Fore and back

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Fore and back
2ob2o2b$2obobob$6bo$3ob3o$o6b$bobob2o$2b2ob2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART ]] #C [[ GPS 2 THUMBSIZE 2 ]]
Pattern type Oscillator
Oscillator type Muttering moat
Billiard table
Number of cells 24
Bounding box 7 × 7
Frequency class 30.6
Period 2 (mod: 1)
Heat 4
Volatility 0.15 | 0.15
Kinetic symmetry .cxc
Rotor type Pole 2
Discovered by Achim Flammenkamp
Year of discovery 1994

Fore and back (or complementary blinker[1]) is a period-2 oscillator that was found by Achim Flammenkamp on July 12, 1994.[2] It has the same rotor as the blinker.

Commonness

Main article: List of common oscillators

Fore and back is about the thirty-eighth most common naturally-occurring oscillator in Achim Flammenkamp's census, being less common than boat on spark coil and block on griddle, about as common as xp2_8e1t2gozw23, and more common than trans-block on candlefrobra and trans-beacon down on long bookend.[3] It is the 33rd most common oscillator on Adam P. Goucher's Catagolue. It is the most common oscillator that is generally agreed to be a billiard table, though some instead give this title to the more common test tube baby, which counts under a looser definition.[4]

Formation

Fore and back typically forms via the predecessor below.

2b3o$obobo$2bo3bo$bo2b3o$5bo2$2b2o$2b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ GPS 6 THUMBSIZE 2 ]]
(click above to open LifeViewer)

Glider synthesis

In August 2013, a 24-glider synthesis of this oscillator was found by Martin Grant, based on a soup provided by Lewis Patterson. Several days later Mark Niemiec improved this result, having found a 20-glider synthesis.[5]

In October 2014, Tanner Jacobi found a predecessor for this pattern based on a soup from Adam P. Goucher's apgsearch script,[6] which was eventually optimized to a 6-glider synthesis[7] in November.

See also

References

  1. ↑ "Complementary blinker". The Life Lexicon. Stephen Silver. Retrieved on December 3, 2018.
  2. ↑ Dean Hickerson's oscillator stamp collection. Retrieved on March 14, 2020.
  3. ↑ Achim Flammenkamp (September 7, 2004). "Most seen natural occurring ash objects in Game of Life". Retrieved on January 15, 2009.
  4. ↑ Dave Greene (July 3, 2019). Re: Thread for basic questions (discussion thread) at the ConwayLife.com forums
  5. ↑ Lewis Patterson (August 4, 2013). Re: Synthesising Oscillators (discussion thread) at the ConwayLife.com forums
  6. ↑ Tanner Jacobi (October 15, 2014). Re: Soup search results (discussion thread) at the ConwayLife.com forums
  7. ↑ Tanner Jacobi (November 8, 2014). Re: Soup search results (discussion thread) at the ConwayLife.com forums