When Chinese American physicist Tsung-Dao Lee shared the 1957 Nobel Prize for Physics with Chen Ning Yang “for their penetrating investigation of the so-called parity laws which has led to important discoveries regarding the elementary particles”, he was only 31 years old.
The two formulated a theory that the left-right symmetry law is violated by weak interaction. In simple words, physicists had long assumed that in a kind of “mirror world” where left and right were reversed and matter changed into anti-matter, the physical laws governing our world would apply, but Lee and Yang discovered, by measuring electrons’ direction of motion during a cobalt isotope’s beta decay, that weak interaction as one of the four basic forces wouldn’t follow this law. It thus changed the assumption that symmetries characterized nature and offered a new way of observing the universe we live in, namely that asymmetry is a condition as natural as symmetry.
Lee and Yang’s achievement also broke the assumption that Chinese people lagged behind those from developed nations. Although the two scientists did their research in the United States and got the Nobel Prize as US citizens, they had grown up in China where they also received their primary to undergraduate education.
Through their achievements and by promoting Chinese-American academic interaction, the two encouraged thousands of Chinese scientists as well as the whole nation. Lee initiated and participated in the China-US Physics Examination and Application, selecting and recommending 915 individuals for higher studies in the US. In 1985, Lee advocated for the establishment of the postdoctoral system and the creation of the China Postdoctoral Science Foundation, the implementation of which has promoted the innovation of China’s education models and concepts, continuously cultivating tens of thousands of high-end scientific researchers for the country. He has given many lectures to students and the public in Beijing, encouraging them to take the path of research in physics.
That’s why so many in China are mourning his passing away in the US on Monday, at the age of 97. He is mourned not only because of his identity as a Chinese scientist but also because of the scientific spirit he demonstrated, his patriotic sentiments, and his love for the country he was born in.