There is a subtle kind of symmetry called latent symmetry which manifests itself only when the conditions are right. It can occur in systems composed of equal or equivalent components. It lies dormant or latent, and becomes manifest when the components happen to have certain special mutual placements. Although the latent-symmetry idea has been around for more than a decade, not many natural manifestations have been observed to date. But a recognition of the possibility of latent symmetry enables us to formulate a comprehensive symmetry-composition principle enunciated in this book. The principle is applicable to any system composed of equal or equivalent sub-parts. And there are many such systems around. Crystals are an obvious example, the equal components being the unit cells. Several complex networks can also fall within the purview of this principle, if we take note of the approximate nature of their symmetry. This book presents such an all-inclusive view of symmetry in an accessible language. We are surrounded by symmetry and broken symmetry. From the Big Bang onwards, as our universe cooled and expanded, a series of symmetry-breaking transitions occurred, resulting in a gradual evolution of the complexity of life we see today. By now it is well recognized that discovering new broken symmetries (particularly broken gauge symmetries) is the path science must take for going deeper into the mysteries of Nature. At a very fundamental level, laws of physics are all about symmetry. The present edifice of science in general, and physics in particular, would be unthinkable without symmetry. There is a lot of symmetry even in biological systems. This book celebrates symmetry in all its forms, including latent symmetry.
About the Author: Vinod Wadhawan is a condensed-matter physicist, with special interest in symmetry, crystallography, crystal physics, phase transitions, ferroic materials, crystal growth, smart structures, and complex systems. A crystallographer and teacher, he served for two terms as member of the International Union for Crystallography (IUCr) Commission on Teaching. His other books are on ferroic materials (2000), smart structures (2007), and complexity science (2010, 2017/2018). His book on ferroic materials is the first comprehensive book on the subject. He was a recipient of the prestigious Raja Ramanna Fellowship of the Department of Atomic Energy, Government of India, for working at the Bhabha Atomic Research Centre, Mumbai. Before that, he served as 'Outstanding Scientist' and Head, Laser Materials Division, Centre for Advanced Technology, Indore. He was till 2010 an Associate Editor of PHASE TRANSITIONS (Taylor & Francis), having done editorial work for this journal for a quarter of a century. Dr. Wadhawan is the originator of the concepts of optical ferrogyrotropy, acoustical ferrogyrotropy, and latent symmetry. Other terms introduced by him in the scientific literature are superelectrostriction and superpiezoelectricity (by analogy with the concept of superelasticity in physical metallurgy). He also formulated a comprehensive 'tensor classification' of twinning in crystals. He is currently investigating the emergence of symmetry in real-life complex networks. Science popularization is another of his current activities.