Science of Discworld III

by Terry Pratchett

  This mental mishmash is well illustrated by our changing attitudes to Mars. Mars was known to the ancients as a ‘wandering star’, a planet; its reddish colour had bloody associations, so the Romans associated it with their god of war. It also acquired a connection with war in astrology, where the visible stars and planets all had to mean something. We’re going to look at a lot of different associations with Mars,3 as myth and rationality engaged with the red planet, as stories by the hundred employed Mars and Martians, and as the scientific picture of Mars changed over the centuries.

  We shouldn’t ask ‘which is the true Mars?’ We become larger humans by considering all of these aspects; from that stance there really isn’t a true, real, objective planet for our minds to engage with usefully. Our simple, thin causal lines can’t comprehend a real astronomical object, even a world which is actually out there so that we can see it. The ‘it’ we see can be the disc whose apparent lines Giovanni Schiaparelli called ‘canali’, which excited Percival Lowell (whose grasp of Italian seems to have been slight, since the word means ‘channels’) to see them as engineered canals. He wrote Mars as the Abode of Life, and this laid the foundation for the folk Mars of the twentieth century.

  Between the World Wars, everybody in the West, and many in the East, looked into the night sky and saw inimical Martians, a mental residue of that 1920s picture of a drying, dying Mars. The image was overlaid by the War of the Worlds picture of envious, grim, disgusting tripod Martians invading Earth (or at least England). There was a more romantic overlay for many of those out camping, or sleeping out under the stars: Barsoom. Edgar Rice Burroughs, familiar because of his Tarzan stories, invented a Mars whose dried-out seabeds were home to green Martian warrior hordes, six-legged centaur-like creatures whose egg-incubators were visited regularly. John Carter, an American ex-confederate army officer, had wished himself on to Mars, been captured by the green warriors but soon found himself married to a red Martian princess.4 Stanley Weinbaum’s A Martian Odyssey added more dimensions: the Martian called Tweel, who made long hops and landed on his nose, the hypnotic predator that showed you your most desirable images, and attempts at a gosh-wow desert ecology. Then there were stories of Martians coming to Earth, pretending to be human … and humans attempting to interact with a more or less mystical ancient Martian civilisation.

  The best known, perhaps the best crafted of these romantic-mystical portrayals of crude, lumbering Earthmen, insensitive to the ethereal beauties of the Martian crystal cities, were Ray Bradbury’s. In the 1950s and 1960s his tales were read by many outside the fantasy/SF world, and they appeared in widely read magazines like Argosy as well as in SF pulps in railway station bookstores. They laid the mystical ancient Martian foundation for Robert Heinlein to build the most potent of all these Martian tales, Stranger in a Strange Land. Michael Valentine Smith had been a foundling on Mars, brought up and trained in their culture by the ancient Martians. He came to Earth, founded a commune of friends – ‘Water Brothers’ – and started a religion whose ‘grokking the fullness’ of everyday events, from sex to science to swimming, spread to communities of readers. There was a tragic, well-publicised association with the murderous Manson killers, who had used this book as their mantra, but this didn’t harm sales, and the ancient mystical Martians became the standard image.

  Then we learned that Mars has no atmosphere to speak of, that it is cold, dry, laden with frozen carbon dioxide, to the extent that the ‘icecaps’ were probably dry ice. Our machines visited Mars, looked for ‘life’, and found strange chemistry because we inevitably asked the wrong questions. The ‘canals’ died in the public mind, replaced by craters and gigantic volcanoes.

  We have now visited again, and it seems that ancient, wet Mars may have been a reality, there may be at least bacterial life forms under the sand … Much is not yet clear, but what is clear is that our image of Mars has changed yet again.

  Each of us has a variety of associations with Mars. When we weave these many different interpretations and imaginations together, we become a different, wiser kind of creature. As for all of our different Marses … well, those are toys of our imaginations, as we grok the red planet’s fullness.

  If Mars seems a bit of a digression, consider those twin icons of evolution, the archaeopteryx and the dodo. In folk-evolutionary thinking, the archaeopteryx is the ancestor of all the birds, and the dodo is the bird that went extinct about 400 years ago. ‘As dead as a dodo.’ Again, our thinking about these iconic creatures is heavily daubed with unchallenged assumptions, myths, and fictional associations.

  We mentioned archaeopteryx in Chapter 36 (‘Running from Dinosaurs’) of The Science of Discworld, second edition. We think of it as the ancestral bird because it is a dinosaur-like animal with birdlike feathers … and it was the first one to be found. However, by the time of archaeopteryx there were plenty of genuine birds around, among them the diving bird Ichthyornis. Poor old archaeopteryx arrived on the scene far too late to be ‘the’ bird ancestor.

  The recent amazing ‘dinobird’ discoveries in China – transitional creatures part way between dinosaurs and birds – have totally changed scientists’ view of bird evolution. At some stage some dinosaurs started to develop feathers, though they couldn’t then fly. The feathers had some other function, probably keeping the animal warm. Later, they turned out to be useful in wings. Some dinobirds effectively had four wings – two at the front, two at the back. It took a while before the standard ‘bird’ body-plan settled down.

  As for the dodo – we all know what it looked like, right? Fat little thing with a big hooked beak … Such a famously extinct creature must be well documented in the scientific literature.

  No, it’s not. What we have is about ten paintings and half a stuffed specimen.5 We have more specimens of the archaeopteryx than we do of the dodo. Why? The dodo went extinct, remember? And it did so before science really got interested in it. So few people recorded it, or studied it. It was there, not requiring special attention, and then it wasn’t, and it was too late to start studying it. It isn’t even certain what colour it was – many books say ‘grey’, but it was more likely brown.

  Yet, we all know exactly what it looked like. How come? Because we all saw it illustrated by Sir John Tenniel in Alice’s Adventures in Wonderland.

  Say no more.

  The great strength of Discworld narrative is that it makes fun of just those places where ‘education’ has left us feeling a bit vulnerable: where we change the subject in the pub, or when our five-year-old asks us those probing questions. A running joke throughout the Science of Discworld series is what grammarians call ‘privatives’. These are concepts that our minds seem quite happy with, even though a moment’s thought shows that they’re complete nonsense. Chapter 22 of The Science of Discworld discussed this notion, and we recap briefly.

  It is entirely normal to speak of ‘cold coming in the window’ or ‘ignorance spreading among the masses’. The opposites of these concepts, heat and knowledge, are real, but we’ve dignified their absence with words that do not correspond to actual things. In Discworld, we find ‘knurd’, which is super-sober, as far from ordinary sober as drunk is in the alcoholic direction. There are jokes about the speed of dark, which must be faster than the speed of light because dark has to get out of the way. On Discworld, Death exists as a (perhaps the) major character, but on Roundworld that word refers only to the absence of life.

  People habitually label the absence of something with a word, instead of (or as well as) its presence: such words are the aforementioned privatives.

  Sometimes this habit leads to mistakes. The classic case was the label ‘phlogiston’, the substance that appears to be emitted by burning materials. You can see it coming out as smoke, flame, foam … It took many years to demonstrate that burning was an intake of oxygen, not the emission of phlogiston. During the intervening period, many people had demonstrated that when metals burned they got heavier, and had therefore argued that phlogis
ton had negative weight. These were clever people; they weren’t being stupid. The phlogiston idea really did work – until oxygen supplanted its explanations, and alchemists suddenly found that the paths into rational chemistry were easier.

  Privatives are often very tempting. In What is Life?, a short book published in 1944, the great physicist Erwin Schrödinger asked precisely that question. At that time the Second Law of Thermodynamics – everything runs down, disorder always increases – was thought to be a fundamental principle about the universe. It implied that eventually everything would become a grey, cool soup of maximum entropy, maximum disorder: a ‘heat death’ in which nothing interesting could happen. So in order to explain how, in such a universe, life could occur, Schrödinger claimed that life could only put off its individual tiny heat death by imbibing negative entropy, or ‘negentropy’. Many physicists still believe this: that life is unnatural, selfishly causing entropy to increase more in its vicinity than it would otherwise do, by eating negentropy.

  This tendency to deny what is happening before our very eyes is part of what it is to be human. Discworld exploits it for humorous and serious purposes. By building Discworld flat, Terry pokes fun at flat-Earthers; rather, he recruits his readers into a ‘we all know the Earth is round, don’t we?’ fellowship. The Omnians’ belief in a round Disc, in Small Gods, adds a further twist.

  We want to put what rational people are coming to believe into a general human context, so let’s look at what everyone believes. In these days of fundamentalist terrorists we would do well to understand why a few people hold beliefs that are so different from the rational. These unexamined beliefs may be vitally important, because the ignorant people who espouse them think that they provide a good reason for killing us and our loved ones, even though they have never considered alternatives. People Who Know The Truth, by heredity or personal revelation or authority, are not concerned with logic or the validity of premises.

  Nearly everybody who has ever lived has been one of those.

  There have been a few sparse times and places – and we are hoping that the twenty-first century will host a few of them – in which onlookers are more ready to believe a disputant who is unsure, than one who is certain. But in today’s politics, changing your mind in response to new evidence is seen as a weakness. When he was Vice-Chancellor at Warwick University, the biologist Sir Brian Follett remarked: ‘I don’t like scientists on my committees. You don’t know where they’ll stand on any issue. Give them some more data, and they change their minds!’ He understood the joke: most politicians wouldn’t even realise it was a joke.

  In order to discuss the kinds of explanation and understanding that are going to have future values, we need at least a simple geography of where human beings pin their faiths now. What kinds of world picture are most common? They include those of the authoritarian theist, the more-or-less imaginative theist, the more critical deist, and various kinds of atheists – from Buddhists and the followers of Spinoza to those, including many scientists and historians, who simply believe that the age of religion is behind us.

  Most human beings of the last few millennia seem to have been authoritarian theists, and we still have many of them in our world; perhaps they are still a majority. Does this mean that we must give intellectual ‘equal time’ to these views (plural, because they’re all very different: Zeus, Odin, Jahweh …), or can we just dismiss them all with ‘I have no need of that hypothesis’, as Laplace supposedly said to Napoleon. Voltaire, aware that God making man in His image meant that God’s nature might be deduced from man’s, thought it at least possible that God has mischievously misinformed us about reward and punishment. Perhaps sinners are rewarded by Heaven and saints are given a taste of Hell. Our view is that all the various authoritarian theists are the contemporary bearers of an extremely successful memeplex, a package of beliefs designed and selected through the generations to ensure its own propagation.

  A typical memeplex is the Jewish shema: ‘And these words … you shall teach them to your children, muse on them when you get up and when you lie down … Write them upon the doorposts of your house and upon your gates.’ Like e-mail chain letters that threaten you with punishment if you fail to send them on to many friends, and with ‘luck’ if you do send them on, the world’s great religions have all promised pleasures for committed believers and transmitters, but pain for those who fail to adhere to the faith. Heretics, and those who leave the faith, are often killed by the faithful.

  We can easily understand how such beliefs, bolstered as they are from within, have been retained throughout the generations. The promise of an afterlife, espoused by all the sensible people around you, makes many of this life’s sorrows easier to bear. And, as we’ve seen in recent years, belief in a Paradise for those who die fighting for the faith in a Holy War makes you pretty well invincible.6 Such invincibility is a side-effect of the memeplex’s belief tactics, not a certification of the truth of the bomber’s faith. Especially given that nearly all of those who share the bomber’s faith (Islam, Catholicism …) deny that their beliefs justify killing unbelievers.

  This plurality of theist beliefs, especially in today’s mixed-up world with its different cultures and multicultures, encourages a more critical belief in authority, and usually a willingness to admit commonality with other theists. Such common ground encourages the integration of different cultures. Many minorities are assimilated and disappear, but others react by emphasising their individuality. Some of the latter, like the Thuggee worshippers of the death goddess Kali in nineteenth-century India, and the recent al-Qaeda terrorists, gain temporary notoriety that seems to be a triumph of their faith. However, this is usually self-defeating in the longer term. In any event, the number of deaths is no comment, plus or minus, upon the truth of the beliefs that these thugs hold. The faith of these militant minorities sometimes gains sharpness and even subtlety, but it is usually subordinated to the day-to-day exigencies of the violent lives they lead.

  Many great scientists, for example Galileo, were ridiculed when they proposed new insights into the natural world. Scientific crackpots often deduce that because their work is being ridiculed, they must be the new Galileo, but that doesn’t follow. Similarly, men of violence often try to validate their ‘martyrdom’ by comparing themselves to ancient Christians or ghetto Jews, and again the logic is flawed. There is no rational reason to accept any of their gods as part of the real universe, however helpful that belief might be to some people as regards day-to-day living. Despite that, many clever, honest people do feel that a God is necessary to their understanding of how everything is organised. Once a memeplex has caught you, it’s hard to escape.

  We have a little more sympathy with deists, who mostly seem to believe that the universe is extraordinarily complex, yet possesses an overall simplicity, and that this points to some celestial guardian who looks after the whole thing and gives it meaning. Ponder Stibbons and Mustrum Ridcully, in their different ways, edge towards deism; they want to feel that ‘someone’ is at the helm. If challenged, deists usually deny the anthropomorphic character of this guardian, but they still retain a belief in the ability of individual people – perhaps individual ‘souls’ – to relate directly with whoever or whatever is in charge. We personally doubt that such apparent interactions, whether attained by meditation or prayer, are more than self-delusion. But we are happy to live on the same planet as people who believe that they are in direct contact with ultimate causality, however unscientific we may feel that belief to be.

  There is a growing minority of thoughtful people who have given up on the idea of a personal, anthropomorphic God altogether. Some, particularly among Buddhists and Taoists, retain the mystical/metaphysical stance that is characteristic of religion, and consider the ‘scientific’ world to be subservient to a mystical true picture more closely related to subjective experience. In contrast, those of us who were persuaded by Spinoza’s rejection of an anthropomorphic God, not least because neither th
e universe nor an omnipotent deity can exist without being coextensive with everything there is, see the scientific view as exposing both the nature of god, if that is our belief, through the laws by which things work, and the workings of the universe itself.

  Many scientists, particularly those whose endeavours relate closely to the real world, like geologists, astronomers, biologists, ecologists, and polymer chemists, avoid the mystical approach and see their own speciality as exemplifying a complex slice of the universe, with many emergent properties that are not predictable from the detailed substructure. Other scientists, particularly those devoted to reductionist explanations, like physicists, astrophysicists, physical chemists, molecular biologists, and geneticists, retain a version of the mystical approach, but try to explain higher level behaviour in terms of the substructure. Tellingly, many scientists who work at the ‘coal face’ of the subject generally have a respect for the unknown possibilities that the universe might throw at them, whereas workers in more abstract realms like quantum theory have a tendency to go all mystical about their own understanding, or lack of it.

  Most human attempts at an explanation try to find a thin causal chain of logic and narrative, leading from things we accept to whatever it is we are trying to explain. This type of story appeals to human minds, but it is usually an oversimplification, and it leads to serious misunderstandings. The typical television science programme, where a single individual is held to be responsible for some big ‘breakthrough’, paints a wildly inaccurate picture of the incremental process by which most scientific advances are made. Unicausal explanations make nice stories, but fail to capture the complexities of the real world. The most effective explanations are often very varied, and it’s a good idea to find a lot of different ones, if they’re available. Physicists searching for a unification of relativity and quantum theory should perhaps bear in mind the possibility that any unification may turn out to be less effective than the two separate theories, each safely confined to its own domain. Only if you can get several theories to compete, in your mental territory, can you begin to distil understanding.