The Science of Discworld II

by Terry Pratchett

  We don’t want to go too deeply into details of design here. We can think of ways to make the experiment workable, but the discussion would be a bit technical. For example, it seems necessary to make the roll of cloth, the Endless Road, move at a speed that is non-zero, but is also different from the natural speed with which the horse would move if its feet were actually hitting solid ground.6 You might care to think about that, and you might even decide that we’re wrong. And you might even be right.

  We also acknowledge that Phocian’s final experiment is open to many objections. And because the hooves of a trotting horse hit the ground in pairs, it is actually necessary to halve the total length of the charcoal smears before comparing them with the length of the cloth. No matter, these are mere elaborations of what would otherwise be an entirely transparent story: you understand what we’re getting at.

  Taking all this into account, was Phocian a scientist?

  No. Hex has bungled again, for despite Phocian’s years of visibly ‘scientific’ activity, he falls down in two respects. One, open to dispute, is not his fault: he has no peers, no colleagues. There are no other ‘scientists’ for him to work with, or to criticise him. He’s on his own and ahead of his time.7 Just as there cannot be just one wizard, there cannot be just one scientist. Science has a social dimension.8 The second reason, though, is decisive. He is mortified when his work proves that Antigonus, the great authority, is wrong.

  Any genuine scientist would give their right arm to prove that the great authority is wrong.

  That’s how you make your reputation, and it’s also the most important way to contribute to the scientific endeavour. Science is at its best when it changes people’s minds. Very little of it does that, in part because our minds have been built by a culture that is pervaded by science anyway. If a scientist manages to spend 1 per cent of the time discovering things that are not what they expected, they are doing amazingly well. But boy, does that 1 per cent count for a lot.

  This, then, is science. Questioning authority. Complicity between theory and experiment. And being within a community of like-minded people to question your work. Preferably accompanied by a conscious awareness of all of the above, and gratitude to your friends and colleagues for their criticisms. And what’s the aim? To find timeless truths? No, that’s asking too much. To stop frail humans from falling for plausible falsehoods? Yes – including those of people who at least look and sound just like you. And to protect people from their willingness to believe a good story, just because it sounds right and doesn’t upset them. And to protect them from the firm smack of authority, too.

  It took humanity a long time to arrive at the scientific method. No doubt the reason for the delay was that if you do science properly, you often find yourself overturning entrenched, well-established beliefs, including your own entrenched, well-established beliefs. Science is not a belief system, but many areas of human activity are, so it is not surprising to find that the early developers of science often found themselves in conflict with authority. Perhaps the best-known example of this is Galileo, who ran into trouble with the Inquisition because of his theories about the solar system. Sometimes science exposes you to the firm smack instead.

  Science, then, is not just a body of teachable facts, and techniques. It is a way of thinking. In science, established ‘facts’ are always open to question,9 but few scientists will listen to you unless you can offer some evidence that the old ideas are wrong. If the people who invented those ideas are dead, then alternatives can quickly gain acceptance, and the scientific method is working well. If the people who invented those ideas are still around, in influential positions, then they can put a lot of obstacles in the way of the new suggestion and the people who proposed it. Then science is working badly, because people are behaving like people. Even so, the new idea still can displace the accepted wisdom. It just takes longer and needs really solid evidence.

  Let’s contrast science with alternative ways of thinking about the universe. The Discworld worldview is that the universe is run by magic: things happen because people want them to happen. You still have to find the right spell, or the narrative imperative has to be so strong that those things will happen anyway even if people don’t want them to, but the universe exists in order to be there for people.

  On Discworld and Roundworld, the worldview of the priesthood is similar, but with one important difference. They believe that the universe is run by gods (or a god): things happen because the gods want them to happen, don’t care if they happen, or have some ineffable long-term aim in view. However, it is possible for people to ask the priests to intercede with the gods, on their behalf, in the hope of influencing the gods’ decisions, at least in minor ways.

  The philosophical worldview, exemplified by Antigonus, is that the nature of the world can be deduced by pure thought, on the basis of a few deep, general principles. Observation and experiment are secondary to verbal reasoning and logic.

  The scientific worldview is that what people want has very little to do with what actually happens, and that it is unnecessary to invoke gods at all. Thought is useful, but empirical observations are the main test of any hypothesis. The role of science is to help us find out how the universe works. Why it works, or what manner of Being ultimately controls it, if any, is not a question that science is interested in. It is not a question to which anyone can give a testable answer.

  Oddly enough, this hands-off approach to the universe has given us far more control over it than magic, religion or philosophy have done. On Roundworld, magic doesn’t work, so it offers no control at all. Some people believe that prayer can influence their god, and that in this way human beings can have some influence over the world in which they live, like a courtier at a king’s ear. Other people have no such beliefs, and consider the role of prayer to be largely psychological. It can have an effect on people, but not on the universe itself. And philosophy has a tendency to follow rather than lead.

  Science is a form of narrativium. In fact, all four approaches to the universe – magic, religion, philosophy and science – involve the construction of stories about the world. Oddly enough, these different kinds of story often have many parallels. There is a distinct resemblance between many religious creation myths and the cosmol-ogists’ ‘Big Bang’ theory of the origin of the universe. And the monotheistic idea that there is only one God, who created everything and runs everything, is suspiciously close to the modern physicists’ idea that there should be a single Theory of Everything, a single fundamental physical principle that unites both relativity and quantum mechanics into a satisfying and elegant mathematical structure.

  The act of telling stories about the universe may well have been more important to the early development of humanity, and for the initial growth of science, than the actual content of the stories themselves. Accurate content was a later criterion. When we start telling stories about the universe, the possibility arises of comparing those stories with the universe itself, and refining how well the stories fit what we actually see. And that is already very close to the scientific method.

  Humanity seems to have started from a rather Discworldly view, in which the world was inhabited by unicorns and werewolves and gods and monsters, and the stories were used not so much to explain how the world worked, but to form a crucial part of the cultural Make-a-Human kit. Unicorns, werewolves, elves, fairies, angels, and other supernatural were not real. But that didn’t actually matter very much: there is no problem in using unreal things to programme human minds.10 Think of all those talking animals.

  The models employed by science are very similar in many respects. They, too, do not correspond exactly to reality. Think of the old model of an atom as a kind of miniature solar system, in which tiny hard particles called electrons whirl around a central nucleus consisting of other kinds of tiny hard particles: protons and neutrons. The atom is not ‘really’ like that. But many scientists still use this picture today as the basis for their investigatio
ns. Whether this makes sense depends upon what problem they are working on, and when it doesn’t make sense, they use something more sophisticated, like the description of an atom as a probable cloud of ‘orbitals’ which represent not electrons, but places where electrons could be. That model is more sophisticated, and it fits reality more closely than a mini solar system, but it still isn’t ‘true’.

  Science’s models are not true, and that’s exactly what makes them useful. They tell simple stories that our minds can grasp. They are lies-to-children, simplified teaching stories, and none the worse for that. The progress of science consists of telling ever more convincing lies to ever more sophisticated children.

  Whether our worldview is magical, religious, philosophical or scientific, we try to alter the universe so that we can convince ourselves that we’re in charge of it. If our worldview is magical, we believe that the universe responds to what we want it to do. So control is just a matter of finding the right way to instruct the universe about what our wishes are: the right spell. If our worldview is religious, we know that the gods are really in charge, but we hold out the hope that we can influence their decisions and still get what we want (or influence ourselves to accept whatever happens …). If our worldview is philosophical, we seldom tinker with the universe ourselves, but we hope to influence how others tinker. And if our worldview is scientific, we start with the idea that controlling the universe is not the main objective. The main objective is to understand the universe.

  The search for understanding leads us to construct stories that map out limited parts of the future. It turns out that this approach works best if the map does not foretell the future like a clairvoyant, predicting that certain things will happen on certain days or in certain years. Instead, it should predict that if we do certain things, and set up a particular experiment in particular circumstances, then certain things should happen. Then we can do an experiment, and check the reasoning. Paradoxically, we learn most when the experiment fails.

  This process of questioning the conventional wisdom, and modifying it whenever it seems not to work, can’t go on indefinitely. Or can it? And if it stops, when does it stop?

  Scientists are used to constant change, but most changes are small: they refine our understanding without really challenging anything. We take a brick out of the wall of the scientific edifice, polish it a bit, and put it back. But every so often, it looks as if the edifice is actually finished. Worthwhile new questions don’t seem to exist, and all attempts to shoot down the accepted theory have failed. Then that area of science becomes established (though still not ‘true’), and nobody wastes their time trying to change it any more. There are always other sexier and more exciting areas to work on.

  Which is much like putting a big plug in a volcano. Eventually, as the pressure builds up, it will give way. And when it does, there will be a very big explosion. Ash rains down a hundred miles away, half the mountain slides into the sea, everything is altered …

  But this happens only after a long period of apparent stability, and only after a huge fight to preserve the conventional ways of thinking. What we then see is a paradigm shift, a huge change in thought patterns; examples include Darwin’s theory of evolution and Einstein’s theory of relativity.

  Changes in scientific understanding force changes in our culture. Science affects how we think about the world, and it leads to new technologies that change how we live (and, when misunderstood, deliberately or otherwise, some nasty social theories, too).

  Today we expect big changes during our lifetimes. If children are asked to forecast the future, they’ll probably come up with science-fictional scenarios of some kind – flying cars, holidays on Mars, better and smaller technology. They are probably wrong, but that doesn’t matter. What matters is that today’s children do not say: ‘Change? Oh, everything will probably be pretty much the same. I’ll be doing just the same things that my Mum and Dad do now, and their Mum and Dad did before them.’ Whereas even fifty years ago, one grandfather, that was generally the prevailing attitude. Ten or eleven grandfathers ago, a big change for most people meant using a different sort of plough.

  And yet … Underneath these changes, people are still people. The basic human wants and needs are much as they were a hundred grandfathers ago, even if we ever do take holidays on Mars (all that beach … ). The realisation of those needs may be different – a hamburger instead of a rabbit brought down with an arrow you made yourself – but we still want food. And companionship and sex and love and security and lots of other familiar things.

  The biggest significant change, one that really does alter what it is like to be human, may well be modern communication and transportation. The old geographical barriers that kept separate cultures separate have become almost irrelevant. Cultures are merging and reforming into a global multiculture. It’s hard to predict what it will look like, because this is an emergent process and it hasn’t finished emerging yet. It may be something quite different from the giant US shopping mall that is generally envisaged. That’s what makes today’s world so fascinating – and so dangerous.

  Ultimately, the idea that we are controlling our universe is an illusion. All we know is a relatively small number of tricks, plus one great generic trick for generating more small tricks. That generic trick is the scientific method. It pays off.

  We have also the trick of telling stories that work. By this stage in our evolution, we are spending most of our lives in them. ‘Real life’ – that is, the real life for most of us, with its MOT tests and paper wealth and social systems – is a fantasy that we all buy into, and it works precisely because we all buy into it.

  Poor old Phocian tried hard, but found that the old stories weren’t true when he hadn’t quite got as far as constructing a new one. He performed a reality check, and found that there wasn’t one – at least, not one he’d like to believe was real. He suddenly saw a universe with no map. We’ve got quite good at mapping, since then.

  1 Other recorded spellings are cience, ciens, scians, scyence, sience, syence, syens, syense, scyense. Oh, and science. Naturally, the wizards have invented another one.

  2 So called because it is near the larger island of Kythera. This is ‘anti’=near, not ‘anti’ = opposed to. Though, metaphorically, the two usages are close. Think about the meaning of ‘opposed to’. And ‘against’.

  3 The symbols have the following meanings: © = Sun, i = Moon, § = Mercury.

  4 On TV news we are repeatedly told about scientists who are ‘proving’ a theory. Either the people making the programme were trained in media studies and have no idea of how science works, or they were trained in media studies and don’t care how science works, or they’re still wedded to the old-fashioned meaning of the verb ‘prove’, which means to test. As in the phrase ‘the exception proves the rule’, which made perfect sense when it was first stated – the exception casts doubt on the rule by ‘testing’ it and finding it inadequate – and makes no sense at all when it is used today to justify ignoring awkward exceptions.

  5 In this, he is acting exactly like a scientist. Especially if it’s very expensive apparatus.

  6 Gait analysts do put horses on treadmills. However, the closest parallel to Phocian’s experiment is the widespread use of soot-covered cylinders to record insect movements.

  7 There have been many others. One of our favourites is Sir George Cayley, the early nineteenth-century aeronautical pioneer. He did sterling work on wing design, invented the light-tension wheel (effectively the modern bicycle wheel) as a light wheel for aircraft, and would almost certainly have achieved powered flight if only anyone had got around to inventing the internal combustion engine. He didn’t go mad, but he did experiment with an engine that ran on gunpowder.

  8 We’re in danger of heading into postmodernism here, which is a very bad idea when discussing an ancient Greek, and even more so when he’s fictitious. Suffice it to say that science also involves stringent reality-checks, and therefore is not
a purely social activity.

  9 Some current controversies, all ‘respectable’ – that is, with serious evidence for both sides – include: Is new variant CJD related to BSE (mad cow disease)? Has the human sperm count fallen? Was the Moon formed by a Mars-sized body hitting the Earth? Will the universe ever stop expanding? How are birds related to dinosaurs? Is quantum mechanics really random? Was there ever life on Mars? Is the triple-alpha process evidence that our universe is special? And is there anything that does not contain nuts?

  10 Yes, in some cases, it is claimed, werewolves and vampires have their roots in rare human medical conditions. Now try angels and unicorns …

  TWENTY-THREE

  PARAGON OF ANIMALS

  THE WIZARDS WENT BACK TO DEE’S HOUSE in sombre mood, and spent the rest of the week sitting around and getting on one another’s nerves. In ways they couldn’t quite articulate, they’d been upset by the story.

  ‘Science is dangerous,’ said Ridcully at last. ‘We’ll leave it alone.’

  ‘I think it’s like with wizards,’ said the Dean, relieved to be having a conversation again. ‘You need to have more than one of them, otherwise they get funny ideas.’

  ‘True, old friend,’ said Ridcully, probably for the first time in his life. ‘So … science is not for us. We’ll rely on common sense to see us through.’

  ‘That’s right,’ said the Lecturer in Recent Runes. ‘Who cares about trotting horses anyway? If they fall over they’ve only got themselves to blame.’