Zu Chongzhi (Chinese: 祖沖之; 429–500), courtesy name Wenyuan (Chinese: 文遠), was a Chinese astronomer, inventor, mathematician, politician, and writer during the Liu Song and Southern Qi dynasties. He was most notable for calculating pi as between 3.1415926 and 3.1415927, a record in precision which would not be surpassed for nearly 900 years.
HistoryLayer draws the world as it was in any year from 123,000 BCE to
2026. Move the slider and the borders redraw for that year; the map
carries 23,890 events, 12,790 people, 837 wars and 13,183 cities, each
one readable in place. Signing in is optional and lets you keep what
you find.