Basic concepts of ancient astronomy

Here are some basic astronomical concepts, such as seven houses and five latitudes, four elephants in the twenty-eighth palace, three walls, twelve times, except.

One, seven policies and five dimensions: The ancients called the sun and the moon the seven policies of fire, water and earth, also called the seven policies. Among them, the combination of water, fire and soil in Jin Mu is also called five latitudes.

Venus was called a star in ancient times, also called Taibai, because its light color is silvery white and its brightness is extremely strong. In The Book of Songs, the words "When a child rises to see the night, the stars shine" ("Zheng Feng, a female crow") and "When the stars shine" ("Martin, Dongmen Yang") all refer to Venus. Venus is called "Qi Ming" in the east at dawn and "Chang Gung" in the west at dusk.

Jupiter is usually called the Jupiter, or simply "year".

Mercury is also called a star.

The ancient name Mars is confusing.

Saturn is also known as the revitalization or filling star.

It should be noted that the water mentioned in the pre-Qin ancient books when talking about astronomical phenomena does not refer to mercury in the planet, but to the fixed star (camp room) in the star, that is, the bedroom, which is the α β star of Pegasus in the west. For example, Zuo Zhuan's Nineteen Years of Zhuanggong, Water Faint Being Seeded. When talking about astronomical phenomena in ancient books of pre-Qin dynasty, fire is not Mars in the planet, but fire in the stars, especially Antares, which is the alpha star of Scorpio in the west, such as "Fire in July" in the Book of Songs.

Second, 28 huts and four elephants.

The ancients observed the movement of the sun, the moon and the five stars with the stars as the background. Because the position of the stars is relatively stable, they can be used as the position of the movement of the sun, the moon and the five stars. The ancients chose eighteen stars near the equator of the ecliptic as coordinates. Let me introduce the ecliptic and equator first.

The ecliptic is the orbit of the sun in one year imagined by the ancients. The earth revolves around the sun along its own orbital boundary. If you look at the sun from different positions in the earth's orbit, the projection position of the sun on the celestial sphere (an imaginary sphere with infinite radius centered on the earth) will be different. This kind of apparent motion is called the sun's apparent motion, and the track of the sun's annual apparent motion is the ecliptic.

The equator does not refer to the equator of the earth, but the equator of the celestial sphere, which is the projection of the equator of the earth on the celestial sphere.

A star is not a star, but a collection of adjacent stars. The ancients connected several nearby stars, and there were seven nights in the east, west, north and south. Every seven nights, they imagine it as an animal called 28 nights:

Oriental Black Dragon: Corner, end of heart.

Xuanwu in the north: the wall of the virtual danger room of Douniu girl

West White Tiger: Quelou's stomach is full of ginseng.

Southern Suzaku: Well Ghost Liu Yiyi

(Kang 4,No. 1, Ji 1, Mao 3, Zi 1, see Shen 1, Zhen 3). Black Dragon, Xuanwu, White Tiger and Suzaku are also called the Four Elephants. Xuanwu is a hybrid of tortoise and snake.

The ancients observed the movements of the sun, the moon and the five planets in 28 nights. Knowing this, some contents in ancient books are not difficult to understand. In Shangshu, "the moon is out of the blue" means that the moon is attached to it (from the same place, meaning attachment); "Overall" and "Mars stays in Antares" mean that Mars is located in the heart; The book of songs "Taibai eats the Pleiades" means that Venus covers the Pleiades.

Twenty-eight nights are not only used to observe the sun, the moon and the five stars, but also used by the ancients to determine the four seasons of the year. In ancient times, people thought that staying in the south was the first month of spring, and staying in the south was summer and May. In addition, the ancients also took the above 28 nights as the main body and divided the week around the ecliptic into 28 unequal points according to the direction from west to east. So in this sense, 28 nights means 28 different starry regions.

Three walls

In ancient times, besides twenty-eight nights, there were so-called three walls. Since Ziwei Garden, Taiwei Garden and Tianshi Garden.

In the northern sky of the Yellow River basin, the ancients took Polaris as the standard and gathered other stars around it to form an area called Ziweiyuan. Outside Ziwei Courtyard, the star area north of Zhang Yi is Taiwei Courtyard; The star area north of the jumping point in the room is the Shi Tian Wall.

The Big Dipper also plays an important role in ancient astronomy. Beidou consists of Shu Tian, Tian Xuan, Tianji, Tianquan, Yuheng, Kaiyang and Yaoguang. The ancients connected these seven stars and imagined them as a bucket of wine. Shu Tian, Tian Xuan, Tian Ji, Tian Quan, Gu Yuekui; Yuheng, Kaiyang and Yaoguang are bucket handle, which were called Piao in ancient times. The Big Dipper belongs to Ursa major.

The ancients attached great importance to Beidou because it can be used to identify the direction and set the season. Connect Tian Xuan and Shutian into a straight line, extend five times the distance, and you will find the North Star, which is the symbol of the north. The Big Dipper appears in different directions in the sky in different seasons and at different times at night. It seems to revolve around the North Star, so the ancients decided the season according to the direction pointed by bucket handle at the beginning of fainting: bucket handle points to the bucket, and the world is spring; Bucket handle refers to the west, and the world is autumn; Guide to barrel handle, it's summer in the world; The barrel handle refers to the north, and it is winter all over the world.

Four to twelve times.

In order to explain the movement of the sun, the moon and the five stars and the conversion of solar terms, the ancients divided the day around the ecliptic into twelve equal parts from west to east, called twelve times. Every time, there are some stars as signs in twenty-eight huts. Because 12 o'clock is equally divided, the width of 28 places is different, so the starting and ending boundaries of each time at 12 o'clock cannot be consistent with the boundaries between places, and some places belong to two adjacent times. The list is as follows:

Twelve times and twenty-eight nights.

1. Jixing matador

2. The mysterious woman is in danger

3. Be careful of dangerous room walls.

4. Reduce the stomach of Lou Kui Lou

5. Da Liang's stomach is full

6. Stones and gods can identify nerves.

7. Quail first well ghost willow

8. Quail Fire and Willow Star

9. One quail tail.

10. The birthday girl is full of enthusiasm.

1 1. The fire is at the end of the room.

12. analysis of wooden tail skip

Xiao 1，zou 1 zi 1。