Science. Vol 281. 31 jUly 1998.Most chaotic mixing experiments have been restricted to two-dimensional, time-periodic ßows, and this has shaped advances in theory as well. A prototypical, bounded, three-dimensional ßow with a moderate Reynolds number is presented; this system lends itself to detailed experimental observation and allows for high-precision computational inspection. The ßow structure, captured
by means of cuts with a laser sheet (experimental Poincare« section), was visualized with the use of continuously injected ßuorescent dye streams and revealed detailed chaotic structures with high-period islands.
