Chapter 15 Chapter 15 Tang Dynasty "Scientific Monk" and His Party

In the political textbooks in middle school, when it comes to religious issues, we have accepted a fixed concept since childhood, that is, religion is the product of superstition.But when we re-examine the development process of human civilization, we are surprised to find an interesting phenomenon: many great technological inventions in the history of human civilization were created by religious people.The unprecedentedly prosperous Arabic mathematics and civilization are closely related to Islamic culture.In Europe, it was the missionaries who first explored the cure for the Black Death.In medieval Europe, theology once occupied an absolute dominant position, not only because of human superstition about God, but also because of the outstanding contribution made by Catholicism in the great European plague.And looking through the ancient Chinese history, we will also find with great interest that the invention of gunpowder comes from the alchemy of Taoists, and the outstanding achievements of Chinese astronomy, mathematics, and traditional Chinese medicine are largely based on the ideas of Taoism and Buddhism. thought-based.In the star-studded list of ancient Chinese scientists, there are many names of religious figures, the most famous of which are the famous eminent monks of the Tang Dynasty.

For us today, it is hard to imagine what a magical figure Xing Xing is.The history books define him as an "astronomer", but judging from his achievements and contributions, it is far from being as simple as an astronomer.His posthumous title is "Zen Master Dahui". Just from the word "Dahui", it is enough to show his talent and intelligence.In fact, Yiyi made outstanding contributions to the study of Buddhist thoughts and the summary of philosophical thoughts, and he creatively applied religious thoughts to the research of natural science.Although from the perspective of modern science, religious idealism is in sharp contradiction with the development of natural science, but in a specific period of human civilization development, religious thought can become a huge driving force for scientific research.Facing the once unknown world, religion once became the ideological criterion for human beings to understand the world and the universe. In the Tang Dynasty, Yixing's identity was not as simple as an astronomer. One of the leaders.This special identity also has reasons to give us a new understanding of Buddhist thought.As a profound religious knowledge, many contents of Buddhist thoughts are precisely integrated with scientific and technological thoughts.And to this day, many expositions on the origin of the universe and human beings in Buddhist thought still have a great reference effect on the research work of modern science.

Yixing is both a Buddhist monk and an outstanding scientist.Even more fortunately, he lived in the prosperous Tang Dynasty, the golden age of Chinese feudal society. It was an era that fascinated today's intellectuals, and it was also an era when China's humanities and natural sciences were flourishing.Today we are intoxicated by the magnificent style and beautiful sentences of Tang poetry, but we don’t know that in that era, a group of special people used their unique creativity to write poems far more magnificent than Tang poetry.The reason why our Tang Dynasty is called prosperous Tang Dynasty, and the reason why our country’s civilization is called a splendid civilization, those achievements in humanities and academics are certainly proud, but more importantly, the Chinese created enough to lead in that era. The scientific and technological achievements of the world for thousands of years.From the revision of the calendar to the observation of celestial bodies, the Chinese used their wisdom to build a pyramid leading to the mysteries of celestial bodies, and Yi Yi was the person who stood at the top of the golden tower in that era.

Yixing, commonly known as Zhang Sui, was born in Julu, Xingzhou (now Julu, Xingtai, Hebei). His grandfather Zhang Gongjin was the governor of Xiangzhou. He was proficient in astronomy and calendar, and his family gave him a good influence.Regarding his grandfather Zhang Gongjin, he may not have a great reputation in history, but an important decision made in the Xuanwumen Incident has made history remember his name forever.Before the Xuanwumen Incident, Zhang Gongjin was Li Shimin's staff. At that time, Li Shimin asked a wizard to divination for success or failure. As a result, Zhang Gongjin threw the tortoise shell used for divination into the fire.Zhang Gongjin persuaded Li Shimin: "Every divination is used to resolve suspicions and hesitation. Now that there is no doubt, is there any need for divination? If the divination is inauspicious, the situation is unstoppable. I hope Your Majesty will think about it carefully." It was his generous speech that made Li Shimin make his final decision.During the Xuanwumen Incident, after Prince Li Jiancheng was shot and killed, Zhang Gongjin led his troops to guard Xuanwumen, blocked the counterattack of the Prince's Mansion, and made great contributions to Li Shimin's final ascension to the throne.This wise man who does not believe in ghosts and gods is also a erudite scholar, with profound attainments in astronomy and mathematics.Although Zhang Gongjin had passed away for nearly 60 years when Xing Xing was born, the qualities of his grandfather obviously left deep traces on him.He has the same outstanding vision and astronomical achievements as his grandfather, but he does not have the political ambitions of his grandfather, and he has been indifferent to fame and fortune all his life. I don't know how I would feel about my career?

Many celebrities in the heyday of the Tang Dynasty have a common feature, that is, the inheritance of alternative families.The reason why I added the word "alternative" in front of family inheritance is because, unlike the traditional aristocratic families in the Southern and Northern Dynasties, these famous families in the Tang Dynasty often took a path that ran counter to their ancestors.A typical one is Wang Zhongsi, a famous general of the Tang Dynasty, whose father was Wang Haibin, a famous general of the early Tang Dynasty, and Li Shizhi, a famous politician in the Tianbao era, whose ancestor was the prince Li Chengqian who was deposed by Li Shimin that year.In fact, this "alternative inheritance" of Tang Dynasty celebrities is precisely one aspect of Tang Dynasty culture.During the Tang Dynasty, although the imperial examination system had become the basic system for evaluating Chinese officials, the increasing politicization of academics and the marginalization of natural sciences had also become an irreversible trend.However, the culture of the Tang Dynasty also has a flourishing side. The unified social environment and the achievements of civilization accumulated in history have exploded in groups in this era, allowing individuals to have different choices in their life paths.However, the quality of the ancestors still left a deep imprint on the descendants. Wang Zhongsi, who frightened Tubo, was also a talented poet. The Buddhist monks also carry the noble qualities of his grandfather: they don’t believe in heaven, gods, and authority. They can stick to their beliefs and ideas no matter what the political environment is, and they can accomplish great work with silent patience.Moreover, he is far more fortunate than scientists such as Zu Chongzhi. He lives in an era of civilization and openness, and his scientific work has received great support.If it is said that before him, scientific research was still an individual effort, then the scientific activities hosted in the name of the national government have become one of the mainstreams of China's scientific development since the beginning of his party.Although this kind of activity has various political colors, and although the activity itself is full of human beings' confusion about the world, this kind of behavior itself is enough to show the courage and mind of a big country.In the Tang Dynasty, China’s scientific masterpieces and large-scale scientific projects far surpassed the previous generation, and professional science education also reached a complete peak in the Tang Dynasty, which is the most basic symbol of a country’s prosperity and civilization.In this sense, Yixing is very lucky. He has a political environment and living environment that previous generations of scientists did not have, cultural inclusiveness, a free and open atmosphere, and strong economic support all paved the way for his success. the broadest platform.

This is the real meaning of a strong country, and it is also the environment that a pure scholar needs most: political stability, free and open academic atmosphere, highly developed civilization and material achievements.At that time, China was the model country in the minds of all idealists.At that time, the Arab civilization was just booming and was still in the midst of endless wars, the states of Europe were torn apart, and the Eastern Roman Empire was entering its period of decline.On the west side of the earth, fortified fortresses and dark theology imprison the wings of Europeans, while at the other end of China, developed transportation, unified political environment and advanced productivity allow people here to enjoy endless horizons Wide vertical and horizontal sense.And our party is in such an environment, set foot on the stage of history.

Yixing was born in 683 AD. When he was born, his grandfather, the famous Zhang Gongjin, had passed away for nearly 60 years. Because of Wu Zetian, the family that had made great achievements in the Zhenguan Reign is now declining. .But the grandfather who had never met left a rich legacy for the party - his astronomical observation records and various astronomical works. The family's cultural traditions made the party a learned youth. When he was 20 years old, Yixing wrote one volume each of "Da Yan Xuan Tu" and "Yi Jue" to explain Yang Xiong's "Tai Xuan Jing". What is surprising is that he only spent a few days to complete it. this hard work.What's more amazing is his ability to never forget. No matter how incomprehensible the bibliography is, he can explain it in detail after reading it once, and even describe it vividly.He can write beautiful articles, and his eagerness to learn is even more impressive.In order to be able to seek knowledge, he once borrowed books from Yuanduguan, a famous library in the Tang Dynasty, and even read until he forgot to sleep and eat.His hard work and erudition were also well-known in broadcasting at the time.If he followed the normal growth path of a young man, he might take part in the imperial examinations of the Tang Dynasty at that time, and even get to the top few exams. Maybe he would take advantage of the family's shelter to obtain a considerable official position and receive a monthly salary of A generous salary, but unfortunately, this is not the life he expected.If that is the case, perhaps there will be one more learned scholar and one more outstanding statesman in history, but there will be one less enlightened monk, and even less a series of amazing achievements in Chinese astronomy.

Among the Chinese scientists before the line, a very important feature is the inheritance of the family.For example, Zu Chongzhi, a scientist during the Southern and Northern Dynasties, whose family has been engaged in astronomical research for generations. If Zu Chongzhi was born in a family of science and technology, and it is an inevitable choice to devote himself to science, then Yixing obviously has more choices.In fact, in the Tang Dynasty at that time, although there were many people who were proficient in astronomy among the elite, most of them regarded astronomy as a hobby rather than a lifelong pursuit.For example, Zhang Gongjin, the grandfather of Yixing, also has profound attainments in astronomy, but his true identity is a politician.But the line is different, he had the opportunity to join the official career, but resolutely chose to give up.He has no lofty political ideals, only pure and true scientific yearning.From Nanle to Chang'an, he devoted most of his time to astronomy.At the various academic gatherings in Chang'an at that time, he offended powerful figures more than once by refusing invitations from celebrities. At the same time, he was obsessed with various astronomy books to an astonishing degree.Whenever he talked about astronomical research with others, he would never tire of talking about it.He did not come from a family of astronomers, but he was a pure astronomer.

Judging from the environment of Yixing's youth, he also unfortunately lived in a complicated political environment.In Yixing's youth, Wu Zetian's Wu Zhou Dynasty was in full swing, and Wu Zetian's nephew Wu Sansi was in charge of the government, and was once regarded as the best candidate for the heir to the throne.In 703 A.D., Wu Sansi heard about the name of a party, and in order to win the reputation of Li Xian Corporal, he began to deliberately win over.Regarding Wu Sansi, there are many records in history, and it is his cruelty.On the one hand, he specially wins over a group of celebrities to make friends with and gain a good reputation for himself; on the other hand, he resolutely and ruthlessly frames those who do not obey him.In that special environment, the righteous people are afraid to avoid it, while the greedy people dream of using his high branches to make a living. The party that is not interested in official career naturally belongs to the former.But a series of facts prove that disobeying Wu Sansi's invitation will often pay a huge price, and accepting his invitation may lead to a huge political vortex in the court.At that time, the princelings headed by Li Xian and the Wu family headed by Wu Sansi were fighting to the death, and countless historical celebrities also participated in it, which finally resulted in the mutual massacre of the imperial family and countless literati. .Yixing is a simple intellectual, although simple, he also knows the pros and cons of it.He does not want to be a victim of political struggle, his ideal is very simple, devote himself to the research of astronomy, and benefit the common people with what he has learned.But the harsh political environment obviously can't do what he wanted. A 20-year-old young man encountered a major difficult choice when he was just a fledgling. How will he choose?

Yiyi chose a path that no one thought of - becoming a monk. Regarding the reason why Yixing became a monk, the history books did not give too much introduction. It only said that he fled to Songyue Temple in Henan Province to become a monk in order to avoid Wu Sansi's wooing, so the history books also regarded his choice as a way to avoid disaster The way.But the truth is not that simple.Songyue Temple was a famous temple in the Tang Dynasty at that time. After the group fled to Songyue Temple, it happened that the eminent monk Pu Ji Zen Master was promoting the essentials of Zen there. After listening to it, the group was greatly moved.This is actually one of the mentalities of Chinese literati.Because of the frustration of the political environment, they need to seek another sustenance, and full of ideals need a broad platform.Under the political environment at that time, the 20-year-old and his party experienced the biggest change in their lives. Dreaming of making achievements in academics, he encountered the biggest barrier in life.It was at this moment that Puji's lecture gave him a key to life.We always regard Buddhism as a passive way of avoiding the world, but in fact, the real essence of Buddhism lies in "practice" rather than "practice".The spirit of Buddhist religious thought can be a beneficial supplement to traditional Chinese science.Most importantly, in the political environment where Wu Zetian believed in Buddhism, Yixing's choice could be the biggest amulet for himself and his family. In this sense, it was the best he could do at that time. s Choice.

If Xingxing’s decision at the beginning was just an act of refuge, then as time went by, as he gradually understood the thoughts of Tantric Buddhism, he gradually changed his concept. From a scholar to an accomplished monk, we It should be noted that Yixing's attainments in Buddhism are no less than his attainments in astronomy.First of all, he learned Indian at an astonishing speed, and translated a large number of Indian Buddhist scriptures; "Da Ri Jing Shu" is a representative work that embodies his Tantric thoughts.In this treatise on Buddhism, Yixing made a logical summary of the thoughts of Tantric Buddhism introduced to China since the Southern and Northern Dynasties, and clearly put forward his personal religious views on Buddhism. The perfect integration of Dharma and Dharma formed the unique system of Esoteric Buddhism in China. In this sense, it is not too much to say that he is a master of Esoteric Buddhism. After becoming a monk, the party first practiced with Zen Master Puji, but one day, the two masters and apprentices met Yin Chong, a famous book collector in the Tang Dynasty at that time.Yin Chong was amazed when he saw the party, and said to Pu Ji: "This son is talented, and you can't teach him." So with Pu Ji's permission, the party started a long journey to study, and his footsteps traveled all over the country. From Mount Song to Guoqing Temple in Tiantai Mountain, Zhejiang, he left his hard footprints everywhere.Master Zhiqing from Mount Tiantai and Master Wuzhen from Mount Song became his masters successively. This experience is of great significance to the group.In traditional Chinese astronomy research, the Buddhist school has always been an independent system.The Buddhist school has its own unique thoughts on the study of astronomy and calendar, but because of the restrictions of sects and differences in status, although these thoughts have taken root in China, they have been unable to integrate with traditional Chinese astronomical thoughts for a long time.Not only that, there is also a fierce collision between Buddhist schools and traditional Chinese Confucianism and Taoism. This collision is not only limited to the field of science, but also limited to various disciplines and fields.The significance of the Tang Dynasty to Chinese culture lies in the fact that although the unification tradition of Chinese Confucianism has long existed, the Tang Dynasty perfectly solved this problem.In this era, the integration of various schools of thought gave birth to a series of successful civilizations, and also melted the unique ideas and concepts of each religion into the vigorous blood of the Chinese nation.The inclusive and all-encompassing feature of Chinese civilization, with Confucian civilization as the main body, was brought into full play during this period. It is also this feature that enables our nation to remain resilient despite political and cultural catastrophes time after time. Survive and thrive day by day, and Xingxing is just one of the bridges in this process. The characteristic of Yixing is that in his youth, he had systematically studied the theories of traditional Chinese astronomy, and in his middle age, he had systematically accepted the edification of Buddhist thoughts and Buddhist theories about the universe and astronomy. idea.The theories of two different schools blended in his concept, and finally formed his unique concept of astronomy.We always think it is easy to learn from each other's strengths, but those who can really do it are often wise men who can surpass the world.During this long period of more than 10 years, he and his party walked through thousands of rivers and mountains, gave up the lucrative official position and the courtship of powerful people, willingly endured a life of poverty and hardship, and tirelessly searched for the true meaning of Buddhism and science during the lonely journey. This is the theme of Yixing's life during this time.If today, a kid from a rich family would rather choose a hard ascetic life and study knowledge in the difficult drifting, this will definitely be regarded as a fairy tale like the Arabian Nights, and perhaps it will be hyped by various websites and news media.But 1,000 years ago, Yixing was taking this step piously. From a young scholar who became famous to a lonely monk, he paid an unimaginable sacrifice and a heavy price.Saying goodbye to the rich life and the bustling city, walking alone in the desolate countryside and the cold mountains and rivers, I thought of the figure of this eminent monk trekking countless times, under the blue lamp of the ancient Buddha, he silently recited scriptures , In the morning bell and evening drum, he calmly flipped through the classics.In the thousands of rivers and mountains, he trekked with difficulty, knocking on the door of the farmhouse, and melted a simple bowl of vegetarian food.Wang Bo once wrote in "The Preface to the Pavilion of the King of Teng" that "the poor and the stronger, the ambition not to fall into the sky", may be the portrayal of this wise man. If we regard Yixing as a scientific theorist at this point, we are not comprehensive enough.Yixing has rich scientific and theoretical attainments, and he even introduced Buddhist thought into the study of astronomy.But at the same time, he is an outstanding doer.Before him, no scientist in Chinese history could pay as much attention to the actual observation of astronomy as he did.His detailed records of astronomical observation data are astonishing.Even during the years of studying abroad, he also wrote thick astronomical observation notes, and even every data is extremely detailed.One of his creative achievements is that he discovered the movement of stars through long-term astronomical observations, and further discovered and understood the laws of motion of the sun, moon and stars. A more complete star catalog was produced.And what's more exciting is that for the first time in history, he put forward the view that the distance from the moon to the earth is closer than the sun.In that era when the understanding of the universe was still vague, this discovery was undoubtedly of epoch-making significance. Monk is the profession of a group, and Buddhism is the pursuit of a group, but history predestined that his life will not go down this lonely track.In fact, after Wu Zetian's death, the Tang Dynasty government conscripted a party more than once.In 710 A.D., Tang Ruizong sent Wei Anshi, a stay-at-home guard in Hubei, to invite a party to enter the palace. The party who had no intention of official career rejected the invitation again, and went to Dangyang, Hubei to learn Vini.Many subsequent enlistments were also rejected by the party.In 721 A.D., Li Longji, Emperor Xuanzong of the Tang Dynasty, sent his family uncle Li Qia to pick up his party in person. This was a great honor at that time. Finally, the party no longer refused, and he returned to Chang'an after a long absence.The reason why he changed his mind was not because of the grand etiquette of the Tang Dynasty, but because of a great task entrusted to him by the Tang Dynasty—revising the calendar. When it comes to the calendar, I have to talk about the development of the Chinese calendar since the Northern and Southern Dynasties.In the Chinese astronomical theory before the Southern and Northern Dynasties, there has always been a mistake: the sun circles the sky from the winter solstice of this year to the next winter solstice forever.There is no distinction between the celestial cycle (that is, the period in which the earth really revolves around the sun once) and the year cycle (the return year, that is, the cycle in which the sun is directly on the winter solstice this year and returns to the winter solstice next year).Yu Xi of the Eastern Jin Dynasty measured that the sun has some gaps from the winter solstice point of this year to the winter solstice point of next year, and the sun cannot return to its starting point of the previous year.This gap is called precession in astronomy, and when the "Yuanjiali" was formulated in the Southern Dynasties, scholars in Liangzhou had already proposed the concept of "leap year", and believed that there were 221 leap years in 600 years.However, He Chengtian, who was the revisioner, did not adopt this result.In the Southern Dynasties at that time, the common national calendar was still the "Yuanjia Calendar" used by He Chengtian. Zu Chongzhi keenly discovered this problem and wrote the "Daming Calendar".In the "Da Ming Calendar", Zu Chongzhi distinguished the tropical year and the sidereal year, and introduced the precession into the calendar for the first time. The measured precession is one degree in November 45 years (the current measurement is about 70.7 years in one degree), and a tropical year is set as 365.24281481 days (Today's test is 365.24219878 days).It was the most accurate data until the fifth year of Ningzong Qingyuan in the Southern Song Dynasty (1199 A.D.) before Yang Zhongfu made the Tongtian Calendar.It adopts a new leap week with 144 leaps in 391 years, which is more precise than the leap week with 7 leaps in 19 years used in previous calendars. The number of months and days at the fixed node is 27.21223 days (27.21222 days today). The accurate measurement of the number of months and days at the node makes Accurate eclipse forecasts become possible.Zu Chongzhi used the Ming calendar to calculate the time of four lunar eclipses that occurred in 23 years from the thirteenth year of Yuanjia (436 AD) to the third year of Ming Dynasty (459 AD), and the results were completely consistent with the reality; The conclusion of Chaochen once fixed Jupiter's revolution period as 11.858 years (11.862 years in today's survey); it gave a more accurate five-star rendezvous period, and the rendezvous period of Mercury and Jupiter is also close to the modern value.A method of measuring the length of the sun's shadow at noon to determine the time of the winter solstice was proposed. In the Kaiyuan era, the calendar used by the Tang Dynasty was the "Qide Calendar" compiled by Li Chunfeng, but the prohibition of several solar and lunar eclipses made the Tang Dynasty very angry.In fact, "Qideli" is also one of the famous calendars in Chinese history, but the ancient Chinese calendar had a major disadvantage before the Tang Dynasty, that is, although it paid attention to the results of observation, the revision of the calendar largely required Rely on calculated data.This makes the accuracy of the calendar very limited.It was against this background that the party returned to Chang'an, and what he accepted was such a difficult task.There is a lot of preparatory work to be done by the party, as he said to Tang Xuanzong: "If you want to create a calendar and establish a yuan today, you must know the advance and retreat of the zodiac. Please ask the Taishi Order to measure the star degree." He proposed that the actual observation data shall prevail. The basis for formulating the calendar, although this proposition was realized in his previous years, was not fully implemented due to the limitations of the crude equipment and the environment, but this time was different. It is an important event in China, and it is the first time in history to revise the calendar in the name of the country.Yixing has better conditions than his predecessors, and the wealth of knowledge he has accumulated in decades of study tours has also played an important role from this moment.The revision of this calendar almost exhausted the last few years of Xingxing's life, the hard study tours and arduous search, perhaps just for this most important moment in his life, from this moment on, all his life will surely be Contribute to this great cause. In the process of revising the calendar, Yixing made and improved a series of astronomical observation instruments, which not only provided important help for the revision of the new calendar, but also had a profound impact on astronomy in later generations. Among them, the most representative one is Copper armillary sphere and zodiac globe.The principle of the copper armillary sphere is to drive the machine with water to rotate at the speed of one week per day. There are two mechanical wooden figures on it, which naturally beat the drum every quarter and the bell every morning.This kind of instrument is more than 600 years earlier than the appearance of the Western self-ringing clock, and it can be called the first in the world, and the way this armillary sphere evolves and transforms nebulae is also more delicate and detailed than Zhang Heng's armillary sphere.The party used this newly made instrument to observe the changes of the sun, moon and stars, and found that the data was quite different from that of the Han Dynasty. He used these brand new data as the basis for revising the calendar. After the production of the new instrument was completed, a group of people organized manpower to launch a huge movement-measurement of solar shadow.This is actually the first time in the history of human astronomy that the movement of the meridians has been measured.The behavior of the party was strongly supported by the government of the Tang Dynasty at that time. This is also a scientific project that can only be completed by a powerful country.Beginning in the twelfth year of Kaiyuan, this movement has been carried out on a large scale across the country.A total of 12 observation points were selected across the country, and people were sent to conduct on-the-spot surveys.This project concentrated almost all the scientific and technological elites of the Tang Dynasty at that time. Such an operation is a miracle no less than the Great Wall.Based on the actual measurement results at that time, a group calculated about 526 miles (300 steps per mile in Tangli, or 454.363 meters), and 270 steps, with a difference of more than two inches. an inch away."Although this data is quite different from today's value, it is the first time in the world to use scientific methods to actually measure the length of the meridian, and its epoch-making significance to the history of science cannot be overstated.And this movement was 90 years earlier than the measured meridian of the Muslim king Almamun in 814 AD. In 727 A.D., the revision of this calendar, which exhausted all the blood and effort of a line, was finally completed.This calendar consumed a lot of manpower and material resources, covering almost all corners of the area ruled by the Tang Dynasty at that time.And Yixing is even more deliberate, handling every measurement data in person, and presiding over the measurement plan.This calendar, which has condensed countless people's efforts, has more meticulous and accurate characteristics than contemporary calendars.After its advent, it was introduced to Japan and India and other countries, and it has been used for hundreds of years.Li Longji personally named this calendar - "Dayan Calendar". However, on the eve before the publication of this calendar, Xingxing closed his tired eyes because of overwork. He was only 45 years old that year.He did not see the promulgation and implementation of this calendar in China with his own eyes, nor did he think about the great significance that what he had done would have great significance for future generations.But he knew he had done a great job and that his country would benefit immensely from his efforts. "Da Yan Li" is divided into 7 chapters: first, calculate the average time of solar terms and lunar moons (buzhongshuoshu); second, calculate 72 pentads (one pentad is counted as 5 days, and use the changes of birds, animals, plants and trees to describe the climate. change) (Step Fa Convergence Technique); third, calculate the movement of the sun (Step Rifu Technique); fourth, calculate the movement of the moon (Step Moon Lishu); fifth, calculate the time (Step Track Omission); Sixth, the calculation of solar and lunar eclipses (step rendezvous technique); seventh, calculation of the movement of the five major planets (step five-star technique).This writing method has a systematic content, reasonable structure, and strict logic, so it was used until the end of the Ming Dynasty.It can be seen that "Da Yan Li" plays an important role in our country's calendar.Although "Da Yan Li" was the best calendar at that time, it was opposed by the conservatives shortly after its promulgation.Later, the "Linde Calendar", the "Jiuzhi Calendar" and "Dayan Calendar" introduced from India were used to calculate respectively. Three or four are accurate, and "Jiu Zhi Li" is only accurate once or twice out of ten times.In the face of the facts, "Da Yan Li" was able to continue to be used. "Da Yanli" developed the concept of precession of predecessors, creatively proposed the method of calculating food fraction, discovered the formula of quadratic interpolation method with unequal intervals, new quadratic equations and formulas, and used the ancient Qitong technique in calendar calculations.Yiyi also wrote many treatises for "Da Yan Li".It's a pity that not many have been handed down; at that time and future generations, they admired his skillful skills and proficiency in calendar calculations very much, so many related works of others also use the name of Yixing.According to the records in various books, there are 32 kinds and 75 volumes with one-line names.As for the volume of "Da Yan Xuan Tu", the volume of "Yi Jue" mentioned in "Old Book of Tang Yixing Zhuan", and the "Astronomical Records" in "Book of Later Wei" "Astronomical Records" four volumes), may be the work of Yixing, but unfortunately it has been lost and cannot be verified, but his great contribution and achievements to astronomy are indelible. On that lonely night 1,000 years ago, the exhausted group finished another day's work. In front of him was a vast sea of ​​files and measurement data. Under the dim light, "Da Yan Li" was like a newborn child. Vigorously growing.He looked at all kinds of data in front of him, looking forward to the bright future of this new calendar, thinking that it will benefit the people of the country in future generations, he finally closed his tired eyes that night, and he smiled. If one sentence can be used to sum up Xing Xing's life, then I would rather say: "Ying Xing, a genius among Chinese scientists, is also a lucky one among Chinese scientists." I think this may be the most appropriate evaluation for him.The most critical element of his success, who is talented, is that he lived in a passionate Tang Dynasty, an era that countless intellectuals were fascinated by.And from the life experience of Yixing, we can feel the most critical elements of the success of this era: the Tang Dynasty established the most complete science and technology education system and scientific development system, and historically carried out scientific research and development activities of national behavior, More importantly, the gentry system had disintegrated in the Tang Dynasty, and scientists became the purest scientists, and the open country also allowed all kinds of ideas to be inclusive.In that era, China's scientific research system was developed and the depth of scientific development was as deep as that of the United States today, and countless foreign scholars came here from far away, only willing to witness the glory of Chinese civilization with their own eyes.If it is said that before Yiyi, the success of many scientists could be attributed to the success of individuals, then in the Tang Dynasty, the success of science became more of a group success and national success.The subsequent Song and Yuan dynasties continued the inherent scientific system of the Tang Dynasty. Under the background that the imperial examination system led to the increasing marginalization of natural science, science still stubbornly occupied the stage of history with its unique status.From "Da Yanli" to "Mengxi Bitan", from "Mengxi Bitan" to "Shoushili", this is the golden age of Chinese science itself. After Xingxing passed away, his posthumous title was Zen Master Dahui. In my opinion, this kind of Dahui not only belongs to him, but also belongs to the prosperous Tang Dynasty.There is a saying in the song of the band of the Tang Dynasty: "Tonight's cup reflects the bright moon paper, incense and ink fly all over the river / Tonight's cup reflects the bright moon, heroes and heroic spirits are shining / Fate is branded along the palm lines, sober up without dreams tonight / Walking into myths along fate is like returning to the Tang Dynasty in a dream.” I want to review Yi Yi’s resume, this song may represent the simplest hope of contemporary Chinese.