This is a personal favorite among the 7 chapters of The Accidental Universe because the subject is close to home. Being exposed to the study of physical sciences for so many years, symmetry unfolded itself naturally in principles, equations, geometry, code, and form. But symmetry is not exclusive to the physical sciences. It's everywhere. It is math. It is art. It is architecture. It is poetry.
Since I was an undergraduate, I found elegance in symmetry. We are compelled to seek symmetry, formulate it and recreate it. But why? There seems to be an unspoken assurance to it. Somehow, symmetry is intuitive and simple but offers profound implications.
Here, Lightman begins with the story of "Higgs boson" and the synthesis of the forces of nature. He ties symmetry with natural selection, the "energy principle", geometry. I enjoyed the story of the perfectly hexagonal honeycombs which I would tell later on to my father-in-law who is fond of bees in his golf course. I realize that for the longest time, I had not relished a story with such childlike fascination as I was reading this chapter.
"Perhaps in asking why the pervasive symmetries in nature are found appealing to the human mind and imitated in our human-made constructions, we are making an erroneous distinction between our minds and the remainder of nature. Perhaps we are all the same stuff. After all, our minds are made of the same atoms and molecules as everything else in nature."
"Viewed in this way, our human aesthetic is necessarily the aesthetic of nature. Viewed in this way, is nonsensical to ask why we find nature beautiful. Beauty and symmetry and minimum principles are not qualities we ascribe to the cosmos and then marvel at their perfection. They are simply what is, just like the particular arrangement of atoms that make up our minds. We are not observers on the outside looking in. We are on the inside too."
The Gargantuan Universe
Lightman tells that the history of human civilization is measured in terms of the scale of maps produced from an illustration of a plot of land in a clay tablet to distances probed by modern telescopes in deep space. Lightman attempts to paint a picture of the incredible vastness of the observable universe, which to humans seems emotionally remote, even detached. Lightman briefly becomes philosophic as he muses on man's apparent insignificance in the face of infinity.
"...we can conclude that the fraction of stuff in the visible universe that exist in living form is something like ... one-millionth of one-billionth of 1 percent. If some cosmic intelligence created the universe, life would seem to be only an afterthought. And if life emerged by random processes, vast amounts of lifeless material were needed for each particle of life. Such findings cannot help but bear upon the question of our significance in the universe."
The Lawful Universe
Lightman writes about the deterministic universe contrasting against unpredictable human affairs. The laws of nature governing the physical universe freed humans from the capriciousness of gods during Lucretius' era, satisfying in Lightman's words, a deep emotional need for order and reason. But humans are part and parcel of the physical universe and therefore must be governed by the same laws. While that is so, human behavior is not something that can be calculated to analytically exact or to machine precision like electron spins. Interspersing science with philosophy, the chapter finally drives home the message of human's deep emotional need for freedom.
"I believe that it is bracing and vital to live in a world in which we do not know all the answers. I believe that we are inspired and goaded on by what we don't understand. And I hope that there will always be an edge between the known and the unknown, beyond which lies strangeness and unpredictability and life."
The Disembodied Universe
This last chapter seemed out of place. The rest of the chapters, except for The Spiritual Universe, make the universe the central character and humanity only secondary to the extent of its subjection and reaction to the former, to the extent of how humans grappled with a universe that is accidental, temporal, symmetric and gargantuan. This last chapter is about humans shaping their own personal universes. It is about humans of the information age living disembodied, digitized lives brought about by modern technology.
It's a different theme altogether, I think. A life of relentless media and communications grabbing our attention, disconnecting us from our actual physical surroundings calls for being more present in the moment, to live each transient and serendipitous fluttering of a butterfly's wings. But maybe that is the author's message. Around us is this invisible digital force made of bytes and packets that connects us in an instant but disconnects us in another way and somehow we must learn to live authentic lives, not in spite of, but all the more because of this.