Cultural Revolution launched by Mao Zedong when he shut down schools and called for a massive youth mobilization to take party leaders to task for their embrace of bourgeois values and lack of revolutionary spirit. The students formed paramilitary groups called the Red Guards and attacked members of the elderly and intellectual population. The population was urged to get rid of old customs, old culture, old habits and old ideas. Frank Dikotter’s book The Cultural Revolution claims tens of millions of people were persecuted and estimates of hundreds of thousands to millions of deaths.
Qian was targeted along with other leaders of the Seventh Ministry by a coup d-etat. One top scientist was beaten to death. Qian’s status fell and he was treated like any other employee. Chou Enlai stepped in to protect him and Qian credited Chou with saving his life. (Qian also knew that Chou was behind the swap that got him out of house arrest in the US and back to China.) At the same time, Qian made a tactical error in supporting Lin Biao, whom he assumed to be Mao’s heir but who fell from grace and was killed in a plane crash in an apparent attempt to leave the country. This turned out to be a huge political mistake and Qian had to write self-criticisms to repent his error. Qian also criticized Deng Xiaopeng to gain favor with the Gang of Four, a group that included Mao’s widow. The Gang of Four was brought down. These actions caused Qian to lose power in the later half of the 1970s. It was after this that Qian became a scientific gadfly, weighing in on architecture, acupuncture, UFOs and qigong.