With the pressure safely equalised, she cut the seal away completely, removed the lid and took out the mirror, careful not to detach the gridded paper that she’d glued beneath it.
Carla held the mirror up to catch the light. There was an unmistakable dull white patina, uniform and complete across the width of the mirror—but not its length. It stretched from one end of the rectangle to a point about halfway along, where it disappeared abruptly. She summoned the calibration notes for the grid onto her thigh. The tarnished region corresponded to a portion of the spectrum running from infrared to green.
Why stop at green? The intense light from the sunstone beam would have shaken the luxagens, making them vibrate, making them radiate their own light in turn… giving them the energy they needed to break out of the mirrorstone’s regular structure, damaging the surface, spoiling the sheen. But why should the color of the light have such a sharply delineated effect? The theory of solids held that a material’s only hope of stability was for its luxagens to sit in energy valleys whose natural frequency of vibration was greater than the maximum frequency of light—so at least that favored, resonant frequency couldn’t generate radiation and aid in the material’s destruction. So why should light have the power to shake luxagens loose on the red side of green but not the blue side? Since every color was far below the resonant frequency, the response should have varied smoothly across the spectrum, without any sudden jumps.
Carla turned the mirror back and forth in front of her eyes, wondering if it could all be an error, an artifact. Maybe an obstacle outside the container had intruded into the blue end of the spectrum—something Onesto had stashed under the bench for part of the night? But that was ridiculous; why would he have done that? And even if he’d set out deliberately to sabotage the experiment, she’d been present for the greater part of the exposure. Blue light had reached the mirror. The color-dependence was real.
As the mirror flared in the firestone’s light, a new feature marring the surface jumped out for an instant and then vanished. It was like glimpsing a white thread on a white floor, only to lose it again. Carla cursed and repeated the motion, over and over, until she found herself staring at a second, faint edge. In the half of the mirror that had seemed to her before to be uniformly shiny and new, there was in fact another, very subtle change in its reflectivity. The tarnish that she’d thought had ended completely at green actually continued—vastly diminished—along a section that stretched almost down to violet. And beyond that? She was no longer prepared to assume that the surface remained pristine; all she could be sure of was that she’d exhausted the discriminatory powers of her vision.
But there were at least two abrupt transitions in the density of the tarnish: two sudden changes in the damage the light had done, depending on its color.
Next to the calibration notes on her thigh, Carla wrote the wavelengths that marked these transitions. She committed them to memory, then started sketching luxagen arrays, doodling calculations, trying to make sense of the numbers. Maybe there was some kind of shift in the response of the mirrorstone when the light’s wavelength crossed some natural length scales dictated by its structure. Luxagens were expected to be separated from their nearest neighbors by roughly the same distance as light’s minimum wavelength, but other regularities showed up at greater distances.
There was no fit, though, between her two numbers and any of the known array geometries.
Carla paced the workshop. If not the wavelengths, what about the frequencies? She did the conversion: the green edge was at three dozen and three generoso-cycles per pause, the violet edge at two dozen and seven. But the frequencies at which luxagens were expected to vibrate, in mirrorstone or any other substance, could only be pinned down to within an order of magnitude—crudely constrained by the known properties of solids and the strength of Nereo’s force. So to what should she compare these frequencies?
To each other. They were in a ratio of five to four. Not exactly, but it was very close.
Carla remeasured the locations of the edges in the tarnish with scrupulous care, then recalculated everything.
Within the range of uncertainty imposed by the measurements, the ratio was indistinguishable from five to four.
4
Carlo said, “I’d like to come back to your team, if you’ll have me. I’m giving up on wheat. I want to work with animals again.”
Tosco reached out for a guide rope and pulled himself away from his workbench. “What’s brought this on?” he asked. “I never thought of you as easily discouraged.”
Carlo tried to block out the anxious humming of the voles; there must have been three or four dozen of the animals in the cages attached to the far wall. It hadn’t taken him long to grow accustomed to the blissful silence of the plant kingdom.
He said, “Do you know what my biggest achievement in the last three years has been? Understanding why some farms end up with all of their wheat-flowers synchronized, while in others the plants split into two groups that take turns producing light.”
“I wouldn’t belittle that,” Tosco said. “Surely the yield is higher when there are staggered shifts?”
“It is,” Carlo replied. “Having half your neighbors sleeping means less ambient light to inhibit production. But the difference is tiny, it’s marginal. What I was really looking for was a way to keep the flowers open for a greater portion of each day—and nothing I tried brought me any closer to that. If I’m getting nowhere, maybe I should admit that I made a mistake by switching fields in the first place.”
Tosco stretched out his top pair of arms in a gesture encompassing the workshop. “So what exactly would you do, if you rejoined us?” One of Carlo’s old colleagues, Amanda, was dissecting a lizard on a bench nearby, with a huddle of students looking on. In the corner behind them another researcher, Macaria, who’d been loading a centrifuge with tissue samples, swung down the safety shield and retreated. Sometimes the different density fractions in organic matter weren’t stable on their own, and the endpoint could be explosive.
Carlo took a moment to summon up his courage; until now he hadn’t put this into words for anyone. “I want to find a way to inhibit quadraparity.”
“I see.” Tosco’s tone was not enthusiastic. “Do you know how many drugs they tested for that, before either of us were born? The only thing that kept the vole population stable in that program was the fact that the fatal treatments balanced the merely ineffectual ones.”
“So it might require something other than a drug,” Carlo ventured.
“We know how to inhibit quadraparity,” Tosco said. “The solution might not be as pleasant as we’d wish—”
“Or as reliable,” Carlo interjected.
“It’s not perfect,” Tosco conceded. “But no treatment is perfect. It’s an innate property of women’s bodies that they produce four offspring under ordinary conditions. Anything that interferes with such a fundamental process is doing damage to their health, by definition.”
“Holin isn’t perfect,” Carlo protested, “but where’s the damage or the pain from that?”
“Putting reproduction on hold isn’t the same as modifying the outcome.”
Carlo couldn’t argue with that, but he couldn’t accept the larger claim either. “Women’s bodies have an innate ability to be biparous, too. It makes sense that it’s normally only triggered by famine; the question is, triggered how? If we could understand that process in detail, why shouldn’t we be able to push the same lever without the usual antecedents?”