Lucifer's Legacy

The Meaning of Asymmetry

Frank Close

• Publisher: Dover Publications
• Year: 2013
• ISBN:
  9780486782140
• Topic: History
• Subtopic: Science History
• Index: History

`This is Frank Close's masterpiece — his best book, and one of the very best introductions to physics for the layperson. Close is a master expositor.` — The (London) Sunday Times
`Close's writing is beguiling, mingling personal and historical anecdote with carefully measured doses of exposition in such a way as to guide the reader painlessly into rather deep intellectual waters.` — Nature `Life, intrinsically related to asymmetries, is the theme of this book, and Close offers us an absorbing and scientifically correct account of symmetry and its deep implications.` — CERN Courier
This thought-provoking work by a physicist and popular science writer explores the origins of asymmetry from the molecular level to that of the universe at large. Frank Close takes the readers on a tour of asymmetry that ranges from the development of human embryos to the mysterious Higgs boson, or `God particle,` and ongoing research at Switzerland's CERN laboratory.

Chapter 1

Lucifer

“Headless body found in topless bar”

(USA newspaper headline)

The world is an asymmetrical place full of asymmetrical beings. If the Creation had been perfect, and its symmetry had remained unblemished, nothing that we now know would ever have been. There would have been no you to read this book, nor me to have written it; there would have been no Paris in the spring, and no Tuileries Gardens. So I would not have come across the headless body—the chance event that started me wondering on the accident, or design, that has created life out of arid equations.

Lest you make this for a seamy pot-boiler, or even Hercule Poirot–style murder mystery, I should make clear at the outset that the body in question was made of stone, its head lying in the gravel at the base of a plinth which bore the legend “Lucifer.” Had it been other than in the Tuileries I would probably have passed by without giving a second glance, but the gardens are beautiful, laid out with mathematical precision. I paused and looked again at headless Lucifer. Its disfigured presence in the midst of an otherwise all pervading perfection was as profound as the unresolved chord that ends Bach’s St Matthew Passion and seemed like a metaphor for existence.

The spring day had started slowly as I had come to Paris by train from London. The carriages had meandered through southern England, as if to give the passengers time to appreciate the picture postcard views of Kent, before speeding through the featureless landscapes of northern France, impatient for the graceful architecture of Paris, among which is one of the most remarkable perspectives in Europe. From the midpoint of the Arc de Triomphe the line of sight along the Champs Elysées leads first to the obelisk at the centre of the Place de la Concorde and then runs the length of the Tuileries Gardens to the open arms of the Louvre. Where this line passes through the Tuileries it has been used like a mirror such that with draughtsmanlike precision the two halves of the gardens are perfect reflections of one another (Fig. 1.1).

To experience the symmetry to the full, first stand at the western end in the Place de la Concorde looking in the direction of the Louvre at the far end of the Tuileries. Within the park and a hundred metres to your right is the Orangerie, a hothouse erected by Napoleon III and now used for art shows; its mirror image, the same distance on your left, is the Musée du Jeu de Paume, Napoleon’s tennis court. Identical mirrored paths connect the two buildings to your position at the park’s entrance. On your immediate left you will see a high stone wall, curved with its concave side towards you; to the right of you is another wall, its arc a perfect mirror of its partner. The pair are a miniature imitation of the curved collonades that caress your arrival before the entrance of St Peter’s in Rome. Whereas statues of angels decorate Michaelangelo’s creation, the entrance to the Tuileries holds sinister statues of philosophers, gods, and dead Frenchmen in its embrace; to your left and to your right the guardians stand in perfect symmetry. The effect though is similar. The pair of symmetric concave curves are like a mother’s arms taking her child; they welcome and encourage you to enter within.

The central avenue leads proudly from the far side of the curve, diametrically opposite you. This gravel carriageway defines the axis of the imaginary mirror, identical trees and flower-beds bordering it to left and right. Were you to rest briefly on one of the benches alongside the path and survey the beauty of the gardens, you would find the view obscured by a corresponding bench across the way. To every statue on one side there is a statue on the other, to every tree a tree, to every flower garden on the north side there is another planted at the same distance to the south. A water fountain sprays from the mouth of a nymph who is gazing soulfully at its clone, forever separated by twice the distance to the centre line of the park.

Fig. 1.1 Map of the Tuileries Gardens

And so it went on until I saw the headless devil twenty metres down a side path. I knew that behind me, as yet unseen, would be a mirror image of this path that would lead to a correspondingly positioned plinth and fiendish statue. I half expected that this too would be broken, so preserving the symmetry of the park, but when I turned and looked I saw that its diabolic twin grinned from its plinth as it had done since its creation. In the entire gardens the designer symmetry was perfect with the sole exception of headless Lucifer.

The symmetry of the Tuileries Gardens and its interruption by the disfigured devil are metaphors for our grander perceptions of the natural world. Symmetry is fascinating and appealing; scientists seek it in their data and incorporate it in their theories, ironically even when there is no immediate evidence for it. Perhaps the most arcane example of this concerns the nature of matter and the fabric of existence embodied in the current cosmophysical description of Creation.

There is direct evidence that the stuff of which we are made is but half of a symmetric whole. Scientists speak casually of antimatter, the faithful opposite matter, the symmetry so perfect that when any particle of matter meets its mirror antiparticle, mutual annihilation occurs. It is the romance of this mutual suicide pact and the accompanying burst of energy that has made antimatter so beloved by science fiction writers and the chosen power source of the Starship Enterprise in “Star Trek.” Physicists at CERN, the European Centre for Particle Physics in Geneva, can even watch this happen, confirming time and again the vulnerability of matter for antimatter. They also see the converse, where a large enough concentration of energy can coagulate into the two forms of substance: matter, as we know it, and its mirror image, antimatter.

So precisely balanced are these twins, so symmetrical their behaviour, that it has become the dogma of the new theology (or at least the one that is popular among cosmologists) that the two were made equally in the Creation. In the beginning, they say, there was no time, no space, no substance of any kind; this is a modern version of “there was darkness on the face of the void.” Then came a burst of energy: “let there be light and there was light.” Where did it come from? You may well ask. I don’t know and nor, in my opinion, does any scientist with certainty. Questions concerning existence “before” this singular happening are wracked with philosophical debate as to whether they are even meaningful: what means “before” if there was no space nor time? Some popular descriptions seem content to portray a will-o’-the-wisp universe which erupted as a quantum fluctuation out of nothing. Maybe it did, but if so then I would feel compelled to ask why it bothered. Questions relating to the “spontaneous” appearance of that first flash of searing heat that we loosely call the Big Bang begin with “why” and, as such, are beyond (current) experimental scientific enquiry.

Much of the sometimes confused debate about science “versus” religion fails to distinguish between the “why?” and “how?” varieties of question. Why the void erupted into light is for others to debate; how our present material universe emerged from that light of creation is within science’s province. Answers come from experiment—a crucial feature that distinguishes our modern scientific saga from other myths. Thus the CERN experiments on the production of the simplest particles and antiparticles out of radiant energy have inspired the current theories on the emergence of matter and antimatter during the Big Bang. A perfect Creation, with its symmetry untainted, would have led to matter and antimatter in precise balance and a mutual annihilation when in the very next instant they recombined: a precisely symmetrical universe would have vanished as soon as it had appeared. Such a uniform cosmic soup could hardly have led to the asymmetrical universe that we are a part of today where antimatter appears to be all but absent.

The current theory is that Creation was barely completed before something interceded; the perfection where the essence of every atom of substance had been counterbalanced by a precise anti-partner was lost forever. This act degraded the symmetry between matter and antimatter, with the result that after the great annihilation, a small portion of the matter was left over. Those remnants are what have formed us and everything around us as far as we can see. We are the material rump of what must have been an even grander Creation.

The flawed opus is what we are left with and, but for which, we would not be. Thus did the broken statue of Lucifer, spoiling the balance of the Tuileries Gardens, so brusquely remind me that the real world is full of asymmetrical features. The sly smirk on the Devil’s face seemed to be one of victory as if humans and even the existence of the entire material universe are permanent legacies of blemishes introduced somehow during the Creation.

This disruption to the great design set me wondering about the multitudes of natural asymmetries that seem to have been necessary for human life to have emerged. Matter defeating antimatter was a necessary step for there to be anything at all, but this alone was not enough. Had that been the end of it, the material universe would have been merely a bland plasma of particles with no periodic table of the elements needed for life nor a solid earth to be the factory for its construction.

The simplest element, hydrogen, formed first, and the force of gravity collected it into the vast clumps that are stars, such as our sun. Had gravity been the only force at work, that would have been the end of the story: elemental pieces of hydrogen, falling in on one another, swirling into the vortices of black holes, and extinction. A simple implosive story perhaps, but with no sentient beings to record it. However, nature differentiated other forces that can transmute the elements, producing the profound version of a material universe that we are privileged to have evolved in.

With hydrogen as the fuel, the stellar cooker first produces helium and then mixes the heavier elements such as carbon, nitrogen, and oxygen—so necessary for life. The sun has been in the first stage, burning hydrogen, for five thousand million years and radiating sunlight across a hundred million miles of space to our planet through that time. It is this warmth that has energized the chemical and biological processes of life, which have in turn needed that vast timespan to evolve complex human systems from primeval DNA.

Here, once more, asymmetry has been necessary. The warmth from the sun, the radiant glory of the electromagnetic force, has vibrated all the way from that distant ball of fire, whereas the force involved in the transmutation of hydrogen in the sun has its sphere of influence smaller than the dimensions of an individual atomic particle. Its strength is much weaker than that of the electromagnetic force. This enfeeblement is what has enabled the sun to survive; had it not been like this, had the force driving the solar furnace been as powerful as the electromagnetic force, all of the solar fuel would have been exhausted within five hundred thousand years—far too brief a time for life on earth, or anywhere, to have emerged. This separation of the electromagnetic force and its aptly named “weak” sibling is but one of the critical asymmetries that has been necessary for our existence.

The structure of the atomic elements also is lopsided. Biology, chemistry, and life are the result of electric currents—coursing through the nervous system, changing food into energy, building our bodies and the very fabric of the planet. It is the journeying of the little electrons, the carriers of electrical charge, that determine everything that we experience. The individual atoms consist of these negatively charged electrons swarming around a static, bulky, positively charged nucleus. All but one of the two thousand parts of the mass of an atom reside in this central nucleus, while the tiny electrons flow from one atom to another; liberated as current they flow through wires and power modern industry; agitated by electric fields they radiate electromagnetic waves. It is these negative charges that communicate and drive the biochemical processes in living things while the positives, too heavy to be easily stirred, tend to stay at home and form the templates of solidity. This asymmetry in mass is crucial for the structure of materials.

However, this alone appears to be insufficient for life. Life appears to thrive on mirror asymmetry, a distinction between left and right in the basic structures of organic molecules. Let me expand on this now, as it will be central to our story.

The positive seeds with their negative captives form atoms and molecules. There are simple ones such as water; more complex examples such as amino acids, proteins, and DNA; and others created by human ingenuity, such as plastics, ceramics, and drugs. Most of these have shapes that differ from their mirror images. Superficially identical in all respects but for the interchange of left and right, one might have reasonably expected that both forms would be equally abundant in nature. However, it is not so; life is mirror asymmetric. This is not simply a matter of there being more right handers than left, or even of our heart and stomach being found, usually, on our left side. The amino acids and molecules of life in one form have the ability to know that they exist and to be cogniscent of the universe; their mirror images are inorganic, lifeless. Life chooses one form while the mirror image is rejected. The body may happily digest a substance in one of the two mirror forms as food while excreting its mirror image unused, or worse, be poisoned by it. How and why has this mirror asymmetry emerged?

The deeper one looks, the more asymmetry becomes apparent and seemingly necessary for anything “useful” to have emerged. Without asymmetry and structure, the universe would have been bland. Have we convinced ourselves that the Creation was perfect on nothing more than wish fulfillment, as evidence of imperfection and asymmetry is all around us and even within us? I wonder whether the multitudes of asymmetries are the proof that we are the end products of chance and that philosophers and scientists have created a quasi-religious parable of symmetry that is obscuring the real explanation. Or was there indeed a perfect symmetrical scheme which included some wonderful single ingredient, yet to be identified, from which all the asymmetries for life have spontaneously emerged?

The focus of much current research is to understand how nature hides symmetry, producing structured patterns out of underlying uniformity. The quest to find the answer and possibly the singular source of all asymmetry, the reason for form and existence, began in the Tuileries Gardens and culminated in this book.

The story divides effectively into three parts. First, the mystery is introduced in Chapters 2 to 4. Then, in Chapters 5 to 7, we meet the forensic tools that have been central in solving it. These chapters tell of the discoveries, a hundred years ago, of X-rays, radioactivity, and of the structure of the atom from which have emerged the modern profound insights into the origins and evolution of life and the universe. These three chapters are self-contained, primarily of historic interest and provide a background for the main story. Chapters 8 to 13 put these forensic tools to work to reveal what scientists currently believe to be the source of structure and asymmetry in nature, and describe how they are now solving the puzzle during the first years of this new century.

Chapter 2

Symmetry at large

Travel from Europe to Australia or from North to South America and you will (nearly) have turned yourself upside down. As children, when we first discover this, we tend to wonder if Australians have difficulty staying on the ground or if, permanently head over heels, eyes bulge with the blood pressure. Later, we may meet our one-time contemporaries from “down under” and discover that they grew up with the same concerns about us. By then we know that gravity pulls everything towards the centre of the earth and that citizens from the antipodes believe themselves to be as upright as those in the north.

Nonetheless, we are inverted relative to one another and, as I discovered on my first visit to the Southern hemisphere, it is possible to tell—at night. It was January and crystal clear in England. As the perfect golden circle of the sun set in the west, Venus and Jupiter began to appear, like mirrors reflecting the sunlight, followed by the full moon rising in the east and Orion dominating the sky to the south. Orion, the hunter, is one of the easiest constellations to recognize, with Betelgeuse and Rigel at his shoulders and feet, and a trio of stars forming his belt from which further stars appear to hang like a dagger. Twenty-four hours later I was in southern Africa. What appeared to be an identical sun to that of the previous evening duly sank below the horizon, but the night sky that replaced it was quite different. Of course it contained many stars such as the Southern Cross that were unknown to me, obscured by the earth to northern eyes, but the constellations over the equator, such as Orion, were present and yet somehow unfamiliar. Orion’s dagger had turned into the phallus of a satyr; the face in the moon looked seriously ill, with its eyes below its mouth. Then I realized what had happened: I was viewing them inverted, as if standing on my head which, in a sense, I was.

While the irregular patterns of the constellations or the defining features in the moon help to show which way up we are by night, it is not so immediately obvious by day. The sun do...