Chaos and Stochastic Models in Physics: Ontic and Epistemic Aspects

TL;DR

This paper clarifies the distinction between ontic determinism and epistemic predictability, analyzing chaos and stochastic models in physics to improve understanding of their roles in describing the physical world.

Contribution

It provides a clear conceptual separation between ontic and epistemic aspects of chaos and stochastic models, supported by analysis of Lyapunov exponents and entropy.

Findings

Determinism is ontic, related to nature's behavior.

Predictability is epistemic, related to human computation.

Deterministic chaos is epistemic but non subjective.

Abstract

There is a persistent confusion about determinism and predictability. In spite of the opinions of some eminent philosophers (e.g., Popper), it is possible to understand that the two concepts are completely unrelated. In few words we can say that determinism is ontic and has to do with how Nature behaves, while predictability is epistemic and is related to what the human beings are able to compute. An analysis of the Lyapunov exponents and the Kolmogorov-Sinai entropy shows how deterministic chaos, although with an epistemic character, is non subjective at all. This should clarify the role and content of stochastic models in the description of the physical world.