A phi line is either of two patterns constructed by Brett Berger on October 2, 2022. The first produces a single glider stream with an irrational bit density of 1/φ.[1] The second emits gliders in a line whose slope is φ (the golden ratio).[2] Both patterns incorporate parts of an extensible8-engine Cordership discovered earlier that same day.
Pattern that emits a southwest glider stream in a line with slope φ (click above to open LifeViewer) RLE:herePlaintext:here
Puffer version
In 1999, Dean Hickerson constructed a pattern that produces a glider stream with density 1/(φ + 1) relative to a complete p120 glider stream, as shown below. Two puffers move east, producing a westward MWSS and a boat every 60 ticks. Two stationary guns produce a glider every 60 ticks and an eastward MWSS every 120 ticks. Half the gliders delete the MWSSs while the other half escape. But when a westward MWSS reaches the guns, it deletes 2 consecutive gliders, allowing one eastward MWSS to escape and suppressing one output glider. When an eastward MWSS hits a boat, it becomes a northeastward glider which deletes one westward MWSS. Thus, each westward MWSS that reaches the guns causes the deletion of a later westward MWSS. If the westward MWSSs are numbered starting at 3, then, for each integer n ≥ 2, MWSS number ⌊(n(φ))⌋ causes the deletion of MWSS number ⌊(n (φ +1))⌋. Also, a glider escapes from the bottom of the pattern about generation 120 ⌊(n (φ + 1))⌋. Relative to a complete p120 glider stream, the resulting stream of gliders has density 1/(φ + 1).[3]
#N p60 version of Irrational 5
#C Two puffers move east, producing a westward MWSS and a boat
#C every 60 gens. Two stationary guns produce a glider every 60
#C gens and an eastward MWSS every 120 gens; half of the gliders
#C delete the MWSSs while the other half escape. But when a
#C westward MWSS reaches the guns, it deletes 2 consecutive gliders,
#C allowing one eastward MWSS to escape and suppressing one output
#C glider. When an eastward MWSS hits a boat, it becomes a NEward
#C glider which deletes one westward MWSS. Thus, each westward
#C MWSS that reaches the guns causes the deletion of a later
#C westward MWSS. Specifically, if the westward MWSSs are
#C numbered starting at 3, then, for each integer K >= 2, MWSS
#C number floor(K phi) causes the deletion of MWSS number
#C floor(K (phi+1)), where phi = (1 + sqrt(5))/2. Also, a glider
#C escapes from the bottom of the pattern about generation
#C 120 floor(K (phi+1)). Relative to a complete p120 glider stream,
#C the resulting stream of gliders has density 1/(phi+1) =
#C (3 - sqrt(5))/2 ~ 0.381966.
#O Dean Hickerson, 1/2/1999
x = 151, y = 91, rule = B3/S23
105b2o$103b2ob2o13b2o$103b4o13b4o$104b2o14b2ob2o$122b2o4$119b2o$113b3o
3bobo$92bo17b3o6bob2o$33bo59b2o15bo9b2o$32bobo57b2o16b3o7bo$15b2o15b2o
bo$15bobo14b2ob2o3b2o39b2o$6bo11bo13b2obo5bo36b3ob2o37b2o$6b2o7bo2bo
13bobo43b5o29b4o4b4o7b2o$18bo14bo45b3o25bo3bo3bo4b2ob2o4b2ob2o13b2o$
15bobo90bo6bo6b2o5b4o13b4o$15b2o87bo3bo5bo15b2o14b2ob2o$105b4o39b2o$
100b3o$98b2ob2o$100b3o18bo$34bo70b4o13b2o$35bo41bo26bo3bo12b2o23b2o$
33b3o42b2o28bo38b2o$12bobo62b2o28bo38b2o$10bo3bo101bo29bo$3b2o5bo15b2o
89b2o$3bo5bo16bo2bo86b2o$10bo19bo116b2o$10bo3bo15bo107b4o4b4o$12bobo
15bo99bo6bo3bo4b2ob2o$26bo2bo6b2o93bo9bo6b2o$26b2o8bobo88bo3bo8bo$38bo
89b4o$38b2o83b3o$30b2o68b3o18b2ob2o$30bo2bo65bobob2o18b3o$16bobo15bo6b
2o56bo3bobo22b4o$14bo3bo15bo7bo56bobo3bo21bo3bo$14bo19bo65b2obobo25bo$
7bo5bo16bo2bo68b3o25bo$7b2o5bo15b2o22b4o$14bo3bo34b6o$16bobo34b4ob2o$
57b2o57bo$117bo$51bo14b2o45bo3bo$49b3o10b4ob2o15b4o26b4o$48bo13b6o15bo
3bo21b3o$48b2o13b4o20bo19b2ob2o$86bo22b3o13b2o8bo$114b4o6b4o8bo$113bo
3bo6b2ob2o3bo3bo$68b2o28b2o17bo8b2o5b4o$68bobo27bobo15bo$9b2o23b2o33bo
29bo$9bobo22bo$2o10bo14bo4bobo70b2o17b2o$o8bo2bo13bobo3b2o70bobo16b2o
7b3o$12bo13b2obo76bo17bo2bo6bo$9bobo14b2ob2o94bo6bobo$9b2o15b2obo97b2o
3b2o$26bobo81b2o$27bo19b2o60bobo$47bo63bo23bo$136bo$132bo3bo$48bo67b4o
13b4o$17b2o27bob2o65bo3bo$17bobo26bo72bo$8b2o10bo14bo10bo71bo$8bo8bo2b
o13bobo9bo2bo$20bo13b2obo9b2o$17bobo14b2ob2o4bo$17b2o15b2obo4b2o$34bob
o$35bo31b2o9b2o$66b2o9bobo$61bo6bo7b3o$38bo21bobo12b3o$37bobo18b2o3bo
12b3o$37b2obo8bobo6b2o3bo13bobo5b2o$25b2o10b2ob2o6bo2bo6b2o3bo14b2o5bo
bo$25bo11b2obo6b2o6b2o3bobo24bo$37bobo5b2o3bo3bo2bo3bo25b2o$38bo8b2o6b
2o$48bo2bo$49bobo!
#C [[ THUMBSIZE 2 THEME 6 GRID GRIDMAJOR 0 SUPPRESS THUMBLAUNCH ]]
#C [[ WIDTH 1000 HEIGHT 700 ]]
Pattern that produces a southeast glider stream with with density 1/(φ + 1) (click above to open LifeViewer) RLE:herePlaintext:here
Gallery
Line with slope φ after approximately 60 million ticks