Author Topic: TIB tying method for a TIB bowline - wanted  (Read 22185 times)

xarax

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Re: TIB tying method for a TIB bowline - wanted
« Reply #30 on: September 19, 2015, 11:00:46 AM »
   And I had pointed out that this "e" does not remain an "e" any more, if seen through a mirror - its "handedness" is not conserved in a mirror-symmetric knot / a mirror transformation - but the knot itself, regarding its structure/name, remains the same ! How do you escape from that ?

Through the Looking-Glass...

   No ! Not the looking glass ! The looking glass does not show the mirror-symmetric image of an object - some old looking glasses just flip the image of the object 180 degrees, they do NOT show a mirror-symmetric view.
   In practical knots, mirror-symmetric knots are considered equivalent ( when they are tied on a material of an almost symmetric structure, not on a laid rope ).
   So, do not ask Alice or Weyl ! Place a screw close to the mirror, and see how the left- or the right-handed helix is mirror-transformed to its opposite/reversed. So, any left- or right-handed helix, including the helix of the nipping loop you mention, will reverse its handedness when viewed through a MIRROR - not through a looking glass - , although the image of the knot itself AND the image of this knot in the mirror will remain images of the same practical knot : the left-handed bowline will remain left-handed, and the right handed will remain right-handed.
   You have a situation where the "two" practical knots ( the "real" one and its reflexion, its image when viewed through a mirror, its mirror-symmetric image ) are the same, BUT the handedness of their nipping loop is not : it has been reversed.

P.S. I suppose that some, at least, of the "looking glasses" based on catadioptric systems (1) will do "mirror transformation" = present the mirror-symmetric image of the objects - but there are many different such systems, some more compound and complex than the others, and I do not know which will do this, and which will reflect the image of the object a second time, through/on the surface of a second mirror, so it will return back to its "original"/"normal", not mirror-symmetric form.

1. https://en.wikipedia.org/wiki/Catadioptric_system
« Last Edit: September 19, 2015, 11:12:04 AM by xarax »
This is not a knot.

knotsaver

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Re: TIB tying method for a TIB bowline - wanted
« Reply #31 on: September 19, 2015, 11:26:47 AM »
I think we have to consider the tying process (how we tie the knot). If we consider the tying process, the two knots (the "real" one and its reflexion) are not the same knot: one is righthanded and the other is lefthanded.
s.
P.S. I simply considered the looking glass as a mirror...

xarax

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Re: TIB tying method for a TIB bowline - wanted
« Reply #32 on: September 19, 2015, 11:57:08 AM »
I simply considered the looking glass as a mirror...

   No, It is a lens ! In a lens, the "right" side of an object remains "right" on the plate where it is focused, behind the lens.
   As I had noticed, there should be catadioptric "looking glasses" / telescopes, which do mirror transformation. I do not know anything more on that subject - I had never used one of those light catadioptric tele-lenses on a camera either ( although they have two mirrors - so I guess they reverse the reflected image two times, and so, in the end, they do not mirror-reverse it at all. )

 
I think we have to consider the tying process (how we tie the knot). If we consider the tying process, the two knots (the "real" one and its reflexion) are not the same knot: one is righthanded and the other is lefthanded.

   Noope !
   Take a picture of a right-handed bowline, and a picture of its mirror-symmetric, and post both of  them in the Forum. Say that the one is a right-handed, bowline, and the other left-handed bowline. Listen to what you will listen... :)
   THAT is my point : the handedness ( of their nipping loops ) changes, but the practical knot ( the bowline ), as such, does not.
   Moreover, the tying process is enough for some knots, as you say, but not for all ! Starting from the Double bowline on-the-bight, and extending both strands of the collar after its tip, without altering the side of the Standing/Tail Ends pair from which the two lines have already passed by, ( so, by transporting the collar, so it collars another pair of segments, further inside the nub ), you can tie more complex Med bowlines, for which we can not say if they are left-or right-handed - simply because we can tie them both ways, by first forming the one or the other single bowline and then retracing it line. It is the fact that the "parent" of all Med bowlines, the Double bowline on-the-bight, can be considered as either a left-handed or a right-handed bowline, that puzzles me. How the "parent" does not have one, only, defined handedness, and the "children" acquire one, and one only ? From which, exactly, point of the double line and afterwards, do the side of the segments around which the two lines of the double line pass by counts ? 
« Last Edit: September 19, 2015, 12:03:14 PM by xarax »
This is not a knot.

knotsaver

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Re: TIB tying method for a TIB bowline - wanted
« Reply #33 on: September 19, 2015, 02:12:15 PM »
Please look at the attached pictures:
to my mind,
ABoK1010 is a RIGHT-right-hand bowline (please look at the hand in the picture)
ABoK1010_mirror is a RIGHT-left-hand bowline (please look at the hand in the picture)
ABoK1034.5 is a LEFT-right-hand bowline
ABoK1034.5_mirror is a LEFT-left-hand bowline

in capital letters the terms (RIGHT and LEFT) as used in ABoK:
RIGHT = tail end is internal
LEFT = tail end is external

knotsaver

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Re: TIB tying method for a TIB bowline - wanted
« Reply #34 on: September 19, 2015, 02:17:46 PM »
...
ABoK1080 is a right-hand double bowline on-the-bight
ABoK1080_mirror is a left-hand double bowline on-the-bight