Universal computation with limited resources: Belousov-Zhabotinsky and Physarum computers

TL;DR

This paper demonstrates that universal computation in unconstrained media like Belousov-Zhabotinsky and Physarum systems requires limited resources, which lead to localized structures used for logical operations.

Contribution

It reveals that resource limitations are essential for enabling collision-based logical computation in chemical and biological media.

Findings

Limited resources induce traveling localizations.

Localizations serve as units for logical circuits.

Systems can perform universal computation under resource constraints.

Abstract

Using the examples of an excitable chemical system (Belousov-Zhabotinsky medium) and plasmodium of Physarum polycephalum we show that universal computation in a geometrically unconstrained medium is only possible when resources (excitability or concentration of nutrients) are limited. In situations of limited resources the systems studied develop travelling localizations. The localizations are elementary units of dynamical logical circuits in collision-based computing architectures.