Catenary:
The catenary is the shape taken by an inextensible, homogeneous, infinitely thin, flexible, massive wire hanging from two points, placed in a uniform gravitational field. Galileo posed the problem and observed that the curve followed by the wire was approximately an arc of parabola, the approximation improves when you extend the wire. These are Leibniz, Jean Bernoulli and Huygens who found, independently in 1691, the right equations. [“Catenary or Funicular Curve“, mathcurve.com]
Yes, I’ve fallen, inadvertently, far behind on my xkcd studies.
