A knotted puzzle buried for a millennium

A Four-Cornered Hat, Wari (Huari) 文化, c. 500–900 C.E., camelid fiber, 17.8 X 18.4 厘米, 57.8 cm circumference, Bolivia or Peru (The Metropolitan Museum of Art)

博士之间的对话. Sarahh Scher and Dr. Steven Zucker