September 10, 2004 | David F. Coppedge

Submarine Engineers Admire Penguins

An ocean engineer from MIT, Franz Hover, says “we never miss marveling at them,” speaking of penguins.  In the cover story of Science News,1 the submarine designer elaborates:

Under the power and guidance of its versatile flippers, a penguin can move through the water faster than 10 miles per hour, turn almost instantaneously, and leap out of the water onto an iceberg.  You’ll never see a submarine do that, Hover points out.   (Emphasis added in all quotes.)

Carrie Lock, author of the article entitled “Marvels of Engineering,” also marvels at the graceful flippers of dolphins, sea lions and whales compared to the crude propellers of man-made underwater craft.  The shape, maneuverability, and flexibility of animal flippers overcomes turbulence and allows quick turns and near-instant stops:

Scientists have long sought to unlock the secrets of nature’s underwater-locomotion schemes, but they’ve usually met with frustration.  Since the mid-1930s, when England’s Sir James Gray declared that dolphins move through water so efficiently that engineering principles were inadequate to explain the mechanism, people have sought to understand marine-animal locomotion.  Now, researchers in the field of biomimetics–the science of mimicking living things–have unlocked some of those secrets and are applying their knowledge to prototype watercraft.

The movement of a swimming penguin is “deceptively simple,” because:

To accomplish its feats, the penguin must generate forces that are huge in proportion to its small body.  Although scientists can’t fully explain how the animal does it, it’s clear that for its size, a penguin’s stroke creates forces relatively larger than those of a propeller and does it more efficiently….
    Penguins are more maneuverable than vessels because their flippers can make different kinds of motions than propellers can.  Penguins’ flippers are attached to their bodies at a single rotation point that’s equivalent to the human shoulder.  The flippers flap up and down, move forward and back, and twist around in the joint.  Propellers, on the other hand, just rotate.  Although they can turn at different speeds, the orientation of their motion is fixed.

Lock discusses several teams working on imitating the flippers of penguins, dolphins, and the scalloped-edge flippers of humpback whales, which reduce turbulent wakes (see 05/11/2004 headline)– this is being investigated by a Pennsylvania biologist named Frank E. Fish.  The Navy is looking at all these engineering projects with great interest.

1Carrie Lock, “Ocean Envy: Scientists look toward marine creatures to improve watercraft designs,” Science News, Week of Sept. 4, 2004; Vol. 166, No. 10, p. 154.

Penguins look funny waddling on the land in their tuxedos, but underwater they are more graceful than ballerinas.  Next time a nature program shows underwater footage of Antarctic penguins, watch it for awhile in wonder.  Then laugh as the camera shifts to land position and films them launching their fat but sleek bodies into the air, only to bellyflop on the ice.  Penguins are cool.  This article barely touches on just one of many wonders of these aquatic birds and their lifestyles in some of the harshest environments on earth.
    An important part of the penguin’s flipper design is a pulley-like tendon that threads the needle of a shoulder bone.  How could that evolve?  Every detail in the anatomy of a penguin flipper is superbly adapted to their habitat, but a flipper alone would be useless without the brain software, sensory organs, digestive, respiratory, circulatory and other systems that work together to make all this exquisite ballet possible.  The systems, in turn, depend for their function on tens of thousands of molecular machines in each cell, coded by gigabytes of programmed information.
    Congratulations to Carrie Lock for sparing us unnecessary Darwinspeak in this interesting story (except in the references, where a paper has a convoluted title, “Convergent evolution in mechanical design of lamnid sharks and tunas”).  Yes, ask the beasts, and thou mightest learn something.  (To Darwinists, another reference is apropos: go to the ant, thou sluggard.)

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Categories: Amazing Facts, Birds, Mammals

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