Silver's p5 is a period-5 oscillator that was found by Stephen Silver on February 17, 2000. 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.
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, followed by a 6-glider version by Martin Grant later the same day. The cheapest known variant, using an eater 1, therefore costs 8 gliders.
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. Other stator variants have since occurred naturally.
- 17P5.2 at Heinrich Koenig's Game of Life Object Catalogs