Beat the Heat: Stable Torus Propagation in Water

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dipole
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Assuming this is a genuine video (it seems to be), what's going on here?

http://h6img.com/g/11/scortching-summer-ahead-beat-the-heat-9.gif

He seems to blow a bubble from the respirator, which somehow forms a stable torus-shape and is able to propagate forward through the water. Does this have a name? Under what circumstances is it possible? What is holding the torus together, besides surface tension?
 
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Dolphins can do the same and make their rings do even stranger things...
 
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CWatters said:
Dolphins can do the same and make their rings do even stranger things...



Yes, at a Northern California water park I witnessed a dophin making rings and playing with them exactly like in the video. It was one of the most amzing things I ever saw.

I thought that what the OP was asking "Why does the air ring knock over the rocks?"

My answer is that I don't know, but maybe someone else has an explanation.
 
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The thing that's knocking the stones over is a vortex in the water. This vortex is in the shape of an annulus (ring) and it's very stable. It's the mass of water that's spinning round the ring of bubbles that carries the energy. The bubbles just happen to be there, because of the way the vortex has been produced.
If you want a fun Christmas Present then look at the AirZooka Air Cannon which produces an invisible ring vortex (in air, this time) which can travel across a room in about a half a second and hit someone in the face or knock a paper cup over. It's the same as a smoke ring, of course, but packs more punch. Great fun with cats and dogs (cruellllll!)