The Last Word On Nothing

I usually avoid talking to people at the gym. But a few weeks ago, the man next to me had his shoes untied, and I couldn’t help myself. The laces were bright red, and extremely long. He was doing side steps that looked like they had high trip potential. And I was extra-sensitive to falls that day–my mother-in-law had ended up in the hospital after losing her footing in her backyard, and this gentleman looked about the same age, and was approaching his exercises with the same determination I imagined she would.

“Could I tie those for you?” I asked. I felt like I needed to give some sort of explanation. “I tie a lot of shoes,” I said.

He laughed, and thanked me. “You must have kids. I remember that,” he said. “When my son was little, even if I double-knotted them, his shoes always came untied, too. I don’t know how he did it.”

That’s the thing, we don’t even have to do anything. Except move our feet. The very action of running—and also, I’d imagine, skipping, dancing, climbing up on the kitchen counter when you’re not supposed to, sprinting through the library after being told not to, hurtling yourself over the guardrail at Glacier Point—creates enough force on shoelaces to make that sweet little bow you tied fall apart, sometimes in a matter of seconds. (The guardrail thing also creates enough of a squeezing force on a parent’s heart to render them at first speechless, then unable to stop yelling.)

Last year, researchers filmed a colleague’s shoes as the shoes were put through their paces on a treadmill. During the run, the shoe hits the ground with seven times the force of gravity, and that force stretches and relaxes the knot, which can begin to wiggle free. As the foot swings to recover and take the next step, the shoelaces whip around, creating inertial forces on the lace. Combined with the loosening knot, the laces fly free. Watching the movements in slow motion, the researchers found that this can all happen in two strides.

But sometimes, laces really do stay tied all day. The researchers aren’t sure why. What they do know is that the moment the knot starts to falter, it can cause “an avalanche of failure,” one said.

They have looked into it further, adding weights at the ends of laces, trying different lengths and styles of laces. One of their interests is in DNA and other microstructures, determining what forces could make them fail, and what arrangements make them resist detangling.

With shoes, there is a way to tie a single knot that makes it less likely to fail. The reef knot, or square knot, holds laces more securely than the granny knot. The easy give-away is that if you tie your laces and the bow turns so that it runs along your shoe, rather than across the top of your shoe, you’re likely tying a granny knot. (I spent a half-hour trying to figure out which one I did. Then I re-learned how to tie my shoe.)

I still remember the feeling of someone else tying my shoe. It feels secure, comforting. Even the rhythm of it, the words you learn as you are taught how to tie it. The rabbit goes around the tree, under the hole, and out the other side. Right over left, left over right, makes this knot both tidy and tight. I can see my neighbor bent over my small sneakers, showing me the rabbit. I can remember my dad’s hands as he tugged at the ends of my laces.

Now I am the one tying, the one teaching. Rabbits, rhymes, I’ll say anything if it helps keep everything together. Maybe I should be saying something to myself: with this knot, I am trying to stop the avalanche of failure. Even though I know nothing can stop it.

The man with the bright red laces knew this. “Are you sure I can’t help?” I asked him.

“Oh, no,” he said, smiling. “They’ll just come untied again anyway.” And then he sidestepped merrily away, his laces slithering along behind him.

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Image by Elilemie (Flickr/Creative Commons license)