BERKELEY California: Mechanical engineers at UC Berkeley, have discovered why shoelaces come undone.
To investigates why laces come undone seemingly randomly after hours of use, one of the researchers was filmed running on a treadmill.
During running, the impact of one foot striking the ground stretches and relaxes the knot. Once loosened, it’s vulnerable to the inertial forces of the swinging leg, which tugs at the ends of the laces, causing them to unravel. People tend to tie their laces in one of two ways: either based on a strong square knot or a weak false knot. Oliver O’Reilly, a Berkeley professor of mechanical engineering, said:
“We were able to show that the weak knot will always fail and the strong knot will fail at a certain time scale, but we still do not understand why there’s a fundamental mechanical difference between those two knots.”
It’s hoped the latest research will help the scientists find out.
Source: UC Berkeley