The Physics of ‘Now’

• arXiv:gr-Qu/0403001v2
• James B. Hartle

IGUS: Information Gathering and Utilizing Systems.

Past, present, and future are not properties of four-dimensional space time but notions describing how individual IGUSes process information.

Imagine a robot that takes a snapshot of the world in a fixed time interval. It keeps the last $n$ snapshots of the world. Those snapshots are processed by $U$ (Unconsciousness) to update its schema, a simple model of the world and then this schema, together with the current snapshot, is used by the consciousness ($C$) to make a prediction of the future and produce behaviors.

This robot experience the present, predict the future, and remember the past. Schema contains the memories and the “models” of the world and others. We can also think of history books as collective schema.