Mystery unravelled: Headphones can form 120 'complex knots' in your pocket because loose ends weave through coiled strands

Physicists tumbled a string in a box 3,415 times to investigate tangling

They used a computer simulation to identify 120 different types of knots

The loose ends of a string or headphone wire weaves through coils that tend to form in confined spaces 'within seconds'

Study of knotting is of interest in mathematics and in DNA biochemistry



Confirming what music fans have thought since they got their first Walkman, it takes just seconds for headphones to tangle inside a bag or pocket.



Using computer simulations, a team of physicists have unravelled exactly why the wires get so tangled, so quickly - and it’s all to do with coils.



When shaken up, the wires form coils and the loose end weaves though the other strands, creating the annoying knots.



Not music to your ears: Physicists have unravelled why wires get tangled up within seconds. When shaken up in a confined space, the wires from coils and the loose end weaves though the other strands, creating an annoying knot (pictured)

THE TUMBLING EXPERIMENT The string was held vertically above the centres of a box and dropped in randomly.

It was then gently rotated to tumble the contents.

After tumbling the box was opened and the ends of the string were joined to preserve the knots created.

A digital photo was taken whenever a complex knot was formed.

The experiment was repeated hundreds of times with each string length to collect statistics, which were collected and interpreted using a computer simulation.

The physicists identified 120 different types of knot and the string crossed a minimum of 11 times in 3,415 trials.

Experts from the University of California, San Diego, investigated the probability of knotting, the type of knots formed and the dependence on string length in their study.



Dorian Rayner and Douglas Smith confirmed that ‘complex knots often form within seconds’ and that stiffer wires are slightly less likely to form such mind-boggling tangles.



The physicists ‘tumbled’ a string inside a box to prove knots form in seconds.



They then used a mathematical knot theory to analyse them - instead of getting bad tempered and pulling at them indiscriminately, which is a popular method for untangling headphones.



They analysed digital photos of the string at different points of knotting and found that almost all the weaves were identified as ‘prime knots.'



The other string theory: The physicists said that stiffer wires are less likely to form such mind-boggling tangles. They tumbled a wire in a box hundreds of times, then used a mathematical knot theory to analyse them. Pictured are two examples of the string before (pictured left) and after tumbling (pictured right)

A total of 120 different types of knot were identified and the wire crossed a minimum of 11 times in 3,415 trials.



After studying all the different combinations, the physicists found that strings tend to form a coiled structure when they are confined in a space and the tangling results from the lose end weaving between the coiled strands.



Interestingly, the tightness of a coil corresponds ‘not perfectly, but to some degree,’ with the radius of the confined space, according to the study, which was published in PNAS.



Physicists are interested in knots as they play a role in many scientific fields including quantum field theory and DNA biochemistry.



Knotting and unknotting of DNA molecules occurs in living cells and viruses and has been extensively studied by molecular biologists and in mathematics, knot theory has been an active field of research for more than a century.