Beyond Brian's Brain
Posted: December 31st, 2017, 6:40 am
One way of "taming" an explosive rule is to treat it as a Generations rule and increase the number of generations, until cell death quells cell birth sufficiently to avoid explosion.
Seeds (B2/S) is explosive, of course, as is Brian's Brain (B2/S/G3, aka /2/3). Adding a fourth generation yields a rule (the unnamed /2/4, which I'd suggest may be called "Brain 4") that's less explosive, but still occasionally blows up:
However, adding another generation (ending up with /2/5; "Brain 5") makes the rule sufficiently stable to apgsearch it. It's fairly slow (~0.25 soups/sec for C1), but I managed to complete a haul. The ash is primarily photons.
/2/6 ("Brain 6") is comparable in terms of both stability, search speed and yield.
I've not looked at higher symmetries or tried other search programs, but I'd be curious what others can find in these rules.
Seeds (B2/S) is explosive, of course, as is Brian's Brain (B2/S/G3, aka /2/3). Adding a fourth generation yields a rule (the unnamed /2/4, which I'd suggest may be called "Brain 4") that's less explosive, but still occasionally blows up:
Code: Select all
x = 20, y = 20, rule = /2/4
B.CB.C3.A2.A.B2CA2B$2C2AB3.C.A.2B2.A2.B$3.BA2.2CACA2.2B.AC$AB5.A.A.BC
2.BA3C$.A.BAC.A2.2C2.A4.A$BA4.2BA3.CBA4.A$BA.CB.2BCA2.AB.A$4.C.C.A2.C
B2.2A2BC$CABA4.B.C3.A.AB.B$C.B.3A.AC.B.CB.AB.B$2A4.2A.C.2A.B2A$.B.C2.
BAB.A.3BA.B$.C.C.B2.C.BAB.2AC$2B.A.B.3B.AB2CBAB$B.B.BA3.BAB2AB3C.C$AC
4.C.2BA4.C2A$2BA2.A.2A2.B3.B2CBC$A.B3.3C2A.2ACA2.C$.2AC2.A3.B.B3.C.B$
CA6.B.2AB3.C.BC!
/2/6 ("Brain 6") is comparable in terms of both stability, search speed and yield.
I've not looked at higher symmetries or tried other search programs, but I'd be curious what others can find in these rules.