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
“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
Carlo 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
“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
“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
“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
