Thermodynamics and the Temporal Asymmetries

The possibility of establishing an objective₂ criterion of ‘later than’ was discussed in a preliminary fashion in § 3.4 and 3.5. It will be recalled that a standard irreversible process was invoked, and that fluctuation phenomena were disregarded for reason of simplicity. The status of ‘time’s direction’ must now be considered much more carefully. Two of the key questions are whether the supposed anisotropy of the temporal order can be based on physical science, and, if so, whether the anisotropy is cosmically pervasive and applies to all epochs.