History of science / 500 CE — 1499 CE
Knowledge in Motion
Translation, calculation and observation
Scholars translate, test and revise knowledge across languages and regions, developing methods and instruments.
Selected stories
Brahmagupta includes zero in arithmetic rules
The Brahmasphutasiddhanta gives rules for zero and signed numbers, treating zero as more than an empty positional marker.
Al-Khwarizmi organizes equation-solving into algebra
Al-Khwarizmi systematically explains linear and quadratic equations for practical needs such as inheritance, trade and measurement.
Al-Razi compares symptoms of smallpox and measles
Al-Razi's medical writings distinguish smallpox from measles through clinical comparison, turning experience into material for critical discussion.
Ibn al-Haytham connects light, vision and experiment
The Book of Optics combines geometry, visual inquiry and experiments, explaining sight through light entering the eye rather than rays emitted from it.
Shen Kuo compares the magnetic needle with geographical direction
Dream Pool Essays discusses a magnetic needle's deviation from geographical south alongside observations of landscapes and natural phenomena.
Su Song and collaborators unite sky observation, display and timekeeping
Su Song, Han Gonglian and collaborators built a water-driven astronomical clocktower linking observation, celestial display and time signals.
Maragha organizes observation and criticism of planetary models
Al-Tusi's observatory brought together instruments, observers and books while reworking planetary models within an Earth-centred framework.
A Maya codex tabulates Venus and eclipse cycles
The Dresden Maya Codex arranges calendrical, Venus and eclipse-related calculations in tables, preserving knowledge older than the surviving manuscript.