Georg Joachim Rheticus - Copernicus

Copernicus

In May 1539, Rheticus arrived in Frombork (Frauenburg), where he spent two years with Copernicus. It is unknown whether he had prior access to Copernicus' Commentariolus, an unsigned, unpublished outline of Copernicus' revolutionary heliocentric theory that Copernicus distributed friends and colleagues three decades before he published De revolutionibus.

In September 1539, Rheticus went to Danzig (Gdańsk) to visit the mayor, who gave him financial assistance to publish his Narratio Prima (First Report) of Copernicus' forthcoming treatise. Rhode in Danzig published Narratio Prima in 1540. While in Danzig, Rheticus interviewed maritime pilots to learn about their problems in navigation. Rheticus also visited Copernicus' friend, Tiedemann Giese, who was Bishop of Culm (now Chełmno).

In August 1541, Rheticus presented a copy of his Tabula chorographica auff Preussen und etliche umbliegende lender (Map of Prussia and Neighboring Lands) to Albert, Duke of Prussia, who had been trying to compute the exact time of sunrise. Rheticus made an instrument for him that determined the length of the day. Rheticus obtained the duke's permission to publish De revolutionibus. Albrecht asked Rheticus to end his travels and return to his teaching position. Rheticus returned to the University of Wittenberg in October 1541. In May 1542, he traveled to Nürnberg to supervise the printing by Johannes Petreius of the first edition of De revolutionibus, but had to leave in fall to take a position in Leipzig, and Andreas Osiander replaced him. Copernicus' major work was published shortly before his death in 1543.