Book review: A Beautiful Question - beauty's relationship to scientific truth
Nobel Prize-winning theoretical physicist Frank Wilczek's exploration ranges from the insights of ancient Greek philosophers to the frontiers of quantum mechanics and string theory
Leading scientists often talk about science in ways that are patently unscientific. In his new book, the Nobel Prize-winning American theoretical physicist Frank Wilczek asks: “Is the world a work of art?” The question is impossible to consider in scientific terms. Any answer is certain to be merely a matter of opinion.
Compared with other branches of science, theoretical physics has produced more than its share of scientific aesthetes, including Albert Einstein and Paul Dirac, who both had the rare experience of producing theories commonly described as beautiful, akin to great works of art. Perhaps it was partly for this reason that these two great scientists took as their lodestar the ill-defined concept of beauty.
For Dirac, mathematical beauty was “almost a religion”. I doubt whether Wilczek would go that far, but he is deeply enamoured of the symmetries and harmonies at the heart of nature. A Beautiful Question is the most recent of the books he has written on this theme and in my view it is his best, most likely to appeal to readers who have plenty of curiosity but little or no knowledge of mathematics.
Wilczek begins with what he calls “a meditation” on ancient Greece. He especially admires Plato, who took a geometric approach to understanding matter and the universe. Although many of these ideas can now look strange to modern eyes, they also appear to be profound, influential and far-sighted. As Wilczek points out, modern theories of the most basic constituents of matter and their most fundamental interactions “are rooted in heightened ideas of symmetry that would surely make Plato smile”.
But it is in the sections dealing with modern theories that Wilczek is at his most illuminating. He describes how Einstein brought “a new style into thinking about nature’s fundamental principles” using “beauty, in the form of symmetry”. Almost a century ago, this led him to a new understanding of gravity, in terms of the curvature of space-time, in his monumental general theory of relativity. The inner workings of atoms are governed not by gravity but by the other fundamental forces (strong, weak and electromagnetic), and they proved even harder to understand.
It took many scientists several decades to experimentally check and give an account of these forces, producing the so-called Standard Model, which Wilczek renames the Core Theory. He aptly describes it as “the grandest achievement of human thought and striving” and explains why symmetries play an essential role in its formulation, though this time he is more subtle.
One of the pleasures of reading a book such as this is to be in the company of a top-drawer thinker who has strained every sinew to find new ways of describing the patterns in nature’s underlying fabric. He gives an especially good account of the strong interaction, which is responsible for keeping the fundamental particles known as quarks and gluons imprisoned in protons and neutrons, mostly found in atomic nuclei. Wilczek was one of the pioneers of this theory, as we see in blazing clarity in his idiosyncratic timeline of quantum physics, in which his name features more often than anyone else’s. (This will raise eyebrows among his peers.)
We are never in any doubt about the answer to Wilczek’s question of whether the world is a work of art. The world does indeed embody beautiful concepts, he argues, noting that this is exactly what Pythagoras foresaw. The ancient Greek mathematician had no inkling of the symmetries of nature that physicists have divined during the past century, yet he was broadly correct about the role they play.
Wilczek outlines how this understanding was gradually achieved, giving due credit to Newton, who first showed how to set up mathematical theories of the world. He also spotlights figures less often associated with this story, such as the Italian Renaissance architect and engineer Filippo Brunelleschi, who explored projective geometry, a branch of mathematics dealing with the relationships between geometric figures that would later become important to physicists. We are told about a crucial contribution made by the German mathematician Emmy Noether: she established links between special symmetries of fundamental theory and conservation laws – for example, energy – making crucial links between deep properties of theory and quantities that experimenters could measure. This was a crucial link between theoretical symmetries and real quantities that experimenters could measure.
Wilczek is perceptive, too, on the work of great Scot James Clerk Maxwell, described here as “the first truly modern scientist”. It was Maxwell who first gave us a unified description of electricity and magnetism by focusing on electric and magnetic fields, and other related quantities. This was an amazingly successful theory, predicting correctly that light is actually a wave of electromagnetism.
At one point, we are alerted to the approach of another “obligatory paragraph of cartoon history”. He is clearly aware that many historians will take exception to his playing fast and loose with the details of their subjects. But you read a book like this not to be educated in history, but to be enlightened by a fresh perspective on modern scientific thinking from an expert with a flair for jargon-free exposition.
Wilczek writes A Beautiful Question with bracing pizzazz, though his liberal deployment of exclamation marks may irritate readers who like their science presented with a Dawkinsian grace.
Having heavily praised the Standard Model, Wilczek points out that it has serious flaws (it cannot account for the behaviour of matter at ultra-high energies, for example). One much-favoured enhancement of the Model is the phenomenon known as supersymmetry, which many experts would dearly love to see showing up at the Large Hadron Collider at Cern, where experimenters first observed the Higgs boson in 2012. Wilczek sketches some basic ideas of supersymmetry, which many of its aficionados regard as too beautiful to be entirely wrong. The same could be said of modern string theory, according to which the most fundamental entities of nature are not only the familiar point-like particles but also unimaginably tiny, wiggling surfaces and pieces of string.
Many theoreticians believe this is a promising step towards a fully unified description of nature at the deepest level, though the theory is still ill-understood and has yet to make a clear-cut prediction that experimenters can check, to test its validity. The theory’s advocates, including several of the world’s leading theoretical physicists, draw encouragement from its surpassing mathematical beauty and the fact that, for the first time, it explains the very existence of gravity. Wilczek does not discuss the theory here, perhaps because he is not convinced that its aesthetic virtues outweigh its shortcomings as a workable account of nature.
In the final analysis, aesthetic arguments in science are as subjective as they are in art, where the concept of beauty has long been infra dig. I am not sure that Wilczek’s line of argument in this book would have been appreciated, for example, by Picasso, who remarked in the late 1940s: “I hate that aesthetic game of the eye and the mind, played by these connoisseurs, these mandarins who ‘appreciate’ beauty.” There is “no such thing” as beauty, he added, apparently not knowing that the world’s leading theoretical physicists had long perceived it in abundance. And, as this book demonstrates, they still do.
A Beautiful Question: Finding Nature’s Deep Design by Frank Wilczek (Penguin Press)