They are the scientific discoveries that hide in plain sight: the mechanics behind ordinary phenomena such as the physics of bursting soap bubbles or how cats lap up milk. Now, a small team of researchers from MIT and the University of Pierre and Marie Curie in Paris have unraveled the everyday mystery of how hair curls under its own weight.
In a new paper published in the journal Physical Review Letters, the researchers describe their solution to what they call “the deceivingly simple problem” of knowing what shape a dangling curved rod, such as a hair strand, will form. Given a strand with a certain natural curvature, they’ve created a toolset to predict whether it will dangle long and straight with a slight curl at the end, or as a tight 3-d helix. It’s the newest finding in a field of science that unravels conundrums that can seem so plain and ordinary that the fact no one knows why they occur can be surprising.