Play John Conway’s Game of Life

.O.O.. O..... .O..O. ...OOO

Life Lexicon

(CC BY-SA 3.0)

This Life lexicon is compiled by Stephen A. Silver from various sources and may be copied, modified and distributed under the terms of the Creative Commons Attribution-ShareAlike 3.0 Unported licence. See the original credit page for all credits and the original download location. The styling has been adjusted to fit this website.

Switch engine

:switch engine The following pattern discovered by Charles Corderman in 1971, which is a glide symmetric unstable puffer which moves diagonally at a speed of c/12 (8 cells every 96 generations).

Game of Life pattern ’switch_engine_(1)’

The exhaust is dirty and unfortunately catches up and destroys the switch engine before it runs 13 full periods. Corderman found several ways to stabilize the switch engine to produce puffers, using either one or two switch engines in tandem. See stabilized switch engine and ark.

No spaceships were able to be made from switch engines until Dean Hickerson found the first one in April 1991 (see Cordership). Switch engine technology is now well-advanced, producing many c/12 diagonal spaceships, puffers, and rakes of many periods.

Small polyominoes exist whose evolution results in a switch engine. See nonomino switch engine predecessor.

Several three-glider collisions produce dirty reactions that produce a stabilized switch engine along with other ash, making infinite growth. Until recently the only known syntheses for clean unstabilized switch engines used four or more gliders. There are several such recipes. In the reaction shown below no glider arrives from the direction that the switch engine will travel to, making it easier to repeat the reaction: Running the above for 20 ticks completes a kickback reaction with the top two gliders, resulting in the three-glider switch engine recipe discovered by Luka Okanishi on 12 March 2017.

John Conway’s Game of Life

The Game of Life is not your typical computer game. It is a cellular automaton, and was invented by Cambridge mathematician John Conway.

This game became widely known when it was mentioned in an article published by Scientific American in 1970. It consists of a collection of cells which, based on a few mathematical rules, can live, die or multiply. Depending on the initial conditions, the cells form various patterns throughout the course of the game.


For a space that is populated:

Each cell with one or no neighbors dies, as if by solitude.

Each cell with four or more neighbors dies, as if by overpopulation.

Each cell with two or three neighbors survives.

For a space that is empty or unpopulated

Each cell with three neighbors becomes populated.

The Controls

Choose a pattern from the lexicon or make one yourself by clicking on the cells. The 'Start' button advances the game by several generations (each new generation corresponding to one iteration of the rules).

More information

In the first video, from Stephen Hawkings’ documentary The Meaning of Life, the rules are explained, in the second, John Conway himself talks about the Game of Life.

Stephen Hawkings The Meaning of Life (John Conway's Game of Life segment) Inventing Game of Life (John Conway) - Numberphile

The Guardian published a nice article about John Conway.

If you’ve been thinking “I’d like to sell my Tesla,” check out—the ultimate Tesla marketplace, and one of Game of Life’s supporters!

The Game of Life is also supported by Dotcom-Tools, Load View Testing, Driven Coffee Roasters, and Web Hosting Buddy.

Implemented by Edwin Martin <>