Math Monday

Math Monday: Star Sphericon

Math Monday: Star Sphericon

A sphericon is a shape that you get by: (1) rotating a symmetric polygon about a mirror axis to get a solid of revolution, (2) cutting the solid into two equal pieces, and (3) putting the pieces back together differently. With a lathe or a 3D printing machine, it is easy to make many kinds of sphericons, with different starting polygons. Here is one based on a star.

Math Monday: The Squared Square

Math Monday: The Squared Square

If you are a cabinet maker, geometry is essential to all the lengths and angles that you calculate. The cabinet shown here goes further and presents the solution to a rather difficult dissection problem. This is the simplest perfect squared square. The entire area is a square and it is divided into squares of distinct integer sizes.

Math Monday: Cardboard Catenary Arches

Math Monday: Cardboard Catenary Arches

By pleating a square sheet of paper with a pattern of concentric squares, one can fold a saddle shape that mathematicians call a hyperbolic paraboloid, sometimes nicknamed a hypar. Erik Demaine led a workshop at a recent Museum of Mathematics event where he showed how multiple hypars can be assembled to make star-like geometric forms.