You know, books are good things. You can learn from them. For example, before I read this book, whenever Copernicus’s name came up I thought something like “Copernicus, sure. He said the earth goes around the sun and got in trouble with the church. Later Kepler put ellipses in instead of circles, Newton did the mathematics, and truth triumphed.”
Not quite. Were it not for the subject of this biography, Georg Joachim Rheticus (1514-1574), Copernicus’s heliocentric idea, widely cited as monumental (“a central and defining epiphany in the history of all science” — Wikipedia), might have subsided and Copernicus could have joined the vast horde of those whose thoughts and writings have been forgotten. (Oresme in the 14th century and Cusa in the 15th had written about a moving earth, but their ideas did not take hold.) In fact, we could still be using the earth-centered Ptolemaic system: I’m sure that with the addition of some more epicycles and perhaps an epiepicycle or two it could have been made sufficiently accurate for all practical purposes. If you respond, “Nonsense!” you may be too heavily influenced by the view, all too commonly held, that the story of the past is one of unremitting progress, with a few small setbacks here and there, culminating at last in the perfection of us. History books are good things when they remind us that neither we nor our world are inevitable.
Rheticus’s father, Georg Iserin, committed crimes sufficiently serious that his head was cut off in 1528 and, in the custom of the time, his name was also cut off and could no longer be used. Thus his son took his mother’s maiden name, de Porris, which he occasionally Germanized as von Lauchen, both meaning “of the leeks”. But he preferred to call himself after the region in which he was born, at one time the Roman province of Rhaetia, and became Georg Rheticus. Names were more mutable in the Renaissance than they are now, which is why Rheticus appears in Cardano’s autobiography as “Giorgio Porro”.
Rheticus’s mother had money enough so that her son could study in Zurich for three years and then attend the University of Wittenberg, becoming a master of arts in 1536. His mathematical talents were so marked that on graduation he was offered a professorship of mathematics there, which he accepted. In 1538–39 he was given leave to travel and visit scholars in southern Germany, and his leave was extended for a year in 1539 so that he could travel to the north. In 1539, he met Copernicus (1473–1543) and spent two years with him.
Over the years, Copernicus had made his heliocentric views known, but only by correspondence. If Rheticus had not turned up, there can be little doubt that he never would have published them, with consequences we can only guess at. But Rheticus, young and energetic, did publish a short account of them in 1540 and he prodded Copernicus to prepare a more complete version. Copernicus did so and Rheticus did the considerable amount of work needed to get it into print. Publication of De revolutionibus occurred in 1543. The legend is that Copernicus saw the printed version for the first time on the day that he died. Be that as it may, it was entirely because of Rheticus that the Copernican revolution could start to take place when it did.
It wasn’t fear of religious opposition that kept Copernicus from publishing. In fact, a cardinal of the Roman church had encouraged him to break into print. At the time, how the sun and the earth comported themselves seems to have been viewed as a mathematical question. It was only after the Council of Trent that the unbiblical nature of heliocentrism started to bother the religious authorities. The church’s index of forbidden books was not authorized until 1562, long after Copernicus’s death, and its first edition did not appear until 1564. Copernicus’s work was duly placed on it, but he would not have suffered from having published it during his lifetime. Not suffered from the church, that is: some of his fellow scholars might very well have tried to take him apart, and he may have feared that. Academic fangs were as sharp then as they are now, if not sharper.
Rheticus’s life after the publication of De revolutionibus was essentially anticlimax. He was lured away from Wittenberg by an offer from the University of Leipzig with a considerably larger salary. As at Wittenberg, he had spent as much time as he could on leave, for example visiting Cardano in 1545. In 1551 he was accused of homosexual activity with a student. He left town quickly and after a trial in absentia was banished from Leipzig for 101 years, after which time, presumably, he could return. It is likely that he then studied medicine in Prague and from 1554 on he made his living as a doctor in Krakow.
He had not forgotten mathematics, and during his time in Krakow he was working on his tables of trigonometric functions. He died at the age of 60 in 1574 before they were published, but as he had served Copernicus, a disciple, Valentin Otto, saw to it that they were printed. After errors were corrected, they were used for hundreds of years. But the computation of tables, no matter how long-lived, is as nothing compared with being the instrument by which a revolution in human thought occurred.
The book’s author, Dennis Danielson, is a professor of English at the University of British Columbia. Thus the book contains no equations at all and mathematical details are not mentioned. I would have liked to know why Rheticus calculated his sines to fifteen decimal places and what method he used, but such things are incidental, as incidental as what medicines he prescribed during his twenty years of doctoring in Poland.
The book is scholarly, with sources and notes, but it is neither dry nor dull. It is well written and the narrative moves along as a good story should. The author only sparingly gives way to the temptation to include novelistic flourishes (“he gazed for the first time at the Frauenburg cathedral backlit by the slowly westering sun”). He is so skillful that he gives the reader the impression of knowing what it was like to be alive in central Europe in the time of Rheticus. Books are good things, and the author has written a good book.
Woody Dudley attained age 70 without being aware of Rheticus. You’re never too old to learn.