|Fig. 1 Axial Precession Calendar|
It is the only calendar I know of that begs the question "how did the Mayans and others of their time know of the Earth's axial precession?"
Not many living today know about the fact of the Earth being tilted, or that the tilt itself rotates in a manner that changes climate over very long periods of time, but in a very slow manner that does not cause catastrophes like Anthropogenic climate change does.
The gist of the natural climate change aspect of the phenomenon is essentially that the Northern and Southern hemispheres change weather patterns.
As the rotating tilt moves the Northern Hemisphere away from direct sunlight impact, and at the same time moves the Southern Hemisphere into more direct sunlight, the results are climate change.
The links upthread in this post link to previous discussions that have graphics to show how that happens.
About each 2,100 years one hemisphere warms up a bit as the other cools a bit.
It is like a natural sharing of the Sun's rays.
But on human timescales it is of no import to us, as it should be.
It could cause sea level changes, and other climate phenomenon that can bring on the need for different agricultural practices as the cycle takes place.
|Fig. 5 Sample CSV File Data|
The graphs at Fig. 2 and Fig. 4 have the same values, except that they take place some 25,960 years apart.
In other words, this is a recurring cycle where the data repeats itself (remember it is symbolic abstraction to illustrate a climate change science point; basic temperature data came from here and here).
The graph at Fig. 3 shows the midpoint of the cycle.
I took a screen shot (Fig. 5) of the CSV file that records data at each 30 degree location, matching the values in Fig. 1. (Note that degree 0 and degree 360 have identical values, as in all such cycles).
The Fig. 5 CSV file contains: 1) the degree of the axial tilt as it proceeds over time, 2) the year when it is at that degree, and 3) the northern (N 1-12) and southern (S 1-12) hemispheres' monthly mean average temperature as it changes over time (note that each Nn, Sn pair of values are for the same calendar month in two different hemispheres).
For example, as N1 is decreasing or increasing depending on which half of the the 25,960 yr. cycle it is in, S1 is doing the opposite.
The 25,960 year cycle beginning 10,948 B.C. and proceeding until 14,972 A.D. is quite a phenomenon.
The previous post in this series is here.