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How and Why Knots Spontaneously Form

CmdrTaco posted more than 6 years ago | from the knot-a-good-story dept.

Biotech 145

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."

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145 comments

Hair (5, Funny)

Verteiron (224042) | more than 6 years ago | (#21856914)

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.

Re:Hair (5, Funny)

nuclearpenguins (907128) | more than 6 years ago | (#21856970)

Gnomes? I'm afraid knot.

Re:Hair (-1, Flamebait)

Anonymous Coward | more than 6 years ago | (#21857132)

Knot! Knot!
Who's there?
You.
You who?
You sound like a Mac user.

Re:Hair (5, Funny)

Anonymous Coward | more than 6 years ago | (#21856972)

It can't be gnomes, it has to be KDEs.

Re:Hair (5, Funny)

sound+vision (884283) | more than 6 years ago | (#21857716)

Gnome has it's own version of knot, it's just called gnot.

Re:Hair (5, Funny)

dbolger (161340) | more than 6 years ago | (#21856986)

A more relevant example would be how you can set up a PC for the first time, and have all the cables carefully arranged so that there is no crossing over or tangling, and yet when you come back six months later, to add a new device or to swap out a cable, every single one of them is wrapped tightly around the others to such an extent that you can't understand how it could come about without somebody doing it intentionally.

Re:Hair (4, Funny)

SetupWeasel (54062) | more than 6 years ago | (#21857246)

I like how a post about a woman's hair gets no moderation, but a reply about computer wires with exactly the same point gets +5.

Since this is Slashdot, all must be right with the universe.

Re:Hair (1, Funny)

ScrewMaster (602015) | more than 6 years ago | (#21857304)

Because the computer reference has relevance to the Slashdot crowd (I mean, they've actually seen this phenomenon happen with cables) but a woman's hair? How often does a basement dweller get close enough to a woman to notice that her hair is tangled or not?

Re:Hair (0)

Anonymous Coward | more than 6 years ago | (#21857808)

I suppose it depends on whether the nice JPG-lady is hi-res enough to not show artifacts when zooming in then?

Re:Hair (3, Insightful)

orasio (188021) | more than 6 years ago | (#21858698)

Because the computer reference has relevance to the Slashdot crowd (I mean, they've actually seen this phenomenon happen with cables) but a woman's hair? How often does a basement dweller get close enough to a woman to notice that her hair is tangled or not?
Ten years have passed. We finally moved out of our parents basement. We grew old. People who are young now are no longer the nerds we were back in the day. Add to that the fact that nerds are much more attractive for the ladies right now, and you will see that most of us have seen a girl from up close, and even touched them with their consent.

It was a nice joke, to say that slashdot people were virgins, but sadly that joke died. Learn to live with it. there are a lot of nerds still here, but B.O. and problems with girls does not define us anymore. In my case, for example, you could make fun of GNU evangelism or something like that, maybe.

Re:Hair (0, Offtopic)

Tarathene Spellborn (1210188) | more than 6 years ago | (#21859672)

And of course, as is the way with things these days, some of us even are women.

Re:Hair & Wires (2, Funny)

TaoPhoenix (980487) | more than 6 years ago | (#21857842)

When I parsed the mentioned comment, it stated "undeclared-your" hair was the subject of the knotting. The Wife's spurious attribution of the cause to small semi-sentient beings does not change the knots in your hair.

Meanwhile, when is the last time you swapped your hair strands around with the purpose of installing new hardware?

Re:Hair & Wires (2, Funny)

SetupWeasel (54062) | more than 6 years ago | (#21857960)

I've never personally purchased a weave, but I hear many women do.

Re:Hair & Wires (1)

Eli Gottlieb (917758) | more than 6 years ago | (#21858020)

Meanwhile, when is the last time you swapped your hair strands around with the purpose of installing new hardware?
The last time I jacked into the Matrix, you insensitive clod!

Oh, dear. I've said too much.

Re:Hair (1)

ConceptJunkie (24823) | more than 6 years ago | (#21858424)

My wife is bald, you insensitive clod!

Re:Hair (1)

Deaddy (1090107) | more than 6 years ago | (#21857562)

I bet it's this strange quantum physics thing and it only does happen if you don't observe it.
At least you'll see how it happens, perhaps because of the inner torsion of the cables or someone just unplugged a cable because he wanted to test something. Maybe one should put Folding@Home to good use.

Hands-on knot theory (5, Insightful)

clawsoon (748629) | more than 6 years ago | (#21857838)

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.

Re:Hands-on knot theory (3, Interesting)

poopdeville (841677) | more than 6 years ago | (#21858332)

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.

You need to make the notion of counting ways to be tangled and untangled more precise. In any case, the problem with real cables is that most cable runs have a half turn in them. But where the turn happens varies. Moreover, the turn introduces distortion in the cable at the turn since it isn't under tension. Heating and cooling, and Type I and II Reidemeister moves [wikipedia.org] caused by the distortion moving do the rest.

But note that these kinds of knots are trivial to untangle if you keep the cables connected, and much harder if you don't, since Type I and II Reidemeister moves can't produce knots, just tangles.

Re:Hair (0)

Anonymous Coward | more than 6 years ago | (#21857904)

without somebody doing it intentionally
So are you a conspiracy theorist, or an intelligent design proponent?

Re:Hair (1)

Dracophile (140936) | more than 6 years ago | (#21859184)

A more relevant example would be how you can set up a PC for the first time, and have all the cables carefully arranged so that there is no crossing over or tangling, and yet when you come back six months later, to add a new device or to swap out a cable, every single one of them is wrapped tightly around the others to such an extent that you can't understand how it could come about without somebody doing it intentionally.

The intelligent designer did it.

Re:Hair (3, Interesting)

captain_dope_pants (842414) | more than 6 years ago | (#21857004)

I used to be a fisherman for a living. Miles and miles of nets, rope etc. When the "knot gnomes" had their way with that lot it was a nightmare!
There are also undersea variants of the "gnot knome". You go to haul your nets after a couple of days and they're gnotted all to hell.

Re:Hair (1, Funny)

Zeros (1016135) | more than 6 years ago | (#21857006)

Or why is it that even when i organize my cables on the back of the computer they will become a huge knot, i think bush just comes every night and tangles them.

It's true, Bush does it. (2, Informative)

Oktober Sunset (838224) | more than 6 years ago | (#21857534)

I heard he spits in your mouth as you sleep too.

Re:It's true, Bush does it. (2)

CarAnalogy (1191053) | more than 6 years ago | (#21857898)

The guy who modded this informative probably wakes up with a foul taste in his mouth every morning.

Oh, the joys of the /. moderation system :)

Re:Hair (1)

sconeu (64226) | more than 6 years ago | (#21859486)

No, that's the late Robert Goulet [youtube.com] who comes and tangles them up.

Re:Hair (1, Funny)

Anonymous Coward | more than 6 years ago | (#21857318)

If your wife lies still while laying, you have other problems than knotted hair.

Re:Hair (0)

Anonymous Coward | more than 6 years ago | (#21857576)

aha a gnomes comment heres my chance

1. see gnome comment on slashdot

2. type ??????

3. modded up!

4. or down

Re:Hair (1)

Zak3056 (69287) | more than 6 years ago | (#21858162)

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.

Well, duh! It actually has a really simple explanation. The gnomes have a business plan, which goes:

1. Tie hair into knots.
2. ???
3. Profit!

Re:Hair (0)

Anonymous Coward | more than 6 years ago | (#21859700)

I suspect Nargles.

Damn (1)

xiang shui (762964) | more than 6 years ago | (#21856968)

I thought this might be about the jungle under my desk.

Re:Damn (1)

xiang shui (762964) | more than 6 years ago | (#21856992)

It is! Oh joy.

That explains the inside of my "wire box" (1)

crovira (10242) | more than 6 years ago | (#21856988)

and I thought it was just me...

TFA revealed some interesting physics.

Re: That explains the inside of my "wire box" (1)

Black Parrot (19622) | more than 6 years ago | (#21857468)

TFA revealed some interesting physics.
But unfortunately didn't tell us anything about how to find knotty girls.

Slashdotted article text (2, Informative)

Anonymous Coward | more than 6 years ago | (#21857010)

http://www.sciencenews.org.nyud.net:8090/articles/20071222/bob11.asp [nyud.net]

Tied Up in Knots
Anything that can tangle up, will, including DNA

Davide Castelvecchi

Knotted threads secure buttons to shirts. Knots in ropes attach boats to piers. You can find knots in shoestrings, ties, ribbons, and bows. But even without Boy Scouts or sailors, knots would be everywhere.

Call it Murphy's Law of knots: If something can get tangled up, it will. "Anything that's long and flexible seems to somehow end up knotted," says Andrew Belmonte, an applied mathematician at Pennsylvania State University in University Park. Belmonte has plenty of alarming anecdotal evidence. "It certainly happens in my house, with the cords of the venetian blind." But the knot scourge is a global one, as anyone who owns a desktop computer can confirm after peeking at the mess of connection cables and power cords behind the desk.

Now, scientists think they may have found out how and why things find their way into knotty arrangements. By tumbling a string of rope inside a box, biophysicists Dorian Raymer and Douglas Smith have discovered that knots--even complex knots--form surprisingly fast and often. The string first coils up, and then its free ends swivel around the other coils, tracing a random path among them. That essentially makes the coils into a braid, producing knots, the scientists say.

The results' relevance may go well beyond explaining the epidemic of tangled venetian blind cords. That's because spontaneous knots seem to be prevalent in nature, especially in biological molecules. For example, knottiness may be crucial to the workings of certain proteins (see "Knots in Proteins"). And knots can randomly form in DNA, hampering duplication or gene expression--so much so that living cells deploy special knot-chopping enzymes.

Raymer's interest in knots began as an answer waiting for a question. Two years ago, he was an undergraduate student working in Smith's lab at the University of California, San Diego (UCSD). Raymer fancied taking a class about the abstract theory of knots, offered by UCSD's math department. Smith told him that he should take it only if he could find a practical use for it--some kind of knot experiment.

Raymer never took the class, but he and Smith did come up with a simple idea for an experiment. They put a string in a cubic container the size of a box of tissue. By tumbling the box 10 times "like a laundry dryer," as Raymer puts it, the researchers hoped to observe knots forming spontaneously on occasion. They didn't have to wait for long: Knots formed right away. "The first couple of times, it was pretty amazing," Raymer says.

The researchers repeated the procedure more than 3,000 times, and knots formed about every other time. Longer strings, or more-flexible strings, tended to knot more often.

The researchers took pictures, planning to gather precise statistics of the types of knots that were forming. Raymer soon realized that, to make sense of the mess, he'd need to teach himself the mathematics of knots after all.

Ready-made tools

The theory of knots began in earnest in the 1860s, under the stimulus of the British physicist William Thomson, later known as Lord Kelvin. Kelvin suggested that atoms of different elements were really different kinds of knotted vortices in the ether. So to lay the foundations of chemistry, he believed, it was imperative to classify knots. Ultimately, physicists discovered that the ether didn't exist. But mathematicians took an interest in knots for knots' sake, as part of the young branch of mathematics called topology.

Topology studies shapes. Specifically, it studies shapes' properties that are not affected by stretching, moving, twisting, or pulling--anything that doesn't break up the object or fuse some of its parts. The proverbial example is that, to a topologist, a coffee mug is the same as a doughnut. In your imagination, you can squash the mug into a doughnut shape, and it will retain the property of having a hole, namely its handle.

A sphere is different. You can stretch a sphere into a stick and bend the stick so its ends touch. But turning that open ring into a doughnut will involve fusing the ends, and that's forbidden.

In topology, a knot is any curved line that closes up on itself, possibly after a circuitous path in three dimensions. A circle is regarded as the "trivial" knot. Two loops are considered to be the same knot if you can turn one into the other by topological manipulation, which in this case means anything that does not break the curve or force it to run through itself.

Topologically, a knotted string is not a real knot, as long as its ends are free. That's because either of the ends can always thread back through any entanglement and undo the knot. An open string, no matter how garbled, is the same as a straight segment. (Mathematicians usually think of strings as being stretchable and infinitesimally thin, so in topology there is no issue of a knot being tight.)

Strictly speaking, then, the string in Raymer and Smith's box was never knotted. But it was still a mess. When the researchers joined the string's ends, they made it into a closed loop, often something that even a mathematician would call a knot.

Raymer soon realized that telling different knots apart, or recognizing when two knots are the same is a tricky business. Topologists usually work with two-dimensional drawings of knots called knot projections. From different points of view, the same curve will look different and so will its projections. Topologists' best tools for distinguishing knots are algebraic expressions called knot polynomials. These are sums of multiples of a variable, such as x, raised to different powers. The variable has no meaning per se, and all the information is in the numbers by which it's multiplied. But the x's make it easier to calculate a knot polynomial starting from a knot projection.

James Alexander, a Princeton University mathematician, invented the first knot polynomial in the 1920s. Two topologically equivalent knots always will give the same Alexander polynomial, no matter how different their projections look. So if two knots have different polynomials, they're certainly nonequivalent. The converse, however, is not true: Some distinct knots have the same Alexander polynomial. That means that the Alexander polynomial is not a fail-safe way of distinguishing knots.

In the early 1980s, Vaughan Jones of the University of California, Berkeley rekindled mathematicians' interest in knots when he defined a new kind of knot polynomial, a discovery that earned him the Fields Medal, the most coveted prize in mathematics. The Jones polynomials distinguish knots with greater, if not complete, accuracy than the Alexander polynomials. That made the Jones polynomials Raymer's choice to catalog his knots.

Tie land

Raymer wrote a computer program to calculate Jones polynomials from the pictures he had taken each time he opened the box. The program found that the humble box had produced at least 120 distinct types of knots. Some were pretty complex.

The most basic measure of knot complexity is the minimal crossing number, the number of overpasses needed to draw the simplest possible projection of the knot. For the trivial knot, that number is zero. The simplest true knot, the trefoil requires that just three crossings be drawn. A few of the knots from the tumbling box required as many as 11, Raymer and Smith report in the Oct. 16 Proceedings of the National Academy of Sciences

Raymer says he and Smith were surprised, because previous knot experiments--physicists have tried a few in recent years--had seen only some of the simplest knots. For example, in 2001 Belmonte and his collaborators showed that a hanging chain (not from Belmonte's venetian blinds) tended to knot up when shaken. In 2006, a team led by physicist Jens Eggers of the University of Bristol in England got a ball chain to form knots by setting it on a vibrating dish.

De Witt Sumners, an applied mathematician at Florida State University in Tallahassee, says he was not surprised that knots would form in a box. In computer simulations, mathematicians have found that random motion creates paths that almost always tie themselves up. Together with Stu Whittington of the University of Toronto, Sumners demonstrated mathematically in 1988 that if you wait long enough, these random walks will get knotted virtually 100 percent of the time.

Sumners suspects that with longer tumbling, Raymer and Smith would have gotten knots almost always, instead of just every other time. "They should have spun longer," to see the full effects, Sumners says.

In their paper, on the other hand, Raymer and Smith propose a theoretical explanation for the mess in their box that differs from the most general type of random walk. Because their string tended to coil up whether or not it formed knots, they created a mathematical model of a bundle of coils as a series of parallel, horizontal strands. In a computer simulation, Raymer and Smith allowed one of the strands--representing one of the free ends of the string--to cross over or under one of the others in the bundle. After several such steps, the strands had braided, which often meant that the string as a whole was now knotted.

This simplified model didn't reproduce the exact results of their experiment, but it did predict that specific knots had about the right odds of forming within the allowed time.

Jam-packed

Belmonte calls the braid model "very obvious, but maybe not universal," meaning that different physical phenomena probably tie knots in different ways. In bacterial DNA, for example, one way that knots can form is by genetic recombination. That's when, to facilitate the reshuffling of genes, enzymes cut DNA at two places and reattach the ends in a different order. Bacterial genomes are circular, so recombination can produce veritable knotted loops.

In the late 1990s, biochemists discovered enzymes that seem able to detect when DNA has a knot. The enzymes then undo the knot by brute-force cut and paste.

Keeping DNA tidy may be crucial to some of the cell's most important functions. That's because copying DNA and reading out the information it contains are performed by other enzymes, called polymerases, which walk along DNA. "When [a polymerase] comes to a knotted area, it will be stuck," Belmonte says.

Scientists have discovered similar knot-busting enzymes in cells that have open-string chromosomes, such as in humans. The presence of such enzymes suggests that knotting may be an issue for human chromosomes as well. And scientists have also found knots in mitochondria, cellular organelles that contain loop DNA.

Another place where DNA knots can form is inside viruses, says Andrzej Stasiak, a structural biologist at the University of Lausanne in Switzerland. Viruses build containers called capsids in which the viruses tightly pack their DNA for traveling from one host cell to the next. In some viruses, the capsid keeps DNA at a pressure of more than 60 atmospheres.

Stasiak says that the packing process probably produces coiling similar to that seen by Raymer and Smith. Their coil-and-braid model could help explain why the DNA of some viruses often ends up being knotted.

But even if Raymer and Smith's results don't prove to be directly relevant to the molecules of life, they are "a very good beginning" for a general study of physical knots, according to Belmonte. "Now we can at least ask these questions: Are there universal laws of knots?"

Re:Slashdotted article text (0)

Anonymous Coward | more than 6 years ago | (#21857438)

"By tumbling a string of rope inside a box, biophysicists Dorian Raymer and Douglas Smith have discovered that knots--even complex knots--form surprisingly fast and often. The string first coils up, and then its free ends swivel around the other coils, tracing a random path among them. That essentially makes the coils into a braid, producing knots, the scientists say."

Summary: Putting strings inside a box and shaking it around makes them become knotted together surprisingly fast. This is due to the knot force.

Wrong title (0)

Anonymous Coward | more than 6 years ago | (#21858626)

Shouldn't the title be something like "How often do knots spontaneously form"? The experiment doesn't give any new information on why knots form. On the other hand it may give some information of how fast the knots form and the probability of knots at equilibrium.

All knotted up for next year. (5, Funny)

theleoandtherat (1115757) | more than 6 years ago | (#21857042)

Any tip about packing christmas lights?

Wrap them (4, Informative)

Chmcginn (201645) | more than 6 years ago | (#21857162)

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.

Re:All knotted up for next year. (1, Informative)

Anonymous Coward | more than 6 years ago | (#21857330)

Real Simple has a great list [tinyurl.com] of holiday organization tips, including this one which tackles the problem of Christmas lights.

Re:All knotted up for next year. (4, Informative)

SimonTheSoundMan (1012395) | more than 6 years ago | (#21857374)

Google 'reverse coil' or 'overhand coil'. Wires tangle because people do not know how to coil them up correctly.

Re:All knotted up for next year. (1)

Phroggy (441) | more than 6 years ago | (#21857676)

Those didn't help at all. Do you have a more specific link?

Re:All knotted up for next year. (0)

Anonymous Coward | more than 6 years ago | (#21857788)

For those who need to actually do things.

Google on coiling rope ropes

http://www.ehow.com/how_2126422_coil-rope-line.html [ehow.com]

Re:All knotted up for next year. (0)

Anonymous Coward | more than 6 years ago | (#21857692)

Exactly. As I learned during an internship "don't force the cable to wind up tightly, it'll break it, let it tell you how it wants to be winded up". Which means if you're blessed with at least some amount of fine motor skills, you'll feel when the cable is winded up right.

Re:All knotted up for next year. (1)

kestasjk (933987) | more than 6 years ago | (#21858060)

But the wires aren't moving! How can they tangle up if they're not moving?? How can a box of Christmas lights left for a year in a closet get more tangled up than they were when placed in the closet?

Someone should make a time sequence film of Christmas wire tying itself in knots.

Re:All knotted up for next year. (1)

Kutsal (514445) | more than 6 years ago | (#21858436)

When I do that (i.e, Google "overhand coil"), I get this article, which tells me to Google "overhand coil" and when I do that, I get this article again..... Aaaah...

Oh!.. Wait..

How very subtle; what a perfect example of a knot... ;)

Re:All knotted up for next year. (2, Informative)

Leebert (1694) | more than 6 years ago | (#21859092)

Try this, it should get you started:

http://en.wikipedia.org/wiki/Over/under_cable_coiling [wikipedia.org]

(having myself wrapped probably hundreds of miles of cable with this technique.)

Re:All knotted up for next year. (1)

gstoddart (321705) | more than 6 years ago | (#21858722)

Google 'reverse coil' or 'overhand coil'. Wires tangle because people do not know how to coil them up correctly.

Oddly enough, as of 3:16pm EST, googling for 'overhand coil' -- the second search result on google is this thread.

Sadly, I think now simply mentioning an uncommon term on Slashdot is enough to completely skew search results since Slashdot rates so damned high.

Too odd. :-P

Cheers

Re:All knotted up for next year. (1)

BooRolla (824295) | more than 6 years ago | (#21859512)

So I did the search and I found your search request as the 2nd link.

http://www.google.com/search?hl=en&q=overhand+coil&btnG=Search [google.com]

Since I was sent here by google, you must be the expert. Can you explain the method?

ps- I'm impressed google spidered that so quickly.

Re:All knotted up for next year. (1)

Wellington Grey (942717) | more than 6 years ago | (#21859612)

How odd. The google result for "overhand coil [google.co.uk] " lists your post at #2 mere hours after you posted it. The overhand coil must not be a popular method.

-Grey [silverclipboard.com]

Re:All knotted up for next year. (1)

WallaceAndGromit (910755) | more than 6 years ago | (#21857720)

I have found that if you roll each strand up, and place each strand in a separate plastic grocery bag (the type that they bag your food in at the store), then place the bagged strands into a box, they do not tangle. Makes it much easier on yourself the next year.

Re:All knotted up for next year. (3, Informative)

gbutler69 (910166) | more than 6 years ago | (#21857738)

I've found that rolling them up in a ball, like one would yarn, works absolutely perfectly. It never tangles. It's compact. It's easy. It seems a little counter-intuitive, but, if you think about it, why do women who knit or crotchet wrap their yarn in balls? Because it works!

Re:All knotted up for next year. (0, Troll)

LilGuy (150110) | more than 6 years ago | (#21859784)

Hmm, I assumed it was some kind of reminder as to why they were knitting or crocheting in the first place.

Re:All knotted up for next year. (1)

rubah (1197475) | more than 6 years ago | (#21858104)

we use sheets of cardboard 8)

I kid you knot? (1)

lorg (578246) | more than 6 years ago | (#21857056)

I wonder if this will explain why the cord on my phone, mouse and headphones always gets tangled up ...

Do we really need an answer? (5, Funny)

pla (258480) | more than 6 years ago | (#21857096)

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?

Re:Do we really need an answer? (1)

fuego451 (958976) | more than 6 years ago | (#21857766)

Great and Manifold are the Blessings of his Holy Pastaness but I don't recall the simplest overhand knot in hundreds of pots of spaghetti that I have cooked. Perhaps I should reevaluate my faith and say some Hail Marinaras .

Proof of His Power!! Proof! (1)

TheCouchPotatoFamine (628797) | more than 6 years ago | (#21858422)

There is no parallel to this miracle even as mysterious as transubstantiation itself! It is He that keep the pasta flowing! He that make it slide!

*bells ringing in the streets* we have proof! *bells ringing in the streets*

Re:Do we really need an answer? (1)

ExploHD (888637) | more than 6 years ago | (#21859112)

Beware! The Anti-Pasta is coming!

Yes, but what about shoe laces, huh? (5, Funny)

Prototerm (762512) | more than 6 years ago | (#21857164)

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.

Re:Yes, but what about shoe laces, huh? (2, Informative)

Jugalator (259273) | more than 6 years ago | (#21857248)

but what about the way knots spontaneously come undone in your shoe laces?
That's often because they're in that case an unbalanced granny knot [kovaya.com] . :-)

Re:Yes, but what about shoe laces, huh? (3, Interesting)

Tony Hoyle (11698) | more than 6 years ago | (#21857320)

What gets me is how knots form when both ends of the cable are plugged into something. And they form in such a way that there's no way to untangle it without unplugging everything and painstakingly unpicking it from the mess.

Re:Yes, but what about shoe laces, huh? (1)

RealGrouchy (943109) | more than 6 years ago | (#21857944)

The answer to that is in String Theory. You see, in 11-dimensional space-time, the entire universe folds over itself, leaving the seemingly paradoxical knots you mention as the only trace.

- RG>

Re:Yes, but what about shoe laces, huh? (4, Informative)

Anonymous Coward | more than 6 years ago | (#21857408)

Shoelaces come undone due to the type of knot being used. There is an entire site http://www.shoeknots.com/ [shoeknots.com] devoted to this, and another site http://shoelaceknot.com/shoelace/index.htm [shoelaceknot.com] with exhaustive details on shoelaces in general.

[disclaimer: I maintain one of the sites]

Re:Yes, but what about shoe laces, huh? (1)

ScrewMaster (602015) | more than 6 years ago | (#21857440)

[disclaimer: I maintain one of the sites]

If we guess which one do we get a free pair of shoelaces?

Re:Yes, but what about shoe laces, huh? (1)

Lord Bitman (95493) | more than 6 years ago | (#21857482)

Why are you still wearing shoes with laces? Technology has progressed beyond the need for such archaic devices.

Re:Yes, but what about shoe laces, huh? (1)

satoshi1 (794000) | more than 6 years ago | (#21857954)

Because velcro looks silly.

Re:Yes, but what about shoe laces, huh? (1)

Eric52902 (1080393) | more than 6 years ago | (#21858470)

Yeah, nothing says, "suave, classy and sophisticated," like the smooth tearing sound of Velcro shoe straps...

Re:Yes, but what about shoe laces, huh? (0)

Anonymous Coward | more than 6 years ago | (#21857892)

"The tips at the end of shoelaces are called 'aglets'. Their true purpose is sinister."

The Question, Justice League Unlimited, "Question Authority"

simple solution... (1)

mangu (126918) | more than 6 years ago | (#21858064)

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?

I tie my shoes with wires and cables. The only problem is when I want to take them off...

Re:Yes, but what about shoe laces, huh? (1)

sjhs (453964) | more than 6 years ago | (#21858324)

Posts like this make me wish moderation scores went above +5.

Re:Yes, but what about shoe laces, huh? (1)

MarkRose (820682) | more than 6 years ago | (#21859036)

I used to have this problem for years, until I learned a simple trick: tie the knot backwards (left-over-right instead of right-over-left or vice-versa). When the string in the knot and the bow run parallel to each other, the increased friction holds the bow together.

tagged (1)

Digitus1337 (671442) | more than 6 years ago | (#21857350)

!knotcometonaught = notknotcometonaught?

Fishing line (3, Funny)

Eudial (590661) | more than 6 years ago | (#21857358)

Fishing line is epic.

It can be straight, but the moment it comes into contact with anything, or disappears outside of the line of view, or for no apparent reason at all, it's a virtual loom of spontaneous knots.

Re:Fishing line (1)

Watson Ladd (955755) | more than 6 years ago | (#21857854)

That's because applying a forgetful functor to an epic results in multiple morphisms in the preimage connecting the ends of the arrow, hence loops in the graph.

Re:Fishing line (1)

GrEmLiN76X (1130251) | more than 6 years ago | (#21858194)

True story.. I remember one time as a yougin' off to Grandma's house, I had my fishing pole with me. Now, for some silly reason I had a bunch of fishing line running through all of the loops going up the pole, instead of reeled in and simply tied off at the end like it should have been. I must have had twenty or thirty strands of line looped between the eyelets on the pole. I leaned the pole up against the screen door and walked away for a moment, and when I came back, I went to grab the pole and open the door, and every strand of fishing line had been wrapped on the under side of the door handle! The door handle looked something like this: |] but without the gap at the top and bottom. There was NO way to pass anything behind it. Yet every strand had somehow passed through the door handle and I had to untie and deloopify about fifteen feet of fishing line. I was there for a good ten minutes trying to figure it out. The whole rod never left my sight when I walked away. Nobody ran up and untied it and tediously wrapped it all back around the fishing rod, passing every strand behind the door handle as if it were some sort of sick prank. I honestly never figured that one out...

Science meets philosophy. (0)

Anonymous Coward | more than 6 years ago | (#21857432)

In this case it began with the same question:

Why knot?

Re:Science meets philosophy. (1)

ScrewMaster (602015) | more than 6 years ago | (#21857460)

No, that's knot the question.

Re:Science meets philosophy. (1)

c6gunner (950153) | more than 6 years ago | (#21858382)

Do or do knot, there is no twine.

Easy explanation. (0)

Anonymous Coward | more than 6 years ago | (#21857454)

Subatomic particles are actually microscopic Boy Scouts.

knotted Apples (1)

owlnation (858981) | more than 6 years ago | (#21857480)

Despite being pretty much a Macfan boy I have one MAJOR irk with Apple -- the stuff they make all their cable out of. It has to be the most knottable substance known to mankind.

Every single time I pick up the earphones from my iPod they are knotted. I am very careful to wrap them in a way I think they will stay unknotted, but every time, every time, they are knotted again.

Drives me nuts.

Doesn't anybody know how to tie a knot? (2, Interesting)

CaptScarlet22 (585291) | more than 6 years ago | (#21857544)

Spongebob: Doesn't anybody know how to tie a knot? (lightning appears as well as the Flying Dutchman)

Flying Dutchman: Did somebody say knot?

Spongebob: (eyes grow large) I did.

Flying Dutchman: So, you wanna tie knots, do ya? Well, do ya?

Spongebob: Yes, please, Mr Flying Dutchman, sir.

Flying Dutchman: Then you've come to the right flying ghost, kid. You're looking at the first place winner in the fancy knottin' contest for the last 3,000 years!

Spongebob: Hooray! (floats up into the air and into a heart)

Flying Dutchman: (grabs Spongebob) You're gonna have to not do that. And stop staring at me with them big old eyes! (Spongebob's eyes shrink) Now, stand back and watch me be knotty. (laughs and pulls out a rope) Haha! Behold! (rope is in pretzel shape) The pretzel knot!

Spongebob: Ohh. (Flying Dutchman makes the rope into 2 diamonds)

Flying Dutchman: The double-diamond knot! (holds the rope, now in the shape of a square, in front of Spongebob) The square knot! (rope slithers over and squeezes Spongebob) The constrictor. (Grabs Spongebob and pulls him apart revealing a knot that looks like intestines) The gut knot! (Flying Dutchman makes a knot in the shape of a pillow) The pillow knot. (turns the knot over where Spongebob is sleeping. Then he makes the knot into a butterfly) The butterfly knot.

Spongebob: Ohh...

Flying Dutchman: Wait! There's more. (Spongebob takes out a pen and paper and his glasses) The monkey chain! (shows the rope as a chain) The monkey's fist! (shows the rope into a ball) The monkey! (shows the rope as a monkey)

Monkey: Ohh, ohh!

Flying Dutchman: This one here's a loop knot, otherwise known as the 'poop loop'. (pulls the rope)

Rope: Poooop!

Spongebob: (laughs) Those are great, Mr Flying Dutchman, sir! Now can you show me how to tie my shoes?

Flying Dutchman: (laughs) I don't know how to tie me shoes. I haven't worn shoes for over 5,000 years! (holds a sock with two blue stripes up) But sometimes I like to wear this little sock over me ghostly tail. (laughs as he flies off. Scene cuts to Spongebob crawling into his pineapple)
No need to RTFA, I bet the Flying Duchman would know...we should ask him!!

Loose ends cause most of the trouble... (5, Interesting)

jddj (1085169) | more than 6 years ago | (#21857590)

As a kayaker, I'm familiar with a rescue tool called a throw bag [riversafe.org.nz] . 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:

  • Tie a rope through a hole in the bottom of a bag.
  • Stuff the bag with the rope, leaving the tail end of the rope sticking out of the top.
  • Grab the tail end of the rope and throw the bag towards the person who needs the rope.
  • Watch as the rope magically pays out of the bag, completely free of knots or tangles.
  • Don't get so awed by the rope coming out untangled that you let go of the end...

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!

Re:Loose ends cause most of the trouble... (1)

blackest_k (761565) | more than 6 years ago | (#21857736)

thats an interesting point,

  wonder if anyone does this for computer cables I guess you could get a similar effect with a sheet of paper and a couple of elastic bands create a paper tube poke in the wire seal it with 2 elastic bands or a couple of paper clips

yes it seems to work

Re:Loose ends cause most of the trouble... (0)

Anonymous Coward | more than 6 years ago | (#21858056)

Awesome, I'll store all my wired Hardware in a throw bag. Each.

Re:Loose ends cause most of the trouble... (1)

GrEmLiN76X (1130251) | more than 6 years ago | (#21858274)

Like someone else mentioned, how do computer cables still seem to knot when BOTH ends are plugged into something?

I'm looking down at my headphone cord right now and its knotted and tangled around a microphone cord, and a couple of data/power cables. Everything is plugged in at both ends and the cables almost never get moved around. But that won't stop them from tangling!

Re:Loose ends cause most of the trouble... (1)

Danny Rathjens (8471) | more than 6 years ago | (#21859306)

I think that has to do with torsion(twisted pairs of wires unwinding?) and the multi-material composition of wires as opposed to ropes made of a single woven material(I've never seen braids twist, just loosen).

Re:Loose ends cause most of the trouble... (1)

c6gunner (950153) | more than 6 years ago | (#21858354)

Neat. We used the same idea for rappelling out of choppers - just drop the bag, attach your carabiner, and off you go.

Re:Loose ends cause most of the trouble... (1)

cshake (736412) | more than 6 years ago | (#21859246)

Those are also used by rock climbers, and is commonly referred to as 'flaking' the rope. When you get to the bottom of the face, you open the rope bag and can just pull on one end. When you're done, just pull the sheet out of the bag, tie one end to a loop in the rope bag, then throw the rest on to the sheet an arm's length at a time. Most good rope bags come with two different loops to tie to that are easily distinguished, so you know which end is the 'top' of the pile.

Then you just take the sheet, roll it into the bag, and you've got a rope completely free of tangles that is also rolled in a waterproof bag on all sides, even under the bag's zipper. Can't get much easier than that.

Metolius Rope Bag [mountaingear.com]

Knotted DNA? (1)

rotenberry (3487) | more than 6 years ago | (#21857700)

The photo of the DNA in the article does not appear knotted to me. Does anyone have a link to a DNA image that is truly knotted?

It looks knotted to me (1)

tinkerton (199273) | more than 6 years ago | (#21858560)

If you go clockwise from the top the thread goes over a thread, then under, over, under, over and under to get back to its starting point.
Once you agree with that, I think the string can't be twisted to become an simple loop.

There is an interesting feat of DNA more or less counter to the example given: how a chromosome manages to unfold into a string with length of the order of centimeters during cell division without getting completely entangled.

Re:Knotted DNA? (0)

Anonymous Coward | more than 6 years ago | (#21858650)

If you follow the strand and look at it closely enough, you'll see that it alternately goes over and under; it's not just lying in loops.

Knot-unknot asymmetry (4, Insightful)

SpinyNorman (33776) | more than 6 years ago | (#21857772)

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?!

Re:Knot-unknot asymmetry (0)

Anonymous Coward | more than 6 years ago | (#21859266)

This knot idea might be a philosophical truth, as much as evolution can be said to be: Evolution occurs when there is an imperfect replicator which creates non-identical copies which replicate differently than their parents.

Knots might just simply be part of life in 3-space for reasons you state: any frictiony, limp "string" experiences a knot ratcheting effect and greaterer difficulty with spontaneous knot unraveling than tying.

I wonder how differently, if at all, the article experiment outcome would have been were the experiment performed in freefall (or "zero-G").

So this is where string theory leads us? (3, Funny)

rickb928 (945187) | more than 6 years ago | (#21857796)

How hard is this? The Universe is a box full of string. Knots form. Some make pretty big knots.

Eventually, when the chimps write a decent but unpopular novel, balls of string form. Many balls. In time, these seem to have gathered and caused all sorts of interesting phenomenae, like stars, Western clothing, and Jessica Alba.

Unfortunately, this can only end one of two ways...

1- The string gets untangled. All devolves into a box of string again. Knots form again.

2- All this gets emptied into another box. Sold at a yard sale. Who knows what happens with the new owner... Actually, even if the string gets untangled, it ends up in a yard sale.

Physics. It's really all about yard sales.

Knots, you say? (1)

Bootarn (970788) | more than 6 years ago | (#21858066)

Does this also explain why shoelaces tie themselves into knots while I'm sleeping? I have long suspected my cat, but I guess science has a better explanation...

whatknot (1)

slothman32 (629113) | more than 6 years ago | (#21858204)

I read along time ago baton a whatknot. It's supposed to be what flat "ropes" like seatbelts become. Anybody know what I am talking about?

Re:whatknot (0)

Anonymous Coward | more than 6 years ago | (#21859324)

What?

Spontaneous Knots? (1)

TimeSpeak (873865) | more than 6 years ago | (#21858284)

A foundation for proof of the String Theory!
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