Decoherence

Definition

Decoherence can be viewed as the loss of information from a system into the environment (often modeled as a heat bath), since every system is loosely coupled with the energetic state of its surroundings.

Context

In quantum mechanics, we appeal to decoherence as a process that explains the emergence of a quasi-classical order. Decoherence has no classical counterpart. Moreover, it is an apparently irreversible process. See the wiki page on "Entropy Problems" for a discussion of the boundary conditions that determine the flow of time and whether Decoherence of an Entangled State has a foundational roles in the origin of time.