To begin with, let's turn back to the ecliptic, which I mentioned in the previous chapter as marking out the apparent yearly path of the Sun against the starry background of the celestial sphere.
To make it easier to consider that background, those stars which can be seen from the north temperate zone have been grouped into patterns called "constellations" by the ancient stargazers. The constellations we now recognize are essentially those used by ancient Greek astronomers.
The constellations do not have real existence, of course, for the stars that make them up have no interconnection, by and large, but are strewn helter-skelter over the surrounding hundreds of light-years. The configurations happen to be what they are only because we are looking at the sky from a certain place and, since the stars (including our own Sun) are all moving at a certain time. Shift our position a thousand light-years in space or a million years in time and the sky would be unrecognizable. The Greek astronomers, however, assumed the constellations to have real existence--made up of eternally fixed points of light attached to a solid firmament. Modern astrologers, who retain a distorted-Greek astronomy, act as thought they believe the same (and maybe some really do).
The path of the ecliptic passes through twelve of these constellations, so that the Sun remains in each for roughly a month. In fact, the division was probably deliberately set at twelve for this purpose since the month was the chief unit of time in the lunar calendars used by the ancient Bablylonian and Greek stargazers.
This means that the Moon makes one circle of the sky while the Sun passes through a single one of these constellations. (This is only approximately true, but close enough to satisfy primitive astronomers and modern astrologers.) Besides 12 is an easy number to divide evenly by 2, 3, 4, and 6--an important consideration for those without an efficient system of number symbols, such as the ancient Babylonians and Greeks.
The names of the twelve constellations are in Latin even today but all have common English translations. In the order in which the Sun passes through them they are: (1) Aries, the Ram; (2) Taurus, the Bull; (3) Gemini, the Twins; (4) Cancer, the Crab; (5) Leo, the Lion; (6) Virgo, the Virgin; (7) Libra, the Scales; (8) Scorpio, the Scorpion; (9) Sagittarius, the Archer; (10) Capricornus, the Goat; (11) Aquarius, the Water Carrier; and (12) Pisces, the Fishes.
Because seven of the twelve constellations are imagined in the figures of animals (eleven if you count human beings as animals, leaving only Libra as inanimate), they are referred to, all together, as the "zodiac," from Greek words meaning "circle of animals."
The star configurations don't really resemble the objects they are named for. It took a most lively and metaphoric imagination to see them, but I suppose the less sophisticated Greeks thought that pictures of rams and bulls, and perhaps even the real things, existed in the sky. It may be that modern astrological devotees thinks so, too, assuming they think at all.
The ancients, in constructing the constellations, made no attempt to have them take up fixed and equal fractions of the celestial sphere. They grouped them into what seemed natural star-combinations so that some constellations are large and sprawling and others are quite compact. Virgo, for instance, covers much more space in the sky than Aries does.
What's more, the Sun, in making its way along the zodiac, crosses some constellations along a wide diagonal, others along a relatively narrow corner. The Sun, therefore, does not remain equal times in each constellation.
Modern astronomers have fixed the boundaries of the constellations on the celestial sphere (including those constellations near the South Celestial Pole which were only observed by Europeans in modern times), following as best they could the groupings as described by the ancients. These boundaries, convenient as reference points in astronomy, are now universally adopted by astronomers, and if we follow those we can work out how long the Sun remains within each constellation of the zodiac. (see Table 1).
Table 1
Passage of Sun Constellation (days) ___________________________________ Aries 22 Taurus 35 Gemini 26 Cancer 21 Leo 38 Virgo 47 LIbra 25 Scorpio 24* Sagittarius 34 Capricorn 30 Aquarius 24 Pisces 39 * For 18 of these days it is actually in Ophiuchus
As you see, the Sun is in Virgo for almost seven weeks, while it is in Cancer for only three weeks. Scorpio is the queerest case. In the interval between Libra and Sagittarius, the Sun is in Scorpio for only six days! For eighteen days thereafter, if we go by the established boundaries of the constellations, the Sun is in Ophiuchus, the Serpent Bearer, which is not considered a constellation of the zodiac at all by the astrologers.
None of this fine detail of constellation inequality is, of course, given any attention whatever by astrologers. It may be that to do so would place undue strain on their mathematical resources. Less cynically, it might be reasoned that astronomical boundaries of the constellations are merely man-made and need not be given credence. This is true, of course, but so also are the constellations themselves purely man-made, as is the convention that divides the ecliptic into twelve parts, rather than ten or one hundred.
In any case, astrologers make it easier for themselves by pretending that the constellations are equal in width and that the Sun remains an equal number of days in each. That simplifies the mathematics and reduces the strain on the astrologer.
In order to account for the fact that when astrologer speak of the "Sun in Aries," it may really not be in Aries, as might be pointed out by some mocking astronomer, there is an astrological convention that wipes out the constellations altogether. The astrologers speak of the signs of the zodiac. These signs have the same names as the constellations but have no connection with them. The twelve signs of the zodiac are all equal in size and the Sun remains an equal length of time in each. It then doesn't matter whether the Sun is in the constellation of Aries or not; the astrologer says it is in the sign of Aries.
That accounts for the fact that people of every degree of ignorance and mis-education go around eagerly asking each other, "What's your sign?" and receiving as an answer the name of a constellation.
In this way, on the basis of the imaginary constellations, then, astrologers have built up a still more imaginary system of signs with which to impress fools and out of which to make a buck.
The ecliptic itself remains nearly fixed over the eons since it is a reflection of the plane of revolution of the Earth about the Sun and this doesn't change much. (The Greeks, of course, believed the Sun really moved along the ecliptic and I wouldn't be surprised if some astrologers believed that, too.)
The position of the Sun affects the seasons and the lengths of day and night, in accordance with the relationship of the ecliptic to the Celestial Equator, and the position of the Celestial Equator shifts with the precession of the equinoxes (which I discussed in the previous chapter).
The points where the Celestial Equator crosses the ecliptic are the equinoxes ("equal nights," because at that time, day and night are equal in length.) The Sun is at one of those points on March 20 and at the other, six months later, on September 23.
If we concentrate on those equinoxes, we find that their positions relative to the stars slowly shift as the Earth's axis wobbles (hence "precession of the equinoxes"). In a period of 785 years the equinoxes move completely around the ecliptic, moving from east to west in the direction opposite to that in which the Sun moves along the ecliptic.
The length of time during which either equinox remains within a particular constellation of the zodiac depends upon the width of that constellation along the line of the ecliptic and is easily calculated (see Table 2).
Table 2 Passage of equinox Constellation (years) ____________________________________________ Aries 1,550 Taurus 2,469 Gemini 1,840 Cancer 1,480 Leo 2,680 Virgo 3,329 LIbra 1,760 Scorpio 1,700* Sagittarius 2,400 Capricorn 2,125 Aquarius 1,700 Pisces 2,760 *For 1,225 years of this period, the equinox is actually in Ophiuchus.
Of course, if we want to even out the widths of the constellations, we can say that an equinox remains within any given constellation of the zodiac for 2,148 years.
Let's consider the equinox that comes on March 20. This is usually referred to as the "vernal equinox" because it marks the beginning of spring by the conventions of the north temperate zone. (It marks the beginning of autumn in the south temperate zone, but we northerners have them southerners outnumbered.)
At the present moment, when the Sun marks the vernal equinox by crossing the Celestial Equator on its way northward, it is in the constellation Pisces, somewhat west of the center. Each successive vernal equinox, the point of crossing moves to 0.014 degrees (or 0.84 minutes of arc) farther west. Eventually, some time in the future, it will slip into Aquarius; and if we look backward into the past, it was once in Aries.
In fact, if we accept the now-conventional boundaries of the constellation, the point of the vernal equinox was located exactly at the western boundary of Aries at about 100 B.C. and had been in Aries, progressively farther eastward, for fifteen hundred years previously during all the time that astrological speculations had developed and grown more sophisticated in Babylonia and Greece. Since the vernal equinox is one logical place at which to begin the year (though we Westerners now use another), it became customary to start the list of constellations of the zodiac with Aries. Astrologers still do, though the excuse is now two thosand years out of date.
If we concentrate on the situation as it was in 100 B.C., we can say that the Sun entered Aries at the moment of the vernal equinox, passed eastward through Aries' full width, then went on through Taurus, Gemini, and so on.
Since the sun passes through Aries in twenty-two days, it remains in that constellation from March 20 to April 11, at which time it enters Taurus, where it remains for thirty-five days, and so on. Of course, if we even out the widths of the constellations and use the sign instead, the Sun enters the sign of Aries on March 20 and then stays in each sign for just one twelfth of a year, or not quite 30.5 days. In Table 3 you will find the day on which the Sun enters each constellation and each sign of the zodiac--in 100 B.C.