A “bathtub vortex” is created by taping two bottles together. Air moving up the inside of the vortex allows water to spin smoothly down.
Water trickles down a ‘Zen Board’, turning the top surface transparent and allowing the black backing to show through.
Just after impact, a droplet forms a ‘crown’ splash. Then the droplet wake collapses and forms the Worthington jet.
The Rayleigh-Plateau instability describes the breakup of a falling stream, here seen just before impact with a Worthington jet.
