What is the Yellow Sutra?

The longitude of the ecliptic refers to the longitude of the sun or the longitude of the celestial sphere, which is the coordinate value used to determine the position of the celestial body on the celestial sphere in the ecliptic coordinate system. In this system, the celestial sphere is divided into two hemispheres by its equatorial plane.

The ancients divided the solar terms by the method of regulating qi, and divided 360 degrees into 24 equal parts, each equal part was 15 degrees, which became a solar term. The number of days between two solar terms is about 15 days, that is, there are 24 solar terms throughout the year.

"seventy-two waiting episodes of the moon order" explains: "everything is shocked and shocked by thunder, so it is called a sting, and it is a sting from it." As soon as the spring thunder rings, all the insects sleeping in the soil wake up, so this solar term is called a fright.

On the day of "thunder", "thunder is loud and everything grows." Spring breeze warms the air and is full of spring. After being stung, plants will grow wildly, often in lightning speed, and they will bloom. There are many plants and trees there. This is "fright".

Extended data

The origin of the yellow meridian

The ecliptic is the path of the sun through the celestial sphere in a year, and it will cross the celestial equator twice a year, once at the vernal equinox and once at the autumnal equinox. Since there is no obvious point on the ecliptic that can be regarded as longitude 0 degrees, the vernal equinox is arbitrarily designated as the position of ecliptic 0 degrees, and the longitude of celestial bodies is the angular distance from celestial bodies to the vernal equinox.

Zodiac coordinates are very useful for celestial bodies in the solar system. For example, the longitude of the sun given in the almanac is measured by the yellow meridian. The earth revolves around the sun for about 365 days and 5 hours, with a journey of 940 million kilometers. This orbit is called the ecliptic.

Reference source Baidu Encyclopedia-Zodiac (longitude-ecliptic coordinate system)

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