Chapter 109 Specific heat capacity allowed the Mongols to conquer the world
"Temperature and precipitation actually affected the course of history."
In the secret room next door, Zhang Yuchu woke up from his thoughtful state.
There are a vast number of Chinese classics from past dynasties, and Longhu Mountain has preserved many strange books on the deduction of the laws of historical evolution.
Zhang Yuchu even turned over the pages of "Tui Bei Tu" and the like.
But Zhang Yuchu suddenly discovered that these explanations of history and predictions of the future based on mysticism seemed not to be as reliable as Jiang Xinghuo's statement?
"Zhang Tianshi, what do you think of Mr. Jiang's statement about the impact of temperature and precipitation on history?"
Zhu Gaochi turned to look at Zhang Yuchu, a "taoist scholar", and asked for his opinion.
From Zhu Gaochi's perspective, just now Zhang Yuchu and Zhang Tianshi were completely immersed in the content of the lecture and couldn't extricate themselves.
At this time, even if Zhang Yuchu didn't want to admit it, he could only say it.
"What Jiang Xinghuo said does make some sense."
Of course, regarding whether there are immortals in this world, Zhang Tianshi tossed and turned last night and still firmly believed that there were no.
Yuan Gong and Dao Yan must have not done enough and failed to understand.
We at Longhu Mountain have cultivated immortals for more than a thousand years. Do I still not know whether there are immortals in this world?
Therefore, Zhang Yuchu still did not admit that Jiang Xinghuo was an immortal in his heart. He just believed that his knowledge was indeed a little more profound than others, and his knowledge was indeed a little sharper than others.
Just a little bit.
Of course, Zhang Tianshi has always been known for his knowledge, so he will not let himself be obviously disadvantaged.
"Actually, when it comes to the relationship between elephants and hot and cold, there is something to be said for it." Zhang Yuchu said.
"Oh?" Zhu Gaochi looked at him and said, "Zhang Tianshi might as well talk about it."
"According to the classics of Longhu Mountain, well, it can be traced back to the period of the Five Dou Rice Sect. At that time, the master once obtained an ancient fragment."
Zhang Yuchu started to talk about ancient secrets that no one knew were true or false. This opening sentence was similar to the "long long ago" in Western stories.
"In ancient times, Dayu controlled floods and divided the nine states. He divided the world into Jizhou, Yanzhou, Qingzhou, Xuzhou, Yangzhou, Jingzhou, Liangzhou, Yongzhou, and Yuzhou. Yuzhou is the center, and other states surround Yuzhou."
"And the word 'Yu' means a person holding a spear and leading an elephant."
"In other words, during the Xia Dynasty, elephants lived in the Central Plains, and the temperature at that time should have been extremely warm."
"Even at the end of the Shang Dynasty, there are records: The merchants obeyed Xiang and abused the Dongyi people, so the Duke of Zhou used his troops to drive them away to the south of the Yangtze River."
"Also, Zhou Gongxiang, King Wu, punished Zhou and attacked Yan. In three years, he attacked his king. He drove Fei Lian to the corner of the sea and killed him. He destroyed the country by fifty. He drove tigers, leopards, rhinoceros and elephants far away. The world was very happy."
"The ancients thought that elephants were driven to extinction by the Duke of Zhou, but this may also be because the Central Plains is no longer suitable for elephants to survive. Later, people in the Zhou Dynasty never saw elephants again."
"Since these people have never seen an elephant and heard it from the older generation, but don't know what it looks like, they have the word 'imagination'."
Xia Yuanji smiled: "What Zhang Tianshi said is interesting, is this how 'imagination' comes about? I am quite ignorant."
Zhu Gaochi also laughed loudly, and his worried mood improved slightly.
On the opposite side of the wall, the lectures did not stop.
"For the Tang Dynasty, although the drop in temperature led to a reduction in grain production, due to the separatist rule of vassal towns, the food pressure on the central government in the middle and late Tang Dynasty was actually not that great."
A smile appeared on Jiang Xinghuo's lips.
"Many people don't need the emperor's care at all. They can support themselves. Whether they can support themselves or not has nothing to do with the emperor. If there is rebellion in the local area, it should be resolved by the local area. The emperor can just write an edict to recognize the military envoy or stay as a post."
After laughing about the anarchist Tang Dynasty in the middle and late period, Jiang Xinghuo continued to talk about Tubo just now.
"But it's different for Tubo. After the annexation of Zhangzhong, Tubo's population was about one million. Even at its peak, it occupied Longxi and Tianzhu north of the Ganges River, and the population of all other ethnic groups under its rule was All counted together, that’s three million.”
"Even though Tibet usually conscripted all able-bodied adult males as soldiers, in order to support up to one-tenth of the army, Tibet had cultivated all the arable fields on the plateau just to survive."
"After the temperature dropped, the fragmented Tang Dynasty could still be maintained, but Tubo's food production was completely unable to be self-sufficient, and it could not be satisfied by looting. The entire Tubo dynasty collapsed directly, degenerating from a dynasty into a large slave tribe. The plateau with abundant water plants and moist soil has also become a semi-uninhabited land with an extremely sparse population. Until the Hongwu Dynasty, there was still no sign of recovery."
After listening to this story, not only Zhu Gaoxu but also Li Jinglong fell into deep thought.
Temperature and precipitation are two factors that are not even noticed in daily life.
It can actually determine the fate of a dynasty!
Li Jinglong wanted to refute, but after repeated thinking, he finally found that there was no way to refute!
This is the fact before us.
Otherwise, how to explain Tubo's "its rise and fall are also sudden"?
While the two were deep in thought, Jiang Xinghuo continued: "Of course, Tubo is still doing well. Although it is still lingering, it will survive after all. Most of the countries in the Western Regions have completely disappeared due to lack of precipitation. In the desert."
"In Tang poetry, the country most often mentioned by frontier poets and the most innocent is Loulan."
"Wang Changling: Huangsha wears golden armor in a hundred battles, and Loulan will never be returned until it is broken.
Li Bai: I am willing to put my sword down from my waist to kill Loulan.
Gao Shi: The horse's hoof passes through the Moon Cave, and the swordsmanship refers to Loulan.
Cen Shen: Loulan was cut off the year before last, and the branch of Pingyue was removed.
Du Fu: How late is it to return to the country? The Loulan behead has not yet been returned. "
Jiang Xinghuo himself couldn't help laughing and said, "I don't know who Lou Lan offended, but he is so unlucky. As long as he is a famous poet, he will not be able to attain enlightenment unless he kills Lou Lan."
Zhu Gaoxu and Li Jinglong also laughed.
However, Jiang Xinghuo stopped laughing after laughing and sighed.
"It's a pity that Loulan was not killed one by one by these poets, but was destroyed by the gradually disappearing precipitation."
"In the past, the ancient city of Loulan was located on the edge of the Juyan Sea. It was really an inland sea, with rivers such as the Shule River, Kongque River, and Tarim River flowing into it. The water and grass were abundant, and there were flocks of cattle and sheep."
"However, by the middle and late Tang Dynasty, even the vegetation could no longer survive due to the decrease in precipitation."
"Loulan is already the country with the highest number of household registrations in the Western Regions. During the Tang Dynasty, among the countries under the jurisdiction of the Western Regions Protectorate, except for Yutian and Ningmi, which had 3,300 households, they were tied for first place, followed by Loulan has 1,500 households (about 14,000 people and an army of more than 2,000 people), and the rest of Jingjue, Qiemo, Xiaowan, Pishan and other countries actually only have a few hundred households and thousands of people."
Jiang Xinghuo continued: "Today, all the countries in the Western Regions like Loulan have long been destroyed, and even the capital has been abandoned. There is not even a living person left in it, because the local area cannot survive at all. It has been far from the Tang Dynasty. Hundreds of years have passed, if you have the opportunity to take a look, there is still no grass growing around the ancient city of Loulan, and most of the supply stations along the way have been destroyed, which is one of the reasons why the Silk Road was almost cut off."
After listening, Zhu Gaoxu and Li Jinglong were somewhat shocked.
This kind of shock is not the kind of being hit on the head by some huge news, but a kind of heavy feeling that these things that happened in the heavy history appear silently before their eyes again.
They seemed to see the once beautiful city buried under the yellow sand of the distant Western Regions. The charming orchids had long been turned into withered bones and gone with the wind. Only the Poplar euphratica forest that had not fallen for thousands of years told the stories that had happened there. .
The once powerful Tang Dynasty, the famous Tubo, and the mysterious and beautiful Loulan all came to different fates due to temperature and precipitation.
So what will happen to Ming Dynasty in the future?
"Although the Tang Dynasty and Tubo perished, temperature and precipitation will continue to affect the historical process of Chinese civilization,"
"In the middle and late Tang Dynasty, the temperature dropped and the climate began to become cold, and this cooling process that caused coldness did not happen overnight, and there would even be ups and downs in the process."
"After the chaos of the late Tang Dynasty and the Five Dynasties, the Northern Song Dynasty ushered in a period of warming. At that time, not only the Youyun Sixteen States in the north became suitable for farming and living again, but even Hebei also formed large areas of lakes, swamps, and rivers. The Northern Song Dynasty even relied on these lakes and rivers to build defense lines on the plains to block the Liao people from going south."
Just when the two people's emotions were slightly lifted, Jiang Xinghuo's words turned low.
"But the good times did not last long. After just over a hundred years, on the eve of the demise of the Northern Song Dynasty, the temperature began to drop again, and this warm period that lasted for a hundred years came to an end."
"Historical records state that on December 20, the fourth year of Daguan in the Northern Song Dynasty, it snowed heavily in Quanzhou, and Quanzhou Port even froze. In the first year of Zhenghe in the Northern Song Dynasty, Taihu Lake completely froze."
"And the Jin people in Liaodong also began to walk out of the mountains and forests because they couldn't bear the cold, and went south to destroy the Liao and Song Dynasties."
"However, the cold period after the rebound from the warm period lasted for a very long time."
Zhu Gaoxu blurted out: "Mongols!"
"Yes, the impact of temperature on grasslands far exceeds that of plains." Jiang Xinghuo nodded.
Li Jinglong asked tentatively: "It was also because the grasslands were getting colder that the Mongols were forced to integrate and go south to conquer the world? But why are the grasslands affected by temperature far more than the plains?"
"Because the grasslands are farther from the ocean than the plains are from the ocean."
Seeing that the two of them didn't understand much, Jiang Xinghuo explained the principle.
"In addition to temperature, there is another thing here, which is the temperature difference."
"Did you know that water bodies can adjust temperature differences?"
Li Jinglong nodded and said, "As I said just now, take the example of West Lake."
"It's different from that. Let me tell you another concept called 'specific heat capacity'."
Jiang Xinghuo smiled and said: "The meaning of this term is actually very simple. It is the heat required for objects of the same weight to raise the same temperature."
"Do you believe that with the same heat consumed in gold, the temperature of gold will rise much more than that of water?"
Li Jinglong rubbed his chin. He usually didn't notice this phenomenon at all.
So, Li Jinglong looked at Zhu Gaoxu.
Li Jinglong recently discovered an advantage of Zhu Gaoxu, that is, he seems to have rich life experience.
Sure enough, Zhu Gaoxu did not disappoint him, and used his simple life experience to give a real example.
"I really do know."
Zhu Gaoxu moved his neck and said: "Once I saw a craftsman burning golden beans for me. They were probably made from a small piece of dog head. At that time, he happened to be boiling a large pot of water next to him. I thought there was a difference in weight, but It shouldn't be big. The quality of the coal used in it is the same, and the quantity shoveled in is about the same."
"What's the result?" Li Jinglong asked curiously.
"They are all burned in a container. The gold melts quickly and the water has not yet smoked."
Zhu Gaoxu's common sense of life has once again succeeded in giving examples, although most people will not have the experience of burning gold beans with a piece of gold nugget.
"Probably so."
Jiang Xinghuo said: "This is the meaning of specific heat capacity. In other words, when water rises to the same temperature and drops to the same temperature, it absorbs a lot of heat and releases a lot of heat."
The secret room next door.
"This is wrong!"
"Think about it, Your Highness." Zhang Tianshi frowned slightly and said, "If we follow Jiang Xinghuo's statement, then since the ocean releases cold air, the plains closer to the ocean should cool down more than the grasslands. Why is the grassland affected by the cooling instead? What’s bigger?”
Zhu Gaochi thought for a moment and said, "Maybe it's because the grassland is closer to the north?"
"It doesn't make sense."
Xia Yuanji was also a little confused. If Jiang Xinghuo didn't mention the concept of "specific heat capacity", then according to the previous statement, temperature determines precipitation, and precipitation determines the dividing line between farming and nomadic life.
This statement is easier for them to accept. After all, it is common sense in real life.
The further north you go, the less rain there is.
But now Jiang Xinghuo said that the ocean released cold air, but the grassland was affected more than the plains. This sounded unreasonable.
Because it stands to reason that the plains are closer to the ocean than the grasslands, so the temperature drop in the plains should be greater. After being transmitted to the grasslands, the impact on the grasslands should be smaller.
"Listen to what Master Jiang has to say."
Xia Yuanji signaled Master Zhang to be calm and calm.
On the other side of the wall, Li Jinglong also thought of this issue first.
"Shouldn't the plain be closer to the sea?"
"No, you got it wrong."
Jiang Xinghuo's answer shocked Li Jinglong.
"Many phenomena actually violate your daily cognition."
"Can you give an example?" Li Jinglong asked.
"Before, he answered the difference in temperature between the valley and the mountain top. Now think about another question." Jiang Xinghuo asked almost without thinking: "For example, do you think the difference between day and night temperature is larger at the beach or in the mountainous area? bigger?"
Li Jinglong began to think deeply, and as the thinking time extended, his expression gradually became unbelievable.
"When I was visiting the West Lake, I went to see the Qiantang River tide and stayed at the Qiantang River at night. At that time, it seemed that there was not much difference in temperature between day and night. It was hotter during the day and colder at night."
Immediately afterwards, Li Jinglong deduced an answer that made him somewhat incredible.
"In other words, the closer you are to the ocean, the smaller the temperature difference is?"
"Yes!"
Jiang Xinghuo recently liked to guide two students to draw correct conclusions through their own thinking, which made him feel that he was not engaging in cramming education.
"Water bodies can effectively adjust temperature differences, and grasslands have large temperature differences precisely because of the lack of water bodies. Have any of you been to grasslands?"
"I've been there."
In a physical sense, Zhu Gaoxu, who traveled around and killed people, once again surpassed Li Jinglong in terms of life experience.
"What do you think of the temperature difference between day and night there?" Jiang Xinghuo asked.
"It's extremely hot during the day and extremely cold at night, and the same is true in the Gobi desert." Zhu Gaoxu recalled the painful things.
"So you understand? Temperature and temperature difference are different."
Jiang Xinghuo said: "On the grassland, since there is no huge body of water with a huge specific heat capacity like the ocean to adjust the temperature difference, the temperature difference between day and night on the grassland is huge. Think about it, what are the consequences of a huge temperature difference?"
Li Jinglong pondered for a moment and then said: "It should be extremely difficult for grass and trees to grow, because the grass will be very hot during the day, and it will freeze and frost at night. When it is cold and hot, the grass and trees can't stand it, and the cattle and sheep naturally can't stand it. It’s unbearable, let alone people who are more sensitive to temperature differences. They have to go shirtless during the day and wear cotton-padded jackets at night. As a result, the grasslands will wither and the cattle and sheep will lose weight, and people on the grasslands will inevitably choose to go south!”
"That's the reason. Nomadic people actually rely more on temperature and precipitation to survive than agricultural people."
Jiang Xinghuo said briefly: "The principle is very simple. In grasslands, the most important thing is grass. Warm sunshine and abundant precipitation will make the grass on the grassland more and more lush, and cattle and sheep eat grass. , the more grass they eat, the better, the fatter they will grow, and the nomadic herdsmen will be able to eat more beef, mutton, and milk, and become stronger and better at fighting."
"Once the temperature drops, due to the lack of huge water bodies with high specific heat capacity, the grassland environment will become extremely harsh, leading to a vicious cycle. That is, droughts and locust plagues will cause grass to grow poorly, cattle and sheep will decrease, and the cold will make nomadic herders The amount of food needed to preserve body temperature is increasing, while the amount of food required is decreasing.”
"If you are a nomad living in such a grassland environment, what do you think you should do now?"
Zhu Gaoxu adheres to the consistent views he has adhered to since his economics and civil studies class.
"How could I wait to starve to death? I must have beaten others to death while I still had the strength, and then snatched away the food."
"What a coincidence, the Mongolians think the same way." Jiang Xinghuo nodded.
"So do you understand? In other words, it was Birejung who forced the Mongols to conquer the world."
The second chapter is still a little later. I'm checking the information and proofreading it. I can't remember some professional knowledge clearly. I'm really afraid of making mistakes.