Puzzling Visual Maths For The Curious Minded #4  
     
  archimedes lab logo
Archimedes Laboratory Project

Mental & Perceptual Activities that Enhance Critical and Creative Thinking Skills

Social Media Contact us Like us on Facebook Circle us on Google+ Follow us on Twitter Pin it Thumb up this page

 

 

Puzzling Visual Maths

Button Backward

How to ‘magically’ untie a shoelace double knot Button Forward
 

Topology is a fascinating branch of mathematics that describes the properties of an object that remain unchanged under continuous “smooth” deformations. Actually, many 3D puzzles are based on topological principles and understanding some very basic principles may help you analyze whether a puzzle is possible or not.

Puzzle-Meister G. Sarcone created this amusing everyday-life topological puzzle to help children to easily take their shoes off.

Double knot puzzleAs you know, the standard shoelace knot is designed for quick release and easily comes untied when either of the working ends is pulled. Thus, most people think that tying a shoelace into a double knot is an effective method of making the knot “permanent”. But is it true?

So, let’s make a standard shoelace knot following the steps ‘a’ to ‘f’ of the diagram: take a shoelace in each hand (a) and cross one lace over the other (b). Poke the end of the lace through the cross hole and pull both ends tight (c). Form with each lace a loop (d). Then, wrap a loop around the other loop and pass it through the cross hole (e) in order to tie both loops tight in a half hitch (f). To make the double knot, cross again the loop over and wrap it around the other loop (g) and pull both loops until tight (h).

Now try to untie your shoelaces WITHOUT touching the double knot!

 
Click to show/hide the solution
 

 

You can comment and discuss this puzzle on our FaceBook fan page.

 

From the same Author
Impossible Folding Puzzles
Impossible Folding Puzzles
Pliages, dĚcoupages et magie
Pliages, découpages & magie
Libro MateMagica
MateMagica: Giochi d'ingegno con la matematica
 
     
 
 

archimedes lab logoArchimedes Laboratory Project
Mental & Perceptual Activities that Enhance
Critical and Creative Thinking Skills

Social Media Contact us Like us on Facebook Circle us on Google+ Follow us on Twitter Pin it Thumb up this page
arrow 1ABOUT arrow 1SITEMAP arrow 2 SERVICES arrow 2 PRODUCTS arrow 1SUBMIT arrow 1ADVERTISE arrow 1CONTACT
 

 

   For Publishers
   Workshops
  Books
  Puzzles
  Prints & Posters
  Illusory Art
     
Archimedes in the bathtub
 
Contact us Like us on Facebook Circle us on Google+ Follow us on Twitter Pin it Thumb up this page
 
  © 1997-2014 G. Sarcone [Archimedes-lab.org] All rights reserved  
  Creative Commons LicenseArchimedes Laboratory™ by Gianni A. Sarcone is licensed under a
Creative Commons Attribution - NonCommercial - NoDerivatives 4.0 International License