|Excerpt / Summary|
Many studies have investigated the relations between various aspects of the different arrows of time. Most of these studies take it as a given that the psychological arrow of time derives from
the thermodynamic arrow of time i.e, from the second law of thermodynamics). Yet until now no mathematical proof of this connection has been offered. This has allowed some to even go so far as to make the claim that the two arrows of time are not related at all .
Without reducing the psychological arrow of time to a mathematically well-defined phenomenon, there is no way to rigorously prove (or disprove) a relation between the psychological arrow of time and the thermodynamic one. Here and in , the "mathematically well-defined phenomenon" is taken to be the human ability to remember the past but not the future. In short, it is presumed that there is no aspect of the psychological arrow of time which can not be explained by the asymmetry of human memory.
This paper is an overview of an analysis of memory systems and their relationship with the second law. (The full analysis can be found in .) This analysis shows that the asymmetry of human memory is a direct reflection of the asymmetry of the second law. In this way it explains why the future is both the temporal direction into which "information is dissipated" (due to the second law) and the direction into which "information is preserved" (via our ability to remember the past but not the future). The implication of this analysis is that if the second law "went the other way", then we would remember the future, not the past and the psychological arrow would point towards the past not the future.
The analysis reviewed in this paper also shows that memory in (abstract) computers need not be directly affected by the second law. Consequently, such memory can infer the future as readily as the past and possesses no psychological arrow of time. This is in accord with the well-known reversibility of computation