The Mysterious Bell Knot Challenge

I unplug the receiver and cord from the body of the phone. Then I stand on my desk, holding the cord near the RJ end, and let the receiver dangle. The receiver spins for a while and after gravity has run its course, the knots are gone. I then get down off the desk and plug the phone back in.

Can somebody help me find my "cord" on my cell phone? ;)

I always assumed that the cause of the knot is the tendency for a person to rotate the head set once each time it is picked up and put down. It would be interesting to see what a phone cord looks like for a left handed person as I know with right handed people, the coils tend to coil tighter and twist together.

If the cord just unwinds when disconnected and left to dangle, that's one thing. But every now and then it gets a reverse curve that looks like one of the coils is deleted (usually you get two of these with a section of regular coils between them). These cannot be gotten rid of by hanging the cord, even with the head set attached.

I looked down to find no fewer than three of these little mistries. They all seen to have formed where ever the cord is doubled over itself like at the lowest point of the hang or where it hangs over the desk edge. It seems more kink problem than a twist problem. Maybe it is a combination of the two.

I saw this on the web at costcentral.com site... they should come standard in phone sets! Ever been on the phone with that nagging in-law and had your attention diverted to that old and twisted coiled handset cord? Don't you just wish you could disconnect them and fix that cord? The Belkin Twist Free Adapter will allow you to focus all your attention on the moaning and groaning. With this novel invention, at least your handset cord will never be twisted again. The Belkin Twist Free Adapter attaches to your coiled handset cord and prevents knots, twists or tangles. Our Price $8.40 Availability as of 7:33am 6/9/06 Out of Stock

I have observed that the so-called "Bell Knot" (I never knew there was a name for them!) also occurs in the Slinky toy, a spring steel coil. It occurs when the toy is stretched and gets tangled on itself. In trying to untangle the toy, the loops are sometimes forced to invert themselves, spiralling in the opposite direction. I believe that you will always create an even number of "knots" if the ends are fixed. I just successfully tried this on my phone cord. I was unable to create an odd number of "knots" while the cord was attached to the handset and phone. If you are careful and do not exceed the elastic limits of the material you may be able to pull on the loops between the knots until they are almost straight and allow them to revert to their original orientation.

I believe the "Bell Knot" creation happens because the greatest spring force is in the plane of the coiled loop and only a slight amount in the "twist" which gives the helix its direction. When phone cords and Slinky toys get tangled through stretching, twisting, flopping, etc., the tendency is to pull on the ends to pull the loops apart and untangle them. When they are caught on other loops and cannot untangle in the direction they should, they will "untangle" in the opposite direction since that also allows the coil to resume its shape, acheiving a new "meta-stable" state and creating the Bell Knots.

So, what's the answer? I have one in my phone cord now that I'm anxiously waiting to remove.

I am unable to reproduce this. I think a link to a youtube proof is in order...

the "good answer" above is total crap. following the method described doesn't yield a true bell knot at all because the direction of the sprial is not reversed. simply pulling the cord will undo the type of kink described.

this is the type of thing that drives people insane. i can find no explanation as to how a phone cord spontaneously reverses its spiral from counterclockwise toward the handset to clockwise toward the handset or vice versa, nor can i find an explanation as to how to undo such a phenomenon. i suggest someone carry one of these bewitched cords into a quantum singularity and see what happens.

THE SOLUTION!

I studied this for a while and I really didn't believe that some sort of knot-reversal could climb its way up the length of the cord and it turns out that the way it happens and the way to undo it are far simpler.

The best way to learn how to undo the knot is to learn how to create one. Simply find a section of telephone cord that is in its "healthy" spiral state and take hold of one loop with your left hand and the one right next to it with your right hand. Now just twist the whole wire with one hand twisting the loop one way and the other way with the other hand. If you go the wrong way you obviously just make the coils smaller and tighter. You have to go the way where it starts getting wacky and it will eventually pop into that dreaded knot that has driven us all crazy! Just grab the coils on both sides of the knot and twist in the opposite direction to go back to normal. yay! :)

I found you can just take the phone cord and wrap it FLAT around your finger (so it looks the same as a 'healthy' section of cord) starting right before the section where the knot is located, and keep going past the knot until things look normal again - then remove your finger. I just removed two of these annoyances in my spiral phone cord.

Being of a devout Repub persuasion I think it must be a Democratic conspiracy. Maybe this election is gettinig to me. I just kept twisting the cord and worked the knot down to the end.

These knots appear when you twist the cord so much that it finds another stable position by binding itself. The most clever way to solve this problem is to unplug the cord then twist the cord where the knot is. To be sure that you twist the cord in the right direction, you'll notice that the cord will make a precise reversed "U" shape. You just have to continue the twisting until the cord gets back to its original position.