Joseph told STOMP via email last night (Aug 18):
“Received this from an overseas acquaintance.
“Nice to watch after a stressful day.”
In the email forwarded to STOMP:
“Be sure to set your video player to auto repeat.
“Fascinating to watch, enjoy!
“The attached video is of dolphins playing with silver-coloured rings which they have the ability to make under water to play with.
“It isn’t known how they learn this, or if it’s an inbred ability.
“As if by magic, the dolphin does a quick flip of its head and a silver ring appears in front of its pointed beak.
“The ring is a solid, doughnut-shaped bubble about 2 feet across, yet it doesn’t rise to the surface of the water!
“It stands upright in the water, like a magic doorway to an unseen dimension.
“The dolphin then pulls a small silver doughnut from the larger one.
“Looking at the twisting ring for one last time a bite is taken from it, causing the small ring to collapse into thousands of tiny bubbles which head upward towards the water’s surface.
“After a few moments the dolphin creates another ring to play with.
“There also seems to be a separate mechanism for producing small rings, which a dolphin can accomplish by a quick flip of its head.
An explanation of how the dolphins are able to create these silver water rings is also given:
“An explanation of how dolphins make these silver is that they are ‘air-core vortex rings’.
“Invisible, spinning vortices in the water are generated from the tip of a dolphin’s dorsal fin when it is moving rapidly and turning.
“When dolphins break the line, the ends are drawn together into a closed ring.
“The higher velocity fluid around the core of the vortex is at a lower pressure than the fluid circulating farther away.
“Air is injected into the rings via bubbles released from the dolphins blowhole.
“The energy of the water vortex is enough to keep the bubbles from rising for a reasonably few seconds of play time.
“I could watch this for hours.
“It is so relaxing.
“They seem to be having so much fun and so happy all the time.”
|Dolphin blowing water rings|