p67 Herschel loop

p67 Herschel loop
#C [[p67 Herschel loop]] x = 72, y = 69, rule = B3/S23 19bo20bo$5b2o11bobo7bo11b3o$6bo12bo6b3o14bo23b2o$6bobo16bo16b2o23bo$7b 2o16b2o38bobo$17b2o42b2o2b2o$16bo2bo41b2o$16bo4bo26bo$17b6o22b5o$20bob 2o26bo$5b2o13bobo9b2o14b2o$6bo13b2o10bo14b2o$6bobo37bo$7b2o3$20b2o$20b obo6b2o36b2o$22bo6bo19b2o9b2o5bobo$22b2o6bo17bobo18bo$29b2o17bo10bo2bo 6b2o$12b2o33b2o4b2o$12b2o38bobo5b3o$14bo37bo$12b3o36b2o$11bobo4b2o$12b 2o4bobo$11bo8bo$11bo8b2o$9bo3$70b2o$2b2o66bo$bobo64bobo$bo66b2o$2o3$ 62bo$50b2o8bo$51bo8bo$51bobo4b2o$52b2o4bobo$19b2o36b3o$19bo37bo$9b3o5b obo38b2o$17b2o4b2o33b2o$b2o6bo2bo10bo17b2o$2bo18bobo17bo6b2o$2bobo5b2o 9b2o19bo6bo$3b2o36b2o6bobo$50b2o3$63b2o$25bo37bobo$23b2o14bo10b2o13bo$ 22b2o14b2o9bobo13b2o$21bo26b2obo$22b5o22b6o$23bo26bo4bo$9b2o41bo2bo$5b 2o2b2o42b2o$4bobo38b2o16b2o$4bo23b2o16bo16bobo$3b2o23bo14b3o6bo12bo$ 29b3o11bo7bobo11b2o$31bo20bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART ]] #C [[ GPS 8 THUMBSIZE 2 ZOOM 8 HEIGHT 600 ]]
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Pattern type	Oscillator
Number of cells	294
Bounding box	72 × 69
Period	67 (mod: 67)
Heat	147.3
Volatility	0.91 | 0.91
Kinetic symmetry	.c
Discovered by	David Buckingham
Year of discovery	1996
Rules Outer-totalistic rules B3/S23 – B38/S23 # of rules 21 = 2 Isotropic rules B3/S23 – B34c8/S234c5e
Glider synthesis Fewest gliders 106† Catagolue-generated RLE synthesis †Can be constructed with 15 gliders using the reverse caber tosser universal constructor.
Pattern files Plaintext p67herschelloop.cells RLE p67herschelloop.rle
Identifiers apgcode xp67_woggy8ok46y732aczy02jgyagytca23y1ca23zy111y830211yc12a2kgkczyhckggyd8oyag8s2acwg8gzy3cs2ssgy16a8ow1yb311y2c453y03d886y11z0g8ox111yyg0ggy831e8z23yzy31101y1cczy6ooz08oya6426yzy1c871zw123wg88oy2ggoync88gy14ss2uqz4a4wo81s863y032y3ca23yb64ko011y41zy211y9ok4k08zx8oy38oy71112yc22503y866z0311y2311ygo8y9ggkcy7354czyu113y71

The p67 Herschel loop is the first known period-67 glider gun, discovered by David Buckingham in August 1996. The loop is based on stable Herschel track technology. The loop consists of two instances of L112 and two instances of glider-releasing L156, with eight evenly-spaced circulating signals. The infobox shows the oscillator version; it can be turned into a glider gun by removing eater 1s blocking the glider outputs of the L156.

Along with the period-256 glider gun, this is one of smallest Herschel loops. Surprisingly, an even smaller period-67 Herschel loop-based glider gun was found in 2022, after the discovery of HRx65R.

x = 71, y = 58, rule = B3/S23 21b2o7bo$15b2o4b2o5b3o8bo$16bo10bo9b3o17b2o$16bobo8b2o7bo20bo9bo$17b2o 17b2o20bo7bobo$57b2o8bo2$33b2o30b5o$33b2o30bo4bo$32bo2bo32bobo$13bobo 16b2obo2bo28b3o$16bo19bo2bo17bo7b3o$9bo6bo5bo13bobo17b2o9bo$9bo7bo3bo bo33b2o7bo$11b6o4bo2bo40bo$4b2o9bo6b2o41b4o$4bobo62bo$5bo7bo11b2o38b2o b2o$12b3o10bobo38bobo$9b2o3bo12bo16b2o20bobo$9bo2bo14b2o15bo22bo$10b3o 32b3o$47bo2$ob2o$2obo2$9b2o$9b2o$60b2o$60b2o2$67bob2o$67b2obo2$23bo$23b 3o32b3o$3bo22bo15b2o14bo2bo$2bobo20b2o16bo12bo3b2o$2bobo38bobo10b3o$b 2ob2o38b2o11bo7bo$bo62bobo$2b4o41b2o6bo9b2o$5bo40bo2bo4b6o$4bo7b2o33b obo3bo7bo$3bo9b2o17bobo13bo5bo6bo$3b3o7bo17bo2bo19bo$b3o28bo2bob2o16b obo$obo32bo2bo$o4bo30b2o$b5o30b2o2$3bo8b2o$2bobo7bo20b2o17b2o$3bo9bo20b o7b2o8bobo$12b2o17b3o9bo10bo$31bo8b3o5b2o4b2o$40bo7b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART HEIGHT 600 WIDTH 600 ZOOM 8 GPS 20 ]]

The current smallest known p67 Herschel loop, using a pair of R49s and R152s with 6 evenly-spaced Herschels, with a population of 286 cells and a bounding box of 71 × 58 = 4118. (click above to open LifeViewer) Catagolue: here

A 110-glider synthesis of the oscillator was found in 2019. The synthesis cost was reduced to 108 gliders in August 2023.

External links

• p67 Herschel loop at Adam P. Goucher's Catagolue