A First Survey

Abstract

Mechanics deals with ’ordinary objects’ moving at ’moderate velocities’ (as for example colliding steel balls or planets orbiting around the sun). Elementary particle physics, a topic that will only be discussed very briefly in this introductory course, addresses the properties of minute particles moving in general at much higher velocities. These statements suggest that the areas, which are of interest in physics, can be fitted into a diagram which is characterized by a length and a velocity scale¹ (Fig. 1.1). The concept of length (L) has to be interpreted relatively loosely. As a length one should consider the size of objects (e.g. the diameter of elementary particles, of atoms or of the steel balls and planets mentioned above) as well as the specification of wavelengths (e.g. of water waves, sound waves or electromagnetic waves) or the distances between celestial objects.