Science and Technology Generalist and Mechanical Engineering in Song Dynasty

General scientists in the Song Dynasty, such as Shen Kuo and Su Song, represented the scientific and technological empiricism in the early Song Dynasty. Shen Kuo discovered the existence of magnetic declination by accurately measuring meridian circle, 400 years earlier than Europe. Shen Kuo has also located the North Pole star for centuries. This enables seafarers to use the compass to determine the direction more accurately when sailing. Shen Kuo is also very good at geology. After observing strange natural phenomena for a long time, he expounded a principle of geomorphology and climate change. According to his observation of solar and lunar eclipses at that time, he analyzed that the sun and the moon were spherical, not flat, thus expanding the theory of early astronomers in China. During his tenure as Tian Jian, Shen Kuo recommended Wei Pu, an astronomer and mathematician in the Northern Song Dynasty. Wei Pu used cosmological hypothesis to describe the changes of planetary orbits, including retrograde. With the help of Wei Pu, Shen Kuo recorded and plotted the trajectory of the moon three times a night, thus correcting the mistakes about the movement of the moon, which is another important achievement of him. Unfortunately, however, there were many political opponents in the imperial court who tried to sabotage Shen Kuo's work. In the end, the imperial court accepted their mistakes about the sun and the moon, but only partially adopted the theories about planetary orbit and speed change put forward by Shen Kuo and Wei Pu.

Su Song is one of Shen Kuo's political enemies. 1070, he completed a book on pharmacology-Compendium of Materia Medica, which covered botany, zoology, metallurgy, mineralogy and other related disciplines. This paper includes many drug applications, such as ephedra. He is also the author of five different large-scale star maps, and his large number of surveying and mapping records in cartography have solved the unresolved border territory problem between Song Dynasty and neighboring Qidan since Liao Dynasty. However, Su Song's greatest achievement is the waterway instrument platform. The upper layer is the mechanical-driven armillary sphere (used for astrometry), the middle layer is the armillary sphere (used for celestial operation demonstration), and the lower layer is the Chen Si (automatic timer). 1088 started in Kaifeng, the then capital, and was completed in 1092. Although the application of pendulum machinery in Su Song was thirteen centuries later than that in Europe, Antioch Kitera machinery. Su Song's water transport instrument platform is the earliest known "uninterrupted" chain transmission equipment in the world. The earliest mechanical power transmission chain was invented by the ancient Greek philosopher Philo in the 3rd century BC, and its design points were described in the book A New Instrument and Image Method from 65438 to 0092.

The examples of Shen Kuo and Su Song show that many officials with scientific knowledge were appointed in the Song Dynasty, and these people mastered the knowledge of many disciplines, which was beneficial to the management, military and economic development of the Song Dynasty. These wise men, such as Shen Kuo, involved in many fields, such as mathematics, geography, geology, economy, engineering, medicine, art criticism, archaeology, military strategy, diplomacy and so on. He once accepted a task of border investigation and made a three-dimensional map with wood and sawdust to represent mountains, rivers and roads. Once he worked out all the possibilities of the chess game, and once he worked out the longest war time that the limited manpower and material resources could support to carry food. Shen Kuo also improved the accuracy of clepsydra timing, improved the armillary sphere and sundial, and expanded the width of the armillary sphere to better observe planets such as Polaris. Shen Kuo also did experiments on black boxes, only a few decades later than the first experimenter, the ancient Arabian Hashemite. In ancient literature, the description of natural magnets absorbing iron to prepare magnets was mentioned in Guanzi, Lv Chunqiu and Huainanzi. In the Han Dynasty (202 -220 BC), the spoon-shaped compasses made of natural magnets were used for divination and geomantic omen, but they were never used for navigation. In the Eastern Han Dynasty, Wang Chong (27 years-about 97 years) said in Lun Heng (volume 17) that "SiNa's shovel is a guide on the ground". Besides Shen Kuo and Su Song, there were many important figures in Song Dynasty, many of whom made great contributions to the development and innovation of science and technology at that time. Although the mechanical transmission of drum car has been applied since the Han Dynasty, The History of Song Dynasty provides a more detailed and in-depth description than the previous records.

Red, painted with flowers and birds on all sides, heavy platform, goulan, carved arch. A mile later, the wooden man drummed; Ten miles away, Woodenhead hit the bracelet on the second floor. One shaft, phoenix head, driving four horses. The number of drivers was eighteen, and it increased to thirty in Taizong four years.

Next is the detailed data of Lu Daolong, the chamberlain, about gears and transmission devices. Finally, the working principle of the equipment is described:

"Among them, the flat wheel rotates for one week, the garage is one mile, and the next layer of Woodenhead drums; A week on the flat wheel, ten miles in the garage, Woodenhead playing the upper bracelet. Eight wheels, big and small, with 285 teeth, are all hooked and locked, and dogs' teeth make them. "

The principle of compass is that a Woodenhead in the car indicates the direction. No matter where the car turns, Woodenhead's hand always points to the south. "Although the car was brought back, the hand has been guiding." In Song Dynasty, drum car was associated with south guide car. The South Guide Car was invented by Ma Jun, a machine manufacturer in the Three Kingdoms period. It is made of gear principle, combined with complex differential gear. This is also the principle that all modern cars have the same torque on the rotating wheels and different speeds when turning. These differential gears make the mechanically controlled fingers point in a fixed direction-south. Different from the magnetic pole principle of compass. Yan Su, a naturalist in Song Dynasty, redeveloped the compass in 1027, and his manufacturing method was also recorded in the History of Song Dynasty. Yan Su, like Shen Kuo and Su Song, is also an all-rounder, proficient in temperament and good at writing poetry and painting. He is also a scientist, who improved the lotus engraving, drew the tidal map according to his own tidal theory and wrote down the tidal theory. According to the History of Song Dynasty, Wu Deren combined drums and guided cars in Ji Li 1 107:

"In the first year of Daguan, Wu Deren, Minister of the Interior, introduced the system of South Locomotive and Drum Truck, and the two cars were completed, only in the year of Zong Sili."

The design details of these two equipment combinations are described in detail below. In the textile field, 1 1 century people in China have started to use belt-driven looms. The Silkworm Book written by Qin Guan records the structure, several key components and usage of the silk reeling car in detail. The power is generated by the pedal, and the silk thread is wound on the spool. This book is the earliest record of cars. Plowing and Weaving Map, written by Shaoxing painter Lou Lou in the Southern Song Dynasty, recorded the situation of farming and silkworm weaving in detail in the form of pictures.