The Science of Discworld Revised Edition

as we’d like to believe we can. Still, what can you expect from a slightly brainy ape? We can give ourselves an excuse, an evolutionary one, and it’s this: we’re only halfway from
Australopithecus
(Lucy) to human. It’s not surprising that we keep finding limits to what our brains can comprehend. Neither is it surprising that our mental models won’t fit together to offer a convincing understanding of past events. We’re not smart enough. Yet.
    Wait another million years. Then we’ll show you.
    1 Some pterodactyls were sparrow-sized, and their wings could have carried them easily; but pteranodons can’t have taken off from the sea surface, or climbed up cliffs to hang-glide! Although
Quetzalcoatlus
has been modelled, and flown as a radio-controlled glider, that doesn’t tell us how it lived. Was there perhaps aerial plankton for it to eat?
    2 Though some palaeontologists think that such creatures were not feathered dinosaurs, but flightless birds. According to John Ruben,
Caudipteryx
was merely ‘a Cretaceous turkey, so to speak’.

THIRTY-SEVEN
I SAID, DON’T LOOK UP!

    PONDER WAS WORKING the Rules again. Now they read:
    THE RULES
    1 Things fall apart, but centres hold
    2 Everything moves in curves
    3 You get balls
    4 Big balls tell space to bend
    5 There are no turtles anywhere
    (after this one he’d added
Except ordinary ones)
    6 Life turns up everywhere it can
    7 Life turns up everywhere it can’t
    8 There is something like narrativium
    9 There may be something called bloodimindium (see rule 7)
    10
…
    He stopped to think. Behind him, a very large lizard killed and ate a slightly smaller one. Ponder didn’t bother to turn around. They’d been watching lizards for more than a hundred million years – all day, in fact – and even the Dean was giving up on them.
    ‘
Too
well adapted,’ he said. ‘No
pressure
on them, you see.’
    ‘They’re certainly very dull,’ said Ridcully. ‘Interesting colours, though.’
    ‘Brain the size of a walnut and some of them think with their backsides,’ said the Senior Wrangler.
    ‘Your type of people, Dean,’ said Ridcully.
    ‘I shall choose to ignore that, Archchancellor,’ said the Dean coldly.
    ‘You’ve been interfering again, haven’t you,’ Ridcully went on. ‘I saw you pushing some of the small lizards out of that tree.’
    ‘Well, you’ve got to admit that they
look
a bit like birds,’ said the Dean.
    ‘And did they learn to fly?’
    ‘Not in so many words, no. Not horizontally.’
    ‘Eat, fight, mate and die,’ said the Lecturer in Recent Runes. ‘Even the crabs were better than this. Even the blobs made an effort. When they come to write the history of this world, this is the page everyone will skip. Terribly dull lizards, they’ll be called. You mark my words.’
    ‘They have stayed around for a hundred million years, sir,’ said Rincewind, who felt he had to stand up for non-achievers.
    ‘And what have they done? Is there a single line of poetry? A building of any sort? A piece of simple artwork?’
    ‘They’ve just not died, sir.’
    ‘Not dying out is some kind of achievement, is it?’ said the Lecturer in Recent Runes.
    ‘Best kind there is, sir.’
    ‘Pah!’ said the Dean. ‘All they prove is that species go soft when there’s nothing happening! It’s nice and warm, there’s plenty to eat … it’s just the sea without water. A few periods of vulcanism or a medium-sized comet would soon have them sitting up straight and paying attention.’
    The air shimmered and Ponder Stibbons appeared.
    ‘We have intelligence, gentlemen,’ he said.
    ‘I know,’ said the Dean.
    ‘I mean, the omniscope has found signs of developing intelligence. Twice, sir.’
    The herd was big. It was made up of large, almost hemispherical creatures, with faces that had all the incisive cogitation of a cow.
    Much smaller creatures were trotting along at the edges. They were dark, scrawny and warbled to one another almost without cease.
    They also carried pointed sticks.
    ‘Well …’ Ridcully began, dismissively.
    ‘They’re herding them, sir!’ said Ponder.
    ‘But wolves chase sheep …’
    ‘Not with pointy sticks, sir. And look there …’
    One of the beasts was towing a crude travois, covered with leaves. Several herders were lying on it. They were pale around the muzzles.
    ‘Are they sick, d’you think?’ said the Dean.
    ‘Just old, sir.’
    ‘Why’d they want to slow themselves down with a lot of old