Page 51


My favourite shape

Helicoid Alex Doak

My favourite shape is the helicoid, as it has many interesting geometric properties. Firstly, it is a ruled surface. The helicoid is constructed by moving a straight line in space; in this case by rotating it about an axis while moving along said axis at a constant speed. Ruled surfaces are very popular in architecture, such as hyperboloid cooling towers and, of course, helicoid staircases. Secondly, it is a minimal surface. In fact, it has been proven that the helicoid, along with the plane, are the only ruled minimal surfaces!

Routes You start at A and are allowed to move either to the right or upwards. How many different routes are there to get from A to B?

Source: Answers at

Did you know... can now wear Chalkdust! Soon all the cool kids will be wearing Chalkdust Tshirts. Show o your love for the magazine, while simultaneously making your friends jealous with this stylish addition to your wardrobe. Get yours at


spring 2016

Chalkdust, Issue 03  

Popular mathematics magazine from UCL

Chalkdust, Issue 03  

Popular mathematics magazine from UCL