Video related to the paper: A Work Plan for the Study of non-Smooth Solutions in 3D Fluid Dynamics: The First Regularity Barrier for the Euler Equation (preprint 2025).
The movie shows the intensity of the vorticity component orthogonal to the page. This is a full solution of the 3D Euler incompressible equations. The 3D image is obtained by revolving the square around the vertical left side. No dependence on the angle is assumed. For an instant of the back-and-forth evolution, the vorticity function develops a discontinuity at a single point (the central red line touches the blue line on the left) . This happens very quickly.