Topology of Phone cord twist

FrankSchwab

Senior member
Nov 8, 2002
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OK, it's at least an amusing question...

I have a phone on my desk with a coil cord between the handset and the base. About halfway down the cord, a discontinuity in the twist has developed. A loop has developed, where it appears that the twist has reversed from left-handed to right-handed. Look down at your phone - I'm sure you have a similar problem. In my experience, these loops seem to occur most often in pairs, though singletons are not uncommon.

The cords certainly aren't made this way, but I don't understand what happens to them to create these loops. Even worse, not understanding what's happened to the cord, I have been singularly unsuccessful at unlooping it - all attempts I've made have left the cord looking worse than before I started. Occasionally I'm successful if two loops of opposite orientation are near each other, but I've not been successful dealing with cords where two loops are at opposite ends of the cord. Single loops are even more frustrating.

Yes, I know I have too much time on my hands...

/frank
 

flamingspinach

Senior member
Nov 4, 2004
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They are made in such a way that their natural tendency is to coil like that. However, if you twist them a certain way, in order to maintain the lowest possible potential energy, all the nonconformity (if you will) is concentrated at one point (the loop), after which the rest of the material resumes its normal curve. Remember that the curve is relative, and based on the tension on each particular point of the cord.

-fs
 

winr

Diamond Member
Feb 17, 2001
6,081
56
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Take one side of the cord and hold it at the spot it is twisted and hold it steady.
Take the other side of the cord where it is twisted and turn it one way or the other, you will see when you start twisting it if you are going the right way.






:)
 

Tiamat

Lifer
Nov 25, 2003
14,068
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Bah! Look what you did! Now I just looked at my phone cord and there are 4 of those things and now I'm trying to fix them but failing miserably... :p
 

Peter

Elite Member
Oct 15, 1999
9,640
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Mine doesn't. They are created by picking the phone up with one hand, moving it to the other ear, and putting it back. That's a full circle of rotation, and if you keep doing that against the coil's own spin, it'll curl up.
 

eigen

Diamond Member
Nov 19, 2003
4,000
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Originally posted by: Confide
Definately taking Knot theory next semester... Will get back to you..

have you had topology yet, I am taking it next semester.