One day he slammed out of his study with his single hand holding two of his old alchemical texts, and threw them into the door of a blazing athanor. “Complete nonsense,” he replied bitterly when Bahram cried out for him to stop. “Get out of my way, I’m burning them all.”

  “But why?” Bahram cried. “Those are your books! Why, why, why?”

  Khalid took a lump of dusty cinnabar in his one hand, and shook it before Bahram. “Why? I’ll tell you why! Look at this! All the great alchemists, from jabir to al-Razi to Ibn Sina, all agree that all the metals are various combinations of sulphur and mercury. Iwang says the Chinese and Hindu alchemists agree on this matter. But when we combine sulphur and mercury, as pure as we can make them, we get exactly this: cinnabar! What does that mean? The alchemists who actually speak to this problem, who are very few I might add, say that when they talk about sulphur and mercury, they don’t really mean the substances we usually call sulphur and mercury, but rather purer elements of dryness and moisture, that are like sulphur and mercury, but finer! Well!” He threw the chunk of cinnabar across the yard at the river. “What use is that? Why even call them that? Why believe anything they say?” He waved his stump at his study and alchemical workshop, and all the apparatus littering the yard outside. “It’s all so much junk. We don’t know anything. They never knew what they were talking about.”

  “All right, Father, maybe so, but don’t burn the books! There may be something useful in some of them, you need to make distinctions. And besides, they were expensive.”

  Khalid only snarled and made the sound of spitting.

  Bahram told Iwang about this incident the next time he was in town. “He burned a lot of books. I couldn’t talk him out of it. I try to get him to see the love filling everything, but he doesn’t see it.”

  The big Tibetan blew air through his lips like a camel. “That approach will never work with Khalid,” he said. “It’s easy for you to be full of love, being young and whole. Khalid is old and one-handed. He is out of balance, yin and yang are disarranged. Love has nothing to do with it.” Iwang was no sufi.

  Bahram sighed. “Well, I don’t know what to do then. You need to help me, Iwang. He’s going to burn all his books and destroy all his apparatus, and then who knows what will happen to him.”

  Iwang grumbled something inaudible.

  “What?”

  “I’ll think it over. Give me some time.”

  “There isn’t much time. He’ll break all the apparatus next.”

  Aristotle was Wrong

  The very next day Khalid ordered the blacksmith apprentices to move everything in the alchemical shops out into the yard to be destroyed. He had a black and wild look as he watched it all shed dust in the sunlight. Sand baths, water baths, descensory furnaces, stills, cucurbits, flasks, alumbixes, alembics with double or even triple spouts; all stood in a haze of antique dust. The largest battery-alembic had last been used for distilling rose water, and seeing it Khalid snorted. “That’s the only thing we could make work. All this stuff, and we made rose water.”

  Mortars and pestles, phials, flasks, basins and beakers, glass crystallizing dishes, jugs, casseroles, candle-lamps, naphtha-lamps, braziers, spatulas, tongs, ladles, shears, hammers, aludels, funnels, miscellaneous lenses, filters of hair, cloth and linen: finally everything was out in the sun. Khalid waved it all away. “Burn it all, or if it won’t burn, break it up and throw it in the river.”

  But just then Iwang arrived, carrying a small glass-and-silver mechanism. He frowned when he saw the display. “Some of this you could at least sell,” he said to Khalid. “Don’t you still have debts?”

  “I don’t care,” Khalid said. “I won’t sell lies.”

  “It’s not the apparatus that lies,” Iwang said. “Some of this stuff could prove very useful.”

  Khalid glared at him blackly. Iwang decided to change the subject, and raised his device to Khalid’s attention. “I brought you a toy that refutes all Aristotle.”

  Surprised, Khalid examined the thing. Two iron balls sat in an armature that looked to Bahram like one of the waterwheel triphammers in miniature.

  “Water poured here will weight the rocker, here, and the two doors are one, and open at the same time. One side can’t open before the other, see?”

  “Of course.”

  “Yes, obvious, but consider, Aristotle says that a heavier mass will fall faster than a lighter mass, because it has more of the predilection to join the Earth. But look. Here are the two iron balls, one big and one small, heavy and light. Place them on the doors, set the device level, using a bubble level, high on your outside wall, where there is a good distance to fall. A minaret would be better, the Tower of Death would be better yet, but even from your wall it will work.”

  They did as he suggested, Khalid climbing the ladder slowly to inspect the arrangement.

  “Now, pour water in the funnel, and watch.”

  The water filled the lower basin until the doors suddenly fell open. The two balls fell. They hit the ground at the same time.

  “Ho,” Khalid said, and clambered down the ladder to retrieve the balls and try it again, after hefting them, and even weighing them precisely on one of his scales.

  “You see?” Iwang said. “You can do it with balls of unequal size or the same size , it doesn’t matter. Everything falls at the same rate, except if it is so light and broad, like a feather, that it floats down on the air.”

  Khalid tried it again.

  Iwang said, “So much for Aristotle.”

  “Well,” said Khalid, looking at the balls, then lofting them in his left hand. “He could be wrong about this and right about other things.”

  “No doubt. But everything he says has to be tested, if you ask me, and also compared with what Hsing Ho and Al-Razi say, and the Hindus. Demonstrated to be true or false, in the full light of day.”

  Khalid was nodding. “I would have some questions, I admit.”

  Iwang gestured at the alchemical equipment in the yard. “It’s the same for all this — you could test them, see what’s useful and what’s not.”

  Khalid frowned. Iwang returned his attention to the falling balls. The two men dropped a number of different items from the device, chattering away all the while.

  “Look, something has to be bringing them down,” Khalid said at one point. “Bringing them, forcing them, drawing them, what have you.”

  “Of course,” said Iwang. “Things happen by causes. An attraction must be caused by an agent, acting according to certain laws. What the agent might be, however . . .”

  “But this is true of everything,” Khalid said, muttering. “We know nothing, that’s what it comes down to. We live in darkness.”

  “Too many conjoined factors,” Iwang said.

  Khalid nodded, hefting a carved block of ironwood in his hand. “I’m tired of it, though.”

  “So we try things. You do something, you get something else. It looks like a causal chain. Describable as a logical sequence, even as a mathematical operation. So that you might say, reality manifests itself thus. Without worrying too much about defining what force it is.”

  “Perhaps love is the force,” Bahram offered. “The same attraction as of persons to persons, extended between things in a general way.”

  “It would explain how one’s member rises away from the Earth,” Iwang said with a smile.

  Bahram laughed, but Khalid said only, “A joke. What I am speaking of could not be less like love. it is as constant as the stars in their places, a physical force.”

  “The sufis say that love is a force, filling everything, impelling everything.”

  “The sufis,” Khalid said scornfully. “Those are the last people on Earth I would consult if I wanted to know how the world works. They moon about love and drink lots of wine and spin themselves. Bah! Islam was an intellectual discipline before the sufis came along, studying the world as it is, we had Ibn Sina and Ibn Rashd and Ibn Khaldun and all the rest, and
then the sufis appeared and there hasn’t been a single Muslim philosopher or scholar since then who has advanced our understanding of things by a single whit.”

  “They have too,” Bahram said. “They’ve made it clear how important love is in the world.”

  “Love, oh yes, all is love, God is love, but if everything is love and all is one with Allah, then why do they have to get so drunk every day?”

  Iwang laughed. Bahram said, “They don’t really, you know.”

  “They do! And the good fellowship halls fill up with good fellows looking for a good time, and the madressas grow emptier, and the khans give them less, and here we are in the year 1020 arguing over the ideas of the ancient Frengis, without a single idea why things act the way they do. We know nothing! Nothing!”

  “We have to start small,” Iwang said.

  “We can’t start small! Everything is all tied together!”

  “Well, then we need to isolate one set of actions that we can see and control, and then study that, and see if we can understand it. Then work onwards from there. Something like this falling, just the simplest movement. If we understood movement, we could study its manifestations in other things.”

  Khalid thought about that. He had finally stopped dropping things through the device.

  “Come here with me,” Iwang said. “Let me show you something that makes me curious.”

  They followed him towards the shop containing the big furnaces. “See how you obtain such hot fires now. Your waterworks drive the bellows faster than any number of puffers ever could, and the heat of the fire is accordingly higher. Now, Aristotle says fire is trapped in wood, and released by heat. Fair enough, but why does more air make the fire burn hotter? Why does wind drive a wildfire so? Does it mean air is essential to fire? Could we find out? If we built a chamber in which the air was pulled out by the bellows rather than pushed in, would the fire burn less?”

  “Suck air out of a chamber?” Khalid said.

  “Yes. Arrange a valve that lets air out but won’t let it back in. Pump out what’s there, and then hold any replacement air out.”

  “Interesting! But what would remain in the chamber then?”

  Iwang shrugged. “I don’t know. A void? A piece of the original void, perhaps? Ask the lamas about that, or your sufis. Or Aristotle. Or just make a glass chamber, and look in it.”

  “I will,” Khalid said.

  “And motion is easiest of all to study,” Iwang said. “We can try all manner of things with motion. We can time this attraction of things to the Earth. We can see if the speed is the same up in the hills and down in the valleys. Things speed up as they fall, and this might be measurable too. Light itself might be measurable. Certainly the angles of refraction are constant, I’ve measured those already.”

  Khalid was nodding. “First this reverse bellows, to empty a chamber. Although surely it cannot be a true void that results. Nothingness is not possible in this world, I think. There will be something in there, thinner than air.”

  “That is more Aristotle,” Iwang said. “ — Nature abhors the void.” But what if it doesn’t? We will only know when we try.”

  Khalid nodded. If he had had two hands he would have been rubbing them together.

  The three of them walked out to the waterworks. Here a canal brought a hard flow from the river, its gliding surface gleaming in the morning light. The water powered a mill, which geared out to axles turning a bank of heavy metal-working hammers and stamps, and finally the rotating bellows handles that powered the blast furnaces. It was a noisy place, filled with sounds of falling water, smashed rock, roaring fire, singed air; all the elements raging with transmutation, hurting their cars and leaving a burnt smell in the air. Khalid stood watching the waterworks for a while. This was his achievement, he was the one who had organized all the artisans’ skills into this enormous articulated machine, so much more powerful than people or horses had ever been. They were the most powerful people in all the history of the world, Bahram thought, because of Khalid’s enterprise; but with a wave Khalid dismissed it all. He wanted to understand why it worked.

  He led the other two back to the shop. “We’ll need your glassblowing, and my leather and iron workers,” he said. “The valve you mention could perhaps be made of sheep intestines.”

  “It might have to be stronger than that,” said Iwang. “A metal gate of some sort, pressed into a leather gasket by the suck of the void.”

  “Yes.”

  No Jinn in This Bottle

  Khalid set his artisans to the task, and Iwang did the glassblowing, and after a few weeks they had a two-part mechanism: a thick glass globe to be emptied, and a powerful pump to empty it. There were any number of collapses, leaks and valve failures, but the old mechanists of the compound were ingenious, and attacking the points of failure, they ended up with five very similar versions of the device, all very heavy. The pump was massive and lathed to newly precise fits of plunger, tube and valves; the glass globes were thick flasks, with necks even thicker, and knobs on the inside surfaces from which objects could be hung, to see what would happen to them when the air in the globe was evacuated. When they solved the leakage problems, they had to build a rack-and-pinion device to exert enough force on the pump to evacuate the final traces of air from the globe. Iwang advised them not to create such a perfect void that they ended up sucking in the pump, the compound, or perchance the whole world, like jinni returning to their confinement; and as always, Iwang’s stone face did not give them any clue as to whether he was joking or serious.

  When they had the mechanisms working fairly reliably (occasionally one would still crack its glass, or break a valve), they set one on a wooden frame, and Khalid began a sequence of trials, inserting things in the glass globes, pumping out the air, and seeing what resulted. All philosophical questions on the nature of what remained inside the globe after the air was removed, he now refused to address. “Let’s just see what happens,” he said. “It is what it is.” He kept big blank-paged books on the table beside the apparatus, and he or his clerks recorded every detail of the trials, timing them on his best clock.

  After a few weeks of learning the apparatus and trying things, he asked Iwang and Bahram to arrange a small party, inviting several of the qadi and teachers from the madressas in the Registan, particularly the mathematicians and astronomers of Sher Dor Madressa, who were already involved in discussions of ancient Greek and classical caliphate notions of physical reality. On the appointed day, when all those invited had gathered in the open-walled workshop next to Khalid’s study, Khalid introduced the apparatus to them, describing how it worked and indicating what they could all see, that he had hung an alarm clock from a knob inside the glass globe, so that it swung freely at the end of a short length of silk thread. Khalid cranked the piston of the rack-and-pinion down twenty times, working hard with his left arm. He explained that the alarm clock was set to go off at the sixth hour of the afternoon, shortly after the evening prayers would be sung from Samarqand’s northernmost minaret.

  “To be sure the alarm is truly sounding,” Khalid said, “we have exposed the clapper, so that you can see it hitting the bells. I will also introduce air back into the globe little by little, after we have seen the first results, so you can hear for yourself the effect.”

  He was gruff and direct. Bahram saw that he wanted to distance himself from the portentous, magical style he had affected during his alchemical transmutations. He made no claims, spoke no incantations. The memory of his last disastrous demonstration — his fraud — must have been in his mind, as it was in everyone else’s. But he merely gestured with his hand at the clock, which advanced steadily towards six.

  Then the clock began to spin on its thread, and the clapper was visibly smashing back and forth between the little brass bells. But there was no sound coming from the glass. Khalid gestured: “You might think that the glass itself is stopping the sound, but when the air is let back into the flask, you will see that it isn??
?t so. First I invite you to put your car to the glass, so you can confirm that there is no sound at all.”

  They did so one by one. Then Khalid unscrewed a stopcock that released a valve set in the side of the flask, and a brief penetrating hiss was joined by the muted banging of the alarm, which grew louder quickly, until it sounded much like an alarm heard from an adjoining room.

  “It seems there is no sound without air to convey it,” Khalid commented.

  The visitors from the madressa were eager to inspect the apparatus, and to discuss its uses in trials of various sorts, and to speculate about what, if anything, remained in the globe when the air was pumped out. Khalid was adamant in his refusal to discuss this question, preferring to talk about what the demonstration seemed to be indicating about the nature of sound and its transmission.

  “Echoes might elucidate this matter in another way,” one of the qadis said. He and all the other visiting witnesses were bright-eyed, pleased, intrigued. “Something strikes air, pushes it, and the sound is a shock moving through the air, like waves across water. They bounce back, like waves in water bounce when they strike a wall. It takes time for this movement to cross the intervening space, and thus echoes.”

  Bahram said, “With the aid of an echoing cliff we could perhaps time the speed of sound.”

  “The speed of sound!” Iwang said. “Very nice!”

  “A capital idea, Bahram,” Khalid said. He checked to make sure his clerk was noting all done or said. He unscrewed the stopcock all the way and removed it, so that they all heard the noisy clanging of the alarm as he reached into the flask to turn off the device. It was strange that the clapper should have been so silent before. He rubbed his scalp with his right wrist. “I wonder,” he said, “if we could establish a speed for light too, using the same principle.”

  “How would it echo?” Bahram asked.

  “Well, if it were aimed at a distant mirror, say . . . a lantern unveiled, a distant mirror, a clock that one could read very precisely, or start and stop, even better . . .”