[BITList] Dolphins

[John Feltham]

This is really incredible and to watch these wonderful creatures is  
amazing.

The attached video is of dolphins playing with silver colored 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, donut  
shaped bubble about 2-ft 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 donut 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 a 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 dolphins make these silver rings 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 dolphin's blowhole. The energy of the water vortex is enough to  
keep the bubbles from rising for a reasonably good few seconds of play  
time.




ooroo

If you don't hear the knock of opportunity - build a door.

Anon.


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