Shen Kuo introduced his research achievements in three papers: On the Hunyi, On the Floating Leak and On the Landscape, elaborated the principle of instrument transformation in detail, and expounded his own astronomical views, which played an important role in the history of astronomy in China.
Physicist+chemist+mathematician
Shen Kuo's achievements in physics research are also extremely rich and precious. The opinions and achievements recorded in Meng Qian's Bi Tan involve mechanics, optics, magnetism, acoustics and other fields. In particular, he has made outstanding achievements in magnetic research. Shen Kuo explicitly talked about the deflection angle of the magnetic needle for the first time in Meng Qian Bi Tan. In terms of optics, Shen Kuo made a popular and vivid exposition on pinhole imaging, concave mirror imaging, and the zoom-in and zoom-out functions of concave-convex mirror through personal observation experiments. He also made some scientific explanations for the light transmission reason of the so-called "transparent mirror" (a bronze mirror that can see the front pattern on the back) handed down from ancient China, which promoted the later research on "transparent mirror". In addition, Shen Kuo also did experiments on the piano to study the phenomenon of acoustic vibration.
In chemistry, Shen Kuo has also made some achievements. When I was in Yanzhou, I studied Lu Yan's oil reserves and uses. Taking advantage of the fact that oil is not easy to burn completely to produce carbon black, he pioneered the process of making cigarette ink with petroleum carbon black instead of pine carbon black. He has noticed that oil resources are abundant and "born in infinity", and predicted that "this thing will never be used in the world", which has been verified today. In addition, the name "petroleum" was first used in "Shenkuo", which is much more appropriate than the previous names such as stone paint, stone grease water, fierce fire oil, kerosene, naphtha and stone candle. In Meng Qian Bitan's "Taiyin Xuan Jing" (gypsum crystal), Shen Kuo distinguished several kinds of crystals from morphology, deliquescence, cleavage and heating dehydration, and pointed out that although they have the same name, they are not the same thing. He also talked about examples of metal transformation, such as the physical phenomenon of changing iron into copper with copper sulfate solution. These means of identifying substances described by him show that people's research on substances at that time has broken through the observation of simple surface phenomena and began to explore the internal structure of substances.
Shen Kuo also has excellent research in mathematics. Starting from the actual calculation needs, he founded "gap product technology" and "convergence technology". Shen Kuo put forward a correct method to find the total stack number of jars and chess pieces by studying the volumes of jars and chess pieces with gaps, that is, the "gap product method", that is, the second-order arithmetic progression summation method. Shen Kuo's research has developed the arithmetic progression problem since Nine Chapters of Arithmetic, and opened up the research direction of higher-order arithmetic progression in the history of ancient mathematics in China. In addition, Shen Kuo also studied the relationship among arc, chord and vector in a circular bow from the calculation of field, and put forward the first simple and practical approximate formula for calculating arc length from the length of chord and vector in the history of mathematics in China, which is called "the skill of meeting circles". The establishment of this method not only promotes the development of plane geometry, but also plays an important role in astronomical calculation and makes an important contribution to the development of ball science in China.
Geographer+medical scientist
Shen Kuo also made many outstanding conclusions in geosciences, which reflected that China's geosciences reached the advanced level at that time. He correctly discussed the reasons for the formation of the North China Plain: according to the banded distribution of snail shells and oval gravel between the cliffs of Taihang Mountain in Hebei Province, it was inferred that this area was a seashore in ancient times, and the North China Plain was formed by sediment carried by rivers such as the Yellow River, Zhangshui River, Hutuo River and Sanggan River. During his inspection in eastern Zhejiang, he observed the geomorphological features of Yandang Mountain peak, analyzed its causes, and clearly pointed out that it was the result of water erosion. He also made a similar explanation based on the geomorphological features of the loess area in northwest China. He also observed and studied similar bamboo shoots and various fossils such as peach pit, reed root, pine tree, fish and crab excavated from underground, clearly pointed out that they were the remains of ancient animals and plants, and inferred the ancient natural environment from the fossils. All these show Shen Kuo's valuable materialism. In Europe, it was not until the Renaissance that the Italian Leonardo da Vinci began to discuss the nature of fossils, more than 400 years later than Shen Kuo. When Shen Kuo visited the border of Hebei Province, he made a three-dimensional geographical model of the mountains, roads and terrain he visited on the board. This practice was quickly extended to the border States. In the ninth year of Xining (A.D. 1076), Shen Kuo was ordered to compile the map of counties in the world. He consulted a large number of files and books, and after nearly 20 years of unremitting efforts, he finally completed the masterpiece "Shouling Map" in the history of cartography in China. This is a large atlas, with 20 maps, including a large map, one foot high and two feet wide; Small picture; Eighteen maps for each road (according to the administrative divisions at that time, the whole country was divided into eighteen roads). The scale and detail of the map are rare before. In painting, Shen Kuo put forward nine methods, such as grading, quasi-viewing, mutual integration, side inspection, competition, square inclination and straight pedaling, which are generally consistent with Pei Xiu's famous six-body painting method in the Western Jin Dynasty. He also subdivided all directions into twenty-four directions, which further improved the accuracy of the map and made important contributions to ancient cartography in China.
Shen Kuo is also proficient in medicine and biology. He was interested in medicine since he was a child and devoted himself to medical research. He collected many prescriptions and cured many critically ill patients. At the same time, his knowledge of medicinal botany is also extensive, and he can actually find out, distinguish authenticity and correct mistakes in ancient books. He once put forward a new theory of "five difficulties"; Shen Kuo's medical works include Prescription, etc. The existing Su Shen Liang Fang was made by later generations attaching Su Shi's Miscellaneous Treatise on Medicine to the Prescription.
Materialist.
Shen Kuo has a simple materialistic thought and a viewpoint of development and change. He believes that "the change of heaven and earth, the violence of cold and summer, the drought of floods and the locusts of moths all have laws", and points out that "the principle of going with the sun and going against the yin has its own origin, following nature and coming unexpectedly." That is to say, the changes of things in nature are regular, and these laws exist objectively, regardless of human will, and these laws also exist objectively, regardless of human will. He also believes that there are normal and abnormal changes in the laws of things, and we can't stick to fixed rules. It was these correct ideas and viewpoints that prompted him to make great achievements in science and technology at that time. Shen Kuo once put forward the view that known knowledge is limited and human knowledge is infinite, which has great influence on the development of science.
The ideological tendency of materialism is also manifested in Shen Kuo's attaching great importance to the practical experience and inventions of the working people, and constantly drawing wisdom and strength from the working people at that time. He once said: "As for the technical equipment, the size, black, yellow and reddish can all be made by saints! People who work a lot, a group of teachers and people in the fields are unpredictable. " In order to explore medical knowledge, he "asked to see everywhere he went, whether he was a doctor, a stranger, a villain, or even a scholar-bureaucrat's house or a hermit in the mountains." In Meng Qian Bi Tan, he recorded many outstanding contributions of the working people in the Song Dynasty in science and technology, which is admirable. For example, movable type printing invented by Buyibi (the last day+the second day), the architectural achievements of folk craftsmen Yu Hao and carpenters, the advanced method of closing the dragon and blocking the mouth created by He Gong Gao Chao, the deeds of civilian astronomer Wei Pu Li Xiu, and the valuable experience gained by many unsung heroes in the production struggle such as steelmaking in Hebei and tea planting in Fujian, etc. It is precisely because of Shen Kuo's detailed account that the achievements of many working people who have made contributions have been preserved and passed down.
The tendency of materialism determines that Shen Kuo's description of natural phenomena and scientific and technological achievements is scientific. His observation and description of things are very detailed, specific and accurate, and there is no bad habit of ordinary literati exaggerating in feudal times. So through his account, we can clearly judge the production technology and natural science level he reached at that time. For example, Shen Tuo's records of lightning, mirage, tornado, earthquake, meteorite and other natural phenomena are very detailed, appropriate and vivid, making people feel as if they were there.
Shen Kuo can study objective things from the viewpoint of development and change, and draw correct conclusions. When discussing many problems about mathematics, meteorology and medicine, he repeatedly stressed the need to adapt to local conditions and adapt to the times. For example, February and August in ancient times were the season for picking herbs, but Shen Kuo pointed out that the growth of medicinal materials was influenced by natural conditions and cultivation conditions, and there were different requirements for picking herbs, such as taking roots, leaves, buds, flowers and fruits. Therefore, it is necessary to choose the time of drug collection according to different situations, and it is not possible to "fix the month" rigidly. Shen Kuo's point of view is very reasonable.
Shen Kuo didn't just observe some superficial natural phenomena. He also tried to explore its scientific truth and put forward an explanation of the law of development and change of things. The explanations of many problems, such as the formation reasons of the peaks of Yandang Mountain and North China Plain, the location of Twenty-eight Hostels and the formation of fossils, are in line with modern scientific principles. In order to find out the truth of Yang Ai (concave mirror)' s imaging, he observed the shadows of birds in the air, compared the imaging differences by himself, and finally made a more correct explanation. These are the important reasons for his success in science.