This is a visualization of what happens when Pappus's theorem is iterated. Pappus's theorem is a basic theorem in projective geometry, going back to Pappus of Alexandria, an ancient Greek mathematician. The image illustrates the research in the paper Pappus's Theorem and the Modular Group, I.H.E.S. Publications Mathematiques , Vol. 78 pp. 187-206, by Richard Evan Schwartz. Credit: Rich Schwartz. Courtesy: National Science Foundation.
Water Flow from a Spouting Cylinder
A spouting cylinder provides a visual demonstration of incompressible fluid pressure as a function of depth. Since water is nearly incompressible this is an experiment children can do themselves.