Difference between revisions of "OCA:Move"

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===Spaceships===
===Spaceships===
[[Image:move_glider.gif|framed|right|The jellyfish<br />{{JavaRLE|moveglider|brief}}]]There are at least 16 spaceships known in the move rule.<ref name="Eppstein" /> Of these, by far the most well-known is the '''jellyfish''', which is only one known to occur naturally from [[soup]] and travels at [[speed]] c/7 diagonally.
[[Image:move_glider.gif|framed|right|The jellyfish<br />{{JavaRLE|jellyfish|brief}}]]There are at least 16 spaceships known in the move rule.<ref name="Eppstein" /> Of these, by far the most well-known is the '''jellyfish''', which is only one known to occur naturally from [[soup]] and travels at [[speed]] c/7 diagonally.


===Guns===
===Guns===

Revision as of 23:53, 5 June 2009

Move
x=0, y = 0, rule = B368/S245 ! #C [[ THEME Inverse ]] #C [[ RANDOMIZE2 RANDSEED 1729 THUMBLAUNCH THUMBNAIL THUMBSIZE 2 GRID ZOOM 6 WIDTH 600 HEIGHT 600 LABEL 90 -20 2 "#G" AUTOSTART PAUSE 2 GPS 8 LOOP 256 ]]
LifeViewer-generated pseudorandom soup
Rulestring 245/368
B368/S245
Character Stable

Move (or Morley[1]) is a Life-like cellular automaton in which cells survive from one generation to the next if they have 2, 4, or 5 neighbours. Cells are born if they have 3, 6, or 8 neighbours. Random starting patterns tend to stabilize into ash consisting of small still lifes and period 2 and 4 oscillators. It also contains one commonly-occurring slow-moving spaceship and slow-moving puffer. The time required to stabilize is generally much shorter than in the Game of Life.

Notable patterns

The move rule contains a large variety of known patterns, including many guns, spaceships[2], and puffers.

Still lifes

Below is an enumeration of small still lifes in the move rule.[3] Despite the abundance of interesting moving patterns in this rule, there are relatively few still lifes. It can be seen that there are still lifes of arbitrarily large size by noting that for every odd number of cells greater than 5, there is an obvious extension of the Z-pentomino for that number of cells that is a still life. Also, every lake is a still life, so for any n ≥ 3, there is at least one still life with 8n cells.

Size Count
≤ 3 0
4 1
5 1
6 2
7 2
8 4
9 1
10 3
Small still lifes in the move rule
RLE: here

Spaceships

The jellyfish
RLE: here

There are at least 16 spaceships known in the move rule.[2] Of these, by far the most well-known is the jellyfish, which is only one known to occur naturally from soup and travels at speed c/7 diagonally.

Guns

Jason's bow, a period 404 double-barreled gun
Download RLE: click here

At least 11 guns have been found, most of them by Stephen Morley and Jason Summers.[4] The first gun to be constructed was called Safalra's bow and was discovered on September 21, 2002 by Stephen Morley. It shoots two c/7 diagonal spaceships in opposite directions every 404 generations. Jason's bow, shown to the right, is a smaller version of Safalra's bow that was found by Jason Summers.

Other patterns

One puffer that commonly appears from random starting configurations is shown below. Its period is 170 and it travels at speed 13c/170. It is formed by a common six-cell pattern, which is the smallest pattern that exhibits infinite growth in this rule.

A six-cell starting configuration of the puffer
A common puffer
Download RLE: click here

References

  1. The name given to this rule in Golly, in reference to Stephen Morley, who has extensively studied it.
  2. 2.0 2.1 "Move (B368/S245)". David Eppstein. Retrieved on March 28, 2009.
  3. Computed using the EnumStillLifes.c script located here.
  4. "b368s245 Guns". Stephen Morley. Retrieved on March 28, 2009.