# Glen Whitney

Executive Director, Museum of Mathematics

## Fractal Holiday

Happen to have any spheres with mirrored surfaces lying around? If so, you can make your own sphere inversion fractals, as today's gallery of pictures shows. Here's the basic idea: take three different-colored reflecting balls and arrange them so that each just kisses both of the other two. Read more »

## Planes and Trains and Polyhedra

Math Mondays is back from a travel-induced hiatus, but never fear, mathematical making continued unabated during the travels. In fact, on one plane ride, I just happened to have a bit of free time, and the materials to make the roundest 25-hedron possible (more on what that is, later). Unfortunately,... Read more »

## Folding Challenge: Can you do It?

Your challenge, should you choose to accept it, is to use the information in this article to construct an actual physical model of one of the more interesting shapes or surfaces featured there, and send a photo to [email protected] -- if enough photos come that way, there will be a... Read more »

Here's the challenge: see if you can find a way to have five (or more?) cylinders of an aspect ratio at least close to 9.5 : 7 all touch each other simultaneously, and send a picture of the configuration to [email protected] -- the first/best solutions will be posted in a... Read more »

## Parabolic Falls

Today's post chronicles the creation of Parabolic Falls, a new participatory mathematical sculpture for Illuminating Mathematics, the first gala celebration of the National Museum of Mathematics this past Oct. 1. Read more »

## Creating a Knitting Needle Hypercube Shadow

There has been lots of making going on at MoMath lately, which we'll take a look at over the next few posts. Recently, one of our Math Encounters speakers needed a projection of a hypercube into three dimensions as part of a demonstration. So we used Great Stella 4D to... Read more »

## Plenty of Polyhedra

Today's will be the last Bridges column, at least until next year -- not because there isn't plenty more to share, but because there have just been too many other things stacking up on the Math Mondays shelves. The final installment for this year is devoted to polyhedra and some... Read more »