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: 2) by Zinho on Thursday April 13 2017, @02:09PM (4 children)
The article does a good job explaining why shoelaces require sturdy knots; in my experience, most people whose shoes untie themselves are simply tying bad knots. [fieggen.com]
This is such a widespread problem that there was even a TED talk on it, [ted.com] which is a must-watch in my opinion for anyone with perpetually loose laces.
TED not enough?
Animated shoelace knot tutorial [animatedknots.com]
More shoelace knots than anyone will ever need [fieggen.com]
Knots can be hard to wrap your head around, and today's society is doing a bad job of passing the skill on to new generations. I love seeing the feeling of empowerment a good shoelace knot gives to a person who's struggled with it their whole life. =^)
"Space Exploration is not endless circles in low earth orbit." -Buzz Aldrin
(Score: 2) by tangomargarine on Thursday April 13 2017, @03:23PM (2 children)
I did the guy's analyzer and it said I was tying them correctly, but if I don't double-knot them they perpetually come undone within a few hours.
He also claims that most shoelaces sold these days are harder to keep tied by virtue of how they're manufactured.
"Is that really true?" "I just spent the last hour telling you to think for yourself! Didn't you hear anything I said?"
(Score: 2) by Zinho on Thursday April 13 2017, @04:13PM (1 child)
He also claims that most shoelaces sold these days are harder to keep tied by virtue of how they're manufactured.
That's quite true, many of them are quite slick and the strands don't bind to each other very well. On my boots I'll typically apply some wax to the laces while I'm shining up the leather; I've found that helps quite a bit.
"Space Exploration is not endless circles in low earth orbit." -Buzz Aldrin
(Score: 0) by Anonymous Coward on Thursday April 13 2017, @11:24PM
Dr Zog's Shoelace Wax!
(Score: 0) by Anonymous Coward on Thursday April 13 2017, @05:30PM
For a mind-stretching exercise, try to reverse the way you have always tied your laces...to make the same knot, but with the "other handedness".