In 1956, Henri Lott led a French expedition that discovered 10,000 murals in the Sahara Desert.

The next year, he brought back to Paris a reproduction of the mural with a total area of ​​about 11,600 square feet and photos, which instantly became a sensation around the world.

Judging from the large number of ancient cultural relics unearthed, it can be seen that about 10,000 to 4,000 years ago, the Sahara was not a desert, but a prairie, an oasis with lush vegetation. At that time, many tribes or ethnic groups lived on this beautiful and fertile land, creating

a highly developed culture.

The most important feature of this culture is the widespread popularity of polished stone tools and the manufacture of pottery, which is a sign of the development of productivity. There are also Saharan inscriptions and ancient Tiphina inscriptions in the murals, indicating that the culture at that time had developed to a very high level.

.

This news was undoubtedly extremely shocking and sensational at the time. No one could imagine that the yellow sand land that spreads over nine million square kilometers used to be a dense forest and grassland.

Nowadays, human beings have already had a more detailed understanding of the history of the earth. With two facts confirmed, it is no longer worth making a fuss over.

However, when everyone sees the scene of herds of cattle and sheep on the mural, and then compares it with the lonely scene outside the cave, they can still feel the shock and surprise in it.

The expression form or technique of the murals is not complex, but the content is rich and colorful.

Judging from the strokes, a rough and simple touch emerges spontaneously.

Bi Fang came closer and gently blew away the dust on the wall. The picture instantly became clearer, and even the colors seemed to become brighter.

"Before the industrial era, pigments were a very expensive thing."

"But humans have never lacked ingenuity in making paints. During the Ice Age, when human life was savage and short, they could still find time to create art."

"Blumbos Cave on the coast of West Africa has unearthed the remains of tools dating back 100,000 years: pumice stones and stone hammers used to pound red ocher pigments, as well as mixes of animal fat and urine to decorate bodies, hides and caves

Abalone shells on the wall.”

“In the caves of Chauvet, Lascaux and Altamira, the pigments used for the petroglyphs painted between 1,500 and 3,500 years ago are black charcoal, chalk and bone fragments, as well as red ochre, which is red and yellow like earth.

Iron oxide minerals also bear witness to early humans’ superb skills in using color.”

"But the classic true red color cannot be extracted from iron oxide minerals, because the latter's red color comes from soil and is not as glorious in color as the red color of sunset or blood."

"Most of the murals use different rocks and soil, such as red iron oxide, white kaolin, ocher, green or blue shale, etc. as pigments. Some also use blood and animal fats. What we have in front of us is

This kind of thing.”

Bi Fang got closer and smelled it. Even after thousands of years, he could still smell something different. It was an injured cow with gurgling blood flowing from its abdomen. Perhaps in order to express it more vividly, the painter

Real blood was used directly.

Perhaps it was too long ago, and the red color of blood can no longer be seen on the murals, but more like brown.

On the other hand, the colors in other parts of the picture are more vivid, and red can be seen at a glance.

Bi Fang stepped forward and smelled it.

"It is painted by grinding the red rock on the platform into powder and adding water as pigment. Since the pigment fully penetrates into the rock wall, the long-term contact with the rock wall causes chemical changes and dissolves into one, so the picture is vivid.

The color can be maintained for a long time. After thousands of years, the color is still bright and eye-catching after being exposed to wind and sun.”

"It can be considered a rather strange phenomenon."

[What is the skill of judging the type of paint by nose?]

【I want to learn this】

【Why do you want to learn everything? Don’t teach!】

[Diao]

On the rock wall that stretches for more than ten meters, there are many human figures besides cattle and sheep.

Many of them are majestic warriors, showing an awe-inspiring and inviolable majesty. They hold spears and bucklers and ride on chariots at high speed, showing the scene of a battle.

There are also some wearing loincloths and small hats; some are unarmed and look like they are percussing instruments; some look like they are making offerings, like they are welcoming the arrival of the "god", perhaps a symbolic portrayal of offering sacrifices to the gods;

The figures are all in dancing poses.

As for the inside, it was too dark to see clearly, so Bi Fang did not light a torch rashly.

"Honestly, I don't know much about murals, so I can only make a match from a historical perspective and chemical pigments. I can't analyze it from a cultural perspective."

[Teacher Fang is joking]

【I only understand Yididian】

[Look at the boss’s humility]

"However, in addition to cultural value, murals also have many other practical values, such as changes in historical climate. In addition to natural sampling analysis, the study of historical climate is also inseparable from such historical data. The two are mutually reinforcing.

"

Proxy evidence for reconstructing historical climate generally falls into two broad categories.

The first is historical document records, which can be roughly divided into weather records, meteorological disaster records, phenological records, regional climate characteristics and their impact records, etc. according to the record content.

The second is natural proxy evidence, currently commonly used mainly include tree rings, ice cores, stalagmites, corals, lake and bay sediments, etc.

"Historical climate research is an important part of historical geography, especially historical physical geography. The main purpose is to study the history of climate, reveal the laws of climate change in the past, and use the past to serve the present."

"Many studies now point out that the era of human influence on the natural evolution of the earth has arrived. When the human living environment faces severe challenges such as global warming and frequent extreme weather and climate events, it becomes more important to study climate change in historical periods.

It’s extremely important.”

"Okay, since there are murals here, we'd better not disturb them. The pigment material is very sensitive to carbon dioxide."

"The Altamira cave paintings, one of Spain's 12 greatest treasures, were seriously damaged in the 1960s and 1970s due to carbon dioxide brought in by a large number of tourists."

"It has been open to limited numbers since then, and now the waiting list for visiting has been three years in the future."

"Let's try another cave and see if there is nothing there."

After taking a final look at the murals, Bi Fang led Alpha out of the cave and went to several other caves on the same rock wall to look at them. He found that in addition to the one just now, the other ones also had corresponding paintings.

, accounting for approximately two-thirds of the total.

In those caves without murals, Bi Fang also discovered some other interesting things.

"In the wild, when you encounter a cave, don't get excited and think it's time to explore. Dark and moist caves are the favorite refuges of many poisonous animals, especially in the desert, where the sun is scorching during the day, and animals have to find dark places.

To escape the heat, caves are their first choice.”

No longer worried about damaging the mural, Bi Fang lit a torch, squatted down, and used the torch to attract the attention of the poisonous snake in front of him.

"Look, a horned viper."

Bi Fang smiled.

The Desert Horned Viper is a snake that is easily recognized by ordinary people because it has two clearly visible horns on its head.

At this time, this horned viper was crouching behind a rock, with its body the same color as gravel, curled up tightly, like a spring compressed to the extreme, and it was obviously ready to attack.

Although I have caught venomous snakes several times in the desert, a missed attempt on a venomous snake often means death, and there are only zero times, so Bi Fang did not dare to get too close.

【I saw it in the animal world!】

【Are all vipers poisonous? 】

[Is this today’s lunch? (dog head)]

[Damn, this corner is so domineering!]

【Confirmation rate】

[Is this horn a bone? It grows on the head? That’s a bit awesome]

"No, unlike the hardened keratin of rhinoceros horns, the two horns on the horned viper's head are extensions of the snake's normal scales. In other words, you can't see these two small horns on its skull."

"The two corners can even fold, so that when it passes through the underground sand layer, they will flatten the top of the head. They will also fold when touched."

"As a desert-dwelling snake, the horns could theoretically protect their eyes from the sun's harsh rays, keeping their vision intact while crawling across the dunes."

"But it's also possible that they use their horns for lure, rubbing their scales up and down and side to side, disguised as squirming worms and other species, and lure rodents, and then hunt those rodents."

"One of the hallmarks of this species is that it buries itself in loose sand dunes with only its eyeballs exposed, so that passing animals see only its horns and eyes."

Bi Fang held the torch close, and the audience could clearly see the snake's lower body buried in the gravel.

The cave has been exposed to wind and sun all year round, and there is a lot of gravel accumulated within the first few meters.

"This snake is almost never found in human habitations. They have been carefully evolved to survive in desert areas. They store precious moisture and morning dew from recently eaten prey in their scales."

"It is said that Celestus in Greek mythology was created in the image of a horned viper."

Celastrus is one of the little-known chapters in Greek mythology. It is a terrifying horned snake monster.

Legend has it that this beast was reborn in the Libyan desert from the blood of Medusa. It is an evil head that can regenerate.

"According to legend, while waiting for travelers to pass by, Celaestus jumped out of the sand and dragged him into the sand with his fangs. The beast moved sideways, said to be because thousands of years ago,

Helen of Troy stepped on its back as she eloped with Paris, in exactly the same way as the horned viper."

The Desert Horned Viper is one of the 4 species of rattlesnakes in the world. Instead of gliding forward, it moves directly to the side, with only two small body parts touching the ground, in order to minimize contact with the scorching desert floor.

Professional researchers can directly determine the number of scales on the horned viper's abdomen through the snake prints left on the sand, and then determine its body size and age.

"As for its toxicity, I won't say much. It is very strong. If you are bitten, you may die. The venom will destroy the cell membrane and the core of these cells. Death is usually kidney failure, because the cells rupture and the organs cannot function normally.

"
To be continued...