Farīd al-Dīn Abu al-Ḥasan ‘Alī b. al-Fahhād’s astronomical tradition as represented in the prolegomenon to his Alā’ī zīj (1172 AD) shows his experimental examination of the theories of his predecessors and testing the circumstances of the synodic phenomena as derived from the theories developed in the classical period of medieval Middle Eastern astronomy against his own observations. This work was highly influential in late Islamic astronomy and was translated into Greek in the 1290s. He evaluated al-Battānī’s Ṣābi’ zīj (d. 929 AD) and al-Khāzinī’s Sanjarī zīj (fl. 1115 AD) with regard to the conjunction between Jupiter and Saturn in 1166 AD and found the errors of, respectively, about 35 and 10 days in the times predicted, which are verified by a recalculation on the basis of these works and modern theories. His inspection of the four solar theories established by his Islamic predecessors with respect to the quantitative differences between their predicted times for the occurrence of the vernal equinoxes is also correct. His calculation of the parameters of the solar and lunar eclipses in April 1176 has the errors of up to 1 h in the time and one digit in the magnitude. A general result of this study is that solely the evaluation of the synodic phenomena could mislead the judgment about the reliability and worthiness of the contemporary theories.

中文翻译：

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伊本法哈德与公元 1166 年的大合流

Farīd al-Dīn Abu al-Ḥasan 'Alī b. 法哈德的天文学传统体现在他的 Alā'ī zīj（公元 1172 年）的序言中，展示了他对前辈理论的实验检验，并检验源自中世纪古典时期发展的理论的会合现象的情况中东天文学反对他自己的观察。这项工作在晚期伊斯兰天文学中具有很高的影响力，并在 1290 年代被翻译成希腊语。他评估了 al-Battānī 的 Ṣābi' zīj（公元 929 年）和 al-Khāzinī 的 Sanjarī zīj（公元 1115 年）关于木星和土星在公元 1166 年的合相，发现分别为约 35 和 10在这些作品和现代理论的基础上，通过重新计算来验证所预测的时代的天数。他对他的伊斯兰前辈所建立的四种太阳理论的考察，关于他们预测的春分发生时间之间的数量差异也是正确的。他对 1176 年 4 月日食和月食参数的计算，时间误差高达 1 小时，量级误差高达一位数。本研究的一个普遍结果是，仅仅对会合现象的评估可能会误导对当代理论的可靠性和价值的判断。他对 1176 年 4 月日食和月食参数的计算，时间误差高达 1 小时，量级误差高达一位数。本研究的一个普遍结果是，仅仅对会合现象的评估可能会误导对当代理论的可靠性和价值的判断。他对 1176 年 4 月日食和月食参数的计算，时间误差高达 1 小时，量级误差高达一位数。本研究的一个普遍结果是，仅仅对会合现象的评估可能会误导对当代理论的可靠性和价值的判断。