Scientifically Speaking, Your Shoes Are Untied

It’s a beautiful spring day. You’ve decided to take a quick walk outside to grab a coffee. As you stroll back to the office, medium half caff with almond milk in hand, you see your shoelace is starting to come untied. Knowing you’re almost back to work, you choose to wait it out. Then it happens. Now completely untied and flying through the near-ground breeze with zero regard for your wellbeing, the laces trip you up. The coffee falls from your hand, erupting on the sidewalk and splashing the passing leg of the gentleman in front of you. The cyclist who was approaching at just the right moment to see everything unfold, rides right into the bumper of a young mother removing her now-crying child from its carseat. Your slight inconvenience now has four unintentional victims. What was the cause of this mundane social massacre? Fate? Karma? Plain bad luck? No.

According to The Roles of Impact and Inertia in the Failure of a Shoelace Knot, a scientific paper recently written by mechanical engineer Oliver O'Reilly and his colleagues at UC Berkeley and published in Nature International Weekly Journal of Science, our shoelaces are put through the physical wringer with every single step we take. From the paper:

The scientists expected that the knots would come undone slowly. But their slow-motion footage — focused on the shoelaces of a runner on a treadmill — showed that the knots rapidly failed within one or two strides. To figure out why, O’Reilly and his colleagues used an accelerometer on the tongue of a shoe to measure the forces acting on a knot. They found that when walking, the combined impact and acceleration on a shoelace totals a whopping 7 gs — about as much as an Apollo spacecraft on reentry to Earth’s atmosphere.

An untied shoe may not seem like a scientific breakthrough, but O’Reilly and his colleagues surmise that a better understanding of knots has serious potential to make a positive impact. Untangling the true mystery of knots could lead to improved surgical ties, protect undersea optical networking cables from breaking, and enable more realistic animations of hair in computer graphics.

This revelation got us thinking, are there scientific explanations for other mundane misadventures we all experience every day? Our (not-quite-as-scientific-as-those-other-guys) findings suggested that there are, and that opportunities to solve these problems abound.

Without hyperbole, there are few things in life as cringeworthy as a bad handshake. Whether it’s your fault or not, they’re simply no fun for anyone. Did you hang on too long? Not long enough? Too hard? Too soft? Did you not stretch your hand far enough, so now the other person is left putting a kung-fu grip on just your fingers like a passive aggressive visitor to Downton Abbey? These are serious questions, and depending on who is on the other end of said handshake, could have serious implications.

Studies show that your concerns are valid. Handshakes are more than simple greetings. They’re how we size other people up, much in the same way animals smell each other. In fact, a new report says our handshakes are actually human smell tests. Using hidden cameras, researchers watched over 270 people after shaking hands with someone else. In the moments after the encounters, the test subjects sniffed their hands 22% of the time. If the person on the other end of the handshake was of the same sex, the sniffing was twice as likely to take place, and post-handshake behaviors were adjusted accordingly. The team behind this experiment concluded that handshaking is a chemosignalling behavior, a way to transmit information from our bodies.

Our suggested solution: A line of hand creams or sanitizers with scents formulated to make a specific impression on other people. Got a job interview? Scrub on some ‘Confidence.’ Meeting your partner’s parents for the first time? Lather up ‘Stability.’ These scents shouldn’t be overpowering or too obvious, but a subtle hint of ‘Compassion’ could tip the scales in your favor.

The Bizzaro to the shoelace’s Superman, tangled headphones are a public and personal nuisance that need to be eradicated post haste. For those of you rocking Apple Air Pods or other similarly wireless headphones, this problem is mercifully a thing of the past. However, for many, the dilemma still exists.

What summons this kind of sonic monster? It all comes down to physics. Scientists writing in Discover Magazine found that “complex knots often form within seconds, and that stiffer strings are less likely to get knotted up.” After running their data through various simulations, the team concluded that headphone knots are formed when jostled (like in a pocket or a bag). The loose ends form coils, which then weave themselves through other strands in the cord. And just like that, you start your workout already annoyed.

Our suggested solution: It’s 2017. Cut the cord and go wireless. Or, if you must have the comfort of wired sound, choose something with a thicker, preferably braided cord like those offered by Master & Dynamic.

The Urban Dictionary defines Sidewalk Chicken as:

When you and a stranger are walking in opposite directions on the sidewalk and, despite how far away you are, how much space to your sides you have, and multiple attempts to get out of each other's way, you always seem to step in the same direction, resulting in you bumping into one another.

We’re all guilty of committing this social sin at one point or another. A routine stroll down the sidewalk suddenly turns into an awkward two-step between you and a total stranger. No amount of “Excuse Me’s” or casual laughs or absence of eye contact will alleviate the issue. One of you is going to have to give, and unfortunately that tends to never occur until it’s already far too late.

Recognizing the catastrophic toll this cringe-inducing phenomenon was taking on our collective strides, the authors behind Adjustments of Speed and Path when Avoiding Collisions with Another Pedestrian conducted experiments where subjects walked a set length that was designed in such a way that they could not avoid a socially awkward ‘collision.’ What the experiments found was that people will take conscious note of the oncoming interaction and adjust both their path and speed accordingly to avoid a game of Sidewalk Chicken. Paths with sharper angles require more complex collision avoidance strategies, versus wider angles where only a path adjustment is necessary.

Our suggested solution: Sidewalk lanes! If cars and bikes can have them, why can’t our feet? If the sidewalk is wide enough, there’s plenty of space to divide it into two equal halves following the same right-hand-side rules of the road. Take this idea a step further and turn it into a public art project using solar-powered glow-in-the-dark paint like these Polish bike lanes.


The beauty of science is that it’s all around us and never ending. We could keep exploring everyday ideas like the ones listed above forever, and maybe we will again some day soon. For now though, let’s take what we’ve learned and put these simple revelations into practice to make life for all of us a little easier and a lot less awkward. That’s an idea worth shaking on.