A Map of the Heavens

Much of the genius of Nicolaus Copernicus (1473–1543) lay in a mix of audacity and exactitude. His boldest leaps of insight sprang from laborious plodding. Years of careful computation, based on sporadic stargazing with the crudest of instruments, lay behind his astonishing discoveries: Our earth was not the fixed center of the universe, nor did the sun and the stars move around us in perfect epicycles, as Ptolemy had argued more than a millennium earlier; in fact, our earth not only revolved around the sun but rotated on its axis. Nor were the heavens themselves static: They moved as well.

When his "On the Revolutions of the Heavenly Spheres" finally appeared in 1543, after decades of delay — he saw the first printed copy on the very day of his death — he not only turned human beings out of the cozy nest of their fondest assumptions, but rejoiced in the eviction. In the first book of his great work, he states, "Indeed, the Sun as if seated on a royal throne governs his household of stars as they circle around him." A heliocentric cosmos demonstrated to him "the marvelous symmetry of the universe."

As Jack Repcheck demonstrates in his excellent "Copernicus' Secret: How the Scientific Revolution Began" (Simon & Schuster, 255 pages, $25), the Polish astronomer and mathematician is not simply the pure empiricist we might recall. Born as Mikolaj Kopernik in the town of Torun on the Baltic coast, Copernicus combined religious fervor with scientific rigor in almost equal measure.

Of course, this wasn't unusual in the 16th century: Virtually all scientists then were believers, but most of them looked to nature only for confirmation of their own (quite false) preconceptions. Copernicus overturned these totally, and yet that radical act of demolition only deepened his wonder. His brilliant disciple Georg Joachim Rheticus, who persuaded Copernicus to publish his masterwork and then saw it through the press, put it best when he said, "There is something divine in the circumstance that a sure understanding of celestial phenomena must depend on the regular and uniform motion of the terrestrial globe alone." Mr. Repcheck is modest enough to describe his book as "lighter fare." It is indeed brisker and less detailed than such earlier, and masterful, accounts as Owen Gingerich's wonderful "The Book That Nobody Read" (2004), but while Mr. Gingerich was principally interested in tracing the strange destiny of Copernicus' epochal book, Mr. Repcheck tries to bring Copernicus the man himself into sharper focus. This is no small task: Copernicus was not only "a retiring hermit-like scholar who wanted nothing more than to be left alone," as Mr. Repcheck aptly describes him. He was also a man with secrets, at least one of them scandalous.

Copernicus was trained as a doctor, and he achieved renown as a healer, but he was a man of the church as well. For decades, following his pious father's example, he served as canon in the little town of Frombork and was punctilious in his ecclesiastical duties. As his fame as a scholar spread — though he published almost nothing, rumors of his novel astronomical insights attracted attention — his private life came under scrutiny. And, as became clear, that scrutiny was warranted: It turns out that his housekeeper, whom Copernicus coyly called "a proper female relative," was in fact his mistress.

Her name was Anna Schilling, an attractive married woman who, as Mr. Repcheck puts it a bit coyly himself, became "deeply interested in astronomy." Copernicus' superior, Johannes Dantiscus, bishop of Chelmno, fumed over the affair, and ordered Copernicus to boot "the Frombork wench" out of his house. This response was a bit rich. After all, Dantiscus, while posted to Spain, had himself dallied with a mistress and had fathered two illegitimate children (including a daughter whom he proudly named Dantisca). Copernicus stalled and squirmed but in the end stood fast. He proved as stubbornly loyal to his mistress as he was to his astronomical computations.

Mr. Repcheck tells this, and a host of other stories, extremely well, and with great flair. He is especially good at setting Copernicus vividly in his time. This was after all not only an age of world-altering discovery about our solar system. During Copernicus' lifetime, Columbus discovered America, the Renaissance was in full swing, and the Reformation, with all its upheavals and denunciations — some of which affected Copernicus personally (some of his closest friends came under suspicion) — swirled about him even in his remote retreat.

Mr. Repcheck's book comes with excellent maps and fascinating illustrations, including one of Copernicus's face, reconstructed from his skull, which was unearthed in 2005 in the crypt of Frombork cathedral. With his long bony nose, austere and down-turned lips and hooded eyes, the astronomer looks like a man who has stared unblinkingly into the full blaze of his true sovereign, the sun.

eormsby@nysun.com