Roger M McCoy
The earliest humans on earth no doubt sensed the immensity of the cosmos even though they could not fully comprehend. Simply by seeing the night sky they were aware of the Moon, and that the stars moved in unison across the sky through the night without changing their arrangement. They also must have noticed that a few features (the planets) seemed to move independently of all the others. On almost any night they might have seen with awe a few falling stars (meteors). Then to their great wonderment an occasional object (comet) would appear with no apparent regularity, remain visible for several days, then disappear. As mentioned in the first science blog, these people created stories about the origin of these heavenly bodies, how they moved, and what held them in place. Also they often attached supernatural myths to sun, moon and stars, and viewed some of the rare events, like comets and supernova (exploding stars), as omens of good or bad events in the future. There was usually a certain individual (shaman, seer, prophet, or priest) in any group that interpreted the meaning of these cosmic displays.
One of Plato’s (428BCE-348BCE) students, Eudoxus, proposed that the universe consisted of a series of concentric spheres rotating separately with Earth at the center (geocentric). Later Aristotle (384 BCE-322 BCE) adopted the idea as the grand design of the cosmos. The innermost sphere contained the moon, then a separate sphere for each of the then-known planets: Mercury, Venus, the Sun, Mars, Jupiter, and Saturn. Yes, the Sun was then viewed as a planet. The outermost sphere held all the stars in their position as they rotated around Earth in twenty-four hours. Some later cosmic diagrams added a sphere beyond the stars called the sphere of Divine Intelligence. Aristotle’s concept
of concentric spheres persisted among astronomers into the sixteenth century.
Bit by bit, scientists began to try to understand the nature of our well-ordered universe. The first scientist of note was a sixteenth-century Polish man named Nicolaus Copernicus (1473-1543), and he is sometimes called the inventor of the solar system.
Copernicus is known for his open challenge to the long-held geocentric belief that the Moon, Sun, planets and all the stars rotate around a motionless Earth every twenty-four hours. Even as a youth Copernicus was interested in astronomy, and at the age of twenty-seven he was reading anything he could find about astronomy, works by men such as Aristotle and Ptolemy. This excerpt by Ptolemy was still the common geocentric belief in Copernicus’ time:
If the Earth did orbit it must be the most violent of all motions seeing that it makes one revolution in such a short time. …the Earth would move so fast that any time a bird lifted off its perch, or any time a cat leapt up, these poor creatures should go howling off into space, their world ripped out from under them. This is shown not to be the case, hence the Earth is immobile.
Inspiration for heliocentrism came to Copernicus from his avid reading habits. He learned that early Greeks like Plato, and later Aristotle, believed in geocentrism and an immobile Earth, but a few such as Aristarchus and Philolaus, and a Syrian philosopher, Al-Urdi, suggested that Earth rotated on its axis and made the Sun and stars appear to move. Copernicus cited these men in an early draft of his book De revolutionibus orbium coelestium (On the Revolutions of the Celestial Spheres) but not in the final publication. Probably he was concerned about public and papal reaction if he used pre-Christian sources.
One big problem with such a new idea was that it went counter to Christian beliefs which held that Earth and humanity were the central focus of all creation. In one statement Copernicus wrote, “The Sun is appropriately called the lantern of the universe. As though seated on a royal throne, the Sun governs the family of planets revolving around it.” This statement was enough to stir a controversy.
In order to present his new idea in a way the Church might accept, Copernicus wrote a lengthy letter to Pope Paul III in 1543. His letter was a proposal advocating a reform of the cosmic order and at the same time obtaining the pope’s approval. Despite this effort Copernicus was still criticized roundly by the Church. Here are some excerpts from his letter of dedication to the pope. (Very slightly edited for clarity)
The philosopher’s [read scientist’s] aim is to seek truth in all things
as far as God has permitted human reason—yet I hold that opinions
which are quite erroneous should be avoided. I thought I also might
easily be permitted to try to show whether by postulating some motion
of the Earth, more reliable conclusions could be reached regarding the
revolution of the heavenly bodies than those of my predecessors.
Thinking therefore for myself to ascribe movement to the Earth must
indeed seem an absurd performance on my part… Nor do I doubt that
ingenious and learned mathematicians will sustain me, if they are
willing to recognize and weigh…with that thoroughness which
Philosophy demands, those matters which I propose in this work
will demonstrate these theories.
[At this point he makes a hopeful stroke to the pope’s ego.]
I have preferred to dedicate these lucubrations [studies] of mine
to Your Holiness rather than to any other, because, even in this
remote corner of the world where I live, you are considered to be the
most eminent man in dignity of rank and in love of all learning and
even of mathematics, so that by your authority and judgment you
can easily suppress the bites of slanderers from critics.
[Here he asserts certainty that his idea is correct
and based on his analysis.]
If perchance there shall be idle talkers, who, though they are
ignorant of all mathematical sciences, nevertheless assume the
right to pass judgment on these things, and if they should dare to
criticize and attack this theory of mine because of some passage
of Scripture which they have falsely distorted for their own purpose,
I care not at all; I will even despise their judgment as foolish.
Despite this, Copernicus managed to maintain a good relationship with the Church. The papal office showed little concern for his heliocentric theory at first and did not actually impose a ban on heliocentric beliefs until the seventeenth century. The ban lasted from 1616 until 1835, and was finally lifted 292 years after Copernicus’ letter of dedication to the pope in 1543.
The most intense resistance came from sixteenth-century Protestant theologians such as John Calvin (1509-1564) and Martin Luther (1483-1546). John Calvin wrote a fiery sermon about those who are so “deranged…they will say that that the sun does not move, and that it is the earth which shifts and turns. …we must indeed confess that the devil possesses them…” Nevertheless, Copernicus’ idea withstood the testing and tweaking by later scientists and heliocentrism prevailed.
Copernicus gave the world a new, innovative idea that caught on with other scientists who followed. Galileo (1564-1642) was the next major proponent. After his confrontation with the Church, heliocentrism became accepted among scientists as the only model of the solar system that could answer all questions about its function.
Copernicus’ idea initiated a revolution because it changed the way people viewed the universe and showed that long-held beliefs could be wrong. His effort promoted greater intellectual curiosity and inquiry about the universe. His heliocentric view of our solar system also initiated a new approach to astronomy and spurred many subsequent investigations.
Thomas Kuhn wrote in his book, The Structure of Scientific Revolutions (1962), that a fundamental test of the validity of a theory is its ability to answer questions about the natural world. If some fundamental questions are left unanswered, the theory is flawed and the unanswered questions will eventually lead to a new theory.
Copernicus is a good example of those rare creative thinkers who have an insight that changes the way people see the cosmos and sparks a revolution in the scientific approach to learning. He challenged the view that Earth and its inhabitants were at the center of the universe and proposed that the Earth orbits the Sun, just like the other planets. The discoveries of Copernicus and other scientific theorists occurred around the same time as the religious Reformation of the sixteenth century when people were already questioning the general structure of the scientific, religious, and political components of society. This very gradually led to a greater freedom of thought throughout Europe.
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Kuhn, Thomas. The Copernican Revolution: Planetary Astronomy in the
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