Thief of Time - Paradox

'Mr Jeremy, we want you to build us a clock that is accurate.'

'All my clocks are accurate,' said Jeremy, staring at his feet. He wasn't due to take his medicine for another five hours and seventeen minutes, but he was feeling the need for it now. 'And now I must ask-'

'How accurate are your clocks?'

'Better than a second in eleven months,' said Jeremy promptly.

'That is very good?'

'Yes.' It had been very good. That was why the Guild had been so understanding. Genius is always allowed some leeway, once the hammer has been pried from its hands and the blood has been cleaned up.

'We want much better accuracy than that.'

'It can't be done.'

'Oh? You mean that you can't do it?’

'No, I can't. And if I can't, then neither can any other clockmaker in the city. I'd know about it if they could!'

'So proud? Are you sure?'

'I'd know.' And he would. He'd know for certain. The candle clocks and the water clocks... they were toys, which he kept out of a sort of respect for the early days of timekeeping, and even then he'd spent weeks experimenting with waxes and buckets and had turned out primitive clocks that you could, well, very nearly set your watch by. It was okay that they couldn't be that accurate. They were simple, organic things, parodies of time. They didn't grind across his nerves. But a real clock... well, that was a mechanism, a thing of numbers, and numbers had to be perfect. She put her head on one side again. 'How do you test to that accuracy?' she said. They'd often asked him that in the Guild, once his talent had revealed itself. He hadn't been able to answer the question then, either, because it didn't make sense. You built a clock to be accurate. A portrait painter painted a picture. If it looked like the subject, then it was an accurate picture. If you built the clock right, it would be accurate. You didn't have to test it. You'd know.

'I'd know,' he said.

'We want you to build a clock that is very accurate.'

'How accurate?'

'Accurate.'

'But I can only build to the limit of my materials,' said Jeremy. 'I have... developed certain techniques, but there are things like... the vibration of the traffic in the street, little changes in temperature, that sort of thing.'

Lady LeJean was now inspecting a range of fat imp-powered watches. She picked one up and opened the back. There was the tiny saddle, and the pedals, but they were forlorn and empty.

'No imps?' she said.

'I keep them for historical interest,' said Jeremy. 'They were barely accurate to a few seconds a minute, and they'd stop completely overnight. They were only any good if your idea of accuracy was “around two-ish”.' He grimaced when he used the term. It felt like hearing fingernails on a blackboard.

'How about invar?' said the lady, still apparently inspecting the museum of clocks. Jeremy looked shocked.

'The alloy? I didn't think anyone outside the Guild knew about that. And it is very expensive. Worth a lot more than its weight in gold.'

Lady LeJean straightened up. 'Money is no object,' she said. 'Would invar allow you to reach total accuracy?’

'No. I already use it. It's true that it is not affected by temperature, but there are always... barriers. Smaller and smaller interferences become bigger and bigger problems. It's Xeno's Paradox.’

***

The Thief of Time - p22-24