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Tuesday, June 9, 2009

Snakes use scales to slither


Snakes use scales to slither:Mathematical model suggests 'sideways' friction is key.
Written by Roberta Kwok
Image at left:Lancehad snake

"Snakes rely on the frictional properties of their scales to slither, a new study suggests. The work could explain how snakes move across bare terrain such as sand and roads, where they can't push off rocks and branches."
"The researchers, led by mechanical engineer David Hu of the Georgia Institute of Technology in Atlanta, found that the resistance of a snake's belly scales is highest when its body is sliding sideways, rather than forwards or backwards. Snakes also seem to lift the parts of their bodies where friction is slowing movement the most, enabling them to slither faster."
"Although scientists knew that snakes slide forwards more easily than backwards, "no one had measured the sideways friction", says Hu. "That's the key to their motion." "

"Snakes can move by folding themselves into pleats, contracting their bellies, contorting into helices or slithering in an S-shape. Previous experiments showed that snakes perform this last type of motion, called lateral undulation, by pushing their flanks off obstacles in their path1. Scientists suggested that the snakes' belly scales, which can catch on small bumps in the ground, might also aid movement. But exactly how the scales' frictional properties contributed to slithering hadn't been fully explored. "

"The model also suggests that slithering depends much more on frictional than inertial forces, with frictional forces estimated to be an order of magnitude greater. This is intriguing, because for many other forms of land-based movement such as running and hopping, "body inertia is everything", says Bruce Young, a vertebrate anatomist at the University of Massachusetts Lowell. However, he notes that other forms of snake locomotion may not follow the same model."
"Hu says the study might help engineers to design better snake robots, which can be used to manoeuvre into tight spaces. Some snake robots have wheels that resist sideways motion, but roboticists might be able to replicate slithering without using wheels if they can find a material with frictional properties similar to scales, he says."

"Howie Choset, a roboticist at Carnegie Mellon University in Pittsburgh, Pennsylvania, says that most snake robots rely on movements other than lateral undulation, such as rolling. Still, Hu's work might inspire a closer look at the frictional properties of snake skins on future robots, he says."
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Thoughts worth thinking about

"Our subconscious minds have no sense of humor, play no jokes and cannot tell the difference between reality and an imagined thought or image. What we continually think about eventually will manifest in our lives."-Sidney Madwed

Laws alone can not secure freedom of expression; in order that every woman and man present their views without penalty, there must be spirit of tolerance in the entire population.- Albert Einstein Too often we underestimate the power of a touch, a smile, a kind word, a listening ear, an honest compliment, or the smallest act of caring, all of which have the potential to turn a life around. - Leo Buscaglia

A person's true wealth is the good he or she does in the world. - Mohammed

Our task must be to free ourselves... by widening our circle of compassion to embrace all living creatures and the whole of nature and its beauty. -Albert Einstein

The best way to find yourself, is to lose yourself in the service of others. - Ghandi

The unselfish effort to bring cheer to others will be the beginning of a happier life for ourselves. - Helen Keller

Aim for success, not perfection. Never give up your right to be wrong, because then you will lose the ability to learn new things and move forward with your life. Remember that fear always lurks behind perfectionism. Confronting your fears and allowing yourself the right to be human can, paradoxically, make yourself a happier and more productive person. - Dr. David M. Burns

Life is as dear to a mute creature as it is to man. Just as one wants happiness and fears pain, just as one wants to live and not die, so do other creatures. -His Holiness The Dalai Lama

Mankind's true moral test, its fundamental test (which lies deeply buried from view), consists of its attitude towards those who are at its mercy: animals. And in this respect mankind has suffered a fundamental debacle, a debacle so fundamental that all others stem from it. -

Milan Kundera, The Unbearable Lightness of Being

The worst sin towards our fellow creatures is not to hate them, but to be indifferent to them. That's the essence of inhumanity. -George Bernard Shaw

Ego's trick is to make us lose sight of our interdependence. That kind of ego-thought gives us a perfect justification to look out only for ourselves. But that is far from the truth. In reality we all depend on each other and we have to help each other. The husband has to help his wife, the wife has to help the husband, the mother has to help her children, and the children are supposed to help the parents too, whether they want to or not.-Gehlek Rinpoche Source: "The Best Buddhist Writing 2005 pg. 165

The hostile attitude of conquering nature ignores the basic interdependence of all things and events---that the world beyond the skin is actually an extension of our own bodies---and will end in destroying the very environment from which we emerge and upon which our whole life depends.