The Straight Dope
Having seen more than my share of photographs of snowflakes, I recently noticed that most seem to be perfect mirror images. How can the spines on ONE side of the flake possibly know what random shapes those on the OTHER are assuming in an essentially random freezing environment? Why would not all snowflakes be nonsymmetrical masses of frozen material with absolutely NO symmetry whatsoever? –Pete Formaini, Ithaca, New York As water vapor rises into the colder upper atmosphere it cools, and when chilled enough condenses into infinitesimal water droplets, which commonly form around particles of dust, sea salt, etc, known as nucleation sites....