Tycho and Kepler (23 page)

The University of Tübingen in Kepler’s day still officially taught Ptolemaic astronomy, and Mästlin gave his students a good grounding in it. However, though he was a cautious man and far from out-spoken on the subject, he was one of a mere handful of scholars in all
Europe who believed that Copernicus’s system of the cosmos should be taken literally, that the planets, including Earth, did in fact orbit the Sun.

Kepler also encountered the writings of Cardinal Nicholas of Cusa, who had insisted a century before Copernicus that Earth did not lie motionless in the center of the universe. Kepler reported, “I have by degrees
⁵
—partly out of Mästlin’s lectures,
partly out of myself—collected all the mathematical advantages which Copernicus has over Ptolemy.” Kepler soon came to agree with Mästlin, and he added a religious spin of his own to Copernican astronomy that made it seem to him even more likely to be correct.

In a universe created in the image of God, it made sense that the Sun, the brightest and most splendid of all objects, the source of
light and warmth, should symbolize its Creator and be the center of all things. This was not an original idea. As early as the fifth century
B.C
. some Pythagoreans, in a pagan society, had thought similarly, except that they made the center of the universe not Earth or the Sun but an invisible fire. Classically educated Kepler was not ignorant of the Pythagoreans.

Kepler’s idea went further.
In both the Ptolemaic and the Copernican systems, the stars were in the outermost sphere. This sphere enclosed the universe and defined the extent of its space. To Kepler the sphere of the stars symbolized Christ,
⁶
the Son of God. Kepler further reasoned that a sphere was generated by an infinite number of equal straight lines radiating from its center. Hence, the area between the symbol of God
the Father, in the center, and the symbol of God the Son, encompassing the universe, represented the third member of the Christian Trinity, the Holy Spirit. In keeping with Christian doctrine of the Trinity, the three united in one. Neither in the spiritual universe nor in the physical universe could one of the three exist alone. Each required the others.

Kepler came openly to the defense
of Copernican astronomy in two formal academic debates
⁷
during his university years. He used his religious arguments along with others that sounded more like those of an astronomer. For instance, he argued that the time each planet takes to complete its orbit, and the planets’ distances from the Sun,
made
better sense in the Copernican arrangement. The Sun was the source of all change and motion,
and therefore it would not be surprising to find that the closer a planet was to the Sun, the faster it traveled—a line of thought that would prove fruitful for Kepler in the years to come.

From the Pythagoreans and Plato, as well as from neo-Platonic thinkers of Kepler’s own era, he absorbed another idea that under-girded his preference for the Copernican system and guided his speculation
and the course of his research from that time on. The philosophy that had impelled Copernicus to put the Sun in the center of the universe and had inspired the design of Tycho’s Uraniborg was the worldview insisting that a profound hidden harmony, simplicity, and symmetry must surely underlie all the apparent complication and complexity of nature. This notion set fire to the spiritual and scientific
imagination of young Kepler. A universe created by God could not be other than the perfect expression of such underlying order. What the goal of transforming astronomy was for Tycho Brahe, the search for this harmony in nature became for Kepler: an obsession that would occupy him for a lifetime.

Although during his student years Kepler worked busily and happily on astronomical questions and
even wrote an essay about how the movements of the heavens would look from the Moon, he apparently remained oblivious to the possibility of pursuing any career other than theology. He passed the examination that signaled the end of his education in the arts, placing second among fourteen candidates, and received his master’s degree in August 1591. He was nineteen. In a letter requesting that his
scholarship be continued, the university senate paid him a tribute: “Young Kepler
⁸
has such an extraordinary and splendid intellect that something special can be expected from him.”

Kepler began the course of theological studies as something of a rebel, at least privately, for his earlier religious scruples continued. He now entered the realm of powerful men who opposed Calvinist teaching
as
ferociously as they did Catholicism. On such questions Kepler wisely chose to keep his thoughts to himself, not even sharing them with those mentors who most cherished him as a pupil. But in the privacy of his own mind, doubts about some Lutheran doctrines so oppressed him that he had to, as he put it, push aside all these complicated matters and sweep them completely out of his heart when he received
Communion.

Meanwhile, the theological infighting that he now witnessed more closely as a student of theology in one of the leading schools so repelled Kepler that he grew to despise the entire controversy. He felt that such behavior was completely at odds with Christ’s teaching, and he believed more strongly than ever that mutual tolerance between the divisions of the Reformation church was
the only appropriate course. He was a devout Christian, and all his life this continued to mean that when it came to the intricacies of doctrine, he would not mindlessly accept the dicta of others.

However much Kepler’s professors guessed about his views or shook their heads at his occasional attempts to defend Copernican theory, they nevertheless continued to recognize his promise. Kepler,
though inwardly nagged by doctrinal doubts, had good reason to envision a smooth road lying before him and to imagine himself in clerical robes in a pulpit. Meanwhile, immersed in his studies, he was spending one of the happiest periods of his life. He would later conclude that whatever other forces came into play—exceptional insight into his talents, unfavorable judgment about his unorthodox views,
or simple bureaucratic irrationality—it was definitely the will of God that brought an end to his happiness and set in motion a sudden and staggering change of plans.

The third theological year
⁹
at Tübingen was probably a “holding year” of sorts, during which students who had completed their studies sought and found jobs. Just short of the end of this year, Kepler received the devastating
news that his time at his beloved university was to end abruptly, and not in the way he had intended. A Protestant
seminary
school in Graz, Styria, in southern Austria, needed a mathematics teacher who knew history and Greek. The school appealed to the University of Tübingen, and Tübingen chose Kepler.

Graz seemed impossibly remote, in an area that was completely foreign to him. He had no
plan or desire to be a mathematics teacher: He loved the subject and thought he might have a talent for it, but he considered himself not at all accomplished yet as a mathematician. He had been certain of his calling to be a pastor and serve his church. Surely, he thought, the move to Graz could not be God’s will any more than it was his own.

On the other hand, Kepler’s faith and his knowledge
and experience of the way God guided the lives of men and women, as well as his sense of duty, told him that he must not be selfish. He hadn’t been put into the world for himself alone. If it
was
God’s will that he go to Graz and teach mathematics, he should not insist that he had a “higher calling.” Furthermore, he had promised himself, when he had seen friends employing every device possible
to avoid obedience when faced with similar distant postings, that he would be more dignified if it happened to him. Recalling that noble resolve, he admitted ruefully that he had thought he was “tougher than I actually
¹⁰
was.”

Kepler consulted his two grandfathers and his mother. Though disappointed that they would not see him in the pulpit, all thought it best to follow the advice of the
Tübingen faculty. Kepler managed to engineer a compromise that left open the possibility of returning to service in the church, and with that settled he agreed to move to Graz.

The transfer was set in motion. Kepler could not go without the permission of the duke of Württemberg. Officials at Tübingen and the inspectors of the school in Graz sent letters requesting that Kepler be allowed to
leave the duchy, and the duke gave his approval.

The twenty-two-year-old Kepler left his beloved Tübingen on March 13, 1594, with a heavy heart. The move to Graz was a venture into alien territory. Even the calendar was different: Because Württemberg still used the old Julian calendar, Kepler lost ten days
when
he came to the border of Bavaria, where they used the newer Gregorian calendar.
He arrived in Graz, by that calendar, on April 11. Kepler trusted the will of God, but he could not have imagined how essential this strange, unexpected, seemingly senseless journey was in getting him to his future, to Tycho Brahe.

W
HILE
K
EPLER WAS BASKING
in the rarefied scholarly atmosphere of the University of Tübingen, at the close of
the 1580s and during the first years of the 1590s, the utopia of Uraniborg had begun to fray a little around the edges.

The Tycho who had built Uraniborg and Stjerneborg had usually enjoyed good relationships with most people. He did have serious conflicts with the peasants on Hven, but the customs of the time and the islanders’ unusual immunity from those customs prior to his arrival made
those conflicts almost inevitable. Otherwise, Tycho seems to have commanded genuine respect. He had founded and presided ably over an entirely unprecedented institution that drew both humble students and a scholarly elite from all over Europe and Scandinavia. Even in those days when an aristocrat could expect obedience, he had to have been a skilled manager. Students and assistants worked for him
untiringly and apparently with great devotion. His ability to recognize the potential of men of lower classes and his willingness to elevate them to the level of valued colleagues—Steenwinkel being a case in point—set him apart from most of his aristocratic peers. He seems to have been a faithful husband to his commoner wife, concerned about his children, popular among commoner scholars and friends
such as Pratensis, and well liked by royalty such as King Frederick and Wilhelm of Kassel. To a remarkable extent for a nobleman living at the end of the sixteenth century, Tycho had chosen to ignore the chasms between the social strata and had managed to bridge them.

His relationship with a new assistant who came to Hven in 1589 exemplified his continuing success in doing so. Longomontanus,
as
the
man called himself, was the Latinized name for the farm where he was born in western Jutland to a poor peasant family. Poverty and the need to help his widowed mother run the farm had delayed Longomontanus’s education, but the pastor of the local church had recognized his potential and seen to his schooling. Longomontanus was twenty-six by the time he entered the University of Copenhagen.
Scarcely a year later, in 1589, he came to Uraniborg on the recommendation of his professors and was soon one of the most skilled and exacting astronomers there. His humble origins did not prevent his becoming one of Tycho’s favorites and an intimate friend of the family. Tycho trusted him sufficiently to make him his personal secretary. Longomontanus was popular with Tycho’s two sons, Tycho and
Georg, and Tycho chose him (perhaps because of his maturity) to chaperon them when they traveled to visit relatives.

Nevertheless, in spite of his lack of regard for social divisions and the scorn he had poured on the nobility, Tycho had not ceased to be an aristocrat. It was in his blood and upbringing. If for him the traditional nobility had stopped being much more than a weary charade,
the symbolism of Stjerneborg indicated that it had been supplanted by a much more vigorous and much older aristocracy, in which Tycho saw himself the heir by divine right to Hipparchus, Ptolemy, and Copernicus, men who left kings like Frederick in the dust. Nor had Tycho shed the trappings and pride of nobility. He had transformed them, with embellishments, to adorn this different kingdom. Here, the
old social class distinctions really had, to a certain extent, become extinct, but Tycho was still on the top—higher, in fact, than he had been in the old order, and potentially more of a tyrant.

The picture of Tycho that has chiefly come down in history is not a sympathetic one, and a few years later he would appear mercurial, autocratic, and paranoid to Kepler, who was initially inclined
to revere him. The finer side of Tycho never disappeared completely, and previous instances of tyranny and paranoia may have escaped the
records
, but evidence points to a change in his temperament in the early 1590s. In the autumn of 1590 he imprisoned his tailor for three days before the man succeeded in escaping from Hven by night. In 1591 Tycho’s jester, a dwarf named Jepp, tried to flee from
Uraniborg, and Tycho had him beaten. None of that was perhaps out of character for the lord of a fief, but as the decade continued, there was increasing evidence of a less likable aspect to Tycho’s personality.