# Unit cell

A **unit cell** is a subset (usually rectangular or square) of the Life plane that tiles over the plane, along with a fixed number of distinct patterns, with each tile assuming one of the patterns, such that it simulates a cellular automaton, possibly itself. A **unit Life cell** is a unit cell that simulates the Game of Life. To avoid single cells themselves being considered unit cells, the size of a unit cell must be greater than 1x1.

The first unit Life cell was constructed by David Bell in 1996.^{[1]} It employs standard glider logic to determine whether or not a glider should be present. The two states differ by a single glider. In 2004, Jared Prince modified David Bell's unit Life cell to support two (and therefore multiple) layers of Life universes, coined "deep cell".^{[2]}

More recently OTCA metapixel was constructed that simulates any Life-like cellular automaton.^{[3]} Designed to run quickly in HashLife, it has the advantage of having two states that are clearly distinct when zoomed out.

## References

- ↑ Paul Callahan (March 1, 1996). "The Unit Life Cell".
- ↑ Jared Prince (September 27, 2004). "Game of Life Deep Cell".
- ↑ "OTCAmetapixel".

## External Links

- Unit Life cell at Eric Weisstein's Treasure Trove of Life

- Unit cell at the Life Lexicon