Nicolaus Copernicus - Essay Example

Nicolaus Copernicus was a Polish astronomer, mathematician and economist who developed the heliocentric (Sun-centered) theory of the solar system in a form detailed enough to make it scientifically useful. His theory about the Sun as the center of the Universe, opposed to the traditional geocentric theory that placed Earth at the center, is considered one of the most important discoveries ever, and is the fundamental starting point of modern astronomy and modern science itself (it inaugurated a scientific revolution). His theory affected many aspects of human life, opening the door for young astronomers, scientists and scholars to take a skeptical attitude toward established dogma (Armitage, 1951). Copernicus' major theory was published in the book, De revolutionibus orbium coelestium (On the Revolutions of the Heavenly Spheres) in the year of his death, 1543, though he had arrived at his theory several decades earlier. The book marks the beginning of the shift away from a geocentric (and anthropocentric) universe with the Earth at its center. Copernicus held that the Earth is another planet revolving around the fixed sun once a year, and turning on its axis once a day. He arrived at the correct order of the known planets and explained the precession of the equinoxes correctly by a slow change in the position of the Earth's rotational axis. He also gave a clear account of the cause of the seasons: that the Earth's axis is not perpendicular to the plane of its orbit. He added another motion to the Earth, by which the axis is kept pointed throughout the year at the same place in the heavens; since Galileo Galilei, it has been recognized that for the Earth not to point to the same place would have been a motion. Copernicus also replaced Ptolemy's equant circles with more epicycles. This is the main source of the statement that Copernicus' system had even more epicycles than Ptolemy's. With this change, Copernicus' system showed only uniform circular motions, correcting what he saw as the chief inelegance in Ptolemy's system. But while Copernicus put the Sun at the center of the celestial spheres, he did not put it at the exact center of the universe, but near it. Copernicus' system was not experimentally better than Ptolemy's model. Copernicus was aware of this and could not present any observational "proof" in his manuscript, relying instead on arguments about what would be a more complete and elegant system. From publication until about 1700, few astronomers were convinced by the Copernican system, though the book was relatively widely circulated (around 500 copies are known to still exist, which is a large number by the scientific standards of the time). Many astronomers, however, accepted some aspects of the theory at the expense of others, and his model did have a large influence on later scientists such as Galileo and Johannes Kepler, who adopted, championed and (especially in Kepler's case) sought to improve it. Galileo's observation of the phases of Venus produced the first observational evidence for Copernicus' theory. The Copernican system can be summarized in seven propositions, as Copernicus himself collected them in a Compendium of De revolutionibus that was found and published in 1878: 1. Orbits and celestial spheres do not have a unique, common, center. 2. The center of the Earth is not the center of the Universe, but only the center of the Earth's mass and of the lunar orbit. 3. All the planets move along orbits whose center is the Sun, therefore the Sun is the center of the World. (Copernicus was never certain whether the Sun moved or not, claiming that the center of the World is "in the Sun, or near it.") 4. The distance between the Earth and the Sun, compared with the distance between the Earth and the fixed stars, is very small. 5. The daytime motion of the Sun is only apparent, and represents the effect of a rotation that the Earth makes every 24 hours around its axis, always parallel to itself. 6. The Earth (together with its Moon, and just like the other planets) moves around the Sun, so the motions that the Sun seems to be making (its apparent motion during the daytime, and its annual motion through the Zodiac) are nothing else than effects of the Earth's actual motions. 7. These motions of the Earth and of the other planets around the Sun, can explain the stations, and all the particular characteristics of the planets' motions. Whether these propositions were "revolutionary" or "conservative" was a topic of debate in the late twentieth century. Thomas Kuhn argued that Copernicus only transferred "some properties to the sun many astronomical functions previously attributed to the earth." Other historians have since argued that Kuhn underestimated what was "revolutionary" about Copernicus' work, and emphasized the difficulty Copernicus would have had in putting forward a new astronomical theory relying alone on simplicity in geometry, given that he had no experimental evidence. Copernicus' major work, was the result of decades of labor. It opened with an originally anonymous preface by Andreas Osiander, a theologian friend of Copernicus, who urged that the theory did not necessarily have implications outside the limited realm of astronomy. Copernicus' actual book began with a letter from his (by then deceased) friend, the Archbishop of Capua, urging Copernicus to publish his theory. Then, in a lengthy introduction, Copernicus dedicated the book to Pope Paul III, explaining his ostensible motive in writing the book as relating to the inability of earlier astronomers to agree on an adequate theory of the planets, and noting that if his system increased the accuracy of astronomical predictions it would allow the Church to develop a more accurate calendar (calendar reform then being an important question and one of the major reasons for Church funding of astronomy). Copernicus' theory is of extraordinary importance in the history of human knowledge. Many authors suggest that only Euclid's geometry, Isaac Newton's physics and Charles Darwin's theory of evolution have exerted a comparable influence on human culture in general and on science in particular. Many meanings have been ascribed to Copernicus' theory, apart from its strictly scientific import. His work affected religion as well as science, dogma as well as freedom of scientific inquiry. Copernicus' rank as a scientist is often compared with that of Galileo (Goodman & Russel, 1991). Copernicus' work contradicted then-accepted religious dogma: it could be inferred that there was no need of an entity (God) that granted a soul, power and life to the World and to human beings - science could explain everything that was attributed to Him. Copernicanism, however, also opened a way to immanence, the view that a divine force, or a divine being, pervades all things that exist - a view that has since been developed further in modern philosophy. Immanentism also leads to subjectivism: to the theory that it is perception that creates reality, that there is no underlying reality that exists independent of perception. Thus some argue that Copernicanism demolished the foundations of medieval science and metaphysics. Copernicus' concept marked a scientific revolution. Some, indeed, equate it with the initiation of "the scientific revolution" (Kuhn, 1957). Immanuel Kant captured the symbolic character of Copernicus' revolution - its transcendent rationalism - postulating that it was human rationality that was the true interpreter of observed phenomena. More recent philosophers, too, have found continuing validity and philosophical meaning in Copernicanism. Works Cited: 1. Angus Armitage, The World of Copernicus, New York, Mentor Books, 1951. 2. David C. Goodman and Colin A. Russell, eds. The Rise of Scientific Europe, 1500-1800 (Dunton Green, Sevenoaks, Kent: Hodder & Stoughton: The Open University, 1991). 3. Thomas Kuhn, The Copernican Revolution: Planetary Astronomy in the Development of Western Thought (Cambridge, MA: Harvard University Press, 1957). Read More