21 Apr
2015
21 Apr
'15
6:09 p.m.
On Tue, Apr 21, 2015 at 4:36 PM, Bill Gosper <billgosper@gmail.com> wrote:
Everybody knows that the area and population growth of a bounded 2D cellular automaton pattern is limited to ~ time^2, but it never occurred to me that there is a theoretically minimal positive (diameter) growth rate ~ sqrt(log t),
... which follows from a counting argument. Nice! (Obviously you mean minimum positive growth rate; any still life has growth rate zero, and infinitely many patterns shrink to nothing.) -- Mike Stay - metaweta@gmail.com http://www.cs.auckland.ac.nz/~mike http://reperiendi.wordpress.com