Aren't you sick of Feng Shui books and websites that talk about the Four Celestial Animals but don't have much more to offer on them except another set of pretty pictures, some poetry, or a fancy New Age way of explaining them?
Perhaps it is because the people who write the books care so little about Chinese culture and science that they cannot do more than offer you illustrations and bad poetry. Perhaps these authors can mumble something from Yijing, "Looking at the signs in the heavens, one thereby ascertains the changes of the seasons," but what do they mean, and what does it matter to the Four Celestial Animals?
Scholars know that the Chinese sky was, in some ways, a reflection of human society — but that idea occurred only with the rise of the Han. It's also true that Shang (Yin) chiefs hunted tigers, used the plastrons of river turtles (Bie) to communicate with their honored dead, and performed ceremonies to honor the Bird Star (Niao), who they believed was God's messenger. Yin chiefs also used water dragons (long) to symbolize the dark, watery Xia who ruled before them.
It is also fact that the astronomical traditions of Yao's time (c. 2300 BCE and found in Yaodian, part of the Book of Documents) were known to later astronomers, and that they were consulted — that's how Chinese worked out the concept of precession. The old myth about Gong Gong and Zhuan Xu getting into a brawl that knocked Earth off its seat is really a story about precession. After all, the tilt is what gives our planet its seasons. (The Chinese also thought it nicely explained why their rivers run to the east.)
A grave at Puyang (Henan) was built roughly 700 years before Yao's time. The northern part of the grave is round and the southern part is square. The northern part of the grave features two legbones and a pile of shells that indicate Beidou (what we call the Big Dipper). At the west of the dead man lies a fancy mosaic made of cowrie shells and it is shaped like a tiger. To the east of the six-foot-tall skeleton lies another mosaic of the same material and it is shaped like a dragon.
These Celestial Animals were mega-constellations that each ruled seven xiu ("lunar mansions," uneven sectors of the sky). Interestingly, xiu were also used by Indians and Arabs, so the system is incredibly old —which is probably why the oldest xiu names feature only one Chinese character! Both the xiu and the Four Celestial Animals date from at least the Neolithic, but more systematic xiu and celestial animals were refined over time. Gustav Schlegel thought the Four Celestial Animals originated roughly 16,000 years ago, and Julius Staal (with the aid of a planetarium) came up with the same figure, but nobody really knows for sure. What we do know is that kanyu shia (Feng Shui adepts) use compasses marked with xiu.
In Yao's time, Canglong or Green (Spring) Dragon consisted of seven eastern xiu. Canglong's "heart" was in xiu sector Xin (our alpha Scorpii, the southern "boundary" of the galaxy and crossroads of the ecliptic). Astronomers identified the heart as Huo, the Fire Star — our Antares and the astronomical emblem of the Yin dynasty — which was Ishara to the Babylonians, Selket-Serqet to the Egyptians, and the scorpion-tailed goddess of the Maya. When the Yin ruled, Huo appeared above the eastern horizon at dusk and indicated the arrival of spring.
People knew it was summer when Red Bird (Zhuque, the southern set of xiu sectors) was visible at night in the southeast. (Xiu sectors Liu, Xing, Zhang, and Yi indicate bird parts, but the Bird Star itself is mentioned on oracle bones and in Yaodian.) The heliacal rising of Sirius-Anubis along with Cancer in 2000 BCE heralded summer — and Sirius is identified in Chinese lore with Archer Yi's bow and arrow, the Celestial Dog, and the Celestial Jackal (part of the first sector of Red Bird). In Mesopotamia the bow and arrow were known as mul.ban and mulgag.si.sa (Sirius as the "arrow-star") — and the dog is the terrestrial, Feng Shui version of the tiger. It is also found in kabalistic schematizations of the directions, as the dog-headed sphinx of the west. Goddess Satit aims the Chinese version of the bow and arrow at the head of Sothis in Hathor's zodiac at Dendera.
Autumn began when the stars of White Tiger (Baihu) set heliacally with the sun in the west. (This constellation consisted of the set of western xiu, but Shen comprised the tiger's body and Zui defined its head.)
Bie the river turtle, also known as Spiritual Turtle or Linggui, was a sacred animal whose shell was used for plastromancy from at least the time of the Yin. (Fu Xi supposedly discovered the Luoshu on the "back" of river turtle Bie, which reminds us that there are two astronomical systems coded into that famous diagram.) Turtle plastrons also symbolized a suit of armor, which gave the turtle its name Black Warrior (Xuanwu). Winter arrived when the stars of Black Warrior rose in the northeast and set in the northwest. Only the xiu sectors Xu and Wei (in our Aquarius) were connected to this constellation. The snake twining around the Dark Warrior's body seems to be part of Canglong, because xiu sector Ji of the dragon contains a very ancient constellation, Bie (Corona Australis, near the end of Scorpio), exactly positioned to be entangled in her tail. Fu Xi and the great goddess Nu Gua are generally depicted with winding serpent bodies that suggest circular orbits intersecting at intervals. Yao and Gun passed through the Black Warrior as part of their transformation into three-legged turtles or dragons. It's easy to see why this great constellation is traditionally associated with divination, mystery, ritual cannibalism, and transformation.
The Four Celestial Animals and the xiu were probably in use all over Asia before the time of Yao. After all, Yao and Sargon of Akkad were contemporaries; the Pleiades were a landmark on everyone's calendar and used throughout Asia as a cardinal point. In 3102 BCE their heliacal rising indicated the equinox. In 1250 BC, at their heliacal setting, the Pleiades became the Hesperides, the evening harbingers of the day of the equinox. An equinoctial lunar festival of sacrificed rams was celebrated in Akkad and in China. Fire Star inagurated a fire festival. Other points honored the full moon or sun at the solstices.
The Mandate of Heaven — the xuangui or "dark scepter" that symbolized a clustering of all five naked-eye planets — was given to Yu, whose dancing pattern performed the Big Dipper, in the Dark Palace (Xuan Xu, in the longitude of xiu sector Yingshi, linked with alpha Pegasi) on February 26, 1953 BCE, a date that corroborates the Bamboo Annals. In the Songshu it says a "river diagram" of red and green "writing" was presented to Yu by the same "spirit" that announced the transfer of power for Shang and Zhou. Because of this astronomical portent the Xia supplanted the Miao. (In many ancient cultures, a calendar out of sync with precession created dire political and religious consequences — it portended the fall of dynasties and spiritual movements.)
The mandate passed to the Yin because of precessional shift, noticed in 1576 BCE when the xuangui appeared in Sagittarius. The scepter passed again to the Zhou in 1059 BCE, and for the occasion King Wen composed "Song of the Phoenix." In the Mandate of the Zhou, the "spirit" was the star that formed the "beak" of Red Bird due to precessional shift. Mozi said that Red Bird held the scepter in its beak and landed on Mt. Qi (that is, Red Bird's timing and azimuth of setting on the northwest horizon created this effect.)
As Above, So Below
The most basic premise of Huang-Lao philosophy is that heaven is round and the Earth is square. The Yin (Shang) thought that the earth was shaped like the character ya (which looks like a Greek cross, but the ya was laid out in the cardinal directions). An even older idea (from the Pleistocene, most likely) conceives heaven and earth together looking like a turtle, with its domed carapace covering the flat plastron. But for Huang-Lao adepts, the heaven-round, earth-square concept was based on astronomical observation.
The ideal circle of the round heavens is the celestial equator. Around its perimeter are two points where the ecliptic crosses it, in the northeast and southwest. These points indicate the spring and autumn equinoxes (coincidentally, spring and autumn were the only two seasons that the Yin recognized). Two points that indicate the solstices are found in the southeast and northwest, where the ecliptic and equator are farthest from each other. This gives us a total of four points, separated on our celestial circle by 90-degree arcs. If you connect these dots they form a square, and that square is the flat Earth, bounded by the four seasons. The four corner points are the "hooks" that form a square within the celestial circle. The Spiritual Turtle (sometimes a dragon, fish, or bird) was identified with the physical shape of the cosmos, and the ya-xing was based on this set of "hooks" in the northwest, southwest, southeast, and northeast.
The square Earth within the heavenly circle also appears on the shanzi jing or "mountain mirrors" of the Warring States period, which explained the limits of the Known World. Eventually these "hooks" were transferred to game boards called liubo (early Chinese chessbords show the Milky Way divided into two camps), and to Celtic brandubh boards. This is where we see the beginnings of "star chess" that is, what early Europeans called Celestial War, other board games, and playing cards (including Tarot).
Ancient Chinese expressed celestial measurements in degrees (du) and talked about celestial motion as left or right movements along the equator and ecliptic. (Traditionally there were 365.25 degrees —even on a compass.) Someone making measurements on Earth explained them in terms of the cardinal directions and linear units, which is what we know about Feng Shui.
The Chinese sky had been divided into twelve sectors to follow the movement of Jupiter, the Year Star, which was identified with the constellation Sheti. The astrological year, or "Xia sequence," begins with the month designated by the third Earthly Branch, sector yin, which is the month just after the spring equinox and indicates waxing yang and the Wood Element. In the Branches, yin contained the Dajiao star (alpha Bootes, the Court of the Celestial King). The beginning month of the year, the first month of spring, was identified with the handle of Beidou pointing in the direction of sector yin. Yin was also called Shetige, or "the starting point of Sheti" (it is, again, not a Chinese word). The beginning of the year resonated with the starting point of the Jupiter cycle.
And so sector Jiao, the New Year star, was the first of the xiu. All months and their correlates begin with sector yin. All eightfold correlates (winds and directional phenomena) begin with the northeast direction. So the celestial circle was divided by twelve (for celestial and calendrical measurements), and/or eight (for cardinal and intercardinal directions). The planes of the celestial circle were divided into five or nine segments. The "palaces" consisted of a circle surrounded by four wedges oriented to the cardinal directions. On earth this was expressed as a central square surrounded by squares or rectangles in the cardinal directions, the shape of the character ya. The Earth as ya-xing has five parts, and five was geographically meant as a depiction of two-dimensional space. (For three dimensions there are six divisions.)
All these divisions of six, five, and four date at least from the time of the Yin. And the division of Earth into five parts and the magical importance of the number five (the preeminent number of change in Yijing) led to the development of Five Element Theory. To some extent this explains why the Neijing Suwen — the premier Taoist text — says, "Heaven gives birth to the five phases and the three qi."
For Chinese, the astronomical year begins with sector zi. Zi contains the winter solstice, it is identified with north, and is located at a point on the celestial circle that resonates with the midpoint of the northern edge of flat and square Earth on a line that connects the dots at northwest and northeast on the celestial circle. The Twelve Branches constitute the twelve months of the solar year and the twelve years of the orbit of Jupiter. The "nine fields" consist of a circle surrounded by eight wedges extending in eight directions, but not by splitting up the four "palaces." Whether palaces or fields, they are defined by arcs. The arcs' midpoints corresponded to the cardinal and intercardinal directions. For instance, the northern palace consists of 45 degrees on either side of true north, and the northern field is 22.5 degrees on either side of true north.
When "the gods fell to Earth," poetically speaking, terrestrial features were mapped as the 3x3 grid of nine squares in a larger square. This system, supposedly created by Zou Yan of the Jixia Academy in Qi (c. 300 BCE), was accepted by Huang-Lao Taoists as the preeminent image of the flat Earth. It was eventually applied to Yu's nine provinces, Mengzi's well-field system, the fenye or field-allocation system, the Hall of Light or mingtang, and (of course) Feng Shui.