Figure eight

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Figure eight
2o$2obo$4bo$bo$2bob2o$4b2o! #C [[ THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART ]] #C [[ GPS 4 THUMBSIZE 2 ]]
Pattern type Oscillator
Number of cells 12
Bounding box 10×10
Frequency class 23.4
Period 8
Mod 8
Heat 16.5
Volatility 1.00
Strict volatility 1.00
Discovered by Simon Norton
Year of discovery 1970

Figure eight (or less frequently, big beacon[1]) is a period 8 oscillator found by Simon Norton in 1970. With 12 cells in its initial phase, it is the smallest known period 8 oscillator, behind blocker at 15 cells. It is known that no period 8 oscillators exist with 10 or fewer cells.[2]

As a building block for larger oscillators

Because it produces a domino spark in one of its phases, it is useful for constructing larger oscillators that have period that is a multiple of eight. For example, it appears in tumbling T-tetson (period 8), sailboat (period 16), caterer on figure eight (the smallest period 24 oscillator), and figure eight on 36P22 (period 88).

As a reflector

Figure eight has the ability to act as a 90-degree glider reflector when it is combined with a block, boat and eater 1. The input path (in green) and output path (in red) of the glider are shown below.

Figure eight acting as a reflector
RLE: here


Figure eight is the tenth most common naturally-occurring oscillator in Achim Flammenkamp's census, being less common than the great on-off but more common than the spark coil.[3] On Catagolue, it is the most common period 8 oscillator, being more common than blocker.[4]

Image gallery

See also


  1. "Big beacon". The Life Lexicon. Stephen Silver. Retrieved on June 14, 2011.
  2. Mark Niemiec (1998). "Life Period-8 Oscillators". Retrieved on February 5, 2009.
  3. Achim Flammenkamp (September 7, 2004). "Most seen natural occurring ash objects in Game of Life". Retrieved on January 15, 2009.
  4. Adam P. Goucher. "Statistics". Catagolue. Retrieved on October 27, 2018.

External links

  • 12P8.1 at Heinrich Koenig's Game of Life Object Catalogs