Experimental Mathematics

Modeling Snow Crystal Growth I: Rigorous Results for Packard's Digital Snowflakes

Janko Gravner and David Griffeath

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Digital snowflakes are solidifying cellular automata on the triangular lattice with the property that a site having exactly one occupied neighbor always becomes occupied at the next time step. We demonstrate that each such rule fills the lattice with an asymptotic density that is independent of the initial finite set. There are some cases in which this density can be computed exactly, and others in which it can only be approximated. We also characterize when the final occupied set comes within a uniformly bounded distance of every lattice point. Other issues addressed include macroscopic dynamics and exact solvability.

Article information

Experiment. Math. Volume 15, Issue 4 (2006), 421-444.

First available in Project Euclid: 5 April 2007

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Mathematical Reviews number (MathSciNet)

Zentralblatt MATH identifier

Primary: 37B15: Cellular automata [See also 68Q80]
Secondary: 68Q80: Cellular automata [See also 37B15] 11B05: Density, gaps, topology 60K05: Renewal theory

Asymptotic density cellular automaton exact solvability growth model macroscopic dynamics thickness


Gravner, Janko; Griffeath, David. Modeling Snow Crystal Growth I: Rigorous Results for Packard's Digital Snowflakes. Experiment. Math. 15 (2006), no. 4, 421--444. http://projecteuclid.org/euclid.em/1175789778.

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