2.2: Heliocentrism vs. Geocentrism: A Case Study

The difficulty with applying the scientific method to this type of astronomical “experiment” is that one cannot “experiment” on this big of a system. There is no “control group.” However, we can still use the structure of the method to show how, over several centuries and several countries in Europe, heliocentrism became the norm.

Hypothesis: The First Modern Statement of the Theory

A Pole with the Latin pen name Nicolaus Copernicus (1473-1543) determined that the best way to explain all the “odd” astronomical data was to switch the positions of the Sun and the Earth. Poland was (and still is) a predominantly-Catholic country in Eastern Europe, so for much of his life Copernicus kept this theory to himself. Copernicus did not want to question the Church and be subject to persecution (or worse) from Poland’s secular leadership, especially as the Reformation spread throughout Europe.

Copernicus was not the first to profess of the heliocentric theory: some ancient and even medieval writers wrote about this possibility: Most labeled it as nonsense after weighing it with the common sense, beauty, and sense of self-worth attained from geocentrism.

Copernicus was convinced throughout his mature life that heliocentrism was the correct theory to describe the movement of the Earth and the Sun—however, the data still did not “match” perfectly, even with a heliocentric Earth-Sun swap in the system.

Nonetheless, Copernicus wanted to publish his views, and he did so in 1543, the last year of his life. He did this intentionally, as he knew he was dying and therefore knew that the Church couldn’t persecute him too much—on this planet, at least. Approving the final proofs of his book (On the Revolutions of the Heavenly Bodies) from his death-bed, Copernicus died before the book came out. However, as he had suspected, the Church was not pleased: Church officials placed the book on the Index.

The Data: Galileo Galilei and His Telescope

Throughout the next century, the “Copernican system” (as heliocentrism was now called) gathered more and more followers among the small new “scientific” community. This was especially true after more sophisticated observations emerged from the development of the telescope. However, it should be noted that, throughout the 17th century, the common people had not yet “converted,” as the theory still seemed like nonsense, especially when the Church labeled it as incorrect.

Though the telescope originally arrived in Europe through Holland, an Italian scientist, Galileo Galilei (1564-1642), perfected it and first aimed it at the night-time sky for scientific purposes. What he discovered was a major blow to Aristotelianism: the moon and the Sun were not perfect spheres but had ridges, mountains, and “sunspots” (first seen by Galileo and, many historians suspect, the cause of his later blindness).

The biggest observation that started to convert some in the scientific community to heliocentrism, however, was the published discovery of new moons. In his book The Starry Messenger (1610), Galileo wrote of sightings of four moons of Jupiter, which he named after his patrons, calling them “the Medicean Stars.” (Does that name look familiar from Chapter 1?) The fact that Galileo observed moons orbiting around a planet that was not Earth directly contradicted Aristotle’s and the Church’s position that the Earth was the center of everything in the universe. Jupiter was now seen to have moons while revolving around the Sun itself. Why couldn’t the Earth’s motion be the same, especially if this new system better described the observations coming from telescopes all over Europe?

At that point in 1610, however, Galileo refrained from commenting on the significance of his theory, fearing Church retaliation. Galileo waited until a mathematician pope was in Rome (another 20 years and then some) before coming out strongly in favor of the Copernican system in his book written in Plato’s dialogue style: Dialogue Concerning Two Chief World Systems (1632). While the geocentric-favoring figure technically had the last word, it was clear from the text that the evidence for heliocentrism far outweighed the evidence for geocentrism.

Advocates of geocentrism, however, claimed that the telescopes were faulty, that Galileo twisted the data, or that God had put this new evidence as “a test” for believers’ true faith. The Church put the book on the Index and the Inquisition put Galileo on trial and showed him instruments of torture that could be used to “convince” him of the geocentric truth. Galileo backed down and publicly took back his views, but he did not escape punishment. Fearing that Galileo would flee to Protestant Northern Europe, Church officials placed him under house arrest: he was “grounded” for the rest of his life, conducting small inclined plane experiments as his eyesight continued to fail him.

The Mathematical “Conclusion”: the Law of Universal Gravitation

The Church was right to fear the continuation of Galileo’s work in the North. In Anglican England, a brilliant young mathematician and scientist named Isaac Newton (1643-1727) was convinced that heliocentrism described the true way God had set up the universe. (We might call Newton a “mystic” today, in addition to a scientist, as he spent just as much time on alchemy and determining the exact date/time of God’s Creation of the universe as he did on gravity.)

Newton undertook to develop a system of precise mathematical laws that would support heliocentrism and accurately describe the entirety of the data about the planets. Luckily, he was a genius and his Latin book Principia Mathematica (1687) presented some very convincing mathematical manipulation and argued for a new math-based law that would more accurately describe the entirety of the known universe: the Law of Universal Gravitation. With “gravity” guiding him, Newton was not just able to describe the past observations. He was able to predict future observations such as eclipses, something that had not been possible under any variant of the geocentric theory ever proposed.

With Newton’s findings, the world was literally flipped upside-down. By the mid-18th century, heliocentrism had prevailed and geocentrism was seen as a superstition of the past. Nonetheless, due to the ever-critical nature of the scientific method, major holes in Newton’s theory came to light relatively quickly: while Aristotle’s theory lasted more than 2000 years, the “truth” of Newton’s theory lasted 300 or so. (We’ll see about this “relatively quick light” in Chapter 7.)

The “new world” of scientific questioning (and uncertainty) was in place, and nothing physical, chemical, or biological could ever again be viewed with complete faith (and therefore without skepticism).

(The Church was a little behind the curve, though: the Inquisition’s errors with Galileo were finally apologized for in 1992.)


6 thoughts on “2.2”

  1. It is interesting how everyone feared the Church for voicing their opinions but in todays world, we are encouraged to share our views. We don’t have to worry about being persecuted or tortured by people within the Church but rather, they help us get through challenges.

  2. It is crazy that the Church put Galileo was grounded for the rest of his life. Imagine being under house arrest or “grounded” when your a grown man for the rest of your life. That is just insane to even think about that the church did this back then.

  3. What I think was so interesting was how the Chruch handled “defiances of the Church” back then and how the Church would have handeled what Galileo and Copernicus were saying, im pretty sure the Church would have wanted to contuniue their studies and see were it would take them.

  4. Even though we have come a long way in having our own opinion, you still see people who base their beliefs on what the church stands for. Religion is often a reason someone gives to support their belief even though other evidence can prove it to be false. If you ask someone their opinion today on certain topics many state “because of my religion” as a reason for their belief instead of science or facts.

  5. It’s interesting that Copernicus had to hide his views from the Church and the people in fear of facing a punishment. He had evidence to support his theory but he wanted to wait until his death to publish a book because of the fear he felt of the Church.

  6. I thought it was kind of crazy how Copernicus knew he would get punished for his beliefs and had to wait until he died to publish his book. I also think it was kind of cool how it was called “the Copernican system” because Copernicus probably didn’t think that his writing and theories would get so far that the system would be named after him.

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