p29 pre-pulsar shuttle
|p29 pre-pulsar shuttle|
|View animated image|
|View static image|
|Number of cells||54|
|Discovered by||David Buckingham|
|Year of discovery||1980|
p29 pre-pulsar shuttle (or prime) is a period-29 shuttle oscillator discovered by David Buckingham on August 2, 1980, making it the first oscillator of that period to be found. In terms of its 54 cells it is the smallest known period-29 oscillator.
The oscillator works by combining the 15-generation, two-tub pre-pulsar shuttle mechanism used in Eureka with a 14-generation pre-pulsar shuttle mechanism. Hassling pre-pulsars in this way was the only known way of constructing period-29 oscillators until the discovery of the p29 traffic-farm hassler.
In September 1994 Bill Gosper found that two copies of a variant of pre-pulsar shuttle 29 could be used to hassle a pentadecathlon, resulting in p29 pentadecathlon hassler. Gosper used this to construct the p58 toadsucker.
Some variants of this shuttle are also known and have been synthesised over the years. For example, a linear form with two pre-pulsars and two house siamese shillelaghs was synthesized in 28 gliders by Mark Niemiec and Heinrich Koenig in September 2007. Later, a 43-glider synthesis for another 56-cell variant (56P29) was found by Martin Grant in October 2013, which has since been reduced to 33 gliders.
A fourfold symmetric variant of this oscillator was first known to appear semi-naturally in December 2014, in a soup found by Richard Schank using apgsearch. As discovered by Jeremy Tan, it has a very simple 24-glider synthesis because just four lumps of muck and four pi-heptominoes with fourfold rotational symmetry produces the oscillator plus eight blocks farther out. A 31-glider synthesis for the infobox form was also provided in the same post.
Generation 4 reveals two pre-pulsars (black)
being hassled by a 15-generation mechanism (green)
and a 14-generation mechanism (red)
- p26 pre-pulsar shuttle
- p28 pre-pulsar shuttle
- p47 pre-pulsar shuttle
- p58 pre-pulsar shuttle
- p55 pre-pulsar hassler
- Dean Hickerson's oscillator stamp collection. Retrieved on December 8, 2019.
- More Glider Constructions at Game of Life News. Posted by Heinrich Koenig on September 16, 2007.
- Martin Grant (October 11, 2013). Re: Synthesising Oscillators (discussion thread) at the ConwayLife.com forums
- Richard Schank (December 18, 2014). Re: Soup search results (discussion thread) at the ConwayLife.com forums
- Jeremy Tan (June 7, 2019). Re: Synthesising Oscillators (discussion thread) at the ConwayLife.com forums
- 54P29.1 at Heinrich Koenig's Game of Life Object Catalogs
- New Oscillators at Game of Life News. Posted by Heinrich Koenig on January 08, 2009.