Greg Egan - The Eternal Flame

“For argument’s sake,” Councilor Prospero said, “let’s suppose that we do find a way to fuel the Peerless with orthogonal matter. Where would that get us? If we could bring the unused portion of the Object back to the home world, would that be fuel enough to move the planet itself?”

“No.”

“Or enough to power a swarm of rockets that could evacuate every one of the ancestors?”

“I very much doubt it,” Carla replied.

“So what use is any of this?” Prospero asked bluntly.

“What use was there in launching the Peerless in the first place?” Carla snapped back. “All I’m proposing is the best means I can think of to improve our understanding of orthogonal matter. I can’t tell you where that might lead us—except to a much-needed reduction in our ignorance on the subject.”

Giusta said, “And we thank you for your proposal, Carla. I think it’s time we heard from the next witness.”

Carla retreated and stood beside Ivo. “Don’t let them get to you,” he said quietly. “They can’t help acting out their own internal squabbles, even when they have company.”

It was Tamara’s turn to address the Council. “If we do hope to exploit the Object,” she said, “or to conduct even the most modest experiments there, we’re going to need to establish some permanent means to navigate safely between the Object and the Peerless . Many of the beacons we launched for the first flight of the Gnat are running out of sunstone or failing in other ways—and they’re all spreading out too far to remain useful for much longer.

“What I propose is a new system of beacons, arranged in a grid that remains fixed relative to the Peerless . That will require manual supervision of each beacon’s deceleration; there’s no other way that we’d be able to get the final velocities low enough. But even if the Council chooses to take no further interest in the Object, I propose that we launch these beacons regardless. We ought to be able to navigate the void around the Peerless at will, whenever the need arises. Suppose another body like the Object is sighted. Consider how much easier it would be to deal with, if we could send observers out to get a fix on its location immediately.”

Councilor Dino said, “You want to keep another gross of beacons out there in the sky, stocked up with sunstone, flashing once a bell… just in case we need them?”

“That was my original plan,” Tamara confessed. “But after listening to my colleague here, I’ve had a much better idea.” She turned to face Carla. “Don’t worry, I’m not going to take you up on that ‘light clock’ nonsense you were feeding me on the Gnat .”

Dino was bemused. “It’s reassuring to hear that we’ll be spared nonsense, but—”

Tamara said, “We won’t need to put lamps in these beacons, or clockwork. Just optics! If Carla can build the light source she’s described, the beam it produces would only spread out a little as it traveled across the void. We could light the beacons from home: illuminate them all from the Peerless , keeping them simple and sparing us the need to refuel them or make repairs.”

Carla listened, delighted, as Tamara fleshed out her new scheme on the spot. Carla hadn’t given much thought to the infrastructure needed to make travel to the Object routine, but if she’d conspired with the navigators from the start they could not have made the case for her light source any stronger.

Ivo spoke next, then Ada. Though they all had different priorities, nobody was proposing a method of their own for manipulating luxagen-swapped rock. It would be light or nothing.

Giusta announced a recess in the hearing. Carla paced the chamber, wishing she’d brought her groundnuts along for comfort. Light or nothing—but most of the people she’d spoken to since the voyage had recoiled in horror when she explained just how dangerous orthogonal matter had turned out to be. And though Massimo’s line of questioning had been irritating, there was no denying that any attempt to exploit the stuff as fuel would carry enormous risks. Massimo and Prospero would not be alone in preferring to leave the Object sitting in the void, untouched.

Ivo approached her. “How would you identify the material for your light source?” he asked. “Just trial and error, or could you narrow down the candidates from their absorption spectra?”

“In principle the spectra should help,” Carla replied. “But to be honest, I’ve never been able to take a spectrum and turn it into a map of energy levels.”

Ivo was surprised. “It’s that difficult?”

Carla hummed softly. “Think of all the ways you can distribute luxagens among the energy levels. The only clear rule is that when the solid is in darkness, you’d expect all the luxagens in a given band to end up in that band’s highest level.”

Ivo pondered this. “Can’t you predict the number of luxagens per band? Or the number per valley?”

Carla said, “Remember the stability puzzle you posed, on the Gnat ?”

“Why don’t solids implode under pressure?”

“I did the calculations,” she said, “and the problem didn’t go away: I can’t explain why there should be any limit on the number of luxagens you can squeeze into each valley. So here I am rattling on about new ways to exploit the energy levels in solids… but I can’t actually tell you why every planet in the cosmos doesn’t shrink down to the size of a grain of sand.”

“Hmm.” Ivo tried not to sound too pleased. “I’m glad I wasn’t just imagining the problem, but I’d be a lot happier if I knew how to fix it.”

“I think we’ve all missed something,” Carla admitted. “The wave model can’t be completely wrong, but there must be some detail, some innocent-sounding premise that we rely on without thinking—” She realized belatedly that her gut had started spasming from hunger, the deep muscular twitches sending visible waves across her chest. Ivo politely looked away while she regained control.

The Councilors filed back into the chamber. Carla couldn’t read the decision from their faces; Silvano did not look happy, but then neither did Massimo and Prospero.

Giusta spoke on the Council’s behalf. “We thank all the witnesses for their testimony, and assure them that we’ve carefully considered their proposals. The judgment of this Council is that we must develop technology to allow a program of cautious experimentation into the nature and potential uses of orthogonal matter. For the time being, we require all such experiments to be conducted either in the vicinity of the Object or at similar remove in the void, with a strict moratorium on the transport of orthogonal matter into the Peerless .

“The only practical means to advance this program known to the Council is Carla’s proposal to develop a coherent light source. Accordingly, we ask her to submit a detailed schedule of resources and personnel for approval.”

“Congratulations,” Ivo whispered.

“Since the other proposals put to us today are all contingent on the same technology,” Giusta continued, “we will defer any decision in those cases until Carla’s team are able to report on the success or failure of their efforts.”

Carla was ecstatic. As the Councilors departed she stood swaying, listening to the good wishes of Ada and Tamara but unable to respond.

The lights of the chamber flared, becoming painfully bright. Carla tried to close her eyes but if she succeeded it made no difference. A voice addressed her from the whiteness. “Are you all right? Carla?” Someone put a hand on her shoulder, shaking her gently.

The lights faded. Tamara’s face was in front of her.