Dromo's Den

[Up] [Dromo's Den]

Hipparchus Biography

Hipparchus Image

HIPPARCHUS, (flourished between 161 and 126 B.C.). A Greek astronomer and mathematician. He was born in Nicæa, Bithynia, but his astronomical work was done on the island of Rhodes and possibly also in Alexandria. Of his personal history nothing is known. He was the founder of genuinely scientific astronomy and also of a part of that science which lies on the borderland of astronomy and geometry, viz., trigonometry. In this field he computed a table of chords which, although lost, is known to us through the works of Theon of Alexandria (q.v.), who wrote about 365 A.D. It is probable, too, that this is the Hipparchus who wrote on combinatory analysis, and that the Arabs were correct in attributing to him a knowledge of the quadratic equation. Certain it is that Ptolemy was indebted to him for much of the Almagest (q.v.). According to Fabricius, Hipparchus wrote nine separate works; but of these only the Commentaries on the Phœnomena of Aratus and Eudoxus has come down to us. The text of these Commentaries was edited by Manitius and published, with a German translation, at Leipzig in 1894. From the Almagest we learn that it was Hipparchus who first discovered the precession of the equinoxes, determined the place of the equinox among the stars, invented solar and lunar theories, invented the astrolabe (q.v.), determined longitude by means of lunar eclipses, and drew up a catalogue of 1080 stars, determining the longitude and latitude of each (this catalogue has been preserved in the Almagest). As Ptolemy was also an astronomer, there is some difficulty in allotting to each his meed of praise for the discoveries mentioned in the Almagest, which difficulty has given rise to some discussion. Consult: J. B. J. Delambre, Histoire de l'astronomie ancienne (Paris, 1817); Robert Grant, History of Physical Astronomy (London, 1852); Lewis, Historical Survey of the Astronomy of the Ancients (ib., 1862); Hugo Berger, Die geographischen Fragmente des Hipparch (Leipzig, 1870); Rudolf Wolf, Geschichte der Astronomie (Munich, 1877); Paul Tannery, Recherches sur l'histoire de l'astronomie ancienne (Paris, 1893).