To understand something complicated by thinking about it for a long time
Why is it that when you lace up your shoes and walk or go for a run, the laces become loose and eventually undo completely? Well, wonder no longer because a team of scientists at University California Berkley has managed to ‘unravel’ the problem. During experiments involving the use of slow-motion cameras, mechanical engineers discovered that gradual lace loosening is caused by a ‘complex interaction of forces’.
In non-technical language, what happens as we walk or run is that the force applied to the knots causes them to constantly stretch and then relax. This action eventually causes the knots to loosen and eventually undo completely. In addition, it doesn’t really matter what type of laces you have on your shoes; some are better than others but if you walk or run for long enough they all succumb to knot loosening.