The Science of Discworld Revised Edition

out, followed by a billiard ball. Ponder pulled aside a cluster of flags of all nations.
    ‘Just natural fallout,’ he called out. ‘Oh …’
    The Bursar ambled around the side of the reacting engine, waving a squash racket.
    ‘Ah, Ponder,’ he said. ‘Have you wondered if Time isn’t simply Space rotated through a right angle?’
    ‘Er … no …’ said Ponder, watching the man carefully for signs of thaumic breakdown.
    ‘It would certainly make pretzels very interesting, don’t you think?’
    ‘Er … have you been playing squash, sir?’ said Ponder.
    ‘You know, I’m really coming to believe that a closed contour is a boundary, up to parametrization, if and only if it is homotopic to zero,’ said the Bursar. ‘And, for preference, coloured green.’
    ‘Did you touch any switches, sir?’ said Ponder, maintaining a careful distance.
    ‘This thingy here does make some shots very difficult,’ said the Bursar, hitting the reacting engine. ‘I was trying to hit the rear wall around last Wednesday.’
    ‘I think perhaps we should leave,’ said Ponder in a clear, firm tone. ‘It will soon be teatime. There will be jelly,’ he added.
    ‘Ah, the fifth form of matter,’ said the Bursar brightly, following Ponder.
    The other wizards were waiting just outside the door.
    ‘Is he all right?’ said Ridcully. ‘I mean by general bursarial standards, of course.’
    ‘It’s hard to tell,’ said Ponder, as the Bursar beamed at them. ‘I think so. But the reacting engine must had been putting out quite a high flux when he went in.’
    ‘Perhaps none of the thaumic particles hit him?’ said the Senior Wrangler.
    ‘But there’s millions of them, sir, and they can pass through anything!’
    Ridcully slapped the Bursar on the back.
    ‘Bit of luck for you, eh, Bursar?’
    The Bursar looked puzzled for a moment, and then vanished.

FORTY-EIGHT
EDEN AND CAMELOT

    THIS BOOK WASN’T called The
Religion of Discworld
for a reason, although – Heaven knows – there is plenty of raw material. 1 All religions are true, for a given value of ‘truth’.
    The disciplines of science, however, tell us that we live on a world formed from interstellar debris some four billion years ago in a universe which itself is about 15 billion years old (which is science-speak for ‘a very long time’); that in the ensuing years it has been pummelled and frozen and re-arranged on a regular basis; that despite or rather
because
of this, life turned up very quickly and seems to spring back renewed and re-formed from every blow; and that we ourselves evolved on this planet and, with the suddenness of a bursting dam, became Top Species in a very short period of time.
    Actually, science tells us that many cockroaches, bacteria, beetles, and even small mammals might argue that last statement, but since they are not good at debate and can’t speak, who cares what they think? Especially since they can’t, eh? A key thing about big brains is this: they know big brains are good.
    Most of us don’t think like scientists. We think like the wizards of Discworld. Everything in the past was leading inevitably to Now, which is the important time.
    While the news that the Earth is a small planet in a dull part of the universe has caught on in recent centuries, it’s only in the last few decades that the words ‘the Earth’ have come to mean, for a significant proportion of any society, ‘the planet’ rather than ‘the soil’.
    It was probably those photographs of the Earth seen from the Moon that did it. We saw the whole planet as a single
thing
, rather than just the bit of it that we were standing on. And it looked fragile, and kind of lonely …
    We watch the fireworks as great balls of ice plummet into the atmosphere of a nearby planet and, although any one of them would have
seriously
troubled the Earth, the event was just that: a firework display. As one old lady told a news reporter, ‘that sort of thing happens in Outer Space’. But we’re in Outer Space, too, and it might pay us to get good at it.
    The dinosaurs were not, as suggested in
Jurassic Park
, ‘selected for extinction’ – they were clobbered by a very large rock, and/or its after-effects. Rocks don’t think.
    The dinosaurs were in fact doing very well, and had merely neglected to develop three-mile thick armour plating. They
may
even have evolved something that we’d recognize as ‘early civilization’; we shouldn’t underestimate how much the