The description of phenomena in our daily world is a subtle problem since everybody has his personal point of view and different observers of the same phenomenon will provide different descriptions sometimes guided by personal preferences. Even the description of stationary objects depends on the position of the observer, the viewing angle and the relative motion of the observer who might be sitting in a car or train or be located in a rotating system. Furthermore, not all phenomena in our daily life are subject of a physical description and physical ‘objects’ need to be properly defined. Another mandatory requirement is that observations from observes in different systems must follow some transformation rules such that they can clearly specify if their observations are different or identical. A mathematical description is required to clearly define ‘identical’ results.