Author Topic: Parts of a Knot 2  (Read 3913 times)

75RR

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Parts of a Knot 2
« on: May 23, 2013, 01:49:54 AM »
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« Last Edit: August 18, 2013, 12:27:48 AM by 75RR »

roo

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Re: Parts of a Knot 2
« Reply #1 on: May 23, 2013, 02:12:30 AM »
Nub:  Too informal and unclear.  It makes me think of a lump, and knots have lumps everywhere.  "Body" would be clearer.
Crossing Point:  There are crossing points everywhere in a knot.
Eye Leg of the Bight/Eye Leg of the Standing part:  What a jumble of confusion.  "Standing Part Leg" would be better as would "Free End Leg".
Bight:  Bights are everywhere if you strain the meaning (making this pointless), but this is not consistent with the historical usage of "bight".
Nipping Turn:  This isn't always clear in all knots, it changes from knot to knot and even changes in the same knot based on load path.
Entry Region:  Who cares?  But if someone did care, one could just say "where the standing part enters the knot".  That more clearly defines what is entering.
Connective Eye Loop:  Loop is abundantly clear and is already used in common usage.  Double redundancy is most unwanted.
Collar:  Again, like his weird usage of "bight", collars could be interpreted to be everywhere.  How many "collars/bights" can you find in the Zeppelin Loop?  Who cares?
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roo

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Re: Parts of a Knot 2
« Reply #2 on: May 23, 2013, 03:03:58 PM »
And yet one may have to refer to one of them. As in the third crossing...
Please no.  Third crossing from what point?  From what point of view?  In the age of digital photography there's no excuse such cumbersome and unclear mapping.

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Definitions are for people who care!
If one cares about clarity, one should leave the subtle twists and turns inside a knot to diagrams or images if there's any possibility of misinterpretation.
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roo

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Re: Parts of a Knot 2
« Reply #3 on: May 23, 2013, 09:21:45 PM »
If one cares about clarity, one should leave the subtle twists and turns inside a knot to diagrams or images if there's any possibility of misinterpretation.

As you can see in the high-resolution .jpg the thingamajig is now under the what-do-you-call-it, while the doodad is, as you have no doubt observed, no longer held as tightly by the thingamabob, because the thing, no not that thing the other thing is now ...

Perhaps the happy union of words and images would be best.
I like to use colors or arrows to highlight areas of interest on the rare occasion such discussion of internal knot structure comes up.  A standard Paint program usually suffices.  In all my posts, I think I've done that around two or three times if I recall correctly.
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IPAtch

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Re: Parts of a Knot 2
« Reply #4 on: May 24, 2013, 05:33:41 AM »
This might be worth your time

http://www.bethandevans.com/pdf/8_strength.pdf

This is something I stumbled across a while ago. I wouldn't take it as authoritative but you might find it useful, or if you can find a working email link to the author, you might find someone excited to discuss terminology with you.

Anyways, starting on page 7 is a terms section.  The author uses "stem" instead of standing part/entry point. The author also uses the terms "nub" and "collar"

As to your questions:
1. There is some agreement on the terms. If you closely examine the diagram, the term nub is used to refer to 2 separate areas (10 and 12) that could be and are called by other terms, and I wouldn't say that 12 is where the standing part enters the "nub" but rather where it enters to knot or the collar. I also wonder if some terms might change depending on if a knot was finished differently (like say, a yosemite finish) or doubled, etc
2. I think more terms/drawings are needed, and a diagram would probably be needed for each knot, or at least each family of knots (a double bowline wouldn't need another, or even a double sheet bend, while a trucker's hitch probably would) to make things clear... sorta defeating the purpose of the terminology.


Also, in the diagram, the region marked being of highest stress and strain, at least according to the paper linked above, would actually be what you have labeled as the entry point, where all the strain is placed on a single strand that is being bent. Everywhere else in the knot, the load is distributed among more material.

Dan_Lehman

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Re: Parts of a Knot 2
« Reply #5 on: May 25, 2013, 04:28:49 AM »
I'm glad that you found the thread on this very topic that
I started some ages ago; yes, that thread got no (tr)action,
as people seem to have timEnergy only for the keyboard
--not for researching knots-terms usage.  (I still think that
such research is worthwhile.)  So, I needn't reiterate all
that I wrote there (in my keyboard exercise).

Nub:  Too informal and unclear.  It makes me think of a lump, and knots have lumps everywhere.  "Body" would be clearer.
While I disagree with the negative view of "nub", I concur
in seeing "body" as apt and also nicely lending itself to having
"limbs", which could be the term for departing-from-body
strands.  (Ah, "strand" : another conundrum --the whole or
parts of a rope?!)

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Crossing Point:  There are crossing points everywhere in a knot.
... and variously, depending upon perspective.  I do have
troubles coming to a sure grip with this notion.  (The cited
image & attached definitions, mind you, are created expressly
for the bowline and not necessarily implied to be general.)

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Eye Leg of the Bight/Eye Leg of the Standing part:  What a jumble of confusion.  "Standing Part Leg" would be better as would "Free End Leg".
As I've argued elsewhere, these imply a bassackwards view
--"of the ..." should be of the object of focus, the eye!
"thru" & "tail" could be short modifiers that work (though
both have first initial "t" to frustrate minimal abbreviation)
--"thru" being SPartside, where tension could be envisioned
to run through the nub/body, in contrast to the tail, which
is w/o tension (until one contemplates mid-line eyeknots!).

BTW, I believe that an analysis of knots-book usage will show
"standing part" to be something extant primarly/only at the
time of TYING --not a term defined for a tied/complete knot
(except in some looking back and matching parts then & now).

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Bight:  Bights are everywhere if you strain the meaning (making this pointless), but this is not consistent with the historical usage of "bight".
I'm less sure of the ubiquity and more doubtful of the history :
the nautical/geographical "bight" seems much milder than some
inland, riverway "bight", and both not quite as sharp as the
knotting "bight" when used for "doubling", which stand in
stark contrast with the "in the bight" sense of just w/o ends!?

But the common knots-books definitions of "loop" and "bight"
combine to make a bowline neatly observed as the
marriage of a loop & bight !

What do do?!

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Nipping Turn:  This isn't always clear in all knots, it changes from knot to knot and even changes in the same knot based on load path.
Yes, this has strong sense with the bowline but less in general.
Of course, it lends itself naturally to "turNip" --and how can we
pass up something like that?!   ;D

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Entry Region:  Who cares?  But if someone did care, one could just say "where the standing part enters the knot".  That more clearly defines what is entering.
It will likely be a fuzzy area in many cases.  One might prefer
to speak of "initial deflection", although I could see the protest
that, no, there might be cases to point to where there is NO
deflection (think blood knot)) at the point of initial contact
on entry (and in this regard, that point seemed significant in
a strangle /poacher's noose in some testing as the SPart
(of the noose, not of the knot part of the noose) broke there,
tightly squeezed but not really bent/deflected !).

There is some point where a limb joins the body.

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Connective Eye Loop:  Loop is abundantly clear and is already used in common usage.  Double redundancy is most unwanted.
"Loop" is used (like "bight") in conflicting ways,
and while it is the term that is commonly used in this
way, that doesn't free one from confusion with its other
uses.  One hears/reads of "eye splice", but never "loop splice",
hence my preference for "eye knot" or "eyeknot".

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Collar:  Again, like his weird usage of "bight", collars could be interpreted to be everywhere.  How many "collars/bights" can you find in the Zeppelin Loop?  Who cares?
Hmmm, in some cases I'd say that "collars" are perspicuous,
not everywhere; e.g., in the zeppelin eyeknot I count just
the same two as for the end-2-end knot of that infamously
named knot.
Perhaps it's workable at least as a term to be used in certain
cases, but not generally ?!  --with the obvious cases : i.e.,
where there are turns that well fit the bowline-like working.


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roo

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Re: Parts of a Knot 2
« Reply #6 on: May 25, 2013, 05:18:42 PM »
  One hears/reads of "eye splice", but never "loop splice",
hence my preference for "eye knot" or "eyeknot".
I wouldn't have much of a problem with "eye" if all loops were so small as to hold their eye-like shape, but I'd feel a bit silly calling a two or three foot long loop an "eye".
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