Our "six pillows' secret pendant" is a very special piece of math jewelry. Its shape is given by a single equation. Have you ever seen a pendant like this before?
The photo shows a smoothed Kummer surface in steel (inflated with bronze). This post also features links to plastic versions of this shape. The Kummer surface is a classic from the 19th century; our model is a smoothed version of it.
This object looks like a piece of art. But in fact, it is "just" a mathematical curve, called 7/3 torus knot. Imagine a donut, and then tie a cord around it in some interesting way.
This so-called Boy surface represents a fascinating example of a non-orientable surface. The first such surface was constructed by Werner Boy in his dissertation in 1902.
This version of Clebsch's famous diagonal surface model features colored lines and two additional planes. One intersects the surfaces in a line and a hyperbola, the another one in three lines.
Our modern version of Clebsch's historical - nowadays quite famous - diagonal surface model is the main figure in our photo from the series "math sculptures in context". It is the pure white version with the 27 straight lines.
