Tycho and Kepler (5 page)

In Tycho’s day a conjunction of the planets was considered to have more than astronomical interest. It was of great astrological significance. For practice, Tycho was casting predictions and horoscopes of famous men (without their knowledge) and recording
the results in a notebook.

Despite the best efforts of Vedel to keep his charge on track with his studies of other subjects, Tycho was soon practicing his astronomy more openly. Bartholomew Schultz, a more advanced student at Leipzig, gave him some instruction and introduced him to the more technical side of the subject. Tycho needed a better instrument. He managed to acquire one—his first
real astronomical instrument—a cross staff, or radius. On May 1, 1564, when he was seventeen, he entered his first observation from it in his log. After that, he often “stayed awake the whole night
⁵
through, while my governor [Vedel] slept and knew nothing about it; for I observed the stars through the skylight.”

Though Schultz showed him a trick, using “transversal points” that would allow
him to obtain more refined measurements (
see figure 7.8c
), Tycho soon became dissatisfied with the imprecision of his radius. He began to discover errors in his data, which he traced to faulty logic in its construction. The only recourse was to rectify them with a table of corrections, for he “had no opportunity
⁶
of having a new [instrument] made, since my governor, who held the purse strings,
would not allow things of this kind to be made for me.” Tycho had already begun to be more seriously concerned about the precision of observations than anyone before him, or any of his contemporaries.

The next December, 1564, on Tycho’s eighteenth birthday, one of the professors at dinner described an illiterate craftsman he had met as “an astronomer by nature.” Tycho recorded that phrase
in his notebook. The same month he set himself a research project to test a popular notion that the day-to-day positions of the heavens during the twelve days of Christmas, beginning on December 25, presaged the month-by-month pattern of the weather for the next twelve months. During those twelve days Tycho recorded every feature he could of the heavens, planning to check the weather throughout the
coming year to see whether the data agreed.

Figure 2.1: The cross staff, or radius:
⁴
To find the apparent or “angular” distance (
see appendix 1
) between two stars, an observer sighted from where the “eye” appears in the drawing and slid the crossbar up and down the staff until the distance between the two stars was exactly covered by the length of the crossbar. Tycho’s cross staff was more sophisticated. Like the one shown here, it
had two sights on the crossbar, and one of them was movable. He adjusted the movable sight so that he could see one star through it and the other through the sight fixed at the center of the crossbar. He then found the angular distance between the two stars by reading the scales etched on the crossbar and the staff and using a table of tangents.

The following May, 1565, Tycho and Vedel returned
home on a vessel that threaded its way among warring ships. Denmark was once again engaged in combat with its perennial rival, Sweden. Disembarking at Copenhagen, Tycho continued his journey to Knutstorps Borg, taking observations and recording the latitude at each stop on the way.

Knutstorps Borg in May 1565 was much larger and more impressive
than
it had been when Tycho was born there. In
1551 Otte and Beate had rebuilt the ancient manor house. From a causeway and drawbridge over the lake, a gate now led into a square central court surrounded by four ranges of buildings. Those on the north and south side had tall, steep roofs with scalloped end gables. The walls were three to four feet thick, with arrow-slit windows, for the castle was intended to be a fortress as well as a stately
home.

Though Otte and Beate’s manor was never directly threatened, the war with Sweden came close to Knutstorp in the form of border raids. Beate’s mother and father, Tycho’s grandparents, died defending their castle, Baahus. Even more drastic for Tycho was the death of his uncle Jørgen in June 1565. Jørgen was vice admiral of the Danish fleet, which was in Copenhagen for repairs and reprovisioning.
King Frederick and Jørgen had been drinking, and the king fell into the water under Amager Bridge. Jørgen dived in to rescue him. The king recovered, but Jørgen either drowned there or died almost immediately thereafter from injuries or illness attributable to his rescue effort.

His foster father’s death should have left Tycho a wealthy man. Jørgen had no children of his own, and he had been
in the process of making Tycho his legal heir. Unfortunately that process had not been completed. Inger held life tenancy of the manor at Tostrup as her “widow’s jointure,” but eventually, at her death, the castle and the income from its hundreds of tenants would not come to Tycho but revert to general distribution among the Brahe family. Meanwhile, responsibility for Tycho, who at eighteen had
not yet reached his majority, fell to his natural mother and father.

Tycho left Denmark again a year later, in the spring of 1566. Somehow he had convinced his father to allow him to continue his education abroad rather than take advantage of the excellent opportunity the war provided to begin a career of civil service to the king. This time Tycho’s destination was Wittenberg, where Anders
Vedel was already working toward his master of arts degree. Five months after
Tycho
arrived in Wittenberg, an epidemic struck the town, and most of the students fled. Tycho moved to the more northern university town of Rostock and began studies there in September. This move, though not particularly significant for Tycho’s future as an astronomer, was extremely significant for his future physical
appearance.

On December 10, Tycho was a guest at a betrothal celebration. During the dancing, he fell to quarreling with another aristocratic Danish student, his third cousin, Manderup Parsberg. The quarrel may have erupted as the result of some levity, at Tycho’s expense, about an unfortunate astrological prediction he had made that autumn. There had been an eclipse of the Moon on October
28 that Tycho concluded presaged the death of Suleiman the Great, the Turkish sultan. With a flair for the dramatic and poetic, Tycho composed a Latin poem announcing this prediction. Then the news arrived that the sultan had already been dead for six months.

Whether or not it was an insult having to do with that embarrassment that precipitated Tycho’s and Parsberg’s dispute, it did not end
at the betrothal celebration. The two young men resumed their argument at another party on December 27.

Two days later, December 29, Tycho’s astrological computations told him that there would be some sort of accidental happening. In spite of the fact that one of his predictions of late had been notoriously inaccurate, he decided to take the warning seriously and not go out at all that day.
However, when evening fell, he ventured downstairs in his lodging house to supper. Before long he and Parsberg were quarreling again, wrought up, each demanding that the other draw his sword.
⁷
They rose abruptly from the table and went out into the churchyard.

A woman in the room knew Danish and understood the seriousness of the dispute. She urged other diners to pursue the young men and prevent
their damaging or murdering one another. It was too late. The company emerging from the dining room found a bloody scene. A blow from Parsberg’s broadsword had cut away a good portion of
Tycho’s
nose and just missed proving fatal. Later portraits show a diagonal scar across Tycho’s forehead and a curving line across the bridge of his nose. Tycho endured a lengthy, painful, and anxious period of
convalescence that winter. His doctors couldn’t reverse the disfigurement, for skin grafting, though done in other parts of the world, was unknown in Europe until about two decades later.
^fn2
Fortunately, infection did not set in, and sufficient scar tissue formed.

Although Tycho lost part of his nose at Rostock, he gained two new interests that remained with him for the rest of his life: medicine
and alchemy. When he returned to Denmark in April, he was already experimenting with ways to replace his nose artificially. Later descriptions indicate that eventually, with fair success, he made a false nose by blending gold and silver to a flesh color, or used copper for everyday wear. He held the nose in place with an adhesive salve that he always carried with him in a small box.

When Tycho
left Denmark for the Continent a third time, the next December (1567), he did so over much stronger protests from his father. The war had offered a superb opportunity to begin a political career, which Tycho had ignored. Now the steady recovery of Peder Oxe’s influence made success for Tycho, as foster son of Peder’s sister, a certainty, if Tycho would only be persuaded to enter public life.
Tycho had come of age when he turned twenty-one earlier that December, but that didn’t leave him free to flout his father’s will, for he was still dependent on him for financial support. Tycho had just missed inheriting his uncle’s fortune, and it was doubtful that he would be able to earn a living in the pursuits he was choosing. Nevertheless, to Otte Brahe’s intense frustration, his eldest son turned
his back again on a promising future and headed across the Baltic to Rostock.

Though modern popular opinion might have it that in earlier
centuries
an aristocrat had unlimited opportunity, while the lower classes were sadly constrained in their career choices, the fact is that in the Europe of Tycho’s day a nobleman’s son was fairly strictly limited to the career paths that Tycho’s forebears
and relatives took—knighthood, the administration of fiefs, or government civil service. Tycho enjoyed university life, but there was no future in that, for most scholarly positions in the universities were closed to noblemen.

There was, however, another possibility: a canonry. The cathedrals in Denmark and Norway—having recently become Lutheran—still retained their rich landed endowments.
Royal administrators awarded the positions of canons of the chapters of these cathedrals both to government servants and to men of learning. Commoners and noblemen alike were eligible for a canonry, which carried with it the income from the endowment. Becoming a Lutheran canon did not require a man to enter holy orders, live in the cathedral precincts, or assume a less secular lifestyle. It was the
ideal solution for someone who wanted to have a career as an astronomer and a scholar while upholding tradition and retaining his dignity as a member of the nobility, without trespassing on the career opportunities of men of another class of society. There was an excellent precedent, for Nicolaus Copernicus had been a canon of a cathedral chapter.

Hence, while Tycho was returning to foreign
climes, heedless of the future, his more sober friends and relatives at court, who included the influential Peder Oxe, set to work to procure a canonry for him. On May 14, 1568, royal letters patent designated Tycho to take up the next vacant canonry at Roskilde Cathedral. The position was reserved for him, though he had to wait for an opening. Although he could not know it had happened, there had
been a minuscule tightening of the cords that would draw him over the next thirty-two years to that February day at Benatky when Johannes Kepler arrived.

Meanwhile, Tycho’s lodgings in the law college at Rostock were providing an excellent setting for astronomical observations, and he was also finding time for his new interest in medical alchemy. But
when
university authorities charged him
a hefty fine, possibly because of the duel with Parsberg, Tycho left rather than pay it and traveled south. At Arnstadt there was to be a ceremony in which Count Günther of Schwarzburg-Rudolstadt presented Tycho’s younger brother Steen with his spurs, a warhorse, and a harness of armor. Steen’s training had taken the traditional path, and he was now well ahead of Tycho on that path.

By September,
Tycho’s meanderings across Europe had taken him to Basel, and there he matriculated at yet another university. After a few months he moved on to Freiburg, where he was impressed by some celestial models demonstrating planetary motions according to the theories of Ptolemy and Copernicus.

As Tycho’s restlessness and his travels continued, he gradually came to realize that after nine years of
university he had learned all he could from professors and books. It was time to embark on more independent work, to direct his own life and education, and especially to experiment with the design and construction of his own observing instruments. His cross staff, even though it was one of the best available and he had found ways to compensate for some of its deficiencies, had long ago proved inadequate
to Tycho’s needs.

In spring 1569 Tycho’s travels brought him to the fine old imperial city of Augsburg, and he found it so much more congenial than any of the other cities he had visited that he stayed for fourteen months. It was in Augsburg that he began to follow through seriously on the plans to improve his instruments.