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

Chapter 70 Advance Guidance

Perhaps the most well-known achievement of Jean Perrin is the discovery of the formula for the distribution of sol particles with height, and the very accurate determination of the Avogadro constant, which is widely used in high school chemistry and is almost compulsory, through experiments, so as to completely It established the concept of molecular motion in thermodynamics, shattered the "energy theory", and finally put the crown of victory on atomic theory.

However, these are things around 1908.

Boltzmann committed suicide in 1906, and if he had lived two more years, he could have seen the victory of atomism.

Now Jean Perrin has not studied Avogadro's constant, and the subject he is studying is X-rays.

Li Yu has seen the photos left by Jean Perrin, but they are all of his appearance in old age. Now Perrin is still a young man in his thirties, and the difference from the photos is not small.

"You are Professor Perrin?" Li Yu asked.

Pei Lan stood up from the chair, "Exactly! You must be the legendary Li Yu."

Li Yu said with a smile, "Is it a legend or not? I'm not a legend, I'm just a scholar."

Perrin shook hands with him, "What the newspaper said is indeed true, you are so young! I have read the paper you wrote, and the analysis of X-rays can be described as remote and in-depth. I am going to conduct in-depth research according to the paper. .”

Li Yu rubbed his brows. He didn't want Perrin to continue to study rays, because as a latecomer, Li Yu knew that Perrin's real advantage lay in molecular thermodynamics.

As for the ray, although Perrin has also made some achievements, compared with the molecular thermodynamics that won him the Nobel Prize in 1926, it can be pushed back.

So Li Yu said: "Professor Pei Lan, I personally think that now is not the best time to study X-rays, and the experimental conditions are not available." Li Yu slowed down and said, "No, not only the experimental conditions are not available, but Not even an experimental theory.”

Perrin was startled, and asked in surprise, "Why do you say that?"

"Because atomic theory does not have a deep foundation, only when atomic theory is established can it be possible to carry out subsequent X-ray diffraction experiments."

Li Yu's thesis is based on pure theory, which is very similar to the work of pure theoretical physicists such as Einstein and Planck. They are not good at doing experiments, but focus on theoretical derivation.

There are still many differences between experimental physicists and theoretical physicists, and Perrin obviously has a deep understanding of experimental physics.

As I said before, in this era, physics is in an era led by experimental physicists, and theoretical physicists always derive experimental results after they have been obtained.

However, Li Yu first gave the theory in advance, and later required experimental physicists to conduct experiments.

It is also easy to understand that Einstein's theory of relativity is also pure theoretical physics. It was not until many years later that experiments were made one after another to verify the correctness of the theory of relativity little by little.

Perrin pondered, "Then what should I study?"

"Naturally, it is the determination of Avogadro's constant." Li Yu blurted out, almost saying that this is the discovery that allowed him to win the Nobel Prize.

"Avogadro's constant?" Perrin asked puzzled, "If I remember correctly, Mr. Maxwell had already determined the result 30 years ago."

Li Yu immediately said: "It's been too long! And you should be able to find that the numerical error is too large. If you want thermodynamics to continue to develop, you must have an accurate numerical value."

Perrin is a smart person, and he has indeed been confused about X-ray research with little success.When Li Yu said this, he immediately understood: "No wonder the newspaper said that you are not only proficient in ray science, but also proficient in thermodynamics and astronomy. I saw you today, and it is true. I will definitely start the research topic of thermodynamics as soon as possible!"

Li Yudao: "Great! You are a genius in thermodynamics, I believe you will succeed!"

In fact, it was Einstein in 1905, three years later, who prompted Perrin to determine Avogadro's constant.

Einstein was very eager to know this value, because it is of great importance to the theory of heat.Einstein gave the measurement methods and formulas, but he couldn't do experiments at all, so he could only hope for a genius in experimental physics.

The genius that Einstein longed to turn out to be born was naturally Jean Perrin.

Li Yu can only say that he guided Perrin three years in advance, and he sincerely hopes that Mr. Boltzmann will see his theory truly recognized by the world in his lifetime.

Maybe he will stop committing suicide because of this, otherwise the life of this physicist is really unfortunate.

As soon as we met, I couldn't help but talk about scientific research topics, and let Perrin know that Li Yu was indeed a real talent. He turned to the topic and said, "I am here tonight on behalf of the President of the University of Paris, and I invite you to come to our school tomorrow for a lecture. Speech, do you have time, sir?"

Li Yu felt that he was not that famous yet, so he said, "It's not suitable."

Perrin said: "It's just an ordinary academic conference. You can just talk about your research on rays, thermodynamics and astronomy. You also know that few people can understand so much now. Everyone is very fond of you, an all-rounder in physics. expect."

Li Yu smiled and said, "Your University of Paris also has an all-rounder in mathematics."

Of course Perrin knew who he was referring to: "You mean Professor Poincaré, that's why the school is very interested in you, a rare all-rounder."

Poincaré was the mathematical leader of his day, and the last known to have a comprehensive knowledge of mathematics and its applications.

Li Yu was not too good at refusing, so he said, "Okay, since that's the case, let's give a small-scale speech, don't make too much noise, just treat it as an academic seminar."

Perrin said: "Great, see you tomorrow at the University of Paris!"

After sending Pei Lan away, Li Yu didn't want to go back and continue drinking. He didn't like wine bars.Anyway, he ate about the same, and he also tasted a glass of the bottle of Remy Martin. He didn't know much about wine, and he couldn't tell whether it was good or bad.

I drank that glass of wine entirely because I was a little curious when I read Benshan's sketch that Remy Martin was very expensive.

Now that I've had wine and food, why don't I find a clean place by myself, and I'll just write an outline for tomorrow's speech.

You said that this matter is serious, and you have no precautions. When you first arrive in France, you will go to the University of Paris to give a speech.

The later University of Paris has been split and its name no longer exists, becoming the Sorbonne University and the University of Paris Cité.But the University of Paris at the beginning of the 7th century was still very strong, and there were many talented people, including seven Nobel Prize winners.This does not include Pasteur, who has passed away. If he lived a few more years, he would definitely be a Nobel Prize winner.By the way, Qian Sanqiang was also a Ph.D. student at the University of Paris.

Li Yu is really a bit confused at the moment, maybe he will meet some big boss tomorrow.

(End of this chapter)