Читать книгу Why Us?: How Science Rediscovered the Mystery of Ourselves - James Fanu Le - Страница 13

‘The world will never starve for want of wonders, but only for want of wonder.’

G.K. Chesterton

The world is so full of wonder, it is a wonder we do not see it to be more so. Every dawn the ‘undeviating and punctual’ sun rises on the horizon to flood our lives with the light and warmth that drive the great cycle of organic life – thirty million times more natural energy in a single second than that generated by manmade power stations in a whole year. And punctually at dusk, its setting brings the day to a close with a triumphant explosion of purple, red and orange streaked across the sky. ‘Of all the gifts bestowed upon us,’ wrote the Victorian art critic John Ruskin, ‘colour is the holiest, the most divine, the most solemn.’ Those limitless nuances of colour and light that suffuse our daily lives mark too the procession of the seasons, a constant reminder of the profound mystery of self-renewing life.

And there is nothing so full of wonder as life itself, the more so now we know that the vital actions of even the humblest bacterium, smaller by far than the full stop at the end of this sentence, involve the concerted action of thousands of separate chemical reactions, by which it transforms the nutrients absorbed from soil and water into the energy and raw materials with which it grows and reproduces itself. But life there is, and marching down through the ages in such an abundance of diversity of shape, form, attributes and propensities as to encompass the full range and more of what might be possible. And what variety! ‘No one can say just how many species there are in these greenhouse-humid jungles,’ writes naturalist and broadcaster David Attenborough of the forests of South America.

There are over forty different species of parrot, over seventy different [species of] monkeys, three hundred [species of] humming birds and tens of thousands of [species of] butterflies. If you are not careful, you can even be bitten by a hundred different kinds of mosquito … Spend a day in the forest, turning over logs, looking beneath bark, sifting through the moist litter of leaves and you will collect hundreds of different kinds of small creatures: moths, caterpillars, spiders, long-nosed bugs, luminous beetles, harmless butterflies disguised as wasps, wasps shaped like ants, sticks that walk, leaves that open wings and fly … One of these creatures at least will almost certainly be undescribed by science.

And the millions of species with which we share the planet themselves represent a mere 1 per cent of those that have ever been, each form of life the opportunity for a further myriad of subtly different variations on a theme. Why should the extraordinary faces of the bat family, whose near-blindness should make them indifferent to physical appearances, nonetheless exhaust the possibilities of the design in the detailed geometry of their faces? Why should the many thousands of species of birds yet be so readily distinguishable one from the other by their pattern of flight or the shape of their wing, the colour of their plumage or the notes of their song?

But birds, as the American naturalist Frank Chapman once observed, are ‘nature’s highest expression of beauty, joy and truth’, whose annual migration exemplifies that further recurring mystery of the biological world, those idiosyncrasies of habits and behaviour that defy all reason – like the Arctic tern, that every year traverses the globe, setting out from its nesting grounds in northern Canada and Siberia, winging its way down the coasts of Europe and Africa to the shores of the Antarctic, only to turn round and return northwards again: a round journey of twenty-five thousand miles that takes them eight months, flying twenty-four hours a day. How swiftly they fly, how confidently across the pathless sea at night!

And while we might rightly wonder how the Arctic tern knows how to navigate by the stars, it seems almost more wonderful still that the salmon should find its way from the depths of the ocean back to the same small stream from whence it set out, detecting through its highly developed sense of smell the waters of its spawning ground; or that the common European eel should cross the Atlantic twice, first from its breeding grounds off the North American coast to the rivers of Europe – and then back again. ‘The number of [such] admirable, more or less inexplicable traits that one might cite is limited not by the inventiveness of nature,’ writes biologist Robert Wesson, ‘but rather by the ability of scientists to describe them.’ There are, he points out, an estimated twenty thousand species of ant, of which only eight thousand have been described. So far biologists have got round to studying just one hundred of them in depth, each of which has its own unique, bizarre pattern of behaviour – such as ‘the female of a parasitic ant which on finding a colony of its host, seizes a worker, rubs it with brushes on her legs to transfer its scent making her acceptable to enter the host colony’. How did there come to be such sophisticated and purposive patterns of behaviour in such minute creatures?

And yet that near-infinite diversity of life is permeated by an underlying unity, where everything connects in the same web of self-renewing life. The rain falling on the mountains feeds the springs that fill the streams. Those streams become rivers and flow to the sea, the mists rise from the deep and clouds are formed, which break again as rain on the mountainside. The plants on that mountainside capture the rainwater and, warmed by the energy of the sun, transform the nutrients of the soil, by some extraordinary alchemy, into themselves. A grazing animal eats that same plant to set up another complex web of connections, for it in turn is eaten by another, and its remains will return to the earth, where the microbes in the soil cannibalise its bones, turning them back into their constituent chemicals. And so the process of reincarnation continues. Nothing is lost, but nothing stays the same.

Wheels within wheels; and across that vast landscape of living things, from the highest to the lowest, the survival and prosperity of man is yet, as J. Arthur Thomson, Professor of Natural History at Aberdeen University reminds us, completely dependent on the labours of the humble earthworm, without whose exertions in aerating the dense, inhospitable soil there could never have been a single field of corn.

When we pause to think of the part earthworms have played in the history of the earth, they are clearly the most useful of animals. By their burrowing, they loosen the earth, making way for the plant rootlets and the raindrops; by bruising the soil in their gizzards they reduce the mineral particles to more useful forms; they were ploughers before the plough. Five hundred thousand to an acre passing ten tons of soil every year through their bodies.

So, the world ‘will never starve for want of wonders’, the more so for knowing and wondering how the sky above and the earth below and ‘all that dwell therein’ – including the human mind, with its powers of reason and imagination – originated as a mass of formless atoms in that ‘moment of singularity’ of the Big Bang fifteen billion years ago.

The poet William Wordsworth, seeking to catch the enfolding delight of that sky above and earth below, called it ‘the sublime’,

Whose dwelling is the light of setting suns,

And the round ocean and the living air,

And the blue sky,

A spirit that impels and rolls through all things.

The feelings evoked by nature and ‘the sublime’ were, for the American poet Walt Whitman as for so many poets and writers, the most powerful evidence for a hidden, mystical core to everyday reality.

‘There is, apart from mere intellect,’ he wrote, ‘a wondrous something that realises without argument an intuition of the absolute balance, in time and space of the whole of this multifariousness we call the world; a sight of that unseen thread which holds all history and time, and all events like a leashed dog in the hand of the hunter.’

That sublime nature has always provided the most powerful impetus to the religious view, its celebration a central feature of all the great religions. For the German theologian Rudolph Otto (1869–1937), the ‘sublime’ was a ‘mysterium tremendum et fascinans’: both awesome, in whose presence we feel something much greater than our insignificant selves, and also fascinating, compelling the human mind to investigate its fundamental laws.

This brings us to the second of the dual meanings of ‘wonder’ suggested at the close of the preceding chapter, to ‘wonder why’, which, as the Greek philosopher Plato observed, ‘is the beginning of all knowledge’.

‘The scientist does not study nature because it is useful to do so,’ wrote the nineteenth-century French mathematician Henri Poincaré. ‘He studies it because he takes pleasure in it; and he takes pleasure in it because it is beautiful. If nature were not beautiful, it would not be worth knowing, and life would not be worth living … I mean the intimate beauty which comes from the harmonious order of its parts and which a pure intelligence can grasp.’

The greatest (probably) of all scientists, Isaac Newton, seeking to comprehend that ‘harmonious order of parts’, would discover the fundamental laws of gravity and motion, that, being Universal (they hold throughout the universe), Absolute (unchallengeable), Eternal (holding for all time) and Omnipotent (all-powerful), he inferred, offered a glimpse into the mind of the Creator. Newton captured this dual meaning of wonder, to ‘wonder at’ and to ‘wonder why’, in his famous confession that the most he could hope to achieve was to illuminate the workings of some small part of that sublime world: ‘I do not know what I may appear to the world,’ he wrote, ‘but to myself I seem to have been only like a boy playing on the sea shore, diverting myself now and then, finding a smoother pebble than ordinary, whilst the great ocean of truth lay all undiscovered before me.’

The wonders of the world are so pervasive that to the seemingly less sophisticated minds of earlier ages (such as Newton’s) they were best understood as ‘natural miracles’. To be sure, the undeviating and punctual sun, the cycle of life, the infinite variety of living things, their interconnectedness to each other, these are all part of nature, and are faithful to its laws. They are ‘natural’. But the totality of it all, its beauty and integrity and completeness, that ‘great undiscovered ocean of truth’, lie so far beyond the power of the human mind to properly comprehend, they might as well be ‘a miracle’. Thus science and religion were cheerfully reconciled, the scientist seeing his task as a holy calling, where Robert Boyle, the founder of modern physics, would perceive his role as ‘a priest in the temple of nature’.

This is scarcely the modern view. Most people, of course, acknowledge the beauty and complexity of the world and find it admirable, even uplifting – but you could search in vain for a textbook of biology or zoology, astronomy or botany, or indeed of any scientific discipline, which even hints that there is something astonishing, extraordinary, let alone ‘miraculous’, about its subject. Science no longer ‘does’ wonder, which is more readily associated nowadays with the incurious mysticism and incense of the New Age. Science prefers to cultivate an aura of intellectual neutrality, the better to convey its disinterested objectivity, its commitment to the ‘truth’. Hence the highly technical, and to the outsider often impenetrable, prose of its texts and learned journals, from which any sense of wonder is rigorously excluded.

There are, as will be seen, several important reasons for this modern-day lack of astonishment, but the most important is undoubtedly the general perception that science, since Newton’s time, has revealed those ‘natural miracles’ to have a distinctly non-miraculous, materialist explanation – culminating in that firestorm of scientific discovery of the past fifty years, which has integrated into one coherent narrative the entire history of the universe from its origins to the present day. To be sure, science may not capture the beauty and connectedness of it all, the ‘sublime spirit that rolls through all things’, but this is more than compensated for by the sheer drama and excitement of the events it has so convincingly described.

The scale of that intellectual achievement is so great that there might seem little room any more for the ‘natural miracles’ of an earlier age, or to ‘wonder’ whether there might after all be more than we can know. It would certainly require a truly Olympian perspective, capable of surveying the vast landscape of science, to recognise where and what the limits to its knowledge might be – and that would seem an impossibility. Yet it is not quite so, for while that landscape is indeed vast, and far beyond the comprehending of any individual, it is nonetheless sustained by three great unifying phenomena that impose order on the world – which on examination can tell us something very profound about science and the limits of its materialist explanations.

It is fruitless – always has been, always will be – to pose that most elementary of all questions: ‘Why is there something rather than nothing?’ The same however does not apply to the second and supplementary question: ‘Why, given there is something, are both the physical universe (and all that it contains) and all life (in its infinite diversity) so ordered?’ They should not be, for anything left to itself will tend towards chaos and disorder, as fires burn out and clocks run down – unless countered by a compensating force imposing order, restituting lost energy.

There are (to put it simply) three ‘forces for order’: first the force of gravity, as discovered by Sir Isaac Newton, the glue that binds the universe together; next the all-powerful genes strung out along the Double Helix, imposing the order of form, the shape, characteristics and attibutes unique to each of the millions of species of living things; and thirdly the human mind, that imposes the order of understanding on the natural world and our place within it. These three forces control or sustain all (or virtually all) phenomena in the universe, and stand proxy for the ‘vast landscape’ of science. Thus, if they are knowable scientifically as belonging to that materialist, second-order reality of the physics and chemistry of matter (where water is a combination of two molecules of hydrogen and one of oxygen), then by definition there is nothing in theory that science cannot know. But if they are not so knowable, one can only infer that they exert their effects through some other force that lies beyond the range of science and its methods to detect. We start with Sir Isaac Newton’s theory of gravity.

Isaac Newton, born in 1642 into a semi-literate sheep-farming family in rural Lincolnshire, was one of the tiny handful of supreme geniuses who have shaped the categories of human knowledge. From the time of Aristotle onwards, and for the best part of two thousand years, the regularity and order of the physical world was as it was because it was divinely ordained to be so: the punctual and undeviating sun, the movement of the planets across the heavens, the passage of the seasons and apples falling from trees. Newton’s genius was to realise that these and numerous other aspects of the physical world were all linked together by the hidden force of gravity.

Soon after graduating at the age of twenty-three from Cambridge University, Newton was compelled by an epidemic of bubonic plague to return to his home in Lincolnshire. There, over a period of just two years, he made a series of scientific discoveries that would not be equalled till Einstein, almost 250 years later. These included the nature of light and the mathematical method of differential calculus, with which it is possible to calculate the movement of the planets in their orbit. Newton’s most famous insight came when, sitting in his garden, he saw an apple fall from a tree. He ‘wondered’ whether the force of the earth’s gravity pulling the apple to the ground might reach still further, and hold the moon in its orbit around the earth.

Newton’s friend Dr William Stukeley would later record his reminiscences of that great moment.

After dinner, the weather being warm, we went into the garden and drank tea, under the shade of some apple trees, only he and myself. Amidst other discourse, he told me he was just in the same situation as when, formerly, the notion of gravitation came into his mind. It was occasioned by the fall of an apple, as he sat in a contemplative mood. Why should that apple always descend perpendicularly to the ground, thought he to himself? Why should it not go sideways or upwards, but constantly to the earth’s centre? Assuredly, the reason is, that the earth draws it. There must be a drawing power in matter … and if matter thus draws matter, it … must extend itself through the universe.

Newton’s ‘notion of gravitation’, of ‘matter drawing on matter’, would resolve the greatest conundrum of the movement of those heavenly bodies, why they remained in their stately orbits (the moon around the earth, the earth around the sun) rather than, as they should by rights, being impelled by their centrifugal force into the far depths of outer space. Newton, being a mathematical genius, calculated the strength of that countervailing force of gravity, showing it to be determined by the masses of the moon and earth, earth and sun respectively, multiplied together and divided by the distance between them, and so too throughout the entire universe. By the time Newton published his epic three-volume Principia Mathematica in 1697, describing the theory of gravity and the three laws of motion, he had transformed the divinely ordained physical world into which he was born into one governed by absolute and unchallengeable universal laws known to man, where everything was linked to everything else in a never-ending series of causes – all the way into the past and indefinitely into the future.

From the beginning, the force of gravity at the moment of the Big Bang imposed the necessary order on those billions of elementary particles, concentrating them into massive, heat-generating stars. Several thousand millions of years later, the same force of gravity would impose order on our solar system, concentrating 99 per cent of its matter within the sun to generate the prodigious amounts of energy, heat and light that would allow the emergence of life on earth. And anticipating the future? Newton’s friend, the Astronomer Royal Edmond Halley, used Newton’s laws to work out the elliptical orbit of the comet that bears his name and so predict its seventy-six-year cycle of return. Three hundred years later, NASA scientists would use those same laws to plot the trajectory of the first manned space flight to the moon. Newton’s laws can even predict when it will all end – in five thousand million years’ time (or thereabouts), when the prodigious energy generated by our sun will be exhausted, and our earth will perish.

As time has passed, so the explanatory power of Newton’s laws of gravity has grown ever wider, to touch virtually every aspect of human experience: the movement of the sun and stars (obviously), the waxing and waning of the moon, the ebb and flow of the tides, the contrasting climates of the Arctic Circle and the sand-swept desert, the cycle of the seasons, rain falling on the ground, the shape of mountains sculpted by the movement of glaciers, the flow of rivers towards the sea, the size of living things from whale to flea and indeed ourselves – for we could not be any bigger than we are without encountering the hazard, posed by gravity, of falling over.

Newton’s laws epitomise, to the highest degree, the explanatory power of science, through which for the first time we humans could comprehend the workings of that vast universe to which we belong. But, and it is a most extraordinary thing, three hundred years on, the means by which the powerful, invisible glue of gravity imposes order on the universe remains quite unknown. Consider, by analogy, a child whirling a ball attached to a string around its head, just as gravity holds the earth in its perpetual orbit around the sun. Here, the string (like gravity) counteracts the centrifugal force that would hurtle the ball (the earth) into a distant tree. But there is no string. Newton himself was only too well aware that there had to be some physical means by which gravity must exert its influence over hundreds, thousands, of millions of miles of empty space. It was, he wrote, ‘an absurdity that no thinking man can ever fall into’ to suppose that gravity ‘could act at a distance through a vacuum without the mediation of anything else, by which that action and force may be conveyed’.

Perhaps, he speculated, space was suffused by an invisible ‘ether’ composed of very small particles that repelled one another and by which the sun could hold the earth in its orbit – though this would mean that over a very long period the movement of the planets would gradually slow down through the effects of friction. But in 1887 an American physicist, Albert Michelson, discovered that there was no ‘ether’. Space is well named – it is empty. Put another way, Newton’s theory encompasses the profound contradiction of gravity being both an immensely powerful force imposing order on the matter of the universe, linking its history all the way back to the beginning and anticipating its end, yet itself being non-material. This extraordinary property of gravitation requires some sort of context, by contrasting it with, for example, that equally potent invisible ‘force’ electricity, which at the touch of a switch floods the room with light. But whereas electricity is a ‘material’ force – the vibration of electrons passing along a copper wire – gravity exerts its effects across billions of miles of empty space, through a vacuum of nothingness.

Newton’s theory stands (for all time), but has been modified in two directions. First, in 1915, Albert Einstein in his General Theory of Relativity reformulated the concept of gravity to allow for space to be ‘elastic’, so that a star like our sun could curve and stretch the space around it – and the bigger the star, the greater the effect. Matter, Einstein showed, warps space. This takes care of the more bizarre phenomena in the universe, such as ‘black holes’, that capture even the weightless particles of light – but for all that the profound Newtonian mystery of how gravity exerts its force through the vacuum of space remains unresolved.

Next, it has emerged that Newton’s gravitational force is not alone, being just one of four (similarly non-material) forces, including those that bind together the atomic particles of protons and neutrons – whose disruption generates the prodigious energy of an atomic explosion. In the twentieth century, the conundrum of the non-materiality of those gravitational forces was compounded when it emerged that their strength is precisely tuned to permit the consequent emergence of life and ourselves. If the force they exert were, for example, ever so slightly stronger, then stars (like our sun) would attract more matter from interstellar space, and being so much bigger would burn much more rapidly and intensely – just as a large bonfire outburns a smaller one. They would then exhaust themselves in as little as ten million years, instead of the several billion necessary for life to ‘get going’. If, contrariwise, the force of gravity were ever so slightly weaker, the reverse would apply, and the sun and stars would not be big enough to generate those prodigious amounts of heat and energy. The sky would be empty at night, and once again we humans would never have been around to appreciate it. It is, of course, very difficult to convey just how precise those forces necessary for the creation of the universe (and the subsequent emergence of life on planet earth) had to be, but physicist John Polkinghorne estimates their fine tuning had to be accurate to within one part in a trillion trillion (and several trillion more), a figure greater by far than all the particles in the universe – a degree of accuracy, it is estimated, equivalent to hitting a target an inch wide on the other side of the universe.

Isaac Newton’s theory of gravity is the most elegant idea in the history of science. Nothing touches its combination of pure simplicity, readily understandable by a class of ten-year-olds, and all-encompassing explanatory power. His contemporaries were dazzled that so elementary a mathematical formula could account for so much – prompting the poet Alexander Pope to propose as his epitaph in Westminster Abbey:

Nature and nature’s laws lay hidden in night

God said Let Newton be! And all was light.

Still, Newton’s gravitational force, imposing ‘order’ on the physical universe, clearly fails the test of scientific ‘knowability’, for while we can fully comprehend all its consequences we are ‘left with that absurdity that no thinking man can ever fall into’ of having to suppose that a non-material force can ‘act at a distance’ across millions of miles of empty space without the mediation of anything by which that action and force may be conveyed. Thus, ironically, this most scientific of theories, grounded in the observation of the movements of the planets expressed in mathematical form, subverts the scientific or materialist view which holds that everything must ultimately be explicable in terms of its material properties alone.

We turn now to the living world of plants, insects, fishes, birds and ourselves, which is billions upon billions upon billions of times more complex than Newton’s non-living, physical universe. Hence, the two forces that impose order on that world, the Double Helix imposing the order of form on living things, and the human brain and its mind imposing the order of understanding, will be profounder than the glue of gravity by similar orders of magnitude. We might anticipate that these two further forces of order will, like Newton’s theory of gravity, similarly prove to be non-material, and therefore fail the test of scientific knowability. But to ‘get there’ we must first come to grips with how we have come to suppose otherwise, and specifically how in the mid-nineteenth century Darwin’s grand evolutionary theory, as set out in the twin texts of On the Origin of Species and The Descent of Man, offered an apparently all-encompassing and exclusively materialist explanation for the phenomena of life.