Physics is the most basic and all-encompassing subject, which has a far-reaching impact on the development of the whole science. In fact, physics is a modern name equivalent to the so-called "natural philosophy" in the past, and most of modern science comes from natural philosophy. Students in many fields find themselves studying physics because it plays a fundamental role in all phenomena. In this chapter, we try to explain what are the basic problems in other sciences. Of course, it is impossible to really handle these complex, exquisite and wonderful things in the dam area in such a short space. It is precisely because of the limitation of space that we can't discuss the relationship between physics and engineering, industry, society and war, or even the most amazing relationship between mathematics and physics. According to our point of view, mathematics is not a science in the sense that it is not a natural science, and its correctness is not tested by experiments. By the way, it should be clear from the beginning that if something is not science, it is not necessarily bad. For example, hobbies are not science. So, if something is not science, it doesn't mean there is something wrong with it; It just means it's not science.

The backbone of humanities can be called "literature (literature), history (history), philosophy (philosophy)", and art can also be added. The broader "humanities" can also include modern languages and classical languages, linguistics, archaeology, and even social sciences that contain humanitarian content and use humanitarian methods for research. A convenient way to distinguish between "humanities" and "social sciences" in liberal arts is that all disciplines in liberal arts that are not so practical and therefore less profitable and easy to be unpopular are generally "humanities", while those that are more practical, profitable and popular, such as economics and law, are generally "social sciences".

Physics belongs to natural science, while humanities belongs to social science. Generally speaking, natural science studies the development law of natural field, social science studies the development law of social field, and the development law of social field is based on the study of natural field.