They are there as a tribute to his
sensitive
genius.
Richard-Dawkins-Unweaving-the-Rainbow
RICHARD DAWKINS - UNWEAVING THE RAINBOW
SCIENCE, DELUSION AND THE APPETITE FOR WONDER.
'The product of a beguiling and fascinating mind and one generous enough to attempt to include all willing readers in its brilliantly informed enthusiasm'
MELVYN BRAGG, OBSERVER
Keats accused Newton of destroying the poetry of the rainbow by explaining the origin of its colours, thus dispelling its mystery. In this illuminating and provocative book, Richard Dawkins argues that Keats could not have been more mistaken and shows how an understanding of science inspires the human imagination and enhances our wonder of the world.
'A brilliant assertion of the wonder and excitement of real, tough, grown- up science'
A. S. BYATT, DAILY TELEGRAPH, BOOKS OF THE YEAR
'The way Dawkins writes about science is not just a brain-tonic.
It is more like an extended stay on a brain health-farm . . . You come out feeling lean, tuned and enormously more intelligent'
JOHN CAREY, SUNDAY TIMES
'For Dawkins there is more poetry, not less, in the rainbow- because of Newton
,. . Warming to his theme, he weaves rainbows of wonder from other provinces of science . . . and then unleashes his fury on those who accuse scientists like him of being unimaginative for not believing in horoscopes, telepathy, ghosts and gods'
MATT RIDLEY, SUNDAY TELEGRAPH
'Beautifully written and full of interesting, original ideas. Essential reading, for those who care about science'
LEWIS WOLPERT, THE TIMES
PREFACE
A foreign publisher of my first book confessed that he could not sleep for three nights after reading it, so troubled was he by what he saw as its cold, bleak message. Others have asked me how I can bear to get up in the mornings. A teacher from a distant country wrote to me reproachfully that a pupil had come to him in tears after reading the same book, because it had persuaded her that life was empty and purposeless. He advised her not to show the book to any of her friends, for fear of contaminating them with the same nihilistic pessimism. Similar accusations of barren desolation, of promoting an arid and joyless message, are frequently flung at science in general, and it is easy for scientists to play up to them. My colleague Peter Atkins begins his book The Second Law (1984) in this vein:
We are the children of chaos, and the deep structure of change is decay. At root, there is only corruption, and the unstemmable tide of chaos. Gone is purpose; all that is left is direction. this is the bleakness we have to accept as we peer deeply and dispassionately into the heart of the Universe.
But such very proper purging of saccharine false purpose; such laudable tough-mindedness in the debunking of cosmic sentimentality must not
be confused with a loss of personal hope. Presumably there is indeed no purpose in the ultimate fate of the cosmos, but do any of us really tie our life's hopes to the ultimate fate of the cosmos anyway? Of course we don't; not if we are sane. Our lives are ruled by all sorts of closer, warmer, human ambitions and perceptions. To accuse science of robbing life of
the warmth that makes it worth living is so preposterously mistaken, so diametrically opposite to my own feelings and those of most working
scientists, I am almost driven to the despair of which I am wrongly suspected. But in this book I shall try a more positive response, appealing to the sense of wonder in science because it is so sad to think what these complainers and naysayers are missing. This is one of the things that the late Carl Sagan did so well, and for which he is sadly missed. The feeling of awed wonder that science can give us is one of the highest experiences of which the human psyche is capable. It is a deep aesthetic passion to rank with the finest that music and poetry can deliver. It is truly one of the things that makes life worth living and it does so, if anything, more effectively if it convinces us that the time we have for living it is finite.
My title is from Keats, who believed that Newton had destroyed all the poetry of the rainbow by reducing it to the prismatic colours. Keats could hardly have been more wrong, and my aim is to guide all who are tempted by a similar view towards the opposite conclusion. Science is, or ought to be, the inspiration for great poetry, but I do not have the talent to clinch the argument by demonstration and must depend, instead, on more prosaic persuasion. A couple of the chapter titles are borrowed from Keats; readers may also spot the occasional half-quotation or allusion lacing the text from him (as well as others). They are there as a tribute to his sensitive genius. Keats was a more likeable character than Newton and his shade was one of the imaginary referees looking over my shoulder as I wrote.
Newton's unweaving of the rainbow led on to spectroscopy, which has proved the key to much of what we know today about the cosmos. And the heart of any poet worthy of the title Romantic could not fail to leap
up if he beheld the universe of Einstein, Hubble and Hawking. We read
its nature through Fraunhofer lines - 'Barcodes in the Stars' - and their shifts along the spectrum. The image of barcodes carries us on to the
very different, but equally intriguing, realms of sound ('Barcodes on the Air'); and then DNA fingerprinting ('Barcodes at the Bar'), which offers
the opportunity to reflect on other aspects of the role of science in society.
In what I call the Delusion section of the book, 'Hoodwink'd with Faery Fancy' and 'Unweaving the Uncanny', I turn to those ordinary superstitious folk who, less exalted than poets defending rainbows, revel in mystery and feel cheated if it is explained. They are the ones who love a good ghost story, whose mind leaps to poltergeists or miracles whenever something even faintly odd happens. They never lose an opportunity to quote Hamlet's
There are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy.
and the scientist's response ('Yes, but we're working on it') strikes no chord with them. For them, to explain away a good mystery is to be a killjoy, just as some Romantic poets thought about Newton's explaining of the rainbow.
Michael Shermer, editor of Skeptic magazine, tells a salutary story of an occasion when he publicly debunked a famous television spiritualist. The man was doing ordinary conjuring tricks and duping people into thinking he was communicating with dead spirits. But instead of being hostile to the now-unmasked charlatan, the audience turned on the debunker and supported a woman who accused him of 'inappropriate' behaviour because he destroyed people's illusions. You'd think she'd have been grateful for having the wool pulled off her eyes, but apparently she preferred it firmly over them. I believe that an orderly universe, one indifferent to human preoccupations, in which everything has an explanation even if we still have a long way to go before we find it, is a more beautiful, more wonderful place than a universe tricked out with capricious, ad hoc magic.
Paranormalism could be called an abuse of the legitimate sense of poetic wonder which true science ought to be feeding. A different threat comes from what may be called bad poetry. The chapter on 'Huge Cloudy Symbols of a High Romance' warns against seduction by bad poetic science; against the allure of misleading rhetoric. By way of example, I look at a particular contributor to my own field whose imaginative writing has given him a disproportionate - and I believe unfortunate - influence on American understanding of evolution. But the dominant thrust of the book is in favour of good poetic science, by which I don't, of course, mean science written in verse but science inspired by a poetic sense of wonder.
The last four chapters attempt, with respect to four different but interrelated topics, to hint at what might be done by poetically inspired scientists more talented than I am. Genes, however 'selfish', must also be 'cooperative' - in an Adam Smithian sense (which is why the chapter 'The Selfish Co-operator' opens with a quotation from Adam Smith, though admittedly not on this topic but on wonder itself). The genes of a species can be thought of as a description of ancestral worlds, a 'Genetic Book of the Dead'. In a similar way, the brain 'reweaves the world', constructing a kind of 'virtual reality' continuously updated in the head. In 'The Balloon of the Mind' I speculate on the origins of our own species' most unique features and return, finally, to wonder at the poetic impulse itself and the part it may have played in our evolution.
Computer software is driving a new renaissance, and some of its creative geniuses are benefactors and simultaneously renaissance men in their
own right. In 1995, Charles Simonyi of Microsoft endowed a new professorship of Public Understanding of Science at the University of Oxford, and I was appointed its first holder. I am grateful to Dr Simonyi, most obviously for his far-sighted generosity towards a university with which he had no previous connection, but also for his imaginative vision of science and how it should be communicated. This was beautifully expressed in his written statement to the Oxford of the future (his endowment is in perpetuity, yet he characteristically eschews the wary meanness of lawyer language) and we have discussed these matters from time to time since becoming friends after my appointment. Unweaving the Rainbow could be seen as my contribution to the conversation, and as my inaugural statement as Simonyi Professor. And if 'inaugural' sounds a little unbecoming after two years in the job, I may perhaps take a liberty and quote Keats again:
By this, friend Charles, you may full plainly see Why I have never penn'd a line to thee: Because my thoughts were never free, and clear, And little fit to please a classic ear.
Nevertheless, it is in the nature of a book that it takes longer to produce than a newspaper article or a lecture. During its gestation this one has spun off a few of both, and broadcasts as well. I must acknowledge these now, in case any readers recognize the odd paragraph here and there. I first publicly used the title 'Unweaving the Rainbow', and the theme of Keats's irreverence towards Newton, when I was invited to give the C. P. Snow Lecture for 1997 by Christ's College, Cambridge, Snow's old college. Although I have not explicitly taken up his theme of The Two Cultures, it is obviously relevant. Even more so is The Third Culture of John Brockman, who has been helpful, too, in a quite different role, as my literary agent. The subtitle 'Science, Delusion and the Appetite for Wonder' was the title of my Richard Dimbleby Lecture, 1996. Some paragraphs from an earlier draft of this book appeared in that BBC televised lecture. Also in 1996, I presented a one-hour television documentary on Channel Four, Break the Science Barrier. This was on the theme of science in the culture, and some of the background ideas, developed in discussions with John Gau, the producer, and Simon Raikes, the director, have influenced this book. In 1998 I incorporated some passages of the book in my lecture in the Sounding the Century series broadcast by BBC Radio 3 from the Queen Elizabeth Hall, London. (I thank my wife for my lecture's title, 'Science and Sensibility', and don't quite know what to make of the fact that it has already been plagiarized in, of all places, a supermarket magazine. ) I also have used paragraphs from the book in articles commissioned by the Independent, the Sunday Times and the Observer. When I was honoured with the 1997 International Cosmos Prize, I chose the title 'The Selfish Cooperator' for my prize lecture, given in both Tokyo and Osaka. Parts of the lecture
have been reworked and expanded in chapter 9, which has the same title. Parts of chapter 1 appeared in my Royal Institution Christmas Lectures.
The book has benefited greatly from constructive criticisms of an earlier draft by Michael Rodgers, John Catalano and Lord Birkett. Michael Birkett has become my ideal intelligent layman. His scholarly wit makes his critical comments a pleasure to read in their own right. Michael Rodgers was the editor of my first three books and, by my wish and his generosity, he has also played an important role in the last three as well.
I would like to thank John Catalano, not just for his helpful comments
on the book but for http://www. spacelab. net/~catalj/home. html, whose excellence - which has nothing whatever to do with me - will be apparent to all who go there. Stefan McGrath and John Radziewicz, editors at Penguin and Houghton Mifflin respectively, gave patient encouragement and literate advice which I greatly valued. Sally Holloway worked
tirelessly and cheerfully on the final copy-editing. Thanks also to Ingrid Thomas, Bridget Muskett, James Randi, Nicholas Davies, Daniel Dennett, Mark Ridley, Alan Grafen, Juliet Dawkins, Anthony Nuttall and John Batchelor.
My wife, Lalla Ward, has criticized every chapter a dozen times in various drafts, and with every reading I have benefited from her sensitive actor's ear for language and its cadences. Whenever I had doubts, she believed in the book. Her vision held it together, and I wouldn't have finished it without her help and encouragement. I dedicate it to her.
1
THE ANAESTHETIC OF FAMILIARITY
To live at all is miracle enough.
MERVYN PEAKE, The Glassblower (1950)
We are going to die, and that makes us the lucky ones. Most people are never going to die because they are never going to be born. The potential people who could have been here in my place but who will in fact never see the light of day outnumber the sand grains of Arabia. Certainly those unborn ghosts include greater poets than Keats, scientists greater than Newton. We know this because the set of possible people allowed by our DNA so massively exceeds the set of actual people. In the teeth of these stupefying odds it is you and I, in our ordinariness, that are here.
Moralists and theologians place great weight upon the moment of conception, seeing it as the instant at which the soul comes into existence. If, like me, you are unmoved by such talk, you still must
regard a particular instant, nine months before your birth, as the most decisive event in your personal fortunes. It is the moment at which your consciousness suddenly became trillions of times more foreseeable than it was a split second before. To be sure, the embryonic you that came into existence still had plenty of hurdles to leap. Most conceptuses end in early abortion before their mother even knew they were there, and we are all lucky not to have done so. Also, there is more to personal identity than genes, as identical twins (who separate after the moment of fertilization) show us. Nevertheless, the instant at which a particular spermatozoon penetrated a particular egg was, in your private hindsight, a moment of dizzying singularity. It was then that the odds against your becoming a person dropped from astronomical to single figures.
The lottery starts before we are conceived. Your parents had to meet, and the conception of each was as improbable as your own. And so on back, through your four grandparents and eight great grandparents, back to where it doesn't bear thinking about. Desmond Morris opens his autobiography, Animal Days (1979), in characteristically arresting vein:
Napoleon started it all. If it weren't for him, I might not be sitting here now writing these words . . . for it was one of his cannonballs, fired in the Peninsular War, that shot off the arm of my great-great grandfather, James Morris, and altered the whole course of my family history.
Morris tells how his ancestor's enforced change of career had various knock-on effects culminating in his own interest in natural history. But he really needn't have bothered. There's no 'might' about it. Of course he owes his very existence to Napoleon. So do I and so do you. Napoleon didn't have to shoot off James Morris's arm in order to seal young Desmond's fate, and yours and mine, too. Not just Napoleon but the humblest medieval peasant had only to sneeze in order to affect something which changed something else which, after a long chain reaction, led to the consequence that one of your would-be ancestors failed to be your ancestor and became somebody else's instead. I'm not talking about 'chaos theory', or the equally trendy 'complexity theory', but just about the ordinary statistics of causation. The thread of historical events by which our existence hangs is wincingly tenuous.
When compared with the stretch of time unknown to us, O king, the present life of men on earth is like the flight of a single sparrow through the hall where, in winter, you sit with your captains and ministers. Entering at one door and leaving by another, while it is inside it is untouched by the wintry storm; but this brief interval of calm is over in a moment, and it returns to the winter whence it came, vanishing from your sight Man's life is similar-, and of what follows it, or what went before, we are utterly ignorant.
THE VENERABLE BEDE, A History of the English Church and People (731)
This is another respect in which we are lucky. The universe is older than a hundred million centuries. Within a comparable time the sun will swell to a red giant and engulf the earth. Every century of hundreds of millions has been in its time, or will be when its time comes, 'the present century'. Interestingly, some physicists don't like the idea of a 'moving present', regarding it as a subjective phenomenon for which they find no house room in their equations. But it is a subjective argument I am making. How it feels to me, and I guess to you as well, is that the present moves from the past to the future, like a tiny spotlight, inching its way along a gigantic ruler of time. Everything behind the spotlight is in darkness, the darkness of the dead past. Everything ahead of the spotlight is in the darkness of the unknown future. The odds of your century being the one in the spotlight are the same as the odds that a penny, tossed down at random, will land on a particular ant crawling somewhere along the road from New York to San Francisco. In other words, it is overwhelmingly probable that you are dead.
In spite of these odds, you will notice that you are, as a matter of fact, alive. People whom the spotlight has already passed over, and people whom the spotlight has not reached, are in no position to read a book. I am equally lucky to be in a position to write one, although I may not be when you read these words. Indeed, I rather hope that I shall be dead when you do. Don't misunderstand me. I love life and hope to go on for a long time yet, but any author wants his works to reach the largest possible readership. Since the total future population is likely to outnumber my contemporaries by a large margin, I cannot but aspire to be dead when you see these words. Facetiously seen, it turns out to be no more than a hope that my book will not soon go out of print. But what I see as I write is that I am lucky to be alive and so are you.
We live on a planet that is all but perfect for our kind of life: not too warm and not too cold, basking in kindly sunshine, softly watered; a gently spinning, green and gold harvest festival of a planet. Yes, and alas, there are deserts and slums; there is starvation and racking misery to be found. But take a look at the competition. Compared with most planets this is paradise, and parts of earth are still paradise by any standards. What are the odds that a planet picked at random would have these complaisant properties? Even the most optimistic calculation would put it at less than one in a million.
Imagine a spaceship full of sleeping explorers, deep-frozen would-be colonists of some distant world. Perhaps the ship is on a forlorn mission
to save the species before an unstoppable comet, like the one that killed the dinosaurs, hits the home planet. The voyagers go into the deep-freeze soberly reckoning the odds against their spaceship's ever chancing upon a planet friendly to life. If one in a million planets is suitable at best, and it takes centuries to travel from each star to the next, the spaceship is pathetically unlikely to find a tolerable, let alone safe, haven for its sleeping cargo.
But imagine that the ship's robot pilot turns out to be unthinkably lucky. After millions of years the ship does find a planet capable of sustaining life: a planet of equable temperature, bathed in warm starshine, refreshed by oxygen and water. The passengers, Rip van Winkles, wake stumbling into the light. After a million years of sleep, here is a whole new fertile globe, a lush planet of warm pastures, sparkling streams and waterfalls, a world bountiful with creatures, darting through alien green felicity. Our travellers walk entranced, stupefied, unable to believe their unaccustomed senses or their luck.
As I said, the story asks for too much luck; it would never happen. And yet, isn't that what has happened to each one of us? We have woken after hundreds of millions of years asleep, defying astronomical odds. Admittedly we didn't arrive by spaceship, we arrived by being born, and we didn't burst conscious into the world but accumulated awareness gradually through babyhood. The fact that we slowly apprehend our world, rather than suddenly discover it, should not subtract from its wonder.
Of course I am playing tricks with the idea of luck, putting the cart before the horse. It is no accident that our kind of life finds itself on a planet whose temperature, rainfall and everything else are exactly right. If the planet were suitable for another kind of life, it is that other kind of life that would have evolved here. But we as individuals are still hugely blessed. Privileged, and not just privileged to enjoy our planet. More, we are granted the opportunity to understand why our eyes are open, and why they see what they do, in the short time before they close for ever.
Here, it seems to me, lies the best answer to those petty-minded Scrooges who are always asking what is the use of science. In one of those mythic remarks of uncertain authorship, Michael Faraday is alleged to have been asked what was the use of science. 'Sir,' Faraday replied. 'Of what use is a new-born child? ' The obvious thing for Faraday (or Benjamin Franklin, or whoever it was) to have meant was that a baby might be no use for anything at present, but it has great potential for the future. I now like to think that he meant something else, too: What is the use of bringing a baby into the world if the only thing it does with its life is just work to go on living? If everything is judged by how 'useful' it is - useful
for staying alive, that is - we are left facing a futile circularity. There must be some added value. At least a part of life should be devoted to living that life, not just working to stop it ending. This is how we rightly justify spending taxpayers' money on the arts. It is one of the justifications properly offered for conserving rare species and beautiful buildings. It is how we answer those barbarians who think that wild elephants and historic houses should be preserved only if they 'pay their way'. And science is the same. Of course science pays its way; of course it is useful. But that is not all it is.
After sleeping through a hundred million centuries we have finally opened our eyes on a sumptuous planet, sparkling with colour, bountiful with life. Within decades we must close our eyes again.
They are there as a tribute to his sensitive genius. Keats was a more likeable character than Newton and his shade was one of the imaginary referees looking over my shoulder as I wrote.
Newton's unweaving of the rainbow led on to spectroscopy, which has proved the key to much of what we know today about the cosmos. And the heart of any poet worthy of the title Romantic could not fail to leap
up if he beheld the universe of Einstein, Hubble and Hawking. We read
its nature through Fraunhofer lines - 'Barcodes in the Stars' - and their shifts along the spectrum. The image of barcodes carries us on to the
very different, but equally intriguing, realms of sound ('Barcodes on the Air'); and then DNA fingerprinting ('Barcodes at the Bar'), which offers
the opportunity to reflect on other aspects of the role of science in society.
In what I call the Delusion section of the book, 'Hoodwink'd with Faery Fancy' and 'Unweaving the Uncanny', I turn to those ordinary superstitious folk who, less exalted than poets defending rainbows, revel in mystery and feel cheated if it is explained. They are the ones who love a good ghost story, whose mind leaps to poltergeists or miracles whenever something even faintly odd happens. They never lose an opportunity to quote Hamlet's
There are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy.
and the scientist's response ('Yes, but we're working on it') strikes no chord with them. For them, to explain away a good mystery is to be a killjoy, just as some Romantic poets thought about Newton's explaining of the rainbow.
Michael Shermer, editor of Skeptic magazine, tells a salutary story of an occasion when he publicly debunked a famous television spiritualist. The man was doing ordinary conjuring tricks and duping people into thinking he was communicating with dead spirits. But instead of being hostile to the now-unmasked charlatan, the audience turned on the debunker and supported a woman who accused him of 'inappropriate' behaviour because he destroyed people's illusions. You'd think she'd have been grateful for having the wool pulled off her eyes, but apparently she preferred it firmly over them. I believe that an orderly universe, one indifferent to human preoccupations, in which everything has an explanation even if we still have a long way to go before we find it, is a more beautiful, more wonderful place than a universe tricked out with capricious, ad hoc magic.
Paranormalism could be called an abuse of the legitimate sense of poetic wonder which true science ought to be feeding. A different threat comes from what may be called bad poetry. The chapter on 'Huge Cloudy Symbols of a High Romance' warns against seduction by bad poetic science; against the allure of misleading rhetoric. By way of example, I look at a particular contributor to my own field whose imaginative writing has given him a disproportionate - and I believe unfortunate - influence on American understanding of evolution. But the dominant thrust of the book is in favour of good poetic science, by which I don't, of course, mean science written in verse but science inspired by a poetic sense of wonder.
The last four chapters attempt, with respect to four different but interrelated topics, to hint at what might be done by poetically inspired scientists more talented than I am. Genes, however 'selfish', must also be 'cooperative' - in an Adam Smithian sense (which is why the chapter 'The Selfish Co-operator' opens with a quotation from Adam Smith, though admittedly not on this topic but on wonder itself). The genes of a species can be thought of as a description of ancestral worlds, a 'Genetic Book of the Dead'. In a similar way, the brain 'reweaves the world', constructing a kind of 'virtual reality' continuously updated in the head. In 'The Balloon of the Mind' I speculate on the origins of our own species' most unique features and return, finally, to wonder at the poetic impulse itself and the part it may have played in our evolution.
Computer software is driving a new renaissance, and some of its creative geniuses are benefactors and simultaneously renaissance men in their
own right. In 1995, Charles Simonyi of Microsoft endowed a new professorship of Public Understanding of Science at the University of Oxford, and I was appointed its first holder. I am grateful to Dr Simonyi, most obviously for his far-sighted generosity towards a university with which he had no previous connection, but also for his imaginative vision of science and how it should be communicated. This was beautifully expressed in his written statement to the Oxford of the future (his endowment is in perpetuity, yet he characteristically eschews the wary meanness of lawyer language) and we have discussed these matters from time to time since becoming friends after my appointment. Unweaving the Rainbow could be seen as my contribution to the conversation, and as my inaugural statement as Simonyi Professor. And if 'inaugural' sounds a little unbecoming after two years in the job, I may perhaps take a liberty and quote Keats again:
By this, friend Charles, you may full plainly see Why I have never penn'd a line to thee: Because my thoughts were never free, and clear, And little fit to please a classic ear.
Nevertheless, it is in the nature of a book that it takes longer to produce than a newspaper article or a lecture. During its gestation this one has spun off a few of both, and broadcasts as well. I must acknowledge these now, in case any readers recognize the odd paragraph here and there. I first publicly used the title 'Unweaving the Rainbow', and the theme of Keats's irreverence towards Newton, when I was invited to give the C. P. Snow Lecture for 1997 by Christ's College, Cambridge, Snow's old college. Although I have not explicitly taken up his theme of The Two Cultures, it is obviously relevant. Even more so is The Third Culture of John Brockman, who has been helpful, too, in a quite different role, as my literary agent. The subtitle 'Science, Delusion and the Appetite for Wonder' was the title of my Richard Dimbleby Lecture, 1996. Some paragraphs from an earlier draft of this book appeared in that BBC televised lecture. Also in 1996, I presented a one-hour television documentary on Channel Four, Break the Science Barrier. This was on the theme of science in the culture, and some of the background ideas, developed in discussions with John Gau, the producer, and Simon Raikes, the director, have influenced this book. In 1998 I incorporated some passages of the book in my lecture in the Sounding the Century series broadcast by BBC Radio 3 from the Queen Elizabeth Hall, London. (I thank my wife for my lecture's title, 'Science and Sensibility', and don't quite know what to make of the fact that it has already been plagiarized in, of all places, a supermarket magazine. ) I also have used paragraphs from the book in articles commissioned by the Independent, the Sunday Times and the Observer. When I was honoured with the 1997 International Cosmos Prize, I chose the title 'The Selfish Cooperator' for my prize lecture, given in both Tokyo and Osaka. Parts of the lecture
have been reworked and expanded in chapter 9, which has the same title. Parts of chapter 1 appeared in my Royal Institution Christmas Lectures.
The book has benefited greatly from constructive criticisms of an earlier draft by Michael Rodgers, John Catalano and Lord Birkett. Michael Birkett has become my ideal intelligent layman. His scholarly wit makes his critical comments a pleasure to read in their own right. Michael Rodgers was the editor of my first three books and, by my wish and his generosity, he has also played an important role in the last three as well.
I would like to thank John Catalano, not just for his helpful comments
on the book but for http://www. spacelab. net/~catalj/home. html, whose excellence - which has nothing whatever to do with me - will be apparent to all who go there. Stefan McGrath and John Radziewicz, editors at Penguin and Houghton Mifflin respectively, gave patient encouragement and literate advice which I greatly valued. Sally Holloway worked
tirelessly and cheerfully on the final copy-editing. Thanks also to Ingrid Thomas, Bridget Muskett, James Randi, Nicholas Davies, Daniel Dennett, Mark Ridley, Alan Grafen, Juliet Dawkins, Anthony Nuttall and John Batchelor.
My wife, Lalla Ward, has criticized every chapter a dozen times in various drafts, and with every reading I have benefited from her sensitive actor's ear for language and its cadences. Whenever I had doubts, she believed in the book. Her vision held it together, and I wouldn't have finished it without her help and encouragement. I dedicate it to her.
1
THE ANAESTHETIC OF FAMILIARITY
To live at all is miracle enough.
MERVYN PEAKE, The Glassblower (1950)
We are going to die, and that makes us the lucky ones. Most people are never going to die because they are never going to be born. The potential people who could have been here in my place but who will in fact never see the light of day outnumber the sand grains of Arabia. Certainly those unborn ghosts include greater poets than Keats, scientists greater than Newton. We know this because the set of possible people allowed by our DNA so massively exceeds the set of actual people. In the teeth of these stupefying odds it is you and I, in our ordinariness, that are here.
Moralists and theologians place great weight upon the moment of conception, seeing it as the instant at which the soul comes into existence. If, like me, you are unmoved by such talk, you still must
regard a particular instant, nine months before your birth, as the most decisive event in your personal fortunes. It is the moment at which your consciousness suddenly became trillions of times more foreseeable than it was a split second before. To be sure, the embryonic you that came into existence still had plenty of hurdles to leap. Most conceptuses end in early abortion before their mother even knew they were there, and we are all lucky not to have done so. Also, there is more to personal identity than genes, as identical twins (who separate after the moment of fertilization) show us. Nevertheless, the instant at which a particular spermatozoon penetrated a particular egg was, in your private hindsight, a moment of dizzying singularity. It was then that the odds against your becoming a person dropped from astronomical to single figures.
The lottery starts before we are conceived. Your parents had to meet, and the conception of each was as improbable as your own. And so on back, through your four grandparents and eight great grandparents, back to where it doesn't bear thinking about. Desmond Morris opens his autobiography, Animal Days (1979), in characteristically arresting vein:
Napoleon started it all. If it weren't for him, I might not be sitting here now writing these words . . . for it was one of his cannonballs, fired in the Peninsular War, that shot off the arm of my great-great grandfather, James Morris, and altered the whole course of my family history.
Morris tells how his ancestor's enforced change of career had various knock-on effects culminating in his own interest in natural history. But he really needn't have bothered. There's no 'might' about it. Of course he owes his very existence to Napoleon. So do I and so do you. Napoleon didn't have to shoot off James Morris's arm in order to seal young Desmond's fate, and yours and mine, too. Not just Napoleon but the humblest medieval peasant had only to sneeze in order to affect something which changed something else which, after a long chain reaction, led to the consequence that one of your would-be ancestors failed to be your ancestor and became somebody else's instead. I'm not talking about 'chaos theory', or the equally trendy 'complexity theory', but just about the ordinary statistics of causation. The thread of historical events by which our existence hangs is wincingly tenuous.
When compared with the stretch of time unknown to us, O king, the present life of men on earth is like the flight of a single sparrow through the hall where, in winter, you sit with your captains and ministers. Entering at one door and leaving by another, while it is inside it is untouched by the wintry storm; but this brief interval of calm is over in a moment, and it returns to the winter whence it came, vanishing from your sight Man's life is similar-, and of what follows it, or what went before, we are utterly ignorant.
THE VENERABLE BEDE, A History of the English Church and People (731)
This is another respect in which we are lucky. The universe is older than a hundred million centuries. Within a comparable time the sun will swell to a red giant and engulf the earth. Every century of hundreds of millions has been in its time, or will be when its time comes, 'the present century'. Interestingly, some physicists don't like the idea of a 'moving present', regarding it as a subjective phenomenon for which they find no house room in their equations. But it is a subjective argument I am making. How it feels to me, and I guess to you as well, is that the present moves from the past to the future, like a tiny spotlight, inching its way along a gigantic ruler of time. Everything behind the spotlight is in darkness, the darkness of the dead past. Everything ahead of the spotlight is in the darkness of the unknown future. The odds of your century being the one in the spotlight are the same as the odds that a penny, tossed down at random, will land on a particular ant crawling somewhere along the road from New York to San Francisco. In other words, it is overwhelmingly probable that you are dead.
In spite of these odds, you will notice that you are, as a matter of fact, alive. People whom the spotlight has already passed over, and people whom the spotlight has not reached, are in no position to read a book. I am equally lucky to be in a position to write one, although I may not be when you read these words. Indeed, I rather hope that I shall be dead when you do. Don't misunderstand me. I love life and hope to go on for a long time yet, but any author wants his works to reach the largest possible readership. Since the total future population is likely to outnumber my contemporaries by a large margin, I cannot but aspire to be dead when you see these words. Facetiously seen, it turns out to be no more than a hope that my book will not soon go out of print. But what I see as I write is that I am lucky to be alive and so are you.
We live on a planet that is all but perfect for our kind of life: not too warm and not too cold, basking in kindly sunshine, softly watered; a gently spinning, green and gold harvest festival of a planet. Yes, and alas, there are deserts and slums; there is starvation and racking misery to be found. But take a look at the competition. Compared with most planets this is paradise, and parts of earth are still paradise by any standards. What are the odds that a planet picked at random would have these complaisant properties? Even the most optimistic calculation would put it at less than one in a million.
Imagine a spaceship full of sleeping explorers, deep-frozen would-be colonists of some distant world. Perhaps the ship is on a forlorn mission
to save the species before an unstoppable comet, like the one that killed the dinosaurs, hits the home planet. The voyagers go into the deep-freeze soberly reckoning the odds against their spaceship's ever chancing upon a planet friendly to life. If one in a million planets is suitable at best, and it takes centuries to travel from each star to the next, the spaceship is pathetically unlikely to find a tolerable, let alone safe, haven for its sleeping cargo.
But imagine that the ship's robot pilot turns out to be unthinkably lucky. After millions of years the ship does find a planet capable of sustaining life: a planet of equable temperature, bathed in warm starshine, refreshed by oxygen and water. The passengers, Rip van Winkles, wake stumbling into the light. After a million years of sleep, here is a whole new fertile globe, a lush planet of warm pastures, sparkling streams and waterfalls, a world bountiful with creatures, darting through alien green felicity. Our travellers walk entranced, stupefied, unable to believe their unaccustomed senses or their luck.
As I said, the story asks for too much luck; it would never happen. And yet, isn't that what has happened to each one of us? We have woken after hundreds of millions of years asleep, defying astronomical odds. Admittedly we didn't arrive by spaceship, we arrived by being born, and we didn't burst conscious into the world but accumulated awareness gradually through babyhood. The fact that we slowly apprehend our world, rather than suddenly discover it, should not subtract from its wonder.
Of course I am playing tricks with the idea of luck, putting the cart before the horse. It is no accident that our kind of life finds itself on a planet whose temperature, rainfall and everything else are exactly right. If the planet were suitable for another kind of life, it is that other kind of life that would have evolved here. But we as individuals are still hugely blessed. Privileged, and not just privileged to enjoy our planet. More, we are granted the opportunity to understand why our eyes are open, and why they see what they do, in the short time before they close for ever.
Here, it seems to me, lies the best answer to those petty-minded Scrooges who are always asking what is the use of science. In one of those mythic remarks of uncertain authorship, Michael Faraday is alleged to have been asked what was the use of science. 'Sir,' Faraday replied. 'Of what use is a new-born child? ' The obvious thing for Faraday (or Benjamin Franklin, or whoever it was) to have meant was that a baby might be no use for anything at present, but it has great potential for the future. I now like to think that he meant something else, too: What is the use of bringing a baby into the world if the only thing it does with its life is just work to go on living? If everything is judged by how 'useful' it is - useful
for staying alive, that is - we are left facing a futile circularity. There must be some added value. At least a part of life should be devoted to living that life, not just working to stop it ending. This is how we rightly justify spending taxpayers' money on the arts. It is one of the justifications properly offered for conserving rare species and beautiful buildings. It is how we answer those barbarians who think that wild elephants and historic houses should be preserved only if they 'pay their way'. And science is the same. Of course science pays its way; of course it is useful. But that is not all it is.
After sleeping through a hundred million centuries we have finally opened our eyes on a sumptuous planet, sparkling with colour, bountiful with life. Within decades we must close our eyes again. Isn't it a noble, an enlightened way of spending our brief time in the sun, to work at understanding the universe and how we have come to wake up in it? This is how I answer when I am asked - as I am surprisingly often - why I bother to get up in the mornings. To put it the other way round, isn't it sad to go to your grave without ever wondering why you were born? Who, with such a thought, would not spring from bed, eager to resume discovering the world and rejoicing to be a part of it?
The poet Kathleen Raine, who read Natural Sciences at Cambridge, specializing in Biology, found related solace as a young woman unhappy in love and desperate for relief from heartbreak:
Then the sky spoke to me in language clear, familiar as the heart, than love more near. The sky said to my soul, 'You have what you desire!
'Know now that you are born along with these clouds, winds, and stars, and ever-moving seas and forest dwellers. This your nature is.
'Lift up your heart again without fear, sleep in the tomb, or breathe the living air, this world you with the flower and with the tiger share. '
'Passion' (1943)
There is an anaesthetic of familiarity, a sedative of ordinariness, which dulls the senses and hides the wonder of existence. For those of us not gifted in poetry, it is at least worth while from time to time making an effort to shake off the anaesthetic. What is the best way of countering the sluggish habituation brought about by our gradual crawl from babyhood? We can't actually fly to another planet. But we can recapture that sense
of having just tumbled out to life on a new world by looking at our own world in unfamiliar ways. It's tempting to use an easy example like a rose or a butterfly, but let's go straight for the alien deep end. I remember attending a lecture, years ago, by a biologist working on octopuses, and
their relatives the squids and cuttlefish. He began by explaining his fascination with these animals. 'You see,' he said, 'they are the Martians. ' Have you ever watched a squid change colour?
Television images are sometimes displayed on giant LED (Light Emitting Diode) hoardings. Instead of a fluorescent screen with an electron beam scanning side to side over it, the LED screen is a large array of tiny glowing lights, independently controllable. The lights are individually brightened or dimmed so that, from a distance, the whole matrix shimmers with moving pictures. The skin of a squid behaves like an LED screen. Instead of lights, squid skin is packed with thousands of tiny bags filled with ink. Each of these ink bags has miniature private muscles to squeeze it. With a puppet string leading to each one of these separate muscles, the squid's nervous system can control the shape, and hence the visibility, of each ink sac.
' In theory, if you wire-tapped the nerves leading to the separate ink pixels and stimulated them electrically via a computer, you could play out Charlie Chaplin movies on the squid's skin. The squid doesn't do that, but its brain does control the wires with precision and speed, and the skinflicks that it shows are spectacular. Waves of colour chase across the surface like clouds in a speeded-up film; ripples and eddies race over the living screen. The animal signals its changing emotions in quick time: dark brown one second, blanching ghostly white the next, rapidly modulating interwoven patterns of stipples and stripes. When it comes to changing colour, by comparison chameleons are amateurs at the game.
The American neurobiologist William Calvin is one of those thinking hard today about what thinking itself really is. He emphasizes, as others have done before, the idea that thoughts do not reside in particular places in the brain but are shifting patterns of activity over its surface, units which recruit neighbouring units into populations becoming the same thought, competing in Darwinian fashion with rival populations thinking alternative thoughts. We don't see these shifting patterns, but presumably we would if neurones lit up when active. The cortex of the brain, I realize, might then look like a squid's body surface. Does a squid think with its skin? When a squid suddenly changes its colour pattern, we suppose it to be a manifestation of mood change, for signalling to another squid. A shift in colour announces that the squid has switched from an aggressive mood, say, to a fearful one. It is natural to presume that the change in mood took place in the brain, and caused the change in colour as a visible manifestation of internal thoughts, rendered external for purposes of communication.
SCIENCE, DELUSION AND THE APPETITE FOR WONDER.
'The product of a beguiling and fascinating mind and one generous enough to attempt to include all willing readers in its brilliantly informed enthusiasm'
MELVYN BRAGG, OBSERVER
Keats accused Newton of destroying the poetry of the rainbow by explaining the origin of its colours, thus dispelling its mystery. In this illuminating and provocative book, Richard Dawkins argues that Keats could not have been more mistaken and shows how an understanding of science inspires the human imagination and enhances our wonder of the world.
'A brilliant assertion of the wonder and excitement of real, tough, grown- up science'
A. S. BYATT, DAILY TELEGRAPH, BOOKS OF THE YEAR
'The way Dawkins writes about science is not just a brain-tonic.
It is more like an extended stay on a brain health-farm . . . You come out feeling lean, tuned and enormously more intelligent'
JOHN CAREY, SUNDAY TIMES
'For Dawkins there is more poetry, not less, in the rainbow- because of Newton
,. . Warming to his theme, he weaves rainbows of wonder from other provinces of science . . . and then unleashes his fury on those who accuse scientists like him of being unimaginative for not believing in horoscopes, telepathy, ghosts and gods'
MATT RIDLEY, SUNDAY TELEGRAPH
'Beautifully written and full of interesting, original ideas. Essential reading, for those who care about science'
LEWIS WOLPERT, THE TIMES
PREFACE
A foreign publisher of my first book confessed that he could not sleep for three nights after reading it, so troubled was he by what he saw as its cold, bleak message. Others have asked me how I can bear to get up in the mornings. A teacher from a distant country wrote to me reproachfully that a pupil had come to him in tears after reading the same book, because it had persuaded her that life was empty and purposeless. He advised her not to show the book to any of her friends, for fear of contaminating them with the same nihilistic pessimism. Similar accusations of barren desolation, of promoting an arid and joyless message, are frequently flung at science in general, and it is easy for scientists to play up to them. My colleague Peter Atkins begins his book The Second Law (1984) in this vein:
We are the children of chaos, and the deep structure of change is decay. At root, there is only corruption, and the unstemmable tide of chaos. Gone is purpose; all that is left is direction. this is the bleakness we have to accept as we peer deeply and dispassionately into the heart of the Universe.
But such very proper purging of saccharine false purpose; such laudable tough-mindedness in the debunking of cosmic sentimentality must not
be confused with a loss of personal hope. Presumably there is indeed no purpose in the ultimate fate of the cosmos, but do any of us really tie our life's hopes to the ultimate fate of the cosmos anyway? Of course we don't; not if we are sane. Our lives are ruled by all sorts of closer, warmer, human ambitions and perceptions. To accuse science of robbing life of
the warmth that makes it worth living is so preposterously mistaken, so diametrically opposite to my own feelings and those of most working
scientists, I am almost driven to the despair of which I am wrongly suspected. But in this book I shall try a more positive response, appealing to the sense of wonder in science because it is so sad to think what these complainers and naysayers are missing. This is one of the things that the late Carl Sagan did so well, and for which he is sadly missed. The feeling of awed wonder that science can give us is one of the highest experiences of which the human psyche is capable. It is a deep aesthetic passion to rank with the finest that music and poetry can deliver. It is truly one of the things that makes life worth living and it does so, if anything, more effectively if it convinces us that the time we have for living it is finite.
My title is from Keats, who believed that Newton had destroyed all the poetry of the rainbow by reducing it to the prismatic colours. Keats could hardly have been more wrong, and my aim is to guide all who are tempted by a similar view towards the opposite conclusion. Science is, or ought to be, the inspiration for great poetry, but I do not have the talent to clinch the argument by demonstration and must depend, instead, on more prosaic persuasion. A couple of the chapter titles are borrowed from Keats; readers may also spot the occasional half-quotation or allusion lacing the text from him (as well as others). They are there as a tribute to his sensitive genius. Keats was a more likeable character than Newton and his shade was one of the imaginary referees looking over my shoulder as I wrote.
Newton's unweaving of the rainbow led on to spectroscopy, which has proved the key to much of what we know today about the cosmos. And the heart of any poet worthy of the title Romantic could not fail to leap
up if he beheld the universe of Einstein, Hubble and Hawking. We read
its nature through Fraunhofer lines - 'Barcodes in the Stars' - and their shifts along the spectrum. The image of barcodes carries us on to the
very different, but equally intriguing, realms of sound ('Barcodes on the Air'); and then DNA fingerprinting ('Barcodes at the Bar'), which offers
the opportunity to reflect on other aspects of the role of science in society.
In what I call the Delusion section of the book, 'Hoodwink'd with Faery Fancy' and 'Unweaving the Uncanny', I turn to those ordinary superstitious folk who, less exalted than poets defending rainbows, revel in mystery and feel cheated if it is explained. They are the ones who love a good ghost story, whose mind leaps to poltergeists or miracles whenever something even faintly odd happens. They never lose an opportunity to quote Hamlet's
There are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy.
and the scientist's response ('Yes, but we're working on it') strikes no chord with them. For them, to explain away a good mystery is to be a killjoy, just as some Romantic poets thought about Newton's explaining of the rainbow.
Michael Shermer, editor of Skeptic magazine, tells a salutary story of an occasion when he publicly debunked a famous television spiritualist. The man was doing ordinary conjuring tricks and duping people into thinking he was communicating with dead spirits. But instead of being hostile to the now-unmasked charlatan, the audience turned on the debunker and supported a woman who accused him of 'inappropriate' behaviour because he destroyed people's illusions. You'd think she'd have been grateful for having the wool pulled off her eyes, but apparently she preferred it firmly over them. I believe that an orderly universe, one indifferent to human preoccupations, in which everything has an explanation even if we still have a long way to go before we find it, is a more beautiful, more wonderful place than a universe tricked out with capricious, ad hoc magic.
Paranormalism could be called an abuse of the legitimate sense of poetic wonder which true science ought to be feeding. A different threat comes from what may be called bad poetry. The chapter on 'Huge Cloudy Symbols of a High Romance' warns against seduction by bad poetic science; against the allure of misleading rhetoric. By way of example, I look at a particular contributor to my own field whose imaginative writing has given him a disproportionate - and I believe unfortunate - influence on American understanding of evolution. But the dominant thrust of the book is in favour of good poetic science, by which I don't, of course, mean science written in verse but science inspired by a poetic sense of wonder.
The last four chapters attempt, with respect to four different but interrelated topics, to hint at what might be done by poetically inspired scientists more talented than I am. Genes, however 'selfish', must also be 'cooperative' - in an Adam Smithian sense (which is why the chapter 'The Selfish Co-operator' opens with a quotation from Adam Smith, though admittedly not on this topic but on wonder itself). The genes of a species can be thought of as a description of ancestral worlds, a 'Genetic Book of the Dead'. In a similar way, the brain 'reweaves the world', constructing a kind of 'virtual reality' continuously updated in the head. In 'The Balloon of the Mind' I speculate on the origins of our own species' most unique features and return, finally, to wonder at the poetic impulse itself and the part it may have played in our evolution.
Computer software is driving a new renaissance, and some of its creative geniuses are benefactors and simultaneously renaissance men in their
own right. In 1995, Charles Simonyi of Microsoft endowed a new professorship of Public Understanding of Science at the University of Oxford, and I was appointed its first holder. I am grateful to Dr Simonyi, most obviously for his far-sighted generosity towards a university with which he had no previous connection, but also for his imaginative vision of science and how it should be communicated. This was beautifully expressed in his written statement to the Oxford of the future (his endowment is in perpetuity, yet he characteristically eschews the wary meanness of lawyer language) and we have discussed these matters from time to time since becoming friends after my appointment. Unweaving the Rainbow could be seen as my contribution to the conversation, and as my inaugural statement as Simonyi Professor. And if 'inaugural' sounds a little unbecoming after two years in the job, I may perhaps take a liberty and quote Keats again:
By this, friend Charles, you may full plainly see Why I have never penn'd a line to thee: Because my thoughts were never free, and clear, And little fit to please a classic ear.
Nevertheless, it is in the nature of a book that it takes longer to produce than a newspaper article or a lecture. During its gestation this one has spun off a few of both, and broadcasts as well. I must acknowledge these now, in case any readers recognize the odd paragraph here and there. I first publicly used the title 'Unweaving the Rainbow', and the theme of Keats's irreverence towards Newton, when I was invited to give the C. P. Snow Lecture for 1997 by Christ's College, Cambridge, Snow's old college. Although I have not explicitly taken up his theme of The Two Cultures, it is obviously relevant. Even more so is The Third Culture of John Brockman, who has been helpful, too, in a quite different role, as my literary agent. The subtitle 'Science, Delusion and the Appetite for Wonder' was the title of my Richard Dimbleby Lecture, 1996. Some paragraphs from an earlier draft of this book appeared in that BBC televised lecture. Also in 1996, I presented a one-hour television documentary on Channel Four, Break the Science Barrier. This was on the theme of science in the culture, and some of the background ideas, developed in discussions with John Gau, the producer, and Simon Raikes, the director, have influenced this book. In 1998 I incorporated some passages of the book in my lecture in the Sounding the Century series broadcast by BBC Radio 3 from the Queen Elizabeth Hall, London. (I thank my wife for my lecture's title, 'Science and Sensibility', and don't quite know what to make of the fact that it has already been plagiarized in, of all places, a supermarket magazine. ) I also have used paragraphs from the book in articles commissioned by the Independent, the Sunday Times and the Observer. When I was honoured with the 1997 International Cosmos Prize, I chose the title 'The Selfish Cooperator' for my prize lecture, given in both Tokyo and Osaka. Parts of the lecture
have been reworked and expanded in chapter 9, which has the same title. Parts of chapter 1 appeared in my Royal Institution Christmas Lectures.
The book has benefited greatly from constructive criticisms of an earlier draft by Michael Rodgers, John Catalano and Lord Birkett. Michael Birkett has become my ideal intelligent layman. His scholarly wit makes his critical comments a pleasure to read in their own right. Michael Rodgers was the editor of my first three books and, by my wish and his generosity, he has also played an important role in the last three as well.
I would like to thank John Catalano, not just for his helpful comments
on the book but for http://www. spacelab. net/~catalj/home. html, whose excellence - which has nothing whatever to do with me - will be apparent to all who go there. Stefan McGrath and John Radziewicz, editors at Penguin and Houghton Mifflin respectively, gave patient encouragement and literate advice which I greatly valued. Sally Holloway worked
tirelessly and cheerfully on the final copy-editing. Thanks also to Ingrid Thomas, Bridget Muskett, James Randi, Nicholas Davies, Daniel Dennett, Mark Ridley, Alan Grafen, Juliet Dawkins, Anthony Nuttall and John Batchelor.
My wife, Lalla Ward, has criticized every chapter a dozen times in various drafts, and with every reading I have benefited from her sensitive actor's ear for language and its cadences. Whenever I had doubts, she believed in the book. Her vision held it together, and I wouldn't have finished it without her help and encouragement. I dedicate it to her.
1
THE ANAESTHETIC OF FAMILIARITY
To live at all is miracle enough.
MERVYN PEAKE, The Glassblower (1950)
We are going to die, and that makes us the lucky ones. Most people are never going to die because they are never going to be born. The potential people who could have been here in my place but who will in fact never see the light of day outnumber the sand grains of Arabia. Certainly those unborn ghosts include greater poets than Keats, scientists greater than Newton. We know this because the set of possible people allowed by our DNA so massively exceeds the set of actual people. In the teeth of these stupefying odds it is you and I, in our ordinariness, that are here.
Moralists and theologians place great weight upon the moment of conception, seeing it as the instant at which the soul comes into existence. If, like me, you are unmoved by such talk, you still must
regard a particular instant, nine months before your birth, as the most decisive event in your personal fortunes. It is the moment at which your consciousness suddenly became trillions of times more foreseeable than it was a split second before. To be sure, the embryonic you that came into existence still had plenty of hurdles to leap. Most conceptuses end in early abortion before their mother even knew they were there, and we are all lucky not to have done so. Also, there is more to personal identity than genes, as identical twins (who separate after the moment of fertilization) show us. Nevertheless, the instant at which a particular spermatozoon penetrated a particular egg was, in your private hindsight, a moment of dizzying singularity. It was then that the odds against your becoming a person dropped from astronomical to single figures.
The lottery starts before we are conceived. Your parents had to meet, and the conception of each was as improbable as your own. And so on back, through your four grandparents and eight great grandparents, back to where it doesn't bear thinking about. Desmond Morris opens his autobiography, Animal Days (1979), in characteristically arresting vein:
Napoleon started it all. If it weren't for him, I might not be sitting here now writing these words . . . for it was one of his cannonballs, fired in the Peninsular War, that shot off the arm of my great-great grandfather, James Morris, and altered the whole course of my family history.
Morris tells how his ancestor's enforced change of career had various knock-on effects culminating in his own interest in natural history. But he really needn't have bothered. There's no 'might' about it. Of course he owes his very existence to Napoleon. So do I and so do you. Napoleon didn't have to shoot off James Morris's arm in order to seal young Desmond's fate, and yours and mine, too. Not just Napoleon but the humblest medieval peasant had only to sneeze in order to affect something which changed something else which, after a long chain reaction, led to the consequence that one of your would-be ancestors failed to be your ancestor and became somebody else's instead. I'm not talking about 'chaos theory', or the equally trendy 'complexity theory', but just about the ordinary statistics of causation. The thread of historical events by which our existence hangs is wincingly tenuous.
When compared with the stretch of time unknown to us, O king, the present life of men on earth is like the flight of a single sparrow through the hall where, in winter, you sit with your captains and ministers. Entering at one door and leaving by another, while it is inside it is untouched by the wintry storm; but this brief interval of calm is over in a moment, and it returns to the winter whence it came, vanishing from your sight Man's life is similar-, and of what follows it, or what went before, we are utterly ignorant.
THE VENERABLE BEDE, A History of the English Church and People (731)
This is another respect in which we are lucky. The universe is older than a hundred million centuries. Within a comparable time the sun will swell to a red giant and engulf the earth. Every century of hundreds of millions has been in its time, or will be when its time comes, 'the present century'. Interestingly, some physicists don't like the idea of a 'moving present', regarding it as a subjective phenomenon for which they find no house room in their equations. But it is a subjective argument I am making. How it feels to me, and I guess to you as well, is that the present moves from the past to the future, like a tiny spotlight, inching its way along a gigantic ruler of time. Everything behind the spotlight is in darkness, the darkness of the dead past. Everything ahead of the spotlight is in the darkness of the unknown future. The odds of your century being the one in the spotlight are the same as the odds that a penny, tossed down at random, will land on a particular ant crawling somewhere along the road from New York to San Francisco. In other words, it is overwhelmingly probable that you are dead.
In spite of these odds, you will notice that you are, as a matter of fact, alive. People whom the spotlight has already passed over, and people whom the spotlight has not reached, are in no position to read a book. I am equally lucky to be in a position to write one, although I may not be when you read these words. Indeed, I rather hope that I shall be dead when you do. Don't misunderstand me. I love life and hope to go on for a long time yet, but any author wants his works to reach the largest possible readership. Since the total future population is likely to outnumber my contemporaries by a large margin, I cannot but aspire to be dead when you see these words. Facetiously seen, it turns out to be no more than a hope that my book will not soon go out of print. But what I see as I write is that I am lucky to be alive and so are you.
We live on a planet that is all but perfect for our kind of life: not too warm and not too cold, basking in kindly sunshine, softly watered; a gently spinning, green and gold harvest festival of a planet. Yes, and alas, there are deserts and slums; there is starvation and racking misery to be found. But take a look at the competition. Compared with most planets this is paradise, and parts of earth are still paradise by any standards. What are the odds that a planet picked at random would have these complaisant properties? Even the most optimistic calculation would put it at less than one in a million.
Imagine a spaceship full of sleeping explorers, deep-frozen would-be colonists of some distant world. Perhaps the ship is on a forlorn mission
to save the species before an unstoppable comet, like the one that killed the dinosaurs, hits the home planet. The voyagers go into the deep-freeze soberly reckoning the odds against their spaceship's ever chancing upon a planet friendly to life. If one in a million planets is suitable at best, and it takes centuries to travel from each star to the next, the spaceship is pathetically unlikely to find a tolerable, let alone safe, haven for its sleeping cargo.
But imagine that the ship's robot pilot turns out to be unthinkably lucky. After millions of years the ship does find a planet capable of sustaining life: a planet of equable temperature, bathed in warm starshine, refreshed by oxygen and water. The passengers, Rip van Winkles, wake stumbling into the light. After a million years of sleep, here is a whole new fertile globe, a lush planet of warm pastures, sparkling streams and waterfalls, a world bountiful with creatures, darting through alien green felicity. Our travellers walk entranced, stupefied, unable to believe their unaccustomed senses or their luck.
As I said, the story asks for too much luck; it would never happen. And yet, isn't that what has happened to each one of us? We have woken after hundreds of millions of years asleep, defying astronomical odds. Admittedly we didn't arrive by spaceship, we arrived by being born, and we didn't burst conscious into the world but accumulated awareness gradually through babyhood. The fact that we slowly apprehend our world, rather than suddenly discover it, should not subtract from its wonder.
Of course I am playing tricks with the idea of luck, putting the cart before the horse. It is no accident that our kind of life finds itself on a planet whose temperature, rainfall and everything else are exactly right. If the planet were suitable for another kind of life, it is that other kind of life that would have evolved here. But we as individuals are still hugely blessed. Privileged, and not just privileged to enjoy our planet. More, we are granted the opportunity to understand why our eyes are open, and why they see what they do, in the short time before they close for ever.
Here, it seems to me, lies the best answer to those petty-minded Scrooges who are always asking what is the use of science. In one of those mythic remarks of uncertain authorship, Michael Faraday is alleged to have been asked what was the use of science. 'Sir,' Faraday replied. 'Of what use is a new-born child? ' The obvious thing for Faraday (or Benjamin Franklin, or whoever it was) to have meant was that a baby might be no use for anything at present, but it has great potential for the future. I now like to think that he meant something else, too: What is the use of bringing a baby into the world if the only thing it does with its life is just work to go on living? If everything is judged by how 'useful' it is - useful
for staying alive, that is - we are left facing a futile circularity. There must be some added value. At least a part of life should be devoted to living that life, not just working to stop it ending. This is how we rightly justify spending taxpayers' money on the arts. It is one of the justifications properly offered for conserving rare species and beautiful buildings. It is how we answer those barbarians who think that wild elephants and historic houses should be preserved only if they 'pay their way'. And science is the same. Of course science pays its way; of course it is useful. But that is not all it is.
After sleeping through a hundred million centuries we have finally opened our eyes on a sumptuous planet, sparkling with colour, bountiful with life. Within decades we must close our eyes again.
They are there as a tribute to his sensitive genius. Keats was a more likeable character than Newton and his shade was one of the imaginary referees looking over my shoulder as I wrote.
Newton's unweaving of the rainbow led on to spectroscopy, which has proved the key to much of what we know today about the cosmos. And the heart of any poet worthy of the title Romantic could not fail to leap
up if he beheld the universe of Einstein, Hubble and Hawking. We read
its nature through Fraunhofer lines - 'Barcodes in the Stars' - and their shifts along the spectrum. The image of barcodes carries us on to the
very different, but equally intriguing, realms of sound ('Barcodes on the Air'); and then DNA fingerprinting ('Barcodes at the Bar'), which offers
the opportunity to reflect on other aspects of the role of science in society.
In what I call the Delusion section of the book, 'Hoodwink'd with Faery Fancy' and 'Unweaving the Uncanny', I turn to those ordinary superstitious folk who, less exalted than poets defending rainbows, revel in mystery and feel cheated if it is explained. They are the ones who love a good ghost story, whose mind leaps to poltergeists or miracles whenever something even faintly odd happens. They never lose an opportunity to quote Hamlet's
There are more things in heaven and earth, Horatio, Than are dreamt of in your philosophy.
and the scientist's response ('Yes, but we're working on it') strikes no chord with them. For them, to explain away a good mystery is to be a killjoy, just as some Romantic poets thought about Newton's explaining of the rainbow.
Michael Shermer, editor of Skeptic magazine, tells a salutary story of an occasion when he publicly debunked a famous television spiritualist. The man was doing ordinary conjuring tricks and duping people into thinking he was communicating with dead spirits. But instead of being hostile to the now-unmasked charlatan, the audience turned on the debunker and supported a woman who accused him of 'inappropriate' behaviour because he destroyed people's illusions. You'd think she'd have been grateful for having the wool pulled off her eyes, but apparently she preferred it firmly over them. I believe that an orderly universe, one indifferent to human preoccupations, in which everything has an explanation even if we still have a long way to go before we find it, is a more beautiful, more wonderful place than a universe tricked out with capricious, ad hoc magic.
Paranormalism could be called an abuse of the legitimate sense of poetic wonder which true science ought to be feeding. A different threat comes from what may be called bad poetry. The chapter on 'Huge Cloudy Symbols of a High Romance' warns against seduction by bad poetic science; against the allure of misleading rhetoric. By way of example, I look at a particular contributor to my own field whose imaginative writing has given him a disproportionate - and I believe unfortunate - influence on American understanding of evolution. But the dominant thrust of the book is in favour of good poetic science, by which I don't, of course, mean science written in verse but science inspired by a poetic sense of wonder.
The last four chapters attempt, with respect to four different but interrelated topics, to hint at what might be done by poetically inspired scientists more talented than I am. Genes, however 'selfish', must also be 'cooperative' - in an Adam Smithian sense (which is why the chapter 'The Selfish Co-operator' opens with a quotation from Adam Smith, though admittedly not on this topic but on wonder itself). The genes of a species can be thought of as a description of ancestral worlds, a 'Genetic Book of the Dead'. In a similar way, the brain 'reweaves the world', constructing a kind of 'virtual reality' continuously updated in the head. In 'The Balloon of the Mind' I speculate on the origins of our own species' most unique features and return, finally, to wonder at the poetic impulse itself and the part it may have played in our evolution.
Computer software is driving a new renaissance, and some of its creative geniuses are benefactors and simultaneously renaissance men in their
own right. In 1995, Charles Simonyi of Microsoft endowed a new professorship of Public Understanding of Science at the University of Oxford, and I was appointed its first holder. I am grateful to Dr Simonyi, most obviously for his far-sighted generosity towards a university with which he had no previous connection, but also for his imaginative vision of science and how it should be communicated. This was beautifully expressed in his written statement to the Oxford of the future (his endowment is in perpetuity, yet he characteristically eschews the wary meanness of lawyer language) and we have discussed these matters from time to time since becoming friends after my appointment. Unweaving the Rainbow could be seen as my contribution to the conversation, and as my inaugural statement as Simonyi Professor. And if 'inaugural' sounds a little unbecoming after two years in the job, I may perhaps take a liberty and quote Keats again:
By this, friend Charles, you may full plainly see Why I have never penn'd a line to thee: Because my thoughts were never free, and clear, And little fit to please a classic ear.
Nevertheless, it is in the nature of a book that it takes longer to produce than a newspaper article or a lecture. During its gestation this one has spun off a few of both, and broadcasts as well. I must acknowledge these now, in case any readers recognize the odd paragraph here and there. I first publicly used the title 'Unweaving the Rainbow', and the theme of Keats's irreverence towards Newton, when I was invited to give the C. P. Snow Lecture for 1997 by Christ's College, Cambridge, Snow's old college. Although I have not explicitly taken up his theme of The Two Cultures, it is obviously relevant. Even more so is The Third Culture of John Brockman, who has been helpful, too, in a quite different role, as my literary agent. The subtitle 'Science, Delusion and the Appetite for Wonder' was the title of my Richard Dimbleby Lecture, 1996. Some paragraphs from an earlier draft of this book appeared in that BBC televised lecture. Also in 1996, I presented a one-hour television documentary on Channel Four, Break the Science Barrier. This was on the theme of science in the culture, and some of the background ideas, developed in discussions with John Gau, the producer, and Simon Raikes, the director, have influenced this book. In 1998 I incorporated some passages of the book in my lecture in the Sounding the Century series broadcast by BBC Radio 3 from the Queen Elizabeth Hall, London. (I thank my wife for my lecture's title, 'Science and Sensibility', and don't quite know what to make of the fact that it has already been plagiarized in, of all places, a supermarket magazine. ) I also have used paragraphs from the book in articles commissioned by the Independent, the Sunday Times and the Observer. When I was honoured with the 1997 International Cosmos Prize, I chose the title 'The Selfish Cooperator' for my prize lecture, given in both Tokyo and Osaka. Parts of the lecture
have been reworked and expanded in chapter 9, which has the same title. Parts of chapter 1 appeared in my Royal Institution Christmas Lectures.
The book has benefited greatly from constructive criticisms of an earlier draft by Michael Rodgers, John Catalano and Lord Birkett. Michael Birkett has become my ideal intelligent layman. His scholarly wit makes his critical comments a pleasure to read in their own right. Michael Rodgers was the editor of my first three books and, by my wish and his generosity, he has also played an important role in the last three as well.
I would like to thank John Catalano, not just for his helpful comments
on the book but for http://www. spacelab. net/~catalj/home. html, whose excellence - which has nothing whatever to do with me - will be apparent to all who go there. Stefan McGrath and John Radziewicz, editors at Penguin and Houghton Mifflin respectively, gave patient encouragement and literate advice which I greatly valued. Sally Holloway worked
tirelessly and cheerfully on the final copy-editing. Thanks also to Ingrid Thomas, Bridget Muskett, James Randi, Nicholas Davies, Daniel Dennett, Mark Ridley, Alan Grafen, Juliet Dawkins, Anthony Nuttall and John Batchelor.
My wife, Lalla Ward, has criticized every chapter a dozen times in various drafts, and with every reading I have benefited from her sensitive actor's ear for language and its cadences. Whenever I had doubts, she believed in the book. Her vision held it together, and I wouldn't have finished it without her help and encouragement. I dedicate it to her.
1
THE ANAESTHETIC OF FAMILIARITY
To live at all is miracle enough.
MERVYN PEAKE, The Glassblower (1950)
We are going to die, and that makes us the lucky ones. Most people are never going to die because they are never going to be born. The potential people who could have been here in my place but who will in fact never see the light of day outnumber the sand grains of Arabia. Certainly those unborn ghosts include greater poets than Keats, scientists greater than Newton. We know this because the set of possible people allowed by our DNA so massively exceeds the set of actual people. In the teeth of these stupefying odds it is you and I, in our ordinariness, that are here.
Moralists and theologians place great weight upon the moment of conception, seeing it as the instant at which the soul comes into existence. If, like me, you are unmoved by such talk, you still must
regard a particular instant, nine months before your birth, as the most decisive event in your personal fortunes. It is the moment at which your consciousness suddenly became trillions of times more foreseeable than it was a split second before. To be sure, the embryonic you that came into existence still had plenty of hurdles to leap. Most conceptuses end in early abortion before their mother even knew they were there, and we are all lucky not to have done so. Also, there is more to personal identity than genes, as identical twins (who separate after the moment of fertilization) show us. Nevertheless, the instant at which a particular spermatozoon penetrated a particular egg was, in your private hindsight, a moment of dizzying singularity. It was then that the odds against your becoming a person dropped from astronomical to single figures.
The lottery starts before we are conceived. Your parents had to meet, and the conception of each was as improbable as your own. And so on back, through your four grandparents and eight great grandparents, back to where it doesn't bear thinking about. Desmond Morris opens his autobiography, Animal Days (1979), in characteristically arresting vein:
Napoleon started it all. If it weren't for him, I might not be sitting here now writing these words . . . for it was one of his cannonballs, fired in the Peninsular War, that shot off the arm of my great-great grandfather, James Morris, and altered the whole course of my family history.
Morris tells how his ancestor's enforced change of career had various knock-on effects culminating in his own interest in natural history. But he really needn't have bothered. There's no 'might' about it. Of course he owes his very existence to Napoleon. So do I and so do you. Napoleon didn't have to shoot off James Morris's arm in order to seal young Desmond's fate, and yours and mine, too. Not just Napoleon but the humblest medieval peasant had only to sneeze in order to affect something which changed something else which, after a long chain reaction, led to the consequence that one of your would-be ancestors failed to be your ancestor and became somebody else's instead. I'm not talking about 'chaos theory', or the equally trendy 'complexity theory', but just about the ordinary statistics of causation. The thread of historical events by which our existence hangs is wincingly tenuous.
When compared with the stretch of time unknown to us, O king, the present life of men on earth is like the flight of a single sparrow through the hall where, in winter, you sit with your captains and ministers. Entering at one door and leaving by another, while it is inside it is untouched by the wintry storm; but this brief interval of calm is over in a moment, and it returns to the winter whence it came, vanishing from your sight Man's life is similar-, and of what follows it, or what went before, we are utterly ignorant.
THE VENERABLE BEDE, A History of the English Church and People (731)
This is another respect in which we are lucky. The universe is older than a hundred million centuries. Within a comparable time the sun will swell to a red giant and engulf the earth. Every century of hundreds of millions has been in its time, or will be when its time comes, 'the present century'. Interestingly, some physicists don't like the idea of a 'moving present', regarding it as a subjective phenomenon for which they find no house room in their equations. But it is a subjective argument I am making. How it feels to me, and I guess to you as well, is that the present moves from the past to the future, like a tiny spotlight, inching its way along a gigantic ruler of time. Everything behind the spotlight is in darkness, the darkness of the dead past. Everything ahead of the spotlight is in the darkness of the unknown future. The odds of your century being the one in the spotlight are the same as the odds that a penny, tossed down at random, will land on a particular ant crawling somewhere along the road from New York to San Francisco. In other words, it is overwhelmingly probable that you are dead.
In spite of these odds, you will notice that you are, as a matter of fact, alive. People whom the spotlight has already passed over, and people whom the spotlight has not reached, are in no position to read a book. I am equally lucky to be in a position to write one, although I may not be when you read these words. Indeed, I rather hope that I shall be dead when you do. Don't misunderstand me. I love life and hope to go on for a long time yet, but any author wants his works to reach the largest possible readership. Since the total future population is likely to outnumber my contemporaries by a large margin, I cannot but aspire to be dead when you see these words. Facetiously seen, it turns out to be no more than a hope that my book will not soon go out of print. But what I see as I write is that I am lucky to be alive and so are you.
We live on a planet that is all but perfect for our kind of life: not too warm and not too cold, basking in kindly sunshine, softly watered; a gently spinning, green and gold harvest festival of a planet. Yes, and alas, there are deserts and slums; there is starvation and racking misery to be found. But take a look at the competition. Compared with most planets this is paradise, and parts of earth are still paradise by any standards. What are the odds that a planet picked at random would have these complaisant properties? Even the most optimistic calculation would put it at less than one in a million.
Imagine a spaceship full of sleeping explorers, deep-frozen would-be colonists of some distant world. Perhaps the ship is on a forlorn mission
to save the species before an unstoppable comet, like the one that killed the dinosaurs, hits the home planet. The voyagers go into the deep-freeze soberly reckoning the odds against their spaceship's ever chancing upon a planet friendly to life. If one in a million planets is suitable at best, and it takes centuries to travel from each star to the next, the spaceship is pathetically unlikely to find a tolerable, let alone safe, haven for its sleeping cargo.
But imagine that the ship's robot pilot turns out to be unthinkably lucky. After millions of years the ship does find a planet capable of sustaining life: a planet of equable temperature, bathed in warm starshine, refreshed by oxygen and water. The passengers, Rip van Winkles, wake stumbling into the light. After a million years of sleep, here is a whole new fertile globe, a lush planet of warm pastures, sparkling streams and waterfalls, a world bountiful with creatures, darting through alien green felicity. Our travellers walk entranced, stupefied, unable to believe their unaccustomed senses or their luck.
As I said, the story asks for too much luck; it would never happen. And yet, isn't that what has happened to each one of us? We have woken after hundreds of millions of years asleep, defying astronomical odds. Admittedly we didn't arrive by spaceship, we arrived by being born, and we didn't burst conscious into the world but accumulated awareness gradually through babyhood. The fact that we slowly apprehend our world, rather than suddenly discover it, should not subtract from its wonder.
Of course I am playing tricks with the idea of luck, putting the cart before the horse. It is no accident that our kind of life finds itself on a planet whose temperature, rainfall and everything else are exactly right. If the planet were suitable for another kind of life, it is that other kind of life that would have evolved here. But we as individuals are still hugely blessed. Privileged, and not just privileged to enjoy our planet. More, we are granted the opportunity to understand why our eyes are open, and why they see what they do, in the short time before they close for ever.
Here, it seems to me, lies the best answer to those petty-minded Scrooges who are always asking what is the use of science. In one of those mythic remarks of uncertain authorship, Michael Faraday is alleged to have been asked what was the use of science. 'Sir,' Faraday replied. 'Of what use is a new-born child? ' The obvious thing for Faraday (or Benjamin Franklin, or whoever it was) to have meant was that a baby might be no use for anything at present, but it has great potential for the future. I now like to think that he meant something else, too: What is the use of bringing a baby into the world if the only thing it does with its life is just work to go on living? If everything is judged by how 'useful' it is - useful
for staying alive, that is - we are left facing a futile circularity. There must be some added value. At least a part of life should be devoted to living that life, not just working to stop it ending. This is how we rightly justify spending taxpayers' money on the arts. It is one of the justifications properly offered for conserving rare species and beautiful buildings. It is how we answer those barbarians who think that wild elephants and historic houses should be preserved only if they 'pay their way'. And science is the same. Of course science pays its way; of course it is useful. But that is not all it is.
After sleeping through a hundred million centuries we have finally opened our eyes on a sumptuous planet, sparkling with colour, bountiful with life. Within decades we must close our eyes again. Isn't it a noble, an enlightened way of spending our brief time in the sun, to work at understanding the universe and how we have come to wake up in it? This is how I answer when I am asked - as I am surprisingly often - why I bother to get up in the mornings. To put it the other way round, isn't it sad to go to your grave without ever wondering why you were born? Who, with such a thought, would not spring from bed, eager to resume discovering the world and rejoicing to be a part of it?
The poet Kathleen Raine, who read Natural Sciences at Cambridge, specializing in Biology, found related solace as a young woman unhappy in love and desperate for relief from heartbreak:
Then the sky spoke to me in language clear, familiar as the heart, than love more near. The sky said to my soul, 'You have what you desire!
'Know now that you are born along with these clouds, winds, and stars, and ever-moving seas and forest dwellers. This your nature is.
'Lift up your heart again without fear, sleep in the tomb, or breathe the living air, this world you with the flower and with the tiger share. '
'Passion' (1943)
There is an anaesthetic of familiarity, a sedative of ordinariness, which dulls the senses and hides the wonder of existence. For those of us not gifted in poetry, it is at least worth while from time to time making an effort to shake off the anaesthetic. What is the best way of countering the sluggish habituation brought about by our gradual crawl from babyhood? We can't actually fly to another planet. But we can recapture that sense
of having just tumbled out to life on a new world by looking at our own world in unfamiliar ways. It's tempting to use an easy example like a rose or a butterfly, but let's go straight for the alien deep end. I remember attending a lecture, years ago, by a biologist working on octopuses, and
their relatives the squids and cuttlefish. He began by explaining his fascination with these animals. 'You see,' he said, 'they are the Martians. ' Have you ever watched a squid change colour?
Television images are sometimes displayed on giant LED (Light Emitting Diode) hoardings. Instead of a fluorescent screen with an electron beam scanning side to side over it, the LED screen is a large array of tiny glowing lights, independently controllable. The lights are individually brightened or dimmed so that, from a distance, the whole matrix shimmers with moving pictures. The skin of a squid behaves like an LED screen. Instead of lights, squid skin is packed with thousands of tiny bags filled with ink. Each of these ink bags has miniature private muscles to squeeze it. With a puppet string leading to each one of these separate muscles, the squid's nervous system can control the shape, and hence the visibility, of each ink sac.
' In theory, if you wire-tapped the nerves leading to the separate ink pixels and stimulated them electrically via a computer, you could play out Charlie Chaplin movies on the squid's skin. The squid doesn't do that, but its brain does control the wires with precision and speed, and the skinflicks that it shows are spectacular. Waves of colour chase across the surface like clouds in a speeded-up film; ripples and eddies race over the living screen. The animal signals its changing emotions in quick time: dark brown one second, blanching ghostly white the next, rapidly modulating interwoven patterns of stipples and stripes. When it comes to changing colour, by comparison chameleons are amateurs at the game.
The American neurobiologist William Calvin is one of those thinking hard today about what thinking itself really is. He emphasizes, as others have done before, the idea that thoughts do not reside in particular places in the brain but are shifting patterns of activity over its surface, units which recruit neighbouring units into populations becoming the same thought, competing in Darwinian fashion with rival populations thinking alternative thoughts. We don't see these shifting patterns, but presumably we would if neurones lit up when active. The cortex of the brain, I realize, might then look like a squid's body surface. Does a squid think with its skin? When a squid suddenly changes its colour pattern, we suppose it to be a manifestation of mood change, for signalling to another squid. A shift in colour announces that the squid has switched from an aggressive mood, say, to a fearful one. It is natural to presume that the change in mood took place in the brain, and caused the change in colour as a visible manifestation of internal thoughts, rendered external for purposes of communication.
