The zodiac is widely known as a band of twelve celestial constellations. It also contains a mathematical model for cosmographic depiction, based on observations of the sun, moon, and visible planets as they traverse the celestial ecliptic. Here wee consider the zodiac as a timepiece or calendar; how this system of planets and constellations emerges from elementary geometric patterns; and how these patterns inform the symbols of the zodiac and frame our world view.
The ZodiacThe true origin of the zodiac is uncertain. Versions of a wheel composed of twelve celestial constellations have been found throughout the world in Egypt, India, Asia, Greece and Rome, the Americas, and Islam. But the zodiac as we know it, a circle of twelve distinct constellations divided equally into 30° sections, probably dates to the fifth century B.C.. 1 Independent of its function to interpret human behavior, the zodiac likely developed as a vehicle for measuring time, evolving over thousands of years from the practice of timing the sowing of crops and other agricultural events to the rising and setting of familiar star groups. The calendar that developed in fifth century B.C. Greece reflects the zodiac's band of 360°, approximating the number of earth rotations, or days, in the sun's yearly round. The zodiac's twelve 30° sections approximate the number of lunar cycles or months during the same period. The division of the zodiac at the equinoxes and tropics locates the sun's position in the celestial ecliptic at each of the four seasons. Even the days of the week invoke the zodiac's planetary deities [Gleadow 1969, 16-18; Mailly Nesle 1981, 22, 33]. 2 Definitions: "A Astrology" is from the Latin astrologia, from the Greek astrologia (from astron "the stars" + logia "versed in tales or stories") which means "knowledge of the stars, astronomy" or "telling of the stars." "A Astronomy" is from the Latin astronomia, from the Greek astronomia (from astron "the stars" + nomos "arranging") which means "star-arranging" [Lewis 1879, Liddell 1940, Simpson 1989.Astrology is based on the positions of the sun, moon, and planets relative to one another and to the twelve constellations through which they appear to travel. The signs and planets that comprise astrology's symbols are metaphors for archetypal states, spiritual states, psychological states, temporal cycles, and the composition of matter. In this article, we set aside questions of how or whether these planets and constellations influence human behavior, illuminate the past, or predict the future. Our purpose is to consider the traditional western zodiac as a timepiece or calendar, based on natural observations of the sun, moon, and visible planets against the background of constellations that comprise the ecliptic. How does the zodiac emerge from elementary geometric shapes and patterns and how do these patterns inform astrology's symbols? s x 106 RACHEL FLETCHER -The Geometry of the Zodiac
