Boatstretcher

A boatstretcher is any wickstretcher that stretches a boat. The first one to be discovered, boatstretcher 1, was found by Hartmut Holzwart in June 1993. Note that in any boatstretcher, the point of the boat can be removed to get a tubstretcher, although long tubs are called barges.

A 39-glider synthesis for a crab-based tubstretcher was constructed on February 12, 2017, by Tanner Jacobi and Adam P. Goucher. Goldtiger997 reduced this to 32 gliders on October 27, 2019. By hitting the tubstretcher with two gliders in the right position, it is possible to destroy it and leave behind an arbitrarily long boat, proving that an N-bit still life for any odd N can be constructed with no more than 34 gliders.

Likewise, BlinkerSpawn discovered that a single glider can destroy the tubstretcher while also turning the boat into an arbitrarily long barge, showing that a still life with any even-numbered population can be constructed with no more than 33 gliders. On March 22, 2017, it was shown by Goldtiger997 and BlinkerSpawn that, even without using the reverse caber tosser, an arbitrarily large oscillator can be constructed with 45 and 46 gliders respectively for odd and even N, by tying a quadpole to the still life. These upper limits were then gradually reduced to their current values of 19 and 17 gliders for even- and odd-population still lifes, and 24 and 26 gliders for even- and odd-population oscillators, due to progressively cheaper crab syntheses.

Gallery

8b2o3b$7b2o4b$9bo3b$11b2o$10bo2b2$9bo2bo$b2o5b2o3b$2o5bo5b$2bo4bobo3b$ 4b2o2bo4b$4b2o7b$8bo4b$7bobo3b$8bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 GPS 2 AUTOSTART TRACKLOOP 32 -1/4 -1/4 ZOOM 9 ]]

The crab as a tubstretcher (click above to open LifeViewer) RLE: here Plaintext: here

x = 24, y = 15, rule = b3/s23 12b2o10b$3o9bobo9b$o2b3o6bo9bob$bobo16b2obo$6bo4b2o2bo3b2o2bo$4bo6b2o 2bob2o2bo2b$6bob2obo3b5o4b$15b2o7b$7bo2b6o8b$8b7o9b$10b3o11b2$13bo10b$ 12bobo9b$13b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART GPS 2 ZOOM 9 TRACKLOOP 32 -1/4 -1/4 ]]

A swan stretching a boat (click above to open LifeViewer) RLE: here Plaintext: here

#C A slide gun and a backward Corder-rake can stretch a tub #C at c/124. #C Jason Summers, 6 Apr 1999 x = 152, y = 159 124b3o$124b3o$$123boobo$122bo3bo$122b3o$108boo$108boo3$125bo$124bobo$ 125bo$125boo$100boo23boo$100boo23bo$124boobo$107bobo11boboobo$106boo 13bo4bo10bo$105bo15bobo13boo$106boboo25b5o$108bobo29bo$92boo14bo11boo 12bo5boo$92boo14boobo8boo15boob3o$110boo20boobboobobo$133boobbobbo$ 137boo$107boo24boboo10b3o$107boo24bo13bobbo$146bo4bo$84boo60b3obbo$84b oo40boo17bo5bo$125bobbo15b7o$87boo37boo16bo$86b3o4boo3bo45bo$85bo6bobb oobo46boo$85b4obb5obbo$86b3o3b3o$93b3o$94boo35boo14bo$95bo35boo13bobo$ 112bo33boboo$111bobo21boo11boo$19boo89booboo19bobbo8b3o$19boo92boo19bo bo10bo$44boo61boo26bo7bobbo$44boo63bobb3o27bo6bo$20bo81boo3boobo31bo6b o$19b3o23bo55bobbo4bobbo29b3o4bo$18bo3bo21bobo55boo5bo$20bo23bobo63boo $17bo5bo21bo$17bo5bo87bo$18bo3bo86booboo$19b3o20booboboo61bo$8boo32bo 5bo45boo17bo29boo$8boo33bo3bo45bobbo14bo31boo$44b3o47boo$$22bo55boo$ 78boo35b3o$114bo3bo$22bo91boo3bo$20bobo95bo16boo$21boo20bo70b4o17boo$ 42bo69boobo$7b3o32b3o67bobbo$6bo3bo102boo$5bo5bo3boo3boo$6bo3bo18bo$7b 3o6bo3bo9bo32b3o$7b3o7b3o8b3o14b5o15bo61boo$17b3o15bo8bob3obo13bo5boo 55boo$37bo7bo3bo19bobo$33bobbo9b3o22bo$47bo$5b3o25boo$4booboo3bo5boo6b oo$4booboo4boo3boo5bobbo$4b5o3boo14bo17boo$3boo3boo18bo17boo$25boobo$ 19bo5boo$18boo$18bobo23bo40bo$19bo6boo17bo10bo27bobo$16booboo5boo8bo6b 3o10boo27bo$16bo3bo10b3oboobboo14bobo$18boo11b4o4boo$35boo$$19bo$bb3o 6b3o5b3o$bo3bo7bo8bo$o5bo5bo8boo$ooboboo49boo$56boo$24bo$6bo15booboo$ 5boo$21bo5bo5b3o$4boboo27bo$3bobboo13booboboo6bo$3b4o$$43b3o$bboo3boo 36bo6bo$5bo38bo6bobo$bbo5bo41bo3boo$3booboo42bo3boo3boo$4bobo14boo27bo 3boo3boo$5bo16bo17boo9bobo$5bo13b3o17bobo10bo$19bo19bo$38boo$bboo8b4o 10bo$3bo7bo7boo5boo19bobo$3o8bo3boobboo4bobo18bo$o5boo4bobboo24boobbo 4bo$6boo33boobobboboo$29bo15boo7boo$6bo20b3o24boo$5bobo18bo5bo$5bobo 18boo4b3o$6bo28bo$34boo20boo$$3booboboo14bo12bo$3bo5bo12booboo9b3o$4bo 3bo26bo3bo$5b3o3bo9bo5bo9bo14boo3boo$11boo21bo5bo7boo3b5o$10bobo8boobo boo6bo5bo6boo4booboo$35bo3bo9bo3booboo$36b3o15b3o$20boo$20bobo18boo$ 21bo20boo$8bo12boo18bo$8bo11b3o29b3o$7bobo10boo30b3o$6booboo12bo27bo3b o$5bo5bo38bo5bo$8bo42bo3bo$5boo3boo27bo12b3o$22bo15b3o$21b3o14b3o$9bo 10b5o$9bo9boo3boo10boo3boo$10bo9b5o11boo3boo$20bo3bo$21bobo$7boo13bo 16bo$7boo29bobo$37boo14boo$21boo14boo14boo$21boo14b3o$38bobo$39boo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 ZOOM 1.5 HEIGHT 500 WIDTH 500 AUTOSTART ]]

Tubstretcher discovered by Jason Summers, April 6, 1999 (click above to open LifeViewer) RLE: here Plaintext: here

#Cc/124 pseudo tub-stretcher #CJason Summers, 2-Sep-1999 x = 346, y = 313, rule = B3/S23 126boo$126bobb3o$127bob3o13$120boo$119bobo$121bo12$98bo$98boo$97bobo$ 104boo$105boo$104bo3$19boo133bo$19boo131bobo$44boo107boo$44boo5$90boo$ 19b3o67bobo$18bo3bo21b3o44bo$17bo5bo19bo3bo$8boo7booboboo$8boo32bo5bo$ 42boo3boo$20bo$8bo10bobo$7b3o9bobo23bo$6bo3bo8boo23boboo$8bo9bo25bo$5b o5bo5b3o24bo3bo$5bo5bo4bo3bo24bobbo$6bo3bo4bob3obo23b5o18bo$7b3o6b5o4b o19b5o18boo$26boo16boo3boo16bobo$25boo18b5o24boo$38bobo5b3o26boo$38boo 7bo26bo$10bo28bo$$180bo$10bo21bobo144bo$8bobo22boo144b3o$9boo22bo$18b oo6boo$18boo6bobo$27b3o16boo$3boo3boo18boo16boo$17bo7boo33boo$4bo3bo9b o6b3o31bobo$5b3o8b3o42bo$5b3o$26boo$3bo11bo10boo4bobboo$bbobo11bo14bo 3boobboo130bo$bbobo10bo15bo7boo129bobo$3bo28b4o11bobo121bo$48boo$19bo 28bo$oo3boo12b3o162bo$o5bo15bo160boo$21boo160bobo24boo$bo3bobboo28bo 17boo151boo$bb3o4boo27boo16boo153bo$8bo28bobo3$48bo$48boo163boo$47bobo 162boo$5bo15boo3boo186bo$3booboo15b3o$22bo3bo$bbo5bo14bobo21boo$24bo 20bo3bo161boo$bbooboboo35bo5bo160boo$43boobo3bo8boo$21boo21bo5bo8boo$ 22bo7boo8boo3bo3bo151boo$19b3o7bobo7bobo5boo151bobo$19bo11bo7bo162bo$ 13boo23boo$bboo8b3o$3bo7bobobbobboo$3o8boobboobboo25bo$o5boo7boo24b3ob oobboo152b3o$6boo33b4o4boo154bo$29bo15boo7boo148bo$27b3o24boo$26bo5bo$ 26boo4b3o$35bo206boo$34boo152bo52boo$5b3o7boo37b3o131boo53bo$4bo3bo5bo bo26b3o8b3o130bobo$16bo26bo9bo3bo$3bo5bo34bo$3boo3boo42boo3boo$16boo 227boo$16bobo17b3o6b3o196boo$8boo6bo4boo3boo7bo3bo7bo198bo$8bobo12b3o 8bo5bo5bo4boo$10bo11bo3bo7booboboo10bobo$9boo12bobo25bo$6bo17bo$6bobbo 30bo$6bo14b3o15boo10bo$21b3o$38boboo129boo$5booboboo25bobboo128bobo$ 37b4o131bo$5bo5bo7boo3boo26b3o$20b5o26bo3bo$6booboo10b3o12boo3boo7bo5b o$8bo13bo16bo10bo5bo$36bo5bo10bo119b3o$37booboo9bo3bo119bo$38bobo11b3o 119bo$39bo13bo$7boo30bo$7boo$53boo219boo$21boo30boo103bo114boo$21boo 135boo115bo$39boo116bobo$39boo$$293boo$277boo14boo$276boo$278bo8$141b oo$140bobo$142bo131b3o$276bo$275bo3$109boo32b3o$109boo34bo131boo$87boo 55bo131bobo$87boo34boo153bo$74bo4bo10boo31boo$72bobo4bo10b3o5boo$64boo 4boo7bo10boo6boo$64boo4boo11boobboo39bo$70boo8boobbobboo39boo$72bobo5b 4o43bobo131boo$74bo7bo17boo47bobo110boo$99bobbo4boo3boo35bo3bo107bo$ 88boo12bo50bo7bo$88boo12bo5bo3bo26boo8bo4bo4b4o146boo$85bo13boobo6b3o 27boo12bo4boboboo144boo$85boo12boo8b3o37bo3bo3bobbob3o8boo135bo$84bobo 62bobo6boboboo9boo$159b4o$72boo26boo59bo$71bobo26boo5boo41bo$61boo7bo 6boo4bo24bo22boo4b3o10bobo$61boo7bobbobbobbobbobo20b3o7boo14bobo3bo12b oo$70bo6b3oboboo20bo8boo16b3o3bo$71bobo6booboo31bo16boo$72boo7boboo45b oo$82bobo9boo34b3o111b3o$83bo10bobo46boo101bo$96bo46boo100bo$96boo33b oo204boo$131boo204boo$113b3o$98boo15bo131boo$98bo15bo22boo107bobo78b3o $88boo6bobo19boo13boobobboboo105bo80bo$87b3o6boo19b3o13bo4bobboo185bo$ 75bo8boboo26boboo19bo14b3o$75bobo6bobbo26bobbo16bobo15bo$76bobo5boboo 10bo15boboo35bo9bo$63boo11bobbo7b3o8boo8boo7b3o5boo35bobo165boo$63boo 11bobo9boo7bobo7bobo8boo5bobo22bobo8boboo66boo96bobo$75bobo24boo3bo19b o22bobbo6booboo10boo55boo97bo$75bo9bo14bobbobboo19boo12boo10boo6boboo 10boo54bo$86boo53boo8bo3boo5bobo$85boo13bobbo34bo7boo5boo8bo$101bobbo 24boo6boo6bo4bobbo$102bobo23bobo6bobo10bobo$90boo11bo26bo183boo$90boo 223boo$102boo210bo$77boo23boo42bo7bo$75bobbo66b4o5bobo$74bo7b3o3bo51b oobbobboo8boo4boo$66boo6bo6bo3b5o20boo9b3o16boobboo11boo4boo$66boo6bo 7bo3booboo9boo8bobbo9bo13boo10bo7boo$75bobbo3bo3boob3o8boo12bo7bo5bo7b 3o10bo4bobo$77boo5b4oboo23bo12b4o6boo10bo4bo59b3o$86b4o24bo11boobobo8b oo74bo61boo$88bo14boo5bobbo11b3obobbo7boo73bo62boo$102bobo5boo14boobob o127boo$102bo24b4o127bo3bo29boo$101boo25bo113boo13bo5bo28boo$217boo23b oo13bo3boboobboo$216bobo14boo3bo6boo10bo5bo3boo17b3o8b3o$218bo14bobo3b o5b3o10bo3bo16bo6bo12bo$234b5o6boo12boo17b3o6bo10bo$235b3o4boo9bobo22b 3o$242boo10boo13boo48boo$254bo14boo5boo3boo34bobbo$276boo3boo17boo14bo 15bobo$201boo67bo28bobo6boo6bo10b3obbo3bo$202boo65bobo29bo6boo6bo19bo$ 201bo66bobbo45bobbobboo7bo4bo4boo$267bobbo8boo38boobbobbobo7bo5boo$ 324b3o5bo3bo$238bo9boo17bobbo61bobo$237bobo7b4o18boo5boo$230boo4boboo 5b3obbobbobo21bo6boo14boo$230boo3booboo9boobbobbo17b3o8boo13boo15bo$ 236boboo6bo9boo16bo9bo15boo14bo$237bobo5bo8bo3boo41bo14b3o$164boo72bo 6bo10boo10bobo29bobo$164boo87bobbo6boo4boo28boobo$144boo107bobo7bobo3b o42boo$142bobbo32boo85bo46boo$129bobo9bo7b5o24boo85boo33boo$129bo3bo7b o6bo5bo16b3o10b3o113boo$119boo12bo7bo7boo3bo10bo5bo14bo$119boo8bo4bo7b obbo7bo9booboo4bo12bo81boo$133bo10boo121bo35bobboo11boo$129bo3bo28bo5b o86bo9bobo17bo11bo4bo3boobboo7bobo$129bobo8bobo12boo48bo49boo8boo18boo 9boo4bo7boo7bo$141boo12bobbo3booboboo18boo13b4o37boo11boo22boo4boo8bob o4b4o$141bo44bobo12b4o16bo20b3o3bo7b3o21boo4b3o$155bobbo29bo5boo5bobbo 8boo5bobo16boboo4b4o5boo22boo4boo45bobo$154bobbo36boo5b4o14bo3boo7boo 5bobbo4bo4bobboo20boo6boo7boo32boo3bobbo$154bobo45b4o3boobobo4bo3boo3b oobboo5boboo5bo3bobbo20bobo6bo8bobo24boobboob3o5boo$155bo49bobbo3boo5b o3boo3boo12b3o3boobo19boo3bo19bo23bobo3bo3bo3bo3boo4boo$209bo10bobo20b oo25bobboboo19boo6boo4boo7bo8bobo5boo6boo$125bo10bo18boo52bobbo8bo48bo 29b3obo5boo7bobbo6boobbobbo$125boo9boo17boo5boo7boo97bo31boobo13bo13bo bo$116boobboo4boo7bobo4bo20bo8boo12boo69bo12boboo27bo18bobo$116boobboo 4b3o13bobo15b3o8bo14boo84boo47boo$120boo4boo15bobo14bo41bo56bo$125boo 16bobbo54bo57bo$125bo17bobo39boboo12b3o67boo39bo$142bobo4boo4bobo27bob o55bo27boo20boo16boo10boo$142bo6bobo4boo28bo11boo41b4o6boobboo35bobo 16bobo9boo$151bo4bo29boo10boo40boboboo5b4obobbobo32bo11boo12boo6bo3boo $151boo33boo47boobbobbob3o5boobo3bo3bo19bo20bo3bo10b3o5bo3bobo$186boo 47boo3boboboo4bo12bo5boo11b4o17bo5bo10boo6b5o$241b4o14bo4bo4boo10boobo bo6bobo6bobbo3bo13boo4b3o$153boo49boo37bo19bo16b3obobbo3bo3bo13bo13boo $153bo28bo10b4o7bobo52bo3bo17boobobo4bo8bo7bo$141boo8bobo17boo8boo5boo 7bo6bo54bobo10boo8b4o4bo4bo3bo4boboo$141boo8boo18boo8bobo4boobboo3bo 73bobo9bo7bo8boo$128bo4bo10boo21bo6boo16boobbo74bo19bo3bo$126bobo4bo 10b3o20bo6b3o93boo21bobo$124boo7bo10boo28boo36boo8bo$118boo4boo11boobb oo20boo6boo7boo30bobbo6bobo$118boo4boo8boobbobboo19bobo6boo7bobo24boo bbo3bo7bobo$126bobo5b4o19boo3bo19bo4bo3bo14b3obboobbo7bobbo3boo$128bo 7bo20boobboo19boobbo4bo4boo5boboo16bobo4boo$186bo4bo4boo5bobbo8b3o4bob o$187b3o13boboo15bo$156boo48b3o$156boobo47boo$159bo$159bo37bo$156bobbo 20boo14boo$130boo9boo14boo20bobo14bobo8bobo$130bobo9boo37bo23bo3bo$ 125boo4b3o7bo6bo44boo10bo12boo$121b4obbo4b3o12bobo17boo24bobbo7bo4bo8b oo$121b3oboo4b3o12bo3boo3boo9bobo28bo7bo$130bobo13bo3boo3boo8b3o4boo4b o18bo7bo3bo$130boo14bo3boo12b3o4bobboobobo17bo9bobo$147bobo15b3o4b3obo 3bo12bobbo$148bo9boo6bobo4boobo3bo12boo$157bobo7boo6boo3bo$157bo19bobo $156boo20bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 ZOOM 1.5 HEIGHT 500 WIDTH 500 AUTOSTART AUTOFIT ]]

Pseudo-tubstretcher discovered by Jason Summers, September 2, 1999 (click above to open LifeViewer) RLE: here Plaintext: here

See also

• Crab
• Swan

External links

• Boatstretcher at the Life Lexicon