Slashdot Mirror
How and Why Knots Spontaneously Form
palegray.net writes "Scientists believe they have found the underlying reasons why knots are so common in the universe. This research helps us understand how knotty arrangements in various molecules lead to biological patterns, as in certain proteins. The article also provides a look at the field of topology, and how it relates to knots."
But can they explain why knots form in your hair after laying still for as little as an hour? My wife blames gnomes, and I'm inclined to agree with her.
End of lesson. You may press the button.
Any tip about packing christmas lights?
This research helps us understand how knotty arrangements in various molecules lead to biological patterns, as in certain proteins.
Because He reached out his noodly appendage and put the spark of life in our universe.
"And the earth was without form, and void; and straightness was upon the face of the pan. And His Noodly Appendage moved upon the face of the sauce.
And FSM said, Let there be knots: and there were knots.
And FSM saw the knots, that they were good: and FSM divided the knots from the straightness as happens when you boil short and long pasta at the same time.
And FSM called the knots Spaghetti, and the straightness he called Ziti. And the strands and tubes were the first course."
Duh?
Get a long sheet (about 50 cm x 2-5 meters, depending on the number of lights.) Starting at one end, wrap it around the short end of the rectangle, then fold it over about 10 cm. Repeat until all your lights are in a big cigar tube.
Have you been touched by his noodly appendage?
That explains why knots spontaneously form in wires and cables when you stick them in a box, but what about the way knots spontaneously come undone in your shoe laces? Perhaps in an alternate universe, shoe laces spontaneously knot themselves, and wires and cables untangle in storage. Of course, with that sort of altered physics, Homer Simpson would probably be the President of the United States.
Oh, wait.
"My country, right or wrong; if right, to be kept right; and if wrong, to be set right." --Senator Carl Schurz (1872)
As a kayaker, I'm familiar with a rescue tool called a throw bag. Apparently, throw bags were developed for the maritime industry, then downsized for kayakers.
The theory is quite simple, but it's amazing to watch how well it works:
I've watched these bags work time and time again, amazed that with the rope just stuffed into the bag, they work reliably. I've used store-bought bags and ones I've made myself and have never seen the rope tangle.
I realize that without loose ends proper knots can't form, but with a throw bag, you don't even get close to tangles!
Surely the fundamental reason why knots form (or rather why they persist/accumulate)is because of the inherent assymmetry of them formign/unforming.
A loose end in a jumble of coils, if jiggled around, is almost bound at some point to pass though a coil and form a potential knot, but a knot once formed is by no means destined to become unknotted, especially once additional knots form on the loose end thereby securing earlier knots.
If the chance of becoming knotted is less than the chance of becoming unknotted, then there's going to be a trend towards becoming increasingly knotted (to some limit where the accumulated knots limit mobility of the mass).
It seems there may also be a ratcheting effect once a loose knot forms - the knot/loop being bulky will more likely catch on the surrounding mass then the single stands leading into it, so that if the loose ends get tugged by the jiggling of the surrounding mass then the knot will tighten.
But there again I'm just a dude who uses string rather than a high powered topologist getting paid to research string, so what do I know?!
As a sysadmin who has spent days untangling hundreds of tangled cables from the backs of too-crowded racks - hundreds of A/V lines criss-crossed by dozens of network lines criss-crossed by power cords - I've had some time to think about practical knot theory. I've established two primary hypotheses:
1. Placing cables is difficult because you are not just defining the position of that cable, you are also defining the position of every other cable in relation to that cable. As the number of cables rises, the complexity increases combinatorially. (Or exponentially. Or something. I faked my way through those math classes.)
2. There are many more ways for cables to be tangled than to be untangled, so statistically, tangling is overwhelmingly likely. It's like entropy that way: There are many more ways for particles to move in different directions than there are ways for particles to move in the same direction, so it takes special effort or special circumstances to get them all to line up.