The young man’s face peered shyly around the edge of Professor Sand’s office door like a rabbit checking a clearing in the woods for predators. Sand almost missed the faint motion, his attention on the lecture notes that he hadn’t quite had time to finish reviewing before class.
“Excuse me,” the young man announced, in case any predators had missed spotting him. “Do you have a minute?”
Extracting himself from his notes and glancing at the clock—five minutes to class time—Dr. Sand considered whether he had time to chat, wondering with a faint smile if the young man really meant “a minute.” The fellow looked a bit older than the typical student, perhaps twenty-five or twenty-six, and that meant he might find the courage to linger longer than most. The younger ones, when they did work up the courage to hop into the hunting grounds of a full professor, were usually in a hurry to escape. In this case, perhaps there was just enough time to learn the purpose of the visit and set up an appointment for later.
“Sure,” Sand said. “Have a seat.”
He waited for a moment to encourage the young man to speak first. After thirty years at the university, he understood that nurturing student maturity was his real job—teaching space engineering being only a vehicle. However, when the young man failed to speak and seemed transfixed by a photo on the wall of Sand at Aiken Base on the Moon, the narrowing window of time before class took precedence over the small lesson. Dr. Sand prompted gently.
“What can I do for you?”
“Oh, yes, sorry.” The young man turned quick intelligent eyes on Dr. Sand. “I was just noticing the picture. I’d sure like to go to the Moon.”
“Well, it’s becoming more common,” Dr. Sand answered with a pleased smile. “I was involved in setting up the first telescope array there. It was a nice opportunity.”
“It’s the Moon that I want to talk to you about,” the young man said. “My name is Aaron Seiler. Do you have time to answer a couple of questions?”
Clear, polite, and to the point. Dr. Sand tweaked up his ongoing assessment of Aaron. Shy maybe, perhaps a little awkward socially, but self-confident and professional.
“Actually, I have class right now,” Dr. Sand answered, sending his notes to the lecture room with a click of his mouse. “Could we set up an appointment for later today? I have office hours from two to four this afternoon.”
“That would be great,” Aaron said, standing. “Say two-thirty?”
“Sure.” Sand waved Aaron toward the door then followed him out of the office. “I’ll see you then.”
Aaron arrived at precisely two-thirty. Sand wondered if he had lurked in the hallway outside just to be sure he’d be exactly on time, something he would have done himself in his younger days. Probably would do still, now that he stopped to think about it. Promptness was a sign of professional courtesy and respect for other people’s time. He was starting to like this young man.
“So, what’re your questions?” Sand asked, once Aaron found a seat on one of the two chairs tucked into his cozy university-office-sized office.
“A prisoner being held at Moon base has disappeared.” Aaron leaned forward slightly as he spoke. “Vanished without a trace. I need to learn how he did it.”
Sand’s thoughts went through a have-I-been-transported-into-another-reality? moment. There were no prisons at Moon base. Not yet, anyway. Even if there were prisons, anyone escaping would certainly make the news, and there hadn’t been any news. Heck, even arresting one of the thirty-five or so loonies would make the news.
For the first time, Sand took note of Aaron’s Navy jacket. Did he have access to classified information about Aiken Base to which Sand was not privy?
Nonsense. The military might be able to ship people around Earth in secret, although that was becoming more difficult since ratification of the Mass and Energy Balance Treaty. But they certainly couldn’t send people and material to the Moon without those with access to Treaty data—like Sand—knowing about it. You just couldn’t hide that kind of thing anymore.
That passed through Sand’s mind in a moment. What he said was slightly less articulate.
“What?” He pinched the end of his nose.
Aaron gave an awkward laugh and hit his forehead in embarrassment. “No, no. I’m sorry. I mean, this is a story for my English class. I need to figure out how someone might make a spectacular escape on the Moon.”
“Ah,” Sand breathed, sitting back in his chair. He hadn’t realized he practically had his nose in Aaron’s face. “I see.”
It was nice to have affirmed, once again, that the world made sense and that the impossible remained confined to the realm of fiction.
“So, why come to me?”
“I thought you probably know more about the Moon than anyone, and could help me figure out a truly spectacular, impossible escape.”
“If it’s impossible, you don’t actually need my help.” Sand fiddled with his short beard and grinned slightly. “Just make it up.”
“No, I can’t do that.” Aaron answered, deadly serious. “I don’t really mean ‘impossible,’ just improbable. Or unexpected. You know, something that will make a good story.”
“I’m not a writer myself, so I suppose I wouldn’t know. But aren’t stories about people? Why not just write a story about life on the Moon, the cramped quarters, the loneliness, the dedication of the scientists who work outside the protection of Earth’s atmosphere and magnetic field, the stark beauty of the meteor-tossed landscape? Why make it something spectacular and unlikely?”
Aaron Seiler glanced down at his hands, busy making little finger-steeples in his lap.
“Well, actually, I’m trying to impress my professor.”
Sand watched the young man for a second, becoming suspicious that there was more here than met the eye.
“It seems to me that if you want an ‘A,’ good writing is a better bet than spectacular escapes,” Sand put just a hint of reprimand in his voice.
“Well, yeah, I suppose,” Aaron met Sand’s eyes again. “If I can just ask you a few . . . questions?”
Sand smiled slightly. “So, you’re taking a class with Dr. Flannagan?”
Dr. Flannagan was the new assistant professor in the English department this fall, having come directly to the university from the graduate program at Madison. Sand had met her at the dinner for new faculty. She couldn’t be over twenty-six, about the age he estimated for Aaron. Very bright young woman.
Bright and lovely. Rich blonde hair. Athletic figure. A smile that set even his old heart aflutter.
“Uh, yeah. Dr. Flannagan.” Aaron tapped his fingers on Sand’s desk like a piano keyboard.
“Aha.” Sand inserted a reserved tease into his voice. He doubted the appropriateness of romantic interest in a professor in one’s major, but understood that the hearts of young men didn’t always consider appropriateness.
“So.” Aaron pulled his personal computer from his pocket and accessed a list. “What might happen on the Moon, and not on Earth, that can explain the escape?”
“Hmm. Unless the Moon causes some form of dementia, why would anyone build a less secure prison on the Moon than on Earth? Wouldn’t any escape on the Moon be just as possible on the Earth?”
“I don’t know . . . wouldn’t there be different natural laws or something?” Aaron winced as the words left his mouth. He probably hadn’t meant to use the word “laws.”
“If the laws of physics changed from one place to another, the universe would be a scary place indeed!” Sand’s laugh boomed in the small office.
“I didn’t really mean natural laws.” Aaron didn’t crack a smile. Whether he was irritated at this exasperating professor or at himself, Sand wasn’t sure. “But surely there are conditions that differ on the Moon.”
Aaron’s clarity in correcting his error impressed Sand. He abandoned his lesson on points of wording.
“Well, gravity is lower, about one-sixth that of Earth. So, maybe if someone built a prison without a roof the prisoner could simply hop out.”
Sand glanced sidelong at Aaron who rolled his eyes and managed a pained smile. Sand took courage and continued.
“Pressure is lower, about a million billion times less—basically, a vacuum. So, if they built walls unable to bear the one-ton pressure on every square foot, a prisoner might give them a good whack and watch them explode outward. Of course, we’re back to the dementia model. Why would anyone overlook the factors on the Moon that must be taken into account to survive there in the first place?”
“Maybe it’s not a prison,” Aaron said. “Maybe prisons haven’t been built yet. There aren’t prisons there now you know.”
“That’s because psychological screening makes them unnecessary.”
“Do you really think that psychological screening prevents someone from committing a crime?” Aaron asked. “Even if a nutcase doesn’t slip through, sometimes crime is a calculated choice of a rational, but selfish, mind.”
“True.” Sand liked the young man’s ability to analyze how people think. “That sounds like the subject of an interesting story.”
“No, I need something more technical, something surprising,” Aaron said, doggedly.
“Even if the building is not designed to be a prison, it must be secure,” Sand prompted. “After all, why would someone put a prisoner in a non-secure facility? If they did, his escape wouldn’t be particularly surprising. On the Moon, any building can be made perfectly secure simply by removing all the pressure suits.”
“Maybe there are pressure suits available, but the building has a different function from any on Earth, and the difference leads to unexpected methods of escape.” Aaron’s eyes wandered around the room trying to catch up with his thoughts. “What kind of facilities might be on the Moon but not Earth?”
Sand considered for a moment. “Well, there’s the Lunar Melting Facility. Helium-three and other valuable volatiles are driven off the lunar regolith for collection, and the remaining material is made into vesiculated bricks.”
“Ah! I know about Helium-three.” Aaron’s voice grew louder with excitement. “Sharon . . . I mean Dr. Flannagan says we should write about what we know. But in what way does the facility differ from buildings on Earth?”
“The walls have to be highly refractory, to withstand the heat and vapors. Aluminum-rich refractory materials are made from anorthosite, abundant in the lunar highlands. It’s hard but brittle.”
“So, maybe the prisoner could find a way to shatter the walls, blow them apart from the inside.”
“And, of course, the prisoner would be allowed a few explosives. . . .” Sand studiously cleaned some vacuum oil from the lab from under one of his fingernails.
Aaron grinned sheepishly. “Not at all. He’d have to use the unique natural laws of the Moon. Surely scientists there don’t pass the same ones.”
“Their legal system must indeed be different.” Sand grinned back.
“If the facility is used to heat regolith,” Aaron resumed, “maybe the regolith itself can be adapted to make a bomb. Isn’t there a lot of combustible metal in the lunar regolith?”
Sand glanced at the young man in surprise. He hadn’t expected an English major to know about the reduced metal in the lunar regolith, a property very different from any Earth soil.
“There’s a lot of metallic iron, yes, accumulated from micrometeorites and chemical reduction by the solar wind. The small size and high surface-to-volume ratio of the metal might make it combustible in a highly oxygenated atmosphere. But you need to separate it from the regolith, and then you need a lot of oxygen, a lot more than you can get from a pressure suit canister.”
“To separate iron, I’d need a hammer and magnet,” Aaron said thoughtfully. “A hammer to separate the metal from the gangue, and a magnet to collect the separated residue.”
Sand leaned forward. “And the facility certainly has electricity to power the heaters that melt the soil. Electricity and wires can be used to make an electromagnet.”
“The metal would spring toward the magnet like . . . ” Aaron hesitated.
“Like a young man’s eyes toward the intriguing curve of his professor’s lips,” Sand completed for him.
Aaron’s face turned red, but he pretended not to hear. “But where to get oxygen. The Moon is notoriously short of it.”
“Actually not. The Moon is about 40% oxygen—no shortage at all.”
Aaron frowned. “More than Earth’s 21%? But that doesn’t make sense. . . .”
“Earth has 21% oxygen in its atmosphere, but the Moon’s 40% oxygen is chemically bound in the rock. Earth rocks are also 40% oxygen, but we don’t think about using it on Earth because oxygen is readily available in the air.”
“The lunar processing facility houses tons of regolith containing oxygen,” Aaron said. “But how do you get the oxygen out of the rock and into a reactive molecular form?”
“Electrolysis,” Sand proposed after a moment’s silence. “The facility is already designed for melting rock, and has electrical power. Two electrodes placed in the melt, and an electrical current, will produce reduced metals at the cathode and oxygen at the anode.”
“Like splitting hydrogen and oxygen out of water in a high school electrolysis experiment.” Aaron nodded.
There was a brief pause.
“You’re not an English major are you?” Sand asked.
“No, physics. That’s closer to my interests and my training in the Navy.”
“What did you do in the Navy?”
“I taught quantal entanglement communications protocols. That was when it was all still classified. When the method became generally available in the private sector, after I left the Navy, I started my own business to help midsized companies set up secure systems to communicate overseas.”
“I could tell that you knew some science.” Sand realized for the first time that Aaron wasn’t a student in Dr. Flannagan’s department. The young man’s interest in her might not be as inappropriate as he had supposed, at least once the present writing course was completed.
“You seem to be putting a lot of effort into a class not required for your major.”
Aaron steepled his fingers in his lap again. “Yeah. I don’t think about physics much between six and nine on Monday’s.”
Sand could imagine how Flannagan’s pert nose and the turn of her neck as she looked from one student to another might keep the attention of more than one young man. He suppressed his annoyance with the unfairness of student course evaluations.
“So, do you like writing or do you like Professor Flannagan?”
Aaron played the piano on his desk. “Both I suppose. I do understand our different stations in life. That’s why I want to get some science into my story, so she can see I’m not dumb.”
Sand frowned slightly. He didn’t want to get Dr. Flannagan into trouble. The boundaries of ethics and university rules didn’t always coincide. But, he’d always believed more in ethics than rules.
“I’m not sure you’re going to impress an English professor with all this factual detail. However exciting it is to you and me, it isn’t necessarily the way to a woman’s heart.”
Aaron looked surprised, maybe embarrassed, by Sand’s reference to women’s hearts. “I don’t know if I—” He stopped abruptly.
“Why don’t you just go talk to her? She can help with your story, and maybe you can get to know her better.”
“Why would she want to talk to me?” Aaron asked, a low growl in his throat. “She’s got a PhD, and I couldn’t even afford college. Scholarships only covered about half. I spent all my time since trying to make enough money to go.”
“If she’s the kind of person that you might like to know, she probably isn’t going to judge you for that,” Sand observed.
“My last girlfriend did.” He gave a snort.
“When I asked her to marry me, she laughed. Said I was twenty-seven years old and hadn’t even gone to college.”
“Well, you sure lucked out there.” Sand smiled faintly.
“It didn’t feel lucky.” He didn’t smile.
“You’re a bright young man. You have things to offer. I’m sure Dr. Flannagan will see that.”
“Maybe. Maybe I can talk to her once she sees I’m a pretty smart guy. That’s why I need this story to be so good.”
“Ah.” Sand wasn’t sure about the wisdom of Aaron’s strategy, but knew the difficulty of turning young men from such ardent paths.
“We still have a problem with the escape,” Aaron continued. “If the prisoner managed to manufacture both combustible metal powder and oxygen, and blow the building apart, his body would still be found lying in the blast debris. He hasn’t disappeared.”
“It seems to me that your bigger problem is this: Why would the prisoner blow himself to smithereens?”
Aaron didn’t seem to register this concern.
“Is it possible for the blast to vaporize him entirely?”
Sand plucked a paper from the waste basket beside his desk and did a quick calculation, muttering to himself.
“Hmmm. Burning iron at say its melting point . . . 240 kilojoules exothermic heat per mole . . . say a ton . . . and a ton of additional air, wall and rock . . . take an average heat capacity of 0.5 kilojoules per kilogram per degree . . . “
He carried the last digit and rounded. “The temperature could reach close to three thousand degrees Celsius. Iron can’t burn much above that anyway. But, that’s certainly a high enough temperature to vaporize someone, at least in the presence of oxygen.”
Aaron looked excited, but Sand quickly continued.
“The problem is that, even if you do use literary smoke-and-mirrors to extract a ton of iron from the regolith and then aerate and ignite it all simultaneously, the high temperature lasts only fractions of a second before the rising pressure blows out the walls. Body water will absorb latent heat as it evaporates, keeping a human body too cool to vaporize completely, at least until the water is entirely evaporated.”
“Like boiling water.” Aaron’s face scrunched. “Its temperature doesn’t change until the liquid is completely evaporated, even if you add more heat.”
“Yes, and evaporating all the water would take longer than the time needed for the walls to give way. Once the walls collapse, adiabatic cooling of the expanding gas ball will quickly drop the temperature. The net result: you get a charred body but a body nonetheless. No disappearing prisoner.”
Aaron slumped back in his chair and sat in silence for a moment.
“Where is the Aiken Base, anyway? Maybe its location is significant.”
“We put the Aiken Base in Aiken Basin.” Sand smiled at his wordplay.
Usually people would ask, somewhat befuddled, “why do you say it twice?”
And he’d say “that’s the joke see . . . Aiken Base IN Aiken Basin.” When they didn’t get the joke even after his explanation—or perhaps they simply didn’t find it funny—he would usually cut his losses and go on.
With Aaron Seiler, he didn’t have to provide the explanation. The bright young man laughed out loud.
Sand really liked this young man. Nicely peculiar, a real soul mate.
“That’s at the South Pole, right? Why there?”
“The impact basin, the largest in the solar system, provides an excavation into the lunar interior, so, the geologists like it. Also, the location has low light pollution from Earth, making it good for the astronomers. There’s plenty of water available in shadowed cold traps, and water is worth more than gold on the moon. Plus, the sun never sets on some of the high mountains on the crater rim, providing solar power through the entire four-week lunar day.”
Aaron thought for a moment. “I don’t see how any of this helps get rid of my prisoner.”
“You know, if you just need to make the prisoner vanish, I might have a way for you to do it,” Sand said, intending to be facetious. “The facility that you’re holding him in produces molten rock. Rock is a silicate solution—basically, a mixture of every element in the periodic table. When molten, it’s close to a perfect solvent, dissolving nearly every material known. What doesn’t vaporize due to high temperature will certainly dissolve in the molten rock. Voilà! Vanished prisoner.”
Aaron’s face lit with excitement. “Yes, that’s it!”
Professor Sand smiled and waited for him to see the problem.
“But wait,” he said. “Why would the prisoner jump into a vat of molten rock?”
“Motivation,” Sand answered, “is a problem for the writer to solve!”
A few weeks later, Sand saw Aaron on campus, out in the quadrangle where the sidewalks crisscrossed among the big oak trees and fountains. He was walking and talking with Dr. Flannagan. They stopped in front of the English building and chatted for a moment longer before she waved goodbye and climbed the granite steps to Cobern Hall. Sand watched Aaron’s eyes follow her up the steps.
“Still enjoying Creative Writing 201, I see,” Sand said.
Aaron jumped and turned embarrassed eyes toward him.
“How did your story go?” Sand asked.
Aaron grimaced slightly. “Well, I got a ‘C.’ She thought it had too much technical detail and that the characters’ actions didn’t make much sense.”
“Oh,” Dr. Sand responded, not too surprised.
“However, I did take your advice.” Aaron’s face perked up. “I went to talk to her, so now we’re meeting regularly to discuss my writing.”
“Ah,” replied Sand.
Aaron looked at his shoes briefly, then looked up. “Do you think someone like me has a chance with Professor Flannagan?”
“You mean because she’s a liberal literati and you’re a stuffy scientist?” Sand scrunched up his face in mock concern.
Aaron remained serious. “Well, yeah. And I’m just a student.”
“Well, you with Professor Flannagan isn’t a problem for me. But I’m a conservative engineer. Folks from the liberal departments on campus might not like merging such different academic traditions. Loss of diversity and all that.”
Sand grinned just slightly. Aaron tried to grin back, but it looked rather forced.
“Well I guess I better get to class,” Aaron said.
On impulse, Sand reached out to pat the young man’s shoulder. “Speaking as an engineer, I’ve noticed that the best materials are always composites. Differences make things strong.”
Aaron managed a more enthusiastic smile. “My meetings with Professor Flannagan are going well. Sometimes our conversation wanders to other topics. Maybe after I graduate. . . . “