Astronomers help choose Baghdad's foundation date

Aryabhata's parameters are reckoned for mean noon at Ujjain on 21 March 499, giving his mathematical astronomy a precise temporal starting point.

Aryabhata used sine tables and algorithms to calculate celestial motion, helping establish a powerful Indian computational tradition.

His verse describes a rule yielding 3.1416, demonstrating sophisticated numerical work expressed through Sanskrit mnemonic poetry.

Aryabhata's notation encoded numbers through syllables, showing that mathematical representation can take forms other than modern written numerals.

The new Abbasid capital was founded on 30 July 762 and became a major center for scholarship, administration and translation.

The city's multilingual scholarly environment later supported translations and original work in arithmetic, algebra, geometry and astronomy.

Baghdad's planned circular form joined surveying, geometry, architecture and imperial symbolism in a major urban project.

Al-Azhar opened in Fatimid Cairo and developed into a long-lived institution of learning.

Alongside religious and linguistic studies, scholars taught inheritance arithmetic, astronomy, timekeeping and related mathematical subjects.

Al-Azhar shows how mathematics was transmitted through teaching communities rather than only through famous books and individuals.