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New model predicts the force required to tie simple knots

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New model predicts the force required to tie simple knots
> http://phys.org/news/2015-09-required-simple.html

> Got rope? Then try this experiment: Cross both ends, left over right,
> then bring the left end under and out, as if tying a pair of
> shoelaces. If you repeat this sequence, you get what's called a
> "granny" knot. If, instead, you cross both ends again, this time
> right over left, you've created a sturdier "reef" knot.

> The configuration, or "topology," of a knot determines its stiffness.
> For example, a granny knot is much easier to undo, as its
> configuration of twists creates weaker forces within the knot,
> compared with a reef knot. For centuries, sailors have observed such
> distinctions, choosing certain knots over others to secure
> vessels—largely by intuition and tradition.

> Now researchers at MIT and Pierre et Marie Curie University in Paris
> have analyzed the mechanical forces underpinning simple knots, and
> come up with a theory that describes how a knot's topology determines
> its mechanical forces.

> The researchers carried out experiments to test how much force is
> required to tighten knots with an increasing number of twists. They
> then compared their observations with their theoretical predictions,
> and found that the theory accurately predicted the force needed to
> close a knot, given its topology and the diameter and stiffness of
> the underlying strand.

> "This is the first time, to the best of our knowledge, that precision
> model experiments and theory have been tied together to untangle the
> influence of topology on the mechanics of knots," the researchers
> write in a paper appearing in the journal Physical Review Letters.


   How can one knot be curious?

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New model predicts the force required to tie simple knots Sam Wormley <swormley1@gmail.com> - 2015-09-08 14:22 -0500
  Re: New model predicts the force required to tie simple knots jimp@specsol.spam.sux.com - 2015-09-08 19:48 +0000
    Re: New model predicts the force required to tie simple knots "reber g=emc^2" <herbertglazier0@gmail.com> - 2015-09-08 13:07 -0700

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