Having gone through nine years of compulsory education, you can also call him teacher!

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There is a scientist who is the leader of many well-known physicists in our country and the "founder" of Chinese physics research. Scholars such as Qian Sanqiang, Qian Weichang, Yang Zhenning, Deng Jiaxian, and Li Zhengdao were all his students.

This legendary teacher is Wu Youxun.

Wu Youxun

Wu Youxun, courtesy name Zhengzhi, was born on April 26, 1897 in Shixiwu Village, Heling Township, Gao'an City, Jiangxi Province. In 1921, he went to the United States to study physics at the University of Chicago and became a graduate student of AH Compton. In the autumn of 1926, Wu Youxun returned to China and taught at Jiangxi University, National Central University (now Nanjing University), National Fourth Sun Yat-sen University, and Tsinghua University.

Wu Youxun is easy to leave an impression on people. He is tall, 1.8 meters. He is intimidating without getting angry, and has the natural image of being able to control a situation. He once used his resignation as a guarantee to protect students in the patriotic movement.

Everyone says that he is "tough", but few people know that behind his upright appearance, what supports him is his passion to serve the motherland, his strong pursuit of academic independence, and his sincere love for scientific research.

He became famous in the international physics community for his X-ray scattering spectrum.

"Wu, there are good scientific research conditions in the United States and a bright future." Compton, a famous physicist and professor at the University of Chicago, could not understand why his beloved disciple, who had obtained a doctorate and stayed on to teach at the university, insisted on returning to China when there were so many graduates looking forward to staying in the United States.

"After all, I am a Chinese." After Wu Youxun received a suggestion from Jiangxi gentry inviting him to participate in the preparation of Jiangxi University, he resolutely gave up the opportunity to pursue his career at the forefront of world science and decided to return home immediately.

The story begins in the winter of 1921, when Wu Youxun passed the examination for a government-sponsored overseas student and boarded a ship to the United States. Two years later, he studied under Compton.

Compton is famous for the Compton effect, which is regarded as a milestone or turning point in the history of modern physics. However, at first, the paper published by Compton only involved a scattering material, graphite. Although clear data was obtained, it was limited to a special condition and was difficult to be convincing.

Wu Youxun successively made X-ray scattering curves of 7 substances and spectra of X-ray scattering of 15 elements, and refuted various denials of the Compton effect with scientific facts.

For a time, Wu Youxun became famous in the physics world.

His paper was ranked first at the 135th meeting of the American Physical Society, and he read three papers at the 140th meeting of the American Physical Society. His X-ray scattering spectrum curves using 15 elements as scatterers are recognized as the classic illustration of the Compton effect.

In the autumn of 1926, Wu Youxun returned to his motherland. In the impoverished Chinese academic world, this tall man "opened up new frontiers".

The Ten Years of Spring in the Department of Physics at Tsinghua University

Wu Youxun is not only an outstanding physicist, but also an outstanding educator.

In fact, while studying for his doctorate in the United States, he paid great attention to absorbing and digesting the academic thoughts of American university education, and formed his basic conception of Chinese university education - "university education and scientific research development go hand in hand, and teachers do not leave the forefront of scientific research."

According to his son Wu Zaisheng's recollection, Wu Youxun "joined" Tsinghua University with mature academic ideas and clear academic goals.

In 1929, Wu Youxun took the lead in organizing my country's first team of "famous teachers" in the Department of Physics at Tsinghua University - they were both accomplished scientists and excellent teachers.

From 1929 to 1932, he published 11 papers on a series of topics related to X-ray scattering. The first paper was published in Nature magazine in 1930. This was also the first time that the modern physics research results done by Chinese people in their homeland were published in the form of papers in international mainstream academic journals.

From 1929 to 1938, it was the spring of the Department of Physics at Tsinghua University. During those 10 years, it cultivated a large number of scientific elites for the first time in China - 22 of them later became academicians, accounting for more than 30% of the total number of students.

1938. From left: Zhou Peiyuan, Liang Sicheng, Chen Daisun, Lin Huiyin, Liang Zaibing, Jin Yuelin, Wu Youxun, Liang Congjie

During the War of Resistance Against Japanese Aggression, Wu Youxun led all teachers in the college to engage in scientific research. In eight years, the Department of Physics of Southwest Associated University published nearly 100 papers at home and abroad. Even when compared with the international level at that time, its scientific research achievements were at the forefront.

A group photo of the leaders of Tsinghua University (Southwest Associated University stage). Wu Youxun is the third from the right

Wu Youxun contributed to the establishment and recognition of the Compton effect through systematic, sophisticated experiments and insightful theoretical analysis in X-ray scattering research, and creatively developed a general theory of X-ray scattering by polyatomic gases.

Therefore, he was elected as an academician of the Academy of Natural Sciences in Halle, Germany, becoming the first Chinese to be awarded the title of academician by a Western country.

In those days, people used to refer to Ye Qisun and Wu Youxun as "Ye and Wu". Ye and Wu "give way" to each other for the position of director of the Department of Physics, which left a good story in Tsinghua University. Regardless of the give-and-take, the academic spirit of "focusing on academics, doing practical things, and ignoring fame and fortune" jointly advocated by Ye and Wu has become the support of the academic spirit of Tsinghua University and Southwest Associated University.

A patriot with a far-sighted vision

In 1950, under the arrangement of Zhou Enlai, Mao Zedong met Wu Youxun in Zhongnanhai. Mao Zedong asked him three major questions: the current status of Chinese science and technology, how science and technology can serve the country's economic construction, and what principles should be followed for the development of Chinese science and technology itself.

Wu Youxun believes that these research results have reached the international advanced level, but overall, China's science has many shortcomings and poor equipment conditions, especially in engineering and technical sciences that are closely related to the development of the national economy, which are almost blank.

Therefore, he agreed that the country's future scientific and technological development should first follow the principle of closely integrating with the actual needs of national economic construction. At the same time, in terms of basic theoretical research, China should also strive to maintain and create international advanced levels in those areas where it already has some foundations.

Finally, he talked about China's need to develop atomic energy and research atomic bombs, and introduced how he and his colleagues had specially trained and selected a considerable number of overseas students to study nuclear physics before and after the victory of the War of Resistance Against Japan, as well as how he, Sa Bendong and Zhao Zhongyao had drawn up a mathematics, physics and chemistry plan.

He expressed confidence that after breaking through the Western blockade in the future, as long as the country can solve the funding problem, China will be able to design and manufacture its own atomic bomb.

Mao Zedong listened very carefully and was very warm and polite from beginning to end. After the meeting, he and Zhou Enlai accompanied Wu Youxun to the door and watched the car drive away.

Chairman Mao, Wu Youxun (second from left), Zhu Kezhen (third from left), etc. in 1953

In the early 1950s, Wu Youxun proposed to set up an Institute of Electronics in the Chinese Academy of Sciences and transferred Chen Fangyun from the Shanghai Institute of Physiology and Biochemistry of the Chinese Academy of Sciences to Beijing for preparation. This was the beginning of electronic research work in New China.

In fact, many people in the scientific community at that time believed that electronic technology only had a service role. It was only under Wu Youxun's insistence that the establishment of the Institute of Electronics was retained. Later, the rapid development of electronic technology around the world made people have to admire his foresight.

In the 1960s, the "new coaxial pumped ruby ​​laser" he supervised and directly participated in, and the "artificial insulin synthesis" project for which he was directly responsible, both achieved world firsts.

When the University of Science and Technology of China was founded in 1958, he had served as vice president of the Chinese Academy of Sciences for many years. Although he was old, he still taught physics courses at the university in person and devoted himself to cultivating talents.

Throughout his life, he tried his best to fulfill his life goal of "focusing on academics and doing practical things" until the last moment of his life.

END

This article is compiled from China Science Daily, China Physics Teaching Reference, and Mao Zedong and Shanghai Democratic Figures.

Editor/Xiao Xitushuo