Jābir b. Aflaḥ on the four-eclipses method for finding the lunar anomaly period
The four-eclipse method was used by pre-Ptolemaic astronomers, especially Hipparchus, for finding the lunar period in anomaly. It is described by Ptolemy in Almagest IV.2 where he adds new considerations to be fulfilled in order to obtain a correct period in anomaly. Jabir b. Aflab, who lived in ear...
| Autor: | |
|---|---|
| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2006 |
| País: | España |
| Institución: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/376925 |
| Acceso en línea: | http://hdl.handle.net/10261/376925 |
| Access Level: | acceso abierto |
| Palabra clave: | Greek astronomy Medieval astronomy Ibn Aflaḥ, Jābir Iṣlāḥ al-Majisṭī Ptolomy Almagest Hipparchus Lunar theory Lunar periods Lunar eclipses Astronomía griega Astronomía medieval Ibn Aflaḥ, Ŷābir Iṣlāḥ al-Maŷisṭī Ptolomeo Almagesto Hiparco Teoría lunar Fases lunares Eclipses lunares |
| Sumario: | The four-eclipse method was used by pre-Ptolemaic astronomers, especially Hipparchus, for finding the lunar period in anomaly. It is described by Ptolemy in Almagest IV.2 where he adds new considerations to be fulfilled in order to obtain a correct period in anomaly. Jabir b. Aflab, who lived in early twelfth-century al-Andalus, considers this method in his Islāh al-Majistī. In his opinion, Ptolemy did not understand the conditions stated by the ancients. Jābir b. Aflah provides a complete set of conditions that makes Ptolemy's additions to the method unnecessary. In any case, the method presented by Jābir b. Aflah is more coherent and elegant from a mathematical point of view that Ptolemy's. |
|---|