
Untangling the mechanics of knots - kercker
http://news.mit.edu/2015/untangling-mechanics-knots-0908
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Mithaldu
MIT has been confusing me to no end. Over the past year i've seen them act
like the worst scum of PR by using clickbait tiles, and weird actions like
disabling the fullscreen button so you don't leave their blog page. Somehow
that doesn't gel with my image of them actually doing good research.

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rtkwe
It's pretty simple, they're not the same people. The news/PR arm is the one
making all those "worst scum of PR" decisions and the research is separate.
Science press has always been hyperbolic compared to the papers actually put
out.

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elektromekatron
_" For example, a granny knot is much easier to undo, as its configuration of
twists creates weaker forces within the knot. For centuries, sailors have
observed such distinctions, choosing certain knots over others to secure
vessels — largely by intuition and tradition."_

This author does not know knots. Granny knots are weaker, but are generally
harder to undo than a reef as they pinch themselves up, whereas a reef can be
undone by holding both lines securely with their tails and just pushing, and
it is the combination of how easy they are to undo after being under strain
and the fact they lie flat, that makes the reef generally the preferred knot
to the granny.

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JoeAltmaier
Agreed. In fact Ashley (definitive work: the Ashley book of Knots) requires a
knot to be easy (or at least possible) to un-do.

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clort
Well, you get my upvote just for mentioning that massive tome .. but do they
not recognise knots which just cannot be undone? I can't check as my copy is
in storage but I'm thinking specifically of the fishermans blood knot, or
knots like a monkeys fist which aren't designed to be undone though perhaps
they are considered something else? I have a turks head on a pole on my boat
which I made some years ago, I'm pretty sure it could be undone, but not
easily as I think the end is tucked in to hide it.

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blacksmith_tb
Yes, the constrictor knot comes to mind, for example. I am surprised there
isn't any discussion of the weakening of the line caused by the knot - in
fact, the 10 knots requiring 1,000 times the force makes me wonder why that
doesn't cause the line to fail (though I suppose the initial amount needed is
very small). I am also a little nonplussed by their dismissal of sailors'
knowledge as mere 'tradition', which seems like saying that the builders of
Notre Dame didn't really understand their engineering, but were just part of a
tradition of building...

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JoeAltmaier
Glad you mentioned the 'constrictor' \- one of two knots invented in the 1900s
(all others of course documented in the 1800s and before) and by Ashley
himself (as I'm sure you already knew). What is the other knot?

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MasterQueef
Can they also find out why a t-shirt I throw in the dryer comes out completely
inside out? Because that's really impressive.

