Tycho and Kepler (36 page)

Rudolph’s response on December 10 set matters straight: Tycho
was
to have his wooden outbuildings and “little rooms,” bays along the cliff for the instruments. Tycho’s salary also was to be paid, in part out of rents from Brandeis.

By late autumn so much remodeling was going
on at Tycho’s castle that there was less living and working space than there had been to start. Also, the plague had come nearer, and two thousand had died in the district. Tycho moved his family to another castle twenty miles downriver because “the women were frightened,”
⁷
as he reported it.

All this activity had not made Tycho forget about Ursus. In September he had begun investigating the
man’s whereabouts and learned of his flight from Prague. Tycho secretly consulted the official censor. Because Ursus had published his book without first submitting it to censorship, it was within the censor’s power to summon him and assign punishment. But with the imperial court absent from the city, there was no court before which Ursus could be summoned. Tycho had to wait, but he reaffirmed
his intention to track “the beast” down and drag him out of hiding.

T
HAT AUTUMN
, Johannes Kepler and his family faced an increasingly ominous situation in Graz. Kepler could no longer escape into mathematical and philosophical speculation and ignore the threat hanging over him. There were rumors that soon any Lutheran moving away from Graz
might not be allowed to take away his possessions or trade or sell them, confirming the fear that had earlier made the Keplers decide to try to weather the storm rather than relocate elsewhere. The loss of Barbara’s substantial inheritance and all her possessions would have been catastrophic.

Nevertheless, to stay was becoming untenable. Oppressive ordinances touched the family directly, and
forced conversions to Catholicism were surely not far away. Riots broke out continually in the city and nearby countryside. “No matter what fate
⁸
might await
me
if I move elsewhere,” wrote Kepler, “I know for certain that it will not be worse than that which threatens us here so long as the present government continues.”

He did not have many options. Returning to Württemberg to take up a clerical
position, the ambition he had painfully relinquished when posted to Graz, was out of the question, because his disagreement with Tübingen orthodoxy, begun as a student, was now stronger than ever. “I could never torture myself
⁹
with greater unrest and anxiety than if I now, in my present state of conscience, should be enclosed in that sphere of activity,” he wrote.

One possibility was a university
professorship in philosophy or even in medicine. Kepler appealed to Mästlin, asking whether there might be a position like that available at Tübingen or whether he should look elsewhere. He inquired about the cost of living in Tübingen—the price of bread, wine, and rent. Mästlin replied that, sadly, he had no advice to offer and lamented that Kepler had not sought the counsel of a wiser man
with more political experience, “for in these matters
¹⁰
I am as innocent as a child.” He reported the prices of grain and wine but advised Kepler not to hope for a future in Tübingen. Kepler also wrote to Herwart von Hohenburg, who had been such a helpful friend in the past. Von Hohenburg failed Kepler this time. His own position was insecure, and he needed to be exceedingly discreet.

With
each failure, Kepler’s thoughts returned to Tycho Brahe, whose success in Prague had been reported to him by von Hohenburg. Prague was not, after all, so far away. Tycho had mentioned the possibility that Kepler might like to use his observations. The idea that that suggestion could possibly be construed as an invitation or even as a job offer seemed tempting but outrageous. Kepler would have to
leave his family behind in Graz, for the letter had said nothing of them, and he would have to put his own mind and talents at the disposal of another man, rumored by some to be a tyrant. He had already offended that man, and Tycho’s forgiveness had been gracious but condescending.

With the new year, 1600, and a new century, came the invitation from Johann Friedrich Hoffmann, baron of Grünbüchel
and Strechau, member of the diet of Styria and councillor to Emperor Rudolph. Hoffmann offered Kepler not only a way to get from Graz to Prague, but an introduction to Tycho Brahe. Kepler’s wavering ended.

Kepler would have begun the journey in Hoffmann’s carriage with much more confidence had he known about a letter from Tycho that arrived shortly after his departure. Tycho had repeated his
invitation—and this time it clearly
was
an invitation, insisting that Kepler must come to Prague, not because he was “being forced out of Graz” but of his own free will and because he “desired joint
¹¹
studies” with Tycho. If he chose to come, Tycho was prepared to help and advise him and his family.

Kepler and Hoffmann’s ten-day journey from Graz to Prague passed through rolling countryside
studded with promontories, many of which were crowned by castles. Prague itself was situated around such a promontory, with an enormous castle complex that even included a cathedral. This complex, a great city within a city, was the seat of the Holy Roman Emperor. Renaissance mansions of some of Europe’s most powerful aristocrats lined the higher parts of the steep streets that climbed the hill
from the river called the Vltava by the local population and the Moldau or Moldova by their rulers. Farther down, nearer the river, were the homes of courtiers and craftsmen, and there was much more of the city at the other end of a long, stone, towered bridge that spanned the river.

Kepler, still unaware of Tycho’s second invitation, stayed for a few days as guest of Baron Hoffmann. Cosmopolitan
Prague was a different world from the Graz Kepler had left. Bustling, exhilarating, a mixture of narrow, malodorous streets, wider avenues, and broad marketplaces, it was alive with many ethnic groups and languages. The court attracted a diverse community of noblemen and ambassadors from all over Europe, as well as opportunists and hangers-on,
and
this community in turn provided a living for hundreds
of tradesmen, craftsmen, scholars, and artists.

It was some days before Kepler was able to get word to Tycho that he was in the city. However, “as soon as I arrived,”
¹²
Kepler reported, he had an unpleasant encounter with Ursus, who had not fled far after all. At first Kepler kept his identity a secret from Ursus, “lest he intensify the situation to a brawl,” but he spoke to the older man
sharply about how little he liked Ursus’s recent book. As the incident continued, Kepler let Ursus know who he was and told him that “since he decided to drag me, who had written as a pupil, unwillingly into the judge’s chair, he should therefore permit me to discard a pupil’s modesty and assume a judge’s authority in this literary contest and in my turn decide publicly what seems to be the mathematical
issue.”

By January 26 Tycho, back from his brief flight from the plague, had heard of Kepler’s arrival. He wrote to Kepler again with extreme cordiality: “You will come
¹³
not so much as guest but as very welcome friend and highly desirable participant and companion in our observations of the heavens.” He sent his son Tycho and Tengnagel in his own carriage to Prague with instructions to bring
Johannes Kepler back with them. Kepler had every reason to anticipate from Tycho as warm and accommodating a welcome as Tycho had received six months earlier from Emperor Rudolph.

17

A
D
YSFUNCTIONAL
C
OLLABORATION

1600

THE CARRIAGE IN
which Kepler rode must have creaked, shifted on its axles, and tilted as the horses began the steep pull up the road to the top of the bluff where Benatky Castle stood. Kepler’s mood cannot have been other than one of excitement and exhilaration, with most qualms about the impending meeting overridden by anticipation that Tycho
Brahe, better than any other man alive, would be able to understand and value his ideas. The intellectual relationship and the access, at last, to Tycho’s observational data that Kepler looked forward to, and that Tycho had promised in his letters, must surely have made the future appear as rich, fertile, and limitless as the plains and skies that opened to view as the road climbed.

Tycho’s
arrangement for Kepler to ride from Prague in the carriage with his eldest son had been flattering and consistent with the tone of his most recent correspondence, and Kepler’s welcome at Benatky was no disappointment. The venerable astronomer granted him a cordial initial interview. Tycho Brahe’s mystique was as powerful as any monarch’s, and to Kepler he probably seemed like a character from legend
who had turned out to be real. Kepler reported that Tycho offered to reimburse his travel expenses, and
he
“saw immediately”
¹
that there was “no fear that I would regret the trip.”

Alas, it was not long before Kepler’s mood deteriorated to bleak disillusionment, homesickness, and panic about the future. The promise of that welcome turned out to have been a cruel mirage. In the days that followed
his arrival, Benatky’s harried lord turned to other matters. The bustle and confusion of a castle under reconstruction went on around a bewildered Kepler as though he were not there. Perhaps he should not have been surprised. Only recently he had visited the court in Württemberg and barely been allowed to sit at the Trippeltisch. Tycho’s households at Uraniborg and Benatky, though they in some
ways resembled the establishment of a university professor, still had much in common with the court of a feudal ruler, where a man of lower status rarely had contact with that ruler except for the sight of him at the dining table.

Kepler’s plight was not helped by the fact that Tycho was in an unusually distracted state. He was worried about his instruments, not only the four left on Hven
but the others that were still in Magdeburg. He was trying to supervise the renovation of a castle teeming with workmen who needed his direction, for in his mind alone existed the vision of what the reconstruction would look like when it was completed. He was coming to grips with the huge disappointment of learning that a promise of financial support from the emperor did not mean that money would
be forthcoming. Not for Tycho, nor for Kepler—nor for anyone else at Benatky—were circumstances conducive to systematic and productive scientific work. Tycho, like Kepler, was homesick, frustrated, uncertain of the future, and on the verge of financial disaster.

At first it seemed there would be nothing for Kepler to do that he personally could consider worthwhile. There were workmen to be
dodged morning, noon, and night; there were women—Tycho’s wife and daughters and their attendants—chattering in Danish (which Kepler, of course, did not speak) as they, too, tried to live normally
amid
uprootedness and turmoil. In spite of the crowded conditions, Kepler called the situation “a reigning loneliness
²
of people.” He particularly despised mealtimes—boisterous, rowdy, claustrophobic
for a man accustomed to the peace and quiet of his own home. The meals were served in a room on the second floor of the castle, with Kirsten and their family joining Tycho and whatever assistants and visitors were currently in residence. Kepler had never, even in his student days, drunk as much wine as they did at this table. Yet these uncomfortable mealtime intervals were his only opportunity to
learn anything at all about the observations he desperately wanted to consult. Sometimes, as casually as he might cast a bone to his dogs or a tidbit of sweet to his jester, Tycho would come forth with a snippet of precious astronomical information; “One day . . . the apogee
³
of one planet, the next day the nodes of another!” grumbled Kepler. And as for the collegiality Tycho had promised him—the
discussion of “lofty topics,
⁴
face to face in an agreeable and pleasant manner”—it seemed Kepler could do no better than occasionally command Tycho’s attention between bites for a few fleeting words.

Perhaps Kepler should have paid more heed to the way Tycho had referred, in his letters, to his most highborn assistant, Tengnagel. He had called him
domesticus
—servant or employee. A “hired hand”
was the way Kepler later described his own status at Benatky in a letter to Mästlin—and a rather junior hired hand at that. Kepler soon realized that though he had been led to believe he would be treated as Tycho’s esteemed colleague, he needed first to climb his way up the ladder in competition with other “assistants.” His competitors included some with considerable skill and seniority, like
Longomontanus and Tengnagel, as well as Tycho’s own son. Kepler was the intellectual match of any of them, yet a month after his arrival he had not improved his position. There was even more competition when Johannes Müller, mathematician to the elector of Brandenburg, arrived, bringing his family with him. It seemed that Tycho had brought Kepler here only to waste his time: “One of the
most
important
⁵
reasons for my visit to Tycho,” Kepler wrote to von Hohenburg, “was the desire to learn from him more correct figures for the eccentricities in order to examine my
Mysterium
and
Harmony
. But Tycho did not give me the chance to share his knowledge.” Kepler could not at first understand why Tycho was being so secretive.