Cool Universes in the Cosmos of Cellular Automata

The parent of this page is: Conway's Game of Life: a Java Applet with Autodetection of Patterns.

Readers familiar with the Game of Life (see our main page; if not already familiar, visit our introduction) are probably aware of the existence of a number of "otherworlds": cellular automata similar in nature(1) to the Game of Life, but where the rules for when cells survive or are born are different, resulting in patterns and structures with very surprising appearances and behavior. The purpose of this page is to present a number of such universes that seem to be extremely fascinating.

Due to the large amount of available information, rather than putting everything in a single page, we prefer to devote individual pages to each of those cool universes. Click on any of the pictures, below, to move to the page where the corresponding world is described. For another view at classification of cellular atomata we encourage the reader to take a look at David Eppstein's classification (see bottom of his page). However, we follow our own empirical "classification" below, because we are unable to characterize with certainty every case presented here as belonging to one of Prof. Eppstein's four classes.

"Otherworldly" Cellular Automata

Expanding Universes
(most patterns expand to infinity)


Patterns smaller than around 12 x 12 become oscillators of very high periods. Also, the slowest glider resides here!


Patterns have an aboeba-like appearance. Most patterns larger than around 100 x 100 expand, but extremely slowly; others vanish.


Most patterns explode fast with an aboeba-like border, acquiring a texture with maze-like appearance.

Coagulating Blobs

Almost all patterns expand slowly in a circular-like shape, creating coagulating blobs in the central region. The blobs join and expand, containing inverse still lives and oscillators.


Rectangles filled randomly at a density of around 30% produce blobs that first shrink fast, but then start expanding slowly, resulting in coral-like or sponge-like patterns.


Stable Universes
(most patterns initially expand, then stabilize)


Patterns grow in unexpected directions, until they stabilize to colorful oscillating stains.


Contracting Universes
(most patterns contract, either disappearing, or becoming oscillators)

Oscillators Rule

Patterns shrink densely into tiny oscillators of periods between 1 and 16.

Spontaneous Creation

Patterns shrink sparsely into oscillators, and a puffer and a spaceship are almost always created.

Spontaneous Self-replication

Also known as "high life", this universe often produces spontaneously a self replicating pattern.

Chaotic Universes
(most patterns contract, but a few of them move or glide, disturbing the debris and producing further action)




1. Cellular automata such as Conway's Game of Life and all the automata presented here belong to the class of totalistic cellular automata, so called because in order to find whether a cell will be born, survive, or die, we count its alive neighbors and base our decision on the total sum of that counting. Another possibility is to take into account the specific location of some neightbors. (E.g., to state that a cell is born if its upper and lower-left neighbors are simultaneously alive.) Still other possibilities are to count more than the immediate eight neighbors, to allow more than two states for each cell (i.e., alive and dead), to work in less or more than two dimensions, to work with a non-orthogonal space (e.g., hexagonal), and so on.

Back to the main page