Terry Pratchett - The Science of Discworld I

He would have expected an entire universe to be heavier, but this one seemed on the light side. It was probably all that space.

The Archchancellor had explained at length to him that although he would be called the Egregious Professor of Cruel and Unusual Geography, this was only because that was cheaper than repainting the title on the door. He was not entitled to wages, or to teach, or express any opinions on anything, or order anyone around, or wear any special robes, or publish anything. But he could turn up for meals, provided he ate quietly.

To Rincewind, it sounded like heaven.

The Bursar appeared right in front of him. One moment there was an empty corridor, the next moment there was a bemused wiz­ard.

They collided. The sphere went up in the air, turning gently.

Rincewind rebounded from the Bursar, looked up at the ball curving through the air, flung himself forward and down with rib-scraping force and caught it a few inches from the stone floor.

'Rincewind! Don't tell him who he is!'

Rincewind rolled over, clasping the little universe, and looked back along the passage. Ridcully and the other wizards were advancing slowly and cautiously. Ponder Stibbons was waving a spoonful of jelly invitingly.

Rincewind glanced up the Bursar, who was looking perplexed.

'But he's the Bursar, isn't he?' he said.

The Bursar smiled, looked puzzled for a moment, and vanished with a 'pop'.

'Seven seconds!' shouted Ponder, dropping the spoon and pulling out a notebook. 'That'll put him in ... yes, the laundry room!'

The wizards hurried off, except for the Senior Wrangler, who was rolling a cigarette.

'What happened to the Bursar?' said Rincewind, getting to his feet.

'Oh, young Stibbons reckons he's caught Uncertainty,' said the Senior Wrangler, licking the paper. 'As soon as his body remembers what it's called it forgets where it's supposed to be.' He stuck the bent and wretched cylinder in his mouth and fumbled for his matches. 'Just another day at Unseen University, really.'

He wandered off, coughing.

Rincewind carried the sphere though the maze of dank passages and into his office, where he cleared a space for it on a shelf.

The ice age had cleared up. He wondered what was happening down there, what gastropod or mammal or lizard was even now winding up its elastic ready to propel itself towards the crown of the world. Soon, without a doubt, some creature would suddenly develop an unnecessarily large brain and be forced to do things with it. And it'd look around and probably declare how marvellous it was that the universe had been built to bring forward the inevitable development of creature-kind.

Boy, was it in for a shock ...

'Okay, you can come out,' he said. 'They've lost interest.'

The Librarian was hiding behind a chair. The orangutan took university discipline seriously, even though he was capable of clap­ping someone on both ears and forcing his brain down his nose.

'They're busy trying to catch the Bursar right now,' said Rincewind. 'Anyway, I'm sure it couldn't have been the apes. No offence, but they didn't look the right sort to me.'

'Ook!'

'It was probably something out of the sea somewhere. I'm sure we didn't see most of what was going on.'

Rincewind huffed on the surface of the globe, and polished it with his sleeve. 'What's recursion?' he said.

The Librarian gave a very expansive shrug.

'It looks okay to me,' said Rincewind. 'I wondered if it was some sort of disease ...'

He slapped the Librarian on the back, raising a cloud of dust. 'Come on, let's go and help them hunt ...'

The door shut. Their footsteps died away.

The world spun in its little universe, about a foot across on the outside, infinitely large on the inside.

Behind it, stars floated away in the blackness. Here and there they congregated in great swirling masses, spinning about some unimaginable drain. Sometimes these drifted together, passing through one another like ghosts and parting in a trailing veil of stars.

Young stars grew in luminous cradles. Dead stars rolled in the glowing shrouds of their death.

Infinity unfolded. Walls of glittering swept past, revealing fresh fields of stars ...

... where, sailing through the endless night, made of hot gas and dust but recognizable nevertheless, was a turtle.

As above, so below.

In a manner of speaking. They happen because things obey the rules of the universe. A rock has no detectable opinion about gravity.

Like the denizens of any Roundworld university, they have unlimited time for research, unlimited funds and no worries about tenure. They are also hy turns erratic, inventively malicious, resistant to new ideas until they've become old ideas, highly creative at odd moments and perpetually argumentative - in this respect they bear no relation to their Roundworld counterparts at all.

Wizard or 'Real' Squash bears very little relationship to the high speed sweat bath played elsewhere. Wizards see no point in moving fast. The ball is lobbed lazily. Certain magical inconsistencies are built into the floor and walls, however, so that the wall a ball hits is not necessarily the wall it rebounds from. This was one of the factors which, Ponder Stibbons realized some time after­wards, he really ought to have taken into consideration. Nothing excites a magical particle like meeting itself coming the other way.

Or at least, less radioactive. We can but hope.

He was the victim of a magical accident, which he rather enjoyed. But you know this.

They say that every formula halves the sales of a popular science book. This is rubbish - if it was true, then The Emperor's New Mind by Roger Penrose would have sold one-eighth of a copy, whereas its actual sales were in the hun­dreds of thousands. However, just in case there is some truth to the myth, we have adopted this way of describing the formula to double our potential sales. You all know which formula we mean. You can find it written out in symbols on page 118 of Stephen Hawking's A Brief History of Time - so if the myth is right, he could have sold twice as many copies, which is a mindboggling thought.

The fine structure constant is defined to be the square of the charge of an electron, divided by 2 times Planck's constant times the speed of light times the permittivity of the vacuum (as a handy lie, the last term might be thought as 'the way it reacts to an electric charge'). Thank you.

As yet unmeasured, but believed to be faster than light owing to its ability to move so quickly out of light's way.

Actually you can eat salt. But nobody outside Discworld goes to a restaurant to order a basalt balti.

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 universites 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.