On February 15, 2022, Dave Greene wrote:
NewLifeCA 15 Feb 2022: where did this new period-30 gun come from?
I'm sending more NewLifeCA emails than I usually would -- please don't expect this to be the normal rate going forward! -- but these are exciting times.
As some of you have already heard, a new period-30 glider gun was discovered today, that needs only one queen-bee shuttle instead of the two colliding shuttles that have been the norm for the past half-century or so:
Code: Select all
x = 28, y = 18, rule = B3/S23
14b2o$14bo2bo3$14bob2o2b2o$9b2o2bobo4bo$9bo4bo6b3ob2o$2b3o8bo9bob2o$2b
3o5bo2bo$2o22b3o$2o13bo8bo2bo$2o12bobo9b2o$12b2o3bo$8b3ob2o3bo$12b2o3b
o$6bo7bobo$6bo8bo$6bo!
There are other options for the sparkers that help with the glider extraction, including the use of a pentadecathlon, which takes a bit more space but allows this gun mechanism to be glider-constructed relatively easily. In a standard p30-gun synthesis, the two queen bees have to be started up by two gliders with precise relative timing, but here there's only one queen bee to start up, so the trigger glider can be delayed by any multiple of fifteen ticks and it will still work fine:
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#C see the following link for a one-glider seed for a
#C standard Gosper glider gun, for comparison purposes --
#C this new one is significantly simpler:
#C https://conwaylife.com/forums/viewtopic.php?p=71963#p71963
x = 75, y = 83, rule = B3/S23
7bo$6bobo$6b2o9$7bo$6bobo$6b2o4$7bo$7b3o$10bo$9b2o3$b2o$obo$2o2$32b2o$
7b3o5b2o9b2o4bobo$14bobo9b2o4bo$5bo8b2o$5bo5bo$5bo5bo$11bo47$73bo$72b
2o$72bobo!
Alternate sparkers even allow glider streams to be extracted from both ends of one queen-bee shuttle -- though there's not a whole lot of point since only one stream at most can escape without interfering with the other one:
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x = 38, y = 28, rule = B3/S23
6bo2bo3b5o2b5o3bo2bo$3bo2bo2bo7bo2bo7bo2bo2bo$2bob3o2b5o3bo2bo3b5o2b3o
bo$3bo30bo2$bo23bo$o2bo3bo11b2o4b3o7b3o$o2bo2b3o10b2o2b2ob2o6b3o$2bob
2obobo6b2o6bo3bo$4b3ob3o4b3o6b2ob3o$4b2obobo6b2o6bo5bo$2b3ob3o10b2o2b
2obobobo3b2o$bobo3bo11b2o4b2obob2o2bobo$bo34bo$2o12bo21b2o$15bo$13b3o
2$20bo$18b2o$19b2o2$23b2o$19bo3b2o$18bobo$17bobo$17bo$16b2o!
Here's some background on the developments leading up to this discovery.
Adam P. Goucher's "Catagolue" (not a misspelling) has been gathering "apgsearch" soup-search results for just about seven years now, from anyone willing to contribute CPU-hours to running random soups and contributing the resulting censuses of objects. New objects that have never been seen in a soup before get their own page on Catagolue, like
this one that showed up this morning.
The single-engine p30 gun showed up in tetramer form in the 31x31 soup pattern that that page links to:
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x = 31, y = 31, rule = B3/S23
2b2o2bo2b3obo3bob3o2bo2b2o$4obo3b2obob3obob2o3bob4o$obobob3obo2b2ob2o
2bob3obobobo$ob2ob2obo4b5o4bob2ob2obo$obo8b9o8bobo$ob3o3b3ob2obob2ob3o
3b3obo$b4obo4bo2bobo2bo4bob4o$bo2bob2ob6ob6ob2obo2bo$2obo2bob2ob2obobo
b2ob2obo2bob2o$2b2ob2ob4o7b4ob2ob2o$3o2b4o4b2ob2o4b4o2b3o$3bob2obobo2b
5o2bobob2obo$b2o4b3o3bo3bo3b3o4b2o$3obo4b5obob5o4bob3o$2ob2o2b6ob3ob6o
2b2ob2o$2bobobob2o3b5o3b2obobobo$2ob2o2b6ob3ob6o2b2ob2o$3obo4b5obob5o
4bob3o$b2o4b3o3bo3bo3b3o4b2o$3bob2obobo2b5o2bobob2obo$3o2b4o4b2ob2o4b
4o2b3o$2b2ob2ob4o7b4ob2ob2o$2obo2bob2ob2obobob2ob2obo2bob2o$bo2bob2ob
6ob6ob2obo2bo$b4obo4bo2bobo2bo4bob4o$ob3o3b3ob2obob2ob3o3b3obo$obo8b9o
8bobo$ob2ob2obo4b5o4bob2ob2obo$obobob3obo2b2ob2o2bob3obobobo$4obo3b2ob
ob3obob2o3bob4o$2b2o2bo2b3obo3bob3o2bo2b2o!
On the "ConwayLife Lounge" Discord server, this new arrival was quickly noticed, reduced to dimer form and then to the monomer forms shown above.
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This is not the first gun to show up in a "semi-natural" (symmetric) soup, however. Jason's Summers' p156 gun shows up quite regularly in the D4_x4 symmetry, in various forms, as the large number of soup links shows:
https://catagolue.hatsya.com/object/yl7 ... 035/b3s23/
https://catagolue.hatsya.com/object/xp3 ... yg33/b3s23
https://catagolue.hatsya.com/census/b3s23/D4_x4/yl312
(lots of trivially different ways to suppress some of the glider streams)
And just three days ago a semi-natural period-46 bi-gun showed up in a different symmetry, C2_2. This one is probably less likely to show up naturally any time soon (i.e., in an asymmetric soup), but of course it's
not impossible.
Before that, in mid-December, a single-engine period-46 gun showed up, but that wasn't a soup-search result; it was an engineered discovery using a new catalyst -- in fact, the same "traffic stop" mechanism that also completed the period-38 oscillator last month.
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The first gun appearance in C1 (asymmetric 16x16) soups is one of the big events that has yet to happen on Catagolue. Catagolue is approaching the point where it has collected enough soups that a gun might be expected to spontaneously occur -- we seem to be in about the right order of magnitude, anyway.
The reason why so many new things are showing up in symmetric soups all of a sudden is that Charity Engine,
https://www.charityengine.com/ , has recently taken an interest in donating a small percentage of its spare capacity to our particular brand of mathematical research... and the people running the scripts have decided to prioritize symmetric soups rather than C1 soups.
This decision was made on the grounds that interesting new oscillators can more commonly be found in symmetric soups. There's been a significant increase in focus on finding new oscillators and oscillator periods in the last year, based largely on the work of a newcomer to the forums named David Raucci, or "hotDogPi".
-- Okay, enough Life news for now. I'm kind of hoping things will maybe quiet down for a little while...!
Keep the cheer,
Dave