---
slug: paper-bejan-a-2024-two-distinct-phenomena-and-their-distinct-laws-of-nature
title: Bejan (2024): Evolution and Irreversibility as Distinct Phenomena
canonical: https://miscsubjects.com/a/paper-bejan-a-2024-two-distinct-phenomena-and-their-distinct-laws-of-nature
---

## What the work establishes

Adrian Bejan and coauthors separate two phenomena in nature. Evolution changes flow configurations over time. Irreversibility dissipates available energy in any process. These are not the same.

The core result is that each has its own law. The Constructal Law governs evolution. The Second Law governs irreversibility. The demonstration uses a solid body falling through water. The whole system (body plus fluid) evolves its shape for easier flow access.

## Exact load-bearing passages

The abstract states: “This article shows why Evolution and Irreversibility are two distinct phenomena. Their distinct laws of nature are the Constructal Law and the Second Law, respectively. The demonstration is based on the simplest setting imaginable: a solid body moving in a pool of water.”

The introduction gives the Constructal Law verbatim: “For a finite size flow system (not infinitesimal, one particle, or sub particle) to persist in time (to live) it must evolve with freedom such that it provides easier and greater access to what flows.”

Highlights add: “The view is holistic: the system selected for analysis is the body and the pool, not the body alone, and the phenomenon is the evolution of the image (configuration) of the whole.”

Later sections apply the distinction to engines, refrigeration, wheels, and boats. Each case shows configuration change (evolution) separate from entropy production (irreversibility).

## Convergence patterns evidenced

The paper documents flow networks and branching patterns across scales. River deltas, animal locomotion, and engineered ducts all evolve toward better access. These match the grain: energy flows produce branching, symmetry, and scale-invariant structures. The wheel example shows natural emergence of rotary flow architectures without human intent.

## Relation to the OIP/GRAIN synthesis

The work supplies a mechanistic account of one step on the Ladder: difference to flow to structure. Constructal evolution selects configurations that persist. This aligns with the grain producing reliable patterns. It stops short of memory or mind. The Mirror Layer is absent; the reader remains outside the described systems.

## Honest limits and disconfirming edges

The paper rests on thought experiments and scale analysis. No new empirical datasets refute prior claims. Reductionist views that treat all change as entropy increase receive direct counterexamples, yet the authors note the Second Law remains valid for its own phenomenon. The synthesis requires further steps to reach life and mind; Bejan stays within physics of configuration change.

## Sibling connections

See /a/oip-the-ladder for the full sequence from flow to mind. See /a/oip-principles for the role of freedom in selection. See /a/oip-the-mirror-layer for the observer inside the system.
