The main purpose of this text is to use elementary particles and the forces interacting with them and motions resulting from these particles and their motions to establish a model of atom that explain what make up an atom, and how they run to keep atoms stable. The text covers the topics such as space and time, forces and motions, photons, mass, electricity and magnetism.

In the text “The Cause of Motion”, I argue the following 6 flaws in the definition of inertia and the law of inertia and propose a solution to correct these problems and mechanism for inertial motion. 1. The definition of inertia does not answer the cause why the object has inertia. 2. The law of inertia does not answer what is the cause of motion. 3. Stationariness and rectilinear motion at constant velocity are two effects that need two causes to explain. 4. We have not found the elementary particles or properties responsible for inertia in matter. 5. The inertial motion of the same matter in gaseous, liquid, solid or other states is completely different. 6. No experiment has proved the existence of inertia or the law of inertia.