33 Different Ways To Lace Shoes

Pentru cei împătimiţi de look-ul adidaşilor sau în general al încălţămintei, am descoperit care este cel mai important lucru! Nu contează că sunt murdari de noroi sau vechi(vintage), nu contează dacă sunt ultimul răcnet! Orice adidas trebuie să aibă minim o pereche de  şireturi cât mai interesante. Desigur asortate, pentru clasici...sau cât mai aiurite, pentru cei mai excentrici! Spun minim...pentru că prefer varianta cu dublu şiret.

Şiret de pantofi a fost inventat în 1790 de către Harvey Kennedy. Deşi există unele surse care spun că acest lucru ar fi eronat şi inventatorul adevărat, este necunoscut. Este o realitate faptul că, înainte de 1790, nu au existat şireturi şi după 1790, Harvey Kennedy a realizat aproape două milioane şi jumătate de dolari (aproape o cincizeci de miliarde de dolari azi) din brevetul privind şiretul pantofilor de piele.
Găsiţi nenumărate modele, tipuri de combinare a culorilor şi mai ales explicaţiile necesare pe un site:Ian's Shoelace Site - Bringing you the fun, fashion & science of shoelaces. Aici după cum este menţionată şi în descrierea site-ului moda şi ştiinţa sunt înbinate în tot felulde modele care mai de care mai trăznite, în legarea de şireturi. Totul se rezumă la matematică şi este foarte simplu. Explicaţia de mai jos sper să vă lămurească dacă vă puteţi limita la aceleaşi număr de a lega sireturile!

"It hardly seems possible that there could be quite that many ways to feed a lace through 12 eyelets! So let's look at the mathematics: 

• Feed through one of 12 eyelets from either inside or outside. That's 24 possible ways to start.
• Continue through one of 11 remaining eyelets from either inside or outside (x 22 more ways).
• Then 10 remaining eyelets (x 20 more ways). We've only gone through three eyelets and we're already up to 24 x 22 x 20 = 10,560 ways!
• By the time we reach the last eyelet (x 2 more ways), the possible ways have multiplied to 24 x 22 x 20 x 18 x 16 x 14 x 12 x 10 x 8 x 6 x 4 x 2 ways, a staggering total of 1,961,990,553,600.

That's almost 2 TRILLION possibilities!

This number can be halved for those paths that are mirror images of other paths, and halved again for those that follow the identical path from opposite directions. That still results in almost 500 billion ways.

Then again, we can multiply by the many different ways the laces can be crossed or interwoven prior to passing through those eyelets, and multiply again if we allow the laces to either pass through any eyelet more than once or skip any eyelet, and even more if we use two or more laces per shoe. This results in almost infinite possibilities, limited mainly by the length of the shoelaces.

In the real world however, we can place some sensible constraints, such as:

• The lace should generally start and finish from the top pair of eyelets.
• The lace should pass through each eyelet only once.
• Each eyelet should contribute to pulling together the sides of the shoe.
• The lacing should not be too difficult to tighten or loosen.
• Any pattern formed should be relatively stable.
• Ignore irrelevant variations (eg. changing the direction through a single eyelet).
• Above all, the finished result should be visually pleasing.

So how many possible ways are there to lace a shoe with 12 eyelets if we DO take into account some or all of the above constraints? This requires far more complicated maths than the simple multiplications above. For example:

The above combinatorial equation came from research by Australian mathematician Burkard Polster, who caused a sudden worldwide surge of scientific and academic interest in the mathematics of shoelacing following the publication of an article in the respected journal "Nature" in December 2002.

Although not quoted in the Nature article, Polster's calculation for the number of real-world lacing methods for a typical shoe with 12 eyelets came to 43,200 .
I'm therefore sure that the number of lacing methods on this site is destined to grow as I discover more worthwhile methods from the thousands of possibilities that I haven't yet explored.