The Science of Discworld Revised Edition

the Big Savannah In The Sky or merely because it’s manifestly not a good idea to stay in a place where elephants get killed is unknown). But they work some magic for us. They add narrativium to our culture. They bring pain, hope, despair, and comfort. They wind up our elastic. Good or bad, they’ve made us into people.
    We wonder if the users thought that that cold-focusing mirror worked some magic for them. We can think of several ways in which it might appear to. And some very clever friends of ours are persuaded that souls might exist, too. Nearly everything is a process on some level. To a physicist, matter is a process carried out by a quantum wave function. And quantum wave functions exist only when the person you’re arguing with asserts that they don’t – so maybe souls exist in the same way.
    In this area, we have to admit the science doesn’t know everything. Science is
based
on not knowing everything. But it does know some things.
    1 And if so: congratulations! You are a human being, thinking narratively.
    2 Light on the Disc travels at about the same speed as sound. This does not appear to cause problems.
    3 And a terrible thing it is, akin to a state of horrible depression. Hence the affliction of Captain Vimes in
Guards! Guards!
who needs a couple of drinks simply to become sober.
    4 Well … most people.
    5 ‘Desperate’ is another privative – it means ‘no hope’.
    6 Death’s apprentice – well, he’d have to train a successor. Not in case he
dies:
so he can retire. Which he does (temporarily) in
Reaper Man
    7 Indeed, it is a ‘fundamental constant’ of the Discworld universe that things exist because they’re believed in.
    8 ‘Truth’ is a privative in the same way that ‘sober’ is – until you invent lies, you don’t know what the truth is. Nature appears to, otherwise animals would not have invested so much effort on very effective camouflage.

TWENTY-THREE
NO POSSIBILITY OF LIFE

    IT WAS DIFFICULT eating sandwiches that you couldn’t see. Rincewind was aware that back in the real world the Librarian was handing them to him, and he had to take it on trust that they were going to be cheese and chutney. As it turned out, he detected a hint of banana, too.
    The wizards were shocked. It’s terrible to find that you can’t do what you like with your own universe.
    ‘So we can’t just magic life into the Project?’ said the Dean.
    ‘I’m afraid not, sir,’ said Ponder. ‘We have quite a lot of control over things, but only in a very subtle way. I
have
gone into this.’
    ‘I don’t call moving huge worlds very subtle,’ said the Dean.
    ‘In Project terms, even moving the moon into place took a hundred thousand years,’ said Ponder. ‘Time prefers to move faster in there. It’s amazing what you can move if you give it a little push for that long.’
    ‘But we’ve done so many things –’
    ‘Just moved things around, sir.’
    ‘Seems a shame to have made a world and there’s no one to live on it,’ said the Senior Wrangler.
    ‘When I was small, I had a model farmyard,’ said the Bursar, looking up from his reading.
    ‘Thank you, Bursar. Very interesting,’ said the Archchancellor. ‘All right, let’s play by the rules. What do you have to move around to get people?’
    ‘Well … bits of other people, my father told me,’ said the Dean.
    ‘Bad taste there, Dean.’
    ‘Many religions start with dust,’ said the Senior Wrangler. ‘And then you bring it alive in some way.’
    ‘That’s pretty hard even with magic,’ said the Archchancellor. ‘And we can’t use magic.’
    ‘Up in Nothingfjord they believe that all life was created when the god Noddi cut off his … unmentionables and hurled them at the sun, who was his father,’ said the Senior Wrangler.
    ‘What, you mean his … underwear?’ said the Lecturer in Recent Runes, who could be a bit slow.
    ‘First of all we can’t physically exist inside the Project, secondly that sort of thing is unhygienic, and thirdly I doubt very much if you’ll find a volunteer,’ said the Archchancellor sharply. ‘Anyway, we’re men of magic.
That
is superstition.’
    ‘Can we make weather, then?’ said the Dean.
    ‘I think H EX can let us do that,’ said Ponder. ‘Weather is only pushing stuff around.’
    ‘So we can aim lightning at anyone we don’t like?’
    ‘But there isn’t anyone on the world, whether we like them or not,’ said Ponder wearily. ‘That’s
the point
.’
    ‘And