Welcome to brain stuff from how stuff works, Hey, brain stuff lauring vogebam here. During the Bronze Age, the Inca built the largest pre Columbian empire in the Americas, extending along the west coast of South America from Bolivia to Chile. They not only thrived in the harsh climate and dry steep slopes of the High Andes, they also served up a master class in technical road building that would have
made the Romans quake in their sandals. Thanka created a twenty five thousand mile highway system that's about forty kilometers, complete with rope bridges across treacherous mountain chasms. They also engineered millions of acres of high altitude terraced farmland and constructed an earthquake proof citadel on top of a craggy mountain peak one point five miles that's two point four kilometers above sea level. They even figured out how to
freeze dry potatoes. But unlike the neighboring Maya and Aztecs, and the ancient Mesopotamians, Chinese, and Egyptians, the Inca never developed a system of writing. What they did have were kipou, or knotted lengths of cord made from lama or alpaco wool or cotton. They hung in rows like a curtain, from a thicker central rope, which was sometimes coiled up to resemble a string mop. These bundles were often color coded, although most surviving keepu are now our uniform camel color
and could contain just a few strings or hundreds. When the Spanish arrived and wiped out the entire Incas civilization,
they found keepu everywhere, but destroyed many of them. In the nineteen twenties, a science historian named Leland Locke, studying the keepu at the American Museum of Natural History in New York City, discovered the knots and the keepu represented numbers, and the bundles of textiles were most likely record keeping devices similar to advocacies, probably used to hold census data or to keep track of the contents of storehouses or
how many llamas were paid as tribute. He realized that the height of a knot and its position on its cord civilized units tens, hundreds, thousands, and so on, and the position of a string off the main rope could denote things like specific people or villages. But even after Locke cracked the code, he noticed that some of the keep who he studied seemed to be anomalies. He figured
these were used for ceremonial purposes. There are, however, anecdotal clues that entire narratives could be passed along through KEEPU. A one seventeenth century Spanish conquistador reported meeting an incoman on the road who carried keep that he said, told of all the deeds of the Spanish and Peru, good and bad. Keep you couriers reportedly ran all over the
Incan Empire, the cords looped over their shoulders. But finding living people now who can help researchers unravel the secret of the knots has proved very difficult, if not impossible, so keep Bleu research has made slow progress in the past century. Since the early nineteen nineties, Harvard anthropologist named Gary Urton has been working to decipher what, if anything, the keep boos that don't fit the normal mold of accounting devices might mean collecting a database of over nine
hundred CEBU. In the process, Burton has discovered that beyond the position and height of the knots, there are other factors to take into consideration when reading a keepu, the color of the string, the direction the knots are twisted,
and the type of knots used. Through cross referencing keepu in the Harvard collection with Spanish documents from the exact time and location in Peru where they originated, he has recently been able to prove that the direction the knots are tied in could denote which clans individuals belonged to. Another researcher named Sabine Highland at St. Andrew's University in Scotland has recently found that some keepu still exist within
villages in the Andes. The locals there have shared some new information about them, for instance, that the different materials used in the strings is significant, and their understanding is that the devices were used to tell stories of warfare. Highland also reports evidence of phonetic symbols in the strings. It could be for all their ingenuity, the Incas never learned to use symbolic written language, but it looks like they may have been just a little more creative with
their storytelling than any other major civilization to date. Today's episode was written by Jesselin Shields and produced by Tyler Clang. For more on this and lots of other historical topics. Visit our home planet, how stuff works dot com.