Why would social science need the help from quantum mechanics? First, there are many unanswerable questions in social science. Are financial markets predictable? How to predict the financial markets? These important questions are not answerable in the existing framework of finance or economics. One important paradox in social science is the psychohistory paradox proposed by Asimov. In his novels, Asimov highlighted a paradox of human society: if the future events of a human society are predictable using psychohistory, people could take the advantage of that prediction to prevent the future events from happening, and the original prediction would be proven wrong. The psychohistory paradox is very real and fundamental in the human society. Second, the existing framework of modern physics can neither explain nor predict the human behavior. It is ridiculous and totally unacceptable that the same modern physics, which often boasts about the accurate descriptions and predictions of the tinniest elementary particles to the largest structures of the universe with amazing accuracies, cannot handle the simple human behavior observed in our everyday life. The flaws of the existing framework of modern physics must be fixed. Third, it is the internal logic of science. If the human free will is a quantum phenomenon as many people believe and social science is all about human choices, social science must be a branch of quantum physics. Fourth and last, quantum social science, or psychohistory, brings powerful tools and new insights to social science. Quantum social science can answer all the previously unanswerable fundamental questions in social science, and re-frame every problem in politics, economics, and other social science to be a physics problem. This paper summarizes the logic flow from the creation of JJW interpretation of quantum mechanics and physics laws of social science (PLSS) to their impacts on economics, finance, politics, and other fields of social science, natural science, and theology. Since many applications of PLSS are still unknown, this paper serves as an introduction to quantum social science and its applications. The central ideas of PLSS are very simple, yet it has profound logic consequences on many corners of human knowledge. The primary goal of this paper is to convey the beauty and simplicity of the framework of quantum social science or psychohistory
