There do exist r18 oscillators with all live cells of the same spatial parity of all even periods, and as such there exist phoenix agars of all even periods.AGreason wrote: November 4th, 2019, 10:16 pm Blinkerspawn and I have been working on some results derived from the above in the discord, and have determined that the p6 and 8 agars are both embeddings of stripe oscillators into the form of phoenix agars. (specifically, they're a simple background pattern XORed with the specified stripe patten). So any wolfram rule 18 (which describes the behavior of those stripes) spatially periodic even-length oscillator in which all on cells have equal spatial parity (that is, the distance between any pair of on cells is even) can be converted into a cgol phoenix agar of the same period. Oscillators of this form for periods 2, 4, 6, 8, 10, 12, 14, 24, 28, 30, 62, 124, 126, 1022 have been found via brute force search.
The question now is if there exist such r18 oscillators of all even periods, and if so how to construct them.
(On discord: https://discord.com/channels/3579222555 ... 2070934702)
I have the proof as a pdf, but I can't attach a pdf here, so attaching the LaTeX source as a txt file.
This makes the status of phoenix oscillators as far as I know:
Finite, period 2: examples known
Finite, periods other than 2: Proven impossible by apg with earlier partial results by David Silver and myself.
Infinite, even periods: all exist, by this result.
Infinite, period 3, 5, or 7: Proven impossible by me using SAT solvers
Infinite, odd period >7: Believed not to exist but not proven.