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CHAPTER 1
The Big Questions
Confronting the Mystery of Existence
FOR THOUSANDS OF YEARS, human beings have contemplated the world about them and asked the great questions of existence: Why are we here? How did the universe begin? How will it end? How is the world put together? Why is it the way it is? For all of recorded human history, people have sought answers to such "ultimate" questions in religion and philosophy or declared them to be completely beyond human comprehension. Today, however, many of these big questions are part of science, and some scientists claim that they may be on the verge of providing answers.
Two major developments have bolstered scientists' confidence that the answers lie within their grasp. The first is the enormous progress made in cosmology — the study of the large-scale structure and evolution of the universe. Observations made using satellites, the Hubble Space Telescope, and sophisticated ground-based instruments have combined to transform our view of the universe and the place of human beings within it. The second development is the growing understanding of the microscopic world within the atom — the subject known as high-energy particle physics. It is mostly carried out with giant particle accelerator machines (what were once called "atom smashers") of the sort found at Fermilab near Chicago and the CERN Laboratory just outside Geneva. Combining these two subjects — the science of the very large and the science of the very small — provides tantalizing clues that deep and previously unsuspected linkages bind the micro-world to the macro-world. Cosmologists are fond of saying that the big bang, which gave birth to the universe billions of years ago, was the greatest ever particle physics experiment. These spectacular advances hint at a much grander synthesis: nothing less than a complete and unified description of nature, a final "theory of everything" in which a flawless account of the entire physical world is encompassed within a single explanatory scheme.
The Universe Is Bio-Friendly
One of the most significant facts — arguably the most significant fact — about the universe is that we are part of it. I should say right at the outset that a great many scientists and philosophers fervently disagree with this statement: that is, they do not think that either life or consciousness is even remotely significant in the great cosmic scheme of things. My position, however, is that I take life and mind (that is, consciousness) seriously, for reasons I shall explain in due course. At first sight life seems to be irrelevant to the subject of cosmology. To be sure, the surface of the Earth has been modified by life, but in the grand sweep of the cosmos our planet is but an infinitesimal dot. There is an indirect sense, however, in which the existence of life in the universe is an important cosmological fact. For life to emerge, and then to evolve into conscious beings like ourselves, certain conditions have to be satisfied. Among the many prerequisites for life — at least, for life as we know it — is a good supply of the various chemical elements needed to make biomass. Carbon is the key life-giving element, but oxygen, hydrogen, nitrogen, sulfur, and phosphorus are crucial too. Liquid water is another essential ingredient. Life also requires an energy source and a stable environment, which in our case are provided by the sun. For life to evolve past the level of simple microbes, this life-encouraging setting has to remain benign for a very long time; it took billions of years for life on Earth to reach the point of intelligence.
On a larger scale, the universe must be sufficiently old and cool to permit complex chemistry. It has to be orderly enough to allow the untrammeled formation of galaxies and stars. There have to be the right sorts of forces acting between particles of matter to make stable atoms, complex molecules, planets, and stars. If almost any of the basic features of the universe, from the properties of atoms to the distribution of the galaxies, were different, life would very probably be impossible. Now, it happens that to meet these various requirements, certain stringent conditions must be satisfied in the underlying laws of physics that regulate the universe, so stringent in fact that a bio-friendly universe looks like a fix — or a "put-up job," to use the pithy description of the late British cosmologist Fred Hoyle. It appeared to Hoyle as if a superintellect had been "monkeying" with the laws of physics. He was right in his impression. On the face of it, the universe does look as if it has been designed by an intelligent creator expressly for the purpose of spawning sentient beings. Like the porridge in the tale of Goldilocks and the three bears, the universe seems to be "just right" for life, in many intriguing ways. No scientific explanation for the universe can be deemed complete unless it accounts for this appearance of judicious design.
Until recently, "the Goldilocks factor" was almost completely ignored by scientists. Now, that is changing fast. As I shall discuss in the following chapters, science is at last coming to grips with the enigma of why the universe is so uncannily fit for life. The explanation entails understanding how the universe began and evolved into its present form and knowing what matter is made of and how it is shaped and structured by the different forces of nature. Above all, it requires us to probe the very nature of physical laws.
The Cosmic Code
Throughout history, prominent thinkers have been convinced that the everyday world observed through our senses represents only the surface manifestation of a deeper hidden reality, where the answers to the great questions of existence should be sought. So compelling has been this belief that entire societies have been shaped by it. Truth seekers have practiced complex rituals and rites, used drugs and meditation to enter trancelike states, and consulted shamans, mystics and priests in an attempt to lift the veil on a shadowy world that lies beneath the one we perceive. The word occult originally meant "knowledge of concealed truth," and seeking a gateway to the occult domain has been a major preoccupation of all cultures, ranging from the Dreaming of Aboriginal Australians to the myth of Adam and Eve tasting the forbidden fruit of the tree of knowledge.
The advent of reasoned argument and logic did nothing to dispel the beguiling notion of a hidden reality. The ancient Greek philosopher Plato compared the world of appearances to a shadow playing on the wall of a cave. Followers of Pythagoras were convinced that numbers possess mystical significance. The Bible is also replete with numerology, for example, the frequent appearances of 7 and 40, or the association of 666 with Satan. The power of numbers led to a belief that certain integers, geometrical shapes, and formulas could invoke contact with a supernatural plane and that obscure codes known only to initiates might unlock momentous cosmic secrets. Remnants of ancient numerology survive today: some superstitious people still believe that numbers such as 8 and 13 are lucky or unlucky.
Attempts to gain useful information about the world through magic, mysticism, and secret mathematical codes mostly led nowhere. But about 350 years ago, the greatest magician who ever lived finally stumbled on the key to the universe — a cosmic code that would open the floodgates of knowledge. This was Isaac Newton — mystic, theologian, and alchemist — and in spite of his mystical leanings, he did more than anyone to change the age of magic into the age of science. Newton, together with a small number of other scientific luminaries who included Nicolaus Copernicus, Johannes Kepler, and Galileo Galilei, gave birth to the modern scientific age. The word science is derived from the Latin scientia, simply meaning "knowledge." Originally it was just one of many arcane methods used to probe beyond the limitations of our senses in the hope of accessing an unseen reality. The particular brand of "magic" employed by the early scientists involved hitherto unfamiliar and specialized procedures, such as manipulating mathematical symbols on pieces of paper and coaxing matter to behave in strange ways. Today we take such practices for granted and call them scientific theory and experiment. No longer is the scientific method of inquiry regarded as a branch of magic, the obscure dabbling of a closed and privileged priesthood. But familiarity breeds contempt, and these days the significance of the scientific process is often underappreciated. In particular, people show little surprise that science actually works and that we really are in possession of the key to the universe. The ancients were right: beneath the surface complexity of nature lies a hidden subtext, written in a subtle mathematical code. This cosmic code contains the secret rules on which the universe runs. Newton, Galileo, and other early scientists treated their investigations as a religious quest. They thought that by exposing the patterns woven into the processes of nature they truly were glimpsing the mind of God. Modern scientists are mostly not religious, yet they still accept that an intelligible script underlies the workings of nature, for to believe otherwise would undermine the very motivation for doing research, which is to uncover something meaningful about the world that we don't already know.
Finding the key to the universe was by no means inevitable. For a start, there is no logical reason why nature should have a mathematical subtext in the first place. And even if it does, there is no obvious reason why humans should be capable of comprehending it. You would never guess by looking at the physical world that beneath the surface hubbub of natural phenomena lies an abstract order, an order that can't be seen or heard or felt, but deduced. Even the wisest mind couldn't tell merely from daily experience that the diverse physical systems making up the cosmos are linked, deep down, by a network of coded mathematical relationships. Yet science has uncovered the existence of this concealed mathematical domain. We human beings have been made privy to the deepest workings of the universe. Other animals observe the same natural phenomena as we do, but alone among the creatures on this planet, Homo sapiens can also explain them.
How has this come about? Somehow the universe has engineered, not just its own awareness, but also its own comprehension. Mindless, blundering atoms have conspired to make not just life, not just mind, but understanding. The evolving cosmos has spawned beings who are able not merely to watch the show, but to unravel the plot. What is it that enables something as small and delicate and adapted to terrestrial life as the human brain to engage with the totality of the cosmos and the silent mathematical tune to which it dances? For all we know, this is the first and only time anywhere in the universe that minds have glimpsed the cosmic code. If humans are snuffed out in the twinkling of a cosmic eye, it may never happen again. The universe may endure for a trillion years, shrouded in total mystery, save for a fleeting pulse of enlightenment on one small planet around one average star in one unexceptional galaxy, 13.7 billion years after it all began.
Could it just be a fluke? Might the fact that the deepest level of reality has connected to a quirky natural phenomenon we call "the human mind" represent nothing but a bizarre and temporary aberration in an absurd and pointless universe? Or is there an even deeper subplot at work?
The Concept of Laws
I may have given the impression that Newton belonged to a small sect that conjured science out of the blue as a result of mystical investigation. This wasn't so. Their work did not take place in a cultural vacuum: it was the product of many ancient traditions. One of these was Greek philosophy, which encouraged the belief that the world could be explained by logic, reasoning, and mathematics. Another was agriculture, from which people learned about order and chaos by observing the cycles and rhythms of nature, punctuated by sudden and unpredictable disasters. And then there were religions, especially monotheistic faiths, which encouraged belief in a created world order. The founding assumption of science is that the physical universe is neither arbitrary nor absurd; it is not just a meaningless jumble of objects and phenomena haphazardly juxtaposed. Rather, there is a coherent scheme of things. This is often expressed by the simple aphorism that there is order in nature. But scientists have gone beyond this vague notion to formulate a system of well-defined laws.
The existence of laws of nature is the starting point of this book, and indeed it is the starting point of science itself. But right at the outset we encounter an obvious and profound enigma:
Where do the laws of nature come from?
As I have remarked, Galileo, Newton, and their contemporaries regarded the laws as thoughts in the mind of God, and their elegant mathematical form as a manifestation of God's rational plan for the universe. Few scientists today would describe the laws of nature using such quaint language. Yet the questions remain of what these laws are and why they have the form that they do. If they aren't the product of divine providence, how can they be explained?
Historically, laws of nature were discussed by analogy to civil law, which arose as a means of regulating human society. Civil law is a concept that dates back to the time of the first settled communities, when some form of authority was needed to prevent social disorder. Typically, a despotic leader would concoct a set of rules and exhort the populace to comply with them. Since one person's rules can be another person's problem, rulers would often appeal to divine authority to buttress their power. A city's god might be literally a stone statue in the town square, and a priest would be appointed to interpret the god's commandments. The notion of turning to a higher, nonmaterial authority as justification for civil law underpins the Ten Commandments and was refined in the Jewish Torah. Remnants of this notion survived into the modern era as the concept of the divine right of kings.
Appeal was also made to an invisible higher power in support of laws of nature. In the fourth century BCE the Stoic philosopher Cleanthes described "Universal Nature, piloting all things according to Law." The order of nature was perhaps clearest in the heavens — the very domain of the gods. Indeed, the word astronomy means "law of the stars." The first-century BCE Roman poet Lucretius referred to the way in which nature requires "each thing to abide by the law that governs its creation." In the first century CE, Marcus Manilius was explicit about the source of nature's order, writing that "God brought the whole universe under law." It was a position wholeheartedly embraced by the monotheistic religions: God the Creator was also God the Lawmaker, who ordered nature according to his divine purposes. Thus the early Christian theologian Augustine of Hippo wrote that "the ordinary course of nature in the whole of creation has certain natural laws."
By the thirteenth century, European theologians and scholars such as Roger Bacon had arrived at the conclusion that laws of nature possess a mathematical basis, a notion that dates back to the Pythagoreans. Oxford University became the center for scholars who applied mathematical philosophy to the study of nature. One of these so-called Oxford Calculators was Thomas Bradwardine (1295–1349), later to become archbishop of Canterbury. Bradwardine has been credited with the first scientific work to announce a general mathematical law of physics in the modern sense. Given this background, it is no surprise that when modern science emerged in Christian Europe in the sixteenth and seventeenth centuries, it was perfectly natural for the early scientists to believe that the laws they were discovering in the heavens and on Earth were the mathematical manifestations of God's ingenious handiwork.
The Special Status of the Laws of Physics
Today, the laws of physics occupy the central position in science; indeed, they have assumed an almost deistic status themselves, often cited as the bedrock of physical reality. Let me give an everyday example. If you go to Pisa in Italy, you can see the famous leaning tower (now restored to a safe inclination by engineering works). Tradition says that Galileo dropped balls from the top of the tower to demonstrate how they fall under gravity. Whether or not this is true, he certainly did carry out some careful experiments with falling bodies, which is how he came to discover the following law. If you drop a ball from the top of a tall building and measure how far it falls in one second, then repeat the experiment for two seconds, three seconds, and so on, you will find that the distance the ball travels increases as the square of the time. The ball will fall four times as far in two seconds as in one, nine times as far in three seconds, and so on. Schoolchildren learn about this law as "a fact of nature" and normally move on without giving it much further thought. But I want to stop right there and ask the question, Why? Why is there such a mathematical rule at work on falling bodies? Where does the rule come from? And why that rule and not some other?
(Continues…)
Excerpted from "The Goldilocks Enigma"
by .
Copyright © 2006 Paul Davies.
Excerpted by permission of Houghton Mifflin Harcourt Publishing Company.
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