Note 2 — PART I The Special Theory of Relativity

Every description of the scene of an event or of the position of an object in space is based on the specification of the point on a rigid body (body of reference) with which that event or object coincides. This applies not only to scientific description, but also to everyday life. If I analyse the place specification “Times Square, New York,”2 I arrive at the following result. The earth is the rigid body to which the specification of place refers; “Times Square, New York,” is a well-defined point, to which a name has been assigned, and with which the event coincides in space.3