Greg Egan - The Arrows of Time

‘The diagram calculus is beautiful.’ Lila didn’t use that word lightly. ‘It’s the most promising approach I’ve seen for a long time.’

Beautiful… but still merely promising? Agata wasn’t offended; she knew that she hadn’t taken the project to completion herself. But what had Lila and her students been doing in the interim? She wasn’t vain enough to imagine that they’d been hanging back, waiting for her to join them in the flesh and guide them forward.

‘So how much progress has there been?’ Agata pressed her. ‘The effects of curvature and topology were still very sketchy in the version I sent you – but I’m sure people must have found ways to tidy up most of the loose ends by now.’

Lila hesitated. ‘I’m afraid things are much where you left them.’

‘Where I left them?’ Agata was confused. ‘When did all of this reach you?’

‘Almost three years ago,’ Lila replied.

Agata couldn’t hide her disappointment. ‘And no one’s tried to take it any further?’ She’d put ten years of her life into the diagram calculus, and the whole physics community had spurned the approach.

‘The lack of progress isn’t from a want of trying,’ Lila insisted. ‘And you shouldn’t take it personally. It’s got nothing to do with the quality of your work or the way it’s been received. The problem is far more widespread than that.’

Agata was mollified, but still confused. ‘What problem?’

‘We’ve all hit a dead patch,’ Lila said sadly. ‘Chemists, biologists, astronomers, engineers. Since they switched on the messaging system, there hasn’t been a single new idea across the mountain.’

‘You mean no one’s been sending back new ideas?’ Agata had predicted as much – but surely that self-censorship hadn’t surprised anyone.

‘Oh, the messages have contained no innovations,’ Lila confirmed. ‘But neither has the work itself.’

‘I don’t understand,’ Agata admitted.

Lila said, ‘If people did innovate, the results would leak back to them one way or another. I know you believed that they’d be able to keep quiet, so everything would go on as usual. But everything has not gone on as usual. We’ve had no new ideas since the system was turned on – because if we’d had them, we would have heard of them before we’d had a chance to think of them ourselves. The barriers to information flow are so porous now that the knowledge gradient has been flattened: the past contains everything the future contains… which means the future contains nothing more than the past.’

Agata was stunned. If this was true, the messaging system had undermined the whole reason for the mountain’s existence. Every generation before her had advanced their understanding in one field or another. What would her own generation be famous for? Rendering the creation of new knowledge impossible.

She dragged herself out of the dismal fantasy. To have lost three years was appalling, but the disaster would be self-limiting in the end.

‘So how long does this go on?’ she asked Lila.

‘About a dozen more stints.’

That would be five stints after the Surveyor returned. ‘I’m surprised people didn’t act sooner.’ The self-censorship hypothesis predicted an absence of news of future innovations – but news of their absence could have been sent back as soon as the dire situation was apparent. ‘I suppose it’s the writing we found on Esilio that tips the balance in the end?’ Agata suggested. ‘The system could hardly have been shut down before the Surveyor returned with that discovery, if it’s a crucial element in swinging the vote.’

Lila said, ‘The system isn’t shut down by a vote.’

Agata couldn’t understand why her tone was so bleak. She’d endured three frustrating years, but the dark times would soon be over. ‘So the Council plans to act unilaterally?’

‘There is no vote, there is no plan, there is no explanation,’ Lila replied. ‘All we know is that we’ve received no messages from any time later than a dozen stints from now. And in the run-up, there’s nothing telling us why.’

‘The data just cuts out?’ Agata glanced up from the console; the expression on Tarquinia’s face was as grim as Lila’s voice.

‘Yes.’

‘So there’s a glitch of some kind,’ Agata concluded. She couldn’t take all this ominous brooding seriously; she’d seen the proof with her own eyes that the Peerless would survive all the way to the reunion.

‘No,’ Lila said flatly. ‘We ended up building more channels. They operate independently, so there could hardly be a glitch in all of them.’

Agata struggled to unpick the logic of that. ‘You had to build a second channel, even though the first one already told you that it wouldn’t help… because if you hadn’t built it you couldn’t have known that it wouldn’t help. But why build a third?’

‘We built a dozen.’ Lila buzzed, darkly amused. ‘You’re forgetting the Council’s paranoia. They weren’t convinced that they were being honest with each other about this event, so the process couldn’t stop until they each had a messaging channel of their own – built and run by people they’d vetted themselves.’

Agata was distracted for a moment by the sight of Ramiro, rocking back and forth with one hand against his tympanum, trying to contain his mirth.

‘So what came of all that?’ she asked. ‘Putting aside our own paranoia and assuming that at least one Councillor who found the truth would let us know.’

Lila said, ‘With every channel, the story’s been the same: the messages cut out at exactly the same time, and nothing that’s sent back while the system is still working tells us why.’

‘I just found a picture of you in the archives,’ Greta said. ‘There’s a banner behind you saying WELCOME HOME, but all in all it’s still quite sad. You look so old and worn down that you might be that woman’s uncle, not her brother. And her children don’t seem happy to see you at all.’

‘You sound like an actor who’s over-rehearsed her lines,’ Ramiro replied. ‘I suppose you’ve studied the recording of this conversation a dozen times?’

Greta buzzed derisively. ‘Don’t flatter yourself.’

‘No? Your first interaction with the Surveyor , in the middle of a political crisis? You didn’t send that back to the earliest moment that the bandwidth of the oldest channel allowed?’

‘I’ve read a summary, of course.’ Greta had to make it clear that she’d done her duty. ‘But I promise you, there wasn’t anything worth studying.’

Ramiro suspected that she was telling the truth; the technical reports would have been more valuable. But even if this conversation had been worthless to her, it didn’t follow that he’d get nothing out of it himself.

‘Thank you for the bomb,’ he said. ‘That really came in handy.’

‘Any time.’

‘So are you still on the Peerless ?’ he wondered. ‘Or have you evacuated already?’

‘I’m where I need to be.’

‘In the administrative sense, or the teleological?’ He waited, but Greta didn’t dignify that with a reply. ‘I’m guessing that there are a dozen evacuation craft, one for each Councillor – more or less copied from the Surveyor ’s plans. You started building them just after the system was switched on, when you learnt that Esilio was habitable and the Peerless might be in danger. You would have liked to improve the design or speed up the construction and make dozens more – but poor Verano found himself unable to innovate that much.’

Greta said, ‘All you need to know is that the Council will continue to govern across the disruption. The system proved its worth from the start.’