The spring equinox has just passed, and Qingming is approaching.

In the cycle of the twenty-four solar terms, time flies.

The concept of the twenty-four solar terms, which was gradually established from the Xia Dynasty to the Zhou Dynasty, has been widely used for more than two thousand years.

It not only contained advanced scientific and technological knowledge at that time, promoted and served China's economic and social development in history, but also greatly benefited today's meteorological research - traditional Chinese meteorology is a complete knowledge system, and the twenty-four solar terms are precious The role and value of meteorological science and technology cultural heritage need to be further explored and perceived by the academic community and the public.

From birth to formation, the technological history of the twenty-four solar terms

  The twenty-four solar terms are the common sense of the Chinese people and the background knowledge in the world Chinese character culture circle.

Historically, the twenty-four solar terms have gone through a long process of development and improvement.

In the early stage of Chinese civilization, the growth of production capacity and population reproduction of the ancestors promoted the progress of astronomy, meteorology and agricultural science and technology.

They strive to explore the reasons for changes in the surrounding weather and environment, explain the world with a simple view of nature, and have preliminary development in observing astronomical phenomena, detecting solar terms, forming proverbs, and recognizing nature.

  The one most closely related to the twenty-four solar terms is astronomy.

There were developed astronomical observations in ancient China, which promoted the development of ancient meteorology, and made ancient Chinese meteorology have the ideological system and characteristics of astronomy to some extent.

It should be said that the twenty-four solar terms have both meteorological significance and astronomical calendar significance, which shows that the influence of ancient Chinese astronomy on meteorology is very far-reaching.

  The ancient Chinese attached great importance to the observation of astronomical weather, and in the observation of the sky, there was naturally the observation of the weather.

The ancient observatory of Taosi Temple in Xiangfen, Shanxi is a typical representative in this regard.

It belongs to the Taosi site of the Longshan Culture. Archaeologists have determined that the site is about 2100 BC. It is the earliest ancient observatory site discovered in China so far.

Through field simulation observations, experts determined that the rammed earth pillars at the early Taosi site were used to construct observation slits, and one of their main functions was to observe the sunrise, set the solar terms, and possibly observe other celestial phenomena.

This shows that the ancestors used the gap between the two soil pillars to observe the changes of the sun, thereby inferring the seasonal changes and solar terms.

  This belonged to "high-tech" content at that time, or represented a strong "hard" power.

Because such observations need to consider the surrounding environment, air visibility, position changes over the years, reliability and comparison of solar terms records, etc., which requires a certain accumulation of knowledge in astronomy, meteorology, geography, mathematics, etc., which will in turn promote development of these disciplines.

Moreover, this observation method is a transition from casual watching the sunrise to observation in a specific reference object and fixed mode, and even a leap from qualitative to partially quantitative - this was quite an amazing science and technology more than 4,000 years ago!

  The twenty-four solar terms are not born like this, they have also undergone changes.

  During the period of Yao and Shun, ancestors gradually discovered the cycle of solar terms in a year in their life experience. Some concepts of solar terms were proposed in oral traditions, and then gradually appeared in written records.

Many of the names are different from today, such as "Day Zhong, Ri Yong, Xiao Zhong, Day Short, Minute, To, Open, Close, Day and Night Equinox, Spring Equinox, Autumn Equinox, Winter Solstice, Summer Solstice, Summer Solstice", etc. Some are slowly disappearing.

There is an early record of solar terms in "Shangshu Yaodian", which includes the words "day middle, day long, night middle, day short", which may be the earliest solar terms known so far.

  "Xia Xiaozheng" may be the earliest surviving almanac in China, and the folk lunar calendar is sometimes called "Xia Li", which may be influenced by this almanac to some extent.

In this book, according to the astronomical calendar, there are many names of solar terms, such as the "first month" recorded in "Xia Xiaozheng".

These terms were gradually absorbed into the twenty-four solar terms, and the Xia calendar has been widely used until today because it can promote agricultural activities and has become one of the foundations of traditional Chinese agriculture.

  In the Zhou Dynasty, Chinese ancestors used Tugui to measure the sundial (that is, erect a pole on the plane to measure the length of the sun's shadow at noon) to determine the four solar terms of winter solstice, summer solstice, spring equinox and autumn equinox.

In the Spring and Autumn Period and the Warring States Period, the words about solar terms were more abundant.

In "Guanzi", it is proposed that "not knowing the four seasons is the foundation of losing a country", indicating that the society at that time attached great importance to and application of seasonal factors such as weather.

Many solar terms systems and other meteorological-related knowledge are also recorded in Guanzi.

In the solar term system at that time, there were thirty solar term systems, divided into 8 festivals in spring and autumn, 7 festivals in winter and summer, and each solar term was 12 days.

This is the early form of the twenty-four solar terms.

In "Guanzi·Junchenxia", it says "the time of reviewing the sky", which means that only when human beings understand the laws of the myriad of weather between heaven and earth, including solar terms, can they not violate such laws and serve agricultural production well.

"Guanzi" also discusses the application of meteorological laws to military warfare, which promoted Qi's hegemony from the perspective of meteorology.

  The solar terms essentially reflect an objective law, so everyone's understanding and names tend to be the same, and gradually there is a relatively consistent concept of the twenty-four solar terms.

The most complete and complete records and names of the twenty-four solar terms in China appear in the chapter "Huainanzi·Tianxun", which records the phenological changes in the middle and lower reaches of the Yellow River in my country.

"Huainanzi" was written by Liu An, the king of Huainan, in the early Western Han Dynasty. Many people are familiar with it because it is mainly based on Taoism, and at the same time it is mixed with the theories of various pre-Qin schools.

But in fact, there are many discussions on natural phenomena in the book, especially the contributions to Chinese traditional meteorology. It not only completes the discussion of the twenty-four solar terms first, but also records the observation of wind and humidity.

Calendar, agriculture, climatology... The twenty-four solar terms had a multi-faceted impact on ancient China

  After the twenty-four solar terms came into being, a strict knowledge system was gradually formed, which played a role in promoting the development of various aspects of society in ancient China.

Here, we only exemplify its effects on calendars, agriculture, and climatology.

  The twenty-four solar terms have a great influence on the production of almanacs in later generations, and have been deeply imprinted on the long history of China.

It is one of the core theories of traditional Chinese meteorology, and has gradually become the essence of ancient Chinese traditional culture.

For example, the Western Han Dynasty's "Taichu Calendar" was the first relatively complete Han calendar in ancient China, and it was also the most advanced calendar in the world at that time. The twenty-four solar terms were incorporated into it, which brought great influence to the production and life of agriculture and animal husbandry. Great convenience.

The "Taichu Calendar" also uses the month with no qi as the intercalary month, which is more reasonable than the previous year-end intercalation method.

  The impact of solar terms on agriculture is even greater. For example, careful calculation of the time of the winter solstice is conducive to arranging agricultural production in the coming year.

Due to the vast territory of China, the exact time of the winter solstice varies from place to place.

For example, after the Southern Song Dynasty moved to the south, the length of the shadow of the winter solstice was different from that in the Central Plains.

There are also problems in the astronomical calendar in the famous ancient book "Shu Shu Jiu Zhang", which involves the calculation of the twenty-four solar terms.

For example, the question of "Pushing Qi and Governing the Calendar": "Asking the Taishi test is futile. In the fourth year of Qingyuan, Wuwu, the winter solstice, on the 39th day of the winter solstice, ninety-two quarters and forty-five minutes; Four quarters and twelve minutes. Do you want Jiatai Jiazi's qigong, over-year-old, and fighting points to get how many?" The "Qigu" in it refers to the winter solstice.

  The same goes for other solar terms.

Zeng Xiongsheng, an agricultural historian, pointed out that Qin Jiushao's book has detailed calculations on the winter solstice and other solar terms.

This is mentioned in "Kui Ri and Wei", the title is "Ask the past dynasties to survey the scene, but the Tang Dayan calendar is the most dense. The Chongtian calendar of this dynasty, the winter solstice scene in Yangcheng is 12 feet, 7 inches, 1 minute and 50 seconds, and the summer solstice scene. One foot, four inches, seven minutes and seventy-nine seconds, which is the same as the Dayan calendar. The jubilee calendar starts today, and the winter solstice scene in Lin'an is one zhang, eight inches, two minutes and twenty-five seconds, and the summer solstice scene is nine inches and one minute. How many days is the difference between the scenery and the summer solstice in Yangcheng, compared to the size of the summer scenery in the Dayan calendar, what is the difference?" This is the need to calculate the length of the sun shadow in the Lin'an Prefecture at that time, which is today's Hangzhou city, after the summer solstice. The length of the sun shadow on the summer solstice in Yangcheng (now Dengfeng, Henan Province) is the same—the latitude of the two places on the earth is different, and the length of the sun shadow will be different.

  China is one of the largest crop origin centers in the world, and agro-meteorological science sprouts early and develops rapidly.

After the twenty-four solar terms gradually appeared, the more specific seventy-two monarchs corresponded to them, mainly guiding agricultural production through comprehensive knowledge of astronomy, meteorology, and phenology—one monad for five days, 365 days a year for seventy-two monads, three Wait for a season.

The twenty-four solar terms and seventy-two monads that reflected the seasons and agricultural activities appeared thousands of years ago and played an important role in the development of ancient Chinese agricultural society. So far, various proverbs describing and predicting the weather are still used in agricultural production and daily life. influence.

  The twenty-four solar terms also reflect phenological changes.

In the era of Emperor Gaozu of the Tang Dynasty, Linghu Defen recorded solar terms and phenological phenomena such as "Jing Zhe... Tao Shi Hua" in his book "Book of Zhou".

It is based on this record, supplemented by other documents, that many meteorologists and climatologists believe that the climate in the Yellow River basin was relatively warm during the Tang Dynasty.

Such discoveries have given today's global climate change research a far-reaching historical coordinate—the study of ancient solar terms and phenology knowledge has now become an important branch of contemporary atmospheric science and occupies an important position in climate change research.

Excavate traditional meteorological science and technology cultural heritage and promote modern meteorological research

  The research on the general history of meteorological science and technology shows that the historical development of Chinese meteorology and the development of world meteorology have both commonalities and their own unique status.

On the one hand, China's relatively closed and unique geographical environment makes the regional characteristics of ancient Chinese meteorology more obvious; on the other hand, the strong influence of traditional Chinese culture makes ancient Chinese meteorology have more obvious traditional Chinese cultural characteristics—— Emphasis is placed on accumulating meteorological knowledge from production practice and daily life, and after forming a complete knowledge system, it has been applied in practice.

This is more obvious in the field of twenty-four solar terms.

  Ancient Chinese meteorology contains profound cultural connotations.

"Heaven" and "Qi" in ancient China have the same origin, which makes ancient Chinese meteorology with traditional Chinese cultural characteristics from the very beginning, and embarked on a different development path from the Western meteorology that started from philosophical thinking at the same time in the West. Its cultural and regional characteristics constitute the keynote of the ancient Chinese meteorological history of more than 4,000 years.

Among them, the twenty-four solar terms are represented, which have both astronomical and meteorological meanings. They have been passed down for thousands of years and have become the carrier of China's typical cultural heritage.

  Ancient Chinese meteorology is also one of the representatives of ancient Chinese science and technology development.

It is widely recognized in the history of science that China has four traditional disciplines: traditional astronomy, arithmetic, agriculture, and traditional Chinese medicine.

However, after years of research, scholars of meteorological science and technology have proposed that traditional Chinese ancient meteorology has naturally become the fifth traditional discipline.

Among them, the traditional meteorological scientific and technological knowledge with the twenty-four solar terms as the core, etc., contributed to the formation of this conclusion.

  The vast literature and classics in ancient my country have extensively recorded important information for the ancients to observe nature and understand the weather.

With the development of farming civilization, they invented ancient meteorological instruments to measure wind, humidity, precipitation, phenology, etc., and formed meteorological theories such as the twenty-four solar terms, relative rain, sky observation, and climate. The very distinctive Chinese traditional meteorological scientific knowledge system has produced a series of meteorological relics with high historical value, scientific and technological value, social value and cultural value in its development process, that is, meteorological scientific and technological cultural heritage.

  The author even believes that the four traditional disciplines have gradually lost their original characteristics more or less in the historical process of modern Western learning.

However, ancient Chinese meteorology has not completely disappeared today, especially the ancient meteorological knowledge framework centered on the twenty-four solar terms and the seventy-two monarchs is still popular in Chinese society and plays an important practical role.

  For today's meteorological research and business, the twenty-four solar terms have far-reaching influence and enlightenment.

The meteorological science with a history of more than 4,000 years has developed to today, forming a luxuriant subject group.

The twenty-four solar terms are not only important research contents in the history of meteorological science and technology, phenology research, agricultural meteorology, meteorological science popularization and other disciplines, but also have enlightenment for the research of meteorological forecast and public service.

For example, the twenty-four flower letters that Chinese people love are directly related to the knowledge of the twenty-four solar terms.

There are differences in flower letters in different places, and there are also slight differences in the same place every year. For related tourism and economic activities, accurate forecasting is very important.

Continuing to study the 24 solar terms in depth, applying the scientific and technological knowledge and cultural heritage in it, can better exert its modern value.

  As a science-based and basic public welfare undertaking, meteorological undertakings have unique and important value to realize meteorological modernization and meteorological technological innovation, and contribute to the high-quality development and service of meteorological undertakings. Building a strong meteorological country.

At the same time, an in-depth understanding of the 24 solar terms can better understand the long and profound history of the development of Chinese meteorological science and technology, and correctly understand the great contribution the Chinese nation has made to the progress of the world's meteorological science and technology. Self-confidence in science and technology, enriching the historical and cultural nourishment of the whole society and the connotation of meteorological science and technology and culture, serving the needs of high-quality development of meteorological undertakings and building a meteorological power.

(Author: Chen Zhenghong, a professor-level senior engineer at the Meteorological Officer Training College of China Meteorological Administration)