East-West Question | Centennial Astronomy Master Han Tianqian: Why did Chinese astronomy change from "stargazing with naked eyes" to "gazing at the sky"?

(Question from East and West) Han Tianqian, a centenarian astronomy leader: Why did Chinese astronomy change from "gazing at the stars with the naked eye" to "gazing at the sky"?

　　China News Agency, Wuhan, April 3rd: Han Tianqian, a hundred-year-old astronomy leader: Why did Chinese astronomy change from "stargazing with naked eyes" to "gazing at the sky"?

　　Author Wu Yili Zhang Qin

　　For more than three thousand years, China has continuously recorded various astronomical phenomena.

Ancient Chinese astronomers compiled more than 100 astronomical calendars and invented a large number of astronomical instruments.

Today, Chinese astronomy has made a series of new achievements and breakthroughs, and the Chinese people have a broader vision and stronger ability to explore the vast universe.

　　Han Tianqian, who is 100 years old this year, is a famous Chinese terrestrial astronomer and astro-geodynamicist, one of the founders of Chinese astronomy and geodesy, and has witnessed the development of Chinese astronomy for more than 70 years.

Recently, Han Tianqian accepted an exclusive interview with China News Agency's "Dongxiwen", looking back at the process of Chinese astronomy from "stargazing with naked eyes" to "gazing at the sky".

The following is a summary of the interview transcript:

China News Service reporter: China is one of the earliest countries in the world to produce astronomy, and it is also one of the earliest countries to have a calendar. What astronomical achievements in ancient China led the world and still have an impact today?

Han Tianqian:

The comet silk book in the Western Han Dynasty, the star map left over from the Tang Dynasty, the guest star recorded in the Song Dynasty... China has left thousands of astronomical observation data in the past, and it is still contributing to modern astronomical research today.

　　Chinese astronomy has germinated as early as the primitive society of the Neolithic Age. Since the Xia Dynasty, there have been full-time astronomical officers, who are engaged in long-term and systematic observations, and at the same time collect and sort out scattered astronomical knowledge.

In the Qin and Han Dynasties of the Warring States Period, ancient Chinese astronomy formed a complete system centered on the calendar and astronomical observation.

The calendar is the main part of ancient Chinese astronomy. It is not only the work of compiling the calendar such as the calculation of the synodic, the twenty-four solar terms, and the placement of the intercalary moon, but also a series of azimuth astronomical topics such as the calculation of the solar and lunar eclipses and the positions of the planets, similar to the compilation and calculation. The current astronomical calendar.

The Ancient Star Observatory in Dengfeng City, Henan Province was built in the early Yuan Dynasty and has been around for nearly 800 years. It is the oldest astronomical observatory in China.

Photo by Zhou Qinjun issued by China News Agency

　　The ancient Chinese calendar adopts the combination of yin and yang, with the movement cycle of the sun as the year, the cycle of the moon as the month, and the intercalary month to coordinate the relationship between the year and the month.

The ancients divided the year into 24 segments according to the change of the position of the sun in a year and the evolution sequence of the ground climate caused by it, and divided them into 12 months to reflect the four seasons, temperature, phenology, etc. Production is closely related, which is very remarkable and complex reckoning.

During the mango season in the twenty-four solar terms, farmers in Rongcheng, Shandong plant sweet potatoes (commonly known as sweet potatoes).

Photo by Yang Zhili issued by China News Agency

　　As the "Book of Changes" said: "Observe astronomy to observe time change." Astronomical observation is another main content of ancient Chinese astronomy, including methods, instruments and records of astronomical observation.

Since ancient times, the rich records of solar eclipses, lunar eclipses, lunar occultations, sunspots, meteors, comets, and novae preserved in China are important reference materials for modern astronomy.

　　China News Service reporter: During the Ming and Qing Dynasties, "Western learning spread eastward", and Western science was introduced into China on a large scale.

What kind of collisions and fusions did the Westerners, represented by Matteo Ricci, bring Western astronomical knowledge and traditional Chinese astronomy?

　　Han Tianqian: Although China has had astronomical research since ancient times, there were only two purposes at that time, one was agricultural production, and the other was divination.

Ancient Chinese astronomy paid attention to the "unity of man and nature". The purpose of observing celestial phenomena is to predict good and bad luck. The so-called "astronomy" is like a tool for "fortune-telling and divination", and it cannot be regarded as a real natural science research.

　　In the 16th century, missionaries represented by Matteo Ricci came to China one after another. At the same time, they brought a lot of European scientific knowledge, including Western astronomy, which led to the development of ancient Chinese astronomy.

The most important aspect of the spread of Western astronomy in China is the publication of the "Chongzhen Almanac".

This is an encyclopedia of Western classical astronomy. For quite a long time, this work has been the main textbook for Chinese scholars to study astronomy.

In addition, missionaries also introduced many astronomical instruments, such as telescopes.

Chongzhen almanac compiled by Xu Guangqi.

Photo by China News Agency Huang Dong

　　It was not until the early days of the founding of New China that the Chinese began to truly study astronomical phenomena and astronomical laws.

Today, Chinese astronomical research continues to develop.

The "China Sky Eye", which started construction in 2011 and opened in 2016, has been opened to the world and has achieved a series of important scientific achievements.

This is the world's largest and most sensitive single-aperture radio telescope, and a representative "business card" of China's technological innovation.

The "China Sky Eye" (FAST) located in Pingtang County, Guizhou Province is currently the world's largest and most sensitive single-aperture radio telescope.

Photo by China News Agency reporter Qu Honglun

China News Service: At the end of 1953, China began to use the imported Wilt T4 all-around theodolite for astronomical measurements.

The T4 all-around theodolite you proposed uses the contact micrometer to measure the time according to the double star magnitude method to realize the semi-automatic recording of astronomical time measurement. Why is it called "China's Ginger method" by the astronomical circle?

Han Tianqian:

At the end of 1953, China began to use an imported instrument, the Wilt T4 all-around theodolite, to conduct first-class astronomical surveys for the Yellow River.

At 30 years old, I participated in this program.

With the help of foreign experts, the teachers and friends of the Geodetic Survey Group of the Institute of Geography of the Chinese Academy of Sciences quickly mastered the use of the Wilt T4 all-around theodolite, which was called the world's most advanced astronomical measuring instrument at that time.

　　When night falls and the stars appear, it is our busiest time.

Stargazing, measuring points, counting, calculating, drawing... A point of 50 kilometers, we have to complete the task of nearly 100 measuring points in a short period of time, day and night, and the task is heavy.

Although the Wilt T4 all-around theodolite is "all-round", the manual operation is relatively complicated, the calculation is cumbersome, and the operation time is long. At that time, the Soviet Union failed to solve these problems for decades.

So, I began to think about whether I could think of "new ways" on foreign equipment.

After many calculations, we succeeded, and the ergonomics increased by more than 5 times.

This calculation method was affirmed by the State Administration of Surveying and Mapping at that time and was compiled into the "Detailed Rules for Astronomical Measurements".

　　After the completion of the Yellow River astronomical survey task, in the late 1950s, I proposed the T4 almighty theodolite to use the contact micrometer to measure the time according to the double star magnitude method, to realize the semi-automatic recording of astronomical time measurement, greatly improving the time measurement accuracy, and it was widely used by astronomy. It is called "China's Ginger method".

This scientific research achievement has been used by the Chinese surveying and mapping department as one of the important methods for measuring high-precision astronomical coordinates.

During this period, we also organized and calculated the horizontal position table of 2,628 stars in China's geodetic astronomical survey, the Jinger star alignment table, and the optimal technical plan for the determination of astronomical basic points, which attracted the attention of astronomical experts.

Young Han Tianqian is doing astronomical observation work.

Photo courtesy of the Institute of Precision Measurement Science and Technology Innovation, Chinese Academy of Sciences

China News Service reporter: You have witnessed the process of Chinese astronomy from being poor and white, stargazing with the naked eye, to establishing a complete theoretical and technical foundation for terrestrial astronomy.

What difficulties did the initial Chinese astronomical research have?

Han Tianqian:

In May 1960, the team from the Institute of Geography of the Chinese Academy of Sciences received the task of conducting astronomical surveys on the Qinghai-Tibet Plateau, the "roof of the world".

We set off from Lanzhou City, Gansu Province by "Jiefang" truck and arrived in Lhasa after 11 days.

Overcoming altitude sickness, fighting for more than 30 starry nights in Lhasa, continuously conducting measurement and scientific research, and for the first time solving the problem of human instrument difference in the determination of astronomical azimuth angle, providing a basis for research and analysis of the astronomical geodetic network, and establishing the first astronomical foundation on the plateau. point.

　　Then, we went to Yangbajing, Tuotuo River, Kunlun Mountain and other places with an altitude of 4000-5000 meters to measure a batch of astronomical points. It lasted more than 5 months and successfully completed the task, filling a gap in the history of Chinese astronomical measurement at that time.

　　At the end of 1962, I led the team to build Wuchang Shichen Station.

Accurate world time is the basic basis necessary to determine the ground longitude and azimuth, and the determination of longitude and azimuth is an important part of the geodetic survey.

Accurate world time is required for the preparation of precise national maps, the determination of boundary lines, mining exploration, the development of water conservancy resources, long-distance aviation and navigation, and the observation of artificial satellites.

Therefore, the preparation of Wuchang Time Station is of great value for China to improve the timing of world time.

After accepting the assignment, we reviewed and analyzed a large number of Chinese and foreign materials, and began to work on design and selection of construction teams.

　　After more than a year, Wuchang Shichen Station was completed ahead of schedule with quality and quantity.

Years of astronomical time measurement, keeping time with clocks, broadcasting by radio signals, and recording time numbers on time service stations have proved that Wuchang Shichen Station has reached the first-class level in China.

We also use the Wuchang Time Station to conduct research on China's comprehensive time correction building and the earth's rotation. We are the first in China to propose that the correction of the solid tide effect should be included in the difference of the star catalog system. level of contribution.

In the China International Earth Rotation Joint Survey in 1980, the observation accuracy of the classical optical instruments at Wuchang Shichen Station and other domestic astronomical observatories reached the international best level, winning honor for the country.

Han Tianqian in his youth.

Photo courtesy of the Institute of Precision Measurement Science and Technology Innovation, Chinese Academy of Sciences

China News Agency reporter: After 70 years of chasing stars and building dreams, what advice do you have for contemporary youth?

Han Tianqian:

I have been observing the starry sky, measuring the longitude and latitude, the vastness of the universe, the stability of the planet, and the loneliness of scientific research. I often remind people on the ground that the field of vision must be broad, and not to be happy and sad overnight.

All my life, I have gone from being poor and white in Chinese astronomy to stargazing with the naked eye. Today, I have established a complete and necessary theoretical and technical foundation for terrestrial astronomy. I believe that there will always be a brighter starry sky waiting for us. No matter how dark the surroundings are, extend the observation mirror. , expand a little, and you will surely see the light.

　　I am 100 years old this year.

These 100 years have coincided with several waves of science and technology in physics, astronomy, and surveying and mapping.

Technological innovation can bring the accuracy and imagination of scientific research to a new level, and of course bring new opportunities and directions.

Since the epidemic, even at my age, I have felt the vigorous development of the Internet, health codes, online takeaways, grocery shopping, medical consultations, and prescription of medicines. Behind everyone's life, the digital ecology is booming, and this is destined to happen. bring many new opportunities.

Now that new opportunities have emerged, we must try them out and grasp them firmly.

　　The sky is bright and dark, and life has its ups and downs.

When we take a long-term view, the stars are always brighter, and life is full of twists and turns.

(over)

Interviewee Profile:

　　Han Tianqian, a famous Chinese geodetic astronomy and astro-geodynamics, one of the pioneers of Chinese astronomical geodesy.

Born on February 11, 1923 in Haitai Village, Xiangshan County, Zhejiang Province, in October 1943, he was admitted to the Department of Geodesy of the Central School of Surveying and Mapping.

He used to be the executive director of the Chinese Astronomical Society and the director of the Astro-Geodynamics Professional Committee, as well as the director of the Chinese Society of Surveying and Mapping, and the editorial board of the Chinese Journal of Surveying and Mapping.