Life/CA "did-you-know" sandbox

[confocaloid]

What are facts about Conway's Life or other cellular automata that you consider unique or interesting?
You may also post something that's only currently true (and may become false in future, due to new discoveries or reductions). However, such "temporary did-you-know" tend to be somewhat less interesting than statements likely to remain true forever.

Note that many of these will not really fit into the wiki collection for different reasons:

• likely to become outdated over time (due to improvements or new discoveries) and would need constant maintenance/update efforts if added
• or may not be sufficiently unique/noteworthy to appear in the wiki collection
• or about other cellular automata; the wiki is primarily about Conway's Life

Unnatural objects with low glider cost

To begin this thread, here are some "temporary" did-you-knows:

• ... long⁹ snake (apgcode xs15_y3g853zwg8421z65) is currently the only 15-bit strict still life that remains unnatural (i.e. did not yet appear in the b3s23/C1 census on Catagolue)? There are currently 62 unnatural 16-bitters.
• ... As of the time of this post, Snake pit 2 (xp3_g8o0eh5mggz122q92t0643zy011) is the only unnatural p3 oscillator with a known 6-glider synthesis, xp3_ggka60uh224a4z1 is the only unnatural p3 oscillator with a known 7-glider synthesis, and there are currently no unnatural p3 oscillators with glider cost lower than 6?
  Here are the current Catagolue glider syntheses of these two unnatural period-3 oscillators:

  Code: Select all

  x = 97, y = 31, rule = B3/S23
  24bo$23bo$23b3o47bo$73bobo9bo$51bobo19b2o8b2o$2bo49b2o30b2o$obo49bo$b
  2o3$34b2o$33bo2bo$33b2obo42bo$36bob2o37b2o$31b6obobo37b2o4bo$30bo3bobo
  3bo43b3o3b2o$30bobob6o47bo2bo4bo$31b2obo51bobobo2b2obo$34bob2o49b2obob
  4o$34bo2bo53b2o$8b3o24b2o$10bo$9bo53b3o$28b2o35bo$20b3o5bobo33bo$20bo
  7bo$21bo34b2o$55bobo$5b3o49bo6b3o$7bo58bo$6bo58bo!
  #C [[ GRID THEME Catagolue ]]
  

• ... As of the time of this post, there are five unnatural p4 oscillators with a known 8-glider synthesis (xp4_ogiljgz6a888arzw652, xp4_1770e6zy0ce0ssg, xp4_g88eh5e0e5he8gz01178a707a871, xp4_178cw8k453zy0or1, xp4_651u062s0ccz330346078a6) and none with glider cost lower than 8?
  Here are the current Catagolue glider syntheses of those five unnatural period-4 oscillators:

  Code: Select all

  x = 215, y = 169, rule = B3/S23
  30bobo$2bo27b2o$3bo27bo160bo$b3o60bo126bo$65b2o59bo64b3o$64b2o61bo$87b
  o37b3o$86bo$61bo24b3o90bo$59bobo115bobo17bobo$35b2o23b2o116b2o17b2o$8b
  o6bo19bobo54bo59b2o7b2o35bo$6bobo6bobo18bo55bo2bo56bo8bo$7b2o6b2o22bo
  52bo2bo57b3o3bobo50b2o$34b6o40bobo10bobo60bo2b2o47b2obo2bo$33bo2bo43b
  2o11bobo25b2o32bobo46b2obobobob2o$33b2o3b2o41bo13b2o23bobo33b2o25b2o9b
  o9b2obobobo$36bo2bo30bo24b2o25bo23bo9b2o24bobo9bobo10bo3bo$33b6o31b2o
  24bobo46b2o10b2o25bo9b2o11bobobob2o$16b2o6b2o7bo35bobo24bobo46bobo9b2o
  45b2obobobob2o$15bobo6bobo9bo59bo2bo20b2o10b3o22b2o45bo2bob2o$17bo6bo
  10bobo58bo2bo21b2o11bo70b2o$36b2o61bo20bo12bo$90b2o88bo$90bobo33b3o51b
  2o17b2o$63b3o24bo37bo50bobo17bobo$65bo61bo71bo$64bo$86b2o58b2o$29b3o
  53b2o59bobo$bo27bo57bo58bo38b3o$b2o27bo95b2o59bo$obo122bobo58bo$127bo
  35$156bo$155bo$155b3o10$63bobo$64b2o$64bo30$101bo$102bo$100b3o2$114bob
  o$114b2o$115bo4$151b2o3b2o$150bo2bobo2bo$150bob2ob2obo$148b3o2bobo2b2o
  $147bo3bo5bo2bo$148b3o2bobo2b2o$150bob2ob2obo$150bo2bobo2bo$151b2o3b2o
  7$112b2o$112bobo$112bo21$157b3o$142b2o13bo$142bobo13bo$142bo3$62b3o$
  64bo$63bo!
  #C [[ GRID THEME Catagolue ]]
  

[Citation needed]

"Did you know" entries should start with "that". Please look at the following example.

• ... that switch engine ping-pong costs only seven gliders despite having a very large bounding box?

[confocaloid]

.

[confocaloid]

reply to a deleted post

[hotdogPi]

... that no period-48 oscillators had a synthesis until recently (to the point that http://conwaylife.com/ref/mniemiec/period.htm still says there aren't any), despite being extremely commonplace now?
... conversely, that the page linked above knew of a p41 years before we did?
... that even though I've found some guns that were in the smallest 10 at the time (p21, p54, p55), the smallest that's my own has fallen down to 23rd place?
... that there's no evidence that the fleet was found in 1970, but we know the tumbler was?
... that we have a whole bunch of users from China but zero (that I know of) from India, despite the two countries having similar populations?
... that there are two medium-common regions that are pi+loaf (b3o$o3bo$o4bo$b2obo$3bo! and b3o$o$ob2o$b2o!)
... that there are two lifelib packages in Python, one of which is completely irrelevant to this community?
... that the census of small common evolving patterns thread was created in 2016 but ignored until 2021 and put to great use in oscillator searches (both mine and CatForce) after that?
... that "butterfly" in the early 2000s decade referred to a different pattern than it does now?

[dvgrn]

... long⁹ snake (apgcode xs15_y3g853zwg8421z65) is currently the only 15-bit strict still life that remains unnatural (i.e. did not yet appear in the b3s23/C1 census on Catagolue)? There are currently 62 unnatural 16-bitters.

Ha, "temporary" was the right word for this one!

As I write this (1/18/2025) there are still 62 unnatural 16-bitters, but the long⁹ snake has been found -- and it forms at T=450, so it doesn't even cheat by being just a few ticks in from the starting soup. It looked like several of the stages before T=450 would be glider-constructible.

[LuveelVoom]

... long⁹ snake (apgcode xs15_y3g853zwg8421z65) is currently the only 15-bit strict still life that remains unnatural (i.e. did not yet appear in the b3s23/C1 census on Catagolue)? There are currently 62 unnatural 16-bitters.

Ha, "temporary" was the right word for this one!

As I write this (1/18/2025) there are still 62 unnatural 16-bitters, but the long⁹ snake has been found -- and it forms at T=450, so it doesn't even cheat by being just a few ticks in from the starting soup. It looked like several of the stages before T=450 would be glider-constructible.

Dvgrn, did you know that 400spartans just released a 162-cell unsynth still life?