Kepler's Witch (21 page)

Matthias was not as intelligent or as open-minded as his brother. He had few talents except for the applications of power, and he used Rudolf's interest in the occult to help bring him down, claiming that Rudolf was too easy with Protestants and that he dabbled in un-Christian things. Matthias did have ambition enough, and his desire for power and revenge on his older brother often choked him. Moreover, he was good at one thing Rudolf was not—he had a gift for intrigue. Rudolf hated him and feared him most of all. He took every opportunity he could to humiliate him, refusing him money and any position of power within the empire. He even forbade him to marry. After Ernest died in 1595, however, Matthias, who was next in line, became the imperial heir. Fearing the worst, Rudolf retreated more and more into his private quarters and into the galleries of his mechanical wonders, slowly abandoning the affairs of state, refusing to meet with foreign ambassadors, and flying into sudden rages.

All of his relationships gradually fell apart. His sexual life was complicated, since he was attracted to both young boys and young girls. For years, he had been scheduled to marry his Spanish cousin Isabel, but postponed the wedding year after year. His mother begged him to marry in long letters sent from Spain, but somehow he found a reason to postpone it one more year. Finally, after waiting until she was thirty-two years old, Isabel married Rudolf's younger brother Albert, the former cardinal. Hearing about their wedding, Rudolf raged about the palace in grief and anger.

 

T
HIS WAS THE PALACE
that Kepler came to after Tycho's death and in which he joined the small clusters of attendants and imperial employees waiting for word on their salaries; occasionally he was summoned by the emperor to answer a question or perform some errand. A decade before, John Dee and the earless Edward Kelley, once alchemists and astrologers to Queen Elizabeth I, had haunted the castle, speaking with angels in secret and at least once, according to them, turning a pound of lead into a
pound of gold. Kelley had lost his ears after being unmasked as a charlatan. The team gave alchemical advice to Rudolf until Kelley announced that the archangel Uriel had spoken to him in the night, telling him that he and his partner, John Dee, should share their wives. Dee's wife, who was younger and prettier than Kelley's, put her foot down, and from that point on the partnership faded.

Ten years later, Kepler would have been standing in roughly the same place Dee and Kelley stood, in the vaulted Wenceslas Hall in the old royal palace or in one of the great rooms of Rudolf's Italian palace, waiting in line or for an appointment. Perhaps, in one corner of the room was an old man standing quietly, the only Jew ever to have had an audience with the emperor. Kepler would have known him and perhaps spoken with him. This was the mysterious Judah Löw, the great rabbi of Prague, a master of the Kabbalah. The details of his interviews with the emperor remain unknown, even today, though there are stories. One has the rabbi ushered into a wide room with a single table and two chairs. In the corner is the opening to an antechamber covered with a red curtain. The man who meets the rabbi is not the emperor, but one of his councilors, who engages the rabbi in a long, involved conversation about occult matters. He asks Rabbi Löw about his teachings, about the mysticism of the Kabbalah, and about the secrets of the universe. The conversation becomes more involved, ranging widely, until suddenly Emperor Rudolf bursts into the room from behind the curtain, where he had been listening all the while. The rabbi and the councilor stand, the emperor takes the councilor's place at the table, and the conversation continues.

This same castle, filled in Kepler's time with scientists and charlatans, mystics and philosophers, was where, seven years after Kepler had left the city, two Catholic representatives to the Diet, along with their secretary, were thrown out of a window in the old Bohemian chancellery. They survived, but the Thirty Years' War began, the war that would hound Kepler to his tomb.

L
ETTERS FROM
K
EPLER TO
J
OHANN
G
EORG
B
RENGGER
O
CTOBER
4,1607

N
OVEMBER
30, 1607

Where Kepler writes the
Astronomia Nova
in Prague, a city full of magic and political intrigue.

D
URING THE YEARS
K
EPLER LIVED IN
P
RAGUE
, from 1600 to 1612, he stayed in three different residences. The first was with Tycho in a house in No
y Svet, a neighborhood just west of Praz
y Hrad, the Prague Castle, atop the great hill overlooking the city, a short walk for Kepler. Later, when he moved down to the Old Town, it was quite a walk up the Steep Stair, and then a leisurely walk down a narrow lane that worms over the hills until it ends. The houses, the buildings, the garden walls are all taupe colored, with red tile roofs and ornate gables. Old brass lanterns gone green are fixed to the garden walls. Tycho and Kepler's house is No. 1 No
y Svet, hidden, nearly forgotten by the people dining at the fashionable restaurant next door. Kepler's second home was across the street from the Emmaus monastery, Na Slovanech, near the church of St. John Nepomuk on the Rock. Both of these houses are in the New Town, across the river from the Old, both part of the maze of communities hustled around the walls of the old castle like supplicants calling for imperial favor.

The last five years of his time in Prague, Kepler lived at 5 Karlova Street, across the road from the Jesuit residence inside the Counter-Reformation university, the Clementinum. This house was in the Old Town, on the other side of the river, a hundred feet from the Charles Bridge, eight or nine blocks south of the Jewish ghetto, and four or five blocks west of the Old Town Square. In the same square, Kepler's friend Johannes Jessenius, the kindly anatomy professor from Wittenberg who acted as intermediary between Tycho and Kepler, eight years after Kepler's departure from the city, as an example to the rebellious would be beheaded by Ferdinand II, once the Archduke of Styria, by then the Holy Roman Emperor.

As in any medieval town, the streets of Prague are fit for pedestrians, horses, and small carts and wind a serpentine path up a gentle incline from the river. Nowadays, there are restaurants and shops selling textiles, marionettes, and Russian stacking dolls. On Karlova Street, just up from Kepler's house, one shop sells Prague crystal, while a second sells linen. It is not difficult to imagine the same street in Kepler's day, narrow, snaky, and stuffed with commerce—food sellers and wine merchants, stand-up bars, and traveling puppet shows. In the Old Town Square or near the foot of the bridge, the puppeteers played out folktales and morality plays. Traveling companies of players acted out national histories and fairy tales. Because there were no streetlights, the area around Kepler's house at 5 Karlova Street fell asleep soon after dark, after the players and the puppet theaters had all packed up and moved on, after the street musicians had wiped the river air from their violins, gathered a few copper coins, and walked home. They glanced into each pocket of shadow as they walked, like everyone in Prague, wary of petty thieves. There were cutpurses aplenty in the capital, who would steal from monks as easily as from merchants. The river air carried the sour smell of decaying water plants mixed with the nose-twitching odor of animal death. In the fall and winter and into early spring, mists wafted up from the Vltava, covering the Charles Bridge and leaving only the towers sticking out of the white lake of fog.

Prague is baroque with images, sometimes pretentious, sometimes saccharine, and sometimes mystical. A darker face hides truths that the city
refuses to reveal. On the Charles Bridge is a statue celebrating the forced conversion of twenty-five hundred Jews to Christianity. The solemn, severe face of the preacher is matched by the subservience of the converted Jews, so that conversion becomes indistinguishable from conquest. The religious art haunting the city carries both spiritual and political messages, but underlying it is a grab for the numinous, an attempt to capture both the ecstasy and the torment of faith, where men and women alike are caught up in the folds of God. No art or science can in fact capture what the numinous is, for it is an encounter beyond words. Kepler tried to find it in the heavens.

If Prague is astonishing for the jaded modern tourist, so used to heroic skylines and afternoon wonders, how much more astonishing it must have been for a man from provincial Leonberg. The architecture of royalty was constructed in layers, courtyard within courtyard, the old palace dominated by the massive Gothic towers of St. Vitus Cathedral, with walls as high and imposing as St. Peter's, like fingers stretching upward, barely scraping the bottom of heaven. Kepler had made his mark in the empire, to be sure, but his situation as a Lutheran was always tenuous, and the titans who lived in Prague Castle, if only by turning over in their sleep, could create such waves as could easily swamp Kepler's little boat. One can imagine Kepler, a man born in little Weil der Stadt, beginning at the foot of the castle stair and winding up the hill past the guard post to the stone walls, to the cathedral towers, to the ornate palace of the emperors. One can imagine his staring upward, as every ordinary mortal was expected to do, filled with insecurity and fear by the enormity of the architecture. In mimicry of the heavens; in mimicry of God.

But anyone who was awake in Kepler's day would have known, after a quick tour through the Old Town, that the emperors, for all their divinity, sat upon shifting sands. The city was too diverse for a simple, uncomplicated rule. No king could command the people. He either led them or terrorized them—there was little room for anything in between. Traditionally, three nations inhabited the city, twisting the folds of its history—the Czechs, the children of Libuše and Prøemysl, who first built it; the Germans, the countrymen and retainers of the Habsburgs, who ruled it;
and the Jews, who lived as shadows, packed away in their ghetto, and suffered inside it. Of the three, the first two go back Roman times, while the Jews go back to the Middle Ages. The first two entered as settlers and conquerors. The last entered as refugees.

The history of the Czech people has been like a man carrying a stack of dishes on his head; every day the neighbors clap, shout, pound the floor, rush at him, and make faces, because they want to see it fall. Magyars, Poles, Germans, Turks—all have conquered and all have been conquered. While the Habsburgs ruled, as they did for nearly a thousand years, the German minority dominated the city, hangers-on in the imperial Habsburg court. These were no working-class Germans. All were would-be aristocracy, mixed with a burgeoning bourgeoisie. In an aristocratic society, numbers didn't matter; what mattered was power.

Prague has always been a city of mystic spectacle. Whether from the mists that cover the Charles Bridge at night, from the alchemists and Rosicrucians, or from incursions of gypsies wandering through the city, Prague has always walked halfway in shadow. Although outwardly Catholic, the nation looks back to John Commenius and the Bohemian Brethren, to Jan Hus and the Utraquists, and feels that somehow something righteously Protestant has been stolen from it.
Cuius regio, eius religio
.

Corresponding to Prague's history of near madness—Rudolf II, Edward Kelley—is its history of genius—Tycho Brahe, Johannes Kepler. Kepler wrote his first two mature works in Prague—the
Astronomiae Pars Optica
and the
Astronomia Nova
. In the former, he laid the groundwork for Newton's later science of optics by setting out the rules of refraction. He discovered that the reason the moon or the sun appears larger at the horizon is optical, rather than astronomical. In the latter, his
Astronomia Nova,
he set up the first two of his three laws of planetary motion. These laws are:

1. The law of ellipses:
   Each planet follows an elliptical orbit in which the sun sits at one focus of the ellipse.
   
2. The law of equal areas:
   The radius vector joining a planet and the sun sweeps out an equal area over an equal period of time.
   

To arrive at these conclusions, Kepler had to break with a great deal of tradition. First, the idea that the planets followed ellipses rather than perfect circles with uniform motion was near heresy. Even Kepler accepted the tradition as a reasonable starting place until he began his work on the orbit of Mars, when he eventually broke with it to make his theory fit Tycho's observations. This was a new attitude. Astronomers in Kepler's day were interested in accounting for the appearances, in creating a model that would apply geometry to motion, and the model often dominated. Although some astronomers were realistic enough to look for a relationship between the model and what actually happened, the reality they found was all too often simply an application of the model. Kepler took a different tack. He wanted to know what was actually happening, what the path of the planet actually was. In pursuing the secret of God's mind, he had to be willing to be surprised. The Aristotelians, on the other hand, had a vision of the way a well-ordered universe ought to operate, for not only was the model true, it was righteously true.

In Kepler's day, reaching back through the Middle Ages to the time before Christ, to Aristotle, people assumed in a commonsense way that the heavens were perfect. They were silent; they were orderly; they were beautiful. Standing in an open field in the middle of the night, anyone could see the great vaulted heavens arching overhead and the blue-white stars, lucid and overpowering, scintillating in the night against the black background of the sky. Such beauty harrows the soul and purifies the mind, and for Aristotle and his followers such beauty had to be perfect, for imperfection was a thing of the earth, not a thing of heaven, the place where the gods lived.

But all things for Aristotle were stacked into hierarchies. There were perfect flowers and imperfect flowers—the rose was at the top, the queen of all flowers. The diamond was the most perfect of gems. The circle was the most perfect of shapes. How could it be otherwise? The circle was simple, uncomplicated, and elegant. Therefore, since the perfect shape was the circle, the motions of the heavens had to be circular. For two thousand years, people believed this—they believed it the way we believe in democracy. There was a moral as well as a geometrical elegance to it. The vision
passed from Aristotle to Ptolemy, who, being an observant fellow, realized that, although the philosopher's perfect circles were elegant, they never fit exact observation, and he set about making Aristotle's vision connect to the appearances.

One observation that had to be explained was that there were two types of planetary motions: the lower and the upper. The lower planets—Mercury and Venus—moved in an uncomplicated way. The upper planets, however—Mars, Jupiter, and Saturn—were more mysterious and more complex. Every day, Mars advanced along the plane of the ecliptic from west to east until in a period of about 780 days it completed one revolution. So far so good, but as each of these upper planets neared its position most opposite to the sun, where it could be seen at its highest point in the sky at midnight, it seemed to stop. It would hold that position for a short while and then, curiouser and curiouser, begin to move backward. After a while, it would halt again and roll forward once more. No one quite knew what to make of this. They called these meandering stars “planets,” that is, wanderers, misfits who were out of step with the divine march of the heavens. The planets were oddly halfway between the perfect regularity of the stellar sphere and the frightening oddity of the comets, which appeared out of nowhere and flashed across the sky for a few months, only to vanish once again, predicting famines, floods, and the deaths of kings. Ptolemy's answer to this strangeness was the invention of epicycles, circles that turned on the larger circles of the planetary orbits, circles upon circles, perfect circles upon perfect circles.