PEUERBACH, GEORG VON

born c. 1421, Peuerbach, Austria died April 8, 1461, Vienna Austrian mathematician and astronomer instrumental in the European revival of the technical understanding of the astronomical ideas of Ptolemy (fl. c. AD 140) and the early use of sines in Europe. Nothing is known of Peuerbach's life before 1446, when he entered the University of Vienna (B.A. in 1448). Between 1448 and 1451 he traveled, notably in northern Italy, where he lectured on astronomy in Padua. Returning to Vienna, he became a master of arts in 1453 and lectured on Latin poetry at the university. His own literary aspirations appear in Latin love poems addressed to a young Carthusian novice and in two letters preserved in a collection of model epistles. He established a solid reputation in mathematics, astronomy, and astrology, interspersing his academic duties with service as a court astrologer. His first astrological position was with King Ladislas V of Bohemia and Hungary (d. 1457), and thereafter with the latter's uncle, the Holy Roman Emperor Frederick III. Peuerbach's student and colleague Johannes Mller von Knigsberg (commonly known by his Latin name of Regiomontanus) collaborated on these and other projects, noting discrepancies between observations and predictions and recording observations of lunar eclipses and two comets (including Halley's comet in 1456). Peuerbach's best-known work, the Theoricae novae planetarum (1454; "New Theories of the Planets"), began as lectures to the Viennese "Citizens' School" (Brgerschule), which Regiomontanus copied in his notebook. An influential university textbook, the Theoricae novae planetarum eventually replaced the widely used, anonymous 13th-century Theorica planetarum communis (the common "Theory of the Planets"). By the late 17th century, this textbook had appeared in more than 50 Latin and vernacular editions and commentaries, while introducing such students as Nicolaus Copernicus (1473-1543), Galileo Galilei (1564-1642), and Johannes Kepler (1571-1630) to an updated and simplified version of Ptolemy's Almagest that gave a physical interpretation to its mathematical models. Peuerbach also computed an influential set of eclipse tables, Tabulae eclipsium (c. 1459), based on the Alphonsine Tables, that circulated widely in manuscript before the first Viennese edition (1514). Peuerbach composed other treatises, most still in manuscript, devoted to elementary arithmetic, sine tables, calculating devices, and the construction of astronomical instruments (gnomons, astrolabes, and quadrants). At the urging of Cardinal Bessarion, Peuerbach began an epitome, or abridgment, of Ptolemy's Almagest in 1460. At Peuerbach's untimely death he had finished only the first six (of 13) books; Regiomontanus not only completed the work (c. 1462), published in 1496 as Epytoma1/4in Almagestum Ptolomei, but he also raised it to new critical heights. Michael Shank