PZ: And what do we know about the intellectual climate of Warmia at the time? Once he returned from Italy, did he have anyone at all to talk to about his passions and discoveries?
WO: His uncle, for all his faults and despotism, was a Renaissance man, in the sense that he was very interested in Italy and its culture. He certainly discussed poetry or painting with him. However, we know nothing about his interest in astronomy.
On the other hand, those pioneering discoveries that were being made at the time using mathematical methods were also of great political importance. This was the period when, thanks to Gemma Frisius, the science known as geodesy was born. His uncle was certainly interested in the fact that with the help of these technical innovations it was possible to calculate the exact distance from Elbląg to Tolkmicko or to the Vistula Spit. This was important, as various border treaties referred to some from-here-to-there line, but no one knew how to determine it clearly. And Copernicus came equipped with the knowledge of how things are done in the developed West, and he certainly had someone to talk to about that.
Very soon Copernicus found soulmates among the subsequent canons of Warmia. He must have discussed all this with one of his closest friends, Tiedemann Giese (later Bishop of Chełmno and Warmia) and probably Fabian Luzjański. In that period, Copernicus travelled extensively on business and certainly met various intellectuals of the time, such as Laurentius Corvinus, the personal poet of the city of Wrocław, with whom he worked and who revealed that Copernicus explained to him various interesting things about astronomy. So he had someone to talk to about it, although it was a rather narrow and elite group.
PZ: He came across the heliocentric lead by collecting crumbs of the knowledge of that period. I find here the Arabic thread to be particularly interesting…
WO: Here we must distinguish between a theory and a hypothesis, i.e. a loose idea. The heliocentric hypothesis was already in circulation in antiquity. One could therefore downplay the role of Copernicus – as he himself did in his introduction to De revolutionibus in an attempt to soften the implications of his work.
We have solid reasons to believe he frequented Venice (he certainly had books published in that city in his collection) and certainly Padua, which was for some time part of the Venetian State. Venice had rich commercial and political relations with Byzantium and the Arab world. It was a city where, for example, transactions to buy Christians out of slavery took place. Many of those who lived there had contacts with the Oriental world, and Arab astronomy was more advanced than its European counterpart at the time.
It is just a supposition, but Copernicus may have met a man in Venice who explained to him how the astronomers of the Islamic world dealt with the paradoxes associated with the geocentric model. Since he was in such a city, it would be strange if he did not seek access to, for example, the maps of the skies devised by Arabic scholars.
These are indirect crumbs of evidence: it is known, for example, that Copernicus used a type of sundial unusual for Western civilisation. The ones we know from numerous parks and gardens have a so-called gnomon, which casts a shadow on the dial, while Copernicus used a sundial equipped with a mirror that casts a dot-like reflection of light, like a laser pointer. We will never know why he used this particular type – or whether it was a coincidence that it was a popular design in the Islamic world.
As is often the case when studying Copernicus, the absence of evidence can be considered as evidence itself. His theory was sufficiently heretical that in the introduction to De Revolutionibus he wrote about the fact that at one time he had a conversation with a certain heterodox scientist who gave him an interesting idea. He would have had enough common sense to keep quiet about it.
PZ: In order to read suspicious books, he had to learn Greek, and thus he also gained some fame as a translator. But why didn’t he translate any better books?
WO: I will only point out here that knowledge of Greek itself was still okay – after all, Thomas Aquinas had rehabilitated Aristotle. However, it was a rare skill in Europe at the time. It was from this era that the saying ‘pretend to be Greek’ [pretending to be smart] originated: chroniclers recorded impostors who mumbled something in an incomprehensible language, claiming to be experts in ancient medical knowledge.
And why did he choose this and not some other work? Theoretically, he explains it himself in an introduction styled as a letter to his uncle: he found it to be an exquisite collection of truths about human nature. The book itself is odd and no one would talk about it today if it were not for the fact that Copernicus translated it. It is a collection of apocryphal letters attributed to historical figures; in style it is somewhat reminiscent of school reading assignments. I suspect the answer is terribly trivial: books written in Greek were hard to come by. So, my guess is that he scraped up what he could buy and what was accessible to be read.