Erratum: On the Revolutions

On my list of books to read, on the shelf at the library, the right size for my back pack and a good length for my journey: I read Dava Sobel’s “A More Perfect Heaven: How Copernicus Revolutionized the Cosmos” while birding in Panama. This is not a book report, but I learned something that relates to a previous post (on Wislawa Szymborska) and any further references of mine to Copernicus’ study of planetary movement.

Copernicus had been reluctant to publish his observation that the sun not the earth was at the center of the universe. Without the intervention of a young German mathematician, Georg Joachim Rheticus, he might not have written his treatise. For political/religious, geographic, technological and health reasons, Copernicus was not involved in the typesetting and printing of his tome. Neither was Rheticus proofreading up to press time. That task was passed on toward the end of the printing process to one Andreas Osiander, a former Catholic priest who had become a disciple of Martin Luther.

Sobel writes: “Osiander had a history with Rheticus and Copernicus. His letters of the year before bespoke his great interest in their publishing venture, though his religious beliefs colored his opinion of all astronomical models and hypotheses. As he had told them, any number of competing sets of conjectures might account for the observed heavenly motions, but nothing short of divine revelation could determine which set, if any, truly corresponded to reality. And so, since it was impossible to know the truth, one astronomer should refrain from insulting another by insisting he had uncovered the actual workings of the celestial spheres.” (page 185)

Copies of the printed book that once were in Rheticus’ care have been defaced. Copernicus’ protege used a red crayon to cross “of the Heavenly Spheres” out of the title. Sobel infers from Rheticus’ markings that those words might have been an unauthorized addition by Osiander to divert attention from the most unsettling part of Copernicus’ finding, namely that the earth traveled around the sun.

I will, from now on, refer to Copernicus’ work as “On the Revolutions” and return Sobel’s book to the library.