January 29, 2013 | 4 On Sunday, I wrote about my public
statistics session at ScienceOnline. Today, I’ll tell you a
little about my other session, Hands-on Math, co-moderated by
Matthew Francis. If you come to our session, you might get to
take home a mathematical surface of your very own. Meet Ellie.
She may look like an oddly shaped pillow, but she is much, much
more. In the first place, Ellie is a surface with genus 2. She
has two holes, which you can see a little better in this
picture. Surfaces show up all over the place in mathematics, and
Ellie is a very interesting surface with a lot of properties to
explore. For example, she is a translation surface. These
surfaces are formed by taking a polygon in the Euclidean plane,
in this case an L-shaped piece of fabric, and gluing (or sewing)
parallel sides of the same length together. I’ll let Diana
Davis’s “Dance Your Ph.D.” video explain it another way. In the
first scene, whenever the dancer crosses one of the edges of the
double pentagon, she re-emerges i