A discussion on symmetry in physics in the aftermath of the Cultural Revolution

The text below is from T.D. Lee, Symmetries, Asymmetries, and the Word of Particles, University of Washington Press, Seattle, 1988. (Disclaimer: this post is by no means an endorsement of Mao Zedong or the Cultural Revolution.)

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“Tell me, why should symmetry be of importance?” asked Chairman Mao Zedong.

That was on May 30, 1974, when China was still in the turmoil of the Cultural Revolution and the Gang of Four was at the zenith of its power. I was especially depressed to find, in that ancient land of civilization, that education had been almost totally suspended. I hoped desperately that somehow there would be a way to improve, however slightly, the course of events.

At about six o’clock that morning, the phone in my room at the Beijing Hotel had rung unexpectedly. I was told that Mao would like to see me in one hour at his residence in Zhong Nan Hai, inside the former imperial palace. I was even more surprised that when he saw me the first thing he wanted to find out was about symmetry in physics.

According to Webster’s dictionary, symmetry means “balanced proportions” or “the beauty of form arising from such balanced proportions.” In Chinese, symmetry is 对称, which carries an almost identical meaning. Thus it is essentially a static concept. In Mao’s view, the entire evolution of human societies is based on dynamic change. Dynamics, not statics, is the only important element. Mao felt strongly that this also had to be true in nature. He was, therefore, quite puzzled that symmetry should be elevated to such an exalted place in physics.

During our meeting, I was the only guest. A small end table was placed between our chairs, on which there were pads, pencils, and the ever present green tea. I put a pencil on the pad and tipped the pad toward Mao and back toward me. The pencil rolled one way and then the other. I pointed out that at no instant was the motion static, yet as a whole the dynamic process had a symmetry. The concept is by no means static; it is far more general than its common meaning indicates and is applicable to all natural phenomena from the creation of our universe to every microscopic subnuclear reaction. Mao appreciated the simple demonstration. He then asked more questions about the deeper meaning of symmetry, and also about other physics topics. He expressed regret that he had not had the time to study science, but he remembered a set of science books by J. Arthur Thomson which he had enjoyed reading when he was young.

Our conversation gradually shifted from natural phenomena to human activities. In the end, Mao accepted my limited proposal that the education of at least the very brilliant young students should be maintained, continued, and strengthened. This led, with the strong support of Zhou Enlai, to the elite “youth class,” a special intensive education program for talented students form the early teens through college. It was established first at the University of Science and Technology in Anhui and later, because of its success, also at other Chinese universities.

The next day, at the airport, I received a farewell present from the Chairman: a four-volume set of the original 1922 edition of The Outline of Science by J. Arthur Thomson.

To the general chaos produced by the Cultural Revolution, this meeting brought only a minute amount of order. Nevertheless, in a very limit way perhaps it does indicate a correlation between man’s intrinsic urge to search for the symmetry in nature and his desire for a society that is both meaningful and more balanced.