Light bulb

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Light bulb
x = 7, y = 9, rule = B3/S23 b2obo$bob2o2$2b3o$bo3bo$bo3bo$2bobo$obobobo$2o3b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART ]] #C [[ GPS 2 ZOOM 20 LOOP 2 ]]
Pattern type Oscillator
Oscillator type Babbling brook
Billiard table
Number of cells 23
Bounding box 7×9
Period 2
Mod 2
Heat 3
Volatility 0.12
Strict volatility 0.12
Rotor type Filament
Discovered by Unknown
Year of discovery 1971

Light bulb is a period-2 oscillator that was found in 1971.[1][2] Its rotor, known as the filament,[3] is the only known 3-cell period 2 rotor, and it can be embedded in a slightly smaller stator, giving the 21-cell variant shown below. Two other variants of this oscillator are also known.[4] Various other small induction coils can also be used in place of the snake at the top of the bulb, including house and bookend, (the latter of which has a known 6-glider synthesis for the resulting oscillator) though these lead to larger bounding boxes.

First soup-based syntheses for this oscillator were discovered by Mark Niemiec on December 17, 2004 based on results from Andrzej Okrasinski's census, costing 11 gliders for the house-stabilized version and 16 for the bookend-stabilized version.[5]

x = 9, y = 9, rule = B3/S23 3bo$b3o$o$6o$6bo$2bo3bo$2b2obo$6b3o$8bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 AUTOSTART GPS 2 ]]
A variant of the light bulb
that is 2 cells smaller
(click above to open LifeViewer)
RLE: here Plaintext: here


  1. Robert Wainwright (September 1971). Lifeline, vol 3, page 3.
  2. Dean Hickerson's oscillator stamp collection. Retrieved on March 14, 2020.
  3. Heinrich Koenig. "Filament". Game of Life Dictionary.
  4. "Period 2 Oscillator Rotors". Retrieved on March 16, 2009.
  5. Jason Summers' jslife pattern collection. Retrieved on January 5, 2020.

External links