Physics, Experience, Life. II. Quantum toy models of life

Description

Title: Physics, Experience, Life. II. Quantum toy models of life

Author: Ding Jia

Abstract: Margolus’ Critters cellular automata was proposed in the 1980s as a reversible variation of Conway’s Game of Life. The model admits complex patterns such as gliders, which move around and respond to environmental perturbations like living creatures.
In this work, we introduce a quantum version of the Critters model to study living systems in a toy model quantum world. The quantum model is more than a quantum cellular automaton with global unitary evolution built out of local unitaries. In addition, it comes with specific prescriptions for when and how quantum reductions occur. In this model, a living system such as a glider is characterized as a holistic persistent pattern that generates its own components and maintain its own living conditions. In the midst of environmental interactions, a living system can come into being or disintegrate. Between birth and death, each individual living system has its own life dynamics written in transitions between system configurations. The transitions are generically probabilistic as induced by quantum reductions to resolve ambiguities in system identity.
In the understanding of this model, the life dynamics of living systems forms the basis for all empirical predictions of quantum physics. Quantum physics in turn applies to all living and cognitive phenomena, as opposed to just phenomena in the microscopic domain or controlled laboratory settings. There is no separate domain governed by `classical physics’. In situations like Schrödinger’s cat and Wigner’s friend, each individual living system (the cat, the friend, the observer) has its own life dynamics. In its own life dynamics, quantum reduction occurs only to the living system itself, but not to any environmental degrees of freedom (including other living systems) in the whole universe.

Version history

• Original versions: Article v1.0
• Article v1.1: minor updates to improve presentation and correct typos