Editing Computational irreducibility (section)

==The idea==

{{Expand section|date=January 2022}} Many [[physical systems]] are complex enough that they cannot be effectively measured. Even simpler programs contain a great diversity of [[behavior]]. Therefore no model can predict, using only [[initial conditions]], exactly what will occur in a given physical system before an experiment is conducted. Because of this [[undecidable problem|problem of undecidability]] in the formal language of computation, Wolfram terms this inability to "shortcut" a [[system]] (or "program"), or otherwise describe its behavior in a simple way, "computational irreducibility." The idea demonstrates that there are occurrences where theory's predictions are effectively not possible. Wolfram states several [[phenomena]] are normally computationally irreducible.<ref>{{Cite web |title=Stephen Wolfram: A New Kind of Science {{!}} Online—Table of Contents |url=https://www.wolframscience.com/nks/ |access-date=2025-02-03 |website=www.wolframscience.com |language=en}}</ref>

Computational irreducibility explains why many natural systems are hard to predict or simulate. The Principle of Computational Equivalence  implies these systems are as computationally powerful as any designed computer.