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

Chapter 691 Compton Scattering

On the ship, Li Yu was leisurely reading a magazine on the deck.

Liang Sicheng and Lin Huiyin came over, "Mr. Academician."

"Please take a seat, both of you," Li Yu said, and then asked, "Have you recovered from your leg injury?"

"Much better." Liang Sicheng said.

Liang Sicheng participated in the National Humiliation Day commemoration event more than half a year ago. At that time, he and his younger brother Liang Siyong were riding a motorcycle. As a result, they were hit by a car of a senior official of the Presidential Palace. The motorcycle fell on Liang Sicheng's legs, and the senior official drove away without stopping.

Later, when he learned that the person who was hit was Liang Qichao's son, the senior official was terrified and asked President Li Yuanhong to come to his house to apologize and pay a large sum of medical expenses.

Liang Sicheng's leg injury was not completely healed and he still had some limp.

However, it seems that during the more than three months of hospitalization, the relationship between him and Lin Huiyin, who had been taking care of him, quickly warmed up.

Liang Sicheng asked: "What are you looking at, sir?"

Li Yu said: "The first issue of Yusi magazine contained an interesting article written by Lu Xun titled "On the Collapse of Leifeng Pagoda."

Liang Sicheng sighed, "It's such a pity that Leifeng Pagoda collapsed. I always wanted to go and see it, or at least copy a draft. But I will never have the chance again."

"Isn't Leifeng Sunset missing from the Ten Scenic Spots of West Lake?" Lin Huiyin asked, "Why did it collapse all of a sudden?"

Li Yu said: "As early as the Jiajing period of the Ming Dynasty, this tower was burned down by Japanese pirates. For hundreds of years afterwards, for some reason, people kept saying that Leifeng Pagoda was a Buddhist pagoda with divine power, and that the bricks of the pagoda had the effects of "warding off evil spirits" and "bringing a son". Therefore, nearby residents stole many bricks from the pagoda, and finally it collapsed without being able to support itself."

When Lu Xun wrote the article "On the Collapse of Leifeng Pagoda", he was criticizing the fact that feudal ideas had not yet been eliminated.

Liang Sicheng said: "If it collapses, it can be rebuilt. The ancients left their appearance in their paintings."

"It would be best if we could rebuild it," said Lin Huiyin.

Li Yu took out a few books and said, "This is a book called 'Yingzao Fashi' compiled by Li Jie, who was once the Minister of Works in the Northern Song Dynasty. It is an official book on architectural design and construction in the Northern Song Dynasty, similar to today's architectural design manual. I'll give it to you."

Liang Sicheng and Lin Huiyin were overjoyed: "Where did you get this, sir?"

Li Yu said, "I have so many ancient books that I have built a museum for them. I saw this book last year, but it uses the vocabulary of Song Dynasty craftsmen, which is like reading a book from heaven. If you two study architecture, it will definitely be useful to you."

Liang Sicheng flipped through the book for a while and found it difficult to understand. However, the more he read, the happier he was: "The existence of a monograph on architecture in the Northern Song Dynasty shows that ancient Chinese architecture is indeed worth studying."

"Have you two really decided to apply to the Department of Architecture?" Li Yu asked.

Lin Huiyin said firmly: "This is the long-cherished wish of both of us."

"I understand," Li Yu said, "Almost all architecture departments in American universities exclude female students. If you can eventually get excellent grades in all subjects, I will definitely write a letter of recommendation in person and ask the school to give you a degree."

Lin Huiyin said happily: "Thank you, sir!"

Historically, after Lin Huiyin and Liang Sicheng arrived in Philadelphia, USA, they spent a month on tutoring. When they reported to the Department of Architecture at the University of Pennsylvania, the school informed them that in order to facilitate school management, the Department of Architecture only accepted male students and not female students.

The school administrators believed that students in the Department of Architecture often had to work on drawings at night, and it was not appropriate for a girl to stay in the drawing room late at night. Moreover, the heavy drawing tasks of the Department of Architecture were not something a woman could undertake.

After all, it was an era without CAD, and drawing was entirely done manually, which was indeed quite tiring. It was common to spend a whole day and night to complete a drawing.

However, the two had made up their minds and after discussion, they decided to apply for the Department of Fine Arts and then take the main courses of the Department of Architecture.

So in the end, Lin Huiyin got a degree in fine arts; Liang Sicheng continued to pursue a master's degree in architecture.

It seems that it was not until 2023 that the University of Pennsylvania posthumously awarded Lin Huiyin a bachelor's degree in architecture.

Li Yu added: "By the way, I met Dr. Hu Shih before I boarded the ship, and he told me that Xu Zhimo had begun pursuing a woman named Lu Xiaoman, and it seemed that she had not yet divorced."

Lu Xiaoman's current husband is still Wang Geng.

Lin Huiyin sighed: "Zhi Mo is still too sentimental. Sometimes he can't tell what love is. I hope he is well."

At that time, Liang Sicheng had already established a romantic relationship with Lin Huiyin, but Xu Zhimo still tried every means to pursue Lin Huiyin. Liang Sicheng and Lin Huiyin liked to go to the Songpo Library in Beihai Kuaixuetang for dates, and Xu Zhimo often went there to "harass" them.

Liang Shiqiu, a classmate of Liang Sicheng, once recalled: "Liang Sicheng told me that Xu Zhimo often went to Songpo Library to be an unwelcome third party. Songpo Library was closed on Sundays as usual, but Liang brought his own key to enter and exit because of his special relationship. Liang could not tolerate the harassment, so he posted a note on the door with the words "Lovers want to be left alone" in large letters. Xu Zhimo had no choice but to leave and withdrew from the competition."

Of course, it was impossible for Xu Zhimo to really give up.

Liang Sicheng said: "I feel like I've heard the name Lu Xiaoman before."

Li Yu said: "She is a part-time foreign language translator for Gu Weijun, the Minister of Foreign Affairs. She has become a little famous in Beijing's social circles in the past two years."

Liang Sicheng suddenly realized: "So that's how it is."

It won't be long before Xu Zhimo will marry Lu Xiaoman, starting a tragic marriage story...

-

After arriving at the west coast of the United States, several people boarded the train.

Liang Lin and his partner went to Philadelphia, while Li Yu got off the train early at Chicago Station and hailed a taxi to the University of Chicago.

After going straight to Compton's laboratory, Li Yu saw Wu Youxun doing experiments.

"Mr. Li Yu?" Compton saw him first.

"Professor Compton," Li Yu shook hands with him, and then immediately asked, "How is the experiment going?"

Compton praised him highly: "I have never seen such a talented student. Wu is an experimental genius! He has done experiments over and over again that even I cannot reproduce."

Li Yu said: "One of you is responsible for theory, and the other is specialized in experiments, it's a good match."

Compton said: "The main task of this phenomenon (Compton effect) is to reproduce it experimentally. Theoretically, it is not difficult, after all, it is based on Mr. Einstein's light quantum hypothesis."

Li Yu smiled and said, "Professor Compton has actually learned the Chinese quality of modesty."

"Because Wu's performance was so outstanding," Compton said.

"What's the situation now?" Li Yu asked.

"Wu is trying the fifteenth material," Compton said.

The Compton effect is not complicated to explain. When a beam of high-frequency electromagnetic waves, such as X-rays, is irradiated on graphite, two beams of electromagnetic waves with different frequencies will be scattered: one beam has the same frequency as the original beam, and the other beam has a lower frequency and is related to the scattering angle.

The wave theory obviously cannot explain this phenomenon, because according to the wave theory, the frequency of electromagnetic waves will not change due to reflection and scattering.

But it makes sense to explain it using the light quantum theory, that is, energy is lost after the collision. A few months ago, Compton had just derived a formula using the light quantum theory. After substituting constants such as Planck's constant and the speed of light, he indeed obtained a formula that is only related to the angle of incidence.

For theoretical physicists, this formula is not too complicated and there is nothing complicated or new about it.

The key point of this experiment is that it can thoroughly confirm the existence of photons, thus putting the final nail in the coffin for the wave-particle duality of light.

This is what is most valued by the academic community.

Therefore, whether the experiment can be repeated is crucial.

Li Yu said, "Fifteen kinds of materials? Is that necessary?"

"It is necessary," Compton said. "This experiment has not yet been recognized by the physics community. Professor William Duan of Harvard University believes that the experimental results are caused by the material of the box, which is called the 'box effect'. Wu decided to add other materials in order to expand the scope of application of the experiment and increase its universality."

Initially Compton used only graphite.

Li Yu asked: "Did they all succeed?"

Compton nodded. "It's incredible! I admire Chinese students' ability and attitude in studying. Wu stayed in the laboratory or dormitory for more than half a year to do experiments. He didn't even reply to letters from home. I didn't know about it until his father sent four urgent telegrams. I asked him to reply to the telegrams, and then I started to do experiments again."

Li Yu understood why he worked so hard: Chinese people are too eager to succeed.

Dozens of minutes later, Wu Youxun suddenly said happily: "It's done!"

Only then did he realize that Li Yu and Compton were added to the laboratory.

"Teacher, Mr. Academician!"

Li Yu smiled and said, "Congratulations!"

Wu Youxun said: "I hope Professor Duan won't say anything this time."

“Unless they can do it themselves,” Compton said.

Li Yuze looked around and asked, "Did you use a special X-ray spectrometer?"

"Is there any problem?" Wu Youxun asked.

Li Yu thought for a moment and said, "If you want other physicists to accept the result of Compton scattering, it would be best to do a public experiment at Harvard University using William Duane's own equipment."

"Public experiment?" Compton said. "This is not a medical experiment. If a public experiment goes wrong due to probability issues, it will be discredited."

Wu Youxun said confidently: "I can do it!"

Compton looked at Wu Youxun in surprise: "Wu, this is very risky!"

"I have done this experiment hundreds of times, and there will definitely be no problem," said Wu Youxun.

"Very good!" Li Yu said, "I will contact Harvard University now and send an open letter to the American Physical Society. Everyone should go to Harvard to bear witness."

Li Yu knew very well that only in this way could Wu Youxun gain a firm foothold, stand out from the crowd, and win the Nobel Prize in Physics together with Compton.

Li Yu is an old friend of Harvard and the American Physics Annual Meeting. Everyone knows that he has always supported the light quantum hypothesis. If it really works this time, it will definitely shock the entire physics circle, especially those who study quantum theory, and it will boost their confidence.

On that day, almost half of the celebrities in the American physics circle gathered at Harvard University, and Millikan, who had already left the University of Chicago, also came.

Millikan is now the president of California Institute of Technology and just won the Nobel Prize in Physics last year, and his fame has reached its peak.

William Duane arranged an experimental venue in the auditorium. As a more traditional physicist, he was still reluctant to believe the counterintuitive conclusion of wave-particle duality, so he never accepted the light quantum hypothesis.

"Professor Compton," William Duane said, "you haven't given up the box effect yet and invited such a big team."

Compton said: "Since you are here, it means you are very confident."

"Don't be ridiculous!" Duan laughed, "The light will reduce its frequency after reflection. It's impossible if you just think about it!"

Li Yu asked: "Why is it impossible?"

"Obviously, if light is reflected or scattered and its frequency is reduced, that is, its wavelength is increased, what does that mean? It means that the entire spectrum is shifted to the red end. If you look in the mirror, won't you appear red?" Duan said.

Duan was extremely satisfied with his explanation, which is why many classical physicists firmly opposed Compton scattering. After all, no one has ever found that looking in the mirror can make a person red.

Compton shrugged. "This is a theoretical question. It is not my job to explain it. I am just explaining a real experimental phenomenon."

Duan said calmly, "Then please let Mr. Compton show his skills."

Compton would definitely not leave the court, and said to Wu Youxun beside him: "Are you ready?"

"I can't wait." said Wu Youxun.

Duan was surprised to see the skinny Chinese man slowly walking up to the lab table. "A Chinese?!"

Wu Youxun, who was sitting on the lab table, said calmly, "Gentlemen, I am about to begin."

I have done this experiment countless times, and even if I use Harvard's experimental equipment, it makes no difference. Physics experiments are supposed to be universal, and if others can't do it successfully, then there is a problem.

In a short time, Wu Youxun completed the experiment easily. During the experiment, he even kept explaining to the physics experts in the audience in English, as if he was the lecturer.

The result was quite successful, and Li Yu was the first to lead the applause.

Even Millikan was impressed and exclaimed: "Another Chinese!"

Compton was extremely excited and said to Duan, "Professor Duan, seeing is believing. If you still can't succeed next time, it can only mean that it's your problem."

Bridgman, another physics professor at Harvard and winner of the 1946 Nobel Prize in Physics, could not help but walk up to the stage, shook hands with Wu Youxun and said, "Sir, you are indeed a master of physics! Your results will be officially announced at the annual physics conference!"

Wu Youxun was as humble as ever: "It's all thanks to my mentor Compton. I just did it according to his request."

"No! Your contribution is equally great!" Li Yu had to interrupt at this time, "We are all studying science, and we should seek truth from facts. It is as important as it should be, don't you think, Professor Compton?"

Compton was in a good mood and immediately said, "That's right! If the American Physical Society annual meeting invites us to present a paper on this discovery, you are the most suitable person!"

It was easier to talk with his words, but Li Yu still chose to add a layer of insurance: "When you two finish your papers, you can publish them in SCIENCE. Be sure to indicate your names."

Historically, although Wu Youxun read the paper at the American Physics Annual Meeting, he insisted on not signing his name on the paper, and all the credit was given to Compton - their paper was published in another physics journal.

Compton was indeed good to Wu Youxun, but there was no need to be too modest. This time, Li Yu would definitely let both of their names be published on the paper; by then, he would have the right to nominate for the Nobel Prize, and he would definitely help Wu Youxun win the Nobel Prize in Physics.