Fact #1. In temperate and tropical latitudes (south of the Arctic Circle, north of the Antarctic Circle), the sun rises in the east and sets in the west. On a flat horizon, sunrise will be due east and sunset due west twice a year, on the vernal equinox (near March 21) and the autumnal equinox (near September 21). The site of Dzibilchaltun in Yucatan is justifiably famous with tourists partly because of spectacular site alignments on equinox sunrise.
|Equinox sunrise, Dzibilchaltun|
|Equinox sunrise + 30, Dzibilchaltun near Merida|
|Serpent image created by the equinoctial afternoon sun|
Fact #2. The earth's spin axis is tilted 23.5 degrees from the plane of the ecliptic, the hypothetical plane that intersects both the earth and the sun. This tilt causes the seasons as days lengthen toward summer solstice (near June 21) and shorten toward winter solstice (near December 21).
|Visual representation of earth's tilted axis|
|Entryway, Temple of Karnak, Winter Solstice|
Fact #3. The earth's rotational axis slowly changes orientation, moving in a circle that requires about 25,770 years to complete. This phenomenon, called axial precession, is illustrated in the graphic below.
Because of the earth's rotation, the sky at night seems to wheel in a huge circle around the pole star. This time lapsed image captures the essence of apparent star motion, noted by ancient sky watchers around the globe.
|Stars in apparent rotation around the pole star|
|Precession Polar Star Chart|
These celestial phenomena gave rise to systems of cardinal directionality broadly similar to the one we use today. Biblical authors, for example, called their cardinal points zaphon, negev, kedem and yam, words derived largely from their Levantine geography.
|Biblical Cardinal Directions|
In the New World scribal tradition, east was also the direction of sunrise. See "The Defeat of Cabracan" phrases 4, 14 in Popol Vuh Electronic Library, Allen J. Christenson translator and editor, Provo, UT: Brigham Young University, 2007. See the blog article "Water Fight on the River - Round Ten" for a number of other indications the ancient Mesoamericans knew and used an astral-based system of cardinal directionality similar to our own.
The Aztec Calendar Stone served many purposes and illustrated many cosmological, chronological and geographic concepts among the ancient Nahuatl of central Mexico. Among other things, the Aztec Calendar Stone was a classic compass rose, dividing space into equal quadrants centered on the cardinal points we know today as north, south, east and west with ordinal points NE, SE, SW and NW.
We commissioned Mexican graphics artist Fernando Vazquez to create a compass rose based on the Aztec Calendar Stone with cardinal, ordinal and intermediate points indicated. We will use this graphic to help us keep everything straight as we wander through the Book of Mormon text examining all occurrences of the words "north," "south," "east," and "west" with variants.
|Aztec Calendar Stone, National Museum of Anthropology, Mexico City|
|Aztec Calendar Stone as Compass Rose|