Delanceyplace: The World In Motion
We now think of Galileo's proof that the sun was the center of our solar system as the dawn of the scientific age, and he is often called "The Father of Modern Science." However, all scientific discovery is a continuum-the result of the work of many people. Though it is commonly known Galileo relied on Poland's Nicolaus Copernicus, we now know that Copernicus's work owed a debt to the Muslim astronomers Ibn al-Shatr and Nasir al-Din al-Tusi, whose works were published by Cardinal Ferdinand de Medici. Galileo owed an even greater debt, one he never acknowledged, to the meticulous work of the German Johann Kepler and his mentor, the Dane Tycho Brahe, writes Thomas Christensen.
Despite his personal eccentricities Tycho Brahe (1546-1601) had compiled decades of data from his celestial observations that were far more meticulous and precise than anything previously available. His elevation of observation over speculation was one of the key developments leading to the modern concept of inductive scientific investigation. Kepler (1571-1630), though appreciative of the benefit of accurate data, was less capable of obtaining it directly. A bout of smallpox in childhood had left him frail and sickly, with a severe visual handicap: he was short-sighted and had double vision in one eye. Nor did he have the means to construct a large observatory like Tycho's Uraniborg. So he depended on Tycho for the data he needed to elaborate his theories of celestial harmony. ...
When the published version of Kepler's The Cosmographic Mystery [the first published defense of the Copernican system] appeared, Kepler was still convinced that his connection of the planetary orbits to the five regular solids was a fundamental breakthrough toward discovering God's plan for the universe. With great enthusiasm he mailed copies to all of the influential people he could think of who had an interest in astronomical topics or might assist him in his career, but the results of these mailings would be disappoint- ing. Still, among the recipients was a thirty-three-year-old professor of mathematics at the University of Padua [Galileo Galilei], who wrote back to confess that he too was a Copernican, subscribing to the radical notion that the earth orbited around the sun. But he was afraid, he said, to state that belief publicly. Kepler responded by urging him to speak out, but Galileo did not acknowledge this second letter- in fact, he would not be in touch with Kepler again for thirteen years. The reason, according to Albert Einstein, was vanity, which he considered a failing of many great scientists. 'It has always hurt me to think,' he wrote in a letter to a friend, 'that Galileo did not acknowledge the work of Kepler.' ...
Kepler's working calculations on the orbit of Mars take up nine hundred pages in a minuscule hand. How many more pages would he have needed if he had had to make his calculations using Roman instead of Arabic numerals? It is no longer possible to see the Scientific Revolution as a self-contained European phenomenon; exchange of ideas between Islamic West Asia and Christian Europe was a lively and vital component of the new scientific discoveries.
Kepler had been an enthusiastic Copernican since his student days, when his embrace of heliocentrism was probably more intuitive than rational. Galileo was a more reluctant Copernican, who tried to avoid addressing the issue until led to confront it through his astronomical observations and other research. ... Copernicus (1473-1543), who had pub- lished his groundbreaking book On the Revolutions of the Celestial Spheres just before his death in 1543, had been significantly influenced by Islamic astronomical research made centuries before his lifetime.
In 1957 Otto Neugebauer, a scholar researching Copernicus, happened on some diagrams by the fourteenth-century astronomer Ibn al-Shatr, and he recognized that they were identical to some in Copernicus' work. Later he found that Copernicus had also relied on the work of Nasir al-Din al-Tusi, an even earlier astronomer, who had tried to revise traditional Ptolemaic astronomical theory to make it better conform to actual observation. ... It was subsequently discovered that Copernicus had even used the same letters as al-Tusi to designate the points in a key diagram, removing any lingering doubt that Copernicus had access to the work of Muslim astronomers. (Evidence for Copernicus's reliance on the work of early Islamic astronomers is summarized by George Saliba in his Islamic Science and the Making of the European Renaissance). ...
A remarkable Arabic publishing operation was funded by Cardinal Ferdinand de Medici, Duke of Tuscany, in Italy in the late sixteenth century. The Medici Oriental Press-relying on the library of a Turkish scholar who had fled a dispute in his homeland, arrived at Venice around 1577, and converted to Christianity-published a number of Arabic-language books. Among those publications was one based on the work of Nasir al-Din al-Tusi, one of the astronomers whose work Copernicus drew upon.
Author: Thomas Christensen
Title: 1616: The World in Motion
Date: Copyright 2012 by Thomas Christensen