LifeWiki Did-You-Knows

[hotdogPi]

LLSSS can't handle high periods. It was tried for the loafer and couldn't prove anything above five cells.

[WhiteHawk]

LLSSS can't handle high periods. It was tried for the loafer and couldn't prove anything above five cells.

Oh. Darn.

Still, I don't think it would be too hard to prove that there is no smaller ship in life than loafer or copperhead for their respective speeds even without LLSSS.

[dvgrn]

Still, I don't think it would be too hard to prove that there is no smaller ship in life than loafer or copperhead for their respective speeds even without LLSSS.

By "smaller" do you mean smaller in bounding box, or smaller in population? It's probably worth making that distinction in the DYK item somehow.

If it were easy to prove loafer or copperhead the smallest by either metric, then it would very likely have been done already. It will be awesome if a proof shows up, but please don't get your hopes up too far -- it's surprisingly hard to close off all the unlikely edge cases, even for situations where "everybody knows" that nothing smaller is actually likely to be found.

[WhiteHawk]

By "smaller" do you mean smaller in bounding box, or smaller in population? It's probably worth making that distinction in the DYK item somehow.

If it were easy to prove loafer or copperhead the smallest by either metric, then it would very likely have been done already. It will be awesome if a proof shows up, but please don't get your hopes up too far -- it's surprisingly hard to close off all the unlikely edge cases, even for situations where "everybody knows" that nothing smaller is actually likely to be found.

Both pop and BB - I don't think it matters for either since they're both fairly compact. I do get that the unlikely edge cases are not to be discounted if a search were conducted, but I still think that it really is likely there is no other spaceship that is smaller for either. Of course, the Copperhead itself was small enough to be discovered had a full brute-force search within the diameter of it's smallest BB been conducted, but wasn't known until 2016.

Perhaps this conundrum should be noted as a separate Did You Know along the lines of "...though the Loafer is currently considered the fifth-smallest non-flotillae spaceship, and is by far the smallest known with speed c/7, there is currently no definitive proof that it is the smallest c/7 ship in life?" (I don't know where copperhead currently ranks among non-flotillae)

[pifricted]

xs34_gbb8brzdl5l5ozw11011 can find in the ash of from one R-pentomino colide one boat, one beehive and four blocks.

Code: Select all

x = 26, y = 21, rule = LifeHistory
18.2A$2.A15.2A$3A$.A$14.2A$14.2A$24.2A$24.2A2$12.A$11.A.A6.2A$11.A.A6.
2A$12.A6$18.A$17.A.A$18.2A!

[confocaloid]

xs34_gbb8brzdl5l5ozw11011 can find in the ash of from one R-pentomino colide one boat, one beehive and four blocks.

Code: Select all

x = 26, y = 21, rule = LifeHistory
18.2A$2.A15.2A$3A$.A$14.2A$14.2A$24.2A$24.2A2$12.A$11.A.A6.2A$11.A.A6.
2A$12.A6$18.A$17.A.A$18.2A!

With so many colliding objects (six common stationary objects and one common versatile active object), there are lots and lots of similar examples.
A few common objects collide to create an explosion, and the final pattern contains an uncommon object somewhere.

Many soup-based glider syntheses have a similar collision in the main step. This is preceded by one or more steps constructing the stationary constellation, and then creating spaceship(s) and/or active object(s) needed to create the explosion. And then followed by one or more steps of cleanup, where all the unwanted junk surrounding the rare object is removed.

In other words, there are way too many similar examples. It is impossible to put them all into "Did you know?" items, and there is no obvious reason to pick a single example (and without such a reason, it feels arbitrary to pick a specific example for "Did you know?").

For comparison, two examples of 'remarkable collisions' are the half-bakery reaction and the three-block shifter reaction.
See also Omnibus and Index fossil.

[confocaloid]

[...]
For comparison, two examples of 'remarkable collisions' are the half-bakery reaction and the three-block shifter reaction.
See also Omnibus and Index fossil.

Speaking of 'remarkable collisions', I think the following reaction deserves a mention in some "Did you know?" item, although I'm unsure what could be an accurate description of this reaction in the DYK format:

AforAmpere's recent discovery of an ash constellation that turns into its mirror image with an 8-cell offset when you hit it with a single glider --

Code: Select all

x = 581, y = 368, rule = B3/S23
bo$2bo$3o46$579bo$578bo$578b3o46$81bo$82bo$80b3o46$499bo$498bo$498b3o
46$161bo$162bo$160b3o46$419bo$418bo$418b3o46$241bo$242bo$240b3o46$339b
o$338bo$338b3o25$306b2o$306b2o$296bo17b2o$296bo16bo2bo$296bo17b2o!
#C [[ X 21 Y 150 Z 6 AUTOSTART ]]

-- makes it a little difficult to resist building some kind of spaceship/rake that pulls this impressively improbable thing along behind it.

Calcyman has pointed out that one obvious candidate for such a spaceship would be an Orthogonoid -- specifically an Orthogonoid with odd horizontal symmetry, which requires a slightly different design [...]

[WhiteHawk]

"... that the period-21 glider gun discovered in 2021 was the seventh smallest gun in bounding box when found?"

What was the relevance of this fact with regards to life? What was special about it being so small? (e.g. It was the smallest odd-period gun at the time.)

"... that all known glider eaters take at least four ticks to recover to their original state after eating a glider?"
There are periodic glider eaters which take three ticks, but this is true for stable glider eater. I don't think that is clear here and newcomers may get the wrong impression.

EDIT: Like with the snippets, give recent and not-so-recent updates in the Life world, it may be helpful to review the Did-you-knows

[dbell]

Item 25 needs to be updated from 177 to 168 cells.

BCNU,
-dbell

[Resu]

The did-you-know item "the smallest known sawtooth pattern in Conway's Life consists of only 168 cells?" contains a redlink to sawtooth 168.

[PK22]

Item 54 is outdated - there are only 11 unsynthesised p2s now, not 14:

Combination of both lists, unless I missed something:
Unsynthesised:
xp2_35g41h54gzx3x3
xp2_m24g441lpz03
xp2_31a0nzwc850e
xp2_31a0nzw4490ac
xp2_k51h4gljzw3
xp2_35g411l4z22403
xp2_0m24gl3z2a882
xp2_3hk2060szw2251
xp2_62k030288zx3048d
xp2_3l04g4gljzw3
xp2_31q07z7020ac

[ThePlayzr]

Is there a did you know like this:
... That after the HWSS was discovered in 1970, no other spaceships were discovered until 1989, in which 6 new spaceships were discovered?
If there isn't, there should be, as that is almost 20 years with no spaceships.

[hotdogPi]

Is there a did you know like this:
... That after the HWSS was discovered in 1970, no other spaceships were discovered until 1989, in which 6 new spaceships were discovered?
If there isn't, there should be, as that is almost 20 years with no spaceships.

Yes, it's #17.

[ThePlayzr]

Yes, it's #17.

Cool! Whoever made #17 gets a smiley face

[WhiteHawk]

Number 164

"... that if a glider collides with a U-turner in a certain way, the ash will contain a 15-bit still life with apgcode xs15_6t1egoz11?"

Is this really notable? There are a lot of reactions just like this one where glider collides with reaction X to produce Object Y

[dvgrn]

Is this really notable? There are a lot of reactions just like this one where glider collides with reaction X to produce Object Y

It's in the "maybe notable enough, not going to worry about it" category for me.

Newcomers to soup-watching tend to get excited about anything not in the top 20 showing up -- hats, big S's, moose antlers, scorpions, and suchlike. But those are all in the 1-in-500,000 range, at rarest.

But you won't see an asymmetrical 15-bit still life congealing out of simple-active-object-plus-one-glider very often. That particular object is at the 1-in-37-million level, at #175 -- and it's the second of only five objects in that list that are so unfamiliar that they haven't even been given any kind of systematic descriptive label.

[WhiteHawk]

That particular object is at the 1-in-37-million level, at #175 -- and it's the second of only five objects in that list that are so unfamiliar that they haven't even been given any kind of systematic descriptive label.

Perhaps this particular Did-you-know could be amended to note the still-life's rarity. There also are no direct links to show this interaction as far as i can tell (the 4g synthesis linked appears to involve a different predecessor)

[mmmmmmmmm]

This is more of a forum did-you-know, but out of the 1828 members on the forums, 749 members have made 1 or 0 posts. In fact, just 523 of our 1828 members have made more than 10 posts.

[WRAPboi]

Did you know that there are only two c/2 ships in Think Free or Die, the "diamond" and "meatloaf", although more are trying to be found actively?

[WhiteHawk]

Did you know that there are only two c/2 ships in Think Free or Die, the "diamond" and "meatloaf", although more are trying to be found actively?

I don't think that's notable. There are probably a lot of rules where only 2 ships are known that people could be "actively" looking for more (but really are using limited search function abilities to perform other tasks).

"... that the period-21 glider gun discovered in 2021 was the seventh smallest gun in bounding box when found?"

What was the relevance of this fact with regards to life? What was special about it being so small? (e.g. It was the smallest odd-period gun at the time.)

Unrelatedly, this "did you know" is still listed even though I would presume it would be better to keep as a note on the page for this gun (where it is indeed noted) and not included on the actual "did you know" list.

It's akin to saying "the loafer was the fifth smallest spaceship in population when found" (which still is true) when the actual impressive thing about it was that it was (and still is) the smallest odd-period spaceship and, most importantly, the first c/7 orthogonal spaceship, while the p21 glider gun doesn't even hold the distinction of being the smallest odd-period gun anymore

[PK22]

... that whilst no elementary oblique spaceships were found in B3/S23 until 2018, and none have occurred naturally, at least two naturally occurring reactions have been discovered in B38/S23 that travel in an oblique direction?

I think that the 'at least two' is obsolete here - it is easy to verify from b38s23/C1 that the only such natural reactions are the (5,2)c/190 spaceships and puffers and the (101,3)c/1884 puffer.
I think it can be rewritten in the form:

... that whilst no elementary oblique spaceships were found in B3/S23 until 2018, and none have occurred naturally, two unique naturally occurring reactions have been discovered in B38/S23 that travel in an oblique direction?

[WhiteHawk]

... that whilst no elementary oblique spaceships were found in B3/S23 until 2018, and none have occurred naturally, at least two naturally occurring reactions have been discovered in B38/S23 that travel in an oblique direction?

I think that the 'at least two' is obsolete here - it is easy to verify from b38s23/C1 that the only such natural reactions are the (5,2)c/190 spaceships and puffers and the (101,3)c/1884 puffer.
I think it can be rewritten in the form:

... that whilst no elementary oblique spaceships were found in B3/S23 until 2018, and none have occurred naturally, two unique naturally occurring reactions have been discovered in B38/S23 that travel in an oblique direction?

I think this one is fine. There could be a super-rare third (or fourth, or fifth, or...) one which could appear naturally but hasn't yet. It's always going to be in the realm of "could exist except we haven't seen it show up yet naturally or otherwise" that another one could exist in B38/S23 or in Life itself

[PK22]

I think this one is fine. There could be a super-rare third (or fourth, or fifth, or...) one which could appear naturally but hasn't yet. It's always going to be in the realm of "could exist except we haven't seen it show up yet naturally or otherwise" that another one could exist in B38/S23 or in Life itself

I disagree. The DYK talks about natural reactions that “have been discovered”, and at present, only two oblique reactions are known to be natural. Either the ‘at least two’ or ‘have been discovered’ part needs to be removed.

[WhiteHawk]

"... that the single seldom-used extra transition of Pedestrian Life (B38/S23) from Life leads to several non-pedestrian linear growth patterns, including a reflectorless rotating glider gun, a set of (5,2)c/190 technology and a messy oblique p1884 puffer?"

Maybe good to note that these things are all/mostly naturally occuring/have naturally occuring variants?

Also, an idea for Sir Robin/Solifuge did-you-know: How many times smaller are each from the first known ships of their displacement?

Another few for solifuge:
"...the underlying reaction behind the camelship known as "Solifuge", while only made into a climber the day before it's completion, had been known since 1994 in the p124 lumps of muck shuttle?"
"... Solifuge is the smallest self-supporting macro spaceship at over 17 times smaller than the previous smallest macro-spaceship, the leaf bug 2, and over 169 times smaller than the previous smallest-known camelship?"

[mmmmmmmmm]

Number 174 is outdated. It says:
...that the only known orthogonal spaceships in non-strobing outer-totalistic rules with speed c/2 < v < c have v = 2c/3, though in strobing rules there are also known spaceships of speed 3c/4, 3c/5, and 5c/8?
But should say;
...that the only known orthogonal spaceships in non-strobing outer-totalistic rules with speed c/2 < v < c have v = 2c/3 or 3c/5, though in strobing rules there are also known spaceships of speed 3c/4 and 5c/8?