Crawler

A crawler or climber is a reaction in which two objects (or groups of objects) collide, leaving one of the objects moved backwards or forwards to a degree, and the other forward. Crawler reactions are commonly used to create engineered spaceships, also known as caterpillars.

List of crawlers

17c/45 pi heptomino crawler

x = 29, y = 55, rule = B3/S23 14bo$14bo$14bo16$13b3o13$14bo$13b3o$12b2ob2o4$14bo$12bo3bo$10bo7bo$10b o7bo$10b2ob3ob2o4$3b2o4b2o7b2o4b2o$3bobob2o11b2obobo$6b2o5bobo5b2o$8b 2o3bobo3b2o$bo7b2o7b2o7bo$2o6bo4bobo4bo6b2o$o7b2o3bobo3b2o7bo$bobo8bo 3bo8bobo$bo2bo19bo2bo$2b2o21b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ TRACKLOOP 45 0 -17/45 GPS 22.5 ZOOM 12 Y 12 THUMBSIZE 2 AUTOSTART ]]

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Perhaps the first and most well known climber is the infamous 17c/45 reaction, consisting of a pi heptomino running over a blinker, moving it back 6 cells and rephasing it, whilst the pi heptomino moves forward 17 cells. This takes place in 45 generations.

The reaction was known for a long time, however the idea of a spaceship powered by this reaction was mentioned much later in 2002 by David Bell who had discovered reactions between multiple pies, which emitted gliders. After much work, Gabriel Nivasch finished construction of caterpillar, the first 17c/45 orthogonal spaceship, on 31 December 2004.

Research has been conducted into building much smaller 17c/45 spaceships with pi crawlers, analogously to the silverfish. Discussion has been ongoing since as early as 2013.

31c/240 Herschel crawler

x = 66, y = 148, rule = B3/S23 5b2o57b2o$5b2o57b2o30$5b2o57b2o$5b2o57b2o30$5b2o57b2o$5b2o57b2o18$60b 3o$60bo2bo$60bo2bo$59b4o$12b3o44b2o$13bo44bo$11b3o45bo$59bo8$3b2o$3b2o 8b2o41b2o$13b2o41b2o5$2bo$bobo$o3bo$o3bo$4bo$b3o7$5b2o57b2o$5b2o57b2o 12$13b2o41b2o$13b2o41b2o17$5b2o57b2o$5b2o57b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART GPS 60 X 0 Y 40 TRACKLOOP 240 0/240 -31/240 THUMBSIZE 2 ZOOM 4 HEIGHT 480 ]]

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Another orthogonal crawler, the 31c/240 reaction, consisting of a Herschel crawling though blocks.

Four 31c/240 spaceships are known, three of which use the crawler; shield bug, centipede, and silverfish. The fourth, centipede caterloopillar, relies on universal constructor technology instead of conventional crawlers.

(23,5)c/79 Herschel climber

58bo$56boo$57boo41$32bo$32bobo$32boo15$18bo$16booboo$16booboo$17bob3o$ 16b3o4$17boo$17boo$$16bo$15bobooboo$14boo4boo$14booboo$16bo8$23bo$24bo $22b3o10$bbo$oo$boo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART GPS 39.5 X -10 Y 15 TRACKLOOP 79 5/79 -23/79 THUMBSIZE 2 ZOOM 10 HEIGHT 480 ]]

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The (23,5)c/79 Herschel climber involves a Herschel reacting with a stream of gliders, emitting more gliders behind it in the same way, displacing the Herschel by 23 cells vertically and 5 horizontally in the space of 79 generations. It can also crawl on certain still lifes as well as gliders.

This climber has been engineered and other components assembled by hand to create waterbear, which was the fastest known oblique spaceship until the discovery of Sir Robin in 2018.

(34,7)c/156 Herschel climber

x = 297, y = 199, rule = B3/S23 262b2o$263b2o$262bo23$274b2o$274b2o19b2o$283b2o10b2o$282bo2bo$283b2o3$ 240b2o$240b2o19b2o$249b2o10b2o$248bo2bo$249b2o3$194bo11b2o$194b3o9b2o 19b2o31b2o$194bobo18b2o10b2o32b2o$196bo17bo2bo42bo$215b2o4$140b2o$140b 2o16$149b2o$148bobo$150bo142b2o$281b2o10b2o$280bo2bo$281b2o4$259b2o$ 247b2o10b2o$246bo2bo$247b2o3$192bo11b2o$192b3o9b2o19b2o$192bobo18b2o 10b2o$194bo17bo2bo$213b2o4$138b2o$138b2o16$147b2o$146bobo$148bo50$3b2o $2bobo$4bo38$b2o$obo$2bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ HEIGHT 600 WIDTH 600 THUMBSIZE 2 ZOOM 4 X 70 Y -40 AUTOSTART TRACKLOOP 312 -34/156 7/156 ]]

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The (34,7)c/156 Herschel climber is another notable oblique climber. An unnamed (34,7)c/156 caterpillar has been built using this climber.

(13,1)c/31 Pseudo-B climber

x = 37, y = 108, rule = B3/S23 o$b2o$2o19$8bo$6bobo$7b2o19$13bobo$14b2o$14bo17$24bo$23b3o$23bob2o$24b o2bo$25b2o$25bo2$22b2o$21bo2$20bobo2bo$20bob3obo$19b3ob2obo$20bobo$20b 3o$21bo8$29bo$27bobo$28b2o19$34bobo$35b2o$35bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ HEIGHT 640 THUMBSIZE 2 GPS 15.5 X 5 Y 10 ZOOM 12 AUTOSTART TRACKLOOP 31 1/31 -13/31 ]]

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An interesting climber, the (13,1)c/31 Pseudo-B climber involves a climbing reaction that never isolates itself into a Herschel or B-heptomino. A spaceship based on it was first mentioned by Gabriel Nivasch as an afterthought on his caterpillar article.

No spaceships have been built with this reaction as of yet.

(27,1)c/72 Herschel climber

x = 127, y = 164, rule = B3/S23 74bobo$74b2o$61bobo11bo35bobo$61b2o48b2o$62bo49bo2$125bo$124bo$124b3o 37$55bobo$55b2o$42bobo11bo35bobo$42b2o48b2o$43bo49bo2$106bo$105bo$105b 3o37$36bobo$36b2o$23bobo11bo35bobo$23b2o48b2o$24bo49bo2$87bo$86bo$86b 3o14$27bo$26b3o$25b5o$25b2ob3o$26b2ob2o$12b3o13bo33b3o12b3o$13bo49bo 16bo$13b3o47b3o11bo2bo$78b2o$78b2o$77bo2bo$77bo$79b2o2$26b2o$26b2o$33b 2o$12b2o16b5o27b2o$12b2o14bo4bo28b2o$19bo8bo3b3o34bo$18bobo6bo4b4o2bo 29bobo6b2o$17b2obo6bobo2bo2b3obo27b2obo6b2o$15b2o2bo8bo3b3o2bobo25b2o 2bo$15b5o4bo8bo4bo26b5o4bo$14bo4bo3bobo4bobo31bo4bo3bobo2b3o$14bob3o4b obo4bobo31bob3o4bob3obo8bo$15b3o2bo3bo40b3o2bo3bo2bo9b3o$16bo49bo10b3o 2bo2bo4bo$17bo4bo44bo4bo8bo6bobo$17bo4bo44bo4bo9bo5b2o$21bo49bo11b3o 13$13bobo$13b2o$obo11bo35bobo$2o48b2o$bo49bo2$64bo$63bo$63b3o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART GPS 36 X -10 Y 1 TRACKLOOP 72 1/72 -27/72 THUMBSIZE 2 ZOOM 4 HEIGHT 480 ]]

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Much research has been conducted into a spaceship based on the (27,1)c/72 Herschel climber, though discussion on it died out in mid-2019.

(13,4)c/41 B-heptomino climber

x = 40, y = 65, rule = B3/S23 37bo$37bobo$37b2o21$24bo$22b2o$23b2o20$9bo$4b3o2bo$3bo2bo3bo$3b2obo3$ 3bo$b2o$2b2o10$2o$2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART GPS 34 X -17 Y 16 TRACKLOOP 41 4/41 -13/41 THUMBSIZE 2 ZOOM 13 HEIGHT 480 ]]

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Consists of a B-heptomino climbing on gliders. Was initially proposed in 2014, but no development happened until a brief burst of work in early 2021.

(31,5)c/137 climber

x = 142, y = 301, rule = B3/S23 118bo5bo$118bo5bo$118bo5bo2$120b3o$47b3o3b3o2$51bo$51bo$51bo6$133b3o3b 3o2$137bo$72bo5bo58bo$72bo5bo58bo$72bo5bo2$74b3o10$112b3o3b3o2$116bo$ 43bo5bo66bo$43bo5bo66bo$43bo5bo2$45b3o6$129bo5bo$129bo5bo$129bo5bo2$131b 3o$66b3o3b3o2$70bo$70bo$70bo8$108bo5bo$108bo5bo$108bo5bo2$110b3o$37b3o 3b3o2$41bo$41bo$41bo6$101b3o19b3o3b3o$102bo$102b3o22bo$62bo5bo58bo$62b o5bo58bo$62bo5bo$31b3o$31bobo30b3o$31bo2bo$32b3o$32b3o$30bo2bo$33bo68b o$30bo72bo$101b3o$32bo68b3o$31bo70b2o$31b2o$100bo5bo$100bo5bo$100bo5b o$33bo$32b3o67b3o$31b2ob2o$32b3o$33bo5$104b2o13bo5bo$104b2o13bo5bo$119b o5bo2$34b2o85b3o$34b2o20b3o3b3o2$60bo$60bo$60bo11$94b3o3b3o2$98bo$25b o5bo66bo$25bo5bo66bo$25bo5bo2$27b3o3$69bo$69bobo27b2o$2bo66b2o28b2o12b 3o3b3o$2o$b2o114bo$29b2o86bo$29b2o16bo2bo6b3o57bo$47bo2bo5bob2o$47bo2b o3bob2o$45bo8b3o$47bo$45bob2o$46bo2b2o57b2o$48bo58b3o$107bo2bo$107b2o b2o$107b2ob2o$106b2ob2o$107bo$53b2o53b3o$53b2o35bo5bo12bo$90bo5bo$84b o5bo5bo$83b2o$83bobo6b3o$19b3o3b3o2$23bo$23bo$23bo6$105b3o3b3o2$109bo $44bo5bo58bo$44bo5bo58bo$44bo5bo2$46b3o4$110b2o$110b2o3$48b2o$48b2o$84b 3o3b3o2$88bo$15bo5bo22bobo41bo$15bo5bo23b2o41bo$15bo5bo23bo2$17b3o6$101b o5bo$101bo5bo$101bo5bo2$103b3o$38b3o3b3o2$42bo$42bo$42bo3$105b2o$74bo 30b2o$72b2o$73b2o$43b2o$43b2o35bo5bo$80bo5bo$80bo5bo2$82b3o$9b3o3b3o2$ 13bo$13bo$13bo6$95b3o3b3o2$99bo$34bo5bo58bo$34bo5bo58bo$34bo5bo2$36b3o 4$100b2o$100b2o3$38b2o$38b2o$74b3o3b3o2$78bo$5bo5bo66bo$5bo5bo66bo$5b o5bo$75bo$7b3o63bobo$74b2o5$91bo5bo$91bo5bo$91bo5bo2$93b3o$28b3o3b3o2$ 32bo$32bo$32bo3$95b2o$95b2o4$70bo5bo$70bo5bo$70bo5bo2$72b3o11$85b3o3b3o2$89bo$89bo$89bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 Y -15 AUTOSTART TRACKLOOP 137 5/137 -31/137 THUMBSIZE 2 ZOOM 4 HEIGHT 600 ]]

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This has been discussed somewhat as of late 2022.

(10,7)c/75 climber

x = 116, y = 141, rule = B3/S23 2bo$obo$b2o27$26bobo$27b2o$27bo26$53bo$54bo$52b3o27$78bo$79b2o$78b2o27$ 105bo$103bobo$104b2o13$113bo$112bobo$111bo3bo$112bobo5$112bo$111bobo$ 112bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART GPS 45 X 57 Y 67 TRACKLOOP 450 -42/450 -60/450 THUMBSIZE 2 ZOOM 10 HEIGHT 480 ]]

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A spaceship based on this fuse has also been discussed, however its potential is doubtful.

Half-bakery reaction

x = 59, y = 53, rule = B3/S23 57bo$56bo$56b3o12$36bo$34b2o$35b2o22$20b2o$19bo2bo$19bobo$17b2obo$16bo 2bo$16bobo$17bo2$4b2o$3bo2bo$3bobo$b2obo$o2bo$obo$bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART GPS 45 X -15 Y 15 TRACKLOOP 290 -3/290 -6/290 THUMBSIZE 2 ZOOM 10 HEIGHT 480 ]]

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There is a well-known reaction in which a glider crashes into the side of a half-bakery, shifting the loaves and releasing a glider. This reaction has been used to create Half-baked knightship and parallel HBK, and was later used to create the HBK caterpillar.

(28,3)c/84 climber

x = 124, y = 65, rule = B3/S23 10bo$9b2o$9bobo6$29b3o$b2o25b5o$2o25b5obo$2bo22b2o2b3ob2o$25b2obo2b3o $24b2o6bo$25bo2bo$19b2o5b3o$19b2o4$23bo$22b3o$21b5o$20b2o3b2o$21b5o$22b 3o$23bo9b2o11bo$26b3o4b2o9b3o$25bo3bo14bobo$25bo3bo14bo27b2o$25bo3bo42b obo$18b2o6b3o43bo$18b2o6$63b3o$63bo$64bo13$121b2o$121bobo$121bo7$112b 3o$112bo$113bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART WIDTH 800 GPS 45 X -30 Y -15 TRACKLOOP 84 28/84 3/84 THUMBSIZE 2 ZOOM 10 HEIGHT 480 ]]

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Consists of a pair of Herschels climbing a track consisting of pairs of gliders. While it emits three gliders for every two it receives, it also emits an extra block. Research started in late 2023.

Fuses which could be made into climbers

The following lists fuses which show potential for being made into workable climbers, but progress is yet to be made.

(8,1)c/32 p128 Herschel fuse

x = 193, y = 88, rule = B3/S23 bo$2bo$3o26$65bo$66bo$64b3o26$129bo$130bo$128b3o25$192bo$191b2o$190b2o $191bo$192bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART GPS 45 X 95 Y 42 TRACKLOOP 384 -24/96 3/96 THUMBSIZE 2 ZOOM 10 HEIGHT 480 ]]

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This fuse eats gliders, spitting out double the amount of gliders, but leaving blocks behind in the process.

(40,7)c/244 Herschel fuse

x = 138, y = 29, rule = B3/S23 137bo$137bo$137bo5$97bo$97bo$97bo5$57bo$57bo$57bo5$17bo$17bo$17bo$o$2o $b2o$bo$o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART GPS 45 X -80 Y 5 TRACKLOOP 976 160/976 -28/976 THUMBSIZE 2 ZOOM 8 HEIGHT 480 ]]

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Consuming blinkers, a new blinker is produced with a significant shift. However, a large cluster of debris is left in the other direction, making stabilisation appear challenging.

See also

• Herschel climber
• Herschel-pair climber
• Reburnable fuse

External links

• 13131: The B-Heptomino/Glider Spaceship Thread (discussion thread) at the ConwayLife.com forums
• (23,5)c/79 spaceship components (discussion thread) at the ConwayLife.com forums
• (27,1)c/72 caterpillar challenge (discussion thread) at the ConwayLife.com forums
• (34,7)c/156 caterpillar (discussion thread) at the ConwayLife.com forums
• (13,4)c/41 crawlers (discussion thread) at the ConwayLife.com forums