Georg Joachim von Lauchen, also known as
Rheticus (16 February 1514 – 4 December 1574), was a
mathematician,
cartographer, navigational-instrument maker, medical practitioner, and teacher. He is perhaps best known for his
trigonometric tables and for being
Nicolaus Copernicus' sole pupil, who facilitated the publication of Copernicus'
De revolutionibus orbium coelestium (
On the Revolutions of the Heavenly Spheres).
Rheticus was born at Feldkirch, Austria. Both his parents possessed considerable wealth, and the father, Georg Iserin, was the town physician. However, he abused the trust of many of his patients, stealing belongings and money from their homes. In 1528 he was convicted and executed for his crimes, and as a result his family was stripped of their surname. The son took as his last name a form of the Latin name for his home region, Rhaetia, a Roman province that had included parts of Austria, Switzerland and Germany; he would be called Rheticus.
After Iserin's death, Achilles Gasser took over his medical practice. Gasser helped Rheticus continue his studies and was a strong support to him. Rheticus studied at Feldkirch, Zürich and the University of Wittenberg, where he received his M.A. in 1536.
Two years later, Melanchthon arranged a two-year leave for Rheticus to study with noted astronomers. Rheticus took this opportunity to visit Copernicus in Frombork (Frauenburg). Leaving Wittenberg in October 1538, he first went to Nuremberg to visit the publisher Johannes Schöner and the printer Petreius. Here Rheticus was given works by Regiomontanus and others, intended as presents for Copernicus. He proceeded on to Peter Apian in Ingolstadt and Joachim Camerarius in Tübingen, then to Achilles Gasser in Rheticus' hometown.