Ptolemy's geocentric model
The Renaissance, a period of learning and enlightenment, literally rebirth, grew out of the Dark Ages, where ancient knowledge was lost. During the Renaissance, ancient Greek scientific texts were rediscovered, and scientists devoted themselves to clarifying the thinking found in these texts. Many realized that previously unchallenged ideas needed to be examined.
One such revered idea was Ptolemy's geocentric, or Earth-centered, theory concerning the structure of the universe. A group of noteworthy scientists, including Nicolaus Copernicus, Giordano Bruno, Galileo Galilei, and Johannes Kepler, challenged that theory. This brought about significant scientific debate as well as reactions from the Roman Catholic Church. Copernicus's book advocating heliocentrism, De Revolutionibus, was placed on the Catholic Church's Index of Banned Books. Giordano Bruno, an ardent believer in heliocentrism, was burned at the stake, and Galileo Galilei, whose observations supported heliocentrism, faced years of house arrest.
Debates surrounding the heliocentric theory raged for years before its public acceptance. Scientists risked their lives in order to facilitate the growth of modern science generally and heliocentrism specifically. The ordeals of these scientists were not in vain, for this debate shaped modern science into what it is today, and it changed the way we view the world.
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