FASHION, FAITH, AND FANTASY IN THE NEW PHYSICS OF THE UNIVERSE By Roger Penrose,
Princeton, $29.95
Discoveries in science, claimed the novelist and essayist, Arthur Koestler, are not a clean, rational advance along a straight ascending line; the manner in which epoch-making achievements were made reminded him more of a sleepwalker's performance than an electronic brain's. The acerbic Koestler described the progress of science as a history of collective obsession and controlled schizophrenia. On reading the Oxford mathematician Roger Penrose's latest tome I was reminded of Koestler's derisive comments.
Penrose (picture) is dismayed by what seems to him as fashion, faith and fantasy in current physical research. The book's title is the same as the three-part lecture he delivered at the invitation of the Princeton University Press in 2003. The theme of the talk, he confesses, might have been a somewhat rash suggestion on his part, but it nevertheless conveyed the misgivings he had had about three areas of the current thinking in theoretical physics.
It requires chutzpah, even for a scientist as celebrated as Penrose, to attack three reigning champions at Princeton, home to some of the best minds engaged in physics research. He may talk of his apprehension before he faced his expert audience, but I have a feeling that the choice of the lecture's topic was deliberate. If one elects to claim that economics isn't a science, can one think of giving vent to one's feelings at a better precinct than the London School of Economics or Harvard?
The first salvo of Penrose's attack is aimed at the string theory. Events, or changes in the Universe, are the outcome of any one among the four forces acting on various agents. The earth's roundtrip about the sun is caused by gravity; the blades of your ceiling fan rotate due to electromagnetism; radioactivity from some elements is the handiwork of the so-called weak force; and strong force compels protons and neutrons to squeeze together within the tiny volume of the atomic nucleus. Why are there four forces? Wouldn't one have been aesthetically more welcome?
Nature, it seems, favours aesthetic beauty; what's known today as electromagnetism was once perceived as two separate forces - electricity and magnetism. Physicists like Michael Faraday and James Clerk Maxwell showed that they were two sides of the same coin. In the early 1970s, Steven Weinberg, Sheldon Glashow and Abdus Salam independently proved that the weak force could be clubbed with electromagnetism, a feat which won them the Nobel Prize in 1979.
Albert Einstein, convinced as he was in the aesthetic beauty in nature's modus operandi, sought this kind of unification earlier. He tried to mould gravity and electromagnetism, the two known forces during his lifetime, into one, pursuing his goal for several decades, in fact to the last day of his life. Undaunted by the great man's failure to unify the two, today's physicists are more ambitiously seeking to unite the four forces. Since electromagnetism, weak and strong forces are all described in the language of quantum mechanics and gravity by general relativity, the craved-for unification of four forces would demand a marriage of quantum mechanics and relativity. But the two theories are like chalk and cheese. The toughest challenge in theoretical physics today is to synthesize these two with a view to producing the so-called Theory of Everything, achieving which, says Penrose's British colleague, Stephen Hawking, will make studies in fundamental physics as redundant as going in for mountaineering after scaling the Everest. String theory is one such ambitious ToE. It is solely based on an aesthetically pleasing mathematical superstructure.
What irks Penrose isn't the expedition per se; he is one among such goal-chasers, his take being a different one. He finds string theory's assumption of six more dimensions - in addition to our familiar four (three of space and one of time) -unacceptable. Also, anathema to him is the fact that despite their tall claims string theorists haven't been able to explain why the masses of many particles have the values they do. The proponents view - that those masses are different in various universes and we happen to find them what they are simply because we live in this cosmos - doesn't cut much ice with Penrose.
So why are young PhDs flocking towards string theory by the hordes? The answer, says Penrose, is fashion. He turns sociologist in analysing the trend, claiming, in essence, that the string theory is famous for being famous. It garners the highest amounts of funding because almost every particle physicist wants to dabble in it. There are hardly any takers for the alternative paths to unification.
Penrose's other two disparaging epithets - faith and fantasy - are reserved for two more areas of physics: quantum mechanics and cosmology, respectively. While admitting that quantum mechanics is the most successful of all physical theories, passing all experimental tests with flying colours, he thinks its success has been oversold; many experts forget that its applicability can be limited only to the subatomic world, and expect its predictive power will hold sway in macroscopic world too. That's a hope Penrose thinks will be dashed eventually. And as can be judged from the invective (fantasy), his peeve is at its worst against the inflation theory, which contends that the Universe underwent a tremendous expansion only a fraction of a second after its birth in the Big Bang.
Going through Penrose's critique of his peers' attempts to decipher the cosmos on its smallest and largest scales, I was reminded of the dictum that all scientific theories are true until proved false. Maybe the same can be said of his own takes - twistor theory and conformal cyclic cosmology as opposed to string theory and inflation, respectively. Remember George Bernard Shaw's aphorism? The minority is sometimes right, but the majority is always wrong.
