Mathematical Principles of Natural Philosophy is an important work of Newton's philosophy of physics. This book is divided into three volumes. The first volume "On the Motion of Objects" expresses Newton's three laws; The second volume is also on the motion of objects, which discusses the motion of objects under resistance, which is the precedent of fluid mechanics; The third volume, On the Cosmic System, discusses the Cosmic System.
The mathematical principle of natural philosophy summarizes the achievements of modern celestial mechanics and ground mechanics, provides a set of basic concepts for classical mechanics, and puts forward three laws of mechanics and the law of universal gravitation, thus making classical mechanics a complete theoretical system. This book means the maturity of classical mechanics, and the theoretical system of classical mechanics established in it has become the standard scale of modern science.
brief Introduction of the content
The purpose of mathematical principles of natural philosophy is to explore natural forces from various moving phenomena, and then use these forces to explain natural phenomena. The core contents throughout the book are the three laws of motion and the law of universal gravitation.
This book is divided into five parts. The first part is a long "explanation" written in front of the text, which defines and explains some concepts used in the book, such as force, celestial body, mechanics, motion, quantity of matter and so on. The second part is "axiom or law of motion".
Three laws of object motion are introduced in detail: the law of inertia, the law of relationship between force and motion, and the law of action and reaction. The third part is the first volume of this book, which discusses the motion of objects in free space without resistance; The fourth part is the second volume of this book, which compares the movements of different objects in the blocking medium.
The formula that the magnitude of resistance is proportional to the first and second squares of object velocity is obtained. The elasticity and compressibility of gas and the speed of sound in air are also discussed.
The fifth part is the third volume of this book, which deduces the law of universal gravitation on the basis of the argumentation in the first four parts, and illustrates the existence of universal gravitation with a large number of natural facts, including the deviation of moon movement, the change of ocean tides, the length of precession and so on.