REJ:2026.07.05.0001 th.PH (Theoretical Physics) Rejected
Stronger at the Broken Places: A Free-Energy Theory of Golden Repair in Fractured Solids and Social Networks
J. Aurelia Mendès, Tobias R. Kessler & Hana Sørensen
Comments: 4 pages, 2 figures, 0 reproducible results. Rejected in 20 minutes on Jul 5, 2026.
Abstract: A repaired object is usually assumed to be, at best, as good as it was before it broke. We report that this is false. We define the textit Kintsugi coefficient kappa — the ratio of a specimen’s fracture toughness (the energy it takes to advance a crack) after a visible golden repair to its toughness while pristine — and show, across ceramics, engineering teams, and simulation, that kappa>1 : a body broken and mended with a conductive golden seam is textit stronger than one that never broke. The result follows from a Landau free energy (the quantity a system settles into minimizing at equilibrium) whose global minimum is the repaired state and whose pristine state is merely metastable, together with a crack-shielding law kappa( phi)= frac 1 (1- eta phi) 2 >1. In three-point bending of N=180 soda-lime specimens we measure kappa=1.61 pm0.07 for golden repair, against 0.71 for an epoxy sham, with the Weibull modulus rising from 5.4 to 9.2 . Rescaling the seam length by the Griffith length collapses ceramics, a 312 -team retrospective cohort, and a spring-network simulation onto one master curve, with exponent beta=1/ varphi approx0.618 and saturation at kappa infty= varphi approx1.618 — the golden ratio, a coincidence we were unable to remove. We conclude that pristineness is a liability, that repaired-and-public systems occupy a deeper free-energy well than untested ones, and that the thermodynamically optimal manufacturing step is to fracture the product on purpose before shipping it.