Author Topic: The Sheetbend loop knot and the Carrick bend loop knot.  (Read 2381 times)

Dan_Lehman

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Re: The Sheetbend loop knot and the Carrick bend loop knot.
« Reply #30 on: August 19, 2018, 08:36:34 PM »
Take a bight of cord.  Now in the doubled cord ...
It is an interesting quality of English that this action
of "doubling" a cord can be equally expressed as . . .
"halving" it !  Should we sanction such uses?
(OOOps, did it again, didn't I !  ::)  ;D  ).

(Hope I didn't slow down or slow up this great debate.)

 ;)

DerekSmith

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Re: The Sheetbend loop knot and the Carrick bend loop knot.
« Reply #31 on: August 19, 2018, 09:41:34 PM »
@Dan
Quote
It was my one-time hope that one could define what
you present --an entanglement w/ends exiting our  view--
as a *tangle* which would be the basis for then defining
*knots* by attaching loading specifications.

I believe Dan , that your 'one time hope' is exactly the way we should define our knots - defining the structure of a core / nub / tangle, then turning this structure into a working force machine by defining the function of the  lines exiting that structure.

What we are lacking at the moment is some unified form of identifying which line we are referring to as we appoint external functionality.

Derek

Dan_Lehman

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Re: The Sheetbend loop knot and the Carrick bend loop knot.
« Reply #32 on: August 21, 2018, 12:06:29 AM »
@Dan
Quote
It was my one-time hope that one could define what
you present --an entanglement w/ends exiting our  view--
as a *tangle* which would be the basis for then defining
*knots* by attaching loading specifications.

I believe Dan , that your 'one time hope' is exactly the way we should define our knots - defining the structure of a core / nub / tangle, then turning this structure into a working force machine by defining the function of the  lines exiting that structure.

What we are lacking at the moment is some unified form of identifying which line we are referring to as we appoint external functionality.

Derek
But, Derek, as I remarked, it's not so neat & clean ::
i.p., that the *tangle* (I use the net-knot/bowline one
for thinking --asymmetric, simple, well-known) comes
with a bias already, versus some things that COULD
arise from the topological entanglement.  With
the bowline one, in a Lapp bend the part that is the
SPart for the bowline is unloaded, and really doesn't
point out of the nub as it does for the bowline/sheet
bend/
... !?  What to do.  AND should the marlinespike
constructions available from this topological tangle
be included?  --can one assign rigidness to one piece
of the material?  (The bowline is readily seen in Cape
May trawler dock lines
 --which are in use, not out to make theoretical
   contributions to knotting(!)--
to be equivalent via loading to a pile-hitch noose,
which is hardly *visible* in considering a net-knot.
.:. So, maybe we just have a related set of tangles
capturing possible biases?

Your additional point about taking a given tangle
and establishing a point of reference is indeed one
further challenge. It could be that some standards
body just works from some reasonable guidelines
per tangle and assigns the reference item.


--dl*
====

agent_smith

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Re: The Sheetbend loop knot and the Carrick bend loop knot.
« Reply #33 on: August 21, 2018, 01:09:24 AM »
Derek,

I am working on an update to my 'Analysis of Bowlines' paper.

One area I intend to revamp is the definition of a 'nipping structure'.
I will be adding a qualifying statement that all nipping structures must be TIB (tiable-in-the-bight).
Another way to look at this is to say that a nipping structure is topologically equivalent to the unknot.

Ashley's conceptualization of [a] 'Bowline' is found at illustrations #1010, #1012, #1013 and #1034 1/2.
Note: #1016 is interesting and there is a clue here to Ashley's mindset - he used the phrase "based on a Bowline" to describe the structure. It did have a nipping structure based on a helix. I think the collar may have confused him...
#1033 confused him - likely because what he would have observed as a 'bight' was not in the obvious form as #1010. But #1033 does have a nipping loop that is in the classic helix form.
#1057 & #1058 must be errors - I have no rational explanation as to why he awarded these knots the title of 'Bowline'.
We also have #1072, #1074 (which has some resemblance to #1016), #1080 and #1087.
#1079 is interesting in that the title 'Bowline' is avoided.

In general terms, these 'eye knots' (aka loop knots) / Bowlines, are built from nipping structures that take the form of a helix (either single of double helices).

If I could travel back in time and show Ashley an 'eye knot' built from #206 Crossing hitch or #559 Marlinspike hitch, I wonder what he would say? Would he regard these eye knots as deserving of the title 'Bowline'?

In my view, I think that nipping structures that take the form of a helix are the classical notion of a 'Bowline' - and that if the nipping structure is of a different form (but still TIB and non-jamming) - perhaps Ashley would agree to the title of 'Virtual Bowline'?

And this is why an eye knot based on a #46 nipping structure (overhand knot) must be excluded from the title of 'Bowline'. #46 is not TIB.

Mind you, if I could travel back in time and meet Ashley face-to-face, I would also urge him to lock down the definition of what constitutes a 'loop' :)
« Last Edit: August 21, 2018, 02:23:04 AM by agent_smith »

DerekSmith

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Re: The Sheetbend loop knot and the Carrick bend loop knot.
« Reply #34 on: August 21, 2018, 04:14:09 PM »
@ Mark
Quote
#1033 confused him - likely because what he would have observed as a 'bight' was not in the obvious form as #1010. But #1033 does have a nipping loop that is in the classic helix form.

In what way do you feel that Ashley was 'confused' by #1033?  As depicted, it has a collar and a nipping helix loaded both ends - doesn't that fit your criterion?  Just how long must bight legs be to qualify as a bight?

Derek

agent_smith

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Re: The Sheetbend loop knot and the Carrick bend loop knot.
« Reply #35 on: August 22, 2018, 02:44:13 PM »
per Derek:
Quote
In what way do you feel that Ashley was 'confused' by #1033?

Derek, clearly and obviously - Ashley identified illustration #1033 as a Carrick loop.

As far as my ability to read Ashley's description of #1033, I could not see specific words that described or identified it as a 'Bowline'.

That is, he did not identify #1033 as being a 'Carrick Bowline' or any type of 'Bowline'.

#1033 characteristics:
[ ] has a nipping component that is based on a helix that is loaded at both ends, and is also TIB and non jamming
[ ] the nipping loop is free to encircle and clamp both legs of the collar

So I am making an assumption that he was confused by the 2 legs of the collar (which you may prefer to conceptualize as a 'bight') entering the nipping loop from opposite directions. I speculate that this 'bight' component didn't appear quite right to him, and so he dismissed it as being a type of 'Bowline'.
« Last Edit: August 24, 2018, 01:26:18 AM by agent_smith »

DerekSmith

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Re: The Sheetbend loop knot and the Carrick bend loop knot.
« Reply #36 on: August 22, 2018, 05:51:18 PM »
Quote
Derek, clearly and obviously - Ashley identified illustration #1033 as a Carrick loop.

As far as my ability to read Ashley's description of #1033, I could not see specific words that described or identified it as a 'Bowline'.

That is, he did not identify #1033 as being a 'Carrick Bowline' or any type of 'Bowline'.

Indeed, he showed no signs of confusion you suggest he suffered.  His words are quite clear:-

"1033.  The CARRICK LOOP has the same formation as one of the so-called CARRICK BENDS.  It is easy to untie, but has no advantages over others that are simpler.

You state "#1033 confused him", where do you find his confusion?

Derek

agent_smith

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Re: The Sheetbend loop knot and the Carrick bend loop knot.
« Reply #37 on: August 23, 2018, 12:35:10 AM »
Quote
Indeed, he showed no signs of confusion you suggest he suffered.

Quote
You state "#1033 confused him", where do you find his confusion?

In my personal estimation, I think that you are suffering from a form of self-induced confusion in your persistence with this matter :)

Your confusion (with respect to misunderstanding my point) - stems from an unwillingness to take a different viewpoint of what I wrote. You are fixated on a single word - and this fixation appears to be unyielding and resolute.
Try imagining this matter from this viewpoint; virtually all of the building blocks required to build a 'Bowline' were staring him in the face. And yet, despite virtually all of the building blocks being present, he apparently was unable to join all of the dots and see #1033 from a different perspective. Sort of like you being unable to see from a different perspective.

I advanced the word 'confused' to describe this missed phenomena. Now, you may not like that choice of word and may wish to fixate on it in some way to challenge me. And thats fine... But you should consider that the word 'confused' does not have to have demeaning interpretation toward Ashley. Some highly experienced people can become 'confused' by different visual inputs - eg pilots in the cockpit of an aircraft can become confused - and this does not imply that they are incompetent.

I guess we'll never really know if Ashley was 'confused' by what he held in his hand some 70 or so years ago.
But, if you feel the onus of proof lies with me to prove beyond a reasonable doubt that Ashley was 'confused', then by court room standards, I would likely be unable to conclusively prove it.

EDIT NOTE:
I have added some images to show that there are 2 different eye knots bearing the word 'Carrick' in their name. One is more closely aligned (in terms of geometry) to #1439 Carrick bend than the other. I believe that Ashley was possibly thinking in terms of the #1439 derived Carrick eye knot when he made his remarks, and not the form taken by #1033 (which has a different geometry). But, given the use of word 'carrick' in both knots, this is another potential source of confusion!
It should also be pointed out that the #1439 derived Carrick eye knot exists in an unstable dressing state...in that, when load is applied, it undergoes a transformation to a energy stable state.
« Last Edit: August 23, 2018, 02:10:52 AM by agent_smith »

DerekSmith

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Re: The Sheetbend loop knot and the Carrick bend loop knot.
« Reply #38 on: August 23, 2018, 05:28:12 PM »
Thanks Mark for the clarification,

I do not believe for one moment that Ashley was confused, either personally, nor perceptually by the lacing he displayed in #1033.  I believe that Ashley's perception of a dressed and set knot was well beyond being seduced by the apparent structure of a lacing, which is what I believe is perhaps what you and others have fallen foul of.

Your most excellent image of the lacings of #1033 holds all the attributes you claim he 'should' have been able to identify as a Bowline.

- excellent photography Mark -
 - a collar around the SP, a double loaded nipping helix, and collar legs within the nipping helix.

But Ashley was not stupid enough to be seduced by a lacing diagram - he would have dressed and set the knot, then seen immediately that it is as he described it "1033. The CARRICK Loop has the same formation as one of the so called single CARRICK BENDS".

Unless you are seduced into seeing in the lacings what you wish to see, then there is NO CONFUSION.

Your SP loaded Nipping Helix component vanishes in the fog of preconception.  It becomes part of a Carrick Component, and the now functional Nipping Helix, looking decidedly like a Simple Hitch Component has only a loop leg to load it.  There is not the slightest semblance of a Bowline left unless you count the all too seductive Collar around the SP (which of course is present in just about every knot).

Quote
But, given the use of word 'carrick' in both knots, this is another potential source of confusion!

So it seems, but not for Ashley !!

Quote
It should also be pointed out that the #1439 derived Carrick eye knot exists in an unstable dressing state...in that, when load is applied, it undergoes a transformation to a energy stable state.

It is interesting that you made the above observation (although it is an unstable 'lacing state', not 'dressing state').  Dressing the knot forms it into the stable, low energy state, it will hold under load.

But, given you understand this is a function of Carrick style lacings, why did you not apply the same knowledge to #1033 ?  Ashley clearly did...

Derek

agent_smith

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Re: The Sheetbend loop knot and the Carrick bend loop knot.
« Reply #39 on: August 24, 2018, 02:24:12 AM »
per Derek:
Quote
Your most excellent image of the lacings of #1033 holds all the attributes you claim he 'should' have been able to identify as a Bowline.
It appears that you are not reading carefully enough - and the trail of breadcrumbs is leading you off the flight path. I used the phrase 'type of Bowline'.
I believe that #1033 Carrick is a type of 'Bowline'.
I didn't (on this occasion) use the specific phrase 'virtual Bowline' - largely because the nipping loop takes the form of a helix, is loaded at both ends, is TIB, and freely able to encircle and clamp both legs of the collar.
In hindsight, I should have used the phrase 'virtual Bowline'.
NOTE: I am still working on a set of 'rules' for using the term 'virtual' as a qualifier - and indeed, in the past had toyed with alternative descriptors such as 'pseudo Bowline' and 'sub Bowline'.

Quote
Unless you are seduced into seeing in the lacings what you wish to see, then there is NO CONFUSION.

I think your use of the word confusion is misplaced - because in this instance you are seduced into seeing structural components in #1033 Carrick 'loop' which actually differ from the #1439 derived Carrick eye knot. The alternating weave in the #1439 derived Carrick eye knot follows the uniform over-under-over-under repeating pattern. In #1033 Carrick 'loop', not quite - there is a break in the uniformity.
Also, in #1033 Carrick 'loop' both legs of the collar are encircled by the nipping loop.

However, in the initial dressing state of #1439 derived Carrick eye knot, the nipping loop does not encircle both legs of the collar. Also, the geometry in the #1439 derived Carrick eye knot is a 'dressing state' - it is transitory. As soon as load is applied, it undergoes a transformation. Interestingly, after transformation into an energy stable dressing, the nipping component then encircles both legs of the collar.

Quote
Your SP loaded Nipping Helix component vanishes in the fog of preconception.
I think you may be lost in a fog of your own preconception :)
The nipping loop in #1033 Carrick 'loop' remains functional.
The core structure of #1033 does not undergo a transformation. Its dressing is not transitory (ie not a 'dressing state').

Ashley may have believed that he was looking at the uniform and repeating weave pattern of a #1439 Carrick bend - and it does appear to be so with a cursory glance. With closer inspection, the over-under-over-under pattern is not uniform in #1033 - this should be apparent to you unless you are seeing through fog!

I think illustration #1016 is an important clue. Initially, there is a functional nipping loop but, the last item in completing the dressing deactivates the nipping loop. And I think that Ashley understood this.

However, he was either confused by illustrations #1057 and #1058 or, it is an error that wasn't caught in time before before publication. In my view, these structures do not qualify as 'Bowlines' or even 'Virtual Bowlines'.

Pilots can become confused in a cockpit of an aircraft. This does not mean they are stupid or incompetent. The word 'confused' does not have to be constructed with a demeaning interpretation. And I think you are confused with my use of the word confused - and are confusing it with an alternative dictionary meaning for confused.  :D

DerekSmith

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Re: The Sheetbend loop knot and the Carrick bend loop knot.
« Reply #40 on: August 26, 2018, 10:34:54 AM »
@ Mark,

Clarity !!!

Quote
I think you may be lost in a fog of your own preconception :)
The nipping loop in #1033 Carrick 'loop' remains functional.
The core structure of #1033 does not undergo a transformation. Its dressing is not transitory (ie not a 'dressing state').

Now I see why we are in disagreement - #1033 has TWO stable states.

If I take the lacing as per your image of #1033 and carefully tighten it down, then I am able to 'freeze' the structure into a perfect definition of a Bowline - and it is stable...

AND

A Carrick is a self dressing component, automatically folding into the lowest energy form, so, if I take the #1033 lacings as per your image and simply load it (esp SP vs Collar loop leg), it dresses into the Carrick form I have been talking about, and almost certainly the form Ashley understood the knot would take which most certainly falls way outside of the Bowline definition.

So, we have a knot with a split personality.  I have now tied and loaded this knot repeatedly, and can state that it has so far never self dressed into the Bowline form, which is a slight indication that the Carrick form is the lower energy (most stable) form [1.]

So, having cleared up the confusion -  how will you now classify this Schizoid knot?

Derek

[ Note 1,  closest path is not necessarily the path to lowest energy state]