Quipu

The ancient incas used quipus (pronounced "key-poos"), memory banks made of strings and knots, for storing numbers. Until recently, the oldest-known quipus dated from about A.D.650. However, in 2005, a quipu from the Peruvian coast city of Caral was dated about 5,000 years ago. The incas of south America had a complex civilization with common state religion and a common language. Although they did not have writing, they kept extensive records encoded by logical numerical system on quipus, which varied in complexity from the three to around three thousand cords. Unfortunately, when the Spanish came to South America, they saw the strange quipus and thought they were works of the Devil. The Spanish destroyed thousands of them in the name of God, and today only 600 quipus remain. Knots types and positions, cord directions, cord levels, and color and spacing represent numbers mapped to real-world objects. Different knot groups were used for different powers of 10. The knots were probably used to record human and material resources and calendar information. The quipus may have contained more information such as construction plans, dance patterns, and even aspects of inca history. The quipu is significant because it dispels the notion that mathematics flourishes only after a civilization has developed writing; however, societies can reach advanced states without ever having developed written records. Interesting, today there are computer systems whose file managers are called quipus, in honor of this very useful ancient device. One sinister application of the quipusby the incas was as a death calculator. Yearly quotas of adults and children were ritually slaughter, and this enterprise was planned using a quipu. Some quipus represented the empire, the cords referred to roads and the knots to sacrificial victims.