The basic theoretical model of modern quantum mechanics was developed around 1926. This lecture is the retrospect of the thrilling history, mainly introducing several major conceptual breakthroughs.  

Xie Dan is the tenured professor of Tsinghua department of Mathematical Sciences and Yau Mathematical Sciences Center. His research covers supersymmetric field theory and superstring theory. He recently works on the systemic research of N=2 and N=1 supersymmetry in four dimensions.