by Neil Clarke
Zhu Dagun nodded as if he was. “That’s right, Your Highness.”
“Just call me Old Wang. ‘Your Highness’ sets my teeth on edge. I’ll start now; keep stirring, don’t stop.” He set up a three-paned white paper screen to lean over the mouth of the flask, put on his mask, and slowly poured the green vitriol into the small jar. At first, all Zhu Dagun noticed was a stench that burned its way right through the cotton mask and up his nose, strong enough to make his brain ache and his eyes tear. Then he saw a miraculous purple cloud was floating up out of the jar, unfurling lazily. Zhu Dagun shivered in fright, but Prince Lu only laughed. “Finally! With this crude method for extracting iodine, that’s half my big plan taken care of! Don’t stop, keep stirring until the reaction finishes. I need to see just how much pure iodine I can extract from one pound of dried seaweed . . . Are you interested in how I created sulfuric acid and nitric acid? This is the first step in the Long March of establishing basic industry, you know.”
“I’d love to hear,” Zhu Dagun said automatically.
Prince Lu seemed delighted. “I was pretty good at chemistry back in high school, and I majored in mechanical engineering as an undergrad, so I got a decent foundation. I couldn’t have made it this far otherwise. At first I wanted to use the alchemists’ method of making sulfuric acid from bluestone, but I couldn’t find more than two pounds of it in the city, not nearly enough. Then I happened to see the massive piles of pyrite ore in the iron foundry. Treasure, right for the taking! Heating pyrite gives you sulfur dioxide, and dissolving that gives you sulfurous acid; let that sit for a while and you get sulfuric acid. You can purify that in clay jars; it’s how the munitions factories in Communist Shanbei managed, back in the day.
“With sulfuric acid taken care of, nitric acid wasn’t hard. The biggest problem was the limited supply of saltpeter, which we also needed to make gunpowder. I had to mobilize everyone in the Institute to scrape crusted urine off the bases of walls to refine into potassium nitrate. Our entire place reeked! Fortunately, people in this city have a habit of pissing anywhere there’s a wall. If it weren’t for that, we couldn’t have built the foundations of industry in Jinyang.”
Zhu Dagun flushed. “Sometimes the urges of the bladder are too great. Both men and women commonly take off their trousers and relieve themselves where they stand. Please humor the crude customs of the countryside, Your Highness.”
While they were speaking, the contents of the two jars had been combined into one, and the purple cloud had disappeared. Prince Lu spread the white paper screen out on the table and scraped the surface with a flat scrap of bamboo, removing a layer of purplish black powder. “The iodine in seaweed is easily oxidized in air under acidic conditions, creating elemental iodine. Very good, let me send them orders to follow my recipe and manufacture this in batches, and we’ll do the next experiment.” He crossed the room, sat down in front of the text tray in the corner, and began banging out a missive. Zhu Dagun walked over to look and discovered that this strange prince typed with lightning speed. He didn’t even glance at the characters, but typed blind with unfailing accuracy. “Your type tray looks like a different model, Your Highness,” Zhu Dagun blurted.
“Old Wang, call me Old Wang,” said Prince Lu. “The principle’s the same, but each terminal uses two sets of movable type. The bottom set is used for input and the top set’s used for output. Watch.” He pressed the carriage return to end his message and stood up to grab a crank handle and turn it. The crank turned a roller on which a seventeen-inch-wide length of calligraphy paper had been spooled, passing it smoothly over the text tray. The movable type in the tray, to which ink had been applied, suddenly began to rise and fall, stamping characters onto the paper.
Zhu Dagun bent down to pick up the paper and began to read. “The experiment data is correctly recorded. I’ve told the chemistry department to oversee it. Return.” He looked at the prince with admiration. “This is far clearer and more convenient! White paper and black ink simply reads better to the eye. When are you releasing this on the markets? We’ll support it with all our might!”
Prince Lu laughed. “This is only a prototype. Version two-point-one will use the same mechanism found in printers to stamp the output on the same line, instead of inking the characters all over the place and making it hard to read. You like the internet too? The thing I was least used to about this era was the lack of internet access, so I racked my brains to come up with this. I finally get to feel like a proper nerdy shut-in again.”
“Your August Highness—er . . . Old Wang,” Zhu Dagun corrected himself when he saw Prince Lu’s expression. “May your servant ask, from which prefecture did you originally hail? Are you a scholar of the Central Plains? You have an extraordinary air about you, after all.”
Prince Lu sighed. “The better question is, from what dynasty did I hail? The era I come from is one thousand sixty-one years, three months, and fourteen days distant.”
Zhu Dagun didn’t know if he was joking or raving. He did the arithmetic on his fingers and laughed obsequiously. “I see that you achieved the Way in Emperor Wu of Han’s time, and have lived on to today as an immortal!”
“Not one thousand years in the past,” Prince Lu said unhurriedly. “One thousand years in the future—and nine hundred billion forty-two universes away.”
9.
Zhu Dagun didn’t understand Prince Lu’s ravings, and he didn’t have time to dwell on them, because the next experiment had begun. Prince Lu placed a silver-plated copper coin into a small carved wooden chest, set the cup of newly-made iodine beside the coin, closed the lid, and lit a small clay brazier next to the chest to heat it a little. Soon, purple vapors came billowing out through the cracks in the chest. Heavens, we’re about to get some pills of immortality, Zhu Dagun thought, as he carefully waved the fan as Prince Lu instructed, afraid even to breathe too hard.
A while later, Prince Lu pushed the brazier aside, opened the chest, and reached in with a soft cloth. He carefully lifted the copper coin, cushioned on the cloth, revealing that its silver surface was coated with something yellowish. Zhu Dagun peeked inside the chest and didn’t see any pills of immortality, but Prince Lu did an excited dance. “It worked! It really worked! Look, this yellow stuff is called silver iodide. All I have to do now is scrape it off into a jar and put it somewhere dark. I can perform another magic trick with this: put this coin somewhere dark, expose it to light for about ten minutes, develop the image with mercury fumes, and fix it with saltwater. Once it’s rinsed and dry, the coin will be covered with a picture of this room, identical in every last detail! This is the Daguerreotype process, which takes advantage of silver iodide’s photosensitivity. But we’re storing up silver iodide for something else, so I’ll have to show you at a later date.”
“Without an artist, how can one obtain a picture?” Zhu Dagun asked, confused. “And . . . what miraculous powers does the yellow powder have? Does it impart health and sagehood on one who imbibes it?”
Prince Lu laughed. “It’s not that kind of magic. In my day, silver iodide had two main uses. One was photosensitivity, like I mentioned. The other, well, you’ll see.” He worked as he spoke, scraping the powder off the coin into a small porcelain bottle, before pulling off his mask and stretching. “That’s all for now. I’m done for the morning. I’ll send out the instructions for manufacturing silver iodide, and then I can rest. You haven’t eaten, right? We can eat together later. You’re tall and strong, and pretty good with your hands—it must be all that alchemy experience. I have some things I want to ask you, so don’t wander off. I’ll be right back.”
Prince Lu sat down at the text tray and began to type at a rattling pace. Now and then he cranked out a length of calligraphy paper and read it, nodding to himself. Zhu Dagun just stood there in the room, afraid to touch anything and accidentally break it, or trigger some mighty magic.
At this point, he finally remembered why he was there. He reached for his sleeve pouch, felt the copy of
the Analects there, and took a deep breath. “Your Highness, there’s something that I don’t understand,” he said, looking down. “I hope you can advise your servant.”
“Go ahead, I’m listening.” Prince Lu was still at the text tray, cranking the spool of calligraphy paper, too busy to spare a glance.
Zhu Dagun asked, “Your Highness, are you Han or Hu?”
“Don’t be pretentious, call me Old Wang,” came the reply. “I’m Han. I grew up in Beijing’s Xichen District. My ma’s Hui Muslim, but I took after my ba. I may have played in the Niujie and Jiaozi neighborhoods as a kid, but I can’t live without pork, so no dice.”
Zhu Dagun had already learned to ignore Prince Lu’s incomprehensible ramblings. “If Your Highness is Han, why do you live in Jinyang instead of the southern lands?”
“You wouldn’t understand even if I explained,” said Prince Lu. “I’m Han, but I’m not a Han from your era. I know perfectly well that, of the Five Dynasties and Ten Kingdoms, Liang, Tang, Jin, Zhou, and even your so-called Great Han were founded by other ethnic groups, and most of your people are Hu too. But once my plan succeeds, I’ll be back at my point of departure, and this temporal node of your universe won’t have a thing to do with me, got it?”
Zhu Dagun took a step closer. “Your Highness, how are we going to defeat the Song army?”
“We can’t,” said Prince Lu. “We don’t have the soldiers or the food, and we can’t mass produce firearms. Flintlock muskets are easy to manufacture, but we don’t have nearly enough sulfur to make gunpowder. We scoured the city and only found a couple dozen pounds. We can’t do more than occasionally fire a cannon to give a scare. But that brings me to my next point. Though we can’t defeat the Song troops, we can hold out pretty easily. As long as Zhao Guangyi doesn’t find out how Liao is sending us grain under the surface of the water, Jinyang survives another day. Tying empty barrels to full barrels and sending them along the bottom of the Fen River is a trick you ancients would never think of.”
Zhu Dagun raised his voice. “But the commoners are hungry and weary, and the soldiers wail with pain and exhaustion! The longer Jinyang holds on, the more its tens of thousands of residents suffer, Your Highness!”
“Hey, good point.” Prince Lu turned on his stool. “Everyone else is delighted to work here—not only are they pardoned for their crimes, they can even earn some money. But you don’t sound like them. Let’s talk, then. I haven’t had anyone normal to talk to in months. It’s been”—he pulled out a piece of paper, took a look, and drew another X on it—“three months, seven and a half days since I was dropped here. I’ve got twenty-three and a half days before the observational platform automatically returns. The schedule will be tight, but judging from my current progress, I should be able to make it.”
Zhu Dagun understood only the faint longing for home that underlay his words. He immediately recited, “The Master said: as long as parents are alive, one should not journey far from them without method. When one’s father lives, observe one’s aspirations; when he does not, observe one’s actions; if in time they do not deviate from the father’s way one can be termed filial. Your Highness has long been away from your home and must miss your parents dearly. Foxes die with their heads pointing toward their burrow; crows feed their parents in their old age; lambs kneel before they drink from their mother’s teat; stallions will not mate with their dam—”
Prince Lu sighed. “Okay, we’re still not on the same frequency here. Can you shut up and listen?”
Zhu Dagun immediately shut up.
Prince Lu spoke slowly. “I’m sure you don’t know the alternate universe theory or quantum mechanics, so I’ll go over them briefly. My name is Wang Lu. I was an ordinary nerd, amateur writer of chuanyue novels, and professional time traveler. In my time, we’d perfected the multiverse theory, so that anyone could go to an agency, rent an observational platform, and go time traveling. At one time, people estimated the number of parallel universes overlaying each other to be around 10^(10^118), but more precise calculations later on indicated that, due to overlap between different diverged branches, only about three hundred quadrillion universes exist at any one time. Countless particle-level possibilities cause universes to endlessly emerge, split, merge, and disappear, and yet even the two parallel universes with the most differences are astonishingly similar on a physical level, even as their places on a timeline diverge further and further.
“In a way, this makes things boring, since humanity’s exploration of deep space remains stalled, and its understanding of the universe as a whole is very shallow. Even in the most advanced universe I’ve been to, humanity’s reach has gone no further than Alpha Centauri, just next door. But in another way, this makes things interesting, since with the invention of the wave function engine it means that we can step across to other parallel universes at our convenience. For topological reasons, the more similar the destination universe, the less energy it takes to travel there. The most advanced observational station we have can send travelers three hundred trillion universes away, though the commercially available equipment only has a maximum range of around forty trillion.”
Zhu Dagun kept nodding while he felt his sleeve pouch, inwardly debating whether to take out the dagger and persuade Prince Lu’s heart or take out the Analects and persuade his mind once he finished his raving. There was no one else in the room, creating a prime opportunity to make his move. It wasn’t that Zhu Dagun didn’t want to act promptly, but that he himself still felt somewhat undecided as to which esteemed personage he should act on behalf of.
Prince Lu picked up his teacup and took a sip, then continued. “I accepted a job from the Peking University history department, a research task to tally the population of the Sixteen Prefectures during the late Five Dynasties and Ten Kingdoms period. A parallel universe like yours is located toward the front of the timeline, which makes it an excellent place for historical observation.
“Don’t think just anyone can get a time travel license. You have to train systematically in quantum theory, computer operation, ground transportation, emergency drills, and more, and pass the test to get a job. If you want to lead tour groups, you have to take the Time Travel Tour Guide Examinations too. Due to the physical similarity between parallel universes, I activated the observational platform at Xuanwu Gate in Beijing to travel nine hundred billion forty-two universes and arrive here. By my calculations of revolution and rotation elements, I should have been able to arrive in You Prefecture. Who knew that my observational platform was getting long in the tooth? The wave function engine radiator boiled over, right in the middle of the trip! I had to pour in eight bottles of mineral water and a crate of Red Bull to get it to limp to the destination. The moment I arrived in this universe, the crown bar burst through the tank. That was the end of the engine. I crashed into a gully in Shanxi by the Fen River. My luggage, equipment, and spare fuel tanks were wiped out.
“It took me ten days to patch together the engine, only to discover all the fuel had leaked out. The bit left in the oil lines could hop me two or three universes over at most. What use would a few hours forward be?”
The sounds of shouting and fighting from outside grew louder. The Song army had begun another assault on East City gate. Prince Lu turned to glance at the report scrolling out above the text tray and typed a few characters himself. “Don’t worry.” He laughed. “We’ll take care of it as usual. I’ll move two bladder catapults over . . . Where was I? Ah, right, the wave function engine could just barely start, and raising the angular speed made the engine oil give off blue smoke like a tractor, but the main problem was that I didn’t have any fuel. Taking that census was of course out of the question, but even worse, since I hadn’t filed this private job with the Ministry of Civil Affairs’ Multiverse Administrative Office, I couldn’t just call the time police for help when they’d put me in jail for three to five years! If I wanted to get home, I needed some way to gather fuel. I didn’t have a choice but to hide m
y things in the gully and sneak into Jinyang.”
“Your Highness, you say you didn’t have any fuel, but isn’t the city full of fire-oil?” Zhu Dagun couldn’t resist interrupting. “Many carriages on the street burn fire-oil.”
Prince Lu sighed. “If only it combusted oil. Let me put it this way, the fuel tank didn’t hold real, physical fuel, but potential energy, the elastic potential between parallel universes. If I wanted to fill my tank, I needed to create a universe split. When a new universe split off as a result of some decision point, I’d be able to gather this escaped potential energy to power my return. This potential energy isn’t something intangible like entropy values. It’s more like when you snap a bamboo pole in two, and you hear the crack as it splits apart? I don’t understand it that well myself, but either way I had to create a big enough event to make the universe split. Now, how could I do this? Let’s take an example from history—on the fourteenth of the third month this year, a resident of Jinyang slipped from the parapets and fell to his death in the Fen River. The incident was witnessed by twenty people and recorded in minor history books. If, on the fourteenth of the third month, I grabbed his collar and saved his life, I’d create a change. But it wouldn’t be big enough. Out of the one hundred quadrillion universes where this event occurred, he was saved in one quadrillion of them even without me. In that moment, the parameters in one of those universes would change until it perfectly matched the universe we’re in, and the two universes would merge. Of course, you and I wouldn’t feel anything from where we stand, but the potential would decrease, and even remove fuel from my tank. To cause a new universe to split off, I have to create a big enough change, a change so big that no precedent exists in any one of the one hundred quadrillion universes past this point in the timeline. I managed to use the beat-up wave function computer to find a possibility, one that I could achieve without any modern equipment to help me.”
