14-billion-years-later:

Soap Films and the Minimal Surface

One subject of particular interest to me is soap films, while they hold wonder for children they’re also amazing in scientific terms. The  shape and structure of a soap films is determined by what configuration minimizes surface area, this is why bubbles are round. However other interesting shapes known as minimal surfaces arise such as the catenoid and helicoid. The catenoid is the shape formed by rotating a caternary around it’s axis of symmetry, the catenary in turn is the shape formed by a hanging chain. The helicoid is a minimal surface that can be formed from a catenoid without any deformation or stretching. Both of these shapes (along with the plane) have zero mean curvature and also minimize surface area and as such are energetically favorable shapes for soap films (with boundaries) to exist in.

Image: 1, 2, 3, 4