According to Mark Niemiec's life webpage (which I don't believe is in the public domain yet, but I have a local copy), the only objects with 12 cells are:
- 121 still-lifes;
- 6 period-2 oscillators (hexapole, cis-beacon-on-table, trans-beacon-on-table, phoenix, fox, and xp2_s0i0j0ezw1);
- 1 period-3 oscillator (the caterer);
- 2 period-4 oscillators (mazing and mold);
- 1 period-8 oscillator (figure-8);
- 1 period-15 oscillator (pentadecathlon).
So far, 130 of these 132 objects have appeared in b3s23/C1; we are still waiting for the period-2
phoenix and the period-1
very^5 long snake. Any speculation as to which will appear first, and when?
(All objects of 11 or fewer cells have already been seen in the census, the rarest being the pentapole.)
Anyway, I was wondering how large the Catagolue could grow before reaching internal limitations (the limiting factor probably being the 1MB maximum entity size imposed by the Google App Engine). I think that we can safely reach an object count of 50 * 10^12 before this is likely to become an issue (coinciding with reaching about 40000 distinct still lifes
of the same bit count), so Catagolue should be able to withstand the current load for at least another three years or so.
I'm excited to see what rare objects emerge over the coming months. We've already seen various flotillae, a couple of bi-pentadecathlons, Elkies' p5, a buckaroo and a twin-bees shuttle. I wouldn't be surprised if the following small oscillators show up reasonably soon:
- Achim's p5 (pseudo-barberpole)
- Silver's p5
- Smiley
- Achim's p8
Larger oscillators seem plausible, such as the trans-twin-bees-shuttle and several variant stabilisations of the queen bee shuttle. I imagine that the Gosper glider gun has a frequency of less than 10^-15, so it's incredibly unlikely that we'll see one in this census.
Spaceships have the additional challenge of having to be produced on the boundary of a reaction, but the following small spaceships seem like reasonable contenders:
- Boring flotillae
- Coe ship
- Loafer
The popularity of spontaneous bilaterally symmetric explosions may also lead to larger moving objects:
- Pufferfish
- x66
- Schick ship
Does anyone else have a similar 'wish list'?