A Man of Science and Engineering in Troubled Times Wandering in the Late Qing Dynasty

Chapter 133 Demography Boss

The present time actually belongs to the winter vacation of the college, but the Beiyang Armed Forces Crash Academy is an early military academy after all, which is unusual, and the vacation is very short compared to it.

That's why Li Yu had time to teach Wu Peifu and Sun Chuanfang in Tianjin, and also learned to ride and shoot.

Shooting may sound like a kind of "insurance" and may not be useful, but riding a horse is a common skill in life.

Li Yu is now working hard to practice in order to master this "basic skill" in the early twentieth century.

When returning to the hotel that day, Li Yu saw a young man waiting for him, who ran over when he saw Li Yu.

"Mr. Li Yu! It's finally your turn!"

Li Yu was afraid of bumping into someone while riding a horse, so he quickly said, "Be careful!"

He pulled the rein far away, then got off the horse and asked, "Your Excellency?"

The other party said: "I am dismounting Yuanshan, whose name is Yinchu. I heard that Mr. is now in Tianjin. I am here to pay a visit."

Ma Yinchu...

Isn't this the famous Chinese demography No.1 in the future!

His "New Population Theory" was the first in China to put forward the theory of population control and fewer and better births, which has influenced China's national policy for decades.

The impact is not insignificant.

Li Yu said, "Hello!"

Ma Yinchu said: "It took me a long time to find out from the newspaper office the hotel where my husband is staying, and I rushed over here in a hurry."

Li Yu said, "So you are also in Tianjin?"

Li Yu remembered that Ma Yinchu should be from Zhejiang, and later served as the president of Zhejiang University.

"I heard that the university is going to start school. I went to Tianjin last year, but the school hasn't started yet." Ma Yinchu said.

"Peking University Hall?" Li Yu asked again.

Ma Yinchu said: "Yes, it is helpless to say that I have been admitted to the Beiyang University, but because the Eight-Power Allied Forces occupied the school building, the school's equipment, documents, and case files were destroyed, and it was forced to close. I have already taught myself almost Two years."

Li Yu praised: "It's not easy to learn by yourself, Mr. has amazing perseverance! Let's go upstairs and have a cup of tea first."

Li Yu rented a suite, and the room was not small.

After making the tea, Li Yu asked, "What major do you study, sir?"

Ma Yinchu said: "It's metallurgy, but I'm more interested in numbers, especially those magical expressions, so I want to study economics in the future."

The so-called "magic way of expression" is naturally the Arabic numerals, letters, and symbols that are common in later generations.

But economics itself is indeed inseparable from mathematics.

Li Yu said, "Why hasn't classes resumed at the Beiyang University? The Beijing Normal University where I am is already started at the end of last year."

Ma Yinchu said helplessly: "The previous school building was badly damaged and can no longer be used. We had to find a new location. The new campus is located in Xigu, and it is said that the school will start in the next year."

Later generations here have become the East Campus of Hongqiao Campus of Hebei University of Technology.

"Speaking of after the year, won't you go back to Zhejiang?" Li Yu asked again.

"I'll leave in a few days, but I'll be back soon." Ma Yinchu said, "From now on, the university will send students to study abroad every year. I have wasted more than two years and I want to catch up with the progress as soon as possible."

Li Yu said: "Yes, there is no time to waste, and now there is a lot of waste waiting to be done, and there is no waiting for anyone."

Ma Yinchu said: "I have read Mr.'s reports before, and I cut out all kinds of news myself. I am especially interested in the book "Fractal and Chaos" written by Mr. It is a pity that I have searched Tianjin bookstores, but I can't buy it at all. "

"That's easy! I'll get you a copy." Li Yu directly took out a copy from the cabinet and handed it to him, "I've given it to you."

"How can this be done!" Ma Yinchu refused.

"It's okay, you may be interested in this knowledge in the future." Li Yu said.

"I was thinking, maybe I can't understand..." Ma Yinchu said.

Li Yu said: "It's not a big problem. I have made a step-by-step progression of difficulty in this version. If you plan to study economics in the future, sir, you will use the theory in fractals."

"Fractal?" Ma Yinchu said, "To tell you the truth, I just saw reports about Mr. Master's theory in the newspaper, as well as the miraculous 'carp effect'. But when it comes to the specific theory, I don't know."

"In this case, you should read this book carefully." Li Yu said with a smile.

Ma Yinchu's English is proficient, and he can understand it completely. After flipping through the book, he said, "How about I pay the price according to the price behind?"

Why is it so difficult to deliver a book...

Li Yu had no choice but to say: "You don't have to be polite to me! These books were given to me by the publishing house, and they didn't cost any money. They even have to pay me for the manuscript."

Ma Yinchu said gratefully: "Thank you so much sir! Well, if possible, can you sign again..."

"of course can."

Li Yu signed the signature, and discussed with him for a while the application of fractal and chaos in economic theory, especially told him about a well-known typical model in chaos theory: the logistic equation.

In fact, this equation is very simple, and it is just an iteration of a quadratic equation in one variable.

And the logistic equation discusses the population growth model.

Ma Yinchu also has a little understanding of demography. He said: "I have read the "Evolution of Heaven" translated by Mr. Yan Fu, which mentioned Mr. Darwin's 'natural selection, survival of the fittest', and I also know that Mr. Darwin once Influenced by the scholar Malthus. But then I read Mr. Malthus's book, he mentioned that the population will increase exponentially, but the food will increase linearly, and there will be terrible disasters. But why is your equation just a one-dimensional quadratic equation ?”

It was indeed Malthus who first proposed population control in the world, and Darwin did regard Malthus as his idol throughout his life.However, Li Yu didn't want to discuss with him whether the "Malthusian disaster" was a "Malthusian trap" or not, which belongs to the category of political economy.

Li Yu said: "Although it is a quadratic equation, it is already nonlinear, and there are fractals and chaos hidden in it. From a mathematical point of view, even such a simple population growth model and such a rudimentary one-variable quadratic equation iteration also hide Chaos. Simply put, the conclusion of this model is that when the population growth rate reaches a certain value, the population is difficult to predict.”

"There is also chaos here?" Ma Yinchu was bewildered.

Li Yu said: "Of course, so chaos is everywhere. The population growth model is just a manifestation of chaos in nature."

Li Yu found the paper, "Let me do the calculation for you."

The process is not complicated, as long as you understand the quadratic equation in one variable, you can understand it completely, but the mathematical ideas embodied in it are very profound.

It's just that the famous period-doubling bifurcation diagram will have to be discovered by Ma Yinchu himself in the future.

How should I put it, Li Yu is still selfish now!

And this selfishness is not only for himself, he also hopes to subtly use various methods to inspire, guide and even train some of his own scientists, so that they can gradually have greater inventions and discoveries.

After all, one's own power is too small, just like the matter of the library, only as much power as possible can be combined to form a synergy.

He doesn't just want to let his scientific research go smoothly, he wants to turn it into a hurricane and bring the local scientists to rise!
Ma Yinchu looked at the formulas on the manuscript paper, and expressed his admiration: "It seems that I have learned too little after all! I never thought that the ideas in simple mathematical formulas can be so profound. I have to study it with great concentration in the past few years."

Li Yu said: "There is still a lot of time in the future, I hope this book can help you."

(End of this chapter)