ConwayLife.com

xs19_c9jcj96z023 in 22g (down from 35g)

x = 50, y = 50, rule = B3/S23
$38bo$38bobo$38b2o3$15bo$16b2o$15b2o$33bobo5bo$33b2o5bo6bo$34bo5b3o4bo
bo$12bo8bo25b2o$13b2o4b2o$12b2o6b2o4$7bobo$8b2o$8bo3$27bo$26bobo6b2o$
25bobobo5bobo$24bo2bo2bo4bo$13b2o9bobobobo$14b2o9b2ob2o$13bo5$12bo$12b
2o$11bobo3 ...

xs19_2eg6p5iczx121 in 22g (down from 46g)

x = 54, y = 46, rule = B3/S23
52bo$51bo$51b3o4$bo$2bo$3o$38bo$38bobo$15bobo20b2o$16b2o$16bo2$35bo$
33b2o$34b2o10$35b2o$34bo2bo$34bobobo$32b2obo2bo$32bo2bobo$34bobo$35bo
7$25b3o5bo$27bo4b2o$26bo5bobo$39bo$38b2o$38bobo!


The most expensive xs19 is now ...

xs19_ck3qiczdb in 10g (down from 16g)

x = 123, y = 18, rule = B3/S23
47bo66bo$48bo11bo52bo$46b3o10bo53b3o$59b3o38b2o$55bobo29bo12bo$56b2o
30bo12bo$2bo41b2o10bo29b3o11b2o8b2o$obo42b2o54bob2o5b2o9bo$b2o41bo55bo
2bobo14bo$100b2o3bo14b3o$4b2o47b2o37bo9b3o$4bobo45bo2bo35bobo8bo$4bo
48b2o36bobo ...

xs18_4s0f9aczw113 in 12g (down from 15g).

x = 125, y = 47, rule = B3/S23
123bo$122bo$122b3o6$3bo$4bo$2b3o3$4bo$5bo46bo39bo$3b3o45bobo37bobo$51b
obo37bobo$52bo39bo2$108bo$51b2o38b2o13bobo$51b2o38b2o14b2o$6bo105b2o$
6b2o105b2o$5bobo43b2o38b2o19bo$51b2o38b2o24bo$82b2o32b2o$41b2o38bo2bo
31bobo ...

xs16_8kk8a53z641 in 10g (down from 11g).

x = 297, y = 251, rule = B3/S23
291bo$291bobo$291b2o95$16bo$14bobo177b2o$15b2ob3o172bo2bo6bo$18bo175bo
bo4bobo$19bo175bo6b2o5$207bo$206bo$206b3o3$207b2o$206b2o$208bo7$5bo$3b
obo178b2o$4b2o178b2o$b2o$obo$2bo84$295bo$294b2o$294bobo37$66b3o$68bo$
67bo ...

xs19_3lkaik8z343 in 7g (down from 17g).

x = 104, y = 17, rule = B3/S23
47bo$48bo$46b3o2$98bo$87bo9bobo$88bo8bobo$57bo28b3o9b2ob2o$55b2o43bo2b
o$42b2o8bo3b2o33b2o5b2o2bo$b2o38bo2bo8bo36bo2bo3bo2b2o$obo39b2o7b3o37b
2o4b2o$2bo$4b2o$4bobo46b2o$4bo48bobo$53bo!


This reduces xs20_3lkaik8zw3452 from ...

xs19_04al5a4z69611 in 29g (down from 42g)

x = 834, y = 192, rule = B3/S23
571bo$571bobo$571b2o36$699bobo$699b2o$700bo8$2bo$obo666bobo$b2o667b2o$
670bo3$10b3o$10bo$6b2o3bo$5bobo$7bo2$663bo$662bobo$662bobo$50b3o72b3o
73b3o67b3o189b3o197bo2$85bo572b2o7b2o$85bobo569bo2bo5bo2bo41bobo$70bob ...

xs18_o8b9k8zca32 in 17g (down from 24g)

x = 137, y = 64, rule = B3/S23
70bobo$70b2o$71bo18$30bo$29bo$29b3o$4bo$5bo$3b3o$8bo$9bo$2bo4b3o$obo$b
2o19bo106bo5bo$23b2o103bobo3bo$22b2o104bobo3b3o$33bo95bo$31b2o$32b2o$
40bo$39bo$27bo11b3o$25bobo73bo$26b2o74bo$100b3o2$16bobo$17b2o85b3o$17b
o2$15bo7b2o ...

154-cell unsynthesizable still life:

x = 23, y = 22, rule = B3/S23
6b2o$5bo2bo3b2o$5bo2bo3bo3b2o$3b2ob2ob2obo2bo2bo$3bo2bo2bo2b2o2bo2bo$b
2o2bo2bo2bo2b2ob2obo$o2b2ob2ob2obo2bo2bobo$bobo2bo2bo2b2o2bo2bo$2o3bo
2bo2bo2b2ob2o$bo2b2ob2ob2o2bo2bo3b2o$bobo2bo2bo2b2o2bo2bo2bo$2bobo2bo
2bo2bob2ob2obo ...

p18 glider gun, based on partial by Period1GliderGun

x = 73, y = 83, rule = B3/S23
34b2o4b2o$35bo4bobo$32b3o7bo$32bo2b3o3bob2o$29b2obobo3bo3bo2bo$30bobob
o2b2o5b2o$29bo2b4o2b4o$30b2o5b2o25b2o$32b2ob2ob5o21bobo$30b2o2bobo12b
2o7b2o6bo$30bo2bo2bobobobo3b2o2bo3bo3bobob4ob2o2b2o$31bob6o4bo3bobo3bo ...

An idea that might allow for a p14 (p14n) glider reflector and it simply requires finding a p7 sparker: x = 31, y = 16, rule = B3/S23
13bo$12bo$12b3o14bo$27b2o$9bo18b2o$9bobo$9b2o12b2o$23bo$23bobo$4b2o5b
2o15b2o$3bobo4b4o13b4o$5bo3bo2b2o5b2o5bo2b2o$9bo10b2o4bo$3o5bo10bo5bo$
2bo$bo!

This is ...

Is the last sentence ("the only known finite...") still true today, or solutions without that property are known now?
Does the restriction come from aiming to make it harder to change cells? (Changing an alive cell into a dead cell will lead to some adjacent dead cell having 3 alive neighbours and ...

Relevant posts:

Infinite stable agar: https://conwaylife.com/forums/viewtopic.php?f=7&t=3180&start=100#p139666
Finite still life: https://conwaylife.com/forums/viewtopic.php?p=140258#p140258
306-cell still life reduction: https://conwaylife.com/forums/viewtopic.php?p=140295#p140295
p2 agar: https ...

184-cell unsynthesizable still life:

x = 23, y = 25, rule = B3/S23
11b2o$10bo2bo$8bo2bobo$8b2obo2b2o$5b2obo2b2obo2b2o$3b3obo2bo2bo2b2obo$
2bo5b2obo2b2o4bo$3bob2obo2b2obo2b2obo$4b2obo2bo2bo2b2obo$2o6b2obo2b2o$
o2bob2obo2b2obo2b2o$b3ob2o2bo2bo2bob2o$8b2obo2b2o$3b2ob2o2bob2o2bob3o ...

4c/4 orthogonal in B27/S1278 and B278/S1278

x = 81, y = 37, rule = B27/S1278
7bo$26bo33bobo$4bo5bo25bo21bo5bo$24bo10b3o19bo3bo3bo11bo$bobobo18bobo
9bob2o17bo2bob2o2bo8b5o$o26b2obo3b2o4bob2o22bo7b4ob2o$obo2bo25b2o9b2o
15bo8bo5bo4bo$7bo12b2o4bo4b4obo24bobo15b2o$bo4b2o5bo3bob2o4bobo8bobo3b ...

May I get a Trusted flag on my LifeWiki account? My username is also 400spartans. Thanks!

Edit 2: can you give any details about how you found it?


I'm just using Torma and Salo's program (https://github.com/ilkka-torma/gol-agars) with two minor tweaks to speed things up. First, I exclude patterns which are just a repetition of some smaller tiling. And second, this came up in a ...

The smallest you can get it is population 306. (Confirmed with LLS.) x = 34, y = 28, rule = LifeHistory
12.2C4.2C$12.C5.C$7.2C5.C5.C7.2C$6.C.A4D2A4D2A4D2AD.C$2.2C.A2DAD2A2DA
D2A2DAD2A2DADA$2.C.2ADA2D2ADA2D2ADA2D2ADA2D2A$3.4D2A4D2A4D2A4D2A3DC$
3.2ADA2D2ADA2D2ADA2D2ADA2D2AD.C$3 ...

I personally think the exposition would be a bit improved if you separate the following steps and explain them a little more:


Yeah I think that part is better explained with a little bit of abstraction. Note that below when I refer to "cell" I mean a particular generation of a cell. For the ...

The article https://conwaylife.com/wiki/Density states:
The maximum average density of an oscillating agar is conjectured but not proven to be 1/2. The current upper bound is 8/13, proven by Hartmut Holzwart in 1992.


The following is a proof that the maximum average density of an oscillating ...

Below is a collection of ships from the Discord p1 photon-finding project in gliderdb format. This should cover all the p1 photons listed on our spreadsheet that are not already included in gliderdb.

:praosylen, 2020:B2456/S5:B245678/S1578:1:0:-1:10:9:o8bo$3bo2bo$b2ob2ob2o$2b2o2b2o$2b6o$bobo2bobo ...

6c/15 blinker puffer found with ikpx2:

x = 17, y = 92, rule = B3/S23
3b3o3b3o$3bobo3bobo$bo3bo3bo3bo$bo2bo5bo2bo$b2ob2o3b2ob2o$3b3o3b3o$5b
2ob2o$2o2b3ob3o2b2o$bo2b3ob3o2bo$bo2b2o3b2o2bo3$6b3o$7bo$6b2o$5bobo$5b
o2bo$8bobo$9b3o$5bob3o2bo$5bo2bo3$7bobo$7b3o$10bo$10b2o$9bo$10bob2o$
10b4o$11bo2bo ...

EDIT: Unrelated, I believe this is the shortest possible c/3 spaceship:

spaceship



Shortest possible appears to be this height-7 one:


x = 51, y = 7, rule = B2n3/S23-q
4bo5b3o7b3o15b3o5bo$3b2o3bo3b2obo3bo3b2o10bob2o3bo3b2o$2bo3b3o3b2ob2o
4bo3bo3bo4b2ob2o3b3o3bo ...

iNoMed's tub puffer can be used to make the following T-rake:

x = 20, y = 18, rule = B3-kq4j/S2-n36c
2b2o$o4bo$6bo$o5bo$b6o3$14b2o$13b4o$13b2ob2o$15b2o2$11b3o$11b2o$11b2o
4b2o$13b4ob2o$13b6o$14b4o!

A T + boat -> G reaction can be used to make the following G-rake:

x = 20, y = 32, rule = B3 ...

xp2_31agozw8k871 in 12G, there's probably a more efficient cleanup (those last 2 gliders in the middle reaction are technically cleanup).

x = 169, y = 78, rule = B3/S23
100bo$98b2o$99b2o22$166bo$151bo14bobo$2bo147bobo13b2o$3bo147bo$b3o156b
2o$159bo2bo$160b2o5$7bo59bo$8bo58bobo$6b3o43bo14b2o71bo ...