On the Flow of Time

TL;DR

This paper argues that the universe's evolution, including irreversibility and emergence, challenges the traditional block universe view, proposing an evolving block universe where spacetime and entities develop over time.

Contribution

It introduces the concept of an evolving block universe, emphasizing the importance of time-irreversible processes and the evolution of spacetime itself, contrasting with traditional time-symmetric models.

Findings

Decoherence and measurement processes are inherently time-irreversible.

The universe's evolution is better represented by an evolving block model.

Spacetime evolves along proper time, not fixed surfaces.

Abstract

Current theoretical physics suggests the flow of time is an illusion: the entire universe just is, with no special meaning attached to the present time. This paper points out that this view, in essence represented by usual space-time diagrams, is based on time-reversible microphysical laws, which fail to capture essential features of the time-irreversible nature of decoherence and the quantum measurement process, as well as macro-physical behaviour and the development of emergent complex systems, including life, which exist in the real universe. When these are taken into account, the unchanging block universe view of spacetime is best replaced by an evolving block universe which extends as time evolves, with the potential of the future continually becoming the certainty of the past; spacetime itself evolves, as do the entities within it. However this time evolution is not related to any preferred surfaces in spacetime; rather it is associated with the evolution of proper time along families of world lines. The default state of fundamental physics should not be taken to be a time irreversible evolution of physical states: it is an ongoing irreversible development of time itself.