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Georgia L. Irby-Massie

Greek polymath who worked in mathematics, astronomy, and mechanics. He is especially famous for descriptions of automata (air-, water-, and steam-powered mechanical devices) and steam-powered aeolipiles. “Hero’s engine,” deriving from Ctesibius of Alexandria’s design (290250 bce), is the first device to transform steam into rotary motion. The aeolipile consists of a hollow sphere attached by pipes to an enclosed water-filled cauldron. When the cauldron is heated, the sphere spins on a pivot as it releases steam (Pneumatics 50).

Hero’s much disputed floruit was pinpointed by Neugebauer (1975, 846), who noted that Hero used eyewitness evidence of a lunar eclipse of 62 ce, visible from both Rome and Alexandria, to calculate the distance between those two cities (Dioptra 35). Making no use of Ptolemy of Alexandria (127after 146 ce Hero likely predated Ptolemy Neugebauer Very little is known of Hero s life His mathematical corpus ...

Article

Ness Creighton

Egyptian astronomer, whose full name was Abu’l-Hasan ʿAli B. Abi Saʿid ʿAbd Al-Rahma, Ahmad B. Yunus Al-Sadafi, was one of the most prominent Muslim astronomers, not only of his time, but in terms of general influence. His al-Zidj al-kabir al-hakimi, considered one of the finest surviving astronomical handbooks, has been used extensively as a source of data by early and modern astronomers.

Ibn Yunus was the son of an eminent Egyptian historian ʿAbd al Rahnan and great grandson of the companion Yunus of the legal scholar al Shafi i While his exact date of birth is unknown it can be inferred from his reported age at the date of his father s death that he was born in the year 950 CE He is known not only as an astronomer but also as a poet and a musician having had much reported talent with the lute Some of Ibn Yunus s poems ...

Article

Michael A. B. Deakin

mathematician, astronomer, and geographer, was the principal figure of the “silver age” of ancient Greek mathematics. Little is known of his life; what the sources tell us is contradictory and unreliable. The little we do know reliably is gleaned rather from what survives of his writing. His principal work, at least in what has survived, is the Synagoge or Collection, and even this has not reached us in its entirety. It is described as having comprised eight books, of which the first and part of the second are missing. The only other work of his that survives in the original Greek (and that only in part) is a commentary on Ptolemy’s Almagest. Beyond these are works in other languages that are thought to be translations of originals by him. An Arabic commentary on Book X of Euclid’s Elements may be a translation of a work he is ...

Article

Ptolemy  

Prudence Jones

was an ancient Alexandrian astronomer geographer and philosopher Almost nothing is known about the life of Claudius Ptolemy or as he would have called himself Claudius Ptolemaeus From astronomical observations he made in Alexandria we know he was active between 127 and 141 CE As a scientist in Alexandria he was probably connected with the Library of Alexandria His name indicates that he was a Roman citizen and that citizenship was probably conferred upon him or upon one of his ancestors by someone named Claudius perhaps even the emperor Claudius He shares the name Ptolemy with the rulers of the Ptolemaic dynasty which controlled Egypt from 323 to 30 BCE although there is no evidence that he was related to that family The name Ptolemaeus could indicate that he was born in the Egyptian city of Ptolemais but it is not known whether he was born there or at Alexandria ...

Article

Theon  

Michael A. B. Deakin

Alexandrian astronomer and mathematician was the leading mathematician of his era and the last attested member of the famed Alexandrian Museum The mid to late fourth century of the Common Era was not a time conducive to mathematics Indeed Constantius a Roman Emperor of the day promulgated a law to the effect that no one may consult a soothsayer or a mathematician The word soothsayer is the key mathematicians were bundled together with numerologists and other such charlatans Small wonder that the great mathematical achievements of earlier researchers like Archimedes were no longer being actively pursued or extended The research agenda of Archimedes and the great works of synthesis such as Euclid s could scarcely be expected to flourish in such a climate of opinion Contemporaneous with this shift of opinion was a rising tide of militancy in Christianity which in particular saw the destruction of the Alexandrian Serapeion and ...