I watched Er Chuang’s short video, and everything went numb!

【Zuo Zongtang was furious when he learned about this and cursed Li Hongzhang. 】

【Li Hongzhang was furious when he learned about this and persecuted Zuo Zongtang's subordinates. 】

【Zuo Zongtang, who was already ill, fell ill again. 】

【On September 5, 1885, Zuo Zongtang died of illness in Fuzhou at the age of ~~74. 】

【Before his death, Zuo Zongtang left a will, which was also his lifelong regret: "I led the army to the south, but I have not yet launched a major attack and expanded the prestige of our country. I regret this for the rest of my life and cannot rest in peace!"--】

……

"Ah."

Many ancient people from all dynasties sighed and felt extremely sorry for Zuo Zongtang.

Such a loyal minister and general could only end up with regrets in the end. It can only be said that he was born at the wrong time.

……

[As we all know, China's poverty and weakness in modern times is a humiliating history of losing sovereignty and humiliating the country. ]

[In that era when all the powers wanted to humiliate and divide the land of China, Zuo Zongtang's recovery of Xinjiang Province was as dazzling as a star in the night sky, and it was one of the few highlights. ]

[An old horse is still in the stable, worrying about the country and the people. This is the portrayal of this lonely and brave man of the Qing Dynasty. ]

[It was precisely because of Zuo Zongtang's going against the trend that the territory of Xinjiang Province in China was preserved, the precarious late Qing Dynasty was able to avoid the crisis of national division, and the Chinese nation regained this last bit of face. ]

……

After a conclusion.

This video ends.

On the giant screen in the sky.

The video refreshes.

A new video appears.

[The underlying logic of agricultural society: Why does agricultural society develop so slowly? ]

……

After this line of headlines, there is a preface.

……

[If you ask everyone this question: Why did the technological explosion occur after the Industrial Revolution? ]

[You may think of reasons such as the improvement of productivity, the liberation of thought, the use of fossil energy, etc. ]

[The same question, if we ask it in a different way, why is the technological achievement of human beings in the long agricultural society so low? ]

[Maybe many friends think of the same set of answers: slow productivity improvement, ideological confinement, too low energy conversion efficiency, etc. ]

[However, this explanation is a bit too pale, just like saying that you have no money because you don’t work hard. ]

……

The plane of Emperor Taizong of the Tang Dynasty.

When Li Shimin saw this, his heart was shocked and he immediately concentrated his mind. His eyes looking at the giant screen in the sky became more focused.

In fact, he had thought about this question before.

In the agricultural society before the Industrial Revolution, for thousands of years, although there were many dynasties, human society basically did not have much revolutionary changes.

Whether it was production or military, various technologies were also developing, but relativelyFor the development of human society after the Industrial Revolution, it is completely different.

It can be said that after the Industrial Revolution, human society has been advancing at full speed.

Various new technologies and new items have emerged in an endless stream.

So, what is the reason for this difference?

Even some of the reasons mentioned in this passage, he has thought about them.

But then comes a new question: If these reasons are the cause, how did these reasons come about?

While thinking, Li Shimin looked forward to the content of the next video.

……

[Many friends often use fancy boiling water to summarize the development of mankind. ]

[But in fact, before the first industrial revolution, humans were not even worthy of boiling water. ]

[From the birth of mankind to the present, we have only boiled water for more than 200 years. ]

[So, what restricted the development of pre-industrial society? And what promoted the industrialization of human society? 】

[In this video, let's talk briefly about why agricultural society developed so slowly? 】

……

Many ancient people throughout the dynasties were inspired and watched more seriously.

Li Shimin was not the only one curious about this question.

These ancient people were also very interested.

……

[First of all, let's start with the core concept of this series: energy. 】

[From our daily food, clothing, shelter and transportation to the movement of celestial bodies in the universe, they can all be regarded as processes of energy conversion. 】

[In the primitive hunting and gathering period, we can regard human activities as plants converting solar energy into chemical energy through photosynthesis and storing it in organic matter. 】

[These organic substances are either directly used by humans through gathering activities and become fuel for the human body, or eaten by animals, and then humans obtain energy through hunting activities. 】

【During this period, human activities were still very similar to the omnivorous animals that can be found everywhere in nature. They used the energy in food to survive, reproduce and provide energy for the next foraging activity. 】

……

For the concept of "energy".

The ancient people of all dynasties have already learned about it in previous videos.

Therefore, many ancient people understood this passage.

In their understanding, this is equivalent to people obtaining food from the outside world through hunting or picking, and eating food gives people strength, or in other words, energy.

……

【The emergence of agriculture changed all this. 】

【Humans began to be able to grow crops and raise livestock to obtain energy, which made the source of human energy certain. 】

【Although the energy return rate of early agricultural production was only 25% to 50% of that of hunting and gathering activities on average, the certainty of food acquisition methods allowed the population to expand rapidly. 】

【In the 8th century between 10,000 years ago and 2,000 years agoIn 1,000 years, the population has risen from about 5 million to 133 million, an increase of 25 times. 】

[Before that, it took humans nearly 1 million years to increase the population by 42 times. 】

……

"Is the difference so big?"

Many ancient people from all dynasties were shocked.

This data comparison is too obvious.

The plane of Taizu of the Ming Dynasty.

Zhu Yuanzhang sighed:

"This is the role of agriculture, so we must insist on agriculture as the basis."

Zhu Biao on the side did not speak.

Because he was thinking about a question: when the energy return rate of agricultural production is obviously not as good as that of hunting and gathering activities, how can the certainty of food acquisition methods be used to allow the population to expand rapidly?

Soon, from the perspective of energy consumption, he thought of a possible reason: that is, the energy consumed by hunting and gathering activities is far greater than the energy consumed by agricultural production.

Because agricultural production behavior is generally fixed.

Hunting and gathering activities are not fixed. You don’t know where the target object is, so you have to look for it everywhere.

In this process of searching, a lot of effort will be spent, or a lot of energy will be lost.

So.

If we only consider the energy return rate, agricultural production is not as good as hunting and gathering activities.

But if we take into account the loss, the food obtained from agricultural production, or the energy gain, is far greater than that of hunting and gathering activities.

Under such circumstances, the population of human society has achieved rapid growth.

……

[It seems that the population growth rate has doubled. ]

[But almost all the increased population was invested in agricultural production, and it lasted until the first industrial revolution. ]

[In areas where industrialization began, the proportion of agricultural population began to drop below 90%. ]

[This is the problem brought by agriculture itself. 】

【Before this, because the refresh of food was controlled by nature, it was a cycle in itself. 】

【And human intervention successfully created an energy gap in this cycle. 】

【In natural ecosystems such as woodlands, trees and shrubs obtain energy from sunlight, absorb carbon dioxide from the air, and absorb mineral nutrients from the soil through their roots to achieve growth. 】

【These key parts become leaves, stems and roots of plants, and when they are eaten, they become part of the animal body. When the animal excretes or dies and rots, these nutrients return to the soil from which they came. 】

Barrage flew out:

"Good guy, all energy will not disappear out of thin air, it will only be transformed from one form to another. Is this the conservation of energy in nature?"

"Reply-Yes, it sounds like a conservation cycle in which energy does not increase or decrease."

"Reply-It can't be a cycle without loss? It doesn't feel like a complete conservation of energy?"

"Reply - who can know this?"

"..."

Many ancient people from all dynasties were a little confused.

They seemed to understand the concept of "energy conservation" mentioned by people in later generations.

……

[But the nature of farmland is fundamentally different. ]

[The only purpose of human beings to serve plant growth is to obtain and use it for human beings. Even if you spread most of the remaining plant residues back to the fields, you still remove the parts that are actually eaten. ]

[What's more, some of those residues are used as fuel. ]

[All agriculture has the same energy basis. Plants convert solar energy through photosynthesis to fix energy, and become food for humans and livestock, provide recycled waste to supplement fertility for the soil, and provide fuel to smelt metals needed to make simple farm tools. ]

……

The plane of Emperor Chengzu of the Ming Dynasty.

Zhu Di thought hard.

According to his understanding, does this mean that agricultural production breaks what later generations call the "energy conservation cycle"?

Because agricultural production will divert part of the energy obtained for other purposes.

"Then to re-establish this energy conservation cycle, do we need to supplement this energy?"

Zhu Di's mind turned quickly.

……

[Under ideal conditions, traditional agriculture is completely renewable. ]

[But in fact, humans often exhaust the energy reserves of the land very quickly. ]

[Poor agricultural activities will not only greatly reduce the fertility of the land, but may also cause excessive erosion or desertification, resulting in reduced yields or even abandoned farmland. In this way, year after year, the land will continue to become more barren. ]

[This will inevitably require humans to invest energy as a subsidy to meet the growth needs of crops. ]

……

Many farmers in past dynasties suddenly thought of something they had seen in the previous video: chemical fertilizers in later generations.

This thing can improve the fertility of the land.

"It would be great if there were fertilizers."

These farmers thought in their hearts.

……

[Those places where permanent settlements and agricultural production first appeared are often places where God has blessed people. ]

·· ·········Please send flowers····· ······

·· ··········Please send flowers····· ······

[The most typical example is the ancient Egyptians who lived by the Nile River. ]

[The Nile River solved two most critical problems for local residents. ]

[The annual floods carry fertile silt, which helps them restore the fertility of the fields, while moistening the land on both sides and solving most of the agricultural water problems, and these two are the key factors affecting food production. 】

【Relying on the advantages of natural conditions, people in such areasThey save a lot of energy. 】

[Their main agricultural labor focuses on plowing, sowing, harvesting, grinding and other contents. 】

The barrage flew out:

"The Nile River Basin, the ancient God-chosen land for growing grain."

"Ancient Egypt relied on the Nile River Basin to develop agricultural civilization."

"..."

Many emperors of all dynasties saw this and their eyes lit up.

Grain-growing treasure land!

That's really a good place!

They all kept this place in their hearts.

In the future, when they start the Age of Exploration after the Industrial Revolution, this is the place to be conquered.

……

[But as the population increases, when new arable land needs to be reclaimed, the situation will be different. 】

[In addition to the labor that must be done just now, it is also necessary to solve the problem of nutrients and water for crops. 】

【At this time, humans must provide energy subsidies for the growth of crops. Irrigation facilities must be repaired and maintained, organic fertilizers must be collected, fermented and transported to the land, wells must be dug, and if the land is too sloped, does it need to be leveled? 】

……

Many farmers from past dynasties nodded.

They are very familiar with these farming processes.

……

【In addition, there are a series of problems that need to be solved as humans expand arable land. 】

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【In the process of solving these problems, on the one hand, the organizational capacity of agricultural society is strengthened, while the population density continues to increase, relying on food surplus to promote social progress and complexity. 】

【But on the other hand, this requires humans to invest more energy to ensure food supply. 】

[This leads to a lower energy return, that is, the ratio of food output to energy cost, that is, the labor input, which is often lower, and these labors are almost all human and partly animal power. 】

[If we compare it with the primitive hunting and gathering period, we will find that: people used to cut grass and pick fruits, but now they go to the fields to do farm work; people used to chase prey, but now they raise animals. 】

[The driving force for social progress has hardly changed, except that various draft animals are involved. 】

[In short, they are all flesh and blood. 】

……

Daqin plane.

Qin Shihuang vaguely understood.

He suddenly remembered a sentence he heard in the video of the Industrial Revolution: "Use machines to produce machines."

Machines can replace flesh and blood and provide greater and more energy for social progress.

Therefore, the development speed of industrial society will far exceed that of agricultural society.

"It should be so."

Qin Shi Huang continued to look at the giant screen in the sky, waiting to verify his thoughts.

……

[In this way, we can regard pre-industrial society as a flesh-and-blood machine. ]

[The power of this machine is the sum of human power and animal power, plus almost negligible wind and water power. ]

[Let's talk about the biological energy of human power and animal power first. ]

[Most adult men can only maintain useful work output at a power of 75 watts to 120 watts. ]

……

"? What does that mean?"

Many ancient people in all dynasties were confused.

What is a watt? What is power? What is useful work?

They don't understand.

……

[There are only two ways to get a higher power output. ]

[Either concentrate a large number of individuals, and if 100 people don't work, find 1,000, or change and enhance muscle strength through mechanical devices. 】

【However, the first method soon encountered limitations, especially when moving objects with large mass but relatively small volume. 】

【On the one hand, the number of people that can be accommodated in a space is limited, and on the other hand, the strength of the human body is limited, and the weight that can be lifted is often less than its own weight. 】

……

"Huh? Is that so?"

In the dimension of Emperor Wu of the Han Dynasty, Liu Che first heard the saying "the weight that a person can lift is often less than his own weight" and found it quite novel.

However.

Liu Che thought again, it is not absolute.

There are also people who can lift objects that are much heavier than their own weight, such as Xiang Yu who lifted the tripod.

……

【This can only be hoped for by some simple machines, which generally reduce the force by increasing the distance. 】

[For example, levers, wedges and pulleys used by almost all ancient civilizations, and then simply expanded and combined to design capstans, treadmills and gears that can enable human power to continuously lift, grind, hammer and other tasks. 】

[But don't forget that these are all powered by only 75 watts of human power. 】

[In some cases, when a larger power source is needed, it is necessary to rely on draft animals. 】

……

"Cow?"

Hearing this, the first draft animal that came to the minds of many ancient people in all dynasties was this. Menmen.