The Copernican Revolution
The 16th Century was a time of tremendous upheaval for it marked major changes
in the world of scientific and religious thinking. Martin Luther led the Protestant
Reformation with his 95 theses and the Diet of Wurms defense of this thinking
in 1517 and 1519. Since this event marks the opening of the door to scientific
thinking as well as a split from the Church by a large number of people, you
are now asked to learn more about the details of Martin Luther's life and how
his writings affected the people as much as did the writings of Copernicus,
Galileo, and Newton. If you have not already done so, please click on Martin
Luther to learn about the Reformation and how the writings of Luther may
have spurred Copernicus to share his new ideas of the solar system with the
Copernicus - the first real challenge to the Ptolemaic theory came in 1543,
with the publication of a book by Polish churchman Mikolaj Kopernik, better
known by his Latinized name of Nicolaus Copernicus. His main objection to the
geocentric, or earth-centered, theory was its clumsiness. He recognized that
many of the complications could be removed by putting the sun in the central
place of the system and allowing everything to revolve around it. In this he
was correct, but he was still convinced that all celestial orbits must be perfectly
circular, and he was even reduced to bringing back epicycles. To see a nice
set of images and text regarding the proposed heliocentric model of Copernicus,
click on his image at the left. To learn more details about his life, click
and go to his biographical account. I apologize that some of the weblinks in
the biography no longer operate, but the site is still worth the visit. Within
this course, I have highlighted the heliocentric model and will propose my ideas
about the importance of his great intellectual leap upon all of science and
mankind ever since.
Copernicus accomplished much in his thinking of the motions of the planets,
more so than he expected. At the left is his ideas of how planets revolved around
the sun. He worked out a detailed theory of the moon in orbit and set the distance
of the moon at about 60 times the earth's radius - a figure close to what we
He noted that the moon's orbit was not an earth-centered circle.
He concluded that the earth was definitely a planet.
Whereas Ptolemy argued against the idea of a rotating earth because the mountains
would be ripped from their roots, Copernicus argued more forcefully that such
a rotation would have an even great effect on the sky which has a larger radius.
Since neither happened, why not at least look at the earth's rotation as causing
the sun to appear to orbit the earth.
Copernicus was the first to recognize that Polaris does not stay in the same
position because the axis of the earth slowly wobbles.
He justified his conclusions: "... in the midst of all stands the sun.
For who could in this most beautiful temple place this lamp in another or better
place than that from which it can at the same time illuminate the whole? Which
some not unsuitably call the light of the world, others the soul or ruler. Trismegistus
calls it the visible God, the Electra of Sophocles, the all-seeing. So indeed
does the sun, sitting on the royal throne, steer the revolving family of stars."
By no means did Copernicus desire to remove God from the Universe. To him, God
could more accurately occupy the central place in creation, with man revolving
around God. The Sun would be the embodiment of the eternal, all-powerful, and
light and life-giving God.
Essentially, Copernicus desired to bring about a harmony of the natural world,
created by God, and the spiritual world, described by God in the Bible. Furthermore,
as seen to the left, God created everything with perfection, and thus all orbital
paths were perfect circles, even as they were in the drawings of Ptolemy.
was well aware that his ideas would offend the Church; to regard the Earth as
anything but supreme would be to invite a charge of heresy. Prudently, he withheld
publication of his book until he was dying in 1543, even though he developed
his theory in 1507. His little book was entitled "de Revolutionibus"
and the cover page appears to the right of this text.
It has always be difficult for my students to grasp the importance of Copernicus'
work as well as his personal struggle with sharing his ideas with the public.
One needs only look at the history of the Church to see the origins of this
struggle. Nicolaus Copernicus was a devout Catholic. To pronounce a heliocentric
model would most certainly mean his excommunication, and the prospect of eternal
death and damnation were a chance he refused to take. For almost 1400 years,
the European world had accepted the geocentric model of Ptolemy. As mentioned
earlier in the history discussion, this model satisfied the observations of
people, their personal philosophy of self-centeredness, the religious convictions
as espoused in the Judeo-Christian Bible, as well as the sheer complexity of
the mathematics and epicycle motions.
Copernicus reasoned that all of the motions that he observed in the sky could
be accounted for with a sun-centered system, and without the necessity of complicated
epicycle motions. He realized, however, that his views would stir up controversy
and perhaps mean trouble for him from the Church. Being raised by Church leaders,
Copernicus wished to offend no one, so he withheld publication of his treatise
until near his death.
His fears were well-founded, as some later Copernicans found to their cost:
one of them, Giordano Bruno, was burned at the stake in Rome in 1600. (This
was only one of Bruno's crimes in the eyes of the church, but it certainly was
a serious one.) Finally, Copernicus' book was placed on the Papal Index, where
it remained until 1835. Nicolaus Copernicus was the individual who developed
a heliocentric model of the solar system and took the chance of sharing his
ideas publicly. While the tiny book was quickly banned for public reading through
an edict of the Pope, there were a few curious minds who found the heliocentric
idea of great interest. To see how the Copernican model was proven correct,
move on to the page which tells a remarkable story of
an egocentric astronomer named Tycho Brahe.
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