Copernican Revolution Continued
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.
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.
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
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