Scientists unveiled the mystery behind the unseen hand which is constantly undoing our shoelaces. Researchers from the University of California, Berkeley, looked at what happens with a tied shoelace during walking. They published their results in the journal Proceedings of the Royal Society.
Researchers initiated a number of experiments to see what processes took place in a shoelace during walking. They discovered that certain events might cause it to become undone. For the experiment, they used two kinds of knots and looked how each of them became untied.
The two knots analyzed were regarded as weak and strong. The weak one is also known as the false or granny knot. The strong one is represented by the square knot. They recorded people running on a treadmill who wore their shoelaces tied in these knots. Then, they looked at the recordings in slow motion and observed what physical processes occurred before they became untied.
Disclosing the physics behind a knot becoming undone
They discovered a complex play of forces which work together and undo the knot. To sum it up, the center of the knot gets deformed, as the inertia of the free ends and the loops of the lace is brought into action by the swinging caused by walking.
More precisely, the process of the undoing of a shoelace has three stages. The first stage occurs when the shoe constantly hits the floor or the ground. This sends an impact which affects the knot. The second stage involves the movement of the legs which causes the free ends to swing. In the end, the shoelaces slip and knot is no longer strong, so it comes undone.
As expected, the experiments showed that the weak knot becomes untied more quickly than the strong knot. However, this process takes place during seconds, and the untying mechanism is the same for both knots.
The research is not comprehensive
Researchers say that their study is not complete yet. They did not take into consideration certain factors which could have influenced the untying process. For instance, they did not look at different shoelace materials or test more surfaces for walking. Thus, more research is needed until they can fully understand the untying of shoelaces and the factors which influence it.
However, this research might have applications in other fields as well. If scientists come to understand knots, they might find out why such molecular ties become untied in DNA or other microscopic structures.
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