Richard Dimbleby lecture (BBC TV)
12th November 1996
aristotle was an encyclopedic polymath, an all time intellect. Yet you know more than he did about the world. You also can have a deeper understanding of how everything works. Such is the privilege of living after Newton, Darwin, Einstein, Planck, Watson, Crick and their colleagues.
I am not saying you are more intelligent than Aristotle, or wiser. For all I know, Aristotle was the cleverest person who has ever lived. That is not the point. The point is only that science is cumulative and we live later.
Aristotle had a lot to say about astronomy, biology and physics. But his views sound weirdly na?ve today. He could walk straight into a modern seminar on ethics, theology, political or moral philosophy, and contribute. But let him walk into a modern science class and he would be a lost soul, because science advances.
Here is a small sample of the things you could tell Aristotle, or any other Greek philosopher, and surprise and enthral them, not just with the facts themselves but with how they hang together so elegantly.
The earth is not the centre of the universe. It orbits the sun-which is just another star. There is no music of the spheres, but the chemical elements, from which all matter is made, arrange themselves cyclically, in something like octaves. There are not four elements but about 100. Earth, air, fire and water are not among them.
Living species are not isolated types with unchanging essences. Instead, over a time-scale too long for humans to imagine, they split and diverge into new species, which go on diverging further and further. For the first half of geological time our ancestors were bacteria. Most creatures still are bacteria, and each one of our trillions of cells is a colony of bacteria. Aristotle was a distant cousin to a squid, a closer cousin to an ape (strictly speaking, Aristotle was an ape, an African ape, a closer cousin to a chimpanzee than a chimp is to an orangutan).
The brain is not for cooling the blood. It is what you use to do your logic and your metaphysics. It is a three dimensional maze of a million million nerve cells, each one drawn out like a wire to carry pulsed messages. If you laid all your brain cells end to end, they would stretch round the world 25 times. There are about four million million connections in the tiny brain of a chaffinch, and proportionately more in ours.
The process of accumulation does not stop with us. Two thousand years hence, ordinary people who have read a couple of books will be in a position to give a tutorial to today's Aristotles: to Francis Crick, say, or Stephen Hawking. So does this mean that our view of the universe will turn out to be just as wrong?
Let us keep a sense of proportion about this. Yes, there is much that we still do not know. But surely our belief that the earth is round and not flat, and that it orbits the sun, will never be superseded. That alone is enough to confound those, endowed with a little philosophical learning, who deny the very possibility of objective truth: those so-called relativists who see no reason to prefer science over aboriginal myths.
Our belief that we share ancestors with chimpanzees, and more distant ancestors with monkeys, will never be superseded although details of timing may change. Many of our ideas, on the other hand, are still best seen as theories or models whose predictions, so far, have survived the test. Physicists disagree over whether they are condemned forever to dig for deeper mysteries, or whether physics itself will come to an end in a final "theory of everything."
Meanwhile, there is so much that we do not yet know, we should proclaim those things that we do, so as to focus attention on problems that we should be working on.
Far from being over-confident, many scientists believe that science advances only by disproof of its hypotheses. Konrad Lorenz said that he hoped to disprove at least one of his own hypotheses every day before breakfast. A formative influence on my undergraduate self was the response of an elder statesman of the Oxford zoology department when an American visitor had just publicly disproved his favourite theory. The old man strode to the front of the lecture hall, shook the American warmly by the hand and declared in ringing, emotional tones: "My dear fellow, I wish to thank you. I have been wrong these 15 years." And we clapped our hands red. Can you imagine a government minister being cheered in the House of Commons for a similar admission?
Yet there is hostility towards science. And not just from the green ink underlining brigade, but from published novelists and newspaper columnists. Newspaper columns are notoriously ephemeral, but their drip drip, day after day repetition gives them influence and we have to notice them. A peculiar feature of the British press is the regularity with which some of its leading columnists return to attack science-and not always from a vantage point of knowledge. Bernard Levin recently wrote in The Times under the headline "God, me and Dr Dawkins" and it had the subtitle: "Scientists don't know and nor do I-but at least I know I don't know."
It is no mean task to plumb the full depths of what Bernard Levin does not know, but here is an illustration of the gusto with which he boasts of it.
"Despite their access to copious research funds, scientists have yet to prove that a quark is worth a bag of beans. The quarks are coming! The quarks are coming! Run for your lives! Yes, I know I shouldn't jeer at science, which, after all, gave us mobile telephones, collapsible umbrellas and multi-striped toothpaste, but science really does ask for it... Now I must be serious. Can you eat quarks? Can you spread them on your bed when the cold weather comes?"
The distinguished Cambridge scientist, Sir Alan Cottrell, wrote a brief letter to the editor: "Sir: Mr Bernard Levin asks 'Can you eat quarks?' I estimate that he eats 500,000,000,000,000,000,000 quarks a day."
It has become almost a clich? to remark that nobody boasts of ignorance of literature, but it is socially acceptable to boast ignorance of science and proudly claim incompetence in mathematics. In Britain, that is. I believe that the same is not true of Germany, the US and Japan.
People certainly blame science for nuclear weapons and similar horrors. It has been said before, but needs to be said again: if you want to do evil, science provides the most powerful weapons to do evil; but equally, if you want to do good, science puts into your hands the most powerful tools to do so.
An equally common accusation is that science goes beyond its remit. It is accused of a grasping takeover bid for territory that properly belongs to other disciplines such as theology. On the other hand-you cannot win!-listen to the novelist Fay Weldon's hymn of hate against "the scientists" in the Daily Telegraph.
"Don't expect us to like you. You promised us too much and failed to deliver. You never even tried to answer the questions we all asked when we were six. Where did Aunt Maud go when she died? Where was she before she was born?... And who cares about half a second after the big bang; what about half a second before? And what about crop circles?"
More than some colleagues, I am happy to give a simple and direct answer to both those Aunt Maud questions. But I would certainly be called arrogant and presumptuous, going beyond the limits of science.
Then there is the view that science is dull and plodding, with rows of biros in its top pocket. Here is another columnist, AA Gill, writing on science in the Sunday Times.
"Science is constrained by the plodding stepping stones of empiricism... What appears on television just is more exciting than what goes on in the back of it... There are stars and there are stars, darling. Some are dull, repetitive squiggles on paper, and some are fabulous, witty, thought provoking, incredibly popular..."
The "dull, repetitive squiggles" is a reference to the discovery of pulsars in 1967, by Jocelyn Bell and Anthony Hewish. Jocelyn Bell Burnell had recounted on television the spine-tingling moment when, a young woman on the threshold of a career, she first knew she was in the presence of something hitherto unheard of in the universe. Not something new under the sun, a whole new kind of sun, which rotates, so fast that, instead of taking 24 hours like our planet, it takes a quarter of a second. Darling, how too plodding, how madly empirical my dear!
Could science just be too difficult for some people and therefore threatening? Oddly enough, I would not dare to make such a suggestion, but I am happy to quote a distinguished literary scholar, John Carey, the Merton professor of English at Oxford: "The annual hordes competing for places on arts courses in British universities and the trickle of science applicants testify to the abandonment of science among the young. Though most academics are wary of saying it straight out, the general consensus seems to be that arts courses are popular because they are easier."
My own view is that the sciences can be intellectually demanding, but so can classics, so can history, so can philosophy. On the other hand, nobody should have trouble understanding things such as the circulation of the blood and the heart's role in pumping it round. Carey quoted Donne's lines to a class of 30 undergraduates in their final year reading English at Oxford:
Knows't thou how blood, which to the heart doth flow,
Doth from one ventricle to the other go?
Carey asked them how, as a matter of fact, the blood does flow. None of the thirty could answer, and one tentatively guessed that it might be "by osmosis." The truth-that the blood is pumped from ventricle to ventricle through at least 50 miles of intricately dissected capillary vessels throughout the body-should fascinate any true literary scholar. And unlike, say, quantum theory or relativity, it is not hard to understand. So I tender a more charitable view than John Carey. I wonder whether some of these young people might have been positively turned off science.
Last month I received a letter which began: "I am a clarinet teacher whose only memory of science at school was a long period of studying the Bunsen burner." Now, you can enjoy a Mozart concerto without being able to play the clarinet. You can be a discerning concert critic without being able to play a note. Of course music would come to a halt if nobody learned to play it. But if everybody left school thinking you had to play an instrument before you could appreciate music, think how impoverished many lives would be.
Could we not treat science in the same way? Yes, we have Bunsen burners and dissecting needles for those drawn to scientific practice. But perhaps the rest of us could have classes in science appreciation, the wonder of science, scientific ways of thinking, and the history of scientific ideas, rather than laboratory experience.
It is here that I would seek rapprochement with another apparent foe of science, Simon Jenkins, former editor of The Times and a more formidable adversary than the other journalists I have quoted, because he has some knowledge of what he is talking about. He resents compulsory science education and he holds the idiosyncratic view that it is not useful. But he is thoroughly sound on the uplifting qualities of science. In a recorded conversation with me, he said: "I can think of very few science books I have read that I have called useful. What they've been is wonderful. They have actually made me feel that the world around me is a much fuller... much more awesome place than I ever realised it was... I think that science has got a wonderful story to tell. But it isn't useful. It is not useful like a course in business studies or law is useful."
Far from science not being useful, my worry is that it is so useful as to overshadow and distract from its inspirational and cultural value. Usually even its sternest critics concede the usefulness of science, while missing the wonder. Science is often said to undermine our humanity, or destroy the mystery on which poetry is thought to thrive. Keats berated Newton for destroying the poetry of the rainbow.
Philosophy will clip an Angel's wings,
Conquer all mysteries by rule and line,
Empty the haunted air, and gnomed mine-
Unweave a rainbow...
Keats was, of course, a very young man.
Blake, too, lamented:
For Bacon and Newton, sheath'd in dismal steel, their terrors hang
Like iron scourges over Albion; Reasonings like vast Serpents
Infold around my limbs...
I wish I could meet Keats or Blake to persuade them that mysteries do not lose their poetry because they are solved. Quite the contrary. The solution often turns out more beautiful than the puzzle, and anyway the solution uncovers deeper mystery. The rainbow's dissection into light of different wavelengths leads on to Maxwell's equations, and eventually to special relativity.
Einstein himself was ruled by an aesthetic scientific muse: "The most beautiful thing we can experience is the mysterious. It is the source of all true art and science," he said. It is hard to find a modern particle physicist who does not own to some such aesthetic motivation.
Wordsworth looked forward to a time when scientific discoveries would become "proper objects of the poet's art." And, at the painter Benjamin Haydon's dinner of 1817, he endeared himself to scientists, and endured the taunts of Keats and Charles Lamb, by refusing to join in their toast: "Confusion to mathematics and Newton."
Now, here is an apparent confusion: TH Huxley saw science as "nothing but trained and organised common sense" while Lewis Wolpert insists that it is deeply paradoxical and surprising, an affront to common sense. Science runs the gamut from the tantalisingly surprising to the deeply strange, and ideas do not come any stranger than quantum mechanics. More than one physicist has said something like: "If you think you understand quantum theory, you don't understand quantum theory."
There is mystery in the universe, beguiling mystery, but it is not capricious, whimsical, frivolous in its changeability. The universe is an orderly place and, at a deep level, regions of it behave like other regions, times behave like other times. If you put a brick on a table it stays there unless something lawfully moves it, even if you meanwhile forget it is there. Poltergeists and spirits do not intervene and hurl it about for reasons of mischief or caprice. There is mystery but not magic, strangeness beyond the wildest imagining, but no spells or witchery, no arbitrary miracles.
Even science fiction, although it may tinker with the laws of nature, cannot abolish lawfulness itself and remain good science fiction. Young women do not take off their clothes and spontaneously morph themselves into wolves. A recent television drama is fairytale rather than science fiction, for this reason. It falls foul of a theoretical prohibition much deeper than the philosopher's-"All swans are white, until a black one turns up"-inductive reasoning. We know people cannot metamorphose into wolves, not because the phenomenon has never been observed-plenty of things happen for the first time-but because werewolves would violate the equivalent of the second law of thermodynamics. Of this, Sir Arthur Eddington said: "If someone points out to you that your pet theory of the universe is in disagreement with Maxwell's equations-then so much the worse for Maxwell's equations. If it is found to be contradicted by observation-well, these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation."
There is currently an epidemic of paranormal propaganda on television. In one popular type of programming, conjurers come on and do routine tricks. But instead of admitting that they are conjurers, these television performers claim genuinely supernatural powers. In this they are abetted by prestigious, even knighted, presenters. It is an abuse of what might be called the Richard Dimbleby effect.
In other programmes, disturbed people recount their fantasies of ghosts and poltergeists. Instead of sending them to a psychiatrist, television producers hire actors to recreate their delusions with predictable effects on the credulity of large audiences.
Recently, a faith healer was given half an hour of prime time television to advertise his claim to be a 2000 year-dead physician called Paul of Judaea. Some might call this entertainment, comedy even, although others would find it objectionable, like a fairground freak show.
Now I obviously have to return to the arrogance problem. How can I be so sure that this ordinary Englishman with an unlikely foreign accent was not the long dead Paul of Judaea? How do I know that astrology does not work? How can I be so confident that the television "supernaturalists" are ordinary conjurers, just because ordinary conjurers can replicate their tricks? (Spoonbending, by the way, is so routine a trick that the American conjurers Penn and Teller have posted instructions for doing it on the internet. See http://www.randi.org/jr/ptspoon.html)
It really comes down to parsimony, economy of explanation. It is possible that your car engine is driven by psychokinetic energy, but if it looks like a petrol engine, smells like a petrol engine and performs exactly as well as a petrol engine, the sensible working hypothesis is that it is a petrol engine.
Telepathy and possession by the spirits of the dead are not ruled out as a matter of principle. There is certainly nothing impossible about abduction by aliens in Ufos. One day it may happen. But on grounds of probability it should be kept as an explanation of last resort. It is unparsimonious, demanding more than routinely weak evidence before we should believe it.
It has been suggested that if the supernaturalists really had the powers they claim, they would win the lottery every week. I prefer to point out that they could also win a Nobel prize for discovering fundamental physical forces hitherto unknown to science. Either way, why are they wasting their talents doing turns on television?
By all means let us be open-minded, but not so open-minded that our brains drop out. I am not asking for all such programmes to be suppressed, merely that the audience should be encouraged to be critical. In the case of the psychokineticists and thought readers, it would be good entertainment to invite studio audiences to suggest tests, which only genuine psychics, but not ordinary conjurers, could pass.
How do we account for the current paranormal vogue in the media? Perhaps it has something to do with the millennium-in which case it is depressing to realise that it is still three years away. Less portentously, it may be an attempt to cash in on the success of The X-Files. This is fiction and therefore defensible as pure entertainment.
A fair defence, you might think. But soap operas, cop series and the like are justly criticised if, week after week, they ram home the same prejudice or bias. Each week The X-Files poses a mystery and offers two rival kinds of explanation, the rational theory and the paranormal theory. And, week after week, the rational explanation loses. But it is only fiction, a bit of fun, why get so hot under the collar?
Imagine a crime series in which, every week, there is a white suspect and a black suspect. And every week, lo and behold, the black one turns out to have done it. Unpardonable. You could not defend it by saying: "But it's only fiction, only entertainment."
The popularity of the paranormal, oddly enough, might even be grounds for encouragement. I think that the appetite for mystery, the enthusiasm for that which we do not understand, is healthy and to be fostered. It is the same appetite which drives the best of true science, and it is an appetite which true science is best qualified to satisfy. Perhaps it is this appetite that underlies the ratings success of the paranormalists.
I believe that astrologers are playing on-misusing, abusing-our sense of wonder. They hijack the constellations and employ sub-poetic language like the moon moving into the fifth house of Aquarius. Real astronomy is the rightful proprietor of the stars and their wonder. Astrology gets in the way and debauches the wonder.
To show how real astronomical wonder can be presented to children, I will borrow from a book called Earthsearch by John Cassidy. Find a large open space and take a soccer ball to represent the Sun. Put the ball down and walk ten paces in a straight line. Stick a pin in the ground. The head of the pin stands for the planet Mercury. Take another nine paces beyond Mercury and put down a peppercorn to represent Venus. Seven paces on, drop another peppercorn for Earth. One inch away from earth, another pinhead represents the Moon, the furthest place, remember, that we have so far reached. Fourteen more paces to little Mars, then 95 paces to giant Jupiter, a ping-pong ball. One hundred and twelve paces further, Saturn is a marble. No time to deal with the outer planets except to say that the distances are much larger. How far would you have to walk to reach the nearest star, Proxima Centauri? Pick up another soccer ball to represent it, and set off for a walk of 4200 miles. As for the nearest other galaxy, Andromeda, don't even think about it!
Who would go back to astrology when they have sampled the real thing-astronomy, Yeats's "starry ways," his "lonely, majestical multitude"? The same lovely poem encourages us to "Remember the wisdom out of the old days" which brings me to a piece of wonder from my field, evolution.
You contain a trillion copies of a large, textual document written in a highly accurate, digital code, each copy as voluminous as a substantial book. I am talking, of course, of the DNA in your cells. Textbooks describe DNA as a blueprint for a body. It is better seen as a recipe for making a body, because it is irreversible. But today I want to present it as something different again, and even more intriguing. The DNA in you is a coded description of ancient worlds in which your ancestors lived. DNA is the wisdom out of the old days, the very old days.
The oldest human documents go back a few thousand years, originally written in pictures. Alphabets were invented about 35 centuries ago. The DNA alphabet arose at least 35m centuries ago. Since that time, it has not changed one jot. Not just the alphabet, the dictionary of 64 basic words and their meanings is the same in modern bacteria and in us. Yet the common ancestor from whom we both inherited this precise dictionary lived at least 35m centuries ago.
What changes is the long programmes that natural selection has written using those 64 basic words. The messages that have come down to us are the ones that have survived millions, in some cases hundreds of millions, of generations. For every successful message that has reached the present, countless failures have fallen away like the chippings on a sculptor's floor. That is what Darwinian natural selection means. We are the descendants of a tiny elite of successful ancestors. Our DNA has proved itself successful, because it is here. Geological time has carved and sculpted our DNA to survive down to the present.
There are perhaps 30m distinct species in the world today. So, there are 30m distinct ways of making a living, ways of working to pass DNA on to the future. Some do it in the sea, some on land. Some up trees, some underground. Some are plants, using solar panels-we call them leaves-to trap energy. Some eat the plants. Some eat the herbivores. Some are big carnivores that eat the small ones. Some live as parasites inside other bodies. One species of small worms is said to live entirely inside German beer mats. All these different ways of making a living are just different tactics for passing on DNA. The differences are in the details.
The DNA of a camel was once in the sea, but it has not been there for a good 300m years. It has spent most of recent geological history in deserts, programming bodies to withstand dust and conserve water. Like sandbluffs carved into fantastic shapes by the winds, camel DNA has been sculpted by survival in ancient deserts to yield modern camels. At every stage of its apprenticeship, the DNA of a species has been honed and whittled, carved and rejigged by selection in a succession of environments.
We cannot read these messages yet. Maybe we never shall, for their language is indirect, as befits a recipe rather than a reversible blueprint. But it is still true that we are walking archives of the African Pliocene, even of Devonian seas, walking repositories of wisdom out of the old days. You could spend a lifetime reading such messages and die unsated by the wonder of it.
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 standing in my place but who will never see the light of day outnumber the sand grains of Sahara-more, the atoms in the universe. Certainly those unborn ghosts include greater poets than Donne, greater scientists than Newton, greater composers than Beethoven. We know this because the set of possible people allowed by our DNA so massively outnumbers the set of actual people. In the teeth of these stupefying odds it is you and I that are privileged to be here, privileged with eyes to see where we are and brains to wonder why.
There is an appetite for wonder, and is true science not well qualified to feed it? It is often said that people "need" something more in their lives than just the material world. There is a gap that must be filled. People need to feel a sense of purpose. Well, not a bad purpose would be to find out what is already here, in the material world, before concluding that you need something more. How much more do you want? Just study what is, and you will find that it is already far more uplifting than anything you could imagine needing. You don't have to be a scientist-you don't have to play the Bunsen burner. Science needs to be released from the lab into the culture.
