Copernican Revolution Continued

Tycho Brahe

Ironically, the next main character in the story, Tycho Brahe, was no Copernican; he preferred a hybrid theory which satisfied almost nobody. This Danish nobleman became interested in astronomy when a "new star" suddenly blazed out in the constellation Cassiopea. Known today as a nova, it was considered unique in the history of astronomy. This star was far brighter than anything else in the sky and could even be seen in the daylight. It was a very confusing event for philosophers. Some speculated that it was the reappearance of the Star of Bethlehem, announcing the second coming of Christ. Others warned of disastrous evil about to befall earth. Others believed it was a vaporous exhalation of earth.

Tycho sought to answer these questions. As an observer he was supreme, and he carefully measured the distance between the nova and Polaris. He also fixed the location relative to the stars in Cassiopeia. His results indicated that this star was not a wanderer, but a fixed star. He concluded that the stars were not invariable. This teaching was certainly contradictory to the views of the Church which held that God finished creation after 6 days and then rested. On a side note here, that Bible reference never presumed that God may have stopped creating ever after, but merely rested on the seventh day. Church leaders were convinced that creation was finished with the words, "it was good." To see a new star in the sky went against the finality of creation and caused quite a stir. Tycho Brahe carefully recorded the changing colors as the star faded from view through 1572. Stars could no longer be viewed as unchanging objects. God's creative works were not "finished" at the end of six days. Furthermore, Tycho's study of comets led him to conclude that the spheres described by Ptolemy could not be solid.
He published a short paper De Stella Nova (The New Star) in 1573, and the little book attracted the attention of Danish King Frederik II. The king offered to build an observatory on the island of Hveen just off the Danish coast. Tycho also received a regular source of income as a landlord of some coastal territory, so he was really never in great want for money. There, for two decades from 1575 to 1595 he compiled a star catalogue which was much better than any of his predecessors. He also made accurate measurements of the movements of the planets, particularly Mars. To do this he devised a more accurate instrument and hired much help.
Because the stars did not appear to move as would be expected if the earth acted like a planet, Tycho rejected Copernicus' view and proposed his own system. His model (seen farther down this page) is a hybrid of Ptolemy and Copernicus, and his underlings at his observatory were not all convinced Tycho was correct. He set the earth, stationary, at the center, letting the sun and moon orbit around it, but with the five planets circling the sun, rather than the earth. To see a more detailed depiction of his findings and errant conclusions, click on the image of Tycho above and to the left. To read a detailed biographical account, click on Tycho. As the Copernicus biography is poor with connecting links, so too is the Tycho site, but the webpages of the biography are still helpful.

Tycho Brahe was a really interesting man. Born into nobility, he had both money and influence. It was helpful to have the backing of the king, but with the gain of money and prestige came an ego which was enormous. Some legends hold that when students disagreed with their professor, Tycho would place them in a dungeon beneath his observatory, and then in stocks. When these students realized the error of their ways, and after profuse apologies, Tycho would release them to help him continue the work.

On one occasion, while Tycho was studying at Wittenberg in 1566, a rival famed French mathematician challended the study of Tycho. An argument ensued. When the Frenchman proclaimed his prowess in mathematics, Tycho's ego was bruised and he responded to the challenge by proclaiming he was the greater mathematician. A glove was slapped across the face and a challenge to duel with swords at midnight given to settle the issue as gentlemen. Tycho lost the battle when the Frenchman cut off the nose of Tycho with a sword. Forever after, Tycho required a gold nosepiece to fit over the hole, and a recent stamp of Denmark even shows the golden nose. And to think that these men were fighting over the right to be called a greater math geek.

The picture to your left demonstrates the method Tycho used to create star maps and plot the motion of the planets, sun, and moon. He sat at a chair and pointed to a particular star by name. An assistant would note the vertical angle (declination) of the star, as well as the location against the horizon (right ascension). The time was duly noted and the numbers transferred to a sheet of paper according to the celestial coordinates from the observation. Night after night, Tycho sighted stars and assistants made recordings of data. Of critical importance to the Astronomy community were the maps of the motion of the planets in general, and Mars in particular. Tycho's celestial maps were exquisite in detail and accuracy. Without any doubt, these star maps are his greatest contribution to Astronomy. While he clearly misinterpreted his data, his research was still helpful, as those very maps are accurate even to this day. The diagram below shows Tycho's hybrid model between Copernicus and Ptolemy. It is quite complicated, and although incorrect, even in the eyes of his assistants, he pushed ahead with his ideas probably the result of his oversized ego and aristocratic view of himself.


This very egocentrism led to Tycho's demise. When Frederic II was no longer king of Denmark, Tycho fell out of favor with his successor son, and he finally left the island in 1596, far more poor than before. He returned to Prague and tried to set up a new observatory, but was still low on income. He was named imperial mathematician to the Holy Roman Emperor Rudolph II, and slowly his sense of prestige returned. He hired a youthful Austrian mathematician, Johannes Kepler, to give help in determing the orbital parameters of the planets, but was so threatened by Kepler's intellectual prowess that he eventually refused to allow Kepler access to his voluminous notes. Tycho locked his notes in a vault for his own safekeeping and to guard against a rival interpretation.

In 1601, Tycho was at a banquet for the local nobility. Trying hard to regain his status in the eyes of his former peers, Tycho was conscious of every social grace. Unknown to him, he was suffering from a bladder infection at the dinner. While he had to relieve himself, to arise in the middle of the dinner was a gigantic social faux pax. Struggling mightily within himself to keep from appearing disrespectful and foolish, Tycho sat dutifully at the table throughout the meal. Finally, his weakened bladder burst. Tycho became violently ill and died eleven days later. During that time, Tycho asked Rudolph II to make Kepler imperial mathematician.

I share this information to any students who are still paying attention to all of the reading. When you are in a classroom and need to relieve yourself, and the teacher or professor refuses to let you go, you may cite the experience of Tycho and threaten your own potential bladder burst and potential ugly lawsuit against the obstinate teacher/dictator :)

With no one to safeguard the vault, Kepler got a hold of the notes and over the next nine years began to reinterpret their data. Tycho had excellent star maps, but incorrect interpretative conclusions. Kepler made the correct conclusions, to confirm Copernicus and lay more upon the foundation of the developing Astronomy Revolution.

Once you have completed the study of Tycho Brahe from the CSEP webpage, move on in this course to the work of Johannes Kepler.

Back to Copernicus, the Introduction to History Unit, the Syllabus, or the Home page..

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