Into the New Millennium: Trailblazing Tales From Analog Science Fiction and Fact, 2000 - 2010 (11 page)

The young Norman scampers down the stairs. "Look what you made me do!" he complains. "If you've busted the master's brass balls . . ."

But both are whole. A relief! Albrecht fills them and, this time places the one in Nicole's arms as gently as a nurse returning a mother's newborn. The other, he carries himself. On his way up the stairs, he glances down at the place where the brass heads had struck, and purses his own lips in unconscious imitation.

If the world does turn on itself with a diurnal motion, as Buridan and others suspect it may, it makes precious little noise in doing so. The hinges of the world must be well greased, for it turns over always in quiet moments. It turned over once when Gerard of Cremona picked up his pen. It turns over again when Jean Buridan de Bethune puts his down; and maybe there is just the slightest creak when he does. If there has ever been such a creak, it is then, it is there, in that room.

Possem enit dici, he has written, quod quando deus creavit sphaeras coelestes, ipse incepit movere unamquamque earum sicut voluit; et tunc ab impetus quam dedit eis, moventur adhuc, quia ille impetus non corrumpitur nec diminuitur, cum non habent resistentiam.

Or to put the matter more plainly: A body set in motion will continue in that motion if it meets no resistance.

There. In a few strokes of the pen he has disenchanted the heavens. There is no need to suppose the celestial spheres filled with Aristotle's "fifth element," the
quint essence
, whose natural motion is circular. No need to distinguish celestial from sublunar physics. Since God created the heavens
and
the earth, the same forms that account for earthly motions may also account for those of the heavens. Uniform motion above, where there is no resistance, difform motion below, where there is.

"After leaving the arm of the thrower," he tells his students, "the projectile is moved by an impetus proportional to the body's weight and speed. The body will continue to be moved so long as this impetus remains stronger than the resistance, and,
the impetus being permanent
, motion will be of infinite duration if it be not corrupted nor diminished by a contrary force resisting it, or by one inclining it to a contrary motion."

Nicole bounces with excitement. "Then you don't need the Stagerite's Intelligences to keep the spheres turning!"

Buridan shrugs eloquently. Aristotle is full of crap, his shoulders say. If the Stagerite was wrong on matters of theology, as a Bishop of Paris once decreed, then might he not also be wrong on matters of the physics? "As my own master was fond of saying," he tells his students, "we ought not call upon entities we do not need. One might
assume
that there are many more separate substances than there are even celestial spheres and celestial motions, and invoke whole legions of angels to move them . . ." He waves his arms grandly at this. ". . . but this cannot be demonstrated by arguments originating from the senses, and the philosophy of nature demands always that our arguments be sensible."

Albrecht glances toward the stairway with a contemplative look and his lips part, as if to speak, but the young Norman pipes up. "The world is a gigantic clock that God set in motion at the Creation and runs now by itself!"

"The
machina mundi
," Buridan repeats the common phrase, "runs by the laws of nature set by nature's God."

Albrecht smiles. "A clockwork world? Ach, that has right. The Lord has better things to do than spinning planetary spheres. Saving Nickl's soul wants his full attention."

Oresme tries to knock Albrecht's cap off, but is defeated by the Saxon's height. He settles for making a fig with his left hand. "But master," the young man says, "according to the Stagerite, velocity is the ratio of the motive force to the resisting force. So without resistance, speed must be instantaneous, and a body would be in two places in the same instant, which is impossible."

"Which alone tells us that Aristotle was mistaken," Buridan comments. "Albrecht, would you explain for our bachelor?"

"
Internal
resistance, yngling," the Saxon replies with a swat, easily ducked, toward the Norman's head. "All material bodies are compösed of elements in various proportions; so that in part they fall and in other parts, rise. Thus, a falling body will from its own airy or fiery parts resistance encountah, even in . . ." His voice trails off at the end. ". . . a void."

"Should a void exist," Buridan adds the usual disclaimer. "This ‘intrinsic resistance' makes it difficult to start a heavy body into violent motion." He waves his hand. "The external resistance from the air, pfft! For a heavy body, it is nothing. No, lad, a body resting wants to remain so, by an inner nature which we call ‘inertia.' Or ‘ideleness.'"

"Like Albert? It's hard to get ‘Farm-boy' moving, too!"

Buridan smiles. "Albertus!" he says, because the lean Saxon has not responded to the jape. "You are not listening! What engages that subtle mind of yours?"

The Saxon suspects gentle mockery, for the Franks do love to chatter, and thus confuse Germanic silence with having naught to say. "When Nickl the two heads dropped . . ." he stammers, falling into the rhythms of his milk-tongue. But what notion the plummeting sufflators has suggested goes once more unsaid when Nicole waves the bellows.

"Shit! Someone's plugged the damned thing!"

Buridan snatches it from him before he can remove the plug. "A small gift for Heytesbury when he comes."

"A plugged bellows? Oh, the Picard humor, she is more subtle than even the Saxon."

"Mock not the
Ch'ti
!" Buridan says gravely. "This jape," he says aside to Albrecht, "from a man who drinks from a ‘mug' instead of a ‘tasse,' and whose land boasts ‘castels' rather than ‘kateaus.'"

Albrecht scratches his head. "Don't the French say, ‘
ch
ateau'?"

Buridan waves dismissal. "The French speak with porridge in their mouths. When I eat with the French Nation, the servants affect not to understand Picard."

The Saxon shrugs. "Norman, Picard, French . . . It is to me all the same."

"Well said!" booms a new voice from the doorway, and they turn, and there framed they spy a tall man, all bones and angles, with a nose like a halberd and long, wild hair that suggests motion even while standing still. "Yet they lump your savage folk with mine," he cries, "into a single nation!"

Buridan grins. "Anglo, Saxon, it all sounds the same to me. That's why civilized men use Latin." He rises from his stool and welcomes his guest. "William, how delightful!" The newcomer's youth surprises him—he is but three-and-twenty. Yet he is, after all, a Fellow of Merton College; and while Oxford is not Paris—what town is?—she produces scholars of no mean merit.

The Englishman returns the embrace, though not the kisses on the cheek. "Greetings," he says, "from ‘the Calculators of Merton.' And are these your two prizes? Not very likely specimens, what?" He exchanges a hearty grip with Albrecht and claps young Nicole on the shoulder.

Buridan shrugs. "One manages. I thought we would eat here in my quarters, rather than in the Nations. After all," he indicates the four of them, "in which would we dine, Norman, Picard, or Anglo-German?"

"Your ‘Nations' are like our ‘Colleges,' what? Endowments that provide scholars with room and board? Yes, I rather thought so; though ours are not based on the language the scholars speak. Still, I suppose that if students must board together, they ought to be able to talk together at table. Where shall I be quartered? Here? Excellent! Excellent! Just a moment." And the whirlwind spins and shouts, "Oswy! Oswy!"

The short, burly servant is standing right behind him with a coffer on his shoulder and resignation on his face. "Oswy!" William tells him, "We are to have the room two doors on the right. This side, the
right
. Yes. Two doors."

Oswy turns just as the kitchen maid enters with the goose on a great tray. There is a confusion of coffer and goose, and an evolution much like an
estampe
; then the wench is dancing into the room, the platter precarious, the goose in deadly peril!

Saved by the Norman! A steady hand to the platter, a steadier one to the waist, and all that is lost is a little grease splashed upon the hearthstones, and a few years in Purgatory for the thoughts that rush through the young man's mind. A whisper, a giggle, a nod, then she is at work at the hearth, casting sheep-eyes at Nicole while she impales the goose on the roasting spit. After engaging the spit's chain to the blades, she wrestles the two sufflators to the fire's edge. "This'll do ye up fine, m'sir Rector," she says. "Cook says she's done, but ye should let 'er roast a bit ‘till the skin gets crispy-like afore ye eat 'er."

"Very good, Lizette. You may set the table . . ." Buridan looks around the room, and each table is encumbered with books. ". . . that one. Boys, put the books in their cases, so they don't get soiled. Here, William, this is for you." And he hands his guest the bellows.

Wench, grease, spit, table . . . bellows? The Englishman turns his attention to the device now pressed into his hand. He hesitates, pulls tentatively on the handles, scowls a bit, discovers the plugged nozzle, and falls into a study. Finally, he bursts into laughter. "Nature abhors a vacuum!" he cries.

Stacking the books at the table, Albrecht and Nicole glance at each other, then at the Englishman. "All right . . ." says the Saxon.

"The principle of first and last moments," Heytesbury exclaims. "Surely, your master has . . . He hasn't! Why, what a sorry deficiency!" He waves his hands as he talks, a human windmill. He may fly off like a bird at any moment! "‘Sooth, it is simplicity itself, and illuminates natural philosophy with mathematics."

"‘
Sooth
'?" says Nicole.

"The Merton Calculators," Buridan comments aside to his students, "believe that ratios and geometries can reveal the secrets of nature."

"While the Parisians place their faith in reason," the Englishman parries off-handedly. "Bradwardine says that anyone who studies the
Physics
without mastering mathematics will ‘never enter the portals of knowledge.' The plug will not allow the air to rush in to fill the vacuum, so nature prevents the two plates of the bellows from separating. To see why this is so, consider the separation of two parallel plates in general. Remember, God may do anything short of a logical contradiction, so He may permit a vacuum if He so chooses. But has He ever done so
in fact
?"

He spreads his hands, as if in appeal, to the two students, who remain mute.

"Come now," the Englishman insists. "If two plates are in perfect mathematical contact, with no material between them, and they are separated in such a fashion as to remain parallel, it would seem that a momentary vacuum must be produced. Why?" He stabs a finger at the Norman.

Oresme sees no escape. He twists his hand palm up, as if to say it is obvious. "Because at the moment of the separation the air will rush in from the perimeter, but some brief time must elapse before it reaches the center."

"Excellent! Yet, how can this be?" Heytesbury continues, "Consider first the two plates approaching." His hands are plates. They approach. "The air between them becomes progressively more rarefied; yet at no time does the air actually part to form a vacuum in the center because there is no
last moment
at which rarefaction ceases prior to the contact of the plates. Thus, there is no last instant in which the plates are separated. But there is a first instant in which they are in contact. Rarefaction
approaches
a vacuum, but never attains it because the limiting form—actual contact—is
extrinsic
to the intension of the rarefaction itself."

Albrecht nods. "And separation likewise? There is no first instant of separation?"

Nicole pokes him. "Of course not, Farm-boy. Suppose there
is
a first moment of separation. But, if they are separated, there must be a small distance between them—"

"And so," the Saxon' voice overrides him, "however small, a smaller distance must have preceded it. Thus, we haff a last moment of contact—an
intrinsic
limit to contact, doch?—but no first moment of separation." He shakes his head slowly, grappling with the idea of open and closed sets.

Heytesbury waves his hand dismissively while he paces about the room. "We Mertonians have not determined all the questions the continuum raises, but we do know that Aristotle was wrong about forms. They are not ‘either/or.' They are ‘more or less.' A form like rarefaction can be intensified or diminished. If we could but measure that . . ." This last he says wistfully, gazing upward, as if entreating God for an instrument, any instrument, that could measure density or heat or color or charity.

Dropping his eyes, he notices that the goose turns on the spit with no hand moving it. A problem of impetus! Another of Buridan's pranks? He studies the spit from various angles; spies a chain wrapped around a toothed wheel; crouches and looks up the flue.

"Attend!" the Rector cries. "Your hair!"

But the ends are singed only a little. "There is a wheel with blades in the chimney," the Englishman says as he straightens, snuffing the sparks in his hair, "and the hot air rising to its natural place turns the wheel, which turns the spit."

Buridan nods. "But yes! We call it a
turbinus
, after the spinning top the Romans used as a toy. They are become quite popular of late. It is mere engineering; yet it illustrates the matters philosophical. It is in principle as the water wheel, no? But instead of the water rushing down, it is the air, as is proper, rushing up."

"Exquisite! Both air and water take on the nature of a fluid, what? Oh!" He takes a sharp turn into another topic. "The monks at St. Albans—you know the ‘Instrument Makers'? Abbot Richard has only just died, it grieves me to say—but he crafted a most exquisite instrument . . . You know how the ingeniators are trying to build a portable clock? A peripatetic timepiece for the Aristotelians, hah! ‘Sooth, 'tis not enough to erect one in every town square; now there must be one in every house. Soon, they will dangle on lanyards from our very necks, hah-hah! But the ingeniators
envision
that which they wish to achieve, then they essay divers arrangements of gears and balances to find their way to this vision. I hear they are trying springs; but springs lose potency as they unwind and they've not yet come up with a device to compensate for that. So Abbot Richard, knowing how young men like your Nicole, cannot see far off but only close at hand, envisioned a lens—"