The travelling vortex ring of gas is known in literature as the Helmholtz soliton. Scroll over to “Five Minutes of Knot Theory History” for a short video from

The travelling vortex ring of gas is known in literature as the Helmholtz soliton. Scroll over to “Five Minutes of Knot Theory History” for a short video from demonstration class: http://www.southalabama.edu/mathstat/personal_pages/silver http://www.southalabama.edu/mathstat/personal_pages/silver