ConwayLife.com

you can have a 5x5 pattern, which can clearly be contained in a 6x5 box, thus guaranteeing that 6x5 is minimal I guess it's conceivable that there's no infinite growth pattern that's strictly 6*5, i.e. that 6*5 is the smallest box to go round it, rather than just a box that will. I agree. Let me re...

And so the minimal bounding boxes are: 1 x 39 (1 pattern) [double-checked] 2 x 12 (1 pattern) 3 x 9 (20 patterns) 4 x 7 (31 patterns) some of them even beautiful :) 5 x 5 (1 pattern) [also double-checked] With regards to the 4 x 7 bounding box, you will find the 31 patterns at http://infinitegrowth....

The links at Life's Still Lifes http://delta.cs.cinvestav.mx/~mcintosh/comun/abstracts/abstractstill.html and A Zoo of Life Forms http://delta.cs.cinvestav.mx/~mcintosh/comun/abstracts/abstractzool.html point to the same PDF document: http://delta.cs.cinvestav.mx/~mcintosh/comun/zool/zoo.pdf Fortuna...

Let me rephrase Lewis' question:

"What is the smallest spaceship that is not a glider or a light/medium/heavy spaceship?"

Note: smallest in terms of number of alive cells, size of the bounding box, or both.

Got any clue?

Cool beans, that means that the 2x12 pattern is the unique pattern that fits inside a bounding box of area 24 to exhibit infinite growth.

Unnoticed result, LOL.

It seems that 4 x 7 is minimal.

Edit: Finally, there are thirty-one unique patterns that give rise to infinite growth (i.e. block-laying & glider-making switch engines).

Yes, the script found no patterns with infinite growth inside any 3 x 8 rectangle. Bugs are always possible, though. It would be nice if someone else tries to confirm these results. :P Edit #1: If you find any counterexample inside a 3 x 8 it would be very much appreciated. Edit #2: It's time for th...

Hmm... For nostalgy reasons, mostly, hereby, I suggest the ZX Spectrum font http://www.urbanfonts.com/fonts/ZX_Spectrum.htm as a potential candidate. Just kidding... or not. Something to begin with: the 26 Capital Letters #CXRLE Pos=1,1 x = 206, y = 6, rule = B3/S23 b4o3b5o4b4o3b4o4b6o2b6o3b4o3bo4bo...

Edit #1: Finally, there are twenty unique patterns with infinite growth inside a 3 x 9. All patterns are listed in the link above.

Edit #2: Pattern #15 is interesting because it produces a lightweight spaceship also.

I was wondering: How long is the minimum-length infinite-growing n -cell thick pattern for n=1, 2, 3, 4, 5? Paul Callahan's exhaustive search found the answers for n = 1 (i.e. 1 x 39) and n = 5 (i.e. 5 x 5) in 1997-1998. However, I am not sure if the results for n=2, 3, 4 have been published before....

I find the page on the wiki for uni-dimensional patterns very informative.
Congratulations!

A Life wiki has been created? 463 patterns as of April 2009? It sounds very interesting. I will take a look.

I modified the script to detect escaping gliders (this is a preliminary approach). The shortest patterns that produce escaping gliders are the following two 15-bit patterns: OOO · OOOOO · OOOOO (and its mirror image) 13 cells. It runs for 522 generations. Final population: 150 cells. (4 gliders). OO...

Infinite Growth's blog administrator here.

I am going to modify my script in order to provide a specific answer to your question.
Stay tuned.