April 6 Lecture Notes

   (The 17 wallpaper symmetries)

Old Business:

 - Tuesday evening, 7pm
 - Jim's "How to solve it" is still coming
 - projects?
 - questions / comments ?

New Business:

 - Describe the picture notation: 
      n-rotation, reflection, translation, glide-ref.

 - Explain "fundamental cell"

 - How are these groups?
     * Show how to find group multiplication table.
     * Generators of the group

 - Find symmetry of at least on of "star" pictures

 - Think about Escher pictures in this context.

 - Rotation symmetries are 2,3,4,6-fold.  Why not any other?

 - Why 17 !?