Life Lexicon (W)
Author: Stephen A. Silver
Description: Part of Stephen Silver's Life Lexicon.

Introduction | Bibliography

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:washerwoman (2c/3 p18 fuse) A fuse by Earl Abbe.

    O.......................................................
    OO....O.....O.....O.....O.....O.....O.....O.....O.....O.
    OOO..O.O...O.O...O.O...O.O...O.O...O.O...O.O...O.O...O.O
    OO....O.....O.....O.....O.....O.....O.....O.....O.....O.
    O.......................................................

:washing machine (p2) Found by Robert Wainwright before June 1972.

    .OO.OO.
    O.OO..O
    OO....O
    .O...O.
    O....OO
    O..OO.O
    .OO.OO.

:wasp (c/3 orthogonally, p3) The following spaceship which produces a domino spark at the back. It is useful for perturbing other objects. Found by David Bell, March 1998.

    ..........OO.OO.......
    ........OO.O.OO.OO....
    .....OOO.O..OOO..OOOO.
    .OOO....OOO.....O....O
    O.O.O.OOO.O........OO.
    O.O.O.OOOO............
    .O.O....O..O..........
    ..........O...........
    ..O...................
    ..O...................

:wavefront (p4) Found by Dave Buckingham, 1976 or earlier.

    ........OO...
    ........O....
    .........O...
    ........OO...
    .....OO...OO.
    ....O..OOO..O
    ....O.....OO.
    .....O...O...
    OO.O.O...O...
    O.OO.O.OO....
    ....O.O......
    ....O.O......
    .....O.......

:waveguide See superstring.

:weekender (2c/7 orthogonally, p7) Found by David Eppstein in January 2000. In April 2000 Stephen Silver found a tagalong for a pair of weekenders. At present, n weekenders pulling n-1 tagalongs constitute the only known spaceships of this speed or period.

    .O............O.
    .O............O.
    O.O..........O.O
    .O............O.
    .O............O.
    ..O...OOOO...O..
    ......OOOO......
    ..OOOO....OOOO..
    ................
    ....O......O....
    .....OO..OO.....

:weld To join two or more still lifes or oscillators together. This is often done in order to fit the objects into a smaller space than would otherwise be possible. The simplest useful example is probably the integral sign, which can be considered as a pair of welded eater1s.

:Wheels, Life, and other Mathematical Amusements One of Martin Gardner's books (1983) that collects together material from his column in Scientific American. The last three chapters of this book contain all the Life stuff.

:why not (p2) Found by Dave Buckingham, July 1977.

    ...O...
    ...O.O.
    .O.....
    O.OOOOO
    .O.....
    ...O.O.
    ...O...

:wick A stable or oscillating linearly repeating pattern that can be made to burn at one end. See fuse.

:wickstretcher A spaceship-like object which stretches a wick that is fixed at the other end. The wick here is assumed to be in some sense connected, otherwise most puffers would qualify as wickstretchers. The first example of a wickstretcher was found in October 1992 (front end by Hartmut Holzwart and back end by Dean Hickerson) and stretches ants at a speed of c/4. This is shown below with an improved back end found by Hickerson the following month.

    .................OO..............................
    .............OO....O.............................
    ............OOO.O................................
    O.OO..OO...O...OOOO.O.O....OO.......OO...........
    O....OO..O........O.OOO....O....OO.O..O.OO.O.....
    O.OO....OO.OO....O...........O...O.O.OO.O.OO.....
    ......O.......O.............OO.....O..O.O...OO...
    .....O.........O.O....OOO...O....O..O.O.OOO...O..
    .....O.........O.O....OOO.OO.O..OO.O.O...O..OO.O.
    ......O.......O.............OO.O...OO....OO....O.
    O.OO....OO.OO....O..........O........OO.O.O.OO.OO
    O....OO..O........O.OOO........O...O...OO.O..O.O.
    O.OO..OO...O...OOOO.O.O.......O.O...OO....O..O.O.
    ............OOO.O..............O.....O.OOO....O..
    .............OO....O.................O.O.........
    .................OO...................O..........

Diagonally moving c/4 and c/12 wickstretchers have also been built: see tubstretcher and linestretcher. In July 2000 Jason Summers constructed a c/2 wickstretcher, stretching a p50 traffic jam wick, based on an earlier (October 1994) pattern by Hickerson.

:wicktrailer Any extensible tagalong, that is, one which can be attached to the back of itself, as well as to the back of a spaceship. The number of generations which it takes for the tagalong to occur again in the same place is often called the period of the wicktrailer - this has little relation to the period of the tagalong units themselves.

:windmill (p4) Found by Dean Hickerson, November 1989.

    ...........O......
    .........OO.O.....
    .......OO.........
    ..........OO......
    .......OOO........
    ..................
    OOO...............
    ...OO..OOO.OO.....
    ..........OOOOOOO.
    .OOOOOOO..........
    .....OO.OOO..OO...
    ...............OOO
    ..................
    ........OOO.......
    ......OO..........
    .........OO.......
    .....O.OO.........
    ......O...........

:wing The following induction coil. This is generation 2 of block and glider.

    .OO.
    O..O
    .O.O
    ..OO

:WinLifeSearch Jason Summers' GUI version of lifesrc for MS Windows. It is available from http://entropymine.com/jason/life/software/.

:Winning Ways A two-volume book (1982) by Elwyn Berlekamp, John Conway and Richard Guy on mathematical games. The last chapter of the second volume concerns Life, and outlines a proof of the existence of a universal constructor.

:with-the-grain grey ship A grey ship in which the region of density 1/2 consists of lines of ON cells lying parallel to the direction in which the spaceship moves. See also against-the-grain grey ship.

:WLS = WinLifeSearch

:worker bee (p9) Found by Dave Buckingham in 1972. Unlike the similar snacker this produces no sparks, and so is not very important. Like the snacker, the worker bee is extensible - it is, in fact, a finite version of the infinite oscillator which consists of six ON cells and two OFF cells alternating along a line. Note that Dean Hickerson's new snacker ends also work here.

    OO............OO
    .O............O.
    .O.O........O.O.
    ..OO........OO..
    ................
    .....OOOOOO.....
    ................
    ..OO........OO..
    .O.O........O.O.
    .O............O.
    OO............OO

:W-pentomino Conway's name for the following pentomino, a common loaf predecessor.

    O..
    OO.
    .OO

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