In June 1958, as China’s Great Leap Forward campaign gained traction, state media began reporting astronomical agricultural yields, including claims from central Henan province of over 3,000 jin per mu – more than 22 tonnes per hectare. That month, scientist Qian Xuesen, father of China’s rocket programme, published theoretical calculations on maximum solar energy conversion during crop photosynthesis, which political cadres cited to validate the claims. In the following months, reported yield...