I first read a biography of Copernicus when I was an elevator operator for my summer job in 1954. It was a Mentor paperback with the title “Sun Stand Thou Still.” I learned that there are very few documents that survived in Copernicus’s own hand. He was Polish in a German occupied area of that unhappy country that has rarely stayed independent over the centuries. His uncle helped him with his education and after attending the University at Krakow, he went to Bologna and Padua to study. One of his classmates was Girolamo Fracastoro, who also studied medicine, and an early pioneer in promoting the germ theory of infectious diseases and the person who first named syphilis and treated it with mercury. We do not think of Copernicus as a physician. He followed a medieval tradition of specializing in several fields. Copernicus chose medicine, law, and mathematics, especially the mathematics that could be applied to astronomy. The field of astronomy was dominated in medieval times by astrology which Copernicus avoided as much as he could. Copernicus also chose the path of priesthood so he could pursue academic life.
Copernicus chose the law, especially church (canon) law and affiliated himself with the dioceses in Krakow and later Prussian city of Frauenberg by the Baltic Sea. He served as an ambassador for the state government and helped settle disputes. For his intellectual pleasure, starting at Bologna, he studied astronomy purged of casting horoscopes for patrons. By stressing his legal and medical skills he could avoid the guesswork of horoscopes. At that time (the 1400s) Dante’s view (also Ptolemy’s) of the universe prevailed: the earth was at its center and the largest object in the universe. The sun was a planet and with the stars and other planets made a daily revolution around the earth. Working out the complicated movements of planets like Venus and Mercury was difficult because they showed retrograde movement and sometimes marched forward and stopped and then moved backward. Other planets like Mars, Jupiter and Saturn did not show retrograde movement. Copernicus realized he could both simplify the mathematics of predicting where each planet would be on any given day or year by placing the sun in the center of our solar system. This demoted the earth to the status of a planet. It demoted the moon from being a planet to a satellite of the earth’s. It placed mars and Mercury between the earth and the sun. It placed Mars, Jupiter and Saturn outside the earth’s orbit around the sun.
Why was this revolutionary? Medieval theology assumed the earth was the largest object in the universe and its center. After all, the planets and stars, sun, and moon, were created on the fourth day, after the earth’s creation on the third day in the Book of Genesis. Copernicus’s solar system had no support in reading the Book of Genesis. He also knew it would be unwise to publicize his views but he did prepare a short handout with his major insights and circulated that among his fellow astronomers. He prepared a book-length mathematical analysis of the implications of using the solar system and arranged for its publication as he approached his death. His student Rheticus made sure that was done. As Copernicus suspected, the Copernican model was condemned as heretical by both the Church and the new Protestant theologians. But Copernicus showed that once a scientist launches a theory it is difficult to expunge. Ideas are like the spores of Fracastoro’s theory and they spread to epidemic proportions. It’s why being a scientist is such a joy—the influence of our findings ripple on through the world of human thought