The dark side of the sun - By Terry Pratchett Page 0,7

be told from a handful of numbers, then why need we go on living?’

Joan stood up, crossed to the wardrobe, and took out of it a waist-length white wig.

‘It’s obvious you do not understand p-math, then,’ she said. ‘We go on because to live is still better than to die. That has always been the choice of Humanity, even when we thought the future was a cauldron of possibilities.’

She combed out the wig. ‘We cannot be certain how he will die,’ she continued. ‘You or I, perhaps, may be the ones the Institute chooses to—’

Korodore spun round. ‘I have checked us all by deep-reach, RGD—’

‘Oh, Korodore! I’m sorry. But you have such a touching faith in cause and effect! Don’t you know that in an infinite Totality all universes will happen? There is a universe somewhere where at this moment you will turn into a—’

‘Such things are said, madam,’ he muttered.

‘You disapprove of me,’ she said, and pouted.

He raised his eyes to the gold century disc on her forehead and smiled thinly.

‘Now, you are too old, madam, to try wiles of that kind. But I do disapprove. This meddling is not a good thing. It stinks of magic, witchcraft.’

‘I haven’t studied the pre-Sadhimist religions in any great depth, Korodore.’

‘All right, madam. What happens if Dom doesn’t die?’

‘It’s unthinkable. This is the datum universe – he’ll die. In a sense, the whole universe depends on the fact. If he didn’t die, perhaps he’d discover the Jokers World and that could be terrible.’

‘And if he doesn’t?’

Joan adjusted the wig and opened the window looking out over the sea. The fishing fleet was coming in with the tide, lit by the hanging pinpoint of Widdershins’ blue sun. On the horizon the light glinted sharply off the Tower in the marshes.

‘It’s too hot to sleep,’ she said. ‘I’ll finish this, and then I’ll go down to the jetty.’

‘Mystic law of the universe?’ asked Korodore, as she reopened the book.

‘They are the household accounts, sir,’ she said sharply. ‘A great comfort in times of trial.’

She wondered why she had never dismissed the man as security chief, and the answers queued up in her mind, ranging from his proven efficiency to the mitigating circumstance that he was Earth-born. Perhaps there were many other reasons.

As he turned to go she called him back.

‘With regard to your question about Dom,’ she said, ‘in all humility, p-math is a young art. I doubt if there is anyone adept enough to know. Even the Institute doesn’t know everything.’

‘Dom might. His tutor says he is showing a disconcerting insight. Oh, I don’t question your reasoning. If it is inevitable, perhaps it is better he shouldn’t know. You can see he is the type the Institute hunts down.’

‘You see, we can’t answer all the questions.’

He shrugged. ‘Perhaps you are asking the wrong questions.’

PROBABILITY MATH:

‘As with the first Theory of Relativity and the Sadhimist One Commandment, so the nine equations of probability math provide an example of a deceptively simple spark initiating a great explosion of social change.

‘ “Probability math predicts the future.” So says the half-educated man. A thousand years ago he would have mouthed “E equals MC squared” and believed he had encompassed the soaring castle of mathematical imagination …

‘Probability math arises from the premise that we dwell in a truly infinite totality, space and time without limit, worlds without end – a creation so vast that what we are pleased to call our cause-and-effect datum Universe is a mere circle of candlelight. In such a totality we can only echo the words of Quixote: All things are possible ...’

‘… vindicated with the predicted discovery of the Internal Planets of Protostar Five. Then humanity could be sure – even from this tiny grain of proof. On either “side” were ranged the alternate Universes, uncounted millions differing perhaps by the orbit of an electron. Further, the difference must be greater – until in the looming shadows on the edge of imagination came the universes that had never known time, stars, space or rationality. What p-math did was quantify the possible timelines of our datum universe. It did much more than that, however. Perhaps it brought back the essence of science from the days when it was half an art, when Creation was seen as a marvellous, carefully regulated clock – with all parts harmonizing to make the whole …’

‘… As Sub-Lunar pointed out in those early years, p-math depended on a certain innate mental agility. Many superb practitioners were also incurably insane,