Quipu

Inca knotted-string recording system

2 episodes mention this

Episodes

#4418: Where Is the Internet Still Missing?

96% coverage, but 2.6 billion people are offline. Where are the truly dark spots on Earth?

Jul 21
#4060: How Many Boxes Fit in Your Bedroom?

Why your brain can't guess cubic meters — and how to train it in 10 tries.

Jul 2