Letters from the December 16, 2006, issue of Science News

Familiar pattern

I am a retired high school mathematics teacher who has quilted mathematical ideas for over 20 years. Currently, I am working on a quilt called Pascal’s Pumpkin. I was totally excited by “Swirling Seas, Crystal Balls: Spirals of triangles crinkle into intricate structures” (SN: 10/21/06, p.