Inca Knot Numbers - Numberphile

Alex Bellos discusses how the Incans used knots in string (Quipu) to record numbers.
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Video by Brady Haran and Pete McPartlan

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[coenneedell]

One of my professors is the guy who did a lot of the work on deciphering the more linguistic khipus. The reason why we know they can't all be numerical is because the knots store more information than just number of twists in the knot. Some are left handed, some are right, some are dyed different colors, some use different materials, some use other knots than are needed for the numerical representations. The khipu as a writing system is poorly understood, but it's certain it was used as more than maths! It's fascinating.

[fsf]

I'm Peruvian and I didn't know how Quipus worked. Great video.

[sebastianzaczek]

"these are not numbers" "well actually, these are knot numbers"

[jellewijckmans]

The Inca's did have the wheel. This seems to be persistent myth that confused the fact that they didn't really use wheels in the same way we Europeans didn't because well they don't work well on steep mountains and in dense jungle but they did have them. We have multiple Inca toys that had wheels on them.

[sock]

Yay. I'm glad he pointed out that the reason they didn't use wheels was probably because of mountains and terrain, and not llamas.

Llamas can be made to pull a cart, and the Inca actually did know of wheels, but they were confined to very specific uses or to childrens toys.

[marcoskunrath]

so incas invented CSV; storing integers as strings.

[rubenlarochelle]

When he said "No number goes beyond six" I thought a base-6 system, so I tried to sum the numbers in base 6 but the answer wasn't correct, so I started wondering...
...It was base-10, simply.

[MarkRosa]

In the southwest Okinawan islands there as a very similar system of knotted ropes called barazan. They used knots to keep track of who had paid what taxes (to the Japanese overlords) and who owned what. There were all kinds of innovations like using bigger knots for 5s, and using a separate string for each unit of volume, with the biggest volumes being made from the thickest ropes. Some people even tried to fashion ropes into the shapes of the things they were counting, but there aren't too many examples of that. It is fascinating to see people separated by so much space come up with the same solutions to the same problems!

[sock]

Based on the historic and modern evidence I'm convinced some quipu contain written language. Probably in the form of a syllabary, instead of an alphabet.

[martinvillanueva]

What a great video. I'm from Peru (the capital of the Inca Empire was located in Cusco, Peru of course) and this is the first time someone shows me how to properly read a Quipu!.

[mathwithjanine]

such a cool system of numbers! the strings look so pretty!

[alexandrabenze-horscroft]

From what I learned, the Tawantinsuyu had about 19 million inhabitants at the time of invasion. Only a few decades later it was reduced to about 5 millions. This included most intellectual and scientific L337 and those required for the infrastructure of the empire, among them the khipu scolars. Practically another Alexandrian library burnt to the grounds, only 400 years ago.

[HollowRoll]

I've done the first three chapters of the book and loved it. There's a great balance of difficulty in each chapter, and really interesting history between problems.

[KafshakTashtak]

A quipu with 100 strings is like an excel sheet.

[N.I.R.A.T.I.A.S.]

It's fortunate these knot numbers didn't turn out to be INCAlculable.

I'll show myself out.

[Omnifarious]

The Inca were very weird in having developed a system for recording numbers without apprently having the ability to record language. Which, I suppose, is why people are thinking that maybe qipu's are also a writing system.

[UrThysis]

Fun fact (from a Peruvian) : Quechua is more than a single language, several dialects of Quechua are only spoken and understood in their respective areas but yes, they, for the most part, had a "standardized" language

[benjammin]

If they ever make a Numberphile film, I nominate Michael Sheen to play this dude. It's uncanny!

[JavierSalcedoC]

The Inka were such an amazing civilization, leading a whole continent. They mastered roads, mummification and astronomy. A few quechua words climbed up the language chain to become worldwide recognizable, such as jerky and coke

[masheroz]

And a key plot point in one of the Dirk Pitt novels.