"On the Principles of Social Gravity" proposes a radical new way of thinking about social systems. It explains that all social systems -institutions created of and for human beings e.g. healthcare system, family, military etc., - are held together or governed by nine principles or rules. Using these principles, it examined the problems facing the US healthcare system, criminal justice system, social security, student debt crisis, tax policies, immigration, the political system, and the United Nations. Then, provided novel and unique solutions to them. It expands on the meaning of social entropy and explains how it affects all social systems. It explains new terms like social gravity, de-entropification, primary and secondary contributors, negative and positive homogeneity, positive and negative homogenous group, homogenization, etc. that many readers will find enlightening and very interesting. It is a book that is likely to spark national and even global discussions about many of the institutions we have created. It's originality and usefulness makes it very likely that it will find a wide audience and many of its terms may become popular in the wider society. Since anyone could use the same principles developed in this book to understand and solve the problems with any social system, it will be useful for adoption in the university, for researchers and professors in the social sciences.