Hourglass (mathematics)

In mathematics, an hourglass shape typically refers to a type of graph or distribution that narrows in the middle and widens at the top and bottom. It often describes a pattern where values or curves converge to a central point before diverging again, resembling an hourglass or figure-eight. This shape can represent phenomena such as data distributions, flow patterns, or structural forms that exhibit symmetry and a central constriction. Understanding this shape helps visualize how quantities cluster around a midpoint and then spread out, offering insights into the underlying structure or behavior of the system being studied.