'First step' in solving laces mystery
You could call it shoe string theory - scientists have finally solved the knotty problem of unravelling laces.
Why and how firmly tied shoe laces free themselves has been a maddening mystery ever since humans first donned footwear.
Now experts have the answer. Their research suggests that a blend of two forces act like an invisible hand, first loosening the knot and then tugging until the laces trail on the ground and your securely held shoe becomes a wobbly slipper.
Lead researcher Christopher Daily-Diamond, from the University of California at Berkeley, said: "When you talk about knotted structures, if you can start to understand the shoelace, then you can apply it to other things, like DNA or microstructures, that fail under dynamic forces. This is the first step toward understanding why certain knots are better than others, which no one has really done."