---
title: "Reflector (cellular automaton)"
chunk: 1/1
source: "https://en.wikipedia.org/wiki/Reflector_(cellular_automaton)"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T11:37:59.197641+00:00"
instance: "kb-cron"
---

In cellular automata such as Conway's Game of Life, a reflector is a pattern that can interact with a spaceship to change its direction of motion, without damage to the reflector pattern. In Life, many oscillators can reflect the glider; there also exist stable reflectors composed of still life patterns that, when they interact with a glider, reflect the glider and return to their stable state.


== Types ==
As well as whether a reflector is a still life or an oscillator, a reflector might be characterised by the angle between the input and output spaceships (for example a 180° reflector would flip a spaceship). For most spaceships, this can only be 0°, 90°, or 180°. Another property is whether the reflector is colour preserving. That is, if it doesn't change the state of a spaceship as it gets reflected. If a reflector isn't colour preserving, it's known as colour changing.


== Notes ==


== References ==


== External links ==
New stable 180-degree glider reflector Archived 2012-02-22 at the Wayback Machine, Game of Life News, May 30, 2009
New stable 90-degree glider reflector, Game of Life News, May 29, 2013