Calendar of Events
Notes and Challenges
The grid on the cover is a pattern that could be used to show different
symmetry elements. The color in this case results in the pattern
showing a 3-fold symmetry axis. It is hoped that in the near future
that I (Jin Liu Ch'ang) finishes a paper on the possible types of 2-dimensional
symmetry, which ones were used in the middle ages, and whether different
symmetries were recognized.