WINTER SOLSTICE ALSO MEASURED AT CHICHEN ITZA PYRAMID

From American Egypt, Ancient Cities of the Maya

(December 22 is winter solstice in the Western Hemisphere. The Mayans constructed their pyramid at Chichen Itza to mark the different stages of the sun. Below is a narrative of one of the modern Seven Wonders of the world.)  

The Mayans succeeded in an almost impossible mission with the completion of their structures at Chichen Itza. A poetic combination of form, style, function, religion, philosophy, mathematics and geometry. A true symbiosis of all of their intelligence and art in one location, to be studied and admired by all that visit. 

By far the most impressive aspect of the Pyramid of Kukulcan is it's relationship with the sun and how it reflects the equinoxes and solstices of our solar year with stunning accuracy. Before one can fully understand the workings of the Shadow of the Equinox, a few basics on astronomy need to be reviewed.
An equinox occurs twice each year when our sun, in its orbit around the earth in a fashion unique to these times of the year, passes directly over the Earth's equator and the length of the daylight and evening hours is equal. Hence the word equinox is derived from the Latin for "equal" aequus, and nox meaning "night". 

The spring equinox occurs on March 21. Six months later, on Sept 22, we have the Fall Equinox. The summer solstice occurs on June 21st. On this day earth sees the longest duration of daylight. Six months later is the winter solstice on December 22, when we see the shortest daylight and the longest night of the year. 

On these days the sun almost seems to pause in its orbit before resuming its course, and it is why the word solstice is based on the Latin sol, for "sun", and sistere or "to cause to stand". This cycle then repeats itself as the Earth continues to rotate around the sun. 

It is interesting to note that there are exactly 91 days between each of these events, and 92 days between the June 21 summer solstice and the September 21 equinox. This adds up to a 365 day solar year with the 91 days between each event matching the 91 steps to each side of the pyramid.
Each of these solar events, the two solstices and the two equinoxes, can be measured and predicted using the patterns of light and shadow that fall on El Castillo at various times of the year. 

It is believed that the Mayans used the various shadows and designs formed by the Pyramid to signal the beginning of a harvest or of a planting, to predict the best dates to be married or to be buried, and for other various ceremonial reasons. 

The cycles of the sun also play out to another Mayan tradition of the number 52. To us, it is a coincidence that this is the number of weeks in our standard year. But to the Maya it represented, in years, the time of one "cycle".