Negative spaceship

A negative spaceship (or agar crawler, or bubble) is a finite signal pattern traveling ("crawling") through a periodic agar such as zebra stripes, and thus comparable to a spaceship. The leading edge of the signal removes the agar, and the trailing edge rebuilds the agar some time later. The distance between the two edges is sometimes adjustable, as shown in a lightspeed bubble. The central part of the "spaceship" may consist of dying sparks or even simple empty space.

Below is a sample period-5 negative spaceship, found by Hartmut Holzwart in March 2007, travelling to the left at the speed of light:

x = 55, y = 31, rule = B3/S23:T55,32 55o2$29o2b3o2b19o$30b2o3b2o$24o2b3o3b2o3b4o2b12o$25b2o15b2o$24o2b3o3b 2o5b2o3b2o2b7o$30b2o3bob2o8b2o$24o2b3o2b3o3b2o5b2o3b6o$25b2o12b2ob2o$ 24o3b5o10b2o5b6o$28bo15b2ob2o$24o5bo9bo7b2o2b4o$25bobo6bo3bo10b2o$24o 3bobob5o6bo7b5o$30b3o3bo6bo$24o3bobob5o6bo7b5o$25bobo6bo3bo10b2o$24o5b o9bo7b2o2b4o$28bo15b2ob2o$24o3b5o10b2o5b6o$25b2o12b2ob2o$24o2b3o2b3o3b 2o5b2o3b6o$30b2o3bob2o8b2o$24o2b3o3b2o5b2o3b2o2b7o$25b2o15b2o$24o2b3o 3b2o3b4o2b12o$30b2o3b2o$29o2b3o2b19o2$55o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBNAIL THUMBSIZE 2 HEIGHT 450 ZOOM 10 THEME 6 GPS 6 AUTOSTART ]]

Period-5 negative spaceship (click above to open LifeViewer) RLE: here Plaintext: here

All agar crawlers currently known are faster than c/2, so it is not currently possible to put one in a greyship without it eventually crashing into the front.

Gallery

x = 52, y = 35, rule = B3/S23:T52,35 obobobobobobobobobobobobobobobobobobobobobobobobobo$obobobobobobobobo bobobobobobobobobobobobobobobobobo$obobobobobobobobobobobobobobobobob obobobobobobobobo$obobobobobobobobobobobobobobobobobobobobobobobobobo $obobobobobobobobobobobobobobobobobobobobobobobobobo$obobobobobobobob obobobobobobobobobobo2b2obobobobobo$obobobobobobobobobobobobobobobobo bobo4b2obobobobo$obobobobobobobobobobobobobo2bo2bobo7bobobobobo$obobo bobobobobobobobobobobo4b2obo8b2obobobo$obobobobobobobobobobobobob2o5b 2obo9bobobo$obobobobobobobobobobobobob2o6bobo2bobo3b2obobo$obobobobob obobobobobobobobo2bo5b2obo2bobo2bobobo$obobobobobobobobobobo2b2obo2bo 5bo2bo5bobobobo$obobobobobobobobobo5bobobo7bobo3b3obobobo$obobobobobo bobobobo6b2obo2bobo3bo2b2obo2bobobo$obobobobobobobo2b2o8b2o3b3o2b2o3b o3bobobo$obobobobobobobo5bo7b3o5b2o4bo4b2obo$obobobobobobo7b2o11bobo5b o5bo2bo$obobobobobobo7b2o11bobo5bo5bo2bo$obobobobobobobo5bo7b3o5b2o4b o4b2obo$obobobobobobobo2b2o8b2o3b3o2b2o3bo3bobobo$obobobobobobobobobo 6b2obo2bobo3bo2b2obo2bobobo$obobobobobobobobobo5bobobo7bobo3b3obobobo $obobobobobobobobobobo2b2obo2bo5bo2bo5bobobobo$obobobobobobobobobobob obobo2bo5b2obo2bobo2bobobo$obobobobobobobobobobobobob2o6bobo2bobo3b2o bobo$obobobobobobobobobobobobob2o5b2obo9bobobo$obobobobobobobobobobob obobo4b2obo8b2obobobo$obobobobobobobobobobobobobo2bo2bobo7bobobobobo$ obobobobobobobobobobobobobobobobobobo4b2obobobobo$obobobobobobobobobo bobobobobobobobobo2b2obobobobobo$obobobobobobobobobobobobobobobobobob obobobobobobobo$obobobobobobobobobobobobobobobobobobobobobobobobobo$o bobobobobobobobobobobobobobobobobobobobobobobobobo$obobobobobobobobob obobobobobobobobobobobobobobobobo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBNAIL THUMBSIZE 2 HEIGHT 450 ZOOM 10 THEME 6 GPS 6 ]]

An "Against the grain" negative spaceship (click above to open LifeViewer) RLE: here Plaintext: here

x = 52, y = 51, rule = B3/S23:T52,52 52o2$52o2$52o$47bo$40ob4o4b3o$41b2o5bo$38o5b9o$44bo$36o9b2o2b3o$37bobo 5b2obo$36o3bo5b3ob3o$44bo$38o5b9o$41b2o5bo$40ob4o4b3o$47bo$52o2$52o2$ 25o2b3o2b3o2b3o2b10o$26b2o3b2o3b2o3b2o2bo$23o3bo4bo4bo4bo5b5o$26b2o3b 2o3b2o3b2o3bo$25o2b3o2b3o2b3o2b10o2$52o2$52o2$52o2$23o2b3o2b3o2b3o2b3o 2b7o$24b2o3b2o3b2o3b2o3b2o$23o3b2o3b2o3b2o3b2o3b6o$47bo$21o27b4o$48bo$ 21o27b4o$47bo$23o3b2o3b2o3b2o3b2o3b6o$24b2o3b2o3b2o3b2o3b2o$23o2b3o2b 3o2b3o2b3o2b7o2$52o2$52o2$52o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBNAIL THUMBSIZE 2 THEME 6 HEIGHT 480 GPS 6 ZOOM 11 ]]

"With the grain" negative spaceships (click above to open LifeViewer) RLE: here Plaintext: here

x = 180, y = 60, rule = B3/S23:T100,58 $180o2$180o2$180o2$180o2$180o2$180o2$74o2b3o2b3o2b94o$75b2o3b2o3b2o8b o$74o3b2o3b2o3bob2obo4b83o$89b2o5bo$74o17b89o$92bo$74o19b87o$93bo4bo$ 74o19b2o4b81o$93bo5bo4bo$74o19b2o4b2o4b75o$93bo5bo5bo4bo$74o19b2o4b2o 4b2o4b69o$93bo5bo5bo5bo4bo$74o19b2o4b2o4b2o4b2o4b63o$93bo5bo5bo5bo5bo $74o19b2o4b2o4b2o4b2o4b63o$93bo5bo5bo5bo4bo$74o19b2o4b2o4b2o4b69o$93b o5bo5bo4bo$74o19b2o4b2o4b75o$93bo5bo4bo$74o19b2o4b81o$93bo4bo$74o19b87o $92bo$74o17b89o$89b2o5bo$74o3b2o3b2o3bob2obo4b83o$75b2o3b2o3b2o8bo$74o 2b3o2b3o2b94o2$180o2$180o2$180o2$180o2$180o2$180o2$180o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 ZOOM 9.2 HEIGHT 500 GPS 15 ]]

A "Lightspeed bubble" (click above to open LifeViewer) RLE: here Plaintext: here

See also

• Against the grain
• With the grain

External links

• Negative spaceship at the Life Lexicon
• Re: Agar crawlers (discussion thread) at the ConwayLife.com forums