This column is dedicated to the memory of my father and namesake, James Paul Kelly, who was born on April 18, 1906, the same day as the infamous San Francisco earthquake.
I am far from being a scientist, but I trust the world of science and do quite a bit of reading about scientific theory and the history of science. As marvelous as the world of science is, however, many questions remain unanswered. No, I’m not talking about quantum mechanics or black hole theory. What we are confronted with here is one of the biggest mysteries of all–namely, why do our shoes come untied so often? I am delighted that this mystery might not remain so mysterious for much longer. According to some recent news releases, science may have solved this troublesome problem.
According to an April 11 report from Phys.org, a group of mechanical engineers from University of California, Berkeley, say the explanation “is that a double whammy of stomping and whipping forces acts like an invisible hand, loosening the knot and then tugging on the free ends of your laces until the whole thing unravels.” Isn’t it refreshing to read a scientific report that uses technical terms like “double whammy”? And, I think it is very interesting that this description of why shoes come untied sounds a lot like the Big Bang Theory (not to be confused with the same-titled TV series). Maybe the two are related. We can only hope.
As scientists are wont to do, the Berkeley engineers were interested in more than just shoe laces. What they are really after is deeper insights into “knot mechanics.” One of these engineers, Christopher Daily-Diamond, who is a graduate student and a co-author of the study that appeared in last week’s Proceedings Of The Royal Society, tells us that “When you talk about knotted structures, if you can start to understand the shoelace, then you can apply it to other things, like DNA or microstructures, that fail under dynamic forces.” Even more significant, “This is the first step toward understanding why certain knots are better than others, which no one has really done.” Not even the Boy Scouts?
Needless to say, the Phys.org column comes complete with diagrams and drawings, showing us precisely how laces come undone, even when double-knotted or tied using square or “false” knots. And the secret of why knots come undone has to do with the way we walk and stand still (these are called “swing” and “stance” phases). Here is the full explanation of how this process works: “When running, your foot strikes the ground at seven times the force of gravity. The knot stretches and then relaxes in response to that force. As the knot loosens, the swinging leg applies an inertial force on the free ends of the laces, which rapidly leads to a failure of the knot in as few as two strides after inertia acts on the laces.” There we have–a lifelong mystery explained. Of course, this study is just beginning to understand why some knots last longer than others and how our strides, swings, and stances affect the longevity of our tied laces. If you want to read about this in more detail, consult “The Roles of Impact and Inertia in the Failure of a Shoelace Knot,” as published in the Proceedings of the Royal Society A. Of course, you can watch the inevitable YouTube video, “The Science Of Untied Shoelaces.”
It is probably not surprising that there are many videos and other resources out there focusing on the most efficient way to tie our shoes. One of the best is the three-minute TED talk by Terry Moore, “How To Tie Your Shoes” (which, as the TED site states, “was the very first 3-minute audience talk given from the TED stage, in 2005”). The best thing about this particular talk is the way Moore transforms tying shoes into a meditation on the value of thinking in different and innovative ways. Of course, now that the Berkeley study is out, we realize that no matter which method or methods we use, our shoes will still come untied.
A few years back, I devoted this column to the question of why round shoelaces exist. Seems to me that if we set out to design a shoelace that is destined to come untied, it would be a round one. When compared to flat laces, which come untied much less, round laces are a constant source of irritation. The occasion for that long-ago column was my reading of Nicholson Baker’s clever 1988 mini-novel “The Mezzanine,” which is about an afternoon in the life of an office worker who takes his lunch break to search for a new pair of shoelaces after one of his broke (don’t know if that happened during the “stride” or “stance” phase). I highly recommend your reading Baker’s first literary publication (he has written thirteen others since then), which is perhaps the world’s only novel based on a broken shoelace.
I am happy to report that I have taken steps (no pun intended, I think) to relieve the stress of untied shoelaces–I have simply switched to shoes with no laces. I wear those stylish (yet cheap) slip-on dress shoes and casual shoes that also slip on, or those nerdy walking shoes with velcro fasteners. Why I didn’t think of this years ago I don’t know. Of course, I like the look of shoes with laces much better but I am tired of putting up with the bother of stopping much-too-often to tie untied laces, especially those annoying round ones.
Now that we have solved one of life’s greatest mysteries, we can move on to other perplexing problems. Like why people would rather endlessly wait in a drive-thru line when going inside to conduct business is much quicker. Maybe those Berkley engineers will tackle that annoying problem now that they have published their shoelace masterpiece.
See you next week with a thoroughly untied column.