Georg von Peuerbach

1423-1461

Austrian Mathematician and Astronomer

Author of a work containing a table of sines, Georg von Peuerbach advanced mathematics in general with his use of Hindu-Arabic numerals in his sine tables. His student was the German astronomer Regiomontanus (1436-1476), who completed Peuerbach's monumental work on Ptolemy (c. 100-170), Epitome in Almagestum Ptolemaei, after his teacher's death.

Peuerbach's family name, like many in the Middle Ages, was derived from his hometown of Peuerbach, upper Austria, where he was born on May 30, 1423. He undertook his studies at Vienna and graduated in 1446. Seven years later, he earned a master's degree, then spent the year 1453-1454 travelling through Germany, France, and Italy as an astronomy lecturer. In 1454, he received an appointment as court astronomer to King Ladislas of Hungary.

In 1456, Peuerbach observed what came to be known as Halley's comet and recorded his observations. A year later, on September 3, 1457, he and Regiomontanus observed a lunar eclipse from a site near Vienna and also recorded it. Among Peuerbach's early astronomical works was Tabulae ecclipsium, which contained tables of his eclipse calculations. He later published additional tables and developed several astronomical instruments for making observations, as well as a large star globe.

Theoricae nova planetarum discussed the epicycle theory of the planets first presented by Ptolemy, and included Peuerbach's assertion that the planets revolve in transparent but solid spheres. Despite this erroneous notion, he was forward-thinking in his suggestion that the planets' movement is governed by the sun—an early step toward the refutation of the geocentric (Earth-centered) cosmology propounded by Ptolemy.

Nonetheless, Peuerbach remained a committed devotee of the ancient Greek mathematician right up to the time of his own death in Vienna on April 8, 1461. In 1462 or 1464, Regiomontanus completed the Epitome, which was finally published in 1474.

JUDSON KNIGHT