Physics trips up efforts to keep shoelaces tied
Mix of inertia and pavement pounding loosens knots, sends ends flying

KNOT BAD Shoelace knots don’t unravel at random. Instead, as a runner jogs, the ends of her laces swing due to inertia, and the knot deforms from the force of each footfall. Both effects cause the knot to untie.
C.A. Daily-Diamond, C.E. Gregg and O.M. O’Reilly/Proceedings of the Royal Society A 2017