Why a Speeding Shark is Like a Golf Ball

Shark and Golf Ball Shortfin mako sharks can swim at an amazing, 50 miles per hour.  That is fast!!!  But how do they do it?  Scientists think they have discovered the answer.

The sharks have special scales across their skin that they raise up when they need to swim at a fast speed.  This creates tiny wells on their body and actually helps them to move faster by reducing drag.  It seems strange that by raising these minute scales that they could reduce drag (wouldn’t it create drag and make them slow down like millions of tiny parachutes?).  But their scales work along the same principles as a golf ball does with it many dimples.

The idea is that the dimples on the golf ball and the scales on a shark create tiny whirlpools within the cavities.  These whirlpools create a “buffer layer” between the surface of the shark and the fast moving water around it.  Basically it is like moving a heavy box over marbles rather than dragging it across the floor.

The whirlpools also prevent a turbulent wake from forming behind the shark.  A wake behind an object (for sharks as well as boats) has the effect of slowing it down and making harder to turn.

Scientists hope to use this discovery to design faster and more manuverable underwater vehicles and aircraft.

The Full Article from ABC News…

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    Microbe Finds Arsenic Tasty; Redefines Life


    New Microbe Samples

    NASA scientists have discovered an amazing new life-form that redefines what we consider to be the basic building blocks of life.

    A microbe found at the bottom of Mono Lake in California seems able to live in a solution of arsenic which is poisonous to most other life.  Phosphorus, which used to be considered one of the essential building blocks of life, is replaced by arsenic in this organism.

    Dr. Sasselov, an astronomer at the Harvard-Smithsonian Center for Astrophysics and director of an institute on the origins of life there said, “I would like to know, when designing experiments and instruments to look for life [on other planets], whether I should be looking for same stuff as here on Earth, or whether there are other options.  Are we going to look for same molecules we love and know here, or broaden our search?”

    Seems like we have aliens right here on earth!!!

    Original NYTimes article…

    Dec 10