PD-pair reflector

PD-pair reflector is a pair of pentadecathlons arranged so that their V sparks turn a glider by 90 degrees with a repeat time of 45 ticks. This reaction was found by Mark Niemiec on 6 January 1996, which is relatively recent considering how old pentadecathlon technology is.

Six other arrangements of two pentadecathlons can serve as a 180-degree glider reflector, one of which is demonstrated in 6 bits.

The reflection involves turning a glider into a block, and then that block into a glider.

x = 45, y = 30, rule = B3/S23 43bo$42bo$42b3o9$14b3o2$13bo3bo$13bo3bo2$14b3o3$14b3o2$13bo3bo$13bo3bo $20bo$14b3o3bobo$20b2o2$o2bob2obo2bo$4ob2ob4o$o2bob2obo2bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 X -7 Y 10 Z 14 HEIGHT 480 GPS 15 AUTOSTART LOOP 90 ]]

(click above to open LifeViewer) RLE: here Plaintext: here

x = 229, y = 62, rule = B3/S23 23bo63bo63bo63bo$21b2o62b2o62b2o62b2o$2b2o6b2o10b2o42b2o6b2o10b2o42bo 2b2o4b2o2bo6b2o62b2o$bo2bo4bo2bo51bo4bo2bo4bo51bo3b3o2b3o3bo$bo2bo4bo 2bo51bo4bo2bo4bo52bo2b2o4b2o2bo$bo2bo4bo2bo51bo4bo2bo4bo138bo2bob2obo 2bo$2b2o6b2o54b2o6b2o139b2o2bo4bo2b2o$216bo2bob2obo2bo$16b3o61b3o128b o$16b3o61b3o127bobo$17bo63bo$17bo63bo64b3o$17bo63bo63bo3bo60b3o$16bob o61bobo62bo3bo60b3o$146b3o62bo2$16bobo61bobo$17bo63bo129bo$17bo63bo128b 3o$17bo63bo64b3o61b3o$16b3o61b3o62bo3bo$16b3o61b3o62bo3bo$146b3o61bob o$211bo15$23bo63bo63bo$21b2o62b2o62b2o$2b2o6b2o10b2o62b2o42bo2b2o4b2o 2bo6b2o$bo2bo4bo2bo52bo2bo4bo2bo52bo3b3o2b3o3bo$6o2b6o49b3o2b6o2b3o51b o2b2o4b2o2bo$bo2bo4bo2bo52bo2bo4bo2bo$2b2o6b2o2$16b3o61b3o$16b3o61b3o $17bo63bo65bo$17bo63bo64b3o$17bo63bo63bobobo$16bobo61bobo62bobobo$146b 3o$147bo$16bobo61bobo$17bo63bo$17bo63bo65bo$17bo63bo64b3o$16b3o61b3o62b obobo$16b3o61b3o62bobobo$146b3o$147bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 HEIGHT 480 WIDTH 1100 GPS 15 AUTOSTART T 0 PAUSE 2 LOOP 90 ]]

All known PD-pair reflectors. The rightmost one turns a glider by 90 degrees, while all the others turn a glider by 180 degrees. (click above to open LifeViewer)

External links

• PD-pair reflector at the Life Lexicon