With the Sun at its Center

For 14 centuries, the prevailing view of the workings of the Earth, the Sun, the planets and the stars was the one articulated by the Greek astronomer Ptolemy: that the Earth was a stationary object, and that all other planetary bodies revolved around it in a uniform circular motion. The Ptolemaic model was happily embraced by the Roman Catholic Church as it sought to portray the Creation of Man on Earth as God's masterpiece, the center of God's universe. By the 15th century, European scientists and mathematicians -- who were generally not atheists, but aesthetes who yearned for glimpses of beauty at the nexus of time and space -- grew curious about the troublesome phenomena that the Ptolemaic model seemed to gloss over without easy explanation, such as the fact that the Big Dipper, for example, at certain times looked further away from the Earth than at other times. Over the years, scientists added a plethora of minor amendments to the Ptolemaic model to attempt to explain the observable eccentricities, but Ptolemy's simple, elegant model was beginning to look like a Rube Goldberg invention.

Mikolaj Kopernik (later known by his latinized name, Copernicus) grew up during this time of unresolved skepticism, the son of a merchant. Born on this day in 1473 in Torun, Poland, Copernicus' father died when he was 10, and he was sent to be raised by his maternal uncle, Lucas Watzenrode, the bishop of Ermeland. The bishop set young Mikolaj on a course to become a church canon. He studied liberal arts (including astronomy and astrology) at Cracow before setting off to his uncle's alma mater, the University of Bologna, at 23. There he lived for a time in the household of Bologna's foremost astronomer, Domenico Maria de Novara, who introduced Copernicus to the curative and skeptical literature, including Regiomontanus' Epitome of Ptolemy's Almagest (1496) and Pico della Mirandola's scathing Disputations Against Divinatory Astrology (1496), which argues that one of the flaws with astrology was that no one could agree on the order of the planets floating around the Earth.

With dissent already in the air, the exploration of the new hemisphere of the Earth incidentally discovered by Columbus began to call into question all sorts of fundamental assumptions about the order and primacy of things, and encouraged scientists to consider anew the incompleteness of their knowledge. Meanwhile, Copernicus kept busy: he received a doctorate in canon law at Ferrara in 1503; studied medicine at Padua; served as a scholar in absentia at Wroclaw while assuming the duties of canon at Frauenberg (which involved general administration and occasionally practicing medicine); prepared a Latin translation of the aphorisms of the Byzantine poet Theophylactus Simocattes (published in 1509); and still managed to pursue his astronomical observations in his spare time, building a small tower at Frauenberg from which to observe the sky.

His reputation as an amateur astronomer was great enough, however, for Copernicus to be invited in 1514 to the Fifth Lateran Council to make recommendations on the reform of the calendar. By this time he had begun to articulate a theoretical critique of the Ptolemaic model, quietly showing a summary of his views to a few friends. As a good canon lawyer, he must have predicted that the Church would not be happy with his theories; but after his 25-year old admirer Georg Rheticus published a summary of Copernicus' summary without provoking the Church's anger (in all likelihood they were a bit busy with Martin Luther at the time), Copernicus turned to completing a full dissertation on the heliocentric ("Sun-centered") model.

In what would come to be known as On the Revolution of the Heavenly Bodies, Copernicus argued that the Ptolemaic model, as amended, was like a Mr. Potathead in which the arms, legs, nose, eyes, ears and mouth were all placed in the wrong holes (to paraphrase his paraphrase of Horace's Ars poetica). By contrast, Copernicus wrote, if one assumes that the Sun is a stationary midpoint and the Earth is in motion, by a relatively simple set of calculations the remaining planets fall into orderly orbits around the Sun -- orbits whose length of time increase with a planet's relative distance from the Sun. Thus, Mercury would circumnavigate the Sun in 88 days; Venus, in 225 days; Earth, in one year; Mars, 1.9 years; Jupiter, 12 years; and Saturn, 30 years.

While he admitted that he could not rule out other potential alternative models to the Ptolemaic model -- it would take later mathematicians to uncover solutions for the problems of falling bodies, acceleration and force and ultimately prove that Copernicus was correct -- at least he had constructed one handsome Potatohead, in which all of the pieces fit together into a balanced, harmonious whole.

Copernicus avoided the potential wrath of the Church by waiting 36 years to publish Revolution; legend has it that on his deathbed he was able to hold the freshly minted first edition in his hands before passing away on May 24, 1543 in Frauenberg, East Prussia (now Poland). The cause and its implications would be taken up, in turn, by Galileo, Kepler, Descartes and Newton, among others. To Galileo goes the prize for making Copernicus a posthumously dangerous thinker; after Galileo's Discourse on Floating Bodies (1612), the Church banned Copernicus' Revolution. The Church would finally lift its ban in 1835.

Categories: Astronomy, Physicists, Mathematics