Earthly Branches

From Wikipedia, the free encyclopedia

A fountain in Almaty represnting the 12 animals of the (Kazakh version of the) animal cycle

The Earthly Branches (Chinese: 地支; pinyin: dìzhī; or Chinese: 十二支; pinyin: shíèrzhī; literally "twelve branches") provide one Chinese system for reckoning time.

This system was built from observations of the orbit of Jupiter. Chinese astronomers divided the celestial circle into 12 sections to follow the orbit of 歳星 Suìxīng (Jupiter, the Year Star). Astronomers rounded the orbit of Suixing to 12 years (from 11.86). Suixing was associated with Sheti (ɳ Böotes) and sometimes called Sheti.

In correlative thinking, the twelve years of the Jupiter cycle also identify the twelve months of the year, twelve animals (mnemonics for the system), directions, seasons, months, and Chinese hour in the form of double-hours. When a Branch is used for a double hour, the listed periods are meant. When used for an exact time of a day, it is the center of the period. For instance, 午 (the Horse) means noon or a period from 11am to 1pm. (The jie qi system provided single hours and 15-degree arcs in time and space.)

Chinese seasons are based on observations of the sun and stars, not the weather. Many Chinese calendrical systems have started the new year on the first new moon after the winter solstice.

The Earthly Branches are today used with the Heavenly Stems in the current version of the "traditional calendar" and in Taoism. The Ganzhi (Stem-Branch) combination is a fairly new way to mark time; in the Shang era it was the ten Heavenly Stems that provided the names of the days of the week. The Branches are as old as the Stems (and according to recent archaeology may actually be older), but the Stems were tied to the ritual calendars of Chinese kings. They were not part of the calendrical systems of the majority of Chinese.

Some cultures assign different animals: Vietnam replaces the ox, rabbit, and sheep with the water buffalo, cat, and goat respectively; Japan replaces the pig with the wild boar.

[edit] Directions

The 24 cardinal directions.

Even though Chinese has words for the four cardinal directions - 北 (běi, north), 東 (dōng, east), 南 (nán, south), and 西 (xī, west) - Chinese mariners and astronomers/astrologers preferred using the twelve directions of the Earthly Branches, which is somewhat similar to the modern-day practice of English-speaking pilots using o'clock for directions. Since twelve points were not enough for sailing, twelve midpoints were added. Instead of combining two adjacent direction names, they assigned new names as follows:

• For the four diagonal directions, appropriate trigram names of I Ching were used.
• For the rest, the Heavenly Stems were used. According to the Five Elements theory, east is assigned to wood, and the Stems of wood are 甲 (jiǎ) and 乙 (yǐ). Thus they were assigned clockwise to the two adjacent points of the east.

Following is a table of the 24 directions:

Advanced mariners such as Zhèng Hé used 48-point compasses. An additional midpoint was called by a combination of its two closest basic directions, such as 丙午 (bǐngwǔ) for the direction of 172.5°, the midpoint between 丙 (bǐng), 165°, and 午 (wǔ), 180°.

[edit] See also

• Sexagesimal cycle (干支)
• Chinese calendar
• Image:Chinese cardinal directions study panel.pdf (A study of the cardinal directions chart)

[edit] External links

• Heavenly Stems and Earthly Branches - Hong Kong Observatory

v • d • e Jupiter
Major moons	Io · Europa · Ganymede · Callisto
Characteristics	Cloud pattern · Great Red Spot · Magnetosphere · Oval BA · Rings · Moons
Exploration	Pioneer program · Voyager program · Galileo (spacecraft) · Juno (spacecraft) · Europa Orbiter
Other	Jupiter-crosser asteroid · Earthly Branches · Colonization · Jupiter mass · Comet Shoemaker-Levy 9