Dead spark coil

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Dead spark coil
x = 7, y = 5, rule = B3/S23 2o3b2o$obobobo$2bobo$obobobo$2o3b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C Still life
Pattern type Strict still life
Number of cells 18
Bounding box 7×5
Frequency class 16.3
Discovered by Unknown
Year of discovery Unknown

Dead spark coil (or cis-house on house or JC) is an 18-bit still life. It is composed of two houses that are acting as induction coils to stabilize each other. It is an oscillator in Highlife. One half can eat gliders, but both the top and bottom of that side must have a glider to eat, or else the other side of the house will interfere.


Dead spark coil is the forty-fifth most common still life in Achim Flammenkamp's census, being less common than trans-mirrored R-bee but more common than cis-mirrored hook.[1] It is also the thirty-nineth most common object on Adam P. Goucher's Catagolue.[2]

Dead spark coils are typically formed when two pi heptominoes face each other three cells apart. If they are four cells apart, they instead form a live spark coil.

In D2 +1 symmetry, it is the 12th most common still life, being about 100 times more common than in an asymmetric soup, and it is the most common still life that takes advantage of symmetry to be much more common.

See also


  1. Achim Flammenkamp (September 7, 2004). "Most seen natural occurring ash objects in Game of Life". Retrieved on January 15, 2009.
  2. Adam P. Goucher. "Statistics". Catagolue. Retrieved on June 24, 2016.

External links