A fortnight later, wwei23 found that a toad can turn a premature octomino II into a 90-degree glider, and completed the conduit in plain Life with a couple of unices as sparkers.[2] The first unix provides a dot spark to suppress a B3a birth. The second one can be placed in either of two possible locations, one of which produces an additional 180-degree glider along with the aforementioned one; this unix-specific form results in an adjustable p174+24N glider shuttle/relay.[3] Below is given a list of high periods where the smallest gun by bounding box uses this reaction. The four rows are by itself and with a period doubler, tripler, and quadrupler.
174
198
222
246
270
294
318
348
396
444
492
540
588
636
522
594
666
738
810
882
954
696
792
888
984
Key:
hotcrystal0 reaction
Something else
Periodic reflectors
This article is a stub. You can help LifeWiki by expanding it. It was suggested that the pattern below be rearranged into two shorter rows or split into separate RLEs
In case only the 90-degree reflected color-preserving glider is needed, the device can be adapted to other periods.[4]
A few hours after wwei23's post, Luka Okanishi modified the mechanism and created a true period-51 glider gun.[5] The second unix described above is replaced with the eater1-with-beehiveconstellation used in p5 quinti-Snark; this emits the 180-degree output glider on another transparent lane, 22 half-diagonals away from input, but destroys the octomino II. More notably, Luka collided sparks from two copies of this new reflector and added an eater 1, obtaining an extra glider parallel to both inputs and outputs. This over-unity reaction with a repeat time of 49 turns out to be suitable for building lower-period glider guns.
Since then, various people have found other compatible sparkers of various periods. Collaborative efforts have managed to construct the first true-period guns with periods 49 and 51, as well as to reduce in bounding box for several true gun periods including 52, 57, 65. On May 28, 2022, the p49 gun was significantly reduced due to the discovery of meatball, a slightly smaller sparker which could be used in place of 38P7.2.[6]
Apart from coupling to give guns, this 180-degree reflector is also capable of constituting the smallest known oscillator by population of several periods. 5 was previously on the list, but none of those are SKOP anymore.
