The 19 year Metonic cycle is interesting. I think it is also the orbital period of the moons nodes (aka dragon head/tail or north node/south node or rahu/Ketu in Indian astronomy). I wonder if there is a connection.
Then you’d might find the axial cycle interesting, and this sculpture depicting it.
The plaza’s terrazzo floor is actually a celestial map that marks the time of the dam’s creation based on the 25,772-year axial precession of the earth.
Fascinating, I think Yukteswar Giri (teacher of Yogananda) tried to make a case that the Yuga cycles were tied to the axial precession. Somehow these cosmic manifestation have a parallel on what happens on earth, similar to how the earths rotation around the sun creates some regular periodic change (aka the 4 seasons)
The Metonic cycle likely is the connection. No matter where you are on earth, if you start tracking the years (from the repetition of the seasons) and months (from the lunar phases), you’ll noticed the location of the moon (and, hence, eclipses) repeats itself after 19 years (it’s “almost repeats”, but discovering that takes either over a lifetime of observations or fairly precise measurements and trust in them)
The plaza’s terrazzo floor is actually a celestial map that marks the time of the dam’s creation based on the 25,772-year axial precession of the earth.
https://medium.com/the-long-now-foundation/the-26-000-year-a...