What are the four great inventions in ancient China?

The Four Great Inventions are a viewpoint about the history of China's science and technology, referring to the four great inventions that had great influence on the world in ancient China, and the important creations of the working people in ancient China, referring to papermaking, compass, gunpowder and printing.

This statement was first put forward by Yue Se, a British sinologist, and later inherited by many historians in China. It is generally believed that these four great inventions greatly promoted the development of politics, economy and culture in ancient China. These inventions spread to the west through various channels and had a great influence on the history of world civilization.

Compass is a simple tool to judge the direction. Originally known as Sina. The main component is a magnetic needle that can rotate freely on the shaft. The magnetic needle can be kept in the tangential direction of magnetic meridian under the action of geomagnetic field. The north pole of the magnetic needle points to the geographical north pole, which can be used to identify the direction. It is often used in navigation, geodesy, tourism and military affairs. N of the compass refers to the north, e to the east, w to the west and s to the south.

China is regarded as the country that invented the compass in the world. The invention of the compass is the result of long-term practice and understanding of the magnetism of objects by the working people in ancient China. Due to productive labor, people came into contact with magnetite and began to understand its magnetism. People first discovered the property that magnets attract iron, and later discovered the directivity of magnets. After many experiments and studies, a practical compass was finally invented. The earliest compass was made of natural magnets, which shows that the working people in ancient China discovered the attraction of natural magnets and their iron very early. According to ancient records, as early as the Spring and Autumn Period and the Warring States Period, the productive forces developed greatly, especially agricultural production, which promoted the development of mining and smelting industries. In the long-term production practice, people know magnets from iron ore. The earliest compass was Sina.

history

"China's earliest compass theory is the" induction theory "based on the theory of Yin-Yang and Five Elements." According to Guan Zengjian, Shen Kuo, a great scientist in China in the middle of the1/kloc-0 century, is still puzzled by the compass. His "Meng Xi Notes" introduced the artificial magnetization method of the compass, the discovery of the magnetic declination angle and the erection method of the compass, but he didn't know why the compass was guided-"guided by a magnet" ... it couldn't be justified! Subsequently, scholars put forward various compass theories based on the theory of yin-yang and five elements and people's understanding of the shape of the earth at that time. For example, Guan's Geography refers to Mongolia, which was written in the Song Dynasty at the latest, first put forward the following logic:

"Magnetic needle is made of iron, and iron belongs to gold. According to the five elements, gold is born in water and the north belongs to water, so the water in the north is the son of gold. Iron comes from magnets, which are bred by the spirit of the sun, which belongs to fire and is located in the south, so the south is equivalent to the mother of magnetic needles. In this way, the magnetic needle should not only take care of the mother, but also miss the children, naturally pointing to the north-south direction. "

The compass principle of the Southern Song people still thinks that "the compass refers to the spirit where the sun is located" only revolves around the phenomenon of magnetic declination, and the argument is based on the coordinate system that turns to geographical orientation-the ancients in China thought that the ground was flat and limited in area, so there must be a center on the ground, and the meridian passing through the center is the only north-south direction. Zeng Sanyi, a member of the Southern Song Dynasty, believed that once the geodesy is not on this north-south line, the compass points to nature "less biased". In the Ming Dynasty, it was pointed out that the correct guiding direction was determined by the earth azimuth system, and the deviation angle was determined by the celestial azimuth division system. Guan Zengjian believes that this statement "embodies the embarrassment of traditional compass theory in the face of the contradiction between yin-yang induction theory and magnetic declination".

During the Wanli period of the Ming Dynasty (A.D. 1573 ~ 1620), missionaries came to China, bringing western compass theory, earth theory and related scientific and technological knowledge. Influenced by it, China scholars began to explore the compass theory from a new angle. In this process, the functions of Yin-Yang and Five Elements are gradually weakened, and the analysis from the mechanical point of view is increasing. However, the scientific theory put forward by Gilbert in 1600 is not unified in western academic circles, let alone in the East. Among the missionaries, ferdinand verbiest, a Belgian Jesuit who came to China in 1658, has the most systematic compass theory, but he thinks that the magnetic needle points to the geographical north and south poles of the earth itself, and his theory is still limited to the scope of ancient science, unlike Gilbert who realized that the earth itself has magnets. Ferdinand ferdinand verbiest's theory had a far-reaching influence in China. Until the middle of19th century, some scholars in China still used it to explain the compass problem. At this time, missionaries who came to China in the late Qing Dynasty began to introduce modern western magnetic knowledge to China.

In the pre-Qin period, our ancestors had accumulated a lot of knowledge in this field. When exploring iron ore, they often encountered magnetite, that is, magnetite (mainly composed of ferroferric oxide). These findings have long been recorded. These discoveries were first recorded in several articles in Guanzi: "There are magnets on the mountain and gold and copper under it." There are similar records in other ancient books, such as Shan Hai Jing. The iron-absorbing characteristics of magnets have long been discovered. The main chapter of the nine volumes of Lu's Spring and Autumn Annals is: "Kindly absorb iron, or absorb it." At that time, people called "magnetism" "kindness". They think that magnets attract iron is the attraction of loving mothers to their children. And think: "Stone is the mother of iron, but there are two kinds of stones: kind and unkind. Kindness can attract his children, but not kindness. " It is said that after Qin Shihuang unified the six countries, Epang Palace was built near Xianyang. There is a door made of magnets in the palace. If someone wears armor and hides weapons to assassinate in the palace, they will be attracted by the magnet door. This story tells us that the ancient working people mastered the knowledge of magnetism very early.

When two magnets are put together and close to each other, sometimes they attract each other and sometimes they repel each other. As we all know, a magnet has two poles, one is called N pole and the other is called S pole. Like-sex repulsion, opposites attract. People didn't know this truth at that time, but they could still perceive this phenomenon.

In the Western Han Dynasty, there was an alchemist named Luan Da. He used this characteristic of magnet to make something similar to two chess pieces. By adjusting the mutual position of the polarities of two chess pieces, sometimes the two chess pieces attract each other and sometimes repel each other. Luan Da called it "playing chess". He dedicated the novel to Emperor Wu of the Han Dynasty and gave a live demonstration. Emperor Wu of the Han Dynasty was pleasantly surprised. He was named "General Five Blessingg". Luan made great use of the properties of magnets to make novel things to deceive Emperor Wu of Han Dynasty.

The ancestor of the compass appeared in the Warring States period. It is made of natural magnets. It looks like a spoon with a round bottom, which can be balanced on a smooth "field" and can rotate freely. When it is at rest, the handle of the spoon will point to the south. The ancients called it "Sina", and in the book Han Feizi at that time, there was: "Wang Li Sina took the time first." "Sooner or later" means square, east. Guiguzi recorded the application of Sina, and Zheng people took Sina with them when picking jade to make sure they didn't get lost.

In the Spring and Autumn Period, nephrite and jadeite with hardness of 5-7 degrees can be polished into various shapes, so natural magnets with hardness of only 5.5-6.5 degrees can also be used to make SiNa. In the book Lun Heng, Wang Chong of the Eastern Han Dynasty made a clear record of the shape and usage of Sina. Sina is made of a whole natural magnet after pondering. The handle of the spoon is guided by the pole, so that the center of gravity of the whole spoon falls right in the middle of the bottom of the spoon. The spoon is placed in a smooth field, surrounded by a four-dimensional stem and branches, which synthesize 24 directions. This design was completed through long-term research after the ancients carefully observed many phenomena related to magnetism in nature and accumulated a lot of knowledge and experience. The appearance of Sina is the practical application of people's understanding of the polarity of magnet fingers. However, Sina also has many defects. Natural magnets are hard to find, and they are easy to lose their magnetism when they are impacted and heated during processing. Therefore, Sina's magnetism is relatively weak, and the contact with the site should be very smooth, otherwise it will be difficult to rotate because of the great friction resistance, and the expected guiding effect will not be achieved. Moreover, Sina has a certain volume and weight, which is inconvenient to carry, which may be the main reason why Sina has not been widely used for a long time.

Sina consists of a bronze disc and a magnetic spoon made of a natural magnet. The bronze disc is engraved with 24 directions, and the magnetic spoon is placed on the central circular surface of the disc. When it is at rest, the tail of the spoon points to the south.

The magnetic poles at both ends of each magnet are different, one is called S pole and the other is called N pole. The earth where we live is also a huge natural magnet, with different magnetic poles in the north and south. The South Pole near the Earth's North Pole and the North Pole near the Earth's South Pole. It is precisely because the geomagnetic poles do not completely coincide with the geographical level that the geomagnetic declination phenomenon appears. As we know, like magnetic poles repel and opposite magnetic poles attract, so no matter where on the earth's surface, take a magnetic needle that can rotate freely, and its N pole will always point to the north and its S pole will always point to the south.

More than two thousand years ago, during the Spring and Autumn Period and the Warring States Period, China had already made farm tools out of iron. When working people are looking for iron ore, they find a magnet and know that it can absorb iron.

Meng Qian Bi Tan is a book about ancient science and technology in China written by Shen Kuo (1031-1095), which talks about some problems of magnetism and compass. In "A Supplementary Talk with Meng Xi Bitan", he talked about various phenomena in the process of friction magnetization: "It is always sharp to use a magnet to confront each other, which means that the north is not afraid of stones ... On the contrary, there should be differences between the north and the south, which has not been thoroughly studied." That is to say, after rubbing the sewing needle with a magnet, it sometimes points to the north in a tit-for-tat manner. Magnets have N and S poles, and the direction of sewing needle is different when magnetized, so the direction after magnetization is also different. But Shen Kuo didn't know this truth. He truly recorded this phenomenon and frankly admitted that he didn't think deeply. I hope future generations can explore further.

Papermaking is one of the four great inventions in China and an outstanding development in the history of human civilization.

Ming creation. China is the first country in the world to raise silkworms and weave silk. In ancient China, the working people spun silk from superior cocoons, and the remaining evil cocoons and diseased cocoons were made into silk floss by bleaching. After floating, some residual flocs will be left on the mat. When the flossing frequency is high, the residual flossing on the pad will accumulate into fiber sheets, which can be peeled off after drying and can be used for writing. This kind of floc is called "He Qi" or "square floc" in ancient books because of its small number of by-products. It can be seen that the origin of papermaking in China is related to silk floss.

Cai Lun's improved papermaking (also called Cai Houzhi). In the first year of the Eastern Han Dynasty and the first year of Yuan Xing (A.D. 105), Cai Lun made plant fiber paper suitable for writing with bark, broken fishing nets, rags and hemp heads as raw materials, and improved the paper-making technology, making paper a widely used writing material. It is called "Cai Hou Paper". Have a unified understanding of the concept of paper. What kind of article is called a "paper"?

way

In ancient times, there were papyrus paper in Egypt, parchment paper in Europe, silk tissue paper, silk paper for writing and colorful monkey paper in China. Among them, only Cai Hou paper made of plant fiber has a far-reaching influence on the development of the world paper industry and the spread of human culture, and its basic technology is still in use today. According to the historical records and the research of later generations, the basic points of Cai Lun's papermaking can be summarized as follows: fiber sheets made from plant fibers by cutting, boiling, bleaching, tamping, curtain-making and drying. Fiber sheets that have not been treated by the basic steps of papermaking do not have the basic properties of paper, so they cannot be called paper in the traditional concept of ancient China. Egyptian papyrus is the earliest paper in the world, but parchment was widely used in medieval Europe. Because of the single raw material and limited room for improvement, these two kinds of paper were replaced by China paper which used various materials. There are still some places where papermaking is used to make paper.

A black or brown explosive is made of potassium nitrate, charcoal and sulfur by mechanical mixing. It is first made into powder and then generally made into particles of different sizes according to different uses. It was the only military propellant until smokeless powder was used.

The development of history

Gunpowder was invented by an ancient alchemist during the Sui and Tang Dynasties in China, and it has been 1000 years. The study of gunpowder began with the ancient Taoist alchemy. The ancients refined Dan medicine to live forever. The purpose and motive of alchemy are advanced, but its experimental method still has some advantages, which eventually led to the invention of gunpowder.

Although alchemists have mastered certain chemical methods, their direction is to seek elixir of life, and the invention of gunpowder is a by-product. An alchemist usually "crouches" sulfur, arsenic and other toxic stone medicines before use, and "crouches" means surrendering. The process of losing or reducing toxicity is called "reducing fire".

Sun Simiao, a famous doctor and Taoist priest in the early Tang Dynasty, wrote in the Law of Sulphur Cover in Dan Jing that sulfur and saltpeter should be ground into powder and put into a silver jar or a sand jar. Dig a hole, put a pot in the hole, level the hole and fill it all around. Light three honey locust seeds that have not been eaten by insects one by one, then put them into a pot and set off fireworks with sulfur and saltpeter. When the smoke can't catch fire, stir-fry the charcoal until one-third of the charcoal is extinguished, then anneal it, wait until the mixture cools before taking it, and then subdue the fire.

Qing Xuzi, a famous Taoist priest in the middle Tang Dynasty, put forward a recipe for reducing fire in the Alum Method: "Sulfur is 22 liang, nitrate is 22 liang, and Aristolochia is half San Qian. That's the end. Mix it up. Dig a hole and put the medicine in the pot, even with the ground. Put a piece of cooked fire, marble is big, and when you put it inside, the smoke will gradually rise. " He used Aristolochia instead of Gleditsia sinensis in Sun Simiao's prescription. These two substances play a burning role instead of carbon. All the recipes for latent fire contain carbon, saltpeter should be added to sulfur, and sulfur should be added to saltpeter. This shows that the alchemist intends to burn the drug to remove its virulence. Although the alchemist knew that the mixture of sulfur, nitrate and carbon would have a fierce reaction and took measures to control the reaction speed, the fire accident in the Dan room caused by drug fire still occurred frequently.

There is a story in Tai Ping Guang Ji, which tells that in the early years of Sui Dynasty, a man named Du Chunzi visited an old man who was an alchemist. Lived there that night. Du Chunzi woke up in the middle of the night and saw "purple smoke passing through the house" in the blast furnace, and the house suddenly burned. This may be caused by the negligence of the alchemist when preparing flammable drugs.

There is also an alchemy book called "A Brief Introduction to Zhen Yuan Miao Dao", which also talks about burning people's faces and hands with fire from sulfur, saltpeter, realgar and honey, going straight to the roof and burning houses. This book warns alchemists to prevent such accidents. This shows that the alchemists in the Tang Dynasty mastered a very important experience, that is, sulfur, nitrate and carbon can form a highly flammable medicine, which is called "gunpowder", that is, gunpowder. Because of the invention of gunpowder, it was once regarded as medicine in the process of self-made Dan dispensing.

"A Record of Ming Taizu": "On December 20th, the second year of the apocalypse, Huang Hemeng, a traffic general sent by Mao Zedong (Yuan Keli), the commander-in-chief of Liaoning Province, paid for food, cloth, weapons, gunpowder and other things, and then presented them with stamps and flags to show his gratitude."

Compendium of Materia Medica mentions that gunpowder can cure sores, tinea, insects, dampness and epidemics. Gunpowder can't solve the problem of immortality, and it is easy to catch fire. The alchemist is not interested in him. The formula of gunpowder was transferred from an alchemist to a strategist and became one of the black gunpowder in four great inventions of ancient china.

Spherical powder is wrapped around the head of the arrow shaft. After the fuse is lit, use a bow and arrow to shoot the gunpowder and burn the enemy. There are also gunpowder and poison, plus some asphalt and tung oil. Made into poison pills, burned and shot the enemy with bows and arrows, becoming the "enemy of ten thousand people." In the Song Dynasty, people put gunpowder into bamboo tubes, tied tiny "directional sticks" behind the gunpowder, and ignited the nitrate on the fire tube, so that the gunpowder in the tube burned rapidly, generating forward thrust and making it fly to the enemy line to explode. This is the world's first gunpowder rocket. Later, muskets and guns were invented. These are primitive tubular firearms made of bamboo. They are the ancestors of modern guns.