to you—as if we were just actors following a script—then how can we really be changing each other’s minds? How can we be communicating anything?”
“Do I sound as if I’m making random noises for no particular reason?” Yalda joked.
“No.”
“If there’s a script,” Yalda said, “then we’re the playwrights as well as the actors; there’s no one else who could write our lines. There’s no puppet-master rushing around coordinating everything, forcing us to act against our will—or to make choices that go against our nature—just so history will reach its pre-ordained conclusion.”
“Then how does it work?” Benedetta demanded. “How do things turn out the way they have to?”
Yalda said, “The trick is to stop thinking that it works like fate in the sagas: some tedious monarch overcomes the odds and wins a great battle, because all the bit-players are nothing but cogs whose every action is subservient to his destiny. The reality is the opposite of that: ‘the way things have to be’ is completely unspectacular, and it’s fulfilled at the lowest possible level.
“We don’t know the details for every kind of matter, but in the case of free light the basic building blocks are just cyclic waves. When you make a full circuit of the cosmos in any direction, these waves undergo a whole number of cycles, so they return smoothly to their starting values. That’s it, that’s destiny fulfilled already… because anything constructed from waves like that will automatically share the same property. However complex a pattern of light you build up, it can’t contradict itself when it comes full circle. That’s guaranteed by the lowest-level physics; it doesn’t have to be orchestrated, or scripted, or contrived.”
Benedetta considered this. “So where are
“In our biology,” Yalda said. “I think there’s a degree of consistency between our desires and our actions grounded in the structure of our brains and bodies. What you want, what you do, who you are… these things might not be in perfect harmony, but we’re not prisoners trapped in our bodies while they follow some plan that has nothing to do with us.” At least not until fission took over and split you in four, but Yalda didn’t want to get into that.
Benedetta fell silent as they started across the Great Bridge. Yalda didn’t expect to change her mind on this; the important thing was for her to understand that she could raise anything with her colleagues in the project. When you planned to send a mountain flying through the void at an infinite velocity, there was no such thing as too abstruse a concern.
Finally she said, “I’ll have to think on this more deeply. I can certainly see some force in your arguments.”
Yalda could hear the reservation in her voice. “But?”
Benedetta said, “It’s one thing to argue an abstract case that the future being fixed changes nothing: that there’s really no freedom lost, because our actions are determined in the same way, regardless. The fact remains, though, that we’re
Yalda stopped walking. They were halfway across the bridge, supported by a slender arch of stonework over the blackness of the crevasse. She felt a shudder pass through the skin of her back; she’d just had an eerie sense of knowing what her shy, intense new colleague would say next.
“When our descendants turn around and travel back in time,” Benedetta wondered, “will they still have the luxury we have, of debating this in the abstract? Once past and future are no longer so clear, will they still have the choice to go on seeing things the old way?”
Eusebio counted, “Three. Two. One.”
A distant line of light split the sky, wavering in the heat haze. A pause later the bunker trembled; as the timber boards holding back the sand flexed and rattled, the air filled with fine dust. Yalda and her companions were lying flat on their backs, a stride beneath the ground, but the tilted mirror above let them watch the ascending rocket as if they were upright in the desert, while the tinted clearstone pane protected them from the glare.
Yalda was prepared for the hiss when it came, but not the crack that abruptly bisected the pane along a jagged diagonal. She reached up to support the two pieces before they could slip from the frame and decapitate someone.
Amando cursed quietly and raised his own hands to help; Eusebio did the same, exchanging a glance with Yalda expressing relief that it hadn’t been worse. They’d isolated both the mirror and the pane from ground vibrations, but the shock wave in the air had still been enough to do damage. Nereo didn’t flinch; he was still tracking the rocket with his theodolite, and probably hadn’t even noticed the crack.
Giulio, the journalist from Red Towers, turned to Eusebio chirping with excitement. “To be honest with you, I thought it would just explode on the ground. But it’s really up there!” He was too overwhelmed by the spectacle of the launch to care that he’d narrowly avoided being sliced in two by a giant stone blade.
“That’s what rockets do,” Eusebio replied modestly. “Ascend.”
“When does it fall down again?” Giulio asked.
“This one won’t,” Eusebio predicted.
Yalda wasn’t so sure. Through the protective filter the rocket had almost dimmed to invisibility; Eusebio would have gauged its progress by eye, but it would take the precise measurements of their independent observer to confirm its ultimate destination.
Giulio raised his head so he could peer over the intervening bodies and see what Nereo was up to. Nereo was propped up on a special bench that Amando had constructed; this allowed him to watch a clock with his rear gaze at the same time as he followed the rocket through the theodolite. Yalda could see a list of pairs of times and angles written along the length of Nereo’s right arm; as she watched, he added one more pair then looked away from the theodolite and began producing further columns of numbers. The rocket would still be burning fuel—so there was still a chance that it could lose stability and drive itself back toward the ground—but on the assumption that it would do no worse, now, than if it had simply cut off its engines at the last clear observation, Nereo could give a tentative verdict on its fate.
“It’s escaped the world’s gravity,” Nereo declared. “I suspect it’s heading for an eccentric orbit around the sun with a period of several dozen years.”
“How can it have
His tone of incredulity was appropriate, but he’d missed the point. Nereo said, “At the altitude it had reached on my last observation, gravity is barely diminished—but it was already moving rapidly enough to guarantee that it would never be brought to a halt. Not by the world—though the sun still had hold of it.”
Yalda looked to Amando, and together they managed to slide the tinted pane aside without the pieces falling on them. The bunker’s five occupants climbed to their feet and scrambled up onto the sand, slipping between the ground and the mirror.
Yalda searched the sky, high to the east. There weren’t many Hurtlers today to confuse the view, and she could see a faint gray speck that could only be Eusebio’s house-sized pillar of rock—engines still blazing, still gaining speed. The escape velocity for the sun itself was only three times greater than the world’s. Given the results from earlier yield experiments, if the rocket burned all its fuel without mishap it could actually end up leaving the solar system.
Giulio addressed Eusebio. “You should come to Red Towers and talk about your plans. Nereo’s already given public lectures on rotational physics, so the ideas aren’t completely new to people, but I can run some articles in the
Yalda wondered what was in the crops around Red Towers that was missing from Zeugma’s diet.
Eusebio said, “I’d be delighted.”
Yalda thanked Nereo for his participation. “It’s a pleasure,” he said. “I don’t know if your guess about the Hurtlers is right, but I’m glad someone’s thinking about these possibilities.”
“I can’t interest you in a place on the rocket?”
Nereo buzzed with mirth. “I’d rather stay safe on the ground, and wait for your dozen-fold-great- grandchildren to tell me all the marvelous science they’ve discovered.”
Yalda said, “I get that answer a lot.”
She wished she could have spent longer with Nereo, but he and Giulio needed to get back to Red Towers.
