Symmetry is not just a word; it is a concept. It not only attracts our visual sense; it also plays a major role in our sense of beauty. It holds a paradox, too. Perfect symmetry, for instance, is quite repetitive and predictable, although our minds favour surprises. This explains why we often consider imperfect symmetry to be more beautiful than perfect mathematical symmetry.
Many of the most striking patterns in our natural world are symmetric. Yet, nature isn’t comfortable when it comes to a question of pure symmetry. There’s reason for this. Nearly all the symmetric patterns in nature are less symmetric than they appear to be. Physicist Pierre Curie placed the paradox in perspective, “Effects are as symmetric as their causes.” Our world is full of such effects; they are called ‘spontaneous symmetry breaking.’
Symmetry is a mathematical and an aesthetic pattern. It has something more to it than meets the eye. The human body, for example, is bilaterally symmetric. Its left half is almost the same as its right half. In other words, it is approximate. Yet, our body’s overall form is close to perfect symmetry.
When we conjure up a vision of the left being a reversal of the right, we tend to use words like ‘image.’ In so doing, we propagate the idea of one shape corresponding to the other. The irony is direct. Our ‘image’ idiom is unlike reflection, a mathematical concept. Yet, reflections, as we all know, capture symmetries — from the human body and the petals in a flower to bees’ honeycomb, replete with its hexagonal tiles. This also brings us to one big question. Where do symmetries of natural patterns come from? Toss a pebble in a pond, and you will know. The ripples in a pond are examples of broken symmetry. You are witness to a pattern, by way of circular ripples, one quite distinct from the other, depending upon the point of impact.
Nature exhibits symmetries in small things too. Think of a developing frog embryo. The embryo begins life as a spherical cell. It loses its symmetry when it divides to become a blastula. In next to no time, it gets a symmetrical form. Following this, its symmetry is broken again. Before you know it, a single mirror symmetry is almost directly, naturally achieved. This leads to the bilateral symmetry of the adult frog. You may call this nature’s ‘frog-leap’ to symmetry, as it were.
The laws of physics are mirror symmetric, no less. Any molecule, for example, that is not mirror symmetric may potentially exist in two different forms: left- and right-handed. This brings us to man’s second nature: creating harmony through symmetry. The ancient Chinese art of feng shui, for example, has in it the means to create balance, harmony etc., in our personal environment. Feng shui simply means wind and water. Wind provides the movement, or flow, of universal energy, or chi, which affects everything. Water, it is suggested, provides the container, or receiver, of chi. Feng shui is a time-honoured system of rules, concepts and principles. It explains how our lives are spiritually linked to our environment.
Science, as we all know, recognises four fundamental forces in nature — gravity, electromagnetism, strong and weak nuclear interactions. Weak forces, for instance, violate mirror symmetry — in other words, they act differently in left- or right-handed variations of the same physical anomaly. Yet, the fact remains that all four forces became unified and symmetrically-related when extremely high energy levels prevailed in our early universe.
If such a thing had not happened, our universe would have been different. It could have also been like any of the other universes, which emerged by breaking symmetry in a divergent pattern. It didn’t. Why? As physicist Wolfgang Pauli observed, “The Lord is a weak-left-hander.”