Author Topic: Eternity knot - a nice small stopper.  (Read 12800 times)

xarax

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Eternity knot - a nice small stopper.
« on: February 25, 2014, 12:30:03 AM »
  I have stumbled on the stopper shown in the attached pictures, presented at :
  http://www.nico-matelotage.com/

  It is similar to ABoK#583. It looks like a nice symmetric stopper to me, where the Standing Part follows a very convoluted ( for a such a small knot ) path, with many U-turns. In a way, it resembles the much more complex Whaler s and Double Torus stoppers. It would be interesting to test it on Dyneema ...

« Last Edit: March 16, 2014, 07:04:46 AM by xarax »
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Sweeney

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Re: Eternity knot - a nice small stopper.
« Reply #1 on: February 25, 2014, 10:54:54 AM »
I have been familiar with the Eternity knot for a while now - it is featured in Fusion Knots by JD (his first book) and is one of his early videos on Youtube (http://www.youtube.com/watch?v=VpeaJKTw620 but I had never thought of it as a stopper. For a bulky stopper I use the Celtic button knot - http://www.youtube.com/watch?v=H-bVfokOb2w which is easy to tie and dress.

Barry

xarax

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Re: Eternity knot - a nice small stopper.
« Reply #2 on: February 25, 2014, 11:29:01 AM »
   Thank you, Sweeney,

   So, there should be many other "decorative" stoppers, easy to remember, to tie and to inspect , which can possibly do the job : replace the single/double/triple overhand knot in a Fisherman s knot-like sliding / interpenetrating bend. I thought that, as the multiple nipping turns do not seem to work efficiently on Dyneema, let us replace them with multiple U-turns, and see what happens. The hooked and blooded Fisherman s knot (1) is addressing the same need, with a similar, essentially, manner.
   It has nothing to do with the stopper been bulky or not. If the path of the Standing Part follows "orbits" around the central core, as it does in the Celtic button knot, the turns remain wide, and this may facilitate the line to slip out of the nub. I believe we need successive sharp U-turns, following one other, i.e., many "inner collars".

1.  http://igkt.net/sm/index.php?topic=4792.0
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Sweeney

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Re: Eternity knot - a nice small stopper.
« Reply #3 on: February 25, 2014, 01:02:14 PM »
Xarax,

Have you tried the Blimp knot?

Barry

xarax

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Re: Eternity knot - a nice small stopper.
« Reply #4 on: February 25, 2014, 03:10:49 PM »
   Of course, but only on ordinary material, which doesn't offer any knowledge other than the one we already had.
   When I say that :
 
  Most names are not even wrong : they are silly, misleading, pompous, obscure, etc - because, most of the time, names do not pop up from the characteristics of the knots, but of the characteristics of the knot tyers.  :)
  ...I had more than one points !  :)  What is this "blimp knot" anyway ? Nothing else than a stable form one of the three different fig.9 knots ( the 6_1, the most symmetric of the trio ) can have. See (1) and (2). I have considered the fig. 9 knots as possible knots we can re-trace, to get bends which can replace the triple overhand knot, at (3), and as a "halves" of Fisherman s knot-like sliding / interpenetrating bends, at (4).
   However, I had not tested them on Dyneema - so what I know about their behaviour is next to nothing, indeed ! I don t even know if those forms are stable, in their most symmetric dressing, when tied on Dyneema - perhaps even the smallest perturbation can "break" their symmetry, and so they will settle in another, non-symmetric stable form, as the "blimp knot" does sometimes.
   In short, there is much work to be done, before we abandon the hopes that the stoppers we already know are inadequate as replacements of the triple Fisherman s overhand knots - and who knows what happens with the many "decorative", yet easy to remember, to tie and to inspect, "decorative" knots.
   The hunt is on ! I see no reason to go fishing:)

1. http://igkt.net/sm/index.php?topic=3838.0
2. http://igkt.net/sm/index.php?topic=4764.0
3. http://igkt.net/sm/index.php?topic=3668.0
4. http://igkt.net/sm/index.php?topic=4764.0
« Last Edit: February 25, 2014, 03:25:36 PM by xarax »
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xarax

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Re: Eternity knot - a nice small stopper.
« Reply #5 on: February 26, 2014, 05:55:29 PM »
   Considered as a practical knot ( i.e., nothing eternal... :)), the "Eternity knot" is nothing but two interlinked slipknots. They can be tied as two slipped over-hand knots, or two slipped under-hand knots ( same handedness / chirality ), or as one overhand and one underhand knot ( opposite handedness / chirality )( see the attached pictures). The interested reader can discover them between the knots with 8 crossings (1). I suppose that, when they are loaded as pure stoppers, i.e., from their one only end, they can be stable in those symmetric forms, even if they are tied on Dyneema - but I can not be sure...
   The interesting things with those knots is their meandric shape :  All those sharp U-turns can possibly absorb the tensile forces running through the Standing part before they manage to reach the Tail end, and so they can inhibit the slippage of this end.

1. http://katlas.math.toronto.edu/wiki/The_Rolfsen_Knot_Table#Knots_with_8_crossings
« Last Edit: February 26, 2014, 05:57:00 PM by xarax »
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DerekSmith

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Re: Eternity knot - a nice small stopper.
« Reply #6 on: March 01, 2014, 01:41:24 PM »
I have been criticised in the past for being critical of a decorative knotter bringing what I considered to be a potentially lethal knot onto the Practical board.  My gripe was that generally, decorative knotters are dealing with form and aesthetics without any consideration (rightly) for function in a working (i.e. loaded) environment.

My first impression of this 'stopper' was that it was going to be yet another pretty little construction devoid of functionality, especially as the author Nico-matelotage seems to have published it simply as proof that a knot does not have to be complicated to be pretty.

I was particularly concerned, because the humble 'Stopper' has a potentially critical application, and yet its function is rarely given a moments thought, relegated often to an overhand knot (which perhaps surprisingly turns out to be a quite competent  stopper in many cordages) and little else.  However, with the move to higher tensile strength and lower frictional cords, the role of the 'Stopper' is arguably becoming increasingly important.  Forces that would never reach through knots in older cordage, are today translating all the way through to the dead end of knots tied in modern high strength, high slick ropes.

The role of the stopper is simple - to act as a thickening to the cord and so block any chance of the dead end pulling through the functional knot.  In this respect, the simplest stopper is the thickening caused by a tightly closed bight loop, but to be effective, the constriction has to be drawn into a primary nip so that loading forces first constrict the nip and only residual forces are left to drag the bight lump into the nip.

But that is not the only functional requirement of the stopper.  A key attribute is that the stopper must retain its integrity in the dead end, without any load to sustain it, and it must resist any amount of flogging.  Any forces on the stopper, even its own weight, must serve to maintain or even tighten the stopper.  To achieve this requirement, a stopper must be self sustaining, forces imposed in setting the stopper must act to clamp the knot closed.  The Strangle knot is probably the simplest stopper to satisfy this requirement.

The Strangle also demonstrates the final important functional characteristic.  When the Strangle stopper comes into use by being drawn up against the knot it is protecting, the bearing face comes into contact with the protected knot.  When this happens, the force acting on the Strangle, passes straight through the centre of the Strangle to its back face before wrapping around and nipping its own tail.  By applying the bulk of the load force to nipping its own tail, this nipping grip is then amplified by all the frictional generating turns within the Strangle before finally acting to counter the force being applied to it.

Applying these principles again, the Strangle can be further enhanced as a stopper by 'slipping' the dead end back through the choke of the Strangle, offering the fundamental stopping power of the closed bight loop which must either pull through the choke of the Strangle or be forced to draw the remainder of its tail back through the Strangle choke.

A final enhancement is to take the slipped tail, pass it over the outside of the Strangle and through the slipped eye, drawing the eye moderately closed in order to hold the tail in place.  Now any forces reaching the bight eye are passed around the Strangle gripping it further before being fed into the nip of the bight eye, again applying the principle of taking the load force to the very end of the line, clamping it with the full force of the load and relying on the structure of the knot to further amplify this tail end grip.

Of note, this slipped and back laced Strangle is the only stopper I have seen resist pull through in 500lb Spectra.

The offered knot however, does not satisfy any of the principle requirements and while it might be a novel fashion statement, I do not think we should be promoting knots for important functions when the rapid pace of rope development will soon be putting the abilities of the humble Stopper Knot to the test.

Derek

xarax

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Re: Eternity knot - a nice small stopper.
« Reply #7 on: March 01, 2014, 03:16:45 PM »
...a potentially lethal knot onto the Practical board....decorative knotters are dealing with form and aesthetics without any consideration...

This is NOT the Practical Knots board - and this is NOT a decorative knotter, period. 

...a tightly closed bight loop, but to be effective, the constriction has to be drawn into a primary nip so that loading forces first constrict the nip and only residual forces are left to drag the bight lump into the nip.
Any forces on the stopper...must serve to maintain or even tighten the stopper.
The Strangle also demonstrates the final important functional characteristic....offering the fundamental stopping power of the closed bight loop...

   Nope ! This is only happening to "half" of the possible stoppers, those to which we are more accustomed, when we use ordinary materials. They are based in many nipping structures / loops, constricting the line as it goes through them, and so inhibiting slippage. The other "half" do not work with nipping loops, but with U-turns, "inner collars". The line is following a meandric path inside the knot s nub - and in each of those many U -turns, the tensile forces that "run" through it are partially uploaded and absorbed by friction. The Whaler s stopper was designed to offer many U-turns - not to offer many nipping / constricting places - and works very differently than the Strange, for example.
   A less tight stopper, with many U-turns / "inner collars", can slip much less than a more tight one, with many nipping / constricting loops.

Of note, this slipped and back laced Strangle is the only stopper I have seen resist pull through in 500lb Spectra.

  You mean, of those which you have tested... :) Because you have not tested the Whaler s stopper, I suppose - and neither you have read the relevant thread, or the thread about the hooked and blooded Fisherman s knot. If you had read those threads, you would had understood the reason I have shown the "Eternity" stopper...

   The beauty of this stopper ( which is not based on multiple twists of both lines around each other, but on multiple U-turns of each line around the other, an altogether different, and supposedly more secure, mechanism ) is not easily appreciated by people who may see it, but do bother to tie and try it - as it often happens with the knots presented in this Forum. ( I wonder if "knot tyers" should only be understood as "own-knot tyers - but knot anybody else s ! :)

The offered knot however, does not satisfy any of the principle requirements and while it might be a novel fashion statement

  Where you see "Fashion", I see "Function". Where you see "Function", in the traditional stoppers, based on "half" of the total of the "principle requirements" that can make a stopper, I see "Fashion" - fashion promoted by the traditional knot-tyers tendency to repeat what they already know, and do not even read the texts other knot-tyers write, or see the pictures of the knots other knot tyers show....

  I do not think we should be promoting knots for important functions when the rapid pace of rope development will soon be putting the abilities of the humble Stopper Knot to the test.

  I do promote no-thing - I have seen a knot resembling, re. its many U-turns / 'inner collars", the Whaler s stopper I had tied, and I published it for THAT reason. 
   Even if I had "promoted" ONE knot - which, I repeat, I had not -, you are promoting one truncated, limited, therefore false idea about how stoppers work - and I do not think we should be promoting false knotting principles, when the rapid pace of rope development has already put the abilities of those too-proud stoppers to the test - and has proved their failure.
« Last Edit: March 01, 2014, 05:04:52 PM by xarax »
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xarax

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Re: Eternity knot - a nice small stopper.
« Reply #8 on: March 01, 2014, 03:55:58 PM »
  The Strangle knot is probably the simplest stopper to satisfy this requirement.
  Applying these principles again, the Strangle can be further enhanced as a stopper by 'slipping' the dead end back through the choke of the Strangle, offering the fundamental stopping power of the closed bight loop

  I have tied the Strangle bend, which is a end-to-end knot based on two interlinked Strangle stoppers. It has already been put to test by allene, on Dyneema :

the Strangle bend - shown in the attached pictures - , because the wraps of the one link squeeze the ones of the other. Could you, please, try to pull this bend - because I am dying out of curiosity ! :) Of course, I suppose you would set and pre-tighen the bends a little bid, before the final loading.

The strangle bend slipped against my knot.

  So much for the fashion-able, traditional stoppers, based on nipping / constricting bights. I knew that it will not hold, of course, when it would be tied on a material where the triple Fisherman s knot slipped - but I wished to see the maximum loadings where the slippage would take place, so I could compare them with those of gradually more complex but similar, in their logic, bends. ( Unfortunately, allene was not offering such comparative tests ).
  One may argue that the Strangle bend is, in a way, a retraced Strangle stopper, and that retracing increases the volume of a knot, so it makes all the inner turns wider, facilitating slippage. That is correct - although the cumulative constricting power of both links on the lines penetrating the knot s nub and on the Tail ends should compensate this - if the traditional ideas about how a stopper works were valid.
  No, we do not need many, interweaved or not, nipping / constricting bights, we need more sharp U- turns, more "inner collars" that change abruptly the direction of the Standing Part 180 degrees. That is the space to be conquered with slippery material - we should abandon the lines / planets orbiting around a central core / sun, around one point, and instead ride on lines / satellites turning around themselves, around many points. 
   

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DerekSmith

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Re: Eternity knot - a nice small stopper.
« Reply #9 on: March 01, 2014, 09:31:54 PM »
Quote
  No, we do not need many, interweaved or not, nipping / constricting bights, we need more sharp U- turns, more "inner collars" that change abruptly the direction of the Standing Part 180 degrees.

Yes, as well as the end 'nipping' component I mentioned above, the stopper certainly needs internal structure to facilitate the capstan frictional amplification process.  However, this brings up the complex issue of 'Cogging'.  Simply adding turns without ensuring that the frictional forces fight one another instead of reinforcing one another is false assurance.  There are ample demonstrations of knots with plenty of turns and bulk that will freely rotate and allow the cord to feed through almost as if they were nothing more than pulleys.

So, while I acknowledge that a stopper needs internal frictional producing structure, I also continue to hold that resistance to flogging under no load together with a structure which locks the dead end as it exits the knot, maximises it functional ability to shed force before it manages to pass right through the stopper and act on drawing the dead end into the knot.

Derek

xarax

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Re: Eternity knot - a nice small stopper.
« Reply #10 on: March 01, 2014, 09:51:35 PM »
Simply adding turns without ensuring that the frictional forces fight one another instead of reinforcing one another is false assurance.  There are ample demonstrations of knots with plenty of turns and bulk that will freely rotate and allow the cord to feed through almost as if they were nothing more than pulleys.

  You should use your glasses more !  :) The Whaler s stopper will NOT rotate freely - and that is, I think, because of the "alternating" U - turns ( would be a correct term ? ) - that is, turns to a different direction each time.
  However, I agree that we first have to TEST those monster stoppers, because it is not the first time our predictions were wrong... Knots are more complex machines than we wish to believe they are. People think that the vertebrates are more complex than the invertebrates - until they see what a flexible octopus can accomplish !  :)

the complex issue of 'Cogging'.

  I agree - this is a mechanism I have never been able to understand, and I believe it must be responsible for many unexpected / unpredictable things. The fact that, inside a knot s nub, we can not see torsion as well as we see tension, and we can not see rotation as well as we see translation, does not mean that they do not exist !
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DerekSmith

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Re: Eternity knot - a nice small stopper.
« Reply #11 on: March 01, 2014, 11:35:29 PM »
? ? I think ? that we are in agreement ?

But if we are, then why do I need to use my glasses more?

The Whaler's Stopper is in fact a reasonable example of two of the principles I suggested as being important in a stopper.

If I may plagiarise one of your images -



The knot has, by function of the two OH components, a self contained integrity, although it lacks the value of a tensioned over wrap to hold the OH grip in place, but it should resist unloaded flogging reasonably well.

The from the image, you can see that load escaping the knot the stopper is guarding, would flow straight through the Whaler's to the nipping structure of the back OH and this is putting the most intense grip onto the dead end - so any capstan style frictional action from the rest of the internal structure is amplified by the gripping load applied to the dead end.

It is perhaps of interest that this stopper would also show benefit from slipping the dead end back through the knot and keying it through the slipped bight.

Very similar to the Strangle, but perhaps lacking some of the intrinsic unloaded integrity of the Strangle (it is no use relying on a stopper that resists pull through in slick rope, if it has fallen open due to flogging and is no longer present when you need it to be there).

I have my glases to hand, just in case I have missed something...

xarax

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Re: Eternity knot - a nice small stopper.
« Reply #12 on: March 02, 2014, 01:38:32 AM »
plagiarise one of your images

  "My" images, are not images of me ( fortunately... :)), neither are they images of "my" knots - so they belong to KnotLand, and to all members of this Forum, as I have said time and again. I laugh with people who believe that there are knots that "belong" to them, because they may be the first ones that had happened to tie them - so imagine what I do with people who believe that the pictures of those knots belong to them !  :)
...

   What I find more interesting, than the examination of the stopper part-by-part, is its overall image - an image of many sharp, around-one-rope-diameter U-turns, the one after the other. Count them, to see how many they are, is such a relatively small volume. So, many U-turns - and some nipping structures too, of course. There can be no stopper, indeed, no practical knot, without enough nipping / constricting action. No practical knot can work as a loose knot, because all practical knots work by friction, and friction needs tightness - but that sounds like a tautology to my ears. On the contrary, the realization that we need sharp U-turns, "inner collars", lines turning the one around the other but not all around a central core, orbiting like satellites, not like planets, was not obvious to me...That is what I had attempted to do with the Whaler s knot and stopper - following a previous very clever attempt by Dan Lehman, with his hooked and blooded Fisherman s knot.
   So, do not use your magnifying glasses here, just see the (tight) knot from a distance. The pattern of many sharp U- turns, the one after the other, is obvious. However, the efficiency of this pattern is only conjectured by me - I have not tested this knot and stopper on Dyneema and in the extremely high loads this material can withstand.
   I consider this general pattern quite different (or, at least, distinct )  from the pattern of the double or triple overhand knot, or the Strangle and the Trefoil bends, in particular ( but also to the retraced knots, based on the fig.8, fig.9, etc stoppers ), which failed when they were tested on Dyneema. Therefore, I make a theoretical "cut", and divide the possible stoppers in two broad categories. I had NOT said that half of the stoppers utilize only the nipping / constricting bights mechanism, and the other half the many sharp U-turns mechanism, as you might had understood. ALL knots have nipping / constricting bights., and ALL knots have "outer" or "inner" collars, i.e., U -turns, almost by definition ! Without tightness, there can be no friction, so no practical knot, and without change in direction, the line of the first knot would still be travelling in a straight line to a distant galaxy. I had just tried to lighten the same, very complex thing a practical knot, in general, and a stopper, in particular, is, from two different light sources.
   That was my point. When I started to look the general pattern of those stoppers, their image got imprinted in my mind, in a way... So. when, after a few days, I fell on the Eternity knot s image on the web, entirely by accident, I recognized the "similarity" of it with those stoppers immediately - and I had started to see it as a stopper, not as just another decorative knot. I had not proposed it as a replacement of the triple Fisherman s knot, but I just said it would be interesting to tie and try it, along with the other "similar" many sharp U-turns stoppers, to see what happens.
   The only "local" thing I paid attention when I was tying the Whalers knot and stopper, was to place the last part of the Tail end, the last line of defence against slippage, directly under the Standing part s first curve. Therefore, I had avoided the, perhaps simpler, retucking of the Tail end through the central openings SS369 did with his Double Torus stopper. However, I can not be sure which one of the two stoppers will be proved to be more efficient, by TESTS ( actually, the three stoppers, because there is yet another stopper which can be tied according the scheme of two opposing interpenetrating overhand knots ).
  As I have been careful to point out, how will those stopper "fold" when they will be squeezed from one side ( from the surface on which they will lie, or from the other "half" in the case of a Fisherman s-like knot ), I just can not predict.

  However, I agree that we first have to TEST those monster stoppers, because it is not the first time our predictions were wrong... Knots are more complex machines than we wish to believe they are.

  If those stoppers are used as halves of Fisherman s like bends, they may behave differently, than if they are used as pure stoppers. KnotGod knows what will happen between four overhand knots in a row, squeezed upon each other by the huge forces a Dyneema line can withstand ! Only tests can tell if those stoppers will hold ( I hope they will...), and, if they do, which will break latter, in a higher percentage of MBS of the unknotted line, than the other.

  I said that you may need your glasses, specifically in the part of my reply referring to your statement that the U-turns of the lines may act just like the lines going through pulleys, and they will ROTATE...

Simply adding turns without ensuring that the frictional forces fight one another instead of reinforcing one another is false assurance.  There are ample demonstrations of knots with plenty of turns and bulk that will freely rotate and allow the cord to feed through almost as if they were nothing more than pulleys.

 As you can se now, the lines in the Whaler s stopped will NOT rotate - for many reasons, one of which is that they the U-turns are alternating and balanced ( even if the U-turns of the one half of the knot tend to rotate towards the one direction, the U-turns of the other half counter balance this tendency ).

   My first impression of this 'stopper' was that it was going to be yet another pretty little construction devoid of functionality, especially as the author Nico-matelotage seems to have published it simply as proof that a knot does not have to be complicated to be pretty.

  I do not care why a person presents a knot, neither what he believes about it - I examine the knot itself. This "decorative" knot CAN be functional, and CAN serve as a stopper - and I believe that many other "decorative" knots cam, and they deserve to be examined, and not just dismissed beforehand, without any testing. Therefore, do not bother to read what Nico-whatever or I say - just tie and try the knots, and tell us what do you think about them !
« Last Edit: March 02, 2014, 01:42:47 AM by xarax »
This is not a knot.

DerekSmith

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Re: Eternity knot - a nice small stopper.
« Reply #13 on: March 02, 2014, 11:58:50 AM »
Therefore, do not bother to read what Nico-whatever or I say - just tie and try the knots, and tell us what do you think about them !

Hmmm,

I thought that that is what I had done...

Quote
The knot has, by function of the two OH components, a self contained integrity, although it lacks the value of a tensioned over wrap to hold the OH grip in place, but it should resist unloaded flogging reasonably well.

The from the image, you can see that load escaping the knot the stopper is guarding, would flow straight through the Whaler's to the nipping structure of the back OH and this is putting the most intense grip onto the dead end - so any capstan style frictional action from the rest of the internal structure is amplified by the gripping load applied to the dead end.

Derek

xarax

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Re: Eternity knot - a nice small stopper.
« Reply #14 on: March 02, 2014, 05:10:55 PM »
Therefore, do not bother to read what Nico-whatever or I say - just tie and try the knots, and tell us what do you think about them !

Hmmm,

I thought that that is what I had done....

Then, why do you need to write this :

My first impression of this 'stopper' was that it was going to be yet another pretty little construction devoid of functionality, especially as the author Nico-matelotage seems to have published it simply as proof that a knot does not have to be complicated to be pretty.

Am I misunderstanding the meaning of "especially":)
This is not a knot.