Models

Abstract

In this chapter, we derive the equations that describe the dynamics of fluids and solids. Matter is composed of molecules, atoms and smaller particles that all interact with each other. A description of the dynamics of these micro-structure is possible by fundamental physical laws. Such a particle centered view-point is however not feasible, if large physical objects are considered that consist of many atoms. To describe every particle in one liter of water, more than 1025 molecules must be considered. A description of every single molecule–or even every atom or subatomic particle–in a large scale hydrodynamical problem like the flow of water around a ship is completely out of bounds.