When does a physical system compute?

Area of Science:

• Physical computing
• Foundations of computation
• Information theory

Background:

• Growing interest in non-standard computing systems (quantum, biological).
• Lack of consensus on defining physical computation.
• Confusion surrounding novel computational devices and broad claims of computation.

Purpose of the Study:

• Introduce a formal framework to identify physical computation.
• Define the relationship between abstract computation and physical systems.
• Establish criteria for determining if a physical system is computing.

Main Methods:

• Development of a formal framework for physical computing.
• Analysis of the interaction between abstract computational and physical device levels.
• Comparison with mathematical models in experimental science.

Main Results:

• Physical computing defined as using a physical system to predict abstract evolution outcomes.
• Conditions for computing are established and illustrated with non-standard systems.
• Introduction of the 'computational entity' concept.

Conclusions:

• The proposed framework provides a precise description of computation, simulation, and technology.
• The framework applies to diverse computing contexts, including those without human users.
• Clarifies the definition of physical computing and computational entities.