The ins and outs of tying shoelaces

I rushed in to buy some milk at a late-night Hasidic supermarket on Parc Ave. recently — and suddenly felt my two winter boots lock together in mid-stride. Next thing I knew I was toppling over like a tree, then smashing heavily onto the busy store floor. Orthodox men dressed in black scattered like bowling pins as I rolled over and over on the ground, trying not to kill myself, or anyone else. The owner rushed over and helped me to a chair, where he kindly offered some Band-Aids for my banged-up body. But I left the supermarket with my pride wounded more than the rest of me. It turned out one of my boot laces had come undone and snagged itself on a hook on the other boot, and suddenly: Tiiiimber! What bothered me is I’d knotted my laces fairly tightly that morning, though obviously not well enough. I left the store posing an ancient philosophical question: Why do shoelaces come undone? No matter how tight you tug, they’re often doomed to undo. Before you laugh, I’m far from alone in having loose laces. If you watch NBA basketball on TV, you’ll see the world’s best basketball player, LeBron James, is forever stopping to retie his free-flapping shoestrings. Some of my sports pals think it’s a tactic he uses to get a breather, but there are various video sites showing close-ups of LeBron’s undone sneakers with titles like: “LeBron doesn’t know how to tie his shoelaces.” It’s the same for the game’s second best player, Kevin Durant, whose laces come undone so frequently he often loses a shoe mid-game. The world’s fastest man, Usain Bolt, once won the Olympic 100 metres even though his laces came untied well before the finish line. If anyone should be able to keep their shoestrings tied, you’d think it would be the world’s elite athletes. But they have the same problem as many of us — and it’s hardly new. Shoelaces have been around for 5,000 years and they’ve been coming loose ever since. They started as thin strips of twine, then leather that was forever causing trouble. For instance, in 44 BC, as assassins surrounded Julius Caesar, he tried to rise and run — but I believe he slipped on a shoelace, which eventually led to the fall of the Roman Empire. I jest, but at least someone is taking this whole knotty subject seriously. In 2017, scientists at the University of California investigated this important matter in a report published in the August Proceedings of the Royal Society of London. In an experiment, they focused a close-up camera on people as they ran or walked on a treadmill. Then they studied the knots in super-slow motion to see exactly how — and how quickly — they unravelled. Their conclusion: the standard double bow “granny knot” most of us learned in grade school always came undone in less than 15 minutes of strenuous walking or running (which is why hard-running professional athletes are always re-lacing). You can stand around a bus stop, or even shovel snow without loosening your laces much. But scientists found walking and running both produce “unexpectedly powerful forces, stronger than the most powerful roller-coaster in the world” that pummel the shoelaces’ knot like a hurricane every step we take. Eventually the knot starts to loosen, then the lace ends start to flap like a helicopter, faster and faster — until POW! — even the best knot suddenly unravels. Of course, that usually happens at the worst possible moment, when you’re chasing after a bus, or carrying five grocery bags while walking your dog. Or running into a crowded Parc Ave. supermarket for milk late at night. The scientists also concluded that some knots hold out longer than others. While the basic granny knot kids have learned for millennia comes undone in minutes, a stronger square knot usually lasts longer, sometimes as much as a day of walking. That’s why the internet is filled with sites on “the correct way to tie your laces.” There’s even a TED talk called “How To Tie Your Shoes” by a man who relearned in his late 50s. Sadly, scientists didn’t test the “double knot” most of us also learned in school, where you make a second knot on top of the first, then pull it tight with all your might. But frankly that’s hard to readjust. When I’m playing tennis and need to tighten my laces, I sometimes have to take off my shoe and use my teeth to undo a double knot, while everyone waits and stares. Meanwhile, scientists say many mysteries remain about the physics of knots and why some are stronger than others, so they plan more studies into shoestring theory. But until science solves this puzzle, everyone better take Knot Re-education 303 — or else be like LeBron and me and remember to keep retying their shoes. I kid you knot.