Georg Joachim de Porris, also known as Rheticus (; 16 February 1514 – 4 December 1574), was a mathematician, astronomer, cartographer, navigational-instrument maker, medical practitioner, and teacher. He is perhaps best known for his trigonometric tables and as Nicolaus Copernicus's sole pupil. He facilitated the publication of his master's De revolutionibus orbium coelestium (On the Revolutions of the Heavenly Spheres).

Surname

Rheticus was born at Feldkirch in the Archduchy of Austria. Both his parents, Georg Iserin and Thomasina de Porris, were of Italian heritage and possessed considerable wealth, his father being the town physician as well as a government official. He was educated by his father until the age of 14 when Georg (Iserin) 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 family adopted the mother's maiden name: de Porris. Later as a student at the University of Wittenberg, Georg Joachim adopted the toponym Rheticus, a form of the Latin name for his home region, Rhaetia, a Roman province that had included parts of Austria, Switzerland and Germany. In the matriculation list for the University of Leipzig his family name, de Porris, is translated into German as von Lauchen. The lunar crater Rhaeticus as well as asteroid 15949 Rhaeticus were named for him.

Patrons

After Georg Iserin's death, Achilles Gasser took over his medical practice, helping Rheticus to continue his studies and supporting him, eventually going so far as to furnish him with a letter of introduction to Philipp Melanchthon, a theologian and educator who would become a major patron, having reorganized the whole educational system of the Lutheran Protestant parts of Germany, reforming and founding several new universities during the Reformation. This relationship in particular would soon serve him well as Melanchton possibly chose him specifically for the University of Wittenberg. Rheticus studied at Feldkirch, Zürich and Wittenberg where he received his M.A. in 1536, after which Melanchthon appointed Rheticus as professor of the lower mathematics, arithmetic and astronomy, at the Wittenberg University.

Two years later, Melanchthon arranged a two-year leave for Rheticus to study with noted astronomers. Leaving Wittenberg in October 1538, he first went to Nuremberg to visit the professor of mathematics at the Eigidien Oberschule, Johannes Schöner. In Nuremberg he also made the acquaintance of other mathematicians such as Georg Hartmann and Thomas Venatorius as well as the printer-publisher Johannes Petreius. During his journey, probably in Nuremberg, Rheticus heard of Copernicus and decided to seek him out. It is unknown whether he had access to Copernicus' Commentariolus, an unsigned, unpublished outline of Copernicus' revolutionary heliocentric theory that Copernicus distributed to friends and colleagues three decades before he published De revolutionibus, prior to this or perhaps on consulting Schöner who is believed to have persuaded him. From Johannes Petreius Rheticus was given works by Regiomontanus and others, intended as presents for Copernicus. He went on to Peter Apian at the University of Ingolstadt and Joachim Camerarius at the University of Tübingen, then to his hometown when Rheticus would present Gasser with an edition of Sacrobosco. From Feldkirch he set out on his journey to visit Copernicus in Frombork.

Copernicus

thumb|upright=1.2|Geocentric (upper) and Heliocentric (lower) views of the Solar System.

In May 1539, Rheticus arrived in Frauenburg (Frombork), where he spent two years with Copernicus. Only following its reception, widely considered the best introduction to Copernicus' work, would he then give Rheticus further permission to edit and publish his work in full. In this, Rheticus would prove integral in utilizing previously forged social connections as well as strategically cultivating new ones just to bring it to publication. 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 Chełmno (Culm) and further encouraged him to publish the former's work. At some point, he would additionally become a patron.

In August 1541, Rheticus presented both a copy of Chorographia (containing a systematic approach to the preparation of maps, distinguishing chorography from geography, discussing various methods of cartographic survey by the use of the compass as well as improvements to the aforementioned instrument) and Tabula chorographica auff Preussen und etliche umbliegende lender (Map of Prussia and Neighboring Lands) to Albert, Duke of Prussia. Towards this, Rheticus would allegedly deface every such copy he came across.

In a work now properly attributed to Rheticus tentatively titled Epistolae de Terrae Motu (Letter on the Motion of the Earth), he attempts to reconcile Copernicanism with scripture by employing St. Augustine's principle of accommodation. According to historian Robert Westman, the Epistolae or also known as the Opusculum, published posthumously and anonymously in 1651, demonstrates that Copernicus and Rheticus recognized the problem of conflict between their finding of earthly motion and biblical scripture, and had therefore developed a systematic defense of compatibility. He fled following this accusation, for a time residing in Chemnitz before eventually moving on to Prague.

At his death, the Science of Triangles was still unfinished. However, paralleling his own relationship with Copernicus, Rheticus had acquired a student from Wittenberg who sought him out.

thumb|150px|Frontpage of Canon Doctrinae Triangulorum

Rheticus narrates the third part of John Banville's 1975 novel Doctor Copernicus, relating how he convinced Copernicus to publish the book. The novel itself is less about Copernicus's work than about his life and the 16th century world in which he lived.

The episode "Claudia" of the U.S. science fiction series Warehouse 13 references a teleportation device in the form of a compass said to have been built by Rheticus.

Rheticus is referenced several times in the song "Like Rheticus" on the 2004 album Place by British songwriter Owen Tromans.

Dava Sobel's 2011 book A More Perfect Heaven: How Copernicus Revolutionized the Cosmos features a fictional play about Rheticus' visit to Copernicus, sandwiched between chapters about the visit's pre-history and post-history.

Works

  • Narratio prima de libris revolutionum Copernici (1540)
  • Tabula chorographica auff Preussen und etliche umbliegende lender (1541)
  • De lateribus et angulis triangulorum (with Copernicus; 1542)
  • Ephemerides novae (1550)<!-- Wolf Guenther, or, Wolfgang Gunter, was a printer at Leipzig of little importance. See Friedrich Kapp, Geschichte des deutschen Buchhandels bis in das siebzehnte Jahrhundert. Leipzig, 1886, pp. 154, 304, 574 -->
  • Canon doctrinae triangulorum (1551)
  • Epistolae de Terrae Motu (posthumous)

Notes

References

  • Richard S. Westfall (August 4, 2003). "Rheticus, George Joachim" in Catalog of the Scientific Community of the 16th and 17th Centuries. The Galileo Project.
  • Dennis Danielson (2006). The First Copernican: Georg Joachim Rheticus and the Rise of the Copernican Revolution. Walker & Company, New York.
  • Karl Heinz Burmeister: Georg Joachim Rhetikus 1514-1574. Guido Pressler Verlag, Wiesbaden 1967.
  • Stefan Deschauer: Die Arithmetik-Vorlesung des Georg Joachim Rheticus, Wittenberg 1536: eine kommentierte Edition der Handschrift X-278 (8) der Estnischen Akademischen Bibliothek; Augsburg: Rauner, 2003;
  • R. Hooykaas: G. J. Rheticus’ Treatise on holy scripture and the motion of the earth / with transl., annotations, commentary and additional chapters on Ramus-Rheticus and the development of the problem before 1650; Amsterdam: North-Holland, 1984
  • Burmeister, K. H. "Georg Joachim Rheticus as a Geographer and His Contribution to the First Map of Prussia." Imago Mundi 23 (1969): 73–76. Web.
  • Swerdlow, N. M. “Annals of Scientific Publishing: Johannes Petreius's Letter to Rheticus.” Isis, vol. 83, no. 2, 1992, pp.&nbsp;270–274.
  • Hooykaas, R. Rheticus's Lost Treatise on Holy Scripture and the Motion of the Earth. Journal for the History of Astronomy, p.&nbsp;77. 1984.
  • Grafton, A. (2007). The middleman. American Scientist, 95(2), 177–179.
  • Hugonnard-Roche, et al. Book-Review - Rhetici - Narratio-Prima. Journal for the History of Astronomy, Vol.17, NO. 49/MAY, P.130, 1986.
  • Scienceworld article on Rheticus
  • Narratio Prima, 1540 - Full digital facsimile, Linda Hall Library.
  • Christian Pinter: Der erste Kopernikaner