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

In addition to advanced seminars and societies, Planck naturally asked Li Yu to give several regular lectures to ordinary students at the University of Berlin.

This arrangement is reasonable and reasonable, and Li Yu is already familiar with giving speeches and has no burden.

In view of Li Yu's reputation, many people came to listen to his speeches.

After Li Yu gave a speech titled "Game Theory and Everyone", he met a young Chinese student when he left the auditorium.

"Mr. Li Yu, your knowledge is amazing, but you don't understand many things clearly," the other party said.

There are very few Chinese students studying in Germany. Li Yu asked curiously: "This classmate, what is your name and where are you from?"

The other party said: "Returning to Mr. Academician, I am Zhang Junmai (mai, four tones), courtesy name Shilin, from Baoshan, Jiangsu."

Baoshan has not yet been assigned to Shanghai.

Li Yu said: "Hello, classmate Zhang."

Zhang Junmai was a standard figure of the Republic of China. Within half a century, he enjoyed a high reputation in both political and academic circles.

Zhang Junmai comes from a prominent family in Baoshan. He is the second eldest son of the Zhang family.

Zhang Junmai's brother-in-law is Xu Zhimo. Xu Zhimo will marry his sister Zhang Youyi next year. The two are now engaged. The Xu family and the Zhang family can be said to be well-matched.

Zhang Junmai loves her sister very much. When Zhang Youyi was three years old, her mother planned to bind her feet so that she could find a good partner in the future. ——Although this view sounds ridiculous, many people at this time believed that foot binding was a symbol of wealth and status, because small feet could not do hard work and could only be a rich lady.

As a result, Zhang Youyi screamed in pain after only four days of binding. Zhang Junmai couldn't bear it anymore, so he stopped her mother from binding her feet and said, "If my sister cannot get married, I will be responsible for raising her."

With Zhang Junmai's support, Zhang Youyi became the Zhang family's first genius. ——If her feet were bound, it would be impossible for Xu Zhimo to marry her, considering that he considered himself a new-age human being.

The combination of Xu Zhimo and Zhang Youyi was mainly due to Zhang Gongquan, the third eldest member of the Zhang family. This man was a powerful figure in the Shanghai financial community during the Republic of China. He was the president of the Bank of China and the pocketbook of President Jiang.

Last year, Zhang Gongquan accidentally saw an article written by Xu Zhimo imitating Liang Qichao and felt that this young man was not simple and talented. After many inquiries, it was discovered that he was the son of the richest man in Xiashi, so Zhang Gongquan immediately wrote to Xu Zhimo's father, hoping to marry his sister to Xu Zhimo.

Father Xu readily agreed.

However, at first the Zhang family wanted to marry Zhang Youyi's sister, who is four years older than Zhang Youyi, but Zhang Youyi's mother said that a fortune teller had calculated that if Zhang Youyi's sister got married before the age of 25, her husband would die and the family would be ruined, so the marriage fell through. It’s up to Zhang Youyi.

But after deciding on the marriage of Xu Zhimo and Zhang Youyi, Zhang Youyi's mother went to ask a fortune teller to read her horoscope. The fortune teller said that Xu Zhimo, who was born in the year of the monkey, was not compatible with Zhang Youyi, who was born in the rat year. Only someone who was born in the year of the dog would be a good match for Xu Zhimo.

In order to marry Xu Zhimo, Zhang's mother changed Zhang Youyi's birth date by two years to 1898, which was a dog.

In her later years, Zhang Youyi once recalled with confusion: "Why didn't my mother believe me when she heard the fortune teller told her sister to marry later?"

In short, that's it, Xu Zhimo and Zhang Youyi made an appointment to get married, and then took photos of each other.

When Xu Zhimo saw Zhang Youyi's photo for the first time, he said, "What a country bumpkin." He didn't like it from the beginning.

Many years later, their marriage finally fell through, but Xu Zhimo's child was born to Zhang Youyi, and the Xu family has always liked Zhang Youyi.

Zhang Youyi is by no means a "country bumpkin". This woman later became the first female bank president in my country.

It can only be said that Xu Zhimo's father is very discerning, but it is a pity that he cannot control his son.

Li Yu asked: "You studied at the University of Berlin. What major did you study?"

"Political science," Zhang Junmai said, "Actually, I just came here to take refuge and get a doctorate degree, because I have already obtained a political science degree from Waseda University in Japan."

In 1906, Baoshan selected eight people to study abroad at public expense. Zhang Junmai and Zhang Gongquan were both selected. According to the requirements of the Qing government for studying abroad at public expense, they should study science and engineering. However, Zhang Junmai still chose law and political science, which he was more interested in.

The Baoshan government suspended his public funding, so Zhang Junmai could only earn some tuition by writing articles for Liang Qichao's "Xinmin Congbao" and became a die-hard follower of Liang Qichao.

Li Yu asked: "Taking refuge? Did you also offend Yuan Shikai?"

Zhang Junmai said: "Yes, I wrote some articles in newspapers and periodicals against President Yuan Da, and they were regarded as propaganda articles. Mr. Ren suggested that I come to Germany to study abroad to avoid the limelight."

Li Yu said: "You came at the right time."

After the First World War broke out, Zhang Junmai paid attention to the current situation and went to the Belgian front line to inspect.

Zhang Junmai said: "I didn't know how famous your husband is until I was abroad. Not only is he unparalleled in science, but he can also write good articles. Almost every bookstore has your book."

Li Yu said: "I'm afraid most of the books in the bookstore are Star Wars."

Zhang Junmai said: "I have also read Star Wars. The story is so attractive, and the style is very strange. It seems to have no literary talent, but it is very comfortable to read."

Li Yu said: "This writing style focuses on being easy to understand."

Zhang Junmai said: "It feels very close to the language of foreigners, both are very simple."

These people have not yet experienced the baptism of vernacular writing. When the time comes, they will feel that although they curse vernacular writing, it is really delicious when used.

Li Yu asked: "Germany values ​​technology the most among European countries. You have been here for a while. Do you have any special insights?"

Zhang Junmai said: "I deeply realize that the power of science and technology, politics and law is so terrifying. I never could believe that a country can be so powerful."

Li Yu took advantage of the situation and encouraged: "This is the purpose of studying abroad. Know the gap and then study hard."

At present, Zhang Junmai still admires Europe very much, but after World War I, his attitude changed a bit. He believes that Europe's decline is caused by over-reliance on science and material civilization.

By the way, he was also the instigator of the famous scientific and metaphysical debate in 1923. The spark of the scientific and metaphysical debate was a speech he gave at Tsinghua University.

Zhang Junmai can be regarded as a pioneer in metaphysics.

It is estimated that the two of them will have to stand in different camps in the future.

However, Li Yu had no worries about the scientific and metaphysical debate. The Republic of China was originally a melting pot, and there should be some ideological debate, so that everyone could grow rapidly in the struggle.

Li Yu himself has engaged in debates with many people.

Zhang Junmai suddenly asked: "Does Mr. Academician support Yuan Shikai?"

Li Yu said tactfully: "Whatever happens to Mr. Ren, I will do whatever happens to you."

Moving Liang Qichao out is a good shield.

Zhang Junmai was stunned: "I don't understand Mr. Ren either."

Li Yu said: "In other words, I don't care about military affairs, I only care about science, education and people's livelihood."

Zhang Junmai suddenly realized: "Mr. Academician is more thorough."

Li Yu said: "We should meet again after returning to China. Just study hard here and don't worry about much else."

Zhang Junmai said: "The student took note of it."

——Li Yu stayed in Germany for a while, often going to the observatory to make observations, and then writing some articles on astronomy.

Astronomical results always give people a feeling that they are either ordinary or extremely explosive.

As an extremely ancient subject, astronomy has appeared almost since the birth of human civilization.

But ancient astronomy was mainly pure observation; in the era of Kepler and Newton, astronomy began to be more integrated with physics and mathematics.

Then naturally comes the era of astrophysics using atomic physics.

It's just that we haven't completely entered this stage yet, and Li Yu is not in a hurry.

He wrote an article about white dwarfs to lay the groundwork for future astrophysics articles.

The astronomical community has observed white dwarfs decades ago, and they are best known as the companion stars of the brightest stars in the night sky, the Sirius companion.

The astronomical community has always been puzzled by it because it is calculated to be very strange.

The companion star of Sirius is about one solar mass and has a surface temperature of about 25000 K, but its luminosity is only one ten thousandth of that of Sirius.

According to spectroscopic analysis, it is inferred that its size is equivalent to that of the Earth, that is, it weighs two to three tons per cubic centimeter!

This kind of density cannot be reached by materials on the earth, and it is even unthinkable, so many people are still questioning it.

Historically, it was not until around 1915 that the Sirius companion star was truly established as a white dwarf.

Li Yu is equivalent to being slightly ahead of schedule by a year.

He sent the article to the British magazine Nature.

It’s just that the academic community doesn’t seem to have much energy to pay attention to white dwarf stars. Most of their attention is attracted by radioactivity, quantum theory, and the theory of relativity.

But after all, Li Yu was well-known, and major observatories were very excited after seeing it.

This excitement is more likely to come from the inherent curiosity of human beings: there are so many unknowns in the universe, which greatly stimulates astronomers’ desire to explore.

When things on the European continent were almost busy, Li Yu came to England again.

He is also planning to take the sea route when he returns to China in a while, and also goes to the United States to make arrangements for the company.

The outbreak of World War I was quite sudden for countries outside Europe, and it brought a lot of risks and opportunities. Of course, for companies outside Europe, the opportunities were even greater.

What Li Yu has to do is to make good use of this opportunity.

After arriving in the UK, Eddington, director of the Cambridge Observatory, immediately came to Li Yu to discuss white dwarfs and other related issues.

Eddington said excitedly: "It's incredible! With such a high density, it's hard to imagine the huge pressure up there."

Li Yu was not shocked at all. White dwarfs only weighed a few tons per cubic centimeter. The density of neutron stars discovered in the future was as high as hundreds of millions of tons per cubic centimeter, not to mention black holes.

Li Yu said casually: "The most important thing is that white dwarfs verify the stellar evolution route."

"I wonder if white dwarfs are a relatively rare type of star in the universe." Eddington asked.

"We only discovered white dwarfs after observing a few celestial objects. Since the universe is so large, white dwarfs must be very common." Li Yu said.

Eddington thought for a moment and said: "If this is the case, I think the universe is scary."

Li Yu smiled and said, "I think it's scary too."

Eddington added: "In addition, I also read your article on fine structure constants published in Munich."

"Your research fields are quite broad, including astronomy, relativity, and the quantum field," Li Yu said in surprise, and then asked, "You also study fine structure constants from a physical perspective?"

"No," Eddington said, "I'm thinking mathematically about the meaning of the fine structure constant."

"Mathematics?" Li Yu was even more surprised.

Eddington said: "You group of top physicists can't understand it together, so I decided not to think from the perspective of physics for the time being."

"It's a somewhat sensible idea," Li Yu said, and then asked, "What do you think of the fine structure constant from a mathematical perspective?"

Eddington said: "The fine structure constant has no dimensions, it is a pure number, and since it is a pure number, it can be studied using mathematics."

"It seems to make sense." Li Yu said.

Eddington continued: "Mathematics is perfect, and nature should be simple, so I firmly believe that the reciprocal of the fine structure constant should be an integer, that is, 136, so it should be exactly equal to 1/136!"

This conclusion is obviously too hasty and even somewhat inexplicable.

Li Yu said: "Mr. Eddington is definitely a perfectionist."

Eddington explained: "It gets even trickier if a dimensionless pure number is also a transcendental number like pi."

Li Yu said: "There is a derivation formula for the fine structure constant. The formula includes the basic charge, the speed of light, and Planck's constant. It is not without reason."

"I understand," Eddington said, "but I think there should be other purely mathematical ways of deriving the fine structure constant."

说完，他拿出一张纸，写出了一个等式：16+（16×16-16）/2=136。

"Look," Eddington beamed, "how simple and perfect it is!"

Li Yu couldn't laugh or cry.

Why was it that when Ramanujan, a numbers maniac, came to Cambridge, Eddington was also "infected" and became crazy about pure numbers.

And Eddington has always insisted on his bizarre theory.

A few years later, after more precise calculations, it was found that the fine structure constant was closer to 1/137. Then Eddington firmly believed that it must be exactly equal to 1/137, and went to find a mathematical equation.

Although it feels a bit ridiculous, it shows from another aspect that physicists really have nothing to do with the fine structure constant, but everyone wants to explore the secrets of atoms, which leads to some attempts that are almost "wrong".

Later, people found many equations that are approximately equal to the fine structure constant, and these equations are very Ramanujan style.

Li Yu said: "If it is too coincidental, it will no longer be a coincidence. Mathematics can be used to derive the physics process, but it is not appropriate to rely on mathematics to blindly test the results."

Eddington said: "Mathematics is the ideal version of physics. There must be some connection between the ultimate mystery of physics and the ultimate mystery of mathematics."

This sentence may sound bluffing at first, but there are still problems if you think about it carefully.

Although humans are still striving to pursue a unified model, there are essential differences between mathematics and physics, which cannot lead to a unified model.

Li Yu knew that there was no good theory to refute him at the moment, so he could only say: "As long as it is from a scientific perspective, I think any attempt is worthwhile."