Authors: Greg Egan
Tags: #Science Fiction, #General, #Space Opera, #Fiction
“One curve would be meaningless,” Carla agreed. “But this is where the bad news finally redeems itself. When the energy gap is small enough for a light wave to bridge the two frequencies, the rate at which the probability grows is just proportional to the intensity of the light. But the tiers we found with the mirrorstone suggest that the energy gap is four times too big for that—and for lower frequencies of light, five times too big. In which case, the rate is no longer proportional to the intensity itself: it’s proportional to the fourth or fifth power.”
Assunto grasped the significance of this immediately. “So it’s a higher-order effect,” he said. “The light wave creates a small disturbance in the energy valley, and the effect of that isn’t perfectly linear—so a complete description would have to include ever-smaller terms that depend on the square of the wave, the cube, the fourth power…”
“And the fourth power of the wave,” Carla added, “contains a frequency
four times higher
than that of the wave itself. There is no
light
with a frequency high enough to bridge the energy gap in a stable solid—but the fourth power of the same disturbance oscillates four times faster.”
“So how are you proposing to test all this?” Assunto pressed her.
“In the past, I’ve wasted sunstone,” Carla admitted. “There were things I could have measured that I didn’t even try to record. This time I’ll do it properly, once and for all. With a system of apertures and shutters, in a single run I can expose different parts of the same slab of mirrorstone to different intensities of light, for different lengths of time. The variation in the tarnishing over time should give us the exponential decay curves—and the variation with intensity should confirm the fourth-power rule in the first tier, and the fifth-power rule in the next. If we do find those power rules, surely that will be a sign that we’re on the right track.”
Assunto said, “Last time, the tiers were meant to mark the number of ‘photons’ each luxagen needed to make in order to break free.”
“They still do!” Carla replied. “These powers of the light’s intensity are the only way I know to calculate the tarnishing rates, but that doesn’t mean photons are out of the picture. When a luxagen changes its energy level, it still has to add a whole number of photons to the light: four or five, just as before.”
“But what drives the luxagen from one level to another in the first place?” Assunto answered the question himself. “Not a bombardment with particles, but the shaking of a wave.”
Carla couldn’t deny that. Patrizia’s interpretation of the scattering experiment in terms of colliding particles seemed irrefutable, but as yet there was no way to describe the tarnishing in the same language. They were still groping their way toward the truth, and the argument everyone had once thought settled in the days of Giorgio and Yalda was refusing to lie quietly in its grave.
Assunto said, “I’ll give you the sunstone for one more experiment, but that’s it. No more tinkering with the theory and trying again. If you don’t find the power rules you’ve predicted, you’ll have to accept that your ideas have been refuted and move on. Agreed?”
Carla had known that they were approaching this point, but to hear it put so starkly gave her pause. She could return to her collaborators and work through everything one more time: checking their calculations, revisiting their assumptions. Maybe they’d missed something crucial that would lead them to change their predictions—or something that could sweep away the lingering confusion and provide them with a surer bet.
But in less than two stints, Assunto would be answering to an entirely new Council, and there was no guarantee that he’d still have the power to offer her any sunstone at all. If they ended up losing the chance to perform this last experiment, there were no calculations that could tell them whether or not they’d been wasting their time. They needed to know the result itself, even more than they needed to be right.
Carla said, “Agreed.”
19
C
arlo abandoned the voles a bell earlier than usual to join the celebration in the hall below the main physics workshop. The corridors along the way were lined with posters for Silvano’s next election rally, promising voters the chance to MAKE YOUR CHILDREN PROUD.
Carla had urged him to invite all his colleagues and their families, but as far as he could see only Amanda and her co had turned up. The whole chamber was festooned with chains of small lamps, and—rather cruelly for the women, Carlo thought—there were baskets of seasoned loaves attached to every cross-rope, putting out an aroma that made it hard even for a moderately well-fed man to focus on anything else.
Patrizia, Carla’s young student, clung to a rope near the center of the hall, fending off an endless barrage of congratulations. “It took the three of us to get this far,” she kept saying. “And I didn’t solve the stability problem, that was Carla.” Her modesty appeared entirely sincere, but when Carlo moved among the clusters of physicists orbiting this star all he heard was talk of the urgent need to start applying “Patrizia’s principle” to some new problem or other.
He tried not to begrudge the girl her share of acclaim, but it undercut his sense that he ought to join in the rejoicing out of simple loyalty. What was there to celebrate, really, in this minuscule advance in the theory of solids? It had made Carla happy, and no doubt it would have some kind of payoff eventually, but what urgent need had it fulfilled? The ancestors would be oblivious to however long it took to find the cure to their woes. The travelers didn’t have that luxury.
Carla caught up with him. “Are you enjoying yourself?” she asked.
“Of course.”
“You don’t seem to be talking to anyone.”
Carlo said, “I get all the luxagen-speak I need from you.”
She feigned a punch at his shoulder. “Actually, it’s not all physicists here. Don’t you want to meet the woman who’ll be flying the
Gnat
?”
“That astronomer who found the Object?”
Carla emitted an exasperated hum. “Where have you been hiding for the last stint? Tamara gave birth. This is her replacement, Ada.”
Reluctantly, Carlo followed her across the hall. Ada was surrounded by her own circle of admirers, but they parted for Carla and she made the introductions.
“You’re a biologist, aren’t you?” Ada asked Carlo.
“That’s right.” There was an awkward silence, and Carlo realized that he was expected to say something more about his work, but he knew how that was likely to end. Everyone had heard the story of his amputation, and he was tired of being the butt of that joke.
Ada said, “Maybe you can answer this for me. Why should lizard skin be sensitive to infrared light?”
Carlo was about to deny that any such thing was true, when he realized what she was talking about: one of the chemists had extracted a component of the skin that fluoresced in visible light when it was illuminated with IR. “I’m not sure that it’s actually
sensitive
, in that the animal would know when it’s being exposed to infrared. As far as I’m aware it’s just a fluke, a chemical property with no biological significance.”
“Fair enough,” Ada said. “I was just curious, it seemed so strange.”
Carlo wasn’t really in the mood for small talk, but he didn’t want to embarrass his co. What did he know about this woman? “You must have been surprised when your colleague stepped down,” he ventured.
“It wasn’t that formal,” Ada replied. “She didn’t resign, we just got word from her family.”
“Ah.” That was shocking in its own way, but it made a lot more sense. No one in their right mind would give up the chance to fly the
Gnat
, but it wasn’t unheard of for couples with other plans entirely to wake in the night and let instinct take over.
“I wanted to see the children,” Ada said sadly. “But her co’s a farmer, and they’re quarantined with blight.”
“Quarantined?” Carlo had no reason to doubt her word, but he was taken aback. “I worked with wheat myself, not long ago. Wheat blight’s not usually that hard to control.”
“Her father said it was something new,” Ada explained.
Carlo felt a twinge of anxiety; he’d met half a dozen of his agronomist friends a few days earlier, and they hadn’t mentioned a new strain of blight. Had his defection so offended them that they were shutting him out of the loop? Or maybe they’d just been too busy teasing him about his mutinous fingers.
“Well, good luck with the journey,” he said. He started to back away along the rope when he caught Ada casting a quizzical glance at Carla, as if she’d expected something more from the exchange. Carlo paused, wondering which further nicety would be most appropriate: congratulations on her promotion, or commiserations on the fate of her friend.
Carla said, “Ada’s offered me a place on the
Gnat
.”
Carlo turned to Ada; her expression made it clear that this was the subject she’d been waiting to discuss. “I thought that was all down to the lottery,” he said.
“When the winner pulled out we asked the Council to reconsider,” Ada explained. “They agreed to let us choose a new crew member on the basis of their expertise. Tamara had talked about picking another chemist—but orthogonal matter isn’t something that chemists have actually worked with. Since Carla seems to have solved Yalda’s First Problem… I thought she might stand the best chance of also solving the Third.”
Carlo felt sick. Carla seemed excited, but he could tell that she was fearful too. A moment ago he’d told himself that no sane person could give up a chance like this, but his perspective had undergone a wrenching shift.
“She didn’t solve the stability problem overnight,” he said. “Do you really expect a once-in-a-generation breakthrough to be repeated on demand? Under pressure, in that tiny vehicle…?”
Ada raised a hand reassuringly. “That’s not what I was thinking at all. I don’t expect the mysteries of orthogonal matter to be resolved on the spot. I just want someone with us who’s familiar with the new ideas, and who’ll have a chance of applying them if the opportunity arises. Ivo’s a brilliant chemist with a vast amount of experience, but there’s no point telling him to start thinking of luxagens as waves. And frankly, there’s no point telling me either; I have no idea what it implies.”
Carla said, “We’ll have a few days to decide. But Ada wants to take the final crew list to the new Council for approval at their first meeting, so this is the time to ask her any questions.”
“Right.” Carlo struggled to clear his head. The mere thought of his co inside the
Gnat
as it receded to invisibility was painful enough, but now he had to face up to the purpose of the mission: capturing a mountain-sized mass of fuel by setting it alight. Orthogonal rocks that no one understood sprouting flame wasn’t the worst-case scenario—it was the whole plan.
He looked to Carla again. As anxious as she was, it was plain that this was what she wanted. And after all her work with the tarnishing experiments, all the false starts and blind alleys, all the grief Assunto had given her… didn’t she have the right to this moment of glory? He wasn’t going to tell her to be content that she’d done her bit for the ancestors.
What he owed her now was encouragement. That, and whatever he could do to ensure that she remained safe.
Carlo dragged himself closer to Ada.
He said, “Tell me what you’ll do if you start a wildfire on the Object. I want to know where the
Gnat
would be, relative to the point of ignition, and how you can be sure you’ll be able to get clear in time.”
20
T
he night before the election, Tamara walked to the clearing and checked the clock there, just in case she’d lost track of the date. She hadn’t. For the fourth time in her life the inhabitants of the
Peerless
were about to vote for a new Council.
Weeds were sprouting in the flower bed. It looked as if Tamaro hadn’t slept there for days. Did that mean that he was afraid of her now? Or was he spending his time even closer to her, hiding in the fields, watching and waiting for her children to arrive? Perhaps he believed that merely being present when they opened their eyes would be enough for him to form a bond with them, closing the rift he’d made and restoring the family to normalcy.
Tamara wound the clock, but left the weeds as she’d found them. She milled some flour and made a dozen loaves, then took them back to her camp beside the door. When she’d eaten three loaves she buried the rest in the store-hole, then lay down in her bed. She did not expect to sleep now, but the soil was blissfully cool.
In the morning, vote collectors would come to every farm. They would accept no excuse for neglecting this duty—however busy someone might be, however sick, however indifferent to the outcome. Erminio would have had Tamara’s name struck from the roll, but how could he keep the collectors away from his son? He might claim that Tamaro had business elsewhere and would cast his vote in another location—but then, by the end of the day the missing vote would be noted, the announcement of the tally would be delayed, and locating the miserable shirker would become everyone’s business. On the home world people had paid to become Councilors—and if the historians could be trusted, not one woman had ever attained that office. Tamara had trouble believing that, and the even more surreal corollary: when the
Peerless
returned, in the four years of its absence the situation was unlikely to have changed. True or not, though, the very idea was sufficiently affronting to imbue each election with added gravitas. To fail to vote would be seen as a declaration that the old ways had been just fine.
Tamara closed her eyes, willing the night to pass more quickly. Her fellow prisoner had no hope of sneaking past her, and his shameful dereliction would soon bring both of them all the attention she could have wished for. In a day or two her ordeal would be over.
Unless someone forged Tamaro’s signature. The local vote collectors would be neighbors who’d recognize him by sight, but it could be done in a remote part of the
Peerless
where neither Tamaro nor the impostor was known. The fake Tamaro could then travel back to his usual haunts to cast his own vote, so the tally would add up perfectly. Erminio couldn’t perform the fraud himself, the disparity in age would be too obvious. But if he could bribe a younger accomplice and teach him to mimic his son’s signature, the plan would not be too difficult to execute.