Jabir ibn Aflah

. Abu Muhammad Jabir ibn al - Aflah Ischbili (Arabic أبي محمد جابر بن أفلح الإشبيلي, DMG Abū Muḥmmad Ǧābir b Aflah al - Išbīlī, for other transcriptions also Gabir ben Jabir ibn Aflah and Aflah al - Ishbili; * in 1100 in Seville, † 1160 ), also donor Hispalensis latinized, was a Spanish- Arab astronomer and mathematician who was into Latin known to European scholars through the translations of his works and therefore played an important role in the development of mathematics in Europe. Although other Muslim mathematicians, such as the Persians did Abu al - Wafa, significant mathematical progress, her writings were not translated into Latin and remained the then Western scholars, therefore, unknown.

Little is known about the life of Jabir ibn Aflahs. From his name suffix al - Ischbili ( " Seville " ) in different sources, and a mention of Maimonides ( Arabic name Abu ' Imran Musa ibn Maymun ibn' Ubayd Allah ) can be closed to his birthplace. The Jewish philosopher, lawyer and physician Maimonides was born in Cordoba in 1135 and admits to have met ibn Aflahs son. From this, the approximate life data can be derived.

Jabir ibn Aflah described two astronomical instruments, which can be regarded as a precursor of Torquetums. In spherical trigonometry, a mathematical theorem named after him.

Dschabirs criticisms of Ptolemy's Almagest were known throughout Europe. In his well- known work, Islah al - Madschisti / إصلاح المجسطي / Islah al - maǧisṭī /, correction of the Almagest ', emerges including his famous refutation of Ptolemy. Jabir was able to show that Venus and Mars but may also stand the sun, and not only below this, as Ptolemy's model was. Sure Jabir ibn Aflah was influenced by other Arab authors in writing this work, although the extent and thus the degree of its originality, is no longer traceable. There are similarities to the works of Abu l - Wafa ibn Thabit and Qurra.

Another influence was the work of Jabir ibn Aflah both western and eastern scholars. To integrate Among other things, the Persian astronomer, Qutb al-Din al- Shirazi, a pupil of Nasir al-Din al - Tusi, the Spanish- Arab philosopher Ibn Rushd, known as Averroes, who was born in 1126 in Cordoba, Islamic traditions and Greek thought was looking for. Furthermore, Levi ben Gerson ( Gersonides also ) and Regiomontanus were detectable influence. The latter copied large parts of Ibn Aflahs work in the fourth book of his De triangulis, but concealed his source.