The catenoid is the only known minimal surface that is also a surface of revolution, ...The catenoid was first described by Leonhard Euler in 1740 and is the oldest known minimal surface (a shape of
that forms between two parallel circular rings has the shape of a catenoid, which has the equation r ...Here the film consists of two sections of catenoid and a flat disk meeting at 120 degrees....
Transformation between Catenoid and Helicoid Applet demonstrates the animation panel . Use panel to start/stop transformation. 1999-2005 Last modified: 03.10.2005 --- http://www.javaview.de