Zenith Grant Awardee

Benjamin Schumacher

Kenyon College

Co-Investigators

Michael D. Westmoreland, Denison University

Project Title

Eidostates and physical records of events

Project Summary

We observe, describe, and act upon the world from within the world. The records we possess about events are physical configurations of our memory, and the processes by which we acquire, manipulate, use and delete those records are governed by physical laws. Our \"eidostate\" (from the Greek \"eidos\", meaning \"to see\") is the partial description of the world that we hold based on all the information available to us. This project aims to explore how one part of the universe can construct and amend its description of the whole. In thermodynamics, this leads to a new approach in which Maxwell\'s demon and other \"information engines\" play a central role. In quantum physics, this may shed light on the measurement problem, in which quantum devices gain and use information to control other systems. Of particular interest is the way that physical agents perceive the passage of time based on their records of events. Finally, when many agents interact, their respective eidostates include information about each other. This fact connects eidostates to the field of epistemic logics, which studies the logical properties of the knowledge and beliefs held by reasoners.

Technical Abstract

The acquisition, processing, use and erasure of information by real agents are all physical events, occurring in accordance with dynamical laws. The \"eidostate\" held by such an agent is the coarse-grained description of the world (including the agent itself) inferred by the agent at a given time. It includes any existing physical record of past events and all data that the agent may use to condition future action. Our research will explore the eidostate framework in contexts ranging from thermodynamics and quantum physics to hidden Markov models and epistemic logics. Maxwell\'s demon suggests a novel approach to thermodynamics based on the eidostates of \"information engines\". In quantum physics, eidostates are connected to Zurek\'s \"actionable information\" and potentially shed light on quantum measurement and control. Using hidden Markov models, we can begin to understand how agents construct internal representations of time from sequences of events. By considering many agents – each of which possesses information about the others\' eidostates – we can link the eidostate concept to the field of epistemic logics, in which modal operators represent knowledge and belief about propositions. The physical aspects of agents and their eidostates are reflected in the basic properties of these operators.