The human brain has 100 billion neurons, each neuron connected to 10 thousand other neurons. Sitting on your shoulders is the most complicated object in the known universe. Khipu on display at the Machu Picchu Museum, Cusco, Peru (photo by Pi3.124) The khipu (or quipu) is an ancient Incan device used for recordkeeping and communication. It comprised a complex system of knotted cords to encode and

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