Eugene’s big college-athlete body was too powerful for the Moon’s feeble gravity, and as he paced he bounded over the polished floor. Fitfully he studied the graphs displayed on the softscreens, which showed how the sun’s actual behavior was tracking Eugene’s predictions. “Almost everything’s still nominal,” he said.
“Only the gammas are drifting upward,” Mikhail murmured.
“Yes. Only that. The perturbation analysis must have gone wrong somewhere. I wish I had time to go over it again …” He continued to worry aloud at the problem, talking of higher-order derivatives and asymptotic convergence.
In common with most real-world mathematical applications, Eugene’s model of the sun was like a math equation too complex to solve. So Eugene had applied approximation techniques to squeeze useful information out of it. You took some little bit of it you could understand, and tried to push away from that point in solution space step by step. Or you tried to take various parts of the model to extremes, where they either dwindled to zero or converged to some limit.
All these were standard techniques, and they had yielded useful and precise predictions for the way the sun was going to behave today. But they were only approximations. And the slow, steady divergence of the gamma ray and X-ray flux away from the predicted curve was a sign that Eugene had neglected some higher-order effect.
If Mikhail had been peer-reviewing Eugene’s work, the boy would certainly have come in for no criticism. This was only a marginal error, something overlooked in the residuals. In fact a divergence of fact from prediction was a necessary part of the feedback process that improved all scientific understanding.
But this wasn’t just a scientific study. Life-and-death decisions had been based on Eugene’s predictions, and any mistakes he had made could be devastating.
Mikhail sighed heavily. “We could never save everybody, no matter what we did. We always knew that.”
“Of course I understand that,” Eugene said with a sudden, startling snarl. “Do you think I’m some kind of sociopath? You’re so damn patronizing, Mikhail.”
Mikhail flinched, hurt. “I’m sorry.”
“I have family down there too.” Eugene glanced at Earth. America was turning into the storm, waking to a dreadful dawn; Eugene’s family were about to feel the worst of it. “All I could ever do for them is the science. And I couldn’t even get that right.”
He paced, and paced.
One-eye was frustrated and confused.
Tuft had defied him again. When he had found the fig tree with its thick load of fruit the younger male had failed to call the rest of the troop. And then, when challenged, Tuft had refused to yield to One-eye’s authority. He had just continued to push the luscious fruit into his thick-lipped mouth, while the rest of the troop pant-hooted at One-eye’s discomfiture.
By the standards of any chimpanzee troop, this was a severe political crisis. One-eye knew Tuft had to be dealt with.
But not today. One-eye wasn’t as young as he was, and he was stiff and aching after a restless sleep. And besides it was another hot, still, airless day, another day of the peculiar gloom that had swept over the forest, a day when you felt like doing nothing much but lying around and picking at your fur. He knew in his bones he wasn’t up to taking on Tuft today. Maybe tomorrow, then.
One-eye slunk away from the troop and moodily began to climb one of the tallest trees. He was going to bed.
In his own mind he had no name for himself, of course, any more than he had names for the others of the troop—although, as an intensely social animal, he knew each of them almost as well as he knew himself. “One-eye” was the name given him by the keepers who watched over the troop and the other denizens of this fragment of the Congolese forest.
At twenty-eight, One-eye was old enough to have lived through the great philosophical change that had swept over humankind, leading to his own reclassification as Homo, a cousin of humans, rather than Pan, a “mere” animal. This name change ensured his protection from poachers and hunters, of the kind that had put a bullet into his eye when he was younger than Tuft.
And it ensured his protection by his cousins now, on this worst day in the long history of humankind, and indeed of apes.
He reached the treetop. In his rough nest of folded-over branches he could still smell traces of his own feces and urine from his last sleep. He fiddled with the branches, pulling away loose tufts of his own fur.
Of course One-eye had no awareness of any of the revolution in human thinking, so crucial for his own survival. But he was aware of other changes. For instance, there was the peculiar muddling up of night and day. Over his head no sun was visible, no sky. Strange fixed lights lit up the forest, but compared with the tropical sun they could cast only twilight—which was why One-eye’s body was unsure whether it was time for him to sleep again, even though it was only a few hours since he had woken.
He lay down in his bed, throwing his long limbs this way and that as he thrashed around to get comfortable. He simmered with inchoate resentment at all these unwelcome changes, a bafflement with which many aging humans would have sympathized. And a bloody image of Tuft filled his mind. His big hands clenched as he considered what he would do to put his younger rival in order.
His scattered thoughts dissolved into a troubled sleep.
Heat and light poured from the high noonday sun, and a storm system that spanned a continent lashed. The dome’s silvered walls rippled and flapped with a sound like thunder. But they held.
Stripped to their underwear, in a living room lit only by a single candle, Bisesa and her daughter lay side by side on thin camping mattresses.
It was hot, hotter than Bisesa, with experience of northwest Pakistan and Afghanistan, would have thought possible. The air was like a thick moist blanket. She felt sweat pooling on her belly and soaking into the mattress underneath her. She was unable to move, unable to turn to see if Myra was okay, or even still alive.
She hadn’t heard Aristotle’s voice for hours, which seemed very strange. The room was silent, save for their breathing, and the ticking of a single clock. It was a big old carriage clock that had been an unwelcome legacy from Bisesa’s grandmother, but it still worked, its chunky mechanical innards immune to the EMP surge while softscreens, phones, and other electronic gadgets had been comprehensively fried.
Beyond the flat there was plenty of noise. There were immense booms and crashes like artillery fire, and sometimes what sounded like rain lashing against a wooden roof. That was sunstorm weather, predicted to follow the huge injection of heat energy into the atmosphere.
If things were this bad under the Tin Lid, she wondered how the rest of the country was faring. There would be flash floods, she thought, and fires, and windstorms like Kansas tornadoes. Poor England.
But the heat was the worst thing. She knew the bleak numbers from her military training. It wasn’t just temperature that got you but humidity. Evaporative heat loss through perspiration was the only mechanism her body had available to maintain its inner homeostasis, and if the relative humidity was too high, she couldn’t sweat.
Above thirty-seven degrees or so, beyond the “threshold of decrement,” her cognitive functions were slowed, her judgment impaired, and her manual and tracking skills weakened. At forty degrees and fifty percent humidity, the Army would have described her as a “heat ineffective”—but she could survive for maybe twenty-four hours. If the temperature was raised farther, or the humidity got worse, that time limit would be reduced. Past that point hyperthermia would set in, and her vital systems would begin to faiclass="underline" forty-five degrees, whatever the humidity, would see her succumb to severe heat stress, and death would quickly follow.