Who created the twenty-four solar terms? How many years ago?

In the pre-Qin calendar, there were solar terms such as winter solstice, summer solstice, vernal equinox and autumn equinox. It was not until the first year of Emperor Wu of the Han Dynasty, namely 104 BC, that the new calendar "taichu calendar" was officially promulgated, and the complete "24 solar terms" system was officially released by the court. It has been 2 126 years since (202 1).

There are three main producers in taichu calendar: Luo,, and Luo is particularly important. Luo used his "equatorial armillary sphere" to measure the equatorial distance of Basu, and connected it with the twenty-four solar terms. Through his efforts, the system constructed by linking 24 solar terms with 28 hotels has become a qualitative and quantitative system.

0 1 Luo Xiahong and taichu calendar Since the Warring States Period, the theory of "five virtues and constancy" has prevailed, and emperors should construct political and cultural symbols for their own regimes to show where their destiny lies. At the beginning of the Han Dynasty, this work was not taken seriously, but "the color of Qin Zhengshuo", but the voice of "to be more reasonable, to change course and to take color easily" has always existed.

When Emperor Wu of the Han Dynasty, the national strength was strong and the world was natural. At that time, the monarch and ministers decided to abandon the old system of the Qin Dynasty and establish the "Han system". Change the times, change the new moon, change the official name, seal Mount Tai, open for the first time, and build the political and cultural system of the Han Dynasty. Among them, "calendar revision" is a huge systematic project, involving astronomy, calendar, arithmetic, ground observation and historical records. It needs the cooperation of many departments and disciplines to complete.

Taichu calendar is the first calendar after the reform of Zhuan Xu calendar in Han Dynasty. Because this calendar was formulated by the Han people, it can be called "Han calendar" for short, and it is called "lunar calendar" or "yin and yang calendar" in modern times.

There are three people who take part in this "calendar reform group":,, and Luo. The greatest contribution to the calendar formulation is Luo. By "calendar conversion", Luo means that he is specifically responsible for calculating the cycles of the sun, moon and five stars (Jupiter, Mars, Saturn, Venus and Mercury) and the least common multiple of these "cycles". Hanshu is recorded as Chronology of Shangyuan and Taiji Shangyuan.

In order to calculate the calendar data, Luoxiahong must be based on the measured astronomical data. So, he made an "equatorial armillary sphere" and actually measured the equatorial distance (right ascension, difference) of twenty-eight nights. According to the measured observation data, he first proposed the mating period, taking 135 as the "meeting of the sun", that is, he thought that 1 1 year should have 23 eclipses.

Compared with the old Zhuan Xu calendar, taichu calendar has really made great progress. It takes into account the laws of the sun's movement and the moon's profit and loss, and adopts the average value of the tropic year and the first month of the lunar calendar as the basic cycle. It takes silver moon as the beginning of the year, and puts 24 solar terms into it, which is in tune with the farming rhythm of spring planting, busy summer, autumn harvest and winter leisure, and plays a greater guiding role in agricultural production and life. It takes the month without neutral gas as leap month, but there is no leap in winter, wax and March, which is more reasonable than the year-end leap method in the previous calendar.

These methods in taichu calendar had a lasting influence on the calendars of later generations, and the lunar calendar, which was adjusted and improved by later generations, has been used to this day. Luo Xiahong played his best, calculated calendars and processed data, which made great contributions to the birth of this new calendar and made him famous in history.

The "Han calendar" (lunar calendar and lunar calendar) still in use in China today all retain the "twenty-four solar terms": beginning of spring, rain, fright, vernal equinox, Qingming and Grain Rain; Long summer, Xiaoman, Mangzhong, Summer Solstice, Xiaoshu, Dashu; Beginning of autumn, early summer, white dew, autumnal equinox, cold dew and early frost; Beginning of winter, light snow, heavy snow, winter solstice, slight cold, severe cold.

In taichu calendar, the odd-numbered items in the "Twenty-four solar terms" are called "solar terms" and the even-numbered items are called "neutral gas". The taichu calendar stipulates that the month of winter solstice is 1 1 month, and the first month is the beginning of a year, thus unifying the greetings of the New Year and the greetings of spring days; There was a leap month in 19, but the month without "neutral atmosphere" was regarded as a leap month, which made the Han calendar in China more scientific and more in line with the actual astronomical phenomena.

The "twenty-four solar terms" recorded in Chronology of Zhou Dynasty were determined according to the length of the sun shadow measured on the ground, and the theory of covering the sky was regarded as "cosmology". The "twenty-four solar terms" in Luo's "Calendar" are based on "Huntian" and the solar terms are determined by measuring the position of the sun in "Twenty-eight Nights". There are essential differences between them.

Twenty-four solar terms are a time knowledge system and its practice formed by China people by observing the annual movement of the sun. They are listed in UNESCO's Representative List of Intangible Cultural Heritage of Humanity, which obviously refers to the "knowledge and practice about nature and the universe" in Huntian Shuo and taichu calendar.

Luo He's Huntianyi's "Huntianyi Theory" is the astronomical theory that people in Han Dynasty knew the astronomical phenomena in the universe. Luo was the first person who really laid the foundation of China's Huntian theory. On this basis, Zhang Heng constantly improved Huntian theory and made new and greater achievements. "Huntianyi" is the embodiment of this theory, that is, an instrument for observing the sky, the earth, the sun, the moon and the stars based on "Huntianyun".

Luo developed an armillary sphere and measured the difference of right ascension in 28 nights. For the first time, he brought the 24 solar terms into the calendar completely, and they corresponded to the 28 cottages. "Solar term" is a concept of time, which can be accurate to a certain moment (minute); "Su" (constellation) knows the position of the sun, which is a spatial concept. How accurate can it be?

Of course, Luo is not the terminator or master of the armillary sphere. Astronomers in the late Western Han Dynasty and the Eastern Han Dynasty explained and improved the Huntian theory many times, and verified and improved the Huntian instrument many times, among which Zhang Heng made the greatest contribution. His Notes on Huntian Instrument comprehensively summarizes and systematically discusses Huntian theory, and holds that:

"The sky is like a chicken, the celestial body is round like a projectile, the ground is like a chicken yellow, and it lives alone."

According to this theory, the "armillary sphere" was transformed into a "water transport armillary sphere", which was powered by water leakage. Jia Kui added the ecliptic to the armillary sphere, which made it perfect.

Today, the calendars and armillary sphere completed under the leadership of Luo are flawed in science, such as "starting the calendar by law". We are not demanding of the ancients, but we should objectively and fairly evaluate their astronomical achievements and inherit and carry forward their innovative and realistic spirit.