An eclipse becomes a chronological fixed point

Historical Chinese records describe the Sun rising twice at Zheng. The date is reconstructed as 21 April 899 BCE; the negative year follows this database's BCE convention.

The observation shows how court astronomy combined counting, calendrical cycles and systematic recording long before modern mathematical astronomy.

NASA's reconstructed eclipse path allows historians to compare numerical models with the Bamboo Annals' account.

Accurate calendars mattered for ritual and government, showing that mathematical knowledge developed inside social institutions rather than through isolated individuals.

The Bur-Sagale eclipse was recorded in the Assyrian eponym lists. Its date, 15 June 763 BCE, anchors Near Eastern chronology.

Long sequences of observations enabled scholars to identify regularities in celestial events and refine numerical schemes.

The record shows that numerical astronomy and chronological calculation flourished in Mesopotamia centuries before classical Greek science.

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.