Joseph Silk revels in Frank Wilczek's treatise on how symmetry and harmony drive the progress of science.
A Beautiful Question: Finding Nature's Deep Design
- Frank Wilczek
Can beautiful ideas drive science? In A Beautiful Question, physicist and Nobel laureate Frank Wilczek makes a potent case that they can, hinging on qualities that have served as pathfinders to empirical truth in the physical world. The greatest scientists, from Galileo to Albert Einstein, saw in physics almost infinite beauty, including symmetry, harmony and truth. Today, we fervently hope for a genius with a beauty-inspired Theory of Everything — or at least for the Large Hadron Collider at CERN in Geneva, Switzerland, to discover truth in supersymmetry.
A Beautiful Question is both a brilliant exploration of largely uncharted territories and a refreshingly idiosyncratic guide to developments in particle physics. Vast and eclectic, it covers everything from atomism to the Higgs boson, musical harmony to anamorphic art, dark matter to the origins of the Universe. Wilczek lays out a vision of truth and beauty inspired by great modern physicists and classical philosophers such as Pythagoras and Plato. Lavish illustrations exemplifying beauty in art and science, from William Blake's Ancient of Days to fractal images, are interwoven with quotations from luminaries in the arts and sciences, from Molière to John Archibald Wheeler.
Wilczek begins with the beauty-inspired seeds sown by the ancient Greeks, including the fundamentals of geometry, music and chemistry. The music of the spheres, which Pythagoras described as the hum from celestial bodies whose periodicities echoed a harmony that he alone heard, inspired him and his followers to develop harmonies between beauty, music, mathematics and science. Numbers governed all, from octaves to right-angled triangles. Through perspective, geometry revolutionized classical, then Renaissance, art; through the curvature of space, it revolutionized understanding of gravity. And Wilczek argues that colour, the epicentre of beauty, unites art with biology, chemistry and physics.
The search for symmetry generated enormous rewards in science, a gift that has kept on giving. In the nineteenth century, Michael Faraday gave an elegant display of empirical physics by mapping out the patterns of magnetic lines of force. He went on to show that moving magnetic fields generate electric fields, motivating mathematical physicist James Clerk Maxwell to develop his equations for electromagnetism. These epitomized a fundamental symmetry, allowing a magnetic field in motion to generate an electric field, and vice versa. The fields propagate through space, producing waves of light in all colours of the rainbow. Maxwell's equations also predicted that electromagnetic waves would propagate at frequencies beyond perception by the human eye. Inspired, Heinrich Hertz discovered radio waves. Beauty had succeeded far beyond any intent of Faraday's.
Wielding the sword of beauty to refine scientific thought has a remarkable heritage. Einstein put beauty first in conceptualizing the general theory of relativity. In the dreary postwar climate of 1919, worldwide headlines greeted the successful verification of one of his key predictions — the bending of light by gravity. Another triumph is the standard model of particle physics, whose symmetries led to prediction of the Higgs boson.
Wilczek argues that the quantum core of modern physics, the zoo of elementary particles, stems from beautiful thoughts framed by appeals to symmetry. The Eightfold Way, named by physicist Murray Gell-Mann after the Noble Eightfold Path of Buddhism, organizes elementary particles into octets; the Higgs, discovered in 2012, is the final missing link in the standard model.
Now the search is on for a unifying principle to take us back to simplicity. Supersymmetry, the most beautiful idea of all, unites two fundamental types of particles, fermions and bosons, distinguished by their spins. It postulates massive 'superpartners' for each particle, the lightest of which is a stable candidate for dark matter. Some see a lack of elegance in a theory that has some 120 adjustable degrees of freedom. The situation is, however, being redeemed in part through the enormous efforts of experimental particle physicists to measure many of these numbers. Only one real issue remains: at what energies must one smash particles together to seek supersymmetry's elusive signature? Wilczek optimistically predicts that we will discover this holy grail of physics in five years.
Occasionally the search for beauty has led us astray. Science was set back for centuries by the epicycles with which Greek astronomer Ptolemy described planetary motions. Modern data debunked Fred Hoyle's steady-state theory of the Universe. And even particle physics, with its grand hopes of unification, offers no insight into serious cosmological problems such as why dark matter is more than five times as abundant as ordinary matter. Most recently there has been string theory, the compellingly beautiful union of mathematical simplicity with quantum theory, particle physics and gravity. Its advocates have provoked a controversy: can a theory be so beautiful that we award it scientific accolades for its synthetic capacity without an empirical test, or must we dump it on the scrap heap of history for its lack of grounding truth?
Persistent voices insist that a theory of physics must lead to experimental verification. Wilczek is emphatic about this, as was Isaac Newton, who would like us to see empiricism as the search for truth. If truth and beauty are inseparable, that circle is closed. That is where supersymmetry will rise or fall. I hope for the latter, although I am reconciled to waiting for a new generation of unprecedentedly powerful particle colliders to reach the frontiers of our unifying theory.
About this article
Cite this article
Silk, J. Physics: The impulse of beauty. Nature 523, 156–157 (2015). https://doi.org/10.1038/523156a