"Science: Why Shoelace Knot Failure"
by Nsikan Akpan
The team built a robotic pendulum to examine the math on a deeper level. They found the knot’s failure intensifies overtime. As the length of the loose end increases, so too does its weight relative to the other strand. This trend adds to the inertial forces, until total shoelace failure. Moreover, the bows of your shoelace are not exempt for this flaw.
“Some people will have very long free ends relative to the bow, in that case, the free ends will go first and the bow will just vanish,” O’Reilly said. “The bow can increase in size, and the free ends will vanish.”
When the team added little weights — ranging from 1 to 3 grams — to the free ends of the laces, they found heavier weights caused the shoelace knots to fail at a higher rate. This result suggests laces made from heavier materials may be more prone to screwing up, because unless you’re phenomenally gifted at tying even knots, one free end will likely be longer than the other.
Though the amount of time before a failure varied, the researchers argued these basic knots will eventually slack off. Also, you can try tying a tighter knot, but even those may break your heart.
What was important about the interaction between the weights and the shoelaces?
A) Heavier weights increased the bow size.
B) Heavier weights increased the time before failure.
C) Heavier weights increased the knot failure rate.
D) Heavier weights increased the tightness.