Greg Egan - The Clockwork Rocket

Eusebio joined her, and the screen reprised the simple sketch he’d shown her: the detour, the long slow zigzag into the future that could buy them time, and with it fresh ideas and discoveries. It would be a risky journey, daunting for anyone to contemplate, but the Peerless needed whatever Zeugma’s people could bring to it. Navigating the void was just the start; to keep the community of travelers alive and thriving would take a whole city’s worth of inspiration and expertise.

Daria had advised them not to take questions from the floor; that only invited attention-seeking hecklers. Instead, they set up two desks in a corner of the foyer and invited people to come and speak with them after the performance, quietly, face-to-face.

Yalda had braced herself for a frenzy of disparagement spurred on by the negative coverage in Talk , but the audience as a whole had been no rowdier than the night before, and the individual interlocutors who approached them after the show were, if anything, more polite and encouraging. “I don’t believe a word of your scaremongering,” one young man told Yalda amiably, “but I do wish you luck.”

“Why do you think it’s scaremongering?”

“The world has survived for eons,” he replied. “History might not mention shooting stars like these, but the world is far older than we are. Geologists say the planet has been bombarded many times before; a few more stones from the sky will hardly be a calamity. But if you can send a rocket through the void and bring it back safely, that will be something to admire.”

“I can’t interest you in being a passenger yourself?” Yalda wasn’t taunting him; it might be worth having a thoughtful, good-natured skeptic among the travelers.

He said, “I think my children will stand a better chance of surviving with solid ground beneath their feet.”

Eusebio had to leave for an appointment with a legal adviser about the observatory dispute. Yalda decided to stay on a little longer; the foyer wasn’t empty yet, even if most of the dawdlers seemed to be talking among themselves rather than waiting for the right time to approach her.

When the clock struck two chimes before midnight, she started packing away her information pamphlets. She’d gathered five more names on top of the seven from the night before, and even if these volunteers were willing to do no more than plant crops in an artificial cave inside the mountain, that would be something.

As she stepped away from the desk, a young woman hurried across the foyer toward her.

“I’m sorry,” the woman said. “I wasn’t sure if I should speak to you, but…”

Yalda put down her box of pamphlets. “What did you want to say?”

“I was thinking about your rocket. One thing worries me—” She stopped and lowered her gaze, suddenly shy, as if her words might already have been too presumptuous.

“Go on,” Yalda encouraged her. “If there’s only one thing that worries you, you’re a dozen times more confident than I am.”

The woman said, “When the rocket turns around and comes back toward us… from the point of view of the travelers on the first half of the journey, isn’t it now moving backward in time?”

“Yes it is,” Yalda agreed. “That’s exactly right.”

“And from the point of view of the Hurtlers, and the worlds you think might collide with us… the same thing is true? In the second half of the journey, the rocket will be traveling into their past as well?”

“Yes.” Yalda was impressed; though it was a simple enough observation, only Eusebio and Giorgio had raised it with her before.

The woman looked up, fidgeted anxiously. “Is that… safe ?”

“We don’t know,” Yalda admitted. “To what degree the rocket will carry its own arrow of time, embodied in its passengers and cargo, and to what degree its surroundings will influence the arrow… we don’t know.”

“So you’re hoping the travelers will learn enough on the outward voyage to protect themselves on the inward leg?” the woman suggested.

“I suppose it does come down to that.” Yalda had berated Eusebio for relying on uninvented methods of propulsion, but the truth was they had no hope of preparing the travelers in advance for every hazard the journey would entail.

Gaining courage, the woman said, “I’d be satisfied if you could at least be sure that the rocket was heading into the Hurtlers’ future at the start of the trip. If it takes half an age to prepare for the clash, so be it—but having to face that problem from the very beginning would be too much.”

“Satisfied enough… to approve of the venture?”

“Satisfied enough to be a passenger myself.”

Yalda said, “Can I ask your name?”

“Benedetta.”

Yalda took her over to the desk and recorded her details, trying not to let slip that no one else had come close to making such a commitment—not even the recruiter herself.

“Have you studied somewhere?” Yalda asked her. The first passenger of the Peerless had described her profession as “factory worker”.

“In Jade City,” Benedetta admitted reluctantly, as if this were somehow shameful. “I studied engineering, but only for a year.”

“It’s not important, I was just curious.” Yalda heard the forced joviality in her own voice, and struggled to bring the tone back to normal. Asking Benedetta if she were a runaway might frighten her off completely; it was an issue they’d need to deal with at some point—in order to protect both her and the project—but for now all that mattered was that she was keen, and a quick enough thinker to have spotted a genuine problem.

They were alone in the foyer now. Yalda said, “I’m supposed to be out of here before the cleaners come in at midnight, but we can talk for a bit outside if you’re not busy.”

“There’s nowhere I need to be,” Benedetta replied.

Outside, the city was quiet. A dozen slow Hurtlers were spreading their colors across the sky. As the two of them walked away from the hall across the cobblestones, Benedetta said, “Do you really believe that time loops around on itself?”

“I can’t be certain,” Yalda replied. “But I think the evidence is strong.”

“So the future is no different from the past?”

“The real difference is a matter of what we know,” Yalda said. “What information is easily accessible to us. We can know much more about the past than the future, at least if we don’t try to look back too far. But that’s a product of the vagaries of history; there’s no absolute distinction.”

“But then… everything that’s yet to happen is fixed, just as much as everything in the past?”

“Yes.”

“So why are you striving so hard to change the future?”

Yalda buzzed with delight; she should have seen that coming. “‘Change’ isn’t quite the right word,” she suggested. “You can strive to change a bad law—because the law can be different at different times. But either we survive this encounter or we don’t. Whatever the outcome is, no one will change it.”

Benedetta accepted this, but persisted. “What word should I use then? ‘Influence’?”

“I can live with that,” Yalda said. “I’ll own up to striving to influence the future.”

“But how can you influence the future if it’s as fixed as the past? Do you try to influence what happened yesterday?”

“Not anymore,” Yalda said, “but I certainly did the day before.”

“ Why, though? If you believe that what happened yesterday has always been fixed, wouldn’t it have turned out the same, regardless?” Benedetta wasn’t teasing her, or playing rhetorical games; she genuinely needed an answer.