The aim of this article is to analyse the relation between the second law of thermodynamics and the so-called arrow of time. For this purpose, a number of different aspects in this arrow of time are distinguished, in particular those of time-reversal (non-)invariance and of (ir)reversibility. Next I review versions of the second law in the work of Carnot, Clausius, Kelvin, Planck, Gibbs, Caratheodory and Lieb and Yngvason, and investigate their connection with these aspects of the arrow of time. It (...) is shown that this connection varies a great deal along with these formulations of the second law. According to the famous formulation by Planck, the second law expresses the irreversibility of natural processes. But in many other formulations irreversibility or even time-reversal non-invariance plays no role. I therefore argue for the view that the second law has nothing to do with the arrow of time. (shrink)

It is commonly thought that there is some tension between the second law of thermodynam- ics and the time reversal invariance of the microdynamics. Recently, however, Jos Uffink has argued that the origin of time reversal non-invariance in thermodynamics is not in the second law. Uffink argues that the relationship between the second law and time reversal invariance depends on the formulation of the second law. He claims that a recent version of the second law due to Lieb and Yngvason (...) allows irreversible processes, yet is time reversal invariant. In this paper, I attempt to spell out the traditional argument for incompatibility between the second law and time reversal invariant dynamics, making the assumptions on which it depends explicit. I argue that this argument does not vary with different versions of the second law and can be formulated for Lieb and Yngvason's version as for other versions. Uffink's argument regarding time reversal invariance in Lieb and Yngvason is based on a certain symmetry of some of their axioms. However, these axioms do not constitute the full expression of the second law in their system. (shrink)

This book provides a conceptual foundation for statistical mechanics, which is - more generally - a conceptual framework for understanding natural kinds, which later became the conceptual framework for our reductive-physicalist view of the mind called Flat Physicalism.

Schulman (Entropy 7(4):221–233, 2005) has argued that Boltzmann’s intuition, that the psychological arrow of time is necessarily aligned with the thermodynamic arrow, is correct. Schulman gives an explicit physical mechanism for this connection, based on the brain being representable as a computer, together with certain thermodynamic properties of computational processes. Hawking (Physical Origins of Time Asymmetry, Cambridge University Press, Cambridge, 1994) presents similar, if briefer, arguments. The purpose of this paper is to critically examine the support for the link between (...) thermodynamics and an arrow of time for computers. The principal arguments put forward by Schulman and Hawking will be shown to fail. It will be shown that any computational process that can take place in an entropy increasing universe, can equally take place in an entropy decreasing universe. This conclusion does not automatically imply a psychological arrow can run counter to the thermodynamic arrow. Some alternative possible explanations for the alignment of the two arrows will be briefly discussed. (shrink)

There is a persisting tension that exists between the block universe conception of time in modern physics and philosophy and the conception of time that stems naturally from experience, and entropic asymmetries have been proposed to explain this tension. This article argues that as biochemical processes in the brain depend upon spontaneous entropy increases in the forward-time direction, this should provide an entropic basis for the unidirectionality of psychological processes. As this view does not depend on considerations of abstract information (...) processing or a past hypothesis, it provides advantages over previous entropy-based proposals attempting to explain asymmetries in temporal experience. (shrink)