2012 - Science Or Superstition?/GH/5
The precession of the equinoxes is the astronomical process that underlies the Mayan calendar - and all ancient systems of cyclical time.
Perhaps I should just say a word about what the precession of the equinoxes is. Precession fundamentally is an observation of the heavens and an observation that at certain seasons of the year - particular markers, the equinoxes and the solstices - that if you look at the background of stars behind the Sun, you'll find that that background is very slowly changing, and it's changing at the rate of one degree every 72 years.
The view of mainstream astronomers as to why this is happening is - they hypothesise, they have not proved - that there is a cyclical wobble on the axis of the Earth, rather like the wobble of a top that has been spinning fast but it's spin has begun to decay, and the poles of the top begin to make a great circle. And this is what they believe is happening with the earth.
Now because the Earth is the viewing platform from which we observe the stars, changes in orientation of that viewing platform will cause changes in the observed appearance of positions of the stars in the sky at particular times of the year. And because it's a circular wobble, the whole thing is a cycle that in fact unfolds over a vast span of time - 25,920 years - takes you back from the starting position of the "clock" back fully around the clock to the same position again, so that the constellation that is rising behind the Sun today in our time and for a period of 2,160 years - which we're just entering into the Age of Aquarius, when the constellation of Aquarius has the Sun, it will be 25,920 years before that constellation again rises behind the Sun [on the vernal equinox].