Alan Hensel has taken the trouble of compiling an extensive glossary, which he has included as an ascii text file in his Life pattern archive. This glossary is extracted here for your convenience. Technical revisions suggested by Achim Flammenkamp and Al Hensel were added to this version on 7-Nov-95.

In-line images of patterns have now been added to this glossary. Each picture is linked to a text file that can be downloaded and run in a Life implementation. If you are using a text-only browser, you may prefer to view the original text-only glossary.

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This glossary was
compiled by Al Hensel, with indispensable help from John Conway,
Dean Hickerson, David Bell, Bill Gosper, Bob Wainwright, Noam
Elkies, Nathan Thompson, Harold McIntosh, and Dan Hoey.
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101

A for All

acorn

agar - any pattern that can periodically tile the Life universe, either as a still life or as an oscillator.

aircraft carrier

airforce

ants

aVerage

b-heptomino

b-heptomino shuttle, p46 shuttle, twin bees shuttle

B track - a type of Life object in which one or more b-heptominos are perturbed by oscillators so as to travel in a loop.

babbling brook - an oscillator whose rotor forms a chain, with each cell adjacent only to its 1 or 2 neighbors in the chain.

bakery - 4 loaves:

barber pole - a section of an oscillator or spaceship in which each generation of the section looks the same, except for a sideways shift.

barberpole - any length extension of this p2 oscillator:

barge

beacon

beehive

beehive and dock, beehive on big table

beehive with tail

bi-loaf, half bakery, loaf on loaf

biblock

big S, S-spiral

billiard table - any oscillator that is built inside a stable border. Examples: hertz oscillator, pressure cooker, hustler.

bipole, short barberpole - this length of the barberpole:

blinker

blinker ship - an object which travels while growing larger by leaving an increasing trail of blinkers, but which leaves no permanent exhaust. Example:

block

block and dock, block on big table

block on table

blocker

boat

boat-bit - a memory device in which a bit of information is represented as the presence or absence of a boat adjacent to a snake (or eater or beacon or ...)

boat on boat, boat-tie, bow tie, bi-boat

bookends

boss

brain

breeder - 1: any pattern that grows quadratically by creating multiple copies of a second object, each of which creates multiple copies of a third object. 2: Bill Gosper's original breeder.

bunnies

burloaferimeter

butterfly effect, sensitive dependence on initial conditions - the idea that just a small change in initial conditions, such as a butterfly flapping its wings halfway around the world, can create a large difference in outcomes, such as next month's weather.

caber tosser - a gun of variable period created by bouncing a glider off of a receding spaceship. See life pattern CORDTOSS.

caterer

cell - the fundamental spatial unit operated on by the rules of a cellular automaton during one generation.

cellular automaton - a simulated universe (such as Conway's Game of Life) in which every point's state depends on the states of nearby neighbors at an earlier generation.

census - an accounting of the types of patterns that a larger pattern consists of.

centinal

chemist

Cheshire cat - this famous pattern has been intentionally omitted because it is stupid and everybody hates it.

cis-mirrored R-bee

cis-boat with tail, down boat with tail

clock

cloverleaf, Achim's p4

confused eaters

Conway's Game of Life - a classic game invented by the British mathematician John Horton Conway in 1970. It is one of the simplest cellular automata simulations ever invented, but its richness is surprising. The rules are as follows: - The game is played on a 2-dimensional grid. Each square, or "cell", is binary (either "on" or "off"). - If a cell is off and has 3 neighbors (out of 8), it will become alive in the next clock tick. - If a cell is on and has 2 or 3 neighbors, it survives; otherwise, it dies on the next clock tick.

Cordership - a c/12 diagonally moving spaceship constructed from switch engines.

cross

dart

dead spark coil, JC

diamond ring

domino spark - a 2-bit spark, orthogonally connected, such as the one on the heavyweight spaceship.

double wing, moose antlers

eater - any still life that can repair itself from some attacks.

eater, fishhook - this eater, which eats gliders and fish:

elevener, intentionless

familiar fours - sets of four equal things that tend to crop up. Examples: traffic lights, honeyfarm, blockade, fleet, bakery.

father pattern - any pattern that precedes a given pattern by exactly 1 generation.

fencepost - anything used to stabilize the end of a wick.

figure 8, big beacon

fleet - 4 ships:

flip-flop - any period 2 oscillator, esp. those whose second generation is a mirror image of the first.

flipper - any oscillator or spaceship that forms its mirror image at half its period.

flotilla - a group of spaceships, some of which are being supported.

fourteener, 14-ner

fumarole

fuse - a way for a wick to burn from one end.

garden of eden, GOE - a pattern that has no father pattern.

generation - the smallest fundamental unit of time, during which the rules of a cellular automaton are applied once.

glider

glider gun - any pattern that grows forever by emitting gliders.

Gosper gun, original glider gun

gourmet

grammar - a set of rules used to describe an infinite number of ways that one can connect a set of parts to build one large oscillator, still-life, or spaceship.

grandfather pattern - any pattern that can precede a given pattern by exactly 2 generations.

gray counter

great on-off

gun - any pattern that grows forever by emitting spaceships.

HashLife - a Life algorithm that achieves remarkable speed by storing sub-patterns in a hash table, and using them to skip forward, sometimes thousands of generations at a time. HashLife takes tremendous amounts of memory and can't show patterns at every step, but can quickly calculate the outcome of a pattern that takes millions of generations to complete.

hassler - an oscillator that can alternately change a properly placed object, and then change it back.

hat

heavyweight emulator

heavyweight spaceship, HWSS, big fish

heavyweight volcano

Heisenburp device - a Life object which can detect the passage of a glider without affecting the glider's path or timing.

Hertz oscillator

hexlife - an alternative game similar to Conway's, which is played on a hexagonal grid. No set of rules has yet emerged as uniquely interesting.

HighLife - an alternate set of rules similar to Conway's, but with the additional rule that 6 neighbors generates a birth. Most of the interest in this variant is due to the replicator that evolves from:

honeyfarm - 4 beehives:

hustler

induction coil - any pattern used to stabilize a border. Example:

inductor - an oscillator of one or two-way orthogonal symmetry which depends on mutual symmetry to exist. Examples: pulsar, tumbler.

integral sign

jam

keys

kickback reaction

Kok's galaxy

light bulb

lightspeed wire - a wick that can burn non-destructively at the speed of light, which might be useful for sending a signal or constructing oscillators with periods not currently attainable. Unfortunately, no way has been found to return a signal to its starting point, either by reflecting it or bending it around a corner. Example:

lightweight emulator

lightweight spaceship, LWSS, small fish

line puffer - a puffer whose output comes from a long row of cells generated orthogonal to the direction of motion of the puffer. Some types of line puffers appear to be extensible and have arbitrarily large periods, but this has not been proven.

loaf

long barge

long boat

long ship

loop

lumps of muck, LoM, blockade - 4 blocks:

mango, dove, cigar

mazing

methuselah - any small "seed" pattern that does not stabilize for a very long time. Not used to describe objects that are known to grow forever. Originally defined as a pattern having a population of at most 10 and a Life-span of at least 100. Examples: acorn, bunnies, rabbits.

middleweight emulator

middleweight spaceship, MWSS, medium fish

middleweight volcano

MIT oscillator, cuphook

mold

monogram, JHC

negentropy

octagon II

Orion

oscillator - any pattern that reappears in the same position after a certain number of generations.

paperclip, drain trap

pedestle

penny lane

pentadecathlon, PD

period - the number of generations it takes for an oscillator to repeat, or a spaceship to be displaced exactly. Often the notation pN is used, for example, p2 for period 2. Also, pN/m when symmetry is involved, where m is the number of translations, for example, p6/2 describes a period 6 flipper.

phoenix - any pattern whose cells all die in every generation, and yet lives forever. Example:

pi heptomino

pond

pond on pond, bi-pond

population - the number of live ("on") cells of an object.

predecessor - any pattern that can precede a given pattern by any number of generations.

pressure cooker

pseudo-barberpole

puffer, puffer train - any pattern that moves, leaving a trail.

pulsar, CP-pulsar, pulsar CP 48-56-72

pushalong - a tagalong on the front end of a spaceship. Example:

pyrotechneczum

quad, barberpole intersection

quapole, quadpole, barberpole of length 4 - this length of the barberpole:

queen bee

queen bee shuttle, p30 shuttle

r-pentomino

R2D2

rabbits

rake - any puffer that leaves a trail of spaceships.

relay - an oscillator in which gliders or spaceships travel in a loop.

rephaser

replicator - a Life object which repeatedly forms copies of itself. Such things are known to be possible in Life, but no example is known. But in the HighLife variant, there is a simple replicator.

revolver

roteightor

rotor - the active cells in an oscillator.

sawtooth - a pattern whose population is unbounded, but doesn't tend uniformly to infinity. The population returns to its minimum value at intervals, producing a zig-zag graph. Schick engine

scorpion

scrubber

search program - a program which can find certain interesting Life objects much more quickly than a person can manually. Search programs have found new oscillators, spaceships, and collisions.

shillelagh

ship

ship on boat, boat-ship-tie

shiptie, ship on ship, bi-ship, half fleet

shuttle, piston - any oscillator in which some part moves back and forth. Examples: queen bee shuttle, b-heptomino shuttle.

siesta

sinking ship

skewed quad

smiley

snacker

snake

snake pit

sombreros

space dust - a section of an oscillator or spaceship which is composed of an almost random mixture of live and dead cells. Such objects are very hard to construct.

spacefiller - any pattern that grows quadratically by filling space with still life. spaceship - any pattern that moves, leaving no trail.

spark - any piece of an oscillator or spaceship which dies out, without further interacting with the oscillator or spaceship that created it, but can interact with other objects before dying.

spark coil, grapser

Sparky

speed of light, light speed, c - traveling at one cell per generation. Slower speeds are usually written as fractions of c.

spiral

star

stator - the unchanging cells in an oscillator.

still life - oscillators of period 1; stable patterns.

stretcher - any pattern that grows by stretching a wick or agar.

switch engine:

synthesis, glider synthesis - method of generating a pattern using gliders only.

table on table, ][, pair of tables

tagalong - a dependent part of a spaceship that can be removed without destroying the spaceship.

technician finished product

ternary reaction - a reaction in which 2 gliders on one path and 1 glider on a perpendicular path destroy each other. This is commonly used to double the period of a glider gun.

test tube baby

toad

toadsucker - a hassler that sucks a toad. Example:

toaster, lightweight volcano

traffic circle

traffic jam - a traffic light hassler. Example: traffic circle.

traffic lights - 4 blinkers:

trans-boat with tail, up boat with tail

trice tongs

tripole, short barberpole - this length of the barberpole:

tub

tub with tail

tubber

tumbler

turtle

twinhat, twin peaks

two eaters

unit Life cell - a pattern with two states, which is determined by its previous state and the previous state of its neighbors, using exactly the rules used to compute it; that is, it simulates its own universe. None have been constructed in Conway's Life yet.

unix

very long barge, long long barge

very long boat, long long boat

very long ship, long long ship

volcano - a p5 oscillator with a useful spark.

wick - a long repetitive line of stable patterns or oscillators that can easily burn if ignited at one end.

wicktrailer - an extensible tagalong for a spaceship.

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