100 Years of Relativity Space-Time Structure: Einstein and Beyond ...

CHAPTER 1DEVELOPMENT OF THE CONCEPTS OF SPACE, TIMEAND SPACE-TIME FROM NEWTON TO EINSTEINJOHN STACHELDept. of Physics and Center for Einstein Studies, Boston University,590 Commonwealth Avenue, Boston, MA 02215, USAThe concept of physical change brings together the concepts of spaceand time. The evolution of the latter two concepts, and of relation betweenthem, in physical theories from Newtonian mechanics to generalrelativity is outlined, culminating in the development of the concept ofspace-time and its dynamization. The chrono-geometrical and inertiogravitationalspace-time structures are defined, and the compatibilityrelations between the two are discussed. The philosophical debate betweenabsolute and relational concepts of space and then of space-time isreviewed, as is the contrast between pre-general-relativistic theories withfixed background space-time structures and background-free general relativistictheories. Some implications of this contrast for the problem ofquantum gravity are indicated.1. Introduction: The Changing Nature of ChangeThis chapter discusses the development of the concepts of space and time asemployed in the formulation of various physical theories. These two conceptsin turn are intimately connected with the concept of change, so time, space,and change must be discussed together. When considered apart from thecauses of change, they form the subject matter of kinematics. aTraditionally, one distinguished between two types of change: b(1) the change of position in space of some object in the course of time,i.e., motion; anda Under what circumstances kinematics can and cannot be cleanly separated from dynamicswill form an important topic for later discussion.b Naturally, the two types can be combined to describe changes of the properties of anobject as it changes its position in space.3