Eureka

Eureka
#C A period 30 pre-pulsar shuttle oscillator found in August 1980 x = 18, y = 11, rule = B3/S23 bo14bo$obo4bo7bobo$bo3b2ob2o6bo$7bo4$7bo$bo3b2ob2o6bo$obo4bo7bobo$bo 14bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ AUTOSTART ]] #C [[ GPS 6 LOOP 30 THUMBSIZE 3 WIDTH 600 HEIGHT 480 ]]
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Pattern type	Oscillator
Oscillator type	Shuttle
Number of cells	28
Bounding box	18 × 15
Period	30 (mod: 15)
Heat	22.4
Volatility	0.91 | 0.91
Kinetic symmetry	Unspecified
Discovered by	David Buckingham
Year of discovery	1980
Rules Outer-totalistic rules B3/S23 – B37/S2378 # of rules 23 = 8 Isotropic rules B3-k/S23-ck – B34kq5-e6aek7/S234ckqyz5ackqr6ei78
Glider synthesis Fewest gliders 11 Catagolue-generated RLE synthesis Uploaded synthesis RLE eureka_synth.rle
Pattern files Plaintext eureka.cells RLE eureka.rle
Identifiers apgcode xp30_252y1252z04r4x4r4zz252y1252 Pentadecathlon ID 28P30.1

Eureka (or p30 pre-pulsar shuttle) is a period-30 pre-pulsar shuttle oscillator in which two 15-generation pre-pulsar shuttle mechanisms each composed of two tubs hassle a pre-pulsar. It was found by David Buckingham on August 16, 1980. A slightly different period-30 shuttle can be created by shifting the top half of the shuttle two cells to the left or right (see below). This allows the outermost tubs to optionally be replaced by blocks.

The first known semi-natural appearance of a version of this oscillator was in November 2014 in a soup found by Adam P. Goucher using apgsearch. The monomerised version first occurred in March 2016. A fourfold skewed version appeared in a soup by Charity Engine on February 5, 2022.

Gallery

• 

  Generation 1 of Eureka, which shows that the object being hassled is a pre-pulsar

x = 19, y = 11, rule = B3/S23 15bo$6bo7bobo$2o2b2ob2o6bo$2o4bo4$8bo$2bo3b2ob2o6bo$bobo4bo7bobo$2bo 14bo! #C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]] #C [[ GPS 6 LOOP 30 THUMBSIZE 2 HEIGHT 400 AUTOSTART ]] A skewed variant of Eureka with one tub replaced by a block (click above to open LifeViewer) RLE: here Plaintext: here

External links

• Eureka at the Life Lexicon
• 28P30.1 at Heinrich Koenig's Game of Life Object Catalogs

Adam P. Goucher's Catagolue

(by end stabilisations)

Tub (and block) variants

• eureka

• skewed variant

• [2-fold] dimer
• [4-fold] tetramer

• skewed variant thereof

Pentadecathlon variants

• single pentadecathlon on ends (dimer and tetramer thereof)
• two pentadecathlons on ends (dimer thereof)
• pentadecathlon on either side (dimer, by necessity, to avoid self-intersection)

Other notable seminatural occurrences

• Mutually supporting two queen bees on one end (cis- and trans- versions, trans- one involves much closer interaction)