Enrich Ancient China: fix duplicate title, correct temporal tags, add silk/iron/philosophy dates, key figures, Xia-Shang-Zhou Chronology Project

civilizations/ancient-china.md

@@ -1,35 +1,44 @@
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 # Ancient China
 
-# Ancient China
-
 ## Overview
-Ancient Chinese civilization developed along the Yellow and Yangtze rivers, producing enduring contributions to philosophy, governance, technology, and culture. This entry covers the period from the Shang dynasty through the Han dynasty (~1600 BCE – 220 CE). @t[1600 BCE..220]
+Ancient Chinese civilization developed along the Yellow and Yangtze rivers, producing enduring contributions to philosophy, governance, technology, and culture. This entry covers the period from the Shang dynasty through the Han dynasty (~1600 BCE – 220 CE). @t[~1600 BCE..220 CE]
 
 ## Key Facts
 - Region: East Asia, centered on the Yellow River and Yangtze River valleys
-- Period covered: ~1600 BCE – 220 CE @t[1600 BCE..220]
+- Period covered: ~1600 BCE – 220 CE @t[~1600 BCE..220 CE]
 - Major dynasties: Shang, Zhou, Qin, Han
 - Language: Old Chinese, Classical Chinese
 - Writing: Oracle bone script (~1200 BCE), evolving into seal script and clerical script @t[~1200 BCE]
 
 ## Major Dynasties
-- Shang (~1600–1046 BCE): First historically verified dynasty, oracle bones, bronze casting @t[1600 BCE..1046 BCE] [^1]
-- Zhou (~1046–256 BCE): Longest dynasty, Mandate of Heaven, Confucius, Laozi @t[1046 BCE..256 BCE]
+- Shang (~1600–1046 BCE): First historically verified dynasty, oracle bones, bronze casting @t[~1600 BCE..1046 BCE] [^1]
+- Zhou (~1046–256 BCE): Longest dynasty, Mandate of Heaven, Confucius, Laozi @t[1046 BCE..256 BCE] [^3]
 - Qin (221–206 BCE): First unified empire under Qin Shi Huang, Great Wall, standardization @t[221 BCE..206 BCE]
-- Han (206 BCE – 220 CE): Silk Road trade, paper invention, Confucian state ideology @t[206 BCE..220]
+- Han (206 BCE – 220 CE): Silk Road trade, paper invention, Confucian state ideology @t[206 BCE..220 CE]
 
 ## Achievements
 - Oracle bone script: Earliest Chinese writing ~1200 BCE @t[~1200 BCE]
-- Iron casting by ~500 BCE (centuries before the West) @t[~500 BCE]
-- Silk production and trade
+- Silk production: earliest archaeological evidence ~2700 BCE (Qianshanyang site, Zhejiang) @t[~2700 BCE] [^4]
+- Iron casting by ~500 BCE (centuries before the West) @t[~500 BCE] [^5]
 - Paper invented ~100 CE during the Han dynasty [^2]
-- Confucianism, Daoism, and Legalism as philosophical traditions
+- Confucianism, Daoism, and Legalism as philosophical traditions (Hundred Schools of Thought, ~770–221 BCE) @t[~770 BCE..221 BCE]
 - Great Wall construction begun under Qin Shi Huang ~221 BCE @t[~221 BCE]
 
+## Key Figures
+- Confucius (~551–479 BCE): Founder of Confucianism; active during the Spring and Autumn period @t[~551 BCE..479 BCE]
+- Laozi (~6th century BCE): Founder of Daoism; traditionally associated with the Zhou court @t[~600 BCE..500 BCE]
+- Qin Shi Huang (259–210 BCE): First emperor of a unified China @t[259 BCE..210 BCE]
+
+## Chronological Notes
+The Xia–Shang–Zhou Chronology Project (1996–2000, final report 2022) established absolute dates for early Chinese dynasties using radiocarbon dating and astronomical records, confirming Shang beginning at ~1600 BCE and Zhou at ~1046 BCE. [^3]
+
 ---
 [^1]: Keightley, D. *Sources of Shang History* (University of California Press, 1978)
 [^2]: Tsien, T. *Written on Bamboo and Silk* (University of Chicago Press, 2004)
+[^3]: Xia–Shang–Zhou Chronology Project, final report (2022); see also Shaughnessy, E. in *Cambridge History of Ancient China* (Cambridge University Press, 1999)
+[^4]: Good, I. et al. "New evidence for early silk in the Indus Valley" *Archaeometry* 51.3 (2009); World History Encyclopedia, "Silk" (worldhistory.org)
+[^5]: Wagner, D. *Iron and Steel in Ancient China* (Brill, 1993)
 ---
 
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