Project Delphis: Mystery of the Silver Rings
Mystery of the Silver
Rings
by Don White,
Creator of Project Delphis
The young dolphin gives
a quick flip of her head, and an undulating silver ring appears--as if by
magic--in front of her. The ring is a solid, toroidal bubble two feet across--and
yet it does not rise to the surface! It stands erect in the water like the
rim of a magic mirror, or the doorway to an unseen dimension. For long seconds
the dolphin regards its creation, from varying aspects and angles, with its
vision and sonar. Seemingly making a judgement, the dolphin then quickly
pulls a small silver donut from the larger structure, which collapses into
small bubbles. She then "pushes" the donut, which stays just inches ahead
of her rostrum, perhaps 20 feet over a period of up to 10 seconds. Then,
stopping again, she regards the twisting ring for a last time and bites it--causing
it to collapse into a thousand tiny bubbles which head--as they should--for
the water's surface. After a few moments of reflection, she creates another.
This isn't fantasy, it's real. And it isn't magic, just marvelous. It is
a rare dolphin behavior, and we first saw it in the play of two baby dolphins.
It gives us a little more insight into the superb level of control dolphins
can exercise on their water environment, and underscores the fact that we
can still discover things about dolphins by simply watching them.
I first saw this behavior on one of my relatively rare trips out to the
Delphis lab; the project's principle scientist Ken Marten said that "the
two babies, Tinkerbell and Maui" had been doing it for a little while. My
reaction: "Wow, neato. How the heck do they DO that? Try to get some photo
and video shots of it. It sure is cool". Ken, along with Suchi Psarakos,
Research Assistant and computer programmer, did indeed document the silver
rings (although video and photos don't do the rings justice), and this has
made it possible to both analyze the physics behind the phenomenon and to
watch the dolphins do this trick in slow-motion.
As it turned out, small silver rings weren't the only toys the dolphins
were making for themselves: some of the creations were as large as a basketball
rim. And Tinkerbell proved able to create a silver helix, spiraling perhaps
20 feet long, that would spring into life in a fraction of a second and
remain stable in the water as she swam past, observing it with sonar and
vision. then--presto! she would grab a small silver ring from the helix to
play with, while the rest of the helix degraded into bubbles which would
belatedly "remember" to rise to the surface.
This was a wonderful mystery to ponder. My attempts at re-creating the
rings in a swimming pool succeeded only in getting water up my nose, but
my guesses were confirmed--with better and more rigorous explanation--by
the fluid dynamics class of Suchi's close friend Hans Ramm at Scripps Institute
of Oceanography.
The silver rings, as it turns out, are "air-core vortex rings", and the
helices are a similar phenomenon. Invisible, spinning vortices in the water
are generated from the tip of a dolphin's dorsal fin when it is moving rapidly
and turning. According to Hans: "Being unstable without a boundary nearby,
the vortex line tends to form into a more stable form such as a helix. When
the dolphins break the line, the ends are drawn together into closed rings.
Owing to the Bernoulli effect, 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 long period--on the order of 10 seconds. There also seems to
be a separate mechanism for producing small rings, which a dolphin can accomplish
by a quick flip of its head.
There is little doubt that this is what is occurring. However, understanding
the physics should not diminish our appreciation of this spontaneous act
of creation by a dolphin mind. These young dolphins have detected, understood,
and manipulated a subtle aspect of their environment, for no reason other
than play.
Creation of these rings by dolphins isn't new. (far from it--dolphins were
probably blowing magnificent silver rings while our anscestors were hanging
off tree limbs). It does seem to be a relatively rare behavior, though:
it has been seen before only in a specific group of dolphins documented by
Diana Reiss and Jan Ostman at Marine World. "The fact that ring-blowing is
rare and that we have two babies doing it suggests that one baby learned
it from the other", comments Ken Marten. "Whether it was a case of observational
learning, or one "taught" the other, we don't know... but it'd sure be interesting
to know."
The social situation also seems to affect ring-blowing: " The babies made
them most intensely when they were the only two dolphins in the tank and when
there was only one adult. The behavior stopped entirely when they were outnumbered
by adults, " observed Suchi. "During one intense session with Tinkerbell
there were often two or three rings visible in the tank at one time. She
frequently swam over to me in an excited state, then went and made some more."
The reaction to our documentation of these rings has been universal--people
are fascinated by them. Dr. Ken Norris, the world's leading expert on dolphins,
had never seen it before. Robert Wolff of Apple Computer's Advanced Design
Group made a "quicktime" movie of ring-blowing for display on Mac computers.
Arthur C. Clarke, Earthtrust Advisory Board member, thought they were wonderful--but
debated my offered contention that they might be the first "extraterrestrial
art", pointing to interesting "artistic" achievements by other nonhuman animals.
For myself, I do consider these rings to be "art": the creation and observation
of artifacts by a nonhuman mind, with no use other than entertainment and
aesthetics. One must be constantly wary not to anthropomorphize the actions
of other species--to treat them as though they were human. But after watching
a dolphin create one of these kinetic sculptures--observe it from many angles--and
then destroy it with a bite--it seems a long leap of logic to ascribe any
other motive.
This can, and will, be debated... but the beauty of the rings is beyond
debate. As evidence mounts for "self awareness" and other "intelligent" qualities
in dolphins, I think that it must cause us again to ask the question: what
are these creatures, that they spin silver lariats for the sheer joy of creation?
And what sort of creatures are we, if we cannot appreciate and protect them?