Silver's p5

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Silver's p5
x = 11, y = 7, rule = B3/S23 2o$o$bo2bo$3b2o$3bo3bob2o$2bo4b2obo$2b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART ]] #C [[ GPS 2 THUMBSIZE 2 ]]
Pattern type Oscillator
Number of cells 17
Bounding box 11×7
Period 5
Mod 5
Heat 8.8
Volatility 0.63
Strict volatility 0.63
Discovered by Stephen Silver
Year of discovery 2000

Silver's p5 is a period-5 oscillator that was found by Stephen Silver on February 17, 2000.[1] In terms of its 17 cells it is the third smallest known period 5 oscillator, after pseudo-barberpole and octagon 2. As it has no spark, it appears upon first glance to be useless. Nonetheless, in March 2000, David Eppstein found a way to use it to reduce the size of Noam Elkies' period 5 reflector.

The version in the infobox shows a snake being used in the oscillator. This can be substituted with an aircraft carrier and will still remain a period-5 oscillator, and this snake can be substituted with even larger items such as an eater 1.


A version of this oscillator substituting an eater for a snake first occurred naturally on January 5, 2016, in a soup submitted to Catagolue by Adam P. Goucher.[2] Other stator variants have since occurred naturally.[3]

Glider synthesis

In May 2007 Mark Niemiec found a 14-glider synthesis of a variation of this oscillator that uses an aircraft carrier rather than a snake for stabilization. On September 3, 2020, goldenratio and Tanner Jacobi found an 8-glider component that adds a Silver's p5 rotor to a given still life,[4] followed by a 6-glider version by Martin Grant later the same day.[5] The cheapest known variant, using an eater 1, therefore costs 8 gliders.

See also


  1. Jason Summers' jslife pattern collection. Retrieved on March 14, 2020.
  2. gameoflifeboy (January 5, 2016). Re: Soup search results (discussion thread) at the forums
  3. Ian07 (November 14, 2018). Re: Soup search results (discussion thread) at the forums
  4. Tanner Jacobi (September 3, 2020). Message in #cgol on the Conwaylife Lounge Discord server
  5. Martin Grant (September 3, 2020). Re: Synthesising Oscillators (discussion thread) at the forums

External links

  • 17P5.2 at Heinrich Koenig's Game of Life Object Catalogs