What’s in a Zodiac?
According to The Random House Dictionary of the English Language, 2nd unabridged edition, the Zodiac is:
“1. An imaginary belt of the heavens, extending about 8 degrees on each side of the ecliptic, within which are the apparent paths of the sun, moon, and principle planets. It contains twelve constellations and hence twelve divisions called signs of the zodiac. Each division, however, because of the precession of the equinoxes, now contains the constellation west of the one from which it took its name. “
This is not entirely true, as we will see. But this definition reflects not only the disinformation subtly used to discredit Astrology to the public, but also the bias of the western Ptolemaic astrology in vogue throughout the English speaking world. There are actually four Zodiacs used as systems of measuring the relative positions of planetary placement and movement, for which I’ve contrived the following schematic for reference:
The Sidereal Zodiac
The zodiac implied by the dictionary is the Fixed Zodiac, the Sidereal, or star circle. This is the zodiac used by Indian and Tibetan astrologers. This is by no means the “original” system used, as Cyril Fagan considered it, but it was definitely current with astrology’s early history (and thus astronomy’s as well). It is fixed by virtue of its Fiducial, or starting point. The Fiducial, by the way, is the differential among all zodiacs- or, to word it differently, something astrologers won’t agree about- where the 1st degree of Aries “is”.
Technically, though, a circle can’t really have a beginning or end, so this is why we have multiple systems, but I digress. The Sidereal Fiducial is dual, and consists of two fixed stars, Aldeberan and Antares, located at the mathematical center of the signs Taurus and Scorpio respectively. Thus, by subtracting 45 degrees from the position of Aldeberan along the ecliptic, you find the Fiducial in Aries and its opposite point in Libra.
From this point-0 Aries-the ecliptic is divided every 30 degrees into the signs of the zodiac. Since these fiducial stars hardly move, we call them fixed stars, and the Sidereal is thus called the fixed zodiac, or a zodiac with a fixed starting point. The reason the dictionary is incorrect is the fact that constellations are not of equal size. Therefore the reason the Sidereal zodiac is star based is not because it aligns with the constellations, but because it uses stars to calculate the fiducial. What has precessed is the equinoctial point, or the location along the equator which the Sun crosses on the spring equinox. This brings us to our next zodiac, the Tropical.
The Tropical Zodiac
This is the zodiac familiar to the English speaking world, which uses the equinoctial point as the Tropical Fiducial, subdividing the ecliptic into 30 degree segments or signs. The dictionary spoke of that which is known as the precession of the equinoxes, or the movement of the fiducial. This is why the Tropical is called the mutable zodiac.
Precession occurs because the Earth does not rotate straight on its axis, and its axial motion viewed over a suitable length of time, is unstable, in that it traces a circular path, similar to a spinning top. This causes the point at which the sun crosses the equator on the spring solstice to move approximately 1 degree every 72 years. One tradition in the west views the Sidereal sign this point falls in to demarcate a symbolic “age” lasting approximately 2,000 years (hence the present shift into the age of Aquarius). This relatively slow rate of precession is why the Tropical zodiac is called mutable.
The present difference between the fixed and mutable zodiacs is about 24 degrees, so its fairly easy to calculate that these two fiducials were very closely in alignment approximately 1,728 years ago – about 274 A.D. This is roughly contemporary with Ptolemy’s Almagest, the original sourcebook of astrological calculation, and technique of using the tropical fiducial used in the western world, although scholars vary in there dating of its origin (anywhere from 100-300 A.D.
In terms of the dictionary definition above, it is the Sidereal sign west of the Tropical equivalent that it now contains, not the constellation, because a Constellation is a pattern of fixed stars along the ecliptic, whereas a Zodiac Sign is a 30 degree segment of a circle.
The Constellational Zodiac
The fields of stars along the ecliptic date back into antiquity, but their use in Astrological measurement of the ancient period is difficult to prove. Technically speaking, they vary in size from Virgo spanning about 45 degrees, to Scorpio with a span of a mere 9 degrees. There are actually 13 constellations along the ecliptic, with Ophiuchus spanning 20 degrees between Scorpio and Sagittarius.
Actually, considering that the sun takes apparently 365.5 days to circle the earth, the constellational zodiac fills that span – a natural ellipse rather than a circle. These patterns act as a backdrop for planetary motion that can be visually experienced, rather than both the Sidereal and Tropical, which relegate only 30 degrees each for the “signs” they use.
As such, this is the zodiac referred to by astronomers as the zodiac. In Part Two of this article I’ll discuss why I think this idea is flawed in my opinion, but for the moment this would classify as an actual zodiac, rather than a symbolic zodiac that the other three systems use. But as a system of measurement, its uneven division of the ecliptic leaves much to be desired, even though the actuality of planets moving through constellations is somewhat romantic in conception.
The Draconic Zodiac
This is the black sheep of the zodiac family, having a having a historical significance that is difficult to trace, but it comes to use from India, where it was supposedly used in divination. It uses as its fiducial the Lunar north node, the point at which the path of the sun and the path of the moon intersect, subdividing into 30 degree segments from there.
This point is called in Latin Caput Draconus, or the Head of the Dragon, hence the name Draconic. It moves backwards through the Zodiac at a rate of about 1 degree every month and a half, so I’ve dubbed it the changing Zodiac to differentiate it from the slowly mutating Tropical one. Its quickly moving fiducial gives it very little connection to anything even remotely static in our experience, unlike the tropical which won’t change considerably in one lifetime, so it has a reputation of being untenable in use.
That of course is a subjective judgement that is not relevant to this article, nor reflective of my opinion, but I digress yet again. Popular use today considers the union of solar and lunar motion used as a fiducial to be indicative of spirituality, and this is probably its most effective use, but extensive research is the only way to know for sure.
So what’s in a Zodiac, anyway?
Answering that question has been the subject of this article, but I wanted to divide this issue into two parts so that the information and technicalities can be considered separate from my humble opinion. Nevertheless, a holistic point of view seems to be the wisest, and the relativity of all systems of measurement precludes any attempt to devise a hierarchy to fit them all into. Remember that all astrologers are measuring the same thing – the movement of planets and their relation to each other.