I need to write an essay addressing this question:
"If you were living at the time of Copernicus why would his arugments for a heliocentric universe have been convincing or not convincing?"
Here's my rough draft (ignore the badly formatted references):
I would greatly appreciate it if someone could take a quick look at it and find some mistakes or styling issues.Convincing the World It's Wrong
Although the Copernican theory of the universe was aesthetically pleasing, relatively simple, and offered more predictivity than the older theory, it did not have the physical laws or religious traditions to support it. Moreover, the model did not fit the observations to a greater degree of accuracy than the older model did. As a result, the average person evaluating Copernicus' heliocentric model would not have found it convincing enough to discard the faltering Ptolemaic model of the time.
While the Ptolemaic model of the universe was supported at the time by a well established set of physical rules, the Copernican model tossed these rules aside. At the time of Copernicus the physical laws were based on the writings of a well-known Greek philosopher named Aristotle. Aristotle's physical laws were based on the five elements that make up the universe: Fire, Air, Water, and Earth were the earthly elements and ether made up the heavens including the stars, sun, moon, and planets. According to Aristotle's physical theory the movement of all objects in the universe followed the movement of the elements to their 'resting' location. Earth moved to the center of the Earth, water moved to be above earth, air moved in order to be above water, and fire moved to be above air. In addition, the final element, ether, made up the heavens. When these elements achieved their rest position they had to move in the only other direction possible; they moved in a circular pattern around the 'lower' elements. In Aristotle's universe the objects in the heavens were embedded on rotating concentric celestial spheres. Ptolemy further refined this theory in order to explain retrograde motion and to fit it more accurately to observational data by adding epicycles and "Deferents". Eventually, this system evolved into a complex series of epicycles making it an impractical and weighty theory. This unreasonable complexity is what led Copernicus to create a new theory of the universe. In his new theory, Copernicus' tried to resolve this complexity with the "geometric purity in the celestial motions" (Hawley and Holcomb 39). He was trying to return the heavens to their original perfectly circular motion and give the universe a more aesthetically pleasing form. In this manner he had success by predicting retrograde motion of the planets, seasonal changes on the earth, and the apparent rotation of the heavens in a much simpler way.
Copernicus' theory, however, faced many other criticisms including several physical arguments against it. Some critics posed the logical questions: if the Earth was rotating, how could humans stay on its surface? Moreover, if the Earth was moving around the sun, why would birds not fall off the earth? One of the biggest criticisms of the heliocentric theory was the lack of observed parallax which the theory predicted. If the earth did really move around the sun, the stars should have shifted relative to each other. However, no such shifting was observed due to lack of proper technology at the time and Copernicus' theory suffered from a fatal flaw. People at the time simply did not realize the scale of the universe. These are the reasons why so many knowledgeable astronomers at the time found this theory to be inapplicable to the real world. Moreover, it is important to note that, at the time, these reasons were perfectly valid under the known physical laws.
Religion was also a significant obstacle to the acceptance of the Copernican heliocentric theory. Both "the dominant Roman Catholic Church and the renegade Protestants" suppressed any belief in the Copernican system. Religious figures considered the Copernican system to be heresy against scripture. In fact "many passages in the Christian scriptures support the model of a stationary Earth, including the command by Joshua that the Sun should stand still" (H&H 41). In the dominant religions at the time humans played a central role in the grand scheme of the universe.
If the earth were the center of the universe, then man might well be the greatest object under God's care: if, however, the earth was one of many planets, and not the largest one, then why should man be so important in the scheme of the universe? (Oliver Joseph Thatcher 95)
It was this criticism that Copernicus feared, and this was the main reason why the church attacked the Copernican system.
It also did not help that the Roman Catholic Church was fighting the Protestant dissenters. As a result the church felt threatened by any challenge to its well established belief system. Copernicus knew that the publication of his book could spark outrage and he feared for his life. Thus, he waited patiently until he was on his death bed to publish his book.
The Copernican system, moreover, failed to give more accurate predictions than the Ptolemaic one. In fact, due to his stubborn belief in the immutability of the circle, Copernicus was eventually forced to add "the same complexities as the Ptolemaic system: equants, epicycles, and so forth" just to fit observational data more accurately (H&H 40). What was left to give his theory credibility was only the fact that it was relatively simpler than the Ptolemaic model and explained the universe in a more elegant way. As Thatcher explains, "the knowledge of the time was not sufficient to prove [Copernicus'] theory" correct and a theory without observational evidence to support it is no theory at all (95).
Even though he was unsuccessful at first, Copernicus set off a revolution with the publishing of his book. His case set off what in many respects coincided with a paradigm shift ,as explained by Khun. The defining characteristic of this shift was that Copernicus' theory arose because of an ongoing crisis with the older Ptolemaic theory. Khun describes that a crisis arises when normal science, such as the gathering data on celestial orbits, shows anomalies in its results.
This is exactly what occurred during Copernicus' lifetime; Astronomers gathered large amounts of data that seemed to have anomalies that disagreed with Ptolemaic theory. In order to correct for these anomalies, theorists added more and more epicycles to the Ptolemaic system until its version of the universe involved well over 64 spheres and orbits. This increasing complexity made a "mockery of the original goal of geometric purity in the celestial motions" (H&H 39). It was clear that with every passing year the Ptolemaic model had to increase in complexity in order to agree with the large quantities of data being gathered. Out of this uncertainty and frustration new theories arose which provided alternatives to the current paradigm. Copernicus provided such an alternative in order to "restore the heavens to simple circular motion" (H&H 39). However, as was possible with crisis, the social, cultural, and scientific community at the time did not see his theory as a "better" one that the current one. His theory did not offer the solution to the anomalies that caused the crisis and a solution to these anomalies is what is needed in order to
1. An History of the Christian Church from the Earliest Periods to the Present Time
By George Gregory,
Collection (Library of
Printed for C. and G.
Original from the New York Public Library
3. The Library of Original Sources By Oliver Joseph Thatcher Page 95