The Science of Discworld Revised Edition

this infernal engine.’ He nodded towards the red lever on the plinth.
    ‘I was rather assuming you would do the honours, Archchancellor,’ said Ponder, bowing. ‘All you need to do is pull the lever. That will, ahem, release the interlock, allowing the flux to enter the exchanger, where a simple octiron reaction will turn the magic into heat and warm up the water in the boiler.’
    ‘So it really
is
just a big kettle?’ said the Dean.
    ‘In a manner of speaking, yes,’ said Ponder, trying to keep his face straight.
    Ridcully grasped the lever.
    ‘Perhaps you would care to say a few words, sir?’ said Ponder.
    ‘Yes.’ Ridcully looked thoughtful for a moment, and then brightened up. ‘Let’s get this over quickly, and have lunch.’
    There was a smattering of applause. He pulled the lever. The hand on a dial on the wall moved off zero.
    ‘Well, we’re not blown up after all,’ said the Senior Wrangler. ‘What are the numbers on the wall for, Stibbons?’
    ‘Oh, er … they’re … they’re to tell you what number it’s got to,’ said Ponder.
    ‘Oh. I see.’ The Senior Wrangler grasped the lapels of his robe. ‘Duck with green peas today, gentlemen, I believe,’ he said, in a far more interested tone of voice. ‘Well done, Mr Stibbons.’
    The wizards ambled off in the apparently slow yet deceptively fast way of wizards heading towards food.
    Ponder breathed a sigh of relief, which turned into a gulp when he realized that the Archchancellor had not, in fact, left but was inspecting the engine quite closely.
    ‘Er … is there anything else I can tell you, sir?’ he said, hurriedly.
    ‘When did you
really
start it, Mister Stibbons?’
    ‘Sir?’
    ‘Every single word in the sentence was quite short and easy to understand. Was there something wrong about the way I assembled them?’
    ‘I … we … it was started just after breakfast, sir,’ said Ponder meekly. ‘The needle on the dial was just turned by Mr Turnipseed by means of a string, sir.’
    ‘Did it blow up at all when you started it up?’
    ‘No sir! You’d … well, you’d have
known
, sir!’
    ‘I thought you said back there that we wouldn’t have known, Stibbons.’
    ‘Well, no, I mean –’
    ‘I know you, Stibbons,’ said Ridcully. ‘And you would
never
test something out publicly before trying it to see if it worked. No one wants egg all over their face, do they?’
    Ponder reflected that egg on the face is only of minor concern when the face is part of a cloud of particles expanding outwards at an appreciable fraction of the speed of dark. 1
    Ridcully slammed his hand against the black panels of the engine, causing Ponder visibly to leave the ground.
    ‘Warm already,’ he said. ‘You all right up there, Bursar?’
    The Bursar nodded happily.
    ‘Good man. Well done, Mister Stibbons. Let’s have lunch.’
    After a while, when the footsteps had died away, it dawned on the Bursar that he was, as it were, holding the short end of the string.
    The Bursar was not, as many thought, insane. 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. He did not mind because he much preferred it to the real one, where people shouted too much, and he spent as little time there as possible. Unfortunately this had to include mealtimes. The meal service on Planet Nice was unreliable.
    Smiling his faint little smile, he put down his axe and ambled off. After all, he reasoned, the point was that the wretched thing stayed out of the … whatever it was, and it could certainly do a simple job like that without his watching it.
    Unfortunately Mr Stibbons was too worried to be very observant, and none of the other wizards bothered much about the fact that everything which stood between them and thaumic devastation was blowing bubbles into his glass of milk.
    1 As yet unmeasured, but believed to be faster than light owing to its ability to move so quickly out of light’s way.

FOUR
SCIENCE AND MAGIC

    IF WE WANTED to, we could comment on several features of Ponder Stibbons’s experiment, describing the associated science. For example, there is a hint of the ‘many worlds’ interpretation of quantum mechanics, in which billions of universes branch off from ours every time a decision might go more than one way. And there is the unofficial standard procedure of public opening