In 1571 be became Professor of mathematics (astronomy) at Wittenberg where he met Valentinus Otho and Joachim Rheticus.
Johannes Vermeer | Johannes Kepler | Johannes Gutenberg | Praetorius | Johannes Peter Müller | Michael Praetorius | Johannes Ockeghem | Johannes Rau | Johannes Müller | Johannes Heesters | Johannes Zukertort | Johannes Meursius | Cornelis Johannes van Houten | Johannes Meyer | Johannes Itten | Johannes Blaskowitz | Johannes von Lahnstein | Johannes Mötsch | Johannes Hevelius | Johannes Ciconia | Johannes von Trapp | Johannes von Müller | Johannes Ullrich | Johannes Trithemius | Johannes Theodor Reinhardt | Johannes Magnus | Johannes Leimena | Johannes Ghiselin | Johannes Gad | Johannes Ewald |
In 1573 he came to Wittenberg, proposing to Johannes Praetorius an approximation of Pi as .