by Greg Egan
The target this time was an oligosaccharide, a carbohydrate with nine rings arranged in pleasingly asymmetric tiers, like a small child’s attempt to build a shoe rack. Helpfully, the ChemFactor page kept it fixed on the screen as Latifa scrolled up and down through the long catalog of its potential suitors.
She trusted the software to have made some sensible choices already, on geometric grounds: all of these molecules ought to be able to nestle reasonably snugly against the target. In principle she could rotate the ball-and-stick models any way she liked, and slide the target into the same view to assess the prospective fit, but in practice that made the laptop’s graphics card choke. So she’d learned to manipulate the structures in her head, to picture the encounter without fretting too much about precise angles and distances. Molecules weren’t rigid, and if the interaction with the target liberated enough energy the participants could stretch or flex a little to accommodate each other. There were rigorous calculations that could predict the upshot of all that give and take, but the equations could not be solved quickly or easily. So ChemFactor invited people to offer their hunches. Newcomers guessed no better than random, and many players’ hit rates failed to rise above statistical noise. But some people acquired a feel for the task, learning from their victories and mistakes – even if they couldn’t put their private algorithms into words.
Latifa didn’t over-think the puzzle, and in twenty minutes she’d made her choice. She clicked the button beside her selection and confirmed it, satisfied that she’d done her best. After three years in the game she’d proved to be a born chemical match-maker, but she didn’t want it going to her head. Whatever lay behind her well-judged guesses, it could only be a matter of time before the software itself learned to codify all the same rules. The truth was, the more successful she became, the faster she’d be heading for obsolescence. She needed to make the most of her talent while it still counted.
#
Latifa spent two hours on her homework, then a call came from her cousin Fashard in Kandahar. She went out onto the balcony where the phone could get a better signal.
“How is your grandfather?” he asked.
“He’s fine. I’ll ask him to call you back tomorrow.” Her grandfather had given up on the shortwave and gone to bed. “How are things there?”
“The kids have all come down with something,” Fashard reported. “And the power’s been off for the last two days.”
“Two days?” Latifa felt for her young cousins, sweltering and feverish without even a fan. “You should get a generator.”
“Ha! I could get ten; people are practically giving them away.”
“Why?”
“The price of diesel’s gone through the roof,” Fashard explained. “Blackouts or not, no one can afford to run them.”
Latifa looked out at the lights of Mashhad. There was nothing glamorous about the concrete tower blocks around her, but the one thing Iran didn’t lack was electricity. Kandahar should have been well-supplied by the Kajaki Dam, but two of the three turbines in the hydroelectric plant had been out of service for more than a year, and the drought had made it even harder for the remaining turbine to meet demand.
“What about the shop?” she asked.
“Pedaling the sewing machine keeps me fit,” Fashard joked.
“I wish I could do something.”
“Things are hard for everyone,” Fashard said stoically. “But we’ll be all right; people always need clothes. You just concentrate on your studies.”
Latifa tried to think of some news to cheer him up. “Amir said he’s planning to come home this Eid.” Her brother had made no firm promises, but she couldn’t believe he’d spend the holidays away from his family for a second year in a row.
“Inshallah,” Fashard replied. “He should book the ticket early though, or he’ll never get a seat.”
“I’ll remind him.”
There was no response; the connection had cut out. Latifa tried calling back but all she got was a sequence of strange beeps, as if the phone tower was too flustered to offer up its usual recorded apologies.
She tidied the kitchen then lay in bed. It was hard to fall asleep when her thoughts cycled endlessly through the same inventory of troubles, but sometime after midnight she managed to break the loop and tumble into blackness.
#
“Afghani slut,” Ghamzeh whispered, leaning against Latifa and pinching her arm through the fabric of her manteau.
“Let go of me,” Latifa pleaded. She was pressed against her locker, she couldn’t pull away. Ghamzeh turned her face toward her, smiling, as if they were friends exchanging gossip. Other students walked past, averting their eyes.
“I’m getting tired of the smell of you,” Ghamzeh complained. “You’re stinking up the whole city. You should go back home to your little mud hut.”
Latifa’s skin tingled between the girl’s blunt talons, warmed by broken blood vessels, numbed by clamped nerves. It would be satisfying to lash out with her fists and free herself, but she knew that could only end badly.
“Did they have soap in your village?” Ghamzeh wondered. “Did they have underwear? All these things must have been so strange to you, when you arrived in civilization.”
Latifa waited in silence. Arguing only prolonged the torment.
“Too stuck up to have a conversation?” Ghamzeh released her arm and began to move away, but then she stopped to give Latifa a parting smile. “You think you’re impressing the teachers when you give them all the answers they want? Don’t fool yourself, slut. They know you’re just an animal doing circus tricks.”
#
When Latifa had cleared away the dinner plates, her grandfather asked her about school.
“You’re working hard?” he pressed her, cross-legged on the floor with a cushion at his back. “Earning their respect?”
“Yes.”
“And your heart is still set on engineering?” He sounded doubtful, as if for him the word could only conjure up images of rough men covered in machine oil.
“Chemical engineering,” she corrected him gently. “I’m getting good grades in chemistry, and there’d be plenty of jobs in it.”
“After five more years. After university.”
“Yes.” Latifa looked away. Half the money Amir sent back from Dubai was already going on her school fees. Her brother was twenty-two; no one could expect him to spend another five years without marrying.
“You should get on with your studies then.” Her grandfather waved her away amiably, then reached over for the radio.
In her room, Latifa switched on the laptop before opening her history book, but she kept her eyes off the screen until she’d read half the chapter on the Sassanid kings. When she finally gave herself a break the ChemFactor site had loaded, and she’d been logged in automatically, by cookie.
A yellow icon of a stylized envelope was flashing at the top of the page. A fellow player she’d never heard of called “jesse409” had left her a message, congratulating “PhaseChangeGirl” on a cumulative score that had just crossed twenty thousand. Latifa’s true score was far higher than that, but she’d changed her identity and rejoined the game from scratch five times so far, lest she come to the notice of someone with the means to find out who she really was.
The guess she’d made the previous night had paid off: a rigorous model of the two molecules showed that the binding between them was stable. She had saved one of ChemFactor’s clients the time and expense of doing the same calculations for dozens of alternatives, and her reward was a modest fraction of the resources she’d effectively freed. ChemFactor would model any collection of atoms and molecules she liked, free of charge – up to a preset quota in computing time.
Latifa closed her history book and moved the laptop to the center of her desk. If the binding problems were easy for her now, when it came to the much larger challenge she’d set herself the instincts she’d honed on the site could only take her so far. The raw computing power that
she acquired from these sporadic prizes let her test her hunches and see where they fell short.
She dug out the notebook from her backpack and reviewed her sketches and calculations. She understood the symmetries of crystals, the shifts and rotations that brought any regular array of atoms back into perfect agreement with itself. She understood the thrillingly strange origins of the different varieties of magnetism, where electrons’ spins became aligned or opposed – sometimes through their response to each others’ magnetic fields, but more often through the Exclusion Principle, which linked the alignment of spin to the average distance between the particles, and hence the energy they needed in order to overcome electrostatic repulsion. And after studying hundreds of examples, she believed she had a sense for the kind of crystal that lay in a transition zone where one type of magnetism was on the verge of shifting to another.
She’d sketched her ideal crystal in the notebook more than a year before, but she had no proof yet that it was anything more than a fantasy. Her last modeling run had predicted something achingly close, but it had still not produced what she needed. She had to go back one step and try something different.
Latifa retrieved the saved data from that last attempt and set the parameters for the new simulation. She resisted the urge to stab the CONFIRM button twice; the response was just taking its time weaving its way back to her through the maze of obfuscation.
Estimated time for run: approximately seven hours.
She sat gazing at the screen for a while, though she knew that if she waited for the prediction to be updated she’d probably find that the new estimate was even longer.
Reluctantly, she moved the laptop to the floor and returned to the faded glory of the Sassanids. She had to be patient; she’d have her answer by morning.
#
“Whore,” Ghamzeh muttered as Latifa hurried past her to her desk.
“You’re ten minutes late, Latifa,” Ms Keshavarz declared irritably.
“I’m very sorry.” Latifa stood in place, her eyes cast down.
“So what’s your excuse?”
Latifa remained silent.
“If you overslept,” Ms Keshavarz suggested, “you should at least have the honesty to say so.”
Latifa had woken at five, but she managed a flush of humiliation that she hoped would pass for a kind of tacit admission.
“Two hours of detention, then,” Ms Keshavarz ruled. “It might have been half that if you’d been more forthcoming. Take your seat, please.”
The day passed at a glacial speed. Latifa did her best to distract herself with the lessons, but it was like trying to chew water. The subject made no difference: history, literature, mathematics, physics – as soon as one sentence was written on the blackboard she knew exactly what would follow.
In detention with four other girls, she sat copying pages of long-winded homilies. From her seat she could see a driveway that led out from the staff car park, and one by one the vehicles she most needed to depart passed before her eyes. The waiting grew harder than ever, but she knew it would be foolish to act too soon.
Eighty minutes into her punishment, she started holding her breath for ever longer intervals. By the time she raised her hand there was nothing feigned in her tone of discomfort. The supervising teacher, Ms Shirazi, raised no objections and played no sadistic games with her. Latifa fled the room with plausible haste.
The rest of the school appeared deserted; the extra time had been worth it. Latifa opened the door to the toilets and let it swing shut, leaving the sound echoing back down the corridor, then hurried toward the chemistry lab.
The students’ entrance was locked, but Latifa steeled herself and turned into the warren of store rooms and cubicles that filled the north side of the science wing. Her chemistry teacher, Ms Daneshvar, had taken her to her desk once to consult an old university textbook, to settle a point on which they’d both been unsure.
Latifa found her way back to that desk. The keys were hanging exactly where she remembered them, on labeled pegs. She took the one for the chemistry lab and headed for the teachers’ entrance.
As she turned the key in the lock her stomach convulsed. To be expelled would be disastrous enough, but if the school pressed criminal charges she could be imprisoned and deported. She closed her eyes for a moment, summoning up an image of the beautiful lattice that the ChemFactor simulation had shown her. For a week she’d thought of nothing else. The software had reached its conclusion, but in the end the only test that mattered was whether the substance could be made in real life.
Late afternoon sunlight slanted across the room, glinting off the tubular legs of the stools standing upside-down on the black-painted benches. All the ingredients Latifa needed – salts of copper, barium and calcium – sat on the alphabetized shelves that ran along the eastern wall; none were of sufficient value or toxicity to be kept locked away, and she wouldn’t need much of any of them for a proof of principle.
She took down the jars and weighed out a few grams of each, quantities too small to be missed. She’d written down the masses that would yield the right stoichiometry, the right proportions of atoms in the final product, but having spent the whole day repeating the calculations in her head she didn’t waste time now consulting the slip of paper.
Latifa mixed the brightly colored granules in a ceramic crucible and crushed them with a pestle. Then she placed the crucible in the electric furnace. The heating profile she’d need was complicated, but though she’d only ever seen the furnace operated manually in class, she’d looked up the model number on the net and found the precise requirements for scripting it. When she pushed the memory stick into the USB port, the green light above flickered for a moment, then the first temperature of the sequence appeared on the display.
The whole thing would take nine hours. Latifa quickly re-shelved the jars, binned the filter paper she’d used on the scales, then retreated, locking the door behind her.
On her way past the toilets she remembered to stage a creaking exit. She slowed her pace as she approached the detention room, and felt cold beads of sweat on her face. Ms Shirazi offered her a sympathetic frown before turning back to the magazine she’d been reading.
#
Latifa dreamed that the school was on fire. The blaze was visible from the balcony of her apartment, and her grandfather stood and watched, wheezing alarmingly from the toxic fumes that were billowing out across Mashhad. When he switched on the radio, a newsreader reported that the police had found a memory stick beside the point of ignition and were checking all the students for a fingerprint match.
Latifa woke before dawn and ate breakfast, then prepared lunch for the two of them. She’d thought she’d been moving silently, but her grandfather surprised her as she was opening the front door.
“Why are you leaving so early?” he demanded.
“There’s a study group.”
“What do you mean?”
“A few of us get together before classes start and go over the lessons from the day before,” she said.
“So you’re running your own classes now? Do the teachers know about this?”
“The teachers approve,” Latifa assured him. “It’s their lessons that we’re revising; we’re not just making things up.”
“You’re not talking politics?” he asked sternly.
Latifa understood: he was thinking of the discussion group her mother had joined at Kabul University, its agenda excitedly recounted in one of the letters she’d sent him. He’d allowed Latifa to read the whole trove of letters when she’d turned fourteen – the age her mother had been when he’d gone into exile.
“You know me,” Latifa said. “Politics is over my head.”
“All right.” He was mollified now. “Enjoy your study.” He kissed her goodbye.
As Latifa dismounted from her bicycle she could see that the staff car park was empty except for the cleaners’ van. If she could bluff her way through this final stage she might be out of danger in a
matter of minutes.
The cleaners had unlocked the science wing, and a woman was mopping the floor by the main entrance. Latifa nodded to her, then walked in as if she owned the place.
“Hey! You shouldn’t be here!” The woman straightened up and glared at her, worried for her job should anything be stolen.
“Ms Daneshvar asked me to prepare something for the class. She gave me the key yesterday.” Latifa held it up for inspection.
The woman squinted at the key then waved her on, muttering unhappily.
In the chemistry lab everything was as Latifa had left it. She plucked the memory stick from the port on the furnace, then switched off the power. She touched the door, and felt no residual heat.
When she opened the furnace the air that escaped smelled like sulfur and bleach. Gingerly, she lifted out the crucible and peered inside. A solid gray mass covered the bottom, its surface as smooth as porcelain.
The instruments she needed to gauge success or failure were all in the physics lab, and trying to talk her way into another room right now would attract too much suspicion. She could wait for her next physics class and see what opportunities arose. Students messed around with the digital multimeters all the time, and if she was caught sticking the probes into her pocket her teacher would see nothing but a silly girl trying to measure the electrical resistance of a small paving stone she’d picked up off the street. Ms Hashemi wouldn’t be curious enough to check the properties of the stone for herself.
Latifa fetched a piece of filter paper and tried to empty the crucible onto it, but the gray material clung stubbornly to the bottom where it had formed. She tapped it gently, then more forcefully, to no avail.
She was going to have to steal the crucible. It was not an expensive piece of equipment, but there were only four, neatly lined up in a row in the cupboard below the furnace, and its absence would eventually be missed. Ms Daneshvar might – just might – ask the cleaners if they’d seen it. There was a chance that all her trespasses would be discovered.