Posted on 01/03/2020 8:07:28 AM PST by DUMBGRUNT
But what exactly makes one knot more stable than another has not been well-understood, until now.
MIT mathematicians and engineers have developed a mathematical model that predicts how stable a knot is, based on several key properties, including the number of crossings involved and the direction in which the rope segments twist as the knot is pulled tight.
With confidence in their model, Patil then simulated more complicated knots, taking note of which knots experienced more pressure and were therefore stronger than other knots. Once they categorized knots based on their relative strength, Patil and Dunkel looked for an explanation for why certain knots were stronger than others. To do this, they drew up simple diagrams for the well-known granny, reef, thief, and grief knots, along with more complicated ones, such as the carrick, zeppelin, and Alpine butterfly.
(Excerpt) Read more at phys.org ...
I have had much fun with it over the years and NEVER had any escape.
Once as a student, I used the pull cord from a window shade. The subject panicked and pulled the shade down!
Starting with palms and elbows together, they can only chew through the rope.
Wrists crossed behind the back; there is NO ESCAPE!
Just use Alexander the Great’s method for solving Gordian knots!
Very cool science! Thanks for posting.
What was the knot?
” Listen, strange women lyin’ in ponds distributin’
swords is no basis for a system of government! Supreme executive power
derives from a mandate from the masses, not from some farcical aquatic
ceremony!”
Are you referring to the bowline? Any Boatswain’s Mate knows how good a knot it is.
What was the knot?
Be careful with this one.
When used on friends, use something soft and about 3/8” diameter so it does not cut.
For others, a long shoelace works well, back it up with a couple of half hitches.
Have a stout bandage shears ready.
https://en.m.wikipedia.org/wiki/Constrictor_knot
You can’t come out of a good square knot. That is all you need to know.
MIT mathematicians and engineers have developed a mathematical model that predicts how stable a knot is, based on several key properties, including the number of crossings involved and the direction in which the rope segments twist as the knot is pulled tight.
Sailors and boy scouts didn’t need equations to tell them what they knew.
the bowline?
I’m very familiar with the bowline.
Until that evil car ran me and my bicycle over a few years back, I could tie one around my waist while hanging with the other hand.
I can still do the one-handed part but not the hanging part.
Not a bowline, see #6.
You can’t come out of a good square knot.
Having lived in the Great State of Texas for some time, I knew cowboys and goat ropers.
Many had a wide knowledge of knot tying, but they always were amazed by this one.
A square knot on the right cord will hold ok but getting it snug and keeping it tight, not so much.
The thin wiry ones and females are often very good at getting out.
But not with this one.
See #6.
Beat me to it. Patel should have been tied up and tossed in a trunk. That’s the best way to do his testing.
All well and good in the ivory tower kingdom...except that everyone who's handle ropes, cords or lines knows that material type and mechanics play very important roles in practical usage. As an example, a simple slip knot tied with a hemp rope will retain it's shape and function whereas a polypropylene, stiff and slick, will not, due to difference in amount of friction. Soak the hemp rope, tighten the slip knot and it becomes more difficult to move, plus or minus depending on need.
MIT held off on publishing this discovery until after Odumbo was out of orifice.
Thanks! I was familiar with it. Nasty thing.
I’m always looking for knots that will hold reliably and untie easily (boating).
No knot is stronger than the rope. (NOT SOME HATCHET KNOT)
Splices can be stronger than the rope.
Most knots weaken the rope, sometimes over 50%.
Most knots have been known for a long time.
IIRC about 300? Not included the now computer-generated knots. The computers took the fun out of it for some and gave it to others.
Nothing beats an Arkansas Knife Knot.
Here’s the gCaptain link to his writeup of the article:
https://gcaptain.com/mit-knot-study-science/
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