---
slug: oip-disconfirming-edge-5
title: Disconfirming Edge 5: Branching vs Scale Invariance
canonical: https://miscsubjects.com/a/oip-disconfirming-edge-5
---

**C16** (Branching) contradicts **C10** (Scale Invariance)

**Tension:** If branching networks are optimal transport solutions (C16), they should be engineering-optimal — not necessarily fractal. If they are fractal (C10, scale-invariant), they must follow power-law scaling — but engineering optimality often produces exponential, not power-law, scaling.

**Resolution status:** PARTIALLY RESOLVED

**What would settle it:** A definitive proof that Murray’s Law (r^3) follows from fractal geometry rather than viscous dissipation optimization; OR demonstration that optimal transport under realistic biological constraints necessarily produces fractal, not exponential, scaling.

**Current state:** Bejan’s constructal law claims to derive branching from optimization, but the derivation assumes a fractal Ansatz. WBE (1997) derive the 3/4 scaling exponent from network geometry plus minimization, suggesting both nodes are partially right.

**Honest assessment:** The tension is more apparent than real — both branching and fractality emerge from the same physical constraints (space-filling + minimum cost). But the rival frames of each node are in genuine tension: one says geometry is primary, the other says optimization is primary.

Summary Table: Disconfirming Edges

---

## Corpus map
- C16 (Branching): [C16 in the Encyclopedia](/a/convergence-encyclopedia-c16) · [C16 in the Catalogue](/a/oip-node-c16-branching-optimal-transport)
- C10 (Scale Invariance): [C10 in the Encyclopedia](/a/convergence-encyclopedia-c10) · [C10 in the Catalogue](/a/oip-node-c10-scale-invariance-fractals-allometry)
- Disconfirming edges: [1](/a/oip-disconfirming-edge-1) · [2](/a/oip-disconfirming-edge-2) · [3](/a/oip-disconfirming-edge-3) · [4](/a/oip-disconfirming-edge-4) · [5](/a/oip-disconfirming-edge-5)
- Catalogue hub: [Convergence Catalogue — Public Article](/a/oip-convergence-public-article) · [The Schema](/a/oip-convergence-schema)
