Re: Swim In Water Or Syrup, Human Speed Is the Same

From: richard01 (richardparker01_at_yahoo.com)
Date: 09/28/04 

Date: 28 Sep 2004 04:29:14 -0700

"firstjois" <firstjoisyike@hotmail.com> wrote in message news:<2emdnQYcsqGBdsXcRVn-gA@comcast.com>...
> Rich Travsky wrote:
> >> http://www.nature.com/news/2004/040920/full/040920-2.html
> >>
> >> It's a question that has taxed generations of the finest minds in
> >> physics: do humans swim slower in syrup than in water? And since
> >> you ask, the answer's no. Scientists have filled a swimming pool
> >> with a syrupy mixture and proved it.
> >>
> >> "What appealed was the bizarreness of the idea," says Edward
> >> Cussler of the University of Minnesota, Minneapolis, who led the
> >> experiment. It's a question that also fascinated his student Brian
> >> Gettelfinger, a competitive swimmer who narrowly missed out on a
> >> place at this summer's Olympic Games in Athens.
> >>
> >> Cussler and Gettelfinger took more than 300 kilograms of guar gum,
> >> an edible thickening agent found in salad dressings, ice cream and
> >> shampoo, and dumped it into a 25-metre swimming pool, creating a
> >> gloopy liquid twice as thick as water. "It looked like snot," says
> >> Cussler.
> >>
> >> The pair then asked 16 volunteers, a mix of both competitive and
> >> recreational swimmers, to swim in a regular pool and in the guar
> >> syrup. Whatever strokes they used, the swimmers' times differed by
> >> no more than 4%, with neither water nor syrup producing consistently
> >> faster times, the researchers report in the American Institute of
> >> Chemical Engineers Journal.
> >> ...
> >> But while it might sound like a trivial question, the principle is
> >> actually fundamental. Isaac Newton and his contemporary Christiaan
> >> Huygens argued the toss over it back in the 17th century while
> >> Newton was writing his Principia Mathematica, which sets out many
> >> of the laws of physics. Newton thought that an object's speed
> >> through a fluid would depend on its viscosity, whereas Huygens
> >> thought it would not. In the end, Newton included both versions in
> >> his text.
> >>
> >> Hamstrung by their lack of access to guar gum or competitive
> >> swimmers, Newton's and Huygens' work was mainly theoretical.
> >> Cussler's demonstration shows that Huygens was right, at least for
> >> human-sized projectiles.
> >>
> >> The reason, explains Cussler, is that while you experience more
> >> "viscous drag" (basically friction from your movement through the
> >> fluid) as the water gets thicker, you generate more forwards force
> >> from every stroke. The two effects cancel each other out.
> >>
> >> That's not always the case. Below a certain threshold of speed and
> >> size, viscous drag becomes the dominant force, making gloopy fluids
> >> are more difficult to swim through. Had Cussler done his experiment
> >> on swimming bacteria instead of humans, he would have recorded much
> >> slower times in syrup than in water.
> >>
> >> But for humans, speed depends not on what you swim in, but on what
> >> shape you are. Once the effects on thrust and friction have been
> >> cancelled out, the predominant force that remains is 'form drag'.
> >> This is due to the frontal area presented by a body - try running
> >> with a large newspaper held in front of you and see how much more
> >> difficult it is.
> >>
> >> So the perfect swimmer, whether in water or syrup, has powerful
> >> muscles but a narrow frontal profile. "The best swimmer should have
> >> the body of a snake and the arms of a gorilla," recommends Cussler.
> >>
> >> Obviously, just because we can swim doesn't mean we're built for it
> >> - and apparently far from it.
>
> Shouldn't they have shaved the swimmers first?
>
> Jois

This 'research' is clearly rubbish, much like all those theories about
Ethiopian runners being better than the rest of us because they live
higher up in a 'rarer' atmosphere.

Just try running a spoon through honey, and then through water. if you
don't find any difference, then neither God nor I can help you.

Richard