User:Dvgrn/Readme/Main
Newcomers Start Here: The Hitchhiker's Guide to the Galaxy
First of all, don't panic. There is a lot of jargon and specialized terminology used on the conwaylife.com forums and the ConwayLife Lounge Discord server, but it's mostly quite carefully defined on the LifeWiki and in the Life Lexicon. Many friendly folks can also be found in those first two locations who are very happy to help flatten the learning curve a little bit, if you're willing to dig in and figure things out. For anyone who wants a highly organized walkthrough from the basics up through Conway's Life computational circuitry and self-constructing patterns, there is even a free online Game of Life textbook.
What is Conway's Game of Life?
Conway's Game of Life is not a traditional game; instead, it is a "zero player game" where the outcome is determined by the initial state. Specifically, Life is a cellular automaton developed by the eponymous British mathematician John Horton Conway.
First, let's understand what cellular automaton means. Cellular automata consist of a grid of cells (in Life's case, a grid of squares) that change state every generation based on the state of neighboring cells. Cellular automata can range from extremely complex, with dozens of states and many rules governing the cells' behavior, to extremely simple. Life, thankfully, falls on the simpler side. In Life, cells only have two states, on or off. The state of a cell is determined by the 8 neighboring cells surrounding it. Knowing this information, Life's rules can be described very succinctly:
- If a living cell has 2 or 3 neighbors, it will survive.
- If a dead cell has exactly 3 neighbors, it will be born.
- All other live cells die in the next generation, and all other dead cells stay dead.
Conway developed the Game of Life because he was interested in creating simple cellular automata with complex and unpredictable behavior. Despite being extremely simple and wholly deterministic (in other words, there is no randomness involved), Life has warranted over 50 years of intensive study of its properties.
There are three basic kinds of patterns in the Game of Life:
- Still lives, which do not change from generation to generation and are generally uninteresting, but sometimes interact with other patterns in a useful way
- Oscillators, patterns that repeat after a number of generations
- Spaceships, patterns that move indefinitely across the board.
There exist a whole range of other patterns, however. For example, puffers are spaceships that leave a "trail" of debris behind them, and guns are patterns that repeatedly "fire" spaceships.
Why is Conway's Life interesting?
Firstly, it is important to examine what Conway was looking for when he made the Game of Life. Conway wanted to avoid two common types of cellular automata - those that collapse into static or predictable patterns almost immediately, and those that violently explode into uncontrollable chaos. Instead, he wanted it to be highly difficult to determine whether an initial pattern would survive, keep expanding, or die out. While we now know that the vast majority of small, chaotic patterns eventually stabilize, many of them take hundreds or thousands of generations to actually do so. This makes Life a clear example of order emerging from chaos, as well as an example of complex behavior emerging from simple rules.
Additionally, many small patterns in Life can react with other patterns, enabling the construction of engineered patterns. In fact, it is possible to build a computer in the Game of Life, and it has been long proven to be Turing Complete: in layman's terms, Life is theoretically capable of computing anything your computer can. Many small patterns have non-obvious uses. Gliders, the smallest spaceships in Life, can be used to construct other patterns and can also function as bits on a memory tape. The block, a 2x2 square, has many reactions with other patterns and is used in many guns. There are many small still lives known as eaters which can stabilize various patterns and destroy, or "eat", spaceships. Using relatively simple reactions, many things can be constructed, such as patterns that simulate Life in Life and a computer that calculates and displays the digits of pi.
Another important problem that interested Conway was the existence of a self-replicating pattern in Life. While we now know that several replicators exist, they are all extremely large and carefully engineered patterns. Conway's initial interest was inspired by the fellow mathematician John Von Neumann, who created the first replicating pattern in a cellular automaton. However, Neumann's pattern used an extremely complex rule with many states and arbitrary rules, and the construction of a similar pattern in a more "naturalistic" rule was of great interest to many.
How can I join and contribute to the community?
Read the FAQ page.
See also
the 50th anniversary article commemorating the invention of Conway's Game of Life, NYT