracuse campus, he kept wondering aloud if he was going in the right direction. He seemed awash in mysteries. I found myself in the disconcerting position of recommending that he take this exit, or make that turn, although I had never been in Syracuse before. In spite of our combined ignorance, we managed to make our way without incident to the building where Penrose worked. On entering Penrose's office we discovered that a colleague had left a brightly colored aerosol can labeled Superstring on his desk. When Penrose pushed the button on the top of the can, a lime green spaghetti-like strand shot across the room.
Penrose smiled at this little insider's joke. Superstring is the name not only of a child's toy, but also of an extremely small and extremely hypothetical stringlike particle posited by a popular theory of physics. According to the theory, the wriggling of these strings in a 10-dimensional hyperspace generates all the matter and energy in the universe and even space and time. Many of the world's leading physicists felt that superstring theory might turn out to be the unified theory they had sought for so long; some even called it a theory of everything. Penrose was not among the faithful. "It couldn't be right," he told me. "It's just not the way I'd expect the answer to be." I began to realize, as Penrose spoke, that to him "the answer" was more than a mere theory of physics, a way of organizing data and predicting events. He was talking about
The Answer: the secret of life, the solution to the riddle of the universe.
Penrose is an admitted Platonist. Scientists do not invent the truth; they discover it. Genuine truths exude a beauty, a rightness, a self-evident quality that gives them the power of revelation. Superstring theory did not possess these traits, in Penrose's mind. He conceded that the "suggestion" he set forth in
The Emperor's New Mind--it
