Al-Battani: The Astronomer Who Refined Celestial Measurements and Advanced Trigonometry

Abu Abdallah Mohammad ibn Jabir ibn Sinan al-Raqqi al-Harrani al-Sabi al-Battani (c. 858–929 AD), was one of the most influential Arab astronomers and mathematicians of the Islamic Golden Age. Al-Battani made significant contributions to various fields, particularly astronomy and mathematics.

Contributions to Astronomy

1. Refinement of Astronomical Measurements: Al-Battani made highly accurate measurements of the solar year, calculating it to be 365 days, 5 hours, 46 minutes, and 24 seconds, which is only off by 2 minutes and 22 seconds from the modern value. He also refined the measurement of the inclination of the Earth’s axis.
2. Determination of Eccentricity: He corrected Ptolemy’s findings by determining that the solar orbit is elliptical rather than circular. His observations of the moon and planets were also remarkably precise, leading to improvements in the calculation of orbits and the understanding of planetary motion.
3. Prediction of Eclipses: Al-Battani was one of the first to predict solar and lunar eclipses accurately. His calculations were used to improve the accuracy of astronomical tables, which remained in use for centuries.
4. Trigonometrical Advances: He introduced the use of sine, cosine, and tangent, as well as their respective laws, which later became fundamental tools in astronomy.

Contributions to Mathematics

1. Trigonometric Tables: He produced highly accurate trigonometric tables that were used for centuries. These tables contained values for sine and tangent functions, which were essential for astronomical calculations.
2. Introduction of the Cotangent: He introduced the concept of the cotangent, and his trigonometric relationships were later used by European mathematicians, helping to advance the field in the West.
3. Influence on European Mathematics: Al-Battani’s mathematical works were translated into Latin in the 12th century and played a crucial role in the development of mathematics during the European Renaissance. His work was referenced by notable figures such as Copernicus, Regiomontanus, and Tycho Brahe.

Legacy

Al-Battani’s influence extended beyond his own time and region. His work was foundational for future European scientists who would later build on his ideas. His precise calculations and methods helped bridge the gap between ancient Greek astronomy and the later developments of the Renaissance.

Thanks to Ihjaz Mohamed for the story!