Daqin arrests alchemists, what does it matter to me as a qi refiner?

Chapter 242: I don’t understand, my head hurts, I need to grow a brain!

"If you have a chance, you can look for history books and list the time when drought occurred in the Central Plains and when the northern barbarians invaded south."

"So you can intuitively see that whenever there is a drought in the Central Plains Dynasty, it is the time when the probability of barbarian invasion from the south is highest."

"Even if you don't go south that year, the probability of going south the next year will be greatly increased."

"Why?" Li Shimin did not doubt whether Qin Tian's statement was true or not.

You only need to read history books to judge this kind of thing. There is no need to lie here.

Qin Tian nodded slightly: "If you can accept this statement, then the explanation will be easy."

"Similarly, you can also observe that once a flood disaster occurs in the Central Plains, the probability of barbarian invasion will be greatly reduced."

"Two confirmations, what did you think of?"

Li Shimin was thoughtful.

Qin Tian revealed the answer: "Although the grasslands where the barbarians live are far apart from the Central Plains, in fact, even if they are thousands of miles away and on the same continent, the climate of the two places is closely related."

Li Shimin nodded, seeming to understand what Qin Tian wanted to express.

"Why is it like this?" Sun Simiao had not yet reacted.

"It's very simple, because there are floods in the Central Plains. For the grassland people, it is the season of rich water and grass. Why do they go south to plunder when they can have enough to eat?"

"On the contrary, if the Central Plains lacks moisture, let alone the northern grasslands, the vegetation will dry up, the grasslands will decrease, and people will starve to death. If we don't go south to plunder, what else can we do?"

"Have you ever wondered why the north is mostly covered with grasslands, while the south has very few grasslands and more various forests?"

"Why?"

No one present had ever thought about this matter. In their perception, all this seemed to happen naturally, and there was no reason why.

Qin Tian smiled and said nothing, dipped his finger in some tea, and drew a figure on the table.

"Can you see what this is?"

"This……"

What Qin Tian drew was actually a bit abstract, because Li Shimin had never seen a high-precision map, and Qin Tian's drawing was too accurate, so he was a little hesitant to confirm it.

"This is Chang'an."

Qin Tian clicked lightly on the map.

With the comparison, everyone present immediately understood.

This is the map of Datang!

"Brother Qin is really well-informed, and he can even draw such things casually."

Li Shimin seemed to be testing Qin Tian.

Qin Tian ignored it and drew a curved curve from west to east on the map.

"So, did you find anything?"

Li Shimin frowned. He vaguely sensed something, but he couldn't grasp the fleeting inspiration.

“Above the curve is the grassland, and below the curve is where we live.”

With the explanation, Li Shimin suddenly understood.

The place where the curve passes is a sharp dividing line that separates the nomads from the people of the Central Plains Dynasty.

The line drawn by Qin Tian is the famous 400 mm equal precipitation line.

"Did you see anything?"

Li Shimin frowned and thought hard.

His mind echoed with the terrain in the vast territory of the Tang Kingdom.

"Looking at it this way, the further north you go, the colder the weather becomes and the drier the land becomes!"

Qin Tian glanced at Li Shimin appreciatively.

"So this very well explains why the north and the south have such different living habits and ways."

"Why are the barbarians in the north unwilling to cultivate the land? Is it because they don't want to? That's not the case."

"Because the further north you go, the more difficult and harsh the living conditions become, so they actually don't have the conditions to farm at all!"

The amount of water required for farming is actually quite large, so the amount of precipitation on the grassland simply cannot meet the needs of farming.

They can only survive by grazing.

"However, due to the emergence of drought-tolerant crops such as corn, sweet potatoes and potatoes, many people are actually living a half-farming and half-grazing life above this curve."

Qin Tian pointed his finger: "For example, here, I believe Brother Li must have an impression."

Li Shimin nodded repeatedly.

“What do you think is the biggest difference between farming and ranching?”

"One eats meat and milk, and the other eats grain?"

Li Shimin gave a relatively simple answer.

Qin Tian shook his head and said, "It's controllable."

"Although we all rely on the weather to make a living, on the grassland, a heavy snowfall may freeze to death all the herdsmen's cattle and sheep. In the coming year, the herdsmen will be unable to make a living and will have no choice but to go south to plunder."

"But in farming, even if there are various natural disasters, there are still only a few cases where there is no harvest."

"Bad harvests may happen frequently, but failure to harvest is basically impossible."

"So..." Qin Tian paused: "Compared to the herding people, the life of the farming people is more secure."

"And with the same land, how many people can be fed by the food grown on five acres of land? But what can be done if it is replaced by five acres of pasture?"

The Tang Dynasty itself was highly civilized, and people often raised horses, cattle, and sheep. Li Shimin naturally knew how big the gap was between the two.

“So ultimately, the difference between north and south is just a difference in how much rain it rains!”

"It rains a lot in the south, which allows plants to grow, so there are mostly forests and sufficient conditions for farming."

"But there is less rain in the north, so only crops such as pasture, which consume less water, can grow. Even tall trees cannot grow, let alone farming!"

Li Shimin suddenly found it extremely novel. It was the first time that he saw someone analyzing the problem like this.

This is a completely new angle that has never been thought of before.

"The weather will change, and years of good times will naturally lead to years of disaster." Qin Tian said calmly.

"Imagine what will happen if the weather continues to be dry and precipitation continues to decrease?"

Qin Tian drew a line again with his hand.

"This line separates the grasslands from the Gobi desert."

Then, Qin Tian drew an arrow under the first curve.

"The areas that can be farmed are getting closer and closer to the south, and the pastures that can be used for grazing will also be reduced, and they are getting closer and closer to the south..."

"The result is the barbarian invasion southward!" Li Shimin clapped his hands!

Analyzing national events from this perspective may seem out of place, but if you think about it carefully, it is very reasonable!

The logic that Qin Tian said is intertwined and closely connected, with no flaws at all!

"But if it's the other way around, the south will have good harvests and good weather every year..."

Qin Tian drew an upward arrow with a smile on his lips.

"At this time, it is time for the Central Plains Dynasty to expand northward."

"It was never the will of the khan that forced the barbarians to invade south, but the rain that everyone could see!"

Qin Tian gave his own conclusion. "If there is abundant rain, so what if the barbarians can grow stronger? How many people can they feed with one acre of grassland? How many people can one acre of land in the Central Plains feed?"

"When there is abundant rainfall, the barbarians will never be the opponents of the Central Plains people, because the Central Plains will only develop faster and stronger than them!"

"The harvesting methods of farming are destined to be far more efficient than nomads!"

"But conversely, once the dry season enters, the combat effectiveness of the Central Plains Dynasty will be greatly reduced."

"Isn't this wrong?" Li Shimin retorted subconsciously.

"The Central Plains dynasty is more powerful in the harvest years, so logically speaking, the dry season should be exactly the same!"

Everyone is having a hard time, so why do nomads become more powerful during droughts?

Qin Tian shook his head: "The years of drought mentioned here are not these or that years, but are viewed in cycles of ten years or even hundreds of years."

"The yin and yang cycle and the five elements rotate, and the abundance of rain is actually cyclical."

Naturally, the earth's climate changes are not due to any yin and yang cycle, but this method is easier for these people to accept, so Qin Tiancai said this.

"During this period, there will occasionally be a severe drought during a period of abundant rainfall, or there will be good weather for a few years during a severe drought. These are very normal fluctuations."

“When looking at history, don’t limit yourself to the one-third of an acre of land in front of you, but take a long-term view.”

“What would be the result if precipitation continued to rise over the next 100 years?”

This conclusion has been stated before, so there is no need to say it again.

"But what if it's the other way around? Why are farming peoples often no match for nomadic peoples during droughts?"

Qin Tian reminded: "The answer to this question can also explain why nomads have always been a serious concern for the Central Plains dynasty."

"This……"

This is completely a blind area of ​​knowledge for everyone present, and they have never even thought about this issue before.

Therefore, everyone present, including Li Shimin, fell into deep thought.

Qin Tian raised his eyes and looked at the sky.

"It's getting late, let's call it a day."

"No, how can we stop here!" Li Shimin retorted subconsciously.

But when he looked up, he was surprised to find that the temple fair had ended long ago and the sky was already dark.

"If you don't go back, it will be curfew time." Qin Tian smiled.

Li Shimin was stunned.

But just for a few small talk, how come the whole day is gone?

"No, today..." Li Shimin looked at Qin Tian and swallowed half of what he said back into his stomach.

"No, it's not the time yet, it's not the time to reveal your identity to Qin Tian."

Li Shimin glanced at Yuchi Gong.

Yuchi Gong couldn't understand these things at all, and there were already various circles in his eyes.

Therefore, he stopped listening to the conversations of several people very early on.

I don’t understand, my head hurts, I need to grow a brain!

"Forget it, let's call it a day!" Li Shimin stood up and cupped his hands.

"One day, Shi Dingran will pay a visit in person to thank Brother Qin for his help. By the way, he will ask Brother Qin for the answer to this question."

Li Shimin smiled heartily: "I will also bring my answer when the time comes. If the answer is not good, I hope Brother Qin will not laugh at me."

Qin Tian smiled, bowed to everyone, turned around and left with Muchun and Lingxia.

After leaving, Muchun looked at Qin Tian in surprise, his eyes full of admiration.

"Master, you know a lot!"

Qin Tian smiled slightly: "It's not that I know much, I just stand on the shoulders of giants."

"What giant? Who? Where did the giant come from!"

Lingxia's eyes widened.

Qin Tian laughed dumbly: "Don't think so much, just eat what you have and play with what you have!"

"Oh!" Lingxia nodded heavily.

Heartless, she quickly put the matter behind her and stopped paying attention to it.

On the other side, Yu Chigong asked tentatively: "Sage, do you want to put that..."

Li Shimin hesitated: "No, no need, now is not the time."

"Wait until I try to test his tone!"

Li Shimin was thirsty for talents, so naturally he would not let such a talent who knew both astronomy and geography live in exile.

Today's conversation with Qin Tian is better than ten years of studying for him!

It may seem like these things are of no use at all, but when you know the essence of the matter, many problems will be solved.

Just like Li Shimin had never thought about how to solve the problem of nomads once and for all.

But now, there was a vague idea in his mind.

"Let me think about it, why is this..."

That night, Li Shimin did not sleep.

According to Qin Tian's theory, since farming is better than grazing, why do the statuses between the two reverse during drought seasons?

Li Shimin had no sleep all night, and even when he went to court the next day, he was listless and had dark circles on his face.

Li Shimin thought for three full days, but could not come up with an answer that he thought was perfect.

Even he himself found those ideas ridiculous.

In the end, Li Shimin personally brought Yuchi Gong to visit Qin Tian.

……

"I thought you would wait a few more days before coming." Qin Tian looked at Li Shimin and said with a half-smile.

"There are some things at home that I need to deal with personally, so I wasted some time." Li Shimin's face looked a little unnatural.

"I came here mainly to thank Brother Qin for his help, so I..."

Qin Tian smiled and shook his head: "That's all, this is just a lie to yourself, but you can't fool me."

"Come in, since you want to know the answer to the original question so much, then I will answer it for you!"

Li Shimin hurriedly handed over the results of his thinking over the past few days.

Seeing that Qin Tian was a little surprised, Li Shimin quickly explained: "This is my idea. Please help Brother Qin correct it."

Qin Tian didn't know whether to laugh or cry.

Looking at Li Shimin's paper-like strategy, Qin Tian had an inexplicable feeling of finishing his homework.

But he still opened it and read it again.

"Yes, it is really valuable to be able to think of these." Qin Tian gave his own comments: "Although some of the content is too simple, it is not entirely without merit."

Li Shimin looked helpless.

This was a policy he carefully spent three days writing, but he ended up with such an evaluation in front of Qin Tian?

Although he said that these things were not worth mentioning, Li Shimin was still somewhat proud after writing them.

He even felt that Qin Tian was shocked after seeing this policy statement, and then...

(End of this chapter)