Siddhānta-Śikhara: Great Minds, Big Questions
Meet the minds at the peak of the tradition, from Brahmagupta and Bhāskarācārya to the observers of Kerala, and the big questions they faced: the shape of the Earth, the slow drift of the sky, and how Indian astronomy travelled to Baghdad, China and Southeast Asia, and what it took in return.
Lessons in this chapter
- Brahmagupta-Kṛti: Brāhma-sphuṭa-siddhānta - Algebra Meets Astronomy — The 628 CE book that tested old numbers against the sky, and built algebra to do it
- Bhū-Gola: The Round Earth That Rests on Nothing — Siddhānta cosmology, Mount Meru, and how the astronomers reconciled them
- Bhāskara-Kṛti: Siddhānta Śiromaṇi - The Crown Jewel — Bhāskara's 1150 CE masterwork, and his rule that every number in the sky must come with its proof
- Ayana-Calana: Precession and the Drifting Saṅkrānti — Why Makar Saṅkrānti falls around 14 January, three weeks after the solstice
- Kerala-Paramparā: The Observers of Kerala — Parameśvara to Jyeṣṭhadeva, the school that tested the tables against the sky
- Sūrya-Siddhānta: The Text That Travelled — The Sanskrit astronomy text whose numbers still set the New Year in Myanmar, and whose family still runs calendars across Southeast Asia
- Ādāna-Pradāna: What Came In, What Went Out — The twelve signs came in from the Greek world; Indian tables went out to Baghdad and to the Tang court in China