p29 pre-pulsar shuttle

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p29 pre-pulsar shuttle
x = 28, y = 28, rule = B3/S23 15bo$13b3o$12bo$12b2o2$bo$obo3b3o$bo4bobo6b2o$6b3o6b2o3$19b2o$6b3o10b 2o5b2o$bo4bobo17bo$obo3b3o15bobo$bo22b2o4$13b3o3b3o$13bobo3bobo$13b3o 3b3o4$13bo7bo$12bobo5bobo$13bo7bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART ]] #C [[ GPS 5 ZOOM 10 LOOP 29 ]]
Pattern type Oscillator
Oscillator type Shuttle
Number of cells 54
Bounding box 28×28
Period 29
Mod 29
Heat 41.5
Volatility 0.90
Strict volatility 0.90
Discovered by David Buckingham
Year of discovery 1980

p29 pre-pulsar shuttle (or prime[1]) is a period-29 shuttle oscillator discovered by David Buckingham on August 2, 1980,[1] 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.[2] Later, a 43-glider synthesis for another 56-cell variant (56P29) was found by Martin Grant in October 2013,[3] 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.[4] 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.[5] A 31-glider synthesis for the infobox form was also provided in the same post.


Prepulsar29 gen4.png
Generation 4 reveals two pre-pulsars (black)
being hassled by a 15-generation mechanism (green)
and a 14-generation mechanism (red)
x = 27, y = 18, rule = b3/s23 10b2o3b2o10b$9bo2bobo2bo9b$5b2o3b2o3b2o3b2o5b$5bo15bo5b$2b2obo15bob2o 2b$o2bob2o13b2obo2bo$2obo19bob2o$3bo19bo3b$3b2o17b2o3b$9b3o3b3o9b$9bob o3bobo9b$9b3o3b3o9b4$9bo7bo9b$8bobo5bobo8b$9bo7bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 ZOOM 12 ]]
A slightly larger version of this oscillator,
56P29, with just one pre-pulsar (center) and
an alternate 14-generation stabilization (top)
(click above to open LifeViewer)
RLE: here Plaintext: here
x = 39, y = 39, rule = b3/s23 16b2o3b2o16b$15bo2bobo2bo15b$11b2o3b2o3b2o3b2o11b$11bo15bo11b$8b2obo 15bob2o8b$7bobob2o13b2obobo7b$7bobo19bobo7b$5b2o2bo19bo2b2o5b$4bo4b2o 17b2o4bo4b$4b5o6b3o3b3o6b5o4b$8bo6bobo3bobo6bo8b$2b4o9b3o3b3o9b4o2b$2b o2bo27bo2bo2b3$bo7b3o15b3o7bob$obo6bobo15bobo6bobo$obo6b3o15b3o6bobo$b o35bob2$bo35bob$obo6b3o15b3o6bobo$obo6bobo15bobo6bobo$bo7b3o15b3o7bob 3$2bo2bo27bo2bo2b$2b4o9b3o3b3o9b4o2b$8bo6bobo3bobo6bo8b$4b5o6b3o3b3o6b 5o4b$4bo4b2o17b2o4bo4b$5b2o2bo19bo2b2o5b$7bobo19bobo7b$7bobob2o13b2obo bo7b$8b2obo15bob2o8b$11bo15bo11b$11b2o3b2o3b2o3b2o11b$15bo2bobo2bo15b$ 16b2o3b2o! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 ZOOM 8 HEIGHT 420 ]]
A much larger version of this
oscillator with four pre-pulsars
(click above to open LifeViewer)
RLE: here Plaintext: here
x = 28, y = 28, rule = B3/S23 15bo$13b3o$12bo$12b2o2$bo$obo7b2o$bo7b3o3b2o$10b2o3b2o3$19b2o$10b2o7b2o5b2o$b o7b3o14bo$obo7b2o12bobo$bo22b2o$13b3o3b3o$13b3o3b3o$14bo5bo3$4b3o$4b3o$4b3o$b 3o$b3o9bo7bo$b3o8bobo5bobo$13bo7bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ THUMBSIZE 2 ZOOM 8 ]]
figure eight on p29 pre-pulsar shuttle,
the smallest known LCM oscillator where
some spark cells oscillate at p232
(click above to open LifeViewer)
RLE: here Plaintext: here

See also


  1. 1.0 1.1 Dean Hickerson's oscillator stamp collection. Retrieved on December 8, 2019.
  2. More Glider Constructions at Game of Life News. Posted by Heinrich Koenig on September 16, 2007.
  3. Martin Grant (October 11, 2013). Re: Synthesising Oscillators (discussion thread) at the ConwayLife.com forums
  4. Richard Schank (December 18, 2014). Re: Soup search results (discussion thread) at the ConwayLife.com forums
  5. Jeremy Tan (June 7, 2019). Re: Synthesising Oscillators (discussion thread) at the ConwayLife.com forums

External links