The Science of Discworld Quotes

“Science is not about building a body of known ‘facts’. It is a method for asking awkward questions and subjecting them to a reality-check, thus avoiding the human tendency to believe whatever makes us feel good.”
― Terry Pratchett, The Science Of Discworld

“Sometimes scientists change their minds. New developments cause a rethink. If this bothers you, consider how much damage is being done to the world by people for whom new developments do not cause a rethink.”
― Terry Pratchett, The Science of Discworld

“With magic, you can turn a frog into a prince. With science, you can turn a frog into a Ph.D and you still have the frog you started with.”
― Terry Pratchett, The Science of Discworld

“As humans, we have invented lots of useful kinds of lie. As well as lies-to-children ('as much as they can understand') there are lies-to-bosses ('as much as they need to know') lies-to-patients ('they won't worry about what they don't know') and, for all sorts of reasons, lies-to-ourselves. Lies-to-children is simply a prevalent and necessary kind of lie. Universities are very familiar with bright, qualified school-leavers who arrive and then go into shock on finding that biology or physics isn't quite what they've been taught so far. 'Yes, but you needed to understand that,' they are told, 'so that now we can tell you why it isn't exactly true.' Discworld teachers know this, and use it to demonstrate why universities are truly storehouses of knowledge: students arrive from school confident that they know very nearly everything, and they leave years later certain that they know practically nothing. Where did the knowledge go in the meantime? Into the university, of course, where it is carefully dried and stored.”
― Terry Pratchett, The Science of Discworld

“It was easy to respect an invisible god. It was the ones that turned up everywhere, often drunk, that put people off.”
― Terry Pratchett, The Science of Discworld

“Wizards can put up with any amount of deprivation and discomfort, provided it is not happening to them.”
― Terry Pratchett, The Science of Discworld

“Ponder had invented a little system he'd called, in the privacy of his head, Lies-to-Wizards. It was for their own good, he told himself. There was no point in telling your bosses everything; they were busy men, they didn't want explanations. There was no point in burdening them. What they wanted was little stories that they felt they could understand, and then they'd go away and stop worrying.”
― Terry Pratchett, The Science of Discworld

“Two student wizards were arguing vehemently, or at least repeatedly stating their point of view in a loud voice, which suffices for argument most of the time.”
― Terry Pratchett, The Science of Discworld

“The ‘draw a line’ philosophy offers a substantial political advantage to people with hidden agendas. The method for getting what you want is first to draw the line somewhere that nobody would object to, and then gradually move it to where you really want it, arguing continuity all the way. For example, having agreed that killing a child is murder, the line labelled ‘murder’ is then slid back to the instant of conception; having agreed that people should be allowed to read whichever newspaper they like, you end up supporting the right to put the recipe for nerve gas on the Internet.”
― Terry Pratchett, The Science of Discworld

“Liar-to-children is an honourable and vital profession, otherwise known as ‘teacher’. But what teaching does not do – although many politicians think it does, which is one of the problems – is erect a timeless edifice of ‘facts’.fn3 Every so often, you have to unlearn what you thought you already knew, and replace it by something more subtle.”
― Terry Pratchett, The Science Of Discworld

“Triboplasts played a crucial role in evolution, precisely because they did have internal organs, and in particular they could ingest food and excrete it. Their excreta became a major resource for other creatures; to get an interestingly complicated world, it is vitally important that shit happens.”
― Terry Pratchett, The Science of Discworld

“Reproduction, in particular, is a wonderful method of getting round the difficulties of manufacturing a really complicated thing. Just build one that manufactures more of itself. The first one may be incredibly difficult – but all the rest come with no added effort.”
― Terry Pratchett, The Science of Discworld

“On the contrary, he was a man with both feet firmly on the ground, the only difficulty being that the ground in question was on some other planet, the one with the fluffy pink clouds and the happy little bunnies.”
― Terry Pratchett, The Science of Discworld

“HEX decided to devote part of its time to investigating this interesting thing. It wanted to find out how it had developed, what kept it going … and why, particularly, a small but annoying part of it seemed to believe that if everyone sent five dollars to the six names at the top of the list, everyone would become immensely rich.”
― Terry Pratchett, The Science of Discworld

“Any sufficiently advanced technology is indistinguishable from magic. — ARTHUR C. CLARKE Any technology distinguishable from magic is insufficiently advanced. — GREGORY BENFORD The reason why truth is so much stranger than fiction is that there is no requirement for it to be consistent. — MARK TWAIN There are no turtles anywhere. — PONDER STIBBONS”
― Terry Pratchett, The Science of Discworld

“Darwin’s theory of evolution explains how lower lifeforms can evolve into higher ones, which in turn makes it entirely reasonable that a human should evolve into an orangutan (while remaining a librarian, since there is no higher life form than a librarian).”
― Terry Pratchett, The Science Of Discworld

“One of the great dreams of humanity has been to visit other worlds. It’s starting to look as though this might be a very good idea – not just for fun and profit, but for survival.”
― Terry Pratchett, The Science of Discworld

“To live in harmony with nature, we must know how to sing the same song as nature. To do that, we must understand nature. Good intentions aren’t enough. Science might be – if we use it wisely.”
― Terry Pratchett, The Science of Discworld

“Is the solar system stable?’, which means ‘Could it change dramatically as a result of some tiny disturbance?’ In 1887 King Oscar II of Sweden offered a prize of 2,500 crowns for the answer. It took about a century for the world’s mathematicians to come up with a definite answer: ‘Maybe’. (It was a good answer, but they didn’t get paid. The prize had already been awarded to someone who didn’t get the answer and whose prizewinning article had a big mistake right at the most interesting part. But when he put it right, at his own expense, he invented Chaos Theory and paved the way for the ‘maybe’. Sometimes, the best answer is a more interesting question.) The point here is that stability is not about what a system is actually doing: it is about how the system would change if you disturbed it. Stability, by definition, deals with ‘what if?’. Because a lot of science is really about this non-existent world of thought experiments, our understanding of science must concern itself with worlds of the imagination as well as with worlds of reality. Imagination, rather than mere intelligence, is the truly human quality.”
― Terry Pratchett, The Science of Discworld

“It is known that knowledge is power, and power is energy, and energy is matter, and matter is mass, and therefore large accumulations of knowledge distort time and space.”
― Terry Pratchett, The Science of Discworld

“The High Energy Magic building was getting crowded now. Even the student wizards were taking an interest, and usually they weren't even seen during daylight.”
― Terry Pratchett, The Science of Discworld

“years ago, when it underwent a rapid increase to the current level of 21%. The amount of oxygen in today’s atmosphere is far greater than could ever be sustained without the influence of living creatures, which not only produce oxygen in huge quantities but use it up again, in particular”
― Terry Pratchett, The Science of Discworld

“When humans came to the Americas from Siberia, by way of Alaska, they slaughtered their way right down to the tip of South America in a few thousand years, wiping out dozens of species – giant tree sloths and mastodons (ancient elephants, like mammoths but different), for example. Some”
― Terry Pratchett, The Science of Discworld

“there are three important questions you should ask – especially if it’s a government scientist. These are: ‘Is there any evidence against?, ‘Has anyone looked?’, and ‘If they did, would they expect to find anything?’*2”
― Terry Pratchett, The Science of Discworld

“Captive imaginations do breed quite effectively, because they are protected from the terrible predator known as Thought.”
― Terry Pratchett, The Science of Discworld

“Imagine a lot of creatures of the same species. They are in competition for resources, such as food – competing with each other, and with animals of other species. Now suppose that by random chance, one or more of these animals has offspring that are better at winning the competition. Then those animals are more likely to survive for long enough to produce the next generation, and the next generation is also better at winning. In contrast, if one or more of these animals has offspring that are worse at winning the competition, then those animals are less likely to produce a succeeding generation – and even if they somehow do, that next generation is still worse at winning. Clearly even a tiny advantage will, over many generations, lead to a population composed almost entirely of the new high-powered winners. In fact, the effect of any advantage grows like compound interest, so it doesn’t take all that long. Natural selection sounds like a very straightforward idea, but words like ‘competition’ and ‘win’ are loaded. It’s easy to get the wrong impression of just how subtle evolution must be.”
― Terry Pratchett, The Science of Discworld

“knowledge is power, and power is energy, and energy is matter, and matter is mass, and therefore large accumulations of knowledge distort time and space.”
― Terry Pratchett, The Science of Discworld

“Roy Lewis’s The Evolution Man;”
― Terry Pratchett, The Science of Discworld

“In Brazil, the rainforests of the Amazon are being destroyed at an alarming rate by bulldozing and burning. There are many excellent reasons to prevent this continuing – loss of habitat for organisms, production of carbon dioxide from burning trees, destruction of the culture of native Indian tribes, and so on. What is not a good reason, though, is the phrase that is almost inevitably trotted out, to the effect that the rainforests are the ‘lungs of the planet’. The image here is that the ‘civilized’ regions – that is, the industrialized ones – are net producers of carbon dioxide. The pristine rainforest, in contrast, produces a gentle but enormous oxygen breeze, while absorbing the excess carbon dioxide produced by all those nasty people with cars. It must do, surely? A forest is full of plants, and plants produce oxygen. No, they don’t. The net oxygen production of a rainforest is, on average, zero. Trees produce carbon dioxide at night, when they are not photosynthesizing. They lock up oxygen and carbon into sugars, yes – but when they die, they rot, and release carbon dioxide. Forests can indirectly remove carbon dioxide by removing carbon and locking it up as coal or peat, and by releasing oxygen into the atmosphere. Ironically, that’s where a lot of the human production of carbon dioxide comes from – we dig it up and burn it again, using up the same amount of oxygen. If the theory that oil is the remains of plants from the carboniferous period is true, then our cars are burning up carbon that was once laid down by plants. Even if an alternative theory, growing in popularity, is true, and oil was produced by bacteria, then the problem remains the same. Either way, if you burn a rainforest you add a one-off surplus of carbon dioxide to the atmosphere, but you do not also reduce the Earth’s capacity to generate new oxygen. If you want to reduce atmospheric carbon dioxide permanently, and not just cut short-term emissions, the best bet is to build up a big library at home, locking carbon into paper, or put plenty of asphalt on roads. These don’t sound like ‘green’ activities, but they are. You can cycle on the roads if it makes you feel better.”
― Terry Pratchett, The Science of Discworld

“Mud is lumpy, but the rules of fluid dynamics don’t take account of lumps.”
― Terry Pratchett, The Science of Discworld