TITLE: Is the catenary the trajectory of anything?
QUESTION [11 upvotes]: Notice that the parabola, defined by certain properties, is also the trajectory of a cannon ball. Does the same sort of thing hold for the catenary? That is, is the catenary, defined by certain properties, also the trajectory of something?

REPLY [2 votes]: The relativistic trajectory of an object under the influence of a constant force field perpendicular to its initial direction of motion is a catenary. The trajectory reduces to a parabola in the non-relativistic limit.
(Eg : motion of electron under constant electric field)