Vortex Tube by Doug Hollis consists of a large water vortex, a life-size version of the little "tornado funnel". The vortex is created by pumping water out of the bottom of the cylinder and injecting it back into the top which sets the water spinning. The funnel shape occurs because the water pressure is greater at lower water depths causing a closing-in of the wall of the vortex. The vortex demonstrates a form that manifests in a number of places such as whirlpools, tornadoes, weather systems, galaxies, and snail shells.