question: Why do headphones get so tangled up so easily?
comment: It's because of statistics, imagine that you put your headphones in a tiny washing machine, There are only a couple of hundred arrangements of those headphones that are in a non tangled state. However there are infinitely many arrangements where your headphones are just one big knot. Those headphones that claim that are less prone to getting tangled only do this because they have flat wires. Essentially restrictions one axis of "tangle". So the possible states of tangled get reduced. If you were to make them into rods instead of wires, you would restrict the degrees of motion. And thus the outcome is 99.999% certain it won't be tangled
passages: Introducing a continuous helical groove onto the drum, like the thread of a screw, provides a way to guide the rope when spooling onto or off a drum. However this has been shown to work effectively only when the rope is wrapped in a single layer. When the rope is wrapped in multiple layers, problems remain.
   Because the mechanically interlocked structures are maintained by bulky stoppers at the ends of the strings, if the bulky stoppers are removed, such as removed by a chemical stimulus, rings dethread from the axes. The drastic structural change can be used for programmed drug or gene delivery, of which drug or gene can be released with the rings when the stoppers are cut off at the specific destination.
   Braided ropes (and objects like garden hoses, fibre optic or coaxial cables, etc.) that have no "lay" (or inherent twist) uncoil better if each alternate loop is twisted in the opposite direction, such as in figure-eight coils, where the twist reverses regularly and essentially cancels out.
   BULLET::::- Unclosed loose string subgroup: The pieces of string are not closed, and are not attached to the wire. In this case the ends of the string are fitted with a ball, cube or similar which stops the string from slipping out too easily. Usually the string has to be disentangled from the wire. Sometimes other tasks have to be completed instead, such as shifting a ring or ball from one end of the string to another end.
   It has a 3.5mm TRS connector socket for standard headphones, and takes a TRRS connector (like the iPhone) for stereo headsets. The phone can also be operated in this manner, however loose connections can cause it to randomly stop, skip to another song, or even beep very loudly and redial without permission, even with a regular pair of headphones that does not have these features. There is also no setting available to defeat this behavior, which occurs even with the switch in the locked position.
   Like threadless headsets, threaded headsets can also be internal. Under the internal design, the races and cones are embedded into the head tube, creating a tidy, streamlined appearance. No component is visible between the fork crown and head tube except for perhaps a plastic ring, and only the locknut protrudes from the top of the head tube. In the image shown of the 2016 Brodie Quantum's steering assembly, the lock nut is hidden from view by a plastic cover. The widened top and bottom sections of the head tube contain the bearings. A quill stem inserts into the steering tube.
   Another common substitute is the back of a chair. The disadvantages of this is that the hank is not kept under tension, and thus the yarn has a tendency to get tangled, and one has to stop very often to untangle it.
  
  Section::::Uses.
   Wire rope spooling technology
  
  Wire rope spooling-Technology is the technology to prevent wire rope getting snagged when spooled especially in multiple layers on a drum.
  
  Section::::History.
  
  Ever since the development of wire rope, comprising multiple wire strands, spooling the wire has presented technical challenges. When wrapped in multiple layers, the upper layers have a tendency to crush the lower layers, while the lower layers have a tendency to pinch upper layers. The rubbing of rope against rope also has a tendency to cause wear.
   BULLET::::- Some compact and/or economy model audio mixing desks use stereo jacks for balanced microphone inputs.
  
  BULLET::::- The majority of professional audio equipment uses TS jacks as the standard unbalanced input or output line-level connector. TRS jacks are sometimes used for balanced connections, the latter often alongside (or sometimes in the middle of) and as an alternative to an XLR balanced line connector.
  
  BULLET::::- Modular synthesizers commonly use monophonic cables for creating patches.
   Section::::Knot tying.:Material.
  
  The form of the material will influence the tying of a knot as well. Rope is round in cross-section, and has little dependence upon the manner in which the material is tied. Nylon webbing, on the other hand, is flat, and usually "tubular" in construction, meaning that it is spiral-woven, and has a hollow core. In order to retain as much of the strength as possible with webbing, the material must be tied "flat" such that parallel sections do not cross, and that the sections of webbing are not twisted when they cross each other within a knot.
   Older recording hardware could suffer flanging as a side effect when recording long tracks. As the weight of the tape built on one reel, the pressure on the capstans caused flanging in mixdown or dubbing. This was a problem faced by studio engineers in the 1960s and 1970s when recording large concept pieces, as explained by Ian Anderson of Jethro Tull when recounting the studio challenges of recording "Thick as a Brick".
   There are an enormous number of different ways in which a chain can be curled around in a relatively compact shape, like an unraveling ball of twine with lots of open space, and comparatively few ways it can be more or less stretched out. So, if each conformation has an equal probability or statistical weight, chains are much more likely to be ball-like than they are to be extended — a purely entropic effect. In an ensemble of chains, most of them will, therefore, be loosely balled up. This is the kind of shape any one of them will have most of the time.
   BULLET::::5. Twisted pair wiring – Twisting wires in a circuit will reduce electromagnetic noise. Twisting the wires decreases the loop size in which a magnetic field can run through to produce a current between the wires. Small loops may exist between wires twisted together, but the magnetic field going through these loops induces a current flowing in opposite directions in alternate loops on each wire and so there is no net noise current.
   As long as the clove hitch can feed over the drum, the rope will feed through the device. In a fall, the drum is back driven by the rope as the device slides down the rope; when the drum rotation exceeds a certain angular velocity, it locks off to the frame and the increase in friction induced between the stationary drum and the rope causes the clove hitch to rapidly tighten around the locked drum to arrest the fall.
   By chemically crosslinking the rings contained in the polyrotaxanes, sliding gels are obtained by being topologically interlocked by figure-of-eight crosslinks. Although it is a polymer network (gel), the rings are not fixed on the polyrotaxanes in the polymer network, the crosslinks of rings are able to freely move along the polymer chain. This can equalize the tension of the network, just like a pulley manner, which is referred to pulley effect. In chemical gels, the polymer chains are easy to be broken because the lengths of the heterogeneous polymer are limited or fixed. As a result, when the chemical gel is under a high pressure, the tension can not be equalized to the whole. On the opposite, the weakest part in the network will be broken easier, which leads to the damage of the gel. However, in the slide-ring materials, the polymer chain are able to pass through the figure-of-eight crosslinks which is like pulleys, and equalize the tension of network. As a result, slide-ring materials are applied to construct highly stretchable materials, up to 24 times its length when stretching and this process can be reversible.
   Because of a lack of standardization in the past regarding the dimensions (length) given to the ring conductor and the insulating portions on either side of it in 6.35 mm ( in) phone connectors and the width of the conductors in different brands and generations of sockets, there are occasional issues with compatibility between differing brands of plug and socket. This can result in a contact in the socket bridging (shorting) the ring and sleeve contacts on a phone connector.
  
  Section::::General use.
   BULLET::::- Unclosed fixed string subgroup: The pieces of string are not closed, but are somewhere on its length attached to the wire. In these puzzles the string is not to be disentangled from the wire. One possible task may be to shift a ring or ball from one end of the string to another end.
   Section::::Design.
  
  BULLET::::- Notes:
  
  Section::::Design.:Balanced audio.
   The original purpose of these contacts was for switching in telephone exchanges, for which there were many patterns. Two sets of change-over contacts, isolated from the connector contacts, were common. The more recent pattern of one NC contact for each signal path, internally attached to the connector contact, stems from their use as headphone jacks. In many amplifiers and equipment containing them, such as electronic organs, a headphone jack is provided that disconnects the loudspeakers when in use. This is done by means of these switch contacts. In other equipment, a dummy load is provided when the headphones are not connected. This is also easily provided by means of these NC contacts.
   Nyloc nut
  
  A nyloc nut, also referred to as a nylon-insert lock nut, polymer-insert lock nut, or elastic stop nut, is a kind of locknut with a nylon collar insert that resists turning.
   The ball of yarn formed by a nostepinne is a "center pull" ball, allowing the knitter to remove the working yarn from the center of the ball rather than the outside. This keeps the yarn from rolling around the surface the yarn is sitting on and provides a more consistent tension. These center-pull balls are called "cakes" because of their short, cylindrical shape.
   Honda knot
  
  A honda knot is the loop knot commonly used in a lasso. Its round shape, especially when tied in stiff rope, helps it slide freely along the rope it is tied around. To tie, first place an overhand knot in the end of the rope. Then tie a second overhand knot, pass the running end of the rope through it, and tighten.
   Robert Croak, owner of Toledo, Ohio-based BCP Imports (known for distributing the Livestrong wristbands), encountered the bands on a business trip and decided to re-purpose them as a toy by making them larger and thicker, and marketing them as a kids' fashion accessory.
  
  Section::::Distribution and reception.
   Ball or spherical joint requires that a point in the moving body maintain contact with a point in the fixed body. This joint has three degrees of freedom.
  
  Section::::Wrapping pair/ Higher pair.
  
  A wrapping/higher pair is a constraint that comprises belts, chains, and such other devices. A belt-driven pulley is an example of this pair.
  
  In this type of which is very similar to the higher pair(which is having point or line contact), but having multiple point contact.
  
  Section::::References.
  
  BULLET::::- Hartenberg, R.S. & J. Denavit (1964) Kinematic synthesis of linkages, pp 17,18, New York: McGraw-Hill, online link from Cornell University.
   3-pin XLR connectors and quarter-inch (¼" or 6.35 mm) TRS phone connectors are commonly used for balanced audio signals. Many jacks are now designed to take either XLR or TRS phone plugs. Equipment intended for long-term installation sometimes uses terminal strips or Euroblock connectors.
  