As what has been shown in Chapter 2 earlier, the universe generally can be seen as an ocean of systems, which in turn can be thought of as abstract rotational yoyo fields of different scales that compete with each other. When one focuses on the finance of a nation as a system, the particular financial system of the nation is made up of fluids, such as money, information, knowledge, etc., where other than studying information and knowledge as fluids by making use of continuous and differentiable functions, money should also be treated as a fluid that circulates around all corners of the nation and fuels the entire economy. If in a specific geographic area the money supply is low, then the regional economic development will suffer and the local residents would have to look for employment and other opportunities somewhere else. If this trend continues, the specific region would have to be abandoned eventually. At the same time, money should also be seen as a carrier of other relevant fluids, such as the relevant information and knowledge, which dictate where the opportunities are so that money as a fluid flows to where it could find the maximal returns.