smallest gun

[unname66609]

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#N Simkin's glider gun
#O Michael Simkin
#C A true period 120 glider gun, found on April 28, 2015.
#C www.conwaylife.com/wiki/Simkin%27s_glider_gun
x = 33, y = 21, rule = B3/S23
2o5b2o$2o5b2o2$4b2o$4b2o5$22b2ob2o$21bo5bo$21bo6bo2b2o$21b3o3bo3b2o$
26bo4$20b2o$20bo$21b3o$23bo!

[codeholic]

What did you want to say with this post?

[Freywa]

All he wanted to say was that "the double diamond is the smallest known gun". It is a fact and cannot be discussed to any length.

However he could also have meant the opinion: "the double diamond is the smallest possible gun (by number of cells)." Now that's something more interesting; in B38/S23 the following statorless gun is known (from here):

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x = 8, y = 5, rule = B38/S23
3b2o$2ob2o$2o3b2o$5bobo$5b3o!

But what about Conway's Life? I'd be willing to bet that Simkin's discovery is the smallest possible, but I don't have money or a credit card.

Either way I know from past interactions with him that unname has Chinese as his native language and seems fearful of reproach (i.e. is almost unresponsive to any replies).

[calcyman]

However he could also have meant the opinion: "the double diamond is the smallest possible gun (by number of cells)."

Well, ditching the eater leaves a 29-cell gun with a 22-cell predecessor:

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x = 33, y = 14, rule = B3/S23
o6bo$2o5b2o2$4bo$4b2o4$27bo$22bo4b2o$21bo$20b2o9bo$21b2o8b2o$22bo!

...which suggests it might just appear naturally. By comparison, I can't seem to beat 27 cells for a Gosper gun predecessor:

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x = 5, y = 36, rule = B3/S23
o$2o5$o$obo$2o3$2o$obo$b2o9$3b2o$2bobo$bo2bo2$bo$2o$2bo6$2b2o$3bo!

so that's probably too rare to appear in the foreseeable future.

[The Turtle]

Here is a trivial reduction of Simkin's Glider Gun to 35 cells. I couldn't find this anywhere else.

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x = 33, y = 20, rule = B3/S23
2o5b2o$2o5b2o2$4b2o$4b2o5$22b2ob2o$21bo5bo$21bo6bo2b2o$21b3o3bo3b2o$
26bo5$24bob2o$24b2obo!

The glider stream has period is 120, and the gun has period 240.

[gameoflifeboy]

Here is a trivial reduction of Simkin's Glider Gun to 35 cells.

Wow! I think the LifeWiki article should mention this variation. Even as a pseudo-period gun this still officially beats out the GGG as the smallest single-barrelled glider gun.

[biggiemac]

Here is a trivial reduction of Simkin's Glider Gun to 35 cells. I couldn't find this anywhere else.

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x = 33, y = 20, rule = B3/S23
2o5b2o$2o5b2o2$4b2o$4b2o5$22b2ob2o$21bo5bo$21bo6bo2b2o$21b3o3bo3b2o$
26bo5$24bob2o$24b2obo!

The glider stream has period is 120, and the gun has period 240.

This was mentioned right away as the "standard form" because it has the smallest bounding box. Sorry to steal any thunder.

[biggiemac]

I think this would be the smallest bounding box LWSS gun, as nothing I could make out of GGG was under 2000.

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x = 38, y = 49, rule = B3/S23
3b2o4bo$3b2o4b3o$12bo$11b2o2$b2o2$13b3o$12b2ob2o$12b2ob2o$2o3b2o5b5o$b5o5b2o3b2o$b2ob2o$b2ob2o$2b3o2$12b2o2$6bo$5bobo$4bob2o$3b2ob2o23bo2bo$4bob2o27bo$5bobo23bo3bo$6bo25b4o5$5b2o5b2o$5b2o5b2o$12bo2$10bo3b2o$13bo2bo$13bo3bo$13bo$10bo5bo15b2o$11b2o2bo16b2o$14bo5bo$18bobo8b2o5b2o$19b2o8b2o5b2o6$29bob2o$29b2obo!