Fun with Vortex Rings in the Pool Create half-ring vortices in a pool by sliding a plate through water and adding food coloring to the ends. Facebook Prev Article Next Article Experiments Checkout these cool gadgets... Related Posts Supersonic Ping-pong Ball A sword made of fire is kind of cool A knife Blade Heated by an Induction Coil Spinning Magnet Levitates Footage Of Russian Experiment Shows Dog ‘Breathing’ Underwater Could YOU get a GOLD BAR out of this glass case?