For centuries, Western astronomers operated under the Aristotelian assumption that celestial bodies must move in perfect circles at uniform speeds, as the circle was considered the only geometrically perfect shape worthy of the heavens. Even Nicolaus Copernicus, whose sixteenth-century heliocentric model correctly placed the Sun near the center of the solar system, retained circular orbits and relied on complex epicycles to account for observed discrepancies. It was not until the early seventeenth century that Johannes Kepler fundamentally broke with this classical doctrine. Utilizing the unprecedentedly precise observational records of Tycho Brahe regarding the orbit of Mars, Kepler discovered that no combination of circular paths could reconcile the mathematical models with observed reality. Rather than dismissing the small discrepancy as observational error, Kepler discarded the long-standing philosophical dogma of circular motion in favor of empirical fidelity, ultimately establishing that planets travel in elliptical orbits with the Sun at one focus. In doing so, Kepler shifted the foundational paradigm of astronomy from speculative geometric idealism to rigorous, data-driven physical law.
Which of the following most accurately expresses the main idea of the passage?
- AJohannes Kepler investigated an eight-arcminute discrepancy in the recorded orbit of Mars using Tycho Brahe's observations.
- BTycho Brahe revolutionized seventeenth-century astronomy by replacing Aristotelian geometric idealism with empirical physical laws.
- Johannes Kepler transformed astronomy by rejecting the traditional dogma of circular planetary motion in favor of elliptical orbits based on empirical data.Answer
- DNicolaus Copernicus's commitment to circular planetary paths prevented subsequent astronomers from recognizing the validity of heliocentrism.
- EAristotelian philosophy correctly posited that celestial movements are governed solely by geometrically perfect shapes.