Temporal Arrows in Space-Time

The prevailing current of thought in both physics and philosophy is that\ud relativistic space-time provides no means for the objective measurement of the passage of time. Kurt Gödel, for instance, denied the possibility of an objective lapse of time, both in the Special and the General theory of\ud relativity. From this failure many writers have inferred that a static block universe is the only acceptable conceptual consequence of a four-dimensional world. The aim of this paper is to investigate how arrows of time\ud could be measured objectively in space-time. In order to carry out this investigation it is proposed to consider both local and global arrows of time. In particular the investigation will focus on a) in variant thermodynamic\ud parameters in both the Special and the General theory for local regions of space-time (passage of time); b) the evolution of the universe under appropriate boundary conditions for the whole of space-time (arrow of time,as envisaged in modern quantum cosmology. The upshot of this\ud investigation is that a number of invariant physical indicators in space-time can be found, which would allow observers to measure the lapse of time and to infer both the existence of an objective passage and an arrow of time.\u