What are the four unsolved mysteries of Qin Terracotta Warriors?

First, why isn't there a statue of the Commander-in-Chief? These terracotta warriors, whether infantry, crossbowmen, cavalry or chariots, belong to warrior figures. No data on the commander. Why is this? Some people think it may be based on the Qin system. Before each expedition, the king of Qin would give instructions and appoint a general as commander in chief. When the No.3 pit was built as the headquarters, the general had not been appointed yet, and the craftsmen dared not mold one as a commander at will. The scroll is in the hands of Qin Shihuang in the underground palace of Qin Mausoleum. Others think that it may also be because Qin Shihuang is the supreme commander of Qin Jun. In order to safeguard the absolute authority and sacred dignity of the emperor, the image of Qin Shihuang cannot be shaped in the pit of Terracotta Warriors. These two statements are just guesses, and there is no conclusion. Second, why were the Terracotta Warriors burned? "When excavating the Terracotta Warriors, archaeologists found that almost all the wooden structures in the pits of Terracotta Warriors No.1 and No.2 were burned to charcoal or ashes. Most of the paintings on the ears of pottery figurines and pottery horses were baked by fire, and some blue-gray pottery figurines were burned red. The cave collapsed after being destroyed by fire. Pottery figurines and pottery horses were smashed to pieces, some were uneven, some had different heads, some had broken heads, some had broken arms and legs, some were broken into pieces, and some were broken into pieces, and few were complete. Who started the fire? Future generations speculate that there are three possibilities. First, the Qin people themselves set fire to the objects in the tomb and some buildings around the tomb, so that the souls of the deceased could be taken to the underworld for enjoyment, which is called "Liao Festival". However, if it is really the funeral system and folk custom of the occupation generation, why only burn the No.1 pit and No.2 pit and not the No.3 pit? If the Qin people really burned it themselves, then the interval between completion and burning will certainly not be too long. However, according to archaeological excavations, there are generally more than a dozen layers of silt on the floor tiles under the pit, which can never be formed in four or five years. Second, the Qin Terracotta Warriors and Horses may have been burned by troops led by Xiang Yu. According to historical records such as Han Hoe, Historical Records and Shui Jing Zhu, if Qin Gong burns, the fire will not go out in March. However, there is not a word in the above-mentioned history books that clearly describes that Xiang Yu's army burned Qin Terracotta Warriors and Horses, and even the words Qin Terracotta Warriors and Horses are not mentioned. Therefore, it can only be a guess of later generations to blame Xiang Yu for burning the Terracotta Warriors. Thirdly, the fire in the pit of Terracotta Warriors and Horses is caused by methane and spontaneous combustion caused by the corruption of organic matter such as buried objects in the pit. However, the same pit, the same environmental conditions, why only burned the first pit and the second pit, but the third pit did not catch fire? There is no scientific basis for this. Third, the mystery of making pottery figurines. The terracotta warriors in the pit are made of mud and gray pottery. High temperature and hard texture. After observation, no signs of mildew were found. They must be carved one by one. Both terracotta figures and terracotta horses were originally painted with bright colors. Because the pit was destroyed and buried underground for a long time, almost all the colors fell off. However, we can still see various colors from local colors, including green, pink, vermilion, pink, purple, blue, yellow, orange, pure white, gray, Hershey and so on. Various colors, please, are gorgeous, but they also increase the majesty of the whole military array. These pottery horses have been buried in the dark underground for more than 20 centuries. After unearthed, it still maintains the characteristics of pure color, high density and high hardness. They have reached the state of "perfection" by slapping with their hands. After more than ten years' efforts, contemporary potters can only imitate some simple potters. They tried to copy Ma Tao, but failed in repeated experiments. The outstanding clay sculpture and pottery-making technology in Qin Dynasty amazed future generations. However, its technology and formula were lost, which became the fourth mystery, the mystery of bronze casting sword. The bronze sword unearthed in No.2 pit is 86 cm long and has eight facets, which are extremely symmetrical and balanced. 19 bronze sword, the error is less than 10 wire. Unearthed from the ground after 2000, they are all corrosion-free and clean as new. Through modern scientific methods, these bronze swords are covered with an oxide film with a thickness of about1100-,which contains 2% chromium. This discovery immediately shocked the world. Because this salt oxidation treatment is an advanced technology that has only been mastered in modern times. It is said that Germany invented it by 1937 and the United States by 1950, and applied for a patent. And it can only be realized under a complex set of equipment and process flow. The casting level of Qin people is incredible. What is particularly commendable is that the toughness of these bronze swords is also extremely amazing. A sword was bent by a clay figurine of 150kg, and the bending degree exceeded 450. When the clay figurine moved away, a miracle happened, and the bronze sword bounced straight back and recovered naturally. This exquisite sword casting skill is amazing, which is also a mystery. There are countless mysteries surrounding the Terracotta Warriors. In the future, with the progress of science, archaeologists will gradually find the answer.