Do you know the secrets of the world?

Pyramid:

Pyramid of khufu is the largest pyramid in Giza, with the highest architectural level and the best preservation. It was built around 2570 BC and ordered by Pharaoh Khufu. Pyramid height146.5m. For thousands of years, it has been the tallest building on earth. It is made of 2.3 million polished limestone with an average weight of about 2.5 tons.

There are three tombs in the Great Pyramid. The first one was originally the tomb of Khufu. A few years later, craftsmen dug a second tunnel and built a second grave. Some people think this is to bury the queen. The third tomb, where Khufu was buried, is called "the king's tomb".

Second, Guyaju Caves Grottoes, an eternal mystery of human cultural relics;

It is located in a quiet canyon in the northwest mountainous area of Yanqing, a suburb of Beijing. It is a cave dug by ancient ancestors on a steep rock wall, with a total of 1 17. This is the largest rock dwelling site discovered in China.

On the steep rock wall standing upright on three sides in Yugu, there are artificially carved stone chambers, rectangular or square, with the largest being more than 20 square meters and the smallest being only 3-4 meters. Or single room, or 2-3 rooms connected; Or the suite is parallel, or the upper and lower floors, and there is a typical "three-bedroom". There is a stone cave with two floors above and below, and an annex room. The colonnade is lifelike, which may be the place where cave owners meet or sacrifice. It is magnificent, and the villagers commonly call it "Guanting". In all caves, doors, windows, kang, stove, manger, closet and flue are all available, round and square, which are all in the aesthetic rules.

About the excavation time of Guyaju Caves Grottoes, some people think that it was Yuan, Wei or Tang and Liao Dynasties. What is its purpose and use, bandit's cabin? Garrison the border? Should we avoid war? Ethnic minorities live together? According to inaccurate textual research, this is a rock village where the Xi people lived in the Tang and Liao Dynasties.

But today, in the place where the yellow crane carried the sage to heaven a long time ago, there is no Guyaju Caves Cave.

There used to be a forgotten nation, a place where fireworks were in full bloom, but this nation has disappeared and I don't know where the soul belongs.

Third, the mysterious underwater structure;

1958, American zoologist Dr. Van Rentan came to the Bahamas in the Atlantic Ocean for observation and research. Valentine is an excellent deep-sea diver. When he was exploring underwater, he accidentally found some strange buildings on the seabed near the Bahamas. These buildings are some strange geometric figures-regular polygons, circles, triangles, rectangles, and straight lines stretching for several nautical miles.

10 years later 1968, Dr. Van Rentan announced a new amazing discovery: a huge T-shaped stone wall with a length of 450 meters was found on the seabed near North Bimini Island, which belongs to the Bahamas. This huge stone wall is made of huge stones each exceeding one cubic meter. Stone walls also have two branches, at right angles to the main wall. Dr. Van Rentan was very excited. He continued to explore and soon found more complex building structures-platforms, roads, several docks and a trestle. The whole construction site seems to be an ancient underwater port.

The inventor of the "Pegasus" torpedo, French engineer and diver Hai Bikov came to the scene. He is a master of underwater photography. He used the latest technology at that time to survey this sea area and took some photos. After these photos were published, they caused a great sensation in the world.

1974, a Soviet research ship also came here, and made underwater photography and investigation, which once again proved the existence of these underwater structure sites.

Soon, the Bahamas was crowded with scientists, divers, journalists and explorers from all over the world. And there are more and more arguments around these underwater stone walls. Some geologists point out that these stone walls are only special natural structures, not man-made. But more scholars think it is artificial. Their views on who built these buildings are also quite different. Some people think that the Bahamas is not far from the Yucatan Peninsula, the hometown of Maya, so it may be an ancient building of prehistoric Maya, which sank into the water due to crustal changes. According to the time of land subsidence in Bahamian waters, it is estimated that these underwater structures were built between seven and eight thousand BC, so they should come from the builders of the ancient city of Tiwanaco in South America, but who was the builder of Tiwanaco is a mystery.

It is also said that the late American prophet Keith predicted in 1945 that Atlantis would reappear in the waters north of Bimini Island in 1968 or 1969. Valentine's discovery just confirmed Keith's prediction, so this is the famous Atlantis that sank in BC. ..

Of course, more serious scientists refuse to judge according to predictions, but people can't give a more satisfactory explanation. We can only answer in general that these underwater structures are "possible candidates" and "quite old". As for who did it and when, no one can answer yet.

Fourth;

1 March, 9941day, the second pit of the terracotta warriors and horses of Qin Shihuang, the world-famous "eighth wonder of the world", officially began to be excavated. This is one of the greatest archaeological discoveries since this century.

Bronze spear, crossbow, bronze arrow, broken arrow, etc. Some bronze swords, 86 cm long and with eight sides, were unearthed in the No.2 pit. Archaeologists measured with vernier calipers and found that the errors of these eight sides were less than one hair, and 19 bronze sword had been unearthed. These bronze swords are compact in internal structure, bright and clean in body, with fine grinding lines and no staggered textures. They have been sleeping in the loess for more than two thousand years, but when unearthed, they are as bright as new and extremely sharp. After testing, the researchers found that the surface of the sword has a layer of chromium salt compound with a thickness of 10 micron. This discovery immediately caused a sensation in the world, because this chromium salt oxidation treatment method is only a modern advanced technology. Germany invented and applied for a patent in 1937, and the United States in 1950.

When the archaeologists were cleaning the first hole of the No.1 pit, they found that a bronze sword was bent by a clay figurine of150kg, and the bending degree exceeded 45 degrees. When people removed the clay figurine, an amazing miracle appeared: the narrow and thin bronze sword bounced up instantly and recovered naturally. The "shape memory alloy" that contemporary metallurgists dream of actually appeared in ancient tombs more than 2,000 years ago.

In fact, the method of chromium salt oxidation treatment is by no means an invention of Qin Shihuang's era. As early as the Spring and Autumn Period and the Warring States Period, China people mastered this advanced technology.

During the period of the Five Overlords in the Spring and Autumn Period, Gou Jian, the king of Yue, defeated Fu Cha, the king of Wu, and staged the last scene of the hegemony in the Spring and Autumn Period. The passage of time makes this thrilling war sleep quietly in the long scroll of history, and busy future generations almost forget it.

However, while excavating an ancient tomb in the Spring and Autumn Period, an archaeological team accidentally found a long sword covered with mud, and an ancient seal character on the sword-"The Sword of Gou Jian, the King of Yue, for his own use" jumped into people's eyes. This major archaeological discovery immediately caused a sensation in the whole country, but even more sensational news came from the scientific research report about Gu Jian. The first thing that caught the researchers' attention was: Why didn't this Gu Jian rust after being buried underground for more than 2,000 years? Why is it still cold and sharp? Through further research, it is found that the sword of Gou Jian, the king of Yue, did not rust for thousands of years because it was plated with a layer of chromium-containing metal. As we all know, chromium is a rare metal with high corrosion resistance, and the content of chromium in earth rocks is very low, so it is very difficult to extract it. Furthermore, chromium is a high-temperature resistant metal, and its melting point is around 4000℃.

There are too many secrets in Chinese civilization. Who would have thought that the scientific inventions of the 1950s would appear in more than 200 years BC? Who can imagine that the sword wielded by Qin Shihuang's soldiers turned out to be a masterpiece that has not been invented by modern science? The question is, what attitude do we use to explain the extraordinary precocity of this technology after discovery? We really don't want to see someone explain it by "accident". It should have a more specific explanation. If the above facts are true (at least chromium salt oxidation treatment is true), then we will ask: what is their technical source?

Five:

Mystery of hanging coffins in Jiuquxi, Wuyishan

Like celestial burial and water burial, hanging coffin burial is an ancient form of funeral. The burial site is generally chosen on a high cliff by the river. Coffins are placed in natural or artificial caves tens to hundreds of meters away from the water surface, while others are placed directly on suspended wooden stakes. There are still more than ten hanging coffin remains on the cliffs on both sides of Jiuqu River in Wuyishan.

According to the carbon 14 determination, two well-preserved coffins, Baiyan and Guanyinyan, are more than 3,000 years ago, and the turtle-shaped wooden plate buried with them is a relic with bronze cultural characteristics of Shang and Zhou Dynasties.

According to textual research, there were many tribes, large and small, in the south of China in those days, and most of them had certain cultural commonalities, so they were collectively called Guyue people by modern people. Ships are indispensable tools in the life of ancient Vietnamese, and putting the dead in a boat-shaped coffin is a respect for the dead. Out of respect for the mountains, they placed the deceased in the nearest place to the "gods" so that they would not be disturbed by the world, thus better protecting future generations.

How can a coffin weighing hundreds of kilograms be placed on a cliff? Inferred from the square holes drilled at the front and rear ends of the coffin lid, it was hoisted by hanging ropes. The terrain behind or on both sides of the cliff where hanging coffins are placed is generally gentle. People first transported the coffin up the mountain, sent craftsmen to dig holes or erect stakes, and then hoisted the coffin. Sometimes a parallel passage is dug along the cliff wall first, and the coffins are pushed in turn, so that multiple coffins can be placed centrally, which saves a lot of trouble. According to Wu Renshen of the Three Kingdoms, the people who settled in Rui 'an, Zhejiang and Lianjiang, Fujian are very similar to those who lived in Taiwan Province and Yizhou, and they all have the custom of hanging coffins. This burial custom has been preserved to this day among Yamei people in Lan Yu, a remote island in Taiwan Province.

Six:

The mystery of dinosaur extinction

We humans have lived on the earth for two or three million years, and this history should be said to be not short. But compared with the life span of dinosaurs, it was only a moment.

In the Mesozoic era, the earth was once a world dominated by dinosaurs, and dinosaurs could be found everywhere in both plain forests and swamps. They lived on the earth for1.300 million years, but somehow, the dinosaurs became extinct, and they all disappeared from the earth forever. This is really an eternal mystery.

For more than a hundred years, I don't know how many scientists have tried to uncover the secret of dinosaur childlessness, but they have never been able to justify themselves. With the mutual penetration of natural sciences, some new theories about dinosaur extinction have appeared in recent years.

Some scientists believe that the extinction of dinosaurs was due to the cold climate. At the end of the Cretaceous period 65 million years ago, the world was cold on a large scale, the daily temperature difference increased, and the hot and cold seasons alternated obviously. Dinosaurs used to living in tropical environment could not hibernate like snakes and lizards, nor could they hide in caves to avoid the cold like fur animals. Dinosaurs are warm-blooded animals. They have no appearance and physiological function to resist cold, and they can't resist and adapt to cold attacks. Finally, they are ruthlessly eliminated by nature.

Some scientists assert that the extinction of dinosaurs was the result of crustal movement. About 70 million years ago, there was a strong crustal movement on the earth, which caused some basins to rise and shallow hills to appear, thus causing water and forests to dry up. At the same time, the seabed changed, the sea level dropped by more than 300 meters, the land between Asia and North America began to connect, a large number of animals moved to dinosaur habitats, and food supply was difficult, which made dinosaurs in a state of "food shortage" and gradually died of severe hunger.

Some scientists also suggested that the extinction of dinosaurs was caused by the collision and explosion of stars. In the late Cretaceous, an asteroid with a diameter of about 10 km collided violently with the earth. The impact speed is about 6.5438+10,000 kilometers per hour. During the impact, amazing dust was raised. Dust floats in the atmosphere, even blocking sunlight, making the earth dark for a period of time, the temperature drops, the photosynthesis of plants stops, plants wither, the "food chain" is interrupted, and dinosaurs die one after another.

Other scientists speculate that dinosaurs were poisoned by flowering plants and died out. Dinosaurs lived in Mesozoic, and gymnosperms such as ferns, cycads, ginkgo biloba and conifers dominated the plant kingdom. There are many tannins in these plants, which are harmless to dinosaurs. However, the earliest flowering plants appeared1.200 million years ago. These flowering plants often contain strong alkaloids, which adversely affect the physiology of dinosaurs. Some alkaloids, such as brucine, are very toxic. Dinosaurs swallowed a lot of alkaloids, and the toxin reaction led to serious physiological disorders and death.

The extinction of dinosaurs was due to interspecific competition and intraspecific competition-this is the understanding of other scientists. The activities of one organism often directly or indirectly endanger the survival of another organism, so there is direct or indirect competition, which is called "interspecific competition". For example, meat, competition between animals and herbivores, and competition between animals. In the age of dinosaurs, carnivores with strong reproductive ability and developed brains appeared. They ate many eggs laid by dinosaurs, which led to the death of dinosaurs. Dinosaur eggs were found in Inner Mongolia, Shandong and Guangdong. In particular, Shixing County in northern Guangdong Province found the largest and best preserved dinosaur eggs in the world, with 34 and 35 eggs in a nest respectively, and found the existing dinosaur fossils. In order to survive, creatures of the same species attack each other and devour each other, which is called "intraspecific competition". Tyrannosaurus rex, for example, is a Tyrannosaurus rex in the dinosaur family. Its head is 1.5 meters long, and its jaw has sharp teeth, so it can devour other herbivorous dinosaurs at will. Dinosaurs can be divided into herbivores and carnivores, and they are very long, both of which are more than 20 meters. For example, dinosaurs found in the United States were 27 meters long, and Mamenxilong found in Sichuan, China was 22 meters long and weighed 40 to 50 tons. Dinosaurs about the size of roosters were found in Luban, China, but they were counted as two. This phenomenon of "everything has its vanquisher, the law of the jungle" led to the final extinction of dinosaurs.

Although all the above statements have some truth, each statement can't be justified and can't be fully affirmed by the scientific community. For example, "dinosaurs ate flowering plants and became extinct", then pterosaurs in the air and ichthyosaurs in the water didn't eat flowering plants on land at all, so why did they become extinct at the same time as other dinosaurs? But hadrosaurs, ceratosaurus and other groups are more prosperous after flowering plants appear? In a word, the mysteries in the evolutionary history of these creatures have not been completely uncovered so far.