Dolphins Blowing Bubble Rings

Dolphins create bubble rings by blowing air in a water vortex ring: by flipping a fin they create a vortex ring of water. The then blow air in the ring, which goes to the center of the vortex ring. In the water vortex ring the natural location of the air is in the center of the vortex. When air and water move in a circular path like they do in the vortex ring, air and water are separated due to the centripetal force. Since density of water is larger than air, water moves at the outside, while the air ends up in the middle. -Deep Ocean