Astrophysicist Explores the Science Behind Why Shoelaces Keep Coming Undone
Astrophysicist Dr. Josie Peters explored the science behind repeated shoelace failures for BBC Ideas, analyzing the physical forces that cause them to come undone.
She explained that tying both stages of the knot in the same direction creates a weaker granny knot instead of a sturdier reef knot, a mix-up that a simple change in loop direction can fix. Peters discussed different ways to tie laces, including the famous Ian knot and Berluti knot, and highlighted thousands of years of human innovation in securing one’s footwear.
Astrophysicist Josie Peters explores the surprising science of knots and explains what makes some shoelace knots fail and others stay secure for longer.
The video draws on a 2017 study by mechanical engineers at the University of California, Berkeley, who found that a shoe strikes the ground with about seven times the force of gravity, loosening the knot with every step.
