User:Nold0400/Georg von Peuerbach

Georg von Peuerbach (also Purbach, Peurbach; Purbachius; born May 30, 1423 – April 8, 1461 ) was an Austrian astronomer, mathematician and instrument maker, best known for his streamlined presentation of Ptolemaic astronomy in the Theoricae Novae Planetarum.

Biography
Little is known of Peuerbach's life before he enrolled at the University of Vienna in 1446. He was born in the Austrian town of Peuerbach. A horoscope published eighty-nine years after his death places his date of birth specifically on May 30, 1423, though actual evidence only indicates that he was born sometime after 1421. He received his Bachelor of Arts in 1448. His curriculum was most likely composed primarily of humanities courses, as was usual at the time. His knowledge of astronomy probably derived from independent study, or possibly from studying under Followers of John of Gmunden . as there were no professors of astronomy at the University of Vienna during Peuerbach's enrollment. However, his presence continued the tradition of excellent astronomers from the University of Vienna in the 15th and 16th centuries. It is believed that observing the occultation of Jupiter by the Moon in the year 1451 is what began his career in astronomy. Peuerbach would then spend the remaining years of his life developing tools for astronomy, developing theories, as well as collaborating with Johannes Müller.

From 1448 to 1451 Peuerbach traveled through central and southern Europe, most notably in Italy, giving lectures on astronomy. His lectures led to offers of professorships at several universities, including those at Bologna and Padua. During this time he also met Italian astronomer Giovanni Bianchini of Ferrara. He returned to the University of Vienna in 1453, earned his Masters of Arts, and began lecturing on Latin poetry. He is often credited as a leader in reviving classical Greek and Roman literature in arts and sciences.

In 1454 Peuerbach was appointed court astrologer to King Ladislas V of Bohemia and Hungary. It was in this capacity that Peuerbach first met Ladislas' cousin Frederick who was then serving as guardian to the 14-year-old king and who would later become Frederick III, Holy Roman Emperor. Ladislas resided primarily in Prague and Vienna, allowing Peuerbach to maintain his position at the University of Vienna. During this time Peuerbach met Johannes Müller von Königsberg, better known as Regiomontanus. Müller was currently a student at the university and, after he graduated in 1452 at the age of 15, began collaborating extensively with Peuerbach in his astronomical work.

In 1457, following the assassination of two notable political figures, Ladislas fled Vienna and died later that year. Rather than taking of service with either of Ladislas' successors, Peuerbach accepted an appointment as court astrologer to Frederick III.

Work
One of Peuerbach's best known works is his Theoricae Novae Planetarum (written in 1454, published by Regiomontanus in 1472). It began as a series of lectures transcribed by Regiomontanus. The Theoricae Novae Planetarum was an attempt to present Ptolemaic astronomy in a more elementary and comprehensible way. The book was very successful, replacing the older Theorica Planetarum Communis, sometimes attributed to a certain Gerardus Cremonensis, as the standard university text on astronomy and was studied by many later-influential astronomers including Nicolaus Copernicus and Johannes Kepler.

In 1457 Peuerbach observed an eclipse and noted that it had occurred 8 minutes earlier than had been predicted by the Alphonsine Tables, the best available eclipse tables at the time. He then computed his own set of eclipse tables, the Tabulae Eclipsium. Widely read in manuscript form beginning around 1459 and formally published in 1514, these tables remained highly influential for many years.

Peuerbach wrote various papers on practical mathematics, and constructed various astronomical instruments. Most notably, he computed sine tables based on techniques developed by Arabian mathematicians.

In 1460, Cardinal Johannes Bessarion, while visiting Frederick's court seeking assistance in a crusade to reclaim Constantinople from the Turks, proposed that Peuerbach and Regiomontanus create a new translation of Ptolemy's Almagest from the original Greek. Bessarion thought that a shorter and more clearly written version of the work would make a suitable teaching text. Peuerbach accepted the task and worked on it with Regiomontanus until his death in 1461, at which time 6 volumes had been completed. Regiomontanus completed the project, the final version containing 13 volumes.

Legacy
Peuerbach's work with his student, Regiomontanus, to translate Ptolemy's Almagest would become an important part of the future work done by Nicolaus Copernicus. Though the work was not completed until after Peuerbach's death in 1461, Regiomontanus carried on with the task and eventually the Epitome of the Almagest was published in 1496, nearly 35 years after his teacher’s passing, and 20 years after his own (Regiomontanus died in 1476). This book would go on to be an important reference for Nicholas Copernicus for the creation of his book De Revolutionibus.

Another of Peuerbach's contributions was his input toward Regiomontanus's trigonometric relationships. This trigonometry would be used by future astronomers in the coming century. Regiomontanus would also go on to actually publish Peuerbach's book Theoricae Novae Planetarum. Though a fair amount of Peuerbach's work is believed to have circled astrological academia, his full observations were completely published by Johann Schöner nearly a century after Peuerbach's death. His Theoricae Novae Planetarum would be released in numerous editions between 1472 and 1596, with edits by scholars such as Regiomontanus, Peter Apian, Erasmus Reinhold, and Philip Melanchthon. It is believed that by 1653, at least 56 Latin printings of the text had been published with numerous editions in other languages as well.

Peuerbach’s Theoricae Novae Planetarum became one of the most common astronomy textbooks used to train future scholars. The Theoricae Novae Planetarum was a thorough textbook that would replace the previously used Theorica Planetarum Gerardi. The descriptions of the solid spheres model (common to the Ptolemaic planetary system) seen in the Theoricae Novae Planetarum would go on to remain the believed nature of the spheres. This was until the time of Tycho Brahe, who disproved the existence of solid spheres. The Theoricae Novae Planetarum is also credited with helping to establish much of the technical vocabulary used by astronomers through the seventeenth century.

Peuerbach is also known to have developed and distributed tables that were capable of predicting eclipses of both the sun and the moon, and this practice was continued by Regiomontanus. The manuscript, titled Tabulae Eclipsium, saw continued use, and was used by Tycho Brahe near the end of the sixteenth century. He is also believed to have overseen the collection and duplication of numerous astronomical manuscripts. This culminated in the development of a scientific printing press in Nuremberg by Regiomontanus. The printing press was further used to publish astronomical works such as Peuerbach's own Theoricae Novae Planetarum, as well as the Astronomicon written by the poet Manilius