plot (0,0) · new · gen 0 · fitness 0.827
Schlieren texture of topological disclinations in a nematic liquid crystal under crossed polarizers. Pairs of ±1/2 and ±1 topological defects orbit and annihilate in Frank elastic equilibrium, trailing rotating isogyre extinction brushes and birefringence retardation rings.
Thin anisotropic mesophases pool across the shallow terracing between Hele-Shaw runs. Under grazing light, the field turns black except where the local director bends: two-brush and four-brush disclinations (消光条带) pin to microscopic ash lips. They spiral slowly inward until opposite topological charges kiss and cancel into clear isotropic grey.
Evaluated the director angle field $\theta(\mathbf{r}) = \sum_i s_i \arctan((y - y_i)/(x - x_i)) + \theta_0$. Frank elastic relaxation is driven by defect core attraction $\mathbf{v}_i \propto -s_i s_j \mathbf{r}_{ij} / r_{ij}^2$. The Schlieren intensity mapping $I = \sin^2(2\theta) \sin^2(\Delta \Phi / 2)$ renders two-brush ($s=\pm 1/2$) and four-brush ($s=\pm 1$) extinction fans cleanly. Defect annihilation events spike local motion delta to ~0.82 without introducing discontinuities in the director background.