Is Time an Abstract Entity?

Abstract

For a long time, philosophers and physicists have struggled to understand the physical arrows in time and their connection to the nature of time. One view is to regard the various physical arrows as mere evidence for the temporal orientation of all processes. Since develop ment in time is a fundamental property of any physical system, one may see this feature as a physical manifesta tion of temporal becoming from the future to the past. Another, more radical, view claims that the direction of time itself can be explained in terms of some of these arrows. The view is here that the study of physics can give us a complete and correct answer concerning the nature of time. In association with this claim, it is argued that the physical arrows all depend on one master arrow. The debate attempts to pick out either the cosmological arrow or the thermodynamical arrow as the one upon which all other asymmetries rest, and it is thought that this master arrow determines the direction of time. Whatever view one may hold it generates metaphysical difficulties. Part of the problem is due to the well-known fact that in real life, we find only processes that are asymmetric in time whereas the underlying dynamical laws of physics, which are taken to govern these arrows – be they classical, relativistic, or quantum laws – are time invariant. Thus, the majority of philosophers and physicists agree that physical processes do not exhibit an intrinsic arrow in virtue of certain nomological features, i.e. they believe that the asymmetry is not internal to the physical processes themselves. The upshot is that the physical arrows in time, or nearly all of them, are due to an asymmetric distribution of boundary conditions. Any asymmetrical development of physical processes is due to a contingent asymmetry in the distribution of boundary conditions. The basic laws of physics are symmetric in time and provide no help in marking out the direction of physical processes. The talk will discuss whether physics is able to give us a satisfying understanding of time and its direction. First I reject the idea that the observed asymmetry can be explained in terms of objective becoming. This notion has recently been reintroduced in the debate by several authors. Second, I shall argue that none of known physical arrows can be taken as evidence or as being the basis of the direction of time. Contemporary physics does not provide a proper understanding of this direction because it relies on the existence of intrinsically asymmetrical relations of becoming. I still think, however, that physics may contain the conceptual resources to grasp the direction of time.