It’s the return of Monday Morning Math, a post that goes up each Monday(ish) morning(ish) during the semester with a mathematical tidbit.
Today’s topic is quipu. Here’s a picture of one from the Museo Machu Picchu, Casa Concha, Cusco in Peru .
Quipu (also written as khipu) were used by the Inca people are a way of recording information, like a ledger, that could then be carried or stored. Numbers could be represented with different knots using a Base 10 system (so 2 3 2 would be 232). Meanings could also be represented by different colored cords, and by having substrings off of strings. There could be hundreds of strings on a single quipu.
While relatively few quipu survived, there are examples that are about a thousand years old (!). I first read about them in the book Code of the quipu: a study in media, mathematics, and culture by Marcia Ascher and Robert Ascher but my impression is that in the past few decades there has been a lot more research: (The Khipu Field Guide, for example, appears to have a lot of information.) Wikipedia also has an extensive list of sources.
Bonus Monday Morning Math to make up for not starting last Monday as originally planned! During Hispanic Heritage Month (from September 15 to October 15) the website Lathism.org features a new mathematician each day! Today’s mathematician is Ramón Emilio (Emilio) Fernández, a mathematician at Pace University in New York City who earned a PhD in Engineering Education, Management, and Policy with doctoral thesis in Mathematics Education.
Happy mathing!
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