Knot Language: Recreating Inca Quipu/Khipu

or... How Would You Communicate with Knots in Rope?

Dates: January 22–26, 2007
10am–noon: Lectures
noon–2pm: Lunch & group discussion
2pm onward: Student group work
Location: Room 32-G575, MIT Stata Center.
Credit: 3 units pass/fail for MIT students

MIT 6.096, IAP 2007

[Khipu Research Group] • [Class announcement poster]
The mystery:
The Inca Empire (1438–1533) had its own spoken language, Quechua, which is still spoken by about a third of the Peruvian population. It is believed that the only “written” language of the Inca empire is a system of different knots tied in ropes attached to a longer cord. This system is called quipu or khipu. The ropes also have different colors, which may have encoded information. There is evidence from the Spanish crusades that quipus encoded census data as well as stories. However, no one knows how to decode either kind of information. There are several hundred quipus in the world today, waiting to be read.
The challenge:
Our research group is trying to break the quipu code. But before we can test a hypothesis about how the quipu code might work, we need to come up with some hypotheses. How could the Incas have recorded language with knots on rope? To gain insight into this question, this class will explore how you would record language with knots in rope.
The task:
Students will divide into groups. Each group will develop their own way of “writing with rope”—developing a written language like quipu. The method can use all or only some of what we know about actual quipu (e.g., the different types of knots used). These languages will be interesting in their own right, but they may also shed light into plausible approaches taken by the Incas. Each group will also work on breaking the code developed by another group. This will give us experience in recognizing different types of codes, and ultimately in decoding actual quipu. We will also provide real quipu data from the Urton-Brezine database at Harvard for the ambitious code breaker to work on.
The goal:
We are hopeful that exploring different approaches to recording language with knots will lead to insights into solving the mystery of the quipu. This class has led to formation of the Khipu Research Group.
Gary Urton Heather Lechtman Jean-Jacques Quisquater Erik Demaine Martin Demaine
The class will feature lectures by some of the leading researchers in quipu, describing current knowledge, conjectures, and approaches:
  • Gary Urton archaeology Harvard
  • Heather Lechtman archaeology and ancient technology MIT
  • Jean-Jacques Quisquater electrical engineering Catholic U. Louvain, Belgium Slides in PDF
  • Erik Demaine computer science MIT
  • Martin Demaine computer science MIT
    The class will be held during Monday–Friday, January 22–26, 2007, according to the following schedule:

    10am–noon: Lecture
    (1–2 hours)
    noon–2pm: Free lunch and
    group discussion
    (1–2 hours)
    2pm onward: Student group work
    (design and/or
    Mon., Jan. 22: Class overview, introduction to quipu
    Design groups form and start
    Tues., Jan. 23: History of quipu and its significance
    Design groups continue
    Wed., Jan. 24: Gary Urton lecture
    Introduction to cryptanalysis
    Design groups present some challenges
    Decoding groups begin
    Design groups continue
    Thur., Jan. 25: More on cryptanalysis
    Design groups present more challenges
    Decoding groups continue
    Fri., Jan. 26: Student presentations of decrypting progress
    Student presentations of encodings
    Conclusion and follow-on

    Each day will have 1–2 hours of lectures, and 1–2 hours of group discussion over a free lunch. The remaining time each day will be for students to work in groups, either designing new encodings or decoding puzzles posed by other groups. The last day will be devoted to student presentations of their techniques and results.

    All lectures and group discussions will be held in or around room 32-G575 in the MIT Stata Center. Students can work in this room anytime they wish during the week, although it is easiest to get in during working hours (9am–5pm).
    Erik Demaine, Martin Demaine, and Jean-Jacques Quisquater
    To sign up or find out more information:
    Send email to quipu AT Everyone is welcome (including non-MIT students). MIT students should also register on WebSIS.
    Web Sites Web Articles
    Erik Demaine (photographer) and Martin Demaine (in blue) hike around Machu Picchu, the spiritual center of the Incas. [March 2006]