Rectifier

Rectifier
x = 41, y = 33, rule = B3/S23 bobo7bo$2b2o6bobo$2bo7bobo$11bo12$20b2o$20b2o2$2b2o$bobo$bo$2o$31b2o$ 30bo2bo2b2o$30bobo4bo$11b2o18bo5bob2o$10bobo21b2obobo$10bo23bo2bo2bo$ 9b2o20bo4bo2b2o$31b5o2$33b2obo$33bob2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART ]] #C [[ HEIGHT 470 WIDTH 600 THUMBSIZE 2 ZOOM 12 GPS 30 AUTOSTART OFF ]]
View static image
Pattern type	Stable reflector
Number of cells	59
Bounding box	41 × 33
Angle	180°
Repeat time	106
Colour	Colour-preserving
Discovered by	Adam P. Goucher
Year of discovery	2009
Rules Outer-totalistic rules B3/S23 only # of rules 20 = 1 Isotropic rules B3/S23 only
Pattern files Plaintext rectifier.cells RLE rectifier.rle

The rectifier is a stable 180° glider reflector made up of two eater 1s, a block, a beehive, and an eater 3. The normal tub-stabilised eater 3 can be used here to reduce the population, but the snake-stabilised eater 3 has a smaller bounding box. The rectifier is notable for its recovery time of 106 generations and small number of catalysts. It can replace the boojum reflector in a large number of instances, although in some cases it cannot fit into the space provided due to the transparency of the beehive. It has several advantages over the boojum reflector:

• it has a much lower recovery time, allowing certain guns to be compacted;
• its passive bounding box is slightly smaller, so it can further compact many glider guns;
• its output path is free of catalysts, enabling it to be used as a merge device.

The transparent beehive reaction was discovered by Paul Callahan in 1996.

x = 108, y = 86, rule = B3/S23 8bo$7bobo$8bo2$6b5o$5bo4bo20b2o$4bo2bo23bo$bo2bob2o21bobo$obobo5bo18b 2o$bo2bo4bobo8bo$4b2o2bo2bo7bobo$9b2o8bo2bo$18bo2bo18b2o$17b2o3b2o16bo $15b2o5b2o6bo7bobo$15bo6bo8b2o5b2o$16bo3bo9b2o$16bo3bo$17b3o4$29b2o$ 29b2o$30bo5$36b2o$36bobo$36bo$26b3ob3o$28b4o$28b3o$29bo6$56bobo$57b2o$ 57bo9$77bo$76bobo$76bobo$77bo$62b3o$62bo$63bo7$85b2o2$82b2o3bo$82bo4bo $82bo$68b2o13bo2bo$67bobo$67bo$66b2o$97b2o$96bo2bo2b2o$96bobo4bo2bo$ 77b2o18bo5bobobo$76bobo21b2obo2bo$76bo23bo2bo$75b2o20bo4bo$97b5o2$99bo $98bobo$99bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ HEIGHT 500 WIDTH 600 THUMBSIZE 2 ZOOM 12 X 32 Y 25 THEME Book STARTFROM 106 GPS 15 AUTOSTART ]]

Rectifier reflecting a p106 glider stream, shown with highlighted reaction envelope. A second rectifier is present outside the frame, forming a loop with five gliders (click above to open LifeViewer) RLE: here Plaintext: here

Gallery

• 
  An incoming glider (in green) and an outgoing glider (in red) 167 generations later

SKOPs

Rectifier loops comprise the majority of the smallest known oscillators of a certain period for high periods. Here is a list of them up to period 200:

Period	Number of gliders	Catagolue page	Minimum population
109	10	link	156
121	10	link	156
131	6	link	136
137	2	link	116
139	6	link	136
149	2	link	116
151	6	link	136
153	2	link	116
157	2	link	116
161	2	link	116
163	6	link	136
167	6	link	136
169	2	link	116
173	2	link	116
178	5	link	148
179	6	link	136
181	2	link	116
183	6	link	136
191	6	link	136
193	2	link	116
194	5	link	137
197	2	link	116

Most prime-period SKOPs are rectifier loops, because there's no currently known lower-population way to close a loop using only stable circuitry.

See also

List of smallest-population known oscillators for periods up to 2048, tracked by the Skopje project

External links

• New stable 180° glider reflector at Game of Life News. Posted by Dave Greene on May 30, 2009.
• Rectifier at the Life Lexicon