Bill Gosper, 13-Nov-97: Anyway, I boasted ... that now, someone can probably find a finite configuration which grows so that every cell in the universe is eventually aperiodic.

Allan Wechsler, 14-Nov-97: I see waves of gliders going back and forth across a widening river, while four engines busily lengthen the banks and launch new gliders. Synchronization might be tricky.

Bill Gosper, 16-Nov-97: Right you are. This thing could have been built in the late 70s:

Might be interesting to prove it works. Also, it might work with a p40 rake instead of p60. And it might "leak". But maybe not fatally. And thus be harder to prove.

Hashlife will take this thing about 500000 steps, but eventually thrashes due to the logarithmic NWward creep creating new macrocells. Greenwald's program should be able to run the sucker astronomically far.

Bill Gosper, 19-Nov-97: Here is an almost threefold smaller total aperiodic, based on DBuck's amazing (non-Schick) p12 glider puffer:


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