Thread for basic questions

[dvgrn]

What's the current smallest known Garden of Eden? The Garden of Eden 6 article implies there's a smaller one known but doesn't specify what it is, and there doesn't seem to be an article on it.

Oops, yeah, I had forgotten that that's one of the categories that the LifeWiki is still far behind on. Go to Achim's page on Garden of Eden 6 (the link on the LifeWiki page, which you'll notice is confusingly called "orphan_7th") and follow the Yes links. You'll eventually get to Garden of Eden 11, the latest and greatest. All the intermediate pages were records at one point, but haven't made it to the LifeWiki yet.

There's another Yes link to orphan_12th.html, but that page doesn't exist... yet! Apparently there haven't been any fresh discoveries from Steven Eker for the last couple of years.

Here are the notes I took in 2016 and 2017 about this stuff. There's another slight weirdness in numbering, involving two contenders for the #9 spot. My patch was to not number one of them, and call it "Garden of Eden 8x12" instead:

Dec 13, 2016:
#C Garden of Eden 10
#C 55-cell GOE in 9x11 bounding box
#C Steven Eker, 16 September 2016
x = 11, y = 9, rule = B3/S23
b9o$obo2bobobo$b2o2b4o$ob4o3bo$bo2bobobobo$o2b2o2bo$3o2b5o$2b2obobobo$
ob4o2b2o!

#C 89-cell non-convex orphan for Garden of Eden 10
#C (34 required OFF cells shown in LifeHistory blue state 2)
#C Steven Eker, 16 September 2016
x = 11, y = 9, rule = LifeHistory
.9A$ABA2BABABA$B2A2B4AB$AB4A3BAB$BA2BABABABA$A2B2A2BA2B$3A2B5A$B.2ABA
BABA$A.4A2B2A!

There's a "Garden of Eden 8x12" also found by Steven Eker back in
April, as documented on Achim's website:

http://wwwhomes.uni-bielefeld.de/achim/orphan_9th.html

Can't call the 8x12 pattern "Garden of Eden 9" because that's
presumably the 9x11 one from May of last year. And "Garden of Eden
10" seems to be the label applied to the 55-cell 9x11 GoE above:

http://wwwhomes.uni-bielefeld.de/achim/orphan_10th.html

See also the 5-cell-high GoE in the above link. Apparently Steven
Eker has proven that there's no such thing as a 3-cell-high GoE, but
the 4-cell-high case is still an open question. See Achim's website
again, for the only details on this that I can find anywhere:

http://wwwhomes.uni-bielefeld.de/achim/orphan.html

June 27, 2017:
Looks like shortly after the last Garden of Eden
in December, #10, Steven Eker found another incremental improvement.
Population 50, down from 55 -- and one less required cell in the
orphan, now 88 instead of 89:

#C Garden of Eden 11
#C population 50, bounding box 10x9 plus two protruding cells
#C Steven Eker, 25 January 2017
#C http://wwwhomes.uni-bielefeld.de/achim/orphan_11th.html
x = 11, y = 9, rule = B3/S23
2b2ob3obo$bo2bobobo$ob3o2b3o$bobobo2bobo$b3o2b2o2bo$2o3b2o2bo$obobob3o
$o2bobo2bo$b3o2b4o!

Or with the required OFF cells, in LifeHistory format:

#C 88-cell orphan for Garden of Eden 11
#C http://wwwhomes.uni-bielefeld.de/achim/orphan_11th.html
x = 11, y = 9, rule = LifeHistory
2.2AB3ABA$.A2BABABAB$AB3A2B3A$BABABA2BABA$B3A2B2A2BA$2A3B2A2BA$ABABAB
3AB$A2BABA2BAB$.3A2B4A!

[Ian07]

Oof, that's quite a bit of GoE history to catch up on. I've just created an article for Garden of Eden 11, but can't really be bothered to do the others at the moment.

[77topaz]

I think the RLE you specified is actually the inverse of GoE 11, since Achim's page says it has a minimum of 45 live cells and not 50.

[wildmyron]

I think the RLE you specified is actually the inverse of GoE 11, since Achim's page says it has a minimum of 45 live cells and not 50.

That table is a summary of records including all known GoE's, and presumably applies to a different orphan. I've verified with JLS that the pattern as interpreted by Ian07 is an orphan, but its inverse is not

[dvgrn]

I think the RLE you specified is actually the inverse of GoE 11, since Achim's page says it has a minimum of 45 live cells and not 50.

That table is a summary of records including all known GoE's, and presumably applies to a different orphan. I've verified with JLS that the pattern as interpreted by Ian07 is an orphan, but its inverse is not

Yeah, there are a couple of 45-cell GoEs, but they didn't improve the boundiing box of the GoEs with the record-setting bounding box at the time so they didn't get a "GoE #N" name. The first one was by Nicolay Beluchenko in 2009.

All of the "GoEs of interest" are summarized in the Records table in the LifeWiki Orphans article, with the red color showing records of one kind and another. It's all as clear as anyone could figure out how to make it, short of creating articles for all the GoEs -- but it's still fairly confusing.

I guess the first step is to painfully figure out exactly which of those GoEs are actually GoE #7 through #10, and update the table. The numbers don't necessarily match the numbering of Achim's HTML pages.

[Moosey]

What are the land of lakes and four eaters familiar fours mentioned in the article?

[Hdjensofjfnen]

What are the land of lakes and four eaters familiar fours mentioned in the article?

I don't think those reactions occur frequently enough to be called "familiar fours".

[Moosey]

What are the land of lakes and four eaters familiar fours mentioned in the article?

I don't think those reactions occur frequently enough to be called "familiar fours".

Of course not, otherwise I wouldn’t be asking!
I just want to know seeds for them or something; I want to know what they look like.

EDIT:
Land of lakes:

Code: Select all

x = 4, y = 4, rule = B3/S23
3o$o2bo$2obo$b3o!

Four eaters:

Code: Select all

x = 5, y = 13, rule = B3/S23
b3o$o3bo$o3bo$2ob2o6$2ob2o$o3bo$o3bo$b3o!

[PkmnQ]

It says on the wiki that there is a p61 gun discovered by Luka Okanishi. Can someone give me the pattern?

[dvgrn]

What are the land of lakes and four eaters familiar fours mentioned in the article?

I don't think those reactions occur frequently enough to be called "familiar fours".

Of course not, otherwise I wouldn’t be asking!
I just want to know seeds for them or something; I want to know what they look like.

Would have to ask the source of the rumor. It looks like muzik only added those "unfamiliar fours" at the end of January this year, in an apparent attempt to change the definition of "familiar fours".

I've removed the extra mystery sentence from the article for now. Have never heard of "land of lakes", searches don't turn up any references, and I can't seem to find anywhere that muzik might have seen an unusually common seed for four ponds or (especially) four eaters. Maybe there's something hidden in Catagolue somewhere?

[hkoenig]

Over the years I vaguely remember seeing pairs of bi-ponds appearing, but I don't remember the starting configuration, and don't want to dig around to find it. As for multiple Fishhook Eaters, that's new to me.

In the future, people need to provide specific examples when making those assertions. The same way with people posting just an RLE pattern and expecting me to figure out what makes it worthy of posting, Tell me why you are posting the pattern, and what I should expect to see, otherwise I'll start associating your name on a posting with "wasting my time, again."

[testitemqlstudop]

It says on the wiki that there is a p61 gun discovered by Luka Okanishi. Can someone give me the pattern?

http://conwaylife.com/forums/viewtopic.php?f=2&t=2160

[Moosey]

Would it be possible (yay, I can say possible because I'm providing an upper limit) to make a linear propagator with a smaller bounding box by area than the first one by using LWSSes in a giant loop instead of gliders in a giant loop, thus making a HUGE ORTHOGONAL LINE rather than a HUGE DIAGONAL LINE WITH A LOT MORE TOTAL AREA?

[testitemqlstudop]

like the Orthogonoid?

[Moosey]

like the Orthogonoid?

Yeah, but a linear propagator.

[testitemqlstudop]

Remove some trailing MWSSes from the linear propogator and then you have a LP-esque puffer.

[Moosey]

Remove some trailing MWSSes from the linear propogator and then you have a LP-esque puffer.

I assume you mean the Orthogonoid. Also, if a gemini-like ship is a Geminoid, an orthogonal one an orthogonoid, and a diagonal one a Demonoid, and Gemini is a Geminoid, shouldn’t Orthogoni and Demoni be names for some Orthogonoids or Demonoids?

[dvgrn]

Would it be possible (yay, I can say possible because I'm providing an upper limit) to make a linear propagator with a smaller bounding box by area than the first one by using LWSSes in a giant loop instead of gliders in a giant loop, thus making a HUGE ORTHOGONAL LINE rather than a HUGE DIAGONAL LINE WITH A LOT MORE TOTAL AREA?

Definitely -- except it would probably be MWSSes in the giant loop instead of LWSSes, just like current Orthogonoid circuitry. There are some strange new problems that would have to be solved, though.

The linear propagator has only one construction arm, so to build the far-end Silver reflector it has to send a construction salvo the full length of the diagonal line.

The equivalent for an orthogonal linear propagator... orthoganopropagator? Orthogator! ... would be to send a slow salvo consisting of *WSSes the entire length of the orthogonal line. We can easily make a construction arm that shoots slow LWSS/MWSS/HWSS salvos of either parity and with either even or odd phase.

However, nobody has done the research find recipes that incrementally build blocks, beehives, eater1s, or (especially) Snarks and syringes, using slow salvos of *WSSes. So instead we'd have to add a secondary elbow, converting the slow *WSSes back into slow^2 gliders near the far-end reflector. The secondary elbow is definitely a suboptimal solution -- it would make everything several times more expensive to build

A 180-degree reflector for MWSSes would be quite a bit more expensive to construct than a Silver reflector. And using single-channel technology instead of the linear propagator's antiquated 9hd system with two glider streams doesn't actually improve things that much in this case. Still, yeah, the bounding box would definitely end up a lot smaller.

[testitemqlstudop]

Aren't there stable MWSS-to-Gliders?

[Moosey]

Aren't there stable MWSS-to-Gliders?

I know the answer is yes because I saw one somewhere. I don’t remember where.

[googoIpIex]

What guns do we not have true period guns for?

[testitemqlstudop]

For one there's 19, 23, 34, 38, and 41.

[dvgrn]

Aren't there stable MWSS-to-Gliders?

I know the answer is yes because I saw one somewhere. I don’t remember where.

See MWSS-to-G. If this question is related to the previous question about the Orthogonator, then yes, the existence of these stable converters is why MWSSes are more likely to be used than LWSSes. But we have to make a complete memory loop to hold the recipe, so we also need G-to-MWSS (which we also have, but they're more expensive) and some kind of signal splitter.

No doubt the splitter would be just an extra output glider in the G-to-MWSS, same as in the Orthogonoids, aimed at a construction arm. The key difference is that to make a minimum-area Orthogonator, we'd have to have that construction arm shoot *WSSes instead of gliders -- at least for the stage when the child reflector on the far side of the loop is being constructed.

If we use existing slsparse construction, we'd need an elbow halfway between the two ends of the orthogonal loop, half the loop's width away. This is perfectly possible, and really it's a much more reasonable design. But if you factor in the additional inefficiency of using single-channel recipes instead of 9hd glider-pair recipes and having to build MWSS-to-MWSS reflectors at both ends of the loop, it's not clear that the bounding box would actually end up any smaller than the smallest double-folded-over linear propagator.

[dvgrn]

What guns do we not have true period guns for?

See True#True-period_guns. I think that list is up to date -- and if it isn't, somebody please update it.

[testitemqlstudop]

Assume I have three integers (any programming language) a, b, and c, where they represent in base 2 three rows of one generation, how do you calculate the evolution of b to the next generation?