Distinctive spiral grooves carved on ritual jade rings buried in tombs dating from China’s Spring and Autumn period (771–475 BC) follow a precise mathematical form described by the spiral of Archimedes, 300 years before he lived. I show how precisely drafting these spirals required a precision compound machine in 550 BC, preceding all other machines known to interconvert exactly linear and rotational motion by half a millennium. I also propose a basic mechanical design relying only upon technologies known to have existed at that time.
- Peter J. Lu, “Early Precision Compound Machine from Ancient China” Science. 304, 1638 (2004). [pdf] [Supp. Info]
Print Media Coverage
- “2500 Jahre alte Maschine aus China” Abenteuer Archaologie [Germany] (2004).
- “Anello cinese rivoluziona la storia della tecnologia” Corriere Della Sera [Italy] (2004).
- “Ancient Chinese technical tango” Harvard Gazette (2004).
- “Spirales chinoises” La Recherche [France] (2004).
- “Complex machine carved ancient rings” Nature (2004).
- “Spiral ring reveals ancient complex machines” New Scientist (2004).
- “First Compound Machine Found In China” Popular Mechanics (2004).
- “Uralte Feinmechanik” Bild der Wissenschaft [Germany] (2004).