Summary

Yin and Yang correspond to the binary system (base-2), the Three Harmonies to the ternary system (base-3), the Five Elements to the quinary system (base-5), the Ten Heavenly Stems to the decimal system (base-10), and the Twelve Earthly Branches to the duodecimal system (base-12). The Four Pillars of Destiny (Saju) and Tojeong Bigyeol are based on the sexagesimal system (base-60), 60 of which is the least common multiple of these numeral systems. Our ancestors believed that this system determined fortune and misfortune: they form a cycle that repeats every 60 years, as per the Saju and Tojeong Bigyeol being of base-60. Of course, more complex systems were also used, but as they are unnecessarily complex, they will not be discussed here.

Implication

Our ancestors practiced numerically predicting fortune and misfortune, similar to biorhythms. This, too, can be understood through the least common multiple to determine its cyclical pattern.

Underlying context – Background behind

Having knowledge of the Earthly Branches, Heavenly Stems, Yin and Yang, the Five Elements, and so on can be helpful, but it is not necessary.

Notions – Key ideas

No notions will be described as a deep knowledge of the notions is not necessary to get the central claim.

Index – Source(s)

How to Think Like Mathematicians / 피타고라스 생각 수업
14 The Secrets of the 60 Ganji | Numeral Systems / 60갑자의 비밀 | 진법

Trajectory – Where I’m headed now

None