See a Haaretz story commemorating the Feb. 14,
1917, birthday of a crystallographer.
Related material in this journal —
At the Still Point (June 15, 2013):
The illustration is for those who, like Andy Magid and
Steven Strogatz in the March 2014 AMS Notices,
enjoy the vulgarization of mathematics.
Backstory: Group Actions (November 14, 2012).