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

Chapter 115 Mendeleev
After simply eating the same lackluster lunch in Russia, Markov brought Li Yu to the mathematics seminar room.

Li Yu saw that the entire mathematics department had been invited.

Lyapunov first made an opening speech: "Students, as researchers of mathematics, we know that mathematics is the key to revealing everything in the world, and the method that hides in the dark and controls the operation of the world.

"For hundreds of years, since Peter the Great opened the window to the west and looked at the prosperous and developed Europe through the blue Baltic Sea, we have been advancing and following, hoping to achieve a world comparable to Paris, London, and Gogentin. strength.

"But just when we had no time to look east, in the far east, in a mysterious country, such a great scholar was quietly born. He used profound and mysterious characters to make us realize once again how great mathematics can be, hidden How close the mystery can be to us.

"He continued to explore X-rays, expanded thermodynamics, observed the trajectory of Pluto, and now revealed order in chaos——Li Yu!
"Let's give a warm welcome!"

The students in the audience immediately burst into warm applause.

Li Yu really didn't expect Lyapunov's speech to be so powerful. Sure enough, Russians who engage in academics also know a little bit of art.

Russia is really a magical country. On the one hand, it is full of wildness and absurdity, like Rasputin, who can skyrocket; A world-wide great man like Pavlov.

Those who engage in the career of magic stick can concentrate and even shake the foundation of the country, and those who engage in academics can also shake up ancient and modern fame and history.

Li Yu saw that almost all of the hundreds of students in the audience were holding a copy of his "Fractal and Chaos", so he said: "Speaking of mathematics, I have only scratched the surface, and I can only speak in a few fields. If there is something wrong, please discuss it together and welcome corrections.

"Come here today, according to what Professor Lyapunov told me, is to study and discuss new ideas in mathematics with you, such as the theory of chaos. I have written many interesting fractal structures in the book, and I want to introduce them to you today. A kind of magic triangle."

Li Yu drew an equilateral triangle on the blackboard behind him, and then connected the midpoints of the three sides to form four equilateral triangles.

Continue to connect the midpoints of the regular triangle with three corners as above.That is, the later Sierpinski triangle.

Li Yu said: "I once wrote in a book that fractals are like Russian nesting dolls. They still have fine structures in an infinitely small range. I think you are the most familiar."

Immediately, some students put out a few nesting dolls in the audience: "Yes, Professor Li, we now privately call your fractal structure the 'matryoshka structure', it is really too similar."

Li Yu smiled and said: "Yes, it is very appropriate! You can see that if this pattern is infinitely subdivided, it is also a fractal structure. But what we are going to explore today is how to use mathematics to find its dimensions."

Since he was in the Department of Mathematics, Li Yu naturally had to talk more about mathematics.

Fortunately, the problem of dimensionality has been studied by the German mathematician Hausdorff before, and the explanation is not very difficult. The most important thing is the mathematical idea embodied in it.

The exploration of ideas is also what Lyapunov advocates today.

After Li Yu finished his lecture on fractals, he continued to discuss with them the chaotic phenomena in the field of differential equations. These are relatively mathematical, but it is very harmonious to study with students from the mathematics department.

The students in the audience were very enthusiastic. Although Li Yu didn't have a computer, he didn't have a PPT screen, and the progress of his speech was very slow, but the discussion atmosphere was very strong.

The seminar lasted for most of the afternoon, and later, even people from the Department of Physics, Chemistry, and Biology of St. Petersburg University came to attend.

Due to too many people, Lyapunov had to use the school auditorium the next day, and it almost turned into a speech again.

At the end, many people brought the book "Fractal and Chaos" to Li Yu's signature.

These two days were almost spent on seminars and lectures in the Department of Mathematics and Mechanics. It was not until the third day that Li Yu finally had time to visit Mendeleev in the morning.

Li Yu has the habit of exercising in the morning. In fact, he happened to see this 68-year-old chemical legend in the garden.

"Hi, professor!" Li Yu went up to greet him.

Mendeleev glanced at Li Yu and immediately understood: "Are you the Chinese Li Yu who is lecturing in the Department of Mathematics these two days?"

"Yes, that's me." Li Yu replied, "It's a great honor to meet you!"

Li Yu knew that Mendeleev had studied in Germany for many years and could speak German very well, so he started communicating with him directly in German.

Mendeleev started off a little differently: "Do you speak German?"

Li Yu smiled and said, "Yes, Professor, I really didn't understand Russian."

"It doesn't matter," Mendeleev also said in German, "I know about you. During this period of time, news and university newspapers have often reported about you. You are indeed the person admired by the old president, Lord Calvin. Come on. Come and sit in my office."

Mendeleev's office was as unruly as his beard, with a lot of books, manuscripts, and documents, and it was not very neat.

Li Yu saw a pair of Mendeleev's periodic table of elements hanging on the wall, which was his life's painstaking effort.

In the past few decades, in fact, many people made the chemical periodic table. The German Meyer released the periodic table of elements almost at the same time as Mendeleev.Moreover, Meyer’s fame, prestige, and status at that time were greater than Mendeleev’s. If these two people were compared around 1880 to see who was the greater theoretical chemist, it is likely that most of them Will choose Meyer.

And it is hard to believe that Mendeleev did not believe in atom theory, let alone electrons.

Of course, these belong to the realm of physics.

However, the reason why Mendeleev can become synonymous with the periodic table of elements is indeed because he has a deep understanding of the elements, and others are just trying to arrange the elements in rows.But Mendeleev spent his entire life researching in the laboratory.What is the nature of the elements and how they will react, his understanding is much deeper than others.

The key is that Mendeleev was not at all as conservative as Mayer. His first version of the periodic table brought together all 63 elements known at the time.

Mendeleev went on to boldly predict many new elements, and even urged geologists anxiously: "You search hard, and you will definitely find it!"

It's hard to predict that kind of thing.

Mendeleev categorically predicted the emergence of "aluminium-like" elements (later "gallium" elements).

A few years later, Le Coq did find it, the first element discovered since Mendeleev published the periodic table in 1869.

The most interesting thing is that Mendeleev read the discoverer Le Coq's data on the gallium element, and directly told the experimental chemist that there must be something wrong with his measurement, because the density and mass of gallium are different from his own predictions. .

As soon as Mendeleev's words came out, the entire chemical community was dumbfounded, and everyone felt that Mendeleev was too arrogant.

But soon, it was discovered that Mendeleev was right: Le Coq retracted the original data, and the republished experimental results were in full agreement with Mendeleev's predictions!
The scientific community was shocked to discover that Mendeleev, a theoretical chemist, knew more about the properties of new elements than the chemists who personally discovered them.

Definitely the God of Chemistry!
So how important is Mendeleev to the subject of chemistry? His periodic table of elements is the beacon of chemical elements in the future. It can even be said to show everyone a direct sign: Don’t mess around, just follow what I said. find it!
The effect is almost the same as the impact of Hilbert's 23 problems on mathematics, and the impact of Kelvin's "two dark clouds" on physics.

Science has never been accomplished overnight by one person. In general, Mendeleev's work is like Darwin's theory of evolution and Einstein's theory of relativity.None of them did all the work alone, but they made the greatest contribution, and did it more beautifully than the others.

As Newton said: "If I have seen farther than others, it is because I have stood on the shoulders of giants."

Anyway, Mendeleev became an instant hit, and even the Tsar gave him a special reward.

Mendeleev's status in Russia can be seen from one incident: a few years after the discovery of gallium, he divorced and wanted to marry another one. The conservative local church told him he had to wait seven years, but he bribed a A pastor, successfully held the wedding.According to the law at the time, Mendeleev was suspected of committing bigamy, but no one dared to arrest him.

The reason is that the Tsar himself came forward to speak: "I allow Mendeleev to have two wives, because I only have one Mendeleev."

It's so arrogant.

The periodic table of Mendeleev's elements hanging in front of Li Yu's eyes is not the one he learned in chemistry class in middle and high school. Mendeleev's periodic table is a short-column form, that is, a short-form table.

And now there are only about 70 kinds of elements.

Li Yu looked at the watch and silently compared it with the periodic table in his heart.

Mendeleev said after discovering: "Do you also understand the periodic law of chemical elements?"

"I did learn it before." Li Yu said frankly.

"Oh?" Mendeleev became interested. "Anyway, I don't know mathematics. If you know chemistry, you can talk more. Let me think about it. You are from China... Ah, yes, China! Sweden has been doing this from time to time. Mentioned to me that they found several elements similar to Cerium in my periodic table."

Li Yu didn't understand for a while, "Cerium?"

Mendeleev stood up and pointed to position 58 on the periodic table of elements.

Li Yu suddenly realized that it was Ce.

No wonder he didn't realize it at first, this thing was the second of the lanthanides in the bottom two separate rows of the periodic table.

Cerium was the only known lanthanide element when Mendeleev published the periodic table in 1869, and it was not the first element "lanthanum" among the lanthanide elements known to later generations.

Li Yudao: "I'm really sorry, I only know that this family of elements has similar properties, and I'm not very familiar with the others."

Mendeleev said: "Don't be sorry, I also have a headache for this family of elements, they are too similar."

Li Yu tried his best to think about it in his mind. Although he can recite the first 36 elements very proficiently, and their various chemical properties have been very familiar with them after several years of examinations in junior high school, but he is really familiar with the lanthanide elements. very strange.

When I was in chemistry class, the lanthanides and actinides were basically in the "cold palace", who would take care of them in class.

Li Yu only knew that these things belonged to rare earths, and they should not be so useful now. It was not until many new materials appeared in modern industry many years later that they began to shine.

Li Yu's mind turned, he mentioned China just now, why didn't he think of it!
Li Yudao: "You mean ceramics?"

Mendeleev nodded: "Yes. Sweden has mastered the porcelain making technology and discovered feldspar and clay mines decades ago. They have reported seven new elements, but they can be compared with my periodic table. Well, because I've got a place reserved for them, but I still feel like a mess with them."

"After all, they are rare earths. I know they are often mixed together," Li Yu said.

"It is indeed less, otherwise Europe would not have figured out how you Chinese make exquisite porcelain so late." Mendeleev said.

Li Yu knew in his heart that rare earths are not "rare" at all, and modern industry cannot rely on rare elements if it wants to develop on a large scale.

There are many rare earths distributed in the strata, but there were very few rare earth mines in the [-]th and [-]th centuries.

Mendeleev continued: "They are so similar that it is difficult to fathom them. The Academy of Sciences once asked me to predict, just like "aluminum-like" to predict "cerium-like", but I can only regret that I can't do anything."

Li Yu saw Mendeleev's helplessness, "Are you referring to this long series of blanks on the periodic table?"

Mendeleev said: "Yes, I got them in the wrong order several times, and even later Sweden told me that the previous elements were actually mixtures."

This was a big chemical problem in the early twentieth century, and spectroscopic analysis was not very good for lanthanides.Even if scientists detect dozens of new color bands, they don't know how many new elements they represent.

Mendeleev said: "I'm curious how the Chinese mastered these elements and could then create so many brilliant colors on the surface of porcelain."

Li Yu's mind was full of a laughing and crying expression. He said, "Professor, I really can't answer your question. It may be a thousand years of experience."

The bright colors are a gift of lanthanide elements, which were rich in lanthanide elements in the deposits discovered in Sweden.

The rare earth elements in the earth's crust are evenly distributed, but it's as if someone poured the entire spice rack into a bowl and stirred them again, causing them to tangle and coalesce.

However, the Chinese people's treatment of porcelain is actually much simpler. They are directly referred to as kaolin and feldspar, and they can be used directly if they are easy to use.Nor can people be expected to understand chemical elements 1000 years ago.

Mendeleev said: "Indeed, it seems that this problem will continue to trouble me."

Although Li Yu doesn't know much about lanthanide elements, it seems that this issue can be considered from another angle. He said: "Professor can put it on the shelf for now, after all, there will be at least 10 rare earth elements in the future. Moreover, I know a new cycle The arrangement of the table just keeps the rare earth elements from worrying."

Mendeleev asked in surprise, "A new arrangement?"

"You're taking the liberty." Li Yu picked up a pen and paper and began to write.

Ten minutes later, Li Yu picked up the manuscript paper, "Professor, please read."

In fact, Li Yu drew the long periodic table of chemical elements that he was familiar with.

This kind of periodic table is arranged horizontally according to the atomic weight and the properties of the elements. The positions of the main and subgroup elements are clear and do not interfere with each other.But also very friendly to beginners, easy to popularize.

Mendeleev scrutinized it carefully for a while, and immediately felt the advantages of this arrangement, and praised: "You are really very creative, and it is indeed much easier to look up in this way."

Mendeleev boasted that Li Yu was a little embarrassed, because this was basically the periodic table he was familiar with from the very beginning of his contact with chemistry, so there was nothing creative about it.

Li Yu said: "It's nothing at all, it's just changing from vertical to horizontal. If the professor thinks it's okay, given your status in the chemical industry, maybe you can promote it."

Mendeleev believed deeply: "People's understanding of chemistry is too shallow, and many people still think that chemistry is alchemy. If you can use this kind of element table that is clear at a glance, it will indeed change many people's views. Look When Markov asked me to sign, it was the right thing to do, and you helped me a lot by coming to St. Petersburg."

Li Yu said, "I can't say it's a big deal."

"No," said Mendeleev, "I said it was a big favor! I will certainly mention your contribution to the periodic table in the new book, and you deserve it."

Mendeleev was in a good mood, "You gave me such a good thing, what should I thank you for? Don't refuse."

Li Yu smiled and said, "I gave the professor a handwritten periodic table, and I also hope that the professor can give me a manuscript where you wrote the periodic table."

"You are so funny!" Mendeleev laughed, "No problem!"

If Li Yu hadn't written down the long-form periodic table in advance, the Swiss chemist Werner would have done the work three years later.

In fact, this is really not an important discovery, because when it comes to the periodic table, no one thinks of Werner, but of course it is Mendeleev who made the original pioneering work.

As for this purely formal innovation, it is really similar to what Michelson said, and the improvement is:
The edifice of the periodic table of elements has basically been built, and future generations are nothing more than a little tinkering.

(End of this chapter)