Because science says so
Including why you keep suffering one of the most annoying fashion mishaps: your shoelaces becoming undone. Or, as the mechanical engineers at University California Berkeley call it, ’shoelace knot failure’.
It’s all down to two things really. One, the force of your foot striking the ground, which relaxes the knot.
And second, the force caused by your leg swinging, which unravels the ends of the shoelaces.
Lead researcher Christopher Daily-Diamond told the BBC, ‘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.’
And while some types of shoelaces may be better than others, it’s just a matter of time before the knot failure occurs.
Co-author of the study Christine Gregg tested various laces, and concluded, ‘The interesting thing about this mechanism is that your laces can be fine for a really long time and it’s not until you get one little bit of motion to cause loosening that starts this avalanche effect leading to knot failure.’
So basically any time you walk or run then. Our solution? Double knotting all the way.