You put on your shoes, tie them as firmly as possible, but soon after the laces come undone.
Now scientists think they know what causes one of life's knotty problems.
[...] The researchers say an understanding of shoelaces can be applied to other structures, such as DNA.
[...] They found that when running, your foot strikes the ground at seven times the force of gravity.
Responding to that force, the knot stretches and then relaxes.
As the knot loosens, the swinging leg applies an inertial force on the free ends of the laces, leading to rapid unravelling in as little as two strides.
related stories:
Untangling the Mechanics of Knots
Useful Dead Technologies Redux
(Score: 0) by Anonymous Coward on Thursday April 13 2017, @03:42PM
it is also amazing how somehow a pebbel or small rock finds its way into sandels
that are open in the back but completly closed in the front, around the arch and toes.
its like the piece of earth falls in love we you, awakens from its inert slumber when stepped on,
only to "somehow" muster magical forces to execute a physics defying salto mortales FORWARD, following the moving-away direction of the foot, to slip lovingly into the slightly open heels section of the slipper whilst one strides confidentaly towards
some pressing destination.
one wonders, if the human body, especially the foot can imbue some anti_gravity forces on the things
we step on : )